Pretreatment blood pressure as a predictor of 21-year mortality

Abstract

Our objective was to evaluate pretreatment predictors of longevity, particularly blood pressure, in a large cohort of hypertensive men. During 1974 to 1976, 10,367 male hypertensive veterans (47% black) were identified at screening and subsequently characterized in 32 special Veterans Administration (VA) hypertension clinics. Their mean age was 52 years and mean blood pressure (BP) 154/100 mm Hg. During an average of 21 years of follow-up, 61% died. Risk ratios for all-cause mortality as functions of BP and other risk factors are presented for each variable alone; for each variable controlling for age, race, and BP; and for a multivariate model. We observed that when the entire cohort was divided into deciles by systolic blood pressure (SBP) and by diastolic blood pressure (DBP), the risk ratios for 21-year mortality increased from lowest to highest decile by 178% for SBP and 16% for DBP. When the deciles were computed separately by age group, increases from lowest to highest decile for those less than 40 years of age were 138% for SBP and 263% for DBP. For those over 60 years, the increases were 154% and -10%, respectively. Although blacks were younger and had more severe diastolic hypertension than whites, the risk ratios were similar within each race group. Risk patterns for mean arterial pressure and pulse pressure resembled those for SBP but had smaller gradients. Survival curves for BP groups suggested constant mortality rates during follow-up. Other significant observations included decreasing mortality with increasing body mass index and increased mortality in the Stroke Belt. We concluded that pretreatment SBP strongly predicted all-cause mortality during 21-year follow-up. For the young, both SBP and DBP were strong predictors; for the elderly, only SBP was predictive.