Introduction: Congenital hyperinsulinism (CHI) is a rare genetic disorder of unregulated insulin secretion from the pancreatic β-cells leading to severe hypoglycaemia & permanent neurological deficit if not managed appropriately. Kenotic hypoglycaemia (KH), a diagnosis of exclusion, is by far the most common form of hypoglycemia in children between 15 years of age characterized by recurrent episodes of hypoglycaemia and ketosis.
Aim: To identify the prevalence of kenotic hypoglycaemia in children who had previously been diagnosed with transient CHI.
Methods: Retrospective data of 142 patients with persistent/recurrent hypoglycaemia was analysed. Diagnosis of KH was confirmed by documented low levels of insulin and C-peptide with appropriately elevated free fatty acids, 3-betahydroxybutyrate, cortisol and growth hormone during hypoglycaemia.
Results: Out of the 53 children with transient CHI, 5 children (9.4%) demonstrated KH after resolution of CHI. All were boys with mean (±SD) birth weight of 2.82 kg (±0.45). The average age of initial presentation with hypoglycaemia was 46.8 hours. The mean blood glucose concentration was 1.98 mmol/l (±0.72). All patients required high glucose infusion rate initially 13.70 mg/kg per min (±1.57). 4(80%) children required diazoxide to control the persistent hypoglycaemia [mean dose 7.38 mg/kg per day (±1.94)]. Diazoxide therapy was discontinued at a mean age of 11.25 months (±5.25). The mean age of presentation of KH was 18 months (±2.16). KH developed after an average time period of 6.7 months following the resolution of CHI.
Conclusion: Children with transient CHI are at risk of subsequently developing KH at a variable age period. This emphasises the need for close follow up of these children for early identification of KH and to initiate appropriate management. Further studies are required to understand the change in glucose abnormalities from CHI to KH in this group of patients.