Gait speed and domain-specific cognitive performance in a diverse cohort of the oldest-old: the LifeAfter90 Study

Gait speed is a robust marker of health in older adults and is associated with cognition, yet few studies have examined this in the oldest-old and if there are differences by cognitive domain. We examined the association between gait speed and cognition across three domains in individuals aged 90 + , considering differences by gender and device use. Then, 502 participants were included from the LifeAfter90 Study. Baseline gait speed (meters/second) was measured using the 4-meter walk test. The Spanish and English Neuropsychological Assessment Scale assessed executive function (EF), verbal episodic memory (VEM), and semantic memory (SM). We tested cross-sectional and longitudinal associations of gait speed with cognition using linear mixed-effects models adjusted for age, gender, race/ethnicity, education, device, interview mode, and practice effects. Models were stratified by gender and device. Participants' mean age was 92.9 ± 2.4 years, 62.6% female, 22.3% African American/Black, 20.9% Asian, 12.3% Hispanic/Latino, 35.9% White, and 8.6% multiracial/other. Faster gait speed was associated with better EF (β(95%CI) = 1.3 (0.9, 1.8)), VEM (0.7 (0.1, 1.2)), and SM (0.8 (0.4, 1.3)). Gender-stratified models showed better EF and SM in both sexes and better VEM in women. Device-stratified models showed better EF and SM in both groups and better VEM in nondevice users. Longitudinally, faster gait speed was associated with slower SM decline (0.1 (0.0003, 0.2)). No other longitudinal associations were significant in pooled or stratified analyses. Faster baseline gait speed was linked to better cognitive performance and slower SM decline. Findings varied by domain, gender, and device use, highlighting gait speed's utility in reflecting cognitive variability among those with exceptional longevity.