Long term follow up of persistent hyperinsulinaemic hypoglycaemia of infancy

Twenty six children with hypoglycaemia were diagnosed and followed between 1975 and 1995. Diagnosis was confirmed by a high insulin:glucose ratio, and low free fatty acid and 3-hydroxybutyrate on fasting. All patients were treated with diazoxide at a maximum dose of 20 mg/kg/day. Requirement of a higher dose was considered as a failure of medical treatment and an indication for surgery. Sixteen children responded to diazoxide; 10 failed to respond and underwent pancreatic resection. Six of the latter group started with symptoms in the neonatal period. Eleven of the 26 children have neurological sequelae. Head growth and neurological outcome correlated well. Additionally, non-specific electroencephalogram abnormalities (slow waves) appear to he indicative of subclinical hypoglycaemia during follow up.