The effects of pioglitazone and metformin on plasma visfatin levels in patients with treatment naive type 2 diabetes mellitus

Abstract

Aims: Circulating visfatin levels are altered in insulin resistant states. We evaluated the effects of two insulin-sensitizing hypoglycemic agents on plasma visfatin and adiponectin levels in patients with newly diagnosed and untreated type 2 diabetes mellitus (T2DM).

Methods: Forty-four patients with T2DM were randomized to treatment either with pioglitazone (15-45mg/day) or metformin (1000-2000mg/day). Plasma visfatin and adiponectin levels and homeostasis model assessment of insulin resistance (HOMA-IR) scores were determined at baseline and at 12th week of treatment.

Results: By the end of the 12th week, fasting plasma glucose, HbA1c, HOMA-IR scores and waist circumferences improved equally in both treatment arms. HDL cholesterol and adiponectin levels increased only in the pioglitazone group (p=0.01 and p=0.003, respectively). On the other hand, metformin treatment had additional regulatory effects on BMI, blood pressure and total and LDL-cholesterol levels (p=0.002, p=0.01, p=0.004, p=0.001 and p<0.001, respectively). Neither pioglitazone nor metformin displayed a significant effect on circulating visfatin concentration.

Conclusions: Despite improvements in insulin sensitivity and glycemic regulation, either pioglitazone or metformin treatment did not result in any effect on blood visfatin levels in patients with treatment naïve T2DM.