Endothelial dysfuntion in insulin resistance syndrome

Abstract EN

The objective of this study was to determine and correlate the plasma level of Tumour necrosis factor-a (TNF-a) and Endothelin-l (ET-l) in type 2 diabetic patients with different types of obesity and to find out their correlation with the degree of glycaemic control and serum lipid levels.

The study was performed on three groups of non smoker, type 2 diabetic patients, they were divided into 15 lean patients, 15 gynoid obese patients and 15 android obese patients.

Plasma levels of fasting and 2- hours postprandial glucose, cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol were determined Plasma levels of TNF-a and ET-l were also determined.

The data were analyzed according to student's "t" test and Pearson's correlation coefficient.

TNF-a plasma levels showed significant elevation in android obese diabetics as compared to lean diabetics, due to increased expression from adipose tissue (in the visceral fat).

TNF-a levels showed a significant (P<0.01) positive correlation with both BM1 and ET-l in android obese group only.

Plasma levels of ET-l were also found to be significantly (P<0.01) high in android obese diabetics as compared to lean diabetics.

This was attributed to interaction between TNF-a (present in high levels in android obese patients) and insulin, leading to elevation of ET-1 level.

ET-1 levels showed a significant (P<0.01) positive correlation with BMI in android obese patients only.

We concluded that the insulin resistance syndrome (IRS) is associated with endothelial dysfunction (it is possible that endothelial dysfunction is caused by some other features of IRS or could itself be a common antecedent mechanism) and TNF-a and ET-1 could be a marker to both.

Our data suggest an important role for TNF-a in the pathogenesis of human insulin resistance syndrome as occur in android obesity and type 2 diabetic patients.