title: Thyroid functions after contrast agent administration for coronary angiography: a prospective observational study in euthyroid patients.
abstract: OBJECTIVE
  This study aims to investigate long-term effects of iodinated radiographic contrast media used for coronary angiography (CAG) on the thyroid function in euthyroid patients.
  
  
  METHODS
  In a prospective observational cohort study, nonionic iodinated contrast material was electively used in 101 patients for coronary angiography. The patients were recruited without age restrictions and, at baseline, all had normal levels of free triiodothyronine (FT3), free thyroxine (FT4) and thyrotropin (TSH). The morphology of the thyroid was evaluated by thyroid ultrasonography (USG). Four and eight weeks after CAG, serum TSH, FT3 and FT4 levels were assessed.
  
  
  RESULTS
  Compared to a mean baseline level of 1.49 (25%-75%, range 13-2.21), follow-up TSH levels decreased significantly to 1.45 (25%-75%, range 1.98-0.92, p=0.017) and 1.40 (25%-75%, range 1.89-0.87, p=0.003) at 4 weeks and 8 weeks, respectively (p=0.008). No significant diffe-rence was observed in TSH levels between the 4th and 8th weeks (p=0.833).
  
  
  CONCLUSIONS
  Iodinated radiographic contrast agents may cause subclinical hyperthyroidism in euthyroid patients undergoing CAG.
authors.affiliation: Clinics of Internal Medicine, Dr.Siyami Ersek Thoracic Cardiovascular Surgery Education and Research Hospital, İstanbul-Turkey. sevilfurkan@hotmail.com
authors.forename: Sevil
authors.initials: S
authors.lastname: Özkan
authors.forename: Aslıhan Semiz
authors.initials: AS
authors.lastname: Oysu
authors.forename: Kadir
authors.initials: K
authors.lastname: Kayataş
authors.forename: Refik
authors.initials: R
authors.lastname: Demirtunç
authors.forename: Mehmet
authors.initials: M
authors.lastname: Eren
authors.forename: Hatice
authors.initials: H
authors.lastname: Uslu
authors.forename: Yüksel
authors.initials: Y
authors.lastname: Altuntaş
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000009:adverse effects*; D017023:Coronary Angiography / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000139:chemically induced*; D007472:Iohexol / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000187:drug effects*; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D014284:Triiodothyronine; D007472:Iohexol; D013972:Thyrotropin; D013974:Thyroxine