Relationship between respiratory sarcopenia and respiratory muscle weakness in community-dwelling older adults: a preliminary cross-sectional study

[Purpose] Using new diagnostic criteria, this study aimed to clarify the relationship between respiratory sarcopenia and respiratory muscle weakness in community-dwelling older adults. [Participants and Methods] Basic information, body composition, motor function, respiratory function, and respiratory muscle strength were analyzed for 43 elderly community residents who participated in a health promotion program between 2021 and 2023. Respiratory sarcopenia and respiratory muscle weakness were evaluated based on maximal intraoral pressure and skeletal muscle index. We conducted a comparison among the three groups-respiratory sarcopenia, respiratory muscle weakness, and robustness. [Results] The respiratory sarcopenia group tended to have lower trunk muscle mass compared to the robust group and had significantly lower trunk muscle mass than the respiratory muscle weakness group. The incidence of systemic sarcopenia was significantly higher in the respiratory sarcopenia group than in the other two groups. [Conclusion] These results indicate that respiratory sarcopenia may be associated with the loss of limb muscle mass observed in patients with systemic sarcopenia and a reduction in trunk muscle mass. The risk factors influencing the prognosis of respiratory sarcopenia may vary depending on the method used to assess respiratory muscle weakness. This study provides the foundational data for future research on respiratory sarcopenia.