Gastro-oesophageal reflux disease, upper gastro-intestinal motility and autonomic function in adult asthmatics

Introduction: Asthmatics have increased prevalence of gastro-oesophageal reflux disease (GORD). Oesophageal hypomotility, delayed gastric emptying (GE) and autonomic hypofunction increase GOR. Our aim was to study the relationship of GOR with autonomic function, oesophageal motility and GE in adult asthmatics. Methods: Thirty consecutive mild, stable asthmatics (American Thoracic Society criteria) and 30 healthy volunteers underwent stationary oesophageal manometry, GE by real-time ultrasonography and autonomic function testing (cardiovascular reflex tests). GORD was assessed by symptom assessment and 24-hour pH monitoring. Results: The asthmatics (40% male; mean age 34.8 years (SD 8.4)) and controls (50% male; mean age 30.9 years (SD 7.7)) were comparable. Twenty two (73.3%) asthmatics had increased reflux on pH monitoring. Asthmatics with higher GOR symptom scores had lesser peristaltic contractions (p=0.032), prolonged acid contact times (p<0.001), delayed GE (p=0.097) and decreased antral motility (p<0.001) than those with lower scores and controls. 69% of asthmatics showed hypervagal activity, rest had normal autonomic function, none had a hyperadrenergic response. There was no association between vagal function, oesophageal or gastric motility parameters in asthmatics. Conclusions: A cohort of mild, stable adult asthmatics had increased GOR, decreased oesophageal motility and delayed GE. This was not associated with autonomic hypofunction, but with a hypervagal response. Our findings support the hypothesis that vagal hyperreactivity induced acid secretion leads to a reflex decrease in gastric motility, inducing GOR and secondary reduction in oesophageal motility.