Please use this identifier to cite or link to this item: http://ahro.austin.org.au/austinjspui/handle/1/11251
Title: Cognition and beta-amyloid in preclinical Alzheimer's disease: data from the AIBL study.
Authors: Pike, Kerryn E;Ellis, Kathryn A;Villemagne, Victor L;Good, Norm;Chételat, Gael;Ames, David;Szoeke, Cassandra;Laws, Simon M;Verdile, Giuseppe;Martins, Ralph N;Masters, Colin L;Rowe, Christopher C
Affiliation: Department of Nuclear Medicine, Centre for PET, Austin Health, Heidelberg, VIC, Australia. k.pike@latrobe.edu.au
Issue Date: 16-Apr-2011
Citation: Neuropsychologia 2011; 49(9): 2384-90
Abstract: The 'preclinical' phase of Alzheimer's disease is a future target for treatment, but additional research is essential to understand the relationship between β-amyloid burden and cognition during this time. We investigated this relationship using a large sample of apparently healthy older adults (N=177), which also enabled examination of whether the relationship differed according to age, gender, years of education, apolipoprotein E status, and the presence of subjective memory complaints. In addition to episodic memory, a range of cognitive measures (global cognition, semantic memory, visuospatial performance, and executive function) were examined. Participants were aged over 60 years with no objective cognitive impairment and came from the imaging arm of the Australian Imaging, Biomarkers, and Lifestyle (AIBL) study of ageing. (11)C-PiB PET was used to measure β-amyloid burden and a PiB 'cut-off' level of 1.5 was used to separate participants with low PiB retention from those with high PiB retention. Thirty-three percent of participants had a PiB positive scan. PiB positive participants were 5 years older, twice as likely to carry an apolipoprotein E ɛ4 allele, and their composite episodic memory was 0.26 SD worse than PiB negative volunteers. Linear regressions with β-amyloid burden as a dichotomous predictor, revealed an interaction between β-amyloid burden and gender, as well as age and education effects, in predicting episodic memory and visuospatial performance. In females, but not in males, increased β-amyloid was related to worse episodic memory and visuospatial performance. Furthermore, an interaction between β-amyloid burden and APOE status was found in predicting visuospatial performance, whereby there was a trend for increased β-amyloid to relate to worse visuospatial performance for those without an APOE ɛ4 allele. There were no other main or interaction effects of β-amyloid on any of the other composite cognitive measures. These cross-sectional findings suggest that β-amyloid burden does not have a large effect on cognition in this subset of apparently healthy older people. The finding of gender differences deserves further research to answer definitively the important question of gender susceptibility to adverse cognitive effects from β-amyloid.
Internal ID Number: 21529702
URI: http://ahro.austin.org.au/austinjspui/handle/1/11251
DOI: 10.1016/j.neuropsychologia.2011.04.012
URL: http://www.ncbi.nlm.nih.gov/pubmed/21529702
Type: Journal Article
Subjects: Age Factors
Aged
Aged, 80 and over
Alzheimer Disease.complications.diagnosis.metabolism.pathology.radionuclide imaging
Amyloid beta-Peptides.adverse effects.metabolism
Benzothiazoles.diagnostic use
Carbon Radioisotopes.diagnostic use
Case-Control Studies
Cerebral Cortex.metabolism.pathology.physiopathology.radionuclide imaging
Cognition Disorders.complications.etiology.metabolism.pathology.radionuclide imaging
Cohort Studies
Cross-Sectional Studies
Early Diagnosis
Female
Humans
Longitudinal Studies
Male
Middle Aged
Neuropsychological Tests
Reference Values
Sex Factors
Appears in Collections:Journal articles

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