Alterations of Insulin Resistance and the Serum Adiponectin Level in Patients with Type 2 Diabetes Mellitus Under the Usual Antihypertensive Dosage of Telmisartan Treatment

Background: Insulin resistance plays a central role in the pathophysiology of diabetes complications. Angiotensin II receptor blockers (ARBs) regulate angiotensin II receptor-mediated inhibition of intracellular glucose transporter 4 translocation. Telmisartan, one of the known ARBs, was reported to improve insulin resistance via the increase of peroxisome proliferator-activated receptor g activity in the model animal. This study examined whether this effect was observed in diabetes patients under the usual antihypertensive dosage of telmisartan treatment. Methods: Twenty-seven diabetes patients were chosen for this prospective study. Patient blood pressures were successfully controlled for the most recent 6 months by ARBs other than telmisartan. After informed consent was obtained, we changed to telmisartan from the other ARBs. The parameters of hypertension, hyperlipidemia, glycemic control, and renal function were examined. Results: The values of the homeostasis model assessment of insulin resistance (HOMA-IR) improved from 7.1 +/- 1.5 to 3.8 +/- 3.6 after 3 months. The serum level of adiponectin significantly increased after 6 months. The distributions of other parameters were correlated with that of HOMA-IR or adiponectin. Conclusions: The data indicate that the usual antihypertensive dosage of telmisartan improves insulin resistance and changes adiponectin effect in patients with diabetes mellitus. Adipokine-related insulin resistance and angiotensin II receptor 1-mediated insulin resistance are improved by telmisartan.