1412-P: Sleep Patterns and Metabolic Syndrome Severity among African Americans in the Jackson Heart Study

Objective: To elucidate the relationship between sleep and metabolic dysfunction among African Americans, who are disproportionally affected by cardiometabolic diseases. Methods: This is a cross-sectional analysis of participants in the Jackson Heart Sleep Ancillary Study (2012-2016) who completed 7-day actigraphy and home sleep apnea studies. We used linear regression to assess the associations between metabolic syndrome (MetS) and actigraphy-derived parameters including: sleep timing, total sleep duration and regularity (night-to-night variation measured by within-individual standard deviation in sleep duration), and sleep continuity (sleep maintenance efficiency and fragmentation index). We assessed MetS severity, expressed as a validated sex- and race/ethnicity-specific z-score (MetS-Z), given the high prevalence of each of the MetS components in this cohort. Models were adjusted for age, socioeconomic factors, physical activity, smoking, alcohol use, and the presence of moderate to severe obstructive sleep apnea. Results: Among 660 participants (mean age 63 ± 11 yrs, 66% women, mean BMI 31.8 ± 6.9 kg/m2), mean sleep onset was 23:09 ± 1.4h, mid-sleep time was 2:54 ± 1.2h, total sleep duration was 6.7 ± 1.2h, median night-to-night variation was 1.2h (IQR 0.8-1.5), median sleep maintenance efficiency was 88.9% (IQR 85.6-91.4), median sleep fragmentation index was 28.5% (IQR 23.3-34) and mean MetS-Z score was 0.33 ± 1.1. In adjusted models, later mid-sleep time (β 0.09, p<0.01), increased variation in sleep duration (β 0.004, p<0.01), lower sleep maintenance efficiency (β -0.02, p=0.03), and higher sleep fragmentation index (β 0.01, p=0.02) were associated with higher MetS-Z. Conclusions: Later sleep timing, irregular sleep duration, and poor sleep continuity were associated with higher MetS severity scores among African Americans, highlighting the importance of sleep and circadian disruption as factors that influence metabolic health. Disclosure D.Duan: None. J.Jun: None. R.Ahima: None. A.Bertoni: None. S.Redline: Consultant; Eli Lilly and Company, JAZZ Pharmaceuticals, Apnimed. J.Echouffo tcheugui: None. Funding National Institutes of Health (K23DK133690)