Oxidative Stress Index as a Biomarker of Metabolic Imbalance in Thyroid Disorders

Abstract

ABSTRACT

Background: Thyroid dysfunction is associated with profound metabolic disturbances, including altered lipid metabolism and redox imbalance. Oxidative stress, resulting from excess reactive oxygen species and impaired antioxidant defenses, may exacerbate lipid abnormalities and increase cardiometabolic risk.

Objective: To evaluate lipid profile alterations in relation to oxidative stress markers—total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI)—among patients with hypothyroidism, hyperthyroidism, and euthyroid controls.

Methods: A cross-sectional study was conducted on 285 participants (161 hypothyroid, 76 hyperthyroid, 48 euthyroid). Serum thyroid hormones, lipid profile, and oxidative stress parameters (TOS, TAS, OSI) were measured using standard biochemical methods. Group comparisons were performed using ANOVA with post hoc tests. Correlations between lipid parameters and oxidative stress indices were assessed, and regression analysis identified predictors of metabolic imbalance.

Results: Both hypothyroid and hyperthyroid groups exhibited significantly elevated TOS and OSI with reduced TAS compared to euthyroid controls (p < 0.001). Hypothyroid patients showed higher total cholesterol, LDL-C, and triglycerides, while hyperthyroid patients demonstrated reduced HDL-C and elevated VLDL-C. Correlation analysis revealed that OSI positively associated with atherogenic lipid fractions (LDL-C, TG) and negatively with HDL-C. Regression analysis identified TOS as a positive and TAS as a negative predictor of OSI, confirming that oxidative stress and dyslipidemia jointly contribute to metabolic imbalance in thyroid dysfunction.

Conclusion: Thyroid disorders are characterized by both lipid abnormalities and oxidative stress imbalance, with OSI emerging as a robust biomarker of metabolic disturbance. Integration of oxidative stress markers with lipid profiling may improve risk stratification and management of patients with thyroid dysfunction.

Keywords: Thyroid dysfunction, oxidative stress index, lipid profile, hypothyroidism, hyperthyroidism, metabolic imbalance