Prevalence and severity of sleep-disordered breathing in individuals with Down syndrome using a portable home-based diagnostic device: a pilot study

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Despite the high likelihood of sleep-disordered breathing in this population, diagnostic access remains limited, especially in low-resource settings. This study aimed to determine the prevalence and severity of sleep-disordered breathing in adolescents and adults with DS. This cross-sectional study included adolescents and adults with DS who underwent home type IV polygraphy (Biologix) and completed validated questionnaires assessing OSA risk and excessive daytime sleepiness. Anthropometric data were collected, and correlations with respiratory parameters were analyzed. OSA was highly prevalent, affecting 93% of participants. Mild to moderate OSA predominated (80%). Respiratory events were frequently accompanied by oxygen desaturation, with marked nocturnal hypoxemia (mean minimum SpO₂: 82.4%). Sleep was inefficient and fragmented, with efficiency below 75% in most individuals. Neck circumference showed a significant correlation with nocturnal hypoxemia, whereas age and body weight did not. Subjective sleep questionnaires underestimated OSA severity compared with polygraphy. Sleep-disordered breathing is highly prevalent and physiologically significant in individuals with DS. Home type IV polygraphy proved feasible, well-accepted, and clinically informative for this population. These findings highlight the importance of accessible diagnostic strategies to improve early detection and management of OSA in individuals with DS. Health sciences/Diseases Health sciences/Health care Health sciences/Medical research Health sciences/Risk factors Down syndrome sleep apnea polysomnography portable sleep monitor Figures Figure 1 Introduction Obstructive sleep apnea (OSA) is highly prevalent in the general adult population and is characterized by recurrent episodes of partial or complete upper airway obstruction, resulting in intermittent hypoxemia and sleep fragmentation. OSA is a recognized risk factor for cardiovascular morbidity, including hypertension, coronary artery disease, arrhythmias, and stroke, with nocturnal hypoxemia playing a central pathophysiological role in these outcomes 1 – 3 . Down syndrome (DS), caused by Trisomy 21, affects approximately 1 in 600 to 1 in 2,000 live births worldwide 4 . Individuals with DS exhibit characteristic craniofacial and soft tissue features, including midface hypoplasia, reduced nasal protrusion, mandibular deficiency, palatal constriction, macroglossia, and generalized hypotonia, that predispose to upper airway collapsibility during sleep 5 – 8 . Systemic comorbidities, such as endocrine dysfunction, obesity, immune impairment, and gastroesophageal reflux, further contribute to the elevated risk of sleep-disordered breathing 9 , 10 . As a result, adults with DS exhibit markedly increased OSA prevalence, frequently exceeding 80% 4,11–13 . Polysomnography (PSG) is the gold standard for diagnosing sleep-disordered breathing 14 , 15 . However, its high cost, limited availability, and the behavioral and cognitive challenges common in DS substantially reduce its feasibility 16 , 17 . Moreover, the apnea–hypopnea index (AHI), the primary PSG-derived metric for classifying severity, does not fully capture the physiological impact of nocturnal oxygen desaturation. Recent evidence highlights the importance of hypoxemia-related biomarkers, such as hypoxic burden, oxygen desaturation index (ODI), and the percentage of sleep time spent with saturation below 90% (T90%), as superior predictors of cardiovascular risk when compared with AHI alone 18 – 20 . These metrics reflect not only the frequency but also the depth and duration of oxygen desaturation, which may be especially relevant for individuals with DS, who already present elevated cardiometabolic vulnerability 13 . In this context, portable home-based diagnostic technologies have gained relevance. The Biologix® system, a validated high-resolution oximetry and cardiorespiratory monitoring platform, offers reliable automated cloud-based detection of sleep-disordered breathing and has shown strong agreement with full-night PSG for identifying OSA severity 21 – 23 . Its feasibility, accessibility, and high patient acceptance make it particularly appropriate for adults with DS, who often face barriers to traditional sleep laboratory assessment. Given the high prevalence of OSA in individuals with DS, their increased susceptibility to cardiometabolic complications, and the logistical challenges associated with conventional diagnostic testing, accessible and objective screening tools are essential. Therefore, the present study aimed to determine the prevalence and severity of sleep-disordered breathing in adolescent and adult individuals with Down syndrome using a portable home-based diagnostic device. Material and methods Ethical considerations This study protocol was approved by the Ethics Committee for Human Research of the Institute of Science and Technology, UNESP, São José dos Campos (CAAE: 64173616.4.0000.0077). Study design This was a cross-sectional observational study conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement 24 . The study included adolescent and adult individuals with Down syndrome (DS) who met the predefined inclusion and exclusion criteria. Study population A total of 24 adolescents and adults with DS of both sexes were recruited from three community institutions offering therapeutic and educational support for individuals with neurodevelopmental disabilities: Instituto de Desenvolvimento Humano SOLUS, Associação Mais 21, and Casa Joana, located in the cities of Goiânia and Anápolis, Goiás State, Brazil. Of these, four individuals did not meet the inclusion criteria and two were unable to participate. Among the 18 eligible participants, four recordings were deemed technically insufficient, resulting in a final sample of 15 individuals with DS included in the analysis. Inclusion and exclusion criteria Participants were eligible for inclusion if they were adolescents (≥ 14 years) or adults with a confirmed clinical diagnosis of Down syndrome, and whose legal guardians provided written informed consent. Individuals were excluded if they were non-cooperative or unable to complete the examinations, as well as those with a previous history of adenotonsillectomy 25 . Study variables The following variables were collected: age (years), sex, risk assessment for obstructive sleep apnea (OSA) using the STOP-Bang and Berlin Questionnaires, and excessive daytime sleepiness assessed with the Epworth Sleepiness Scale (ESS). Physiological sleep parameters were obtained through type IV home polygraphy, including oxygen saturation, heart rate, body movement, snoring intensity, estimated sleep time, hypoxic burden, and the calculated risk of atrial fibrillation. Procedures All participants underwent clinical evaluation, structured anamnesis, and administration of sleep- and quality-of-life–related questionnaires. Legal guardians were trained in the installation and operation of the home cardiorespiratory monitoring device. Correct placement was visually confirmed by the research team at the time of installation and later via video call to prevent misplacement during the night of recording. Once proper function of all channels was verified, participants initiated the home type IV sleep study. The devices used and procedures for data acquisition are described below. Epworth Sleepiness Scale (ESS) The ESS is a widely used tool for assessing self-reported excessive daytime sleepiness 26 . The Brazilian version has demonstrated good reliability 27 . The scale includes eight common daily situations, scored from 0 (no chance of dozing) to 3 (high chance of dozing). Scores > 10 indicate excessive daytime sleepiness. For this study, the ESS was adapted to the functional reality of DS individuals who do not drive. The original eighth item, related to falling asleep while driving, was modified to evaluate the likelihood of dozing off as a passenger in a stationary car, as previously suggested for populations with functional limitations 28 . STOP-Bang Questionnaire The STOP-Bang is a validated screening tool