ESPE Abstracts

Combined pituitary function test is a dynamic function test used to evaluate the anterior pituitary gland in patients suspected with hypopituitarism. The test comprises insulin challenge test where intravenous insulin injection in order to induce symptomatic hypoglycemia (serum blood glucose <40mg/dL). Insufficient increase in growth hormone and cortisol after the stimulation confirms the diagnosis of growth hormone deficiency and/or adrenal function insufficiency. However, the test is often very tedious as close medical supervision is required throughout the study and the possibility of life-threatening hypoglycemia event is unpredictable. Also, capillary blood sugar test (BST) and serum glucose level may differ greatly although glucose monitoring is essential. The continuous glucose monitoring system (CGM) is a medical device that allows real-time blood glucose readings. CGM has proven to be beneficial in improving glycemic control of diabetic adolescents and adults. Herein, we provide three cases in which CGM was successfully used in conjunction to BST and serum glucose level during combined pituitary function test to better detect and induce hypoglycemia. Three patients previously diagnosed with multiple pituitary hormone deficiency during childhood were recruited to be re-evaluated at adult age. Dexcom G6 CGM was applied to each patients 5 to 7 days prior to admission. Baseline serum pituitary hormone and glucose samples were obtained before injection of intravenous insulin, gonadotrophin hormone-releasing hormone (GnRH), and thyrotropin-releasing hormone (TRH). CGM sensor glucose level and BST were simultaneously recorded every 5 minutes to assess the glycemic status and monitor when adequate hypoglycemia is reached. In all three patients, CGM sensor glucose level, BST, and serum glucose showed similar glucose trend and suitable hypoglycemia was observed. CGM can not only free patients from frequent painful skin prick tests but also observe glucose decline on real time basis. Thus, continuous glucose monitoring may be a safe aid for clinicians to use during the insulin challenge tests where critical hypoglycemia is induced.