Walking stabilizes cognitive functioning in Alzheimer's disease (AD) across one year

Abstract

AD is a public health epidemic, which seriously impacts cognition, mood and daily activities; however, one type of activity, exercise, has been shown to alter these states. Accordingly, we sought to investigate the relationship between exercise and mood, in early-stage AD patients (N=104) from California, over a 1-year period. Patients completed the Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), and Blessed-Roth Dementia Rating Scale (BRDRS), while their caregivers completed the Yale Physical Activity Survey (YALE), Profile of Mood States (POMS), the Neuropsychiatric Inventory (NPI) and Functional Abilities Questionnaire (FAQ). Approximately half of the participants were female, from a variety of ethnic groups (Caucasian=69.8%; Latino/Hispanic Americans=20.1%). Our results demonstrated that the patients spent little time engaged in physical activity in general, their overall activity levels decreased over time, and this was paired with a change in global cognition (e.g., MMSE total score) and affect/mood (e.g., POMS score). Patients were parsed into Active and Sedentary groups based on their Yale profiles, with Active participants engaged in walking activities, weekly, over 1 year. Here, Sedentary patients had a significant decline in MMSE scores, while the Active patients had an attenuation in global cognitive decline. Importantly, among the Active AD patients, those individuals who engaged in walking for more than 2 h/week had a significant improvement in MMSE scores. Structured clinical trials which seek to increase the amount of time AD patients were engaged in walking activities and evaluate the nature and scope of beneficial effects in the brain are warranted.

Fig. 1

Mean Hours Engaged in Activity (SEM) as measured by the Yale Physical Activity Questionnaire, across the entire AD population at baseline. Results showed that the AD population engaged in Leisurely Walking activities for more hours each week than any other type of physical activity (N = 104; *p < 0.001).

Fig. 2

Baseline and 1-year Mean total MMSE score and Mean total hours engaged in Leisurely Walking activities per week for the AD population. Standard Error of the Mean for MMSE scores and Data Values for all groups are shown. Black dashed: Results for active AD patients who engaged in walking for ~2 h/week (e.g., walking ~2 h/week; N = 34; *p < 1.0e–7). Gray dashed: Results for AD patients engaged in walking for ~1 h/week (e.g., Walking ~1 h/week; N = 50; p > 0.1). Black solid: Results for AD patients who were not engaged in leisurely walking activities at either time point (e.g., Sedentary; N = 20; *p < 0.01).