for OSA risk, composed of eight dichotomous items (yes/no). Scores ≥ 3 indicate high OSA risk. Berlin Questionnaire The Berlin Questionnaire screens for individuals at increased risk of sleep-disordered breathing. It consists of ten items across three categories: snoring/apneas, daytime sleepiness, and hypertension/obesity. Two or more positive categories indicate high OSA risk 29 – 31 . Type IV Polygraphy Type IV home cardiorespiratory polygraphy was performed using the Biologix portable respiratory monitoring system (Biologix Sistemas SA, São Paulo, Brazil). The device recorded multiple physiological variables, including the presence or absence of oxygen desaturation, desaturation intervals, time spent with SpO₂ below 90%, hypoxic burden, snoring intensity, estimated sleep time, atrial fibrillation risk, and the heart rate (HR) signal. HR-derived parameters included mean pulse interval, HR standard deviation, and time-domain heart rate variability (HRV) indices (SDNN, RMSSD, PNN50, SD1, SD2), as well as frequency-domain HRV indices (low-frequency power, high-frequency power, and the LF/HF ratio). Accelerometer-based measurements comprised variance, root-mean-square (RMS) values, skewness, and kurtosis, providing additional information on movement and activity during sleep 23 . All recordings were scored by a board-certified sleep medicine pulmonologist following the standards of the American Academy of Sleep Medicine (AASM) 28 . OSA was defined as the absence of oronasal airflow and ventilatory effort for ≥ 10 seconds. Hypopneas were defined as ≥ 30–90% reduction in airflow accompanied by ≥ 3% oxygen desaturation 15 , 28 . Home monitoring was chosen to minimize behavioral distress, reduce operational costs, ensure feasibility, and improve ecological validity in individuals with DS 32,33 . Statistical analysis Sample size calculations were based on Giannasi et al. 34 , requiring at least 10 participants for α = 0.05 (two-tailed) and 80% statistical power. Data were reported as means and standard deviations. The Shapiro–Wilk test assessed normality. Correlations were examined using Pearson’s coefficient for parametric data and Spearman’s coefficient for non-parametric data. Analyses were performed using IBM SPSS Statistics, Version 22 (IBM Corp., Armonk, NY, USA). A significance level of 5% was adopted for all tests. Results Population characteristics A total of 24 individuals with Down syndrome (DS) were screened, of whom 15 met the eligibility criteria and were included in the analysis. Sociodemographic and clinical characteristics are presented in Table 1 . The sample consisted predominantly of females (73.3%, n = 11), with a mean age of 22.14 ± 7.81 years. Mean body weight was 57.36 ± 11.58 kg, mean BMI was 25.06 ± 5.07 kg/m², and mean neck circumference was 37.80 ± 2.88 cm. Table 1 Sociodemographic and anthropometric characteristics Variable Unit Value Sex Female, n (%) 11 (73.3) Male, n (%) 4 (26.7) Age years 22.14 ± 7.81 Weight kg 57.36 ± 11.58 Body mass index kg/m² 25.06 ± 5.07 Neck circumference cm 37.80 ± 2.88 Sleep-related symptoms Sleep-related complaints were assessed using the STOP-Bang Questionnaire, Berlin Questionnaire and the Epworth Sleepiness Scale (ESS). The most frequently reported symptoms were non-restorative sleep (71.4%), daytime sleepiness or fatigue (64.3%), and restless sleep (42.9%) (Table 2 ). Table 2 Sleep-related symptoms reported Symptom n = 15 (%) Nasal congestion 2 (14.29%) Loud/frequent snoring 4 (28.57%) Difficulty maintaining sleep 5 (35.71%) Restless sleep 6 (42.86%) Non-restorative sleep 10 (71.43%) Daytime sleepiness/fatigue 9 (64.29%) Difficulty concentrating 5 (35.71%) Memory loss 1 (7.14%) More than half of the participants (approximately 60%) exhibited at least one symptom consistent with sleep-disordered breathing (SDB). High-risk classifications for OSA on the Berlin Questionnaire were observed in 14.3% of the sample, a finding identical to that identified using the STOP-Bang criteria (Table 3 ). Table 3 Screening questionnaires for obstructive sleep apnea and excessive daytime sleepiness Measure n = 15 (%) Epworth Sleepiness Scale (ESS) — Normal (0–8) 7 (50%) ESS — Mild (9–12) 5 (35.71%) ESS — Moderate (13–15) 2 (14.29%) ESS — Severe (16–24) 0 (0%) Berlin Questionnaire — High risk (≥ 2 categories) 2 (14.29%) STOP-Bang Questionnaire — High risk (≥ 3 items) 2 (14.29%) Clinical comorbidities Clinical comorbidities observed among participants are summarized in Table 4 . Gastroesophageal reflux disease (GERD) was the most frequent condition (28.6%), followed by heart failure (14.3%), depression (14.3%), and sinusitis (14.3%). Mitral valve regurgitation was reported in one participant (7.1%). Table 4 Clinical comorbidities observed in adults with Down syndrome (n = 15). Comorbidity n (%) Heart failure 2 (14.29%) Depression 2 (14.29%) Gastroesophageal reflux 4 (28.57%) Sinusitis 2 (14.29%) Mitral valve murmur 1 (7.14%) Polygraphic parameters Type IV home polygraphy revealed significant respiratory and oxygenation disturbances during sleep (Tables 5 ). Mean minimum SpO₂ was notably low (82.4%), and participants spent a considerable amount of time with oxygen saturation below 90% (26.8 ± 52.0 minutes). Hypoxic burden was markedly elevated (mean 60.1 ± 23.0%·min/h), highlighting substantial physiological stress during sleep. Table 5 Physiological variables of sleep. Variables Mean ± Standard Deviation Total sleep time (min) 483.89 ± 80.85 Valid recording time (min) 462.91 ± 78.14 Sleep latency (min) 35.87 ± 19.41 Time awake after sleep onset (min) 85.73 ± 69.66 Sleep efficiency (%) 72.93 ± 13.58 Minimum peripheral oxygen saturation (%) 82.40 ± 3.59 Average peripheral oxygen saturation (%) 93.60 ± 1.45 Maximum peripheral oxygen saturation (%) 98.93 ± 1.44 Peripheral oxygen saturation time < 90% (min) 26.82 ± 50.34 Peripheral oxygen saturation time < 80% (min) 0.03 ± 0.08 Number of oxygen desaturations 134.27 ± 73.74 Oxygen desaturation index (events/h) 17.09 ± 8.63 Minimum heart rate (bpm) 45.37 ± 13.70 Average heart rate (bpm) 65.47 ± 8.52 Maximum heart rate (bpm) 112.60 ± 8.95 Hypoxic burden (min/h%) 60.08 ± 22.20 Snoring time (min) 481.1 ± 80.29 Snoring analysis demonstrated a mean snoring duration of 108 ± 110 minutes, indicating frequent and prolonged snoring episodes. Based on the oxygen desaturation index (ODI), 93.3% of the cohort presented with OSA of varying severity: 53.3% mild, 26.7% moderate, and 13.3% severe (Table 6 ). Only one participant (6.7%) showed normal values. Table 6 Classification of obstructive OSA severity based on ODI Classification n = 15 % Normal 1 6.7% Mild OSA 8 53.3% Moderate OSA 4 26.7% Severe OSA 2 13.3% Correlation analyses Correlation analyses explored associations between ODI and anthropometric variables (Fig. 1 ). There was no significant correlation between ODI and weight (r = 0.037, p = 0.895) or age (r = − 0.289, p = 0.298). Neck circumference showed a positive trend toward correlation with ODI, nearing statistical significance (Pearson r = 0.383, p = 0.159; Spearman ρ = 0.482, p = 0.069). A significant correlation was identified between time spent with SpO₂ < 90% and neck circumference (Spearman ρ = 0.588, p = 0.021), suggesting that cervical circumference may be an important predictor of nocturnal hypoxemia exposure. No significant correlations were observed between hypoxic burden and age, weight, or neck circumference. These findings indicate that, within this sample, cumulative nocturnal hypoxia was not influenced by demographic or anthropometric characteristics. Discussion The results of this study demonstrated a high prevalence of obstructive sleep apnea (OSA) in adults with Down syndrome (DS), identified in 93% of participants, with a predominance of mild and moderate forms. These findings are consistent with previous studies 11 , 35 , 36 , reaffirming that OSA is highly prevalent among individuals with DS. When comparing the severity classification (ODI) with studies conducted in children with DS using Type III polygraphy, home nocturnal oximetry, and polysomnography (PSG), adults in the present study exhibited ODI values three to seven times higher than the median reported in pediatric populations 37 , 38 . While the mean ODI in our adult cohort was 17.1 ± 8.9 events/h, children showed a mean of 