Association Between Thyroid Function and Oxidative Stress Markers in Overt and Subclinical Hypothyroid Patients: Observational Cross-Sectional Study in Nepal

Background: Hypothyroidism poses significant health concerns with oxidative stress playing a potential role in its development. However, the mechanisms remain unclear. Methods: The study employed a cross-sectional design, analyzing oxidative stress markers and thyroid function parameters in adult hypothyroid patients at Chitwan Medical College, Nepal. A convenience sampling of 225 patients was used. Data collection involved questionnaires, clinical assessments, and biochemical assays to measure free tri-iodothyronine (T3), thyroxine (T4), thyroid-stimulating hormone (TSH), and superoxide dismutase (SOD) enzyme from serum and malondialdehyde (MDA), glutathione peroxidase (GPx), and total antioxidant capacity (TAC) from plasma. Descriptive statistics, Pearson correlational and linear regression analyses were performed using IBM SPSS (version 20).Results: Subclinical hypothyroidism was most common among overweight individuals aged 46-60, especially in females (117 out of 167). Significant differences (p < 0.001) were observed in thyroid profiles and oxidative stress parameters between subclinical and overt hypothyroid patients. Thyroid-stimulating hormone (TSH) levels showed a positive correlation with glutathione peroxidase (GPx) and malondialdehyde (MDA) and a negative correlation with Superoxide dismutase (SOD) and total antioxidant capacity TAC in both overt and subclinical patients. Conclusion: Hence the subclinical hypothyroidism, prevalent in overweight individuals aged 46-60 particularly in female is very high compare to overt hypothyroidism, where TSH was positively correlated with the Glutathione peroxidase (GPx) and Malondialdehyde (MDA), representing increased TSH levels are associated with increased oxidative stress in body.