Effect of subjective sleep impairment and decreased blood pressure on gender-specific HRV in first-episode and drug-naive patients with major depressive disorder

Effect of subjective sleep impairment and decreased blood pressure on gender-specific HRV in first-episode and drug-naive patients with major depressive disorder | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effect of subjective sleep impairment and decreased blood pressure on gender-specific HRV in first-episode and drug-naive patients with major depressive disorder Wenli Ban, Fengchun Wu, Hehua Li, Sumiao Zhou, Shixuan Feng, Chenyu Liu, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8766171/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 12 You are reading this latest preprint version Abstract Background Major depressive disorder (MDD) exhibits significant gender disparities in prevalence. Previous studies have indicated that differential patterns of sympathetic nervous system activation in different gender may contribute to varying cardiovascular/cerebrovascular risks in MDD, though underlying factors remain unclear. In this study, we aim to investigate the association between subjective sleep alterations, blood pressure, emotional state, and gender-specific sympathetic activation in MDD. Methods We collected and analyzed ECG data from 50 female and 25 male age-matched, first-episode, drug-naive MDD patients. Autonomic nerve function was assessed using heart rate variability (HRV). Subjective sleep indicators of SE, SOL, short sleep, and poor sleep quality were evaluated utilizing the Pittsburgh Sleep Quality Index (PSQI). Emotional characteristics were quantified via the Hamilton Depression Scale-17 (HAMD-17) and Hamilton Anxiety Scale (HAMA). Resting systolic (SBP) and diastolic blood pressure (DBP) were also measured upon arrival. Results In male MDD patients, each 1% reduction in SE was associated with a 0.350ms decrease in SDNN. In females, each 1-minute reduction in SOL was associated with a 0.004-unit increase in LF/HF ratio; while short sleep (< 6h) was associated with increased RMSSD and pNN50 (all p ≤ 0.048). Reduced DBP in males correlated with different patterns (decreased pNN50 and HF(nu); increased LF(nu) and LF/HF ratio) (all p ≤ 0.033). In females, only reduced SBP was associated with each 1-mmHg decrease linked to a 0.040-unit increase in LF/HF ratio. Conclusion Subjective sleep disturbances exhibits disparity in gender-specific patterns of sympathetic-vagal balance in MDD. However, blood pressure reduction consistently correlated with sympathetic activation across both genders, revealing distinct autonomic-mediated pathophysiological pathways that may underlie differential cardiovascular susceptibility in MDD. Major Depressive Disorder gender difference subjective sleep disturbances blood pressure autonomic nerve dysfunction heart rate variability. Figures Figure 1 1. INTRODUCTION Major depressive disorder (MDD), a highly prevalent and debilitating psychiatric condition defined by altered regulation of mood, behavior and affect [ 1 ] , leading to a range of adverse health outcomes [ 2 , 3 ] . Within the DSM-5 diagnostic criteria for MDD, sleep disorders constitute specific sub-items, notably requiring reports of insomnia or hypersomnia occurring nearly daily. Clinically, sleep dysfunction is a frequent manifestation in MDD patients [ 4 ] . Supporting this, the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study revealed that 87.4% of individuals with MDD exhibited concurrent insomnia symptoms, predominantly characterized by prolonged sleep latency and frequent nocturnal awakenings [ 5 ] . Furthermore, alterations in key sleep parameters—including duration, quality, and circadian rhythm are related to detrimental clinical sequelae [ 6 ] . Several studies have reported distinct changes in sleep patterns among depressed patients, encompassing both reduced and extended sleep duration, as well as diminished sleep quality [ 7 ] . Critically, these sleep pattern alterations are closely linked to an increased risk of subsequent cardiovascular disease (CVD). Cross-sectional evidence also indicates that insomnia correlates with metabolic diseases, including hypertriglyceridemia and insulin resistance, particularly in individuals with severe mental disorders [ 8 ] . Additionally, sleep disorders are implicated in dementia risk. A prospective study of cognitively intact male patients demonstrated that alterations in five specific sleep characteristics were significantly associated with accelerated long-term cognitive decline and heightened risk of developing Alzheimer's disease dementia [ 9 ] . Finally, a meta-analysis published in 2023 synthesized evidence suggesting that nsomnia acts as a potential etiological or exacerbating factor for subsequent mental disorders, including depression [ 10 ] . This evidence supports a pernicious bidirectional relationship wherein sleep pathology and depressive illness mutually reinforce each other, thereby complicating clinical trajectories and presenting substantial therapeutic challenges. Collectively, these findings indicate that sleep disorders not only contribute to chronic cardiovascular and cerebrovascular diseases but also may exacerbate MDD symptomatology, which further underscores the necessity and importance of vigilant monitoring and clinical attention to sleep characteristics in the management of MDD patients. Patients with MDD face a substantially elevated risk of cardiovascular morbidity and mortality. Previous studies have demonstrated that MDD patients exhibit significantly higher susceptibility to developing CVD and experience greater mortality rates compared to healthy controls [ 11 ] , with a demonstrable dose-response relationship between depression severity and subsequent cardiovascular mortality/events [ 12 ] . A parallel trend was observed in patients with comorbid MDD and chronic insomnia. Data from the China Health and Retirement Longitudinal Study indicated that both depression and subjective short sleep duration independently increase cardiovascular disease risk [ 13 ] . Furthermore, the analysis revealed that subjective short sleep duration mediates 38.6% of the association between depression and hypertension. Additionally, clinical studies [ 14 ] show that the pathogenesis of cardiovascular events involves multiple interrelated physiological and pathological mechanisms, including inflammatory factors release [ 15 ] , dysregulation of the HPA axis [ 16 ] , excessive the sympathetic nervous system activation [ 17 ] , and endothelial dysfunction [ 18 ] , among others. Another study [ 19 ] suggests that short sleep duration increases the risk of subsequent cardiovascular and cerebrovascular diseases, such as hypertension, potentially linked to excessive activation of sympathetic nerve [ 17 ] . Moreover, research [ 20 ] posits that sympathetic nerve activation represents a common pathway integrating various pathophysiological mechanisms and may play a particularly significant role. Prior investigations into cardiovascular comorbidity in MDD patients suggest that autonomic dysfunction represents one underlying mechanism [ 21 ] . Specifically, depressive symptoms severity has been associated with sympathetic-vagal imbalance [ 22 ] . Similar parasympathetic downregulation is also evident in MDD patients with comorbid anxiety disorders [ 23 , 24 ] . In clinical and scientific settings, sympathetic nerve activity can be assessed using various methods. Common tools for evaluating sympathetic-vagal balance include heart rate variability (HRV) [ 25 ] , baroreflex sensitivity (BRS) [ 26 ] , microneurography (MSNA) [ 27 ] , and sympathetic skin response [ 28 ] . Among these, HRV offers the advantages of non-invasiveness and suitability for continuous monitoring, making it widely applicable in population studies, including those involving mental disorders [ 29 , 30 ] . Notably, a pronounced gender disparity exists in depression epidemiology, with women exhibiting a twofold higher lifetime incidence than men. Studies [ 31 ] further suggest that gender-related differences in sympathetic activation contribute to the differential cardiovascular risk observed in MDD patients. Consequently, we aim to elucidate whether subjective sleep indicators correlate with gender-specific sympathetic activation in depression. Furthermore, several studies [ 32 – 34 ] highlight a potential paradoxical sexual dimorphism: within the context of depression, women, despite exhibiting relatively greater vagal tone, face a significantly elevated risk of adverse cardiovascular events compared to their male counterparts. However, the determinants—such as sleep disorder, anxiety severity, and depression severity—underlying these gender-specific sympathetic activation in MDD remain inadequately investigated. Sustained sympathetic activation is frequently implicated as a potential mechanism increasing cardiovascular diseases [ 35 ] , including hypertension, and has been documented in MDD patients [ 36 , 37 ] . Nevertheless, research examining the association between sympathetic nerve changes, blood pressure and gender specifically in MDD patients is lacking. Therefore, this study also seeks to explore the relationship between blood pressure level and sympathetic-vagal balance in MDD patients stratified by gender. In summary, the established comorbidity between MDD and sleep disturbances holds significant clinical relevance. Accumulating evidence suggests that “subjective sleep impairment” and “co-occurring affective symptomatology” (depressive-anxious load) may synergistically elevate cardiovascular risk profiles, particularly hypertension susceptibility. Crucially, the gender-specific modulation of sympathetic-vagal balance, manifesting as differential sympathetic activation patterns between genders, remains underexplored as a potential mediator in this pathophysiological triad. Therefore, we hypothesized that poorer subjective sleep indicators, worse emotional states (higher depressive-anxious load), and elevated blood pressure in MDD patients are associated with increased gender-specific sympathetic nerve system activity. 2. METHODS 2.1. Participants and Study Design A cross-sectional study was conducted at the Department of Psychiatry, Affiliated Brain Hospital of Guangzhou Medical University between February 2022 and July 2024. The cohort comprises 50 female patients with first-episode, unmedicated MDD and 25 male patients with first-episode, drug-naive MDD. Diagnoses were independently confirmed by two board-certified psychiatrists according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [ 1 ] . The study protocol received ethical approval from the Affiliated Brain Hospital Guangzhou Medical University and complied with Helsinki Declaration guidelines (2013). Written informed consent was obtained from all participants following a comprehensive procedural briefing. All participants underwent centralized assessment including: demographic data collection, standard scale assessment, blood pressure measurement and ECG data acquisition. Inclusion criteria required:: (1) DSM-5 diagnostic criteria of MDD; (2) first-episode presentation (duration ≤ 2 years); (3) lifetime absence of psychopharmacological treatment; (4) age ≥ 18 years. Exclusion criteria encompassed: (1) Significant physical comorbidities potentially affect sympathetic nerve activity (e.g., coronary heart disease, hypertension, diabetes) or severe arrhythmias (e.g., advanced atrioventricular block, frequent ventricular premature contractions) documented by ECG; (2) Coexisting serious psychiatric disorders per DSM-5 (e.g., bipolar disorder, schizophrenia, delusional disorder); (3) History of chronic ethanol abuse or illicit psychostimulant use; (4) pregnancy or lactation; (5) Use of β-blockers (e.g., propranolol) or other drugs that may affect the sympathetic nerve within 3 months; (6) Inability to cooperate with ECG acquisition. 2.2 Clinical data collection Systematically documented parameters included: (1) Demographic parameters (chronological age, biological sex, marital status, occupational classification, geographic residency); (2) Longitudinal medical histories (via clinician-administered structured interviews). Subjective sleep dice were evaluated using the Pittsburgh Sleep Quality Scale (PSQI) [ 38 ] . From the PSQI, we derived four key indicators: (1) Short sleep duration, defined as < 6 hours per night based on Question 4:: “During the past month, how many hours of actual sleep did you get at night?”; (1) Poor sleep quality, categorized as “Poor” or “Extremely poor” responses to Question 6: “During the past month, what do you think of your sleep quality?”; (3) Sleep onset latency (SOL), determined from Question 2: “How many hours did you fell asleep after you stay at bed during the night in the past 1 month?”; (4) Sleep efficiency (SE), calculated as total sleep time (TST) divided by time in bed (TIB) using responses to PSQI Questions 1–4. Depressive symptom severity was assessed using the Hamilton depression rating scale-17 (HAMD-17) [ 39 ] , while anxiety symptoms were quantified with the Hamilton anxiety rating scale (HAMA) [ 40 ] . All clinical evaluators completed standardized training and demonstrated inter-rater reliability in HAMD-17 administration. Resting blood pressure was measured in triplicate recordings at 5-minute intervals following 10 minutes of seated rest using an electronic sphygmomanometer (Omron, HEM-7136, measurement accuracy ± 3 mmHg), which underwent monthly calibration against a mercury sphygmomanometer. The mean values of Systolic blood pressure (SBP) and Diastolic blood pressure (DBP) in the tests were utilized for statistical analyses. Anthropometric measurements (height, weight, waist circumference, hip circumference), electrocardiogram, heart rate, and substance use histories (smoking status, alcohol consumption patterns) were obtained by qualified technicians. 2.3 Evaluation of heart rate variability (HRV) HRV metrics were employed to delineate autonomic nervous system (ANS) function in the MDD cohorts. Participants maintained 24-hour pre-assessment abstinence from psychostimulants (caffeine ≥ 200mg/day), ethanol consumption, and vigorous physical activity. Continuous 10-minute electrocardiographic (ECG) recordings were acquired at a sampling frequency of 10000 Hz. HRV indices were processed using NeuroKit2 [ 41 ] , an open-source Python package for neurophysiological signal analysis (installation details accessible at https://neurokit2.readthedocs.io/en/latest/installation.html , accessed 3 May 2021). Both time-domain parameters (SDNN, RMSSD, pNN50) and frequency-domain parameters (normalized low-frequency power LF(nu), normalized high-frequency power HF(nu), LF/HF ratio) were computed according to established standards by Phyllis K. Stein [ 42 ] . ECG recordings were segmented into consecutive 5-minute epochs, with HRV indices averaged across all segments for final statistical analysis. 2.4 Statistical analysis All data underwent dual-entry verification via EpiData 3.1 (EpiData Association, Odense, Denmark) with cross-checked validation protocols. Statistical analyses were performed using IBM SPSS Statistics version 26.0 (IBM Corp., Armonk, NY). The analytical sequence comprised three phases. First, the age-matching procedure was completed. Demographic equivalence between male and female groups was established through statistical matching. Second, general demographic characteristics, subjective sleep parameters, clinical features, and emotional assessment scores (HAMD-17, HAMA) were compared between male and female MDD groups. Third, multiple linear regression models were constructed to examine relationships between HRV parameters (dependent variables) and subjective sleep characteristics, clinical characteristics, and emotional assessment scores (independent variables). Covariates with established biological relevance to HRV (age, BMI, smoking status, alcohol consumption status) were incorporated into all models using forced entry methodology. Statistical significance was defined as a two-tailed p -value ≤ 0.05. 3. RESULTS 3.1 Participant Characteristics and Group Comparisons A total of 25 male MDD patients and 50 MDD female patients were included in this study. Demographic and clinical characteristics are presented in Table 1 . Age distributions were matched between groups. Compared to their male counterparts, female MDD patients exhibited significantly lower BMI ( t = -2.458, p < 0.001), reduced smoking prevalence ( χ2 = 9.232, p = 0.002), and lower alcohol consumption rates ( χ2 = 4.751, p = 0.029). Clinical assessment revealed significantly lower systolic blood pressure ( t = -4.042, p < 0.001) in MDD female patients versus males. Emotional scales assessment demonstrated higher HAMD-17 scores in MDD female patients ( Z = -2.427, p = 0.015), indicating greater depressive symptoms. Table 1 Demographic, Clinical, and Sleep Characteristics of Depressed Patients a Variables b Male N = 25 Female N = 50 χ2/t/Z P Demographic characteristic Age, year 24.24 ± 2.91 23.82 ± 3.08 -0.554 0.580 BMI, kg/m 2 22.10 ± 3.28 20.15 ± 3.21 -2.458 < 0.001* Smoking (n, %) 10, 40.00 4, 8.00 9.232 0.002* Alcohol (n, %) 14, 56.00 15, 30.00 4.751 0.029* Clinical characteristic SBP (mmHg) 124.52 ± 11.34 113.72 ± 10.69 -4.042 < 0.001* DBP (mmHg) 77.32 ± 8.24 73.76 ± 8.44 -1.736 0.087 Emotional characteristic HAMD-17, total score 21.04 ± 4.15 23.43 ± 3.85 -2.427 0.015* HAMA, total score 16.92 ± 7.21 18.68 ± 4.88 1.250 0.215 Subjective sleep characteristics SOL (min) 104.24 ± 104.74 109.90 ± 85.91 -0.940 0.347 SE (%) 76.14 ± 18.13 72.23 ± 18.64 0.863 0.391 Short sleep duration (n, %) 18, 72.00 38, 76.00 0.141 0.707 Poor sleep quality (n, %) 23, 92.00 47, 94.00 1.757 0.415 Heart rate variability(2min) HR (beats/ min) 80.53 ± 7.56 80.74 ± 10.81 0.087 0.931 SDNN (ms) 42.71 ± 12.85 40.61 ± 11.30 -0.726 0.470 RMSSD (ms) 28.97 ± 11.56 29.86 ± 11.39 0.318 0.752 pNN50 (%) 9.70 ± 11.25 10.92 ± 10.43 -0.427 0.669 LFnu (%) 0.59 ± 0.12 0.49 ± 0.17 -2.585 0.010* HFnu (%) 0.38 ± 0.12 0.48 ± 0.17 2.979 0.004* LF/HF 2.02 ± 1.11 1.54 ± 1.33 -2.304 0.021* Notes: Data are presented as mean±standard deviation for continuous variables, and sample size (percentage) for categorical variables. *There are 75 depressed patients enrolled, including 25 males and 50 females; P-values in bold indicate P < 0.05. a Based on the Major Depressive Disorder diagnostic criteria of the Diagnostic Statistical Mental Disorder-Ⅴ. b All of the subjects under Psychotropic medications (Antipsychotics, Antidepressants, Mood stabilizers, Hypnotic drugs) were excluded. c Subjective sleep characteristic is based on PSQI’s fourth question. Abbreviations: MDD: major depressive disorder; BMI: body mass index; SOL: Sleep Onset Latency; SE: Sleep Efficiency; HAMD-17: Hamilton Depression Rating Scale-17; HAMA: Hamilton Anxiety Rating Scale; SBP: Systolic Blood Pressure; DBP: Diastolic Blood Pressure. HR: Heart rate; SDNN: Standard deviation of all NN intervals; RMSSD: Square root of the mean squared difference of successive NN intervals; pNN50: Percent of NN intervals > 50 ms different from previous (NN) for period of interest; LFnu: [LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF + HF). HFnu: [HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF + HF); LF/HF: LF/HF average over 5-min periods or less; * means P < 0.05. HRV analysis showed significant between-group differences in frequency-domain parameters: Male patients exhibited higher LF ( Z = -2.585, p = 0.010) and LF / HF ( Z = -2.304, p = 0.021), and lower HF ( t = 2.979, p = 0.004). These findings suggest heightened sympathetic nerve activation in male MDD patients. No significant statistical gender-based differences were detected in any of the subjective sleep parameters or in the time-domain HRV indices. 