Aging
Association between gait speed and incident dementia among those aged 90 and older: findings from LifeAfter90 Study Rifat Alam* Rifat Alam Alam Alam Alam Alam Alam Alam Alam University of California Davis, Davis, CA
Background: Slower gait speed has been linked to higher risk of dementia, but evidence is limited among adults aged 90+ years, the oldest-old. We examined the association between gait speed and incident dementia in an ethnoracially diverse cohort of the oldest-old.
Methods: We analyzed 421 LifeAfter90 participants with baseline gait speed measured using the 4-Meter Walk Test (meters/second); z-scored average of two attempts. Incident dementia was identified through clinical assessments occurring every 6 months for up to 11 visits between 2018 and 2025. Follow-up time was defined as years from baseline to dementia, death, or the end of follow-up, whichever occurred first. We used cause-specific Cox proportional hazards models to estimate dementia risk and Fine-Gray models to account for the competing risk of death. Hazard ratios (HR) are reported per 1 SD increase in gait speed, adjusted for age, sex, race/ethnicity, and education.
Results: Participants’ mean±SD baseline age was 92.8±2.3, 63% were women, and 20% self-identified as Asian, 21% as Black, 11% as Latine, 9% as Multiracial/Other, and 38% as White. Over an average±SD follow-up of 2.7±2.1 years, 136 participants developed dementia and 156 died. Faster gait speed was associated with a lower risk of dementia in the cause-specific Cox model (HR=0.67,95%CI=0.55,0.81), and the Fine-Gray model (sHR=0.74,95%CI=0.62,0.90) (Figure 1).
Discussion: Faster baseline gait speed was associated with lower risk of dementia among this diverse cohort of adults aged 90 and older. Our findings remained after accounting for death as a competing event. These results support gait speed as a simple, measurable marker of future dementia risk in the oldest-old.
