Bronchial responsiveness during esophageal acid infusion

The Impact of Erosive Reflux Esophagitis on the Decline of Lung Function in the General Population

BACKGROUND

The impact of reflux esophagitis on the decline of lung function has been rarely reported. This study was performed to evaluate the association between erosive reflux esophagitis and lung function changes.

METHODS

We included patients with normal lung function who underwent esophagogastroduodenoscopy for health screening from a health screening center. Patients with persistent erosive reflux esophagitis on two discrete endoscopic examinations were designated as the erosive reflux esophagitis group. We also selected patients without erosive reflux esophagitis and matched them 1:4 with patients from the erosive reflux esophagitis group. We estimated annual forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC) changes from baseline and compared these estimates by the linear mixed regression model. We also estimated the biannual incidence of chronic obstructive pulmonary disease (COPD).

RESULTS

In total, 1,050 patients (210 patients with erosive reflux esophagitis, and 840 matched controls) were included. The median follow-up duration for spirometry was six years. In patients with erosive reflux esophagitis, mild reflux esophagitis (A grade) was most common (165 patients, 78.6%). The adjusted annual FEV₁ change in patients with erosive reflux esophagitis was -51.8 mL/yr, while it decreased by 46.8 mL/yr in controls (P = 0.270). The adjusted annual FVC decline was similar between the two groups (-55.8 vs. -50.5 mL/yr, P = 0.215). The estimated COPD incidence during the follow-up period was not different between the erosive reflux esophagitis and control groups.

CONCLUSION

In patients with normal lung function, the presence of erosive reflux esophagitis did not affect the annual declines in FEV₁ or FVC.

Focus on gastroesophageal reflux disease in patients with cystic fibrosis

Gastroesophageal reflux disease (GERD) is a common gastrointestinal disorder in cystic fibrosis (CF), and based on various studies, its prevalence is elevated since childhood. There are several pathogenetic mechanisms on the basis of association between CF and GERD. However, there are no specific guidelines for GERD in CF patients, so diagnosis is based on guidelines performed on patients not affected by CF. The aim of this review is to provide the pathophysiology, diagnostic and therapeutic options, complications, and future directions in the management of GERD patients with CF.

On respiratory manifestations of gastroesophageal reflux disease

One of the manifestations of gastroesophageal reflux disease (GERD) is extraesophageal symptoms, in particular, from the upper and lower respiratory tract. Gastroesophageal reflux is capable of both causing respiratory symptoms independently and aggravating the course of already existing diseases of the respiratory system. The article presents available in the literature current information on the pathogenesis of GERD respiratory symptoms, their clinical course, considerations of diagnosis and treatment.

On respiratory manifestations of gastroesophageal reflux disease

One of the manifestations of gastroesophageal reflux disease (GERD) is extraesophageal symptoms, in particular, from the upper and lower respiratory tract. Gastroesophageal reflux is capable of both causing respiratory symptoms independently and aggravating the course of already existing diseases of the respiratory system. The article presents available in the literature current information on the pathogenesis of GERD respiratory symptoms, their clinical course, considerations of diagnosis and treatment.

On respiratory manifestations of gastroesophageal reflux disease

One of the manifestations of gastroesophageal reflux disease (GERD) is extraesophageal symptoms, in particular, from the upper and lower respiratory tract. Gastroesophageal reflux is capable of both causing respiratory symptoms independently and aggravating the course of already existing diseases of the respiratory system. The article presents available in the literature current information on the pathogenesis of GERD respiratory symptoms, their clinical course, considerations of diagnosis and treatment.

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.

Response of the airways and autonomic nervous system to acid perfusion of the esophagus in patients with asthma: a laboratory study

BACKGROUND

Gastro-esophageal reflux disease (GERD) predisposes to airway disease through a vagally-mediated esophago-bronchial reflex. This study investigates this vagal response to esophageal acid perfusion.

METHODS

40 asthmatics with mild stable asthma participated. Each subject underwent spirometry and autonomic function testing (valsalva maneuver, heart rate response to deep breathing and to standing from supine position) four times: a) before intubation, b) after intubation, and then immediately after perfusion with, in random order, c) concentrated lime juice solution (pH 2-3) and d) 0.9% saline. Subjects were blinded to the solution perfused.

RESULTS

Asthmatics were of mean (SD) age 34.3 years (1.3), and 67.5% of them were females. pH monitoring demonstrated that 20 subjects had abnormal reflux and 20 did not. In each group 10 subjects had a positive GERD symptom score. Following perfusion with acid compared to saline, all subjects showed significant decreases in FEV1 and PEFR and significant increases in the mean valsalva ratio and heart rate difference on deep breathing from baseline values, but no changes in FVC or heart rate ratio on standing. There were no significant differences in any of the parameters between subjects with and without reflux.

