J Korean Med Sci. 2026 Apr 13;41(14):e34. doi: 10.3346/jkms.2026.41.e34.
ABSTRACT
BACKGROUND: Hybrid closed-loop (HCL) systems adjust basal insulin levels using real-time glucose levels obtained from continuous glucose monitors (CGM). This study evaluated the MiniMed 770G system in Korean youths with childhood-onset type 1 diabetes (T1D).
METHODS: Of the 457 patients followed-up for childhood-onset T1D for > 1 year at Seoul National University Children’s Hospital and Seoul National University Bundang Hospital between February 2022 and May 2023, 20 patients (10 boys, 10 girls) who used a MiniMed 770G system for ≥ 3 months with a CGM active time of > 70% were enrolled. Glycemic outcomes, including glycated hemoglobin A1c (HbA1c), and CGM-derived metrics (time in range [TIR], time below range, time above range > 180 mg/dL and > 250 mg/dL [TAR 180 and TAR 250], and coefficient of variation [CV]) were analyzed. Generalized estimating equation (GEE) analysis compared glycemic outcomes between auto-mode users (> 85% and ≤ 85%) during the 1-year follow-up.
RESULTS: The median age at HCL initiation was 14.0 years (interquartile range [IQR], 11.2, 17.9), with a median diabetes duration of 6.5 years (IQR, 5.7, 8.9). The numbers of auto-mode (> 85%) users at 3, 6, 9, and 12 months were 10, 9, 9, and 7, respectively. Compared to auto-mode (≤ 85%) users, auto-mode (> 85%) users demonstrated 0.75 lower HbA1c (P = 0.037), 7.0 higher TIR (P = 0.015), 6.7 lower TAR 180 (P = 0.031), and 3.2 lower CV (P = 0.001) during the year using GEE analysis. In an analysis of auto-mode (> 85%) users, the median TIR, TAR, and CV significantly improved from 59% at baseline to 74.5% at 3 months (P = 0.008), and from 65% at baseline to 73% at 6 months (P = 0.012). Neither severe hypoglycemia nor diabetic ketoacidosis was observed throughout the year. The most common reasons for auto-mode exit were hyperglycemia and a lack of calibration.
CONCLUSION: Use of HCL system with auto-mode (> 85%) enhanced glycemic control in youth with childhood-onset T1D during the study period.
PMID:41978923 | DOI:10.3346/jkms.2026.41.e34
