Evaluation of levels of homocysteine, vitamin B12 and folic acidin patients with subclinical hyper- and hypothroidism

Thyroid hormones have an important role on growth and skeletal development. Hyperthyroidism is a clinical condition which is characterized by increased basal metabolism as a result of excessive production of thyroid hormones in tissues. On the other hand, hypothyroidism is characterized by decreased metabolism resulting from insufficient production or ineffectiveness of thyroid hormones.Homocysteine is a sulfur containing amino acid, which plays a role in methionine metobolism. Folic acid and vitamin B12 are essential for remethylization of homocysteine to methionine. Homocysteine levels increases in the deficiency of these vitamins. MDA is an important indicator of lipid peroxidation. Glutathione is present in all mammalian cells at milimolar concentrations and serves several cellular functions including aminoacid transport, maintenance of protein sulfhydryls reduction status, and as defense against oxidizing molecules.This study was performed to investigate whedher hyperthyroidism and hypothyroidism result in changes in levels of homocysteine, vitamin B12, folic asid and antioxidant capacity.In this study 20 subclinic hyperthyroid, 15 clinic hyperthyroid, 20 subclinic hypothyroid and 14 clinic hypothyroid patient were included. Seventeen healthy subject were included in the control group additional disease (Diabetes Mellitus, hypertension, dyslipidemia etc.) We measured Malonyldialdehyde (MDA) level as an evidence of lipid peroxidation and glutatyon (GSH) level as an indicator of antioxidant capacity. GSH levels of subclinical hypothyroid, clinic hypothyroid, subclinic hyperthyroid, clinic hyperthyroid groups were significantly lower than the control group.As a result, while hyperthyroidism and hypothyroidism did not cause any change in vitamin B12, folate and homocysteine levels. Thet resulted in decrease in GSH levels.Keywords: Hyperthyroidism, hypothyroidism, oxidative stress, homocysteine, folic acid, Vitamin B12