The Emerging Utility of Bioimpedance in Patients with Chronic Obstructive Pulmonary Disease

Background and Objectives: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and is frequently associated with multiple comorbidities. Bioelectrical impedance analysis (BIA) provides additional information on body composition and may contribute to the multidimensional assessment of patients with COPD. This study aimed to explore the relationship between BIA-derived parameters and clinical characteristics in hospitalized patients with COPD. Materials and Methods: A cross-sectional analysis of baseline data from a prospective cohort was conducted. A total of 72 hospitalized patients with COPD were included, according to predefined inclusion and exclusion criteria. All patients underwent multifrequency BIA using the InBody 380 device. Sociodemographic, clinical, and paraclinical data were collected and analyzed in relation to BIA-derived parameters. Results: Among the bioimpedance-derived parameters, phase angle (PhA) showed a significant correlation with clinical indices of disease severity, including the body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index and the modified Medical Research Council (mMRC) dyspnea scale. Hydration-related parameters reflecting extracellular fluid distribution were associated with the presence of heart failure as a comorbidity. In addition, the evaluation of body fat using bioimpedance identified a higher number of patients with excess body fat compared with obesity defined according to the classical body mass index-based criteria. Conclusions: BIA may provide clinically relevant information on body composition and fluid distribution in patients with COPD. These findings support the potential role of BIA as a complementary tool in the multidimensional evaluation of multimorbid patients with COPD, although further studies are needed to clarify its prognostic value and clinical applicability.