CONCLUSIONS

Acid stimulation of the distal esophagus results in increased parasympathetic activity and concomitant broncho-constriction in asthmatics irrespective of their reflux state. This strengthens the hypothesis that GER triggers asthma-like symptoms through a vagally mediated esophago-bronchial reflex and encourages a possible role for anti-cholinergic drugs in the treatment of reflux-associated asthma.

Gastroesophageal reflux disease and pulmonary function: a potential role of the dead space extension

BACKGROUND

To evaluate the differences in the existence and size of dead space in patients with and without Gastroesophageal Reflux Disease (GERD and non-GERD) expressed through the size of intrapulmonary shunt (QS/QT).

MATERIAL/METHODS

The study enrolled 86 subjects - 43 patients referred for endoscopy because of symptoms of GERD (heartburn, acid regurgitation, dysfagia) and 43 healthy subjects with similar anthropometric characteristics without GERD symptoms. Based on endoscopy findings, patients were classified into the erosive reflux disease (ERD) group and non-erosive reflux disease (NERD) group. Spirometry values, single-breath diffusing capacity of the lung for carbon monoxide (DLCO) and intrapulmonary shunt (venous shunt - QS/QT) determined by the oxygen method were measured in all participants.

RESULTS

Statistically significant differences between GERD and non-GERD groups in FVC (p=0.034), FEV1 (p=0.002), FEV1/FVC (p=0.001), and PEF (p=0.001) were observed. There were no statistically significant differences in FEF 25% (p=0.859), FEF 50% (p=0.850), and FEF 75% (p=0.058). Values of DLCO (p=0.006) and DLCO/VA (p=0.001) were significantly lower and QS/QT was significantly higher (p=0.001) in the GERD group than in the non-GERD group. However, in both groups the average values of DLCO and DLCO/VA expressed as a percentage of predictive values were within normal range, while the value of QS/QT in the GERD group showed pathological (6.0%) mean value (normal value ≤ 5.0%). There were no significant differences in respiratory function test results between patients with ERD and NERD.

CONCLUSIONS

Our results suggest that microaspiration of stomach contents may cause surfactant damage, development of microatelectasis, and dead space expansion with consequent increase of intrapulmonary (venous) shunt.

Gastroesophageal reflux disease and airway hyperresponsiveness: concomitance beyond the realm of chance?

Gastroesophageal reflux disease and asthma are both quite common the world over, and they can coexist. However, the nature of the relationship between these two diseases remains unclear. In this study, we review controversial aspects of the relationships among asthma, airway hyperresponsiveness, and gastroesophageal reflux disease in adults and in children.

The relationship between gastroesophageal reflux and asthma: an update

Asthma and gastroesophageal reflux disease (GERD) are both common conditions and, hence, they often coexist. However, asthmatics have been found to have a much greater prevalence of GERD symptoms than the general population. There remains debate regarding the underlying physiologic mechanism(s) of this relationship and whether treatment of GERD actually translates into improved asthma outcomes. Based on smaller trials with somewhat conflicting results regarding improved asthma control with treatment of GERD, current guidelines recommend a trial of GERD treatment for symptomatic asthmatics even without symptoms of GERD. However, recently a large multicenter trial demonstrated that the treatment of asymptomatic GERD with proton-pump inhibitors did not improve asthma control in terms of pulmonary function, rate of asthma exacerbations, asthma-related quality of life, or asthma symptom frequency. These data suggest empiric treatment of asymptomatic GERD in asthmatics is not a useful practice. This review article provides an overview of the epidemiology and pathophysiologic relationships between asthma and GERD as well as a summary of current data regarding links between treatment of GERD with asthma outcomes.

Bronchial hyperreactivity in non-atopic children with asthma and reflux: effect of anti-reflux treatment

INTRODUCTION

The prevalence of bronchial hyperreactivity (BHR) or the effect of anti-reflux treatment on BHR in children with asthma and gastroesophageal reflux disease (GERD) is not known.

METHODS

Thirty non-atopic children with persistent asthma were studied. Extended esophageal pH monitoring was used to diagnose GERD and methacholine challenge test (MCT) was used as a marker of BHR and performed before and 2 years after anti-GERD treatment.

RESULTS

Of the 21 patients positive for GERD (group A), 15 had positive MCT suggesting BHR. Of the 9 patients negative for GERD (group B), 5 had positive MCT. On repeat testing 2 years later, 11/15 group A patients and 3/5 group B patients tested negative for BHR. Group A patients were receiving fewer asthma medications and experienced fewer exacerbations than Group B patients.

CONCLUSIONS

BHR is prevalent in children with asthma and GERD and improves with anti-GERD treatment.