Combined associations of work and leisure time physical activity on incident diabetes risk

Introduction This study examines the separate and combined relationships between occupational physical activity (characterized by nonaerobic activities such as heavy lifting and prolonged standing) and leisure time physical activity on future diabetes incidence. Methods Data from Ontario respondents aged 35-74 years from the 2003 Canadian Community Health Survey (N=40,507) were prospectively linked to the Ontario Diabetes Database for diabetes cases until 2017, with statistical analysis performed in 2019. Leisure time physical activity was self-reported and occupational physical activity estimated from occupation titles. The analytical sample consisted of 7,026 employed people without previous diabetes diagnoses, with 846 diabetes cases recorded. Cox proportional hazard models were constructed to evaluate relationships over a median follow-up time of 13.7 years. Results No relationships were observed between occupational physical activity and diabetes. High leisure time physical activity was associated with lower diabetes risk for low occupational physical activity and stationary jobs (hazard ratio=0.63, 95% CI=0.47, 0.85). No association was found for high leisure time physical activity on diabetes risk for high occupational physical activity (hazard ratio=1.07, 95% CI=0.73, 1.56) or low occupational physical activity with movement (hazard ratio=0.92, 95% CI=0.55, 1.55). Conclusions This study suggests that physical activity recommendations exclusively recommending increased physical activity may only be effective for the sedentary part of the working population in reducing diabetes risk. Findings await confirmation in comparable prospective studies in other populations