7621 Utility of Continuous Glucose Monitoring (CGM) In A Community Hospital Setting For Confirmation Of Hyperinsulinemic Syndrome
Authors: Castro Victor Ivan Moncada , Bharara Aditya , Flores Sully Mariel Marquez , Tsai Thomas Claudio Guillermo , Wu Marie Yung-Chen , Lock John P 
Published: October 2024

Disclosure: V.I. Moncada Castro: None. A. Bharara: None. S.M. Marquez Flores: None. T.C. Tsai: None. M. Wu: None. J.P. Lock: None.

Background: Endogenous hyperinsulinemic hypoglycemia in adults is primarily caused by insulinomas, while non-insulinoma pancreatogenous hypoglycemia (NIPH) syndrome is a rare condition, accounting for 0.5-5% of cases of organic hyperinsulinemia.The gold standard diagnostic test for insulinoma is the 72-hour fasting test, but it’s impracticality due to hospitalization, associated costs, and completion difficulties prompts the need for a simpler and cost-effective outpatient screening procedure to alleviate the testing burden on many individuals in the community and reduce associated challenges. To address this, CGM, commonly used in diabetic patients, can be leveraged to detect hypoglycemic episodes, offering a potentially more accessible and enhanced diagnostic option for non-diabetic individuals with hyperinsulinemic states. Case presentation: A 51-year-old non-diabetic female presented with unresponsiveness and hypoglycemia with a glucose level of 34mg/dL upon arrival. Glucagon and dextrose administration led to gradual recovery to her baseline. She reported three significant previous episodes of neuroglycopenic symptoms within the last 7 months. Despite regularly exercising at the gym, she noticed weight gain of around 20 pounds within the past year, attributed to increased meals frequency to relieve the symptoms. Notably, her history is negative for bariatric surgeries or alcohol use. Evaluation revealed obesity (BMI 30.3 kg/m2). Her HA1c was 5.6%, and C-peptide within normal range. The sulfonylurea panel was negative. Negative insulin antibodies, negative IGF-2. Normal morning cortisol, ACTH and thyroid function test. Unable to conduct a 72-hour fasting test in the hospital, the patient was discharged, opting for a conservative 12-hour outpatient fasting insulin assessment after discussing risks and benefits. Fasting insulin level was inappropriately high, 21.8 mcU/mL, suggesting potential hyperinsulinemic hypoglycemia. An abdominal CT scan with IV and oral contrast revealed no pancreatic abnormalities. Utilizing CGM, symptomatic episodes with glucose levels between 45 and 70mg/dL were successfully captured, correlating with the patient’s symptom diary.The etiology of our patient’s endogenous hypoglycemia awaits us, but the utility of this outpatient test underscores its advantages in diagnosing this life-threating condition in nondiabetic patients. Conclusion: Identifying and managing hyperinsulinemic hypoglycemia is complex, but innovative approaches, like integrating CGM systems, have the potential to transform the diagnosis of this condition. These advancements offer simpler and more cost-effective diagnostic procedures, aiming to enhance patient outcomes and optimize the management of hyperinsulinemic hypoglycemia.

Presentation: 6/3/2024