Title:The Relationship Between Plasma Aβ Levels, Cognitive Function and Brain Volumetrics: Sydney Memory and Ageing Study
Volume: 13
Issue: 3
Author(s): Anne Poljak, John D. Crawford, George A. Smythe, Henry Brodaty, Melissa J. Slavin, Nicole A. Kochan, Julian N. Trollor, Wei Wen and Karen A. Mather, Amelia A. Assareh, Pek C. Ng, Perminder S. Sachdev
Affiliation:
关键词:
Aβ1-40、 Aβ1-42、APOE、脑体积、认知、神经心理学测试、MRI、血浆、白质高信号。
摘要: Objectives: Determine whether (1) a relationship exists between plasma amyloid-β (Aβ)1-
40 and 1-42 peptide levels, brain volumetrics and cognitive performance in elderly individuals with
and without amnestic mild cognitive impairment (aMCI), (2) plasma Aβ peptide levels differ between apolipoprotein E
(APOE) ε4 carriers and non-carriers and (3) longitudinal changes in cognition and brain volume relate to Aβ levels.
Methods: Subjects with aMCI (n = 89) and normal cognition (n = 126) were drawn from the Sydney Memory and Aging
Study (Sydney MAS), a population based study of non-demented 70-90 year old individuals; 39 Alzheimer’s disease
(AD) patients were recruited from a specialty clinic. Sydney MAS participants underwent brain MRI scans and were assessed
on 19 cognitive measures and were APOE ε4 genotyped. Plasma levels of Aβ1-40 and 1-42 were quantified using
ELISA. Results: Wave1 plasma levels of Aβ peptides and Aβ1−42/1-40 ratio were lower in aMCI and AD, and Aβ1−42
was positively associated with global cognition and hippocampal volume and negatively with white matter hyperintensities.
The relationships of Aβ1-40 and Aβ1-42 were predominantly observed in ε4 allele carriers and non-carriers respectively.
Longitudinal analysis revealed greater decline in global cognition and memory for the highest quintiles of Aβ1−42
and the ratio measure. Conclusion: Plasma Aβ levels and the Aβ1−42/1-40 ratio are related to cognition and hippocampal
volumes, with differential associations of Aβ1-40 and Aβ1-42 in ε4 carriers and non-carriers. These data support the Aβ
sink model of AD pathology, and suggest that plasma Aβ measures may serve as biomarkers of AD.