Abstract
Background: Cognitive decline in the elderly is associated with chronic cerebral hypoperfusion. While many forms of exercise can slow or reverse cognitive decline, compliance in unsupervised exercise programs is poor. Objective: We address whether passive exercise, that is, muscle stimulation, is capable of reversing postural hypotension in an older adult population sufficiently to significantly improve cognitive function as measured by executive function tests. Subjects and Methods: In this study, 50- to 80-year-old women underwent cognitive testing, long-duration cardiac hemodynamic recordings during quiet sitting, and 60 min of soleus muscle stimulation with continued hemodynamic recording. Results: Two thirds of our subjects were hypotensive (diastolic blood pressure [DBP] < 70 mmHg) after 30 min of quiet sitting. Cognitive performance was significantly better in individuals with higher DBPs (0.79 s per 1-mmHg increase in DBP). Soleus muscle stimulation resulted in an average increase in DBP of 6.1 mmHg, which could translate into a 30% or greater improvement in cognitive performance. Conclusions: Incongruent Stroop testing provides high statistical power for distinguishing differential cognitive responses to resting DBP levels. These results set the stage to investigate whether regular use of calf muscle pump stimulation could effectively reverse age-related cognitive impairment.