Amyloid imaging results from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging

The Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging, a participant of the worldwide Alzheimer's Disease Neuroimaning Initiative (ADNI), performed C-11-Pittsburgh Compound B (Pi B) scans in 177 healthy controls (HC), 57 mild cognitive impairment (MCI) subjects, and 53 mild Alzheimer's disease (AD) patients. High PiB binding was present in 33% of HC (49% in ApoE-epsilon 4 carriers vs 21% in noncarriers) and increased with age, most strongly in epsilon 4 carriers. 18% of HC aged 60-69 had high PiB binding rising to 65% in those over 80 years. Subjective memory complaint was only associated with elevated PiB binding in epsilon 4 carriers. There was no correlation with cognition in HC or MCI. PiB binding in AD was unrelated to age, hippocampal volume or memory. Beta-amyloid (A beta) deposition seems almost inevitable with advanced age, amyloid burden is similar at all ages in AD, and secondary factors or downstream events appear to play a more direct role than total beta amyloid burden in hippocampal atrophy and cognitive decline. Crown Copyright (C) 2010 Published by Elsevier Inc. All rights reserved.