The Association between High-Density Lipoprotein Cholesterol and Diabetic Retinopathy : A Cross-Sectional Study in patients with type 2 diabetic mellitus

Background Diabetic retinopathy (DR) is a major microvascular complication of diabetes mellitus and a leading cause of visual impairment. While dyslipidemia has been implicated in DR pathogenesis, the relationship between high-density lipoprotein cholesterol (HDL-C) and DR remains controversial. This study aimed to investigate the association between HDL-C levels and DR prevalence in patients with type 2 diabetes mellitus (T2DM). Methods A total of 2001 (858 men and 1143 women) patients with T2DM who visited the diabetic clinic in the Internal Medicine out-patient departments of two hospitals in southern Taiwan between April 2002 and November 2004. Demographic and clinical data were collected, and serum HDL-C levels were measured. The association between HDL-C and DR was analyzed using multivariate logistic regression, adjusting for potential confounders and the potential non-line correlation was explored with smooth curve fitting approach. Results Among the 2001 participants, 701 (35.0%) were diagnosed with DR. Our findings revealed a significant inverse linear relationship between HDL-C levels and the risk of DR, with an odds ratio of 0.91 (95% confidence interval: 0.84 to 0.98, p = 0.0327). This suggests that higher HDL-C levels are associated with a reduced risk of developing DR. In the subgroup analysis, the linear correlation between HDL-C and DR was also found in female, different age stage and different DBP stage. Conclusions This study provides a linear relationship evidence that elevated HDL-C levels are associated with a decreased risk of DR in patients with T2DM. Future research should further explore the mechanisms underlying this association and its implications for therapeutic strategies.