title: Thyroid diseases in atomic bomb survivors exposed in utero.
abstract: OBJECTIVE
  The objective of the study was to evaluate the association of thyroid disease with radiation dose in atomic bomb survivors exposed in utero.
  
  
  METHODS
  This was a cross-sectional study.
  
  
  METHODS
  The study was conducted in atomic bomb survivors in Hiroshima and Nagasaki, Japan.
  
  
  METHODS
  Participants included 328 atomic bomb survivors exposed in utero (mean age 55.2 yr, 162 males) who participated in the thyroid study at the Radiation Effects Research Foundation. Examinations were conducted between March 2000 and February 2003.
  
  
  METHODS
  The relationships of various thyroid conditions to atomic bomb radiation dose were measured.
  
  
  RESULTS
  Among the 319 participants excluding nine participants whose exposure radiation dose was not estimated, the mean maternal uterine radiation dose was 0.256 Gy. We observed no significant dose-response relationship for the prevalence of solid thyroid nodules (odds ratio at 1 Gy, 2.78; 95% confidence interval 0.50-11.80, P = 0.22), but the risk estimate was similar to the estimate for childhood exposures. The prevalence of cysts and autoimmune thyroid diseases was not associated with radiation dose (P > 0.30). We could not evaluate the dose response for malignant tumors or benign nodules due to the small number of cases.
  
  
  CONCLUSIONS
  We did not observe a statistically significant linear dose response to radiation for thyroid nodules or autoimmune thyroid diseases 55-58 yr after participants' in utero exposure. However, the risk estimate for solid thyroid nodules was similar for those exposed in utero and those exposed in childhood. Because the study had limited statistical power to detect moderately sized effects, further studies are needed for a definitive conclusion.
authors.affiliation: Department of Clinical Studies, Radiation Effects Research Foundation, 1-8-6 Nakagawa, Nagasaki, Japan. misaima@rerf.or.jp
authors.forename: Misa
authors.initials: M
authors.lastname: Imaizumi
authors.forename: Kiyoto
authors.initials: K
authors.lastname: Ashizawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Neriishi
authors.forename: Masazumi
authors.initials: M
authors.lastname: Akahoshi
authors.forename: Eiji
authors.initials: E
authors.lastname: Nakashima
authors.forename: Toshiro
authors.initials: T
authors.lastname: Usa
authors.forename: Tan
authors.initials: T
authors.lastname: Tominaga
authors.forename: Ayumi
authors.initials: A
authors.lastname: Hida
authors.forename: Nobuko
authors.initials: N
authors.lastname: Sera
authors.forename: Midori
authors.initials: M
authors.lastname: Soda
authors.forename: Saeko
authors.initials: S
authors.lastname: Fujiwara
authors.forename: Michiko
authors.initials: M
authors.lastname: Yamada
authors.forename: Renju
authors.initials: R
authors.lastname: Maeda
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Nagataki
authors.forename: Katsumi
authors.initials: K
authors.lastname: Eguchi
mesh_terms: D001323:Autoantibodies / Q000097:blood; D003430:Cross-Sectional Studies; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005333:Fetus / Q000528:radiation effects*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009689:Nuclear Warfare; D011247:Pregnancy; D015995:Prevalence; D017741:Survivors; D013959:Thyroid Diseases / Q000453:epidemiology*; D013961:Thyroid Gland / Q000276:immunology / Q000528:radiation effects*
chemical_list: D001323:Autoantibodies