The prevalence of gastro-esophageal reflux disease and esophageal dysmotility in Chinese patients with idiopathic pulmonary fibrosis

Relationship Between Esophageal Disease and Pulmonary Fibrosis

Esophageal disorders are prevalent among patients with chronic lung diseases, including idiopathic pulmonary fibrosis (IPF). Gastroesophageal reflux disease (GERD) has been associated with IPF prevalence, severity, and respiratory decline. The pathophysiologic relationship between GERD and IPF is likely bidirectional, with aspiration of refluxate leading to lung inflammation and fibrosis, while the restrictive pulmonary physiology may contribute to altered transdiaphragmatic pressure gradient and increased reflux. Esophageal symptoms are frequently absent and do not predict esophageal dysfunction or pathologic reflux in patients with IPF, and objective diagnostic tools including upper endoscopy, ambulatory reflux monitoring, and high-resolution manometry are often needed. Impedance-based testing that identifies both weakly/non-acidic and acid reflux may provide important additional diagnostic value beyond pH-based acid testing alone. Novel metrics and maneuvers, including advanced impedance measures on impedance-pH study and provocative testing on HRM, may hold promise to future diagnostic advancements. The main treatment options include medical therapy with acid suppressants and anti-reflux surgery, although their potential benefits in pulmonary outcomes of IPF require further validations. Future directions of research include identifying phenotypes of IPF patients who may benefit from esophageal testing and treatment, determining the optimal testing strategy and protocol, and prospectively assessing the value of different esophageal therapies to improve outcomes while minimizing risks. This review will discuss the pathophysiology, evaluation, and management of esophageal diseases, particularly GERD, in patients with IPF, as informed by the most recent publications in the field, in hopes of identifying targets for future study and research.

Incidence, clinical signs, and videofluoroscopic swallow study abnormalities associated with airway penetration and aspiration in 100 dogs

BACKGROUND

Videofluoroscopic swallow studies (VFSS) utilizing penetration-aspiration (P-A) scoring assesses airway protection in people. On VFSS, penetration (ingesta or secretions immediately cranial to the vocal folds) and aspiration (material caudal to the vocal folds) are associated with increased risk of lung injury in people. Penetration-aspiration (P-A) scoring has been validated in animal models, but the incidence of P-A, clinical signs (CS), and dysphagic disorders associated with P-A in dogs are unknown.

OBJECTIVES

Using VFSS, identify the incidence of P-A, compare CS between dogs with and without P-A, and identify predisposing dysphagic abnormalities for P-A.

ANIMALS

One hundred client-owned dogs.

METHODS

Sequential VFSS and associated medical records from dogs presenting to the veterinary teaching hospitals at Auburn University (n = 53) and the University of Missouri (n = 47) were retrospectively reviewed. Statistical comparisons were made using Mann-Whitney tests, one-way analysis of variance (ANOVA) on ranks, multiple linear regression, and Spearman rank order correlation (P < .05).

RESULTS

On VFSS, the incidence of pathologic P-A was 39%. No significant differences in CS were found between dogs with or without P-A (P > .05), with 14/39 dogs with P-A presenting without respiratory CS. Pharyngeal (P < .001) and esophageal (P = .009), but not oral-preparatory (P = .2) dysphagia was more common with P-A. Pharyngeal weakness (P < .001) and esophago-oropharyngeal reflux (EOR; P = .05) were independent predictors of P-A and were moderately and weakly positively correlated with P-A score respectively (P < .001, r = 0.489; P = .04, r = 0.201).

CONCLUSIONS

Penetration-aspiration occurs in dogs in the absence of respiratory CS (i.e., occult P-A). Dogs with pharyngeal weakness and EOR should be considered at risk for P-A.

