Occupational and leisure time physical activity and the risk of nonfatal acute myocardial infarction in Italy

Purpose Physical activity has long been related to a reduced risk of coronary heart disease (CHD), including acute myocardial infarction (AMI). However, the quantitative estimates of the possible protective role of physical activity appear to vary across studies and populations. Methods A case–control study conducted in Italy between 1995 and 1999, including 507 incident cases below 79 years (378 men, 129 women) with a first episode of AMI, and 478 controls (297 men, 181 women) admitted to hospitals for acute conditions. Results Compared with the lowest level of occupational physical activity, the multivariate odds ratios (OR) of AMI for the highest level were 0.61 (95% confidence interval [CI], 0.38–0.97) at age 15 to 19 years, 0.57 (95% CI, 0.34–0.95) at age 30 to 39 years, and 0.51 (95% CI, 0.29–0.90) at age 50 to 59 years. The corresponding values for leisure time activity were 0.54 (95% CI, 0.38–0.77), 0.86 (95% CI, 0.57–1.30), and 1.00 (95% CI, 0.57–1.74), respectively. The association was consistent across strata of age, sex, education, smoking, and other selected covariates. Conclusions The attributable risk for low occupational exercise at age 30 to 39 years was over 10%, indicating the scope for further intervention on this modifiable risk factor in this Italian population, particularly in consideration of the public health importance of CHD.