Correlation of the body roundness index (BRI) with chronic diarrhea and chronic constipation: Findings based on the National Health and Nutrition Examination Survey (NHANES) 2005–2010 data

Correlation of the body roundness index (BRI) with chronic diarrhea and chronic constipation: Findings based on the National Health and Nutrition Examination Survey (NHANES) 2005–2010 data | 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 Correlation of the body roundness index (BRI) with chronic diarrhea and chronic constipation: Findings based on the National Health and Nutrition Examination Survey (NHANES) 2005–2010 data Yinda Wang, Fei Chen, Binzhong Zhang, Zhengwei Song This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5277629/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 31 Jan, 2025 Read the published version in Lipids in Health and Disease → Version 1 posted 13 You are reading this latest preprint version Abstract Aim The study aimed to explore potential links between long-term digestive issues (specifically diarrhea and constipation) and BRI in a representative U.S. population sample. Methods This study adopted a design that is cross sectional, drawing on data from the NHANES, gathered from 2005 to 2010. This comprehensive dataset included health information from a total of 11,235 individuals, providing a robust sample for the analysis. Persistent bowel movement patterns were categorized based on the BSFS—Bristol Stool Form Scale, a widely recognized diagnostic tool. Within this framework, stool types 1 and 2 were designated as indicators of long-term constipation, while types 6 and 7 were identified as markers of persistent diarrhea. To assess the relationship between digestive health and the BRI, this study employed weighted logistic regression analysis. To capture and visualize the nuanced interplay between BRI and gastrointestinal patterns, we utilized advanced nonlinear regression methods, specifically restricted cubic spline (RCS) analyses. Additionally, the research compared the efficacy of various physical measurements—including BRI, WC, BMI (body roundness index, waist circumference, and body mass index, respectively)—to determine their respective predictive power for chronic diarrhea and constipation through comparative analysis of receiver operating characteristic (ROC) curves. Results After comprehensive adjustment in the final statistical model (Model 3), the BRI demonstrated a statistically significant association with diarrhea (odds ratio, OR, of 1.24; 95% confidence interval, CI, ranging from 1.08 to 1.43, with P value of 0.004) However, the association between BRI and persistent constipation was statistically insignificant (OR of 1.13, 95% CI ranging from 0.99 to 1.29, P value of 0.060). Nonlinear regression analysis using RCS analysis further uncovered statistically significant nonlinear positive correlations between BRI and both chronic gastrointestinal conditions. The non-linearity was particularly pronounced for diarrhea ( P = 0.005) and also notable for constipation ( P = 0.037). Further stratified analyses provided additional insights into specific population subsets. The relationship between BRI and persistent diarrhea was particularly evident among individuals with diabetes. In contrast, the correlation between BRI and constipation was stronger in individuals under 60 years of age. ROC analysis indicated that BRI outperformed conventional anthropometric measures (AUC, area under the curve: 0.601). Specifically, BMI, the body mass index, resulted in an AUC of 0.569, while WC produced an AUC of 0.572. However, the AUC value of BRI (0.537) was less effective than BMI (0.551) and WC (0.570) in diagnosing constipation. Conclusions BRI is closely associated with changes in the individual’s bowel habits, particularly in predicting chronic diarrhea. This study highlighted the potential importance of maintaining moderate BRI levels to improve bowel health and prevent disorders like diarrhea. Body roundness index chronic constipation chronic diarrhea National Health and Nutrition Examination Survey obesity Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Persistent bowel disorders, particularly chronic diarrhea and persistent constipation, represent widespread digestive health challenges. These conditions exert a significant impact on global health, affecting a considerable segment of the world’s population. Current epidemiological data indicate that chronic diarrhea impacts approximately 17% and chronic constipation afflicts 14–20% of individuals worldwide. Such long-term digestive disturbances significantly diminish the overall quality of life for those experiencing these conditions [ 1 – 3 ]. Numerous factors can lead to these conditions, with obesity often playing a direct or indirect role in many digestive system diseases [ 4 ], such as nonalcoholic fatty liver disease [ 5 ] and reflux esophagitis [ 6 ]. Notably, diarrhea is a prevalent symptom among obese individuals [ 7 , 8 ]. However, studies show conflicting results regarding the correlation between obesity and constipation [ 9 – 12 ]. While body mass index (BMI) remains the predominant measure for obesity assessment, it lacks precision in determining adipose tissue distribution. Cutting-edge radiological techniques, notably CT/MRI (computed tomography/magnetic resonance imaging, respectively), enable a highly accurate assessment of internal fat distribution. However, these methods are impractical for routine use due to their time-intensive protocols and substantial financial burden [ 13 ]. Thomas and colleagues proposed the BRI in 2013 as an innovative approach to evaluate body composition and visceral adiposity [ 14 ]. This easily accessible, economical, and non-invasive technique yields a more accurate evaluation of overall and intra-abdominal adiposity compared with BMI, potentially improving its prognostic capabilities. The BRI has shown promise as an effective instrument for community-wide health assessment and early identification of metabolic risks. Studies have shown that BRI is significantly correlated with numerous health issues, including cardiovascular disease [ 15 – 17 ], metabolic syndrome [ 18 , 19 ], and diabetes [ 20 , 21 ]. Nevertheless, as a convenient new measurement index capable of assessing intra-abdominal fat and reflecting the degree of central obesity, the relationship between BRI and persistent gastrointestinal disorders, specifically chronic diarrhea and chronic constipation, remains understudied. To bridge this lack of know-how, the research strived to examine the possible relationship of BRI with these chronic bowel conditions. This research seeks to provide new perspectives and contribute to the development of approaches for preventing and managing these chronic gastrointestinal disorders. Materials and Methods Study population The investigation analyzed information acquired through NHANES—National Health and Nutrition Examination Survey, an all-inclusive human healthiness evaluation initiative. This extensive program is conducted and managed by the CDC—Centers for Disease Control and Prevention. The NHANES’ program implements biennial health evaluations on a national scale, assessing the physiological status and dietary profiles of Americans across all age groups. It is worth noting that data pertaining to bowel habits have been incorporated into only three of these survey cycles: 2005–2006, 2007–2008, and 2009–2010. Across these cycles, 17,132 participants aged 20 years and older were enrolled. During this period, a total of 17,132 individuals, all of whom were 20 years of age or older, were recruited as participants. However, the study excluded participants who provided incomplete responses to the bowel health questionnaire (n=1920), incomplete BRI data (n=379), or incomplete data for any covariate (n=3005) Consequently, the final analyzed cohort consisted of 11,235 subjects (Figure 1). The ethical framework and research methodology of the NHANES initiative underwent rigorous scrutiny and received formal approval from the Ethics Review Committee of the National Center for Health Statistics. All subjects consented to take part in the study. The complete dataset is publicly accessible and may be retrieved from https://www.cdc.gov/nchs/nhanes/index.htm. Bowel health questionnaire The gastrointestinal health component of ‘NHANES from 2005 to 2010’ served as a means to scrutinize bowel habits among participants who willingly shared details about their bowel movements. The researcher used the BSFS card, which features color illustrations of seven distinct stool types, for evaluation purposes. Participants who recognized their typical bowel movements as corresponding to BSFS type 1 (defined as distinct, firm pellets akin to nuts) or BSFS type 2 (described as a cohesive mass with a lumpy surface) were classified as experiencing persistent constipation. Individuals whose typical stool type fell into the categories of BSFS type 6 (described as fluffy, irregular-edged pieces with a mushy consistency) or BSFS type 7 (consisting of water-like samples with no solid feces) were considered to have chronic diarrhea. The remaining participants were deemed to have normal bowel function. Anthropometric measures The measurement of WC was conducted using a measuring tape, with readings taken in centimeters at the uppermost edge of the iliac crest. The calculation of BMI and BRI utilized established formulas from the previous literature: the study calculated BMI by