3.2 Sleep Parameters and HRV Associations The results of the multiple linear regression analyses examining the relationship between subjective sleep indicators, blood pressure, and emotional scales with HRV of male and female MDD patients, are detailed in Table 2 – 4 and selectively illustrated in Fig. 1 . Table 2 Linear Regression of Subjective sleep indicators with HRV in Different gender of MDD. Variable 1 SOL SE Short sleep duration Poor sleep quality B 95%CI P B 95%CI P B 95%CI P B 95%CI P HR(beats/min) 0.02 -0.02 ~ 0.06 0.330 -0.16 -0.36 ~ 0.05 0.131 -0.66 -9.12 ~ 7.80 0.872 2.07 -10.97 ~ 15.10 0.743 SDNN(ms) -0.04 -0.10 ~ 0.03 0.261 0.35 0.00 ~ 0.69 0.049* 4.15 -10.55 ~ 18.85 0.561 -13.14 -35.15 ~ 8.87 0.227 RMSSD(ms) -0.02 -0.08 ~ 0.04 0.424 0.28 -0.04 ~ 0.60 0.078 -2.15 -15.53 ~ 11.24 0.741 -12.95 -32.71 ~ 6.80 0.186 pNN50(%) -0.01 -0.07 ~ 0.04 0.619 0.29 -0.02 ~ 0.59 0.064 -3.62 -16.50 ~ 9.25 0.563 -12.66 -31.77 ~ 6.44 0.181 LFnu(%) 0 -0.001 ~ 0.000 0.633 0 -0.003 ~ 0.004 0.807 0.01 -0.13 ~ 0.14 0.931 0.05 -0.15 ~ 0.25 0.629 HFnu(%) 0 -0.000 ~ 0.001 0.604 0 -0.004 ~ 0.002 0.599 0 -0.12 ~ 0.13 0.957 -0.04 -0.23 ~ 0.15 0.646 LF/HF -0.002 -0.007 ~ 0.003 0.493 0.01 -0.02 ~ 0.04 0.569 -0.16 -1.34 ~ 1.02 0.775 0.50 -1.32 ~ 2.31 0.573 Variable 2 SOL SE Short sleep duration Poor sleep quality B 95%CI P B 95%CI P B 95%CI P B 95%CI P HR(beats/min) 0.01 -0.03 ~ 0.05 0.573 -0.03 -0.22 ~ 0.16 0.731 -1.1 -8.82 ~ 6.61 0.775 4.92 -9.42 ~ 19.26 0.493 SDNN(ms) 0.004 -0.04 ~ 0.04 0.851 -0.02 -0.21 ~ 0.18 0.873 5.9 -1.75 ~ 13.56 0.127 -8.32 -22.78 ~ 6.15 0.253 RMSSD(ms) -0.005 -0.05 ~ 0.04 0.816 -0.05 -0.24 ~ 0.15 0.647 7.75 0.08 ~ 15.42 0.048* -9.84 -24.52 ~ 4.85 0.184 pNN50(%) -0.003 -0.04 ~ 0.03 0.864 -0.04 -0.22 ~ 0.14 0.639 7.21 0.25 ~ 14.17 0.043* -11.72 -24.87 ~ 1.43 0.079 LFnu(%) 0 0.000 ~ 0.001 0.159 0 -0.003 ~ 0.002 0.876 -0.04 -0.14 ~ 0.06 0.445 0.15 -0.03 ~ 0.34 0.106 HFnu(%) 0 -0.001 ~ 0.000 0.163 0 -0.002 ~ 0.003 0.839 0.03 -0.08 ~ 0.13 0.599 -0.14 -0.33 ~ 0.05 0.132 LF/HF 0.004 0.000 ~ 0.008 0.038* -0.01 -0.03 ~ 0.01 0.441 0.07 -0.69 ~ 0.83 0.86 0.34 -1.08 ~ 1.76 0.630 Note: 1 means group of Male MDD patients. 2 means group of Female MDD patients. All of the subjects under Psychotropic medications (Antipsychotics, Antidepressants, Mood stabilizers, Hypnotic drugs) were excluded. The liner regression was adjusted for age, body mass index, smoking, and alcohol. Short sleep duration was defined less than 6 hours according to question 2 in the Pittsburgh Sleep Quality Index: “During the past month, how many hours of actual sleep did you get at night”. Poor sleep quality was defined as “Poor or Extremely poor” according to question 6 in the Pittsburgh Sleep Quality Index: “During the past month, what do you think of your sleep quality”. SOL: Sleep Onset Latency. SE: Sleep Efficiency. HR: Heart rate; SDNN: Standard deviation of all NN intervals; RMSSD: Square root of the mean squared difference of successive NN intervals; pNN50: Percent of NN intervals > 50 ms different from previous (NN) for period of interest; LFnu: [LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF + HF). HFnu: [HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF + HF); LF/HF: LF/HF average over 5-min periods or less; B: Non-standardized regression coefficient; β: standardized regression coefficient; CI, confidence interval. * means P < 0.05. Table 3 Linear Regression of Blood pressure with HRV in Different gender of MDD. Variable SBP DBP B 1 95%CI 1 P 1 B 2 95%CI 2 P 2 B 1 95%CI 1 P 1 B 2 95%CI 2 P 2 HR (beats/min) -0.01 -0.35 ~ 0.33 0.963 0.06 -0.26 ~ 0.38 0.687 0.07 -0.41 ~ 0.54 0.779 0.32 -0.07 ~ 0.72 0.106 SDNN (ms) -0.03 -0.62 ~ 0.57 0.920 -0.20 -0.52 ~ 0.12 0.217 -0.07 -0.91 ~ 0.76 0.858 -0.38 -0.78 ~ 0.02 0.060 RMSSD (ms) 0.33 -0.19 ~ 0.84 0.196 -0.01 -0.34 ~ 0.33 0.977 0.65 -0.04 ~ 1.34 0.065 -0.30 -0.71 ~ 0.12 0.153 pNN50 (%) 0.44 -0.04 ~ 0.92 0.068 0 -0.31 ~ 0.30 0.983 0.80 0.18 ~ 1.42 0.014* -0.23 -0.61 ~ 0.15 0.227 LFnu (%) -0.003 -0.01 ~ 0.00 0.189 0 -0.01 ~ 0.00 0.211 -0.01 -0.01~-0.00 0.024* 0.001 -0.004 ~ 0.01 0.626 HFnu (%) 0.003 -0.00 ~ 0.01 0.168 0 -0.001 ~ 0.01 0.118 0.01 0.00 ~ 0.01 0.033* 0 -0.01~ -0.01 0.829 LF/HF -0.01 -0.06 ~ 0.04 0.649 -0.04 -0.06~ -0.01 0.024* -0.07 -1.12~-0.01 0.033* -0.01 -0.03 ~ 0.03 0.728 Note: 1 means group of Male MDD patients. 2 means group of Female MDD patients. The liner regression was adjusted for age, body mass index, smoking, and alcohol. SBP: Systolic Blood Pressure. DBP: Diastolic Blood Pressure. HR: Heart rate; SDNN: Standard deviation of all NN intervals; RMSSD: Square root of the mean squared difference of successive NN intervals; pNN50: Percent of NN intervals > 50 ms different from previous (NN) for period of interest; LFnu: [LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF + HF). HFnu: [HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF + HF); LF/HF: LF/HF average over 5-min periods or less; B : Non-standardized regression coefficient; β : standardized regression coefficient; CI , confidence interval. * means P < 0.05. Table 4 Linear Regression of Emotional scales with HRV in Different gender of MDD. Variable HAMD-17 HAMA B 1 95%CI 1 P 1 B 2 95%CI 2 P 2 B 1 95%CI 1 P 1 B 2 95%CI 2 P 2 HR (beats/min) -0.45 -74.56 ~ 170.70 0.348 0.70 -0.17 ~ 1.57 0.112 -0.26 -0.77 ~ 0.25 0.296 0.65 -0.01 ~ 1.32 0.055 SDNN (ms) -0.27 -2.02 ~ 1.48 0.752 -0.23 -1.14 ~ 0.68 0.606 -0.05 -0.96 ~ 0.87 0.917 -0.08 -0.79 ~ 0.62 0.813 RMSSD (ms) -0.27 -1.85 ~ 1.32 0.728 -0.55 -1.47 ~ 0.36 0.231 -0.05 -0.88 ~ 0.78 0.906 -0.22 -0.94 ~ 0.50 0.541 pNN50 (%) -0.30 -1.84 ~ 1.23 0.683 -0.39 -1.23 ~ 0.45 0.354 -0.12 -0.92 ~ 0.68 0.765 -0.04 -0.70 ~ 0.62 0.904 LFnu (%) 0.001 -0.01 ~ 0.02 0.895 0.001 -0.01 ~ 0.01 0.895 0.001 -0.01 ~ 0.01 0.728 -0.002 -0.01 ~ 0.01 0.717 HFnu (%) -0.003 -0.02 ~ 0.01 0.675 -0.001 -0.01 ~ 0.1 0.889 -0.002 -0.01 ~ 0.01 0.599 0.002 -0.01~ -0.01 0.590 LF/HF -0.004 -0.14 ~ 0.14 0.953 0.02 -0.07 ~ 0.11 0.702 0.007 -0.07 ~ 0.08 0.844 -0.01 -0.08 ~ 0.06 0.720 Note: 1 means group of Male MDD patients. 2 means group of Female MDD patients. The liner regression was adjusted for age, body mass index, smoking, and alcohol. HAMD-17: Hamilton Depression Rating Scale-17. HAMA: Hamilton Anxiety Rating Scale. HR: Heart rate; SDNN: Standard deviation of all NN intervals; RMSSD: Square root of the mean squared difference of successive NN intervals; pNN50: Percent of NN intervals > 50 ms different from previous (NN) for period of interest; LFnu: [LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF + HF). HFnu: [HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF + HF); LF/HF: LF/HF average over 5-min periods or less; B : Non-standardized regression coefficient; β : standardized regression coefficient; CI , confidence interval. * means P < 0.05. Among male patients, higher SE was significantly correlated with a greater SDNN ( B = 0.35 ms per 1% SE increase; Model A; 95% CI = 0.00 ~ 0.09, β = 0.49, p = 0.049), In female MDD patients, SOL positively predicted LF/HF ratio ( B = 0.004 units per 1-min SOL increase; Model F; 95% CI = 0.00 ~ 0.01, β = 0.26, p = 0.038), while short sleep duration (< 6 hrs) was associated with increased RMSSD ( B = 7.75 ms; Model G; 95% CI = 0.08 ~ 15.42, β = 0.29, p = 0.048) and pNN50 ( B = 7.21%; Model H; 95% CI = 0.25 ~ 14.17, β = 0.30, p = 0.043). Additionally, gender-divergent autonomic responses to subjective sleep disturbances were observed. Male patients with MDD exhibited sympathetic activation related to subjective sleep disorders, whereas female patients demonstrated bidirectional alterations in sympathetic regulation—prolonged sleep onset latency associated with sympathetic excitation, while subjective sleep duration less than 6h paradoxically corresponded to sympathetic inhibition with concomitant vagal predominance. 3.3 Blood Pressure and HRV Relationships Furthermore, our detailed investigation into the correlations between systolic/diastolic blood pressure (SBP/DBP) and HRV parameters revealed significant inverse associations with sympathetic activation, as visualized in Fig. 1 . In the MDD male group (model B-E), each 1 mmHg increase in DBP corresponded to statistically significant alterations in multiple HRV indices - specifically, 0.80% ( 95% CI = 0.18 ~ 1.42, β = 0.59, p = 0.014) increase in pNN50, a 0.01% ( 95% CI = 0.00 ~ 0.01, β = 0.47, p = 0.033) increase in HF(nu), a 0.01% ( 95% CI = -0.01 ~ -0.00, β = -0.50, p = 0.024) decrease in LF(nu), and a 0.07-unit ( 95% CI = -1.12 ~ -0.01, β = -0.48, p = 0.033) reduction in the LF/HF ratio. Similarly, in female MDD patients (Model I), we observed parallel but quantitatively distinct relationships, where every 1 mmHg increase in SBP predicted a 0.04-unit ( 95% CI = -0.06 ~ -0.01, β = -0.28, p = 0.024) decrease in the LF/HF ratio, indicating consistent blood pressure-dependent attenuation of sympathetic dominance across both genders despite differential hemodynamic and autonomic regulatory mechanisms. 4. DISCUSSION Our study elucidates the complex interplay between sleep disturbances, blood pressure fluctuations, and gender-specific sympathetic activation patterns in MDD. To our knowledge, this represents the first investigation examining the relationships among subjective sleep indicators, emotional state, blood pressure, and gender- dimorphic autonomic nervous system activity in MDD. The principal findings reveal three key patterns: (1) Male MDD patients demonstrated impaired HRV regulation relative to female counterparts, particularly evident in frequency-domain parameters; (2) Gender-stratified analysis revealed distinct sleep-HRV interactions patterns: increased HRV in males correlated specifically with SE, while female patients displayed inverse HRV associations with both shortened SOL and curtailed sleep duration (< 6h); (3) Blood pressure profiles showed gender-specific HRV correlations by gender—diastolic hypertension accompanied by concomitant HRV reduction characterized males, while females displayed systolic hypertension concurrent with HRV attenuation. These findings demonstrate gender-dimorphic autonomic regulation in MDD, with female patients exhibiting superior HRV modulation compared to males, suggesting heightened sympathetic activation in depressed males. This pathophysiological pattern aligns with prior evidence of gender-specific autonomic dysfunction in MDD [ 43 ] . While gender differences in HRV remain underexplored in current depression research, emerging evidence from MDD-comorbid conditions like somatic symptom disorder (SSD) reveals distinct autonomic patterns. Notably, studies of elderly SSD patients report significantly reduced low-frequency to high-frequency HRV ratios (LF/HF) in females compared to males [ 44 ] . This gender-specific sympathetic pattern contrasts with the stability observed in parasympathetic measures, evidenced by comparably high-frequency HRV (HF-HRV) values across genders. However, contradictory evidence exists. Pediatric research [ 45 ] by Shvartz and colleagues involving children aged 5.5–12.5 years found consistently reduced HRV in females across developmental stages, indicating heightened sympathetic activation despite comparable LF%, HF%, and LF/HF ratios between genders. These paradoxical observations may reflect multifactorial interactions encompassing MDD diagnostic heterogeneity, clinical characteristics, illness duration variability, ethnic diversity, and gender-specific antidepressant treatment responses. We further identified an independent correlation between subjective sleep disorder severity and gender-related HRV modulation in MDD, with progressive sympathetic predominance accompanying worsening SE in male patients and prolonged SOL in females, contrastingly, female patients manifested restrained sympathetic activities associated with shorten sleep duration (< 6h). This pathophysiological cascade in males of MDD, consistent with prior neurocardiac investigations [ 4 , 8 ] , suggests sleep architecture disruption may critically impair the hypothalamic-pituitary-adrenal (HPA) axis function, thereby exacerbating sympathetic-vagal imbalance through excessive noradrenergic activation. Concurrently, sleep disturbances may elevate subsequent cardiovascular/cerebrovascular risk [ 7 ] and potential cognitive impairment [ 46 ] in MDD, compounding physical comorbidities and socioeconomic burdens. Crucially, we observed gender-specific patterns: Male MDD patients showed reduced sleep efficiency primarily associated with decreased SDNN, indicating compromised overall HRV. In contrast, female MDD patients exhibited more complex patterns, where prolonged sleep onset latency was correlated with an increased LF/HF ratio, while shortened sleep duration was related to increased RMSSD and pNN50. These findings partial align with established gender differences in depressive sleep architecture and autonomic regulation [ 47 ] . Silverstein [ 48 ] previously reported that female MDD patients typically experience greater somatic depression, including more pronounced sleep disturbances than males. Our findings extend this understanding by revealing the gender-specific autonomic correlates, suggesting that distinct pathophysiological mechanisms underlie sleep disruption in MDD. Methodologically, time-domain indices RMSSD and PNN50 demonstrate greater stability against heart rate fluctuations and temporal variations than SDNN and frequency-domain metrics [ 41 , 49 , 50 ] , rendering them sensitive indicators of sympathetic modulation. The association between short sleep duration and HRV increase (indicating sympathetic nerve suppression) in female MDD patients may reflect women's degenerative feedback in sympathetic-vagal regulatory capacity [ 31 ] . These findings further emphasize the necessity of gender-specific considerations when developing sleep interventions for MDD patients. Specifically, male patients might derive greater benefit from interventions targeting sleep efficiency improvement. Conversely, females exhibit bidirectional autonomic dysregulation—prolonged sleep onset latency exacerbates sympathetic predominance while curtailed sleep duration (< 6 h) induces sympathetic attenuation. This divergence likely originates from distinct neurobiological pathways (e.g., immune inflammatory response, hormone regulation) mediating differential autonomic responses to specific sleep parameters. This gender-dimorphic pattern corresponds with emerging evidence on neurophysiological differences in sleep regulation. As highlighted in a Sleep Medicine Reviews systematic assessment [ 51 ] , combining light therapy with behavioral strategies may provide scientific rationale for gender-specific interventions. Such integrated approaches could address persistent sympathetic nervous system hyperactivation observed in chronic MDD cases, thereby mitigating associated long-term health consequences. Additionally, our findings offer novel evidence-based guidance for gender-specific antidepressant selection in MDD management. Pharmacodynamic analyses reveal clinically significant temporal variations in treatment responses. For instance, unlike traditional SSRIs whose initial administration may exacerbate insomnia, mirtazapine demonstrates superior 5-hydroxytryptamine receptor 2 (5-HT2) blockade that enhances sleep architecture through reduced sleep latency, extended total sleep time, and improved sleep efficiency [ 52 ] , Optimal management requires gender-specific pharmacotherapy targeting differential sleep dysregulation: female patients benefit from agents that reduce shorten SOL and modulate total sleep time characteristics; while male patients with depression require interventions prioritizing sleep efficiency enhancement. Such studies supporting the need for gender- adapted dosing regimens and pretreatment counseling. Blood pressure-autonomic function also exhibited notable gender differences. Unlike previous studies [ 53 ] , we specifically examined blood pressure on gender-related sympathetic regulation in MDD patients. Male patients showed comprehensive autonomic alterations with diastolic blood pressure reduction, including decreased pNN50 and HF power alongside increased LF power and the LF/HF ratio. Given that LF/HF ratio serves as a sensitive indicator of sympathetic-vagal balance [ 41 ] , these findings suggest a more pronounced sympathetic predominance with lower blood pressure in male MDD patients. Conversely, female MDD patients exhibited a varied pattern where only systolic blood pressure reduction correlated with increased LF/HF ratio. This observation may indicate a blood pressure-sympathetic negative feedback mechanism in MDD, whereby blood pressure elevation reduces sympathetic regulation—consistent with the previous research results in other populations [ 54 ] . Estrogen-enhanced endothelium-mediated vasodilation in the female population [ 53 , 55 ] may explain the greater relevance of blood pressure with HRV-LF/HF ratio in female MDD patients than males. Notably, our analysis did not reveal a direct correlation between the severity of affective symptoms (as measured by HAMD-17 and HAMA) and HRV indices in either gender, contradicting previous reports [ 13 , 23 ] . This suggests autonomic dysfunction-emotional state (including the severity of depression and anxiety) relationships may be mediated through alternative physiological pathways [ 56 ] , such as the hypothalamic-pituitary-adrenal axis function, chronic systemic inflammation, or other mechanisms, rather than direct associations with gender-specific sympathetic nerve activation. 