Is Pulse Pressure an Independent Risk Factor for Incident Stroke, REasons for Geographic And Racial Differences in Stroke

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.