Now you can buy a continuous glucose monitor without a prescription. But do you need one?
Last year, the FDA approved continuous glucose monitors (CGMs) for over-the-counter availability. Historically only available with a prescription, mostly to people with diabetes, CGMs are now on the market. Marketers are actively targeting those who are simply curious about their blood sugar levels. Two devices were approved: Stelo by Dexcom and Lingo by Abbott. The technology looks like a small round patch that attaches to the user’s upper arm. It painlessly penetrates the skin, scans the blood for glucose, and transmits the data to a cell phone. Users can view and interpret the data using an app.
Along with the approval arrived a public debate over the value of continuous glucose monitoring for individuals without diabetes. Is this new tech a must-have, or just another wellness trend?
To give away the ending: for most people, the data from a CGM is TMI (too much information). Speaking to Medscape, Jill Crandall, MD, chief of endocrinology at Albert Einstein College of Medicine and Montefiore Health System in New York City, said, “There has been no credible research to support CGM use by most people who do not have diabetes.” Because of this lack of research, in Dr. Crandall’s opinion, the recent push to market CGMs to people without diabetes seems financially motivated. As of now, there’s no proven guidance on what non-diabetics should do with the data from a CGM. Vital signs like blood pressure and temperature fluctuate based on factors including stress, time of date, recent meals, and many more variables. The same is true of glucose, if not more so. The research just hasn’t been done yet for us to know how to meaningfully interpret blood glucose levels in people without diabetes.
And yet, some experts argue that CGMs have value for some people who are concerned they may be pre-diabetic or diabetic, or who have recently gained weight. In these cases, CGMs could aid early detection of diabetes. Or, the experiential knowledge of seeing a high number after eating certain foods could prove illuminating enough to prompt behavior change, like deciding against a late-night snack.
“It is one thing to know it intellectually,” Sheree Clark, 67, told the Washington Post. “It’s another thing to see it, to watch in real time what you’re doing to yourself.” Clark does not have diabetes, and uses a CGM periodically to learn more about how her body responds to different foods. She said it has helped her lose five pounds and make healthier decisions.
“I don't really think somebody who doesn’t have diabetes needs to be using a CGM all the time or long term,” Douglas Paauw, MD, a professor at the University of Washington School of Medicine, Seattle, told Medscape. “But I have used it in a few people without diabetes, and I think if someone can afford to use it for 2 to 4 weeks, especially if they’ve been gaining weight, then they can really recognize what happens to their bodies when they eat certain foods.”
So while the consensus seems to be that no one needs to start using a CGM over the counter, the curious may want the opportunity to learn more about how their body processes the food they eat.
Using CGMs Wisely
Like other at-home health monitoring technology–blood pressure cuffs, for example–CGMs can be helpful when they work correctly. But they can be worse than no technology at all if they’re malfunctioning, misused, or misread. If you’re trying out a CGM, keep these tips in mind.
Be sure you know how to use the CGM or blood pressure cuff properly in order to get an accurate reading. For best results, a doctor or nurse should provide some training, but this often doesn’t happen when the tools are available over the counter or providers aren’t trained themselves. More providers are learning about CGMs now that they’re widely available. When using a CGM regularly, it is a good idea to ask your doctor for advice on proper procedures, and get a lab test to compare the accuracy of readings.
Consider that the reading is only as good as the technology–and taking action based on a faulty reading could certainly be worse than taking no action at all. Overcompensating for a low reading by taking a sugary drink could cause blood sugar to spike–and the CGM user would then be worse off than they began. One known issue with some CGMs is that their sensor can become dislodged, and if users don’t recognize the problem, they could be relying on inaccurate readings without knowing it. Other factors can cause false readings, too. Be aware that the tech isn’t infallible, and it may take some time for you to become familiar enough with your own glucose level fluctuations to know if a reading is way off.
When you have an accurate reading, you also need to know how to interpret it accurately, and then how, if at all, to apply that interpretation of the numbers to your own individual health. As Dr. Crandall notes above, researchers have yet to establish how non-diabetics should use data from a CGM. Again, talking with your doctor before taking action based on CGM readings is a good idea.
Another factor to consider is whether the person using this at-home tech tends toward obsessive or anxious monitoring of their own health. In these cases, experts say, the ability to constantly monitor glucose levels could be more harmful than helpful.
“Blood glucose level” won’t join the ranks of the other vital signs anytime soon. But thanks to ever-evolving technology, CGMs offer a new window into how our bodies work. The cost for the Stelo CGM is $89 for a monthly subscription or $99 for a one-time purchase of two sensor patches.
