Leisure-time physical activity and development and progression of diabetic nephropathy in type 1 diabetes: the FinnDiane Study

Aims/hypothesis The aim of this study was to assess how physical activity predicts the development and progression of diabetic nephropathy in patients with type 1 diabetes. Methods This prospective study (follow-up time 6.4 +/- 3.1 years) included 1,390 patients (48.5% men, mean age 37.0 +/- 12.4 years, duration of diabetes 20.4 +/- 12.3 years) participating in the nationwide multicentre Finnish Diabetic Nephropathy (FinnDiane) Study. Leisure-time physical activity (LTPA) was assessed using a validated self-report questionnaire. Renal status was defined according to standard clinical cut-off values for urinary AER. Results The total amount of LTPA was not associated with progression in renal status. For the intensity of LTPA, however, the 10 year cumulative progression rate was 24.0% (95% CI 18.8, 28.8), 13.5% (95% CI 10.3, 16.6) or 13.1% (95% CI 10.3%, 16.6%; p = 0.01) of the patients with low, moderate or high intensity LTPA. This pattern was similar to that for the development of de novo microalbuminuria. Corresponding progression rates for LTPA frequency of <1, 1-2 or >2 sessions/week was 24.7% (95% CI 18.3, 30.7), 14.7% (95% CI 10.2, 19.0) or 12.6% (95% CI 9.4, 15.7), respectively (p = 0.003). Conclusions/interpretation This study demonstrates for the first time in a prospective setting the relationship between physical activity and the risk of diabetic nephropathy in patients with type 1 diabetes. The data suggest that physical activity, and in particular its intensity, may have an impact on the initiation and progression of diabetic nephropathy in type 1 diabetes.