The association between sarcopenia and peak expiratory flow decline in middle-aged and older adults: a nationwide cross-sectional and longitudinal study in China

Evidence suggests an association between sarcopenia and impaired respiratory function; however, longitudinal population-based data on the relationship between sarcopenia, its individual components, and peak expiratory flow (PEF) decline remain limited. This study aimed to investigate the cross-sectional and longitudinal associations of sarcopenia and its components with PEF measures among middle-aged and older Chinese adults. Data were obtained from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study (CHARLS). Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. Cross-sectional associations between sarcopenia and PEF measures were examined using multivariable logistic and linear regression models. Longitudinal associations between baseline sarcopenia and subsequent PEF decline were evaluated using multivariable logistic regression models. A total of 9452 participants were included in the cross-sectional analysis. Compared with participants without sarcopenia, those with sarcopenia and severe sarcopenia had higher odds of severe airflow limitation (SAL) (OR = 1.41, 95% CI: 1.20–1.65 and OR = 1.56, 95% CI: 1.26–1.94, respectively). Sarcopenia and its individual components were also associated with lower PEF and PEF% predicted. In the longitudinal analysis of 4804 participants, low muscle strength was the strongest and most consistent predictor of subsequent PEF decline. Participants with low muscle strength had a higher risk of new-onset SAL (OR = 1.54, 95% CI: 1.20–1.98) and a 56%–64% greater risk of PEF% predicted decline across different thresholds. Severe sarcopenia and low muscle mass were also associated with greater risks of moderate-to-severe PEF% predicted decline. Sarcopenia was associated with poorer cross-sectional PEF measures, whereas low muscle strength showed the strongest and most consistent longitudinal associations with subsequent PEF decline. These findings highlight the potential importance of muscle strength preservation for maintaining respiratory health in middle-aged and older adults. This study aimed to investigate the association between sarcopenia and its components with PEF decline using data from the China Health and Retirement Longitudinal Study (CHARLS), employing both cross-sectional and longitudinal analyses. The findings demonstrated that sarcopenia was associated with poorer cross-sectional PEF measures, whereas low muscle strength emerged as the strongest and most consistent predictor of subsequent PEF decline among middle-aged and older adults in China.