5.4 (3.2–7.6) events/h 38 . Although the minimum SpO₂ values were similar between adults and children (≈ 80%), the frequency of desaturations was substantially higher in adults. Moreover, the time spent with SpO₂ < 90% was markedly greater in adults (26.8 ± 52 minutes) than in children (median ≈ 5%) 38 , reflecting longer desaturation events with increasing age. While OSA prevalence reached 93% in our adult sample, pediatric data report prevalence near 84% 37 , which is expected as pharyngeal collapse and obesity risk increase with age. In the present study, OSA severity was categorized as normal in 6.7% (1/15), mild in 53.3% (8/15), moderate in 26.7% (4/15), and severe in 13.3% (2/15). Compared with the findings of Landete et al. 36 in adults with DS, our sample showed a lower proportion of severe cases. Their higher percentage of severe OSA likely reflects sampling bias, since their participants were recruited from sleep clinics with prior suspicion of OSA, thus not representing the general DS population. Beyond respiratory parameters such as the mean ODI (17.1 ± 8.9 events/h) and desaturation index (14.5 ± 7.6 events/h), the minimum SpO₂ of 82.4% and hypoxic burden of 60%/h indicate substantial and recurrent hypoxemia, with potential cardiovascular and metabolic consequences. Although the mean SpO₂ (93.6 ± 1.5%) remained within normal limits, it was close to the lower threshold for mild hypoxemia (≤ 94%) according to Berry et al. 15 . Sleep efficiency was reduced (72.9 ± 14.1%), below the American Academy of Sleep Medicine threshold of 85% for restorative sleep 15 . Estimated total sleep time averaged 349 ± 76 minutes (≈ 5.8 hours), considerably lower than the recommended 7–9 hours for adults 39 . Snoring was common, with a mean duration of 108 ± 110 minutes. A positive trend between neck circumference and ODI (r = 0.383; p = 0.159) and a significant correlation between neck circumference and time with SpO₂ < 90% (ρ = 0.588; p = 0.021) indicate an important role of cervical adiposity in upper airway obstruction, corroborating previous findings 37 , 38 . However, none of the anthropometric variables (age, weight, neck circumference) correlated significantly with hypoxic burden, suggesting that the intensity of intermittent hypoxia does not follow a predictable pattern based on general body measures. This highlights the unique pathophysiology of OSA in DS and underscores the importance of further targeted studies. The craniofacial anatomy typical of DS—including midface hypoplasia, relative macroglossia, mandibular shortening, and high-arched palate 40 , 41 —in combination with muscular hypotonia and gastroesophageal reflux (present in 40% of the sample), likely contributes to increased susceptibility to airway collapse and nocturnal hypoxia. Regarding the diagnostic approach, the use of Type IV home polygraphy in adults with DS proved feasible, acceptable, and well suited to this population. The Biologix portable monitoring system provided accurate measurements of ODI, hypoxic burden, and snoring intensity, showing strong concordance with the apnea–hypopnea index (AHI) obtained via laboratory PSG. This home-based strategy improved adherence to testing, overcoming the low tolerability of traditional PSG previously documented in DS 21–23 . Questionnaire-based assessments (Berlin, STOP-Bang, ESS) supported the polygraphy results, identifying common symptoms such as daytime sleepiness (22.2%) and non-restorative sleep (22.2%), with approximately 60% reporting sleep-related complaints. Nonetheless, questionnaires significantly underestimated disease prevalence compared with polygraphy, emphasizing the need for objective diagnostic methods in DS. Potential autonomic and cardiovascular implications also emerge from these findings. Previous studies demonstrated attenuated sympathetic responses and delayed resaturation in children with DS and sleep-disordered breathing 42 . These characteristics may progress into adulthood, contributing to sustained hypoxemia and chronic ventilatory dysfunction, consistent with the prolonged desaturation times observed in this study (mean SpO₂ < 90% = 26.8 minutes). OSA in DS is multifactorial, involving anatomical, metabolic, hormonal, and genetic components 39 , 43 . Unlike Landete et al. 36 , who found correlations between BMI and both AHI and ODI, as well as between BMI and Tc90%, our study did not detect such relationships. These discrepancies may reflect sample heterogeneity or methodological differences, reinforcing the need for further research. Clinically, our findings support the recommendation that individuals with DS should undergo validated portable sleep monitoring regardless of symptom presentation or obesity status. This aligns with international guidelines and may reduce underdiagnosis and delays in treatment. Overall, this study contributes valuable evidence regarding OSA in DS, reinforcing neck circumference as a potential clinical marker, validating the feasibility of Type IV home polygraphy, and highlighting the importance of longitudinal follow-up to monitor disease progression. The results underscore the relevance and practicality of high-resolution home monitoring in research and clinical care for individuals with DS. Conclusions The findings of this study reinforce the high prevalence, progression, and physiological impact of obstructive sleep apnea (OSA) in individuals with Down syndrome, highlighting the need for objective and accessible diagnostic strategies. AOSA was highly prevalent (93%), with a predominance of mild to moderate cases (80%). Participants exhibited frequent desaturation events and significant hypoxemia (mean minimum SpO₂ of 82.4%), as well as inefficient and fragmented sleep (efficiency < 75%). Neck circumference showed a meaningful association with nocturnal hypoxemia, whereas no correlation was observed with age or body weight. Subjective sleep questionnaires alone were insufficient for screening OSA in this population, underscoring the importance of objective diagnostic methods. The study confirmed that type IV home polygraphy (Biologix) is feasible, well tolerated, and clinically applicable for adults with Down syndrome. Declarations Acknowledgements We would like to thank all the patients and their respective parents who collaborated in the conduct of this research. Author contributions Study design and conceptualization: LVFO, LCG,OAG, GI, MYMY, and WRFJ; Data collection and analysis: CNSN, LPM, RACA, ASGS, SVM, and MYMY; Data curation: LVFO, LCG, GI, CSO,CHMS, and MYMY; Formal analysis: GI, DAAPO, RFO, LCG, CSO, OAG, and LVFO; Investigation: MYMY, LCG, LVFO, and OAG; Methodology: LVFO, LCG, OAG, CHMS, and MYMY; Project administration: LVFO, LCG, CNSN, GI, CSO, AND WRFJ; Resources: LVFO, CNSN, MYMY, and LCG; Supervision: GI, OAG, and LVFO; Writing original Draft: MYMY, OAG, LCG, WRFJ, GI, RFO, DAAPO, and LVFO; Writing – review & editing: MYMY, CNSM, WRFJ, GI, OAG, LCG, ASGS, and LVFO. Critical revision of the manuscript: all authors. Funding The authors affirm that they did not receive any funding for this research from any funding agency in the public, commercial, or not-for-profit sectors. Declarations The authors declare no competing interests. Ethics approval and consent to participate This study protocol was approved by the Ethics Committee for Human Research of the Institute of Science and Technology, UNESP, São José dos Campos (CAAE: 64173616.4.0000.0077). All the parents of the patients involved in the study provided the written Consent Form for participation in the research. Additional information Correspondence and requests for materials should be addressed to corresponding author LVFO Data availability The datasets used and/or analysed during the current study available from the corresponding author on reasonable request. References Peppard, P. E., Young, T., Palta, M. & Skatrud, J. Prospective study of the association between sleep-disordered breathing and hypertension. N Engl. J. Med. 342 , 1378–1384 (2000). Shahar, E. et al. Sleep-disordered breathing and cardiovascular disease: cross-sectional results of the Sleep Heart Health Study. Am. J. Respir Crit. 