MacDonald, Stuart W.S.Hundza, SandraLove, Janet A.DeCarlo, Correne A.Halliday, Drew W. R.Brewster, Paul W. H.Lukyn, Timothy V.Camicioli, RichardDixon, Roger A.2018-08-022018-08-0220172017-02MacDonald, S.W.S.; Hundza, S.; Love, J.A.; DeCarlo, C.A.; Halliday, D.W.R.; Brester, P.W.H.; … & Dixon, R.A. (2017). Concurrent indicators of gait velocity and variability are associated with 25-year cognitive change: A retrospective longitudinal investigation. Frontiers in Aging Neuroscience, 9, article 17. https://doi.org/10.3389/fnagi.2017.00017https://doi.org/10.3389/fnagi.2017.00017http://hdl.handle.net/1828/9818Background/Objectives: Physical function indicators, including gait velocity, stride time and step length, are linked to neural and cognitive function, morbidity and mortality. Whereas cross-sectional associations are well documented, far less is known about long-term patterns of cognitive change as related to objective indicators of mobility-related physical function. Methods: Using data from the Victoria Longitudinal Study, a long-term investigation of biological and health aspects of aging and cognition, we examined three aspects of cognition-physical function linkages in 121 older adults. First, we examined a simple marker of physical function (3 m timed-walk) as a predictor of cross-sectional differences and up to 25-year change for four indicators of cognitive function. Second, we tested associations between two markers of gait function derived from the GAITRite system (velocity and stride-time variability) and differences and change in cognition. Finally, we evaluated how increasing cognitive load during GAITRite assessment influenced the associations between gait and cognition. Results: The simple timed-walk measure, commonly used in clinical and research settings, was a minor predictor of change in cognitive function. In contrast, the objectively measured indicator of walking speed significantly moderated long-term cognitive change. Under increasing cognitive load, the moderating influence of velocity on cognitive change increased, with increasing variability in stride time also emerging as a predictor of age-related cognitive decline. Conclusion: These findings: (a) underscore the utility of gait as a proxy for biological vitality and for indexing long-term cognitive change; and (b) inform potential mechanisms underlying age-related linkages in physical and cognitive function.encognitive changephysical functiongaitvariabilityVictoria Longitudinal StudyArticle