Insulin secretion in the Zollinger-Ellison syndrome

The insulin response to oral glucose ingestion was measured in six patients with the Zollinger-Ellison (ZE) syndrome, five patients with partial gastrectomy (antrectomy for duodenal ulcer) and six matched normal subjects. The blood glucose curves were similar in ZE-patients and gastrectomized controls and significantly above the glucose concentrations in normal controls. The insulin response was three-doubled in ZE-patients, whereas gastrectomized controls only doubled their response in comparison with the normal subjects. Treatment of a hepatic gastrinoma by streptozotocin infusion into the hepatic artery in a patient with diabetes mellitus and hyperinsulinism almost normalized his glucose tolerance and insulin secretion. The results demonstrate that the ZE-syndrome is associated with increased insulin release. We suggest that the hyperinsulinism partly is a consequence of previous gastric surgery and partly due to the insulinogenic effect of gastrin.