title: Racial differences in Helicobacter pylori, serum pepsinogen and gastric cancer incidence in an urban Asian population.
abstract: BACKGROUND
  In Singapore, the highest incidence of gastric cancer occurs in the Chinese (C), with lower rates among Malay (M) and Indian (I) subjects. The purpose of the present paper was to examine whether racial differences in the prevalence of Helicobacter pylori and serum pepsinogen (PG) could account for this difference.
  
  
  METHODS
  A randomized community health survey involving 7000 asymptomatic healthy individuals was conducted. Among the Chinese, Malay and Indian respondents, subjects were matched for age, gender and race and a total of 595 sera were obtained. The H. pylori seropositivity and serum PG levels were determined by ELISA. The dependency of the cumulative gastric incidence rate on H. pylori seroprevalence was evaluated by linear regression. The racial difference in the seroprevalence of H. pylori and low serum PG was determined.
  
  
  RESULTS
  The H. pylori seroprevalence was similar between Chinese and Indian subjects, but significantly lower among Malay subjects (C, 46.3%; M, 27.9%; I, 48.1%). The gastric cancer incidence rates correlated with H. pylori seropositivity for the Chinese and Malay subjects, but not for the Indian subjects. The prevalence of low PG was highest in Indian subjects (PG I low: C, 2.1%; M, 5.4%; I, 14.2%; P < 0.0001; PG I:II ratio low: C, 5.3%; M, 5.9%; I, 12.6%; P = 0.012), even when adjusted for gender and the presence of H. pylori.
  
  
  CONCLUSIONS
  The difference in gastric cancer incidence correlated with H. pylori seroprevalence for Chinese and Malay subjects. The lower incidence of gastric cancer among Indian subjects cannot be explained by differences in H. pylori or serum PG. Other modifying factors such as host and environmental factors may be important.
authors.affiliation: Division of Gastroenterology, Changi General Hospital, Singapore. tiing_leong_ang@cgh.com.sg
authors.forename: Tiing Leong
authors.initials: TL
authors.lastname: Ang
authors.forename: Kwong Ming
authors.initials: KM
authors.lastname: Fock
authors.forename: Subbiah
authors.initials: S
authors.lastname: Dhamodaran
authors.forename: Eng Kiong
authors.initials: EK
authors.lastname: Teo
authors.forename: Jessica
authors.initials: J
authors.lastname: Tan
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People / Q000706:statistics & numerical data*; D002681:China / Q000208:ethnology; D005260:Female; D016480:Helicobacter pylori / Q000276:immunology*; D006801:Humans; D015994:Incidence; D007194:India / Q000208:ethnology; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D020116:Pepsinogen A / Q000097:blood*; D016036:Seroepidemiologic Studies; D012846:Singapore / Q000453:epidemiology; D013274:Stomach Neoplasms / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D014505:Urban Population / Q000706:statistics & numerical data*
chemical_list: D020116:Pepsinogen A