Epidemiological studies suggested that lifetime physical activities (PA) are related with the reduced risk of Alzheimer’s disease (AD) dementia. However, very limited information is available for the association between PA during earlier lifetime and in vivo cerebral AD pathologies in late-life. This study aimed to investigate the relationship of PA in young adulthood and midlife with beta-amyloid (Aβ) accumulation and neurodegeneration in cognitive normal (CN) elderly individuals.
One-hundred sixty five CN elderly subjects aged 61 years or over who participated in the Korean Brain Aging Study for Early Diagnosis and Prediction of Dementia (K-BASE) were included for this analysis. All the subjects underwent comprehensive clinical and neuropsychological assessment, 11C-labelled Pittsburgh Compound B (PiB) positron emission tomography (PET), 18F-fluorodeoxyglucose (FDG)PET, and magnetic resonance imaging. They also completed Lifetime Physical Activity Questionnaire (LTPAQ) for the measurement of PA during young adulthood (21-40) and midlife (41-60). PiB PET images were classified as Aβ positive if the mean PiB standard uptake value ratio (SUVR) was over 1.19 in one of the following regions: the frontal, lateral temporal, lateral parietal, and precuneus/posterior cingulate cortices(PC/PCC). In terms of neurodegeneration, hypometabolism positivity was defined as a mean FDG SUVR of AD-signature regions (the angular, PCC, and inferior temporal areas) <1.386, and cortical atrophy positivity was defined as a mean cortical thickness of AD-signature regions (the entorhinal, inferior temporal, middle temporal, and fusiform gyrus) <2.666 mm.
Among 165 participants, 42 participants classified as Aβ positive, 75 as hypometabolism positive, and 23 as cortical atrophypositive. Aβ positive group showed less PA during young adulthood (age 21-40) than Aβ negative group. Among various types of PA, only leisure activity level was higher in Aβ positive group than negative group. PA level during any lifetime period did not show difference between hypometabolism positive and negative group, or between cortical atrophy positive and negative group.
Our results suggest that the higher PA during young adulthood, leisure activity in particular, may contribute to the delay of the development of AD by reducing amyloid deposition.
Table 1Demographic data and LTPAQ (age≥ 61, cognitive normal elderly) (n = 165)
Mean (SD). Total education (min 0 max 21). P value by independent t-test. Sex, ApoE difference by chi square (2-tailed, Fisher). LTPAQ: (Strength*hr/wk).
© 2017 Published by Elsevier Inc.