PROJECT SUMMARY Black adolescents are at an increased risk of poor cardiometabolic health during both adolescence and later adulthood, including obesity, hypertension, and type 2 diabetes. These cardiometabolic outcomes put Black youth at an increased risk for the development of heart disease, which kills Black adults at twice the rate of White adults. Racial discrimination and poor sleep are theorized as key factors contributing to cardiometabolic health. While studies in adults suggest that sleep may serve as a pathway through which discrimination influences cardiometabolic health, there is a critical gap in our knowledge of this pathway in adolescents. In contrast, community level-supports may protect Black youth against stressors, including the influence of racism and poor sleep. However, studies of the protective nature of community supports have largely focused on psychosocial and behavioral outcomes. Thus, research is needed to examine community-level supports as protective against the impact of racism on poor sleep and cardiometabolic outcomes; and the impact of poor sleep on cardiometabolic outcomes in Black youth. The goal of the proposed study is to examine the role of sleep and community support in the association of racial discrimination and cardiometabolic risk in Black adolescents. This application is responsive to NHLBI’s interest in research promoting cardiometabolic health in the early stages of the life course, including adolescence (NOT-HL-21-020). The aims will be addressed through secondary analysis of a nationally representative sample of Black adolescents, aged 11-12 years old, from the second-year follow-up of the Adolescent Brain Cognitive Development (ABCD) study, the largest long- term study of brain development and child health in the United States. The specific aims are to: (1): test sleep as a mediator of the association between racial discrimination and cardiometabolic risk in Black adolescents, and (2) test community support as a moderator of the associations among racial discrimination, sleep and cardiometabolic risk in Black adolescents. Addressing gaps in our understanding of how sleep and community- level supports contribute to cardiometabolic outcomes in Black adolescents will aid in the development of prevention interventions to promote long-term cardiometabolic health for Black individuals across the lifespan. Further, the research and training outlined in this NRSA F31 pre-doctoral fellowship application will equip me with the necessary skills and support needed to become an independent health disparities researcher with a focus on developing and evaluating strength-based community-level interventions to address health disparities among underserved populations.