Differential associations between education and blood pressure by gender and race

Background: Previous research suggests education is inversely associated with blood pressure, but little work has examined whether this relationship differs by race and gender jointly. Identifying the most vulnerable groups may inform hypertension prevention strategies. In this population-based study, we investigate the association between education and blood pressure overall and across race-by-gender subgroups. Methods: Our analytic sample included participants aged 50 + to the US Health and Retirement Study data from 2006 to 2008 (N = 24,526). Our exposure was education, measured as self-reported years of schooling and modeled as a spline with a knot and discontinuity at 12 years representing high school diploma. We used generalized estimating equations to estimate the relationship between education and repeated measurements of two blood pressure outcomes: systolic blood pressure (SBP) and hypertension (HTN), then included race-by-gender interactions with education to evaluate differential associations. All models were adjusted for age, birthplace, parents’ education, and survey year. Results: Mean age was 64.4 years, mean SBP was 129.9 mmHg, and HTN prevalence was 63.1%. Overall, below 12 years, each additional year of education was not associated with blood pressure, while twelve years of schooling was associated with lower blood pressure (b=-1.02; 95% CI: -2.04, 0.00 for SBP) and each additional year of education after 12 years was associated with lower SBP and lower odds of HTN (e.g., SBP: b=-0.75 mmHg; 95% CI: -0.88, -0.62). We observed some differential relationships by demographic subgroup such that, among Black men, 12 years of education predicted higher odds of HTN compared to White men (interaction OR = 1.60; 95% CI: 1.02, 2.52), and each additional year of education after 12 years was associated with larger SBP benefits for White, Hispanic and Black women compared to White men. Conclusions: We found an overall protective relationship between more education and blood pressure/hypertension such that each additional year of college education was associated with lower blood pressure/hypertension, particularly among White and Hispanic women. However, we also found evidence of diminished benefits to high school degree attainment among Black men compared to other groups in hypertension prevalence.