Gastro-oeseophageal reflux and its relationship to cystic fibrosis lung disease

  • Robert Lord

Student thesis: Phd


Introduction: A number of studies have shown an increased prevalence of gastro-oesophageal reflux in adult and paediatric cystic fibrosis (CF) populations. To date it remains unproven if the increased amounts of reflux shown can affect CF lung disease. The most commonly proposed mechanism by which this may occur is reflux aspiration. The study’s aim was to assess if a relationship exists between reflux and measures of lung disease severity. Methods: A prospective observational study was conducted in stable adult CF patients, measuring reflux with combined oesophageal pH-impedance (n=41). This allowed the following analyses: (I) The reflux measures were described for the entire cohort; (II) The influences of various factors on the amount of reflux were examined, including oesophageal motor function, prescribed medications and co-morbidities; (III) The effect of reflux on respiratory endpoints was assessed; (IV) Mass spectrometry was used to assess the effect of reflux on relative protein abundance within sputum. Results: Reflux was increased in 54% of this cohort using total reflux events. Reflux characteristics assumed to be high-risk for reflux aspiration (proximal and/or supine events) were raised in 41%. Dysfunction of the oesophago-gastric junction correlated with acid exposure. Methylxanthines but no other medications correlated with the number of reflux episodes. No correlation was shown between reflux measures and any respiratory endpoint tested. No differences in relative protein abundance within sputum were demonstrated between those with the highest and lowest measures of reflux. Conclusions: Although there was a high prevalence of increased reflux using pH-impedance, no effect of reflux was demonstrated on the tested respiratory endpoints or relative protein abundance within sputum. This may reflect that it is currently not possible to directly measure the amount of reflux aspiration, which is a major limitation.
Date of Award1 Aug 2019
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorJacky Smith (Supervisor) & Andrew Jones (Supervisor)


  • Gastro-oesophageal reflux
  • Cystic fibrosis

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