Social support, stress, and blood pressure in black adults.

Psychosocial factors arising from socioeconomic disadvantage and discrimination may contribute to the excess risk of elevated blood pressure in African-Americans. The purpose of this study was to assess the association of social support and stress with blood pressure in a community-based sample of 25-to 50-year-old black adults in Pitt County, NC. A stratified random sample of dwellings was selected in 1988, and 1,784 black adults (80% of those eligible) were interviewed. Analyses were sex specific and adjusted for age, obesity, and waist/hip ratio. In separate analyses of emotional support, instrumental support, and stress with blood pressure, all associations were in the predicted direction (inverse for support, direct for stress) but were stronger for systolic than for diastolic blood pressure. Differences in systolic blood pressure associated with low support or high stress ranged from 5.2 to 3.6 mmHg in women and 3.5 to 2.5 mmHg in men. In simultaneous regression analyses of support and stress, each of the separate effects was reduced for women, but a sizable aggregate effect of low support and high stress remained [+7.2 mmHg (95% confidence limits = +1.3, +13.1) for systolic blood pressure and +4.0 mmHg (95% confidence limits = +0.1, +7.9) for diastolic blood pressure.