[Review] Medtronic Enlite VS Dexcom G4

If you don’t know Gary Scheiner MS, CDE, (also a T1D) you should definitely check him out on his website Integrated Diabetes. He authored the book “Think like a Pancreas” among others, which is a recommended book by all of us with T1D.

He recently wrote a REALLY GREAT review after wearing both the Medtronic Enlite and Dexcom G4. Here it is below, here is the direct link to the source of the article Sensor vs Sensor.

<em>As a kid, I loved reading MAD magazine.  It was sarcastic, critical, and held no prisoners.  The “Spy vs. Spy” segment was a personal favorite because of its poignant portrayal of the idiocy of war.
In the diabetes industry, the “war” has traditionally been “meter vs. meter” or “pump vs. pump.”  Today, a major side-battle is brewing between the CGM companies, namely Dexcom and Medtronic.  As insurance coverage and patient/provider acceptance of continuous glucose monitoring grows at an exponential rate, more companies are sure to enter the market.  Abbott’s Navigator system still has a small foothold in some parts of the world, but for now, Dexcom and Medtronic are the sole super CGM powers.  So how do they compare?

For the past 8 weeks, I put each company’s latest system, the Dexcom G4 and Medtronic 530G with Enlite, to a head-to-head test.  Other than wearing the sensors longer than the “approved” number of days, I pretty much followed all of the rules and recommendations that each company provides to users.  Simultaneous calibrations were performed three or four times daily prior to meals, when glucose levels were in a relatively steady state.  The sensors were stored properly and placed in appropriate/adjacent sites, and the sites were rotated consistently.   Extra adhesive was applied over the sensors at the first sign of loosening.  Transmitters and receivers were charged as needed.</em>

Here’s what I found:

Sensor Insertion & Comfort:
Both systems now use very thin introducer needles and automated insertion devices. Enlite inserts at a 90-degree angle and is much easier to insert and more comfortable than Medtronic’s previous Sof-Sensors.
Edge: EVEN

Sensor Longevity:
With a little ingenuity (and a lot of tape), both sensors can work well past their initial life-cycle. Based on my personal experience and that of my clients, I have found that the Enlite sensors last an average of 8-10 days; G4 lasts an average of 12-14.

Alert Settings:
Both systems offer high & low alerts as well as rate of change alerts, albeit Medtronic’s rate of change alerts are much more customizable. Only Medtronic offers predictive alerts and allows the user to vary settings by time of day. Medtronic’s latest system also has a “low suspend” feature that automatically stops the pump’s basal insulin delivery when the glucose falls below a specified threshold – an annoyance during most garden-variety lows, but a potential life saver for those susceptible to severe hypoglycemia without symptoms.

Alert Volume:
Both systems can beep and/or vibrate to alert the user of a potential problem and both have adjustable settings, but Dexcom’s vibrate mechanism is considerably stronger, and it can beep much louder (when desired).

Medtronic’s radio transmitter contains a memory chip that stores up to 40 minutes of data and submits it to the receiver in case the receiver was out of range of the transmission. Which is needed: the signal only travels a few feet (and is frequently lost even when in close proximity), and it must be removed from the sensor and charged at least every six days. Dexcom’s transmitter never requires charging and sends a signal that reaches across a sports field or multiple rooms of a house.

For those who use a Medtronic insulin pump, the convenience of having the CGM display right on the pump itself is tremendous. However, some people (parents, caregivers) prefer to have a receiver/display that can be carried separately or placed away from the sensor. Dexcom’s full-color, high-contrast screen is simply superior to the Medtronic LCD screen.
Edge: EVEN

Dexcom’s download software has some nice features, such as the ability to segment data by day of the week and customize analysis dates. However, it does not work on Mac systems or integrate with data from any pumps or meters (unless you happen to live in certain European countries). Medtronic’s Carelink software is web-based, works on virtually all operating systems, is easy to use and share, integrates sensor data with pump & meter data, and generates reports that do a super job of revealing post-meal-bolus patterns.

