Disrupted sleep, a major public health issue, independently increases risk for cardiovascular disease (CVD). Blacks have increased rates of sleep deficiency, which are likely under-reported. Importantly, these data relate primarily to those of West African ancestry. Our current knowledge of sleep disruption in Blacks, already severely limited in scope, cannot be readily applied to Somali Americans. The majority of Somali immigrants have settled in Minnesota, placing our Minnesota-based research team in a unique position to comprehensively study the mechanisms and consequences of disrupted sleep as a mediator of cardiovascular health disparities in this population. Our preliminary data suggest that Somali Americans have a high likelihood of disrupted sleep, which may put them at increased risk for hypertension and other CVD. Underlying sociocultural, behavioral, environmental and biological factors likely contribute to an increased risk for sleep deficiencies. We therefore propose an inter-disciplinary approach using a socioecological model informed by the National Institute on Minority Health and Health Disparities (NIMHD) Research Framework to determine the types and severity of undiagnosed sleep deficiencies in otherwise healthy Somali Americans, identify mechanisms contributing to their disrupted sleep, and examine the role of sleep deficiencies in raising blood pressure (BP). Our central hypothesis is that Somali Americans will have a high likelihood of sleep deficiencies attributable in part to unique multilevel individual, psychosocial, contextual and behavioral factors, which exert deleterious biological effects. We propose the following aims: Aim 1: Determine the types and severity of previously undiagnosed sleep deficiencies in otherwise healthy Somali Americans. Hypothesis 1: Somali Americans have a high (>50%) likelihood of previously undiagnosed sleep deficiencies (short sleep (<6 hours), insomnia and obstructive sleep apnea). Aim 2: Apply the NIMHD Research Framework to define psychosocial, behavioral, environmental and biological mechanisms mediating sleep deficiencies in Somali Americans. Hypothesis 2: Unique multilevel individual, cultural and environmental risk and protective factors play a mechanistic role in mediating an increased likelihood of disrupted sleep in Somali Americans. Aim 3: Examine the relationship between sleep deficiencies and increased BP in Somali Americans. Hypothesis 3: BP during wakefulness and/or sleep will be increased in those subjects with disrupted sleep, commensurate with type and severity of sleep deficiency, and moderated by factors such as sex and age. The expected outcome of this proposal will be a mechanistic pathway incorporating the NIMHD Research Framework to identify psychosocial, behavioral, contextual and biological factors mediating sleep deficiencies and related increases in BP, and consequently hypertension risk, thus addressing important knowledge gaps in understanding sleep-r...