Glucose tolerance test

The glucose tolerance test is a medical test in which glucose is given and blood samples taken afterward to determine how quickly it is cleared from the blood. The test is usually used to test for diabetes, insulin resistance, impaired beta cell function, and sometimes reactive hypoglycemia and acromegaly, or rarer disorders of carbohydrate metabolism. In the most commonly performed version of the test, an oral glucose tolerance test (OGTT), a standard dose of glucose is ingested by mouth and blood levels are checked two hours later. Many variations of the GTT have been devised over the years for various purposes, with different standard doses of glucose, different routes of administration, different intervals and durations of sampling, and various substances measured in addition to blood glucose.

History

The glucose tolerance test was first described in 1923 by Jerome W. Conn.

The test was based on the previous work in 1913 by A. T. B. Jacobson in determining that carbohydrate ingestion results in blood glucose fluctuations, and the premise (named the Staub-Traugott Phenomenon after its first observers H. Staub in 1921 and K. Traugott in 1922) that a normal patient fed glucose will rapidly return to normal levels of blood glucose after an initial spike, and will see improved reaction to subsequent glucose feedings.