Study of macro- and microelement status in autoimmune thyroiditis among residents of districts of Kyiv region affected by the Chornobyl accident

Abstract

Background. Autoimmune thyroiditis (AIT) is a combined, polygenic, organ­specific disease. The incidence rate of AIT has a tendency to increase throughout the world. There is an upward trend in morbidity in younger age groups. Circulating thyroid peroxidase antibodies are found in 10–15 % of apparently healthy euthyroid persons. The purpose of the study was to establish the macro­ and microelement status in patients with AIT among residents of districts of Kyiv region affected by the Chornobyl accident. Materials and methods. Sixty­one residents from the areas in Kyiv region affected by the Chornobyl accident were examined: 45 persons without thyroid pathology were included in the control group and 16 with AIT — in the experimental group. All patients with a thyroid dose of < 0.3 Gy — ≥ 1 Gy are participants of the cohort studies of Ukrainian­Belarusian­Ameri­can project. The study of micro­ and macroelements was performed by atomic emission spectroscopy with inductively coupled plasma (Dzherelo­2003) on Optima 2100 DV device (PerkinElmer, USA). Results. When studying thyroid status, the group of patients with AIT differed from the controls in terms of increased thyroid volume, high levels of thyroid pe­roxidase antibodies and thyroid­stimulating hormone. Urinary iodine excretion median in the studied groups was not significantly different: in the control group, it was 65.0 µg/l, in the experimental group — 80.6 µg/l, indicating the pre­sence of mild iodine deficiency. The examined patients with AIT had reduced (p < 0.01) magnesium level in the blood serum (the median value was 18.59 mg/l) compared to the control group. The assessment of the chances of correlation between AIT diagnosis and magnesium level below the median one (20.6 mg/l) in the total group of subjects was: odds ratio (OR) = 6.63 (95% confidence interval (CI) [1.73; 24.8]; p < 0.01). Conclusions. The existing diagnosis of AIT is reliably significant in patients with thyroid dose above median value (0.12 Gy)) in the total group of patients surveyed in the Kyiv region: OR = 4.1 (95% CI [1.2; 13.9]; p < 0.05). The odds ratio was highest with a combination of reduced magnesium content and increased thyroid radiation dose: OR = 25 (95% CI [3.16; 179.0]; p = 0.002).

Keywords

• iodine deficiency
• thyroid gland
• autoimmune thyroiditis
• iodine urine excretion
• macro- and microelements
• relative risk of disease