Sleep as a contributor to socioeconomic disparities in hypertension: The Midlife in the United States (MIDUS II) Study

Study Objectives: Hypertension is highly prevalent and is a major risk factor for cardiovascular disease. There is a higher burden of hypertension among individuals of lower socioeconomic status (SES), yet the role of sleep in understanding socioeconomic disparities in hypertension is unclear. We investigated whether sleep quality is a partial mediator of the association between SES and hypertension. Methods: We used data from the Midlife in the United States II Study, 2004-2009 (n = 426). Analyses were conducted in 2023. Participants underwent 7-day actigraphy and clinical assessments. Sleep quality measures included actigraphy-defined wakefulness after sleep onset (WASO) and sleep efficiency. Hypertension was measured via three consecutive blood pressure readings, and SES was measured via educational attainment. Models were fit adjusting for age, gender, race, body mass index, and perceived stress. Results: Participants had a mean age of 53.5 years (SD = 12.4) and 41.0% were African American. The prevalences of poor WASO (>30 minutes), low sleep efficiency (<85%), and hypertension were 77.7%, 67.1%, and 61.0%, respectively. Education was not associated with hypertension. However, individuals with low vs. high sleep efficiency had 24% higher prevalence of hypertension (aPR = 1.24, 95% CI: 1.02 to 1.51), higher systolic blood pressure (a beta = 4.61, 95% CI: 0.69 to 8.53), and higher diastolic blood pressure (a beta = 2.50, 95% CI: 0.10 to 4.89). Education was not significantly associated with sleep after adjustment. There was no evidence of sleep mediating the SES-hypertension relation. Conclusions: Effective interventions to lower hypertension prevalence should consider targeting sleep quality. Future research should explore the intersectionality of SES and race in hypertension.