Blood lipid peroxidation (superoxide dismutase, malondialdehyde, glutathione) levels in Egyptian type 2 diabetic patients

INTRODUCTION: The existence of hyperglycaemia produces increased oxidative stress. The depletion of antioxidants as a defensive body mechanism may increase the risk of diabetic complications. Diabetes mellitus is associated with derangements in the serum levels of several biochemical parameters, and type 2 diabetes mellitus (or non-insulin-dependent diabetes mellitus) is a risk factor for cardiovascular diseases. METHODS: Data of 80 control subjects (male:female, 40:40) and 80 diabetic patients (male:female, 40:40), of similar age, gender, body mass index and duration of diabetes mellitus (for diabetic group), were collected from government and non-government organisations during the period, 2001-2004. Blood samples were also collected. Glucose, glucosylated haemoglobin, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDLC), TC/HDL-C, HDL-C/LDL-C, triacylglycerol, malondialdehyde, glutathione and superoxide dismutase levels were determined. RESULTS: Mean cholesterol, LDL-C, VLDL-C and triacylglycerol levels were significantly higher in patients with type 2 diabetes mellitus in comparison to the control subjects, while the mean value of HDL-C was significantly lower. A significant elevation in malondialdehyde level and decrease in glutathione content were observed in both male and female diabetic patients in comparison to the control subjects. CONCLUSION: The results suggest that the increase in lipid peroxidation, and the decline in antioxidant defences, may appear early in type 2 diabetic patients, before the development of secondary complications. This phenomenon might play an important role in the initiation and progression of diabetic complications. Our results also suggest that there seems to be an imbalance between plasma oxidant and antioxidant systems in patients with type 2 diabetes mellitus.