Association of Continuous Glucose Monitoring Metrics with Incident Diabetic Retinopathy: A Real-World Long-Term Study

We analyzed data from 2253 veterans with type 1 (34%) or type 2 (66%) diabetes who initiated Dexcom continuous glucose monitoring (CGM) between 2015 and 2022, all with ≥10 days of data over a 6-month landmark period. CGM data were merged with electronic health records (EHR). Diabetic retinopathy (DR) was defined from EHR diagnoses. Incident DR was assessed up to 4 years from CGM initiation. Cox models evaluated associations between CGM metrics (mean glucose [MG], time in range [TIR], time above range [TAR], glycemia risk index [GRI], coefficient of variation, and week-to-week average real variability [ARV]) and DR. There were 99 incident DR events. In separate multivariable models, higher MG, TAR, GRI, and ARV, and lower TIR were associated with DR risk; these associations (except ARV) remained significant after landmark HbA1c adjustment and were stronger than for landmark HbA1c itself, suggesting that CGM metrics provide more informative risk stratification than HbA1c alone.