Executive function correlates with walking speed in older persons: The InCHIANTI study

OBJECTIVES: To study the association between performance on psychological tests of executive function and performance on lower extremity tasks with different attentional demands in a large sample of nondemented, older adults. DESIGN: Cross-sectional study. SETTING: Community-based. PARTICIPANTS: Nine hundred twenty-six persons aged 65 and older, without dementia, stroke, parkinsonism, visual impairment, or current treatment with neuroleptics, enrolled in a large epidemiological study. MEASUREMENTS: Trail Making Test (TMT) parts A and B and two performance-based measures of lower extremity function that require different executive/attentional-demanding skills: walking speed on a 4-m course at usual pace and walking speed on a 7-m obstacle course at fast pace. A difference score (Delta TMT), obtained by subtracting time to perform part A from time to perform part B of the TMT, was used as an indicator of executive function. Based on Delta TMT, subjects were divided into poor performance, intermediate performance, and good performance. RESULTS: After adjustment, no association between Delta TMT and 4-m course usual-pace walking speed was found. Participants with poor Delta TMT and with intermediate Delta TMT performance were more likely to be in the lowest tertile for 7-m obstacle course walking speed. CONCLUSION: In nondemented older persons, executive function is independently associated with tasks of lower extremity function that require high attentional demand.