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

Robert J Hancox,Nicholas J Talley,Erin M Flannery,Malcolm R Sears,Jan O Cowan,G Peter Herbison,Richie Poulton,Justina M Greene,D Robin Taylor,Christene R Mclachlan

doi:10.1186/1465-9921-7-142

Robert J Hancox, Nicholas J Talley + Show 8 more

Open Access

https://doi.org/10.1186/1465-9921-7-142

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Abstract

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

Highlights

Several studies have reported an association between asthma and gastrooesophageal reflux, but it is unclear which condition develops first
The frequencies of heartburn and acid regurgitation did not differ between men and women whereas irritable bowel syndrome was more common in women than men (20.3% and 13.6% respectively, p = 0.007, 95% CI for difference 1.9–11.6%)
This study provides longitudinal follow-up of asthma, wheeze and airway responsiveness since childhood, data on gastro-oesophageal reflux symptoms were not collected during childhood or adolescence and we are unable to establish the temporal sequence between respiratory symptoms and airway responsiveness and gastrooesophageal reflux

Summary

Introduction

Several studies have reported an association between asthma and gastrooesophageal reflux, but it is unclear which condition develops first. We explored the associations between respiratory symptoms, lung function, and gastro-oesophageal reflux symptoms in a birth cohort of approximately 1000 individuals. The association between gastro-oesophageal reflux and asthma could have several explanations [4]. Episodes of gastro-oesophageal reflux might trigger wheezing in an individual who has asthma, this does not necessarily indicate an aetiological association between having reflux disease and the asthmatic phenotype. The association between asthma and reflux could be mediated by obesity, which is a risk factor for both conditions [8,9,10,11]. Reflux could give rise to asthma-like symptoms, such as nocturnal cough, but have no effect on lung function or airway responsiveness

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