Ischemic heart disease risk factors after age 50

Previous studies have suggested that the predictive power of the three major risk factors for ischemic heart disease (hypertension, hypercholesterolemia, and cigarette smoking) decreases sharply with age. We re-examined this question in a cohort of 3187 adults aged 50-79 with baseline evaluation in 1972-1974 who were followed at least 9 years during a period of a marked decline in national cardiovascular disease mortality. Four-hundred and eighty-three subjects died, 123 of ischemic heart disease. Predictors of outcome were studied separately in younger (age 50-64) and older (age 65-79) groups. After multivariable adjustment for potential confounders using Cox proportional hazards models, cholesterol retained a significant independent predictor of ischemic heart disease mortality at older ages for both men and women. Cigarette smoking and hypertension were significantly related to all-cause but not to ischemic heart disease mortality in this older population. We suggest that the persistence of cholesterol as an independent predictor of fatal ischemic heart disease in old age may reflect the consequences of a shift in risk factor distribution with deferred selective mortality in a cohort with an overall favorable risk factor status.