title: Mild cognitive impairment due to Alzheimer disease in the community.
abstract: OBJECTIVE
  The newly proposed National Institute on Aging-Alzheimer's Association (NIA-AA) criteria for mild cognitive impairment (MCI) due to Alzheimer disease (AD) suggest a combination of clinical features and biomarker measures, but their performance in the community is not known.
  
  
  METHODS
  The Mayo Clinic Study of Aging (MCSA) is a population-based longitudinal study of nondemented subjects in Olmsted County, Minnesota. A sample of 154 MCI subjects from the MCSA was compared to a sample of 58 amnestic MCI subjects from the Alzheimer's Disease Neuroimaging Initiative 1 (ADNI-1) to assess the applicability of the criteria in both settings and to assess their outcomes.
  
  
  RESULTS
  Fourteen percent of MCSA and 16% of ADNI-1 of subjects were biomarker negative. In addition, 14% of MCSA and 12% of ADNI-1 subjects had evidence for amyloid deposition only, whereas 43% of MCSA and 55% of ADNI-1 subjects had evidence for amyloid deposition plus neurodegeneration (magnetic resonance imaging atrophy, fluorodeoxyglucose positron emission tomography hypometabolism, or both). However, a considerable number of subjects had biomarkers inconsistent with the proposed AD model; for example, 29% of MCSA subjects and 17% of ADNI-1 subjects had evidence for neurodegeneration without amyloid deposition. These subjects may not be on an AD pathway. Neurodegeneration appears to be a key factor in predicting progression relative to amyloid deposition alone.
  
  
  CONCLUSIONS
  The NIA-AA criteria apply to most MCI subjects in both the community and clinical trials settings; however, a sizeable proportion of subjects had conflicting biomarkers, which may be very important and need to be explored.
authors.affiliation: Department of Neurology, Mayo Clinic and Foundation, Rochester, MN; Alzheimer's Disease Research Center, Mayo Clinic and Foundation, Rochester, MN; Department of Health Sciences Research, Mayo Clinic and Foundation, Rochester, MN.
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Petersen
authors.forename: Paul
authors.initials: P
authors.lastname: Aisen
authors.forename: Bradley F
authors.initials: BF
authors.lastname: Boeve
authors.forename: Yonas E
authors.initials: YE
authors.lastname: Geda
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Ivnik
authors.forename: David S
authors.initials: DS
authors.lastname: Knopman
authors.forename: Michelle
authors.initials: M
authors.lastname: Mielke
authors.forename: Vernon S
authors.initials: VS
authors.lastname: Pankratz
authors.forename: Rosebud
authors.initials: R
authors.lastname: Roberts
authors.forename: Walter A
authors.initials: WA
authors.lastname: Rocca
authors.forename: Stephen
authors.initials: S
authors.lastname: Weigand
authors.forename: Michael
authors.initials: M
authors.lastname: Weiner
authors.forename: Heather
authors.initials: H
authors.lastname: Wiste
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Jack
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism / Q000473:pathology; D000544:Alzheimer Disease / Q000150:complications*; D000682:Amyloid / Q000378:metabolism; D015415:Biomarkers; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D011897:Random Allocation; D012111:Residence Characteristics
chemical_list: D000682:Amyloid; D015415:Biomarkers