title: Peptic ulcer bleeding: interaction between non-steroidal anti-inflammatory drugs, Helicobacter pylori infection, and the ABO blood group system.
abstract: BACKGROUND
  Helicobacter pylori infection is found in almost all patients with an uncomplicated ulcer. Non-steroidal anti-inflammatory drug (NSAID) use is the main risk factor for bleeding peptic ulcer. In the older literature ABO blood groups were mentioned as a risk factor. There is continuing uncertainty about the interaction between these risk factors and the development of peptic ulcer bleeding. We therefore determined the separate and combined effect of NSAIDs, H. pylori infection, and the ABO blood group system in patients with a bleeding peptic ulcer.
  
  
  METHODS
  The prevalence of NSAID use, H. pylori infection, and blood group O was determined in 227 patients who were admitted with a bleeding gastric or duodenal ulcer between 1990 and 1997. These results were compared with the expected frequency of these risk factors in the Dutch population.
  
  
  RESULTS
  NSAID use was reported in 48.2% of the patients with a bleeding peptic ulcer. The H. pylori prevalence was 62.0%, whereas blood group O was present in 49.3% of the patients. NSAID use was the strongest risk factor for hemorrhage caused by a peptic ulcer (relative risk, 8.4), whereas the relative risk associated with H. pylori infection and blood group O was 1.5 and 1.2, respectively. With univariate analysis NSAID use and H. pylori infection seemed to be separate risk factors and did not really potentiate each other's effect. Moreover, blood group O did not potentiate the strong effect of NSAIDs.
  
  
  CONCLUSIONS
  H. pylori infection may add only a little to the important risk of NSAID use in the development of bleeding peptic ulcers.
authors.affiliation: Dept. of Gastroenterology and Hepatology, Leiden University Medical Centre, The Netherlands.
authors.forename: J P
authors.initials: JP
authors.lastname: Kuyvenhoven
authors.forename: R A
authors.initials: RA
authors.lastname: Veenendaal
authors.forename: J P
authors.initials: JP
authors.lastname: Vandenbroucke
mesh_terms: D000017:ABO Blood-Group System; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D005260:Female; D016481:Helicobacter Infections / Q000150:complications* / Q000453:epidemiology; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D010438:Peptic Ulcer Hemorrhage / Q000453:epidemiology / Q000209:etiology*; D015995:Prevalence; D012307:Risk Factors
chemical_list: D000017:ABO Blood-Group System; D000894:Anti-Inflammatory Agents, Non-Steroidal