Effect of age on blood pressure parameters and risk of cardiovascular death in men

Background: Elevated blood pressure (BP) is a risk factor for cardiovascular disease (CVD), but it remains unclear which component-alone or in combination-is the best predictor. We sought to determine which BP parameters are important predictors of CVD death across a wide age range. Methods: We used a prospective cohort study design with 53,163 men followed for cause-specific death during a median of 5.7 years in the Physicians' Health Study enrollment cohort. Baseline age, systolic BP and diastolic BP were collected. We calculated relative risks (RRs) and their 95% confidence intervals using Cox proportional hazard models adjusting for major risk factors for CVD, and then stratified by age (39 to 49, 50 to 59, 60 to 69, and 70 to 84 years). Results: There were 459 CVD deaths during follow-up. For each 10 mm Hg increase in systolic BP, the multivariable RRs by ascending age group were 1.46, 1.43, 1.24 and 1.13. The multivariable RRs for each 10 mm Hg increase in diastolic BP were 1.25. 1.20, 1.28, and 1.07. Compared with systolic BP, pulse pressure and mean arterial pressure were not consistent predictors across age ranges, and combining systolic BP with another parameter did not improve the model compared with using systolic BP alone in any age group (all P > .05). Conclusions: In this large cohort of healthy men with no history of hypertension, systolic BP was the most consistent and significant predictor of CVD death across all ages. Diastolic BP was not as strongly associated with risk. Our results support the continuing emphasis on using systolic BP in predicting cardiovascular risk.