Comparative evaluation of angiotensin II receptor blockers on HOMA-R and adiponectin release in hypertensive patients with mild type 2 diabetes

Hypertensive patients with diabetes have been reported to be considered at higher risk for the onset of cardiovascular diseases. Adiponectin, an anti-atherogenic adipocytokine, has been reported to improve insulin resistance. The aim of this study was to comparatively evaluate the effects of the angiotensin II receptor blockers, valsartan and telmisartan, on insulin resistance and adiponectin release in hypertensive patients with type 2 diabetes. Fifty-eight patients were randomly assigned to receive valsartan (n = 29) or telmisartan (n = 29). There was no difference in patient background in either group. Both agents reduced blood pressure to a similar degree, and homeostasis model assessment (HOMA-R) as a marker of insulin resistance was decreased in the valsartan group (3.78 ± 1.69 → 2.98 ± 1.50, p = 0.009) as well as in the telmisartan group (3.91 ± 1.65 → 3.39 ± 1.58, p = 0.046). However, adiponectin levels were significantly increased in the valsartan group (5.49 ± 2.12 → 5.81 ± 2.14 μg/ml, p = 0.028), but not in the telmisartan group (5.92 ± 2.19 → 5.87 ± 1.84 μg/ml, p = 0.781). These results suggest that both valsartan and telmisartan are appropriate anti-hypertensive agents providing improvement of insulin resistance; however, valsartan is the more beneficial agent due to the increase in adiponectin levels compared to telmisartan.