Delayed Gastric Emptying Neither Contributes to Gastroesophageal Reflux nor Disease Severity in Patients With Respiratory Disease

Background and Aims Gastroesophageal reflux (GER) is common and thought to contribute to disease progression in patients with respiratory disease. Delayed gastric emptying (DGE) can increase GER in patients with GER disease, but its effect in patients with respiratory disease, and how differing lung structure (eg, scarring, inflammation) and mechanics (eg, decreased thoracic pressure in restrictive disease, increased abdominal pressure in obstructive disease) influences this is unknown. Our aim was to understand these interrelationships and association with pulmonary function in patients with chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF) and non-IPF interstitial lung disease (non-IPF ILD). Methods We prospectively recruited 22 COPD (aged 34–75 years), 33 IPF (45–74 years), and 19 non-IPF ILD (37–74 years) patients who underwent gastric emptying studies, high resolution impedance manometry, 24-hr pH-impedance, and pulmonary function testing, as part of routine lung transplantation assessment. Results Gastric emptying was delayed in a total of 20(27%) patients; 5(23%) with COPD, 8(24%) with IPF and 7(37%) with non-IPF ILD. Notably, all 7 non-IPF ILD patients with DGE had nonspecific interstitial pneumonia (NSIP; ie, 70% of NSIP patients; P < .02 compared with other groups). DGE irrespective of disease type was not associated with increased acid exposure time, total bolus exposure time or number of reflux events. Furthermore, DGE was not associated with higher intra-abdominal pressure, specific esophageal dysmotility, or worse pulmonary function in any of the respiratory diseases. Conclusion Significantly more NSIP patients have DGE compared with other respiratory diseases. Irrespective of this, DGE had little effect on GER or pulmonary function in any of the respiratory diseases.