The association of gastroesophageal reflux disease with asthma and chronic cough in the adult

Irritability and risk of lung cancer: a Mendelian randomization and mediation analysis

BACKGROUND

There is no research to prove the association between irritability and lung cancer, our study performed a Mendelian randomization (MR) approach to elucidate the causal relationship of irritability with lung cancer risk.

METHODS

Genome-wide association studies (GWAS) data of irritability, lung cancer and gastroesophageal reflux disease (GERD) were downloaded from a public database for two-sample MR analysis. Independent single-nucleotide polymorphisms (SNPs) associated with irritability and GERD were selected as instrumental variables (IVs). Inverse variance weighting (IVW) and weighted median method were used to analyze causality.

RESULTS

There is an association between irritability and lung cancer risk (ORIVW = 1.01, 95% CI = [1.00, 1.02], P = 0.018; ORweighted median = 1.01, 95% CI = [1.00, 1.02], P = 0.046), and GERD might account for about 37.5% of the association between irritability and lung cancer.

CONCLUSIONS

This study confirmed the causal effect between irritability and lung cancer through MR analysis, and found that GERD played an essential mediating role in this relationship, which can partly indicate the role of the "inflammation-cancer transformation" process in lung cancer.

Correlation between gastroesophageal reflux disease lung volumes and exacerbation of bronchial asthma: Italian pilot observational retrospective study GERDAS

Reflux asthma is an entity characterized by typical symptoms and, in some cases, is "silent"; it is more dangerous when associated with obesity and sleep apnea syndrome. Numerous studies demonstrate its high prevalence in the general population, particularly in the pediatric population, where, despite medical specialists' treatment, asthma symptoms remain poorly controlled with a high risk of acute exacerbations. This clinical study aims to show how the addition of a particular type of alginate (Deflux Plus sachets) containing hyaluronic acid and melatonin at low doses administered over a prolonged period of 6 months causes a reduction in vagal reflex stimulation of the esophagus and pulmonary microaspiration reflexes by regulating lower esophageal sphincter motility in asthmatic patients, improving the asthma control test (ATC) score. In the reported statistical analysis, receiver operating characteristic curves were performed for sensitivity and specificity for the analyzed parameters, including the ACT score, with statistically significant data p<0.0001. We conclude that combining conventional therapy for reflux asthma with alginates may improve the risk of acute asthma exacerbations and dynamic lung volumes.

Application of unsupervised deep learning algorithms for identification of specific clusters of chronic cough patients from EMR data

BACKGROUND

Chronic cough affects approximately 10% of adults. The lack of ICD codes for chronic cough makes it challenging to apply supervised learning methods to predict the characteristics of chronic cough patients, thereby requiring the identification of chronic cough patients by other mechanisms. We developed a deep clustering algorithm with auto-encoder embedding (DCAE) to identify clusters of chronic cough patients based on data from a large cohort of 264,146 patients from the Electronic Medical Records (EMR) system. We constructed features using the diagnosis within the EMR, then built a clustering-oriented loss function directly on embedded features of the deep autoencoder to jointly perform feature refinement and cluster assignment. Lastly, we performed statistical analysis on the identified clusters to characterize the chronic cough patients compared to the non-chronic cough patients.

RESULTS

The experimental results show that the DCAE model generated three chronic cough clusters and one non-chronic cough patient cluster. We found various diagnoses, medications, and lab tests highly associated with chronic cough patients by comparing the chronic cough cluster with the non-chronic cough cluster. Comparison of chronic cough clusters demonstrated that certain combinations of medications and diagnoses characterize some chronic cough clusters.

CONCLUSIONS

To the best of our knowledge, this study is the first to test the potential of unsupervised deep learning methods for chronic cough investigation, which also shows a great advantage over existing algorithms for patient data clustering.

