IDIOPATHIC GASTRIC-ACID HYPERSECRETION - COMPARISON WITH ZOLLINGER-ELLISON SYNDROME

Many patients with acid-peptic disease have idiopathic gastric acid hy persecretion defined as a basal acid output >10.0 meq/hr; however, a s ignificant proportion have basal acid outputs >15.0 meq/hr, which is w ithin the range found in Zollinger-Ellison syndrome. Although idiopath ic gastric acid hypersecretion is more common than Zollinger-Ellison s yndrome, it is important that these two disorders be differentiated be cause of differences in treatment and natural history. In the present study, we compared 124 patients with idiopathic gastric acid hypersecr etion and 137 patients with Zollinger-Ellison syndrome. There were no significant differences with regard to age at diagnosis, history of up per gastrointestinal hemorrhage, nausea, vomiting, and family history of duodenal ulcer and other acid-peptic disease. However,;significant differences were observed between patients with idiopathic gastric aci d hypersecretion and patients with Zollinger-Ellison syndrome with reg ard to percentage of males: 77% compared to 64% (P = 0.008), mean seru m gastrin: 60 pg/ml compared to 3679 pg/ml (normal <100 pg/ml) (P < 0. 001), mean basal acid output: 15.4 meq/hr compared to 47.0 meq/hr (P < 0.001), mean age at onset of symptoms: 33 years compared to 41 years (P < 0.001), mean duration of symptoms before diagnosis: 11 years comp ared to five years (P < 0.001), percentage with abdominal pain: 67% co mpared to 82% (P = 0.00004), percentage with diarrhea: 12% compared to 75% (P < 0.000001), percentage with pyrosis: 58% compared to 40% (P = 0.003), percentage with duodenal ulcer: 53% compared to 74% (P < 0.00 0001), and percentage with esophagitis: 31% compared to 42% (P = 0.000 4). The differences in clinical features could be attributed to differ ence in mean basal acid output, and/or differences in levels of basal acid output used for diagnosis of idiopathic gastric acid hypersecreti on (basal acid output >10.0 meq/hr) and Zollinger-Ellison syndrome (ba sal acid output >15.0 meq/hr). When 45 patients with idiopathic gastri c acid hypersecretion and 39 patients with Zollinger-Ellison syndrome with basal acid outputs 15.1-30.0 meq/hr were compared, the main signi ficant differences were with regard to mean serum gastrin: 69 pg/ml co mpared to 655 pg/ml (P < 0.001), percentage of male gender: 82% compar ed to 62% (P = 0.03), and percentage with diarrhea: 16% compared to 64 % (P = 0.000005). These results indicate that in general patients with idiopathic gastric acid hypersecretion and patients with Zollinger-El lison syndrome often have similar clinical features that can be diffic ult to distinguish. However, the increased frequency of diarrhea and f emale gender should lead to a strong suspicion of Zollinger-Ellison sy ndrome, which can be distinguished in almost every case by measurement of serum gastrin.