Insulin resistance is present in patients with Type 2 diabetes mellitus as well as in obese patients without diabetes. The aim of our study was to compare insulin action in diabetic and control persons with or without obesity and to evaluate the influence of serum cholesterol, serum triglyceride and blood pressure on metabolic variables of insulin action. We examined 42 Type 2 diabetic patients and 41 control persons with body mass index (BMI) from 21.1 to 64.5 kg x m(-2), and 33 to 71 years old. The isoglycemic hyperinsulinemic clamp technique was performed at an insulin infusion rate of 1 mU x kg(-1) x min(-1) during 120 min. We evaluated the metabolic clearance rate of glucose (MCR(G), ml x kg(-1) x min(-1)) as the most important indicator of insulin action by isoglycemic clamp. The Pearson's correlation and multiple regression models were used to compare studied factors with the insulin action. We found following predictors of insulin resistance expressed in the relationship with MCR(G): BMI (r = -0.68, p<0.001), plasma glucose concentration (r = -0.66, p<0.001), cholesterol (r=-0.55, p<0.001), triglycerides (r = -0.54, p<0.001) and mean blood pressure (r = -0.38, p<0.01). From the multiple regression analysis we conclude that obesity may have even greater influence on the insulin action than diabetes mellitus itself.

3rd Department of Internal Medicine 1st Faculty of Medicine Charles University Prague Czech Republic

Acute hyperglycemia does not impair microvascular reactivity and endothelial function during hyperinsulinemic isoglycemic and hyperglycemic clamp in type 1 diabetic patients