Objectives Leisure-time physical activity (LTPA) is a well-established protective factor for all-cause mortality and cardiovascular mortality while occupational physical activity (OPA) has shown contradictory results. We examined the association between OPA and all-cause and coronary heart disease (CHD) mortality, and tested its combined effect with LTPA.
Methods The CORDIS Study (Cardiovascular Occupational Risk Factor Determination in Israel Study) is a prospective cohort study of industrial workers examined during 1985–1989 and followed-up for 22 years. Data on self-reported OPA and LTPA among 4819 males (20–70 years old) were merged with data on all-cause and CHD mortality obtained from the National Death Registry.
Results A higher incidence rate of all-cause mortality and CHD mortality was observed among men who performed moderate–hard OPA compared with those who performed none–mild OPA. Multiple regression analysis based on the Cox proportional hazards model showed that moderate–hard OPA was associated with increased risk of all-cause mortality (HR=1.42, 95% CI 1.16 to 1.74, p<0.001), while LTPA (30 min at least twice a week vs less or none) was associated with reduced risk for all-cause mortality (HR=0.61, 95% CI 0.48 to 0.79, p<0.001), after adjusting for potential confounders, including sociodemographic variables, body mass index, comorbidity and lifestyle habits. Employees who performed moderate–hard OPA and no LTPA had the greatest risk for all-cause mortality and employees who performed none–light OPA and LTPA had the lowest risk. Similar but non-significant trends were observed for the association with CHD mortality. Conclusions Moderate–hard OPA among industrial male workers may be deleterious to health and should not be a substitute to LTPA.