Monitoring blood glucose in type 2 diabetes
People with diabetes need to test their blood glucose regularly with blood tests ordered by their doctor, with or without self-monitoring.
Glucose testing strips. An arrow shows you which end of the test strip to insert into the glucose meter. Image: Shutterstock.com
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.
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 know if your diet and diabetes medicines are controlling your diabetes effectively or if these need to be changed.
For most people, the recommended level of HbA1c is 53 mmol/mol (7%) or less. If the HbA1c level is higher than 53 mmol/mol (7%), 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.
In some circumstances the HbA1c test may not be reliable. As the test measures red blood cells, any condition that affects the lifespan of red blood cells will likely produce an inaccurate result. Examples of these circumstances include anaemia and kidney failure. Your health professional will be able to assist in interpretation of your test result.
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 HbA1c units are changing
Until July 2011, your HbA1c result was reported only as a percentage (%). Currently, your result will be presented both as a percentage and as another unit called millimoles per mole (mmol/mol).
This change in units has been made to standardise the way HbA1c results are reported in all countries world-wide.
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 MedicineWise has developed an HbA1c unit converter to help you convert your % HbA1c result into mmol/mol units. Find out more about what the unit change means for you and use the calculator to convert your % units into mmol/mol.
How often will the test be done?
The HbA1c test should be done when your diabetes is first diagnosed and then at least every 6 months after that, or as often as your health professional recommends.
The finger prick test
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.
If you have type 2 diabetes and are taking diabetes medicines that are known to cause low blood sugar or ‘hypos’ (hypoglycaemia), such as insulin or a sulfonylurea, you should discuss with your health professional how regularly you should monitor your own blood glucose levels.
A glucose monitoring device taking a reading from a glucose test strip.
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.
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.
Each type of glucose monitor will need a particular type of test strip, and the instructions tell you where to place a drop of blood from your finger. The arrow shows you which end of the test strip to insert into the glucose meter.
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.
To find out more, read our information on how often you need to self monitor.
Register with the National Diabetes Services Scheme
The National Diabetes Services Scheme (NDSS) can provide diabetes-related blood glucose monitoring equipment at subsidised prices, and provides information and support on a range of topics. Registration is free. Ring them on 1300 136 588 or visit www.ndss.com.au.
- Royal Australian College of General Practitioners and Diabetes Australia. General practice management of type 2 diabetes 2014–15. http://www.racgp.org.au/your-practice/guidelines/diabetes/
- Lab Tests Online. www.labtestsonline.org.au/