A woman rises slinkily from a hot tubher long, wet hair glistening in the sunlight, a picturesque sunrise before herand a continuous glucose monitor perfectly centered on the back of her flawless right arm.
Its a scene from an ad for one of those trendy continuous glucose monitors (also known as a CGM) that recently popped up in my social feed.
It doesnt even slightly resemble my life with a CGMand I should know what that life is like. Ive been a type 1 diabetic for a quarter century, since I was 12. And Ive worn a variety of CGM products for more than a decade, from relatively large sensors stapled into my stomach to pill-sized sensors implanted under the skin of my upper arm.
And let me tell you, its not a glamorous life.
In the latest health wearable trend, manufacturers of technology developed to help diabeticsby warning of potentially deadly high and low glucose episodesare now marketing their products to non-diabetics. Their pitch: A sensor inserted between layers of skin via a spring-loaded needle will offer metabolism insights that may lead to changes in diet and exercise.
Dont get me wrongIm insanely grateful for CGM technology. Its grown so much over the past handful of years, from an anxiety-inducing nuisance that constantly throws false alarms, to truly life-saving technology that almost always reliably warns me of impending high and low glucose levels.
But I look nothing like the model. After years of shooting CGMs into the back of my upper arms (as well as injecting insulin and inserting insulin pump and pod infusion sites there), mine are marred and bruisedto the extent that Im occasionally asked if Im safe at home.
And a long soak in a hot tub? Thats a no-go (or a proceed with extreme caution) for me, as someone for whom a CGM is medically necessary. Diabetics are warned to be extremely careful in hot tubs, since the heat can induce hypoglycemic unawareness that prevents the usual warning signs of low blood sugar levels, like shakiness and sweats.
You would hope my CGM would alert me to a low glucose episode butas I know first hand from attempts at long, hot bathsthey tend to stop reading once submerged for a while. (I spend more time silencing lost signal alarms than truly relaxing.)
If youre relying on reads from your CGM, be wary of extended time in the waterthats one lesson Ive learned from over a decade of CGM-wearing. Here are a few others.
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1. CGMs dont measure blood sugar.
Yep, you read that right. And yep, a bunch of people are saying it wrongeven some of the so-called pros. CGMs dont measure blood glucose levels. They measure glucose in interstitial fluid, between layers of tissue. Glucose tends to flow from blood vessels to the tissue surrounding them. Interstitial fluid glucose levels are similar to blood glucose levels, but lag them by a good 15 minutes or so.
To a non-diabetic, the lag doesnt make a difference. To a diabetic, it can mean a delay in alert of a low glucose level and, thus, treatment.
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2. Food and exercise arent the only factors that impact your glucose levels.
CGMs are being marketed to non-diabetics as a tool that allows them to observe the impact of foods on their glucose levels. But plenty of other factors can impact those levels, from illness and certain medications to stress, lack of sleep, and menstrual cycles. I once went into a very contentious meeting with my sons school with a fairly normal blood glucose level, and left irateand with a reading in the 400s. (The meeting didnt go well, to say the least.)
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3. Sensors are easy to wear for a week or twoand much harder to wear for longer than that.
Some companies are marketing CGMs to non-diabetics as a temporary inconvenience. Wear a sensor for two weeks and gain data on how food impacts your glucose levels valid for an entire year, they claim.
But such a scenario doesnt apply to diabetics, especially ones with hypoglycemic unawareness.
The longer one has diabetes, the greater the chance of developing the condition, a form of neuropathy that makes a CGM a daily necessity. Dont get me wrongIm incredibly grateful for my CGM. But my arms are visibly damagedas was my stomach, when I regularly wore them there.
(Regular CGM users are advised to rotate sites when they canarms, legs, stomach, upper buttocksto preserve real estate. Historically, however, some CGMs were only approved for use on the abdomen or upper buttocks, the later of which cant be reached without help. And, not all sites work well for all diabetics.)
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4. CGMs can ease the cognitive burden of diabeticsbut they may have the opposite effect for non-diabetics.
Its been estimated that type 1 diabetics make around 180 health-related decisions a day in an effort to keep their glucose and ketone levels in check. The medical term for this: cognitive burden.
When I was young, sometimes my dad would sit up on a Saturday morning and monitor my glucose levels using a traditional blood-based monitor, so I could catch some extra sleep. Wearing a CGM is a bit like having that level of helpbut even better, and all the time. It allows me to shift more of my focus elsewhere, knowing that something is keeping an eye on things. It helps shoulder that cognitive burden.
For non-diabetics, however, CGMs could have an opposite effect. Unless you have hypoglycemia, pre-diabetes, or another health condition that puts you at risk for high or low blood glucose levels, you may find that a sensor induces a stressful state of information overload. As someone who doesnt have issues maintaining healthy oxygen saturation or blood pressure levels, I cant imagine being presented with a constant stream of such data (and attempting to process and interpret relatively small variations). Honestly, such a tool would probably send my anxiety through the roofand I have to wonder if CGMs do the same for at least some non-diabetics.
5. Not everyone has equal access to this potentially life-saving technologyand thats a problem.
Insulin, insulin pumps, and now CGMsadd them to the list of expensive treatments diabetics need but cant always afford. For diabeticsespecially type 1scognitive burden is a thing, but so is the financial burden.
But theres a documented lack of access to CGMs among racial and ethnic minorities that cant be explained by socioeconomic status alone. According to a study published this year in the medical journal Diabetes Care, use of diabetes technology like insulin pumps and CGMs was more than 20% lower in Black patients when compared to white patients. And according to a 2021 study in a similar journal, less than a third of Black youth had access to insulin pumps and CGMs, while nearly three-quarters of white patients did (40% of Hispanic patients had access).
Among the reasons: provider bias, systemic racism, and (understandable) mistrust of the medical system, the authors of the later study speculate.
To non-diabetics using CGMs, my message is this: Enjoy the new gadgetthough insertion can be quite painful, which takes away some of the fun. Use the data to improve your health, if you can. And if you find its not everything youd hoped, consider donating your unused, unexpired CGM sensors to a charity like Insulin For Life, which distributes supplies to diabetics in developing countries.
The device that annoys and disappoints you could save a diabetics life.
