Performance of an automated insulin-glucagon delivery system versus automated insulin delivery system during challenging inpatient conditions. A single-blind randomised controlled crossover trial

Aims: To assess the efficacy and safety of an automated insulin-glucagon delivery system (AIGD) compared with an automated insulin delivery system (AID). Materials and methods: In a 33-h, randomised, crossover, inpatient study, 13 participants with type 1 diabetes used the DiaCon system in AIGD and AID modes. Each study period included two overnight stays and standardised challenges: receiving 50% of the calculated insulin bolus for breakfast, 100% bolus for lunch, 130% bolus for dinner, and a 45-min unannounced bicycle exercise at 50% VO _2max. Co-primary endpoints were (1) number of 15-g carbohydrate treatments for plasma glucose <3.0 mmol/L, and (2) percentage of time below 3.9 mmol/L. Results: The number of carbohydrate rescues was lower with AIGD versus AID (15 vs. 20, p = 0.02). Percent time below range (mean ± SD 3.7 ± 2.5% vs. 3.9 ± 3.1%, p = 0.49), in range (TIR) 3.9–10.0 mmol/L (68.8 ± 14.9% vs. 66.9 ± 10.2%, p = 0.41) and above range >10.0 mmol/L (27.5 ± 14.8% vs. 29.2 ± 10.4%, p = 0.46) were similar. Mean glucose and coefficient of variation were comparable between AIGD versus AID (p = 0.30). The post hoc analysis demonstrated that AIGD had significantly higher TIR 0–3 h after exercise and fewer hypoglycaemia events (<3.9 mmol/L) 0–3 h after each meal. No differences were observed in nausea, headache, hunger, and palpitation. Conclusions: Under challenging inpatient conditions, the AIGD system provided similar glucose control as AID but significantly reduced the need for carbohydrate rescue and enhanced TIR after exercise.