SENSITIVITY AND SPECIFICITY OF PEAK EXPIRATORY FLOW RATE FOR RESPIRATORY SARCOPENIA DIAGNOSIS IN COMMUNITY-DWELLING ELDERLY

Y. Do¹, Y. Lim¹, H. Lee¹

¹Gachon University, Health Science, Incheon, Korea (Republic of)

Background: The aging process affects the skeletal muscles and causes sarcopenia in the elderly population. This process also affects the respiratory muscles, causing decreases in its mass, strength, and function which can lead to hypoxic stress, cachexia, decreased activity, and poor quality of life. In this regard, the need to establish the concrete definition of respiratory sarcopenia (RS) has recently been suggested, but standards for RS diagnosis are insufficient.

Purpose: The purpose of this study was to establish optimal criterion for diagnosing RS through the peak expiratory flow rate (PEFR) and the diaphragm thickness. We also examined differences between groups in respiratory parameters.

Methods: A total of 181 community-dwelling elderly participated in this study. Skeletal muscle mass, handgrip strength, and physical performance were assessed for evaluating the presence of sarcopenia according to the Asian Working Group for Sarcopenia 2019 (AWGS) criteria. The diaphragm thickness was assessed using ultrasound for evaluation of the respiratory muscle mass. The maximal inspiratory pressure (MIP), percent predicted forced vital capacity (Pred FVC), and PEFR were evaluated to define the weakness of respiratory parameters composed of respiratory muscle strength and function. Then, participants were classified into 4 groups of robust, possible sarcopenia, sarcopenia, and RS according to the reference standards criteria. The loss of skeletal muscle mass with reduced handgrip strength and/or physical performance was considered sarcopenia according to the AWGS criteria. The MIP lower than the predicted MIP calculated based on age and sex, and FVC lower than 80 were used as criterion for decreased respiratory muscle strength, and deteriorated respiratory function, respectively.

Results: The optimal cut-off point of the PEFR for predicting RS was 3.84 l/s (p = 0.006) with the area under the curve (AUC) of 0.711 (95% CI: 0.623 - 0.788). The sensitivity and specificity were 0.692 and 0.661, respectively. On the other hand, no significant cut-off point was presented through the diaphragm thickness (p = 0.328). There were no significant differences when the AUC of PEFR was compared with that of MIP and Pred FVC (p > 0.05). In addition, the PEFR was found to be significantly associated with sarcopenia diagnostic indicators (p < 0.05), and respiratory parameters (p < 0.001). There were significant differences between groups in respiratory parameters (p < 0.001).

Conclusions: The cut-off point of PEFR can be used as a reasonable standard for RS diagnosis. This study finding can serve as a cornerstone for developing concrete criteria of RS, supporting clinical judgment.

Implications: This study contributes to the development of concrete criteria for RS which is crucial for providing appropriate treatment through accurate diagnosis.

Funding acknowledgements: This research was funded by the Gachon University

Keywords:
Respiratory sarcopenia
Peak expiratory flow rate
Diaphragm thickness

Topics:
Cardiorespiratory

Did this work require ethics approval? Yes

Institution: Gachon University

Committee: Institutional Review Board of Gachon University

Ethics number: 1044396-202206-HR-121-01