Carbohydrate Tolerance Threshold for Unannounced Snacks in Children and Adolescents With Type 1 Diabetes Using an Advanced Hybrid Closed-Loop System

OBJECTIVE: To find a carbohydrate (CHO) tolerance threshold for unannounced snacks to avoid the 2 h increase in glycemia (difference between pre- and postmeal blood glucose [ΔBG]) ≥50 mg/dL in advanced hybrid closed-loop (a-HCL) users. RESEARCH DESIGN AND METHODS: Fourteen children and adolescents with type 1 diabetes (7 females; mean age [± SD] 14.5 ± 3.6 years), users of the Medtronic MiniMed 780G, participated in the study. For 12 days, they did not perform insulin bolus before breakfasts, with defined different quantities and types of CHO, with or without fats, performing blood glucose (BG) before and 2 h after the meal. RESULTS: A cutoff of 19.8 g of total CHO was found to determine a ΔBG of 50 mg/dL. BG never exceeded 250 mg/dL. Mean time in range was ≥70% in the 2 h following each snack. CONCLUSIONS: Unannounced snacks of up to 20 g of CHO can avoid ΔBG ≥50 mg/dL in MiniMed 780G users, although unannounced meals of up to 30 g of CHO are safe.