Association Between Obstructive Sleep Apnea and Regional Fat: A Cross-Sectional Analysis of National Health and Nutrition Examination Survey 2015–2018

<b><i>Purpose:</i></b> The relationship between regional fat and obstructive sleep apnea (OSA) remains poorly understood. This study seeks to explore the link between regional fat and OSA, utilizing data from the National Health and Nutrition Examination Survey (NHANES). <b><i>Methods:</i></b> This cross-sectional analysis used NHANES 2015-2018 data. OSA symptoms were assessed through sleep questionnaires. Regional fat mass (FM) was measured using dual-energy X-ray absorptiometry, including trunk, arm, leg, android, gynoid, and abdominal FM. The fat mass index (FMI) was calculated by dividing FM by the square of height. Logistic regression evaluated the association between regional FMI and OSA, with univariate and stratified analyses to identify potential effect modifiers. <b><i>Results:</i></b> A total of 3,099 participants were included, with 1,595 classified into the OSA group. Significant associations were found between OSA and several regional FMIs, including trunk, arm, leg, android, gynoid, and abdomen. These associations were consistent in males, and in females, leg and gynoid FMI were not linked to OSA. Stratified analyses by race revealed significant associations between OSA and regional FMI indices (trunk, arm, leg, android, gynoid, and abdominal FMI) in non-Hispanic Whites and between OSA and trunk, android, and abdominal FMI in other Hispanics. No associations were observed in the Mexican American or non-Hispanic Black groups. Stratification by body mass index (BMI) indicated distinct profiles: obese individuals (BMI ≥30) showed associations limited to trunk, arm, android, and abdominal FMIs, while nonobese participants (BMI <30) displayed broader associations encompassing all regional FMIs. Both univariate and stratified analyses highlighted abdominal FMI as the strongest predictor of OSA. <b><i>Conclusion:</i></b> Higher regional FMI, particularly abdominal fat, is associated with an increased risk of OSA, with stronger associations observed in male, White, and nonobese populations.