Gastroesophageal reflux disease as a comorbidity in chronic lung diseases: mechanism, clinical impacts and therapeutic uncertainty

Chronic lung diseases, particularly chronic obstructive pulmonary disease and interstitial lung disease, are major contributors to global morbidity and mortality. Gastroesophageal reflux disease (GERD) is highly prevalent in these populations and has been implicated in exacerbations and disease progression. This review examined recent guideline statements for these diseases, as well as observational, physiological, and interventional studies evaluating the association between GERD and chronic lung diseases. The prevalence of GERD in chronic lung diseases has been reported to be as high as 87%. Plausibly, GERD contributes to respiratory morbidity through microaspiration and neurogenic mechanisms. Although associations with acute exacerbations and disease progression are consistent, high-quality evidence demonstrating that GERD treatment modifies long-term pulmonary outcomes remains limited. Future research priorities include standardized diagnosis and classification of GERD phenotypes and their impact on lung disease, validated noninvasive biomarkers of microaspiration, and rigorously designed trials targeting reflux mechanisms with disease-specific endpoints.