Monitoring blood glucose in type 1 diabetes
Tests to monitor diabetes
HbA1c glycated haemoglobin test
People with diagnosed diabetes (type 1 or type 2) will need to have their blood glucose levels monitored using the HbA1c (glycated haemoglobin) test.
HbA1c is a substance found normally in your blood that is made up of glucose attached to haemoglobin (the Hb in HbA1c), which is present in everyone’s red blood cells. High levels of glucose in the blood result in high levels of HbA1c.
Glucose testing strips. An arrow shows you which end of the test strip to insert into the glucose meter.
How is the test done?
A blood sample will be taken and sent to a laboratory for testing. The test should be done at least once every 6 months, or as often as your health professional recommends.
What does it tell me?
The HbA1c test measures your average blood glucose level over the previous 3 months, and gives a reliable estimate of how well your diabetes is being managed. This will help a health professional to decide whether your diet and diabetes medicine are controlling your diabetes effectively or if these need to be changed.
For most people, the recommended level of HbA1c is 7% (53 mmol/mol) or less. If the HbA1c level is higher than 7% (53 mmol/mol), it means that your blood glucose has been too high in the past 3 months. Your health professional will advise you about your target HbA1c target and what you can do to achieve it.
In Australia, HbA1c testing is currently only used for monitoring diabetes treatment after diabetes has been diagnosed, but in some countries, the test is also used to diagnose diabetes.
The HbA1c units are changing
Until July 2011, your HbA1c result was reported only as a percentage (%). From now until July 2013, your result will be presented both as a percentage and as another unit called millimoles per mole (mmol/mol).
After July 2013, your HbA1c result will only be reported in mmol/mol. For example, a result of 7% will now be reported as 53 mmol/mol.
This change has been made to standardise the way HbA1c results are reported in all countries world-wide.
Glucose monitor and a blue finger-prick device, next to an unused glucose test strip. The glucose meter indicates a reading of 8.4 mmol/L glucose from the blood sample on the inserted test strip.
The new way of reporting the units will not mean any changes to the way you are tested, your HbA1c target, or how often you need to be tested. It is simply a different way of reporting the same HbA1c result.
NPS has developed an HbA1c unit converter to help you convert your old HbA1c result into the new mmol/mol unit. Find out more about what the unit change means for you and use the calculator to convert your old units into the new.
How often will the test be done?
The ‘finger prick’ test is a test that you can do to check your own blood glucose levels. It doesn’t involve a laboratory test — you can do the test quickly and easily at home, or when you are out exercising, for example.
If you have type 1 diabetes, you should regularly monitor your own blood glucose levels.
How is the test done?
The test involves applying a pin-prick droplet of blood from a finger to a disposable 'test strip' that has been inserted into a glucose meter. Wash your hands first. Avoid using your forefinger or thumb. A glucose meter is a small electronic device that reads the amount of glucose in your blood on the test strip.
A glucose monitoring device taking a reading from a glucose test strip.
The test can be done first thing in the morning before a meal (a ‘fasting’ test), or at other times of the day, for example 2 hours after a meal. If the test is performed first thing in the morning before eating food, the target blood glucose reading should be between 6–8 millimoles [mmol] per litre [L], and 2 hours after a meal, it should be 6–10 mmol/L.
What does it tell me?
The glucose monitoring device shows the blood glucose level at the time the blood sample is taken. Self-monitoring your blood glucose can help you to manage your blood glucose levels and to keep a record of all blood glucose readings over time, which you show to a health professional. This can help to identify any problems with your diet or the day-to-day management of your diabetes.
- Craig ME, Twigg SM, Donaghue KC, et al for the Australian Type 1 Diabetes Guidelines Expert Advisory Group. National evidence-based clinical care guidelines for type 1 diabetes in children, adolescents and adults. Canberra: Australian Government Department of Health and Ageing, 2011. www.diabetessociety.com.au/downloads/Type1guidelines14Nov2011.pdf (accessed 15 November 2011).
- Lab Tests Online. www.labtestsonline.org.au/