SUN-621 Unraveling the Mystery: A Case of Non-Diabetic Hypoglycemia Attributed to Malnutrition

Abstract Disclosure: J. Samavedam: None. T. Dhar: None. Introduction: Hypoglycemia is common in the inpatient setting and associated with increased mortality. Given the broad differential diagnosis, identifying the underlying cause of hypoglycemia may be challenging. We report a case of asymptomatic hypoglycemia in a non-diabetic patient, describing how evaluation led to consideration of an often overlooked etiology - malnutrition. Clinical Case: A 75-year-old male with malnutrition (baseline albumin of 1.9 g/dL) presented with hypothermia, hypotension and hypoglycemia. He was admitted for urosepsis and treated with antibiotics, vasopressors and stress dose hydrocortisone. Despite resolution of sepsis, hypoglycemia persisted with blood sugars ranging from 40-70 mg/dL. Hypoglycemia was primarily in the setting of fasting. The patient was asymptomatic so Whipple’s triad was not met. He did not receive insulin or oral hypoglycemic agents and screened negative for sulfonylurea use. Hemoglobin A1c was 5.0% excluding diabetes. High dose cosyntropin stimulation test was performed 48 hours after discontinuing hydrocortisone. Morning cortisol was greater than 20 mcg/dL at baseline and one hour after cosyntropin administration. Baseline ACTH level was 14.3 pg/mL (RR: 7.2-63.3 pg/mL). As such, primary and secondary adrenal insufficiency were ruled out. Thyroid function tests were within reference ranges. Pituitary imaging was not pursued as biochemical evaluation did not suggest a central etiology. Hypoglycemia was provoked through a supervised fast during which patient remained asymptomatic. When blood sugar reached a nadir of 42 mg/dL, C-peptide, proinsulin and serum insulin levels were undetectable, with appropriately elevated beta-hydroxybutyrate. This ruled out endogenous and exogenous hyperinsulinemia. Insulin autoimmune syndrome and non-islet cell tumor hypoglycemia were ruled out given absence of insulin antibodies and low IGF-2 level (248 ng/mL, RR: 267-616 ng/mL). Having excluded other etiologies, patient's fasting, non-insulin mediated hypoglycemia was attributed to chronic malnutrition. Discussion: This patient’s hypoglycemia is unusual as it occurred in the absence of factors such as diabetes, alcohol use, bariatric surgery, renal or liver disease. This case is also notable for hypoglycemic unawareness and draws attention to how evaluation may be more challenging when clinical criteria such as Whipple’s triad cannot be applied. Malnutrition is thought to cause hypoglycemia due to reduced glycogen stores and impaired gluconeogenesis. Management consists of modifying diet to consume small, frequent meals rich in complex carbohydrates. This case warrants reporting as it demonstrates an atypical presentation of hypoglycemia and highlights a less common etiology. There is also educational value in revisiting the differential diagnosis and stepwise evaluation of hypoglycemia through the lens of this case. Presentation: Sunday, July 13, 2025