The Levels of the Circulating Cellular Adhesion Molecules ICAM-1, VCAM-1 and Endothelin-1 and the Flow-mediated Vasodilatation Values in Patients with Type 1 Diabetes Mellitus with Early-stage Diabetic Retinopathy

Objective Endothelial dysfunction plays an important role in the development of diabetic retinopathy. The aim of this study was to evaluate endothelial dysfunction using different approaches in patients with type 1 diabete mellitus with early stages of diabetic retinopathy. For this purpose, we investigated the serum levels of cellular adhesion molecules, including intercellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1) and endothelin-1 (ET-1), which have emerged as specific markers of endothelial dysfunction, and measured the flow-mediated dilatation (FMD), a noninvasive technique used to evaluate endothelial dysfunction. Methods The study group included 59 patients with type 1 diabetes mellitus (DM) and 30 age-matched healthy control subjects. The diabetic patients were divided into two groups according to the ophthalmoscopic findings: Group 1, composed of type 1 diabetic patients having no signs of diabetic retinopathy (DRP), and Group 2, composed of type 1 diabetic patients having findings of the early stages of nonproliferative diabetic retinopathy (NPDR). Results The serum levels of ET-1 (fmol/mL), ICAM-1 (ng/mL) and VCAM-1 (ng/mL) were 8.52 +/- 0.699 vs. 478.39 +/- 46.22 vs. 728.64 +/- 35.081 in the patients without retinopathy, 8.91 +/- 1.354 vs. 451.79 +/- 48.262 vs. 863.59 +/- 62.37 in the diabetic patients with NPDR and 10.73 +/- 1.04 vs. 608.15 +/- 74.92 vs. 872.95 +/- 57.63 in the control group. There were no significant differences in the serum levels of the three molecules between the groups. The FMD values were 6.51 +/- 0.46% in the diabetic patients without retinopathy, 6.66 +/- 0.29% in the diabetic patients with NPDR and 6.68 +/- 0.51% in the control group. No significant differences were found between the groups. Conclusion The early stages of diabetic retinopathy cannot be considered in the evaluation of systemic markers of endothelial dysfunction.