Diabetic Retinopathy and Endothelial Dysfunction in Patients with Type 2 Diabetes Mellitus

Background: We investigated the relationship between endothelial dysfunction and diabetic retinopathy (DR) in patients with type 2 diabetes. Methods: We used a cross-sectional design to examine 167 patients with type 2 diabetes mellitus. All patients underwent biochemical and ophthalmological examination. We assessed endothelial dysfunction by a flow-mediated vasodilation method of the brachial artery. Changes in vasodilation (flow-mediated vasodilatation, % FMD) were expressed as percent change over baseline values. Results: The mean+/- standard deviation of patient age was 54.1+/-8.6 years. The % FMD was significantly lower in patients with DR than without DR. The prevalence of retinopathy decreased across increasing tertiles of % FMD. After adjusting for patients' age, sex, diabetes duration, use of insulin, use of antihypertensive, antiplatelet, and lipid lowering medications, systolic blood pressure, fasting plasma glucose, 2-hour plasma glucose, glycated hemoglobin, and urinary albumin excretion, participants with a reduced % FMD were more likely to have DR (odds ratio, 11.819; 95% confidence interval, 2.201 to 63.461; P= 0.004, comparing the lowest and highest tertiles of % FMD). Conclusion: Endothelial dysfunction was associated with DR, which was most apparent when the endothelial dysfunction was severe. Our study provides insights into the possible mechanism of the influence of endothelial dysfunction on the development of DR.