title: Geographic differences in low-dose aspirin-associated gastroduodenal mucosal injury.
abstract: Aspirin, even at low doses, has been known to cause upper gastro-intestinal complications, such as gastroduodenal ulcers, despite the definite benefits from its antithrombotic effects. Helicobacter pylori (H. pylori) is major pathogen responsible for gastroduodenal ulcer formation. There have been conflicting results about the potential interaction between these two ulcerogenic factors and the geographic areas involved. In Western countries, the prevalence of gastroduodenal ulcers is consistently higher in H. pylori-positive low-dose aspirin (LDA) users than in H. pylori-negative ones, suggesting that H. pylori infection exacerbates LDA-induced gastroduodenal mucosal injury in these geographic areas. Meanwhile, previous studies from Japan have generally reported a similar prevalence of LDA-induced gastroduodenal mucosal injury regardless of the presence of H. pylori infection, indicating that the infection is not an overall exacerbating factor for drug-induced injury. H. pylori infection could have a synergistic or antagonistic interaction with LDA use in adverse gastroduodenal events depending on gastric acid secretion. It is well-recognized that the net effect of H. pylori infection on gastric acid secretion shows considerable geographic variation at the population level. While gastric acid secretion levels were not decreased and were well-preserved in most patients with H. pylori infection from Western countries, the majority of Japanese patients with H. pylori infection exhibited decreased gastric acid secretion. Such large geographic differences in the net effect of H. pylori infection on gastric acid secretion could be at least partly responsible for the geographically distinct interaction between LDA use and H. pylori infection on adverse gastroduodenal lesions.
authors.affiliation: Katsunori Iijima, Tooru Shimosegawa, Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Iijima
authors.affiliation: Katsunori Iijima, Tooru Shimosegawa, Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan.
authors.forename: Tooru
authors.initials: T
authors.lastname: Shimosegawa
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001208:Asia / Q000453:epidemiology; D001241:Aspirin / Q000009:adverse effects*; D001315:Australia / Q000453:epidemiology; D004381:Duodenal Ulcer / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D004386:Duodenum / Q000187:drug effects* / Q000382:microbiology / Q000473:pathology; D005060:Europe / Q000453:epidemiology; D005744:Gastric Acid / Q000378:metabolism; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D016481:Helicobacter Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000382:microbiology / Q000473:pathology; D009656:North America / Q000453:epidemiology; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D013276:Stomach Ulcer / Q000139:chemically induced* / Q000175:diagnosis / Q000453:epidemiology* / Q000382:microbiology
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001241:Aspirin
keywords: Gastric acid secretion; Gastroduodenal ulcers; Geographic variation; Helicobacter pylori; Low-dose aspirin