If you’ve ever wondered if the data we’re amassing will be useful, check out the continuous glucose monitor from the medical device company Dexcom.
As a tech narcissist, I’ve been interested for years in how technology can deliver a “quantified self,” or data about myself and how I live. But I can’t say that the data I’ve collected so far, from step counters to sleep monitors, has really taught me anything really useful — until I tried out Dexcom’s latest monitor. It turned out not only to be a good health care story but also a great data story.
The Dexcom G6 Pro gave me insights into how my body was behaving moment to moment, and how I can take charge and control how I feel. For me, this was a kind of academic fascination. But for Ric Peralta, for example, a 47-year-old man who has been living with diabetes for 12 years, it makes a huge difference in how conveniently he can monitor glucose levels and manage life-or-death situations.
This kind of insight that we both got from data is something I would expect to learn from a Star Trek Tricorder. But it’s available today, and it’s why Dexcom has a stock market value of $40 billion and sales close to $1.5 billion a year.
Glucose monitors measure the level of sugar in your blood. For diabetic patients, this is critical. Diabetes affects more than 34 million Americans and is the seventh leading cause of death in the United States. The traditional standard of care for glucose monitoring has been a fingerstick meter, which is painful as some patients need to test their blood by pricking their fingers up to 12 times a day.
In a patient with Type 1 diabetes, the pancreas can’t produce the hormone insulin, which helps the body absorb sugar and remove it from your bloodstream. For Type 2 diabetes patients, their body may not be able to produce or process insulin effectively. Either condition means people have to inject themselves with insulin to take their glucose levels down. But they can only do this if they can accurately measure their blood sugar levels in real time, something that hasn’t been possible or convenient until recently.
More recently, COVID-19 patients with poor glucose control have had bad complications leading to higher fatality rates. “We got an emergency approval from the FDA to use [glucose monitors] in hospitals,” Dexcom CEO Kevin Sayer said in an interview with VentureBeat. “They saw the glucose problems COVID-19 patients were facing. Many of them have diabetes or have high glucose variability.”
Dexcom has been making glucose monitors for years. Each one has been getting smaller and more convenient, in step with the march of Moore’s law — the notion that electronic devices get better every couple of years. Intel chairman emeritus Gordon Moore foresaw in the 1960s that the number of components on a chip doubled every couple of years. That made electronics cheaper, faster, and smaller. And the law has held up for decades, leading to advances such as far better glucose monitors.
Dexcom has ridden this wave. It was founded in 1999, debuted its first short-term monitor in 2004, and went public in 2005. It launched new glucose monitors in 2009, 2012, 2015, 2017, and 2018. The latest G6 Pro debuted in 2020. People can now attach the monitor to an insulin pump, and a software algorithm will figure out how much insulin to release into their bloodstream to counter a rise in blood sugar.
As the electronics became cheaper, Dexcom was able to create cheaper, more effective, battery-operated monitors that measured glucose levels and transferred the data wirelessly in real time, Sayer said.
The smartphone era
Peralta, the diabetes patient, has noticed the difference. When he started using Dexcom’s G5 monitor a few years ago, he had to manually calibrate it every 12 hours. That meant he had to prick his finger twice a day and analyze the blood to see if it matched the monitor’s results. It was also significantly bulkier than the current model. The newer G6 model is much smaller, and it can automatically monitor Peralta’s sugar levels 300 times a day and deliver the data to his Apple Watch.
“This was mind-blowing for me. A dramatic, immediate change for me,” Peralta said. “The fact that I no longer have to constantly calibrate is a huge game-changer for me.”
The Dexcom G6 Pro, which came out this year, is the first device approved for non-diabetic users. For non-diabetics, the Dexcom G6 Pro is OK to use in blinded mode. That means real-time glucose data is hidden from the patient and reviewed retrospectively with their health care professional at the end of the monitoring period. In unblinded mode, diabetic patients can see their glucose data throughout the 10-day sensor wear to gain insights and make treatment decisions in real time. (With that said, a provider could determine that a person might benefit more from seeing the data in real time, so there are scenarios where a healthcare provider might prescribe a G6 Pro off-label and enable a person without diabetes to wear it in unblinded mode. In that way, my usage of the Dexcom G6 Pro could be approved).
The monitors are still expensive at around $900. But roughly 98% of health insurance providers cover the use of these monitors for diabetic patients. It’s going to take a few more spins of Moore’s law to make such devices affordable to the masses. But the newest models are a lot less invasive, so patients are more likely to wear them all the time. And they also have a sharing feature that is critical for caregivers.
Sayer relates one story a customer told him. A young woman shared her glucose monitor results with her mother, who lived in Australia. One day, the young woman went to bed early during a modeling gig in New Orleans — and she didn’t wake up. Her mother saw the alert from the monitor on her smartphone. She called the paramedics, and they broke down the door of her daughter’s hotel room and saved her.
