Is pulse pressure an independent risk factor for incident stroke, REasons for geographic and racial differences in stroke

Abstract

BACKGROUND Pulse pressure (PP) is a potential risk factor of stroke. The relationship of incident stroke with systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and PP was examined. METHODS Data were from the REasons for Geographic And Racial Differences in Stroke national cohort study of 30,239 black and white participants aged ≥45 years, enrolled between 2003 and 2007. PP (SBP-DBP) and MAP (MAP = DBP + 1/3∗PP) were calculated. Telephone follow-up occurred every six months for self or proxy-reported suspected stroke events, confirmed using expert adjudication. Cox-proportional hazards models examined the association of incident stroke for the different BP measurements with multivariable adjustment for sociodemographic and clinical risk factors including gender and race. RESULTS Men and women without prevalent stroke at baseline were analyzed (n = 25,462). During follow-up (mean 6.3±2.3 years, maximum 10 years), 916 strokes occurred. Unadjusted PP (hazard ratio [HR] = 1.30; 95% confidence interval [CI] 1.24-1.35), SBP (HR = 1.22; 95% CI 1.18-1.32), MAP (HR = 1.24; 95% CI 1.16-1.32), and DBP (HR = 1.09; 95% CI 1.01-1.17) were associated with stroke risk; however, after adjustment for SBP and other risk factors, the association with PP was attenuated (HR = 0.98; 95% CI 0.90-1.07), whereas SBP persisted as a predictor (HR = 1.14; 95% CI 1.06-1.23). These associations were consistent across age (younger vs. older >70 years) and race (black vs. white). CONCLUSIONS PP is positively associated with incident stroke, but not independently from SBP; and, there were no significant gender, racial, or regional differences in that association.