Frailty and social, clinical, and CT imaging factors in COPD: a multicenter study

Background Frailty often coexists in patients with chronic obstructive pulmonary disease (COPD) regardless of disease severity and may serve as a treatable trait. We hypothesized that factors associated with frailty may differ by COPD severity. This study aimed to comprehensively explore related factors including symptoms, physical activity, dietary behavior, serum biomarkers, and CT parameters. Methods This cross-sectional analysis of a multicenter prospective cohort study included patients with COPD aged ≥50 years with a smoking history ≥10 pack-years. Frailty was assessed using the Kihon Checklist. Data were collected using questionnaires on symptoms, physical activity, and dietary behavior, as well as blood tests and CT parameters. Associations between frailty and clinical variables were assessed using multivariable linear and logistic regressions in all patients and within the COPD severity subgroups. Results Among 225 patients, 45 (20%) were diagnosed with frailty. These patients were older, more likely to have cardiovascular disease (CVD), and had a higher neutrophil-to-lymphocyte ratio. Stratified by COPD severity, age, forced expiratory volume in 1 s (FEV 1 ), and calorie intake did not differ by frailty status, whereas patients with frailty exhibited more severe symptoms. In multivariable analysis, frailty was associated with social factors (living alone, unemployment), comorbidities (CVD, gastroesophageal reflux disease), and CT airway parameters (WA%), but not emphysema, independent of FEV 1 . Furthermore, living alone was linked to frailty in mild COPD. Conclusion Social factors, comorbidities, and WA% were associated with frailty in patients with COPD. Social factors were more relevant in patients with mild COPD.