Cough and gastro-oesophageal reflux disease

Efficacy and Safety of Ojeok-San Plus Saengmaek-San for Gastroesophageal Reflux-Induced Chronic Cough: A Pilot, Randomized, Double-Blind, Placebo-Controlled Trial

Introduction: Gastroesophageal reflux-induced chronic cough (GERC) is one of the most common etiologies of chronic cough. Despite the growing prevalence and interest in GERC, no effective treatment is currently available. In our study, we used a combination of herbal medicines, Ojeok-san (OJS) plus Saengmaek-san (SMS), for the treatment of GERC. Methods: We conducted a pilot, randomized, placebo-controlled, parallel-arm, single-center clinical trial to assess the feasibility of our study protocol, as our study is the first herbal medicine trial for GERC. All enrolled participants were randomly assigned to either the intervention or placebo group in a 1:1 ratio and were administered trial drugs three times a day for 6 weeks, with an evaluation visit performed every 2 weeks for their efficacy and safety assessment until the follow-up visit (week 8). We evaluated the severity and frequency of cough, cough-specific quality of life, airway hypersensitivity, and reflux-related gastrointestinal symptoms, as well as pattern identification, to investigate the complex mechanisms of reflux cough syndrome. Results: A total of 30 participants were enrolled, and 25 completed the study at Kyung Hee University Korean Medicine Hospital from 26 December 2018 to 31 May 2021. OJS plus SMS significantly improved the cough diary score (CDS), cough visual analog scale, Korean version of the Leicester Cough Questionnaire, Hull Airway Reflux Questionnaire, and Gastrointestinal Symptom Rating Scale after the treatment compared to the baseline. Notably, OJS plus SMS showed significant efficacy in the daytime and total CDS compared with the placebo. Only one adverse event was observed during the trial, and no serious adverse events occurred. Additionally, we achieved successful results in feasibility outcomes by exceeding the ratio of 80%. Conclusion: We confirmed the feasibility of our trial design and demonstrated the potential of OJS plus SMS in relieving the severity of cough and GI symptoms in GERC patients with safe and successful feasibility results. We anticipate that our study results will be used as the basis for further large-scale, well-designed, confirmatory trials to evaluate the safety and efficacy of OJS plus SMS in GERC. Clinical Trial Registration: [https://cris.nih.go.kr], identifier WHO International Clinical Trials Registry Platform, Clinical Research Information Service [KCT0003115].

Clinical characteristics, treatment patterns, disease burden, and persistence/adherence in patients with asthma initiating inhaled triple therapy: real-world evidence from Japan

Objectives: To help optimize triple therapy use, treatment patterns and disease burden were investigated in patients in Japan with persistent asthma who initiated multi-inhaler triple therapy (inhaled corticosteroid/long-acting β₂-agonist/long-acting muscarinic antagonist; ICS/LABA/LAMA).Methods: This retrospective, observational cohort study using health insurance claims data included adults with persistent asthma who initiated triple therapy in 2016. Patients who were prescribed ICS/LABA in 2016 were included as an ICS/LABA-matched cohort. Patients were stratified into those with asthma only and those with asthma and chronic obstructive pulmonary disease (COPD) codes (asthma-COPD overlap [ACO]). Patient data from 1-year prior to 1 year post index date were analyzed.Results: For patients with asthma only in the triple therapy and ICS/LABA cohorts, baseline demographics were similar. A higher proportion of the triple-therapy cohort than the ICS/LABA cohort was receiving high-dose ICS at index (68.2% and 27.6%, respectively), and had experienced an exacerbation in the last year (64.0% and 29.4%, respectively). The proportion of patients with asthma only who developed any exacerbation was lower in the year following initiation of triple therapy compared with the year prior to initiation of triple therapy (45.8% vs 64.0%, respectively). For asthma only patients receiving triple therapy, the mean (standard deviation) proportion of days covered and medication possession ratio was 0.51 (0.36) and 0.86 (0.16), respectively. Similar trends were seen in patients with ACO in the triple-therapy and ICS/LABA cohorts.Conclusion: Evidence from this study may serve as a reference for the use of inhaled triple therapy for asthma.