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11:37:26","extension":"html","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":114335,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8154933/v1/d3f6823982e269997147948d.html"},{"id":97695737,"identity":"6364857e-120d-4efa-b0ab-90a12c6e3617","added_by":"auto","created_at":"2025-12-08 11:37:26","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":113194,"visible":true,"origin":"","legend":"\u003cp\u003eCorrelation analyzes between neck circumference and body mass index with hypoxic load, oxygen desaturation index, and time of oxygen saturation below 90%.\u003c/p\u003e","description":"","filename":"SRFigure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8154933/v1/2cdf16ac99e3bbc1cf4fe8ae.jpg"},{"id":97902502,"identity":"2b7c9652-0433-4ae4-9d2b-6f214beeccd8","added_by":"auto","created_at":"2025-12-10 15:52:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":912972,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8154933/v1/b2345f57-2843-4665-82b3-263a470143f0.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Prevalence and severity of sleep-disordered breathing in individuals with Down syndrome using a portable home-based diagnostic device: a pilot study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eObstructive sleep apnea (OSA) is highly prevalent in the general adult population and is characterized by recurrent episodes of partial or complete upper airway obstruction, resulting in intermittent hypoxemia and sleep fragmentation. OSA is a recognized risk factor for cardiovascular morbidity, including hypertension, coronary artery disease, arrhythmias, and stroke, with nocturnal hypoxemia playing a central pathophysiological role in these outcomes\u003csup\u003e\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eDown syndrome (DS), caused by Trisomy 21, affects approximately 1 in 600 to 1 in 2,000 live births worldwide\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. Individuals with DS exhibit characteristic craniofacial and soft tissue features, including midface hypoplasia, reduced nasal protrusion, mandibular deficiency, palatal constriction, macroglossia, and generalized hypotonia, that predispose to upper airway collapsibility during sleep\u003csup\u003e\u003cspan additionalcitationids=\"CR6 CR7\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. Systemic comorbidities, such as endocrine dysfunction, obesity, immune impairment, and gastroesophageal reflux, further contribute to the elevated risk of sleep-disordered breathing\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. As a result, adults with DS exhibit markedly increased OSA prevalence, frequently exceeding 80%\u003csup\u003e4,11\u0026ndash;13\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003ePolysomnography (PSG) is the gold standard for diagnosing sleep-disordered breathing\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. However, its high cost, limited availability, and the behavioral and cognitive challenges common in DS substantially reduce its feasibility\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. Moreover, the apnea\u0026ndash;hypopnea index (AHI), the primary PSG-derived metric for classifying severity, does not fully capture the physiological impact of nocturnal oxygen desaturation.\u003c/p\u003e\u003cp\u003eRecent evidence highlights the importance of hypoxemia-related biomarkers, such as hypoxic burden, oxygen desaturation index (ODI), and the percentage of sleep time spent with saturation below 90% (T90%), as superior predictors of cardiovascular risk when compared with AHI alone\u003csup\u003e\u003cspan additionalcitationids=\"CR19\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e. These metrics reflect not only the frequency but also the depth and duration of oxygen desaturation, which may be especially relevant for individuals with DS, who already present elevated cardiometabolic vulnerability\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eIn this context, portable home-based diagnostic technologies have gained relevance. The Biologix\u0026reg; system, a validated high-resolution oximetry and cardiorespiratory monitoring platform, offers reliable automated cloud-based detection of sleep-disordered breathing and has shown strong agreement with full-night PSG for identifying OSA severity\u003csup\u003e\u003cspan additionalcitationids=\"CR22\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. Its feasibility, accessibility, and high patient acceptance make it particularly appropriate for adults with DS, who often face barriers to traditional sleep laboratory assessment.\u003c/p\u003e\u003cp\u003eGiven the high prevalence of OSA in individuals with DS, their increased susceptibility to cardiometabolic complications, and the logistical challenges associated with conventional diagnostic testing, accessible and objective screening tools are essential. Therefore, the present study aimed to determine the prevalence and severity of sleep-disordered breathing in adolescent and adult individuals with Down syndrome using a portable home-based diagnostic device.\u003c/p\u003e"},{"header":"Material and methods","content":"\u003cp\u003e\u003cem\u003eEthical considerations\u003c/em\u003e\u003c/p\u003e\u003cp\u003e This study protocol was approved by the Ethics Committee for Human Research of the Institute of Science and Technology, UNESP, S\u0026atilde;o Jos\u0026eacute; dos Campos (CAAE: 64173616.4.0000.0077).\u003c/p\u003e\u003cp\u003e\u003cem\u003eStudy design\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThis was a cross-sectional observational study conducted in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. The study included adolescent and adult individuals with Down syndrome (DS) who met the predefined inclusion and exclusion criteria.\u003c/p\u003e\u003cp\u003e\u003cem\u003eStudy population\u003c/em\u003e\u003c/p\u003e\u003cp\u003eA total of 24 adolescents and adults with DS of both sexes were recruited from three community institutions offering therapeutic and educational support for individuals with neurodevelopmental disabilities: Instituto de Desenvolvimento Humano SOLUS, Associa\u0026ccedil;\u0026atilde;o Mais 21, and Casa Joana, located in the cities of Goi\u0026acirc;nia and An\u0026aacute;polis, Goi\u0026aacute;s State, Brazil. Of these, four individuals did not meet the inclusion criteria and two were unable to participate. Among the 18 eligible participants, four recordings were deemed technically insufficient, resulting in a final sample of 15 individuals with DS included in the analysis.\u003c/p\u003e\u003cp\u003e\u003cem\u003eInclusion and exclusion criteria\u003c/em\u003e\u003c/p\u003e\u003cp\u003eParticipants were eligible for inclusion if they were adolescents (\u0026ge;\u0026thinsp;14 years) or adults with a confirmed clinical diagnosis of Down syndrome, and whose legal guardians provided written informed consent. Individuals were excluded if they were non-cooperative or unable to complete the examinations, as well as those with a previous history of adenotonsillectomy\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003e\u003cem\u003eStudy variables\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe following variables were collected: age (years), sex, risk assessment for obstructive sleep apnea (OSA) using the STOP-Bang and Berlin Questionnaires, and excessive daytime sleepiness assessed with the Epworth Sleepiness Scale (ESS). Physiological sleep parameters were obtained through type IV home polygraphy, including oxygen saturation, heart rate, body movement, snoring intensity, estimated sleep time, hypoxic burden, and the calculated risk of atrial fibrillation.\u003c/p\u003e\u003cp\u003e\u003cem\u003eProcedures\u003c/em\u003e\u003c/p\u003e\u003cp\u003eAll participants underwent clinical evaluation, structured anamnesis, and administration of sleep- and quality-of-life\u0026ndash;related questionnaires. Legal guardians were trained in the installation and operation of the home cardiorespiratory monitoring device. Correct placement was visually confirmed by the research team at the time of installation and later via video call to prevent misplacement during the night of recording. Once proper function of all channels was verified, participants initiated the home type IV sleep study. The devices used and procedures for data acquisition are described below.