Long-term efficacy of type 2 diabetes prevention: the Finnish Diabetes Prevention Study DPS

Abstract Background Lifestyle intervention has been proven to reduce the incidence of type 2 diabetes (T2D) among high-risk individuals, with the effect sustained several years after discontinuation of the counselling. This study aims to assess whether the preventive effect demonstrated in the DPS study persists 23 years after baseline. Methods Middle-aged women (n = 350) and men (n = 172) with overweight and impaired glucose tolerance were randomly allocated into an intensive lifestyle intervention group (IG; n = 265) or a usual care control group (CG, n = 257) between 1993 and 1998. The lifestyle counselling lasting a median of 4 years (range 1-6 years) focused on dietary modification, increased physical activity and weight reduction. Participants remaining free of diabetes were invited to annual/biennial clinical examinations until 2012, which included measurements of weight, physical activity, and diet, and an oral glucose tolerance test to diagnose incident diabetes. Additionally, register-based follow-up continued until 2018, with diabetes diagnoses acquired from the national administrative registers complementing the clinical diagnoses. Results The incidence of T2D per 100 person-years was 4.73 (95% CI 4.05-5.50) in the IG and 5.87 (5.03-6.80) in the CG (p = 0.0448), with a median follow-up time of 12 years. The hazard ratio between groups changed in time, being most pronounced at early follow-up and attenuating towards the end. Ultimately, 172 (65%) participants in the IG and 175 (68%) in the CG had diabetes diagnosis, with the median time from baseline to diagnosis being 15.2 (95% CI 12.5-16.2) years in the IG and 11.0 (8.9-12.9) years in the CG. Weight reduction and adherence to the recommended lifestyle during the intervention phase predicted a decreased diabetes risk during the follow-up. Conclusions Lifestyle counseling delays the onset of type 2 diabetes and can thereby be expected to reduce the life-long costs associated with diabetes treatment. Key messages • The Finnish Diabetes Prevention Study showed that lifestyle counseling for high-risk individuals has a lasting impact and can add 4.3 diabetes-free years. • The reduced type 2 diabetes risk is attributed to weight loss and improvements in physical activity and diet.