Less than five years ago, we heard the first murmurings of continuous glucose monitors (CGMs) being produced for a whole new niche: people without diabetes.
At the time, the idea sounded a little strange. After all, there has not been a lot of research into blood sugar patterns in people who don’t suffer from glucose or insulin-related disease. So what help would a CGM—a device that’s fairly expensive without insurance and a bit invasive—be to a healthy person?
Fast forward to today. There are now multiple fitness and health companies that offer CGM use as part of their subscription service to members living without diabetes. Most of these companies are focused on general health support or weight management.
While the growth of this market has been nothing short of surprising, we think it’s just getting started.
CGM use as a means to help with diet and weight loss are just a couple of the ways these eye-opening devices could be used to improve health. After all, just about everything from sleep to stress affects blood sugar levels. But expanding the use of CGMs to people without diabetes isn’t without its potential complications.
For those who see the possibilities and are willing to work to overcome the issues, this new niche is an open market just waiting for innovative companies to capitalize on it.
Potential Applications for CGM Use Outside of Diabetes Care
Anyone living with diabetes can tell you that just about everything affects blood sugar levels. Eating, sleeping, cardio exercises, weight lifting, and doing literally nothing all have a different effect on your blood sugar. And these effects are not the same person to person. In fact, within the same person, they can change from week to week.
Because blood sugar reacts to every part of our daily lives, it has the unique potential to help us learn more about the state of our health. Not just in terms of diet and weight loss, but with respect to exercise, athletic performance, stress, sleep, side effects from medications, and our potential for future disease.
The healthy body deals with rising blood glucose (BG) levels by releasing more insulin into the bloodstream. This insulin allows cells throughout the body to uptake glucose and put it to use. But if glucose continues to enter the bloodstream after the cells have gotten what they need, the cells will turn the extra sugar into fat.
CGMs provide a visual means for people to see their blood glucose levels rise and fall throughout the day. Overeating will show on the connected app as a spike in glucose or an extended period of higher than optimal blood sugar.
In people with diabetes, the use of a CGM is correlated with an improvement in body mass index and a reduction in waist circumference (1). There’s no reason to believe that being able to see blood glucose numbers and adjust eating habits accordingly wouldn’t have a similar effect on people without diabetes.
Users could also use their CGM to retrain their hunger cues. Many of us reach for food when we’re bored, stressed, or because the clock tells us it’s time to eat. Often, these cues do not parallel a true physiological need to eat. True hunger cues will only be present when blood sugar levels begin to drop.
Interventional studies have shown that CGM use can be helpful in “hunger recognition training” which is proven to aid in weight loss in overweight individuals (2).
Whether a person is struggling with weight or simply looking to optimize their diet to their specific needs, CGMs can be uniquely helpful.
Food items with a high glycemic index (GI) are known to catapult blood sugar up very quickly while those with a low GI slowly raise blood sugar without creating a spike. Most people are unaware that some of the highest GI foods don’t contain much sugar. In fact, both white bread and baked potatoes have a higher GI rating than straight table sugar.
A CGM gives the user better incite into these kinds of dietary relationships while allowing them a customized look at how their body reacts to different foods.
This kind of “food therapy” has been proven effective through many studies looking at food choice in people with prediabetes and people with type 2 diabetes. Interestingly, in one of these large-scale US studies, it was the non-diabetic control group that benefited the most from the CGMs (3). This group, which consisted of non-overweight young adults, saw improvements in time in range more often than the study groups which consisted of people with prediabetes and diabetes.
This proves that CGMs can be used to optimize diet choice and blood sugar numbers even in healthy individuals.
Customizing Exercise Routines
Exercise has many potential benefits in relation to blood glucose. For one, it can quickly bring BG down after a meal without requiring the body to release excess insulin. Consistent exercise can reduce BMI, which increases insulin sensitivity and leads to more stable blood sugar over time. And exercise can help undo some of the damage that results from high BG.
