Postprandial Glycemic Control With Automated Insulin Delivery With Control‐IQ Technology: The Impact of Meal Composition

Abstract

ABSTRACT Aims To evaluate the efficiency of the AID system with Control‐IQ technology and carbohydrate counting (CHC)–based premeal bolus to control postprandial glucose (PPG) after mixed meals with different macronutrient compositions in adolescents with type 1 diabetes (T1D). Material and Methods In this prospective crossover study, 25 adolescents with T1D using an automated insulin delivery (AID—Tandem Tslim X2 with Control‐IQ) consumed three iso‐caloric meals (745 kcal) on separate days: a standard meal (56.5% carbohydrate), a high‐fat (HF) meal (45.9% fat), and a high‐protein (HP) meal (24.4% protein). A CHC‐based bolus was administered 15 min before each meal. Continuous glucose monitoring metrics and AID insulin delivery were assessed over 6 h. The primary outcome was 6‐h time in range (TIR, 70–180 mg/dL). Results Six‐hour TIR was significantly lower after HF (65.2%) and HP meals (49.9%) compared with the standard meal (84.3%) (p < 0.01 and p < 0.001, respectively). Postprandial glucose exposure (AUC above 140 and 180 mg/dL) was significantly higher after HF and HP meals at both 3 and 6 h. The AID system delivered significantly more insulin than the pre‐programmed basal for HF (+26% at 6 h, p < 0.05) and HP meals (+55% at 6 h, p < 0.001), without increasing hypoglycemia. Conclusions Despite a substantial autonomous increase in insulin delivery, AID systems using Control‐IQ technology and a standard CHC‐based pre‐meal bolus have not achieved adequate postprandial glycemic control after HF and HP meals. Proactively timed, meal‐specific insulin strategies are required to improve postprandial outcomes after nutritionally complex meals.