Peter G Gibson, Richard Henry, Jennifer JL Coughlan

Asthma and gastro-oesophageal reflux are both common medical conditions and often co-exist. Studies have shown conflicting results concerning the effects of lower oesophageal acidification as a trigger of asthma. Furthermore, asthma might precipitate gastro-oesophageal reflux. Thus a temporal association between the two does not establish that gastro-oesophageal reflux triggers asthma. Randomised trials of a number of treatments for gastro-oesophageal reflux in asthma have been conducted to determine whether treatment of reflux improves asthma. The objective of this review was to evaluate the effectiveness of treatments for gastro-oesophageal reflux in terms of their benefit on asthma. The Cochrane Airways Group trials register, review articles and reference lists of articles were searched. Randomised controlled trials of treatment for oesophageal reflux in adults and children with a diagnosis of both asthma and gastro-oesophageal reflux. Trial quality and data extraction were carried out by two independent reviewers. Authors were contacted for confirmation or more data. Twelve trials met the inclusion criteria. Interventions included proton pump inhibitors (n=6), histamine antagonists (n=5), surgery (n=1) and conservative management (n=1). Treatment duration ranged from 1 week to 6 months. A temporal association between asthma and gastro-oesophageal reflux was investigated in 4 trials and found to be present in a proportion of participants in these trials. Anti-reflux treatment did not consistently improve lung function, asthma symptoms, nocturnal asthma or the use of asthma medications. In asthmatic subjects with gastro-oesophageal reflux, (but who were not recruited specifically on the basis of reflux-associated respiratory symptoms), there was no overall improvement in asthma following treatment for gastro-oesophageal reflux. Subgroups of patients may gain benefit, but it appears difficult to predict responders.