Esophageal Clearance in Laryngopharyngeal Reflux Disease: Correlation of Reflux Scintigraphy and 24-hour Impedance/pH in a Cohort of Refractory Symptomatic Patients

Objectives

The role of gastroesophageal reflux disease (GERD) in the aetiology of laryngopharyngeal reflux (LPR) is poorly understood and remains a controversial issue. The 24-hour impedance monitoring has shown promise in the evaluation of LPR but is problematic in pharyngeal recording. We have shown the utility of scintigraphic studies in the detection of LPR and lung aspiration of refluxate. Correlative studies were obtained in patients with a strong history of LPR and severe GERD.

Methods

A highly selected sequential cohort of patients with a high pre-test probability of LPR/severe GERD who had failed maximal medical therapy were evaluated with 24-hour impedance/pH, manometry and scintigraphic reflux studies.

Results

The study group comprised 34 patients (15 M, 19 F) with a mean age of 56 years (range: 28-80 years). The majority had LPR symptoms (mainly cough) in 31 and severe GERD in 3. Impedance bolus clearance and pH studies were abnormal in all patients in the upright and supine position. A high rate of non-acid GERD was detected by impedance monitoring. LOS tone and ineffective oesophageal clearance were found in the majority of patients. Scintigraphic studies showed strong correlations with impedance, pH and manometric abnormalities, with 10 patients showing pulmonary aspiration.

Conclusion

Scintigraphic studies appear to be a good screening test for LPR and pulmonary aspiration as there is direct visualisation of tracer at these sites. Impedance studies highlight the importance of non-acidic reflux and bolus clearance in the causation of cough and may allow the development of a risk profile for pulmonary aspiration of refluxate.

Clinical impact of gastroesophageal reflux disease in patients with subacute/chronic cough

BACKGROUND

While gastroesophageal reflux disease (GERD) is one of the commonest causes of subacute/chronic cough along with cough-variant asthma (CVA) and rhinosinusitis, its clinical impact remains unknown. Therefore, we sought to investigate the impact of GERD in patients with subacute/chronic cough.

METHODS

Between April 2012 and March 2018, a total of 312 patients presenting subacute or chronic cough lasting for ≥3 weeks [median cough duration, 4.9 (0.7-434) months] underwent diagnostic tests. GERD symptoms and cough-specific QoL were evaluated through the Frequency Scale for Symptoms of Gastroesophageal reflux (FSSG) and the Japanese version of the Leicester Cough Questionnaire (J-LCQ). According to the FSSG domains, patients with GERD were arbitrarily categorized into 3 groups; acid-reflux predominant, dysmotility predominant, and pauci-symptoms groups, respectively.

RESULTS

The average scores of J-LCQ was 12.5 (SD3.7). One hundred-forty three were diagnosed as having GERD-related cough based on classical reflux symptoms including heartburn and characteristic triggers of cough such as phonation, rinsing, lying, and eating. Most of them (89.8%) had other causative diseases including CVA. Cough lasted longer (p = 0.019) and required a longer time until alleviation (p = 0.003) in patients with GERD than in those without GERD. They also scored lower J-LCQ than counterpart group (p < 0.0001). In terms of symptom stratification, dysmotility predominant group showed significant more response to specific GERD treatments than the remnants (p = 0.002).

CONCLUSIONS

These results indicate that GERD is associated with the aggravation of other causes including CVA. Particularly, dysmotility symptoms may be potential therapeutic target for GERD-related cough.

Cough associated with gastro-oesophageal reflux disease (GORD): Japanese experience

Differences in the aetiology as well as patient background of chronic cough have been recognised among US, UK, and Japan. One of the marked differences has been the prevalence of gastro-oesophageal reflux disease (GORD), which has been one of the top three causes in Western countries. It was indeed uncommon or rare in Japan, but, with the increasing prevalence of GOR itself, chronic cough associated with GORD seems to have become more common. In this article, cough associated with GORD will be reviewed based on literature and our Japanese experience. Further, potentially broader relevance of GORD in chronic cough will also be mentioned, highlighting the potential importance of dysmotiliy/non-acid reflux.