But the relationship between exercise and blood glucose is not that simple. Exercising when blood sugar is low can have negative side effects such as glucose dumping by the liver, hormone spikes that cause overeating following exercise, and exercise-induced hypoglycemia. Some exercises, specifically anaerobic exercise, are known to increase blood glucose, not reduce it.
With a CGM, users have the power to see how different exercises affect their BG, not just during and after the activity, but for days following exercise. Users also have the ability to better schedule their exercise sessions to periods when their blood sugar tends to trend higher, such as after meals. The studious user may even find they can organize their exercise routine using a combination of anaerobic and aerobic exercises to stabilize blood sugar without having to ingest extra calories.
Many studies have shown that CGMs have the power to create better exercise habits in those who wear them. In one such study that followed individuals with impaired glucose tolerance, researchers found that the group using CGMs had a significantly higher increase in attendance and registration rates for additional exercise programs than the control group (4).
Optimizing Athletic Performance
CGMs have a lot of potential uses in the average person, but one of the most overlooked niches for CGM use may be in professional athletes.
To maintain optimal performance, athletes must have enough cellular energy to begin the activity, maintain it without breaking down, and recover quickly when finished. A CGM could provide key details of all three stages to help athletes find the best ways to prepare, maintain, and recover using a highly tailored intake of carbohydrates, protein, and fat.
This is one area where the use of CGMs has been studied more consistently in individuals without diabetes.
One such study found a positive correlation between low to moderate glucose levels and running speed (5). That same study found that eating the right amount of carbohydrates (as opposed to too much or too little) was necessary to maintain level BG and avoid the high BG readings associated with decreased speed.
A similar study looked at the glucose patterns of a professional marathon runner over the course of multiple races. The results revealed that the individual performed best during races where their BG remained stable throughout the entire race, with both dips and rises in BG associated with decreased performance (6).
CGMs have the potential to allow athletes to learn not only what BG patterns are best to optimize performance for them as individuals, but how to achieve those patterns using different macronutrient ratios, serving sizes, and intake rates. Even beyond preparing and performing, CGMs could give them a better understanding of how quickly their body recovers (as demonstrated by a return to normal basal BG patterns) and how eating and rest can aid in hastening that recovery.
When cortisol and adrenaline levels are chronically high, the body suffers. Type 2 diabetes, metabolic disorders, and hypertension have all been linked to chronic stress (7). When these hormones rise in the body, so too does a person’s BG.
This presents an interesting opportunity to use CGMs as a means to aid in stress management practices. Just as blood pressure and heart rate monitors can help warn people when their stress levels are rising, CGMs can add additional data points to not only warn of acute stress reactions but to help track progress over time as stress reduction techniques are introduced.
Due to the complicated relationship between BG, stress, food, and activity, a CGM alone would not be enough to aid in stress management. But when integrated into platforms with multiple input sources, they could provide a valuable metric for data interpretation.
Studies into insulin release and blood glucose levels during sleep have revealed that a slight increase in blood sugar is normal during nocturnal sleep in healthy people (8). This increase is generally gradual and returns to normal basal levels by waking.
A number of sleep issues are known to disturb this cycle.
Sleep apnea causes the body to release adrenaline in order to wake the sufferer during bouts of breathing trouble. The release of this hormone creates spikes in blood sugar. Insomnia has been proven to increase cortisol levels over time. Increased cortisol is associated with higher overall BG levels.
Sleep disturbances in general have been linked to impaired glucose metabolism and higher rates of metabolic disorder (9).
Using a CGM to track nightly blood glucose trends could be highly revealing for those suffering from a sleep disorder. Not only would the data help determine which sleep therapies are working and which aren’t, but the trends over time could be used to determine if early intervention is necessary to prevent the escalation of related diseases such as diabetes.
Many medications, including long-term prescriptions used to treat anxiety, depression, and high blood pressure, are known to increase blood sugar levels. For many, this BG increase is negligible, but for others, it can represent a change from higher than average blood glucose to prediabetic levels.
While occasional A1c testing can provide some evidence as to how a person is reacting to their medications, these tests can’t clearly identify the cause of elevated blood sugar. A CGM, on the other hand, would give the user clear, distinguishable data about when their blood sugar tends to rise and how those trends change when a medication is withheld or substituted.
