Relationship between new-onset falls and neuroimaging markers of Alzheimer's disease in the UK Biobank

BackgroundWhile Alzheimer's disease (AD) is a known risk factor for falls, the association between falls and incident AD is a growing area of study.ObjectiveThe primary aim of this analysis was to examine associations between new-onset falls in older adults and neuroimaging and plasma biomarkers of AD. A secondary aim was to evaluate associations between new-onset falls and neuroimaging markers of motor dysfunction.MethodsData from the UK Biobank study was utilized. Participants were 70 years of age or older at the date of neuroimaging and had no reported history of falls at study enrollment. To determine falls status, participants self-reported data on falls history within the last year prior to neuroimaging.Results15,447 individuals were included in our analysis (No falls, N = 12,522; One fall, N = 2,199, Multiple falls, N = 726). Compared to individuals in the No falls group, individuals in the One fall and Multiple falls group had significantly higher volumes of white matter hyperintensities, while individuals in the Multiple falls group had significantly lower left and right hippocampal volumes. One or more fall was associated with higher plasma levels of pTau181, which did not remain significant after adjusting for multiple comparisons. Plasma amyloid-β 42/amyloid-β 40 ratio did not differ significantly between groups.ConclusionsIn a sample of older adults without history of falls at study enrollment, new-onset falls were associated with decreased hippocampal volumes, which is associated with prodromal AD, as well as an increased volume of white matter hyperintensities, which may also emerge secondary to AD pathology.