Persistent hyperinsulinaemic hypoglycaemia

Abstract

Hyperinsulinism can present throughout childhood but is most common in infancy. Persistent hyperinsulinaemic hypoglycaemia of infancy (HI) is the most important cause of hypoglycaemia in early infancy. The excessive secretion of insulin is responsible for profound hypoglycaemia and requires aggressive treatment to prevent severe and irreversible brain damage. Onset can be in the neonatal period or later, with the severity of hypoglycaemia decreasing with age. HI is a heterogeneous disorder with two histopathological lesions, diffuse (DiHI) and focal (FoHI), which are clinically indistinguishable. FoHI is sporadic and characterised by somatic islet cell hyperplasia. DiHI corresponds to a functional abnormality of insulin secretion in the whole pancreas and is most often recessive, although rare dominant forms can occur, usually outside the newborn period.