Comparison and assessment of thyroid morphology and function in inhabitants of Lower Silesia before and after administration of a single dose of iodine-containing contrast agent during cardiac intervention procedure Ocena morfologii i funkcji tarczycy u mieszkańców regionu Dolnego Śląska przed i po jednorazowym obciążeniu pojedynczą, niefizjologiczną dawką jodu podczas kardiologicznych procedur interwencyjnych

Introduction: Inhabitants living in areas with endemic dietary iodine intake deficiency develop nodular goitre. The aim of our study was to evaluate thyroid morphology and function among adults residing in Lower Silesia and to assess the effect on the thyroid gland of an iodine-based contrasting agent administered during a cardiac intervention procedure. Materials and methods: The first part of the study (evaluation of thyroid gland) was carried out on 120 subjects (78 men and 42 women). From among this group, invasive cardiac procedures were performed on 60 subjects (38 men and 22 women) during the second part of the study. Endocrine tests were repeated one, three, and six months after the invasive procedure. Results: 1) Within the studied group, pathological changes in thyroid morphology were found in 49.1%, and thyroid function disturbances in 9.3%, of all subjects. 2) A decrease in TSH concentration with a corresponding increase in fT3 concentration was seen at the second visit (four weeks after iodine administration) leading to the diagnosis of hyperthyroidism in 15% of subjects. Conclusions: 1) Considering the multitude of silent thyroid pathologies, particular care is required before administering an iodine-based medium. 2) It is reasonable and advisable to monitor TSH and fT3 levels before and at four weeks after administration of an iodine-containing contrast agent. 3) Thyroid morphology and function disturbances after iodine administration do not necessitate treatment, as they are of transient character and only require monitoring. (Endokrynol Pol 2012; 63 (4): 294-299)