High occupational physical activity and its combined effect with leisure-time physical activity on cardiovascular...

The objective of our systematic reviews and meta-analyses were to analyse the associations between high occupational physical activity (HOPA) and cardiovascular (CV) disease (CVD) and CV mortality and the role of leisure-time physical activity (LTPA) and fitness capacity on these associations.Two systematic reviews and related meta-analyses were undertaken using several databases to identify prospective cohort studies. Random-effect models were used to provide ORs and 95% CI, index I² to characterise the associations between the effect of exposure to HOPA on CVD and CV mortality in adjusted and unadjusted models. Stratified analyses according to the level of LTPA were provided. The Newcastle-Ottawa Scale was used to assess the quality of studies.From 25 and 28 prospective studies: compared with workers exposed to low OPA, HOPA increased the risk of CVD non-significantly (+12%), while compared with moderate OPA, a significant excess of risk was found (+24%); HOPA did not significantly increase the risk of CV mortality compared with low and moderate OPA groups. Stratified on the practice of high, moderate and low LTPA, the risks of CVD for the HOPA were ORs: 1.27 (0.86 to 1.88), 1.08 (0.61 to 1.92), 1.28 (1.00 to 1.62) versus low OPA group, respectively. A combination of low physical fitness and high OPA seemed to expose individuals to an elevated risk of CVD.Being exposed to HOPA may have the same effect on CVD as being exposed to low OPA and an excess risk compared with moderate OPA exposure, suggesting a curve effect. The combined effects of leisure and OPA must be considered in future research.