title: The association between delirium and the apolipoprotein E epsilon 4 allele: new study results and a meta-analysis.
abstract: OBJECTIVE
  To determine a possible association between Apolipoprotein E (APOE)sigma4-allele and delirium in a large cohort and combining these current data with former studies in a meta-analysis.
  
  
  METHODS
  Combination of a new prospective cohort study and meta-analysis.
  
  
  METHODS
  Medical department and orthopedic/traumatology department of University hospital from 2003 to 2007.
  
  
  METHODS
  A total of 656 patients aged 65 years and older acutely admitted with a medical diagnosis or after hip fracture.
  
  
  METHODS
  Confusion Assessment Method for delirium, Informant Questionnaire on Cognitive Decline-short form for predelirium global cognitive impairment, and Katz Index of Activities of Daily Living for functionality. APOE was genotyped by mass spectrometer. A meta-analysis was performed combining the current data with published studies analyzing the association between the APOE sigma4-allele and the delirium.
  
  
  RESULTS
  : The 49% of the 76 surgical patients and 35% of the 580 medical patients experienced delirium. Delirious patients were significantly older (82 versus 77 years) and had more frequently functional (66% versus 26%) and cognitive impairment (86% versus 29%) than nondelirious patients. The odds ratio (OR) for delirium adjusted for age, cognitive, and functional impairment of sigma4 carriers compared with non-sigma4 carriers was 1.7 (95% confidence interval [CI]: 1.1-2.6). Four studies were added to the meta-analysis, which included 1,099 patients in total. The OR for delirium in the meta-analysis was 1.6 (95% CI: 0.9-2.7) of sigma4 carriers compared with non-sigma4 carriers.
  
  
  CONCLUSIONS
  This study and meta-analysis suggest an association between delirium and the APOE sigma4 allele.
authors.affiliation: Department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Centre, University of Amsterdam, The Netherlands. b.c.vanmunster@amc.uva.nl
authors.forename: Barbara C
authors.initials: BC
authors.lastname: van Munster
authors.forename: Johanna C
authors.initials: JC
authors.lastname: Korevaar
authors.forename: Aeilko H
authors.initials: AH
authors.lastname: Zwinderman
authors.forename: Mariska M
authors.initials: MM
authors.lastname: Leeflang
authors.forename: Sophia E J A
authors.initials: SE
authors.lastname: de Rooij
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D053327:Apolipoprotein E4 / Q000235:genetics*; D003072:Cognition Disorders / Q000150:complications / Q000235:genetics; D003693:Delirium / Q000150:complications / Q000235:genetics*; D005260:Female; D005838:Genotype; D015577:Geriatric Assessment; D006801:Humans; D008297:Male; D010361:Patients / Q000523:psychology
chemical_list: D053327:Apolipoprotein E4