dividing the participant’s weight (kg) by the square of their height (m), while we derived BRI using a specific equation 364.2–365.5 × (1－[WC(m)/2π]2/[0.5 × height (m)]2)½ [14]. Covariates In this investigation, numerous potential confounding factors affecting BRI and the likelihood of persistent diarrhea and constipation were taken into account. These variables encompassed several categories. (1) Demographic factors: the study accounted for age, male/female, race/ethnicity, single/married status, and education level. (2) Lifestyle factors: The analysis incorporated smoking patterns and alcohol consumption behaviors. (3) Economic status: Socioeconomic status was assessed using the PIR–family poverty-to-income ratio. (4) Health comorbidities: the models included hypertension, cardiovascular disease, and diabetes mellitus (DM). (5) Dietary aspects: the study considered total daily caloric intake and scores on the healthy eating index (HEI). Statistical analysis In accordance with NHANES protocols, this investigation utilized recommended sample weights to improve data accuracy and mitigate the effects of intricate multistage sampling designs on NHANES research. In the statistical analysis, the study presented the results for categorical variables as weighted percentages, reflecting the complex survey design of NHANES. For continuous variables, the study reported weighted means along with their corresponding standard errors to account for sampling variability. To investigate the potential links between BRI and chronic gastrointestinal symptoms, the study employed weighted multivariate logistic regression analyses. These analyses accounted for various confounding factors, with adjustments made for both continuous and quantile outcomes. The analysis employed three distinct models. The initial model (Model 1) was uncontrolled for any variables. The second model (Model 2) incorporated adjustments for key demographic variables. Specifically, this model accounted for race/ethnicity, age, gender, level of education, and single/married status. The most comprehensive model (Model 3) expanded upon Model 2 by additionally controlling for BMI, socioeconomic status (as measured by PIR), lifestyle habits (such as smoking habits, alcohol use patterns), comorbidities (such as DM, high blood pressure, and cardiovascular disease), and dietary factors (specifically total caloric intake and HEI). Additionally, the study utilized weighted RCS curves within Model 3 to further examine potential nonlinear relationships between BRI and chronic bowel symptoms. The research also conducted stratified analyses based on a range of demographic factors and variables related to health, including age categories, male/female, educational level, single/married status, smoking habits, and the presence of common chronic diseases. To assess and contrast the predictive capabilities of WC, BMI, and BRI for long-term diarrhea and constipation, the study analyzed ROC curves and calculated the AUC area. To determine the most effective threshold ‘values for WC, BRI, and BMI’ in predicting chronic diarrhea and constipation, the study utilized the Youden index. The entirety of the statistical computations was performed using R software, (v. 4.2.2; http://www.Rproject.org), with a threshold for statistical significance established at P <0.05. Results The study sample characteristics, grouped by BRI tertiles, are summarized in Table 1. The analysis included a total of 11,235 subjects. The average age of participants was 46.91±0.37 years. The gender distribution of the cohort was nearly balanced, with males comprising 48.25% of the sample. The mean BRI was 5.20±0.05, with BRI ranges defined as 6.02 for the third tertile. The study found that diarrhea affected 6.75% of the overall population, with its prevalence varying across BRI tertiles: (1) lowest BRI tertile: 4.80% prevalence; (2) middle BRI tertile: 6.00% prevalence; and (3) highest BRI tertile: 10.21% prevalence. Constipation was observed in 7.07% of the total sample, showing a different distribution across BRI tertiles: 8.08% in the first tertile, 7.15% in the second tertile, and 5.63% in the third tertile. the statistical analysis uncovered significant differences (a P value <0.05) across BRI tertiles for several factors: demographic characteristics (age, ethnicity, male/female, educational attainment, and single/married status), socioeconomic indicators (PIR), lifestyle habits (smoking habits and alcohol consumption), physical and mental well-being (high blood pressure, diabetes, heart disease), anthropometric measures (BMI, WC), and dietary factors (total caloric intake and HEI). Correlation of BRI with chronic diarrhea and chronic constipation In this study, logistic modeling examining the relationship between chronic intestinal disorders and BRI yielded the following key findings, as presented in Table 2: (A) BRI in its continuous form: (1) Chronic diarrhea: a strong positive link was identified (odds ratio, OR, and 95% confidence interval, CI: 1.15 and 1.11–1.20, respectively; P value of <0.001). The positive relationship continued to be robust following extensive adjustment (OR=1.24, 95% CI=1.08–1.43, P =0.004). (2) Chronic constipation: initially showed a negative trend in crude (OR and 95% CI: 0.94 and 0.89–0.99, respectively; P value equal to 0.020) and partially adjusted models (OR and 95% CI: 0.92 and 0.87–0.97, respectively; P value equal to 0.002). However, this association lost statistical significance in the fully adjusted model (OR and 95% CI: 1.13 and 0.99–1.29, respectively; P value equal to 0.060). (B) BRI as a categorical variable (tertiles): (1) Chronic diarrhea: participants in the highest BRI tertile showed significantly increased risk compared to the lowest tertile after full adjustment (T3 vs T1: OR and 95% CI: 1.65, and 1.09–2.50, respectively: P value equal to 0.020). (2) Chronic constipation: no statistically significant relationship was observed between BRI tertiles and constipation risk (highest vs. lowest tertile: OR and 95% CI: 0.84 and 0.53–1.34, respectively; P =0.458). Nonlinear correlation To explore possible nonlinear associations between BRI and the prevalence of chronic gastrointestinal disorders, the study conducted a weighted multivariable–adjusted RCS analysis. The results of this analysis are presented graphically in Figure 2. The analysis uncovered a complex, nonlinear positive relationship between BRI and both intestinal conditions: diarrhea ( P value for nonlinear association equal to 0.005) and constipation ( P value for nonlinear association equal to 0.037). Chronic diarrhea risk increased significantly at BRI values above 3.4. In contrast, the risk of constipation gradually increased with initial increases in BRI. However, when BRI reached 5.10, the risk of constipation plateaued, and it did not rise again until BRI exceeded 5.78. Subgroup analyses In the present study, subgroup analyses showed significant variations in the correlation between BRI and bowel habits across different subgroups (Figure 3). the analysis revealed significant interactive effects between specific DM subgroups and BRI with respect to diarrhea, as well as between age subgroups and BRI with respect to constipation ( P <0.05). Specifically, BRI exhibited a strong and statistically significant positive correlation with diarrhea in the diabetes subgroup. Furthermore, among individuals under 60 years of age, the likelihood of constipation increased substantially by 20% (OR: 1.20, CI: 1.00–1.44) with each incremental unit of the body shape indicator. Conversely, among participants 60 years of age and above, the study did not detect this positive association. Comparing WC, BMl, and BRI as predictors of chronic bowel issues ROC analysis results (Table 3, Figure 4) showed BRI had a higher predictive power (AUC: 0.601) for diarrhea than BMI (0.569) or WC (0.572). Delong's test confirmed BRI's significantly higher predictive ability for diarrhea compared with both BMI and WC ( P <0.001 for both comparisons). Conversely, in predicting constipation, BRI showed a lower AUC value (0.537) than both BMI (0.551) and WC (0.570). Delong's test revealed significant differences in predictive power: BRI outperformed ‘BMI ( P =0.002) and WC ( P <0.001). These results indicate that BRI was less effective than BMI and WC in predicting constipation. Discussion This investigation broke new ground by exploring the relationship between BRI and the occurrence of intestinal disorders, specifically diarrhea and constipation using a cross-sectional analytical approach. Employing weighted multivariate logistic regression techniques, the research demonstrated that BRI maintained its status as an independent predictor of diarrhea, despite controlling for various potential confounders. In contrast, the study found no statistically significant relationship between BRI and chronic constipation. RCS showed nonlinear relationships between BRI levels and the likelihood of experiencing diarrhea and constipation. Subgroup analyses revealed significant interactions between various diabetic statuses, age groups, and BRI levels, influencing the likelihood of both diarrhea and constipation. In a comparative analysis with other anthropometric indices like BMI and WC, BRI demonstrated a strong predictive capability for diarrhea, but not for constipation. These results underscore BRI's particular efficacy as a predictor of diarrhea occurrence, suggesting that addressing obesity may aid in its