The Hypoglycemic States

Introduction

Spontaneous hypoglycemia in adults is of two principal types: fasting and postprandial. Symptoms begin at plasma glucose levels in the range of 60 mg/dL and impairment of brain function at approximately 50 mg/dL. Fasting hypoglycemia is often subacute or chronic and usually presents with neuroglycopenia as its principal manifestation; postprandial hypoglycemia is relatively acute and is often heralded by symptoms of neurogenic autonomic discharge (sweating, palpitations, anxiety, tremulousness).

The Hypoglycemic States

Introduction

Hypoglycemia due to Pancreatic B cell tumors

Persistent Islet Hyperplasia(NonInsulinoma Pancreatogenous Hypoglycemia Syndrome)

Hypoglycemia Due to Extrapancreatic Tumors

Postprandial Hypoglycemia (Reactive Hypoglycemia)

Alcohol-Related Hypoglycemia

Factitious Hypoglycemia

Immunopathologic Hypoglycemia

Drug-Induced Hypoglycemia

Differential Diagnosis

Fasting hypoglycemia may occur in certain endocrine disorders, such as hypopituitarism, Addison's disease, or myxedema; in disorders related to liver malfunction, such as acute alcoholism or liver failure; and in instances of renal failure, particularly in patients requiring dialysis.

Clinical Findings

These conditions are usually obvious, with hypoglycemia being only a secondary feature. When fasting hypoglycemia is a primary manifestation developing in adults without apparent endocrine disorders or inborn metabolic diseases from childhood, the principal diagnostic possibilities include (1) hyperinsulinism, due to either pancreatic B cell tumors or islet hyperplasia or surreptitious administration of insulin (or sulfonylureas), and (2) hypoglycemia due to non-insulin-producing extrapancreatic tumors.