More and more people who come to me are checking their own blood sugars when in the past, they wouldn’t have. The availability of meters and continuous glucose monitors (CGMs) now makes it simple and relatively easy to check blood sugar at home.
Continuous glucose monitors
A continuous glucose monitor is a little disc that you insert into your body. It’s easy to insert and it’s painless. You simply leave it in there for a couple of weeks and it continuously checks your blood glucose. It gives you readings about every five minutes or so, depending on the version. You can actually drill down to what happened after you had breakfast. If you link it to your smartphone or you use the little device they give with the monitor, it will actually record and give you a graph of your own glucose over the course of the day and then, over the course of two weeks. Sounds great, doesn’t it?
If you have diabetes, a condition of elevated blood glucose, and are on medication for it, you may check your blood sugar with a finger stick and a little needle called a lancet. You would check a little bead of blood using a strip that you put in a small machine – that’s the classic way to check blood glucose. This method, however, hurts over time. Some people come in with their fingers pricked so much that they hurt. No one wants to check blood sugars like that. Trying to make the monitoring of diabetes easier is new technology like these continuous glucose monitors or CGMs, for short. As I explained, you simply insert the little catheter into the arm and it’s designed to stay there for two weeks. It has some adhesive on it, so you can wear it in the shower. Swimming causes some trouble with it sometimes so you don’t want to swim with it. You can use a CGM to measure your own blood sugars even if you don’t have diabetes.
What do CGMs cost?
I think over time, these monitors will become available without a prescription. Currently, in the U.S., this is a prescription-based product, so you have to go to a doctor to approve the idea of you checking your blood sugars. This product is not free; it is not paid for by insurance unless your doctor prescribes it and then has a diagnosis that is codable for it. You can pay $100 at a pharmacy for a two-week supply of Dexcom or Libre, the CGM itself. That’s not too bad, although while that’s affordable for some people, it’s out of reach for others.
Why use a CGM?
The main question that remains to me, having seen a lot of people using a CGM and watching their own blood sugars is, why? Why would you want to do this? We know that eating carbohydrates raises blood sugar and the more sugar and carbohydrates you have, the higher the blood sugar goes. Some people are just curious or maybe they don’t believe the science or a doctor telling them that their blood sugar will go up if they eat an apple. If you are curious, you want to know, you can actually see your blood sugars every five minutes throughout the day.
You have to be a little bit tech-savvy in order to wear one or be trained on how to do it; it works best with a smartphone. Some of my patients can’t figure out how to use it, so you want to have someone show you how to use it.
Caution when using a CGM
A caution I would say in using continuous glucose monitors is don’t freak out and don’t get upset if your blood sugars aren’t totally normal throughout the day. That’s pretty rare. You have to be doing a keto diet, meaning without carbohydrates in it, in order to get this flatline blood sugar of 80 mg/dL (4.4 mmol/L) all day long. In fact, some people on a keto diet notice their blood sugars go down to the 70s and 60s (approx. 3.3 – 3.9 mmol/L), which in the past was thought to be bad. We now know, however, that that’s just part of being on a keto diet; you can get super low blood sugars and feel fine. Ideally, you would have someone to ask, “What does this blood glucose mean?” and not just have to worry about it on your own. Blood glucose that goes up just a little bit, say to 105, 110, or 120 even (5.8 – 6.7 mmol/L) and then comes back down, is not something I get worried about. That can happen even first thing in the morning when you get up when growth hormones or cortisol goes up – it can raise blood glucose. This means that even though you didn’t eat anything, your blood sugar might be highest in the morning. Don’t worry about that. There are these early adopters thinking that the lower the blood sugar the better and if you can just check on yourself, well, it’s not trivial to check it.
There are people who subscribe to what is called “the quantified self” – they want to measure everything and it gets almost to the level of being ridiculous, where you might ask someone, “How are you feeling?” and they start checking that all of the parameters are normal. It’s almost like a computerized feeling of, “If all my numbers are fine, then I’m fine.” How many times have I seen someone change their view of the world by the number on the scale? There are even signs that say, “I will not have a bad day just because there’s a number on my scale.” Of course, numbers can make you feel worried or feel better but I’m talking about the feeling of being able to do what you want to do, getting out and enjoying life, going beyond just having all the numbers in a certain range.
Yes, you can check your blood glucose, and that’ll probably be easier over time. I’m told every few years that they’re close to the watch that checks the glucose and everyone will be wearing it. If my watch could measure my glucose, why wouldn’t I do it? I’ll even probably be checking my glucose and I don’t even check my ketone levels because I know what they’re going to be; they’re going to be where they need to be. Those are just some thoughts about the technology that is there.
The quality of the CGM matters
Another thing: once I got into using the Libre CGM, the technology is not solid over the first two weeks; it’s like there’s a drift that occurs as the second week happens. Not all of these monitors are the same; some are of higher quality that you could actually base your insulin dose on, and others aren’t. If for kicks you wanted to get one of these less expensive ones, they will probably be of lesser quality. Again, you might have to have someone to talk to about what readings to worry about.
If you’re measuring blood sugar and you don’t know about a reading, you can go to the internet. A blood sugar of 150, 160, or 200 mg/dL (8.3, 8.9, 11.1 mmol/L) after a meal is getting into the range of pre-diabetes and diabetes, especially if it’s happening over time. You might be able to diagnose a problem that hadn’t been picked up by getting a conventional glucometer. I would weigh and balance the risks of finding out a number that you’re not sure what it means, because it might cause some anxiety until you get it checked. As far as wearability goes, they’re easy to put on and wear and they work with a phone or the device that they give when you purchase the machines.
Conditions can be reversed without a CGM
I’m conflicted as to whether you should use one or not; it depends on your personality and your ability to afford them. I can accomplish tremendous changes in someone’s health – like the reversal of chronic medical conditions and prevention of them – without using the CGM at all. You can fly a plane without an altimeter. You can actually help someone improve their lifestyle and lower their blood glucose and weight without a machine, without a monitor. We’ve been doing that for ages and people have been flying airplanes without altimeters. If you grow up with one and think that’s the only way to do it then you wouldn’t know, but we can actually reverse and prevent these chronic conditions without a CGM. Don’t let that be a barrier for you to try one of these approaches, because they’re not necessary. Unless you have diabetes – where you should be measuring – it’s just going to validate what you’ve learned, which is that carbohydrates raise blood glucose. You might learn something specific to you, like how going for a walk after a meal changes your blood glucose, or how exercise or fasting affects your blood glucose, but I think it’s going to be small, incremental knowledge based beyond just the limit of carbohydrates being the basis for healthy living.
Watch the full video here.