\u003c/p\u003e\u003cp\u003e\u003cem\u003eEpworth Sleepiness Scale (ESS)\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe ESS is a widely used tool for assessing self-reported excessive daytime sleepiness\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e. The Brazilian version has demonstrated good reliability\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e. The scale includes eight common daily situations, scored from 0 (no chance of dozing) to 3 (high chance of dozing). Scores\u0026thinsp;\u0026gt;\u0026thinsp;10 indicate excessive daytime sleepiness.\u003c/p\u003e\u003cp\u003eFor this study, the ESS was adapted to the functional reality of DS individuals who do not drive. The original eighth item, related to falling asleep while driving, was modified to evaluate the likelihood of dozing off as a passenger in a stationary car, as previously suggested for populations with functional limitations\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003e\u003cem\u003eSTOP-Bang Questionnaire\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe STOP-Bang is a validated screening tool for OSA risk, composed of eight dichotomous items (yes/no). Scores\u0026thinsp;\u0026ge;\u0026thinsp;3 indicate high OSA risk.\u003c/p\u003e\u003cp\u003e\u003cem\u003eBerlin Questionnaire\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe Berlin Questionnaire screens for individuals at increased risk of sleep-disordered breathing. It consists of ten items across three categories: snoring/apneas, daytime sleepiness, and hypertension/obesity. Two or more positive categories indicate high OSA risk\u003csup\u003e\u003cspan additionalcitationids=\"CR30\" citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003e\u003cem\u003eType IV Polygraphy\u003c/em\u003e\u003c/p\u003e\u003cp\u003eType IV home cardiorespiratory polygraphy was performed using the Biologix portable respiratory monitoring system (Biologix Sistemas SA, S\u0026atilde;o Paulo, Brazil). The device recorded multiple physiological variables, including the presence or absence of oxygen desaturation, desaturation intervals, time spent with SpO₂ below 90%, hypoxic burden, snoring intensity, estimated sleep time, atrial fibrillation risk, and the heart rate (HR) signal. HR-derived parameters included mean pulse interval, HR standard deviation, and time-domain heart rate variability (HRV) indices (SDNN, RMSSD, PNN50, SD1, SD2), as well as frequency-domain HRV indices (low-frequency power, high-frequency power, and the LF/HF ratio). Accelerometer-based measurements comprised variance, root-mean-square (RMS) values, skewness, and kurtosis, providing additional information on movement and activity during sleep\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eAll recordings were scored by a board-certified sleep medicine pulmonologist following the standards of the American Academy of Sleep Medicine (AASM)\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e. OSA was defined as the absence of oronasal airflow and ventilatory effort for \u0026ge;\u0026thinsp;10 seconds. Hypopneas were defined as \u0026ge;\u0026thinsp;30\u0026ndash;90% reduction in airflow accompanied by \u0026ge;\u0026thinsp;3% oxygen desaturation\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e,\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eHome monitoring was chosen to minimize behavioral distress, reduce operational costs, ensure feasibility, and improve ecological validity in individuals with DS\u003csup\u003e32,33\u003c/sup\u003e.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eSample size calculations were based on Giannasi et al.\u003csup\u003e34\u003c/sup\u003e, requiring at least 10 participants for α\u0026thinsp;=\u0026thinsp;0.05 (two-tailed) and 80% statistical power.\u003c/p\u003e\u003cp\u003eData were reported as means and standard deviations. The Shapiro\u0026ndash;Wilk test assessed normality. Correlations were examined using Pearson\u0026rsquo;s coefficient for parametric data and Spearman\u0026rsquo;s coefficient for non-parametric data. Analyses were performed using IBM SPSS Statistics, Version 22 (IBM Corp., Armonk, NY, USA). A significance level of 5% was adopted for all tests.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cem\u003ePopulation characteristics\u003c/em\u003e\u003c/p\u003e\u003cp\u003eA total of 24 individuals with Down syndrome (DS) were screened, of whom 15 met the eligibility criteria and were included in the analysis. Sociodemographic and clinical characteristics are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The sample consisted predominantly of females (73.3%, n\u0026thinsp;=\u0026thinsp;11), with a mean age of 22.14\u0026thinsp;\u0026plusmn;\u0026thinsp;7.81 years. Mean body weight was 57.36\u0026thinsp;\u0026plusmn;\u0026thinsp;11.58 kg, mean BMI was 25.06\u0026thinsp;\u0026plusmn;\u0026thinsp;5.07 kg/m\u0026sup2;, and mean neck circumference was 37.80\u0026thinsp;\u0026plusmn;\u0026thinsp;2.88 cm.\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\u003eSociodemographic and anthropometric characteristics\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\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=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eUnit\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eValue\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex\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\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e11 (73.3)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale, n (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e4 (26.7)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eyears\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e22.14\u0026thinsp;\u0026plusmn;\u0026thinsp;7.81\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWeight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ekg\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e57.36\u0026thinsp;\u0026plusmn;\u0026thinsp;11.58\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBody mass index\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ekg/m\u0026sup2;\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e25.06\u0026thinsp;\u0026plusmn;\u0026thinsp;5.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNeck circumference\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ecm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e37.80\u0026thinsp;\u0026plusmn;\u0026thinsp;2.88\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003eSleep-related symptoms\u003c/em\u003e\u003c/p\u003e\u003cp\u003eSleep-related complaints were assessed using the STOP-Bang Questionnaire, Berlin Questionnaire and the Epworth Sleepiness Scale (ESS). The most frequently reported symptoms were non-restorative sleep (71.4%), daytime sleepiness or fatigue (64.3%), and restless sleep (42.9%) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\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\u003eSleep-related symptoms reported\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSymptom\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;15 (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNasal congestion\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2 (14.29%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLoud/frequent snoring\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4 (28.57%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDifficulty maintaining sleep\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e5 (35.71%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRestless sleep\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6 (42.86%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNon-restorative sleep\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e10 (71.43%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDaytime sleepiness/fatigue\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e9 (64.29%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDifficulty concentrating\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e5 (35.71%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMemory loss\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1 (7.14%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eMore than half of the participants (approximately 60%) exhibited at least one