0848 Total sleep time, wake after sleep onset, and inflammation predict obesity in young adult African Americans

Abstract

Abstract Introduction Sleep is vital to maintaining psychological and physiological health. Poor sleep is associated with adverse health outcomes, including obesity. Studies have shown that African Americans disproportionately suffer from poor sleep and the adverse health outcome associated with obesity. We aimed to determine if sleep quality and peripheral inflammation are significant predictors of obesity in a young adult African American sample. Methods Participants were healthy adults with a body mass index of less than 40 between 18- 35 who self-identified as Black or African American and completed a protocol consisting of in-lab polysomnography, ambulatory monitoring and a morning blood draw. Height and weight were collected to derive body mass index (BMI). Total sleep time (TST), wake after sleep onset (WASO), sleep onset latency (SOL), and sleep efficiency (SE) were derived from in-home actigraphy. Venipuncture was used to collect blood samples within 15 minutes of awakening. Once samples were processed, interleukin-6 (IL-6) levels were detected and quantified using enzyme-linked immunosorbent assays (ELISA). Results Significant correlations were found between BMI, WASO, TST, SE, and IL-6. A forward stepwise linear regression was used to identify possible predictors of BMI out of the following candidate variables: TST, SE, WASO, and IL-6. At each step, variables were chosen according to their contribution to the model's R^2. The p-value threshold of 0.05 was used to set a limit on the total number of variables included in the final model. TST, WASO, and IL6 were the significant predictors in the final model that accounted for 26% of the variance in BMI (∆R2 = .260, p<.001). Regression coefficients suggest that IL-6 (β =.388), TST (β= -.234), and WASO (β=.205) predict obesity. Conclusion Total sleep time and wake after sleep onset are modifiable protective and risk factors that appear to be significant contributors to obesity in urban-residing young African Americans. Support (if any) This research was supported by the NIHLB grants R01HL087995 and R01HL136626 and to Dr. Thomas A. Mellman and NCATS grant for a Clinical Translational Science Award UL1-TR001409.