title: Vitamin B12 status, homocysteine and mortality amongst community-dwelling Irish elders.
abstract: BACKGROUND
  Vitamin B12 deficiency is associated with hyperhomocysteinaemia, which is associated with atherosclerosis and increased mortality. High levels of vitamin B12 have also been associated with increased mortality in certain patient populations.
  
  
  OBJECTIVE
  We examined vitamin B12 and homocysteine status and mortality rates in a population of Irish community-dwelling elders over a 3-year period.
  
  
  METHODS
  Prospective, community-based observational cohort study.
  
  
  RESULTS
  Subjects in the highest quartile of homocysteine had increased mortality rates (14.68 vs. 7.32%, relative risk 2.09). This relationship was attenuated when controlled for the presence or absence of a history of stroke or myocardial infarction. There was no relationship between vitamin B12 status and mortality during the observation period.
  
  
  CONCLUSIONS
  Vitamin B12 levels are not associated with death rates in Irish community-dwelling elders. Homocysteine levels are associated with mortality and may act via the mechanism of atherosclerotic disease.
authors.affiliation: Mercer's Institute for Research on Ageing, St. James's Hospital, Dublin 8, Ireland. davidjrobinson@iol.ie
authors.forename: D J
authors.initials: DJ
authors.lastname: Robinson
authors.forename: C
authors.initials: C
authors.lastname: O'Luanaigh
authors.forename: E
authors.initials: E
authors.lastname: Tehee
authors.forename: H
authors.initials: H
authors.lastname: O'Connell
authors.forename: F
authors.initials: F
authors.lastname: Hamilton
authors.forename: A V
authors.initials: AV
authors.lastname: Chin
authors.forename: R
authors.initials: R
authors.lastname: Coen
authors.forename: A M
authors.initials: AM
authors.lastname: Molloy
authors.forename: J
authors.initials: J
authors.lastname: Scott
authors.forename: B A
authors.initials: BA
authors.lastname: Lawlor
authors.forename: C J
authors.initials: CJ
authors.lastname: Cunningham
mesh_terms: D000368:Aged; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D009026:Mortality; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012111:Residence Characteristics; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D006710:Homocysteine; D014805:Vitamin B 12