symptom consistent with sleep-disordered breathing (SDB). High-risk classifications for OSA on the Berlin Questionnaire were observed in 14.3% of the sample, a finding identical to that identified using the STOP-Bang criteria (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\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\u003eScreening questionnaires for obstructive sleep apnea and excessive daytime sleepiness\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMeasure\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;15 (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eEpworth Sleepiness Scale (ESS) \u0026mdash; Normal (0\u0026ndash;8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e7 (50%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eESS \u0026mdash; Mild (9\u0026ndash;12)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (35.71%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eESS \u0026mdash; Moderate (13\u0026ndash;15)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (14.29%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eESS \u0026mdash; Severe (16\u0026ndash;24)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBerlin Questionnaire \u0026mdash; High risk (\u0026ge;\u0026thinsp;2 categories)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (14.29%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSTOP-Bang Questionnaire \u0026mdash; High risk (\u0026ge;\u0026thinsp;3 items)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (14.29%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003eClinical comorbidities\u003c/em\u003e\u003c/p\u003e\u003cp\u003eClinical comorbidities observed among participants are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. Gastroesophageal reflux disease (GERD) was the most frequent condition (28.6%), followed by heart failure (14.3%), depression (14.3%), and sinusitis (14.3%). Mitral valve regurgitation was reported in one participant (7.1%).\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\u003eClinical comorbidities observed in adults with Down syndrome (n\u0026thinsp;=\u0026thinsp;15).\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eComorbidity\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHeart failure\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2 (14.29%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDepression\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2 (14.29%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGastroesophageal reflux\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4 (28.57%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSinusitis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2 (14.29%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMitral valve murmur\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1 (7.14%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003ePolygraphic parameters\u003c/em\u003e\u003c/p\u003e\u003cp\u003eType IV home polygraphy revealed significant respiratory and oxygenation disturbances during sleep (Tables\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Mean minimum SpO₂ was notably low (82.4%), and participants spent a considerable amount of time with oxygen saturation below 90% (26.8\u0026thinsp;\u0026plusmn;\u0026thinsp;52.0 minutes). Hypoxic burden was markedly elevated (mean 60.1\u0026thinsp;\u0026plusmn;\u0026thinsp;23.0%\u0026middot;min/h), highlighting substantial physiological stress during sleep.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePhysiological variables of sleep.\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariables\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eMean\u0026thinsp;\u0026plusmn;\u0026thinsp;Standard Deviation\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTotal sleep time (min)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e483.89\u0026thinsp;\u0026plusmn;\u0026thinsp;80.85\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eValid recording time (min)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e462.91\u0026thinsp;\u0026plusmn;\u0026thinsp;78.14\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep latency (min)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e35.87\u0026thinsp;\u0026plusmn;\u0026thinsp;19.41\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTime awake after sleep onset (min)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e85.73\u0026thinsp;\u0026plusmn;\u0026thinsp;69.66\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSleep efficiency (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e72.93\u0026thinsp;\u0026plusmn;\u0026thinsp;13.58\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMinimum peripheral oxygen saturation (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e82.40\u0026thinsp;\u0026plusmn;\u0026thinsp;3.59\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAverage peripheral oxygen saturation (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e93.60\u0026thinsp;\u0026plusmn;\u0026thinsp;1.45\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximum peripheral oxygen saturation (%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e98.93\u0026thinsp;\u0026plusmn;\u0026thinsp;1.44\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePeripheral oxygen saturation time\u0026thinsp;\u0026lt;\u0026thinsp;90% (min)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e26.82\u0026thinsp;\u0026plusmn;\u0026thinsp;50.34\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePeripheral oxygen saturation time\u0026thinsp;\u0026lt;\u0026thinsp;80% (min)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e0.03\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNumber of oxygen desaturations\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e134.27\u0026thinsp;\u0026plusmn;\u0026thinsp;73.74\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOxygen desaturation index (events/h)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e17.09\u0026thinsp;\u0026plusmn;\u0026thinsp;8.63\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMinimum heart rate (bpm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e45.37\u0026thinsp;\u0026plusmn;\u0026thinsp;13.70\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAverage heart rate (bpm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e65.47\u0026thinsp;\u0026plusmn;\u0026thinsp;8.52\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaximum heart rate (bpm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e112.60\u0026thinsp;\u0026plusmn;\u0026thinsp;8.95\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHypoxic burden (min/h%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e60.08\u0026thinsp;\u0026plusmn;\u0026thinsp;22.20\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSnoring time (min)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e481.1\u0026thinsp;\u0026plusmn;\u0026thinsp;80.29\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eSnoring analysis demonstrated a mean snoring duration of 108\u0026thinsp;\u0026plusmn;\u0026thinsp;110 minutes, indicating frequent and prolonged snoring episodes.\u003c/p\u003e\u003cp\u003eBased on the oxygen desaturation index (ODI), 93.3% of the cohort presented with OSA of varying severity: 53.3% mild, 26.7% moderate, and 13.3% severe (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). Only one participant (6.7%) showed normal values.