Multi-Organ Dysfunction in Cerebral Palsy

Cerebral Palsy (CP) describes a heterogenous group of non-progressive disorders of posture or movement, causing activity limitation, due to a lesion in the developing brain. CP is an umbrella term for a heterogenous condition and is, therefore, descriptive rather than a diagnosis. Each case requires detailed consideration of etiology. Our understanding of the underlying cause of CP has developed significantly, with areas such as inflammation, epigenetics and genetic susceptibility to subsequent insults providing new insights. Alongside this, there has been increasing recognition of the multi-organ dysfunction (MOD) associated with CP, in particular in children with higher levels of motor impairment. Therefore, CP should not be seen as an unchanging disorder caused by a solitary insult but rather, as a condition which evolves over time. Assessment of multi-organ function may help to prevent complications in later childhood or adulthood. It may also contribute to an improved understanding of the etiology and thus may have an implication in prevention, interventional methods and therapies. MOD in CP has not yet been quantified and a scoring system may prove useful in allowing advanced clinical planning and follow-up of children with CP. Additionally, several biomarkers hold promise in assisting with long-term monitoring. Clinicians should be aware of the multi-system complications that are associated with CP and which may present significant diagnostic challenges given that many children with CP communicate non-verbally. A step-wise, logical, multi-system approach is required to ensure that the best care is provided to these children. This review summarizes multi-organ dysfunction in children with CP whilst highlighting emerging research and gaps in our knowledge. We identify some potential organ-specific biomarkers which may prove useful in developing guidelines for follow-up and management of these children throughout their lifespan.

Acute exacerbations of chronic obstructive pulmonary disease (COPD) experiences among COPD patients with comorbid gastrooesophageal reflux disease

AIMS AND OBJECTIVES

To explore perceptions of experience exacerbations of chronic obstructive pulmonary disease among chronic obstructive pulmonary disease patients with comorbid gastrooesophageal reflux disease by focusing on unravelling how patients differentiate and react to symptoms of chronic obstructive pulmonary disease and gastrooesophageal reflux disease.

BACKGROUND

While gastrooesophageal reflux disease has been suggested to be a risk factor for chronic obstructive pulmonary disease exacerbations, no study has explored perceptions of the symptoms leading up to severe exacerbation of chronic obstructive pulmonary disease events among chronic obstructive pulmonary disease patients with comorbid gastrooesophageal reflux disease.

DESIGN

Qualitative design.

METHODS

The analysis was performed in accordance with principles of Grounded Theory methodology. Data were collected via semi-structured interviews from 12 chronic obstructive pulmonary disease patients with endoscopy-diagnosed gastrooesophageal reflux disease who had experienced a chronic obstructive pulmonary disease exacerbation with hospitalisation. Appraisal and analysis using consolidated criteria for reporting qualitative research (COREQ) checklist were undertaken.

RESULTS

The core category of this study was the ineffective management of exacerbation symptoms, which was associated with perceived symptoms pre-exacerbation which contained three overlapping categories of symptom presentation experienced, and chronic obstructive pulmonary disease-related coping strategies, high anxiety and a sense of helplessness in disease management.

CONCLUSIONS

Patients with severe chronic obstructive pulmonary disease with comorbid gastrooesophageal reflux disease presented with some distinctly different atypical symptoms yet used common respiratory symptom management strategies. Patients and practitioners alike need to be more aware of the possibility of other symptoms such as nonspecific symptoms being clues of exacerbation onset for a more effective intervention.

RELEVANCE TO CLINICAL PRACTICE

The medical community needs to educate patients to understand and manage not only chronic obstructive pulmonary disease but also gastrooesophageal reflux disease symptoms so that they are better able to identify the cause of their symptoms, treat them appropriately and seek out medical assistance when necessary.

Gastroesophageal Reflux Disease and Pulmonary Diseases Associated with Aspergillosis: Is There a Connection?

INTRODUCTION

We studied the relationship between GORD and allergic bronchopulmonary aspergillosis (ABPA), chronic pulmonary aspergillosis (CPA), or Aspergillus bronchitis.

BACKGROUND

Gastroesophageal reflux disease (GORD) is well known to initiate or exacerbate pulmonary inflammatory conditions, inducing bronchial asthma and chronic obstructive lung disease.

METHODS

We reviewed four patients referred with elevated Aspergillus serology markers and marked pulmonary symptoms for ABPA, CPA, and Aspergillus bronchitis, and discussed the underlying pathophysiological relationship with GORD. Data were collected retrospectively from medical records included age, gender, predisposing factors for ABPA, chronic pulmonary aspergillosis, or Aspergillus bronchitis; presence of nocturnal reflux, nausea, epigastric pain, Medical Research Council dyspnea scale score, pH manometry data, endoscopic results (ulcers, Barrett's esophagus), treatment of GORD [proton-pump inhibitors (PPIs), surgical operation]; history of smoking, alcohol consumption; concomitant COPD; serological markers (anti-Aspergillus IgG, anti-Aspergillus IgE), and antifungal treatment.

