Racial/ethnic differences in the associations between obesity measures and severity of sleep-disordered breathing: the Multi-Ethnic Study of Atherosclerosis

Objectives The objective of this study was to evaluate associations between obesity measures and sleep-disordered breathing severity among White, Black, Hispanic, and Chinese Americans. Methods The method used in this study was a community-based cross-sectional study of 2053 racially/ethnically diverse adults in the Multi-Ethnic Study of Atherosclerosis. Anthropometry and polysomnography were used to measure obesity and apnea–hypopnea index (AHI). Linear regression models were fitted to investigate associations of body mass index (BMI) and waist circumference with AHI (log transformed) with adjustment for sociodemographics, lifestyle factors, and comorbidities. Results The mean participant age was 68.4 (range: 54–93) years; 53.6% of participants were women. The median AHI was 9.1 events/h. There were significant associations of BMI and waist circumference with AHI in the overall cohort and within each racial/ethnic group. A significant interaction was observed between race/ethnicity and BMI (P_interaction = 0.017). Models predicted that for each unit increase in BMI (kg/m²), the mean AHI increased by 19.7% for Chinese, 11.6% for Whites and Blacks, and 10.5% for Hispanics. Similarly, incremental changes in waist circumference were associated with larger increases in AHI among Chinese than among other groups. Conclusions Associations of BMI and waist circumference with AHI were stronger among Chinese than among other racial/ethnic groups. These findings highlight a potential emergence of elevated sleep-disordered breathing prevalence occurring in association with increasing obesity in Asian populations.