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eClassification of obstructive OSA severity based on ODI\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\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\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eClassification\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en\u0026thinsp;=\u0026thinsp;15\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003e%\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNormal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e6.7%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMild OSA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e53.3%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eModerate OSA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e26.7%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSevere OSA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e13.3%\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003eCorrelation analyses\u003c/em\u003e\u003c/p\u003e\u003cp\u003eCorrelation analyses explored associations between ODI and anthropometric variables (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). There was no significant correlation between ODI and weight (r\u0026thinsp;=\u0026thinsp;0.037, p\u0026thinsp;=\u0026thinsp;0.895) or age (r\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.289, p\u0026thinsp;=\u0026thinsp;0.298). Neck circumference showed a positive trend toward correlation with ODI, nearing statistical significance (Pearson r\u0026thinsp;=\u0026thinsp;0.383, p\u0026thinsp;=\u0026thinsp;0.159; Spearman ρ\u0026thinsp;=\u0026thinsp;0.482, p\u0026thinsp;=\u0026thinsp;0.069). A significant correlation was identified between time spent with SpO₂ \u0026lt; 90% and neck circumference (Spearman ρ\u0026thinsp;=\u0026thinsp;0.588, p\u0026thinsp;=\u0026thinsp;0.021), suggesting that cervical circumference may be an important predictor of nocturnal hypoxemia exposure. No significant correlations were observed between hypoxic burden and age, weight, or neck circumference. These findings indicate that, within this sample, cumulative nocturnal hypoxia was not influenced by demographic or anthropometric characteristics.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe results of this study demonstrated a high prevalence of obstructive sleep apnea (OSA) in adults with Down syndrome (DS), identified in 93% of participants, with a predominance of mild and moderate forms. These findings are consistent with previous studies\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e,\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e,\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e, reaffirming that OSA is highly prevalent among individuals with DS.\u003c/p\u003e\u003cp\u003eWhen comparing the severity classification (ODI) with studies conducted in children with DS using Type III polygraphy, home nocturnal oximetry, and polysomnography (PSG), adults in the present study exhibited ODI values three to seven times higher than the median reported in pediatric populations\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e,\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e. While the mean ODI in our adult cohort was 17.1\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9 events/h, children showed a mean of 5.4 (3.2\u0026ndash;7.6) events/h\u003csup\u003e38\u003c/sup\u003e. Although the minimum SpO₂ values were similar between adults and children (\u0026asymp;\u0026thinsp;80%), the frequency of desaturations was substantially higher in adults.\u003c/p\u003e\u003cp\u003eMoreover, the time spent with SpO₂ \u0026lt; 90% was markedly greater in adults (26.8\u0026thinsp;\u0026plusmn;\u0026thinsp;52 minutes) than in children (median\u0026thinsp;\u0026asymp;\u0026thinsp;5%)\u003csup\u003e38\u003c/sup\u003e, reflecting longer desaturation events with increasing age. While OSA prevalence reached 93% in our adult sample, pediatric data report prevalence near 84%\u003csup\u003e37\u003c/sup\u003e, which is expected as pharyngeal collapse and obesity risk increase with age.\u003c/p\u003e\u003cp\u003eIn the present study, OSA severity was categorized as normal in 6.7% (1/15), mild in 53.3% (8/15), moderate in 26.7% (4/15), and severe in 13.3% (2/15). Compared with the findings of Landete et al.\u003csup\u003e36\u003c/sup\u003e in adults with DS, our sample showed a lower proportion of severe cases. Their higher percentage of severe OSA likely reflects sampling bias, since their participants were recruited from sleep clinics with prior suspicion of OSA, thus not representing the general DS population.\u003c/p\u003e\u003cp\u003eBeyond respiratory parameters such as the mean ODI (17.1\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9 events/h) and desaturation index (14.5\u0026thinsp;\u0026plusmn;\u0026thinsp;7.6 events/h), the minimum SpO₂ of 82.4% and hypoxic burden of 60%/h indicate substantial and recurrent hypoxemia, with potential cardiovascular and metabolic consequences. Although the mean SpO₂ (93.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5%) remained within normal limits, it was close to the lower threshold for mild hypoxemia (\u0026le;\u0026thinsp;94%) according to Berry et al.\u003csup\u003e15\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eSleep efficiency was reduced (72.9\u0026thinsp;\u0026plusmn;\u0026thinsp;14.1%), below the American Academy of Sleep Medicine threshold of 85% for restorative sleep\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. Estimated total sleep time averaged 349\u0026thinsp;\u0026plusmn;\u0026thinsp;76 minutes (\u0026asymp;\u0026thinsp;5.8 hours), considerably lower than the recommended 7\u0026ndash;9 hours for adults\u003csup\u003e\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e. Snoring was common, with a mean duration of 108\u0026thinsp;\u0026plusmn;\u0026thinsp;110 minutes.\u003c/p\u003e\u003cp\u003eA positive trend between neck circumference and ODI (r\u0026thinsp;=\u0026thinsp;0.383; p\u0026thinsp;=\u0026thinsp;0.159) and a significant correlation between neck circumference and time with SpO₂ \u0026lt; 90% (ρ\u0026thinsp;=\u0026thinsp;0.588; p\u0026thinsp;=\u0026thinsp;0.021) indicate an important role of cervical adiposity in upper airway obstruction, corroborating previous findings\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e,\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e. However, none of the anthropometric variables (age, weight, neck circumference) correlated significantly with hypoxic burden, suggesting that the intensity of intermittent hypoxia does not follow a predictable pattern based on general body measures. This highlights the unique pathophysiology of OSA in DS and underscores the importance of further targeted studies.\u003c/p\u003e\u003cp\u003eThe craniofacial anatomy typical of DS\u0026mdash;including midface hypoplasia, relative macroglossia, mandibular shortening, and high-arched palate\u003csup\u003e\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e,\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e\u0026mdash;in combination with muscular hypotonia and gastroesophageal reflux (present in 40% of the sample), likely contributes to increased susceptibility to airway collapse and nocturnal hypoxia.\u003c/p\u003e\u003cp\u003eRegarding the diagnostic approach, the use of Type IV home polygraphy in adults with DS proved feasible, acceptable, and well suited to this population. The Biologix portable monitoring system provided accurate measurements of ODI, hypoxic burden, and snoring intensity, showing strong concordance with the apnea\u0026ndash;hypopnea index (AHI) obtained via laboratory PSG. This home-based strategy improved adherence to testing, overcoming the low tolerability of traditional PSG previously documented in DS\u003csup\u003e21\u0026ndash;23\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eQuestionnaire-based assessments (Berlin, STOP-Bang, ESS) supported the polygraphy results, identifying common symptoms such as daytime sleepiness (22.2%) and non-restorative sleep (22.2%), with approximately 60% reporting sleep-related complaints. Nonetheless, questionnaires significantly underestimated disease prevalence compared with polygraphy, emphasizing the need for objective diagnostic methods in DS.\u003c/p\u003e\u003cp\u003ePotential autonomic and cardiovascular implications also emerge from these findings. Previous studies demonstrated attenuated sympathetic responses and delayed resaturation in children with DS and sleep-disordered breathing\u003csup\u003e\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u003c/sup\u003e. These characteristics may progress into adulthood, contributing to sustained hypoxemia and chronic ventilatory dysfunction, consistent with the prolonged desaturation times observed in this study (mean SpO₂ \u0026lt; 90% = 26.8 minutes).\u003c/p\u003e\u003cp\u003eOSA in DS is multifactorial, involving anatomical, metabolic, hormonal, and genetic components\u003csup\u003e\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e,\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. Unlike Landete et al.