Proactive pharyngeal swallowing exercises: Building muscular reserve in pre-frail older adults

PROJECT SUMMARY: The act of swallowing food and liquid is a basic human function that most people take for granted. Yet, approximately 15% of older adults suffer from impaired swallowing which can lead to malnutrition, frailty and pneumonia. Our previous NIH-funded research has confirmed that age-related decline in the muscles of the pharynx (throat) is associated with negative changes to swallowing mechanics and function, putting older adults at risk for serious health consequences. Given that exercise and nutrition are known powerful stimulators of positive muscular change, we propose to investigate these methods to reverse age-related decline of the pharyngeal swallowing muscles. Specifically, we will test the hypothesis that proactive swallowing exercises (+/- daily protein supplement drinks) will improve the composition, force, and physiology of the pharyngeal muscles. Our study design begins with 12 weeks of no-treatment control, allowing each of our 80-community dwelling older adult participants to serve as their own experimental control. Next, participants will be randomized to complete 12 weeks of pharyngeal exercises (5 days per week) with or without protein drinks. Before and after each phase, our study team will conduct a comprehensive battery of outcome measures to quantify changes to the pharyngeal muscles. Specifically, we will capture pharyngeal muscle composition with magnetic resonance imaging, pharyngeal muscle force with high resolution manometry, and pharyngeal muscle physiology with videofluoroscopy. We expect that proactive swallowing exercises will improve the composition, force, and physiology of the pharyngeal muscles and that these gains will be enhanced in the +protein condition. Finally, we are motivated to identify health-related predictors of treatment success. To that end, we will assess the influence of baseline measures of nutritional status and physical function on treatment success by analyzing biochemical markers extracted from blood samples and by conducting comprehensive analyses of body composition. The global population is rapidly aging and thus many older adults will experience the debilitating impact of impaired swallowing. Therefore, research establishing effective interventions to reverse and/or prevent age-related swallowing muscle decline is timely and important. Building a physiologic reserve in the swallowing muscles can improve the health and quality of life of community-dwelling older adults.