Cough triggers and their pathophysiology in patients with prolonged or chronic cough

BACKGROUND

The character or timing of chronic cough is considered to be unpredictable for diagnosing its cause. However, the associations of cough triggers with cough pathophysiology remains unknown.

METHODS

We developed a closed questionnaire listing 18 triggers that were reported by ≥1% of 213 patients in a retrospective survey. Using this questionnaire, patients with cough-predominant or cough-variant asthma (n = 140) and those with non-asthmatic cough (54) were asked whether their cough was induced by the listed triggers. Associations of triggers with causes of cough, airway sensitivity to inhaled methacholine, exhaled nitric oxide (NO) levels, number of sensitizing allergens, and scores from gastroesophageal reflux (GER) questionnaires were examined. Factor analysis was used to categorize variables, including the 12 most common cough triggers, diagnosis of asthmatic cough, airway sensitivity, and exhaled NO levels.

RESULTS

"Cold air" and "fatigue/stress" induced cough more often in asthmatic coughers than in non-asthmatic coughers. "Spices" and "meals" induced cough more frequently in GER-coughers (n = 19). Patients who marked "cold air" as the trigger were more sensitive to inhaled methacholine and showed higher exhaled NO levels than those who did not mark this trigger. The "post-nasal drip" trigger was associated with elevated exhaled NO levels, and this association was mainly exhibited by patients with cough-predominant asthma. The triggers "pollen" and "mold smell" were associated with a number of sensitizing allergens. The number of triggers was weakly associated with GER scores. By factor analysis, "cold air," "fatigue/stress," asthmatic cough, airway hypersensitivity, and elevated NO levels were categorized into the same factor.

CONCLUSIONS

Several cough triggers may reflect the pathophysiology of prolonged or chronic cough.

Cough and Asthma

Cough is the most common complaint for which patients seek medical attention. Cough variant asthma (CVA) is a form of asthma, which presents solely with cough. CVA is one of the most common causes of chronic cough. More importantly, 30 to 40% of adult patients with CVA, unless adequately treated, may progress to classic asthma. CVA shares a number of pathophysiological features with classic asthma such as atopy, airway hyper-responsiveness, eosinophilic airway inflammation and various features of airway remodeling. Inhaled corticosteroids remain the most important form of treatment of CVA as they improve cough and reduce the risk of progression to classic asthma most likely through their prevention of airway remodeling and chronic airflow obstruction.

Cough and gastroesophageal reflux: insights from animal models

Chronic cough in gastroesophageal reflux disease (GERD) has been attributed to irritation of the esophagus and/or upper airways by reflux of gastric content. Animal models have provided insight into both of these putative mechanisms. In patients with chronic cough and GERD, stimuli associated with reflex in the esophagus sensitize the cough reflex. This sensitization can be reproduced in the guinea pig and is most likely mediated by the esophageal afferent nerve fibers carried by the vagus nerves. Studies in animals have identified several subtypes of vagal esophageal C-fibers that may subserve this function. The putative nociceptive vagal C-fibers in the guinea pig esophagus are stimulated by acid and express the TRPV1 and TRPA1 receptors that confer responsiveness to disparate noxious stimuli. Acute and/or chronic irritation of the upper airways by reflux may contribute to cough by stimulation and/or sensitization of the airway afferent nerves. Studies in animals have identified airway nerves that likely initiate cough due to aspirated reflux; have characterized their pharmacology; and have provided insight into changes of their sensitivity. Studies in animal models have also described the neurophysiology of reflexes that protect the airways from reflux. In conclusion, animal models provide mechanistic insight into the modulation of cough from the esophagus and the pharmacology of neural pathways mediating cough in GERD.

