Leisure-time physical activity at weekends and the risk of Type 2 diabetes mellitus in Japanese men: the Osaka Health Survey

Summary Aims To investigate association between leisure‐time physical activity at weekends and the risk of developing Type 2 diabetes mellitus (DM). Methods Prospective examination of 6013 Japanese men aged 35–60 years who were free of DM, impaired fasting glycaemia, or hypertension at study entry. Type 2 DM was defined by a fasting plasma glucose level ≥ 7.0 mmol/l or a 2‐h post‐load plasma glucose level ≥ 11.1 mmol/l. Data on physical activity obtained from questionnaires consisted of overall leisure‐time physical activity weekly and leisure‐time physical activity at weekends. Results During the 59 966 person‐years follow‐up, 444 cases developed Type 2 DM. Regular physical exercise at least once a week was associated with a reduced risk of Type 2 DM. After adjustments for age, body mass index, daily alcohol consumption, smoking habits, blood pressure levels and a parental history of Type 2 DM, men who engaged in regular physical exercise at least once a week had a relative risk of Type 2 DM of 0.75 (95% CI, 0.61–0.93) compared with men engaging in exercise less often. Even vigorous activity only once a week at weekends was associated with a reduced risk of Type 2 DM. Men who engaged in vigorous activity at least once a week at weekends had a multiple‐adjusted relative risk of Type 2 DM of 0.55 (95% CI, 0.35–0.88) compared with sedentary men. Conclusions Regular physical exercise at least once a week and vigorous activity even only once a week at weekends are associated with a decreased risk of Type 2 DM.