Global Research Trends in Comorbidity Between Chronic Obstructive Pulmonary Disease and Gastro-Oesophageal Reflux Disease: A Bibliometric Study

Background: Chronic obstructive pulmonary disease (COPD) and gastro-oesophageal reflux disease (GERD) frequently coexist and exert bidirectional effects through inflammatory, mechanical, and neurogenic pathways. However, a systematic and integrative summary of global research trends and underlying mechanisms in this field remains lacking. Methods: Relevant publications on the comorbidity of COPD and GERD published from database inception to 2025 were retrieved from the Web of Science Core Collection. After rigorous screening, bibliometric and visualisation analyses were conducted using VOSviewer and CiteSpace to evaluate publication trends, country and institutional distributions, author collaboration networks, and keyword evolution. Highly cited papers were further examined, and recent mechanistic studies were integrated to explore the pathological connections and clinical implications of the two diseases. Results: A total of 208 relevant publications were included. The global number of publications has shown a continuous upward trend, with the United States and Europe leading in both productivity and academic influence, while Asian countries have demonstrated rapid growth. Research hotspots have shifted from epidemiological and symptom-based studies towards mechanistic investigations such as non-acid reflux, microaspiration, systemic inflammation, and Mendelian randomisation. Highly cited works, including Hurst JR (2010, NEJM) and Vogelmeier CF (2017, ERJ), have established the theoretical foundation for COPD exacerbation and comorbidity management. Mechanistically, GERD may exacerbate COPD through acid and bile reflux, oesophago–bronchial reflexes, and systemic inflammatory responses, whereas COPD-related respiratory mechanics alterations and chronic inflammation may in turn promote reflux development. Conclusion: Research on COPD–GERD comorbidity is currently evolving from clinical observation towards molecular and genetic mechanisms, reflecting a clear interdisciplinary trend. Multi-omics studies and integrated management strategies are expected to promote more precise disease phenotyping and personalised treatment. This study elucidates the developmental trajectory of COPD–GERD comorbidity research and provides a theoretical basis and research direction for the advancement of precision respiratory medicine. Keywords: chronic obstructive pulmonary disease, gastro-oesophageal reflux disease, comorbidity, bibliometric analysis