Effect of combined occupational tasks on cardiovascular events: Prime study

Background Sedentary behaviour in leisure time or at home increases cardiovascular risk, but it is uncertain whether this is also the case for occupational activity. Purpose To investigate the qualitative and quantitative effects of different types of occupational tasks and how they interacted together on incidence of cardiovascular disease (CVD). Methods The study included 7796 active middle aged European men from the PRIME cohort. Using Cox proportional hazards analysis, and taking account of anthropometric and biomedical factors, energy expenditure during leisure time and commuting related physical activity, lifestyle habits and social factors, the effects of time spent sitting or standing still, carrying objects and walking at work were investigated to assess how they influenced the incidence of CVD over 10 years’ of follow-up. Results The incidence of CVD from time spent sitting or standing still at work showed a U-shape relationship. u003e300-1200 and 1200-1800mins/week spent sitting or standing at work halved the risk of CVD HR: 0.63[0.42-0.94]; 0.48[0.31-0.76], respectively. The risk was higher for men who routinely carried heavy objects when their jobs involved little or no time spent sitting or standing still at work, although this risk was decreased for men who spent u003e300-1200mins/week sitting or standing still at work. Conclusion The effects of occupational activities on CVD depend not only on the types of occupational tasks but also on the balance of activities at work and the potential compensatory effects of other activities. Cardiovascular prevention strategies should include a range of occupational physical activities.