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Dexcom G6, Libre, and Spike

R

RSJ1301

Member
Messages
19
Type of diabetes
Type 1
Treatment type
Insulin
I have been using the Freestyle Libre system now for about 3 years... have been really impressed by it. My passions are running cycling and being able to keep a handle on my (type 1!) diabetes on the go without having to stop and do blood tests has been amazing. That said, particularly on longer runs the Libre can lag quite significantly and I’ve had to occasionally rescue myself from hypo sysmptoms when the reader is still saying 6 or 7 mmol/l.

A month or so ago I saw an ad for the Dexcom G6 and immediately ordered the one month test kit. So far so good, the sensor has been a bit out at times but mostly seems to be more accurate (compared to my BG meter) than the Libre. I particularly like the fact that I can get the readings on a Garmin watch via the Spike app (indeed it gave me an excuse to buy aforementioned Garmin). I much prefer Spike to the Dexcom app as it is much more flexible and not as intrusive and irritating. Also even in summer the Libre seems to have got too cold to give readings if I’ve been out on my bike... I suspect the G6, mounted on the abdomen, will be at less risk of this.

I’m seriously thinking about switching, having been caught out by hypos in everyday life especially at night it seems perfect. A bit more research has turned up the Blucon and Miaomiao transmitters for the Libre however, which will also work with Spike. I’m also aware that Abbott will be bringing out a Libre 2 in the next year with just this feature but I suspect it will probably be in the same price bracket as the G6 with similar accuracy.

I wonder if anyone had experience of the G6 versus the “augmented” Libre? Which do you prefer?
 
FWIW Abbot say the libre 2 will be the same price as the current one.

Not tried the Dexcom, but the miaomiao is great. I didn't get on with the Blucon - too big, not as reliable.
 
I've recently been running the Libre with MiaoMiao alongside the G6 and what I've noticed is that it is picking up changes in levels around 5-10 minutes ahead of the Libre. I've written about the first five days comparing the Libre with MiaoMiao using the xDrip calibration mechanism (Spike is an iPhone instantiation of this), Libre with MiaoMiao using the xDrip OOP algorithm (this uses the LibreLink library and provides the same readings as the Libre scanner) and the G6 in this post: https://www.diabettech.com/freestylelibre/turning-freestyle-libre-into-cgm-early-observations/

I'd still go with the G6 over the Libre/MiaoMiao combination as it is more often closer to the blood levels I observe (using the Contour Next system, which is considered to be the most accurate in relation to venous sampling).
 
@RSJ1301, I had something very similar with the Libre. I was doing a trail half marathon and my BGs don't normally see dramatic chnges whilst running. For some reason, they did that day. I felt hypo and Libre said I was at 10 mmol/l, so carried on, still felt funny, so did a blood test - 2.1 mmol/l. Was quite scary as I was in the middle of nowhere, with a real risk of having a severe hypo.

Since then I just do blood tests whilst running. I've also noticed the Libre doesn't work when it's cold. As the G6 is as real-time as a BG test, I think it would be as good as a BG test - if it works in the cold. I think an augmented Libre would still suffer from a lag, so sudden drops in BG might not be picked up. However, an augmented Libre is much cheaper, especially if you can get your Libre prescribed (which I have just done after 3 years of self-funding).
 
Very interesting comparison.
I had been led to believe the delay was caused by measuring interstitial fluid rather than blood.
Does the improved timing on the Dexcom G6 mean this myth has been busted or is it using a different mechanism?
 
Thanks for your replies.

I’ve been really hard about this as if I do decide for go for the Dexcom I am committing a not inconsiderable amount of money to an 11 month project. Libre funding in my area is apparently coming “soon” but it seems like there will be a few hurdles to clear first. I really appreciate the CGM aspect of the G6, it has made a real difference to my diabetes management in a short time.

On balance I think I’m going to sign up for an 11 month Dexcom contract. There are several reasons for this. The G6 has been consistently close to my meter readings, far more so than with an average Libre sensor. I also periodically get skin reactions to Libre (OK, three G6 sensors is hardly a robust trial - but the fact that sensors are only on one patch of skin for 10 days rather than 14 might reduce reactions). Libre stops working in the cold for me at least. I’ve also knocked off a significant number of sensors over the years too - adding more hardware to my arm is only going to increase the size of the target!

At the end of the day, though, the critical factors for me are the accuracy, reduced lag, and having my BG right there on my watch that makes the G6 a convincing argument.
 

I use G6 & considered the £159/month contract. However a couple of things stopped me:
First there is the thought that I'm tied to Dexcom when there is the possibility of getting the Libre on the NHS next year.
Secondly I use the G6 with xDrip+ & find that sensors last somewhere around 3 weeks. Importantly my first transmitter lasted me around 5 months. Even then it wasn't dead, but I lost my nerve & bought a replacement. So going the none contract route, buying them as I need them, makes more sense for me personally.
The crucial information you need is how long does a sensor last for you?
 
Good point, I haven’t tried extending the sensors but have found they aren’t that sticky after a week or so... will try with the current one (now held on with Rock Tape!)

At the last moment I find myself with cold feet signing up for a £159/month contract and have just ordered some more Libre sensors and the Miaomiao to compare. I really do appreciate having immediate knowledge of my BG and advance warnings of potential trouble. It’s alrwaf got me out of a potential sticky situation this morning when I had no idea that my BG was dropping and would have had no reason to scan or test otherwise.
 
