title: Plasma amyloid-β and risk of Alzheimer's disease in the Framingham Heart Study.
abstract: BACKGROUND
  Plasma amyloid-β (Aβ) peptide levels have been examined as a low-cost accessible marker for risk of incident Alzheimer's disease (AD) and dementia, but results have varied between studies. We reassessed these associations in one of the largest, prospective, community-based studies to date.
  
  
  METHODS
  A total of 2189 dementia-free, Framingham Study participants aged >60 years (mean age, 72 ± 8 years; 56% women) had plasma Aβ1-42 and Aβ1-40 measured and were followed prospectively (mean, 7.6 ± 3.0 years) for dementia/AD.
  
  
  RESULTS
  Increased plasma Aβ1-42 levels were associated with lower risk of dementia (Aβ1-42: hazard ratio [HR] = 0.80 [0.71‒0.90], P < .001; Aβ1-42-to-Aβ1-40 ratio: HR = 0.86 [0.76‒0.98], P = .027) and AD (Aβ1-42: HR = 0.79 [0.69‒0.90], P < .001; Aβ1-42-to-Aβ1-40 ratio: HR = 0.83 [0.72‒0.96], P = .012).
  
  
  CONCLUSIONS
  Our results suggest that lower plasma Aβ levels are associated with risk of incident AD and dementia. They encourage further evaluation of plasma Aβ levels as a biomarker for risk of developing clinical AD and dementia.
authors.affiliation: The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA. Electronic address: vchourak@bu.edu.
authors.forename: Vincent
authors.initials: V
authors.lastname: Chouraki
authors.affiliation: The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.
authors.forename: Alexa
authors.initials: A
authors.lastname: Beiser
authors.affiliation: Mayo Clinic, Jacksonville, FL, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Younkin
authors.affiliation: The Framingham Heart Study, Framingham, MA, USA; Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.
authors.forename: Sarah Rosner
authors.initials: SR
authors.lastname: Preis
authors.affiliation: The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Galit
authors.initials: G
authors.lastname: Weinstein
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences, Lund University, Malmö, Sweden.
authors.forename: Oskar
authors.initials: O
authors.lastname: Hansson
authors.affiliation: Neuropsychiatric Epidemiology Research Unit, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.
authors.forename: Ingmar
authors.initials: I
authors.lastname: Skoog
authors.affiliation: Inserm UMR 744, Lille, France; Université Lille Nord de France, Lille, France; Institut Pasteur de Lille, Lille, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Lambert
authors.affiliation: The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Rhoda
authors.initials: R
authors.lastname: Au
authors.affiliation: Laboratory of Epidemiology and Population Sciences, Intramural Research Program, National Institute on Aging, Bethesda, MD, USA.
authors.forename: Lenore
authors.initials: L
authors.lastname: Launer
authors.affiliation: The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Wolf
authors.affiliation: Mayo Clinic, Jacksonville, FL, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Younkin
authors.affiliation: The Framingham Heart Study, Framingham, MA, USA; Department of Neurology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: Sudha
authors.initials: S
authors.lastname: Seshadri
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000097:blood* / Q000175:diagnosis; D016229:Amyloid beta-Peptides / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk; D016019:Survival Analysis
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)
keywords: Aβ peptides; Epidemiology; Framingham Heart Study; Incident Alzheimer's disease; Incident dementia; Meta-analysis; Plasma biomarker