The Relation of Blood Pressure to Coronary Heart Mortality in Different Age Groups Varies by Ethnicity

BACKGROUND: The relative importance of pulse pressure, mean arterial pressure, systolic blood pressure (SBP), and diastolic blood pressure (DBP) as predictors of coronary heart disease (CHD) have been shown to change with aging in individuals of white ethnicity, but few published data exist for those of African American ethnicity. METHODS: To assess the role of ethnicity in this relationship we compared the association of BP indices to CHD mortality (from a pooled database of eight prospective cohorts, n = 29829, follow-up 13.8 +/- 7.9 years, 1912 events) in the four age groups (30 to 39, 40 to 49, 50 to 59, and > or = 60 years) by the decrease in the -2 log likelihood in Cox regression analyses of subjects who were not receiving antihypertensive drug therapy at baseline. RESULTS: All BP indices were significant (P < .05) for all age groups in models containing a single BP index. In white subjects, the best predictor of CHD mortality was DBP for persons 30 to 39 years of age, whereas SBP was the best predictor for persons 40 to 49, 50 to 59 and > or = 60 years of age. In African American subjects, SBP was the best predictor in all age groups. When considered jointly, DBP, but not SBP, was significantly associated with CHD mortality in white subjects 30 to 39 years of age. Only SBP was significant in white subjects 40 to 49, 50 to 59, and > or = 60 years of age. In African Americans, SBP, but not DBP, was associated with CHD mortality in all four age groups when both were in the model. CONCLUSION: In African American subjects, SBP was found to be a better predictor of CHD mortality than DBP or pulse pressure. In white subjects, there was a shift in importance from DBP to SBP as predictors of CHD mortality from the 30 to 39-year age group to the older groups.