Abstract 4362446: Sleep as a Mediator Between Stress and Blood Pressure in Older African American Women: RiSE Study

Introduction: African American women (AAW) are disproportionately affected by psychosocial stress and hypertension. While stress is recognized as a cardiovascular risk factor, the behavioral mechanisms linking stress to elevated blood pressure remain insufficiently understood. Sleep disturbances, prevalent in older AAW, may serve as a modifiable mediator in this relationship. This study examined whether sleep quality mediates the relationship between perceived stress and blood pressure among older AAW. We hypothesized that poorer sleep quality would mediate the relationship between higher levels of perceived stress and elevated blood pressure in older AAW. Methods: A cross-sectional analysis was conducted using baseline data from older AAW (aged 50-75) enrolled in the Resilience, Stress, and Ethnicity (RiSE) study. Perceived stress was assessed using the 10-item Perceived Stress Scale, and sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). Blood pressure was measured manually by a trained project manager. Three assessments were taken on the left arm and averaged to calculate mean systolic and diastolic blood pressure. Structural equation modeling was used to examine the mediation model, adjusting for age, body mass index (BMI), and use of antihypertensive medication. Results: The analysis included 117 older AAW (mean age = 62.78 ± 6.70 years). The mean systolic blood pressure was 130.14 ± 15.72 mmHg, and 58% were taking antihypertensive medications. Participants reported poor sleep quality on average (PSQI score = 7.41 ± 3.37). Perceived stress significantly predicted poorer sleep quality (β = 0.21, p < 0.001), and poorer sleep quality led to higher systolic blood pressure (β = 1.08, p = .019). The indirect effect of stress on systolic blood pressure through sleep quality was significant (β = 0.22, p = .034; 95% CI: 0.018–0.432), while the direct effect was not significant (β = 0.17, p = .451), indicating full mediation. Conclusions: These findings suggest that sleep quality may mediate the relationship between perceived stress and blood pressure in older AAW. Although the cross-sectional design and the modest sample size limit causal inference and preclude definitive claims of full mediation, the results highlight the potential importance of targeting sleep in interventions aimed at mitigating the cardiovascular consequences of chronic stress in this high-risk population.