\u003csup\u003e36\u003c/sup\u003e, who found correlations between BMI and both AHI and ODI, as well as between BMI and Tc90%, our study did not detect such relationships. These discrepancies may reflect sample heterogeneity or methodological differences, reinforcing the need for further research.\u003c/p\u003e\u003cp\u003eClinically, our findings support the recommendation that individuals with DS should undergo validated portable sleep monitoring regardless of symptom presentation or obesity status. This aligns with international guidelines and may reduce underdiagnosis and delays in treatment.\u003c/p\u003e\u003cp\u003eOverall, this study contributes valuable evidence regarding OSA in DS, reinforcing neck circumference as a potential clinical marker, validating the feasibility of Type IV home polygraphy, and highlighting the importance of longitudinal follow-up to monitor disease progression. The results underscore the relevance and practicality of high-resolution home monitoring in research and clinical care for individuals with DS.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe findings of this study reinforce the high prevalence, progression, and physiological impact of obstructive sleep apnea (OSA) in individuals with Down syndrome, highlighting the need for objective and accessible diagnostic strategies. AOSA was highly prevalent (93%), with a predominance of mild to moderate cases (80%). Participants exhibited frequent desaturation events and significant hypoxemia (mean minimum SpO₂ of 82.4%), as well as inefficient and fragmented sleep (efficiency\u0026thinsp;\u0026lt;\u0026thinsp;75%). Neck circumference showed a meaningful association with nocturnal hypoxemia, whereas no correlation was observed with age or body weight. Subjective sleep questionnaires alone were insufficient for screening OSA in this population, underscoring the importance of objective diagnostic methods. The study confirmed that type IV home polygraphy (Biologix) is feasible, well tolerated, and clinically applicable for adults with Down syndrome.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to thank all the patients and their respective parents who collaborated in the conduct of this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStudy design and conceptualization: LVFO, LCG,OAG, GI, MYMY, and WRFJ; Data collection and analysis: CNSN, LPM, RACA, ASGS, SVM, and MYMY; Data curation: LVFO, LCG, GI, CSO,CHMS, and MYMY; Formal analysis: GI, DAAPO, RFO, LCG, CSO, OAG, and LVFO; Investigation: MYMY, LCG, LVFO, and OAG; Methodology: LVFO, LCG, OAG, CHMS, and MYMY; Project administration: LVFO, LCG, CNSN, GI, CSO, AND WRFJ; Resources: LVFO, CNSN, MYMY, and LCG; Supervision: GI, OAG, and LVFO; Writing original Draft: MYMY, OAG, LCG, WRFJ, GI, RFO, DAAPO, and LVFO; Writing – review \u0026amp; editing: MYMY, CNSM, WRFJ, GI, OAG, LCG, ASGS, and LVFO. Critical revision of the manuscript: all authors.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors affirm that they did not receive any funding for this research from any funding agency in the public, commercial, or not-for-profit sectors.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeclarations\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study protocol was approved by the Ethics Committee for Human Research of the Institute of Science and Technology, UNESP, São José dos Campos (CAAE: 64173616.4.0000.0077). All the parents of the patients involved in the study provided the written Consent Form for participation in the research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAdditional information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorrespondence and requests for materials should be addressed to corresponding author LVFO\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003ePeppard, P. E., Young, T., Palta, M. \u0026amp; Skatrud, J. Prospective study of the association between sleep-disordered breathing and hypertension. \u003cem\u003eN Engl. J. Med.\u003c/em\u003e \u003cb\u003e342\u003c/b\u003e, 1378\u0026ndash;1384 (2000).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShahar, E. et al. 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Physiol.\u003c/em\u003e \u003cb\u003e298\u003c/b\u003e, H1986\u0026ndash;H1990 (2010).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBhaumik, P., Ganguly, A. \u0026amp; Ghosh, S. Risk factors of obstructive sleep apnea in Down syndrome. \u003cem\u003eProc. Zool. Soc.\u003c/em\u003e \u003cb\u003e78\u003c/b\u003e, 1\u0026ndash;15 (2025).\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":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Down syndrome, sleep apnea, polysomnography, portable sleep monitor","lastPublishedDoi":"10.21203/rs.3.rs-8154933/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8154933/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eDown syndrome (DS) is associated with craniofacial abnormalities, muscular hypotonia, and upper airway obstruction, factors that increase the risk of obstructive sleep apnea (OSA). Despite the high likelihood of sleep-disordered breathing in this population, diagnostic access remains limited, especially in low-resource settings. This study aimed to determine the prevalence and severity of sleep-disordered breathing in adolescents and adults with DS. This cross-sectional study included adolescents and adults with DS who underwent home type IV polygraphy (Biologix) and completed validated questionnaires assessing OSA risk and excessive daytime sleepiness. Anthropometric data were collected, and correlations with respiratory parameters were analyzed. OSA was highly prevalent, affecting 93% of participants. Mild to moderate OSA predominated (80%). Respiratory events were frequently accompanied by oxygen desaturation, with marked nocturnal hypoxemia (mean minimum SpO₂: 82.4%). Sleep was inefficient and fragmented, with efficiency below 75% in most individuals. Neck circumference showed a significant correlation with nocturnal hypoxemia, whereas age and body weight did not. Subjective sleep questionnaires underestimated OSA severity compared with polygraphy. Sleep-disordered breathing is highly prevalent and physiologically significant in individuals with DS. Home type IV polygraphy proved feasible, well-accepted, and clinically informative for this population. These findings highlight the importance of accessible diagnostic strategies to improve early detection and management of OSA in individuals with DS.\u003c/p\u003e","manuscriptTitle":"Prevalence and severity of sleep-disordered breathing in individuals with Down syndrome using a portable home-based diagnostic device: a pilot study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-08 11:37:21","doi":"10.21203/rs.3.rs-8154933/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-02-23T06:10:58+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-02-21T04:43:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"301475303337076982665864161029156380647","date":"2026-02-12T18:23:31+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"115212356489293538929029491500715782369","date":"2026-02-10T17:43:34+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-12-19T07:24:09+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"305044425261337567003616973071057012445","date":"2025-12-14T23:40:57+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-04T04:38:57+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-11-21T08:11:40+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-11-20T14:09:27+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-11-20T14:06:54+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-11-19T11:41:43+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"0d15ce7c-cee5-4d85-90f7-80a39c5f91a6","owner":[],"postedDate":"December 8th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":59213818,"name":"Health sciences/Diseases"},{"id":59213819,"name":"Health sciences/Health care"},{"id":59213820,"name":"Health sciences/Medical research"},{"id":59213821,"name":"Health sciences/Risk factors"}],"tags":[],"updatedAt":"2026-03-25T06:56:03+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-08 11:37:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8154933","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8154933","identity":"rs-8154933","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}