Comparative Effect of Valsartan and Amlodipine on Insulin Resistance in Hypertensive Patients

Objectives: To study the effect of commonly used first line antihypertensive drugs valsartan and amlodipine on insulin resistance parameters in hypertensive patients free from type 2 diabetes mellitus. Patients and methods: In a prospective, randomized study, 32 non-diabetic patients with mild to moderate hypertension attending private clinics in Mosul city were recruited. The patients were randomized into two treatment groups to receive either amlodipine in the dose range of 5-10 mg daily or valsartan in the dose range of 80-160 mg daily. At baseline and 8 weeks of treatment fasting serum glucose (FSG), fasting serum insulin (FSI), homeostasis model assessment for insulin resistance (HOMA-IR), mean systolic and diastolic blood pressures levels were determined. Results: Intragroup comparison showed that after 8 week treatment with amlodipine and valsartan, SBP, DBP, FSI and HOMA-IR for both groups were significantly decreased in comparison with baseline data while FSG where non significantly decreased. Valsartan reduce SBP, FSG, FSI and HOMA-IR more than amlodipine but this reduction was not statistically significant. Conclusion: This study showed that the antihypertensive drugs amlodipine and valsartan have favorable effects on insulin resistance mediated by decreasing HOMA-IR in non-diabetic hypertensive patients. Also, this study illustrated that valsartan seems to have a more potent effect of lowering HOMA-IR than amlodipine in the standard dose.