Why do the published data fail to clarify the relationship between gastroesophageal reflux and asthma?

Comorbidities associated with severe asthma

Background:

Severe asthma can be a challenging disease to manage by the provider and by the patient, supported by evidence of increased health-care utilization by this population. Patients with severe asthma should be screened for comorbidities because these often contribute to poorly controlled asthma. The impact of comorbidities, however, are not completely understood.

Objective:

To review common comorbidities and their impact on severe asthma.

Methods:

A review of relevant clinical research studies that examined comorbidities in severe or difficult-to-treat asthma.

Results:

A number of comorbid diseases, including rhinitis, rhinosinusitis, gastroesophageal reflux, and obstructive sleep apnea, are associated with severe or difficult-to-treat asthma. If present and untreated, these conditions may adversely affect asthma control, quality of life, and/or lung function, despite adequate treatment with step-up asthma controller therapy.

Conclusion:

Treatable comorbidities are associated with severe and difficult-to-control asthma. Failure to recognize these comorbidities may divert appropriate care and increase disease burden. Assessment and management of these risk factors may contribute to improved asthma outcome; however, more investigation is needed to understand the relationship of comorbidities and asthma due to inconsistency in the findings.

Gastroesophageal reflux disease in our asthma patients: the presence of dysphagia can influence pulmonary function

Background

The prevalence of Gastroesophageal Reflux Disease (GERD) in Turkey is reported as 11.6%. Studies of pulmonary function in asthmatics have demonstrated a correlation between lung resistance and the occurrence of spontaneous gastroesophageal reflux. Few studies have included measures of lung diffusing capacity for carbon monoxide. The aim of this study is to assess whether asthma patients had worse lung function and gas diffusion according to diversity of GERD symptoms they concurrently experienced. The secondary aim of the study is to determine the frequency and different faces of GERD in our asthma patients compared to healthy controls.

Methods

Sixty consecutive asthma patients evaluatd at the pulmonary specialty outpatient clinic were included in the study. The control group included 60 healthy volunteers who had normal pulmonary function and routine laboratory tests. A modified version of a self-reported questionnaire developed by Locke and associates at the Mayo Clinic was conducted face-to-face with consecutive asthma patients and control subjects. Pulmonary function measurements were taken using spirometry. DLCO (mL/dk/mmHg) and DLCO/VA (DLCO adjusted according to alveolar volume) were measured using a single-breath technique. Statistical analyses were performed using the SPSS 17.0 statistical software.

Results

DLCO and DLCO/VA were significantly lower in asthma patients who had dysphagia symptoms. Frequent and significant acid regurgitations were seen in 28.33% (n = 17) of patients in the study group and 6.7% (n = 4) of patients in the control group. Severe, troublesome heartburn symptoms were reported by 28.2% (n = 17) of patients in the study group and 16.7% (n = 10) of subjects in the control group. Dysphagia was detected in 38.3% (n = 23) of all asthma cases and in 1.7% (n = 1) of the subjects in the control group.

Conclusions

There were many faces of gastroesophageal reflux disease in our asthmatic patients. Dysphagia was the only GERD symptom influencing on pulmonary function tests, while gastroesophageal reflux symptoms and nocturnal awakening attacks were common in this study.

Prevalence of gastroesophageal reflux disease in patients with asthma and chronic obstructive pulmonary disease

BACKGROUND AND AIM

It is speculated that the prevalence of gastroesophageal reflux disease (GERD) might increase with asthma or chronic obstructive pulmonary disease (COPD). The aim of the present study was to evaluate the prevalence of GERD in patients with asthma and COPD in an area representative of developing countries.

METHODS

A validated GERD questionnaire was conducted face-to-face with 308 consecutive asthma (240 women) and 133 COPD (35 women) patients in the tertiary referral pulmonary outpatient clinic, and 694 controls from the research area. Detailed histories of patients and pulmonary function tests were also recorded.

RESULTS

The prevalence of GERD (heartburn/regurgitation once a week or more) was 25.4%, 17.0%, 19.4% and occasional symptoms (less than weekly) were 21.2%, 16.3% and 27.0% of patients with asthma, COPD and controls, respectively. The prevalence was higher in the asthma group compared with the controls and the COPD group. No significant difference was found between the COPD group and the controls. Heartburn started following pulmonary disease in 24.1% of the asthma group, and 26.4% of the COPD group. The majority of additional symptoms were significantly higher in asthmatics compared with the controls. No difference was found in the consumption of pulmonary medications in asthmatic patients in groups with different symptom frequency. Heartburn was increased 13.8% by the consumption of inhaler medications.

