Varying BG readings

[glucoserat]

Just for a giggle, I've been testing dexcom 7 versus libre 2. Been on the libre for several years, but thought I would try out dexcom when I had a little spare cash one month because it has slightly different alarm options which I thought would be useful during extended exercise. Earlier today I had the libre showing 3.8 and falling slowly, the decom showing 5.5 and steady. One finger gave me blood at 5, the next one along gave me blood at 4. All in all, I was very confused, but I do find the disparity fascinating. Anyone else ever found similar?

 

[Lucyr]

Just for a giggle, I've been testing dexcom 7 versus libre 2. Been on the libre for several years, but thought I would try out dexcom when I had a little spare cash one month because it has slightly different alarm options which I thought would be useful during extended exercise. Earlier today I had the libre showing 3.8 and falling slowly, the decom showing 5.5 and steady. One finger gave me blood at 5, the next one along gave me blood at 4. All in all, I was very confused, but I do find the disparity fascinating. Anyone else ever found similar?

That all sounds fine, everything has an error range, you were probably mid 4s. There’s no point using multiple devices and comparing, you’ll just end up confusing yourself as demonstrated.

 

[glucoserat]

Everything was fine - I'm only doing it for interest. Certainly the libre for me is closer to accurate. The dexcom has tended to read a bit high, and has a much longer lag time. Coupled with a high failure rate and rather poor customer service (which it seems is unusual from other people's experiences) it's been interesting, but not something I'll be trying to adopt full time. Which is a bit of a pity as I find the physical sensor a better size, and the adhesive much better.

 

[helli]

The Dexcom can be calibrated. If you have not done so, I am not surprised it is further out than the Libre.
There may also be a difference in the way the different CGMs handle the lag on 8nterstial fluids. I know Libre predicts the current value but do not know about the Dexcom.

 

[glucoserat]

I have calibrated. It's one of the functions I like about the dexcom. I just think for some reason it doesn't work so well for me as the libre. Reading up, it sounds like the libre 3 incorporates some of the good dexcom features, so I'm intrigued to see how they work, in about the 10 years I assume it'll be before the NHS are using them widely!

 

[Inka]

I’ve found the G7 hugely more accurate than the Libre. It was an absolute revelation! What were your later results? From what you said, it sounds like the G7 was more accurate (G7 at 5.5, Libre at 3.8, fingerprick 5). I haven’t had any failures in almost a year. Sounds like you’ve been unlucky.

 

[nonethewiser]

Personally find lag is much shorter with Dexcom than libre, as for accuracy never really had many issues with libre but it did lose accuracy when bg was in higher figures, as in 10+, where as Dexcom is more in line with bg readings, so overall prefer Dexcom over libre although sensors don't last as long.

 

[glucoserat]

I’ve found the G7 hugely more accurate than the Libre. It was an absolute revelation! What were your later results? From what you said, it sounds like the G7 was more accurate (G7 at 5.5, Libre at 3.8, fingerprick 5). I haven’t had any failures in almost a year. Sounds like you’ve been unlucky.

The second fingerprick (same time, different finger and I had washed my hands) was 4, which was more consistent with how I felt, so I figured that was the one to go with. In general I've found g7 and libre to be about 1 - 1.5 mmol different, usually with the G7 higher. And some times they're bang on the same. Currently showing 6.5 and 5.2, with same trends.

 

[JJay]

I had a free trial of the G7 but although I was impressed by its accuracy compared to BG, it constantly lost signal even when my phone was right next to me. I’m used to Libre2 being “out” by 1-2 most of the time but the signal remains constant even with me upstairs and the phone downstairs, so that’s what I’ll be sticking with for now.