prevention. Historically, the BMI has been criticized for its inability to accurately reflect the correlation between obesity and bowel habits, frequently leading to inconsistent research outcomes [ 10 , 12 , 22 – 24 ]. BRI represents an innovative obesity metric derived using height and WC measurements to assess body composition and fat distribution more comprehensively than conventional metrics like BMI [ 14 ]. A comprehensive meta-analysis has demonstrated BRI's superior predictive capacity for metabolic syndrome when compared to other indices like ‘waist-to-hip ratio, BMI, body adiposity index, and body shape index [ 25 ]. Moreover, research has linked BRI to a range of health conditions, including overactive bladder [ 26 ], cholelithiasis [ 27 ], cardiovascular diseases [ 15 – 17 ], and DM [ 20 , 21 ]. However, prior to this investigation, the relationship between BRI and intestinal function had not been explored in the scientific literature. This study analyzed this correlation for the first time using a large dataset from NHANES. the study identified a significant positive correlation between BRI and diarrhea, enabling effective prediction of diarrhea risk. In the nonlinear correlation analysis between BRI and bowel habits, we observed that the probability of experiencing chronic diarrhea began to increase only when BRI values surpassed 3.40. Additionally, the analysis revealed that the likelihood of chronic constipation demonstrated a progressive increase once BRI values surpassed 5.78. Notably, both values were below the highest tertile of the BRI. This suggested that an elevated BRI may be closely associated with persistent gastrointestinal disturbances, specifically chronic diarrhea and constipation, among those with substantial adiposity. Hence, in severely obese individuals, significant emphasis should be placed on regulating BRI levels to improve bowel habits. Persistent alterations in bowel habits, particularly long-term diarrhea and constipation, rank among the most prevalent digestive issues linked to excess body weight. These conditions significantly diminish the well-being and overall health status of those affected [ 7 , 28 – 32 ]. However, despite their prominence in the medical literature, few studies have explored diarrhea and constipation as aspects of obesity, resulting in a lack of sufficient clinical attention. Numerous studies have investigated the mechanisms linking obesity to bowel habits. However, the specific mechanisms by which obesity leads to diarrhea and constipation remain unclear. Regarding diarrhea, researches have revealed that the expedited movement of contents through the small intestine and distal colon, coupled with an excess of body weight, are potential contributors to the underlying mechanisms of idiopathic bile acid malabsorption [ 33 – 36 ]. Delgado-Aros showed that obesity, causing dysfunction such as accelerated colonic transport, may lead to diarrhea [ 37 ]. Studies focusing on constipation have uncovered that individuals with obesity tend to display reduced concentrations of growth hormone–releasing peptides while simultaneously showing increased levels of leptin. These hormonal imbalances may restrict gastric emptying and slow gastric motility, potentially triggering constipation [ 38 , 39 ]. Furthermore, obesity may increase the amount of fat entering the intestines, which interferes with hormone release and causes the relaxation of smooth muscles in the colon, thereby obstructing the propulsion of intestinal contents and contributing to constipation [ 40 , 41 ]. Study strengths and limitations This study had several strengths. First, it represents the inaugural investigation utilizing an extensive cross-sectional approach with NHANES data to reveal a nonlinear positive relationship between BRI and diarrhea. Second, the methodology was rigorous, incorporating sampling weights, adjusting for numerous potential confounders, and employing sophisticated statistical techniques such as multivariate logistic regression, RCS analysis, and stratified subgroup analysis. These methodological choices significantly bolster the precision and robustness of the results. Finally, the study compared the diagnostic efficacy of BRI with BMI and WC in diagnosing diarrhea, revealing that BRI demonstrates a superior diagnostic performance. Limitations of this study: (1)The cross-sectional approach of this research does not allow for determining causality between BRI and chronic bowel symptoms such as diarrhea and constipation. (2) The findings may not apply to populations outside the U.S. due to the study's limited geographic scope. (3) Information about bowel disorders was collected through self-reported questionnaires, a method potentially subject to recall bias. Participants' recollections of their gastrointestinal symptoms might not always accurately reflect their true health status. Finally, the investigators could not ascertain any additional confounding variables that may have been overlooked in this investigation. Conclusions The analysis revealed a complex, nonlinear positive relationship between BRI values and the likelihood of experiencing long-term diarrhea and constipation. The relationship was especially evident in subjects with severe adiposity. Regulating BRI levels could help improve bowel habits, particularly in cases of severe obesity. Furthermore, BRI demonstrates superior predictive value for chronic diarrhea when compared with traditional ‘anthropometric indicators like BMI and WC.’ These results highlight the possible advantages of sustaining reasonable BRI values in fostering optimal intestinal function and reducing the risk of long-term gastrointestinal issues. Abbreviations AUC, Area under the curve; BMI, Body mass index; BRI, Body roundness index; BSFS, Bristol Stool Form Scale; CI, Confidence interval; CT, Computed tomography; CVD, Cardiovascular disease; DM, Diabetes mellitus; MRI, Magnetic resonance imaging; NHANES, National Health and Nutrition Examination Survey; OR, Odds ratio; PIR, Poverty income ratio; RCS, Restricted cubic spline; ROC, Receiver operating characteristic; WC, Waist circumference. Declarations Acknowledgments The study acknowledge the NHANES program for’ providing the comprehensive database and resources that made this research possible. the study also thank all the contributors for sharing their datasets and all the individuals who volunteered their time and information as subjects in this study, without whom this investigation would not have been feasible. Authors’ contributions The research project was conceptualized and structured by Yinda Wang and Fei Chen. These two researchers were also responsible for data collection and analysis. Together, they produced the first version of the manuscript. Binzhong Zhang and Zhengwei Song revised the manuscript. Yinda Wang provided the final review for the entire text. Each researcher involved provided substantial input to the paper. The final version of this document was reviewed and approved by each of the contributing authors prior to submission. Funding No funding was received for this study. Data availability The datasets analyzed in this research are publicly available. Interested parties can obtain these datasets through ‘the National Center for Health Statistics' official website at https://www.cdc.gov/nchs/nhanes. Ethics approval and consent to participate The present study employed anonymized data obtained from ‘the publicly accessible NHANES database. The study received ethical approval from ‘the National Center for Health Statistics' Ethics Review Committee’ and followed relevant guidelines, including those set forth in ‘the Declaration of Helsinki. Importantly, all NHANES participants gave documented consent before their involvement. This consent process occurred prior to any data collection, ensuring that subjects were fully aware of and agreed to their participation in the survey. Consent for publication The "Consent for publication" section is not needed for this type of study using anonymized ‘public data’. Competing interests The research team declares no conflicts of interest relevant to this study. References Zhao YF, Guo XJ, Zhang ZS, Ma XQ, Wang R, Yan XY, et al: Epidemiology of functional diarrhea and comparison with diarrhea-predominant irritable bowel syndrome: a population-based survey in China. PLoS One 2012, 7:e43749. 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Additional Declarations No competing interests reported. Supplementary Files SupplementaryTable.docx Cite Share Download PDF Status: Published Journal Publication published 31 Jan, 2025 Read the published version in Lipids in Health and Disease → Version 1 posted Editorial decision: Revision requested 07 Dec, 2024 Reviews received at journal 06 Dec, 2024 Reviews received at journal 03 Dec, 2024 Reviewers agreed at journal 02 Dec, 2024 Reviewers agreed at journal 30 Nov, 2024 Reviewers agreed at journal 17 Nov, 2024 Reviews received at journal 11 Nov, 2024 Reviewers agreed at journal 06 Nov, 2024 Reviewers agreed at journal 02 Nov, 2024 Reviewers invited by journal 18 Oct, 2024 Editor assigned by journal 17 Oct, 2024 Submission checks completed at journal 17 Oct, 2024 First submitted to journal 16 Oct, 2024 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. 