A case of congenital hyperinsulinism presenting with diabetes after long-term diazoxide therapy.

Congenital hyperinsulinism (CHI) is the most common form of persistent hypoglycemia in infants, and diazoxide is the most widely used drug for its treatment. Diazoxide suppresses insulin secretion and attenuates hypoglycemia by binding to sulfonylurea receptor 1 and activating K channels. While the short-term side effects of this drug, such as edema and blood cell abnormalities, are well known, the clinical course after its long-term oral administration remains unclear. Furthermore, there are currently no case reports clearly demonstrating a causal relationship between diazoxide and impaired glucose tolerance. We herein describe the case of a 9-year-old girl with CHI complicated with Kabuki syndrome who presented with impaired glucose tolerance due to decreased initial insulin secretion and insulin resistance caused by obesity resulting from diazoxide medication. This is a rare case of the insufficient effects of insulin due to the oral administration of diazoxide, and provides insights for managing the long-term administration of diazoxide to children.