Hyperinsulinemic hypoglycemia. Differential diagnosis by determination of the species of circulating insulin.

Hypoglycemia when associated with hyperinsulinemia is usually a consequence of an insulinoma or the administration of either insulin or an insulin secretagogue. This report describes 14 patients with hypoglycemia whose diagnosis was clarified by the use of a species-specific insulin radioimmunoassay. Eleven of the 14 patients had elevated levels of animal insulin due to surreptitious accidental or malicious administration of insulin. Three of the 14 patients had hyperinsulinemia as the result of excessive human insulin release and were found to have either intrinsic pancreatic disease or secretagogue-mediated insulin release.