Magnetization transfer imaging, white matter hyperintensities, brain atrophy and slower gait in older men and women.

Objective: To assess whether markers of micro- and macrostructural brain abnormalities are associated with slower gait in older men and women independent of each other, and also independent of health-related conditions and of behavioral, cognitive and peripheral function.

Methods: Magnetization transfer ratio [MTR], white matter hyperintensities [WMH], brain atrophy [BA] and brain infarcts [BI] were measured in 795 participants of the AGES-Reykjavik Study cohort (mean 75.6 years, 58.9% women).

Results: In women, lower MTR, higher WMH and BA, but not BI, remained associated with slower gait independent of each other and of other covariates. In men, WMH and BA, but not MTR or BI, remained associated with slower gait independently of each other. Only muscle strength, executive control function and depression test scores substantially attenuated these associations.

Interpretations: MTR in older adults may be an important additional marker of brain abnormalities associated with slower gait. Studies to explore the relationship between brain micro- and macrostructural abnormalities with gait and the role of mediating factors are warranted.