Temporal associations between coughing or wheezing and acid reflux in asthmatics

Abstract

Background and aims-The pulmonary symptoms of patients with lung disease may be ascribed to gastro-oesophageal reflux although a causal relationship between acid reflux and coughing or wheezing has not been proved. Does cough cause reflux or does reflux cause cough? The aim of this study was to evaluate 24 hour oesophageal pH tracings of asthmatics with gastro-oesophageal reflux to determine the temporal association between acid reflux and coughing or wheezing. Methods-The oesophageal tracings of 128 asthmatics from the outpatient clinics who underwent oesophagogastroduodenoscopy, oesophageal manometry, and 24 hour oesophageal pH monitoring were analysed. Three possible temporal relationships between the occurrence of acid reflux and the occurrence of coughs or wheezes were evaluated: (1) pulmonary symptoms preceding reflux; (2) reflux preceding pulmonary symptoms; and (3) unrelated occurrence of both events. Results-Of 128 asthmatics, 53 recorded five or more coughs and 19 recorded three or more wheezes during the 24 hour recording period. Mean acid contact time was similar in asthmatics with and without pulmonary symptoms (12.2 (1.2)% v 10.4 (0.6)%). Of all coughs and wheezes, 46% and 48%, respectively, were associated with acid reflux. For the individual asthmatic, the likelihood of reflux induced coughing increased as the number of coughs increased. Conclusions-Half of all coughs and wheezes in asthmatics are associated with acid reflux into the oesophagus. While an occasional coughing episode can lead to reflux, it is rather the reflux episode in the vast majority of instances that leads to cough. (Gut 2001;49:767-772)

Environmental factors in the etiology of gastroesophageal reflux disease

“…Several of the proposed mechanisms whereby GERD can cause respiratory symptoms are similar in asthma and chronic cough and include a vagally mediated reflex, heightened bronchial sensitivity and microaspiration [136]. In a study where the temporal association between coughing or wheezing and reflux episodes in asthmatics was investigated, it was concluded that although occasional coughing can lead to reflux, the reverse is much more common [137]. In that study, almost half of all occasions of coughs and wheezes were associated with reflux.…”

Airway acidification and gastroesophageal reflux

“…Specifically, a cough that is temporally associated (within 15 minutes) with EBC acidification is highly likely to respond to gastric acid suppression therapy [26•]. Gastroesophageal reflux has been associated unequivocally with respiratory symptoms [4,[27][28][29][30], and there is substantial evidence that acid reflux events most commonly precede the respiratory symptoms [29]. Indeed, although most practicing lung specialists are convinced of the importance of acid reflux to asthma symptoms, they are confused about why the clinical efficacy data for proton pump inhibitors have not been clearly demonstrated [4,30] and remain insufficient for the US Food and Drug Administration to allow these agents to be marketed for respiratory disease.…”

Airway acidification: Interactions with nitrogen oxides and airway inflammation

“…Gastroesophageal reflux (GER) has been associated unequivocally with respiratory disease [2], and excellent data reveal that acid reflux events most commonly precede the respiratory symptoms [26], suggesting causality. Although most practicing allergists and pulmonologists are convinced of the importance of acid reflux to asthma symptoms, they are confused about why the clinical efficacy data for proton pump inhibition (PPI) are not clearer [27,28], and frustrated by the absence of an objective test to diagnose the condition in their patients [29].…”