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.

Objective Prediabetes is a condition between a normal metabolic state and diabetes mellitus, which includes impaired glucose tolerance (IGT), impaired fasting glucose (IFG), or both. Prediabetes is related with undesirable cardiovascular outcomes. Epicardial fat thickness (EFT) has been correlated with cardiovascular risk factors. We herein aimed to assess EFT in prediabetic patients. Methods We evaluated 64 patients with prediabetes and 30 age-and gender-matched healthy subjects. Demographic and anthropometric characteristics [age, sex, height, weight, body mass index (BMI), and waist circumference (WC)] and laboratory findings [fasting plasma glucose (FPG), postprandial plasma glucose (PPG), hemoglobin A1c (HbA1c), low density lipoprotein (LDL), high density lipoprotein (HDL), and triglycerides (TG)] were assessed. Transthoracic echocardiography was used to evaluate EFT. Results There were no significant differences between the case and control groups in terms of age, gender, height, HDL, WC, systolic and diastolic blood pressure (SBP/DBP), or TG (p>0.05). Body weight, BMI, FPG, LDL, and, in particular, EFT were found to be significantly higher in the case group than control group (p<0.05). When compared with the control group, the median EFT was significantly higher in all prediabetic subgroups (IGT or IFG, p<0.001). However, no statistically significant difference was found between each case subgroup (p=0.795). When groups were adjusted according to age, sex, WC, and BMI with covariance test, the EFT remained increased in the prediabetes subgroups compared to the controls (p<0.001). Conclusion We found the EFT levels to be increased in all subgroups of prediabetic patients regardless of FPG and HbA1c. Furthermore, EFT directly correlated with the patients' BMI and WC.