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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-5277629","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":370323542,"identity":"98638fd9-f317-4757-b88d-c29fdcb297f7","order_by":0,"name":"Yinda Wang","email":"","orcid":"","institution":"The Second Affiliated Hospital of Jiaxing University","correspondingAuthor":false,"prefix":"","firstName":"Yinda","middleName":"","lastName":"Wang","suffix":""},{"id":370323543,"identity":"15c01d9b-837a-41cd-9471-e988918bd5b4","order_by":1,"name":"Fei Chen","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8UlEQVRIiWNgGAWjYLACxgYQyXyAQQLMTcCvmgehhS2BZC08BlAxAlrs2c8efvFzh01iv/SZzx8s2w4z8LPnGDD83IHHFp68NMveM2mJM/tyNxhInDnMINnzxoCx9ww+h+WYGTO2HU7ccIZ3Q4JExWEGgxs5BsyMbXi08L+BaNl/hufBAQmDwwz2BLVI5Bg/BtvCw8PYALZFgpCWG2/MGHvb0oxnnGEzZpA4k84jceZZwcFePFrY+3OMP/xss5Ht72F+/FmyzVqOvz1544OfeLQAAZsEjMUsAY2oA3g1ABV+gLEYP+BTNwpGwSgYBSMWAAAuck5B00I3FAAAAABJRU5ErkJggg==","orcid":"","institution":"The Second Affiliated Hospital of Jiaxing University","correspondingAuthor":true,"prefix":"","firstName":"Fei","middleName":"","lastName":"Chen","suffix":""},{"id":370323544,"identity":"2190ddb4-187c-4ef7-8c00-3c5dd89afdc5","order_by":2,"name":"Binzhong Zhang","email":"","orcid":"","institution":"The Second Affiliated Hospital of Jiaxing University","correspondingAuthor":false,"prefix":"","firstName":"Binzhong","middleName":"","lastName":"Zhang","suffix":""},{"id":370323545,"identity":"76ec3b92-3bf7-436e-b905-e9aaab54002b","order_by":3,"name":"Zhengwei Song","email":"","orcid":"","institution":"The Second Affiliated Hospital of Jiaxing University","correspondingAuthor":false,"prefix":"","firstName":"Zhengwei","middleName":"","lastName":"Song","suffix":""}],"badges":[],"createdAt":"2024-10-16 17:08:22","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5277629/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5277629/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12944-025-02451-7","type":"published","date":"2025-01-31T15:56:53+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":67715313,"identity":"4da5da03-d88b-4636-8f78-f49680e736b1","added_by":"auto","created_at":"2024-10-29 03:47:40","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":78154,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFlow diagram of study cohort selection.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5277629/v1/bde97d9a15086d8caae54c63.png"},{"id":67715315,"identity":"6ec11c09-5462-4881-9ac8-bd5f3fbe0516","added_by":"auto","created_at":"2024-10-29 03:47:40","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":345435,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eAssociation between BRI with diarrhea (A) and constipation (B). Adjustment factors included age, sex, race, education attainment, marital status, BMI, PIR, smoking status, drinking status, hypertension, DM, CVD, total energy intake, and HEI.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5277629/v1/e8b5a992f4e0514fd180fc8d.png"},{"id":67716030,"identity":"c04ee40f-6701-407c-9ea3-d4bd7da5ddbe","added_by":"auto","created_at":"2024-10-29 03:55:40","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":584794,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSubgroup analyses between BRI with diarrhea (A) and constipation (B). Each subgroup analysis adjusted for age, sex, race, education attainment, marital status, BMI, PIR, smoking status, drinking status, hypertension, DM, CVD, total energy intake, and HEI.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5277629/v1/f1592abcc0fbb1b1e31f5bbb.png"},{"id":67716029,"identity":"145a3b68-7cdf-4665-8790-dc1aa17c432d","added_by":"auto","created_at":"2024-10-29 03:55:40","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1223919,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eReceiver operating characteristic (ROC) curve analysis for predicting diarrhea (A) and constipation (B).\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5277629/v1/87bd8e086f2987a70a2b5c9f.png"},{"id":75351143,"identity":"e398f86e-487e-4181-aa9c-60d5f2ef05af","added_by":"auto","created_at":"2025-02-03 16:05:00","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3390732,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5277629/v1/a492188b-1be3-46c5-bd50-0073f7248c55.pdf"},{"id":67715314,"identity":"3cf1a920-9442-46f3-93ba-f44db851c1b6","added_by":"auto","created_at":"2024-10-29 03:47:40","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":16240,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryTable.docx","url":"https://assets-eu.researchsquare.com/files/rs-5277629/v1/359bae33342af9456f790bf6.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Correlation of the body roundness index (BRI) with chronic diarrhea and chronic constipation: Findings based on the National Health and Nutrition Examination Survey (NHANES) 2005–2010 data","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePersistent bowel disorders, particularly chronic diarrhea and persistent constipation, represent widespread digestive health challenges. These conditions exert a significant impact on global health, affecting a considerable segment of the world\u0026rsquo;s population. Current epidemiological data indicate that chronic diarrhea impacts approximately 17% and chronic constipation afflicts 14\u0026ndash;20% of individuals worldwide. Such long-term digestive disturbances significantly diminish the overall quality of life for those experiencing these conditions [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Numerous factors can lead to these conditions, with obesity often playing a direct or indirect role in many digestive system diseases [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], such as nonalcoholic fatty liver disease [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] and reflux esophagitis [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Notably, diarrhea is a prevalent symptom among obese individuals [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. However, studies show conflicting results regarding the correlation between obesity and constipation [\u003cspan additionalcitationids=\"CR10 CR11\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. While body mass index (BMI) remains the predominant measure for obesity assessment, it lacks precision in determining adipose tissue distribution. Cutting-edge radiological techniques, notably CT/MRI (computed tomography/magnetic resonance imaging, respectively), enable a highly accurate assessment of internal fat distribution. However, these methods are impractical for routine use due to their time-intensive protocols and substantial financial burden [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThomas and colleagues proposed the BRI in 2013 as an innovative approach to evaluate body composition and visceral adiposity [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. This easily accessible, economical, and non-invasive technique yields a more accurate evaluation of overall and intra-abdominal adiposity compared with BMI, potentially improving its prognostic capabilities. The BRI has shown promise as an effective instrument for community-wide health assessment and early identification of metabolic risks. Studies have shown that BRI is significantly correlated with numerous health issues, including cardiovascular disease [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], metabolic syndrome [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], and diabetes [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Nevertheless, as a convenient new measurement index capable of assessing intra-abdominal fat and reflecting the degree of central obesity, the relationship between BRI and persistent gastrointestinal disorders, specifically chronic diarrhea and chronic constipation, remains understudied. To bridge this lack of know-how, the research strived to examine the possible relationship of BRI with these chronic bowel conditions. This research seeks to provide new perspectives and contribute to the development of approaches for preventing and managing these chronic gastrointestinal disorders.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy population\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe investigation analyzed information acquired through NHANES\u0026mdash;National Health and Nutrition Examination Survey, an all-inclusive human healthiness evaluation initiative. This extensive program is conducted and managed by the CDC\u0026mdash;Centers for Disease Control and Prevention. The NHANES\u0026rsquo; program implements biennial health evaluations on a national scale, assessing the physiological status and dietary profiles of Americans across all age groups. It is worth noting that data pertaining to bowel habits have been incorporated into only three of these survey cycles: 2005\u0026ndash;2006, 2007\u0026ndash;2008, and 2009\u0026ndash;2010. Across these cycles, 17,132 participants aged 20 years and older were enrolled. During this period, a total of 17,132 individuals, all of whom were 20 years of age or older, were recruited as participants. However, the study excluded participants who provided incomplete responses to the bowel health questionnaire (n=1920), incomplete BRI data (n=379), or incomplete data for any covariate (n=3005) Consequently, the final analyzed cohort consisted of 11,235 subjects (Figure 1). The ethical framework and research methodology of the NHANES initiative underwent rigorous scrutiny and received formal approval from the Ethics Review Committee of the National Center for Health Statistics. All subjects consented to take part in the study. The complete dataset is publicly accessible and may be retrieved from https://www.cdc.gov/nchs/nhanes/index.htm.