Hypoglycemia in the Non-diabetic Patient

Under most physiologic conditions encountered in modern life, glucose is the brain’s obligate fuel (Cryer, 117:868-870, 2007). Inadequate provision of glucose to the brain exposes neurons to a high risk of dysfunction and/or injury. Profound or prolonged hypoglycemia may result in cognitive dysfunction, seizures, and, in extreme cases, brain death (Cryer, N Eng J Med 117:868-870, 2007). Therefore, hypoglycemic disorders, although uncommon (Service, J Clin Invest 332:1144-1152, 1995), are clinically relevant. Because symptoms of hypoglycemia such as tachycardia, sweating, tremors, and nervousness are not specific to hypoglycemia, to diagnose a hypoglycemic disorder, it is necessary to document low plasma glucose concentration with concomitant neuroglycopenic symptoms. These symptoms must improve or resolve after correction of the hypoglycemia. This is the basis of Whipple’s triad (Whipple, Can Med Assoc J 66:334-342, 1952). The documentation of Whipple’s triad must underpin the diagnosis of a hypoglycemic disorder. In this chapter, we review the clinical manifestations, causes, evaluation, and management of hypoglycemia in non-diabetic patients.