title: Risk factors for peptic ulcer in Shanghai.
abstract: OBJECTIVE
  To investigate the combined effects of Helicobacter pylori infection and traditional risk factors for peptic ulcer.
  
  
  METHODS
  A case-control study was conducted in chemical factories in Shanghai, China. The cases were 500 people with peptic ulcer randomly selected from all staff who met the selection criteria. The controls were 500 employees randomly selected from the same factories as the cases.
  
  
  RESULTS
  The infection rate for H. pylori was 81% among the cases and 70% among the controls and 85% of all ulcers were duodenal. Current cigarette smoking was common among male cases (80%) and male controls (64%). Univariate analysis suggested that male gender, age, lower socioeconomic status, cigarette smoking, family history of peptic ulcer and infection with H. pylori were all associated with increased risk of peptic ulcer. Separate analyses were performed by sex and occupational group to avoid confounding by cigarette smoking and age. Multivariate analyses showed that for all women and for male staff members, only family history was significantly predictive of peptic ulcer or duodenal ulcer. Among male workers or drivers, however, all the major risk factors were statistically significantly associated with increased risk.
  
  
  CONCLUSIONS
  In a population where the rate of infection with H. pylori is high, the traditional risk factors for peptic ulcer or duodenal ulcer (i.e. family history, male gender, increasing age, lower socioeconomic status and cigarette smoking) are still significant predictors of increased risk of ulcer. If men with ulcers (or with a family history of peptic ulcer) gave up cigarette smoking, morbidity could be reduced in this population.
authors.affiliation: Department of Internal Medicine, Clinical Epidemiology Unit, Zhong Shan Hospital, Shanghai Medical University, Shanghai 200032, China.
authors.forename: J Y
authors.initials: JY
authors.lastname: Wang
authors.forename: S B
authors.initials: SB
authors.lastname: Liu
authors.forename: S Y
authors.initials: SY
authors.lastname: Chen
authors.forename: A
authors.initials: A
authors.lastname: Dobson
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002617:Chemical Industry; D002681:China / Q000453:epidemiology; D004381:Duodenal Ulcer / Q000453:epidemiology / Q000235:genetics; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology; D016480:Helicobacter pylori; D006801:Humans; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D009784:Occupational Diseases / Q000453:epidemiology*; D010437:Peptic Ulcer / Q000453:epidemiology* / Q000235:genetics; D012307:Risk Factors; D012907:Smoking; D012959:Socioeconomic Factors