Effect of somatostatin on basal and glucose induced insulin release in five patients with hyperinsulinaemia

Somatostatin in a dose of 490 mug over 90 min inhibited basal insulin release in one subject with hyperplasia of the pancreatic islets and in two with benign insulin secreting adenomas. These three subjects also showed a marked insulin response to glucose infusion. No inhibitory effect of somatostatin was observed in two patients with benign insulinomas who demonstrated only a minor response to glucose. In the patient with islet hyperplasia and in one of the adenoma patients, who had an exaggerated insulin response to glucose (maximal response 10-30 times the basal insulin value), somatostatin also suppressed glucose induced insulin release. Our data suggest a beneficial therapeutic effect of somatostatin in patients with spontaneous hyperinsulinism with a pronounced insulin response to glucose.