Executive dysfunction occurs early and is prevalent in Alzheimer's disease (AD). This study tested the ability of different measures for identifying changes in executive function and the effect of 6-months of aerobic exercise on executive function in older adults with mild to moderate AD, using a single-group, repeated-measures design (n = 28, age 78.1 ± 8.37). Factor analysis and linear mixed-effects model analyses showed that individually the Exit Interview-25 (EXIT-25), Behavioral Dyscontrol Scale (BDS), and Golden Stroop test were the preferred instruments for measuring changes in executive function in the sample. The COWAT and TMT had substantial floor effects limiting their ability to identify changes in executive function. A single latent factor was sufficient to describe the heterogeneity of executive function. Over 6 months, aerobic exercise maintained executive function (effect size = −0.11, −0.24, −0.27, and −0.21 for the EXIT-25, BDS, Stroop, and latent factor, respectively). Decline in the latent factor (effect size = −0.21, p = 0.06) was minimal and comparable to that in global cognition (effect size = −0.20, p = 0.34). Aerobic exercise may be effective on maintaining executive function in AD.
Bibliographical noteFunding Information:
The design and implementation of the study was funded by the National Institute of Health K12 Career Advancement Award ( RR023247-04 ) and BrightFocus ® Foundation ( A2009344 ). The data analysis and manuscript preparation were supported by the National Institute on Aging of the National Institutes of Health Award Number R01AG043392-01A1 . All subject interviews and data collections occurred at the CTSI that was supported by the National Institutes of Health National Center for Advancing Translational Sciences of the National Institutes of Health Award Number UL1TR000114 . The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
© 2017 Elsevier Inc.
- Alzheimer's disease
- Executive function