Work-Up of the Patient with Hypoglycemia

Abstract

Hypoglycemia must be recognized promptly and treated effectively, if permanent damage to the brain is to be prevented. Rational treatment demands a specific diagnosis of the disease causing the hypoglycemia. Timely determination of blood concentrations of insulin, growth hormone, and cortisol at the time of hypoglycemia can elucidate endocrinologic causes of hypoglycemia. The endocrinologist may be the first consultant to see the patient, and, if these determinations have not been made, often orders a control LED fast. It is important to educate these colleagues of the importance of obtaining metabolic testing before. Patients in whom endocrine evaluations are normal may have ketotic or hypoketotic hypoglycemia. This important distinction is best made by determination of free fatty acids, acetoacetate, and 3-hydroxybutyrate at the time of hypoglycemia. Ketotic hypoglycemia includes the disorders of carbohydrate metabolism and ketolysis as well as the transient disorder termed ketotic hypoglycemia. Hypoketotic hypoglycemia, in the absence of hyperinsulinemia, includes most of the disorders of fatty acid oxidation.