Nocturnal reflux: an untapped target in lung disease?

Abstract

Gastro-oesophageal reflux disease (GORD) is a common condition that is known to have several extraintestinal impacts, including effects in the lung. Observational studies have found associations between GORD and asthma,1 lung cancer,2 respiratory infection,3 exacerbations of lung disease,4 5 and bronchiectasis.6 However, a causal relationship between GORD and lung disease has not been conclusively established. This link has been particularly contentious in idiopathic pulmonary fibrosis (IPF), where epidemiological studies and systematic reviews have suggested that GORD is associated with poor outcomes7–9, and that antiacid treatment may improve survival.10 11 However, other studies have contradicted these findings,12–17 and the overwhelming conclusion is that further work is needed in this area. Emilsson et al add another piece to the puzzle with their analysis of the Swedish CArdioPulmonary BioImage Study (SCAPIS), a large cohort study that comprehensively characterised over 28 000 individuals with questionnaires and chest imaging.18 Patients who self-reported heartburn or regurgitation after going to bed on at least one night per week were grouped as having nocturnal gastro-oesophageal reflux (termed nGER), and their chest imaging was reviewed for lung abnormalities including bronchial wall thickening, bronchiectasis, reticular abnormalities, honeycombing, cysts and ground glass opacities.18 Emilsson et al report an association between nGER and bronchial wall thickening and reticular abnormalities on CT chest, but only in a subgroup of patients with risk factors for the development of lung disease (eg, smoking history, …