Leisure-time cross-country skiing is associated with lower incidence of type 2 diabetes: A prospective cohort study

Background: Cross-country skiing is associated with reduction in risk of adverse vascular outcomes, but its association with type 2 diabetes is uncertain. We aimed to assess the associations between leisure-time cross-country skiing habits and incident type 2 diabetes. Methods: We analysed the data of 2483 middle-aged men with no history of diabetes at baseline in the Kuopio Ischemic Heart Disease prospective study. The frequency, average duration, and intensity of leisure cross-country skiing were assessed at baseline using a 12-month physical activity questionnaire. Hazard ratios (HRs) (95% CIs) for type 2 diabetes were estimated. Results: During a median follow-up of 21.6 years, 539 men developed type 2 diabetes. Type 2 diabetes risk decreased with increasing total volume of cross-country skiing up to 1,215 metabolic equivalent task (MET) hours/year. In analyses adjusted for several established risk factors, when compared with men with no cross-country skiing activity, the HRs (95% CIs) for type 2 diabetes were 0.75 (0.62-0.92) and 0.59 (0.46-0.76) for men who did 1-200 and >200 MET hours/year of cross-country skiing, respectively. Compared with men with no cross-country skiing activity, the corresponding adjusted HRs (95% CIs) for type 2 diabetes were 0.73 (0.60-0.89) and 0.64 (0.50-0.82) for men who did 1-60 and >60 minutes/week of cross-country skiing, respectively. The associations remained consistent following further adjustment for prevalent comorbidities. Conclusion: Total volume and duration of leisure-time cross-country skiing are each inversely and independently associated with future type 2 diabetes risk in a male population. Cross-country skiing undertaken as a leisure activity has the potential to promote public health.