Mitigation Strategies for a Missed Meal Bolus in People with Type 1 Diabetes Using the Minimed™ 780G System

Postprandial glucose control remains a challenge in people with type 1 diabetes (T1D), even when using advanced hybrid closed-loop systems (AHCL) such as the MiniMed™ 780G (MM780G) system. Missed mealtime boluses are common and can significantly impair glycemic outcomes. This study aimed to evaluate a corrective postprandial bolus strategy for missed meal boluses using the MM780G system.

In a prospective, open-label, real-world study, 32 adults with T1D using the MM780G system completed three meal scenarios with standardized meals (∼60 g carbohydrates). The strategies were: (E1) premeal bolus (control), (E2) no bolus (relying on system automation), and (E3) delayed bolus (bolus covering 50% of carbohydrate content, 60 min postmeal). Each participant completed all strategies under remote supervision. Primary outcome was 4-h postprandial time in range (TIR, 70-180 mg/dL); secondary outcomes included time in tight range (TITR, 70-140 mg/dL), time above/below range, and adverse events.

Premeal bolus (E1) achieved the highest TIR (85.5% ± 18.8%), significantly outperforming both E2 (52.3% ± 25.3%) and E3 (63.5% ± 24.0%, P < 0.001). E3 also showed significant improvement over E2 (P < 0.001). TITR followed a similar pattern. Time between 54 and 70 mg/dL was slightly higher for E1 but remained within consensus goals. No significant differences in hypoglycemia (<54 mg/dL) were observed across strategies. Delayed bolus (E3) lowered time above 250 mg/dL compared with E2. No severe hypoglycemia or ketoacidosis occurred.

Premeal bolusing yields optimal postprandial glycemic control with the MM780G. However, when a meal bolus is missed, administering a corrective bolus of 50% carbohydrate content 1 h postmeal significantly improves TIR and TITR without increasing hypoglycemia risk. If correction is not performed, the MM780G system can provide a reasonable partial compensation via autobasal and auto-correction.