1078 Examining the Role of Insomnia Severity as a Potential Mediator between Psychosocial and Environmental Factors and Cardiometabolic Risk Among Blacks

Abstract Introduction Adequate sleep is a key determinant of cardiometabolic health, but epidemiologic evidence among Black adults (BA) remains limited. Psychosocial and neighborhood-level stressors may influence cardiometabolic risk (CMR) directly and through the presence of insomnia. We examined associations of psychosocial and environmental stressors with CMR, associations with insomnia severity, and whether the presence of insomnia mediates these relationships. Methods Cross-sectional data from the ESSENTIAL study were analyzed from 623 BA residing in Miami and New York City (66% female; Mage=40.3, SD= 13.2 [range 18-75 years old]). Insomnia severity was measured with the Insomnia Severity Index (ISI). Psychosocial determinants included social support (Multidimensional Scale of Perceived Social Support), discrimination (Everyday Discrimination Scale), life stressors (Holmes and Rahe Stress Scale), and mental health (SF-12, history of anxiety/depression). Environmental determinants were assessed with the Assessment of Sleep Environment (ASE) and the Neighborhood Environment Walkability Scale–Abbreviated (NEWS-A) indices (residential density & crime). CMR included a history of cardiometabolic risk diagnosis. Unadjusted and adjusted linear regression models identified independent associations of psychosocial and environmental factors (predictors) with ISI (outcome). Mediation analyses for key exposures estimated the indirect (via ISI) and direct effects on CMR. Covariates included age, sex, education, employment, marital status, religious affiliation, income, and location. Results In fully adjusted models, worse mental health (β=-0.24, p<.01), a more disruptive sleep environment (ASE; β=0.10, p< 0.01), higher neighborhood crime, and greater residential density (NEWS-A; β=0.59, p<.05 and β=0.0030, p< 0.05) were independently associated with higher ISI. Older age (β=0.09, p< 0.001) and female sex (β=1.15, p< 0.05) were also independently associated with higher ISI. For CMR, mental health (β=0.59, p< 0.05), sleep environment (β=0.59, p<.05), and neighborhood crime (β=0.59, p< 0.05) showed significant direct associations with CMR. We found no significant indirect effects of ISI in the model. Conclusion These findings underscore the need for culturally tailored precision medicine-based interventions that target key factors such as mental health, sleep and environments to mitigate CMR among BA. Future studies should employ longitudinal methods with larger sample sizes to establish causal relationships with these determinants of sleep and CMR outcomes in Black communities and other populations experiencing similar neighborhood disadvantage. Support (if any) R01HL142066