Effect of metformin on the magnitude of oxidative stress in patients with type 2 diabetes mellitus

: The final glycated products forming in diabetes contribute to the higher atherogenic oxidative modification of low-density lipoproteins (LDL). The impact of glycemic control on the parameters of free radical oxidation was comparatively studied in patients with type 2 diabetes who received metformin (Glucophage, Nycomed) (Group 1, n = 40) and sulfanylurea preparations (Group 2, n - 30, out of them 15 patients took maninil and 15 had diabeton) good glycemic control caused the magnitude of oxidative stress to reduce, which appeared as the decreased levels of primary (lipid hydroperoxides) and secondary (malonic dialdehyde) products of free radical oxidation in LDL and as the enhanced activity of antioxidative defense enzymes. However, with the identical degree of glycemic control, which was determined by the level concentrations of HbA1c and lipids in both groups, the plasma levels of lipid peroxides decreased by more than 5 times in Group 1 patients receiving metformin than in Group 2 patients and the rate of LDL oxidability reduced by 4.5 times. Such a marked effect of metformin on the attenuated manifestations of oxidative stress is indicative of its antioxidative effect independent of the hypoglycemic effect of the drug.