CGMs, Biosensors, and Blood Sugar Awareness
Blood sugar monitoring and management continue to gain interest as useful tools to empower individuals with more insight into their health. This data provides personalized feedback related to health behaviors so people can better understand the impacts of food, movement, sleep, and stress (among other things) on their blood sugar levels. Until recently, accessing this information with devices was less accessible without a prescription or pricier specialty product. New over-the-counter biosensors made by leading companies of glucose monitoring devices have recently made it widely available.
Continuous Glucose Monitors (CGMs) and Glucose Biosensors
What are they, and how do they work? Both a glucose biosensor and a CGM are wearable devices that measure blood glucose (blood sugar) as it circulates in your body throughout the day. They take readings using a small microneedle with a sensor that’s inserted just under the skin into the interstitial fluid (the fluid that surrounds cells below the skin). The application of the sensor is a pain-free process, and glucose readings are transmitted to a smartphone app without any additional action required, allowing for easy monitoring.
The differences between these devices are minor and come down to certain features. The original CGMs are considered medical devices and require a prescription from a doctor, as these have historically been used for individuals diagnosed with diabetes. Insurance coverage varies based on diagnosis, medical necessity, and health insurance plans.
One key area in which a CGM differs from the newer devices (often called glucose biosensors) is that CGMs can provide alerts for high or low blood sugar levels. Since the newer devices are intended for general use and sold over the counter, the glucose biosensors detailed in this article don’t have these features, as someone without diabetes is less likely to need these alerts. Essentially, these devices do the same thing from a monitoring standpoint, and often, the terms are used interchangeably when referenced online. For this reason, we’ll refer to them similarly in this article.
Why use a CGM if you don’t have diabetes?
Why was this type of device made available to individuals without diabetes to track their blood sugar levels and patterns? Because of increasing rates of insulin resistance and diabetes, awareness of this data can be beneficial as a monitoring and prevention tool. Since the sensor tracks blood sugar values continuously, the information provided allows for useful insight regarding your body’s response to things like the foods you eat, your blood sugar levels between meals, how activity or inactivity influences your blood sugar, and other considerations that can vary from day to day. For individuals at risk of diabetes, with a known diagnosis of insulin resistance, or who may be experiencing symptoms with a possible connection to a dysregulated blood sugar (fatigue, cravings, mood swings, dizziness, shaking, sweating, etc.), the insights from a CGM can help to pinpoint patterns or rule out any connection. Individuals may use a monitoring device to assess how their regular health behaviors impact their blood sugar, seeking to learn more about how their everyday habits and choices influence their blood sugar.
A dysregulated blood sugar can also be a driver for various other health conditions or imbalances in the body, such as low energy, mental health challenges, hormone imbalances, excess body weight, and chronic disease. Balanced blood sugar levels are a key factor in weight loss and optimal weight management, as excess glucose in the bloodstream primes the body for energy storage and, over time, can lead to weight gain. Ultimately, these devices have a lot of utility in increasing awareness of what’s happening with blood sugar levels and their connection to health.
How it works and available products
Once the sensor is inserted, it typically has a 14-day “wear time”. This means it will remain attached to your skin (with medical-grade adhesive), and you can shower, sleep, exercise (and sweat!), going about your regular day without concern for it staying on or needing special care. While you’re wearing it, the device collects blood glucose measurements and shares this data with the corresponding smartphone app.
Two of the key products on the market now available over the counter (and to people without a diabetes diagnosis) include Abbot’s Lingo and Dexcom’s Stelo. The functionality of these products is similar, but the specific features of their apps vary, so consider checking out the details of the products and functionality of their apps to see what suits your preferences. Of note, the Lingo is currently only available with Apple iOS, and not available on Android devices. For those using the Stelo, a second app (Dexcom’s Clarity app) is needed to view trends and patterns of data outside the 24-hour glucose levels depicted in the Stelo app.
What does the data tell me, and what do I do with it?
With glucose measurements captured every 1-5 minutes, data is compiled in the app onto a graph that spans the entire day, with the x-axis listing blood glucose reference ranges and the y-axis listing the time of day. The ‘target range’ is highlighted with a different color to make it easy to see if your values fall within this or when they may be outside (above or below). The app features allow you to log foods eaten and activity, which are likely to facilitate changes in blood glucose levels. This is where the details provide the greatest insight. If you’re wondering about a symptom you’re experiencing, you can observe whether there is a connection to changes in your blood sugar by evaluating the readings during the time frame you experienced the symptom. For example, if you feel you may have low blood sugar, you can open the app and evaluate the reading and corresponding patterns.
