Hyperinsulinemia-induced hypoglycemia is the most common cause of persistent hypoglycemia in adults, children, and infants. Our understanding of the disorders responsible for this type of hypoglycemia has been increasing due to the recent discoveries in the molecular and biochemical regulation of insulin secretion. In this article, we review the current knowledge of the pathophysiology, clinical presentation, and diagnosis of disorders that cause hyperinsulinemic hypoglycemia of infancy. We highlight the distinction between the diffuse and focal forms of the disease, especially the promising results with 18F-L-dopa positive emission tomography (PET) scanning for preoperative localization and distinction to guide the extent of surgical removal of pancreatic tissue that may result in cure rather than persistence of disturbed carbohydrate metabolism.
Conclusion: Despite all these discoveries, much remains to be learned, as currently about one third of infants with hyperinsulinemic hypoglycemia have no identifiable cause.