Hemoglobin A1C (HbA1C) or Glycosylated hemogobin
Blood sugar in the blood react with hemoglobin in non-enzymatic reaction called glycation. Hemoglobin is protein with heme(iron) in the middle of the hemoglobin structure inside red blood cell. Life span of hemoglobin is between 90 to 120 days. The glycated hemoglobin (HbA1c) is permanent until breakdown of red blood cell. Therefore Hemoglobin A1C evaluates long-term blood sugar control over three to four months period.1-3 Glycation plays an important role in the development of diabetic retinopathy resulting in blindness, diabetic neuropathy resulting in nerve damage, and diabetic nephropathy resulting in kidney failure.9
This glycation level is a reflection of this detrimental reaction.
Random blood sugar either fasting or post-meal finger print spot test is not reflecting the true control of blood sugar because it is subject to daily or even hourly variation. Sometimes the patient avoid sugary food and strictly fasting from carbohydrate the day or overnight before random blood sugar test, intentionally or not. Intentionally meaning they want to please themselves or their doctor that they have good blood glucose control. Here, HbA1c reflect much better picture of true blood sugar control.
The drawback is HbA1c still less reflective of glucose spike after meal which also deadly.
However it is practical and accurate to assess blood sugar control as well as diagnostic for diabetic. Level above 7.3% associated with accelerated complications of diabetic and accelerated aging. Since glycation is one of the leading theories of aging,4-8 HbA1c should be checked by everybody.
Doctors often follow this blood test in diabetics to monitor disease progression and the effects of treatment. This test does not require fasting. Take all prescription medications as prescribed … but do not take your supplements the morning of the test.
Normally 4 to 6 percent of hemoglobin is glycosylated, which corresponds to average blood glucose between 3.3mmol/L and 6.6 mmol/L. For diabetics, a healthy HbA1c level is less than 7 percent, which corresponds to an average blood glucose level of 8.3 mmol/L or less.
1. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/003640.htm. Accessed January 16, 2008.
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3. Osterman-Golkar SM, Vesper HW. Assessment of the relationship between glucose and A1c using kinetic modeling. J Diabetes Complications. 2006 Sep;20(5):285-94.
4. O’Sullivan JB, Mahan CM. Mortality related to diabetes and blood glucose levels in a community study. Am J Epidemiol. 1982 Oct;116(4):678-84.
5. Asadollahi K, Beeching N, Gill G. Hyperglycaemia and mortality. J R Soc Med. 2007 Nov;100(11):503-7.
6. Palumbo F, Bianchi C, Miccoli R, Del PS. Hyperglycaemia and cardiovascular risk. Acta Diabetol. 2003 Dec;40(Suppl 2):S362-9.
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8. Robert L, Robert AM, Fulop T. Rapid increase in human life expectancy: will it soon be limited by the aging of elastin? Biogerontology. 2008;Jan 4.
9. Nawale RB, Mourya VK, Bhise SB. Non-enzymatic glycation of proteins: a cause for complications in diabetes. Indian J Biochem Biophys. 2006 Dec;43(6):337-44.