Oxidative stress in hypothyroid patients and the role of antioxidant supplementation.

contextThe available data concerning oxidant stress and antioxidant capacity in hypothyroidism are scanty and inconclusive. While some authors suggest that tissues may be protected from oxidant damage because of a hypometabolic state in hypothyroidism, others report increased oxidative stress in hypothyroidism. Selenium acts as a cofactor for the thyroid hormone (TH) deiodinases that activate and then deactivate various THs and their metabolites. Selenium may inhibit thyroid autoimmunity.

aimsThe study was designed, first, to study the impact of oxidative stress in patients of primary hypothyroidism due to autoimmune thyroiditis, by estimation of serum malondialdehyde (MDA) as a biomarker of oxidative stress. Second, to study the change in MDA level pre- and post-L-thyroxine treatment. Finally, to look into the possible role of selenium supplementation on oxidative stress in autoimmune hypothyroidism. SUBJECTS AND

methodsPatients attending endocrine outpatient department (OPD) services of IPGMER and SSKM hospital were considered for the study. Sixty treatment-naive adult patients (age > 18 years) with hypothyroidism were included in the study. The patients were divided into two groups, each comprised thirty patients. One group was treated with L-thyroxine and placebo (Group A). The other group received L-thyroxine replacement along with selenium (100 mcg twice a day) as antioxidant supplementation (Group B). The patients were blinded about selenium and placebo. The study duration for both groups was 6 months. The starting dose of L-thyroxine was 1.6 mcg/kg body weight free thyroxine (FT4), and thyroid-stimulating hormone (TSH) was repeated after 12 weeks. L-thyroxine dose adjustments were done if needed. MDA was assessed at the beginning and at the end of the study, i.e., after 6 months of treatment. The control cohort was composed of thirty healthy adults. Only overt hypothyroidism (OH) cases were included in the study. STATISTICAL ANALYSIS USED: Normality of data was determined using Anderson-Darling test, Shapiro-Wilk test, and QQ plot.

resultsAfter treatment in Group A patients, FT4 showed a significant increment while TSH value decreased. MDA level reduced after treatment, (

conclusionsOxidative stress compounds hypothyroidism. Hypothyroidism is a state of increased oxidative stress. In this study, biomarker, MDA level is high in treatment-naive primary hypothyroid patients. After treatment with L-thyroxine, the stress marker is reduced to a significant extent. MDA can be used as a useful biomarker to measure and monitor oxidative stress. The role of the addition of antioxidant in the form of selenium remained inconclusive.