Study of oxidative stress in type 2 diabetic patients and its relationship with glycated hemoglobin
Objectives: To evaluate the activity of antioxidant enzymes in diabetic patients and also to determine the correlation between hyperglycemia and lipid peroxidation. Methods: Thirty patients with type 2 diabetes and 30 healthy individuals (control group) participated in this case-control study. The patients were referred to Sina Hospital, Hamadan, Iran from April to June 2006. Glycated hemoglobin (HbAlc) was measured as a marker of hyperglycemia using the chromatography method (Biosystem) and malondialdehyde (MDA) was determined using the colorimetric method. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity were assessed using the UV-Vis spectrophotometric technique (Randox kit). Results: The mean of HbA1c was higher in diabetic patients compared to the healthy group, and the difference was statistically significant (p<0.001). Serum MDA in diabetics was higher compared to those of healthy subjects (p<0.001). There were significant differences in activities of SOD and GPx between the 2 studied groups indicating lower activity in diabetic patients (p<0.001). There was a significant relationship between MDA and HbA1c in diabetic and healthy subjects. Conclusion: The data showed an increase in lipid peroxidation and oxidative stress in diabetes and also indicated a positive correlation between the degree of hyperglycemia and oxidative stress. Evaluation of oxidative status and choosing the appropriate treatment may help to support antioxidant defense in these patients.