MON-LB024 Episodic Hypoglycemia in Non-Diabetics: Differentiating Distressing from Deadly

Introduction: Hypoglycemia is rare in patients without diabetes and requires investigation if Whipple’s triad is met. Case Description: Two patients were admitted to the same facility for workup of symptomatic hypoglycemia. Patient A is a 71-year-old man who self-presented due to concern for worsening cognition that was later found to correspond to blood glucose [BG] below 60 mg/dL. Patient B is a 70-year-old man who had a BG of 46 mg/dL on routine labs and was then fitted with a continuous glucose monitor [CGM] that reported nocturnal and post-prandial glucose values <50 mg/dL that corresponded to symptoms of hypoglycemia. Both patients were placed on a 72-hour supervised fast. Patient A’s fast ended after 12 hours. His BG was 38 mg/dL, beta-hydroxybutyrate [BOHB] 0.14 mmol/L, insulin 1.9 μIU/mL, and proinsulin 47 pmol/L. His CT, MRI, and EUS did not reveal any abnormalities, but a Ga-68-dotatate scan showed disease in the uncinate process. Patient B’s fast ended after 55 hours. His BG was 67 mg/dL, BOHB 1.24 mmol/L (peak 2.23 mmol/L), insulin <1.0 μIU/mL, and proinsulin 8.7 pmol/L. Patient A was treated with diazoxide while awaiting surgery. Patient B was discharged with instructions for dietary modification. Discussion: In addition to demonstrating the importance of differentiating life-threatening hypoglycemia from physiologic excursions, a comparison of these patients’ cases underscores the advantages and disadvantages posed by the use of certain emerging technologies in the work up of hypoglycemia. Patient A’s case suggests that Ga-68-dotatate scans can be invaluable for the localization of neuroendocrine tumors although they are not indicated for this purpose. Patient B’s case illustrates the pitfalls of “false positives” on CMG, which measures interstitial rather than BG, for the work up of hypoglycemia. References: Cryer PE, Axelrod L, Grossman AB, Heller SR, Montori VM, Seaquist ER, Service FJ. Evaluation and management of adult hypoglycemic disorders: an endocrine society clinical practice guideline. J Clin Endocrinol Metab. 2009; 94 (3): 709-28. Hofman MS, Lau WF, Hicks RJ. Somatostatin receptor imaging with 68Ga DOTATATE PET/CT: clinical utility, normal patterns, pearls, and pitfalls in interpretation. 2015. Radiographics. 35(2): 500-16. Keen CE. PET/CT radiopharmaceutical agent 68-Ga-Dotatate better identifies neuroendocrine tumors. (June 2016). Retrieved Jan 2, 2019 from https://appliedradiology.com/articles/pet-ct-radiopharmaceutical-agent-68ga-dotatate-better-identifies-neuroendocrine-tumors Service FJ, O’Brien PC. Increasing serum betahydroxybutyrate concentrations during the 72-hour fast: evidence against hyperinsulinemic hypoglycemia. J Clin Endocrinol Metab. 2005; 90 (8): 4555-8. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.