CONCLUSIONS

These results implicate that the prevalence of GERD in asthma and COPD are lower than in published reports in a tertiary referral center. These differences might be related to the characteristics of developing countries, increased consumption of powerful medications in GERD and pulmonary diseases, or methodological flaws in earlier studies.

The utility of ambulatory pH monitoring in patients presenting with chronic cough and asthma

OBJECTIVE

To evaluate the prevalence of gastroesophageal reflux disease (GERD) in patients presenting with asthma and chronic cough.

PATIENTS AND METHODS

The charts of 358 consecutive patients who were referred for ambulatory gastroesophageal pH monitoring to the Lung Centre in Vancouver, British Columbia, were reviewed, and the data of 108 (30%) patients with asthma and 134 (37%) patients with chronic cough were analyzed. The maintenance treatment for GERD was discontinued before patients underwent the pH monitoring study. One hundred eighteen (33%) patients were excluded.

RESULTS

Reflux episodes identified reflux events as the percentage of time where the pH was less than four. For asthma patients, 70 (64.8%) had distal total reflux, 50 (46.3%) had distal upright reflux, 41 (38.3%) had distal supine reflux and 73 (67.6%) had other distal refluxes. Proximal total reflux in asthmatic patients was present in 56 (52%), proximal upright reflux in 55 (51%) and proximal supine reflux in 56 (52%) patients. For chronic cough patients, 70 (52.6%) had distal total reflux, 59 (44.4%) had distal upright reflux, 45 (34.4%) had distal supine reflux and 75 (56%) patients had other distal refluxes. In chronic cough patients, proximal total reflux was present in 70 (52%), proximal upright reflux in 80 (60%) and proximal supine reflux in 59 (44%). Presenting respiratory and/or reflux symptoms were absent in approximately 25% of patients with asthma and reflux, and in approximately 50% of patients with chronic cough and reflux. During pH monitoring, symptoms did not differ significantly between those with and without distal reflux in both study groups, except for more significant heartburn in patients with chronic cough and reflux (RR 2.0).

CONCLUSIONS

The data of the present study support the observation that there is a high prevalence of GERD in patients with asthma or chronic cough. The use of different pH parameters for detecting acid reflux during 24 h ambulatory pH monitoring, such as proximal esophageal acid measurement, should be considered as part of the routine interpretation of such testing. A low threshold for diagnosing GERD in patients with asthma or chronic cough is essential, because respiratory and/or reflux symptoms can be absent or atypical in some of these patients.

Associations between respiratory symptoms, lung function and gastro-oesophageal reflux symptoms in a population-based birth cohort

BACKGROUND

Several studies have reported an association between asthma and gastro-oesophageal reflux, but it is unclear which condition develops first. The role of obesity in mediating this association is also unclear. We explored the associations between respiratory symptoms, lung function, and gastro-oesophageal reflux symptoms in a birth cohort of approximately 1000 individuals.

METHODS

Information on respiratory symptoms, asthma, atopy, lung function and airway responsiveness was obtained at multiple assessments from childhood to adulthood in an unselected birth cohort of 1037 individuals followed to age 26. Symptoms of gastro-oesophageal reflux and irritable bowel syndrome were recorded at age 26.

RESULTS

Heartburn and acid regurgitation symptoms that were at least "moderately bothersome" at age 26 were significantly associated with asthma (odds ratio = 3.2; 95% confidence interval = 1.6-6.4), wheeze (OR = 3.5; 95% CI = 1.7-7.2), and nocturnal cough (OR = 4.3; 95% CI = 2.1-8.7) independently of body mass index. In women reflux symptoms were also associated with airflow obstruction and a bronchodilator response to salbutamol. Persistent wheezing since childhood, persistence of asthma since teenage years, and airway hyperresponsiveness since age 11 were associated with a significantly increased risk of heartburn and acid regurgitation at age 26. There was no association between irritable bowel syndrome and respiratory symptoms.

CONCLUSION

Reflux symptoms are associated with respiratory symptoms in young adults independently of body mass index. The mechanism of these associations remains unclear.