Eosinophilic airway disorders associated with chronic cough

Chronic cough is a major clinical problem. The causes of chronic cough can be categorized into eosinophilic and noneosinophilic disorders, the former being comprised of asthma, cough variant asthma (CVA), atopic cough (AC) and non-asthmatic eosinophilic bronchitis (NAEB). Cough is one of the major symptoms of asthma. Cough in asthma can be classified into three categories; 1) CVA: asthma presenting solely with coughing, 2) cough-predominant asthma: asthma predominantly presenting with coughing but also with dyspnea and/or wheezing, and 3) cough remaining after treatment with inhaled corticosteroid (ICS) and beta2-agonists in patients with classical asthma, despite control of other symptoms. There may be two subtypes in the last category; one is cough responsive to anti-mediator drugs such as leukotriene receptor antagonists and histamine H1 receptor antagonists, and the other is cough due to co-morbid conditions such as gastroesophageal reflux. CVA is one of the commonest causes of chronic isolated cough. It shares a number of pathophysiological features with classical asthma with wheezing such as atopy, airway hyperresponsiveness (AHR), eosinophilic airway inflammation and various features of airway remodeling. One third of adult patients may develop wheezing and progress to classical asthma. As established in classical asthma, ICS is considered the first-line treatment, which improves cough and may also reduce the risk of progression to classical asthma. AC proposed by Fujimura et al. presents with bronchodilator-resistant dry cough associated with an atopic constitution. It involves eosinophilic tracheobronchitis and cough hypersensitivity and responds to ICS treatment, while lacking in AHR and variable airflow obstruction. These features are shared by non-asthmatic eosinophilic bronchitis (NAEB). However, atopic cough does not involve bronchoalveolar eosinophilia, has no evidence of airway remodeling, and rarely progresses to classical asthma, unlike CVA and NAEB. Histamine H1 antagonists are effective in atopic cough, but their efficacy in NAEB is unknown. AHR of NAEB may improve with ICS within the normal range. Taken together, NAEB significantly overlaps with atopic cough, but might also include milder cases of CVA with very modest AHR. The similarity and difference of these related entities presenting with chronic cough and characterized by airway eosinophilia will be discussed.

Gastroesophageal reflux-associated chronic cough in an adolescent and the diagnostic implications: a case report

A 15-year-old girl was referred with a 2-year history of perennial non-productive cough, which had been preceded by Mycoplasma pneumoniae pneumonia and subsequent asthma. Symptoms were only partially responsive to anti-asthma treatment including an inhaled corticosteroid and a leukotriene receptor antagonist. The patient's BMI was 27.8; she had gained over 10 kg in the previous two years. Typical symptoms of gastroesophageal reflux disease were not evident except for belch. Coughing worsened on eating and rising from bed. Although esophagography failed to disclose reflux esophagitis, esophageal pH monitoring revealed significant acid reflux. Asthma was considered well controlled. Treatment with the proton-pump inhibitor rabeprazole resulted in disappearance of cough. Frequency Scale for the Symptoms of Gastroesophageal reflux disease (FSSG) score, a questionnaire evaluating the symptoms of gastroesophageal reflux disease, was initially high but normalized after treatment. Capsaicin cough sensitivity also diminished with treatment.Chronic cough due to gastroesophageal reflux disease has been considered rare in adolescents, but this condition might be increasing in line with the recent trend in adults. Clinical features of gastroesophageal reflux disease-associated cough typical for adult patients and a specific questionnaire for evaluating gastroesophageal reflux disease validated in adults may also be useful diagnostic clues in adolescents.

Prevalence, pathogenesis, and causes of chronic cough

Cough is a reflex action of the respiratory tract that is used to clear the upper airways. Chronic cough lasting for more than 8 weeks is common in the community. The causes include cigarette smoking, exposure to cigarette smoke, and exposure to environmental pollution, especially particulates. Diseases causing chronic cough include asthma, eosinophilic bronchitis, gastro-oesophageal reflux disease, postnasal drip syndrome or rhinosinusitis, chronic obstructive pulmonary disease, pulmonary fibrosis, and bronchiectasis. Doctors should always work towards a clear diagnosis, considering common and rare illnesses. In some patients, no cause is identified, leading to the diagnosis of idiopathic cough. Chronic cough is often associated with an increased response to tussive agents such as capsaicin. Plastic changes in intrinsic and synaptic excitability in the brainstem, spine, or airway nerves can enhance the cough reflex, and can persist in the absence of the initiating cough event. Structural and inflammatory airway mucosal changes in non-asthmatic chronic cough could represent the cause or the traumatic response to repetitive coughing. Effective control of cough requires not only controlling the disease causing the cough but also desensitisation of cough pathways.