I think it's worth looking at what you can do with the G6 and extending sensors and transmitters as I'm sure that will bring the cost down. The last two weeks of playing with Libre and MiaoMiao have, for the n=1 that is me, been far from satisfactory in terms of performance, with approximately 3 days where the output was acceptable and 9 so far where it was too far off, so even at the lower cost, I'd not be happy with the CGM-d up Libre as an option.
 
Do you have to reset the Dexcom sensor before it reaches the 10 day limit with Spike, or will it keep on working regardless?
 
Several coomments on the above posts

I was at a conference back in June about exercise and diabetes. We had a presentation by an Austrian researcher who said he had been working on a project that involved using Libre in sport. He said their results which had not yet been published showed their were problems with Libre accuracy when used in high intensity sports. As some of us at the conference were T1Ds due to run a half marathon the following day and had been given FSL to use this caused some consternation! It seems to tie in with the SamJB's observation above.

I have been using Libre with first Blucon and then MiaMiao for the last 12 months. It is good but not perfect. I kept detailed observations over several months with at least 2 blood tests ad day (using Contour Next). Libre was often consistently high and one sensor low but when below 4 mmoll/l (72 mg/dl) it was accurate or too low so at no time was I in danger of missing a hypo.

The Libre xdrip setup was biased to be low most of the time despte re-calibrating whenever needed but on 2 occasions I was in danger of going hypo while having a reassuring BG readings. To see the full report go to my website bgonmywatch.com and read article "Medtrum is it a contender?" My verdict is that Libre plus trasmitter is not wholly to be trusted but I now have reasonable warning signs so I am happy to use it and my overall management has been transformed. To sum up my experience has been much better than Tim's

I am however consdering changing to G6 and using it with xdrip+ as if we can get 100% more life out of sensors and 50% out of trnsmitters it should be economical.
 
RSJ1301 said:
Do you have to reset the Dexcom sensor before it reaches the 10 day limit with Spike, or will it keep on working regardless?
Click to expand...
I don't use Spike so I am not sure, but on xDrip it auto resets.
 
I can answer my own question... after 10 days it just keeps on going. I hadn’t noticed but checked the sensor duration today and it’s at 11 days without any intervention from me.
 
I use the Libre/blucon with xdrip+ on Sony smartwatch. While not perfect continuous use has been transformative.
Like many self funding libre users I am put off by the price for dexcom.
So my question is can dexcom beat libre on price? (through extending sensors and transmitters)
 
I did various estimates but the Dexcom still came out more expensive. The critical factor is how long you can tolerate the sensor... early on with Libres I got reactions, not now, and I wonder if they have changed the adhesive. The current G6 sensor has been on nearly 12 days and is beginning to get a bit itchy, I think pushing it beyond 14 days might be problematic. Another crucial factor is that I may be able to get Libre on prescription, waiting for my next clinic appointment!
 
I ran the last G6 sensor as long as I could... after nearly 17 days it fell off. Accuracy was near spot on compared to my BG meter up to the end. No sign of any skin reactions. I bought a few Libre sensors and am on to them now, but I’m missing the Dexcom CGM experience already :-(
 
Great thread, this. I’d love to get the G6 once I can afford it. Looks like amazing bit of kit, a Libre++
 
Well I’m on to day 20 of my current G6 sensor. Readings are starting to get a bit noisy, but I’m impressed with how long it has lasted. Looks like you could extend these for a very long time with the right body/immune system. For full disclosure, mine used to stop G5s by 20 days so this is quite unusual.
 
As my G6 trial came to an end I decided I liked the CGM experience so much that I needed to continue it in some manner. With the prospect of Libre on prescription in the New Year I ordered a Miaomiao transmitter.

It arrived very quickly, not from China but Warrington... I wonder if they send over bulk orders to a shipper in the UK and send them out from there. At any rate, no problems with delivery (though there was no order tracking that I could see despite the website's assertions).

My experiences with it as a CGM have not been so positive though. I now have 3 potential sources of data - direct scanning of the Libre, blood glucose, and Miaomiao/Spike. As with Dexcom the Miaomiao needs calibrating regularly for use with Spike. It has been consistently way out... either reading persistently high or low and triggering alarms which have driven me to shut down the app for periods of time. BG and Libre have by contrast been in close agreement, with the usual bit of a delay on the Libre if there are rapid changes in BG. About the only thing I'm getting usefully from the CGM side is whether my BG is going up or down (and even then it's slow to do so)

I upgraded to the latest release of Spike thinking this might help, but if anything it's worse and I have downgraded to the previous version. I suspect this is more an issue with Miaomiao than Spike (which worked very well with the G6); I'm just puzzled that my Libre reader can give such wildly different readings and trends from Spike, and that these are not even consistent differences.

Thinking seriously of the G6 again, if I can stretch out sensors and transmitter life...!

(oh, and btw I didn't get any skin reactions from the G6 adhesive (at least after 3 sensors) but did to the K-tape I used to keep it on later in its life!)
 
RSJ1301 said:
I suspect this is more an issue with Miaomiao than Spike (which worked very well with the G6);
Click to expand...

The MiaoMiao is a dumb device and doesn't do anything with the numbers - it's just responsible for getting them from the sensor to your phone. The translation from raw Libre to what you see is done entirely at the app end (Spike). The Libre reader will have a different algorithm to Spike, so some differences are expected.

Re spike working with the G6 - the raw data from the G6 is different to the raw data from Libre, so the translation algorithms are different.
 
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