A case of neonatal persistent hyperinsulinemichypoglycemia

Abstract

Neonatal hypoglycemia (NH) is a common and important cause of morbidity in newborns. The most common cause of NH is congenital hyperinsulinism (CHI), a phenotypical and genotypical heterogeneous condition characterized by inappropriate insulin secretion. In our case a male, AGA, newborn from vaginal delivery at 37-week gestation, with no risk factors in maternal history, presented with asymptomatic hypoglycemia (30 mg/dL) at 30 minutes after birth. He was subsequently admitted to the NICU because of persistent hypoglycemia associated with symptoms development (peripheral tremors). Newborns can present with a wide variety of symptoms, including irritability, tremor, feeding impairment, coma, or be completely asymptomatic. He was treated with continuous glucose infusions progressively increased to a rate of 12.7mg/kg/min. Because of persistent hypoglycemia ( 72h) and high i.v. glucose needs (10 mg/kg/min) screening tests during fast-induced hypoglycemia were performed and isolated hyperinsulinism was detected. Oral medical therapy with diazoxide was started with benefit. Genetic testing was also performed to characterize CHI. The diagnosis is usually based on clinical and biochemical findings. The mainstay of therapy is oral diazoxide administration. However, in cases refractory to medical therapy, 18F- DOPA-PET can be used to identify specific histological patterns which may need surgical intervention. Neonatal CHI-induced hypoglycemia should always be considered in the differential diagnosis of NH. Prompt diagnosis and genotypic characterization of CHI through clinical, biochemical, radiological, and genetic testing is fundamental for a proper therapeutic management of the condition and for prevention of neurological sequelae.

Keywords

• hypoglycemia
• congenital
• hyperinsulinism
• diazoxide