Occupational Exposure to Ionizing Radiation is Associated with Autoimmune Thyroid Disease

Context: The thyroid gland is a potential target organ for radiation-related damage.

Objective: The aim of the analysis was to investigate the association between occupational exposure to ionizing radiation and autoimmune thyroid disease (AITD).

Design: Our design was the cross-sectional Study of Health in Pomerania.

Setting: The setting was the general community.

Subjects: Analyses were performed in a population-based sample of 4299 subjects. Among them, 160 persons reported a history of occupational exposure to ionizing radiation.

Main Outcome Measure: AITD was defined as the combined presence of hypoechogenicity in thyroid ultrasound and antithyroxiperoxidase antibodies greater than 200 IU/ml.

Results: Females with occupational exposure to ionizing radiation had more often AITD than nonexposed females (10.0 vs. 3.4%; P < 0.05). This association persisted after adjustment for relevant confounders (odds ratio, 3.46; 95% confidence interval, 1.16-10.31; P < 0.05). In males, there were too few subjects who fulfilled the criteria of AITD, but the association between the exposure to radiation and hypoechogenicity of the thyroid gland barely missed statistical significance (odds ratio, 2.20; 95% confidence interval, 0.92-5.26; P = 0.08). In both females and males, subjects who reported a length of exposure of more than 5 yr exhibited the highest risk of the endpoints.

Conclusions: We conclude that occupational exposure to ionizing radiation is related to the risk of AITD. The usage of thyroid protection shields by radiation workers is strongly recommended.