Association Between Diabetic Retinopathy and Flow- Mediated Vasodilation in Type 2 Diabetes

Abstract

Purpose: : Diabetes causes impaired vascular endothelial function. Flow-mediated vasodilation (FMD) has been established as a way to evaluate endothelial function. The main purpose of this study was to examine the association between the stages of diabetic retinopathy, macula edema (ME), and FMD in patients with type 2 diabetes.

Methods: : FMD was measured in patients with type 2 diabetes (n=106; mean age, 60.1±13.6 years) and control subjects without diabetes (n=21; mean age, 58.2±12.2 years) based on changes in the brachial artery diameter before the brachial artery was occluded with a cuff for 5 minutes at 50 mmHg above the systolic blood pressure and after the cuff was released. Patients with diabetes were categorized as having no diabetic retinopathy (NDR), simple diabetic retinopathy (SDR), or proliferative diabetic retinopathy (PDR). We investigated the association between NDR (n=48), SDR (n=33), PDR (n=25) and FMD, duration of diabetes and FMD, and ME and FMD.

Results: : There was a significant (p<0.05) decrease in FMD in patients with diabetes (5.0±3.2%) compared with nondiabetic subjects (8.6±2.8%). In patients with diabetes, FMD was significantly negatively correlated with the disease duration. There was no significant difference between SDR and NDR in FMD, but there were significant decreases in PDR compared with SDR. There was no significant difference between patients with and without ME.

Conclusions: : In patients with type 2 diabetes, FMD was significantly negatively correlated with disease duration, but there was no association between ME and FMD.

Keywords: diabetic retinopathy • retina