title: Does Helicobacter pylori infection explain all socio-economic differences in peptic ulcer incidence? Genetic and psychosocial markers for incident peptic ulcer disease in a large cohort of Danish adults.
abstract: BACKGROUND
  Peptic ulcer epidemiology has changed considerably within the past century. The aim of this study was to assess the 11-year cumulative incidence of peptic ulcer disease and examine the relationship between ulcer incidence and psychosocial and genetic factors.
  
  
  METHODS
  A random sample of 2416 Danish adults with no history of peptic ulcer disease residing in Copenhagen County, Denmark, attended a population-based prospective cohort study in 1983 and 1994. All participants reported whether they had had an ulcer diagnosed within the observation period. Information on socio-economic factors, family history of peptic ulcer disease (PUD) and lifestyle practices was obtained from a questionnaire. Lewis blood group antigens were assessed from blood samples and Helicobacter pylori infection status was determined with an in-house IgG ELISA.
  
  
  RESULTS
  The overall 11-year cumulative incidence proportion of PUD was 2.9% (95% CI (2.2; 3.6)), i.e. 1.6% (95% CI (1.1; 2.1)) for duodenal ulcer, and 1.3% (95% CI (0.8; 1.7)) for gastric ulcer. Poor socio-economic status increased the risk of PUD independently of H. pylori infection (odds ratio 2.7, 95% CI (1.1; 6.1)) and accounted for 17% of all ulcer cases. High physical activity at work increased the risk of PUD in people infected with H. pylori (odds ratio 2.6, 95% CI (0.8; 8.0)). Family history of PUD or Lewis blood group antigens did not relate to ulcer incidence.
  
  
  CONCLUSIONS
  Poor socio-economic status is an important risk factor for PUD that exerts its effect independently of H. pylori infection. Strenuous work may increase the risk of PUD in people with H. pylori infection. Genetic factors do not influence the risk of PUD in Danish adults.
authors.affiliation: Dept. of Surgery D26 and Research Centre for Prevention and Health, Glostrup University Hospital, Glostrup, Denmark.
authors.forename: S J
authors.initials: SJ
authors.lastname: Rosenstock
authors.forename: T
authors.initials: T
authors.lastname: Jørgensen
authors.forename: O
authors.initials: O
authors.lastname: Bonnevie
authors.forename: L P
authors.initials: LP
authors.lastname: Andersen
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005819:Genetic Markers; D016481:Helicobacter Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D011379:Prognosis; D011446:Prospective Studies; D011584:Psychology; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D012959:Socioeconomic Factors; D013276:Stomach Ulcer / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D005819:Genetic Markers