Pre Prediabetes Screening
Type 2 diabetes continues to be a growing problem in developed countries, with an estimated 9 million Americans going undiagnosed every year (10). Diagnosis of this condition often only comes after oxidative stress has created symptoms of chronic inflammation, including cardiac distress and neuropathy.
Once diabetes has been allowed to progress to this stage, reversal can be difficult to achieve. But if caught early, numerous studies have shown that full reversal of abnormal blood sugars is possible long before damage to the cardiovascular system and major organs have become permanent. In fact, the stage at which the disease is caught appears to be of higher importance to the outcome than the intensity of the intervention performed (11).
Treating diabetes and metabolic disorders comes with a high cost both to the patient and the healthcare system. CGMs could provide a low-cost means for pre-prediabetes diagnosis to prevent the disease from entering a stage where costly medical intervention is necessary.
Catching high blood sugar trends isn’t the only thing CGMs are good at. These devices are equally capable of identifying low blood sugar trends.
Currently, the existence of what is referred to as “reactive” or “idiopathic” hypoglycemia is somewhat disputed within the medical community. However, numerous studies have proven that adults and children can suffer from hypoglycemia despite being otherwise healthy and not being treated by medications known to cause low blood sugar (12,13).
Furthermore, the use of CGMs in people who self-report as experiencing low blood sugar has shown that these individuals are almost always correct, with most showing frequent blood sugars below the normal range and some showing clinically significant hypoglycemia (14).
While this condition is still not well understood by the greater medical community, the evidence continues to stack up that idiopathic hypoglycemia can have complications similar to those seen in people with chronic hyperglycemia. Those with chronic low blood sugar are at an increased risk of cardiovascular disease and all-cause mortality (15).
CGMs available through lifestyle and fitness apps currently give people who think they have a problem with hypoglycemia the means to prove their condition regardless of if their physician or insurance provider cares to look into it.
Potential Complications of CGM Use In People without Diabetes
While the potential uses for CGMs in people without diabetes seem almost endless, we need to recognize the possible complications of using this technology to monitor healthy individuals.
The truth is, the number of studies into normal BG trends in healthy adults is lacking. Without comprehensive data to compare to, it is easy to draw false conclusions about what a person is seeing when looking at their own BG trends.
We know healthy blood sugar levels range between 70 to 140 mmol/L, with levels on the higher end expected after meals and levels on the lower end seen during short periods of fasting. But do infrequent spikes above or below this range represent a problem or simply a common occurrence that hasn’t been well studied? Is a flat line throughout the day a good thing or a sign that the body is struggling to get the energy it needs to thrive?
Without more information, the data produced by CGMs could easily be misinterpreted by users and lead to unhealthy changes in diet. It’s also worth pointing out that current CGMs are far from flawless and that those flaws could result in reading inaccuracies that inexperienced users aren’t in a position to identify.
Unhealthy Diet Alterations
Ask any customer of the current CGM subscription companies what they’ve learned from their CGM and you’ll likely hear something along the lines of, “I’ve learned a bagel with cream cheese is less likely to spike my blood sugar than a plain bagel,” or “I’ve learned full-fat yogurt makes a better breakfast for me than low-fat yogurt.”
If you haven’t tried one of these CGMs for yourself, let me save you some time and tell you that fat will always slow glucose metabolism. Now does this mean the key to a healthy lifestyle is to always eat a sizable portion of fat with your carbs?
Science says no. In fact, study after study has shown that a high-fat diet, especially one high in saturated fats like those found in animal products, increases a person’s risk for developing type 2 diabetes much more so than a diet high in carbohydrates (16).
If the goal of using a CGM is to find a way to prevent blood sugar from rising, the solution will always be to stop eating carbohydrates and start eating more protein and fat. It is this misconception that leads many people trying a CGM for the first time to turn to a ketogenic diet. Due to the nature of this diet and how it changes the body’s energy metabolism, smoother glucose trends almost always follow.