Gastroesophageal reflux disease and asthma in children

Gastroesophageal reflux disease (GERD) occurs in about two thirds of children with asthma. It may simply represent a concomitant unrelated finding or it may be responsible for provoking or worsening asthma. GERD could also be a byproduct of asthma itself. In any case, aggressive treatment of GERD seems to improve asthma outcomes. GERD should be suspected in asthma patients who do not have any known risk factors or those who are becoming difficult to treat.

Overuse of acid suppressive therapy in hospitalised patients with pulmonary diseases

OBJECTIVES

Overuse of acid suppressive therapy (AST) has been reported in hospitalised patients, but the use in specific patient categories is unexplored. We assessed the use of and indication for AST and upper endoscopic investigations in hospitalised patients on a pulmonary ward compared with patients on other wards.

METHODS

301 patients were enrolled in the study. 162 were hospitalised on a pulmonary ward with a control group consisting of 139 from both a surgical and general internal medicine ward. Adequate indications for AST were those strongly supported by medical literature.

RESULTS

Among the 301 patients enrolled, 132 (44%) used AST. 78 (59%) had no adequate indication for AST. On the pulmonary ward 79 (49%) patients used AST, compared to only 10 (20%) on the internal medicine ward (P < 0.05). On the pulmonary ward 68% of the patients had no adequate indication for AST, which was more common than inappropriate use of ASTon the control wards (P < 0.05). The most common inadequate indication for AST was peptic ulcer prophylaxis during corticoidsteroid therapy.

CONCLUSION

In hospitalised patients a significant overuse of AST was observed, particularly among pulmonary patients. More adequate use of AST can contribute to substantial savings for the health-care system.

Effects of bronchial obstruction on lower esophageal sphincter motility and gastroesophageal reflux in patients with asthma

The relationship between gastroesophageal reflux and asthma remains unclear. The aim of this study was to analyze the effect of bronchial obstruction on lower esophageal sphincter (LES) motility and reflux in patients with asthma. LES motility and esophageal pH were assessed in eight subjects with intermittent asthma and eight healthy volunteers during three consecutive 30-minute periods: baseline, methacholine-induced bronchospasm, and after inhalation of the beta2-agonist salbutamol. Healthy subjects inhaled 2 mg of methacholine, whereas subjects with asthma inhaled the dose of methacholine causing a 15% fall in FEV(1), as determined by a previous methacholine challenge. LES motility, esophageal pH, and FEV(1) were not significantly different between the three periods in healthy subjects. In patients with asthma, methacholine induced a 21.9 +/- 2.6% decrease in FEV(1) and a concomitant increase in the rate of transient LES relaxation (TLESR) and reflux episodes. Inhalation of salbutamol decreased the rate of TLESRs but not the number of reflux episodes. We conclude that in patients with asthma, methacholine-induced bronchospasm increases the rate of TLESR and the number of reflux episodes. These results support the belief that, in asthma, bronchial obstruction may be responsible for reflux or may aggravate reflux through a mechanism that remains to be further clarified.

Underlying mechanisms of respiratory symptoms with esophageal acid when there is no evidence of airway response

Although a strong association exists between gastroesophageal reflux (GER) and asthma, results of studies designed to maximize the likelihood of identifying that GER worsens pulmonary function in patients with asthma have been negative or inconclusive. Asthma symptoms worsen during symptomatic reflux episodes, and asthma symptom severity correlates with the severity of symptomatic reflux. Various reasons have been proposed to explain these findings. Discomfort associated with GER can cause reflux-associated respiratory symptoms even when pulmonary function is normal. New findings suggest that increases in minute ventilation rather than inhibition of diaphragm activity are responsible for the changes in respiratory sensation during acid perfusion of the esophagus in nonasthmatic subjects. These results may also pertain to asthmatic patients, because increasing minute ventilation can cause dyspnea and bronchospasm in this population. Treating GER, either medically or surgically, may improve asthma symptoms by preventing GER-induced changes in minute ventilation.

Asthma

Asthma is an important and increasingly prevalent respiratory disease. Its proper diagnosis and treatment lie at the heart of improving asthma outcome. Unfortunately, asthma has many faces and is affected by many variables, many of them difficult to control. Like many chronic illnesses, asthma tends to affect the poor and less advantaged individuals in society. Heightened awareness among patients and physicians of the serious nature of the disease is needed to reduce the morbidity and mortality of asthma. Treatment clearly requires a multifaceted approach, including behavioral, environmental, social, and medical interventions, in which the National Asthma Education and Prevention Program guidelines provide a logical, step-wise, and effective approach.