A few weeks ago, I wrote about the wearable health technology that has come of age, giving us a window into the working of our bodies. For me, it represents an important step in taking control of your health – and away from Big Pharma and putting it, whenever possible, where it belongs –  in your hands. Now I’d like to get a little more specific with a primer on one such personalized device, continuous glucose monitors or CGMs. Though they’ve been available for diabetics for about twenty years, now, ever-more refined models are attracting the interest of healthy, health-savvy customers who are using them to see how their blood sugar responds to what they eat, how they sleep, their exercise, stress and other factors – a wise idea if ever there was one. Is it time for you to add one to your health maintenance plan? Quite possibly! Here’s what to consider:

What do they do? 

CGM devices measure the glucose (sugar) in your blood. You’re probably familiar with the single prick glucose monitors – the little needle jab in the finger that gives you a read-out of your blood sugar levels at that moment. A CGM, on the other hand, is a plastic patch (about the size of two quarters) that typically sticks to your arm or abdomen, a wearable biosensor taking continuous readings over the course of the day and wirelessly transmitting them to your smart phone or, if your phone isn’t so smart, a dedicated “reader” device. The CGM gives you a much more complete and useful picture of how your metabolism is responding, in almost real-time, to your life — to the food you eat, the stress you’re under, even the sleep you got last night. (I say “almost real time” because the tiny device’s tiny filament records glucose levels in the “interstitial fluid” just under the skin, which lag behind actual blood levels. The duration of lag varies depending on rate of change of glucose.

Who needs a CGM? 

Currently, most people who use CGMs are diabetic, especially type 1 diabetics whose bodies have stopped making insulin and who need to constantly check their glucose levels so they can balance the food they eat with the amounts of synthetic insulin they inject themselves with. But there is a much larger group of type 2 diabetics – roughly 1 in 10 Americans — who can and are benefitting. The cells in their bodies have grown resistant to the insulin made by the pancreas. They need to carefully monitor their diet to make sure the food they eat, in particular the carbs, don’t over-stress their bodies’ reduced ability to clear the sugar from their bloodstream. If they’re not careful, those glucose levels will continue to rise, bringing on, or worsening, short-term symptoms like weight gain, fatigue, and brain fog. Longer term, we’re talking dramatically higher risk for cardiovascular disease and other life-threatening conditions. A recent multi-center study found that the continuous monitoring of blood glucose translated into better glycemic control than testing the blood the old-fashioned way, with those unpleasant finger pricks. 

CGMs for the rest of us.  

Although there haven’t yet been studies that have proven in some definitive way that CGMs can safeguard or improve metabolic health in people who don’t have diabetes, common-sense says they can help. And, as insulin resistance, pre-diabetes and diabetes rates continue to go up in this country, at least in part, a consequence of the huge amounts of extra sugar that the food industry has been dumping into processed “convenience” foods over the past three decades or so, keeping tabs on glucose levels could be a potential life-saver for many. Currently about a third of Americans over 50 are pre-diabetic and the statistics say that within five years, an estimated one-third of pre-diabetics will cross the line into type 2 diabetes. The trajectory here is obvious. 

Even if your blood sugar levels are “normal” right now (a hemoglobin A1C reading below 5.7), a CGM could provide you with the wake-up call if your metabolism is trending in the wrong direction, before you find yourself in the danger zone. Which means, you need to seriously cut back the carbs, especially the sugar, and increase your level of physical activity, to stop the slide, or ideally, to reverse it. 

Maybe you’re already eating and moving the way you know you should but you’re not seeing the results, for instance in weight-loss, if that’s your goal. Steady glucose readings will let you know that your good work is being appreciated on the inside, and your metabolic and overall health will be better for it. 

CGMs benefits include possibly saving your life.

