Impact of physical activity on early clinical progression of Alzheimer's disease

Abstract

How physical activity (PA) helps reduce the risk of Alzheimer's disease (AD) remains poorly understood at the neuropathological level. This longitudinal observational study aimed to investigate whether late-life PA (PA late ) can moderate the association between AD pathology and clinical progression over two years in non-demented older adults. Older adults without dementia completed clinical assessments at baseline and at a two-year follow-up. At baseline, the participants also received [ 11 C] Pittsburgh Compound B positron emission tomography (PET) and [ 18 F] fluorodeoxyglucose PET, as well as an evaluation for PA late . Among 191 participants, 145 were cognitively normal (CN) and 46 were mild cognitive impairment (MCI). Over the 2-year period, four CN and twenty-two MCI participants progressed to MCI and dementia, respectively. Logistic regression analyses showed that PA late moderated the relationship between AD-signature region glucose metabolism (AD-CM) and clinical progression (OR = 1.073, p  = 0.010, 95% CI 1.017–1.131). Further subgroup analyses indicated that lower AD-CM was significantly associated with increased clinical progression in the low PA group (OR < 0.001, p  = 0.010, 95% CI 0.000–0.034), whereas the relationship was not significant in the high PA group. In contrast, no significant moderating effect of PA late was found on the association between beta-amyloid and clinical progression. Late-life physical activity was associated with an attenuated relationship between AD-related neurodegeneration and early clinical progression in older adults without dementia.