Current Status of Continuous Glucose Monitoring Use in South Korean Type 1 Diabetes Mellitus Population– Pronounced Age-Related Disparities: Nationwide Cohort Study

Background: This study aims to identify the status of continuous glucose monitoring (CGM) use among individuals with type 1 diabetes mellitus (T1DM) in South Korea and to investigate whether age-related disparities exist. Methods: Individuals with T1DM receiving intensive insulin therapy were identified from the Korean National Health Insurance Cohort (2019–2022). Characteristics of CGM users and non-users were compared, and the prescription rates of CGM and sen-sor-augmented pump (SAP) or automated insulin delivery (AID) systems according to age groups (<19, 19–39, 40–59, and ≥60 years) were analyzed using chi-square tests. Glycosylated hemoglobin (HbA1c) levels and coefficients of variation (CV) among CGM users were also examined. Results: Among the 56,908 individuals with T1DM, 10,822 (19.0%) used CGM at least once, and 6,073 (10.7%) used CGM continuously. Only 241 (0.4%) individuals utilized either SAP or AID systems. CGM users were younger than non-users. The continuous prescription rate of CGM was highest among individuals aged <19 years (37.0%), followed by those aged 19–39 years (15.8%), 40–59 years (10.7%), and ≥60 years (3.9%) (P<0.001 for between-group differences). Among CGM users, HbA1c levels decreased from 8.7%±2.4% at baseline to 7.2%±1.2% at 24 months, and CV decreased from 36.6%±11.9% at 3 months to 34.1%±12.7% at 24 months. Conclusion: Despite national reimbursement for CGM devices, the prescription rates of CGM remain low, particularly among older adults. Given the improvements in HbA1c and CV following CGM initiation, more efforts are needed to increase CGM utilization and reduce age-related disparities.