Alterations in the antioxidant status of patients suffering from diabetes mellitus and associated cardiovascular complications

Abstract

In view of the high prevalence of type 2 diabetes mellitus, this study aimed at determining the total plasma antioxidant capacity of type 2 diabetic patients with and without macrovascular complications. The erythrocyte catalase level was also evaluated because of the implication of catalase as a risk factor in diabetes. 90 age-­‐, gender-­‐ and body mass index-­‐matched subjects were used for this study and divided into healthy subjects (Group I, n=30), diabetic patients (Group II, n=30) and diabetic patients with cardiovascular complications (Group III, n=30). Blood samples collected from 90 eligible subjects were analyzed for glucose, HbA1c, urea, creatinine, total cholesterol, triglyceride, HDL and  LDL cholesterol levels. Blood antioxidant activity and erythrocyte catalase levels were assessed. The mean antioxidant status values of Groups II and III were found to be significantly lower than that of Group I (p < 0.05). A significant decrease was also observed in the mean catalase level of Groups II and III as compared to Group I (p < 0.05) while a significant increase in fasting blood glucose level, glycated hemoglobin, triglycerides and urea was observed in Groups II and III compared to Group I. These data suggest that the in vivo antioxidant defense was highly compromised in patients with diabetes and associated cardiovascular complications although they were on medication, thereby suggesting the potential contributory beneficial effects of exogenous antioxidants. Furthermore, a reduction in catalase level may suggest the role of increasing hydrogen peroxide concentration in the disease progression.

KEY WORDS: Antioxidant; Erythrocyte catalase; Cardiovascular complications; Type 2 diabetes mellitus