Background:
The potential to optimize treatment and preventative strategies in the delay and prevention of Alzheimer's disease (AD) relies in part on the capacity to make early diagnoses and monitor disease progression. The Australian Biomarkers Lifestyle and Imaging (AIBL) study is a 3-year longitudinal cohort study that aims to improve understanding of the pathogen-esis and diagnosis of AD using neuropsychological, neuroimaging and biomarker techniques, and to examine lifestyle and dietary factors associated with AD and healthy aging.
Methods:
A total of 1000 volunteers (minimum age 65 years) were recruited, comprising 200 participants from the following groups: 1) AD, 2) mild cognitive impairments, 3) healthy volunteers (ApoE4+), 4) healthy volunteers (ApoE4−) and 5) ‘memory complainers’ (ie healthy volunteers reporting subjective memory complaints). At baseline and 18 months, all participants received a clinical/neuropsychological assessment and blood biomarker analysis, with a subgroup also receiving [C-11]PIB-PET and magnetic resonance imaging scans. Participants also completed questionnaires assessing diet and exercise patterns, with a subgroup receiving actigraph accelerometer measurement of activity levels and dual-energy X-ray absorptiometry measures of body composition.
Results:
Patterns of change in individual measures (neuropsychology, neuroimaging and biomarkers) were examined within each population group. Changes in neuropsychological measures were correlated with neuroimaging and biomarker measures to establish convergent validity.
Conclusions:
This forms the largest study of its kind ever undertaken in Australia. The current study identified neuroimaging, biomarker and neuropsy-chological measurements of longitudinal changes in a large cohort and enhanced knowledge of lifestyle and dietary factors associated with AD and healthy aging.
