For the past ten days, I used to be lucky enough to try the Dexcom G7, the long-awaited, hotly-anticipated, brand latest continuous glucose monitor (CGM) from Dexcom.
The business’ earlier model, the G6, was the “killer app” of CGMs, a tool so user-friendly that it even convinced many individuals without diabetes that they needed the tech, with such exquisite blood sugar accuracy that the FDA allowed Dexcom to inform users that they didn’t need fingersticks anymore. Dexcom didn’t rest on its laurels — the G7 is totally redesigned, and is a big improvement over the old model.
But Dexcom’s biggest competitor, Abbott Laboratories, was busy too. In October 2022, I had the prospect to wear a FreeStyle Libre 3, and I called it the most effective CGM I’d ever tried. How does the Dexcom G7 arise?
To seek out out, I wore each CGMS — one on each arm — for ten days. Dexcom kindly provided me with one sensor to try as a journalist. Abbott has previously done the identical, though this time I used a Libre 3 sensor that I purchased with my very own money (I’m a daily user). In each case, my opinions are entirely my very own.
Here’s the way it went:
In the event you’re used to the older generation of CGMs, you’ll find that each the Libre 3 and the G7 are impressively small. The G6 was pretty sleek, but I way all the time aware that it was there, stuck onto my body, and had a habit of bumping it into door frames the and like.
The brand new G7 is tiny! Dexcom reports that the brand new device is 60 percent smaller than the G6. Even when nothing else concerning the technology were improved in any way, that slim profile can be well value looking forward to.
However the Libre 3 is even smaller than the G7 — it’s concerning the size of two pennies stacked on top of one another.
The reality is that they’re each sufficiently small that I don’t notice them in any respect during my day. They’re as light as heck and about as obtrusive as a Band-Aid.
The Libre 3 wins here, nevertheless it doesn’t really matter — each CGMs are so small that you’ll likely forget you’re wearing them.
Surprise — there aren’t any transmitters here.
Considered one of the main benefits of the Libre system was once the dearth of a transmitter. The Libre sensor, the little round device that you just stick into your skin, was all-in-one. The Libre 3 preserves this easy design.
Against this, the Dexcom G6 required you to snap a transmitter out of your old sensor and into your latest one. Although there have been some benefits to this approach — Dexcom users could hack their G6 transmitter in an effort to get extra days out of their expensive sensors — the method was cumbersome. You needed to cope with two parts, each with a really different working life, and it increased the technical difficulty of the Bluetooth pairing ritual you needed to perform to get each latest sensor working.
The G7 is, just like the Libre 3, an all-in-one sensor. It’s fully disposable. Though the G7 will not be hackable, it’s now far easier to change from an old sensor to a brand new one.
If there was one obvious sticking point with the previous Freestyle Libre CGM systems, it’s the indisputable fact that users didn’t just get their blood sugar numbers routinely beamed to a dedicated receiver or smartphone. They’d to manually scan the sensor by holding their device over the sensor for just a few moments. In our survey of CGM users, manual scanning was regularly mentioned as a significant annoyance with the older generations of Libre CGMs.
This scanning movement is totally unnecessary with the Freestyle Libre 3 — because it was with the G6 and continues to be with the G7.
With either system, your smartphone updates with latest blood sugar readings routinely.
There may be one significant difference between the 2: the Libre 3 will provide latest blood glucose readings every minute, whereas the G7 only updates every five minutes.
It is a clear win for the FreeStyle Libre 3.
The Freestyle Libre 3 is rated for 14 days.
The Dexcom G7 is barely rated for 10 days (10.5 days, really, while you consider the 12-hour “grace period” for switching over to a brand new sensor).
Libre’s longer life is a big advantage — not only does it mean fewer annoying changeovers, nevertheless it also reduces the period of time you spend wearing brand latest sensors, that are less accurate.
Dexcom has told Diabetes Each day that it’s working hard on extending the sensor life to 14 days. But, for whatever reason, they haven’t been able get there yet.
Application & Start-Up
For each models, sensor application was painless and nearly effortless for me. Each comes with an easy-to-use one-piece applicator. Each is pressed flat against the skin. For older CGM models, it was often a superb idea to look at a YouTube video to see exactly find out how to insert the sensor. However the Libre 3 and G7 are each easy and intuitive.
It was easy to pair each CGM with my smartphone. For every, I downloaded the official app, and followed instructions on the app. With the Libre 3’s, you just tap your phone against the sensor in your body. The G7 was barely more complex — you enter (or take a photograph of) a code on the box.
The Libre 3 gives you your first glucose measurement in a single hour.
The G7 is quicker: It’s up and running in just half-hour.
I used to be surprised to see that Dexcom includes and requires you to use a supplemental adhesive. This step was really easy, but I needed to walk over to a mirror and fumble with a donut-shaped sticker to get it properly attached to each the G7 sensor and the encompassing skin. It’s a minor annoyance, and the additional sticker makes the G7 more conspicuous.
The adhesives for each systems performed perfectly for me, staying firmly stuck onto my skin for your complete 10- or 14-day wear length. I didn’t really test it though — it’s not summer, and I wasn’t swimming or sweating.
Adhesive quality is an element for which your mileage may really vary. Many individuals with diabetes struggle with CGM and insulin pump adhesives — there’s a complete Facebook group, with over 15,000 members, dedicated to troubleshooting rashes and adhesive allergies from CGMs. The manufacturers have been at pains to scale back the incidence of those annoying and infrequently deal-breaking skin issues. Nevertheless it’s possible that one system is less complicated in your skin than one other, and that could possibly be enough to make the difference for you.
