VIDEO: Continuous Glucose Monitoring
Transcript
Hi! I wanted to talk today a little bit about something called a continuous glucose monitor, also called CGM, CGMs are relatively new to the market and the concept is that it's a device that reads your blood sugar continuously all day, every day, using a wearable item that you put on your skin with a little teeny filament that goes into your interstitial fluid and reads the amount of sugar floating in there. Everybody has sugar in their blood all the time – if you didn't you'd be dead – but it's supposed to be a pretty tight range. Typically we look for blood sugars between about 60 and 140 milligrams per deciliter of blood. A healthy metabolism can make that range stay tight, almost like a thermostat in your home, no matter what you eat. J like with your thermostat, if you set it to 72 but it's 90 degrees outside and you open the door for a while, your thermostat is just going to start to crank out your AC to keep it at 72 despite the hot weather. Your blood sugar is supposed to be very similar. So if your blood sugar starts to go high because you ate a whole cake, your body should be able to shuttle that sugar into either energy in your muscles or storage as fat through the liver. So even though you ate that whole cake your sugar would never go above 140mg/dL. On the flip side if your sugar starts to get low because you haven't eaten in a long time, maybe it's the middle of the night, your liver can actually do the reverse – it can make sugar out of fat and put it into your blood to keep you safely above about 60mg/dL. Everyone's low is a little different but about 60mg/dL. If that's working well, life is good because you don't have to theoretically put a lot of thought into what you're eating. But what diabetes is or what it starts as is basically a flaw in your internal blood sugar thermostat. So when you eat a cake, you do start to drift above 140mg/dL. Some people will just go above 140mg/dL a little bit, for an hour, and then they'll be back in the normal range. Other folks might shoot all the way up to 300mg/dL and it could take hours to get back below 140mg/dL, or they may never get below 140mg/dL.
So what we recommend is that people who know they have pre-diabetes or diabetes do finger sticks. Finger sticks are a way to figure out what your blood sugar is that very moment. We typically tell people check when they wake up in the morning. If you're waking up high that's not a good sign. You haven't even eaten in 8-12 hours and you're already starting the day high. We know you probably need to change either your medications or your diet. We will tell people to check after they eat because that will help give them an idea of whether what they ate was easily metabolized by their body, or maybe they ate too many carbs for what their body can handle. It's laborious - it means people are poking themselves, getting drop of blood out, four or five or six times a day. It's inconvenient if they’re at work. And ultimately it's still not that much data because it's only telling us that very moment in time what your sugar is.
We also have a metric called the hemoglobin A1c. Hemoglobin A1c is usually done at a doctor's office, we don't generally do that at home. And what that does is look at, on average, how high was your blood sugar for the last 90 days. The problem with a hemoglobin A1c is that it truly is an average. So we sometimes have patients who run high and low, and because of that their hemoglobin A1c looks good. But in reality they're in dangerous ranges often but it just averages out to be okay. And we tell those people “your diabetes is good, you're well managed, you're fine.” But they're not fine because we know that going low frequently is very dangerous – that is hypoglycemia. You could become dizzy, disoriented, you could potentially pass out, and you could even go into a coma if it was very severe. On the flip side, high blood sugar, very high blood sugar, is not as dangerous in the acute phase. You probably will not even really notice you're so high other than maybe blurry vision or fatigue or urinating a lot. But if you are high year after year, day after day, we start to see complications like cardiovascular disease, eye problems, kidney problems, losing sensation in the fingers and the toes, things like that. So both are dangerous. But if someone's high and low often but their average looks good, that's not okay. We need to be intervening on that patient, and that's where continuous glucose monitors come into play.
Continuous glucose monitors literally read your sugar every 5 minutes, so a user can actually say “oh, it looks like if I eat oatmeal for breakfast not only do I go higher than 140mg/dL, but I stay there for 4 hours – that’s not good!” Or they could say “I'm actually going low in the middle of the night and then my body's pumping out sugar to try and get me back to a healthy range and then I end up waking up high, so it's not my dinners fault, necessarily, it's my liver is sort of malfunctioning.” There's just so much data now for an actual diagnosed diabetic who's kept trying to figure out their meds.
I actually think this technology has a lot of potential for pre-diabetics and what I call pre-pre-diabetics – people who think they're fine but maybe they're starting to gain a little weight, or their triglycerides have been high, or their cholesterol has been high and they can't exactly pinpoint what's wrong. The current medical model is basically wait and see. Just get worse until you actually get diagnosed with something and then we'll give you some meds. With technology like this we could see that a theoretically healthy person is going a little bit out of range after their average lunch and maybe we could start to change the diet now before they progress to an actual disease state. I've actually worn a CGM in the past and I am theoretically healthy – no doctor has ever flagged me for anything. I went out of range after eating a burrito (which is not something I always eat but I wanted to test it out with different foods)! A burrito with the tortilla, the rice, the beans – that sent me to about 155 for about 45 minutes. So that's interesting information. I was 32 when I wore that and I may have been a little bit insulin resistant already. I should not test the waters by having a high carb diet all the time. I should lay off and give my body a little bit of a break. Even if I'm just a little bit insulin resistant now, that way I never progress to being very insulin resistant later.
There's a lot of companies coming out with tech around glucose monitoring I'm very hopeful that some of the companies will be more consumer focused as opposed to going through insurance. Right now if you wanted to get a continuous glucose monitor you would need a prescription for it. There's really only two companies that make them right now and that's Dexcom and Abbott, which makes the Freestyle Libre. The Freestyle is a little bit easier to get. If you don't have a diagnosis of diabetes it ends up being about a $130 a month. If you do have diabetes and are injecting insulin a minimum of three to four times a day or on a pump, your insurance will most likely cover it and it will cost you somewhere between $10 and $75 a month depending on your insurance plan. The Dexcom come also has good coverage for diabetics, not so much for cash pay. I don't have a lot of cash pay patients use the Dexcom.
So that's kind of what’s out there right now. I've heard rumors that companies like Apple might be making one even smaller this, like an M&M. I really truly think that it's going to be the next wearable. Fitbit blew up in the last decade but they don't actually tell us all that much. This is real information that people could use to change their diet so I'm very hopeful that they're going come out for the general population. Like I said, most doctors will give you a prescription for one if you ask. If you just wanted to do an exploratory month it doesn't have to be something you wear for the rest of your life. If you just want to buy two sensors for $130, that's a really interesting idea for folks who maybe are trending towards metabolic disease – starting to get the midsection weight gain. It's just so informative to see “oh, a sandwich sends my sugar here, but a steak and broccoli sends it here.” That's information you can use and you know my policy: knowledge is power. You deserve to know what's going on in your body so you can make smart changes.
Follow along as I apply a Freestyle Libre sensor for the first time. (Spoiler alert: it was easy and painless!)