Glycosylated Hemoglobin (HbA1c)

Specimen Required

3cc EDTA BLOOD (CBC VIAL)

Fasting Required

Purpose of the Test

To monitor average blood glucose levels in someone with diabetes and to help treatment decisions. It can also be used to make a diagnosis of type 2 diabetes and to identify prediabetes.

When this test is required

The Department of Health recommends that everyone with diabetes has HbA1c measured at least twice a year. HbA1c may be measured more frequently in those who have just been diagnosed with diabetes, in those whose blood glucose remains too high, or when a treatment plan changes. The test can also be used to diagnose type 2 diabetes. Please speak to your healthcare professional about local guidelines that may be in place, as there maybe variations in local procedures., and there are certain groups of patients in which HbA1c cannot be used to diagnosis diabetes.

What the Test Detects

Some of the glucose in your blood binds to haemoglobin (the protein that carries oxygen in your red blood cells). This combination of glucose and haemoglobin is called haemoglobin A1c (HbA1c). The amount of HbA1c formed is directly related to the average concentration of glucose in your bloodstream. Red blood cells live for 2–3 months, and because of this, the amount of HbA1c in your blood reflects the average level of glucose in your blood during the last 2-3 months. If your diabetes is not well controlled, your blood glucose levels will be high causing higher HbA1c levels.See MoreSee Less

Preparation for the Test

None

Sample Requirements

A blood sample taken from a vein in the arm

Additional Notes

If you have an uncommon type of haemoglobin, known as a haemoglobin variant (for example thalassaemia or sickle cell disease) , accurate results will depend on the method used to measure HbA1c. If you have haemolytic anaemia or heavy bleeding, your test results may be falsely low. If you are iron deficient, this may raise your HbA1c result. HbA1c is not used for diagnosis of diabetes during pregnancy.

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