CGMs (Continuous Glucose Monitors)
Hi, and welcome back to Type 1 Diabetes Explained. Today, we will talk about CGMs. Continuous glucose monitors, commonly abbreviated as CGMs, are small devices that sit just on top of the skin with a small catheter that goes under the skin and measures your blood glucose level periodically. T hey provide an easy way to always know what your blood sugar is without having to check using a meter CGMs come in many shapes and sizes, but all perform generally the same task of reading your blood sugar continuously. Different CGMs have different ways that you’ve read your blood sugar, but most CGMs will come with a receiver specifically designed for the CGM that you can read your blood sugar from. Some CGMs also offer a mobile app that you can use to check your blood sugar on your phone or smart watch. This method offers a convenient and easy way for you to keep track of your blood sugars without having to remember to bring a receiver. Here are some things to remember when using a CGM. Always follow all manufacturer’s instructions for insertion, use, and removal of your CGM. They don’t write the instructions just for fun. They expect you to actually look at them. Also, you may find out things you didn’t know by reading the instructions that can help you stay safe while using CGM. Many CGMs need to be calibrated. This means that you will test your blood sugar with a meter and then enter that number into the CGM. The CGMs ask for this to make sure that they are reading the correct blood sugar value. Always remember to calibrate your CGM based on manufacturer’s instructions. The CGM are designed with algorithms to help correct for incorrect measurements, but calibrating is still necessary to help ensure that your CGM is reading the correct a blood sugar level. It is also important to remember to rotate the sites when you are inserting your CGM. If you repeatedly insert it in the same location scar tissue can build up and this can cause the CGM to stop working or take incorrect readings. It’s also important to keep your CGM site away from an insulin pump site. If they are too close the insulin may interfere with the accuracy of a CGM. Most CGMs are waterproof, but make sure to read the manufacturer’s specifications on whether it can be exposed to water and if certain temperatures will cause damage to the transmitter. Now, let’s look at the basic parts of a CGM. Most CGMs consists of three parts: the sensor, transmitter, and receiver. The sensor is often a small piece of plastic that includes a catheter that sits under the skin and adhesive to help keep it attached. The transmitter is a small device that fits into the sensor and is the part that actually takes the glucose readings from the sensor and transmits them to the receiver, which is a separate device that displays the glucose readings. With some CGMs, a phone or smart watch can be used as a receiver along with a manufacturer provided receiver. CGM’s are generally pretty accurate when reading blood glucose levels assuming that they are calibrated per the manufacturer’s instructions. One major difference between glucose readings from a meter and a CGM is that the meter measures the glucose in the blood while CGMs measured the glucose in the fluid that surrounds the cells in the body. This often means that the CGM has a slight delay when reading glucose, so you may see a difference between a meter and a CGM if you test right after you eat or take insulin. The most common concerns with CGMs are often related to whether it will interfere with normal activities and manageability. CGM’s are small and getting smaller all the time, most measuring in at just over an inch. CGMs are very subtle and hardly noticeable under clothing, and you can definitely still play sports and participate in all of your normal activities while wearing your CGM. Generally CGMs are very easy to manage and only need to be changed once every 7 to 10 days. The CGMs are fairly easy to manage and alleviate the need for as many tests with a meter and help you better manage your blood sugars. It is important to remember that when traveling with CGMs, they cannot go through x-ray or full-body scan machines. These machines can damage the sensor and transmitter. The TSA is familiar with these devices and can perform hand searches of transmitters receivers and extra sensors, so they don’t go through any machines that may damage them. One important thing to remember about CGMs is that they are not always perfectly accurate. If the reading that you’re CGM is giving you seems incorrect or you feel differently than what your CGM says, test with your meter. Remember, when in doubt get your meter out. Your doctor’s will instruct you how to use your CGM and will always be the best person to advise you when operating your CGM. Even though CGMs have a few drawbacks, they are a very useful tool when controlling your Diabetes and can alleviate some stress when managing your blood sugars.