Drivers of Black-White Disparities in Hypertension Risk After Pregnancy: Findings From CARDIA

BACKGROUND: Hypertension is the leading risk factor for cardiovascular disease, with disparities observed by race. Few studies have examined how intersecting social and sex-based biological determinants influence hypertension incidence among parous individuals and across racial groups. The objective of this study was to examine whether female-specific cardiovascular disease risk factors (eg, adverse pregnancy outcomes), individual-level (eg, education), and structural-level (eg, neighborhood) social drivers of health (SDoH), beyond traditional cardiovascular disease risk factors (eg, physical activity), explain the Black-White disparity in hypertension following pregnancy. METHODS: Parous individuals in CARDIA (Coronary Artery Risk Development in Young Adults), a longitudinal cohort study beginning in 1985 to 1986, without hypertension before their first pregnancy were included. Race was self-reported at enrollment. Blood pressure was measured at each examination, with hypertension incidence defined as the first elevated blood pressure (systolic ≥130 mm Hg or diastolic ≥80 mm Hg) or initiation of antihypertensive medication after baseline. Participant follow-up time began at the next exam following their first live delivery. Cox proportional hazards models with time-varying covariates calculated hazard ratios and 95% CIs. To quantify how much each set of covariates explained the Black-White difference in hypertension risk, the percentage reduction in the race coefficient was calculated following the addition of female-specific cardiovascular disease risk factors and SDoH in multivariable-adjusted regression models. RESULTS: Among 1653 participants (29.4±6.1 years), Black women (n=924) had higher hypertension incidence than White women (n=729): 41.4 versus 18.5 per 1000 person-years, respectively; and an earlier median age at onset (42 versus 48 years). Following traditional risk factors, individual-level SDoH explained the largest disparity (7.52%), followed by female-specific factors (2.26%) and structural-level SDoH (1.50%). Black women remained at higher risk after adjustment (hazard ratio, 2.72 [95% CI, 2.17-3.41]). CONCLUSIONS: Parous Black women face substantially higher hypertension rates than White women, persisting after accounting for traditional risk factors, female-specific risk factors, and SDoH.