What is Continuous Glucose Monitoring?
Your blood glucose meter measures the level of sugar in your blood where as continuous glucose monitoring (CGM) is a system that measure sugar levels in the fluid surrounding the cells in your tissue which is called interstitial fluid. A CGM system requires a glucose sensor be inserted just under the skin (subcutaneously). The CGM sensor is then usually left in place for 6-7 days before being removed or replaced. The sensor is attached to a transmitter that sends information wirelessly to a small monitoring device, or receiver. This receiver can be incorporated into some insuin pumps or as a stand-alone device.
A minimum of one calibration every 12 hours is needed to receive sensor glucose readings. Calibration is like buying a watch and setting it for the first time and then checking the time throughout the day to make sure it is right. Calibration is essential for the system to work. To calibrate the CGM device you will need to test your blood glucose using your usual blood glucose meter 2-4 times daily.
Most of the time sugar travels first to your blood and then to your interstitial fluid. Because of this your blood glucose meter readings and sensor 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. Your blood glucose meter reading measures your blood sugar level at that exact moment in time and you must use this reading in making treatment decisions, not your sensor reading. CGM does not eliminate the need for regular blood glucose testing.
Why is Continuous Glucose Monitoring Helpful?
Testing your blood sugar is useful, but it only gives you a blood sugar reading for that particular moment in time. It is like watching a movie but only seeing short clips of the movie every time you test; CGM is like watching the entire movie.
Benefits of CGM
- Helps reduce the frequency and severity of lows by early detection
- Helps with spotting trends in glucose levels
- Helps avoid oncoming high or low glucose levels
- Helps reduce your A1C with tighter control
Drawbacks to CGM
- Can be costly if not covered by your insurance
- More invasive than regular blood sugar testing
- Does not replace regular blood glucose testing as blood glucose is NOT the same as sensor glucose
- Must wear an additional device
Products Available in Alberta
Insulin Pump Integrated Systems:
*Please note the Animas Vibe pump is no longer distributed in North America. Please click here for more information.