Pregnancy as a Window to Racial Disparities in Hypertension.

BACKGROUND: The black-white disparity in hypertension (HTN) among U.S. women persists after accounting for known risk factors. Pregnancy complications may reveal increased risks for later HTN. We examined the contribution of HTN risk factors measured at both midlife and pregnancy to black-white disparities in midlife HTN.

METHODS: Data came from a Michigan-based longitudinal study beginning in pregnancy. At 7-15 years postpregnancy (n = 615, mean age = 37), women were assessed for cardiovascular health, including blood pressure, and categorized as hypertensive (n = 126), prehypertensive (n = 149), and normotensive (n = 340). Midlife risk factors for HTN were assessed in four domains: socioeconomic status (SES), psychosocial, behavioral, and physiological. We used generalized logit models to assess the degree to which each domain attenuated the black (vs. white) odds ratio (OR) for HTN at midlife. We then added indicators of pregnancy health, that is, preterm delivery, prepregnancy body mass index (BMI), C-reactive protein (CRP) levels, depressive symptoms, smoking, hypertensive disorders, and lipid levels.

RESULTS: Black women had 3.3 (95% CI: 2.0-5.5) times the odds of HTN compared to white women after adjusting for age. Following adjustment for midlife SES, and psychosocial, behavioral, and physiological factors, the OR was 2.1 (95% CI: 1.2-4.0). Adjustment for prepregnancy BMI, CRP, and depressive symptoms during pregnancy reduced the OR to 1.9 (95% CI: 1.0-3.7).

CONCLUSIONS: Known risk factors measured at midlife explained some, but not all, of the race disparity in midlife HTN. Indicators of pregnancy health also contributed to the race disparity in HTN at midlife.