Each system brings an analogous suite of additional features, including:
- Glucose alarms
- Glucose trend arrows
- Distant monitoring for relations/caregivers
- Data sharing with healthcare professionals
- Data evaluation within the smartphone app
Though I didn’t use all of those features, I didn’t find a giant difference between the 2 systems. Each app is attractive and intuitive.
Each CGMs are absolutely adequate to make use of for diabetes management.
Throughout the 10-days I tested my two CGMs against one another and against my glucose meter. All three were consistently in the identical ballpark. I felt completely confident using my blood sugar measurements to guide my eating and insulin dosing decisions. I had no need for fingersticks.
Did one system perform higher than the opposite? Probably not. It is feasible that the G7 — despite the indisputable fact that it only updates every five minutes, quite than each one minute — was quicker to discover blood sugar trends. It appeared to award upward and downward arrows before the Libre 3 would during time once I latest, from food or exercise, that my blood sugar was about to alter rapidly. Nevertheless it’s unattainable for me to say if it is a real advantage for the G7 or simply a fluke during a single small experiment.
As I write this line, my Libre 3 believes that I actually have a blood sugar level of 95 mg/dL. The G7 says 98 mg/dL. Such tight agreement was very typical, and neither was consistently lower than the opposite. After 10 days, each app reports the exact same average blood sugar level: 105 mg/dL.
The G7 will be calibrated using a reading from a blood sugar meter. The Libre 3 can’t be calibrated. I never felt the necessity to calibrate, either way.
Each Abbott and Dexcom claim to have created the world’s most accurate CGM. So far as I’m concerned, they’re each plenty accurate.
There have been two exceptions to their general consistency:
- CGM sensors are known to be less accurate in the course of the first 24-48 hours.
In truth, many individuals with diabetes have learned to roughly ignore their CGMs during that first day or two.
To be perfectly honest, my G7 was a nightmare in the course of the first day of use. It repeatedly bombarded me with very loud erroneous low blood sugar alarms. I turned off as many optional alarms as possible, but eventually I needed to bury my phone under a pile of pillows and blankets.
The Libre 3, alternatively, gave me perfect measurements immediately. But I’ve used it long enough to know that the Libre 3 just isn’t perfect each time. In truth, the very first time I used it, it had the identical problem because the G7, sounding false low alarms in the midst of the night. I actually have no reason to suspect that either the G7 or the Libre 3 performs higher than the opposite in the course of the first day or two.
And after that first day, neither device gave me a single false alarm.
- CGM sensors are slower than old-school glucose meters.
A CGM sensor doesn’t actually sample your blood — it samples the interstitial fluid that surrounds the body’s cells. Interstitial fluid carries nutrients from the blood capillaries, including glucose, which makes it a reasonably reliable indication of blood sugar levels.
It takes a bit while for the glucose in your blood capillaries to filter into the interstitial fluid. When your CGM gives you a brand new glucose measurement, it’s really showing you what your blood glucose level was about 10 minutes ago.
This 10-minute gap was plain to see as I tested my blood sugar repeatedly after a having fun with a very difficult meal. My old-school meter registered the glucose spike faster than either CGM did. But this doesn’t matter much — I might quite have a CGM give me continuous slow measurements than must use fingersticks time and again after I ate.
This was the surprise factor that actually made a difference to me.
The Libre 3 has a Bluetooth range of 33 feet, in comparison with the G7’s 20 feet. This made a large difference for me. I don’t have a big house, but once I left my phone in a single room and went to a different, I regularly found that the Dexcom app lost contact with its sensor, while the Libre 3 kept churning out glucose readings. On condition that it could often take the Dexcom several minutes to get back online, the Libre 3 ended up being significantly more reliable.
Given the vagaries and complexities of healthcare economics, it’s unattainable to say which CGM system would cost you more.
For those of us lucky enough to have generous medical health insurance policies (or live in countries with robust socialized healthcare systems), these vital devices could possibly be practically free. For a few of us, they might be out of reach.
As of this writing, a month of Dexcom G7 sensors costs $378 at Amazon’s online pharmacy, with an “estimated” cost of $60 after insurance.
In contrast, an analogous supply of FreeStyle Libre 3 sensors costs a mere $132 — however the estimated cost after insurance is $75.
But we are able to say that the Freestyle Libre products normally cost lower than the competing Dexcom products. That’s been true for years, though the specifics of your insurance situation will ultimately determine your cost.
Neither of the brand new CGM systems is prepared to be used with an insulin pump in an automatic insulin dosing (“closed-loop”) system.
That can change.
Dexcom and Abbott are currently racing to get closed-loop integration going as quickly as possible.
Dexcom seems as if it can have a head start — its G6 can already integrate with the insulin pump and dosing algorithms from Tandem and Omnipod. But Abbott, which has been slower to secure similar relationships, recently announced that it had received FDA clearance to be used with automated insulin delivery.
If closed-loop pumping is your priority, you’ll must wait and see.
All things considered, I preferred the FreeStyle Libre 3. It’s barely smaller, it lasts longer, and I actually appreciated the larger operating range. It is feasible that the Dexcom G7 is a bit bit higher at responding to blood sugar changes, however the difference (if it’s real) is subtle.
But really, these are each outstanding products, and every is lightyears ahead of the technology that was available just one yr ago. You’ll be completely happy with either one. Go together with whichever model your insurance prefers.