ESPE Abstracts

Exercise-induced hyperinsulinism is a hypoglycaemic disorder characterised by inappropriate insulin secretion following anaerobic exercise. Activating promoter mutations in the MCT1 gene (SCLA16A1), located on 1p13 coding for monocarboxylate transporter 1 (MCT1), is shown to associate with EIHI. A 2 year old girl presented with hypoglycaemic seizures following a brief period of viral illness with reduced oral intake. Investigations revealed non ketotic hypoglycaemia with a blood sugar of 1 mmmol/L. She recovered quickly with Intravenous dextrose requiring a maximum Glucose infusion rate of 10 mg/kg/minute. She remained euglycaemic for 72 hours off intravenous fluids. She also remained euglycaemic through a 15 hour period of fast in an attempt to induce hypoglycaemia. Meanwhile her hypoglycaemia screen revealed an insulin level of 142 mcIU/ml. As she did not behave like a hyperinsulinemia hypoglycaemia clinically it was considered erroneous and discharged. Within 36 hours of discharge, she re presented with hypoglycaemic seizures with a blood sugar of 1.1 mmol/L. She once again recovered quickly from the hypoglycaemia. Blood insulin levels was 322 mcIU/ml this time. Once again she recovered quickly. She was discharged on Diazoxide after 72 hours of euglycaemia. She represented once again with lethargy and hypoglycaemia when parents revealed that they had skipped a few doses of diazoxide. Blood Insulin level was 300 mcIU/ml this time. The need for compliance was reinforced. She had no further hypoglycaemic episodes on Diazoxide Further investigation with Extendin Dotonac PET scan revealed diffuse pancreatic uptake suggestive of diffuse nesidioblastoma. Genetic study revealed SLC16 A1 gene mutation which is associated with Familial hyperinsulinemic hypoglycaemia type 7(Exercise induced Hyperinsulinism). Although recommended, the parents refused the genetic test due to financial constraints. She is currently on Diazoxide with recommendation to avoid vigorous physical activity. She has had no further episodes of hypoglycaemia. Exercise induced hypoglycaemia is a very rare cause of hyperinsulinemia hypoglycaemia. Bouts of intense physical activity can lead to excessive insulin release leading to hypoglycaemia. There are only 13 reported case of EIHI worldwide. Although rare, it should also be considered as a possibility especially with individuals presenting with recurrent hypoglycaemia. Rapid diagnosis and prompt management of hyperinsulinaemic hypoglycaemia is essential to avoid hypoglycaemic brain injury, especially in the vulnerable neonatal and childhood periods