Continuous monitoring of blood sugar (glucose, CGM)
Being able to measure blood sugar anywhere and anytime with a blood glucose meter has revolutionized the lives of people with diabetes. Everyone with type 1 diabetes and many with type 2 diabetes have portable blood glucose meters, with which you stick yourself in the finger and analyse the blood sugar in a drop of blood entering the meter. These classic blood glucose meters are certainly good, but there are more modern alternatives that give a much more detailed picture of blood sugar, without having to stab yourself several times a day. These new blood glucose meters are called continuous glucose meters, or CGM which is abbreviation for continuous glucose monitoring. The following photo shows the two components that make up a CGM.
On the arm is seen a round patch that is glued. On the note there is a small needle that sits in the skin. The patch can remain for up to a week. Using the needle in the skin, the sugar content in the tissue is measured, which gives a good picture of the sugar content in the blood (i.e. blood sugar). The values are displayed on the screen.
The device is very useful and it makes it possible to monitor blood sugar in a detailed manner. For example, you can check the dates of different blood sugar levels and how these relate to insulin doses, exercise, work and other activities. Many manufacturers have made it possible to transfer blood glucose values directly to the healthcare provider who can then use the information to improve your treatment.
Who should use CGM?
Many factors, such as leisure activities, occupation and personal wishes, influence the decision to use CGM. In addition, the caregiver’s resources are also important. CGM and insulin pump are expensive aids that today can not be offered to all patients (although it should be so). Children with type 1 diabetes should receive CGM to facilitate blood sugar control. Today, many adults with type 1 diabetes also have CGM. However, very few people with type 2 diabetes have CGM.
Does CGM really show the blood sugar level?
Yes, sir. A CGM has a needle attached to the skin and the needle measures the sugar content in the skin (more specifically, the sugar content of the liquid around the cells in the skin is measured). The sugar content in that liquid (“tissue fluid”) is very similar to the blood sugar level, but there is an important difference. A rapid change in blood sugar is not immediately reflected in the tissue fluid and this is because it takes time for sugar in the blood to get into the tissue fluid. This means that there is a delay between a change in actual blood sugar and a change in the sugar content in the tissue fluid.
So you can say that a CGM measures blood sugar indirectly by measuring the sugar content in the tissue fluid. So with a CGM you can monitor your blood sugar very carefully, from one minute to the next. It facilitates the planning of food, physical activity and dosage of medicines. It also means that you can more easily see when you’re on the way up or down in blood sugar!
The following picture shows the needle in the tissue fluid.
One advantage of continuous glucose measurement (CGM) is that the device always records the glucose level, regardless of what you do (for example, showers, work, exercise or sleep). The device can alarm when blood sugar is too low or too high. It is possible to record times when eating, exercising or taking your medications.
However, it is necessary to knit oneself some time daily to calibrate the apparatus and in addition, the sensor must be replaced after 3-7 days, depending on the model.