Role of Mesenchymal Stem Cells and Extracellular Vesicles in Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial fibrotic disease that leads to disability and death within 5 years of diagnosis. Pulmonary fibrosis is a disease with a multifactorial etiology. The concept of aberrant regeneration of the pulmonary epithelium reveals the pathogenesis of IPF, according to which repeated damage and death of alveolar epithelial cells is the main mechanism leading to the development of progressive IPF. Cell death provokes the migration, proliferation and activation of fibroblasts, which overproduce extracellular matrix, resulting in fibrotic deformity of the lung tissue. Mesenchymal stem cells (MSCs) and extracellular vesicles (EVs) are promising therapies for pulmonary fibrosis. MSCs, and EVs derived from MSCs, modulate the activity of immune cells, inhibit the expression of profibrotic genes, reduce collagen deposition and promote the repair of damaged lung tissue. This review considers the molecular mechanisms of the development of IPF and the multifaceted role of MSCs in the therapy of IPF. Currently, EVs-MSCs are regarded as a promising cell-free therapy tool, so in this review we discuss the results available to date of the use of EVs-MSCs for lung tissue repair.

Gastroesophageal Reflux Disease in Idiopathic Pulmonary Fibrosis: Viewer or Actor? To Treat or Not to Treat?

Background: Idiopathic pulmonary fibrosis (IPF) is a rare and severe disease with a median survival of ∼3 years. Several risk factors have been identified, such as age, genetic predisposition, tobacco exposure, and gastro-oesophageal reflux disease (GERD). Prevalence of GERD in IPF is high and may affect 87% of patients, of whom only half (47%) report symptoms. Objective: The aim of this study is to review current evidence regarding the correlation between GERD and IPF and to evaluate the current studies regarding treatments for GERD-IPF. Methods: A review to identify research papers documenting an association between GERD and IPF was performed. Results: We identified several studies that have confirmed the association between GERD and IPF, with an increased acid exposure, risk of gastric aspiration and bile acids levels in these patients. Few studies focused their attention on GERD treatment, showing how antiacid therapy was not able to change IPF evolution. Conclusions: This review investigating the correlation between GERD and IPF has confirmed the hypothesized association. However, further large prospective studies are needed to corroborate and elucidate these findings with a focus on preventative and treatment strategies.

Cough in Idiopathic Pulmonary Fibrosis

Chronic cough is experienced by most patients with idiopathic pulmonary fibrosis (IPF). It is often the first symptom and is associated with reduced quality of life, increased rates of depression and anxiety, more severe physiological impairment, and disease progression. Although not fully understood, recent gains in understanding the pathophysiology of chronic cough in IPF have been made. The pathophysiology is likely multifactorial and includes alterations in mucous production and clearance, architectural distortion, and increased cough reflex sensitivity, suggesting a role for targeted therapies and multidisciplinary treatment. Modifiable comorbidities can also induce cough in patients with IPF. There is a renewed emphasis on measuring cough in IPF, with clinical trials of novel and repurposed therapies for chronic cough emerging in this population. This review provides an update on the clinical characteristics, pathophysiology, and measurement of chronic cough in patients with IPF and summarizes recent developments in non-pharmacological and pharmacological therapies.

The upper esophageal sphincter in the high-resolution manometry era

BACKGROUND

The evaluation of the upper esophageal sphincter (UES) has been neglected during routine manometric tests for decades, mostly due to the limitations of the conventional manometry which were eventually overcome by high-resolution manometry (HRM).

METHODS

This study reviewed the current knowledge of the manometric evaluation of the UES in health and disease in the HRM era.

RESULTS

We found that HRM allowed more precise measurements, in addition to the parameters as compared to conventional manometry, but most of them still need confirmation of the clinical significance. The parameters used to evaluate the UES were extension, basal pressure, residual pressure, relaxation duration, relaxation time to nadir, recovery time, intrabolus pressure, and deglutitive sphincter resistance. UES may be affected by different diseases: achalasia (UES is hypertonic with impaired relaxation), gastroesophageal reflux disease (UES is short and hypotonic), globus (UES ranges from normal to impaired relaxation to hypertonic), neurologic diseases (stroke and Parkinson - UES is hypotonic in early-stage to impaired relaxation in end-stage disease), and Zenker's diverticulum (UES has impaired relaxation).

CONCLUSION

This review shows that UES dysfunction is part of several disease processes and that the study of the UES is possible and valuable with the aid of HRM.

