Glucose meters are a great tool, but sometimes blood glucose levels need to be monitored closely. In this area of diabetes, a device called a ambulatory glucose monitor (CGM) can be useful. The CGM automatically collects blood glucose readings every 5 to 15 minutes.
CGM can help examine trends and patterns in blood glucose, giving patients and doctors a more complete picture of diabetes. This data can help find ways to better manage diabetes.
There are several devices available for adults and children.
What does it do?
CGM measures the amount of glucose in body fluids. Different devices use microsensors to collect information in different ways. In some cases, the sensors are placed under the skin on the abdomen in a quick and painless way, or they can be adhered to the back of the arm. A transmitter on the sensor then sends the information to a wireless pager-like monitor that can be clipped to a belt.
The monitor displays blood glucose levels in 1-, 5-, 10-, or 15-minute intervals. If the blood glucose drops to a dangerously low or high preset level, an alert is sent.
In the past, only doctors could see the readings collected by the CGM system. Now, anyone can use these devices as part of their home diabetes care. Data can be downloaded on a computer, tablet, or smartphone to see patterns and trends in blood glucose levels. This information can help develop the best plan for managing diabetes, including:
- How much insulin should be used;
- The appropriate exercise program;
- The number of meals and extra meals needed each day;
- The correct type of medication and the correct dose.
CGM is not a replacement for a traditional home glucose monitor and still requires measuring blood glucose several times a day using a regular glucose meter to help the monitor remain accurate. Most monitors still require finger-prick blood collection and the subcutaneous sensor should also be changed every 3-7 days.
If an insulin pump is used, it can also be connected to a CGM system for ambulatory care. There is no need to manually program the pump as with other methods that use finger-prick blood collection. The insulin pump connected to the CGM system is called a “sensor-enhanced pump”.
Why use CGM?
Why use CGM?
Unlike traditional glucose meters, CGM records blood glucose levels throughout the day and night, showing high and low values throughout the monitoring period. The system serves the following purposes.
- Record dangerously low overnight blood glucose levels that would normally go undetected;
- Tracking high blood glucose levels between meals;
- Display early morning blood glucose spikes;
- Evaluate the impact of diet and exercise;
- Determine if the treatment plan is working every day.
However, CGMs are not appropriate for everyone with diabetes. They are more expensive than blood glucose meters and may require some additional training and practice to use the technology correctly. Consult your doctor about whether a CGM is appropriate.
Who can use CGMs?
Your doctor may recommend CGM if you have any of the following conditions.
- Glucose levels that are too high and too low for no apparent reason;
- Gestational diabetes that occurred during pregnancy;
- Using an insulin pump;
- Very low or very high blood glucose levels.
The device is available for adults and children 2 years and older. the FDA has also approved a smartphone app for use with the CGM, which shares blood glucose information immediately. This is a great help for parents and caregivers who can’t be with their sick children all the time.
The future of CGM
Scientists are currently testing new and better CGM systems. The technology is also a key part of researchers’ efforts to build an artificial pancreas, which mimics the body’s natural process of controlling insulin.