Glycemic Variability and Other Risk Factors for Diabetic Retinopathy

Abstract

Background: Hyperglycemia is a known risk factor for diabetic retinopathy (DR) but the association between glycemic variability and DR is unclear. We aim to evaluate the glycemic variability in DR through retrospective continuous glucose monitoring (CGM) and assess its effect on the clinical profile of participants with or without DR. Material and Methods: Retrospective observational hospital-based case-control study. We collected anthropometric and clinical data of 74 people with type 2 diabetes from our ophthalmology database whose retrospective CGM data were available. Among them, 37 had DR (cases) and 37 did not have DR (controls). The data were analyzed using SPSS version 27. Results: Duration of diabetes and glycosylated hemoglobin (HbA1c) was significantly higher and the estimated glomerular filtration rate (eGFR) was significantly lower in the cases compared to the controls. CGM markers, like time-above-range, average glucose, glucose management indicator, were higher while time-in-range was lower in the cases compared to the controls (P = ns). Time-below-range targets in people >65 years were met in a lower proportion (p < 0.05) of people in the cases (50%) compared to the controls (92%). Conclusion: Duration of diabetes, low eGFR, and high HbA1c showed significant association with retinopathy in type 2 diabetes. Although markers of glycemic variability did not show a statistically significant difference in cases compared to controls, all indices of glycemic variability were numerically higher in people with DR. Hypoglycemia in elderly participants with DR and its implications on achieving targets requires more research.