Background and aim: Although strenuous exercise has been reported to increase gastroesophageal reflux, there are few data exploring the mechanism behind this relationship. The aim of this study was to use vigorous exercise as a provocation for strain-induced reflux and examine the correlation between endoscopically assessed EGJ integrity and exercise-induced reflux.
Methods: Ten controls and 10 GERD patients were studied for a 2-day period using the wireless Bravo pH monitoring system. The subjects were randomly assigned to perform 60 min of exercise on day 1 or 2 consuming the same diet on both days. Exercise consisted of 30 min of running and 30 min of 5 resistance exercises. Subjects underwent endoscopy to grade the EGJ "flap valve" and manometry to measure basal LES pressure.
Results: Nineteen subjects completed the 2-day study with 100% data capture during exercise. Median acid exposure was increased more than threefold for both controls and GERD patients during exercise when compared to nonexercise periods. In addition, a strong correlation existed between EGJ grade and % time pH < 4 during exercise while there was not a significant correlation between LES pressure and EGJ grade. These findings were present even after exclusion of hiatus hernia patients (flap valve grade 4).
Conclusions: Exercise caused a threefold increase in esophageal acid exposure in both controls and GERD patients. The degree of exercise-induced reflux is strongly correlated with EGJ morphology and this supports the hypothesis that anatomical integrity of the EGJ is of cardinal importance in preventing strain-induced reflux.
Copyright 2004 American College of Gastroenterology