Oesophageal dysfunction in asthmatics

Abstract

INTRODUCTION: Gastro-oesophageal reflux (GOR) predisposes to respiratory symptoms through reflex vagal activity. Asthmatics have oesophageal hypomotility and vagal hyperactivity. Whether this oesophageal hypomotility is primary or secondary to damage from GOR is unclear. METHODS: 30 mild, stable asthmatics (ATS criteria) and 30 healthy volunteers underwent 24-hour ambulatory oesophageal pH monitoring, manometry, autonomic function testing and GORD symptom assessment and gastroscopy. A vagal score using 3 tests (valsalva manouvre, heart rate response to deep breathing and to standing from supine position) was correlated with oesophageal function parameters. Respiratory symptoms during pH monitoring were correlated with reflux events. RESULTS: Asthmatics (mean age 34,8y; 60% female) had more frequent GORD symptoms than controls (mean age 30.9y; 50% female). 10/27 asthmatics had oesophageal mucosal damage, 22/30 showed hypervagal response, none had a hyperadrenergic response. 14/30 asthmatics had ineffective oesophageal motility. Higher GOR-score asthmatics had significantly fewer peristaltic contractions and more simultaneous contractions than controls, and higher oesophageal.acid contact times than those with lower scores. All reflux parameters were significantly higher and acid clearance time prolonged in asthmatics than controls. There was no correlation of vagal function with oesophageal function parameters. 50% of the asthmatics complained of respiratory symptoms during pH monitoring, and reflux episodes usually preceded respiratory symptoms. CONCLUSION: Asthmatics have abnormal oesophageal motility and pathological GOR which usually precede respiratory symptoms. There was no vagal dysfunction, and the vagal function score did not correlate with oesophageal motility parameters. Peristaltic dysfunction may be secondary to damage due to gastro-oesophageal reflux.