Peculiarities of non-malignant endocrine disease in the Chornobyl NPP accident survivors, and hormonal interaction role.

Study objective. Identification of the role of intersystemic hormonal interactions in development of most prevalent central and peripheral non-malignant clinical/metabolic endocrine disorders in the Chornobyl NPP accident (ChNPPA) survivors. Materials and methods. Retrospective assay of non-malignant radiation effects on endocrine system was applied in 18,192 survivors of the ChNPPA. Data from the Clinical/Epidemiological Register of the SI "National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine" for the period of 1993-2003 were involved. Anthropometric values, biochemical and hormonal assay indices, diagnostic thyroid ultrasound data, external radiation dose values were taken into account both with calculated insulin resistance index. Results. Thyroid disease incidence in ChNPPA survivors increased dramatically 10 years upon radiation impact being 39.33 % in average, 14.35 % (р < 0.01 vs. entire population) for nodular goiter, and about 8 % for autoimmune thyroiditis (р < 0.01 vs. the same). As a result of an advanced examination of ChNPPA survivors the incidence of diffuse non-toxic goiter was 40.4 % (χ2Yates = 73.82; р = 0), of nodular goiter - 23.1 % (χ2Yates = 14.13; р = 0.002) vs. values in the control group (4.8 % and 17.6 % respectively). Some hormonal interactions were identified in study subjects indicating the thyroid disease onset under radiation impact through insulin resistance at the background of adipose tissue excess followed by body mass index increase, elevation of serum C-peptide and leptin levels, and onset of lipid metabolic disorders. Conclusions. Significant increase of the incidence of thyroid disease (1.5-3-fold), diabetes mellitus (3-7-fold), pre-obesity and obesity (in 25.67 %), and metabolic syndrome (5-fold) vs. entire population of Ukraine was found in remote terms upon the accident. Intricate pathogenetic intersystemic hormonal interactions were identified predisposing to thyroid disease due to insulin resistance, accompanying hyperinsulinemia, increased body mass index and some other hormonal and biochemical factors.