5. Limitation Methodological constraints warrant consideration. First, the limited sample size (particularly male subgroup underrepresentation, n = 25) may restrict statistical power for detecting subtle effect sizes. Second, the cross-sectional design of our study precludes causal inferences between sleep disturbances, blood pressure changes, and autonomic dysfunction. Third, reliance on subjective sleep measures rather than objective polysomnographic measures introduces potential reporting bias. Future studies should incorporate larger sample sizes, longitudinal designs, and objective sleep monitoring to validate and extend our findings. Additionally, investigating the role of sex hormones and other potential mediating factors would further elucidate the mechanisms underlying observed gender differences. 6. Conclusion This study demonstrates that MDD manifests gender-specific patterns in sleep architecture, blood pressure alterations, and sympathetic activation. Male patients exhibit sympathetic hyperactivity primarily associated with reduced sleep efficiency, whereas females show abhorrent autonomic alterations correlated with both prolonged sleep onset latency and shortened sleep duration. Crucially, we identified divergent blood pressure-autonomic relationships: in males, diastolic hypotension corresponded with sympathetic predominance evidenced by depressed parasympathetic indices (pNN50, HF power) and elevated sympathetic markers (LF power, LF/HF ratio). Conversely, females showed selective sensitivity to systolic blood pressure reductions, which specifically correlated with increased LF/HF ratios. These differential pathophysiological patterns suggest that gender modulates the integration of sleep-cardiovascular-autonomic pathways in MDD, likely through complex regulatory mechanisms involving sex hormones, inflammatory pathways, and adrenal cortex pathways. Our findings underscore the necessity for gender-stratified approaches in managing autonomic dysfunction in depression, with therapeutic strategies requiring tailored consideration of sleep parameters, blood pressure profiles, and autonomic biomarkers specific to each gender. Abbreviations BMI=body mass index DSM=Diagnostic and Statistical Manual of Mental Disorders MDD: major depressive disorder ECG=electrocardiogram PSQI=Pittsburgh Sleep Quality Index SE=sleep efficiency SOL=sleep onset latency HFnu=high frequency normalized unit HR=heart rate SBP=Systolic Blood Pressure DBP=Diastolic Blood Pressure. HR=Heart rate SDNN=Standard deviation of all NN intervals RMSSD=Square root of the mean squared difference of successive NN intervals pNN50=Percent of NN intervals>50 ms different from previous (NN) for period of interest LFnu=[LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF+HF) HFnu=[HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF+HF); LF/HF: LF/HF average over 5-min periods or less HAMD-17=Hamilton Depression Rating Scale-17; HAMA=Hamilton Anxiety Rating Scale Declarations Consent for publication and Availability of data and materials : Consent for publication was obtained from the participants, and the Data will be made available on request. Authorship contribution statement Wenli Ban : Writing – original draft, Visualization, Investigation, Formal analysis, Data curation, Conceptualization. Fengchun Wu : Writing – review & editing, Methodology, Funding acquisition. Hehua Li : Writing – review & editing, Visualization, Formal analysis, Data curation. Sumiao Zhou : Writing – review & editing, Validation, Methodology. Shixuan Feng : Visualization, Software. Chenyu Liu : Resources. Zhendong Zhang : Data curation. Yuanyuan Huang : Writing – review & editing, Supervision, Conceptualization, Project administration, Funding acquisition. Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Ethics approval and consent to participate: The study protocol received ethical approval from the Affiliated Brain Hospital Guangzhou Medical University and complied with Helsinki Declaration guidelines (2013). Written informed consent was obtained from all participants following a comprehensive procedural briefing. Declaration of Clinical trail number: Not applicable. As this study is an observational cross-sectional study, it is not applicable to this entry. Funding sources National Key Research and Development Program of China (2025YFC3410000, 2025YFC3410005) Key-Area Research and Development Program of Guangdong Province (2023B0303020001) National Natural Science Foundation of China (82301688) Natural Science Foundation of Guangdong (2025A1515010507, 2023A1515011383), Science and Technology Program of Guangzhou (2025A03J3357, 202206060005, 2023A03J0856, 2023A03J0839) Guangzhou Key Clinical Specialty (Clinical Medical Research Institute) Acknowledgements: We gratefully acknowledge the financial support provided by the National Key Research and Development Program of China (2025YFC3410000, 2025YFC3410005), National Natural Science Foundation of China (82301688) and so forth. Furthermore, we extend our heartfelt thanks to the main participants who willingly participated in the research. References Washington DC. American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM-5). 5th ed; 2013.[M]. Meshkat S, Duffy F, Tassone SK. Increased odds of metabolic syndrome among adults with depressive symptoms or antidepressant use[J]. Translational Psychiatry. 2025;15(1):68. Zhang Z, Huang Y, Zhou S, et al. Effect of serum antioxidants on cognitive dysfunction in first-episode and drug-naïve patients with major depressive disorder[J]. J Affect Disord. 2025;372:533–9. Li T, Tao S, Jiang T, et al. Moderating effects of insomnia on the association between urinary phthalate metabolites and depressive symptoms in Chinese college students: focus on gender differences[J]. BMC Public Health. 2025;25(1):802. Sunderajan P, Gaynes BN, Wisniewski SR, et al. Insomnia in Patients With Depression: A STAR*D Report [J]. Volume 15. CNS Spectrums; 2010. pp. 394–404. 6. Wallace ML, Stone K, Smagula SF et al. Which Sleep Health Characteristics Predict All-Cause Mortality in Older Men? An Application of Flexible Multivariable Approaches[J]. Sleep, 2018, 41(1). Gangwisch JE, Malaspina D, Posner K, et al. Insomnia and Sleep Duration as Mediators of the Relationship Between Depression and Hypertension Incidence[J]. Am J Hypertens. 2010;23(1):62–9. Zhang W, Sun Q, Chen B, et al. Insomnia symptoms are associated with metabolic syndrome in patients with severe psychiatric disorders[J]. Sleep Med. 2021;83:168–74. Makarem N, Alcantara C, Musick S et al. Abstract 12677: Multidimensional Sleep Health is Associated With Cardiometabolic Health in a Nationally Representative Sample of US Adults[J]. Circulation, 2021, 144(Suppl_1). Hertenstein E, Benz F, Schneider CL, et al. Insomnia—A risk factor for mental disorders[J]. J Sleep Res. 2023;32(6):e13930. Hare DL, Toukhsati SR, Johansson P, et al. Depression and cardiovascular disease: a clinical review[J]. Eur Heart J. 2014;35(21):1365–72. Li G, Yu Y, Lin C, et al. Association between major depressive disorder or depressive symptoms and the risk of vascular complications among patients with type 2 diabetes, and the mediating role of metabolic biomarkers: an analysis of the UK Biobank cohort[J]. eClinicalMedicine. 2025;79:102982. Jin B, Zhang H, Song F, et al. Interaction of sleep duration and depression on cardiovascular disease: a retrospective cohort study[J]. BMC Public Health. 2022;22(1):1752. Bai B, Yin H, Wang H, et al. The combined effects of depression or anxiety with high-sensitivity C-reactive protein in predicting the prognosis of coronary heart disease patients[J]. BMC Psychiatry. 2024;24(1):717. Miller AH, Maletic V, Raison CL. Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression[J]. Biol Psychiatry. 2009;65(9):732–41. Wagner-Skacel J, Mörkl S, Dalkner N, et al. The Impact of Cardiovascular Rehabilitation on Psychophysiological Stress, Personality and Tryptophan Metabolism: A Randomized Pilot Feasibility Study[J]. Antioxidants. 2021;10(9):1425. Grassi G, Bertoli S, Seravalle G. Sympathetic nervous system: role in hypertension and in chronic kidney disease[J]. Curr Opin Nephrol Hypertens. 2012;21(1):46–51. Marston NA, Kamanu FK, Melloni GEM et al. Endothelial cell-related genetic variants identify LDL cholesterol-sensitive individuals who derive greater benefit from aggressive lipid lowering[J]. Nat Med, 2025. Bansil P, Kuklina EV, Merritt RK, et al. Associations Between Sleep Disorders, Sleep Duration, Quality of Sleep, and Hypertension: Results From the National Health and Nutrition Examination Survey, 2005 to 2008: Sleep-Related Problems and Hypertension[J]. J Clin Hypertens. 2011;13(10):739–43. Tobaldini E, Fiorelli EM, Solbiati M, et al. Short sleep duration and cardiometabolic risk: from pathophysiology to clinical evidence[J]. Nat Reviews Cardiol. 2019;16(4):213–24. Shi S, Liang J, Liu T, et al. Depression Increases Sympathetic Activity and Exacerbates Myocardial Remodeling after Myocardial Infarction: Evidence from an Animal Experiment[J]. Volume 9. BAUER W R.PLoS ONE; 2014. p. e101734. 7. Darling AM, Young BE, Skow RJ, et al. Sympathetic and blood pressure reactivity in young adults with major depressive disorder[J]. J Affect Disord. 2024;361:322–32. Chang H-A, Chang C-C, Tzeng N-S, et al. Generalized Anxiety Disorder, Comorbid Major Depression and Heart Rate Variability: A Case-Control Study in Taiwan[J]. Psychiatry Invest. 2013;10(4):326. Bajkó Z, Szekeres C-C, Kovács KR, et al. Anxiety, depression and autonomic nervous system dysfunction in hypertension[J]. J Neurol Sci. 2012;317(1–2):112–6. Malik M, Heart Rate V. Standards of Measurement, Physiological Interpretation, and Clinical Use: Task Force of The European Society of Cardiology and the North American Society for Pacing and Electrophysiology[J]. Ann Noninvasive Electrocardiol. 1996;1(2):151–81. Friedman BH, Thayer JF. Autonomic balance revisited: Panic anxiety and heart rate variability[J]. J Psychosom Res. 1998;44(1):133–51. Shimizu T, Takahashi Y, Kogawa S, et al. Muscle sympathetic nerve activity during central, mixed and obstructive apnea: Are there any differences?[J]. J Neuropsychiatry Clin Neurosci. 1997;51(6):397–404. Mao J, Liu X, Kote A, et al. Skin sympathetic nerve activity in symptomatic and asymptomatic paroxysmal atrial fibrillation[J]. Heart Rhythm. 2024;21(12):2437–44. Liu Y, Huang Y, Zhou J, et al. Altered Heart Rate Variability in Patients With Schizophrenia During an Autonomic Nervous Test[J]. Front Psychiatry. 2021;12:626991. Schiweck C, Piette D, Berckmans D, et al. Heart rate and high frequency heart rate variability during stress as biomarker for clinical depression. A systematic review[J]. Psychol Med. 2019;49(2):200–11. Tobaldini E, Carandina A, Toschi-Dias E, et al. Depression and cardiovascular autonomic control: a matter of vagus and sex paradox[J]. Neurosci Biobehavioral Reviews. 2020;116:154–61. Chambers AS, Allen JJB. Sex differences in cardiac vagal control in a depressed sample: Implications for differential cardiovascular mortality[J]. Biol Psychol. 2007;75(1):32–6. Chen H, Yang CCH, Kuo TBJ, et al. Gender differences in the relationship between depression and cardiac autonomic function among community elderly[J]. Int J Geriatr Psychiatry. 2010;25(3):314–22. Garcia RG, Zarruk JG, Guzman JC, et al. Sex differences in cardiac autonomic function of depressed young adults[J]. Biol Psychol. 2012;90(3):179–85. Grassi G, Seravalle G, Mancia G. Sympathetic activation in cardiovascular disease: evidence, clinical impact and therapeutic implications[J]. Eur J Clin Invest. 2015;45(12):1367–75. Barton DA, Dawood T, Lambert EA, et al. Sympathetic activity in major depressive disorder: identifying those at increased cardiac risk?[J]. J Hypertens. 2007;25(10):2117–24. Brown ADH, Barton DA, Lambert GW. Cardiovascular Abnormalities in Patients with Major Depressive Disorder: Autonomic Mechanisms and Implications for Treatment[J]. CNS Drugs. 2009;23(7):583–602. Doi Y, Minowa M, Uchiyama M, et al. Psychometric assessment of subjective sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects[J]. Psychiatry Res. 2000;97(2–3):165–72. Hamilton M, A RATING SCALE FOR, DEPRESSION[J]. J Neurol Neurosurg Psychiatry. 1960;23(1):56–62. Hamilton M, THE ASSESSMENT OF, ANXIETY STATES BY RATING[J]. Br J Med Psychol. 1959;32(1):50–5. Pham T, Lau ZJ, Chen SHA, et al. Heart Rate Variability in Psychology: A Review of HRV Indices and an Analysis Tutorial[J]. Sensors. 2021;21(12):3998. Stein PK, Pu Y. Heart rate variability, sleep and sleep disorders[J]. Sleep Med Rev. 2012;16(1):47–66. Huang W-L, Liao S-C, Wu C-S, et al. Clarifying the link between psychopathologies and heart rate variability, and the sex differences: Can neuropsychological features serve as mediators?[J]. J Affect Disord. 2023;340:250–7. Huang W-L, Liao S-C, Yang CCH, et al. Measures of Heart Rate Variability in Individuals With Somatic Symptom Disorder[J]. Psychosom Med. 2017;79(1):34–42. Shvartz V, Danilov V, Koroleva S, et al. Reference ranges of gender- and age-related heart rate variability parameters in Russian children[J]. Sci Rep. 2025;15(1):5274. Ricciardiello A, McKinnon AC, Mowszowski L, et al. Assessing sleep architecture and cognition in older adults with depressive symptoms attending a memory clinic[J]. J Affect Disord. 2024;348:35–43. Eid RS, Gobinath AR, Galea LAM. Sex differences in depression: Insights from clinical and preclinical studies[J]. Prog Neurobiol. 2019;176:86–102. Silverstein B. Gender Difference in the Prevalence of Clinical Depression: The Role Played by Depression Associated With Somatic Symptoms[J]. Am J Psychiatry. 1999;156(3):480–2. Pittig A, Arch JJ, Lam CWR, et al. Heart rate and heart rate variability in panic, social anxiety, obsessive–compulsive, and generalized anxiety disorders at baseline and in response to relaxation and hyperventilation[J]. Int J Psychophysiol. 2013;87(1):19–27. Lucini D, Pagani M. Heart rate variability, autonomic regulation and myocardial ischemia[J]. Int J Cardiol. 2020;312:22–3. Wescott DL, Hasler BP, Foust JE, et al. Circadian realignment and depressed mood: A systematic review[J]. Sleep Med Rev. 2025;79:102022. Bostwick JM. A Generalist’s Guide to Treating Patients With Depression With an Emphasis on Using Side Effects to Tailor Antidepressant Therapy[J]. Mayo Clinic Proceedings, 2010, 85(6): 538–550. Narkiewicz K, Phillips BG, Kato M, et al. Gender-Selective Interaction Between Aging, Blood Pressure, and Sympathetic Nerve Activity[J]. Hypertension. 2005;45(4):522–5. Drury ER, Wu J, Gigliotti JC, et al. Sex differences in blood pressure regulation and hypertension: renal, hemodynamic, and hormonal mechanisms[J]. Physiol Rev. 2024;104(1):199–251. Keir DA, Badrov MB, Tomlinson G, et al. Influence of Sex and Age on Muscle Sympathetic Nerve Activity of Healthy Normotensive Adults[J]. Hypertension. 2020;76(3):997–1005. Bucciarelli V, Caterino AL, Bianco F, et al. Depression and cardiovascular disease: The deep blue sea of women’s heart[J]. Trends Cardiovasc Med. 2020;30(3):170–6. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 11 May, 2026 Reviews received at journal 01 Apr, 2026 Reviewers agreed at journal 26 Mar, 2026 Reviewers agreed at journal 24 Mar, 2026 Reviewers agreed at journal 24 Mar, 2026 Reviews received at journal 24 Mar, 2026 Reviewers agreed at journal 18 Mar, 2026 Reviewers invited by journal 16 Mar, 2026 Editor invited by journal 25 Feb, 2026 Editor assigned by journal 10 Feb, 2026 Submission checks completed at journal 10 Feb, 2026 First submitted to journal 10 Feb, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8766171","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":607721911,"identity":"061910ac-f81f-4c1c-a582-e4cfa1cfe5a2","order_by":0,"name":"Wenli Ban","email":"","orcid":"","institution":"Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Wenli","middleName":"","lastName":"Ban","suffix":""},{"id":607721912,"identity":"43ff54e8-d2a9-4203-ae25-23e030e3bf04","order_by":1,"name":"Fengchun Wu","email":"","orcid":"","institution":"Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Fengchun","middleName":"","lastName":"Wu","suffix":""},{"id":607721913,"identity":"8481ed38-8021-4a08-854a-f78ad6eb8097","order_by":2,"name":"Hehua Li","email":"","orcid":"","institution":"Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Hehua","middleName":"","lastName":"Li","suffix":""},{"id":607721914,"identity":"348f0ce7-d49d-48ec-a7e4-776140d7ba48","order_by":3,"name":"Sumiao Zhou","email":"","orcid":"","institution":"Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Sumiao","middleName":"","lastName":"Zhou","suffix":""},{"id":607721915,"identity":"5f49b996-171f-4a3b-aa13-f7d898dbae91","order_by":4,"name":"Shixuan Feng","email":"","orcid":"","institution":"Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Shixuan","middleName":"","lastName":"Feng","suffix":""},{"id":607721916,"identity":"7e3599d6-24ba-4d4c-acab-987c030509a1","order_by":5,"name":"Chenyu Liu","email":"","orcid":"","institution":"Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Chenyu","middleName":"","lastName":"Liu","suffix":""},{"id":607721917,"identity":"7ae895f8-4531-4234-9a92-86cb113a3e7b","order_by":6,"name":"Zhendong Zhang","email":"","orcid":"","institution":"Guangzhou Medical University","correspondingAuthor":false,"prefix":"","firstName":"Zhendong","middleName":"","lastName":"Zhang","suffix":""},{"id":607721919,"identity":"7d319483-3ed7-47af-a552-d1b638618476","order_by":7,"name":"Yuanyuan Huang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA6UlEQVRIiWNgGAWjYBACNv7mAwc+8Njw8LP3f3yQUFFDWAufxLHEhzNk0uQkew4YGzw4c4ywFjmGHGVjHpvDxgY3EswkH7YwE+EwhjNsEjw5aYkNNxLSKhIb2Bj427sT8Gth7j0mIXHGJrGx58GxG4k7ZBgkzpzdQMCWc2kShj1pic3siW03Es+wMRhI5BLSkmMmkfjvcGIbQzJbQWIbM1FajA0O8Bw25uFIY2MgTgsokBt40uQkeM4wSyScOcZD0C/y/c0HDv8BRqX98R7Gjz8qauT423vxa8EAPKQpHwWjYBSMglGAFQAAkYlMZstpCDwAAAAASUVORK5CYII=","orcid":"","institution":"Guangzhou Medical University","correspondingAuthor":true,"prefix":"","firstName":"Yuanyuan","middleName":"","lastName":"Huang","suffix":""}],"badges":[],"createdAt":"2026-02-02 14:38:43","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8766171/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8766171/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104996956,"identity":"ecdde03b-f3a5-4af0-aeb1-b9c04004b879","added_by":"auto","created_at":"2026-03-19 16:16:58","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":260490,"visible":true,"origin":"","legend":"\u003cp\u003eLegend not included with this version.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8766171/v1/60089a845acaff385e3fead7.png"},{"id":105035560,"identity":"bb024bb6-4bcb-45d4-9746-78ad50916281","added_by":"auto","created_at":"2026-03-20 07:26:15","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1519919,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8766171/v1/2c9d3609-3a24-4889-b2e0-7c81fbf4703f.