The effect of levothyroxine replacement therapy on lipid profile and oxidative stress parameters in patients with subclinical hypothyroid.

The purpose of this present study is to investigate the levels of oxidative stress parameters in patients with subclinical hypothyroidism (SH) and the effects of levothyroxine (LT4) replacement therapy on these parameters and lipid profile. At the beginning of the study blood samples were collected from the patients in order to analyse oxidative stress parameters, lipid profile and biochemical markers. After replacement therapy with LT4, in the third month, same tests were performed again. At the baseline superoxide dismutase (SOD) levels were found to be higher in SH patients, compared to the euthyroid group. After LT4 therapy, statistically significant decreases in SOD and catalase levels and increase in HDL-C levels were noticed. LT4 treatment was found to have positive effects on oxidative stress indicators and HDL-C levels.