Use of Continuous Glucose Monitoring to Identify Glucose Dysregulation in Growth Hormone Insensitivity Syndrome

Abstract

Background/Aims: Monogenic forms of growth hormone insensitivity (GHI) and its treatment with recombinant insulin-like growth factor-1 (rIGF-1) are both associated with glucose dysregulation. We used the information provided by continuous glucose monitoring systems (CGMS) for the clinical management of two children with monogenic GHI prior to the commencement of therapy as well as during the years when they received rIGF-1 treatment and continued to do so after the cessation of therapy. Methods: We evaluated the extent of hyper- and hypoglycaemia with CGMS. Results: In one patient, before treatment CGMS identified self-limiting nocturnal hypoglycaemia. Initiation of rIGF-1 treatment resulted in severe and persistent hypoglycaemia with an absence of spontaneous recovery. Corrective dietary measures were instituted. In a second patient, who had a poor growth response to rIGF-1 therapy, CGMS identified significant fluctuations in daytime glucose levels whilst on treatment with evidence of postprandial hyperglycaemia and both rebound and nocturnal hypoglycaemia. Given the lack of improved growth and the documented glucose dysregulation, treatment was stopped and repeat measurements with CGMS 1 month afterwards showed complete resolution. Conclusions: We have demonstrated that CGMS is an effective tool to assess glucose dysregulation in patients with GHI and alters clinical management.