ABSTRACT
Introduction: Diabetes Mellitus is a heterogeneous group of disorders characterized by variable degrees of insulin resistance, impaired insulin secretion and increased glucose production. Free radical injury is important contributing factor for the development of Insulin resistance and impaired insulin secretion. Recently it has been suggested that glycation of antioxidant enzymes could alter the structure and function of antioxidant enzymes such that they are unable to detoxify free radicals. Intake of vitamin E and vitamin C, due to antioxidant property, is associated with reduced risk of development of Diabetes Mellitus Type 2. With this background, this study was planned to explore the role of antioxidant therapy in the management of Diabetes Mellitus Type 2. Objectives: (1) To demonstrate increased oxidative stress in newly diagnosed Type 2 Diabetes Mellitus patients by measuring antioxidant enzymes activities. (2) To study the effect of oral hypoglycaemic agents on oxidative stress in Type 2 Diabetes Mellitus patients. (3) To evaluate the effects of vitamin C, vitamin E and their combination in patients having Type 2 Diabetes Mellitus managed with oral hypoglycaemic agents. Materials and Methods: The study included two groups consisting of 60 euglycemic healthy subjects and 64 newly diagnosed Diabetes Mellitus Type 2 patients. After 3 months of treatment with oral hypoglycaemic drug, the second group was divided into 4 subgroups with 16 subjects in each subgroup and were treated with oral hypoglycaemic agent alone, oral hypoglycaemic agent + vitamin C, oral hypoglycaemic agent + vitamin E, and oral hypoglycaemic agent + vitamin C + vitamin E respectively for further 3 months. Results : Hyperglycemia in patients with Diabetes Mellitus Type 2 is associated with reduced antioxidant status (superoxide dismutase and catalase activities, and reduced glutathione level). Treatment with oral hypoglycaemic agent for 3 months produced euglycemia with partial but statistically significant elevation of catalase activity and reduced glutathione level in blood. Following additional antioxidant therapy with vitamin C and vitamin E produced further significant increase in reduced glutathione level, however fasting plasma glucose level and activities of superoxide dismutase and catalase enzymes were found to be statistically non-significant.Conclusion: Antioxidant therapy with vitamin C and vitamin E in addition to oral hypoglycaemic agent reduces oxidative stress in patients having Type 2 Diabetes Mellitus.