Article

Older adults with amnestic mild cognitive impairment (aMCI) are at
higher risk for developing Alzheimer disease. Physical performance decline on
gait and mobility tasks in conjunction with executive dysfunction has
implications for accelerated functional decline, disability, and
institutionalization in sedentary older adults with aMCI. OBJECTIVES: The purpose
of this study was to examine whether performance on 2 tests commonly used by
physical therapists (usual gait speed and Timed "Up & Go" Test [TUG]) are
associated with performance on 2 neuropsychological tests of executive function
(Trail Making Test, part B [TMT-B], and Stroop-Interference, calculated from the
Stroop Word Color Test) in sedentary older adults with aMCI. DESIGN: The study
was a cross-sectional analysis of 201 sedentary older adults with memory
impairment participating in a longitudinal intervention study of cognitive
function, aging, exercise, and health promotion. METHODS: Physical performance
speed on gait and mobility tasks was measured via usual gait speed and the TUG
(at fast pace). Executive function was measured with the TMT-B and
Stroop-Interference measures. RESULTS: Applying multiple linear regression, usual
gait speed was associated with executive function on both the TMT-B (beta=-0.215,
P=.003) and Stroop-Interference (beta=-0.195, P=.01) measures, indicating that
slower usual gait speed was associated with lower executive function performance.
Timed "Up & Go" Test scores (in logarithmic transformation) also were associated
with executive function on both the TMT-B (beta=0.256, P<.001) and
Stroop-Interference (beta=0.228, P=.002) measures, indicating that a longer time
on the TUG was associated with lower executive function performance. All
associations remained statistically significant after adjusting for age, sex,
depressive symptoms, medical comorbidity, and body mass index. LIMITATIONS: The
cross-sectional nature of this study does not allow for inferences of causation.
CONCLUSIONS: Physical performance speed was associated with executive function
after adjusting for age, sex, and age-related factors in sedentary older adults
with aMCI. Further research is needed to determine mechanisms and early
intervention strategies to slow functional decline.

Langue : ANGLAIS