RESULTS

Four patients with GORD were studied; following PPIs administration two achieved clinical improvement. One had ABPA, one CPA, and two had Aspergillus bronchitis; median age was 57 years [range 39-71]; males-to-females ratio was 1:3. Serological markers for aspergillosis were: median total IgE antibodies 573 KIU/L [range 13.1-850], median Aspergillus IgE-specific antibodies 1.2 kAU/L [range <0.4-24.7], and median Aspergillus IgG titers 71 mg/L [range 20-119]. Aspergillus fumigatus grew in one sputum sample.

CONCLUSION

Clinicians caring for patients with gastroesophageal reflux disease presenting with elevated Aspergillus IgG or IgE antibodies should maintain a high index of suspicion for this association and proceed to appropriate evaluations, including laryngoscopy and endoscopy, initiating specific PPI-directed therapy when indicated.

Helicobacter pylori-Mediated Protection against Extra-Gastric Immune and Inflammatory Disorders: The Evidence and Controversies

A large number of studies link H. pylori infection with a reduced risk of developing extra-gastric conditions such as allergy, asthma, inflammatory bowel disease, coeliac disease and multiple sclerosis. The strength of the evidence for these protective associations is quite variable, and published studies often do not agree. This review article discusses some of the reasons for these discrepancies, and the difficulties faced when designing studies. Examples of some protective disease associations are described in detail, where the evidence is most abundant and thought to be more reliable. The most convincing of these are supported by published mechanistic data, for example with animal models, or incidence of disease exacerbation in humans following H. pylori eradication. Although controversial, this field is very important as the prevalence of H. pylori is decreasing throughout the world whilst many chronic diseases are becoming more common. These trends are likely to continue in the future, therefore it is important that we fully understand if and how H. pylori confers protection.

Gastroesophageal reflux-associated aspiration alters the immune response in asthma

BACKGROUND

A large number of studies point toward chronic aspiration associated with gastroesophageal reflux disease (GERD) as an important factor involved in the development of asthma, the incidence of which has increased dramatically in industrially developed countries. Recent work suggests that medical intervention aimed at acid blockade is not sufficient to relieve the effects of chronic aspiration on asthma pathology, leaving surgical treatment of the disease as one of the few remaining options. This study examined the effect of chronic aspiration on the airway-associated immune response to allergens using a model of experimentally induced airway hypersensitivity in Balb/c mice.

METHODS

The mice received aspiration of gastric fluid on days 1, 8, 15, 22, 29, 36, 43, and 50 and were sensitized to ovalbumin by intraperitoneal (IP) injection on days 33 and 47, challenged with aerosolized ovalbumin on day 54, and killed on day 56. Control mice received sham gastric fluid aspirations, sham induction of airway hypersensitivity, or both.

RESULTS

Chronic aspiration of 50 microl murine gastric fluid once per week for 8 weeks had a profound effect on the immune system in the lung, with upregulation of the macrophage/monocyte-associated cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-12 (IL-12) and profound downregulation of a broad array of T-cell-associated cytokines including interleukins 2, 4, 5, 6, 10, 13, and 23, as well as interferon-gamma. The aspiration-induced depression of IL-5 production in particular was found only in mice with airway hypersensitivity and not in control mice without airway hypersensitivity.

CONCLUSIONS

The results indicate that chronic aspiration of gastric fluid has a profound effect on the nature of the allergic response to aerosolized allergens, suggesting that the aspiration may be an important factor affecting the pathogenesis of asthma.