Systems Biology and Bile Acid Signalling in Microbiome-Host Interactions in the Cystic Fibrosis Lung

The study of the respiratory microbiota has revealed that the lungs of healthy and diseased individuals harbour distinct microbial communities. Imbalances in these communities can contribute to the pathogenesis of lung disease. How these imbalances occur and establish is largely unknown. This review is focused on the genetically inherited condition of Cystic Fibrosis (CF). Understanding the microbial and host-related factors that govern the establishment of chronic CF lung inflammation and pathogen colonisation is essential. Specifically, dissecting the interplay in the inflammation–pathogen–host axis. Bile acids are important host derived and microbially modified signal molecules that have been detected in CF lungs. These bile acids are associated with inflammation and restructuring of the lung microbiota linked to chronicity. This community remodelling involves a switch in the lung microbiota from a high biodiversity/low pathogen state to a low biodiversity/pathogen-dominated state. Bile acids are particularly associated with the dominance of Proteobacterial pathogens. The ability of bile acids to impact directly on both the lung microbiota and the host response offers a unifying principle underpinning the pathogenesis of CF. The modulating role of bile acids in lung microbiota dysbiosis and inflammation could offer new potential targets for designing innovative therapeutic approaches for respiratory disease.

The Perils and Pitfalls of Esophageal Dysmotility in Idiopathic Pulmonary Fibrosis

INTRODUCTION

Gastroesophageal reflux plays a significant role in idiopathic pulmonary fibrosis (IPF). Given the morbidity and mortality associated with IPF, understanding the mechanisms responsible for reflux is essential if patients are to receive optimal treatment and management, especially given the lack of clear benefit of antireflux therapies. Our aim was to understand the inter-relationships between esophageal motility, lung mechanics and reflux (particularly proximal reflux-a prerequisite of aspiration), and pulmonary function in patients with IPF.

METHODS

We prospectively recruited 35 patients with IPF (aged 53-75 years; 27 men) who underwent high-resolution impedance manometry and 24-hour pH-impedance, together with pulmonary function assessment.

RESULTS

Twenty-two patients (63%) exhibited dysmotility, 16 (73%) exhibited ineffective esophageal motility (IEM), and 6 (27%) exhibited esophagogastric junction outflow obstruction. Patients with IEM had more severe pulmonary disease (% forced vital capacity: P = 0.032) and more proximal reflux (P = 0.074) than patients with normal motility. In patients with IEM, intrathoracic pressure inversely correlated with the number of proximal events (r = -0.429; P = 0.098). Surprisingly, inspiratory lower esophageal sphincter pressure (LESP) positively correlated with the percentage of reflux events reaching the proximal esophagus (r = 0.583; P = 0.018), whereas in patients with normal motility, it inversely correlated with the bolus exposure time (r = -0.478; P = 0.098) and number of proximal events (r = -0.542; P = 0.056). % forced vital capacity in patients with IEM inversely correlated with the percentage of reflux events reaching the proximal esophagus (r = -0.520; P = 0.039) and inspiratory LESP (r = -0.477; P = 0.062) and positively correlated with intrathoracic pressure (r = 0.633; P = 0.008).

DISCUSSION

We have shown that pulmonary function is worse in patients with IEM which is associated with more proximal reflux events, the latter correlating with lower intrathoracic pressures and higher LESPs.

Gastroesophageal Reflux Disease and Idiopathic Lung Fibrosis. From Heartburn to Lung Transplant, and Beyond

Idiopathic pulmonary fibrosis (IPF) and gastroesophageal reflux disease (GERD) are undoubtedly related. Even though it is not clear yet which one is the primary disease, they certainly interact increasing each other's severity. Symptoms are unreliable to diagnose GERD in patients with IPF, and objective evaluation with pH monitoring and/or bronchoalveolar lavage analysis is mandatory. Pharmacological treatment with proton pump inhibitors (PPIs) may bring control of IPF in few patients, but PPIs do not control reflux but just change the pH of the gastric refluxate. Surgical therapy based on a fundoplication is safe and effective as it controls any type of reflux, independently from the pH of the gastric refluxate. In patients waiting for lung transplantation (if they can tolerate a laparoscopic operation under general anesthesia), a fundoplication before the operation might block the progression of IPF, while after transplantation it might prevent rejection by preventing the bronchiolitis obliterans syndrome.

