ABSTRACT
Background: The use of uncooked cornstarch every four hours remains the most efficient treatment to prevent recurrent hypoglycemia in individuals with glycogen storage diseases (GSD). However, children must wake up overnight for therapy, and delayed administration of cornstarch can be associated with hypoglycemia, seizures, neurologic injury, and death. Since the introduction of extended-release, waxy maize cornstarch (ER-CS) Glycosade as a medical food, patients and families have benefited from ER-CS by avoiding the overnight dose while maintaining metabolic control. It is recommended that individuals with GSD transitioning to ER-CS be admitted to the hospital for two nights for initial evaluation of the ER-CS dose. This recommendation was made to minimize the risk of hypoglycemia. During this hospitalization, it is recommended glucose levels be measured hourly. The ER-CS package insert states that outpatient transition may be considered if the patient has history of adherence to recommendations, good metabolic control, and the calculated dose falls within the recommended range. Detailed guidance of home transition was not provided. During the COVID-19 pandemic, our clinic developed an outpatient protocol for ER-CS transition. The goal of this protocol was to prevent unnecessary hospitalizations while safely transitioning individuals with GSD to ER-CS. Method(s): We identified patients followed in the Metabolic Genetics Clinic at Texas Children's Hospital with liver GSD who require overnight uncooked cornstarch, have a history of adherence to recommendations, and good metabolic control. Each had a working glucometer, test strips for three nights of hourly blood glucose tests, emergency rescue glucose products, and a personalized hypoglycemia action plan. The trial took place over three nights. During the first 24 h of the trial, the patient followed their previous uncooked cornstarch regimen and feeding schedule with pre-prandial glucose measures. If euglycemia was documented, ER-CS was subsequently used on nights #2 and #3. Patients were monitored with hourly blood glucose measurements and hourly ketones in GSD III or IX. ER-CS doses were calculated following the standard insert packet recommendations. If hypoglycemia was detected on either night, the dose of ER-CS was increased prior to continuing the trial. Families communicated the results of nightly blood glucose logs with the metabolic dietician on the subsequent mornings. Result(s): Three patients with GSD III and one patient with GSD Ia attempted the home ER-CS trial. All patients passed the trial. All glucose levels and ketone levels were obtained as directed. One patient had a documented blood glucose level of 69 at hour eight on the third night of the trial. The dose of ER-CS was subsequently increased. The trial was extended to a fourth night and euglycemia was maintained. No further side effects were reported in the other patients. Conclusion(s): We report successful outpatient ER-CS transitions of multiple patients with GSDs. No adverse events or significant hypoglycemic episodes were recorded during at-home trials. Thus, in patients with GSDs who are compliant with medical recommendations and under good metabolic control, at-home transition to ER-CS can be done safely and effectively without need for hospitalization.Copyright © 2023