Protective Effect of Proton Pump Inhibitor for Survival in Patients with Gastroesophageal Reflux Disease and Idiopathic Pulmonary Fibrosis

BACKGROUND/AIMS: The prevalence of gastroesophageal reflux disease (GERD) is high in patients with idiopathic pulmonary fibrosis (IPF). GERD may cause chronic microaspiration that leads to repeated subclinical lung injury, which leads to pulmonary fibrosis. Although some studies have suggested that proton pump inhibitors (PPI) were associated with a good prognosis in IPF, their effects remain unclear. METHODS: We retrospectively reviewed 786 consecutive adult patients with IPF at Seoul National University Bundang Hospital between April 2003 and March 2015. RESULTS: Mean duration of follow-up was 2.6 ± 2.8 years. Of the 786 patients with IPF, 107 (13.6%) were given diagnoses of GERD, and 103 (13.1%) died due to IPF-related pneumonia or respiratory failure. The prevalence of GERD and the cumulative incidence of de novo GERD increased depending on the period of follow-up in patients with IPF. Patients administered PPI for more than four months had a lower IPF-related mortality rate than patients on PPI less than 4 months (Log-rank P-value = 0.024 in Kaplan-Meier curve). In a univariate and multivariate Cox regression hazard model, younger age (hazard ratio [HR], 1.06; 95% CI, 1.03–1.10; P = 0.001), higher initial forced vital capacity (HR, 0.98; 95% CI, 0.96–0.99; P = 0.004), and longer duration of PPI use (HR, 0.97; 95% CI, 0.95–1.00; P = 0.022), but not a diagnosis of GERD, were significantly associated with lower IPF-related mortality. CONCLUSIONS: In Korean patients with IPF, the prevalence of GERD was lower than in other countries. PPI use for at least 4 months may have a protective effect against IPF-related mortality.