Abstract:OBJECTIVE: To study the diagnosis and treatment of persistent hyperinsulinemic hypoglycemia of infancy. METHODS: The clinical data of 12 infants with persistent hyperinsulinemic hypoglycemia were retrospectively reviewed. RESULTS: Convulsion, cyanosis, lethargy, refusing milk sucking, irritability and sweating were common symptoms. The laboratory findings displayed persistent hypoglycemia and hyperinsulinism in all of the 12 infants. The glucagon test showed positive and no urine ketones were detected in all of the 12 infants. Seven infants were treated with oral diazoxide (5-15 mg/kg daily) and 4 infants showed effective to the therapy. One patient was given subtotal pancreatectomy and the blood glucose level was restored to normal after operation. Of the 12 infants, 6 presented psychomotor retardation in a follow-up of 2 months to 67 months, 3 had loss to follow-up and 3 were still in a follow-up. CONCLUSIONS: The measurement of blood glucose, blood insulin and urinary ketons is helpful in the diagnosis of persistent hyperinsulinemic hypoglycemia of infancy. Diazoxide therapy is effective in some of patients.[Chin J Contemp Pediatr, 2009, 11 (10):809-812]