Evaluation of oxidative stress, enzymatic and non-enzymatic antioxidants and metabolic thyroid hormone status in patients with diabetes mellitus

Aims: Oxidative stress is currently suggested as mechanism underlying diabetes and diabetic complications. The aim of the study was to evaluate the magnitude of oxidative stress in patients with diabetes by measuring the lipid peroxidation as well as the status of the antioxidant defense system, thyroid hormones status and other biochemical variables. Methods: The study population consisted of 100 subjects divided into two groups viz. diabetic (n = 50) and healthy controls (n = 50). Results: The level of thiobarbituric acid reactive substances (TBARS) was found to be increased significantly in diabetic patients compared to healthy controls. On the other hand, the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), reduced glutathione (GSH), vitamin A, vitamin E and vitamin C were found to be decreased significantly in diabetics when compared to control subjects. The level of TSH was significantly decreased whereas the levels of T4 and FT4 were significantly increased in diabetic patients than the control subjects. However, the T3 and FT3 levels did not differ significantly between groups. Conclusion: Our findings indicate that changes in oxidant and antioxidant equilibrium will have biological and possibly pathological role in the development of secondary complications. The study has shown a high incidence of abnormal thyroid hormone status among the diabetics. In our findings demonstrate that detection of thyroid hormone status in the early stage of the disease will help the patients to improve quality of life and reduce the morbidity rate. (C) 2009 Diabetes India. Published by Elsevier Ltd. All rights reserved.