Hypergastrinemia is normally a physiologic response to hypochlorhydria. When hypergastrinemia occurs in the setting of acidic gastric pH, it is considered inappropriate. Gastrinoma is a component of MEN-1 syndrome that results in abnormal gastrin release and acid hypersecretion. Gastric outlet obstruction may lead to stomach distention and persistent stimulation by retained food, causing increased gastrin release and acid secretion. Chronic renal failure leads to a decrease in clearance of gastrin from the circulation, resulting in hypergastrinemia. This increase in circulating gastrin results in stimulation of parietal cells to release acid into the gastric lumen. Therefore, the hypergastrinemia associated with chronic renal failure is inappropriate, given the high serum gastrin level despite low intragastric pH. Retained antrum results when a small portion of antrum is left attached to the duodenal bulb (afferent loop) during a Billroth II surgical procedure. As a result, the G cells from the retained antrum are displaced from the stomach and excluded from the inhibitory effects of gastric acid. The lack of negative feedback leads to persistently high gastrin release and resultant acid production. H. pylori pangastritis results in suppression of acid secretion, leading to a high intragastric pH. Therefore, it represents an appropriate cause for hypergastrinemia.
1. Murugesan S.V., Varro A., Pritchard D.M. Review article: Strategies to determine whether hypergastrinaemia is due to Zollinger-Ellison syndrome rather than a more common benign cause. Aliment Pharmacol Ther. 2009;29:1055-68.