Introduction: The clinical dose of telmisartan necessary for activation of peroxisome proliferator-activated receptor gamma (PPAR-gamma) has not been established. The authors investigated the effect of high-dose telmisartan on serum levels of the high-molecular-weight (HMW) adiponectin in patients with diabetes and hypertension.
Methods: In this open-label, prospective, randomized study, patients with type 2 diabetes and hypertension with poor control of blood pressure by 40 mg/day telmisartan were randomly assigned into the telmisartan 80 mg/day (Tel80) group (dose increase from 40 to 80 mg/day) or the telmisartan 40 mg + amlodipine 5 mg (Tel40 + Aml5) group. Serum levels of HMW adiponectin and parameters of glucose and lipid metabolism were measured at baseline and end of 3-months of treatment.
Results: Although the antihypertensive effects of the two doses of telmisartan were similar, a significant increase in HMW adiponectin levels was noted only in the Tel80 group. The increase was evident particularly in a group of patients whose HMW adiponectin levels were less than 4.0 μg/dL. A significant improvement in homeostasis model assessment of insulin resistance (HOMA-IR), a measure of insulin resistance, was also observed in the Tel80 group only.
Conclusions: In diabetic patients with hypertension, high-dose telmisartan increased HMW adiponectin levels and improved insulin resistance through activation of PPAR-gamma.