What is Continuous Glucose Monitoring?

With new advancements in diabetes technology there are now two main ways people with diabetes monitor their glucose levels – traditional capillary blood glucose levels which are checked by a fingerpoke and glucometer, and interstitial glucose levels monitored using a continuous glucose monitoring system (CGM).

In our bodies sugar travels first to your blood and then to your interstitial fluid. Because of this blood glucose meter readings and sensor glucose readings will rarely be exactly the same, but you can expect them to be close. When sugar levels are rising or falling quickly such as after a meal or after taking insulin, you can expect to see a larger difference between your blood glucose meter reading and your sensor reading.

CGM systems have three main components:

  1. A sensor that is inserted under the skin into the subcutaneous tissue. The sensor reads the glucose levels in the interstitial fluid.
  2. A transmitter that takes the information from the sensor and sends the data to a receiver. Sometimes the sensor and transmitter are combined into a single piece.
  3. A receiver which displays glucose levels, trend arrows, and can alert users to changes in glucose levels. The receiver can be a smart phone, insulin pump, or stand alone device.

CGM systems are now considered the gold standard for glucose monitoring for people with diabetes according to the Diabetes Canada Clinical Practice Guidelines. Some CGM systems are “real-time” systems that constantly push data from the sensor to the receiver while others are “intermittently scanned” and only show data when you scan the transmitter with the receiver.

CGM does not eliminate the need for regular blood glucose testing. Some CGM systems require capillary blood glucose calibrations or have recommendations for situations when a blood glucose should be used for a treatment decision.

Should I get a CGM?

Benefits of CGM

  • Reduced frequency and severity of lows by early detection
  • Helps with identifying trends in glucose levels
  • Notification of oncoming high or low glucose levels
  • Lower A1C through improved glycemic control

Drawbacks to CGM

  • Can be expensive if not covered by insurance
  • Does not completely eliminate the need for fingerpoking
  • Some people experience skin issues due to adhesives
  • Must wear an additional device

Products Available in Alberta

Insulin Pump Integrated Systems:

The integration of CGM and insulin pump therapy has lead to the development of hybrid closed-loop algorithms that automatically adjust insulin delivery within specific parameters to improve glycemic control.

Stand Alone Systems: