Inflammatory markers and frailty in elderly adults with COPD: a cross-sectional study

This study aimed to investigate the discrimination value of inflammatory biomarkers for frailty in hospitalised elderly adults with chronic obstructive pulmonary disease (COPD), and explore the relationship between inflammatory markers and frailty in elderly adults. A cross-sectional study was conducted among elderly inpatients with COPD admitted to a tertiary hospital between March 2024 and June 2025. Frailty was evaluated using the Fried phenotype. Univariate and multivariate logistic regression analyses were used to identify independent risk associated with frailty. Spearman correlation analyses and sensitivity analyses were performed to explore the relationship between inflammatory makers and frailty and assess the diagnostic value of inflammatory makers. Among 553 hospitalised elderly patients with COPD, 35.98% ( n = 199) were frail. Activities of Daily Living (ADL), GOLD rank and C-reactive protein (CRP), absolute neutrophil count (ANC) and interleukin-6 (IL-6) were identified as independent risk factors of frailty. Correlation analyses showed that CRP, ANC, procalcitonin (PCT), white blood cell (WBC) and erythrocyte sedimentation rate (ESR) were significantly associated with frailty. Sensitivity analyses revealed that adding WBC, PCT and ESR modestly improved basic model’s performance, confirming the diagnostic value of these markers. Frailty in elderly COPD patients is strongly correlated with inflammation indicators. Integrating inflammatory biomarkers and disease-specific clinical characteristics can enhance frailty risk discrimination accuracy in this study. Even non-independent inflammatory risk factors retain notable clinical associations with frailty, and an expanded panel of such markers may provide a more objective basis for early identification and targeted management of high-risk elderly COPD patients.