Background and Aims: Carbohydrate counting is a well-established tool for self-management of type 1 diabetes (T1D) and can improve glycemic control and potentially reduce long-term complication risk. However, it can also be burdensome, error-prone, and complicated for the patient. A randomized controlled trial was conducted to investigate glycemic control with carbohydrate counting ("flex") versus simplified meal announcement ("fix") in adolescents with T1D using the MiniMed™ 780G system. The present study reports follow-up data to 12 months. Methods: Adolescents with T1D were randomly assigned 1:1 to use the MiniMed™ 780G system alongside the flex versus fix approaches. Participants were followed for 12 months with outcomes recorded at 3, 6, 9, and 12 months. The primary endpoint was the difference in time-in-range (TIR), and secondary endpoints included glycated hemoglobin (HbA1c) and other glucose and insulin metrics. Results: At 12 months, TIR (proportion of time with sensor glucose 70-180 mg/dL) was significantly lower in the fix versus flex group (72.9% vs. 80.1%, respectively; P = 0.001). There was no significant difference in HbA1c between the fix (6.8% ± 0.5%) and flex groups (6.5% ± 0.5%) at 12 months (P = 0.092), and mean HbA1c was below 7% at all time points in both arms. Conclusions: Glycemic control with simplified meal announcement was maintained over 12 months. On average, the international consensus targets were met in both arms for all time points. The simplified approach represents a viable alternative to carbohydrate counting, particularly in people who find the latter burdensome; however, carbohydrate counting resulted in superior TIR. This study is registered with ClinicalTrials.gov, number NCT05069727.
Keywords: Blood glucose; Diabetes mellitus; Dietary carbohydrates; Hypoglycemic agents; Insulin infusion systems; Type 1.