Use of Diluted Rapid-Acting Insulin in the Minimed™ 780G Automated Insulin Delivery System in a Young Child with Type 1 Diabetes

The MiniMed™ 780G automated insulin delivery (AID) system improves glycemic control in type 1 diabetes (T1D), but Auto Mode requires a total daily insulin dose (TDI) ≥8 U, limiting its use in young children or individuals in the honeymoon phase. We report a 2.5-year case of a child with T1D and TDI < 8 U successfully treated with diluted lispro insulin (1:1 with 0.9% NaCl) delivered via continuous subcutaneous insulin infusion in the 780G AID system. Auto Mode functioned stably, and the boy maintained excellent metabolic control: Time in Range > 80%, Time in Tight Range > 60%, Coefficient of Variation < 33%, and Glucose Management Indicator < 6.5%, with no clinically significant hypoglycemia. This case demonstrates that insulin dilution can safely enable AID in people with diabetes with very low TDI.