There’s something to be said for a system doesn’t take a lot of work in order to function well. Other than having a sensor insertion device that takes some dexterity, Dexcom is the epitome of simplicity. The transmitter requires no charging (Medtronic’s transmitter must be charged every six days). Calibrations may be performed at virtually any time (Medtronic’s must be done according to a schedule). Dexcom hones its data towards calibration entries (Medtronic generates error messages when data is off). Dexcom’s setup and sensor startup startup process is streamlined. Out-of-range signals are much rarer with Dexcom and don’t require extra steps to re-initialize.

Here’s the biggie. Most people are willing to put up with some minor inconveniences if the system generates reliable data on a consistent basis. Medtronic’s original sensor, the “Sof-Sensor,” was infamous for its accuracy and dependability problems. I saw this with my own system as well as with many of my clients who used it. So I went into my personal trial with the 530G with Enlite without any big expectations. And I was pleasantly surprised. Enlite performed admirably. There were far fewer lost signals and data gaps. It wasn’t as “cranky” at the start-up. And the data closely matched the fingerstick calibrations more often than not. But it still wasn’t quite up to par with Dexcom’s accuracy.
Accuracy is best measured by looking at MARD – Mean Absolute Relative Difference. This represents the difference between fingerstick calibrations and sensor glucose values, so a lower MARD is better. A calibration reading of 150 mg/dl and a sensor value of 120 mg/dl represents a MARD of 20%. The overall MARD for each system was as follows:

Medtronic Enlite: 18.66% MARD
Dexcom G4: 12.60% MARD

Keep in mind that this data (particular the Medtronic MARD) differs from data published by the companies from their own pre-market trials. I’d like to think that I put the sensors through a serious real-world test: changes in sleep patterns, travel, lots of unusual foods, extreme exercise conditions, stressful situations, and so on. In other words, the rigors of my normal life.
In terms of which system was more accurate more often, Dexcom had a definite advantage:

Neither system was particularly accurate during the first 24 hours after sensor insertion, with MARDs in the 25% range. But things improved considerably after “day 1” and continued to improve over the life of the sensors. Both systems also tended to underestimate glucose levels more often than overestimating (Dexcom moreso than Medtronic)… which is good for those trying their best to avoid hypoglycemia, but not ideal for those who are easily annoyed by false low alerts.

Percent of Readings
BELOW Calibration Percent of Readings
ABOVE Calibration Exact Matches
with Calibration
Medtronic 57.5% 41.1% 1.4%
Dexcom 68.0% 29.3% 2.7%


So there you have it. Do with it what you will. Both companies (as well as Abbott, from what I hear) are aggressively developing their next generation systems, so this may all be obsolete soon anyway. But for now, I hope it gives you what you need to make an educated decision. Whatever you choose, you’ll be far better off than not using CGM at all!

Thank you for posting. I feel like Enlite has been taking a lot of crap over accuracy. I started using the Enlite system at the end of November. The first 5-6 weeks were pretty crappy accuracy-wise, but now that the sensor has had a chance to learn how to read me it has been unbelievably accurate and consistent compared to the Sof-Sensors I was used to! I was frustrated at first but now am so happy I upgraded!

I have never used a Dexcom so I can’t comment there but I am once again happy with Minimed :slight_smile:

Great post. Just a point of clarification, MARD shouldn’t be calculated using fingersticks as a baseline because they are not themselves accurate enough to be considered a reference number. Doing so will increase MARD as both methods vary–which is what you’re seeing in the results above.

I admit that this is a very informative post that I should have read before deciding what cgm to get. Fortunately, I decided on the Dexcom G4 cgm. After reading your post, I am more at peace with myself for that decision. Thanks.

