People with diabetes need to keep their blood glucose levels in a healthy range, using a device called a glucose meter or glucometer to measure it. However, sometimes they may need continuous glucose monitoring (CGM) to get a bigger and better picture of their glucose levels. An FDA-approved device known as a continuous glucose monitor helps to monitor glucose levels at all times.
The device enables individuals to review trends in real-time, and observe glucose changes over a few hours or even days. The device also triggers alerts when glucose levels go too high or too low.
How does a continuous glucose monitor work?
A tiny sensor associated with the CGM is inserted under the skin, usually on the belly or arm. It tests glucose frequently in regular intervals (typically 5 to 15 minutes), and a wireless transmitter sends the glucose reading to a display device. Some CGMs can send the reading directly to a smartphone or a tablet for review and analysis.
A continuous glucose monitor is different from a blood glucose meter in that the former measures the glucose levels in the interstitial fluid (IF) – the fluid between the body cells, whereas the latter detects the glucose levels directly from the blood. A continuous glucose monitor can be:
- Real-time – the glucose levels can be checked at any time, and the results can be downloaded.
- Retrospective – the glucose levels cannot be seen in real-time, and the results can only be downloaded and analysed.
Advantages of continuous glucose monitoring
For most people with diabetes, continuous glucose monitoring is the key to achieving target blood glucose. It is most beneficial for people who need to test their glucose levels frequently. The device is suggested for adults and children aged two years and above (typically the ones that have juvenile diabetes).
The doctor may recommend a CGM all the time, or only for a few days, to help manage diabetes. The advantages are:
- Glucose levels can be tracked throughout the day and night.
- Glucose levels can be checked during the night when the levels are generally not tested.
- A rise or drop in glucose levels can be tracked, which will help people with diabetes to take early action.
- CGM helps to reduce the number of finger-prick tests.
- CGM can help improve the levels of HbA1c as it helps to tailor the insulin dose more carefully.
- It helps patients to reduce hypoglycemia (low glucose) events, as they can notice a downward trend even before the sugar levels sharply drop.
- The device can be used to set triggers and alarms for very high and low glucose spikes.
- CGM helps evaluate and measure the effects of diet and exercise on sugar levels.
- It aids in determining the effectiveness of the treatment plan at a detailed level.
Things to remember while using a continuous glucose monitor
- The sensor needs to be replaced every 3 to 7 days, depending on the model used. Whenever the sensor is changed, the transmitter has to be attached to the new sensor.
- Some devices need to be calibrated by checking the blood glucose on a glucose meter twice a day.
When is continuous glucose monitoring recommended?
The National Institute for Health and Clinical Excellence (NICE) has provided guidelines for CGM recommendations in adults and children.
Continuous glucose monitoring is suggested for adults if:
- They have had more than one incidence of severe hypoglycemia in a year with no known cause.
- They are unaware of hypoglycemia events.
- They have high blood sugar.
- They have an extreme fear of hypoglycemia.
- They have a high HbA1c level despite testing their glucose several times a day.
CGM is usually recommended for people with type 1 diabetes. However, not all of them would need CGM.
Continuous glucose monitoring is suggested for children if:
- They experience frequent, severe hypoglycemia.
- They demonstrate fits and anxiety.
- They are unable to recognize or even communicate with others about hypoglycemia symptoms. It could be because of developmental or neurological issues.
- They are under school age.
- They are athletes playing high levels of sport.
- They are unable to manage diabetes because of other issues such as anorexia or steroid treatment.
- They have very high blood sugar levels even after adjusting insulin doses.
The data from CGM helps find better ways to manage diabetes. Since CGM systems measure glucose levels continuously, they provide data on how fast and in what direction the glucose levels are changing. Unlike a regular glucose meter, which requires deliberate action to measure glucose, CGM works even when one is asleep. Continuous glucose monitoring helps to make the right decision on diabetes treatment. They are also proven to reduce HbA1c levels and lower the incidence of hypoglycemic events.
Individuals with diabetes should consider using a CGM only on specific recommendation by their doctor. Speak with the Apollo 247 experts using our online consult feature.