Lipid peroxidation and antioxidant enzyme status in Type 2 diabetics with coronary heart disease

Lipid peroxides are thought to be formed by free radicals and may play an i mportant role in the development of atheromatous vascular diseases. The rel ationship between serum lipids, lipoproteins, lipid peroxides [thiobarbitur ic acid reactive substances (TBARS)] and erythrocyte antioxidant enzymes [c atalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD)] was investigated in non-insulin-dependent diabetic patients with and witho ut coronary heart disease (CHD), and a comparison was made for all the abov e parameters with non-diabetic patients with CHD. Lipid peroxide concentrat ions were significantly increased in both groups of diabetic patients and a lso in non-diabetic patients with CHD, compared to those in control subject s. Diabetic patients with CHD had higher levels of TEARS compared to those diabetics without CHD. Hyperlipidaemia and abnormal lipoprotein levels were observed in all three groups of patients. Increased total cholesterol and LDL-cholesterol were observed in diabetics with CHD compared to those witho ut CHD. Among the erythrocyte antioxidant enzymes, CAT activity was increas ed, GPx activity was decreased and no change was observed in SOD activity i n both groups of diabetic patients and non-diabetic patients with CHD compa red to those in controls. A clear correlation was observed between the CAT activity and lipid peroxide concentrations in all the diabetic patients. Th ese observations suggest that there are similar abnormalities in lipid meta bolism and erythrocyte antioxidant enzymes in diabetic patients and non-dia betic patients with CHD. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.