Relationships among peak expiratory flow rate, body composition, physical function, and sarcopenia in community-dwelling older adults

Background and aim Although respiratory muscle strength is known to decrease with age, the relationship between pulmonary function and sarcopenia remains to be examined. The present study aimed to determine the relationship between peak expiratory flow rate (PEFR) and skeletal muscle mass/sarcopenia in community-dwelling older adults. Methods We utilized data from 427 older adults (age 74.4 +/- 5.3 years, men/women 157/270) who had participated in the 2015 Otassha Kenshin, a longitudinal study that excluded participants with air-flow limitations. Diagnoses of sarcopenia were based on criteria outlined in the Consensus Report of the Asian Working Group for Sarcopenia and adjusted for Japanese individuals. We compared body composition, physical function, and lung function between patients with and without sarcopenia. Receiver operating characteristic analysis (ROC) for sarcopenia was performed using PEFR, calf circumference, and body mass index. Results Sixty-five participants (men/women 12/53) were diagnosed with sarcopenia. Patients with sarcopenia were older than those without sarcopenia, and had lower height, weight, body mass index, skeletal muscle mass, appendicular skeletal mass, and skeletal muscle index. Stepwise multiple regression analysis identified whole-body skeletal mass as an independent factor for PEFR. ROC analysis of sarcopenia identified a cut-off value of 5.0 L s for PEFR, with a sensitivity of 0.62, specificity of 0.77, and area under the curve of 0.73 (95% CI 0.67-0.79; P < 0.001). Discussion and conclusion Our findings suggest that physical function is more strongly associated with respiratory muscle mass than total skeletal muscle mass and that PEFR may be a valid indicator of sarcopenia.