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.

Acidification of the oesophagus acutely increases the cough sensitivity in patients with gastro-oesophageal reflux and chronic cough

Gastro-oesophageal reflux disease (GORD) is one of the most common causes of chronic cough; however, the mechanisms by which GOR initiates coughing are incompletely understood. We address the hypothesis that acidification of oesophagus acutely increases the cough reflex sensitivity in patients with GORD and chronic cough. Nine patients with GORD with chronic cough and 16 patients with GORD without cough were recruited. In a randomized double blind study, saline and acid (HCl, 0.1 mol L(-1)) were separately infused into oesophagus via naso-oesophageal catheter. Cough reflex sensitivity to inhaled capsaicin was determined immediately after completion of each infusion. Infusion of acid into oesophagus increased capsaicin cough reflex sensitivity in patients with GORD and chronic cough. In contrast, acid had no effect on the cough sensitivity in patients with GORD without cough. In a separate study, acid infusion into oesophagus did not affect the cough sensitivity in 18 healthy subjects. We conclude that acid in the oesophagus acutely increases the cough reflex sensitivity to capsaicin in patients with GORD and chronic cough. This phenomenon may contribute to the pathogenesis of cough due to GORD.

Analysis and evaluation of environmental tobacco smoke exposure as a risk factor for chronic cough

Exposure to environmental tobacco smoke (ETS) and active tobacco smoking has been shown to increase symptoms of bronchial asthma such as bronchoconstriction but effects on other respiratory symptoms remain poorly assessed. Current levels of exposure to tobacco smoke may also be responsible for the development of chronic cough in both children and adults. The present study analyses the effects of tobacco smoke exposure as potential causes of chronic cough. A panel of PubMed-based searches was performed relating the symptom of cough to various forms of tobacco smoke exposure. It was found that especially prenatal and postnatal exposures to ETS have an important influence on children's respiratory health including the symptom of cough. These effects may be prevented if children and pregnant women are protected from exposure to ETS. Whereas the total number of studies adressing the relationship between cough and ETS exposure is relatively small, the present study demonstrated that there is a critical amout of data pointing to a causative role of environmental ETS exposure for the respiratory symptom of cough. Since research efforts have only targeted this effect to a minor extent, future epidemiological and experimental studies are needed to further unravel the relation between ETS and cough.

Analysing the causes of chronic cough: relation to diesel exhaust, ozone, nitrogen oxides, sulphur oxides and other environmental factors

Air pollution remains a leading cause of many respiratory diseases including chronic cough. Although episodes of incidental, dramatic air pollution are relatively rare, current levels of exposure of pollutants in industrialized and developing countries such as total articles, diesel exhaust particles and common cigarette smoke may be responsible for the development of chronic cough both in children and adults. The present study analyses the effects of common environmental factors as potential causes of chronic cough. Different PubMed-based researches were performed that related the term cough to various environmental factors. There is some evidence that chronic inhalation of diesel can lead to the development of cough. For long-term exposure to nitrogen dioxide (NO2), children were found to exhibit increased incidences of chronic cough and decreased lung function parameters. Although a number of studies did not show that outdoor pollution directly causes the development of asthma, they have demonstrated that high levels pollutants and their interaction with sunlight produce ozone (O3) and that repeated exposure to it can lead to chronic cough. In summary, next to the well-known air pollutants which also include particulate matter and sulphur dioxide, a number of other indoor and outdoor pollutants have been demonstrated to cause chronic cough and therefore, environmental factors have to be taken into account as potential initiators of both adult and pediatric chronic cough.