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Understanding and managing HbA1c

The HbA1c test is a measure of an average blood glucose (average blood sugar) level over the past few months and can be used as an indicator of your pre-diabetes control. Inside the body the glucose (sugar) sticks to part of the red blood cells called haemoglobin – haemoglobin is what gives blood cells their red colour.

This sugar-haemoglobin combination is called HbA1c. Once the red blood cells become ‘stuck’ to the sugar they stay stuck until the red blood cell dies. This takes about three months. As red blood cells die, new ones are produced. If the new red blood cells don’t end up with glucose stuck to them, because of better blood glucose control, then the overall HbA1c will decrease.

What do HbA1c tests measure?

The HbA1c counts the number of red blood cells that have glucose attached to them, and reports it as a percentage. The results are measured as mmol/mol. HbA1c tests need to be done by a health care professional. These are usually done every three months.

Why is testing HbA1c important?

HbA1c levels give doctors and those living with pre-diabetes invaluable information. HbA1c levels do not fluctuate quickly because once the red blood cells are attached to glucose, they remain that way until they die (up to three months). For this reason HbA1c levels give a picture of blood glucose control over a long period of time. HbA1c is an important indicator of a person’s risk of developing complications of diabetes.