Use of the loop open-source automated insulin delivery system in children with Type 1 diabetes: six-month results from a single center

Abstract

Introduction: As an alternative to commercial automated insulin delivery (AID) systems, open-source AID (OS-AID) technologies such as Loop had growing interest among people with type 1 diabetes (T1D). This study aimed to evaluate the 6-month glycemic outcomes of children using the Loop iOS.3 system. Methods: A total of 50 children aged 2-18 years with a minimum 6-month T1D duration initiated Loop OS-AID between May 2023 and May 2024. Data from continuous glucose monitoring and insulin delivery were collected and analyzed at baseline, 3 months, and 6 months. Primary outcomes included time in range (TIR, 3.9-10 mmol/L [70-180 mg/dL]), time above range (TAR), time below range (TBR), glucose management indicator, and HbA1c. Results: TIR improved significantly from 68.3% at baseline to 72.7% at 6 months (p = 0.003). The proportion of participants with TIR >70% increased from 46% to 66% (p = 0.012). The mean HbA1c value showed a significant decrease from baseline to month 6 (53 mmol/mol [7.0%] vs. 49 mmol/mol [6.6%], p = 0.006), although HbA1c measurements were available for a limited number of participants. TAR1 >10 mmol/L (180 mg/dL) decreased (2 vs. 17.1, p < 0.001), while TAR2 >13.8 mmol/L (250 mg/dL) showed a slight, nonsignificant reduction (5 vs. 4, p = 0.363). TBR1 <3.9 mmol/L (70 mg/dL) and TBR2 <3 mmol/L (54 mg/dL) remained stable (3 vs. 3, p(1) = 0.474

0.7 vs. 0.9, p(2) = 0.560). The basal insulin ratio dropped significantly (40.3% vs. 19.7%, p < 0.001), suggesting a shift in dosing dynamics due to the algorithm's automatic correction bolus strategy. Conclusion: Use of the Loop OS-AID system resulted in improved glycemic outcomes without increased risk of hypoglycemia or diabetic ketoacidosis. These findings support Loop as a safe and effective alternative for pediatric T1D management. Further large-scale and longer term studies are warranted.