Body Mass Index and Total and Cardiovascular Mortality in Men With a History of Cardiovascular Disease

Abstract

Previous studies designed to identify an association between body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters) and cardiovascular or total mortality in populations with known atherosclerotic disease have shown conflicting results. In this study, we used the Physicians' Health Study enrollment cohort to examine the risk of total and cardiovascular mortality among men reporting a history of myocardial infarction or stroke, excluding those who reported a history of cancer. Cause-specific death was ascertained for 5010 men during a mean follow-up of 5.0 years. End points were classified as total deaths and deaths due to cardiovascular causes. Four BMI categories (<22.0, 22.0-24.9 [referent], 25.0-27.9, and > or =28.0) were created a priori. We used proportional hazards models to calculate age and multivariate-adjusted relative risks (RRs) for each BMI category for each end point. Compared with men with a BMI of 22.0 to 24.9, men with a BMI of 28.0 or greater had an age-adjusted RR of 1.11 (95% confidence interval [CI], 0.91-1.36), a multivariate RR of 1.04 (95% CI, 0.84-1.28) in a model that did not include biological mediators of obesity, and a multivariate RR of 1.06 (95% CI, 0.78-1.44) in a model that included these mediators. The RRs for cardiovascular mortality were similar, at 1.07 (95% CI, 0.85-1.35), 1.01 (95% CI, 0.79-1.29), and 1.01 (95% CI, 0.71-1.43), respectively. A BMI of less than 22.0 was associated with a small increased risk of total mortality and cardiovascular mortality. These findings indicate that elevated BMI may not be strongly associated with total or cardiovascular mortality among men with previously manifested coronary artery disease.