Background: While gait has been linked with cognition, few studies have contrasted the strength of the relationships between gait speed and cognitive domains in people with cognitive impairment (CI).
Objectives: Investigate the association between gait speed and global cognitive function and cognitive domains in older people with CI.
Method: Three-hundred-and-nine community-dwelling people with CI (mean age 82 years, 47% female, and mean gait speed 0.62±0.23 m/s) were included using baseline data from the Intervention-Falls in Older Cognitively Impaired Study (iFOCIS). Usual gait speed (m/s) was measured over 2.4 m. Global cognitive function and individual cognitive domains (attention; memory; verbal fluency; language; visuospatial ability) were assessed using the Addenbrooke's Cognitive Examination-III (ACE-III). Additionally, executive function was assessed using the Frontal Assessment Battery (FAB).
Results: Participants mean±standard deviation ACE-III and FAB scores were 62.8±19.3 and 11.4±4.6, respectively. In separate multiple linear regression analyses adjusting for confounders, global cognitive function, and each cognitive domain, was significantly associated with gait speed. Executive function demonstrated the strongest association (FAB: standardized β= 0.278, p < 0.001, adjusted R2 = 0.431), and remained significantly associated with gait speed when adjusted for attention, memory, language, and visuospatial ability.
Conclusion: In this large study of older people with CI, global cognition and each cognitive domain were associated with gait speed. Executive function had the strongest association, possibly reflecting the higher-level cognitive processes and complex motor task responses required for gait control. Future longitudinal studies are needed to explore the temporal relationships between declines in executive function and gait, and whether the facilitation of executive function lessens gait decline.
Keywords: Aged; cognition; dementia; executive function; gait; walking speed.