title: Time Trends in Helicobacter pylori Infection and Atrophic Gastritis Over 40 Years in Japan.
abstract: BACKGROUND
  Helicobacter pylori infection produces progressive mucosal damage that may eventually result in gastric cancer. We studied the changes that occurred in the presence and severity of atrophic gastritis and the prevalence of H. pylori infection that occurred coincident with improvements in economic and hygienic conditions in Japan since World War II.
  
  
  METHODS
  The prevalence of H. pylori infection and histologic grades of gastric damage were retrospectively evaluated using gastric biopsy specimens obtained over a 40-year period. Gastric atrophy and intestinal metaplasia were scored using the updated Sydney classification system.
  
  
  RESULTS
  The prevalence of H. pylori and severity of atrophy were examined in 1381 patients including 289 patients examined in the 1970s (158 men; mean age, 44.9 years), 787 in the 1990s (430 men; 44.2 years), and 305 in the 2010s (163 men; 53.2 years). Overall, the prevalence of H. pylori infection decreased significantly from 74.7% (1970s) to 53% (1990s) and 35.1% (2010s) (p < .01). The prevalence of atrophy in the antrum and corpus was significantly lower in the 2010s (33, 19%, respectively) compared to those evaluated in either the 1970s (98, 82%) (p < .001) or 1990s (80, 67%) (p < .001). The severity of atrophy and intestinal metaplasia also declined remarkably among those with H. pylori infection.
  
  
  CONCLUSIONS
  There has been a progressive and rapid decline in the prevalence of H. pylori infection as well a fall in the rate of progression of gastric atrophy among H. pylori-infected Japanese coincident with the westernization and improvements in economic and hygienic conditions in Japan since World War II.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Tomoari
authors.initials: T
authors.lastname: Kamada
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Haruma
authors.affiliation: Department of Gastroenterology and Metabolism, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Ito
authors.affiliation: Department of General Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Inoue
authors.affiliation: Division of Endoscopy and Ultrasound, Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Manabe
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsumoto
authors.affiliation: Department of General Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kusunoki
authors.affiliation: Division of Endoscopy and Ultrasound, Department of Clinical Pathology and Laboratory Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Jiro
authors.initials: J
authors.lastname: Hata
authors.affiliation: Health Service Center, Hiroshima University, Higashihiroshima, Japan.
authors.forename: Masaharu
authors.initials: M
authors.lastname: Yoshihara
authors.affiliation: Department of Internal Medicine, Saiseikai Hiroshima Hospital, Hiroshima, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Sumii
authors.affiliation: Department of Pathology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Akiyama
authors.affiliation: Department of Endoscopy, Hiroshima University Hospital, Hiroshima, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Shiotani
authors.affiliation: Department of Medicine, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, TX, USA.
authors.forename: David Y
authors.initials: DY
authors.lastname: Graham
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005753:Gastric Mucosa / Q000473:pathology; D005757:Gastritis, Atrophic / Q000453:epidemiology* / Q000473:pathology; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000502:physiology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000473:pathology; D055815:Young Adult
keywords: Gastric atrophy; Helicobacter pylori; gastric cancer; intestinal metaplasia; salt intake; smoking