Amyloid deposition and cognition in older adults: The effects of premorbid intellect

Abstract

Although amyloid deposition remains a marker of the development of Alzheimer's disease, results linking amyloid and cognition have been equivocal.Twenty-five community-dwelling non-demented older adults were examined with 18F-flutemetamol, an amyloid imaging agent, and a cognitive battery, including an estimate of premorbid intellect and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). In the first model, 18F-flutemetamol uptake significantly correlated with the Delayed Memory Index of the RBANS (r =2.51, p=.02) and premorbid intellect (r =.43, p= .03). In the second model, the relationship between 18F-flutemetamol and cognition was notably stronger when controlling for premorbid intellect (e.g., three of the five RBANS Indexes and its Total score significantly correlated with 18F-flutemetamol, r's =2.41 to 2.58). Associations were found between amyloid-binding 18F-flutemetamol and cognitive functioning in non-demented older adults. These associations were greatest with delayed memory and stronger when premorbid intellect was considered, suggesting that cognitive reserve partly compensates for the symptomatic expression of amyloid pathology in community-dwelling elderly. © The Author 2013. Published by Oxford University Press. All rights reserved.