Cardiorespiratory Response to Exercise Testing in Individuals With Alzheimer's Disease

Abstract

Billinger SA, Vidoni ED, Honea RA, Burns JM. Cardiorespiratory response to exercise testing in individuals with Alzheimer's disease. Objective To examine exercise testing response in Alzheimer's disease (AD) and possible disease-related change over time. Design Retrospective assessment of a 2-year observational study. Setting University medical center. Participants Individuals without dementia (n=50) and with AD (n=31). Interventions Not applicable. Main Outcome Measures Participants underwent a clinical dementia evaluation and performed an incremental exercise test using a treadmill and the modified Bruce protocol at baseline and at a 2-year follow-up. We examined oxygen consumption, minute ventilation, heart rate, and ventilatory equivalents for oxygen and carbon dioxide at submaximal and peak exercise intensities to determine whether the measures were different between groups or over time. Results Participants with AD and those without dementia performed similarly at submaximal effort, and both groups showed similar changes in exercise response over 2 years. However, nondemented individuals had consistently higher values of oxygen consumption ( P≤.02) and minute ventilation at peak effort at baseline ( P=.003). Conclusions Individuals with AD demonstrate physiologic responses to submaximal exercise effort that are not significantly different than individuals without dementia. However, differences are apparent at the extreme of effort.