Patients with type I glycogen storage disease (glucose-6- phosphatase deficiency) have marked hypoglycemia in infancy but tend to become normoglycemic as they grow older. In addition, these patients characteristically demonstrate abnormal glucose tolerance curves. Since a major mechanism for the maintenance of normal blood glucose levels is lacking in this disease, investigation of the levels of circulating insulin and the regulation of its release in a group of such patients was made.
Three well-known stimuli for secretion of insulin in normal man were studied in two adolescent and three adult patients with type I glycogen storage disease. Basal plasma insulin levels were repeatedly approximately 50 to 60 per cent ot normal. Ingestion of glucose alone, glucose plus prtrteiu Or infusion of arginine monochlorid resulted in significantly less than normal increase in insulin.