Background: Research regarding the effects of occupational physical activity on health remains inconsistent. We analyzed the association of occupational physical activity with all-cause and cardiovascular disease (CVD) mortality. Methods: We analyzed two cohorts with baseline assessments from 1977 to 1993 ("National Research Program 1A" (NRP1A) and "MONItoring of trends and determinants in CArdiovascular disease" [MONICA]) and mortality follow-up until 2015 using adjusted Cox regression models. Results: We included 4396 NRP1A participants (137 793 person-years of follow-up, 1541 deaths) and 5780 MONICA participants (135 410 person-years, 1158 deaths).All-cause mortality was higher for men in the high compared with the low occupational physical activity category according to NRP1A (hazard ratio [HR] 1.25, 95% confidence intervals [CI] 1.05-1.50). CVD mortality was higher for men in the moderate compared with the low occupational physical activity category according to MONICA (HR, 1.41; 95% CI, 1.03-1.91). Results for women were not statistically significant.
Conclusions:We observed higher total and CVD mortality risks in men with higher occupational physical activity but inconsistent results for women and across cohorts. K E Y W O R D S linkage, Swiss National Cohort, MONICA, National Research Program 1A (NRP1A), work-related physical activity 1 | INTRODUCTION Evidence suggests that physical activity has several health benefits including a decrease in the risk of cardiovascular disease (CVD), diabetes, several types of cancer, and osteoporosis 1 following a dose-response relationship. 2 Furthermore, the cardiovascular system seems to benefit in particular from leisure-time physical activity. A meta-analysis suggests CVD risk reductions of 20%-30% for moderate (vs low) and of 30%-40% for vigorous (vs low) leisure-time physical activity. 3 Similarly, risk reductions of 35% in CVD mortality and of 33% in all-cause mortality in the most active compared with the least active participants were observed in another meta-analysis. 4 In general, earlier research regarding an association between physical activity and health focused on leisure-time physical activity. While the beneficial effects of this type of physical activity on the cardiovascular system are well documented, 3 the literature regarding occupational physical activity is rather inconsistent. 5 Some studies Am J Ind Med. 2019;62:559-567.wileyonlinelibrary.com/journal/ajim