So, you may be wondering, why track glucose every minute of the day? Isn’t the reading from my annual physical enough? In a word, no — once a year is nowhere near enough! To really get a handle on glucose, you need data, with accuracy and frequency and CGM covers all the bases. With a CGM, it’s a bit like having a health coach with you at all times, tracking what’s working for your body and what’s not – exactly the kind of highly personalized data that can help save your life. Why else am I such a fan? Let me count the ways:

  • CGMs eliminate mystery: no more guessing what your numbers might be in between annual checkups. CGMs provide a moment-to-moment, real-time picture of what your glucose levels are in the moment, and more importantly, how they’re reacting to all the things that can impact them, like food, sleep, stress, mood, physical activity, etc. 
  • CGMs inspire better choices: simply put, when you know where the metabolic potholes are, you can avoid them by tailoring your choices to best support your unique metabolism. It’s a no-brainer nudge that some patients need to (more consistently) make healthy food and lifestyle choices that will help keep glucose levels stable.
  • CGMs are eye-openers: these days, so many foods have extra sugar and carbs tucked into them, they’re not so easy to avoid. However, having a CGM on your team makes it much easier to identify the less obvious spikers and empower you to make wiser choices. Think of a CGM as a highly personalized roadmap to guide you on your optimal dietary path.
  • CGMs don’t sugar-coat the truth: the numbers don’t lie – and seeing them reflected back to you in real time will help keep you honest. No more blithely under-estimating sugar consumption. The continuous flow of data shows us exactly where we’re at, like a non-stop truth bomb – CGMs keep it very, very real. 
  • CGMs take your levels personally: all of us have glycemic variability (more on that below). Our blood sugar levels respond more strongly to some foods more than others, and a number on a nutrition label won’t tell you how high the jump. A CGM however will – because it is all (exactly) about you.

Variability matters and CGMs tells you yours.

A certain way of eating – lots of non-starchy veggies, healthy fats and sufficient protein – is, generally speaking, good for most folks. And knowing the amount of carbohydrates and a particular food’s glycemic index – a measure of how much it will raise blood sugar levels – can be a helpful guide when eating for your best metabolic health. But a CGM can give you something beyond good advice and counting carbs and/or glycemic index numbers (which is quite impractical) – it serves up data on how your body, and your body alone, responds to food. The truth is, for all the attention paid to the “diet wars” (low-fat vs. low-carb vs. Paleo, etc.), different people’s metabolisms respond differently to the same foods, based on their individual genetics, epigenetics and microbiome. The variability is huge. 

The CGM can tell you which specific foods will cause your blood sugar levels to spike and which won’t. It may clue you in to the ways in which your body’s response to the same food depends on how stressed you are and how much sleep you got last night. You may discover that the order you eat what’s on your plate affects how well or poorly you limit the rise in glucose after a meal. My personal experience and those of my patients has found for instance, that if we eat higher carb foods after a salad, our blood sugars don’t spike as much, or if we go for a walk, even a five minute one, after a meal, our blood sugar comes down much more rapidly. The information gleaned on how your body responds to all aspects of your lifestyle, can be invaluable. 

Make note of it all – and eat accordingly.

Having your fasting blood glucose, hemoglobin A1C and insulin levels checked annually is important, but we now know that metabolic health is more than a single number at a single point in time. The beauty of a CGM is that it goes beyond a single glucose number to give you a picture of the ebb and flow of blood sugar levels during the course of the day, especially after carb-heavy meals. Even if your hemoglobin A1C levels are still in the normal range, you may discover that you register dramatic glucose spikes and troughs after you’ve eaten a carb-heavy meal. That means you’ve got high “glucose variability,” which, researchers have discovered, is itself a risk-factor for developing health problems associated with diabetes. Forewarned is forearmed. 

How much are they and how can you find one?

Most insurance plans will cover the CGM systems for those diagnosed with diabetes. Lucky enough to have not crossed the line just yet? Then you might need to be a bit more creative, as in, obtaining a CGM system via your doctor, assuming they are open to writing you an “off-label” prescription, which may run you roughly $75 a month. Abbot and DEXCOM are the two largest makers. But regardless of how you are able to procure yours, make sure your doc is in the loop to help you understand and interpret the readings and next steps for keeping your health moving in a positive direction for as long as possible.

Interested in this type of more granular, data-driven, precision wellness? Check out www.joinhearty.com

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