Glycated Haemoglobin Test.

Also called "hemoglobin A1c" "HbA1c" or, slightly incorrectly, "glycohemoglobin." A long and complicated name this, so what does it mean?

Well, if we break it down we find:-
The Hb bit stands for haemoglobin, a protein in the red blood cells that transports oxygen.

There are several variations of haemoglobin but the one that makes up the greatest part, about 90% in fact, is haemoglobin A.

The '1' bit is a subtype of A and the 'c' bit is a subscript to the '1'.

What is the purpose of this test?

This simple lab test shows how well your blood glucose levels are being controlled in the long term by working out the average glucose in your blood over the last 3 months.

Diabetics trying to get the disease under control should have this test every three months to check how they are doing. Once they are under good control twice a year should be enough.

How the test is done?

A sample of blood is taken at your doctor's surgery in exactly the same way as for a FBS. This blood sample is sent to a laboratory for testing, and the results are then sent back to your doctor.

How does this test measure the glucose over such a long period?

Glucose attaches to the haemoglobin in the red blood cell, in a process known as glycosylation. Once attached the glucose remains there for the life of the red cell, and a red cell can live for 120 days.

The more sugar in the blood the more of it attaches to red blood cells. In the lab the glycohaemoglobin is separated from the rest of the haemoglobin and the results are expressed as a percentage of the total.

What do the test results mean?

A result of 4-6% is that of a normal person without diabetes. People with diabetes should aim for 7% or less. If your percentages are over that then that means you need to change something in the way you are trying to control your diabetes.

What can gave an affect on the results?

1. Diseases affecting haemoglobin eg. Anaemia.
2. Supplements like Vitamins C & E.
3. High Lipid levels.
4. Kidney disease.
6. Liver disease.

If you are curious about how your HbA1C relates to that of your home blood glucose monitor then go to HBA1c Converter to find the conversion.