Pulmonary manifestations of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) may cause, trigger or exacerbate many pulmonary diseases. The physiological link between GERD and pulmonary disease has been extensively studied in chronic cough and asthma. A primary care physician often encounters patients with extra esophageal manifestations of GERD in the absence of heartburn. Patients may present with symptoms involving the pulmonary system; noncardiac chest pain; and ear, nose and throat disorders. Local irritation in the esophagus can cause symptoms that vary from indigestion, like chest discomfort and abdominal pain, to coughing and wheezing. If the gastric acid reaches the back of the throat, it may cause a bitter taste in the mouth and/or aspiration of the gastric acid into the lungs. The acid can cause throat irritation, postnasal drip and hoarseness, as well as recurrent cough, chest congestion and lung inflammation leading to asthma and/or bronchitis/ pneumonia. This clinical review examines the potential pathophysiological mechanisms of pulmonary manifestations of GERD. It also reviews relevant clinical information concerning GERD-related chronic cough and asthma. Finally, a potential management strategy for GERD in pulmonary patients is discussed.

Esophageal manometry and 24-h esophageal pH-metry in a large sample of patients with respiratory symptoms

OBJECTIVE

To determine the prevalence of gastroesophageal reflux disease (GERD) and to evaluate the esophageal motor profile of patients with respiratory symptoms referred to a digestive motility referral center for esophageal function testing.

METHODS

The results of esophageal manometry and 24-h esophageal pH-metry were analyzed.The inclusion criterion was presenting respiratory symptoms, with or without accompanying digestive symptoms.

RESULTS

Of the 1,170 patients included in the study, 602 (51.5%) reported having digestive and respiratory symptoms (DRS group), and 568 (48.5%) reported having only respiratory symptoms (RS group). Asthma was diagnosed in 142 patients in the RS group (RS-A subgroup) and in 201 of those in the DRS group (DRS-A). Of the 346 cases of esophageal dysmotility, hypomotility was found in 175 (14.3% and 15.6% in the DRS and RS groups, respectively), and lower esophageal sphincter (LES) hypotonia was found in 411 (40.3% and 30.2%, respectively). Hypotonia correlated with GERD. Exposure of the distal esophagus to acid was markedly abnormal in the supine position. The prevalence of GERD in the sample as a whole, the RS-A/DRS-A subgroups and the RS-A subgroup alone was 39.8%, 44.0% and 35.2%, respectively

CONCLUSIONS

Hypotonic LES was the most common abnormality and correlated with GERD. Although GERD was more evident in the DRS group, approximately one third of the patients in the RS group also presented GERD (silent GERD). The findings suggest that GERD can be an extrapulmonary cause of chronic respiratory symptoms unresponsive to conventional therapy.

Chronic aspiration shifts the immune response from Th1 to Th2 in a murine model of asthma

BACKGROUND

Chronic aspiration associated with gastro oesophageal reflux disease (GERD) is thought to play a substantial role in the development of asthma, the incidence of which is dramatically increasing in industrially developed countries. The majority of data examining the association between aspiration and asthma has been obtained from epidemiological studies, which show that between 50 and 90% of individuals with asthma experience some element of GERD. This study describes the effect of chronic aspiration on a model of experimentally induced airway hypersensitivity in Balb/c mice.

MATERIALS AND METHODS

Four experimental groups were utilized: Aspiration/Asthma, Sham/Asthma, Aspiration/Sham and Sham/Sham. Mice were sensitized with aerosolized 1% ovalbumin on days 1 to 10 (sensitization phase), followed by repeated exposure on days 31 to 40 (challenge phase). Aspiration events occurred on days 1, 8,15, 22, 29, 36, 43 and 50. Animals were sacrificed on days 56 and 57.

RESULTS

Chronic aspiration of 10 microL of murine gastric fluid per week for eight weeks produced an injury pattern distinct from that of acute aspiration, with lung injury characterized by hyperplasia, neutrophil infiltration of the bronchioles and relative parenchymal sparing. Aspiration during induction of ovalbumin-induced airway hypersensitivity was associated with a trend toward decreased production of antiovalbumin IgG, antiovalbumin IgE, and total IgE. Further, aspiration induced a substantial and significant increase in antiovalbumin IgG1/IgG2a ratios, consistent with a shift toward a predominantly Th2 response.

CONCLUSION

These findings indicate that chronic aspiration has a profound effect on the nature of the immune response to aerosolized allergens in a model of experimentally induced airway hypersensitivity.