I just started using the Medtronic pump and enlite, but I had used Dexcom G4 for months before buying the pump for my night lows and the suspend feature. I am thinking of wearing the dexcom again as it seemed a better fit for me, especially seeing the screen easier. Does anyone else wear the dexcom and the Medtronic pump at the same time, instead of the enlite and just monitor the device manually. I realize the suspend feature would have to be manually done because of the lack of sensor but think it would work better for my day to day. I even thought of wearing both sensors at the same time - ridiculous but worth a try.

This may be a dumb question but can I use the Dexcom CGM with my Medtronic 554 pump? I’ve tried the Enlite sensor and due to its huge inaccuracies would like to try something else. Does anyone know as I’m sure Medtronic will want me to stay with their Enlite system. Just wondering about compatibility.

hi @Brazilia,

i don’t think its a dumb question. the dex and your pump are not compatible (no you can’t use the dex CGM AND your Medtroinc pump as the reciever)

it doesn’t stop you from using the Dexcom CGM, you will just need to carry a separate dex CGM receiver such as the G4 Platinum Receiver.

If you decided to use the DEX CGM and receiver, Medtronic would have nothing to say about this because it will be completely separate from the pump, you will need to contact Dexcom and see if you can get authorization (insurance) to pay for it.

in some people, the CGM just doesn’t work accurately, no matter what sensor they use. Sometimes it’s because of tricky calibrations, other times it’s body reactions to the sensor and body chemistry. Hope it works out for you and good luck!

I’m getting ready to get my Daughter set-up with the newest Dexcom CGM. She uses the Medtronic MiniMed and coordinating CGM. Does anyone know if Dexcom offers an exchange program on their competitors devices?

I know minimed has an exchange program for Dexcom’s supplies because Dexcom is selling them out. I’m currently using the Dexcom sensor with the minimed pump and love it! Being able to see the trends in the days of the week has allowed me to gain a significant amount of insight and more control of my blood sugars, the MARD for dexcom readings are even better now that they made a software update to the transmitter late February. Getting my insurance company to approve the Dexcom sensor and transmitter was a hassle though since I already had the enlite sensor. They didn’t realize that medtronic had a 60 day no return policy for the enlight sensors and transmitter.

Getting my insurance company to approve the Dexcom sensor and transmitter was a hassle though since I already had the enlite sensor. They didn’t realize that medtronic had a 60 day no return policy for the enlight sensors and transmitter.

Ah, could you expand on that a bit? First, I’m not familiar with Medtronic’s 60 day no return policy. What is it? Second, how would not being able to return something to Medtronic be something your insurance company or you would benefit from?

I’m not understanding what point you might be making.


I know minimed has an exchange program for Dexcom’s supplies because Dexcom is selling them out.

Again, not understanding. Did you perhaps intend to say that Dexcom is outselling Medtronic? I’m not sure what “Dexcom is selling them out” might mean.

From Wikipedia: “Selling out is a common idiomatic pejorative expression for the compromising of a person’s integrity, morality, authenticity or principles in exchange for personal gain, such as money.”



Thanks for sharing. We are at our 4th year with the MiniMed so I’m hoping our insurance will be helping us get into a new device. I have done much reading on the newest Dexcom Gen 4 Share and the soon 5 and it’s very exciting.

Be well.
-w. bryan

I think the inaccurate readings from medtronic’s CGM have led a lot of people to switch to Dexcom’s CGM. I was told by my insurance that I needed to return medtronic’s CGM (enlite transmitter and sensors) to medtronic before they would be willing to cover the costs of another CGM from Dexcom. Thing is they didn’t realize that medtronic doesn’t take the CGM back if you’ve had it for longer than 60 days and I had to find that out myself after being on the phone for hours at a time. The entire process was a real hassle but worth it in the end.

Medtronic has worked well for me for the past 16 years. I too just upgraded to Enlite. See little difference, but remain happy with results.


People are fun aren't they??? Great story!



It just shows how we need to get more awareness about diabetes out there.