PHYSICAL-ACTIVITY AND 23-YEAR INCIDENCE OF CORONARY HEART-DISEASE MORBIDITY AND MORTALITY AMONG MIDDLE-AGED MEN - THE HONOLULU HEART PROGRAM

Background The purpose of the study was to examine the association bet ween physical activity and 23-year incidence of coronary heart disease morbidity and mortality. This cohort study continues to follow 8006 J apanese-American men who were 45 to 68 years of age and living on Oahu , Hawaii, in 1965, for the development of coronary heart disease morbi dity and mortality. Methods and Results The Framingham physical activi ty index was calculated by summing the product of average hours spent at each activity level and a weighting factor based on oxygen consumpt ion. Study subjects were divided into tertiles of physical activity in dex at baseline. Relative risks and 95% confidence intervals (CI) for incidence of coronary heart disease morbidity and mortality were obtai ned using the Cox model. After age adjustment and using the lowest phy sical activity index tertile as a reference group, the relative risk f or coronary heart disease incidence for the highest tertile of physica l activity was 0.83 (CI, 0.70 to 0.99). After adjusting for age, hyper tension, smoking, alcohol intake, diabetes, cholesterol, and body mass index, the relative risk was 0.95 and CI included 1 (CI, 0.80 to 1.14 ). For coronary heart disease mortality, the age-adjusted relative ris k was 0.74 (CI, 0.56 to 0.97) and 0.85 (CI, 0.65 to 1.13) after risk f actor adjustment. Conclusions The results suggest that the impact of p hysical activity index on coronary heart disease is mediated through i ts effects on hypertension, diabetes, cholesterol, and body mass index . These findings support the hypothesis that physical activity is inve rsely associated with coronary heart disease morbidity and mortality a nd suggest that physical activity interventions in middle-aged men, by improving cardiovascular risk factor levels, may have significant pub lic health implications in the prevention of coronary heart disease.