title: Association between thyroid autoimmunity andHelicobacter pyloriinfection.
abstract: OBJECTIVE
  There have been controversial reports linkingHelicobacter pyloriinfection to autoimmune thyroid disease (AITD). However, data regarding the relationship are limited for Asian populations, which have an extremely high prevalence ofH. pyloriinfection. We performed this study to investigate the association betweenH. pyloriinfection and AITD in Koreans.
  
  
  METHODS
  This study involved adults aged 30 to 70 years who had visited a health promotion center. A total of 5,502 subjects were analysed. Thyroid status was assessed by free thyroxine, thyroid stimulating hormone, and anti-thyroid peroxidase antibody (TPO-Ab). Immunoglobulin G (IgG) antibodies toH. pyloriwere measured as an indication ofH. pyloriinfection. We compared the prevalence of TPO-Ab in subjects with and withoutH. pyloriinfection.
  
  
  RESULTS
  H. pyloriIgG antibodies were found in 2,875 subjects (52.3%), and TPO-Ab were found in 430 (7.8%). Individuals positive forH. pyloriAb were older than those negative forH. pyloriAb (p< 0.01). The proportion of females was significantly higher in the TPO-Ab positive group (41.0% vs. 64.2%,p< 0.01). Prevalence of TPO-Ab positivity was higher in subjects withH. pyloriinfection (8.6% vs. 7.00%,p= 0.03), and this association was significant after adjusting for age, sex, and body mass index (odds ratio, 1.02; 95% confidence interval, 1.00 to 1.03;p= 0.04).
  
  
  CONCLUSIONS
  In our study, prevalence of TPO-Ab positivity is more frequent in subjects withH. pyloriinfection. Our findings suggestH. pyloriinfection may play a role in the development of autoimmune thyroiditis.
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Yun Mi
authors.initials: YM
authors.lastname: Choi
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Tae Yong
authors.initials: TY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Dongnam Institute of Radiological & Medical Sciences, Busan, Korea.
authors.forename: Eui Young
authors.initials: EY
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Jang
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Min Ji
authors.initials: MJ
authors.lastname: Jeon
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Won Gu
authors.initials: WG
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Young Kee
authors.initials: YK
authors.lastname: Shong
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Won Bae
authors.initials: WB
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000276:immunology; D005260:Female; D016481:Helicobacter Infections / Q000150:complications* / Q000453:epidemiology; D016480:Helicobacter pylori; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D013967:Thyroiditis, Autoimmune / Q000150:complications* / Q000453:epidemiology / Q000276:immunology
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D033862:Iron-Binding Proteins; C056626:thyroid microsomal antibodies; C056658:TPO protein, human; D007453:Iodide Peroxidase
keywords: Autoimmunity; Helicobacter pylori; Thyroid