Thyroid function, thyroid immunoglobulin status, and urinary iodine excretion after enteral contrast-agent administration by endoscopic retrograde cholangiopancreatography.
OBJECTIVE
The aim of this study was to examine the occurrence of clinically relevant changes in thyroid function after enteral administration of contrast agent by endoscopic retrograde cholangiopancreatography (ERCP).


METHODS
In this study 70 patients without a history of thyroid disease who had not recently undergone thyroid-specific or thyroid-influencing therapy were examined. Patients were examined on two or three occasions using a standardized questionnaire regarding symptoms of hypothyroidism and hyperthyroidism. The parameters of thyroid function (TT3, TT4, FT4, thyroid-stimulating hormone (TSH)) and urinary iodine excretion were measured on day 0 and on day 21 post-ERCP, and in 23 patients additionally on day 42 post-ERCP. Based on ultrasonographic results, four groups differing in thyroid morphology were distinguished.


RESULTS
The data show that an average amount of only 4.7 g of enterally applied iodine is associated with a lasting decrease of TSH, especially in patients with enlarged organs with nodular transformation. As far as TT3 is concerned, there was a significant increase in all patient groups; regarding FT4 we only observed a marked increase in the group with enlarged, nodular thyroid glands. There was a notable increase in urinary iodine excretion on day 21, and a further increase on day 42 post-ERCP. Clinical symptoms of hyperthyroidism did not occur.


CONCLUSIONS
We conclude that before administration of iodine-containing contrast agent for ERCP in patients without a history of thyroid disease, thyroid ultrasonographic examination, rather than TSH measurements, should be performed, in order to identify patients already at risk for hyperthyroidism before diagnostic enteral contrast-medium application.
Fassbender
W J
WJ
Medizinische Klinik III, Universitätsklinikum der RWTH, Aachen, Germany. wjfassbender@post.klinikum.rwth.aachen.de
Vogel
C
C
Doppl
W
W
Stracke
H
H
Bretzel
R G
RG
Klör
H U
HU
D000284:Administration, Oral; D001323:Autoantibodies / Q000097:blood; D002760:Cholangiopancreatography, Endoscopic Retrograde; D003287:Contrast Media / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D006980:Hyperthyroidism / Q000175:diagnosis / Q000000981:diagnostic imaging; D018828:Immunoglobulins, Thyroid-Stimulating / Q000097:blood*; D007453:Iodide Peroxidase / Q000276:immunology; D007455:Iodine / Q000652:urine*; D007472:Iohexol / Q000008:administration & dosage / Q000009:adverse effects* / Q000031:analogs & derivatives; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013954:Thyroglobulin / Q000276:immunology; D013961:Thyroid Gland / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000502:physiology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014463:Ultrasonography
D001323:Autoantibodies; D003287:Contrast Media; D018828:Immunoglobulins, Thyroid-Stimulating; D014284:Triiodothyronine; D007472:Iohexol; C038192:iopromide; D013972:Thyrotropin; D013954:Thyroglobulin; D007455:Iodine; D007453:Iodide Peroxidase; D013974:Thyroxine