Dexcom G5 – A Month Later

So, I’m finally getting to write some of my thoughts around the Dexcom G5 Mobile system. While I do see it as an upgrade to the G4, I don’t see it as a must-have.

Unlike when we went from the Seven+ to the G4, there wasn’t a huge hardware change other than the transmitter is now Bluetooth and can talk to a phone without the constant need of a receiver. However, notice I said “constant” need. There are times when the phone seems to not pick up signal very well for me, even when I’m holding my phone not even 2 feet away from the transmitter. Other times, it’s great at picking up signal. Mostly, I lose signal at night, so I keep my G5 receiver by my bed or in my bed with me. Otherwise, I will take it with me if we’re going on a long trip just so I know if my phone dies, I have a backup. I tend to stash it in my bra under my arm in the band so it has a comfy home. I’m used to storing my pump there when I wear a dress, so it’s no big deal to keep it there too.

On the side of whether or not the signal length is shorter or longer, technically, they both were rated to have signal for up to 20 feet – however, the G4 seemed to get much greater distance than that. I guess I got spoiled. Now it seems I have to almost always have my phone attached to my hand or butt (it stays in my back pocket mostly).

It is pretty nice to be able to have my Dexcom in my phone though when I have to make a quick trip somewhere – just grab the phone, ID and debit card and go.

And I like that when I calibrate on my phone, it carries over to the receiver when I get in range of it. No need to calibrate both devices, and both devices also show the same sensor glucose value. Now, with that being said, I wish that they synced missing data between the two when they were in range. So, if I’m out of range of my receiver for a while, it would fill in gaps from my phone.. and vice-versa.

I almost miss my G4 at times, simply because I don’t like having to use the Follow app to view the data on my Apple watch. I like that there is a separate app for the Share2 app. It seems they could make the Share2 app fill-in the gap like it used to do when the receiver was out of range and then brought back in range for the G4.

I ran both the G4 and the G5 side-by-side for a week as many were stating they felt they were getting better accuracy (Need a diabetes device guinea pig? Call me!). I even did myself. But, after watching it on both screens and calibrating with the same numbers, they were both relatively the same over time, so I don’t really feel one was more accurate than the other (unless you were going from the pediatric version of the G4, which did not have the 505 software, to the G5 which does – then, yes, I could see that being more accurate).

As far as the Clarity app, I still don’t like it. But, one thing I saw a lot of people having an issue with was the Estimated A1c and feeling that it could be off from their actual A1c. Two things come to mind with this – 1) they’re not really supposed to exactly match because what Clarity gives you is a rough estimate based on your sensor average… which leads me to…

2) (yes, I feel I need a separate paragraph for this one) Your estimated A1c and estimated sensor average are only going to be as accurate as your meter. I know, I know, a lot of people say that if the FDA approved it, it’s accurate enough. I call baloney. I’ve done my own testing of several meters on the market, as well as several other people, and I’ve read many different charts with statistics of different meters available, and I personally have chosen the Bayer Contour Next line of meters for my own peace of mind. Why? It’s not about testing them against each other with the same drop of blood for me, but how they test when ran two or three times back to back. If I have a meter that runs numbers of 136, 178 and 154 in succession, then I tend to raise an eyebrow. However, if I find one that runs 136, 131 and 138 in succession for three drops, it tends to make me feel more confident about the readings that meter is giving me when testing just one drop for a bolus. Out of all of the ones I’ve tried, the Contour Next brand worked better and had tighter deviations, so it’s what I’ve stuck with. But, as always, I’m not a medical doctor or medical scientist, so my own thoughts and testing are simply to appease me. Don’t take my word for it – if you’re curious, do your own testing and research.

And, back to Clarity and the A1c Estimation and the actual A1c correlation… here’s mine:

Clarity vs actual A1c

All in all, the G4 is still a good, solid, reliable product. The G5 is more a convenience system that gives you options. And options are good. 🙂

3 thoughts on “Dexcom G5 – A Month Later”

  1. Such a valid point in #2; not so much about CGM, but about meters in general. I think people tend to overlook that; but when doing two finger sticks in succession to calibrate a new Dex sensor, it becomes apparent.

    As for Clarity, I find it more of a “how am I doing?” gauge than a “how can I do better” tool. And the estimated A1c is only based on a two week average, and if you run on a good week/bad week cycle, that number may not be so close to your 3 month average. (But I just had my blood drawn for A1c this morning, so it won’t be long before I see how well they match)

  2. I had diabetes burnout and gave up in all technology for 6m. Endo suggested g5. I’m Gadget Girl I jumped on it. Transmitter life 6 weeks vs 6 months on g4. Not happy. Range as a tennis pro was 40 feet on g4, now less than 20. Night time as blogger says mostly out of range. I like having readout on phone but disappointed with the rest.

  3. I am a pretty technical sort of person who has had type 1 diabetes for 46 years. I was an early adopter of home glucose monitoring (1980) and have used a number of different meter systems over the past 37 years. As my diabetes is difficult to control, and as I am a hyperactive outdoorsman I have at times taken over 20 bG samples per day. All told I’ll have to say I have quite a bit of experience with bG meters from 6 different manufacturers.

    Several years ago I contributed more than 200,000 words of self management advice to a diabetic forum in which countless folks wondered aloud just how accurate bG are in RealLife. So I decided to run an exhaustive test to determine that. I approached 3 different meter manufacturers with a request for 3 meters (randomly selected by me from different drug stores to ensure no cheating) each and one thousand test strips. After assembling the samples I began a series of comparison tests. Four days into the project I was caught between laughter and tears! Meter readings were literally all over the place in a near totally radom pattern. Meter A might read 85, meter B 135 and meter C 68! Repeat testing with a particular meter also sometimes produced dramatically different results! Long story short, I terminated the experiment as being a waste of time.

    Subsequent to this I conducted extensive researchon the Internet regarding meter accuracy/repeatablity and I was not pleased with what I discovered. One particular study proved very unsettling. A group of hospitals in the midwest ran a several month study of inpatient diabetics with a most impressive protocol. To whit all fingerstick samples were collected by experienced professionals thus ruling out patient error. Better yet,
    veinous blood samples were collcted at the same time as the finger sticks and tested by the hospitals labs. The results were not reassuring! I don’t any longer have access to the data but if memory serves their results RE both absolute accuracy and repeatability were even worse than mine!

    Looking into matters further I was horrified by what I found. Turns out that the FDA “Standards” much touted by meter manufacturers were so sloppy as to be almost funny..although I must add that by this point my sense of humor was at an all-time low!

    Turns out that the 20% error that seems so reassuring ain’t all it seems to be. To whit the reading can be either 20% high or 20% low. Since we have no idea whether a particular reading is on the high or low side what this adds up to is the confidence level is really 40%! Not a big deal when dealing with bG readings in the mid 200s perhaps. But rather unsettling when readings are in the 80-120 range I try to maintain!

    Worse yet, manufacturers are only required to submit a few meters for testing. Once! There are no repeat tests required through manufacturing cycles qnd nothing whatever to ensure that manufacturers randomly select the sample meters from the production line. In other words there is nothing to keep them from building few “special” meters to submit for testing.

    Ignorance is sometimes more blissful that knowledge and at times I kind of wished I’d never unearthed this decidely unpleasant information. Nometheless from this distance in time I’d have to say that the distrust I have in meter readings as been a help rather than a hinderance…hope it proves to be the same for those reading this.

Tell me what you think!