Objective: The aim of the study was to evaluate the effect of gliclazide modified release ( MR) treatment on adiponectin, interleukin 6 ( IL-6), and tumor necrosis factor-alpha( TNF-alpha) plasma concentrations in type 2 diabetic patients.) Research design and methods: 24 randomly selected type 2 diabetic patients, aged 61.2 +/- 15.4 years, with poorly controlled glucose level ( mean glycated hemoglobin [ HbA(1c)] 7.6 +/- 1.1%) despite treatment with diet and/or oral hypoglycemic agents, were included in the study. All of the patients, after a 2-week run-in period, were given gliclazide MR for 12 weeks. At baseline, and after gliclazide MR treatment, HbA(1c) and plasma concentrations of IL-6, TNF-alpha, and adiponectin were measured., Results: Gliclazide MR treatment produced significant reductions in fasting plasma glucose from 7.6 +/- 1.4 to 6.6 +/- 1.2 mmol/L, p < 0.01), HbA(1c) ( from 7.6 +/- 1.1 to 6.9 +/- 0.8%, p < 0.01), and plasma IL-6 concentrations ( from 2.5 +/- 1.8 to 1.8 +/- 1.2 pg/ mL, p < 0.05). A significant increase in plasma adiponectin level was noted ( from 6.4 +/- 3.3 to 7.6 +/- 4.4 mu g/mL, p < 0.05). Plasma TNF-alpha concentrations and homeostasis model assessment of insulin resistance ( HOMA-IR) decreased after treatment, but these changes did not reach statistical significance. Conclusions: Gliclazide MR improves glycemic control and, in addition, has a positive influence on the plasma level of some inflammatory markers and adiponectin. Increased plasma adiponectin and decreased plasma IL-6, and TNF-alpha levels may explain, at least in part, the anti-atherogenic action of this drug reported elsewhere.