Continuous glucose monitoring

The sensor is a small electrode that is inserted under the skin using a special insertion device to do this - the sensation is similar to having an insulin injection.
The sensor measures your interstitial glucose level, which is the glucose found in the fluid between the cells.  The sensor is connected to a transmitter which sends the data wirelessly to your handheld monitor.

These are some of the features of the CGM:

• A visual display of your current interstitial glucose level.
• A trend arrow indicating whether your glucose level is falling or rising.
• A trend graph showing results over the last three, six or 24 hours.
• An alarm setting to alert you when your glucose level is high or low.
• Uploading of data to allow you to review progress.
• The ability to link directly to insulin pumps.  Not all insulin pumps can do this.

Interstitial fluid is a thin layer of fluid around your tissue cells. Glucose levels in the interstitial fluid lag behind glucose levels in your blood by up to 15 minutes.  The lag time is longest if your blood glucose level is changing rapidly, after eating or if you are exercising.  Due to the lag time, you should also do a fingerprick blood glucose check if you are considering additional insulin or treatment for hypoglycaemia.

CGM monitors your glucose level continuously and sends data to your display device on an ongoing basis. You can set it to alert you when your reading is high or low and you can easily view trends and patterns.

With flash glucose monitoring, it is only when you scan your sensor that you can take a reading and see trends (although newer versions of flash also include the option for high and low alarms).

• You can track your glucose levels throughout the day and night.
• You can see what your levels are like at times when you don’t normally test, e.g. during the night.
• You can see trends: when your glucose levels are starting to rise or fall, so you can take action earlier and avoid a hypoglycaemic episode (a ‘hypo’).
• Fewer fingerprick checks are necessary.
• It helps you achieve and maintain your target HbA1c level.
• You can set it to alert you when your glucose level is high or low.

• It is easy to become overwhelmed with the amount of data.
• You may find wearing the sensor uncomfortable or feel that it is unattractive.
• You need to be motivated to benefit from the data provided.
• Lots of alarms can be annoying.

Click on the video below to hear what young people think about using CGM.

Speak with a member of the team if you are interested in learning more about how to get CGM.
The DOT team supports two CGM devices: the Dexcom system and the Medtronic system.  There a number of things to consider when choosing between the two, including whether or not you are using an insulin pump (or plan to use one) and/or hybrid closed loop - ask the team for more information.