Idiopathic pulmonary fibrosis and gastroesophageal reflux disease: A population-based, case-control study

BACKGROUND

It is unknown whether gastroesophageal reflux disease (GERD) is a risk factor or consequence of idiopathic pulmonary fibrosis (IPF). This study aimed to determine whether patients with IPF were more likely to have GERD compared with age- and sex-matched controls who either had 1) interstitial lung disease (ILD) other than IPF or 2) no diagnosed lung disease (population control).

METHODS

We used the medical records-linkage system of the Rochester Epidemiology Project (REP) to identify patients with IPF who resided in Olmsted County, Minnesota, from January 1, 1997, through June 30, 2017. IPF cases were each matched with patients from 2 control groups (non-IPF ILD controls and population controls). We used conditional logistic regression to model associations between GERD diagnosis and IPF case status. P values were adjusted for multiple comparisons by using the Bonferroni adjustment (P values < .025 were considered statistically significant).

RESULTS

One hundred thirteen IPF cases were identified and matched to 226 population controls and 226 controls with non-IPF ILD. After multivariable adjustment, the odds of having GERD were 1.78 times higher (95% CI, 1.09-2.91; P = .02) in IPF cases compared with population controls. After multivariable adjustment, the odds of having GERD were 0.46 times lower (95% CI, 0.23-0.94; P = .03) in IPF cases compared with non-IPF ILD controls.

CONCLUSION

GERD may be an important contributor to the development of lung fibrosis. Thus, it should be investigated and addressed adequately when detected in patients with IPF and patients with non-IPF ILD.

Reflux Aspiration Associated with Oesophageal Dysmotility but Not Delayed Liquid Gastric Emptying

INTRODUCTION

Severe oesophageal dysmotility is associated with treatment-resistant reflux and pulmonary reflux aspiration. Delayed solid gastric emptying has been associated with oesophageal dysmotility; however, the role of delayed liquid gastric emptying (LGE) in the pathophysiology of severe reflux disease remains unknown. The purpose of this study is to examine the relationship between delayed LGE, reflux aspiration, and oesophageal dysmotility.

METHODS

Data were extracted from a prospectively populated database of patients with severe treatment-resistant gastro-oesophageal reflux disease. All patients with validated reflux aspiration scintigraphy and oesophageal manometry were included in the analysis. Patients were classified by predominant clinical subtype as gastro-oesophageal reflux (GOR) or laryngopharyngeal reflux. LGE time of 22 min or longer was considered delayed.

RESULTS

Inclusion criteria were met by 631 patients. Normal LGE time was found in 450 patients, whilst 181 had evidence of delayed LGE. Mean liquid half-clearance was 22.81 min. Reflux aspiration was evident in 240 patients (38%). Difference in the aspiration rates between delayed LGE (42%) and normal LGE (36%) was not significant (p = 0.16). Severe ineffective oesophageal motility (IOM) was found in 70 patients (35%) and was independent of LGE time. Severe IOM was strongly associated with reflux aspiration (p < 0.001). GOR dominant symptoms were more common in patients with delayed LGE (p = 0.03).

CONCLUSION

Severe IOM was strongly associated with reflux aspiration. Delayed LGE is not associated with reflux aspiration or severe IOM. Delayed LGE is more prevalent in patients presenting with GOR dominant symptoms.

Management of interstitial lung diseases: A consensus statement of the Indian Chest Society (ICS) and National College of Chest Physicians (NCCP)

BACKGROUND

Interstitial lung disease (ILD) is a complex and heterogeneous group of acute and chronic lung diseases of several known and unknown causes. While clinical practice guidelines (CPG) for idiopathic pulmonary fibrosis (IPF) have been recently updated, CPG for ILD other than IPF are needed.

METHODS

A working group of multidisciplinary clinicians familiar with clinical management of ILD (pulmonologists, radiologist, pathologist, and rheumatologist) and three epidemiologists selected by the leaderships of Indian Chest Society and National College of Chest Physicians, India, posed questions to address the clinically relevant situation. A systematic search was performed on PubMed, Embase, and Cochrane databases. A modified GRADE approach was used to grade the evidence. The working group discussed the evidence and reached a consensus of opinions for each question following face-to-face discussions.

