Walking While Talking and Risk of Incident Dementia.

INTRODUCTION: Walking while talking (WWT) is a performance-based test of divided attention that examines cognitive-motor interactions. The purpose of this study is to examine the predictive validity of WWT for dementia and dementia subtypes.

METHODS: We prospectively studied the associations of WWT performance at baseline with risk of developing incident dementia in 1,156 older adults (mean age: 78.28 ± 5.27 years, 60.7% female) enrolled in the Einstein Aging Study using Cox proportional hazard models. Associations were reported as hazard ratio (HR) with 95% confidence intervals (CI).

RESULTS: Over a median follow-up of 1.90 years (interquartile range: 4.70 years), 85 participants developed incident dementia (53 Alzheimer dementia [AD] and 26 vascular dementia [VaD]). Three gait domains were derived using principal component analysis. Only variability, which loaded heavily for swing time standard deviation (SD) and step time SD, was associated with an increased risk of incident dementia per 1 point increase (HR: 1.24, 95% CI: 1.02-1.54) and VaD (HR: 1.50, 95% CI: 1.06-2.12) after adjusting for demographics, disease burden, mental status, and normal walking velocity. Among eight individual gait variables, only swing time variability SD was associated with increased risk for both incident dementia (HR: 1.35, 95% CI: 1.03-1.77) and VaD (HR: 1.78, 95% CI: 1.12-2.83). Variability and swing time SD were not significantly associated with risk of incident AD.

CONCLUSIONS: Complex walking as assessed by the WWT task is a simple and pragmatic tool for assessing risk of developing dementia, especially VaD, in older adults.