Open-label, Randomized Crossover Study Between Telmisartan and Valsartan on Improving Insulin Resistance and Adipocytokines in Nondiabetic Patients with Mild Hypertension

Objective: The comparative effect of telmisartan and valsartan upon insulin resistance and adipocytokines in nondiabetic patients with mild hypertension is unclear. Methods: Fifty nondiabetic patients with untreated mild hypertension were randomly assigned to telmisartan (40 mg/day) and valsartan (80 mg/day) groups and were switched in a crossover manner at 3-month intervals. Serum leptin, adiponectin, hsCRP and the HOMA-R were measured before and at 3 months during each treatment period. Results: The HOMA-R significantly improved over the 3 months in the high insulin resistance group (HOMA-R>/=2.5) during the telmisartan treatment period (p=0.042), but not during the valsartan period. Both telmisartan and valsartan significantly decreased serum leptin levels in each female group during each treatment period (p<0.001 and p<0.001, respectively), but not in the male groups. Serum adiponectin did not increase in either treatment group. Serum hsCRP levels also significantly decreased in the high hsCRP subjects (>/=0.1) of both treatment groups (p=0.044 and p=0.015, respectively). Conclusions: Telmisartan significantly improved insulin resistance, possibly through the effect on PPAR-gamma, while both telmisartan and valsartan significantly decreased serum leptin levels in female groups and hsCRP in both genders, suggesting no significantly different effects on adipocytokines by either drug in nondiabetic patients with mild hypertension.