Differences in cough strength, respiratory function, and physical performance in older adults with and without low swallowing function in the repetitive saliva swallowing test

Abstract

[Purpose] In older adults, the risk of aspiration pneumonia increases because of coexisting factors such as age-related decline in swallowing function, inefficient cough, reduced respiratory function, and poor physical performance. This study aimed to investigate the differences in cough strength, respiratory function, and physical performance in community-dwelling ambulatory older adults with and without low swallowing function. [Participants and Methods] In 225 community-dwelling ambulatory older adults, swallowing function (the repetitive saliva swallowing test, RSST), cough strength (peak cough flow), lung function (forced vital capacity, forced expiratory volume in 1 second/forced vital capacity), respiratory muscle strength (maximum inspiratory and expiratory pressures), and physical performance (30-second chair stand test and Timed Up and Go test) were evaluated. Participants with low swallowing function in RSST (low RSST group) were compared to age- and sex-matched participants without low swallowing function (control group). [Results] Peak cough flow and maximum inspiratory and expiratory pressures were significantly lower in the low RSST group (n=14) than the control group (n=14). [Conclusion] These preliminary results suggest that community-dwelling ambulatory older adults with low swallowing function in RSST might have lower cough and respiratory muscle strength, even if they have relatively preserved lung function and physical performance.