Inspiratory Muscle Strength and Cardiorespiratory Fitness in Sarcopenic and Dynapenic Older Adults: A Cross-Sectional Study

Abstract

BACKGROUND AND PURPOSE: While sarcopenia and dynapenia, common in older adult, are known to affect general motor function, their specific effects on inspiratory muscle strength and cardiorespiratory fitness have not been adequately investigated. Therefore, the aim of our study was to compare inspiratory muscle strength and cardiovascular fitness levels in sarcopenic, dynapenic, and older adults without sarcopenia or dynapenia. METHODS: The study included 75 community-dwelling older adults aged 65-85. Individuals were divided into 3 groups: dynapenic, sarcopenic, and control groups (older adults without sarcopenia or dynapenia), according to the ISarcoPRM diagnostic algorithm, which includes measuring anterior thigh thickness by ultrasonography. The S-index, flow, and volume parameters were measured using the Powerbreathe K5 system to assess inspiratory muscle strength in older adults. A 2-minute step test (2MST) was used to assess cardiorespiratory fitness. RESULTS: The sarcopenic group had lower values than the control in the S-index, flow, and volume parameters ( p < .05). In the 2MST, which evaluates cardiorespiratory fitness, all three groups were different from each other, and the sarcopenic group had the lowest scores ( p < .05). It was observed that anterior thigh muscle thickness had a low correlation with volume ( r = 0.347, p = .002). Anterior thigh muscle thickness had a moderate correlation with S-index ( r = 0.405, p < .001), flow ( r = 0.421, p < .001), and 2MST ( r = 0.454, p < .001). CONCLUSION: It is thought that loss of respiratory muscle strength in older adults is seen in individuals with loss of muscle mass (sarcopenic).