Abstract
Introduction
Nocturnal gastroesophageal reflux (nGER) has been associated with various respiratory symptoms, but the pathogenesis is still unclear. Our aim was to investigate the association between nGER and exacerbations of respiratory symptoms, with assessment of inflammatory biomarkers both in plasma and exhaled air.
Methods
Participants in the European Community Respiratory Health Survey III (ECRHS III) in Iceland who reported any symptoms of nGER (n=53) as well as age and gender paired controls (n=67) were studied further by using questionnaires, blood tests, laryngeal fiberscopy, exhaled breath condensate (EBC), particles in exhaled air (PEx) measurements and 24 hours esophageal pH impedance measurements. Exacerbations were defined as having at least one episode of marked worsening of respiratory symptoms in the previous 12 months.
Results
Exacerbations were more common in the nGER group compared to controls (19% vs 6%, p=0.03). In EBC, 8-isoprostane was increased in subjects with nGER compared with controls (median (IQR): 2.9 pg/ml (2.7-3.8) vs. 2.8 pg/ml (2.4-3.3), p=0.05). Interleukin 8 (IL-8) in plasma was significantly increased only among those with both exacerbations and nGER compared with controls (median (IQR): 1.8 pg/ml (1.2-5.0) vs. 0.2 pg/ml (0.2-2.5), p=0.01). A positive association was also found between exacerbation frequency and IL-8 level in plasma (p=0.01). Neurokinin A, substance P, surfactant protein A and NO in exhaled air were not related to nGER or exacerbations.
Conclusion
In a general population sample, nGER is associated with more frequent exacerbations of respiratory symptoms and their inflammatory profile seems to differ from those without nGER.
- © 2014 ERS