Continuous Glucose Monitoring Systems
Images above show in order: Dexcom G6, Medtronic Guardian and Libre 2
Continuous glucose monitoring (CGM) systems provide 'real-time' information by measuring glucose levels every few minutes. This provides a trace (see image below) as well as information on whether glucose levels are stable, rising or falling. This offers more detail than a single 'finger-prick' glucose value and use of CGM has been associated with improved glucose control.
Click here to be taken to the JDRF website section on CGM.
CGM systems
Freestyle Libre
The Freestyle Libre 2 is not technically a 'CGM' system as it does not continuously display glucose levels but will display a current glucose level (with a trend arrow) when the reader device is swiped over the sensor. It also has the added feature of High or Low Alerts if this is set up using the Reader or Mobile Phone device. It is also able to produce 24 hour glucose traces (like the example above), so long as the sensor is scanned at least every 8 hours. The major advantages of the Libre system are that it does not require calibration with 'finger prick' capillary blood glucose levels and is significantly less expensive than Dexcom and Medtronic systems. The disadvantages is that it cannot communicate with insulin pumps. One year's use of the Libre costs approximately £1300.
Click here to be taken to the official Libre website or click here for the RHCYP Libre 2 Guidance resource.
LibreLink for Iphones and LibreLink for Android: which turns your phone into a Libre reader. One major benefit of this app is that it will work with the Libre View to directly upload all your glucose data to the cloud which allows your clinic to see this data to better support you. To link with your clinic please use the correct practice code: Clinic Practice Codes
RHCYP have also created a helpful Video Resource about Libre 2 which can be accessed here and is ideal for sharing with school staff also to enhance transition and knowledge from Libre 1 to Libre 2.
Medtronic Guardian
Medtronic CGM systems can be used by patients on multiple daily injections but are most useful for those using Medtronic insulin pumps, as the sensor can communicate directly with the pump. The major advantage of this is the ability to take advantage of the 'SmartGuard Technology' feature, which anticipates insulin needs and automates the basal delivery every 5 minutes as well as (with current model 780G) deliver automatic corrections to support higher glucose whilst help protect from lows. Alarms can be set to inform users when their glucose levels rise above or fall below acceptable limits. These devices require calibration with 'finger prick' glucose tests. The annual cost of Medtronic's CGM system is approximately £3000. Click here to be taken to the official Medtronic website.
Dexcom
The Dexcom G6 system can be used in patients using multiple daily injections or pumps. The G6 will transmit sensor glucose levels to T Slim X2 insulin pumps allowing use of the Basal IQ or Control IQ technology derived by Air Liquide. The Dexcom G6 is capable of transmitting results to iphones and, like Medtronic's device, will alarm when glucose levels fall below or rise above personally set limits. This device is licensed for ‘zero finger pricks’ and does not require calibration. The annual cost of the Dexcom system is around £3000. Click here to be taken to the official Dexcom site.
If you are considering using a CGM system, please contact your diabetes specialist for advice. Deriving the maximum benefit from these systems requires appropriate education on how best to use them and also requires regular reflection and feedback on the huge amounts of information such systems provide.