At least once a year, your doctor should check your long-term diabetes control by taking a blood sample from your arm.
The most common test is the HbA1c test, which indicates your blood glucose levels for the previous two to three months. The HbA1c measures the amount of glucose that is being carried by the red blood cells in the body.
For most people with diabetes, the HbA1c target is below 48 mmol/mol, since evidence shows that this can reduce the risk of developing diabetic complications, such as nerve damage, eye disease, kidney disease and heart disease.
Individuals at risk of severe hypoglycaemia should aim for an HbA1c of less than 58 mmol/mol. However, any reduction in HbA1c levels (and therefore, any improvement in control), is still considered to have beneficial effects on the onset and progression of complications.
You will now be getting used to seeing your HbA1c results reported using the IFCC (International Federation of Clinical Chemistry) reference measurement procedure of mmol/mol. A rough guide to the equivalent values can be found in the following conversion table:
To help you with the transition from the percentage system you were used to, we have developed a converter:
Convert HbA1c % to mmol/mol and vice versa
Further information on the change in measurement can be found under 'Related information'.
If your red blood cells are affected by, for example, anaemia, sickle cell anaemia or thalasaemia (all of which involve a lack of or abnormal type of haemoglobin – the oxygen-carrying part) then your doctor may carry out a blood test for fructosamine.
Fructosamine gives an average result for the previous 14 to 21 days. If you normally have a fructosamine test, discuss your individual target with your doctor.
Reviewed April 2012