Effects of octreotide on circulating islet B cell products in endogenous hyperinsulinism

Summary: The role of somatostatin analogues in the medical management of insulinomas is unclear. We describe an elderly patient with clinical and biochemical features of endogenous hyperinsulinism attributable to a benign islet B cell disorder whose incapacitating neuroglycopaenic symptoms responded dramatically to octreotide 50 pg subcutaneously at 2200 h each night. Octreotide suppressed inappro-priate plasma concentrations ofinsulin thereby preventing fasting hypoglycaemia. Fasting concentrations of proinsulin, and 32-33 split proinsulin, as determined by two-site monoclonal antibody-based immunoradiometric assays, were also suppressed by octreotide