Association of respiratory function with sarcopenia in older outpatients: cross-sectional analysis of baseline data from the JUSTICE-TOKYO prospective cohort study.

PURPOSE: Sarcopenia, characterized by loss of muscle mass and function, can affect the respiratory muscles and impair pulmonary function. However, evidence on the association between sarcopenia and respiratory function in older adults remains limited. This study examined the relationships among outpatients attending a hospital for older adult medicine.

METHODS

Baseline data from 810 outpatients aged ≥ 65 in the JUSTICE-TOKYO study were analyzed. Individuals with asthma, chronic obstructive pulmonary disease, or interstitial lung disease were excluded. The mean age was 78.2 ± 6.1 years, and 341 (42.1%) were male Sarcopenia was diagnosed based on 2019 Asian Working Group for Sarcopenia criteria. Pulmonary function measures included vital capacity (% predicted), forced expiratory volume in one second (% predicted), FEV1/FVC ratio, and peak expiratory flow rate (PEFR). Receiver operating characteristic (ROC) curve analyses were performed to assess the diagnostic performance of VC (% predicted) and PEFR for sarcopenia.

RESULTS

Sarcopenia was identified in 170 patients (21%; 102 men,68 women). Patients had a higher prevalence of myocardial infarction, heart failure, and malignancies. ROC curve analyses showed that VC (% predicted) had an optimal cutoff of 94.2% (sensitivity:0.653, specificity:0.613), and area under the curve(AUC) of 0.66. The diagnostic performance of VC (% predicted) was comparable to PEFR (AUC: 0.70 in men and 0.69 in women).

CONCLUSION

Respiratory function, particularly VC (% predicted), was significantly associated with sarcopenia in older adult outpatients. VC (% predicted) demonstrates diagnostic performance comparable to PEFR and may serve as a practical parameter for sarcopenia risk identification in clinical practice.