Primary Prevention of Type 2 Diabetes Mellitus in the European Union: A Systematic Review of Interventional Studies

Interventions for primary prevention are crucial in tackling type 2 diabetes (T2D) by offering a structured approach to implementing lifestyle modifications, such as community-based programs. The aim of this study was to demonstrate the effectiveness of primary prevention interventions in preventing or delaying the onset of T2D in the 28 EU member states (EU-28). The present systematic review is registered on PROSPERO (CRD42020219994), and it followed the PRISMA guidelines. Eligibility criteria comprised original interventional studies reporting incidence of T2D in member states of the EU-28. A total of 23,437 records were initially retrieved, of which 16 met the eligibility criteria for inclusion. These interventional studies, published between 2003 and 2021, provided data from Spain, the UK, Finland, the Netherlands, and Denmark. Thirteen studies were of low quality, two were moderate, and one was high-quality. Three studies focused solely on dietary interventions, twelve studies combined diet, physical activity, and lifestyle counseling, and one study applied repeated health checks with personalized feedback and lifestyle advice. Overall, 10 studies reported a significant reduction in T2D incidence exclusively among high-risk individuals following the interventions with HR: 0.4 (95% CI: 0.3-0.7) to 0.75 (95% CI: 0.58-0.96). Only a few studies reported that primary lifestyle interventions decreased T2D risk, thus limiting generalizability. While lifestyle improvements were noted on high-risk groups, significant risk reduction among healthy individuals was not observed. Multicomponent interventions combining dietary modifications, physical activity, and personalized lifestyle counseling were the most effective in reducing the incidence of T2D among high-risk populations in the EU-28.