Thyroid Function in Health Care Workers Exposed to Ionizing Radiation.

OBJECTIVES: To analyze possible alterations of thyroid function related to dosimetric values in health care workers exposed to ionizing radiation.

MATERIALS AND METHODS: Forty-six health care workers exposed to ionizing radiation at a tertiary hospital previously exposed to ionizing radiation were included in the study. Age, sex, history of thyroid diseases, thyroid hormones, work post, service, dosimetric values of previous year, and 5 y period were considered. Alterations of thyroid function and other variables were analyzed by exact logistic regression univariate model.

RESULTS: 7.1% workers showed an increased serum thyroid-stimulating hormone without free T3 or free T4 alteration. A significant relationship between workers with increased thyroid-stimulating hormone and dosimetric values of previous year (odds ratio 6.35, 95% confidence interval 1.20-98.1, p = 0.021) and previous 5 y period of radiation exposure (odds ratio 1.72, 95% confidence interval 1.12-3.34, p = 0.007) was obtained.

CONCLUSION: An increased risk of subclinical hypothyroidism related to radiation doses was observed in this pilot study on a group of health care workers exposed to ionizing radiation.