Prab at 02:42, 22 May 2023

2023-05-22T02:42:51Z

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'''Glycated hemoglobin''' (commonly referred to as HbA1c) is a form of [[hemoglobin]] (Hb) that is chemically linked to a [[sugar]], usually [[glucose]]. This process, known as glycation, occurs when glucose in the bloodstream attaches to the hemoglobin molecule non-enzymatically, i.e., spontaneously without the help of an enzyme<ref>{{cite journal |title=The pathobiology of diabetic complications: A unifying mechanism |url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1083337/ |journal=Diabetes |year=2005 |volume=54 |issue=6 |pages=1615–1625 |author=Brownlee, M}}</ref>.
[[File:GlycationViaAmadoriRgmt.svg|Glycated|thumb]]
==Biochemical Basis==

Monosaccharides such as glucose, [[galactose]], and [[fructose]] can spontaneously bond with hemoglobin when present in the bloodstream. However, glucose is less likely to do so than galactose and fructose, which may explain why glucose is used as the primary metabolic fuel in humans<ref>{{cite book |title=Essentials of Glycobiology |url=https://www.ncbi.nlm.nih.gov/books/NBK310274/ |year=2017 |edition=3rd |publisher=Cold Spring Harbor Laboratory Press |author=Varki, A., Cummings, R.D., Esko, J.D., et al.}}</ref>.

==Clinical Significance==

The percentage of glycated hemoglobin in an individual's blood is directly proportional to the average blood glucose concentration over the previous three months, which is the lifespan of a red blood cell. Therefore, HbA1c is a useful long-term marker of blood glucose control and is used as a diagnostic and monitoring tool in the management of [[diabetes mellitus]]<ref>{{cite journal |title=Hemoglobin A1c (HbA1c) and blood glucose (BG) equivalents |url=https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2911067/ |journal=Diabetes Technology & Therapeutics |year=2010 |volume=12 |issue=6 |pages=399–418 |author=Bode, B.W., et al.}}</ref>.

==Testing and Interpretation==

HbA1c levels are typically measured by blood tests conducted in a clinical laboratory. An HbA1c level of 6.5% or higher on two separate tests indicates diabetes. A result between 5.7% and 6.4% is considered prediabetes<ref>{{cite web |title=A1C test |url=https://www.mayoclinic.org/tests-procedures/a1c-test/about/pac-20384643 |publisher=Mayo Clinic |accessdate=2023-05-18}}</ref>.

==See Also==

* [[Hemoglobin]]
* [[Diabetes mellitus]]
* [[Prediabetes]]
==References==
<references />
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{{diabetes}}
[[Category:Biochemistry]]
[[Category:Diabetes]]
[[Category:Blood tests]]
[[Category:Clinical medicine]]

Glycated hemoglobin - Revision history

Prab at 02:42, 22 May 2023