Effect of ionizing radiation on thyroid function among medical workers in department of cardiovascular medicine / 中国辐射卫生

ABSTRACT

@#<b>Objective</b> To examine the possible effect of ionizing radiation on thyroid function among medical workers in the department of cardiovascular medicine. <b>Methods</b> Forty-six medical workers in the department of cardiovascular medicine with exposure to ionizing radiation were enrolled as the study subjects. Subjects’ demographic features were collected. Serum free triiodothyronine (fT3), free thyroxine (fT4), and thyroid-stimulating hormone (TSH) levels were measured using chemiluminescence assay, and the annual personal dose equivalent (<i>H</i>p (10)) received in 2019 and the fiver-year cumulative <i>H</i>p (10) from 2015 to 2019 were measured using a thermoluminescent personal dosimeter. The associations of altered thyroid functions with subjects’ age, sex, previous history of thyroid diseases, family history of thyroid diseases, working post, work seniority, and previous history of exposure to ionizing radiation were evaluated using an exact logistic regression model. <b>Results</b> The incidence of subclinical hypothyroidism (elevated serum TSH level without alteration in fT3 or fT4 level) was 6.5% among the study subjects. The <i>H</i>p (10) was 0 to 4.5 mSv among the subjects in 2019, with a mean dose of (0.2 ± 0.7) mSv and a median dose of 0 mSv, and the five-year cumulative <i>H</i>p (10) from 2015 to 2019 was 0 to 11.6 mSv, with a mean dose of (0.8 ± 2.3) mSv and a median dose of 0 mSv. The exact logistic regression analysis showed that the altered thyroid functions were not significantly associated with age, sex, previous history of thyroid diseases, family history of thyroid diseases, working post, work seniority, or previous history of exposure to ionizing radiation (all <i>P</i> > 0.05). <b>Conclusion</b> Long-term exposure to low-dose ionizing radiation may be associated with an increased risk of subclinical hypothyroidism among medical workers in the department of cardiovascular medicine.