Gait speed predicts decline in attention and psychomotor speed in older adults: the health aging and body composition study.

BACKGROUND/AIMS Gait speed is cross-sectionally associated with attention and psychomotor speed in older community dwellers. It is unclear if gait speed predicts decline in these cognitive domains over time. METHODS Usual gait speed (m/s) over 6 m was measured at baseline in 2,776 Health, Aging and Body Composition Study participants (mean age +/- SD 73.5 +/- 2.8 years, 53% women, 37% blacks). The Digit Symbol Substitution Test (DSST) was administered at baseline and after 5 years to assess attention and psychomotor speed. We used multivariate logistic regression models to calculate the risk of DSST 5-year decline [>1 SD from mean change (9 points)] across quartiles of gait speed, adjusting for demographics, weight, physical activity, comorbidities, depression and Modified Mini-Mental State Examination. RESULTS After 5 years, 389 (17.1%) participants declined in DSST. Compared to those in the highest quartile of gait speed (>1.35 m/s), participants in the lowest quartile (<1.05 m/s) were more likely to decline in DSST independently of the considered covariates (OR 1.74, 95% CI 1.21-2.51, adjusted p for trend across quartiles = 0.006). CONCLUSIONS In this cohort of older community dwellers, gait speed independently predicted a decline in DSST after 5 years.