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effect of subjective sleep impairment and decreased blood pressure on gender-specific HRV in first-episode and drug-naive patients with major depressive disorder","fulltext":[{"header":"1. INTRODUCTION","content":"\u003cp\u003eMajor depressive disorder (MDD), a highly prevalent and debilitating psychiatric condition defined by altered regulation of mood, behavior and affect\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e, leading to a range of adverse health outcomes\u003csup\u003e[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]\u003c/sup\u003e. Within the DSM-5 diagnostic criteria for MDD, sleep disorders constitute specific sub-items, notably requiring reports of insomnia or hypersomnia occurring nearly daily. Clinically, sleep dysfunction is a frequent manifestation in MDD patients\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]\u003c/sup\u003e. Supporting this, the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study revealed that 87.4% of individuals with MDD exhibited concurrent insomnia symptoms, predominantly characterized by prolonged sleep latency and frequent nocturnal awakenings\u003csup\u003e[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003c/sup\u003e. Furthermore, alterations in key sleep parameters\u0026mdash;including duration, quality, and circadian rhythm are related to detrimental clinical sequelae\u003csup\u003e[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u003c/sup\u003e. Several studies have reported distinct changes in sleep patterns among depressed patients, encompassing both reduced and extended sleep duration, as well as diminished sleep quality\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e. Critically, these sleep pattern alterations are closely linked to an increased risk of subsequent cardiovascular disease (CVD). Cross-sectional evidence also indicates that insomnia correlates with metabolic diseases, including hypertriglyceridemia and insulin resistance, particularly in individuals with severe mental disorders\u003csup\u003e[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e. Additionally, sleep disorders are implicated in dementia risk. A prospective study of cognitively intact male patients demonstrated that alterations in five specific sleep characteristics were significantly associated with accelerated long-term cognitive decline and heightened risk of developing Alzheimer's disease dementia\u003csup\u003e[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]\u003c/sup\u003e. Finally, a meta-analysis published in 2023 synthesized evidence suggesting that nsomnia acts as a potential etiological or exacerbating factor for subsequent mental disorders, including depression\u003csup\u003e[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u003c/sup\u003e. This evidence supports a pernicious bidirectional relationship wherein sleep pathology and depressive illness mutually reinforce each other, thereby complicating clinical trajectories and presenting substantial therapeutic challenges. Collectively, these findings indicate that sleep disorders not only contribute to chronic cardiovascular and cerebrovascular diseases but also may exacerbate MDD symptomatology, which further underscores the necessity and importance of vigilant monitoring and clinical attention to sleep characteristics in the management of MDD patients.\u003c/p\u003e \u003cp\u003ePatients with MDD face a substantially elevated risk of cardiovascular morbidity and mortality. Previous studies have demonstrated that MDD patients exhibit significantly higher susceptibility to developing CVD and experience greater mortality rates compared to healthy controls\u003csup\u003e[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]\u003c/sup\u003e, with a demonstrable dose-response relationship between depression severity and subsequent cardiovascular mortality/events\u003csup\u003e[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]\u003c/sup\u003e. A parallel trend was observed in patients with comorbid MDD and chronic insomnia. Data from the China Health and Retirement Longitudinal Study indicated that both depression and subjective short sleep duration independently increase cardiovascular disease risk\u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]\u003c/sup\u003e. Furthermore, the analysis revealed that subjective short sleep duration mediates 38.6% of the association between depression and hypertension. Additionally, clinical studies\u003csup\u003e[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]\u003c/sup\u003e show that the pathogenesis of cardiovascular events involves multiple interrelated physiological and pathological mechanisms, including inflammatory factors release\u003csup\u003e[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u003c/sup\u003e, dysregulation of the HPA axis\u003csup\u003e[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]\u003c/sup\u003e, excessive the sympathetic nervous system activation\u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e, and endothelial dysfunction\u003csup\u003e[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]\u003c/sup\u003e, among others. Another study\u003csup\u003e[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]\u003c/sup\u003e suggests that short sleep duration increases the risk of subsequent cardiovascular and cerebrovascular diseases, such as hypertension, potentially linked to excessive activation of sympathetic nerve\u003csup\u003e[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u003c/sup\u003e. Moreover, research\u003csup\u003e[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]\u003c/sup\u003e posits that sympathetic nerve activation represents a common pathway integrating various pathophysiological mechanisms and may play a particularly significant role.\u003c/p\u003e \u003cp\u003ePrior investigations into cardiovascular comorbidity in MDD patients suggest that autonomic dysfunction represents one underlying mechanism\u003csup\u003e[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]\u003c/sup\u003e. Specifically, depressive symptoms severity has been associated with sympathetic-vagal imbalance\u003csup\u003e[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]\u003c/sup\u003e. Similar parasympathetic downregulation is also evident in MDD patients with comorbid anxiety disorders\u003csup\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]\u003c/sup\u003e. In clinical and scientific settings, sympathetic nerve activity can be assessed using various methods. Common tools for evaluating sympathetic-vagal balance include heart rate variability (HRV)\u003csup\u003e[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]\u003c/sup\u003e, baroreflex sensitivity (BRS)\u003csup\u003e[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/sup\u003e, microneurography (MSNA)\u003csup\u003e[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]\u003c/sup\u003e, and sympathetic skin response \u003csup\u003e[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/sup\u003e. Among these, HRV offers the advantages of non-invasiveness and suitability for continuous monitoring, making it widely applicable in population studies, including those involving mental disorders\u003csup\u003e[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]\u003c/sup\u003e. Notably, a pronounced gender disparity exists in depression epidemiology, with women exhibiting a twofold higher lifetime incidence than men. Studies\u003csup\u003e[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]\u003c/sup\u003e further suggest that gender-related differences in sympathetic activation contribute to the differential cardiovascular risk observed in MDD patients. Consequently, we aim to elucidate whether subjective sleep indicators correlate with gender-specific sympathetic activation in depression. Furthermore, several studies\u003csup\u003e[\u003cspan additionalcitationids=\"CR33\" citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]\u003c/sup\u003e highlight a potential paradoxical sexual dimorphism: within the context of depression, women, despite exhibiting relatively greater vagal tone, face a significantly elevated risk of adverse cardiovascular events compared to their male counterparts. However, the determinants\u0026mdash;such as sleep disorder, anxiety severity, and depression severity\u0026mdash;underlying these gender-specific sympathetic activation in MDD remain inadequately investigated. Sustained sympathetic activation is frequently implicated as a potential mechanism increasing cardiovascular diseases\u003csup\u003e[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]\u003c/sup\u003e, including hypertension, and has been documented in MDD patients\u003csup\u003e[\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]\u003c/sup\u003e. Nevertheless, research examining the association between sympathetic nerve changes, blood pressure and gender specifically in MDD patients is lacking. Therefore, this study also seeks to explore the relationship between blood pressure level and sympathetic-vagal balance in MDD patients stratified by gender.\u003c/p\u003e \u003cp\u003eIn summary, the established comorbidity between MDD and sleep disturbances holds significant clinical relevance. Accumulating evidence suggests that \u0026ldquo;subjective sleep impairment\u0026rdquo; and \u0026ldquo;co-occurring affective symptomatology\u0026rdquo; (depressive-anxious load) may synergistically elevate cardiovascular risk profiles, particularly hypertension susceptibility. Crucially, the gender-specific modulation of sympathetic-vagal balance, manifesting as differential sympathetic activation patterns between genders, remains underexplored as a potential mediator in this pathophysiological triad. Therefore, we hypothesized that poorer subjective sleep indicators, worse emotional states (higher depressive-anxious load), and elevated blood pressure in MDD patients are associated with increased gender-specific sympathetic nerve system activity.\u003c/p\u003e"},{"header":"2. METHODS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Participants and Study Design\u003c/h2\u003e \u003cp\u003eA cross-sectional study was conducted at the Department of Psychiatry, Affiliated Brain Hospital of Guangzhou Medical University between February 2022 and July 2024. The cohort comprises 50 female patients with first-episode, unmedicated MDD and 25 male patients with first-episode, drug-naive MDD. Diagnoses were independently confirmed by two board-certified psychiatrists according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)\u003csup\u003e[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003c/sup\u003e. The study protocol received ethical approval from the Affiliated Brain Hospital Guangzhou Medical University and complied with Helsinki Declaration guidelines (2013). Written informed consent was obtained from all participants following a comprehensive procedural briefing.\u003c/p\u003e \u003cp\u003eAll participants underwent centralized assessment including: demographic data collection, standard scale assessment, blood pressure measurement and ECG data acquisition. Inclusion criteria required:: (1) DSM-5 diagnostic criteria of MDD; (2) first-episode presentation (duration\u0026thinsp;\u0026le;\u0026thinsp;2 years); (3) lifetime absence of psychopharmacological treatment; (4) age\u0026thinsp;\u0026ge;\u0026thinsp;18 years.\u003c/p\u003e \u003cp\u003eExclusion criteria encompassed: (1) Significant physical comorbidities potentially affect sympathetic nerve activity (e.g., coronary heart disease, hypertension, diabetes) or severe arrhythmias (e.g., advanced atrioventricular block, frequent ventricular premature contractions) documented by ECG; (2) Coexisting serious psychiatric disorders per DSM-5 (e.g., bipolar disorder, schizophrenia, delusional disorder); (3) History of chronic ethanol abuse or illicit psychostimulant use; (4) pregnancy or lactation; (5) Use of β-blockers (e.g., propranolol) or other drugs that may affect the sympathetic nerve within 3 months; (6) Inability to cooperate with ECG acquisition.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Clinical data collection\u003c/h2\u003e \u003cp\u003eSystematically documented parameters included: (1) Demographic parameters (chronological age, biological sex, marital status, occupational classification, geographic residency); (2) Longitudinal medical histories (via clinician-administered structured interviews).\u003c/p\u003e \u003cp\u003eSubjective sleep dice were evaluated using the Pittsburgh Sleep Quality Scale (PSQI)\u003csup\u003e[\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]\u003c/sup\u003e. From the PSQI, we derived four key indicators: (1) Short sleep duration, defined as \u0026lt;\u0026thinsp;6 hours per night based on Question 4:: \u0026ldquo;During the past month, how many hours of actual sleep did you get at night?\u0026rdquo;; (1) Poor sleep quality, categorized as \u0026ldquo;Poor\u0026rdquo; or \u0026ldquo;Extremely poor\u0026rdquo; responses to Question 6: \u0026ldquo;During the past month, what do you think of your sleep quality?\u0026rdquo;; (3) Sleep onset latency (SOL), determined from Question 2: \u0026ldquo;How many hours did you fell asleep after you stay at bed during the night in the past 1 month?\u0026rdquo;; (4) Sleep efficiency (SE), calculated as total sleep time (TST) divided by time in bed (TIB) using responses to PSQI Questions 1\u0026ndash;4.\u003c/p\u003e \u003cp\u003eDepressive symptom severity was assessed using the Hamilton depression rating scale-17 (HAMD-17)\u003csup\u003e[\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]\u003c/sup\u003e, while anxiety symptoms were quantified with the Hamilton anxiety rating scale (HAMA)\u003csup\u003e[\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]\u003c/sup\u003e. All clinical evaluators completed standardized training and demonstrated inter-rater reliability in HAMD-17 administration. Resting blood pressure was measured in triplicate recordings at 5-minute intervals following 10 minutes of seated rest using an electronic sphygmomanometer (Omron, HEM-7136, measurement accuracy\u0026thinsp;\u0026plusmn;\u0026thinsp;3 mmHg), which underwent monthly calibration against a mercury sphygmomanometer. The mean values of Systolic blood pressure (SBP) and Diastolic blood pressure (DBP) in the tests were utilized for statistical analyses. Anthropometric measurements (height, weight, waist circumference, hip circumference), electrocardiogram, heart rate, and substance use histories (smoking status, alcohol consumption patterns) were obtained by qualified technicians.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3 Evaluation of heart rate variability (HRV)\u003c/h2\u003e \u003cp\u003eHRV metrics were employed to delineate autonomic nervous system (ANS) function in the MDD cohorts. Participants maintained 24-hour pre-assessment abstinence from psychostimulants (caffeine \u0026ge;\u0026thinsp;200mg/day), ethanol consumption, and vigorous physical activity.\u003c/p\u003e \u003cp\u003eContinuous 10-minute electrocardiographic (ECG) recordings were acquired at a sampling frequency of 10000 Hz. HRV indices were processed using NeuroKit2\u003csup\u003e[\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]\u003c/sup\u003e, an open-source Python package for neurophysiological signal analysis (installation details accessible at \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://neurokit2.readthedocs.io/en/latest/installation.html\u003c/span\u003e\u003cspan address=\"https://neurokit2.readthedocs.io/en/latest/installation.html\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e, accessed 3 May 2021). Both time-domain parameters (SDNN, RMSSD, pNN50) and frequency-domain parameters (normalized low-frequency power LF(nu), normalized high-frequency power HF(nu), LF/HF ratio) were computed according to established standards by Phyllis K. Stein\u003csup\u003e[\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]\u003c/sup\u003e. ECG recordings were segmented into consecutive 5-minute epochs, with HRV indices averaged across all segments for final statistical analysis.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.4 Statistical analysis\u003c/h2\u003e \u003cp\u003eAll data underwent dual-entry verification via EpiData 3.1 (EpiData Association, Odense, Denmark) with cross-checked validation protocols. Statistical analyses were performed using IBM SPSS Statistics version 26.0 (IBM Corp., Armonk, NY). The analytical sequence comprised three phases. First, the age-matching procedure was completed. Demographic equivalence between male and female groups was established through statistical matching. Second, general demographic characteristics, subjective sleep parameters, clinical features, and emotional assessment scores (HAMD-17, HAMA) were compared between male and female MDD groups. Third, multiple linear regression models were constructed to examine relationships between HRV parameters (dependent variables) and subjective sleep characteristics, clinical characteristics, and emotional assessment scores (independent variables). Covariates with established biological relevance to HRV (age, BMI, smoking status, alcohol consumption status) were incorporated into all models using forced entry methodology. Statistical significance was defined as a two-tailed \u003cem\u003ep\u003c/em\u003e-value\u0026thinsp;\u0026le;\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. RESULTS","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Participant Characteristics and Group Comparisons\u003c/h2\u003e \u003cp\u003eA total of 25 male MDD patients and 50 MDD female patients were included in this study. Demographic and clinical characteristics are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Age distributions were matched between groups. Compared to their male counterparts, female MDD patients exhibited significantly lower BMI (\u003cem\u003et\u003c/em\u003e = -2.458, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), reduced smoking prevalence (\u003cem\u003eχ2\u003c/em\u003e\u0026thinsp;=\u0026thinsp;9.232, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.002), and lower alcohol consumption rates (\u003cem\u003eχ2\u003c/em\u003e\u0026thinsp;=\u0026thinsp;4.751, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.029). Clinical assessment revealed significantly lower systolic blood pressure (\u003cem\u003et\u003c/em\u003e = -4.042, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) in MDD female patients versus males. Emotional scales assessment demonstrated higher HAMD-17 scores in MDD female patients (\u003cem\u003eZ\u003c/em\u003e = -2.427, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.015), indicating greater depressive symptoms.