HbA1c (glycosylated haemoglobin) is your average blood glucose (sugar) levels for the last two to three months. It provides a good indication of glycaemic control over the previous 2-3 months and should be measured every 3- 6 months. It is important that you know what HbA1c is, what your result means and what to do if it is too high because a little increase in the levels of your HbA1c could lead to diabetic complications.
The World Health Organisation (WHO) recommendations that
“HbA1c can be used as a diagnostic test for diabetes providing that stringent quality assurance tests are in place and assays are standardised to criteria aligned to the international reference values, and there are no conditions present which preclude its accurate measurement.”
An HbA1c of 6.5% is recommended as the cut point for diagnosing diabetes. A value of less than 6.5% does not exclude diabetes diagnosed using glucose tests.”
What does HbA1c mean?
HbA1c glycated haemoglobin is produced when the glucose (sugar) in your body sticks to your red blood cells. When your body can’t use the sugar properly more of it sticks to your blood cells and builds up in your blood. Red blood cells live for about 2-3 months, which is why the test is carried out every three months.
The HbA1c test
You can check your HbA1c yourself if you have a kit, but it is best for your doctor, or some medical laboratories around do it for you. The home testing kits is useful as it gives you the chance to get a good idea of your HbA1c level in between getting scheduled HbA1c tests from your doctor.
However, the home tests should not be used as a substitute for the tests from your doctor and should be not be used in place of an official diagnosis. You can check it every 3-6 months. You may need it more often if you’re blood sugar levels are not stable, planning to get pregnant, or if you recently changed treatment. The test is sometimes called haemoglobin A1c or A1c.
You should get the results quickly. The result of the test lets your doctor know if they need to make any changes to your treatment or medication. The test will give you a result in the form of a number. It is important that you understand what this number means and what your target level is. It may be worth keeping a diary of the result to help you keep track of your treatment.
HbA1c can change because you have changed your diet or exercise regimen, if you have been ill, if you take a medication that can alter glucose level like steroids or even if you’re stressed.
Ideal levels and targets
The ideal HbA1c level after you have been diagnosed with diabetes is 48mmol/mol (6.5%) or below. However, as everyone is different, your doctor may give you an individual target. If you’re at risk of Type 2 diabetes, your target level should be below 42mmol/mol (6%).
Conditions where HbA1c is not appropriate for the diagnosis of diabetes include:
- Pregnant women
- Those who high risk who are acutely ill
- Children and young people
- When Type 1 diabetes is suspected
- Those who have had symptoms of diabetes for less than 2 months
- Those who have increased red cell survival e.g splenectomy.
- Renal dialysis patients
- Those who have iron and B12 deficiency
- Those who are taking medications that may cause a rapid increase in glucose levels e.g. steroids
- Those who have acute pancreatic damage or pancreatic surgery
- Those whose HbA1c is under 48 mmol/mol (6.5%)
- Those who have haemoglobinopathy
- Those who have haemolytic anaemia
- Those who have severe blood loss
- Those who have splenomegaly
- Those who are taking antiretroviral drugs