[The study of blood serum trace elements in comparison with the structural and functional characteristics of goiter and the carriage of antithyroid antibodies in some regions of Russia].

The study of the sufficiency with essential trace elements in the context of thyroid pathology is especially relevant, since the development and progression of thyroid diseases have various pathogenetic mechanisms, which largest proportion is provoked by insufficient intake of key trace elements, primarily iodine. The aim of the research was obtaining primary data on the sufficiency with essential trace elements of the population in the some regions of the Russian Federation, comparing the data obtained with the prevalence of goiter and the carriage of antibodies to thyroid peroxidase (AT-TPO). Material and methods . The Cross-Sectional Population Study was conducted in medical institutions of the Republics of Crimea, Republics of Tuva and Bryansk region (persons applied for outpatient consultations). The scope of the study was 387 people aged 18 to 65 years (the average age was 40±5 years). All of them underwent: collection of medical history, endocrinologist examination with palpation of the thyroid gland (TG), ultrasound examination of TG, blood sampling to assess the levels of thyroid-stimulating hormone (TSH), AT-TPO, iodine, selenium, zinc. Ultrasound of the TG was performed in the supine position using a portable ultrasound machine LOGIQe (China) with a multi-frequency linear probe 10-15 MHz. During the study, the volume of the thyroid gland, the presence of nodular formations and their characteristics according to the TIRADS classification, TG structure and its echogenicity were assessed. Iodine, selenium and zinc level were measured using tandem mass spectrometry with ionization in inductively coupled plasma (Agilent 8900 ICP-MS Triple Quad). TSH and Ab-TPO were determined by chemiluminescent immunoassay on the Architect i2000 automatic analyzer. Results . All regions are comparable in terms of iodine availability, but differ in the severity of natural iodine deficiency. The median concentration of iodine in blood serum practically coincided in all three regions, amounting to 39.8 μg/l in the Republic of Crimea; 38.8 μg/l in the Republic of Tyva and 43.4 μg/l in the Bryansk region. Comparing these results with foreign data, as well as with our results on urinary iodine level, obtained by routine cerium-arsenite method, we can assume that iodine content in blood serum corresponded to the lower limit of the normal target values. The median concentration of selenium in blood serum also practically coincided in all three regions, amounting to 68.2, 72.1 and 62.8 μg/l, respectively, and probably meets the criteria for optimality. The median serum concentration of zinc in Bryansk region residents corresponded to a deficiency (491.3 μg/l) and was significantly lower compared to the indicator in the Republics of Crimea and Tyva (1633.2 and 1667.6 μg/l, respectively, values above optimal). Among the examined, the proportion of people with AB-TPO carriership was 23.5% (Republic of Crimea - 20.9%, Republic of Tuva - 26.4%, Bryansk region - 20.7%), with impaired thyroid function - 9.6% (6.2% - hypothyroidism, 3.4% - thyrotoxicosis). The frequency of goiter varied from 10 to 13.8%. There were no significant differences in the frequency of occurrence, ultrasonic characteristics of goiter and thyroid nodules by regions. Conclusion . However, the results obtained do not allow to unequivocally judge the absence of micronutrient deficiency in the population of the regions of the Russian Federation, since used the ICP-MS method requires the development of our own reference values of trace elements; in the absence of the latter, data from similar foreign studies were taken as standards. In addition, in further studies it will be important to take into account additional criteria for assessing trace element deficiency, for example, activity of superoxide dismutase and alkaline phosphatase as indirect markers of zinc deficiency, etc. Correlation between blood serum concentration of trace elements and the frequency and structural characteristics of goiter, the carriage of Ab-TPO, and dysfunction of the TG was not revealed.