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBowel health questionnaire\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe gastrointestinal health component of \u0026lsquo;NHANES from 2005 to 2010\u0026rsquo; served as a means to scrutinize bowel habits among participants who willingly shared details about their bowel movements. The researcher used the BSFS card, which features color illustrations of seven distinct stool types, for evaluation purposes. Participants who recognized their typical bowel movements as corresponding to BSFS type 1 (defined as distinct, firm pellets akin to nuts) or BSFS type 2 (described as a cohesive mass with a lumpy surface) were classified as experiencing persistent constipation. Individuals whose typical stool type fell into the categories of BSFS type 6 (described as fluffy, irregular-edged pieces with a mushy consistency) or BSFS type 7 (consisting of water-like samples with no solid feces) were considered to have chronic diarrhea. The remaining participants were deemed to have normal bowel function.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAnthropometric measures\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe measurement of WC was conducted using a measuring tape, with readings taken in centimeters at the uppermost edge of the iliac crest. The calculation of BMI and BRI utilized established formulas from the previous literature: the study calculated BMI by dividing the participant\u0026rsquo;s weight (kg) by the square of their height (m), while we derived BRI using a specific equation 364.2\u0026ndash;365.5 \u0026times; (1－[WC(m)/2\u0026pi;]2/[0.5 \u0026times; height (m)]2)\u0026frac12; [14].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCovariates\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this investigation, numerous potential confounding factors affecting BRI and the likelihood of persistent diarrhea and constipation were taken into account. These variables encompassed several categories. (1) Demographic factors: the study accounted for age, male/female, race/ethnicity, single/married status, and education level. (2) Lifestyle factors: The analysis incorporated smoking patterns and alcohol consumption behaviors. (3) Economic status: Socioeconomic status was assessed using the PIR\u0026ndash;family poverty-to-income ratio. (4) Health comorbidities: the models included hypertension, cardiovascular disease, and diabetes mellitus (DM). (5) Dietary aspects: the study considered total daily caloric intake and scores on the healthy eating index (HEI).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analysis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn accordance with NHANES protocols, this investigation utilized recommended sample weights to improve data accuracy and mitigate the effects of intricate multistage sampling designs on NHANES research. In the statistical analysis, the study presented the results for categorical variables as weighted percentages, reflecting the complex survey design of NHANES. For continuous variables, the study reported weighted means along with their corresponding standard errors to account for sampling variability. To investigate the potential links between BRI and chronic gastrointestinal symptoms, the study employed weighted multivariate logistic regression analyses. These analyses accounted for various confounding factors, with adjustments made for both continuous and quantile outcomes. The analysis employed three distinct models. The initial model (Model 1) was uncontrolled for any variables. The second model (Model 2) incorporated adjustments for key demographic variables. Specifically, this model accounted for race/ethnicity, age, gender, level of education, and single/married status. The most comprehensive model (Model 3) expanded upon Model 2 by additionally controlling for BMI, socioeconomic status (as measured by PIR), lifestyle habits (such as smoking habits, alcohol use patterns), comorbidities (such as DM, high blood pressure, and cardiovascular disease), and dietary factors (specifically total caloric intake and HEI). Additionally, the study utilized weighted RCS curves within Model 3 to further examine potential nonlinear relationships between BRI and chronic bowel symptoms. The research also conducted stratified analyses based on a range of demographic factors and variables related to health, including age categories, male/female, educational level, single/married status, smoking habits, and the presence of common chronic diseases. To assess and contrast the predictive capabilities of WC, BMI, and BRI for long-term diarrhea and constipation, the study analyzed ROC curves and calculated the AUC area. To determine the most effective threshold \u0026lsquo;values for WC, BRI, and BMI\u0026rsquo; in predicting chronic diarrhea and constipation, the study utilized the Youden index. The entirety of the statistical computations was performed using R software, (v. 4.2.2; http://www.Rproject.org), with a threshold for statistical significance established at \u003cem\u003eP\u003c/em\u003e \u0026lt;0.05.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe study sample characteristics, grouped by BRI tertiles, are summarized in Table 1. The analysis included a total of 11,235 subjects. The average age of participants was 46.91\u0026plusmn;0.37 years. The gender distribution of the cohort was nearly balanced, with males comprising 48.25% of the sample. The mean BRI was 5.20\u0026plusmn;0.05, with BRI ranges defined as \u0026lt;4.26 for the first tertile, 4.26\u0026ndash;6.02 for the second tertile, and \u0026gt;6.02 for the third tertile. The study found that diarrhea affected 6.75% of the overall population, with its prevalence varying across BRI tertiles: (1) lowest BRI tertile: 4.80% prevalence; (2) middle BRI tertile: 6.00% prevalence; and (3) highest BRI tertile: 10.21% prevalence. Constipation was observed in 7.07% of the total sample, showing a different distribution across BRI tertiles: 8.08% in the first tertile, 7.15% in the second tertile, and 5.63% in the third tertile. the statistical analysis uncovered significant differences (a \u003cem\u003eP\u003c/em\u003e value \u0026lt;0.05) across BRI tertiles for several factors: demographic characteristics (age, ethnicity, male/female, educational attainment, and single/married status), socioeconomic indicators (PIR), lifestyle habits (smoking habits and alcohol consumption), physical and mental well-being (high blood pressure, diabetes, heart disease), anthropometric measures (BMI, WC), and dietary factors (total caloric intake and HEI).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCorrelation of BRI with chronic diarrhea and chronic constipation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this study, logistic modeling examining the relationship between chronic intestinal disorders and BRI yielded the following key findings, as presented in Table 2: (A) BRI in its continuous form: (1) Chronic diarrhea: a strong positive link was identified (odds ratio, OR, and 95% confidence interval, CI: 1.15 and 1.11\u0026ndash;1.20, respectively; \u003cem\u003eP\u003c/em\u003e value of \u0026lt;0.001). The positive relationship continued to be robust following extensive adjustment (OR=1.24, 95% CI=1.08\u0026ndash;1.43, \u003cem\u003eP\u003c/em\u003e=0.004). (2) Chronic constipation: initially showed a negative trend in crude (OR and 95% CI: 0.94 and 0.89\u0026ndash;0.99, respectively; \u003cem\u003eP\u003c/em\u003e value equal to 0.020) and partially adjusted models (OR and 95% CI: 0.92 and 0.87\u0026ndash;0.97, respectively; \u003cem\u003eP\u003c/em\u003e value equal to 0.002). However, this association lost statistical significance in the fully adjusted model (OR and 95% CI: 1.13 and 0.99\u0026ndash;1.29, respectively; \u003cem\u003eP\u003c/em\u003e value equal to 0.060). (B) BRI as a categorical variable (tertiles): (1) Chronic diarrhea: participants in the highest BRI tertile showed significantly increased risk compared to the lowest tertile after full adjustment (T3 vs T1: OR and 95% CI: 1.65, and 1.09\u0026ndash;2.50, respectively: \u003cem\u003eP\u003c/em\u003e value equal to 0.020). (2) Chronic constipation: no statistically significant relationship was observed between BRI tertiles and constipation risk (highest vs. lowest tertile: OR and 95% CI: 0.84 and 0.53\u0026ndash;1.34, respectively; \u003cem\u003eP\u003c/em\u003e=0.458).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNonlinear correlation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo explore possible nonlinear associations between BRI and the prevalence of chronic gastrointestinal disorders, the study conducted a weighted multivariable\u0026ndash;adjusted RCS analysis. The results of this analysis are presented graphically in Figure 2. The analysis uncovered a complex, nonlinear positive relationship between BRI and both intestinal conditions: diarrhea (\u003cem\u003eP\u0026nbsp;\u003c/em\u003evalue for nonlinear association equal to 0.005) and constipation (\u003cem\u003eP\u0026nbsp;\u003c/em\u003evalue for nonlinear association equal to 0.037). Chronic diarrhea risk increased significantly at BRI values above 3.4. In contrast, the risk of constipation gradually increased with initial increases in BRI. However, when BRI reached 5.10, the risk of constipation plateaued, and it did not rise again until BRI exceeded 5.78.