title: Histamine-2 receptor antagonist use and incident dementia in an older cohort.
abstract: OBJECTIVE
  To examine whether histamine-2 receptor antagonist medications (H2RAs) are associated with a lower incidence of all-cause dementia or Alzheimer's disease (AD), as some studies have suggested.
  
  
  METHODS
  Prospective population-based cohort
  
  
  METHODS
  Group Health, an integrated health maintenance organization, Seattle, Washington.
  
  
  METHODS
  Two thousand nine hundred twenty-three participants aged 65 and older without dementia at baseline, with initial recruitment between 1994 and 1996.
  
  
  METHODS
  Follow-up occurred every 2 years to identify incident dementia and AD using standard criteria. Exposure to H2RAs was determined based on automated pharmacy data. Three aspects of exposure (time-varying) were examined based on standard daily dose (SDD): cumulative use, intensity of use (highest SDD in any prior 2-year window), and cumulative use stratified according to recency (1-3 years vs >3 years before).
  
  
  RESULTS
  Over a mean follow-up of 6.7 years, 585 subjects developed dementia (453 developed AD). Total cumulative exposure was not associated with dementia (P=.35; omnibus test) or AD (P=.23). The adjusted hazard ratios for the highest exposure category (>1,080 SDDs) compared with light or no use were 1.28 (95% confidence interval (CI)=0.95-1.72) for dementia and 1.41 (95% CI=1.00-1.97) for AD. Intensity of use was not associated with dementia (P=.39) or AD (P=.63). Examining exposure according to recent and distant cumulative use also showed no association with dementia (P=.11) or AD (P=.30).
  
  
  CONCLUSIONS
  No association was found between H2RA use and risk of all-cause dementia or AD using more-detailed and -extensive information about past H2RA use than any prior study.
authors.affiliation: School of Pharmacy, University of Washington, Seattle, Washington, USA. slgray@u.washington.edu
authors.forename: Shelly L
authors.initials: SL
authors.lastname: Gray
authors.forename: Rod
authors.initials: R
authors.lastname: Walker
authors.forename: Sascha
authors.initials: S
authors.lastname: Dublin
authors.forename: Sebastien
authors.initials: S
authors.lastname: Haneuse
authors.forename: Paul K
authors.initials: PK
authors.lastname: Crane
authors.forename: John C S
authors.initials: JC
authors.lastname: Breitner
authors.forename: James
authors.initials: J
authors.lastname: Bowen
authors.forename: Wayne
authors.initials: W
authors.lastname: McCormick
authors.forename: Eric B
authors.initials: EB
authors.lastname: Larson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003704:Dementia / Q000188:drug therapy* / Q000453:epidemiology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006635:Histamine H2 Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D015994:Incidence; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D014861:Washington / Q000453:epidemiology
chemical_list: D006635:Histamine H2 Antagonists