The association between coronary heart disease (CAD) risk factors with submaximal exercise performance was examined among 12,866 men at high risk in the Multiple Risk Factor Intervention Trial (MRFIT). Men were selected from a risk score based on serum cholesterol level, diastolic blood pressure and number of cigarettes smoked per day. Multivariate analysis using exercise ST depression as the dependent variable showed age, diastolic blood pressure and serum cholesterol level were significant positive predictors of ST depression and cigarettes per day, body mass index and heart rate at rest were significant negative predictors of ST depression. Similarly, multivariate analysis, using exercise duration as the dependent variable, revealed that age, cholesterol level, body mass index and heart rate at rest were significant negative predictors of exercise duration, whereas cigarettes per day and leisure-time physical activity were significant positive predictors. Some of these relationships with exercise performance are consistent with established epidemiologic CAD risk factor associations and others are not. The MRFIT selection process, which resulted in smokers who were significantly younger and who had significantly lower levels of other CAD risk factors than nonsmokers, was partially responsible.
Bibliographical noteFunding Information:
From the Division of Epidemiology, School of Public Health, and the Biometry Department, University of Minnesota, Minneapolis, Minnesota; Halifax Infirmary, Dalhousie University, Halifax, Nova Scotia, Canada; Division of Heart and Vascular Disease, National Heart, Lung, and Blood Institute, Bethesda, Maryland; the MRFIT Coordinating Center, Minneapolis, Minnesota; and the Department of Community Health and Preventive Medicine, Northwestern University School of Medicine, Chicago, Illinois. This study was supported in part by MRFIT ECG Grant NO1 HL2-2976 from the National Institutes of Health, Bethesda, Maryland. Manuscript received June 24, 1985; revised manuscript received November 5,1985, accepted November 6,1985.