Evaulation of antioxidant status and oxidative stress markers in type II diabetes mellitus

The risk of developing vascular diseases in diabetic patients is significantly increased. Its etiology may involve oxidative damage by free radicals, and protection against such damage can be offered by antioxidant systems. To study the antioxidant status and oxidative stress in patients with type II diabetes mellitus. (n=30) and controls (n=28), we measured total antioxidant capacity by ferric reducing ability of plasma (FRAP) assay, malondialdehyde (MDA) as a final product of lipid peroxidation by HPLC method, carbonyl groups, thiol groups, vitamin E and C in plasma samples. In addition, we analyzed biochemical parameters such as blood glucose, HBA1c, cholesterol, triglycerids, HDL-C, LDL-C, bilirubin and uric acid. A significant increase in MDA concentration was found in diabetic patients compared to controls (P<0.005). There was also a significant drop in plasma thiol groups (P<0.05), while no significant difference was observed in total antioxidant capacity, carbonyl groups, vitamin E and C between two groups. Plasma vitamin E/cholestrol ratio was significantly lower in diabetic patients than controls. In conclusion, we have shown that there is enhanced oxidative stress in patients with type II diabetes, an important factor in the pathogenesis of diabetic complications.