The Temporal Relation of Physical Function with Cognition and the Influence of Brain Health in the Oldest-Old

Introduction:Physical function and cognition seem to beinterrelated, especially in the oldest-old. However, thetemporal order in which they are related and the role ofbrain health remain uncertain.Methods:We included 338participants (mean age 93.1 years) from two longitudinalcohorts: the UCI 90+ Study and EMIF-AD 90+ Study. Wetested the association between physical function (ShortPhysical Performance Battery, gait speed, and handgripstrength) at baseline with cognitive decline (MMSE, memorytests, animalfluency, Trail Making Test (TMT-) A, and digitspan backward) and the association between cognition atbaseline with physical decline (mean follow-up 3.3 years).We also tested whether measures for brain health (hippo-campal, white matter lesion, and gray matter volume) wererelated to physical function and cognition and whetherbrain health was a common driver of the association be-tween physical function and cognition by adding it asconfounder (if applicable).Results:Better performance on all physical tests at baseline was associated with less declineon MMSE, memory, and TMT-A. Conversely, fewer associa-tions were significant, but better scores on memory, TMT-A,and digit span backward were associated with less physicaldecline. When adding measures for brain health as con-founder, all associations stayed significant except formemory with gait speed decline.Conclusion:In the oldest-old, physical function and cognition are strongly related,independently of brain health. Also, the association betweenphysical function and cognitive decline is more pronouncedthan the other way around, suggesting a potential forslowing cognitive decline by optimizing physical function.(c) 2024 The Author(s).Published by S. Karger AG, Basel