Abstract
Background: The association between long-term glycemic variability and diabetic retinopathy (DR) among patients with type 2 diabetes has not been clarified yet. Objective: The aim of this study was to investigate the association of visit-to-visit variability of hemoglobin A1c (HbA1c) and glycated albumin (GA) with the risk of DR in patients with type 2 diabetes. Design: A prospective cohort study of 315 patients (191 males and 124 females) with at least 3 measurements of HbA1c and GA prior to baseline was performed. Different GA and HbA1c variability markers were calculated, including coefficient of variation (CV), variability independent of the mean (VIM), and the average real variability (ARV). Cox proportional hazard regression models were used to explore the association between visit-to-visit HbA1c and GA variability and the risk of DR. Results: During a mean follow-up period of 3.42 years, 81 participants developed incident DR. Multivariate-adjusted hazard ratios (HRs) of DR across tertiles of GA-CV values were 1.00, 1.42, and 2.12 (P for trend=0.027), respectively. When we used GA-VIM and GA-ARV values as exposures, similar positive associations with the risk of DR were found. Multivariable-adjusted HRs of DR associated with each unit increase in GA-CV, GA-VIM, and GA-ARV were 1.05 (95% CI 1.02-1.09), 1.69 (95% CI 1.24-2.32), and 1.13 (95%CI 1.04-1.23), respectively. However, there was no significant association between visit-to-visit variability of HbA1c and the risk of DR after multivariate adjustment. Conclusion: The visit-to-visit variability of GA can predict the risk of incident DR in patients with type 2 diabetes, and the prediction ability is independent of the average HbA1c levels.