Introduction:
Advanced hybrid closed loop (AHCL) insulin delivery systems offer considerable benefits to individuals with type 1 diabetes (T1D) in terms of glucose control and quality of life. With increasing numbers of regular users, real-life long-term data on long-term AHCL effectiveness become available.

Material and methods:
This was a single-centre retrospective study. We included children and young adults (age 5–25 years ) with established T1D (≥ 3 m) who started MiniMed780G therapy between January 2021 and April 2022. We excluded those naïve to continuous glucose monitoring (CGM) or insulin pumps, as well as those without good-quality baseline CGM data. Included patients were followed for 12 months, with CGM and pump data retrieved from 14-day periods before transition and 3, 6, 9, and 12 months following the start of automode. Clinical data (body weight, height, glycated haemoglobin concentration) were recorded from the most recent outpatient visits.

Results:
Among 81 patients who started AHCL therapy, 46 met the criteria for analysis (mean age 11.5 ±4.4 years, diabetes duration 4.4 ±3.6 years, mean glycated haemoglobin 7.0 ±1.0%). Over the year following transition, we noted a significant improvement in time in target range 70–180 mg/dl (TIR, baseline: 69.1 ±12.0% to 12 m: 76.9 ±8.5%, p < 0.0001) and time in tight range 70–140 mg/dl (baseline: 45.3 ±14.2% to 12 m: 53.3 ±10.4%, p < 0.0001). Time below target range 70 mg/dl (TBR70 mg/dl) decreased significantly for 24-hour records (p = 0.0020). Importantly, those improvements were not accompanied by an increase in daily dose of insulin or body mass index.

Conclusions:
A prolonged 12-month-long observation in a routine care setting demonstrates that for young CGM- and pump users with T1D, switch AHCL offers sustained benefits in glucose variability.