Leisure-time physical activity and risk of type 2 diabetes in patients with established vascular disease or poorly controlled vascular risk factors

Aim: To investigate the effect of leisure-time physical activity on the incidence of type 2 diabetes (T2DM) in patients with manifest arterial disease, or poorly controlled risk factors. Methods: We examined 3940 patients with manifest arterial disease, hypertension or hyperlipidemia, aged 55.2 +/- 12.2 years. Leisure-time physical activity was measured by a questionnaire and metabolic equivalent (MET) hours per week (h/wk) were calculated. Incident T2DM was evaluated by a specific diabetes questionnaire. Results: Most patients (65%) were physically inactive (0 MET h/wk), 12% were insufficiently physically active (0-10.5 MET h/wk) and 23% were sufficiently physically active (>= 10.5 MET h/wk). During a mean follow-up of 4.7 years, 194 (5%) incident cases of T2DM occurred. Sufficiently physically active patients had a lower incidence of diabetes (hazard ratio (HR) 0.55, 95% confidence interval (CI) 0.37-0.83). Patients who were physically active and not-obese (BMI < 30 kg/m(2)) were at the lowest risk for developing T2DM (HR 0.18, 95% CI 0.12-0.28) compared with patients who were physically inactive and obese. Conclusions: Leisure-time physical activity is associated with a decreased risk of T2DM in patients with manifest arterial disease, or poorly controlled risk factors. The combination of physical activity and non-obesity is associated with an even lower risk of the development of type 2 diabetes than the sum of their independent, protective effect. (C) 2009 Published by Elsevier Ireland Ltd.