Continuous glucose monitoring (CGM) involves wearing a small device that monitors the glucose levels day and night. The CGM device consists of 3 parts:
- a small sensor that sits just under the skin (which is ‘like a pump cannula’);
- a transmitter (this is attached to the sensor and sends data wirelessly to the display device), and
- a display device (this shows whether the person’s glucose levels are high, low or within range).
CGM can be used by those on insulin pump therapy, on insulin injections, and by people taking other diabetes medication. Some CGM devices have alarms to indicate when the glucose levels are too high or too low.
Lydia talks about her CGM and how she uses it.
Young people we spoke to felt that using CGM has really helped with the management of their diabetes, and they found it easy to use. They felt that using CGM was less time consuming and intrusive than doing blood sugar tests or the ‘finger-prick test’. But they also understood that what the CGM sensor measures is the glucose in the interstitial fluid (the fluid between the cells) and not the sugar levels in the blood.
Sophie does a finger prick test every time before driving and when she finds she is going low’s or high’s. At all other times she is happy to get her readings from her CGM.
Young people said that the use of a CGM has seriously reduced the need to do finger prick tests several times a day. But they still depend on blood sugar tests when trying to understand why they are going high or low. They also understood that it is a DVLA requirement to always do a finger-prick test before they drive to check if their sugar levels are within the permitted range (5 or above).
Lewis says he does a couple of finger prick tests a day but more often when using new CGM sensors. Before the CGM he was doing up to 20 tests a day.
Lydia does the finger prick test before driving, but most of her readings are based on CGM data. The CGM graphs are a source of information to her care team.
The data provided by the CGM is very useful to find out if the insulin therapy is working well. Young people said that the CGM device has made it easier to understand their glucose pattern better and identify issues such as the ‘dawn phenomenon’ which, before using the device, could have been attributed to having the wrong insulin regime rather than a simple spike in their blood glucose levels at the point of waking up. The use of CGM and knowing how their blood sugar levels are doing throughout the day and night made the young people we spoke to feel ‘more in control’ of their diabetes and ‘less scared of doing an extra insulin shot when going low’.
Lewis’s Care Team secured funding for his insulin pump after the continuous glucose monitor showed that his insulin therapy was not working well for him.
The CGM has helped Sophie to become more confident at managing her diabetes and she intervenes when necessary e.g. doing insulin correction doses.
Young people we talked to use CGM data to produce graphs which show how their blood sugars have been doing within a certain period of time or, help to identify the periods when they are likely to go hypo (low blood sugar) or hyper (high blood sugar). The information can also help them understand the relationship between exercise and diet and how they can affect blood sugar levels.
The ability to scan her CGM at any time and during different activities has made Sophie aware of the constant changes happening in her blood sugar levels.
There are various types of CGM devices on the market but the main consideration when purchasing one seemed to be its cost. The young people we talked to said that they were self-financing their CGM and that they go for the one that is affordable and reliable. Lewis’s parents bought him the CGM device, but the hospital funds the sensors. Initially, Lydia got the monitor and sensors on a clinical trial but after it finished, she decided to continue using it so now she pays for it herself.
Sophie says that her CGM is reliable and is one of the cheapest in the market but it doesn’st have any fancy stuff’s. She thinks they are rarely funded by the NHS.
Some young people were told about CGM by their care team but most of them have got to know about CGM through social media.
Lewis’s parents use a remote monitoring system called NightScout that allows Lewis and his parent’s access to Lewis’s CGM data via an android phone. This project is developed and maintained by an online community of parents of children with type1 diabetes and it is free and open to all.