Oxidative stress is important in the development and progression of diabetes mellitus. The aim of this study is to compare six methods used to evaluate its intensity. Malondialdehyde concentration was determined by the Bioxytech LPO 586 kit, and two methods based on malondialdehyde – thiobarbituric acid reaction. Absorbances were determined using the Beckman DU-68 photometer. We also determined the activities of superoxid dismutase and glutathion peroxidase using a Cobas Mira Plus. We used a biophotonic scanner to determine the skin carotenoid score. Results: Good correlation was observed between malondialdehyde concentrations determined by the three methods, showing higher concentrations in diabetics compared to non-diabetic patients. Antioxidant enzymes showed physiological values in almost all diabetics. The skin carotenoid score was significantly lower in diabetics compared to non-diabetic subjects of the same age-goup (p<0,05). Conclusions: Evaluation of lipoperoxidation end products is a better indicator of the intensity of oxidative stress compared to enzyme activity. Skin carotenoid determination is a modern, non-invasive method to evaluate antioxidant protection.
Keywords: oxidative stress, malondialdehyde, diabetes mellitus