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSubgroup analyses\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the present study, subgroup analyses showed significant variations in the correlation between BRI and bowel habits across different subgroups (Figure 3). the analysis revealed significant interactive effects between specific DM subgroups and BRI with respect to diarrhea, as well as between age subgroups and BRI with respect to constipation (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.05). Specifically, BRI exhibited a strong and statistically significant positive correlation with diarrhea in the diabetes subgroup. Furthermore, among individuals under 60 years of age, the likelihood of constipation increased substantially by 20% (OR: 1.20, CI: 1.00\u0026ndash;1.44) with each incremental unit of the body shape indicator. Conversely, among participants 60 years of age and above, the study did not detect this positive association.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparing WC, BMl, and BRI as predictors of chronic bowel issues\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eROC analysis results (Table 3, Figure 4) showed BRI had a higher predictive power (AUC: 0.601) for diarrhea than BMI (0.569) or WC (0.572). Delong\u0026apos;s test confirmed BRI\u0026apos;s significantly higher predictive ability for diarrhea compared with both BMI and WC (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.001 for both comparisons). Conversely, in predicting constipation, BRI showed a lower AUC value (0.537) than both BMI (0.551) and WC (0.570). Delong\u0026apos;s test revealed significant differences in predictive power: BRI outperformed \u0026lsquo;BMI (\u003cem\u003eP\u003c/em\u003e=0.002) and WC (\u003cem\u003eP\u003c/em\u003e\u0026lt;0.001). These results indicate that BRI was less effective than BMI and WC in predicting constipation.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis investigation broke new ground by exploring the relationship between BRI and the occurrence of intestinal disorders, specifically diarrhea and constipation using a cross-sectional analytical approach. Employing weighted multivariate logistic regression techniques, the research demonstrated that BRI maintained its status as an independent predictor of diarrhea, despite controlling for various potential confounders. In contrast, the study found no statistically significant relationship between BRI and chronic constipation. RCS showed nonlinear relationships between BRI levels and the likelihood of experiencing diarrhea and constipation. Subgroup analyses revealed significant interactions between various diabetic statuses, age groups, and BRI levels, influencing the likelihood of both diarrhea and constipation. In a comparative analysis with other anthropometric indices like BMI and WC, BRI demonstrated a strong predictive capability for diarrhea, but not for constipation. These results underscore BRI's particular efficacy as a predictor of diarrhea occurrence, suggesting that addressing obesity may aid in its prevention.\u003c/p\u003e \u003cp\u003eHistorically, the BMI has been criticized for its inability to accurately reflect the correlation between obesity and bowel habits, frequently leading to inconsistent research outcomes [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan additionalcitationids=\"CR23\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. BRI represents an innovative obesity metric derived using height and WC measurements to assess body composition and fat distribution more comprehensively than conventional metrics like BMI [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. A comprehensive meta-analysis has demonstrated BRI's superior predictive capacity for metabolic syndrome when compared to other indices like \u0026lsquo;waist-to-hip ratio, BMI, body adiposity index, and body shape index [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Moreover, research has linked BRI to a range of health conditions, including overactive bladder [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], cholelithiasis [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], cardiovascular diseases [\u003cspan additionalcitationids=\"CR16\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], and DM [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. However, prior to this investigation, the relationship between BRI and intestinal function had not been explored in the scientific literature. This study analyzed this correlation for the first time using a large dataset from NHANES. the study identified a significant positive correlation between BRI and diarrhea, enabling effective prediction of diarrhea risk.\u003c/p\u003e \u003cp\u003eIn the nonlinear correlation analysis between BRI and bowel habits, we observed that the probability of experiencing chronic diarrhea began to increase only when BRI values surpassed 3.40. Additionally, the analysis revealed that the likelihood of chronic constipation demonstrated a progressive increase once BRI values surpassed 5.78. Notably, both values were below the highest tertile of the BRI. This suggested that an elevated BRI may be closely associated with persistent gastrointestinal disturbances, specifically chronic diarrhea and constipation, among those with substantial adiposity. Hence, in severely obese individuals, significant emphasis should be placed on regulating BRI levels to improve bowel habits.\u003c/p\u003e \u003cp\u003ePersistent alterations in bowel habits, particularly long-term diarrhea and constipation, rank among the most prevalent digestive issues linked to excess body weight. These conditions significantly diminish the well-being and overall health status of those affected [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan additionalcitationids=\"CR29 CR30 CR31\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. However, despite their prominence in the medical literature, few studies have explored diarrhea and constipation as aspects of obesity, resulting in a lack of sufficient clinical attention. Numerous studies have investigated the mechanisms linking obesity to bowel habits. However, the specific mechanisms by which obesity leads to diarrhea and constipation remain unclear. Regarding diarrhea, researches have revealed that the expedited movement of contents through the small intestine and distal colon, coupled with an excess of body weight, are potential contributors to the underlying mechanisms of idiopathic bile acid malabsorption [\u003cspan additionalcitationids=\"CR34 CR35\" citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. Delgado-Aros showed that obesity, causing dysfunction such as accelerated colonic transport, may lead to diarrhea [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Studies focusing on constipation have uncovered that individuals with obesity tend to display reduced concentrations of growth hormone\u0026ndash;releasing peptides while simultaneously showing increased levels of leptin. These hormonal imbalances may restrict gastric emptying and slow gastric motility, potentially triggering constipation [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. Furthermore, obesity may increase the amount of fat entering the intestines, which interferes with hormone release and causes the relaxation of smooth muscles in the colon, thereby obstructing the propulsion of intestinal contents and contributing to constipation [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eStudy strengths and limitations\u003c/h2\u003e \u003cp\u003eThis study had several strengths. First, it represents the inaugural investigation utilizing an extensive cross-sectional approach with NHANES data to reveal a nonlinear positive relationship between BRI and diarrhea. Second, the methodology was rigorous, incorporating sampling weights, adjusting for numerous potential confounders, and employing sophisticated statistical techniques such as multivariate logistic regression, RCS analysis, and stratified subgroup analysis. These methodological choices significantly bolster the precision and robustness of the results. Finally, the study compared the diagnostic efficacy of BRI with BMI and WC in diagnosing diarrhea, revealing that BRI demonstrates a superior diagnostic performance. Limitations of this study: (1)The cross-sectional approach of this research does not allow for determining causality between BRI and chronic bowel symptoms such as diarrhea and constipation. (2) The findings may not apply to populations outside the U.S. due to the study's limited geographic scope. (3) Information about bowel disorders was collected through self-reported questionnaires, a method potentially subject to recall bias. Participants' recollections of their gastrointestinal symptoms might not always accurately reflect their true health status. Finally, the investigators could not ascertain any additional confounding variables that may have been overlooked in this investigation.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe analysis revealed a complex, nonlinear positive relationship between BRI values and the likelihood of experiencing long-term diarrhea and constipation. The relationship was especially evident in subjects with severe adiposity. Regulating BRI levels could help improve bowel habits, particularly in cases of severe obesity. Furthermore, BRI demonstrates superior predictive value for chronic diarrhea when compared with traditional \u0026lsquo;anthropometric indicators like BMI and WC.