Experiences from a structured single-centre transition program for patients with Type 1 diabetes in Italy: a longitudinal sex-stratified analysis

Abstract Background Transition from paediatric to adult care represents a critical phase for individuals with Type 1 Diabetes (T1D), often associated with suboptimal glycaemic control and loss to follow-up. Structured transition programs may mitigate these risks, yet longitudinal data from real-world settings are limited, particularly regarding sex-specific differences. This study aimed to evaluate the outcomes of a structured, single-centre transition program in Italy. Methods We conducted a retrospective, longitudinal, observational study on 187 patients (108 males and 79 females) with T1D transitioning from the Paediatric Unit to the Adult Endocrinology and Prevention and Care of Diabetes Unit at IRCCS Sant’Orsola University Hospital, Bologna, between June 2017 and June 2025. The transition protocol included a joint paediatric–adult visit, shared electronic records, and subsequent structured follow-up every 4–6 months. We collected demographic, anthropometric and clinical parameters at the baseline joint visit and during follow-up. We evaluated the HbA1c slope after transition for those who had at least 3 follow-up visits: worsened HbA1c was defined when the slope was > 0.5. A validated satisfaction questionnaire was administered after 12 ± 3 months of follow-up. Results Mean age at transition was 20 ± 2 years. Females more frequently used insulin pumps at baseline (53% vs. 30%, P = 0.036) and had higher prevalence of autoimmune diseases. Only 10% ( n = 19) were lost to follow-up, without sex-related differences ( P = 0.990). Seven of these 19 patients moved to other regions/abroad for personal reasons. Patient-reported satisfaction with the new diabetology team was moderate (31%) to high (61%), but 52% of women vs. 30% of men declared to have been fairly or very worried about transition ( P = 0.018) and 28% of women (vs. 11% of men) considered themselves minimally or not at all prepared ( P = 0.018). At 12 months ( n = 141), we observed a stability of HbA1c levels (58.0 ± 12.2 vs. 58.7 ± 12.5 mmol/mol, P = 0.414), confirmed in both sexes; HbA1c levels remained stable also at the end of follow-up ( n = 126; P = 0.122). HbA1c at joint visit was the only significant predictor of HbA1c worsening after transition, with a lower risk for higher baseline levels (OR 0.96 [95% CI 0.93–0.99] for 1 mmol/mol increase; P = 0.021). Conclusion In a structured transition program, we observed stable glycaemic control, low loss to follow-up, and high patient satisfaction. One third of losses was due to causes unrelated to diabetes. Women expressed more concern about transition and less preparedness but showed comparable glycaemic control over time.