Background: The aim of this study was to assess and compare reflux frequency during prolonged multichannel intraluminal impedance and pH monitoring with special attention to the 2-hour postprandial interval after the major meal in patients on or off proton pump inhibitor (PPI) therapy.
Materials and methods: We retrospectively analyzed multichannel intraluminal impedance and pH studies performed in 110 patients monitored on (n=70) or off PPI (n=40) to assess number of acid and nonacid reflux episodes per hour (RE/h).
Results: Patients on PPI had significantly higher mean number of nonacid than acid RE/h during the total monitoring and 2-hour postprandially (pp). The mean number of nonacid RE/h was significantly higher during 2-hour pp than the total monitoring period (4.5 vs. 1.7). Patients off PPI had significantly higher mean number of acid than nonacid RE/h only during the total monitoring. The total number of RE/h was significantly higher during 2-hour pp than the total monitoring (5.1 vs. 2.3). Patients on PPI had significantly higher mean number of nonacid RE/h whereas patients off PPI had significantly higher mean number of acid RE/h throughout total monitoring and 2-hour pp. Number of RE/h was numerically (2.3 vs. 1.7) but not statistically greater off PPI than on PPI during total monitoring.
Conclusions: The total number of reflux episodes increases during the postprandial period irrespective of PPI therapy. Maximal rate of reflux episodes occurs during the postprandial period and is the same whether taking PPI or not.