BACKGROUND/OBJECTIVES: The aim of this study was to identify the sociodemographic and systemic risk factors associated with diabetic retinopathy (DR) across varying durations of diabetes mellitus (DM) and to evaluate the potential effect of anemia on the occurrence of DR. METHODS: The retrospective cross-sectional study was based on the National Health and Nutrition Examination Survey (NHANES) 2005-2020, which included a total of 2,487 participants with Type 2 diabetes mellitus. Individuals were stratified into two groups based on DM duration: group 1 (≤ 10 years) and group 2 (> 10 years). Univariate weighted logistic regression and weighted multivariate logistic regression with adjustment for covariates (Models 1-3) were used to explore the risk of DR occurrence across different DM durations, as well as the synergistic effect of DM duration and anemia on DR occurrence. RESULTS: Weighted univariate logistic regression analysis revealed that insulin use, diabetic nephropathy (DN), and education level were significantly associated with DR across both DM duration groups. In group 1, factors such as hemoglobin A1c, total cholesterol, low-density lipoprotein cholesterol, and fasting plasma glucose were positively correlated with DR, whereas an earlier age of DM diagnosis and higher family income were protective factors. In group 2, anemia and urinary albumin-to-creatinine ratio were positively associated with DR, whereas eGFR was negatively associated with DR (all p 10 years is an independent risk factor for DR (Model 3: OR = 1.53, 95% CI 1.08-2.16, p = 0.017). The combination of prolonged DM duration and anemia significantly increased the risk of DR, with a synergistic effect observed even after full adjustment (Model 3: OR = 2.24, 95% CI 1.30-3.84, p = 0.004). CONCLUSIONS: Sociodemographic and systemic risk factors for DR vary across DM duration groups. Insulin use, DN, and education level were significantly associated with DR in all DM duration groups. Notably, the combination of prolonged DM duration (> 10 years) and anemia significantly increased the risk of DR, demonstrating a synergistic effect.
Liu et al. (Thu,) studied this question.