Persistence of Oxidative Stress in Newly Diagnosed Hypothyroid Patients Despite Effective Thyroxin Therapy
Background and Aim: We have earlier reported increased oxidative stress (OS) in newly diagnosed hypothyroid patients. However, the comprehensive effect of thyroxin supplementation on OS, insulin resistance, inflammation, and glycation levels has not been analyzed. Therefore, in the present study, we have analyzed the effect of thyroxin therapy in newly diagnosed hypothyroid patients on OS and various biochemical markers after normalization of thyroid profile. Methods: Out of 67 recently diagnosed primary hypothyroid patients, 37 patients were recruited for this study based on the criteria of strict adherence to thyroxin treatment protocol and regular follow‑up. Venous blood samples were analyzed before and 6 months after initiation of therapy for glucose, thyroid and lipid profiles, insulin, ultrasensitive C‑reactive protein (usCRP), and anti‑thyroperoxidase (TPO) antibody. Antioxidants such as glutathione, glutathione peroxidase, catalase, and glutathione S‑transferase, and oxidized products such as malondialdehyde (MDA), and protein carbonyl (PCO) levels were analyzed as parameters of OS. HbA1 and fructosamine were assayed as glycation indices, and lipid risk factor for coronary artery disease was calculated from lipid profile. The parameters were re‑assayed 6 months later after normalization of thyroid profile. Results: OS (MDA; P < 0.01 and PCO; P < 0.01) did not come back to normal level despite attainment of normal thyroid profile following treatment. Dyslipidemia (P < 0.05) and inflammation (P < 0.05) were significantly associated with OS. Furthermore, levels of triglyceride, anti‑TPO antibody, and usCRP were higher in patients even after successful treatment. Conclusion: OS in treated hypothyroid patients despite normalization of thyroid profile persists longer which could partly be due to the residual inflammation and/or dyslipidemia.