In many of my recent posts, I have discussed using a continuous glucose monitor (CGM), Dexcom, but I realize that I have not really explained how it works or my journey in obtaining it. Most of the general public, some healthcare professionals, and even some people with diabetes do not know of or understand what CGM is. Prior to using CGM myself, I had some misconceptions about it.
It took me a while to finally decide that I wanted to use CGM. My reasons for not wanting a CGM were the cost and having to have something inserted in me at all times. It would be a constant reminder of my diabetes–not that diabetes wasn’t constantly on my mind anyway! After attending a type one diabetes summit in November and hearing many fellow diabetics say that the one diabetes tool that drastically changed their care and that they would never want to give up was CGM (they would rather give up their pump than CGM!), I began looking into it more.
In December, I started the process of filling out the paperwork needed to obtain the CGM. Once I received the CGM, it took me about a month before I finally inserted a sensor for the first time, partly because I was busy with school and didn’t have time to read all the information and also because I was scared to do it on my own. Finally, in the beginning of March, I set up an appointment with the diabetes educator to assist and teach me the proper way to insert my CGM.
The above picture shows the device that is used to insert the sensor into the body; I was so intimidated and scared by this device at first! I pull off the white paper on the bottom and stick the device against my abdomen. I then pull off the clear plastic wing. In the round, plastic part, there is a needle inside that is plunged into my skin when I push down on the white plastic part. There are a few more minor steps in the process that remove the device but leave the sensor in place.
The above picture shows what the sensor looks like. The side that is shown is what would be against my body. The small wire that is sticking up in the middle is what stays inside my body and measures the glucose level. The sensor is technically supposed to be changed every 7 days, but to save money, time, and pain, many people leave it in longer. The longest I have gone is 2.5 weeks, but usually average about 1.5-2 weeks.
So how does the CGM work? Well, as I already showed, the sensor is inserted into the body and measures the glucose. There is a transmitter attached on the outside of the sensor. In the picture, it is the gray piece in the center of the sensor. The transmitter sends the information to the receiver–the pink device in my hand that graphs my blood sugar and shows whether my blood sugar is trending upward, downward, or staying level. I have to be within 20 feet of the receiver for it to be able to receive the information. Contrary to how it sounds, it doesn’t continuously measure my glucose; the glucose level is updated every 5 minutes, so there is some lag time between the CGM and fingerstick blood glucose.
The receiver also alerts (vibrates and/or beeps depending on the setting) when my blood sugar is low or high. The user can customize their low and high blood sugar ranges, though there is a preset unchangeable low alert set at 55. I have mine set to 80 for low and 300 for high. I chose 80 because of the lag time; my CGM might say I’m 80 but I could really be in the 60s! Also, if it is highly accurate and it shows I’m 80 when fingerstick shows I’m in the 80s or 70s, it gives me time to have a glucose tablet or something to bring my blood sugar up some and prevent having a low blood sugar. I chose 300 as the high level because my blood sugar often spikes into the 200s after meals, and I don’t want to have alerts going off every time I eat.
Once I got used to the insertion process, I absolutely love my CGM and can’t imagine how I managed my diabetes without it! The insertion process was painful at first, and it took me about an hour to rip off the tape and old sensor and insert the new one. Now it doesn’t take me very long at all and doesn’t usually hurt as much.
The American Association of Diabetes Educators (AADE) held a summit to identify the best practices in regard to CGM. I identified with many of the benefits they discussed. As I already mentioned, the CGM gives me early warnings for low blood sugar. It also is beneficial because I often have hypoglycemia unawareness, meaning that I don’t always feel symptoms of low blood sugar. This happened a lot at night, so my mom would set alarms throughout the night to come and fingerstick me prior to getting the CGM. Now the CGM alerts and wakes me up if my blood sugar goes low or high. She is now able to sleep through the night, and there have been many nights where my blood sugar is within range and I get to have uninterrupted sleep!
Another benefit the AADE identified is insight into the effects of physical activity on glucose levels. My job as a certified nursing assistant is very physically demanding. Now that I have a CGM, I can see what my glucose levels are without taking a break to fingerstick and am alerted if my blood sugar goes low, which it often does! Another benefit is better diabetes management. My A1C has decreased since I started using the CGM. Without it, my lowest A1C was above 7%. With the CGM, my A1C has averaged 6.6%!