title: Prior intra-operative hypotension is not a risk factor for development of Alzheimer's disease.
abstract: OBJECTIVE
  A retrospective, population-based, case-control study was carried out to evaluate episodes of prior intra-operative hypotension as a potential risk factor for Alzheimer's disease (AD).
  
  
  METHODS
  Patients were all incident cases of AD from 1975-1984 who resided for 40 years or more in Olmsted County prior to their onset of dementia (N = 252). One age and gender-matched control for each case was selected from all registrations for care at Mayo Clinic during the year of onset in the incident case. Each case and control group had 252 individuals.
  
  
  RESULTS
  Of these, 27 cases and 32 controls had at least one ten minute or longer episode of intra-operative hypotension of a systolic blood pressure of less than 90 mm Hg prior to the year of onset of dementia in the matched AD patient. We did not find a significantly increased risk of AD for hypotensive episodes of less than 75 or 90 mm Hg.
  
  
  CONCLUSIONS
  It is unlikely that intra-operative hypotensive events of this degree increase the risk of AD.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: N I
authors.initials: NI
authors.lastname: Bohnen
authors.forename: E F
authors.initials: EF
authors.lastname: Wijdicks
authors.forename: E
authors.initials: E
authors.lastname: Kokmen
authors.forename: M A
authors.initials: MA
authors.lastname: Warner
authors.forename: L T
authors.initials: LT
authors.lastname: Kurland
mesh_terms: D000544:Alzheimer Disease / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007022:Hypotension / Q000150:complications / Q000453:epidemiology*; D007431:Intraoperative Complications / Q000453:epidemiology*; D008297:Male; D008910:Minnesota; D012189:Retrospective Studies; D012307:Risk Factors