Meal-stimulated gastric acid secretion and integrated gastric acidity in gastro-oesophageal reflux disease

Background: No current methods exist to determine meal-stimulated gastric acid secretion in humans under conditions that approximate those of daily living with the ingestion of breakfast, lunch and dinner. Methods: Gastric and oesophageal pH were measured in 26 healthy subjects and in 59 subjects with gastro-oesophageal reflux disease. Meal-stimulated gastric acid secretion was calculated from the buffer capacity of the meals determined in vitro and from the time required for the gastric pH to decrease to pH 2 in vivo following ingestion of the meal. Results: There was a significant correlation between gastric secretion with each meal and the corresponding post-prandial integrated gastric acidity. There was also a significant correlation between meal-stimulated gastric secretion and integrated gastric acidity from 09.00 to 22.00 h in both subjects with gastro-oesophageal reflux disease and controls. In subjects with gastro-oesophageal reflux disease, gastric secretion and integrated gastric acidity from 09.00 to 22.00 h were significantly higher than those in controls. There was a significant correlation between oesophageal acidity and integrated gastric acidity from 09.00 to 22.00 h in subjects with gastro-oesophageal reflux disease. Conclusions: As post-prandial gastric acidity is increased in subjects with gastro-oesophageal reflux disease, it seems likely that increased gastric acidity is an important aetiological factor in this disease.