title: Helicobacter pylori infection and gastritis: the Systematic Investigation of gastrointestinaL diseases in China (SILC).
abstract: OBJECTIVE
  Helicobacter pylori infection remains common in East Asia, though its prevalence is decreasing in Western countries. H. pylori-related atrophic gastritis (AG) may reduce the likelihood of gastroesophageal reflux disease (GERD). We investigated the prevalence of H. pylori infection and AG and their association with endoscopic findings and symptom-defined GERD in Shanghai.
  
  
  METHODS
  A representative random sample of 3600 Shanghai residents aged 18-80 years was invited to complete a general information questionnaire and a Chinese version of the Reflux Disease Questionnaire, to provide blood samples for H. pylori serology and pepsinogen (PG) I/II assay (to detect AG, defined as PGI < 70 µg/L and/or PGI/PGII < 7), and to undergo endoscopy. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by multivariate logistic regression.
  
  
  RESULTS
  A total of 1022 Shanghai residents underwent endoscopy and were valid for inclusion in the study. Of these, 71.7% tested positive for H. pylori, 63.8% had AG and 30.5% had moderate/severe AG (PGI < 50 µg/L and/or PGI/PGII < 5). Helicobacter pylori infection was equally common in all age groups. Severity of AG increased with age in women. Reflux esophagitis was inversely associated with AG (OR, 0.23 [CI, 0.09-0.55] for moderate/severe AG compared with no H. pylori or gastritis). However, symptom-defined GERD showed no clear association with AG.
  
  
  CONCLUSIONS
  Helicobacter pylori infection and AG are very common in Shanghai, and the infection is acquired early in life. Atrophic gastritis is inversely associated with reflux esophagitis but is not significantly associated with symptom-defined GERD.
authors.affiliation: Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Duowu
authors.initials: D
authors.lastname: Zou
authors.forename: Jia
authors.initials: J
authors.lastname: He
authors.forename: Xiuqiang
authors.initials: X
authors.lastname: Ma
authors.forename: Wenbin
authors.initials: W
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Xingang
authors.initials: X
authors.lastname: Shi
authors.forename: Ping
authors.initials: P
authors.lastname: Ye
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Gong
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yan
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Man
authors.forename: Li
authors.initials: L
authors.lastname: Gao
authors.forename: John
authors.initials: J
authors.lastname: Dent
authors.forename: Joseph
authors.initials: J
authors.lastname: Sung
authors.forename: Börje
authors.initials: B
authors.lastname: Wernersson
authors.forename: Saga
authors.initials: S
authors.lastname: Johansson
authors.forename: Zhaoshen
authors.initials: Z
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000706:statistics & numerical data*; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D016099:Endoscopy, Gastrointestinal; D004942:Esophagitis, Peptic / Q000175:diagnosis / Q000208:ethnology* / Q000382:microbiology; D005260:Female; D005757:Gastritis, Atrophic / Q000175:diagnosis / Q000208:ethnology* / Q000382:microbiology; D005764:Gastroesophageal Reflux / Q000175:diagnosis / Q000208:ethnology* / Q000382:microbiology; D006306:Health Surveys; D016481:Helicobacter Infections / Q000175:diagnosis / Q000208:ethnology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult