Association of executive function and performance of dual-task physical tests among older adults: analyses from the InChianti study

Background: previous studies have reported an association between cognitive function and physical performance, particularly among older adults. Objective: to examine the association between executive function and performance difference on complex versus usual walking tasks in a sample of non-demented older adults. Design: population-based epidemiological study of older people residing in the Chianti area (Tuscany, Italy). Participants: 737 community-dwelling individuals aged 65 years and older. Methods: gait speed (m/s) was measured during the performance of complex walking tasks (walking/talking, walking/picking-up an object, walking/carrying a large package, walking over obstacles, walking with a weighted vest) and reference walking tasks (7 m usual pace, 7 m fast pace and 60 m fast pace). Executive function was assessed using the Trail Making Test (TMT). Other measures included Mini-Mental State Examination (MMSE), sociodemographic characteristics and selected physiological impairments. Results: gait speed for the selected reference and complex walk tasks was consistently lower among participants with poor executive function. Per cent decline in gait speed compared with the reference task differed by executive function for certain tasks (e. g. walking/obstacles: 30 versus 24% decline in low versus high executive function respectively, P = 0.0006) but not for others. Conclusions: poor executive function is associated with measures of gait, including specific challenges. Overall, the results showed that the cost associated with the addition of a challenge to the basic walking task differs by executive function and the nature of the task. Further research is needed to determine whether improvement in executive function abilities translates to better performance on selected complex walking tasks.