Dexcom G4 review, compared to original

Diabetes Technology Glucose Monitoring
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Just started with the G4 this past weekend, and wanted to give a brief review compared to the orginal Dexcom, in case anyone is on the fence about upgrading.

The executive summary is that so far, the G4 has been far better than the original, and the form factor/range is also much better.

Rcvr Size: Looking at the raw numbers when comparing the two is deceiving. In actual use, the G4 receiver is now thin enough to not be a bother when stored in a jeans pocket with my car keys. It seems to be less than half the volume of the original... The original was very large, leaving no space for anything else in the pocket, and the range was so short it had to be kept close to my body which combined to be a pretty big hassle. The new rcvr size is probably my favorite feature of the new model.

Range: There is no comparison. The new G4 works even when in another room, through multiple walls. The old one would occasionally lose signal if it was in the pants pocket on the opposite side of my body from the transmitter!

Transmitter: The transmitter is indeed a bit more bulky. I wear relatively loose shirts, and I never noticed the old tranmitter through the shirt. With the new one, I do sometimes see a bit of a wrinkle in the shirt, depending on how I'm standing/sitting. Not a big deal.

Comfort: About the same. Tape is the same. I might not be the best person to ask, as I never have issues with the stock tape, even when swimming or working out frequently.

Accuracy: The G4 is worlds better than the original, at least for me, for this first sensor. I had an issue with the original where it would run high for the first 3-4 days of a sensor, each time I calibrated I had to input a lower sugar reading. It was normal for it to be off by 30-50 points early in the cycle, if not more. Even at the end of the week, it would often be off by 20 points or so. When I asked about it here, the concensus was that perhaps my body was taking that long to reduce swelling/get used to the probe. On the other hand, with this first sensor on the G4, it has been accurate within 3-10 points every single time I have checked. I am only calibrating when asked (following the basic rules of not calibrating early in the morning or when my sugar is rising or dropping quickly), so this new accuracy doesn't seem to be due to lots of calibrations or any special usage. I don't know if this is just good luck on the first sensor, but I am thoroughly impressed.

UI: Honestly, I could care less about the color screen, but it is certainly nicer than the original. It does take longer to turn the screen on which is a bit irritating. I haven't used the new alert options, as I always use "vibrate". I do wish Dex would come up with a software update that allows different daytime and nighttime profiles, so I can expand my nightime alerts without so much button clicking.

Hope this helps anyone sitting on the fence. If you have any questions, just ask.

--Carey

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One other downer is the the 7 Plus USB worked fine on an iMAC running Windows. However the G4 USB interface does not work. You can run the Dexcom Studio SW fine but cannot connect your G4 to the iMAC. Only option I found was to download onto a PC and then forward the results onto the iMAC. I'm based in the UK and Dexcom helpline will not speak to me - can someone in the US ask them why they cannot spend 5 mins fixing the USB interface.

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Carey - I'm now 42 days into using the G4. My current sensor is on day 15. My first fingerstick this morning was 93 mg/dl and the G4 read 85 mg/dl. I agree with your review based on your first sensor. Overall I am very happy with its performance. My first sensor was also correlated closely with my fingerstick readings. I had almost no data dropouts for that sensor and wore it for 16 days.

My second sensor, however, was not as good. I had several ??? readings and it took several days to start tracking my fingersticks closely. It did get on track but several sustained data dropout periods in the second week motivated me to swap it out in the middle of the second week.

The third sensor performed much like the first with a high correlation with fingersticks and very few data dropouts. One thing with this sensor though is when I roll over at night and pressure it against my bed (it's on my left side between the top of the hip and the bottom of the ribs) it causes it to dive dramatically to hypo territory. I've had a few situations where it woke my up with the 80 or 55 alarm and my fingerstick revealed a BG in the 90-100 mg/dl range. I've tried to avoid rolling onto my left side.

I'm using the Studio software everyday now. It has helped me adjust my basal rates.

Thanks for the review. From 42 days out, I give the G4 high marks with its ability to make my life with T1 diabetes better.

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Terry- new to this website but not diabetes. (20+ yrs T1DM) just got the G4 a week ago and I’m really liking it a lot too. (I did a trial run on the 7+) question to you and anyone else about extending the use of the sensors: I have heard that we can get more than the stated 7 days out of them. So what are the steps I need to do in order to keep using the inserted sensor? (I’m on day 5 now and everything including the adhesive is working just fine!) appreciate any/all insights.

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You can wait until the current sensor actually ends, or you can chose 'Stop Sensor'. I usually do Stop Sensor, so it can be at a time that's convenient for me.

Then just do Start Sensor, without actually changing the sensor. The receiver won't know the difference.

You will get another 2 hour period of no readings, and then it will ask for 2 BGs, just like the original startup.

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awesome! that sounds very straightforward. thanks very much. I’ll give it a try…

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Carey, thanks for all the information. I am on the fence about the G4 Platinum only because with the CGM I have now my finger picks are so different than the CGM. There are some times they are fairly close but usually my CGM is 40 to over 100 more points than the finger pick. My insurance does not cover the CGM's so I am concerned about getting the G4 if it is not quite a bit better than the one I have. These CGM's, receiver and sensors are expensive when they come out of your pocket and then paying for new sensors each month.
Thanks again, very helpful.
jb

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Hi, when you say Original Dex, were you referring to the Dexcom7plus?
Each year my Ins. pays for a new CGM. I'll be getting the new G4 in about April. I believe the CGM is great although there is loads of room for improvement.
Close to three years with Dex.
Do you still feel the same now regarding G4 as you did when you wrote your opinion on Dec. 12, 2012?
I am most interested in anyone's opinion as to G4 keeping more accurate readings,or not, than Dex.7Plus.
I'm in my 61ST year as a T1 diabetic and accept it almost as much as I dispise it.