Editing Glucose tolerance test (section)

{{Short description|Medical test of how quickly glucose is cleared from the blood}}
{{Infobox diagnostic
| name            = Glucose tolerance test
| image           = Glucose metabolism.svg
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| caption         = A diagram of [[glucose]] metabolism
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| purpose         = To determine how quickly glucose is cleared from blood
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The '''glucose tolerance test''' ('''GTT''', not to be confused with [[GGT 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.<ref>{{MeshName|Glucose+Tolerance+Test}}</ref> The test is usually used to test for [[Diabetes mellitus|diabetes]], [[insulin resistance]], impaired [[Pancreatic beta cell function|beta cell function]],<ref name="pmid21802577">{{cite journal|vauthors=DeFronzo RA, Abdul-Ghani M|title=Assessment and treatment of cardiovascular risk in prediabetes: impaired glucose tolerance and impaired fasting glucose|journal=[[American Journal of Cardiology]]|volume=108|issue=3&nbsp;Suppl|year=2011|pages=3B–24B |doi=10.1016/j.amjcard.2011.03.013|pmid=21802577}}</ref> 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.<ref name=IQWiG-GTT>{{cite web|last=Institute for Quality and Efficiency in Health Care|title=Glucose tolerance test: how does it work exactly?|url=https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0010385/|work=Informed Health Online|publisher=Institute for Quality and Efficiency in Health Care|access-date=22 June 2013}}</ref> 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.