Association of physical activity, brain volume, and plasma biomarkers of Alzheimer’s disease: The Shanghai Aging Study

Abstract

AbstractBackgroundThis study aimed to explore the potential relationship between physical activity and brain volume as well as plasma biomarkers of Alzheimer’s disease in the Chinese population.MethodThis cross‐sectional analysis included 99 dementia‐free community‐dwelling older adults from the Shanghai Aging Study. Physical activity was assessed based on questionnaires and further transformed into metabolic equivalent values (MET‐hours). Older adults were then divided into two groups: low physical activity (≤21.0 MET‐hours) and high physical activity (>21.0 MET‐hours), based on the median of MET‐hours. Data on age, sex, years of education, and smoking status were collected through questionnaires. DNA was extracted from the blood or saliva samples to conduct apolipoprotein E (APOE) genotyping. Histories of hypertension and diabetes were confirmed by the medical records. Voxel‐based morphometry analysis was performed to quantify brain volumes. Hippocampal volume estimates were obtained using the free surfer image analysis suite. Plasma β amyloidAβ40, Aβ42, Tau, and neurofilament light (Nfl) were measured by the single‐molecule array. Multivariate linear models were used to examine the association between physical activity, brain volumes, and plasma biomarkers.ResultWe observed a significant inverse association between physical activity and the level of plasma Aβ40 (high vs. low physical activity, β = ‐17.883, r = ‐0.222, p = 0.039) and a marginally significant association between physical activity and the level of plasma Aβ42 (high vs. low physical activity, β = ‐1.394, r = ‐0.204, p = 0.058), after adjusting for age, sex, years of education, APOE ε4, smoking, hypertension, and diabetes. Physical activity displayed no significant associations with plasma Tau, Nfl as well as brain volumes.ConclusionThe protective effect of physical activity on cognition might rely on its effect on the β amyloid burden.