\u0026rsquo; These results highlight the possible advantages of sustaining reasonable BRI values in fostering optimal intestinal function and reducing the risk of long-term gastrointestinal issues.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eAUC, Area under the curve; BMI, Body mass index; BRI, Body roundness index; BSFS, Bristol Stool Form Scale; CI, Confidence interval; CT, Computed tomography; CVD, Cardiovascular disease; DM, Diabetes mellitus; MRI, Magnetic resonance imaging; NHANES, National Health and Nutrition Examination Survey; OR, Odds ratio; PIR, Poverty income ratio; RCS, Restricted cubic spline; ROC, Receiver operating characteristic; WC, Waist circumference.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study acknowledge the NHANES program for\u0026rsquo; providing the comprehensive database and resources that made this research possible. the study also thank all the contributors for sharing their datasets and all the individuals who volunteered their time and information as subjects in this study, without whom this investigation would not have been feasible.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe research project was conceptualized and structured by Yinda Wang and Fei Chen. These two researchers were also responsible for data collection and analysis. Together, they produced the first version of the manuscript. Binzhong Zhang and Zhengwei Song revised the manuscript. Yinda Wang provided the final review for the entire text. Each researcher involved provided substantial input to the paper. The final version of this document was reviewed and approved by each of the contributing authors prior to submission.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding was received for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets analyzed in this research are publicly available. Interested parties can obtain these datasets through \u0026lsquo;the National Center for Health Statistics\u0026apos; official website at https://www.cdc.gov/nchs/nhanes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe present study employed anonymized data obtained from \u0026lsquo;the publicly accessible NHANES database. The study received ethical approval from \u0026lsquo;the National Center for Health Statistics\u0026apos; Ethics Review Committee\u0026rsquo; and followed relevant guidelines, including those set forth in \u0026lsquo;the Declaration of Helsinki. Importantly, all NHANES participants gave documented consent before their involvement. This consent process occurred prior to any data collection, ensuring that subjects were fully aware of and agreed to their participation in the survey.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe \u0026quot;Consent for publication\u0026quot; section is not needed for this type of study using anonymized \u0026lsquo;public data\u0026rsquo;.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe research team declares no conflicts of interest relevant to this study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eZhao YF, Guo XJ, Zhang ZS, Ma XQ, Wang R, Yan XY, et al: Epidemiology of functional diarrhea and comparison with diarrhea-predominant irritable bowel syndrome: a population-based survey in China. PLoS One 2012, 7:e43749.\u003c/li\u003e\n\u003cli\u003eChoung RS, Locke GR, 3rd, Schleck CD, Zinsmeister AR, Talley NJ: Cumulative incidence of chronic constipation: a population-based study 1988-2003. Aliment Pharmacol Ther 2007, 26:1521-1528.\u003c/li\u003e\n\u003cli\u003eBlack CJ, Ford AC: Chronic idiopathic constipation in adults: epidemiology, pathophysiology, diagnosis and clinical management. Med J Aust 2018, 209:86-91.\u003c/li\u003e\n\u003cli\u003eCamilleri M, Malhi H, Acosta A: Gastrointestinal Complications of Obesity. Gastroenterology 2017, 152:1656-1670.\u003c/li\u003e\n\u003cli\u003eShin A, Xu H, Imperiale TF: Associations of chronic diarrhoea with non-alcoholic fatty liver disease and obesity-related disorders among US adults. BMJ Open Gastroenterol 2019, 6:e000322.\u003c/li\u003e\n\u003cli\u003eEusebi LH, Ratnakumaran R, Yuan Y, Solaymani-Dodaran M, Bazzoli F, Ford AC: Global prevalence of, and risk factors for, gastro-oesophageal reflux symptoms: a meta-analysis. Gut 2018, 67:430-440.\u003c/li\u003e\n\u003cli\u003eLinghu E: Obesity and chronic diarrhea: a new syndrome? Chin Med J (Engl) 2022, 135:1806-1807.\u003c/li\u003e\n\u003cli\u003eHan K, Wang X, Wang Y, Niu X, Xiang J, Ru N, et al: Prevalence of chronic diarrhea and its association with obesity in a Chinese community-based population. Chin Med J (Engl) 2024.\u003c/li\u003e\n\u003cli\u003eWang GN, Zhang K, Xiong YY, Liu S: The relationship between functional constipation and overweight/obesity in children: a systematic review and meta-analysis. Pediatr Res 2023, 94:1878-1886.\u003c/li\u003e\n\u003cli\u003eXiang N, Xu L, Qian H, Zhang D: Multiple obesity indices suggest a close relationship between obesity and constipation: evidence from NHANES. BMC Public Health 2024, 24:1273.\u003c/li\u003e\n\u003cli\u003eKoppen IJ, Velasco-Ben\u0026iacute;tez CA, Benninga MA, Di Lorenzo C, Saps M: Is There an Association between Functional Constipation and Excessive Bodyweight in Children? J Pediatr 2016, 171:178-182.e171.\u003c/li\u003e\n\u003cli\u003eSilveira EA, Santos A, Ribeiro JN, Noll M, Dos Santos Rodrigues AP, de Oliveira C: Prevalence of constipation in adults with obesity class II and III and associated factors. BMC Gastroenterol 2021, 21:217.\u003c/li\u003e\n\u003cli\u003eFang H, Berg E, Cheng X, Shen W: How to best assess abdominal obesity. Curr Opin Clin Nutr Metab Care 2018, 21:360-365.\u003c/li\u003e\n\u003cli\u003eThomas DM, Bredlau C, Bosy-Westphal A, Mueller M, Shen W, Gallagher D, et al: Relationships between body roundness with body fat and visceral adipose tissue emerging from a new geometrical model. Obesity (Silver Spring) 2013, 21:2264-2271.\u003c/li\u003e\n\u003cli\u003eLi Y, He Y, Yang L, Liu Q, Li C, Wang Y, et al: Body Roundness Index and Waist-Hip Ratio Result in Better Cardiovascular Disease Risk Stratification: Results From a Large Chinese Cross-Sectional Study. Front Nutr 2022, 9:801582.\u003c/li\u003e\n\u003cli\u003eWu M, Yu X, Xu L, Wu S, Tian Y: Associations of longitudinal trajectories in body roundness index with mortality and cardiovascular outcomes: a cohort study. Am J Clin Nutr 2022, 115:671-678.\u003c/li\u003e\n\u003cli\u003eWang J, Wu M, Wu S, Tian Y: Relationship between body roundness index and the risk of heart failure in Chinese adults: the Kailuan cohort study. ESC Heart Fail 2022, 9:1328-1337.\u003c/li\u003e\n\u003cli\u003eRico-Mart\u0026iacute;n S, Calder\u0026oacute;n-Garc\u0026iacute;a JF, S\u0026aacute;nchez-Rey P, Franco-Antonio C, Mart\u0026iacute;nez Alvarez M, S\u0026aacute;nchez Mu\u0026ntilde;oz-Torrero JF: Effectiveness of body roundness index in predicting metabolic syndrome: A systematic review and meta-analysis. Obes Rev 2020, 21:e13023.\u003c/li\u003e\n\u003cli\u003eLi Z, Fan C, Huang J, Chen Z, Yu X, Qian J: Non-linear relationship between the body roundness index and metabolic syndrome: data from National Health and Nutrition Examination Survey (NHANES) 1999-2018. Br J Nutr 2024, 131:1852-1859.\u003c/li\u003e\n\u003cli\u003eLiu B, Liu B, Wu G, Yin F: Relationship between body-roundness index and metabolic syndrome in type 2 diabetes. Diabetes Metab Syndr Obes 2019, 12:931-935.\u003c/li\u003e\n\u003cli\u003eZhao Q, Zhang K, Li Y, Zhen Q, Shi J, Yu Y, et al: Capacity of a body shape index and body roundness index to identify diabetes mellitus in Han Chinese people in Northeast China: a cross-sectional study. Diabet Med 2018, 35:1580-1587.\u003c/li\u003e\n\u003cli\u003eYang X, Sun Z: Association between weight-adjusted-waist index and bowel habits. Sci Rep 2024, 14:17658.\u003c/li\u003e\n\u003cli\u003eTalley NJ, Howell S, Poulton R: Obesity and chronic gastrointestinal tract symptoms in young adults: a birth cohort study. Am J Gastroenterol 2004, 99:1807-1814.\u003c/li\u003e\n\u003cli\u003eHu J, Zou H, Qiao X, Wang Y, Lv M, Zhang K, et al: The relationship between oxidative balance scores and chronic diarrhea and constipation: a population-based study. BMC Public Health 2024, 24:1366.\u003c/li\u003e\n\u003cli\u003eWitarto BS, Witarto AP, Visuddho V, Wungu CDK, Maimunah U, Rejeki PS, et al: Gender-specific accuracy of lipid accumulation product index for the screening of metabolic syndrome in general adults: a meta-analysis and comparative analysis with other adiposity indicators. Lipids Health Dis 2024, 23:198.\u003c/li\u003e\n\u003cli\u003eZhang Y, Song J, Li B, Wu Y, Jia S, Shu H, et al: Association between body roundness index and overactive bladder: results from the NHANES 2005-2018. Lipids Health Dis 2024, 23:184.\u003c/li\u003e\n\u003cli\u003eWei C, Zhang G: Association between body roundness index (BRI) and gallstones: results of the 2017-2020 national health and nutrition examination survey (NHANES). BMC Gastroenterol 2024, 24:192.\u003c/li\u003e\n\u003cli\u003eLevy RL, Linde JA, Feld KA, Crowell MD, Jeffery RW: The association of gastrointestinal symptoms with weight, diet, and exercise in weight-loss program participants. Clin Gastroenterol Hepatol 2005, 3:992-996.\u003c/li\u003e\n\u003cli\u003eAro P, Ronkainen J, Talley NJ, Storskrubb T, Bolling-Sternevald E, Agr\u0026eacute;us L: Body mass index and chronic unexplained gastrointestinal symptoms: an adult endoscopic population based study. Gut 2005, 54:1377-1383.