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDemographic, Clinical, and Sleep Characteristics of Depressed Patients\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003cp\u003eN\u0026thinsp;=\u0026thinsp;25\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003cp\u003eN\u0026thinsp;=\u0026thinsp;50\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eχ2/t/Z\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eDemographic characteristic\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge, year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.24\u0026thinsp;\u0026plusmn;\u0026thinsp;2.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.82\u0026thinsp;\u0026plusmn;\u0026thinsp;3.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-0.554\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.580\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI, kg/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22.10\u0026thinsp;\u0026plusmn;\u0026thinsp;3.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20.15\u0026thinsp;\u0026plusmn;\u0026thinsp;3.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.458\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmoking (n, %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10, 40.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4, 8.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e9.232\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.002*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlcohol (n, %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14, 56.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15, 30.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.751\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.029*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eClinical characteristic\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSBP (mmHg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e124.52\u0026thinsp;\u0026plusmn;\u0026thinsp;11.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e113.72\u0026thinsp;\u0026plusmn;\u0026thinsp;10.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-4.042\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDBP (mmHg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e77.32\u0026thinsp;\u0026plusmn;\u0026thinsp;8.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e73.76\u0026thinsp;\u0026plusmn;\u0026thinsp;8.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-1.736\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.087\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eEmotional characteristic\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHAMD-17, total score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.04\u0026thinsp;\u0026plusmn;\u0026thinsp;4.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e23.43\u0026thinsp;\u0026plusmn;\u0026thinsp;3.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.427\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.015*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHAMA, total score\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16.92\u0026thinsp;\u0026plusmn;\u0026thinsp;7.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18.68\u0026thinsp;\u0026plusmn;\u0026thinsp;4.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.250\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.215\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSubjective sleep characteristics\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSOL (min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e104.24\u0026thinsp;\u0026plusmn;\u0026thinsp;104.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e109.90\u0026thinsp;\u0026plusmn;\u0026thinsp;85.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-0.940\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.347\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSE (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e76.14\u0026thinsp;\u0026plusmn;\u0026thinsp;18.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72.23\u0026thinsp;\u0026plusmn;\u0026thinsp;18.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.863\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.391\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eShort sleep duration (n, %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e18, 72.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e38, 76.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.141\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.707\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePoor sleep quality (n, %)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23, 92.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e47, 94.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.757\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.415\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eHeart rate variability(2min)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHR (beats/ min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e80.53\u0026thinsp;\u0026plusmn;\u0026thinsp;7.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e80.74\u0026thinsp;\u0026plusmn;\u0026thinsp;10.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.087\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.931\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSDNN (ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42.71\u0026thinsp;\u0026plusmn;\u0026thinsp;12.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40.61\u0026thinsp;\u0026plusmn;\u0026thinsp;11.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-0.726\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.470\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRMSSD (ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28.97\u0026thinsp;\u0026plusmn;\u0026thinsp;11.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e29.86\u0026thinsp;\u0026plusmn;\u0026thinsp;11.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.318\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.752\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epNN50 (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.70\u0026thinsp;\u0026plusmn;\u0026thinsp;11.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10.92\u0026thinsp;\u0026plusmn;\u0026thinsp;10.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-0.427\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.669\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLFnu (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.49\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.585\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.010*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHFnu (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.979\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.004*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLF/HF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.02\u0026thinsp;\u0026plusmn;\u0026thinsp;1.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.54\u0026thinsp;\u0026plusmn;\u0026thinsp;1.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e-2.304\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.021*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eNotes: Data are presented as mean\u0026plusmn;standard deviation for continuous variables, and sample size (percentage) for categorical variables. *There are 75 depressed patients enrolled, including 25 males and 50 females; P-values in bold indicate P\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003ea\u003c/sup\u003e Based on the Major Depressive Disorder diagnostic criteria of the Diagnostic Statistical Mental Disorder-Ⅴ.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003eb\u003c/sup\u003e All of the subjects under Psychotropic medications (Antipsychotics, Antidepressants, Mood stabilizers, Hypnotic drugs) were excluded.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003e\u003csup\u003ec\u003c/sup\u003e Subjective sleep characteristic is based on PSQI\u0026rsquo;s fourth question.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eAbbreviations: MDD: major depressive disorder; BMI: body mass index; SOL: Sleep Onset Latency; SE: Sleep Efficiency; HAMD-17: Hamilton Depression Rating Scale-17; HAMA: Hamilton Anxiety Rating Scale; SBP: Systolic Blood Pressure; DBP: Diastolic Blood Pressure. HR: Heart rate; SDNN: Standard deviation of all NN intervals; RMSSD: Square root of the mean squared difference of successive NN intervals; pNN50: Percent of NN intervals\u0026thinsp;\u0026gt;\u0026thinsp;50 ms different from previous (NN) for period of interest; LFnu: [LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF\u0026thinsp;+\u0026thinsp;HF). HFnu: [HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF\u0026thinsp;+\u0026thinsp;HF); LF/HF: LF/HF average over 5-min periods or less; * means \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eHRV analysis showed significant between-group differences in frequency-domain parameters: Male patients exhibited higher LF (\u003cem\u003eZ\u003c/em\u003e = -2.585, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.010) and LF / HF (\u003cem\u003eZ\u003c/em\u003e = -2.304, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.021), and lower HF (\u003cem\u003et\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.979, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.004). These findings suggest heightened sympathetic nerve activation in male MDD patients. No significant statistical gender-based differences were detected in any of the subjective sleep parameters or in the time-domain HRV indices.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.2 \u003cb\u003eSleep Parameters and HRV Associations\u003c/b\u003e\u003c/h2\u003e \u003cp\u003eThe results of the multiple linear regression analyses examining the relationship between subjective sleep indicators, blood pressure, and emotional scales with HRV of male and female MDD patients, are detailed in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e and selectively illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eLinear Regression of Subjective sleep indicators with HRV in Different gender of MDD.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"16\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c14\" colnum=\"14\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c15\" colnum=\"15\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c16\" colnum=\"16\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariable\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eSOL\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003eSE\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c12\" namest=\"c10\"\u003e \u003cp\u003eShort sleep duration\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c16\" namest=\"c14\"\u003e \u003cp\u003ePoor sleep quality\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c14\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c15\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c16\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHR(beats/min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.02\u0026thinsp;~\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.330\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.36\u0026thinsp;~\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.131\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-0.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-9.12\u0026thinsp;~\u0026thinsp;7.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.872\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e2.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-10.97\u0026thinsp;~\u0026thinsp;15.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.743\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSDNN(ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.10\u0026thinsp;~\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.261\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.00\u0026thinsp;~\u0026thinsp;0.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.049*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e4.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-10.55\u0026thinsp;~\u0026thinsp;18.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.561\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-13.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-35.15\u0026thinsp;~\u0026thinsp;8.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.227\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRMSSD(ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.08\u0026thinsp;~\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.424\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.04\u0026thinsp;~\u0026thinsp;0.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.078\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-2.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-15.53\u0026thinsp;~\u0026thinsp;11.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.741\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-12.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-32.71\u0026thinsp;~\u0026thinsp;6.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.186\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epNN50(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.07\u0026thinsp;~\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.619\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.02\u0026thinsp;~\u0026thinsp;0.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.064\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-3.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-16.50\u0026thinsp;~\u0026thinsp;9.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.563\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-12.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-31.77\u0026thinsp;~\u0026thinsp;6.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.181\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLFnu(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.001\u0026thinsp;~\u0026thinsp;0.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.633\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.003\u0026thinsp;~\u0026thinsp;0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.807\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-0.13\u0026thinsp;~\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.931\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-0.15\u0026thinsp;~\u0026thinsp;0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.629\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHFnu(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.000\u0026thinsp;~\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.604\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.004\u0026thinsp;~\u0026thinsp;0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.599\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-0.12\u0026thinsp;~\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.957\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-0.23\u0026thinsp;~\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.646\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLF/HF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.007\u0026thinsp;~\u0026thinsp;0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.493\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.02\u0026thinsp;~\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.569\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-1.34\u0026thinsp;~\u0026thinsp;1.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.775\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-1.32\u0026thinsp;~\u0026thinsp;2.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.573\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariable\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eSOL\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003eSE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c12\" namest=\"c10\"\u003e \u003cp\u003eShort sleep duration\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c16\" namest=\"c14\"\u003e \u003cp\u003ePoor sleep quality\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHR(beats/min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.03\u0026thinsp;~\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.573\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.22\u0026thinsp;~\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.731\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-1.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-8.82\u0026thinsp;~\u0026thinsp;6.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.775\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e4.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-9.42\u0026thinsp;~\u0026thinsp;19.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.493\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSDNN(ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.04\u0026thinsp;~\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.851\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.21\u0026thinsp;~\u0026thinsp;0.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.873\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e5.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-1.75\u0026thinsp;~\u0026thinsp;13.56\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.127\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-8.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-22.78\u0026thinsp;~\u0026thinsp;6.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.253\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRMSSD(ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.005\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.05\u0026thinsp;~\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.816\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.24\u0026thinsp;~\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.647\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e7.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.08\u0026thinsp;~\u0026thinsp;15.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.048*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-9.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-24.52\u0026thinsp;~\u0026thinsp;4.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.184\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epNN50(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.04\u0026thinsp;~\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.864\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.22\u0026thinsp;~\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.639\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e7.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.25\u0026thinsp;~\u0026thinsp;14.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.043*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-11.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-24.87\u0026thinsp;~\u0026thinsp;1.