Racial and socioeconomic disparities in sleep and chronic disease: results of a longitudinal investigation.

OBJECTIVES Sleep problems appear to differentially affect racial minorities and people of lower socioeconomic status (SES). These population subgroups also have higher rates of many debilitating diseases such as obesity, type 2 diabetes mellitus (T2DM), hypertension, coronary heart disease, stroke, and mortality. Considering the presence of social disparities in sleep and chronic disease, this research aims to assess the role of sleep disparities in the incidence of obesity, T2DM, hypertension, and/or cardiovascular disease (CVD). DESIGN The Boston Area Community Health (BACH) Survey is a population-based random-sample cohort of 5502 participants aged 30-79. Sleep restriction (< or = 5 hours/night) and restless sleep were assessed at baseline. Health status was ascertained at baseline and approximately 5 years later among 1610 men and 2535 women who completed follow-up. SETTING Participants completed an in-person, home visit, interview at baseline (2002-2005) and follow-up (2006-2010). PARTICIPANTS Boston, Massachusetts residents (2301 men, 3201 women) aged 30-79 years from three racial groups (1767 Black, 1876 Hispanic, 1859 White) participated in the BACH Survey. RESULTS There were significant differences in the prevalence of sleep-related problems at baseline by both race and SES as well as significant disparities in the incidence of T2DM, high blood pressure and cardiovascular disease at follow-up. Restless sleep was associated with an increased risk of obesity, T2DM, and CVD. However, we found that sleep does not mediate social disparities in health outcomes. CONCLUSIONS Results from the BACH Survey confirm large social disparities in health outcomes as well as large social disparities in short sleep duration and restless sleep. However, sleep did not appear to mediate the relationship between race, SES, and health disparities.