Abstract
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major global health burden frequently complicated by systemic comorbidities. Anemia, a common yet underrecognized condition in COPD, is associated with adverse clinical outcomes including reduced exercise capacity and increased mortality. However, the overall research landscape and evolving trends of anemia-related studies in COPD have not been systematically characterized. Therefore, this study aimed to identify research hotspots and emerging trends in anemia-related research in COPD using a bibliometric approach, and to inform future mechanistic and clinical investigations. METHODS: Publications from 1954 to 2025 were retrieved from the Web of Science Core Collection (WOSCC) database. Bibliometric and visualization analyses were performed using R Bibliometrix to characterize publication trends, global contributions, citation patterns, and thematic evolution. RESULTS: A total of 864 English-language original research articles from 80 countries were included in the analysis. The United States and China were identified as the leading contributors, together accounting for over one-third of total publications. Early research (1954-2019) focused predominantly on epidemiologic and outcome-based themes such as "anemia", "outcomes", and "risk factors". Since 2020, the field has shifted toward integrative clinical-mechanistic directions, emphasizing "chronic kidney disease", "iron metabolism", "hypoxia", "systemic inflammation", and "comorbid complications". Co-citation analysis identified Chambellan A et al. [2005] and Anker SD et al. [2009] as cornerstone works that bridged prognostic and metabolic dimensions. Emerging trends highlight an increasing focus on multi-organ interaction models, iron homeostasis biomarkers, and translational interventions targeting anemia and systemic inflammation in COPD. CONCLUSIONS: This bibliometric analysis provides a comprehensive overview of global research on anemia in COPD, elucidating its thematic evolution from descriptive epidemiology to systemic, pathophysiology-informed investigation. The findings underscore a growing recognition of anemia as a dynamic mediator of disease progression, and point toward future research directions involving integrated comorbidity management, standardized biomarker evaluation, and mechanism-driven therapeutic strategies.