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.079\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLFnu(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u0026thinsp;~\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.159\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.003\u0026thinsp;~\u0026thinsp;0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.876\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-0.14\u0026thinsp;~\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.445\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-0.03\u0026thinsp;~\u0026thinsp;0.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.106\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHFnu(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.001\u0026thinsp;~\u0026thinsp;0.000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.163\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.002\u0026thinsp;~\u0026thinsp;0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.839\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-0.08\u0026thinsp;~\u0026thinsp;0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.599\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e-0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-0.33\u0026thinsp;~\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.132\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLF/HF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u0026thinsp;~\u0026thinsp;0.008\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.038*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-0.03\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.441\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-0.69\u0026thinsp;~\u0026thinsp;0.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c13\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c14\"\u003e \u003cp\u003e0.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c15\"\u003e \u003cp\u003e-1.08\u0026thinsp;~\u0026thinsp;1.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c16\"\u003e \u003cp\u003e0.630\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"16\"\u003eNote: \u003csup\u003e1\u003c/sup\u003e means group of Male MDD patients. \u003csup\u003e2\u003c/sup\u003e means group of Female MDD patients. All of the subjects under Psychotropic medications (Antipsychotics, Antidepressants, Mood stabilizers, Hypnotic drugs) were excluded. The liner regression was adjusted for age, body mass index, smoking, and alcohol. Short sleep duration was defined less than 6 hours according to question 2 in the Pittsburgh Sleep Quality Index: \u0026ldquo;During the past month, how many hours of actual sleep did you get at night\u0026rdquo;. Poor sleep quality was defined as \u0026ldquo;Poor or Extremely poor\u0026rdquo; according to question 6 in the Pittsburgh Sleep Quality Index: \u0026ldquo;During the past month, what do you think of your sleep quality\u0026rdquo;. SOL: Sleep Onset Latency. SE: Sleep Efficiency. HR: Heart rate; SDNN: Standard deviation of all NN intervals; RMSSD: Square root of the mean squared difference of successive NN intervals; pNN50: Percent of NN intervals\u0026thinsp;\u0026gt;\u0026thinsp;50 ms different from previous (NN) for period of interest; LFnu: [LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF\u0026thinsp;+\u0026thinsp;HF). HFnu: [HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF\u0026thinsp;+\u0026thinsp;HF); LF/HF: LF/HF average over 5-min periods or less; B: Non-standardized regression coefficient; β: standardized regression coefficient; CI, confidence interval. * means P\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eLinear Regression of Blood pressure with HRV in Different gender of MDD.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"14\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c14\" colnum=\"14\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eSBP\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e \u003cp\u003eDBP\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c14\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHR (beats/min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.35\u0026thinsp;~\u0026thinsp;0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.963\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.26\u0026thinsp;~\u0026thinsp;0.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.687\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.41\u0026thinsp;~\u0026thinsp;0.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.779\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.07\u0026thinsp;~\u0026thinsp;0.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.106\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSDNN (ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.62\u0026thinsp;~\u0026thinsp;0.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.920\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.52\u0026thinsp;~\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.217\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e-0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.91\u0026thinsp;~\u0026thinsp;0.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.858\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-0.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.78\u0026thinsp;~\u0026thinsp;0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.060\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRMSSD (ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.19\u0026thinsp;~\u0026thinsp;0.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.196\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.34\u0026thinsp;~\u0026thinsp;0.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.977\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.04\u0026thinsp;~\u0026thinsp;1.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.065\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.71\u0026thinsp;~\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.153\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epNN50 (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.04\u0026thinsp;~\u0026thinsp;0.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.068\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.31\u0026thinsp;~\u0026thinsp;0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.983\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.80\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.18\u0026thinsp;~\u0026thinsp;1.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.014*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-0.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.61\u0026thinsp;~\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.227\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLFnu (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.01\u0026thinsp;~\u0026thinsp;0.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.189\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.01\u0026thinsp;~\u0026thinsp;0.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.211\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.01~-0.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.024*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.004\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.626\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHFnu (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.00\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.168\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.001\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.118\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e0.00\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.033*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.01~ -0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.829\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLF/HF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.06\u0026thinsp;~\u0026thinsp;0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.649\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.06~ -0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.024*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e-0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-1.12~-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.033*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.03\u0026thinsp;~\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.728\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"14\"\u003eNote: \u003csup\u003e1\u003c/sup\u003e means group of Male MDD patients. \u003csup\u003e2\u003c/sup\u003e means group of Female MDD patients. The liner regression was adjusted for age, body mass index, smoking, and alcohol. SBP: Systolic Blood Pressure. DBP: Diastolic Blood Pressure. HR: Heart rate; SDNN: Standard deviation of all NN intervals; RMSSD: Square root of the mean squared difference of successive NN intervals; pNN50: Percent of NN intervals\u0026thinsp;\u0026gt;\u0026thinsp;50 ms different from previous (NN) for period of interest; LFnu: [LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF\u0026thinsp;+\u0026thinsp;HF). HFnu: [HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF\u0026thinsp;+\u0026thinsp;HF); LF/HF: LF/HF average over 5-min periods or less; \u003cem\u003eB\u003c/em\u003e: Non-standardized regression coefficient; \u003cem\u003eβ\u003c/em\u003e: standardized regression coefficient; \u003cem\u003eCI\u003c/em\u003e, confidence interval. * means \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eLinear Regression of Emotional scales with HRV in Different gender of MDD.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"14\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c14\" colnum=\"14\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c4\" namest=\"c2\"\u003e \u003cp\u003eHAMD-17\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c14\" namest=\"c12\"\u003e \u003cp\u003eHAMA\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003csup\u003e\u003cem\u003e1\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003e\u003cem\u003eB\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c13\"\u003e \u003cp\u003e\u003cem\u003e95%CI\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c14\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003csup\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHR (beats/min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-74.56\u0026thinsp;~\u0026thinsp;170.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.348\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.17\u0026thinsp;~\u0026thinsp;1.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.112\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e-0.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.77\u0026thinsp;~\u0026thinsp;0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.296\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.01\u0026thinsp;~\u0026thinsp;1.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.055\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSDNN (ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-2.02\u0026thinsp;~\u0026thinsp;1.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.752\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e-0.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-1.14\u0026thinsp;~\u0026thinsp;0.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.606\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e-0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.96\u0026thinsp;~\u0026thinsp;0.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.917\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e-0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.79\u0026thinsp;~\u0026thinsp;0.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.813\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRMSSD (ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-1.85\u0026thinsp;~\u0026thinsp;1.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.728\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e-0.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-1.47\u0026thinsp;~\u0026thinsp;0.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.231\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e-0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.88\u0026thinsp;~\u0026thinsp;0.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.906\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e-0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.94\u0026thinsp;~\u0026thinsp;0.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.541\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epNN50 (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-1.84\u0026thinsp;~\u0026thinsp;1.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.683\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e-0.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-1.23\u0026thinsp;~\u0026thinsp;0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.354\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e-0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.92\u0026thinsp;~\u0026thinsp;0.68\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.765\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e-0.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.70\u0026thinsp;~\u0026thinsp;0.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.904\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLFnu (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.01\u0026thinsp;~\u0026thinsp;0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.895\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.01\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.895\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.01\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.728\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e-0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.01\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.717\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHFnu (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.003\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.02\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.675\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e-0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.01\u0026thinsp;~\u0026thinsp;0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.889\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e-0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.01\u0026thinsp;~\u0026thinsp;0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.599\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.01~ -0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.590\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLF/HF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e-0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e-0.14\u0026thinsp;~\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.953\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e-0.07\u0026thinsp;~\u0026thinsp;0.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e0.702\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c9\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c10\"\u003e \u003cp\u003e-0.07\u0026thinsp;~\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c11\"\u003e \u003cp\u003e0.844\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c12\"\u003e \u003cp\u003e-0.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c13\"\u003e \u003cp\u003e-0.08\u0026thinsp;~\u0026thinsp;0.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c14\"\u003e \u003cp\u003e0.720\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"14\"\u003eNote: \u003csup\u003e1\u003c/sup\u003e means group of Male MDD patients. \u003csup\u003e2\u003c/sup\u003e means group of Female MDD patients. The liner regression was adjusted for age, body mass index, smoking, and alcohol. HAMD-17: Hamilton Depression Rating Scale-17. HAMA: Hamilton Anxiety Rating Scale. HR: Heart rate; SDNN: Standard deviation of all NN intervals; RMSSD: Square root of the mean squared difference of successive NN intervals; pNN50: Percent of NN intervals\u0026thinsp;\u0026gt;\u0026thinsp;50 ms different from previous (NN) for period of interest; LFnu: [LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF\u0026thinsp;+\u0026thinsp;HF). HFnu: [HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF\u0026thinsp;+\u0026thinsp;HF); LF/HF: LF/HF average over 5-min periods or less; \u003cem\u003eB\u003c/em\u003e: Non-standardized regression coefficient; \u003cem\u003eβ\u003c/em\u003e: standardized regression coefficient; \u003cem\u003eCI\u003c/em\u003e, confidence interval. * means \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAmong male patients, higher SE was significantly correlated with a greater SDNN (\u003cem\u003eB\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.35 ms per 1% SE increase; Model A; \u003cem\u003e95% CI\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.00\u0026thinsp;~\u0026thinsp;0.09, \u003cem\u003eβ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.49, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.049), In female MDD patients, SOL positively predicted LF/HF ratio (\u003cem\u003eB\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.004 units per 1-min SOL increase; Model F; \u003cem\u003e95% CI\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.00\u0026thinsp;~\u0026thinsp;0.01, \u003cem\u003eβ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.26, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.038), while short sleep duration (\u0026lt;\u0026thinsp;6 hrs) was associated with increased RMSSD (\u003cem\u003eB\u003c/em\u003e\u0026thinsp;=\u0026thinsp;7.75 ms; Model G; \u003cem\u003e95% CI\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.08\u0026thinsp;~\u0026thinsp;15.42, \u003cem\u003eβ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.29, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.048) and pNN50 (\u003cem\u003eB\u003c/em\u003e\u0026thinsp;=\u0026thinsp;7.21%; Model H; \u003cem\u003e95% CI\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.25\u0026thinsp;~\u0026thinsp;14.17, \u003cem\u003eβ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.30, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.043). Additionally, gender-divergent autonomic responses to subjective sleep disturbances were observed. Male patients with MDD exhibited sympathetic activation related to subjective sleep disorders, whereas female patients demonstrated bidirectional alterations in sympathetic regulation\u0026mdash;prolonged sleep onset latency associated with sympathetic excitation, while subjective sleep duration less than 6h paradoxically corresponded to sympathetic inhibition with concomitant vagal predominance.