title: Helicobacter pylori infection is a protective factor for bleeding gastric ulcers but not for bleeding duodenal ulcers in NSAID users.
abstract: BACKGROUND
  The effect of Helicobacter pylori infection on NSAID-induced gastroduodenal damage is unclear.
  
  
  OBJECTIVE
  To determine the role of H. pylori and NSAID use in complicated peptic ulcers.
  
  
  METHODS
  A total of 185 consecutive patients with bleeding peptic ulcers and 185 hospitalized matched controls were studied prospectively. Additionally, 75 consecutive uncomplicated peptic ulcers and 75 community controls were also studied. Active H. pylori infection was determined by urea breath test and/or both urease test and histology. Serum CagA and VacA status were determined at random in 135 infected patients and 82 controls. NSAID use was determined by structured data collection.
  
  
  RESULTS
  H. pylori (odds ratio [OR]=5. 98; 2.9-12.3) and NSAID use (OR=5.74; 3.4-9.7) were independent risk factors for duodenal ulcer bleeding, whereas NSAID use was the main risk factor for bleeding gastric ulcers (OR=12.4; 5.5-27.9). Interaction of both factors was associated with reduced risk for bleeding gastric ulcers (OR=0.19; 0.04-0.88) but not for bleeding duodenal ulcers, which showed a similar risk to any one factor alone. This was observed for all types of NSAID use, including low-dose aspirin, and infection by CagA positive strains. H. pylori was the only factor involved in common uncomplicated duodenal ulcers.
  
  
  CONCLUSIONS
  Interaction of both H. pylori infection and NSAID use decreases the risk of bleeding due to gastric ulcers, but not that due to duodenal ulcers.
authors.affiliation: Service of Gastroenterology, University Hospital, Zaragoza, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Santolaria
authors.forename: A
authors.initials: A
authors.lastname: Lanas
authors.forename: R
authors.initials: R
authors.lastname: Benito
authors.forename: M f
authors.initials: Mf
authors.lastname: Pérez-Aisa
authors.forename: M
authors.initials: M
authors.lastname: Montoro
authors.forename: R
authors.initials: R
authors.lastname: Sainz
mesh_terms: D004381:Duodenal Ulcer / Q000150:complications* / Q000382:microbiology*; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000209:etiology* / Q000382:microbiology*; D016481:Helicobacter Infections / Q000503:physiopathology*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D010438:Peptic Ulcer Hemorrhage / Q000209:etiology* / Q000382:microbiology*; D011446:Prospective Studies; D012307:Risk Factors; D013276:Stomach Ulcer / Q000150:complications* / Q000382:microbiology*; D014774:Virulence