title: Longitudinal patterns of β-amyloid deposition in nondemented older adults.
abstract: BACKGROUND
  High levels of β-amyloid (Aβ) characterize Alzheimer disease.
  
  
  OBJECTIVE
  To investigate whether longitudinal changes in Aβ deposition can be detected in vivo in older adults without dementia (hereafter referred to as nondemented).
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Community-dwelling older adults.
  
  
  METHODS
  Twenty-four nondemented participants (4 with a baseline Clinical Dementia Rating Scale score of 0.5; mean [SD] age, 79.2 [8.1] years) in the Baltimore Longitudinal Study of Aging underwent serial carbon 11-labeled Pittsburgh Compound B-positron emission tomography ([(11)C]PiB-PET) (follow-up at a mean [SD] of 1.5 [0.5] years), with 5 participants undergoing a third [(11)C]PiB-PET examination.
  
  
  METHODS
  Annual changes in distribution volume ratio (DVR) were evaluated using a global index of cortical DVR (cDVR) and region-of-interest analyses. Given the variability of cDVR at the initial PiB-PET, annual changes in cDVR in those with minimal vs those with elevated initial cDVR were compared.
  
  
  RESULTS
  In nondemented older adults, annual increase in [(11)C]PiB retention is 0.011 DVR per year (0.9%; P = .01), which localizes to the prefrontal, parietal, lateral temporal, occipital, and anterior and posterior cingulate cortices. Annual change in cDVR is greater in older adults with elevated cDVR than in those with a minimal initial cDVR (P = .006).
  
  
  CONCLUSIONS
  Fibrillar Aβ detected by [(11)C]PiB-PET increases over time even in nondemented older adults. Individuals with higher initial [(11)C]PiB retention have greater rates of Aβ deposition, providing evidence of differential rates of Aβ deposition. Moreover, regional vulnerabilities to Aβ deposition allow for more targeted investigation of early Aβ changes.
authors.affiliation: Laboratory of Behavioral Neuroscience, National Institutes of Health Biomedical Research Center, National Institute on Aging, Intramural Research Program, 251 Bayview Blvd., Baltimore, MD 21224, USA. resnicks@grc.nia.nih.gov
authors.forename: Jitka
authors.initials: J
authors.lastname: Sojkova
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yang
authors.initials: Y
authors.lastname: An
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kraut
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.forename: Dean F
authors.initials: DF
authors.lastname: Wong
authors.forename: Susan M
authors.initials: SM
authors.lastname: Resnick
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds; D001057:Apolipoproteins E / Q000235:genetics; D015142:Baltimore; D001921:Brain / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism; D003071:Cognition; D003704:Dementia / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory; D009483:Neuropsychological Tests; D010618:Phenanthrolines; D049268:Positron-Emission Tomography / Q000379:methods; D011446:Prospective Studies; D012111:Residence Characteristics; D013844:Thiazoles; D013997:Time Factors
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D001057:Apolipoproteins E; D002250:Carbon Radioisotopes; D010618:Phenanthrolines; D013844:Thiazoles