Introduction: It is well known that ionizing radiation (IR) exposure increases the risk of thyroid cancer; however less is known about its role in development of autoimmune thyroiditis. Aim of work: to investigate the thyroid gland functions,
level of anti TPO among interventional cardiology team members searching for an association between the level of their occupational exposure to ionizing radiation and the thyroid gland integrity. Materials and methods: This work was carried out in Cardiac Catheterization Unit in National Heart Institute Center. The study comprised two groups, an exposed group of 47 cardiac catheterization workers (19 physicians, 15 nurses and 13 technicians) and a control group of 47 workers matched with the exposed group as regards age and sex. The studied groups were subjected to a detailed questionnaire, full clinical examinations. laboratory investigations in the form of serum thyroid stimulating hormone (TSH), Triiodothyronine (T3), Thyroxine (T4) and antithyroxiperoxidase antibodies (anti-TPO). Radiation exposure was monitored by digital dosimeter. Results: Dosimeter readings were higher among physicians followed by nurses and technicians. Statistically significant higher level of serum TSH, anti-TPO along with statistically significant lower levels of T3, were found among the exposed compared to control groups (P<0.05). Significant positive correlation was detected
between the level of anti-TPO and TSH (r= 0.876 P<0.001). Moreover, a significant negative correlation was found between anti-TPO and each of T3 (r= -0.814 P<0.001) and T4 (r= -0.324 P<0.05). ANOVA and Post Hoc tests showed significantly higher level of anti-TPO with significantly lower levels of T3 among the physicians compared to control group. Conclusion: Autoimmune thyroiditis may be considered as one of the adverse health hazards of occupational exposure to ionizing radiation in cardiac catheterization units. Recommendations: We recommend the regular measurement of thyroid hormone especially TSH and anti-TPO to detect early affection of thyroid gland
among radiation exposed workers.