Sleep quality in asthma: results of a large prospective clinical trial

RATIONALE

Previous studies have suggested that asthmatics have an increased incidence of sleep disturbances. However, these studies have been limited by reliance on population surveys or small numbers of participants.

OBJECTIVES

We sought to measure sleep quality and daytime sleepiness in a cohort of symptomatic asthmatics and to measure the effects of improved asthma control on sleep quality.

METHODS

Data were collected in sub-study of a large multi-center randomized double-masked controlled trial of mild-moderate asthmatics evaluating the effect of low-dose theophylline on asthma control in comparison to montelukast and placebo. Each participant was administered sleep symptom questionnaires at randomization and at the final visit (6 months after randomization). These included the Pittsburgh Sleep Quality Questionnaire (PSQI) and the Epworth Sleepiness Scale (ESS).

MEASUREMENTS AND MAIN RESULTS

Data were available for 487 participants. Baseline mean values were: age 40 +/- 15 years, 74% female, forced expiratory volume in 1 second (FEV(1)) 79 +16 percent predicted, Juniper Asthma Control Questionnaire (ACQ) score 2.35 +/- 0.63, PSQI 7.8 +/-4, and ESS 8.5 +/-4.9. There were no significant differences in the PSQI or ESS between the three treatment groups. Significant correlations were found at baseline between the global PSQI score and ACQ and quality of life and marginally with lung function. Significant correlation existed between improvements in PSQI and ESS with improved asthma control and quality of life.

CONCLUSIONS

Sleep disturbances are common in asthmatics and are associated with asthma control and quality of life. Clinicians caring for asthmatics may need to complete a more detailed sleep history in patients with poorly controlled asthma. In addition, low-dose theophylline does not seem to impair sleep quality in asthmatics.

Review article: respiratory manifestations of gastro-oesophageal reflux disease

BACKGROUND

Respiratory manifestations represent one of the most prevalent and difficult-to-manage extra-oesophageal syndromes of gastro-oesophageal reflux disease.

AIMS

To review the epidemiology, pathophysiological mechanisms and therapeutic outcomes of reflux-related respiratory disorders.

METHODS

Search of the literature published in English using PubMed database.

RESULTS

There is a discrepancy between the high prevalence of reflux in asthmatics and the limited efficacy of antireflux therapies. Asthma per se may cause reflux. Patients with difficult-to-treat asthma and/or nocturnal symptoms should be screened for reflux. Reflux can induce chronic cough through different mechanisms including micro-aspiration and both local and central reflexes. Cough and reflux may precipitate each other. A meta-analysis found no significant difference between placebo and proton pump inhibitors in the resolution of cough. Encouraging results have been reported, following antireflux surgery in patients selected on the basis of pH-impedance monitoring. Attention has been drawn to obstructive sleep apnoea syndrome.

CONCLUSIONS

The role of gastro-oesophageal reflux disease in the pathogenesis of miscellaneous respiratory disorders has been discussed for decades and established in asthma and cough. However, no major therapeutic advances have been reported recently. Future trials should concentrate on patient selection and the control of efficacy using recently developed technologies, such as pH-impedance monitoring.

Evaluation of pantoprazol treatment response of patients with asthma and gastroesophageal reflux: a randomized prospective double-blind placebo-controlled study

OBJECTIVES

To determine the effect that the treatment of GERD has on the clinical management, as well as the respiratory function, of patients with asthma and to evaluate the clinical characteristics of this group of patients.

METHODS

Patients with asthma and concomitant GERD, documented using 24 h pH-metry, were evaluated by means of quality of life questionnaires, as well as questionnaires related to respiratory and digestive symptoms. In addition, esophageal manometry, spirometry and the determination of peak expiratory flow were also performed prior to and after the study. Forty-nine individuals who were diagnosed with GERD by means of 24 h esophageal pH-metry were selected and participated in a clinical randomized double-blind placebo-controlled study, involving the administration of 40 mg/day of pantoprazol for 12 consecutive weeks.

RESULTS

Forty-four individuals completed the study (n = 22 per group). There was significant improvement in the scores for respiratory symptoms and quality of life only in the group that received pantoprazol (p = 0.01 and p = 0.001, respectively). No respiratory function parameters changed in either group.

