Neurologic, Vascular, And Endocrine Morbidity Following Chidhood Exposure To Low And Moderate Doses Of Ionizing Radiation

1599 Background: While the association between exposure to ionizing radiation and cancer is well known, its possible role in the development of other diseases e.g. in the vascular, neurologic and endocrine systems is limited and inconsistent. The aim of this study was to assess the effect of childhood exposure to low and moderate doses of radiation on the development of chronic diseases (other than cancer) based on a large cohort followed for 55 years. Methods: The study population included an exposed group of 13,158 individuals treated with ionizing radiation for tinea capitis and a comparison group of 16,225 unexposed subjects. The mean dose to the head and the thyroid gland were 1.5 Gy and 0.094 Gy respectively and the mean age at exposure was 7.1±3.1y. Data on the outcome variables was obtained through computer linkage of the study database with the largest health care provider registry in Israel. Results: Of the study population, 64% were found to be insured in this heath provider (66.8% among the irradiated and 63.6% among the unexposed group). The two study groups did not differ in current age (mean 62.1+4.5 y), gender, marital status, smoking and BMI. Compared to the unexposed group, the irradiated group demonstrated a significantly (p<0.001 ) increased prevalence of epilepsy (1.8% vs. 2.8%), CVA (6.4% vs. 8%), diabetes (26.5 % vs. 28.2%), hyperthyroidism (8.1% vs. 9.4%), hyper/hypo-parathyroidism (0.6% vs. 1.2%) and depression (8.1% vs. 9.4%), respectively. There was no statistical difference between the groups in the prevalence of dementia and Parkinson's disease. Multivariate models accounting for different variables of interest (e.g. age at exposure, gender, SES) will be presented. Conclusions: These results have practical implications for primary prevention and early detection of therapeutic and diagnostic radiation associated morbidity.