Associations of gait speed and other measures of physical function with cognition in a healthy cohort of elderly persons.

BACKGROUND: Recent evidence suggests that physical decline and slower gait may be associated with early signs of dementia, but more information on healthy older adults is needed.

METHODS: We determined associations between cognitive function, gait speed, and self-reported measures of physical function in 3035 healthy mobile participants of the Ginkgo Evaluation of Memory Study evaluated in 2000-2001. Gait speed was measured over a 15-foot course with participants walking at both their usual and rapid pace. Self-reported difficulties with Activities of Daily Living (ADLs) and other physical function tasks were also collected. Results of the Modified Mini-Mental State Examination (3MSE) determined cognitive function.

RESULTS: The average age of the cohort was 78.6 years (standard deviation [SD] 3.3), and 53.9% of participants were men. Mean gait speed was 0.95 (SD 0.23) m/s at a usual pace and 1.35 (SD 0.58) m/s at a rapid pace. More than three-fourths of participants had 3MSE scores > 90. In multiple logistic models adjusted for demographics and comorbidities, risk of low cognition (defined as 3MSE score of 80-85) was almost twice as great for participants in the slowest quartile of the rapid-paced walking task than for the fastest walkers (odds ratio: 1.96, 95% confidence interval, 1.25-3.08). Associations between cognition and usual-paced walking were borderline, and no relationships were found with self-reported measures of physical function, including ADLs.

CONCLUSIONS: In very healthy older adults, performance-based measures better predict early cognitive decline than do subjective measures, and tasks requiring greater functional reserve, such as fast-paced walking, appear to be the most sensitive in assessing these relationships.