O-20: Regulation of unannounced meals by a closed loop system in adolescents with type 1 diabetes; a multicentre, open-label, randomised, non inferiority trial in real life
G Vermillac, S Franc, M Doron, K Casteels, T Danne, T Biester, C Godot, A Besançon, D Kariyawasam, A Nguyen-Quoc, J Weiskorn, F Reschke, P -Y Benhamou, G Charpentier, J BeltrandAbstract
Introduction
Adolescents with type 1 diabetes (T1D) using hybrid closed-loop systems frequently omit meal announcements, leading to missed pre-prandial boluses and impaired postprandial glycaemic control. Recurrent bolus omission contributes to suboptimal glycaemic outcomes and increases the risk of acute and long-term complications. Evaluating system performance without meal announcement is therefore clinically relevant in this high-risk population.
Objectives
Compare glycaemic control with versus without meal announcement in adolescents with poorly controlled T1D using a closed loop system, and to assess safety.
Methods
It was an international, multicentre, open-label, randomised, crossover, non-inferiority trial in adolescents aged 12–17 years with T1D duration ≥1 year and HbA1c >8% (64 mmol/mol), previously treated with insulin pump therapy or multiple daily injections. After a 14-day baseline phase, participants underwent two consecutive 4-week crossover periods with announced or unannounced meals. The primary endpoint, analysed in the intention-to-treat population, was the mean percentage of time in range (TIR 70–180 mg/dL), with a non-inferiority margin of –2.5%. Secondary endpoints included other glycaemic metrics and safety outcomes, particularly hypoglycaemia.
Results
Between Jan 25 and Nov 22, 2023, 49 adolescents were enrolled. Mean TIR was 54.5% (SD 9.1) during unannounced periods and 60.5% (SD 8.7) during announced periods. The adjusted mean difference (-6·1%, SD 8·9) was not significantly different from zero (p < 0·0001 for rejection of the null hypothesis). No severe hypoglycaemia, diabetic ketoacidosis, or fatal adverse events occurred.
Conclusions
The system prevented hyperglycaemic excursions after unannounced meals in adolescents with T1D and no increase in severe adverse events. These findings support the safe use of hybrid closed-loop technology in adolescents with poorly controlled T1D, even when meal boluses are omitted.