Occupational physical activity in relation to risk of cardiovascular mortality: The Japan Collaborative Cohort Study for Evaluation for Cancer Risk (JACC Study).

We examined the association between patterns of occupational physical activity (OPA) and mortality from cardiovascular disease (CVD) in a Japanese population. A community-based, prospective cohort of 66,161 men and women aged 40-79years without a history of CVD or cancer at baseline (1988-1990) was followed until 2009. OPA was divided into four types: mostly sitting, sitting and standing (sitting/standing), mostly standing, and standing and walking (standing/walking). During follow-up for a median of 19.2years, 3728 deaths from CVD were registered. Compared with mostly sitting OPA, standing/walking OPA was not associated with a reduced risk of CVD mortality for all subjects, but it was associated with a 20% lower risk of CVD mortality among overweight individuals (body mass index ≥25kg/m(2)). Compared with mostly sitting OPA, mostly standing OPA was associated with an approximately 20% higher risk of CVD mortality, especially among overweight individuals or those with lower exercise (<2.5h/week). In conclusion, compared with mostly sitting OPA, standing/walking OPA is associated with lower CVD mortality among overweight individuals, while mostly standing OPA is associated with higher CVD mortality, especially in physically inactive individuals.