What is Continuous Glucose Monitoring?

A Continuous Glucose Monitoring system, also called CGM, is a way to measure blood sugar for people with diabetes. It is a device that is typically worn on the back of the upper arm or stomach, and depending on the specific type, can check blood sugar levels every one to five minutes. If you do the math, this is 288 to 1440 readings per day! For the person using their glucose meter as recommended by their healthcare professional, CGM can provide much more data than traditional blood glucose meters. In addition to more data, there are other differences between CGM and blood glucose meters (BGM). A reading taken by a finger stick using a glucose meter shows your blood sugar level at that moment in time, while CGM shows you the number AND the direction that your blood sugar is going. Imagine having a blood sugar of 100 mg/dL and thinking everything is fine because you are in target range, but not realizing that your blood sugar is dropping.

This could become a dangerous situation especially if you don't feel the usual symptoms of low blood sugar. CGM will display arrows to indicate if blood sugar is dropping and can even show the rate at which it is decreasing. For example, some CGM devices will use one or two arrows pointing down to indicate that blood sugar could drop, typically by more than 60 to 90mg/dL in the next 30 minutes. This information can help a person with diabetes know when to eat to prevent low blood sugar before doing a critical activity, like driving. There are both professional CGM devices, owned by the clinic and available on a short-term basis, and personal CGM devices, which are owned by the person with diabetes and worn on a long-term basis. How Does CGM Work? CGM contains 3 parts: a sensor, transmitter, and receiver, also called a reader. The sensor is worn on the upper arm or stomach at least two inches away from the belly button.

Each system has their own technique on where to place the sensor and how to insert it. This usually involves a simple one or two button press. There is a tiny wire included with the sensor that stays under the skin in the area called interstitial fluid. This is where CGM measures the blood sugar level and is actually above the capillary space, so it goes less deep than a lancing device used with a glucose meter. The transmitter goes on top of the sensor and is what transmits the blood sugar readings to a receiver. Some of the devices have a combined transmitter and sensor, while others require an additional step of attaching the transmitter. Readings are viewed on the receiver. With every device, there is an option to download a mobile application (app) and have the mobile device serve as the receiver. The sensor is worn for 7-14 days depending on the device.

After that, GlycoMode Wellness a new sensor is re-inserted by the person with diabetes or their caregiver. There are also intermittently scanned devices that require a scan to view the blood sugar reading. Other devices are considered real time and the blood sugar reading is always available as long as it is within 20 feet of the receiver. Data can also be downloaded by your doctor's office. The data is downloaded by plugging in the receiver via a USB. If using a mobile app, the data can be connected to the clinic's data management system via Bluetooth®. In addition to sharing data with the clinic, many devices have mobile apps that allow you to share data with family members, friends, and significant others. CGM captures the direct effects of food, physical activity, stress, and medications on blood sugar levels, allowing people with diabetes and their care team to quickly identify if any management changes are needed.