Effect of thyroxine replacement therapy on the redox status of primary hypothyroid patients

BackgroundOxidative stress has been implicated in various pathological conditions but the available studies concerning oxidant stress in hypothyroidism are controversial and inconclusive. While some authors suggest that tissues may be protected from oxidant damage because of a hypometabolic state in hypothyroidism, others report an increased oxidative stress in hypothyroidism. Aims and objectiveThe aim of the study was to determine presence of oxidative stress in patients with primary hypothyroidism and effect of thyroxine supplementation on it. Materials and Method126 patients of primary hypothyroidism (24 males,102 females) based on history and thyroid profile prior to the commencement of therapy were enrolled in the present prospective follow up study (GROUP I). 100 (23 males and 77 females) of these patients were revaluated after three months of levothyroxine replacement therapy in varying doses (50μg-150μg) based on TSH levels (GROUP II). Hundred age and gender matched healthy, euthyroid volunteers were selected as controls for the study (GROUP III). NO was estimated through Greiss reaction, MDA was estimated by thiobarbituric acid method and glutathione through DTNB reagent. ResultsNO levels and MDA levels were significantly higher in pretreatment goup as compared to postreatment and control group(p <.05). Plasma glutathione levels were significantly lower in pretreatment when compared to controls and posttreatment group (p <.05). and there was significant correlation between oxidative stress parameters with thyroid profile. Conclusions – The present study shows that there is an increased oxidative stress in patients with hypothyroidism as compared to healthy controls and that it decreased on treatment with thyroxine supplementation signifying the role of antioxidant therapy in thyroid diseases.