“There’s nothing more powerful than a story like that for someone with Type 1 diabetes,” Sayer said. “The game-changer for us has been the connection to the phone.”
Pretty soon, this measurement technology and real-time monitoring — the stuff of dreams for quantified self practitioners — will become relevant to someone like me, who otherwise had no interest in the devices.
I don’t have diabetes, fortunately. As I agreed to test the monitor, I realized that I was going to get a glimpse inside my body that most people never get a chance to do. I found, as Sayer observed, that I could use this data not as a patient, but as a consumer. I could look at what I was doing and what I was eating and figure out what the effect was on my blood sugar.
It was pretty non-invasive. A nurse showed me how to attach it to the left side of my belly. There was a tiny pin prick when I activated the device, which poked a needle into my skin. After that, I couldn’t feel it anymore. The monitor itself was a little over an inch long and it was glued to my skin. I was able to wear it for 10 days and take showers with it. It automatically uploaded the measurements of my blood sugar in real time to my iPhone. It never fell off.
I was astounded to learn that eating a big pile of spaghetti was one of the things that could push my blood sugar level off the charts and even put me above the 180 milligrams per deciliter threshold that doctors considered to be high.
At the same time, when I went for a jog, I found my glucose levels dropped so much that it dipped below 70 milligrams per deciliter and triggered alerts for me, as if I were in danger of fainting. My average glucose level was 124 milligrams per deciliter, which was within the range of normal, according to an evaluation by Dr. Daniel Katselnik, a diabetes and metabolism specialist in Texas.
The range of numbers for sugar levels is what diabetes patients have to follow very closely.
“The more a person stays within the range, the better quality of life they will have,” Sayer said. “People can stay engaged with their status. You can eliminate hospitalizations and save money. Doctor visits are efficient.”
If someone like Peralta spikes above his limit or falls below the lower threshold, he faces big health risks. If his blood sugar is too high, it can damage his blood vessels. The lows, known as hypoglycemia, can lead to hunger, trembling, heart racing, nausea, and sweating. It can also increase the risk of other problems like heart disease, stroke, nerve problems, and kidney disease. It is a deadly problem, possibly leading to coma or death. An injection of insulin can head it off, but Peralta said that, in the past, the amount of insulin to inject was often a guessing game.
The app shared the data with Dexcom’s Clarity app and the doctor, Katselnik, was able to access my data after I shared my account code with him. He got it in a matter of seconds, and we compared the numbers that the app recorded to my notes on what I was doing at the time. He noted right off the bat that 94% of my results were within the suggested range.
But 5% of the time it was high because of what I ate. And when I was out of the range, I got an alert on my iPhone. I figured out one of those nights was the big spaghetti dinner. Another day I had a spike after a lunch. I noticed when I drank a cup of orange juice, the sugar level went up to 145. When I had a lot of carbs to eat, I got sleepy, as the sugar level were starting the spike upward.
Sayer, who often tests new devices, said he bought doughnut holes for his grandkids and ate a couple of them. He noted that his glucose level was up 10 points during the day because they were so sugary.
“You learn about what you eat, the timing of your meals, and how everything makes a difference,” Sayer said. “You can see here are some meals that may not have been good for you.”
Help for prediabetics
Even after carb binges, my blood sugar returned to average because my pancreas was working well, unlike in a diabetes patient. The doctor said I could prevent diabetes in the future by controlling my diet, like reducing my intake of carbs. Eating carbs with protein and fat reduces the spike. You’ll notice the impact of different foods on your blood sugar. Alcohol will have a definite effect in making your blood sugar spike, though I didn’t try this.
Katselnik also told me that when your blood sugar is spiking, you can bring it down fast by exercising.
That’s a short-term solution. Over the long term, exercising a lot will help reduce the spikes in blood sugar. Katselnik noted that the Dexcom G6 Pro is a good sensor with FDA approval, with an accuracy level that is within 9% of lab testing accuracy. I used a single-use disposable device. There’s a version that has a transmitter that can last 90 days. This is far easier than pricking your finger hourly.
“This is clearly a leap. It’s accurate. It’s easy to use out of the box,” Katselnik said. “You don’t have to calibrate it or do anything along those lines. So you get all the information you want. And the nice thing is you can do it remotely. This is a life-saving device for a fair amount of people, and it’s a standard part of care.”
You can replace the transmitter and keep using it. The sensor lasts about 10 days, so you have to replace that and pop in the existing transmitter when you do that swap. Doctors use the Dexcom monitors on regular diabetes patients, Katselnik said. He uses it on dozens of diabetes patients as well as prediabetic patients who are borderline for having the disease.
