Endothelial Dysfunction in Type 2 Diabetes Patients and its Association with Microvascular Complications: A Cross-sectional Study

Abstract

Introduction: The prevalence of Type 2 Diabetes Mellitus (T2DM) is increasing worldwide. Microangiopathic and macroangiopathic complications are the main causes of morbidity and mortality in diabetes. Endothelial dysfunction is important in the early pathophysiology of vascular complications. Screening is very important in order to prevent these complications. Aim: To investigate endothelial dysfunction, as measured by Flow Mediated Vasodilation (FMD) of the brachial artery, in diabetic individuals. It also aims to explore the correlation between FMD and Glycated Haemoglobin (HbA1c), as well as the association between FMD and microvascular complications such as diabetic neuropathy, diabetic retinopathy, and albuminuria. Materials and Methods: This cross-sectional study was conducted at Mahatma Gandhi Medical College and Research Institute, Puducherry, India, between 2020 and 2021 on 160 patients. All patients diagnosed with T2DM, attending the Outpatient Department (OPD) or admitted to the ward, were enrolled in the study using consecutive sampling. FMD was measured for each patient, and Urine Albumin Creatinine Ratio (UACR) was also assessed. Diabetic retinopathy was evaluated through fundus examination, and diabetic neuropathy was screened using the monofilament test. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) version 27.0 to determine the correlation between FMD and these variables. Results: A total of 160 patients were enrolled in this study, including 104 (65%) males and 56 (35%) females. The median age was 52 years, and the participants had a median Body Mass Index (BMI) of 29.5 kg/m2 . The median HbA1c was 8.7%. The median Fasting Blood Sugar (FBS) and Postprandial Blood Sugar (PPBS) levels were 145 mg/dL and 242 mg/dL, respectively. The median FMD among all patients was 5.6%, with an Interquartile Range (IQR) of 4.9% to 6.6%. There was an inverse correlation between HbA1C and FMD values, with a correlation coefficient of -0.718 (p-value <0.01), indicating a strong and significant inverse correlation. Patients with significant macroalbuminuria had a lower median FMD compared to non albuminuric patients, and this difference was statistically significant. The median FMD was also lower in patients with diabetic neuropathy and retinopathy. Conclusion: The study findings suggest that endothelial dysfunction, as measured by FMD, is significantly impaired in patients with elevated HbA1c and microvascular complications of diabetes mellitus.

Keywords

• endothelium
• hyperglycaemia
• nitric oxide
• vasodilation