Association Between Thyroid Hormones, Lipids and Oxidative Stress Markers in Subclinical Hypothyroidism

Oxidative stress plays a role in the pathogenesis of many chronic diseases. It is recognized in overt hypothyroidism while its existence in subclinical hypothyroidism (SCH) is not well established. The aim of this study was to determine whether there was increased oxidation of lipids and proteins in SCH, and examine their association with lipids and thyroid hormones. Male adults (35-59 years) with SCH (n=467) and euthyroid controls (n=190) were studied. Anthropometric measurements, plasma lipids, thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), total antioxidant capacity (T-AOC), lipid peroxidation products, malondialdehyde (MDA), advanced oxidation protein products (AOPP) and dityrosine concentrations were measured. Plasma concentrations of MDA were significantly higher (p