But fewer rises and falls in BG don’t necessarily mean the user is healthier or less likely to develop diabetes in the long run. While many studies have shown that ketogenic diets are helpful for obese people with diabetes, at least in the short term, there have been no human studies linking keto-like diets to the prevention of diabetes (17). The only data we have to fall back on here is that high-fat diets, like the keto diet, are a known risk factor for developing type 2 diabetes and metabolic disorders.
Without more data on what healthy glucose trends look like, fitness and lifestyle companies that provide CGMs to people without diabetes need to be careful in what they emphasize is the goal of the program. Finding foods that keep your blood sugar readings largely within the normal range is a healthy way to use this tool. Trying to do away with fluctuations within the healthy range by trading carbohydrates like fruits and whole grains for unhealthy fats, is not.
Because so many things in life can affect a person’s blood sugar, it is nearly impossible to use a CGM to look at just one aspect of a person’s health. Someone using a CGM from a fitness subscription may misinterpret high blood sugars as a result of food when really the culprit is stress. Someone using a CGM to track their sleep may see rises and falls early in the night as proof of apnea events when really the culprit is the large pizza they ate before bed.
Current CGM subscription companies have done a good job ensuring their apps have algorithms and professional technicians in place to help users interpret their results. This trend needs to continue as this field grows, but it also needs to improve.
The more data the algorithms have to go off of, the more accurate the advice the user receives will be. In most settings, this means integrating the CGM and the associated app with more biosensors. Fitness trackers, heart rate monitors, ECGs, blood pressure monitors, and other wearables can all provide valuable data to help interpret blood sugar trends. Non-wearables, such as menstrual cycle trackers and diet journals, should also be included.
The integration of these additional devices and apps is even more important in specialty-use cases such as sleep therapy, stress management, and disease screening.
One tool that people living with diabetes have that subscription CGM users do not is access to a blood glucose meter. These devices are invaluable as a means to check the accuracy of a CGM.
Both finger stick meters and CGMs have the potential for false readings. But the number of reasons for a false reading is far higher for CGMs. This is why all people with diabetes are still prescribed a glucose meter on top of their CGM.
This added level of security is not afforded to people without diabetes using these subscription services. And nor would most users want it to be. But the fact is, the current CGMs on the market are not anywhere near 100% accurate. And all struggle to correctly measure low blood sugar readings, often reporting readings near or just below 70 mmol/L as far lower.
Improvement in the accuracy of CGMs is something the diabetic community has been asking for for years. Serving a new, larger set of customers without the same knowledge base and without the tools to verify results, may finally bring about a generation of CGMs that fulfills this wish.
An Open Market for CGM Innovation
Lifestyle and fitness companies have opened the door for the use of CGMs beyond the diabetic community. But the potential uses for these devices go far beyond these niches.
Continuous glucose monitors could provide those suffering from sleep disorders and chronic stress with an inside look at their conditions to better highlight which therapies work and which don’t. Professional athletes and everyday fitness fanatics could use data from a CGM to target their activities to better align with their end goals and optimize their performance. And doctors and patients could use these simple devices to assure medications aren’t causing more harm than good while keeping a vigilant eye out for glycemic trends that might indicate a problem further down the road.
Still, companies looking to break into these new markets need to be aware of the possible complications CGM use in healthy individuals could have. But even here, you’ll find more opportunities than problems. What this market needs are more accurate devices that can integrate readily with a wider range of biosensors, technologies, and platforms. A CGM with this kind of versatility could meet the needs of multiple target markets at once and be ready to take on any new opportunities in the BG monitoring realm that are sure to arise in the future.
With all these possibilities and the potential for improvements at every turn, it’s a wonder more companies aren’t chomping at the bit to enter this market.
If you happen to run an innovative company that sees the possibilities of the growing CGM market, we’re here to provide the tools and experience to make your new product a success.
Here at Sequenex, we specialize in CGM development. We help growing SaMD companies design, develop, and sustain software systems that are purpose built for innovation, connectivity, and interoperability, three necessary characteristics for any company looking to break into this exciting new market.