\u003c/li\u003e\n\u003cli\u003eTalley NJ, Quan C, Jones MP, Horowitz M: Association of upper and lower gastrointestinal tract symptoms with body mass index in an Australian cohort. Neurogastroenterol Motil 2004, 16:413-419.\u003c/li\u003e\n\u003cli\u003eMisra S, Liaw A: Controversies on the relationship between increased body mass index and treatment-resistant chronic constipation in children. JPEN J Parenter Enteral Nutr 2022, 46:1031-1035.\u003c/li\u003e\n\u003cli\u003eWan Y, Zhang D, Xing T, Liu Q, Chi Y, Zhang H, et al: The impact of visceral obesity on chronic constipation, inflammation, immune function and cognitive function in patients with inflammatory bowel disease. Aging (Albany NY) 2021, 13:6702-6711.\u003c/li\u003e\n\u003cli\u003eSadik R, Abrahamsson H, Ung KA, Stotzer PO: Accelerated regional bowel transit and overweight shown in idiopathic bile acid malabsorption. Am J Gastroenterol 2004, 99:711-718.\u003c/li\u003e\n\u003cli\u003ePattni SS, Brydon WG, Dew T, Johnston IM, Nolan JD, Srinivas M, et al: Fibroblast growth factor 19 in patients with bile acid diarrhoea: a prospective comparison of FGF19 serum assay and SeHCAT retention. Aliment Pharmacol Ther 2013, 38:967-976.\u003c/li\u003e\n\u003cli\u003eCamilleri M, BouSaba J: New Developments in Bile Acid Diarrhea. Gastroenterol Hepatol (N Y) 2023, 19:520-537.\u003c/li\u003e\n\u003cli\u003eYang D, Lyu C, He K, Pang K, Guo Z, Wu D: Bile Acid Diarrhea: From Molecular Mechanisms to Clinical Diagnosis and Treatment in the Era of Precision Medicine. Int J Mol Sci 2024, 25.\u003c/li\u003e\n\u003cli\u003eDelgado-Aros S, Camilleri M, Garcia MA, Burton D, Busciglio I: High body mass alters colonic sensory-motor function and transit in humans. Am J Physiol Gastrointest Liver Physiol 2008, 295:G382-388.\u003c/li\u003e\n\u003cli\u003eCamilleri M, Papathanasopoulos A, Odunsi ST: Actions and therapeutic pathways of ghrelin for gastrointestinal disorders. Nat Rev Gastroenterol Hepatol 2009, 6:343-352.\u003c/li\u003e\n\u003cli\u003eWu T, Rayner CK, Young RL, Horowitz M: Gut motility and enteroendocrine secretion. Curr Opin Pharmacol 2013, 13:928-934.\u003c/li\u003e\n\u003cli\u003eHalim MA, Degerblad M, Sundbom M, Karlbom U, Holst JJ, Webb DL, et al: Glucagon-Like Peptide-1 Inhibits Prandial Gastrointestinal Motility Through Myenteric Neuronal Mechanisms in Humans. J Clin Endocrinol Metab 2018, 103:575-585.\u003c/li\u003e\n\u003cli\u003eWang L, Gourcerol G, Yuan PQ, Wu SV, Million M, Larauche M, et al: Peripheral peptide YY inhibits propulsive colonic motor function through Y2 receptor in conscious mice. Am J Physiol Gastrointest Liver Physiol 2010, 298:G45-56.\u003c/li\u003e\n\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":"lipids-in-health-and-disease","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"lhad","sideBox":"Learn more about [Lipids in Health and Disease](http://lipidworld.biomedcentral.com/)","snPcode":"12944","submissionUrl":"https://submission.nature.com/new-submission/12944/3","title":"Lipids in Health and Disease","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Body roundness index, chronic constipation, chronic diarrhea, National Health and Nutrition Examination Survey, obesity","lastPublishedDoi":"10.21203/rs.3.rs-5277629/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5277629/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eAim\u003c/h2\u003e \u003cp\u003eThe study aimed to explore potential links between long-term digestive issues (specifically diarrhea and constipation) and BRI in a representative U.S. population sample.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis study adopted a design that is cross sectional, drawing on data from the NHANES, gathered from 2005 to 2010. This comprehensive dataset included health information from a total of 11,235 individuals, providing a robust sample for the analysis. Persistent bowel movement patterns were categorized based on the BSFS\u0026mdash;Bristol Stool Form Scale, a widely recognized diagnostic tool. Within this framework, stool types 1 and 2 were designated as indicators of long-term constipation, while types 6 and 7 were identified as markers of persistent diarrhea. To assess the relationship between digestive health and the BRI, this study employed weighted logistic regression analysis. To capture and visualize the nuanced interplay between BRI and gastrointestinal patterns, we utilized advanced nonlinear regression methods, specifically restricted cubic spline (RCS) analyses. Additionally, the research compared the efficacy of various physical measurements\u0026mdash;including BRI, WC, BMI (body roundness index, waist circumference, and body mass index, respectively)\u0026mdash;to determine their respective predictive power for chronic diarrhea and constipation through comparative analysis of receiver operating characteristic (ROC) curves.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eAfter comprehensive adjustment in the final statistical model (Model 3), the BRI demonstrated a statistically significant association with diarrhea (odds ratio, OR, of 1.24; 95% confidence interval, CI, ranging from 1.08 to 1.43, with \u003cem\u003eP\u003c/em\u003e value of 0.004) However, the association between BRI and persistent constipation was statistically insignificant (OR of 1.13, 95% CI ranging from 0.99 to 1.29, \u003cem\u003eP\u003c/em\u003e value of 0.060). Nonlinear regression analysis using RCS analysis further uncovered statistically significant nonlinear positive correlations between BRI and both chronic gastrointestinal conditions. The non-linearity was particularly pronounced for diarrhea (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.005) and also notable for constipation (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.037). Further stratified analyses provided additional insights into specific population subsets. The relationship between BRI and persistent diarrhea was particularly evident among individuals with diabetes. In contrast, the correlation between BRI and constipation was stronger in individuals under 60 years of age. ROC analysis indicated that BRI outperformed conventional anthropometric measures (AUC, area under the curve: 0.601). Specifically, BMI, the body mass index, resulted in an AUC of 0.569, while WC produced an AUC of 0.572. However, the AUC value of BRI (0.537) was less effective than BMI (0.551) and WC (0.570) in diagnosing constipation.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eBRI is closely associated with changes in the individual\u0026rsquo;s bowel habits, particularly in predicting chronic diarrhea. This study highlighted the potential importance of maintaining moderate BRI levels to improve bowel health and prevent disorders like diarrhea.\u003c/p\u003e","manuscriptTitle":"Correlation of the body roundness index (BRI) with chronic diarrhea and chronic constipation: Findings based on the National Health and Nutrition Examination Survey (NHANES) 2005–2010 data","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-10-29 03:47:35","doi":"10.21203/rs.3.rs-5277629/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-12-07T07:47:06+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-12-06T22:05:40+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-12-03T15:01:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"178753667917997657794208551854285919284","date":"2024-12-02T12:40:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"200107064434563604293190139158459983519","date":"2024-11-30T18:52:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"279374749437171339447367387220989127630","date":"2024-11-17T07:50:51+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-11T22:23:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"52913553473626067170375523356199558927","date":"2024-11-06T21:56:37+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"246509676432130842987008412305696860196","date":"2024-11-03T01:11:39+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-10-18T06:24:34+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-10-17T09:48:29+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-10-17T05:05:03+00:00","index":"","fulltext":""},{"type":"submitted","content":"Lipids in Health and Disease","date":"2024-10-16T17:05:42+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"lipids-in-health-and-disease","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"lhad","sideBox":"Learn more about [Lipids in Health and Disease](http://lipidworld.biomedcentral.com/)","snPcode":"12944","submissionUrl":"https://submission.nature.com/new-submission/12944/3","title":"Lipids in Health and Disease","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"5ad10be9-55f4-46d1-a957-35e59ab2cebc","owner":[],"postedDate":"October 29th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-02-03T15:58:40+00:00","versionOfRecord":{"articleIdentity":"rs-5277629","link":"https://doi.org/10.1186/s12944-025-02451-7","journal":{"identity":"lipids-in-health-and-disease","isVorOnly":false,"title":"Lipids in Health and Disease"},"publishedOn":"2025-01-31 15:56:53","publishedOnDateReadable":"January 31st, 2025"},"versionCreatedAt":"2024-10-29 03:47:35","video":"","vorDoi":"10.1186/s12944-025-02451-7","vorDoiUrl":"https://doi.org/10.1186/s12944-025-02451-7","workflowStages":[]},"version":"v1","identity":"rs-5277629","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5277629","identity":"rs-5277629","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}