The relationship between oxidative stress and autoimmunity in Hashimoto's thyroiditis.
OBJECTIVE
We have aimed to study the relation between Hashimoto's thyroiditis (HT) and thyroid autoantibodies and oxidative stress parameters in euthyroid, subclinical and overt hypothyroid stages.


METHODS
A total of 124 patients were included in the study; 93 of whom were newly diagnosed with HT (31 patients in each of the euthyroid, subclinical hypothyroid and overt hypothyroid subgroups), aged over 18 and had not received any prior treatment and 31 of whom were healthy volunteers.


RESULTS
Total oxidant status (TOS) and oxidative stress index (OSI) levels were higher, and total antioxidant status (TAS) and total thiol and arylesterase levels were lower in the overt hypothyroid group compared to other groups. TOS and OSI levels increased, and TAS levels decreased significantly in each phase from euthyroid, subclinical hypothyroid, to overt hypothyroid subgroups among HT patients. There was a negative correlation between TAS, log (paraoxonase1) and paraoxonase1/HDL and anti-thyroid peroxidase and a negative correlation between anti-thyroglobulin and total thiol. It was also determined that overt hypothroidism was an individual predictor that effects all of the oxidative stress parameters, but not total thiol, levels.


CONCLUSIONS
Our results suggest that oxidative stress increases continuously during the development of subclinical hypothyroidism and overt hypothyroidism in patients with HT. To determine whether this is a cause or result, randomized, controlled trials that study the effect of antioxidant treatment on the development of overt hypothyroidism and its consequences, e.g., increase in total cholesterol levels, may be performed in euthyroid and/or subclinical hypothyroid patients with HT.
Departments of Internal MedicineBiochemistryEndocrinologyAnkara Numune Training and Research Hospital, Sıhhiye, Ankara 06100, Turkey dr.ihsanates@hotmail.com.
Ihsan
I
Ates
Departments of Internal MedicineBiochemistryEndocrinologyAnkara Numune Training and Research Hospital, Sıhhiye, Ankara 06100, Turkey.
Fatma Meric
FM
Yilmaz
Departments of Internal MedicineBiochemistryEndocrinologyAnkara Numune Training and Research Hospital, Sıhhiye, Ankara 06100, Turkey.
Mustafa
M
Altay
Departments of Internal MedicineBiochemistryEndocrinologyAnkara Numune Training and Research Hospital, Sıhhiye, Ankara 06100, Turkey.
Nisbet
N
Yilmaz
Departments of Internal MedicineBiochemistryEndocrinologyAnkara Numune Training and Research Hospital, Sıhhiye, Ankara 06100, Turkey.
Dilek
D
Berker
Departments of Internal MedicineBiochemistryEndocrinologyAnkara Numune Training and Research Hospital, Sıhhiye, Ankara 06100, Turkey.
Serdar
S
Güler
D000328:Adult; D043303:Aryldialkylphosphatase / Q000378:metabolism; D058070:Asymptomatic Diseases; D001323:Autoantibodies / Q000276:immunology*; D015551:Autoimmunity / Q000276:immunology*; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D050031:Hashimoto Disease / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007037:Hypothyroidism / Q000276:immunology* / Q000378:metabolism; D007453:Iodide Peroxidase / Q000276:immunology; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013972:Thyrotropin / Q000378:metabolism; D013974:Thyroxine / Q000378:metabolism
D001323:Autoantibodies; D013438:Sulfhydryl Compounds; C006606:anti-thyroglobulin; D013972:Thyrotropin; D007453:Iodide Peroxidase; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human; D013974:Thyroxine