A Case of Profound Hypoglycemia in the Setting of Starvation and Beta-Adrenergic Blockade in a Patient with Hyperthyroidism

Abstract

Objective: The objectives of this case report are to describe an unusual presentation of Graves disease presenting with life-threatening hypoglycemia and to discuss rarely considered physiological mechanisms involved in this patient's hypoglycemia. Methods: Clinical evaluation in this case report involved multiple laboratory assays directed towards the confirmation and further evaluation of the potential etiology of the hypoglycemia. Insulin-mediated etiologies of hypoglycemia, hypoglycemia secondary to ingestion of sulfonylureas and glinides, and the patient's hypothalamic-pituitary-adrenal axis were evaluated through assessment of serum insulin, C-peptide, proinsulin, ACTH-stimulated cortisol, and insulin secretagogue serum concentrations. Results: Hypoglycemia associated with thyrotoxicosis is a rare phenomenon. We excluded insulin-mediated causes of hypoglycemia (given undetectable serum proinsulin, insulin, and C-peptide in the setting of concomitant hypoglycemia), oral hypoglycemic agents (given neg...