The role of reflux in the genesis of respiratory symptoms in a cohort of adult asthmatics in Sri Lanka

Abstract

INTRODUCTION: The oesophagus and airways have a common origin. Reflux related respiratory symptoms may be triggered by aspiration of gastric refluxate into airways or a vagally mediated oesophago-tracheo-bronchial. This association has not been reported previously in Sri Lanka. The aim of this study was to describe the association between gastro-oesophageal reflux (GOR) events and respiratory symptoms in a cohort of adult asthmatics in Sri Lanka. METHODS: Thirty stable, mild asthmatics (American Thoracic Society criteria) underwent dual-sensor ambulatory oesophageal pH monitoring. Respiratory symptoms (cough, wheeze, difficult breathing, chest tightness) during monitoring were recorded and correlated with reflux events. RESULTS: Both proximal and distal GOR parameters were significantly higher in asthmatics than controls (P < 0.050; Mann–Whitney U-test). However, there was no difference in any parameter between asthmatics with and without respiratory symptoms. Abnormal proximal acid reflux was documented in 66.7% and distal reflux in 73.3% of 30 asthmatics. Of 102 respiratory symptoms in all asthmatics, majority (72%) were cough episodes. In total, 93% of coughs, 81% of wheeze and all of chest tightness was reflux-associated, where in most, reflux events preceded respiratory symptoms. Of 15 asthmatics with respiratory symptoms, acid exposure was normal in 4 (26%), abnormally high in proximal oesophagus in 9 (60%) and abnormally high in the distal oesophagus in 11 (73%) and abnormal at both levels in 8 (53%). Most reflux events in asthmatics occurred in the upright position. CONCLUSION: Asthmatics have more GOR and associated respiratory symptoms than non-asthmatic volunteers, with reflux episodes preceding respiratory symptoms in most cases. Distal GOR and upright acid exposure was more prominent than proximal GOR.