Association between glycemia risk index and diabetic retinopathy in patients with type 2 diabetes mellitus: A cross-sectional study

Background Glycemia risk index (GRI), a composite metric derived from continuous glucose monitoring, has emerged as a novel indicator of glycemic burden. However, whether GRI is independently associated with diabetic retinopathy (DR) in patients with type 2 diabetes mellitus (T2DM) after adjustment for conventional glycemic measures remains unclear. This study aimed to investigate the independent association between GRI and DR in T2DM patients. Methods This cross-sectional study enrolled 349 T2DM patients at the Endocrinology and Metabolism Department of Shanghai General Hospital. Continuous glucose monitoring (CGM) data were collected over 14 days using the FreeStyle Libre system. Patients were stratified into tertiles based on GRI values. DR was diagnosed through standardized ophthalmological examination. Multivariable logistic regression models were used to examine the association between GRI and DR. Results Higher GRI tertiles were associated with longer diabetes duration, higher HbA1c levels, increased glycemic variability, lower time in range (TIR), and more prevalent insulin use (all P < 0.05). The prevalence of DR increased significantly across GRI tertiles (19.4, 29.9, and 34.7% in the low, middle, and high tertiles, respectively; P for trend = 0.018). After adjusting for confounders including HbA1c and TIR, the highest GRI tertile was associated with a 3.41-fold increased risk of DR compared to the lowest tertile (OR: 3.41, 95% CI: 1.03–11.34, P = 0.045). Subgroup analyses confirmed the consistent association between GRI and DR across various clinical characteristics (all P for interaction > 0.05). Conclusions GRI is independently associated with DR in T2DM patients, even after adjusting for conventional glycemic measures.