What is glycohemoglobin (glycosylated hemoglobin) test?
It is a blood test for blood sugar and reflects a person’s average blood sugar over 3 months because HbA1c binds irreversibly to glucose (glycated Hb) throughout the life span of RBC (120 days).
- Glycohemoglobin Measures the amount of the blood sugar bound to certain components of hemoglobin A and is expressed as %
- In normal adult hemoglobin, hemoglobin A comprises 97% of total Hb
- Hb A contains three minor components; HbA1a, HbA1b, HbA1c (A1C)
- HbA1c binds irreversibly to glucose (glycated Hb) throughout the life span of RBC (120 days). Hb A1c is also known as A1C.
- A1C has high correlation with average plasma glucose and diabetes complications such as retinopathy, renopathy, neuropathy, and others.
- A normal individual’s A1C value would be 4-6% (using the DCCT assay)
- The test has other names such as HbA1c test, and A1C test.
How is A1C being used?
- A1C is directly proportional to the mean (average) blood glucose as well as microvascular and macrovascular complications of DM.
- HbA1c has become a standard assessment of DM medical care since 1993
- HbA1c reflects average glycemia (blood sugar) over the previous 3 months
- HbA1c has been used to monitor glycemic control and to determine whether the patient has achieved the treatment goal
- HbA1c less than 7% has become a part of ADA’s standard care since 1995 for most non-pregnant adult diabetes patients.
– Currently, the American Diabetes Association recommendation for non-pregnant patients is less than 7%