Assessment of Oxidative Stress in Hashimoto's Thyroiditis Patients: Effects of Levothyroxine Sodium Treatment

Background: Hashimoto’s thyroiditis (HT) is a prevalent autoimmune disease characterized by chronic inflammation of the thyroid gland, leading to hypothyroidism. Oxidative stress has been implicated in the pathogenesis of HT, influencing disease progression and therapeutic outcomes. Understanding the dynamics of thiol/disulfide balance, a marker of oxidative stress, in HT patients receiving levothyroxine treatment is crucial for elucidating its role in disease management. Our study has the largest cohort on this topic. Methods: This study enrolled 357 euthyroid HT patients, divided into groups based on levothyroxine treatment status. Thiol/disulfide homeostasis was assessed using the Erel method. Clinical parameters, including thyroid function tests and antibody levels, were measured. Statistical analyses were performed to compare oxidative stress markers between groups. Results: Patients on levothyroxine therapy showed lower native and total thiol levels than untreated patients, indicating potential antioxidant depletion. Higher disulfide/native thiol and disulfide/total thiol ratios in the treated group suggest elevated oxidative stress. There were no correlations between thyroid antibodies (TPO-Ab, TG-Ab) and thiol/disulfide levels. Conclusion: This study highlights alterations in thiol/disulfide balance among euthyroid HT patients, with implications for oxidative stress management in clinical practice. Levothyroxine treatment appears to be associated with oxidative stress markers, suggesting associations that warrant further investigation.