High occupational physical activity and its combined effect with leisure-time physical activity on cardiovascular disease and mortality: systematic reviews and meta-analyses

Abstract

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.

Keywords: Cardiology; Occupational Health; Physical Activity; Workload.

Figure 1. Association between high occupational physical activity and cardiovascular diseases for all participants: unadjusted meta-analysis/adjusted meta-analysis compared with low and moderate reference groups. (a) Unadjusted meta-analysis. (b) Adjusted meta-analysis. BELSTRESS, etude BELge sur le STRESS; CAREMA, the Cardiovascular Registry Maastricht; CCHS, The Copenhagen City Heart Study; CGPS, Copenhagen General Population Study; CSCC, Chin-Shan Community Cardiovascular; CVD, cardiovascular disease; DNHIS, Danish National Health Interview Surveys; GP, general population; INHIS, Italian National Health Interview Surveys; MONICA, MONItoring of trends and determinants in CArdiovascular disease; OPA, occupational physical activity; PAMELA, Pressioni Arteriose Monitorate e Loro Associazioni; SEMM, Study of Employed in the Municipality of Milan; SWP, specific work population; VIP, Västerbotten Intervention Programme; WHI-OS, Women’s Health Initiative-Observational Study; WOLF, Work-Lipids-Fibrinogen.

Figure 2. Association between high occupational physical activity and cardiovascular diseases mortality for all participants: unadjusted meta-analysis/adjusted meta-analysis compared with low and moderate reference groups. (a) Unadjusted meta-analysis, (b) Adjusted meta-analysis. CARLA, CARdiovascular disease Living and Ageing; CCHD, Caerphilly Collaborative Heart Disease; CCHS, The Copenhagen City Heart Study; CKBS, China Kadoorie Biobanks Study; CMS, Copenhagen Male Study; CONOR, Cohort of Norway; CORDIS, Cardiovascular Occupational Risk Factors Determination in Israel Study; CVD, cardiovascular disease; EPIC, European Prospective Investigation into Cancer; FINMONICA, FINLand MONItoring of trends and determinants in CArdiovascular disease; GP, general population; HUNT2, Trøndelag Health Study; MONICA, MONItoring of trends and determinants in CArdiovascular disease; MPPS, Mutlifactor Primary Prevention Study; NRP1A, National Research Program 1 A; OPA, occupational physical activity; SHIP, study of health In Pomerania; SWP, specific work population.

Figure 3. Association between high occupational physical activity and cardiovascular diseases stratified by level of leisure-time physical activity: adjusted meta-analysis (Reference group: low occupational physical activity). BELSTRESS, etude BELge sur le STRESS; CCHS, The Copenhagen City Heart Study; CVD, cardiovascular disease; GP, general population; KIHD, Kuopio Ischaemic Heart Disease; LTPA, leisure-time physical activity; SWP, specific work population.