title: The effect of radioactive iodine treatment on 14C urea breath test results in patients with hyperthyroidism.
abstract: OBJECTIVE
  Radioactive Iodine therapy (RAIT) plays a major role in the treatment of hyperthyroidism. In addition to the thyroid gland, significant amounts of radioactive iodine are maintained in the stomach. The aim of this study was to determine if RAIT has any effect on Helicobacter pylori infection, based on the C urea breath test (UBT).
  
  
  METHODS
  The study included 85 patients with hyperthyroidism scheduled to undergo RAIT and 69 hyperthyroid subjects in whom methimazole treatment was planned. All subjects had pretreatment-positive UBT results, and the test was repeated on the first and third months after RAIT and methimazole treatment.
  
  
  RESULTS
  After a mean RAIT dose of 15 mCi (range, 10-20 mCi), UBT became negative in 13 (15.3%) of 85 patients on the first month and 18 (21.2%) of 85 patients on the third month. All subjects treated with methimazole remained UBT positive on the first and third months of methimazole treatment (100%). Reduction in the number of UBT-positive patients on both the first and the third months after RAIT was statistically significant (P < 0.001). Distribution of hyperthyroidism etiologies and thyroid autoantibody levels in subjects with UBT that became negative and in subjects with UBT that remained positive were similar in the RAIT group (P > 0.05). Urea breath test negativity rates did not differ according to the radioiodine dose.
  
  
  CONCLUSIONS
  Our findings indirectly showed that RAIT might have an antimicrobial effect on H. pylori. Clinical applications of this beneficial effect of RAIT on H. pylori should be further evaluated.
authors.affiliation: From the *Department of Endocrinology and Metabolism, Ministry of Health, Ankara Numune Research and Training Hospital, Ankara, Turkey; †National Institute of Diabetes and Digestive and Kidney Diseases, Diabetes, Endocrine and Obesity Branch, National Institutes of Health, Bethesda, Maryland; ‡Faculty of Medicine, Department of Internal Medicine, Duzce University, Duzce, Turkey; §Department of Nuclear Medicine, Ministry of Health, Ankara Numune Research and Training Hospital, Ankara, Turkey; and ¶Faculty of Medicine, Department of Endocrinology and Metabolism, Hitit University, Corum, Turkey.
authors.forename: Ayse
authors.initials: A
authors.lastname: Arduc
authors.forename: Bercem Aycicek
authors.initials: BA
authors.lastname: Dogan
authors.forename: Ufuk
authors.initials: U
authors.lastname: Ozuguz
authors.forename: Mazhar Muslim
authors.initials: MM
authors.lastname: Tuna
authors.forename: Ferhat
authors.initials: F
authors.lastname: Gokay
authors.forename: Yasemin Ates
authors.initials: YA
authors.lastname: Tutuncu
authors.forename: Serhat
authors.initials: S
authors.lastname: Isik
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Aydin
authors.forename: Irfan
authors.initials: I
authors.lastname: Peksoy
authors.forename: Dilek
authors.initials: D
authors.lastname: Berker
authors.forename: Serdar
authors.initials: S
authors.lastname: Guler
mesh_terms: D013956:Antithyroid Agents / Q000627:therapeutic use; D001944:Breath Tests; D002250:Carbon Radioisotopes; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000532:radiotherapy*; D016480:Helicobacter pylori / Q000528:radiation effects; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000175:diagnosis* / Q000532:radiotherapy*; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008713:Methimazole / Q000627:therapeutic use; D008875:Middle Aged; D011446:Prospective Studies; D014508:Urea
chemical_list: D013956:Antithyroid Agents; D002250:Carbon Radioisotopes; D007457:Iodine Radioisotopes; D008713:Methimazole; D014508:Urea