Lifestyle intervention outcomes in T2DM and the added value of CGM: 6-month results from the Polish cohort of the C4D study

Type 2 diabetes remains a major public health challenge, requiring lifelong management. Structured lifestyle-based interventions are increasingly recognised for their role in supporting self-management. The CARE4DIABETES (C4D) programme, part of a Joint Action funded by the EU4Health initiative, aims to implement and evaluate a behavioural lifestyle model (Reverse Diabetes2 Now) across 12 European countries. C4D is a 12-month, quasi-experimental, structured, digitally supported lifestyle programme comprising multiple group-based educational sessions delivered by a multidisciplinary team (MDT) and addressing nutrition, physical activity, sleep, and stress management. This interim analysis includes the Polish cohort ( n = 38; type 2 diabetes duration ≤ 10 years), presented overall and stratified by continuous glucose monitoring (CGM) users ( n = 21) versus self-monitoring of blood glucose (SMBG, n = 17). At 6 months, participants showed significant improvements. Mean HbA1c decreased by 0.78% points (–10.9%; p < 0.001) to 6.35%. Body weight decreased by 6.04 kg (–6.5%; p < 0.001), waist circumference by 6.77 cm (–6.4%; p < 0.001), fat mass by 2.47 kg (–7.2%; p < 0.001), and triglycerides by 20.3% ( p = 0.023), while total cholesterol, LDL-C, and HDL-C did not change significantly. Improvements were numerically larger in the CGM group. Between-group comparisons of change scores showed greater reductions in body weight and BMI in the CGM group compared with the SMBG group ( p < 0.05; Cohen’s d ≈ 0.9–1.0). The 6-month intensive phase of this structured, group-based lifestyle education programme was associated with clinically meaningful improvements in glycaemic control and anthropometric outcomes. Improvements were greater among CGM users than in the SMBG group, suggesting that integrating CGM into structured education may further enhance programme outcomes.