Metabolic and vascular outcomes after transition to the MiniMed 780G system in adults ≥65 years with type 1 diabetes: a randomised, single-centre study.

AIMS/HYPOTHESIS: Hybrid closed-loop insulin delivery systems are increasingly regarded as the preferred therapy for type 1 diabetes, although evidence in older adults remains limited. The aim of this randomised study was to evaluate the effectiveness and safety of the MiniMed 780G system in individuals with type 1 diabetes aged ≥65 years, with HbA1c<86 mmol/mol (10%), who were naive to this technology, with the primary endpoint based on glycaemic management (time in range). Vascular status and other glycaemic metrics were assessed as secondary outcomes. METHODS: This single-centre, open labelled (outcome assessors were not masked), randomised, controlled, parallel-group trial enrolled 34 participants who were randomly assigned in a 1:1 ratio using a computer-generated randomisation schedule to either advanced hybrid closed-loop (AHCL) therapy or control therapy (multiple daily injections or continuous subcutaneous insulin infusion) and followed for 12 months. RESULTS: Twenty-nine participants completed the study. Baseline characteristics, including glycaemic metrics, were comparable across groups (p>0.05). The AHCL group demonstrated a rapid and sustained improvement in glycaemic management, with time in range increasing from 57.4% at baseline to 79.7% at 12 months (p<0.001), accompanied by reductions in hyperglycaemia as reflected by time above range and time above range 2 (nominal p<0.001; p<0.001), and with no increase in hypoglycaemia across time below range and time below range 2 (nominal p=0.463; p=1). Adjusted between-group differences favoured AHCL for time in range (15.7% [95% CI 8.6, 22.6]) and HbA1c (-5 mmol/mol; [95% CI -9.7, -0.4 mmol/mol] [-0.46%; -0.89%, -0.04%]). No serious adverse events or episodes of diabetic ketoacidosis or severe hypoglycaemia occurred. Post-occlusive reactive hyperaemia showed a shortening of time to maximal flow in the AHCL group, indicating a favourable numerical trend towards improved microvascular function (nominal p>0.05). Retinal vascular status assessed using artificial intelligence remained stable throughout follow-up in both eyes (nominal p=0.710 and p=0.563, respectively). CONCLUSIONS/INTERPRETATION: The MiniMed 780G system appears effective for glycaemic management and safe for use in older adults with long-standing type 1 diabetes and a high burden of comorbidities. A non-statistically significant numerical tendency (p>0.05) in the improvement of vascular function that requires further confirmation was also observed. TRIAL REGISTRATION: ClinicalTrials.gov NCT06207838.