Performance of an automated insulin-glucagon delivery system versus automated insulin delivery system during...

To assess the efficacy and safety of an automated insulin-glucagon delivery system (AIGD) compared with an automated insulin delivery system (AID).

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.

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.

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.