Increase in Erythrocyte Membrane Susceptibility and Oxidative Stress in Patients with Type I Diabetes Mellitus

Increasing evidence suggests that oxidative stress plays a major role in the pathogenesis of diabetes mellitus and the development of its chronic complications. The aims of this study were to investigate the susceptibility of erythrocyte lipids to oxidation and to evaluate antioxidant status in type 1 diabetic patients. Thirty-five young type 1 diabetic patients and 28 age and sex-matched healthy subjects were enrolled in the study. The susceptibility of erythrocytes to oxidation and the released malondialdehyde(MDA), erythrocyte glutathione level(GSH), erythrocyte glutathione peroxidase activity(GSH-Px) and total plasma antioxidants(FRAP) were measured and then compared in both diabetic patients and normal subjects. Results showed that FRAP and erythrocyte GSH content was significantly lower in diabetic patients than in control subjects. The activity of GSH-Px did not differ significantly from values obtained in healthy subjects. Susceptibility of erythrocyte lipids, MDA level, and MDA maximal release were significantly elevated in diabetic patients. The level of MDA was positively correlated with the age of subjects and also with FBS and HbA1c but negatively correlated with FRAP. The erythrocytes GSH content was positively correlated with duration of diabetes and negatively with FBS and HbA1c. FRAP was also negatively correlated with FBS and HbA1c. There was not any significant correlation between measured parameters and cholesterol, triglyceride and creatinine. Thus, it seems that diabetic patients undergo an important oxidative stress, which is related to glycemic control and they are more susceptible to oxidants probably because of disturbed antioxidant status.