“The big use in the future is for patients who are prediabetic or maybe at risk for diabetes, so they can get the data and change their behavior so they don’t become diabetic,” Katselnik said.
Actionable data for diabetes patients
For doctors and patients, these Dexcom monitors are godsends compared to the older machines. Peralta used to have to prick his finger and draw blood and put it into an analyzer to get his sugar level. That involved a lot of time. The new glucose monitors deliver this information instantly, and doctors can look at it instantly. In fact, caregivers can look at someone’s data and call an ambulance if they see the person is having an episode. Patients’ lives are being saved as a result.
“This is true continuous information,” Katselnik said. “The only thing that is comparable is heart-rate data, and that’s super simple compared to blood sugar data. The data can be used to change medications and dosages. We’re in an exciting time. We have fully embraced it at our office.”
Peralta said that his own endocrinologist is very pleased with the results using the Dexcom G6. Peralta is doing some fine-tuning with his routine as he still has some occasional lows. Those times were scary, as Peralta knew he had to do something. One time, he lost his vision and his ability to speak, but he was still conscious. While he couldn’t say anything, the app could send an alert to his wife. She could then engage with him and do something to help him out.
Now Peralta knows that if he is going to go for a strenuous walk in the woods, he has to eat something ahead of time to keep his blood sugar high enough so that his numbers won’t drop too low. Since the app works with the Apple Watch, Peralta can flip his wrist over to see where his blood sugar is at during the day, giving him reassurance or reminding him he has to exercise or eat or use his insulin shots.
“As a Type 1, that’s just part of your daily routine, as you are constantly worried about your numbers,” Peralta said. “With the old fashioned way of the fingerprick, it’s basically you’re gonna burn through more strips than the insurance will provide if you’re constantly checking. And so you’re constantly guessing. ‘How does my body feel? Am I high? Am I low? Am I going up or down? I think I feel this way.’ Instead, I can see exactly where I am now.”
The data is different from the usual data that we get from our devices today. It’s actionable.
“There’s no question that, moment to moment, this completely changes your life as a diabetic,” Peralta said. “As a Type 1, we are living our lives basically, constantly on this fight to just try to keep ourselves alive. If I didn’t have this equipment, if I didn’t have insulin, I would not be here right now. It’s as simple as that. And anything that allows me to approach living a normal life is a powerful tool that is worth having. I can plan out hikes and I can plan out trips.”
The future of the quantified self
Katselnik thinks that body-hacking people and professional athletes will also eat up this data and change their behavior as a result. Athletes who face low blood sugar find that they are completely out of energy. That’s why they need to monitor their energy and drink things like Gatorade to stay at high energy levels.
Back in 2012, Sayer noted an Olympics cycling team used the glucose monitors and found one particular athlete was running out of energy. They asked her what was happening and she said she was dieting because she felt she was bigger than the other athletes. The trainers put a stop to the diet and told her that her skills, not her body shape, was what got her on the team. Once she started eating properly, she was able to perform much better.
Over the long term, Peralta said he can also make good use of the data for his own self-service.
“As long as I have been doing this, I’m starting to notice through some of the other apps that I’m just finding new ways of micromanaging,” Peralta said. “If I’m starting to trend in a certain direction, then I realize that if I just give myself an insulin dose I can flatten that curve a little, but not so much that I’m going to drop off like a rock and be crashing in an hour. After I do this for months, I can see exactly what I need. And I’m definitely having far fewer peaks and valleys.”
Sayer said future products that use this core sensor technology will be able to help people in a variety of ways. You may, for instance, look to your blood sugar for why you’re in a bad mood. You can do something about it, like eat a snack. Artificial intelligence could come into the picture as well and handle a lot of the care so the patient won’t have to be so attentive.
“If I am snippy and biting someone’s head off, I can see it,” Peralta said. “‘Oh, this is why I’m like this. This is why I’m in a bad mood.’ And I started apologizing for what I did and saying, ‘Look, I’m sorry, but this is why.’”
He’s grateful for the technology. “I think I can come pretty darn close to living a normal life,” Peralta said.
At some point, the quantified-self fans will likely be a market opportunity, as the company will be able to make cheaper monitors for those who are just curious about their bodies. “What’s more important about that use case is giving them a meaningful experience, like developing analytics engines around that for somebody who is not a diabetic,” Sayer said.
A sliver-thin Dexcom G7 device is about the size of a nickel, and it will have its own transmitter built into it. It’s in the product pipeline for 2021. I’m waiting for the day when a monitor will look at my breakfast and tell me not to eat the bagel that’s on my plate.
“We obviously have to take the cost out of this to get it to the mass market,” Sayer said. “This is real health care. This is life and death stuff. We have a lot to do. It makes it very easy to go to work every day.”