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e3.3 Blood Pressure and HRV Relationships\u003c/h2\u003e \u003cp\u003eFurthermore, our detailed investigation into the correlations between systolic/diastolic blood pressure (SBP/DBP) and HRV parameters revealed significant inverse associations with sympathetic activation, as visualized in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. In the MDD male group (model B-E), each 1 mmHg increase in DBP corresponded to statistically significant alterations in multiple HRV indices - specifically, 0.80% (\u003cem\u003e95% CI\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.18\u0026thinsp;~\u0026thinsp;1.42, \u003cem\u003eβ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.59, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.014) increase in pNN50, a 0.01% (\u003cem\u003e95% CI\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.00\u0026thinsp;~\u0026thinsp;0.01, \u003cem\u003eβ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.47, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.033) increase in HF(nu), a 0.01% (\u003cem\u003e95% CI\u003c/em\u003e = -0.01 ~ -0.00, \u003cem\u003eβ\u003c/em\u003e = -0.50, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.024) decrease in LF(nu), and a 0.07-unit (\u003cem\u003e95% CI\u003c/em\u003e = -1.12 ~ -0.01, \u003cem\u003eβ\u003c/em\u003e = -0.48, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.033) reduction in the LF/HF ratio. Similarly, in female MDD patients (Model I), we observed parallel but quantitatively distinct relationships, where every 1 mmHg increase in SBP predicted a 0.04-unit (\u003cem\u003e95% CI\u003c/em\u003e = -0.06 ~ -0.01, \u003cem\u003eβ\u003c/em\u003e = -0.28, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.024) decrease in the LF/HF ratio, indicating consistent blood pressure-dependent attenuation of sympathetic dominance across both genders despite differential hemodynamic and autonomic regulatory mechanisms.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. DISCUSSION","content":"\u003cp\u003eOur study elucidates the complex interplay between sleep disturbances, blood pressure fluctuations, and gender-specific sympathetic activation patterns in MDD. To our knowledge, this represents the first investigation examining the relationships among subjective sleep indicators, emotional state, blood pressure, and gender- dimorphic autonomic nervous system activity in MDD. The principal findings reveal three key patterns: (1) Male MDD patients demonstrated impaired HRV regulation relative to female counterparts, particularly evident in frequency-domain parameters; (2) Gender-stratified analysis revealed distinct sleep-HRV interactions patterns: increased HRV in males correlated specifically with SE, while female patients displayed inverse HRV associations with both shortened SOL and curtailed sleep duration (\u0026lt;\u0026thinsp;6h); (3) Blood pressure profiles showed gender-specific HRV correlations by gender\u0026mdash;diastolic hypertension accompanied by concomitant HRV reduction characterized males, while females displayed systolic hypertension concurrent with HRV attenuation.\u003c/p\u003e \u003cp\u003eThese findings demonstrate gender-dimorphic autonomic regulation in MDD, with female patients exhibiting superior HRV modulation compared to males, suggesting heightened sympathetic activation in depressed males. This pathophysiological pattern aligns with prior evidence of gender-specific autonomic dysfunction in MDD\u003csup\u003e[\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]\u003c/sup\u003e. While gender differences in HRV remain underexplored in current depression research, emerging evidence from MDD-comorbid conditions like somatic symptom disorder (SSD) reveals distinct autonomic patterns. Notably, studies of elderly SSD patients report significantly reduced low-frequency to high-frequency HRV ratios (LF/HF) in females compared to males\u003csup\u003e[\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]\u003c/sup\u003e. This gender-specific sympathetic pattern contrasts with the stability observed in parasympathetic measures, evidenced by comparably high-frequency HRV (HF-HRV) values across genders. However, contradictory evidence exists. Pediatric research\u003csup\u003e[\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]\u003c/sup\u003e by Shvartz and colleagues involving children aged 5.5\u0026ndash;12.5 years found consistently reduced HRV in females across developmental stages, indicating heightened sympathetic activation despite comparable LF%, HF%, and LF/HF ratios between genders. These paradoxical observations may reflect multifactorial interactions encompassing MDD diagnostic heterogeneity, clinical characteristics, illness duration variability, ethnic diversity, and gender-specific antidepressant treatment responses.\u003c/p\u003e \u003cp\u003eWe further identified an independent correlation between subjective sleep disorder severity and gender-related HRV modulation in MDD, with progressive sympathetic predominance accompanying worsening SE in male patients and prolonged SOL in females, contrastingly, female patients manifested restrained sympathetic activities associated with shorten sleep duration (\u0026lt;\u0026thinsp;6h). This pathophysiological cascade in males of MDD, consistent with prior neurocardiac investigations\u003csup\u003e[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/sup\u003e, suggests sleep architecture disruption may critically impair the hypothalamic-pituitary-adrenal (HPA) axis function, thereby exacerbating sympathetic-vagal imbalance through excessive noradrenergic activation. Concurrently, sleep disturbances may elevate subsequent cardiovascular/cerebrovascular risk\u003csup\u003e[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]\u003c/sup\u003e and potential cognitive impairment\u003csup\u003e[\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e]\u003c/sup\u003e in MDD, compounding physical comorbidities and socioeconomic burdens. Crucially, we observed gender-specific patterns: Male MDD patients showed reduced sleep efficiency primarily associated with decreased SDNN, indicating compromised overall HRV. In contrast, female MDD patients exhibited more complex patterns, where prolonged sleep onset latency was correlated with an increased LF/HF ratio, while shortened sleep duration was related to increased RMSSD and pNN50. These findings partial align with established gender differences in depressive sleep architecture and autonomic regulation\u003csup\u003e[\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e]\u003c/sup\u003e. Silverstein\u003csup\u003e[\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e]\u003c/sup\u003e previously reported that female MDD patients typically experience greater somatic depression, including more pronounced sleep disturbances than males. Our findings extend this understanding by revealing the gender-specific autonomic correlates, suggesting that distinct pathophysiological mechanisms underlie sleep disruption in MDD. Methodologically, time-domain indices RMSSD and PNN50 demonstrate greater stability against heart rate fluctuations and temporal variations than SDNN and frequency-domain metrics\u003csup\u003e[\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e, \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e]\u003c/sup\u003e, rendering them sensitive indicators of sympathetic modulation. The association between short sleep duration and HRV increase (indicating sympathetic nerve suppression) in female MDD patients may reflect women's degenerative feedback in sympathetic-vagal regulatory capacity\u003csup\u003e[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]\u003c/sup\u003e. These findings further emphasize the necessity of gender-specific considerations when developing sleep interventions for MDD patients. Specifically, male patients might derive greater benefit from interventions targeting sleep efficiency improvement. Conversely, females exhibit bidirectional autonomic dysregulation\u0026mdash;prolonged sleep onset latency exacerbates sympathetic predominance while curtailed sleep duration (\u0026lt;\u0026thinsp;6 h) induces sympathetic attenuation. This divergence likely originates from distinct neurobiological pathways (e.g., immune inflammatory response, hormone regulation) mediating differential autonomic responses to specific sleep parameters. This gender-dimorphic pattern corresponds with emerging evidence on neurophysiological differences in sleep regulation. As highlighted in a Sleep Medicine Reviews systematic assessment\u003csup\u003e[\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]\u003c/sup\u003e, combining light therapy with behavioral strategies may provide scientific rationale for gender-specific interventions. Such integrated approaches could address persistent sympathetic nervous system hyperactivation observed in chronic MDD cases, thereby mitigating associated long-term health consequences. Additionally, our findings offer novel evidence-based guidance for gender-specific antidepressant selection in MDD management. Pharmacodynamic analyses reveal clinically significant temporal variations in treatment responses. For instance, unlike traditional SSRIs whose initial administration may exacerbate insomnia, mirtazapine demonstrates superior 5-hydroxytryptamine receptor 2 (5-HT2) blockade that enhances sleep architecture through reduced sleep latency, extended total sleep time, and improved sleep efficiency\u003csup\u003e[\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]\u003c/sup\u003e, Optimal management requires gender-specific pharmacotherapy targeting differential sleep dysregulation: female patients benefit from agents that reduce shorten SOL and modulate total sleep time characteristics; while male patients with depression require interventions prioritizing sleep efficiency enhancement. Such studies supporting the need for gender- adapted dosing regimens and pretreatment counseling.\u003c/p\u003e \u003cp\u003eBlood pressure-autonomic function also exhibited notable gender differences. Unlike previous studies\u003csup\u003e[\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e]\u003c/sup\u003e, we specifically examined blood pressure on gender-related sympathetic regulation in MDD patients. Male patients showed comprehensive autonomic alterations with diastolic blood pressure reduction, including decreased pNN50 and HF power alongside increased LF power and the LF/HF ratio. Given that LF/HF ratio serves as a sensitive indicator of sympathetic-vagal balance\u003csup\u003e[\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]\u003c/sup\u003e, these findings suggest a more pronounced sympathetic predominance with lower blood pressure in male MDD patients. Conversely, female MDD patients exhibited a varied pattern where only systolic blood pressure reduction correlated with increased LF/HF ratio. This observation may indicate a blood pressure-sympathetic negative feedback mechanism in MDD, whereby blood pressure elevation reduces sympathetic regulation\u0026mdash;consistent with the previous research results in other populations\u003csup\u003e[\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e]\u003c/sup\u003e. Estrogen-enhanced endothelium-mediated vasodilation in the female population\u003csup\u003e[\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e, \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e]\u003c/sup\u003e may explain the greater relevance of blood pressure with HRV-LF/HF ratio in female MDD patients than males.\u003c/p\u003e \u003cp\u003eNotably, our analysis did not reveal a direct correlation between the severity of affective symptoms (as measured by HAMD-17 and HAMA) and HRV indices in either gender, contradicting previous reports\u003csup\u003e[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u003c/sup\u003e. This suggests autonomic dysfunction-emotional state (including the severity of depression and anxiety) relationships may be mediated through alternative physiological pathways\u003csup\u003e[\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e]\u003c/sup\u003e, such as the hypothalamic-pituitary-adrenal axis function, chronic systemic inflammation, or other mechanisms, rather than direct associations with gender-specific sympathetic nerve activation.\u003c/p\u003e"},{"header":"5. Limitation","content":"\u003cp\u003eMethodological constraints warrant consideration. First, the limited sample size (particularly male subgroup underrepresentation, n\u0026thinsp;=\u0026thinsp;25) may restrict statistical power for detecting subtle effect sizes. Second, the cross-sectional design of our study precludes causal inferences between sleep disturbances, blood pressure changes, and autonomic dysfunction. Third, reliance on subjective sleep measures rather than objective polysomnographic measures introduces potential reporting bias. Future studies should incorporate larger sample sizes, longitudinal designs, and objective sleep monitoring to validate and extend our findings. Additionally, investigating the role of sex hormones and other potential mediating factors would further elucidate the mechanisms underlying observed gender differences.\u003c/p\u003e"},{"header":"6. Conclusion","content":"\u003cp\u003eThis study demonstrates that MDD manifests gender-specific patterns in sleep architecture, blood pressure alterations, and sympathetic activation. Male patients exhibit sympathetic hyperactivity primarily associated with reduced sleep efficiency, whereas females show abhorrent autonomic alterations correlated with both prolonged sleep onset latency and shortened sleep duration. Crucially, we identified divergent blood pressure-autonomic relationships: in males, diastolic hypotension corresponded with sympathetic predominance evidenced by depressed parasympathetic indices (pNN50, HF power) and elevated sympathetic markers (LF power, LF/HF ratio). Conversely, females showed selective sensitivity to systolic blood pressure reductions, which specifically correlated with increased LF/HF ratios. These differential pathophysiological patterns suggest that gender modulates the integration of sleep-cardiovascular-autonomic pathways in MDD, likely through complex regulatory mechanisms involving sex hormones, inflammatory pathways, and adrenal cortex pathways. Our findings underscore the necessity for gender-stratified approaches in managing autonomic dysfunction in depression, with therapeutic strategies requiring tailored consideration of sleep parameters, blood pressure profiles, and autonomic biomarkers specific to each gender.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eBMI=body mass index\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDSM=Diagnostic and Statistical Manual of Mental Disorders\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMDD: major depressive disorder\u003c/p\u003e\n\u003cp\u003eECG=electrocardiogram\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePSQI=Pittsburgh Sleep Quality Index\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSE=sleep efficiency\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSOL=sleep onset latency\u003c/p\u003e\n\u003cp\u003eHFnu=high frequency normalized unit\u003c/p\u003e\n\u003cp\u003eHR=heart rate\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSBP=Systolic Blood Pressure\u003c/p\u003e\n\u003cp\u003eDBP=Diastolic Blood Pressure.\u003c/p\u003e\n\u003cp\u003eHR=Heart rate\u003c/p\u003e\n\u003cp\u003eSDNN=Standard deviation of all NN intervals\u003c/p\u003e\n\u003cp\u003eRMSSD=Square root of the mean squared difference of successive NN intervals\u003c/p\u003e\n\u003cp\u003epNN50=Percent of NN intervals\u0026gt;50 ms different from previous (NN) for period of interest\u003c/p\u003e\n\u003cp\u003eLFnu=[LF/ (TP-VLF)] for the measured period (5-min or less). Some calculate LF/ (LF+HF)\u003c/p\u003e\n\u003cp\u003eHFnu=[HF/ (TP-VLF)] for the measured period (5-min or less). Some calculate HF/ (LF+HF); LF/HF: LF/HF average over 5-min periods or less\u003c/p\u003e\n\u003cp\u003eHAMD-17=Hamilton Depression Rating Scale-17;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eHAMA=Hamilton Anxiety Rating Scale\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eConsent for publication and Availability of data and materials\u003c/strong\u003e: Consent for publication was obtained from the participants, and the Data will be made available on request.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthorship contribution statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWenli Ban\u003c/strong\u003e: Writing \u0026ndash; original draft, Visualization, Investigation, Formal analysis, Data curation, Conceptualization.\u0026nbsp;\u003cstrong\u003eFengchun Wu\u003c/strong\u003e: Writing \u0026ndash; review \u0026amp; editing, Methodology, Funding acquisition.\u0026nbsp;\u003cstrong\u003eHehua Li\u003c/strong\u003e: Writing \u0026ndash; review \u0026amp; editing, Visualization, Formal analysis, Data curation.\u0026nbsp;\u003cstrong\u003eSumiao Zhou\u003c/strong\u003e: Writing\u0026nbsp;\u0026ndash;\u0026nbsp;review \u0026amp; editing, Validation, Methodology.\u0026nbsp;\u003cstrong\u003eShixuan Feng\u003c/strong\u003e: Visualization, Software.\u0026nbsp;\u003cstrong\u003eChenyu Liu\u003c/strong\u003e: Resources.\u0026nbsp;\u003cstrong\u003eZhendong Zhang\u003c/strong\u003e: Data curation.\u0026nbsp;\u003cstrong\u003eYuanyuan Huang\u003c/strong\u003e: Writing \u0026ndash; review \u0026amp; editing, Supervision, Conceptualization, Project administration, Funding acquisition.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of competing interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e The study protocol received ethical approval from the Affiliated Brain Hospital Guangzhou Medical University and complied with Helsinki Declaration guidelines (2013). Written informed consent was obtained from all participants following a comprehensive procedural briefing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of Clinical trail number: Not applicable.\u0026nbsp;\u003c/strong\u003eAs this study is an observational cross-sectional study, it is not applicable to this entry.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding sources\u003c/strong\u003e\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eNational Key Research and Development Program of China (2025YFC3410000, 2025YFC3410005)\u003c/li\u003e\n \u003cli\u003eKey-Area Research and Development Program of Guangdong Province (2023B0303020001)\u003c/li\u003e\n \u003cli\u003eNational Natural Science Foundation of China (82301688)\u003c/li\u003e\n \u003cli\u003eNatural Science Foundation of Guangdong (2025A1515010507, 2023A1515011383), Science and Technology Program of Guangzhou (2025A03J3357, 202206060005, 2023A03J0856, 2023A03J0839)\u003c/li\u003e\n \u003cli\u003eGuangzhou Key Clinical Specialty (Clinical Medical Research Institute)\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eWe gratefully acknowledge the financial support provided by the National Key Research and Development Program of China (2025YFC3410000, 2025YFC3410005), National Natural Science Foundation of China (82301688) and so forth. Furthermore, we extend our heartfelt thanks to the main participants who willingly participated in the research.