One insight that may be gathered from using one of these devices to assess connections between blood sugar and physical sensations is that a sharp rise and fall may lead to ‘feelings’ of low blood sugar, even when numbers are within the target range, simply because the sharp rise and fall is a drastic change and can be perceived as a stressor. Our bodies adapt to meet the necessary demands, so if blood sugar rises quickly, the body will release more insulin to lower blood sugar back into the target range. With this insight (how you felt and your blood sugar response), you can evaluate whether you want to change the amount, combination, or timing of your meals or activity to support your body better.
Considerations for what optimizes a blood sugar response include pairing carbohydrate sources with protein, fiber, and healthy fats at meals and snacks. Because carbohydrates come in various forms (fruits, grains, starches, processed foods, etc.), how the body responds to the types and amounts is largely variable between people. Noting your body’s response to these details allows you to adjust and monitor whether the changes help your numbers move in the optimal direction. These adjustments might include changes to the types or amounts of food or activity you incorporate.
For example, we assessed the response to a meal of salmon, rice, and vegetables eaten for lunch two days in a row. One day, the individual went back to the desk and was relatively inactive for a while after the meal. The other day, after the same meal, the individual took a 15-minute walk before returning to work. On the day without the walk, the individual’s glucose level climbed higher overall and dropped lower in the hours before the next meal. This sharp rise and fall led to feelings of perceived hunger that were likely driven by the drastic rise and fall in blood sugar levels. On the day of the walk, the glucose value didn’t climb as high, came down to an optimal range in a shorter period, and didn’t drop too low. This demonstrates how activity (even something as simple as a walk!) can optimize blood sugar response, as our active muscles pull sugar from the bloodstream into cells to be used during activity.
We tried the devices, here are a few simple takeaways
Both Abbott’s Lingo and Dexcom’s Stelo come with detailed instructions for both applications and use of the products. The apps are easy to use, and the data is easy to interpret (although our team of dietitians is always here to help you customize the experience).
For example, here is an image of a day tracked in the Stelo app. The dots on the y-axis correspond to when data was entered, which can be viewed on a different screen. When viewing this screen, you can hover over the time of day to see the blood glucose value. On another screen, you can access the details logged about foods eaten and activity. The Stelo app is more straightforward, providing daily insights. Notifications are minimal, but one example includes an in-the-moment spike detection message received when a sharp change in blood glucose occurs. To view the data compiled over the 14-day wear period, you would need to download the Dexcom Clarity app, which allows for viewing various reports.
*Image from Dexcom, Inc via Stelo app
The Lingo app has more comprehensive features in one place. It also includes the option to track more aspects of lifestyle (such as sleep and stress), as well as to sign up for challenges and receive a score for how your blood sugar responds to various factors, referred to as the ‘Lingo Count’. The goal of this data is to capture the perceived strain of blood sugar changes on your body based on the size and duration of change. The count number is calculated through an algorithm to identify which habits may improve your metabolic health and reduce strain on the body. Each day, you’re given a total number of ‘Lingo points’ that is your target to aim to stay below through changes to diet and activity.
For those motivated by details, this feature may be advantageous. For anyone prone to fixation or concern over additional information, this aspect may be a hindrance to user experience. Luckily, it is an optional feature and can be turned off.
Is a CGM/Biosensor a good fit for you?
The two biosensors referenced in this article have an average cost of less than $100 per month. These products and others on the market may also be flexible spending account (FSA) and health savings account (HSA) eligible. Check your plan details to confirm. If you are managing a diabetes diagnosis, your insurance plan may cover a CGM and/or biosensor.
In our experience, the devices provided easy-to-understand and useful insights regarding the impact of lifestyle habits on blood glucose levels. For someone less familiar with these details, sharing the information provided with a health professional, such as a dietitian, would be a wonderful way to further understand the data and consider adjustments to support progress toward health goals. Our dietitians can assist you with interpreting the data and applying it to support changes in your life, with goals ranging from weight loss to stable energy levels. Whether you’re curious about details of your daily routines, looking to learn more about symptoms, or preventing health concerns related to blood glucose management, a glucose biosensor may be worth considering.
If you’d like to learn more about how diet and lifestyle influence blood sugar levels on a broader scale, consider joining us for our Reset and Rebalance Your Blood Sugar program starting February 4, 2025.
Resources:
https://www.stelo.com/en-us/how-it-works
https://www.hellolingo.com/lingo-experience
https://support.hellolingo.com/hc/en-us/articles/16066221412375-What-is-a-Lingo-Count