Non cancer thyroid and other endocrine disease in children and adults exposed to ionizing radiation after the ChNPP accident.

STUDY OBJECTIVE: To summarize the verified clinical and epidemiological data on the natural history of non cancer endocrine disease in remote period after the ChNPP accident in survivors of adult and children age.

MATERIALS AND METHODS: Retrospective estimation was carried out of data on 24,588 adult persons and 20,087 chil dren survived after the ChNNP accident and being healthy or having any diseases. Data were retrieved from database of the Clinical Epidemiological Registry (CER), NRCRM for the 23 years (1992-2014) of survey. Average total external radiation dose in adults was 0.187 Gy, range of thyroid dose in children was 0.1-1.55 Gy. These data were verifies in a separate clinical study. Anthropometric, laboratory biochemical and hormonal assay values, thyroid ultrasound imaging patterns and radiation dose values were retrieved for the study.

RESULTS: Retrospective data review for the 1992-2014 period indicated that incidence of thyroid disease in all per sons survived after the ChNPP accident run at 40.29% with 35.37% among the clean up workers, 27.24% among evac uees, and 28.6% among population of contaminated territories that all is significantly (p < 0.0001) higher vs. the entire population of Ukraine (3.9%). Following non cancer endocrine diseases were most prevalent in the ChNPP acci dent survivors: nodular goiter (14.35%), chronic autoimmune thyroiditis (~8%), pre obesity and obesity (41.9% and 36.8% respectively), prediabetes and diabetes mellitus (15.5% and 21.4% respectively). Nodular goiter (21.8%), chronic autoimmune thyroiditis (12.95%), pre obesity and obesity (41.71% and 33.61% respectively), and predia betes and diabetes mellitus (8.6% and 12.15% respectively) were most often diagnosed in the ChNPP accident clean up workers. Children evacuated from the 30 kilometer exclusion zone were a critical population group. They were diagnosed diffuse non toxic goiter in 43.68%, chronic autoimmune thyroiditis in 1.74%, primary hypothyroidism in 0.96%, and nodular goiter in 2.57%. Peak prevalence of chronic autoimmune thyroiditis occurred in 2001-2003 i.e. in a period of their intensive pubertal maturation. In children (first generation) of exposed parents the thyroid dis ease was revealed in 42.64%, that exceeded the incidence in control group, chronic autoimmune thyroiditis was found rarer i.e. in 0.45%, diffuse non toxic goiter in 9.5-13.8%, nodular goiter in 1.7%.

CONCLUSIONS: Non cancer endocrine disease in children and adults exposed to ionizing radiation is frequent and reg istered in 3 53% of persons. It occurs in most of survivors 10-15 years upon the impact of radiation factor as a result of man made accident and continues to grow slowly in 30 years.