RESULTS

Statements have been made for each specific question and the grade of evidence has been provided after performing a systematic review of literature. For most of the questions addressed, the available evidence was insufficient and of low to very low quality. The consensus of the opinions of the working group has been presented as statements for the questions and not as an evidence-based CPG for the management of ILD.

CONCLUSION

This document provides the guidelines made by consensus of opinions among experts following discussion of systematic review of evidence pertaining to the specific questions for management of ILD other than IPF. It is hoped that this document will help the clinician understand the accumulated evidence and help better management of idiopathic and nonidiopathic interstitial pneumonias.

Idiopathic pulmonary fibrosis and GERD: links and risks

Gastroesophageal reflux disease (GERD) and idiopathic pulmonary fibrosis (IPF) are two pathological conditions often strictly related, even if a clear relationship of causality has not been demonstrated. GERD is a frequent comorbidity in IPF patients, as demonstrated using combined multichannel intraluminal impedance-pH, despite being mostly clinically silent. According to that, it has been hypothesized that microaspiration of gastric material may play a fundamental role in the fibrotic transformation of pulmonary parenchyma. In contrast, it cannot be excluded that IPF may favor GERD by increasing the negative intrathoracic pressure. Therefore, this relationship is uncertain as well as not univocal. Nevertheless, the latest international guidelines recommend the use of proton pump inhibitors (PPIs) in IPF based on several data showing that PPIs can stabilize lung function, reduce disease flares and hospitalizations. On the contrary, recent studies not only question the relevance of these results, but also associate the use of PPIs with an increased risk of lung infections and a negative prognostic outcome. The aim of this review is to analyze the possible links between GERD and IPF and their possible therapeutic implications, trying to translate this scientific evidence into useful information for clinical practice.

Gastric Acid and Pepsin Work Together in Simulated Gastric Acid Inhalation Leading to Pulmonary Fibrosis in Rats

Background

The clinical association between gastroesophageal reflux disease (GERD) and idiopathic pulmonary fibrosis (IPF) has been known for many years, but it is still unclear. The present study investigated the association between experimentally simulated aspiration and pulmonary fibrosis.

Material/Methods

A total of 120 male Sprague-Dawley rats were randomly divided into a negative control group, a bleomycin group, and 3 simulated aspiration groups. The bleomycin group was administered a one-time intratracheal injection of bleomycin, whereas the 3 simulated aspiration groups were treated either with an intratracheal instillation of gastric fluid combined with pepsin, with pepsin alone, or with hydrochloric acid, all twice a week, and the negative control group was administered normal saline twice a week. Lung tissues were collected to evaluate pathological changes and the mRNA expression levels of connective tissue growth factor (CTGF), type I collagen, and transforming growth factor.

Results

The results demonstrated that the degree of fibrosis in the early stage was low in each of the 3 simulated aspiration groups, but gradually increased over time. The expression levels of the downstream factor of fibrosis, CTGF, and type I collagen also reflected this trend.

Conclusions

The study demonstrates that aspiration of gastric contents can cause pulmonary fibrosis, and mixed aspiration of pepsin and gastric fluid can accelerate this process. This study provides strong evidence in support of a potential association between human GERD and IPF.

Stem Cell-Based Therapies and Tissue Engineering of Trachea as Promising Therapeutic Methods in Mustard Gas Exposed Patients

Tissue engineering and cell-based therapies are promising therapeutic approaches in structural and functional defects of the trachea. Researchers have focused on these approaches to overcome the complications related to such diseases. Patients exposed to mustard gas suffer from massive damage to the respiratory system. Current treatment plans are only palliative and include anti-inflammatory drugs, broncholytics, long-acting β2-agonists, and inhaled corticosteroids. As mustard gas exposure leads to chronic airway inflammation, it seems that tracheobronchomalacia, because of chronic inflammation and weakness of the supporting cartilage, is an important factor in the development of chronic and refractory respiratory symptoms. The previous studies show that regenerative medicine approaches have promising potential to improve the life quality of patients suffering from tracheal defects. It seems that the engineered tracheal graft may improve the respiratory function and decrease symptoms in patients who suffer from asthma-like attacks due to mustard gas exposure. There are several successful case reports on the transplantation of stem cell-based bioartificial grafts in structural airway diseases. Therefore, we hope that the reconstruction of tracheobronchial structure can lead to a decrease in respiratory difficulties in mustard gas-exposed patients who suffer from tracheomalacia. In the present review, we summarize the main aspects of tracheal tissue engineering and cell-based therapies and the possibilities of the application of these approaches in mustard gas-exposed patients.

