[01] Maher K. Ibrahim, Department of Biochemistry, College of Medicine, University of Tikrit, Tikrit, Iraq. [02] Abdul-Monaim H. Al-Samarrai, Department of Chemistry, College of Education, University of Samarra, Samarra, Iraq. [03] Khudhair A. Khudhair, Department of Biochemistry, College of Medicine, University of Tikrit, Tikrit, Iraq.

The present study aimed to assess if leptin concentration is associated with the serum oxidative stress index (represented by MDA level), antioxidant status (represented by GSH), lipid profile, and/or other parameters of blood biochemistry in eu-, hypo- and hyperthyroid patients. MDA, an index of oxidative stress (OS) was elevated in hyperthyroidism and hypothyroidism patients as compared to euthyroid control, while GSH was a highly significant decrease in all patients with thyroid dysfunction as compared to euthyroid control. The results showed a highly significant increase in the sera levels of TC, TG, VLDL in patients with hypothyroidism and a highly significant decrease in TC and LDL levels in patients with hyperthyroidism patients as compared to euthyroid control. In hypothyroidism patients, there was a significant positive correlation between leptin hormone and BMI, TG and VLDL levels. In hyperthyroidism patients, there was only a significant positive correlation between leptin hormone and BMI, whereas a nearly significant positive correlation was observed between leptin hormone and TG & VLDL levels. Also a nearly significant positive correlation was observed between leptin hormone and MDA levels in hypo-, hyper-, and euthyroid control groups, while a nearly significant negative correlation between leptin and GSH in hypo- and hyperthyroid patients. In conclusion the study demonstrated that oxidative stress was increased in hypothyroidism and hyperthyroidism as indicated by the elevated lipid peroxidation product, MDA, while GSH was reduction.

Leptin, Hypothyroidism, Hyperthyroidism, Euthyroid, Oxidative Stress, Lipid Peroxidation, Lipid profile

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