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eWashington DC. American Psychiatric Association. Diagnostic and statistical manual of mental disorders (DSM-5). 5th ed; 2013.[M].\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMeshkat S, Duffy F, Tassone SK. Increased odds of metabolic syndrome among adults with depressive symptoms or antidepressant use[J]. Translational Psychiatry. 2025;15(1):68.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang Z, Huang Y, Zhou S, et al. Effect of serum antioxidants on cognitive dysfunction in first-episode and drug-na\u0026iuml;ve patients with major depressive disorder[J]. J Affect Disord. 2025;372:533\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi T, Tao S, Jiang T, et al. Moderating effects of insomnia on the association between urinary phthalate metabolites and depressive symptoms in Chinese college students: focus on gender differences[J]. BMC Public Health. 2025;25(1):802.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSunderajan P, Gaynes BN, Wisniewski SR, et al. Insomnia in Patients With Depression: \u003cem\u003eA STAR*D Report\u003c/em\u003e[J]. Volume 15. CNS Spectrums; 2010. pp. 394\u0026ndash;404. 6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWallace ML, Stone K, Smagula SF et al. Which Sleep Health Characteristics Predict All-Cause Mortality in Older Men? An Application of Flexible Multivariable Approaches[J]. Sleep, 2018, 41(1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGangwisch JE, Malaspina D, Posner K, et al. Insomnia and Sleep Duration as Mediators of the Relationship Between Depression and Hypertension Incidence[J]. Am J Hypertens. 2010;23(1):62\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang W, Sun Q, Chen B, et al. Insomnia symptoms are associated with metabolic syndrome in patients with severe psychiatric disorders[J]. Sleep Med. 2021;83:168\u0026ndash;74.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMakarem N, Alcantara C, Musick S et al. Abstract 12677: Multidimensional Sleep Health is Associated With Cardiometabolic Health in a Nationally Representative Sample of US Adults[J]. Circulation, 2021, 144(Suppl_1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHertenstein E, Benz F, Schneider CL, et al. Insomnia\u0026mdash;A risk factor for mental disorders[J]. J Sleep Res. 2023;32(6):e13930.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHare DL, Toukhsati SR, Johansson P, et al. Depression and cardiovascular disease: a clinical review[J]. Eur Heart J. 2014;35(21):1365\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi G, Yu Y, Lin C, et al. Association between major depressive disorder or depressive symptoms and the risk of vascular complications among patients with type 2 diabetes, and the mediating role of metabolic biomarkers: an analysis of the UK Biobank cohort[J]. eClinicalMedicine. 2025;79:102982.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJin B, Zhang H, Song F, et al. Interaction of sleep duration and depression on cardiovascular disease: a retrospective cohort study[J]. BMC Public Health. 2022;22(1):1752.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBai B, Yin H, Wang H, et al. The combined effects of depression or anxiety with high-sensitivity C-reactive protein in predicting the prognosis of coronary heart disease patients[J]. BMC Psychiatry. 2024;24(1):717.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMiller AH, Maletic V, Raison CL. Inflammation and Its Discontents: The Role of Cytokines in the Pathophysiology of Major Depression[J]. Biol Psychiatry. 2009;65(9):732\u0026ndash;41.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWagner-Skacel J, M\u0026ouml;rkl S, Dalkner N, et al. The Impact of Cardiovascular Rehabilitation on Psychophysiological Stress, Personality and Tryptophan Metabolism: A Randomized Pilot Feasibility Study[J]. Antioxidants. 2021;10(9):1425.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrassi G, Bertoli S, Seravalle G. Sympathetic nervous system: role in hypertension and in chronic kidney disease[J]. Curr Opin Nephrol Hypertens. 2012;21(1):46\u0026ndash;51.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMarston NA, Kamanu FK, Melloni GEM et al. Endothelial cell-related genetic variants identify LDL cholesterol-sensitive individuals who derive greater benefit from aggressive lipid lowering[J]. Nat Med, 2025.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBansil P, Kuklina EV, Merritt RK, et al. Associations Between Sleep Disorders, Sleep Duration, Quality of Sleep, and Hypertension: Results From the National Health and Nutrition Examination Survey, 2005 to 2008: Sleep-Related Problems and Hypertension[J]. J Clin Hypertens. 2011;13(10):739\u0026ndash;43.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTobaldini E, Fiorelli EM, Solbiati M, et al. Short sleep duration and cardiometabolic risk: from pathophysiology to clinical evidence[J]. Nat Reviews Cardiol. 2019;16(4):213\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShi S, Liang J, Liu T, et al. Depression Increases Sympathetic Activity and Exacerbates Myocardial Remodeling after Myocardial Infarction: Evidence from an Animal Experiment[J]. Volume 9. BAUER W R.PLoS ONE; 2014. p. e101734. 7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDarling AM, Young BE, Skow RJ, et al. Sympathetic and blood pressure reactivity in young adults with major depressive disorder[J]. J Affect Disord. 2024;361:322\u0026ndash;32.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChang H-A, Chang C-C, Tzeng N-S, et al. Generalized Anxiety Disorder, Comorbid Major Depression and Heart Rate Variability: A Case-Control Study in Taiwan[J]. Psychiatry Invest. 2013;10(4):326.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBajk\u0026oacute; Z, Szekeres C-C, Kov\u0026aacute;cs KR, et al. Anxiety, depression and autonomic nervous system dysfunction in hypertension[J]. J Neurol Sci. 2012;317(1\u0026ndash;2):112\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMalik M, Heart Rate V. Standards of Measurement, Physiological Interpretation, and Clinical Use: Task Force of The European Society of Cardiology and the North American Society for Pacing and Electrophysiology[J]. Ann Noninvasive Electrocardiol. 1996;1(2):151\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFriedman BH, Thayer JF. Autonomic balance revisited: Panic anxiety and heart rate variability[J]. J Psychosom Res. 1998;44(1):133\u0026ndash;51.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShimizu T, Takahashi Y, Kogawa S, et al. Muscle sympathetic nerve activity during central, mixed and obstructive apnea: Are there any differences?[J]. J Neuropsychiatry Clin Neurosci. 1997;51(6):397\u0026ndash;404.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMao J, Liu X, Kote A, et al. Skin sympathetic nerve activity in symptomatic and asymptomatic paroxysmal atrial fibrillation[J]. Heart Rhythm. 2024;21(12):2437\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu Y, Huang Y, Zhou J, et al. Altered Heart Rate Variability in Patients With Schizophrenia During an Autonomic Nervous Test[J]. Front Psychiatry. 2021;12:626991.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchiweck C, Piette D, Berckmans D, et al. Heart rate and high frequency heart rate variability during stress as biomarker for clinical depression. A systematic review[J]. Psychol Med. 2019;49(2):200\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTobaldini E, Carandina A, Toschi-Dias E, et al. Depression and cardiovascular autonomic control: a matter of vagus and sex paradox[J]. Neurosci Biobehavioral Reviews. 2020;116:154\u0026ndash;61.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChambers AS, Allen JJB. Sex differences in cardiac vagal control in a depressed sample: Implications for differential cardiovascular mortality[J]. Biol Psychol. 2007;75(1):32\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen H, Yang CCH, Kuo TBJ, et al. Gender differences in the relationship between depression and cardiac autonomic function among community elderly[J]. Int J Geriatr Psychiatry. 2010;25(3):314\u0026ndash;22.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGarcia RG, Zarruk JG, Guzman JC, et al. Sex differences in cardiac autonomic function of depressed young adults[J]. Biol Psychol. 2012;90(3):179\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrassi G, Seravalle G, Mancia G. Sympathetic activation in cardiovascular disease: evidence, clinical impact and therapeutic implications[J]. Eur J Clin Invest. 2015;45(12):1367\u0026ndash;75.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarton DA, Dawood T, Lambert EA, et al. Sympathetic activity in major depressive disorder: identifying those at increased cardiac risk?[J]. J Hypertens. 2007;25(10):2117\u0026ndash;24.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrown ADH, Barton DA, Lambert GW. Cardiovascular Abnormalities in Patients with Major Depressive Disorder: Autonomic Mechanisms and Implications for Treatment[J]. CNS Drugs. 2009;23(7):583\u0026ndash;602.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDoi Y, Minowa M, Uchiyama M, et al. Psychometric assessment of subjective sleep quality using the Japanese version of the Pittsburgh Sleep Quality Index (PSQI-J) in psychiatric disordered and control subjects[J]. Psychiatry Res. 2000;97(2\u0026ndash;3):165\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHamilton M, A RATING SCALE FOR, DEPRESSION[J]. J Neurol Neurosurg Psychiatry. 1960;23(1):56\u0026ndash;62.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHamilton M, THE ASSESSMENT OF, ANXIETY STATES BY RATING[J]. Br J Med Psychol. 1959;32(1):50\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePham T, Lau ZJ, Chen SHA, et al. Heart Rate Variability in Psychology: A Review of HRV Indices and an Analysis Tutorial[J]. Sensors. 2021;21(12):3998.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStein PK, Pu Y. Heart rate variability, sleep and sleep disorders[J]. Sleep Med Rev. 2012;16(1):47\u0026ndash;66.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang W-L, Liao S-C, Wu C-S, et al. Clarifying the link between psychopathologies and heart rate variability, and the sex differences: Can neuropsychological features serve as mediators?[J]. J Affect Disord. 2023;340:250\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang W-L, Liao S-C, Yang CCH, et al. Measures of Heart Rate Variability in Individuals With Somatic Symptom Disorder[J]. Psychosom Med. 2017;79(1):34\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShvartz V, Danilov V, Koroleva S, et al. Reference ranges of gender- and age-related heart rate variability parameters in Russian children[J]. Sci Rep. 2025;15(1):5274.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRicciardiello A, McKinnon AC, Mowszowski L, et al. Assessing sleep architecture and cognition in older adults with depressive symptoms attending a memory clinic[J]. J Affect Disord. 2024;348:35\u0026ndash;43.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEid RS, Gobinath AR, Galea LAM. Sex differences in depression: Insights from clinical and preclinical studies[J]. Prog Neurobiol. 2019;176:86\u0026ndash;102.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSilverstein B. Gender Difference in the Prevalence of Clinical Depression: The Role Played by Depression Associated With Somatic Symptoms[J]. Am J Psychiatry. 1999;156(3):480\u0026ndash;2.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePittig A, Arch JJ, Lam CWR, et al. Heart rate and heart rate variability in panic, social anxiety, obsessive\u0026ndash;compulsive, and generalized anxiety disorders at baseline and in response to relaxation and hyperventilation[J]. Int J Psychophysiol. 2013;87(1):19\u0026ndash;27.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLucini D, Pagani M. Heart rate variability, autonomic regulation and myocardial ischemia[J]. Int J Cardiol. 2020;312:22\u0026ndash;3.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWescott DL, Hasler BP, Foust JE, et al. Circadian realignment and depressed mood: A systematic review[J]. Sleep Med Rev. 2025;79:102022.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBostwick JM. A Generalist\u0026rsquo;s Guide to Treating Patients With Depression With an Emphasis on Using Side Effects to Tailor Antidepressant Therapy[J]. Mayo Clinic Proceedings, 2010, 85(6): 538\u0026ndash;550.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNarkiewicz K, Phillips BG, Kato M, et al. Gender-Selective Interaction Between Aging, Blood Pressure, and Sympathetic Nerve Activity[J]. Hypertension. 2005;45(4):522\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDrury ER, Wu J, Gigliotti JC, et al. Sex differences in blood pressure regulation and hypertension: renal, hemodynamic, and hormonal mechanisms[J]. Physiol Rev. 2024;104(1):199\u0026ndash;251.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKeir DA, Badrov MB, Tomlinson G, et al. Influence of Sex and Age on Muscle Sympathetic Nerve Activity of Healthy Normotensive Adults[J]. Hypertension. 2020;76(3):997\u0026ndash;1005.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBucciarelli V, Caterino AL, Bianco F, et al. Depression and cardiovascular disease: The deep blue sea of women\u0026rsquo;s heart[J]. Trends Cardiovasc Med. 2020;30(3):170\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-psychiatry","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bpsy","sideBox":"Learn more about [BMC Psychiatry](http://bmcpsychiatry.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bpsy/default.aspx","title":"BMC Psychiatry","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Major Depressive Disorder, gender difference, subjective sleep disturbances, blood pressure, autonomic nerve dysfunction, heart rate variability.","lastPublishedDoi":"10.21203/rs.3.rs-8766171/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8766171/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eMajor depressive disorder (MDD) exhibits significant gender disparities in prevalence. Previous studies have indicated that differential patterns of sympathetic nervous system activation in different gender may contribute to varying cardiovascular/cerebrovascular risks in MDD, though underlying factors remain unclear. In this study, we aim to investigate the association between subjective sleep alterations, blood pressure, emotional state, and gender-specific sympathetic activation in MDD.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eWe collected and analyzed ECG data from 50 female and 25 male age-matched, first-episode, drug-naive MDD patients. Autonomic nerve function was assessed using heart rate variability (HRV). Subjective sleep indicators of SE, SOL, short sleep, and poor sleep quality were evaluated utilizing the Pittsburgh Sleep Quality Index (PSQI). Emotional characteristics were quantified via the Hamilton Depression Scale-17 (HAMD-17) and Hamilton Anxiety Scale (HAMA). Resting systolic (SBP) and diastolic blood pressure (DBP) were also measured upon arrival.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eIn male MDD patients, each 1% reduction in SE was associated with a 0.350ms decrease in SDNN. In females, each 1-minute reduction in SOL was associated with a 0.004-unit increase in LF/HF ratio; while short sleep (\u0026lt;\u0026thinsp;6h) was associated with increased RMSSD and pNN50 (all p\u0026thinsp;\u0026le;\u0026thinsp;0.048). Reduced DBP in males correlated with different patterns (decreased pNN50 and HF(nu); increased LF(nu) and LF/HF ratio) (all p\u0026thinsp;\u0026le;\u0026thinsp;0.033). In females, only reduced SBP was associated with each 1-mmHg decrease linked to a 0.040-unit increase in LF/HF ratio.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eSubjective sleep disturbances exhibits disparity in gender-specific patterns of sympathetic-vagal balance in MDD. However, blood pressure reduction consistently correlated with sympathetic activation across both genders, revealing distinct autonomic-mediated pathophysiological pathways that may underlie differential cardiovascular susceptibility in MDD.\u003c/p\u003e","manuscriptTitle":"Effect of subjective sleep impairment and decreased blood pressure on gender-specific HRV in first-episode and drug-naive patients with major depressive disorder","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-19 16:16:54","doi":"10.21203/rs.3.rs-8766171/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-05-11T07:47:55+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-01T19:45:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"197497430009613360497090104473971900711","date":"2026-03-26T16:01:40+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"304203837423923668227377393882772525306","date":"2026-03-24T19:18:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"313772469264988577940444994613036361349","date":"2026-03-24T16:08:13+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-24T07:22:27+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"169823173310646244786315662884047089422","date":"2026-03-18T07:37:47+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-17T03:03:33+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-02-25T19:12:07+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-02-10T12:17:31+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-10T11:10:05+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Psychiatry","date":"2026-02-10T10:15:41+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-psychiatry","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bpsy","sideBox":"Learn more about [BMC Psychiatry](http://bmcpsychiatry.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bpsy/default.aspx","title":"BMC Psychiatry","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"26c6059c-73dc-48ce-892d-e9151d5a8dff","owner":[],"postedDate":"March 19th, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Revision requested","date":"2026-05-11T07:47:55+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[],"tags":[],"updatedAt":"2026-05-11T08:00:04+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-19 16:16:54","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8766171","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8766171","identity":"rs-8766171","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}