Project Summary (Abstract) Cardiometabolic diseases are the leading causes of morbidity and mortality in the U.S. An increasingly recognized health behavior involved in the development of cardiometabolic risk factors is sleep duration. Sleep duration has been linked to the development of obesity, diabetes, and hypertension and may be a key contributor to racial disparities in cardiometabolic health. The majority of studies have examined adulthood sleep duration and adulthood cardiometabolic health, but not the impact of sleep duration across the life span on adulthood cardiometabolic health. Changes in sleep across the life span have been documented with average sleep duration decreasing during adolescence, increasing during transition into adulthood, and declining in later adulthood. However, this approach to examining sleep duration trends of using averages assumes that the overall population follows these exact trends and may mask the various distinct sleep duration trajectories that may exist that can have cardiometabolic health implications in adulthood. Furthermore, racial disparities in sleep among adolescents have been well-documented. Given that sleep duration during adolescence predicts sleep in adulthood, reducing sleep disparities during adolescence may help to alleviate disparities during adulthood, but few studies have examined underlying mechanisms for these disparities. Stressors at the neighborhood and family context may be a contributor to racial disparities in sleep among adolescent as they have been shown to be patterned by race/ethnicity and associated with sleep duration. This proposed project seeks to examine racial disparities in sleep duration across the life course and cardiometabolic risk during adulthood using data from the National Longitudinal Study of Adolescent to Adult Health. Aim 1 will evaluate whether family (e.g. family SES, single parent household, and parental support) and neighborhood stressors (neighborhood SES, perceived safety, and social cohesion) explain racial disparities in short sleep duration among U.S. adolescents. Aim 2 will Identify distinct sleep duration trajectories from adolescence to adulthood and determine whether trajectory membership differs across race/ethnicity groups. Aim 3 will estimate the association between sleep duration trajectories from adolescence to adulthood and adult cardiometabolic risk factors and determine whether this relationship differs by race/ethnicity. Results from this research will improve our understanding of racial disparities in sleep duration across the life span and be used to inform interventions to reduce disparities and improve cardiometabolic health. The applicant has an exceptional mentoring team and training plan that will ensure the successful completion of this proposed project and preparation of the applicant for an academic career.