I wore a continuous glucose monitor (CGM) and here’s what I learned
A continuous glucose monitor (CGM) is a device that is applied to your skin that measures your glucose level on a continuous basis. The sensor sends data to your smartphone and you can see in real time what your blood sugar is doing. CGMs are commonly prescribed to people who have diabetes and use insulin to treat it. The companies that make these devices also sell CGMs to the public, available over the counter and paid out of pocket, not through health insurance. Why would someone without diabetes want to use a CGM?
Diabetes is often diagnosed years after the blood sugar changes start happening. Using a CGM can detect changes much earlier.
You are having a symptom or symptoms that haven’t been explained by a standard medical workup yet, such as difficulty sleeping, low energy, episodic shakiness/sweatiness, difficulty concentrating, or constant hunger
You are simply curious about what your blood sugar is doing throughout the day.
Most CGMs have the ability to connect to your smartphone and give you real time updates on your blood sugar trend. You can see what happens when you eat, exercise, or sleep. A normal fasted blood sugar is less than 100. A normal post-meal blood sugar should never be above 200.
Here’s what I saw when I wore a CGM for roughly a month. I do not have diabetes.
Intense exercise caused a blood sugar spike that quickly returned to normal. Moderate intensity exercise had no glucose spike.
Eating too close to bedtime (1-2 hours beforehand) caused a small blood sugar elevation and this usually corresponded with less restful sleep and an elevated resting heart rate during sleep. I also track my heart rate.
Certain foods caused significant spikes (150-180) that took a while to return to normal: white rice, cookies. Any time I ate carbs without protein at the same time.
I felt hungry if my blood sugar was falling quickly.
Exercise right after a meal, such as going for a walk, blunted the blood sugar response (a rolling hill rather than a spike)
What I liked about wearing a CGM:
I learned what foods cause blood sugar spikes.
I got real time feedback about the choices I was making.
What I didn’t like about wearing a CGM:
It’s cumbersome to wear a device on your skin during certain types of exercise, showering, etc.
It’s easy to get a little obsessed about your numbers.
There were some issues with the biosensors: I had one dud (biosensor didn’t work), and Dexcom sent me a replacement for free. I had one biosensor come off on accident when it got caught on something.
The two CGMs that I tried were the Stelo (by Dexcom) and the Lingo (by Abbott). Both apps were fairly simple to use, and I have an Android device. The Stelo works via Bluetooth. The Lingo works by near-field communication (NFC), which is what you use for contactless payment on your phone.
Overall it was a good learning experience. I would not want to wear a CGM all the time.