Gastroesophageal Reflux Disease in Idiopathic Pulmonary Fibrosis: Uncertainties and Controversies

The mechanisms of idiopathic pulmonary fibrosis (IPF), a rare, devastating disease with a median survival of 3-5 years, are not fully understood. Gastroesophageal reflux disease (GERD) is a frequent comorbidity encountered in IPF. Hypothetically, GERD-associated microaspiration may lead to persistent inflammation impairing lung infrastructure, thereby possibly accelerating the progression of IPF. IPF may increase intrathoracic pressure, which can aggravate GERD and vice versa. On the basis of the possible beneficial effects of antireflux or antacid therapy on lung function, acute exacerbation, and survival, the recent international IPF guideline recommends antacid therapies for patients with IPF, regardless of symptomatic GERD. However, due to newer conflicting data, several national guidelines do not support this recommendation. Elucidation of these questions by further clinical and bench-to-bedside research may provide us with rational clinical diagnostic and therapeutic approaches concerning GERD in IPF. The present review aims to discuss the latest data on the controversial association of IPF and GERD.

Idiopathic Pulmonary Fibrosis: Novel Concepts of Proton Pump Inhibitors as Antifibrotic Drugs

The prevalence of abnormal acid gastroesophageal reflux (GER) is higher in patients with idiopathic pulmonary fibrosis (IPF) than in matched control subjects. Several studies demonstrated that more than one-third of patients with IPF have abnormal esophageal acid exposures. In addition, many of these studies indicate that the majority of patients with IPF have silent reflux with no symptoms of GER. Findings of abnormal reflux persist in a large proportion of patients with IPF placed on antacid therapy such as proton pump inhibitors (PPIs). This seemingly paradoxical observation suggests that either patients with IPF are somehow resistant to PPI-based intervention or PPIs are inherently unable to suppress acid GER. By contrast, patients with IPF who undergo Nissen fundoplication surgery are effectively relieved from the complications of GER, and retrospective studies suggest improved lung function. Retrospective, anecdotal data suggest a beneficial role of PPIs in IPF including stabilization of lung function, reduction in episodes of acute exacerbation, and enhanced longevity. The recent evidence-based guidelines for treatment of IPF approved conditional recommendation of PPIs for all patients with IPF regardless of their GER status. Recently, we have reported that PPIs possess antiinflammatory and antifibrotic activities by directly suppressing proinflammatory cytokines, profibrotic proteins, and proliferation of lung fibroblasts. Our study provides an alternative explanation for the beneficial effect of PPIs in IPF. In this Perspective, we reviewed emerging progress on antifibrotic effect of PPIs using IPF as a disease model. In addition, we summarized surgical and pharmacological interventions for GER and their downstream effect on lung physiology.

Respiratory disease and the oesophagus: reflux, reflexes and microaspiration

Gastro-oesophageal reflux is associated with a wide range of respiratory disorders, including asthma, isolated chronic cough, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease and cystic fibrosis. Reflux can be substantial and reach the proximal margins of the oesophagus in some individuals with specific pulmonary diseases, suggesting that this association is more than a coincidence. Proximal oesophageal reflux in particular has led to concern that microaspiration might have an important, possibly even causal, role in respiratory disease. Interestingly, reflux is not always accompanied by typical reflux symptoms, such as heartburn and/or regurgitation, leading many clinicians to empirically treat for possible gastro-oesophageal reflux. Indeed, costs associated with use of acid suppressants in pulmonary disease far outweigh those in typical GERD, despite little evidence of therapeutic benefit in clinical trials. This Review comprehensively examines the possible mechanisms that might link pulmonary disease and oesophageal reflux, highlighting the gaps in current knowledge and limitations of previous research, and helping to shed light on the frequent failure of antireflux treatments in pulmonary disease.

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.