Acute effects of valsartan on insulin sensitivity in obese, non-hypertensive subjects with and without type 2 diabetes

Background: Two studies were designed to determine whether a single dose (80 mg) of the angiotensin II receptor blocker (ARB), valsartan, alters insulin sensitivity in obese, non-hypertensive subjects with and without Type 2 diabetes. Methods: Insulin sensitivity (S-I), glucose effectiveness (S-G), and acute insulin response (AIR(0-10min)) were measured by means of a 3-hour insulin-modified frequently sampled intravenous glucose tolerance test (FSIVGTT) before and after a single dose of valsartan. Study 1: obese, normotensive non-diabetic male subjects (n = 12), mean (SD) age 37.2 +/- 11.2 years, BMI 32.8 +/- 6.8 kg/m(2); Study 2: obese, normotensive Type 2 diabetic patients (n = 12), mean age 55.7 +/- 6.9 years, BMI 35.0 +/- 6.8 kg/m(2)/l. Both studies were randomised, double-blind, placebo-controlled, single-dose crossover group studies involving subjects in two study days, two weeks apart. After fasting samples were taken, a 300 mg/kg iv glucose bolus was injected at 0 min, and 0.05 U/kg iv insulin was given 20 min later. Blood samples for analysis of glucose and insulin were taken throughout the 3-hour study period. Results: Study 1 (non-diabetic subjects) S-I 2.81 vs. 2.63 x 10(-4) min(-1) per muU/mI (p=0.54), S-G 0.020 vs. 0.020 min(-1) (p=0.90), AlR0-10min 3305 vs. 3450 muU/min/ml (p = 0.71); Study 2 (patients with type 2 diabetes) S-I 0.59 vs. 0.85 x 10(-4) min(-1) per muU/ml (p = 0.15), S-G 0.013 vs. 0.014 min(-1) (p = 0.71), AIR(0-10min) 65 vs. 119 muU/min/ml (p=0.14), placebo vs. valsartan, respectively. Conclusion: In obese, non-hypertensive non-diabetic and Type 2 diabetic subjects a single dose of valsartan does not alter insulin sensitivity.