CONCLUSIONS

In this study, the effective treatment of GERD improved patient quality of life, and the symptoms of asthma significantly decreased in the group that received the medication. There were no changes in pulmonary function parameters.

Ability to control persistent asthma in obese versus non-obese children enrolled in an asthma-specific disease management program (breathmobile)

To determine if asthma control was more difficult to achieve in obese versus non-obese asthmatic children, retrospective analysis was performed on obese and non-obese Los Angeles inner-city children (2 to 18 years of age) with persistent asthma. No difference in time required to achieve control of asthma, ability to maintain control of asthma, baseline pulmonary functions, and number of controllers prescribed was found between the two groups. We conclude that in a Los Angeles inner-city pediatric population, obesity is not a factor in the ability to control asthma.

A meta-analysis of the effect of high weight on asthma

BACKGROUND

Prevalence rates for both overweight and asthma have been increasing among children in developed countries over the past two decades. Some recent studies have postulated a causal relation between these but have lacked power to form a definitive conclusion.

AIM

To estimate the effect of high body weight in childhood on the future risk of asthma.

METHODS

Medline search (1966 to October 2004), supplemented by manual search of reference lists and grey literature. Cohort studies that examined high body weight at birth or during childhood and future outcome of asthma were included. Data from each study were extracted on exposure status, clinical outcome, and study characteristics.

RESULTS

A total of 402 studies were initially identified, of which 12 met the inclusion criteria. The combined results from four studies that examined the effect of high body weight during middle childhood on the outcome of subsequent asthma showed a 50% increase in relative risk (RR 1.5, 95% CI 1.2 to 1.8). The combined results from nine studies that examined the effect of high birth weight on subsequent asthma had a pooled RR of 1.2 (95% CI 1.1 to 1.3). There was consistency among the results in sensitivity analyses examining studies containing only estimates of odds ratios, studies containing only the outcome of physician diagnosis of asthma, and studies including all definitions of high body weight.

CONCLUSIONS

Children with high body weight, either at birth or later in childhood, are at increased risk for future asthma. Potential biological mechanisms include diet, gastro-oesophageal reflux, mechanical effects of obesity, atopy, and hormonal influences. Further research might elucidate the causal pathway, which could improve our understanding of the pathophysiology of asthma and perhaps lead to knowledge of potential preventive interventions.

Activation of the nociceptin/orphanin FQ receptor reduces bronchoconstriction and microvascular leakage in a rabbit model of gastroesophageal reflux

1. Nociceptin/orphanin FQ (N/OFQ) is the endogenous peptide ligand for a specific G-protein coupled receptor, the N/OFQ peptide receptor (NOP). The N/OFQ-NOP receptor system has been reported to play an important role in pain, anxiety and appetite regulation. In airways, N/OFQ was found to inhibit the release of tachykinins and the bronchoconstriction and cough provoked by capsaicin. 2. Here we evaluated the effects of NOP receptor activation in bronchoconstriction and airway microvascular leakage induced by intraesophageal (i.oe.) hydrochloric acid (HCl) instillation in rabbits. We also tested the effects of NOP receptor activation in SP-induced plasma extravasation and bronchoconstriction. 3. In anesthetized New Zealand rabbits bronchopulmonary function (total lung resistance (R(L)) and dynamic compliance (C(dyn))) and airway microvascular leakage (extravasation of Evans blue dye) were evaluated. 4. Infusion of i.oe. HCl (1 N) led to a significant increase in bronchoconstriction and plasma extravasation in the main bronchi and trachea of rabbits pretreated with propranolol, atropine and phosphoramidon. 5. Bronchoconstriction and airway microvascular leakage were inhibited by N/OFQ (3-30 microg kg(-1) i.v.) in a dose-dependent manner. The NOP receptor agonist [Arg14,Lys15]N/OFQ mimicked the inhibitory effect of N/OFQ, being 10-fold more potent, UFP-101, a peptide selective NOP receptor antagonist, blocked the inhibitory effects of both agonists. 6. Under the same experimental conditions, N/OFQ and [Arg14,Lys15]N/OFQ did not counteract the bronchoconstriction and airway microvascular leakage induced by substance P. 7. These results suggest that bronchoconstriction and airway plasma extravasation induced by i.oe. HCl instillation are inhibited by activation of prejunctional NOP receptors.