title: Treatment for Helicobacter pylori infection and risk of Parkinson's disease in Denmark.
abstract: OBJECTIVE
  It has been speculated that gastrointestinal infection with Helicobacter pylori (HP) contributes to the development of Parkinson's disease (PD). We used nationwide Danish registers to investigate this hypothesis.
  
  
  METHODS
  We identified 4484 patients with a first time PD diagnosis between 2001 and 2008 from the Danish National Patient Register (DNPR) and 22, 416 population controls from the Danish Civil Registration System (CRS). Information on drug use was obtained from the National Prescription Registry (NPR). We used logistic regression to compute odds ratios (OR) for the association between treatment for HP and risk of PD.
  
  
  RESULTS
  Prescriptions for HP-eradication drugs and proton pump inhibitors (PPI) 5 or more years prior to the diagnosis of PD were associated with a 45% and 23% increase in PD risk, respectively. Hospitalizations and outpatient visits for gastritis and peptic/duodenal ulcers, however, were not associated with PD.
  
  
  CONCLUSIONS
  Our population-based study suggests that chronic HP infections and/or gastritis contribute to PD or that these are PD-related pathologies that precede motor symptoms.
authors.affiliation: Department of Neurology, Odense University Hospital, Odense, Denmark. hhnielsen@health.sdu.dk
authors.forename: H H
authors.initials: HH
authors.lastname: Nielsen
authors.forename: J
authors.initials: J
authors.lastname: Qiu
authors.forename: S
authors.initials: S
authors.lastname: Friis
authors.forename: L
authors.initials: L
authors.lastname: Wermuth
authors.forename: B
authors.initials: B
authors.lastname: Ritz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D003718:Denmark / Q000453:epidemiology; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology* / Q000209:etiology*; D054328:Proton Pump Inhibitors / Q000627:therapeutic use; D012189:Retrospective Studies; D012306:Risk
chemical_list: D000900:Anti-Bacterial Agents; D054328:Proton Pump Inhibitors