Associations of thyroid status and thyroperoxidase antibodies with serum trace elements

Abstract

BACKGROUND: Studies on the relationship between thyroid autoimmunity and serum trace elements (TE) are ongoing in different parts of the world, however, the data obtained are often contradictory, which determines the relevance of this study. AIM: The aim of the study was to identify associations between thyroid status and Anti-Thyroid Peroxidase antibodies (TPOAb) with serum TE among young women. MATERIALS AND METHODS: The study participants were 859 women aged 18–45, whose Thyroid-Stimulating Hormone (TSH) was in the reference range or above 3.4 µIU/ml and with free Thyroxine (fT4) in the reference range. The exclusion criteria were the presence of menopause and decompensation of chronic diseases. The participants were subdivided into 2 groups: a group of women with TPOAb less than 30 U/ml, designated as TPOAb(-), and a group of women with TPOAb more than 30 U/m, designated as TPOAb (+). The detection of TSH, fT4, and TPOAb in serum was provided by enzyme immunoassay on the Evolis Robotized System using “Thyroid — ELISA- TSH, 0.23–3.4 µIU/ml”, “Thyroid — ELISA free T4, 10–23.2 pmol/l”, “Thyroid ELISA — TPOAb<30 U/ml” test systems. The reference values were taken from the instructions of the manufacturer Alkor Bio group (Russia). Logistic regression analysis was applied to adjudge associations between TPOAb status and serum trace elements. RESULTS: The level of fT4 was lower in the AT-TPO (+) group compared to the AT-TPO (-), p=0.006; Triglycerides, aspartate aminotransferase, alkaline phosphatase was higher in the AT-TPO (+) group compared to the AT-TPO (-). There were more smoking women in the AT-TPO group (-) 4.1% versus 1.3% in AT-TPO (+). It was found that, after adjusting for likely cofounding factors, participants with antibody positivity had significantly lower concentrations of selenium; zinc, iodine, iron. When serum trace elements levels were analyzed in tertiles, the odds ratios TPOAb positivity of tertile 1 were higher that of tertile 3. CONCLUSION: The associations between TPOAb and microelements demonstrate their involvement in autoimmune processes in the thyroid gland.