Lying Libre proving unhelpful

Sophielouise said:

i have recently been given the freestyle Libre trial to get it on prescription due to having a lot of hypos and anxiety, so was testing my blood a lot.

Anyway, I have been through 4 sensors now. At the end of the first I switched from lantus to levimer because I realised I could see my night time glucose with the graphs and it looked problematic (hypos and dawn phenomenon). I noticed I would bottoming out randomly between 4am and 6am and then glucose increasing by 7. I’m talking 2.5 kind of zone for a 2 hour stretch. I always wake up for my hypos so this was worrying me.

The other evening at the beginning of my current sensor I felt fine but my sensor scan read that I was 2.8 and had been for the last half an hour, but my finger prick said I was 5.6. Then the next morning I saw I’d run in the night the random 2.5 for a couple hours like I’d seen before, woke up with similar fingerprick and sensor reading so assumed maybe this is accurate and did some more levimer tweaking. I then set an alarm for 5am every morning for last week to check and I’ve not hypoed once. Weird.

Then, 3 days remaining on sensor, last night I woke up at 5am and sensor had been bottoming out at 2.5 again with fingerprick at 6.4... when I woke in morning the sensor and finger prick were pretty much the same.

I don’t see how this could possibly be the 15 minute delay happening because it only seems to happen at the beginning and end of the sensor (on and off) and I feel fine when it says I’m 2.5 and trust me I have been 2.5 with a fingerprick and felt ghastly.. I know what it’s like. I feel hypos at 4.8.

So, what I’ve worked out is the Libre is an enormous trickster for the first 4 days and last 4 days of wear. Giving us a mere 6 days of reliable readings. Well done freestyle.

Also, on my Libre link uploads to my nurse is saying I’m hypoing for hours on end which isn’t proving to anyone that this trial is useful to helping me with hypos, is it?!

A question: I have been giving myself a break from it for a couple days in between sensors because it drives me mad sometimes, is this going to get me in trouble??

Sorry for long read, diabetes is long winded.

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Hello, welcome!
The libre is known for giving false lows, like compression lows where you either been laying on it or leaning on it in your sleep. It is also known to be inaccurate, a lot of diabetics have been giving it 24 hrs to settle before activating it. It's always good to finger prick for these instances to confirm if it is a low or a high. I tend to find it accurate between 4.5-8.5, anything above or below I finger prick to check. So I typed that on the libre app or put a note to say my finger prick test was this and this.
Another thing is other peeps have been buying the miaomiao transmitter and download other apps to calibrate the sensor.

Sophielouise said:

i have recently been given the freestyle Libre trial to get it on prescription due to having a lot of hypos and anxiety, so was testing my blood a lot.

Anyway, I have been through 4 sensors now. At the end of the first I switched from lantus to levimer because I realised I could see my night time glucose with the graphs and it looked problematic (hypos and dawn phenomenon). I noticed I would bottoming out randomly between 4am and 6am and then glucose increasing by 7. I’m talking 2.5 kind of zone for a 2 hour stretch. I always wake up for my hypos so this was worrying me.

The other evening at the beginning of my current sensor I felt fine but my sensor scan read that I was 2.8 and had been for the last half an hour, but my finger prick said I was 5.6. Then the next morning I saw I’d run in the night the random 2.5 for a couple hours like I’d seen before, woke up with similar fingerprick and sensor reading so assumed maybe this is accurate and did some more levimer tweaking. I then set an alarm for 5am every morning for last week to check and I’ve not hypoed once. Weird.

Then, 3 days remaining on sensor, last night I woke up at 5am and sensor had been bottoming out at 2.5 again with fingerprick at 6.4... when I woke in morning the sensor and finger prick were pretty much the same.

I don’t see how this could possibly be the 15 minute delay happening because it only seems to happen at the beginning and end of the sensor (on and off) and I feel fine when it says I’m 2.5 and trust me I have been 2.5 with a fingerprick and felt ghastly.. I know what it’s like. I feel hypos at 4.8.

So, what I’ve worked out is the Libre is an enormous trickster for the first 4 days and last 4 days of wear. Giving us a mere 6 days of reliable readings. Well done freestyle.

Also, on my Libre link uploads to my nurse is saying I’m hypoing for hours on end which isn’t proving to anyone that this trial is useful to helping me with hypos, is it?!

A question: I have been giving myself a break from it for a couple days in between sensors because it drives me mad sometimes, is this going to get me in trouble??

Sorry for long read, diabetes is long winded.

Click to expand...

If you lay on the Libre sensor in your sleep, the pressure kinda squeezes the interstitial fluids away from the filament so it has nothing to measure and you will get a low reading

I have unreliable results so much so that I took part in 3 different trails at hospital ( 1 trial involved wearing 3 sensors all blind results also had to do BG and record results . Personally I feel very nervous of the readings and then anxious so I test BS on blood meter . But I must add my BS are a bit rollercoaster .

I really value the trend arrows from the Libre. They're a godsend. I always do a finger prink at the higher or lower ends of the ranges. It's just extra data you can extrapolate from at the end of the day. I'm looking forward to receiving the Miao Miao so that I don't have to set the alarm every night, as the thought of hypos still scares me.

I asked a Libre rep at a recent APPG for Diabetes to have built in calibration, as according to the Libre on several occasions I have an estimated HbA1c of 21.

Sophielouise said:

I have recently been given the freestyle Libre

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Give it time, Sophielouise.

You say you've recently been given it. It's not a plug-and-play device, it's got quirks, it takes time to figure those out.

I didn't trust it for a long time, but after a few months, I figured out ways of saying, hmm, libre says this, so bg is probably that.

You're not going to be an expert the first time you start a new job, sport, hobbie; it takes time.

I'm on about my 80th sensor now, I had a lot of frustrations with it to begin with, but there are ways of working round those once you figure out the quirks.

Sticking a third party transmitter like blucon or miaomiao on it and running the output to xdrip+ makes a huge difference - my current sensor after calibration is a reliable 0.2 out.

Don't write it off too soon - it can be made to work.

Sophielouise said:

Thanks Scott, this was helpful. You’re right, it will take time. I don’t know what third party transmitters are so I guess I’ll look into that. Thank you! I just hope the strange readings won’t reflect badly on my trial when they decide if I can get it on prescription. Because as irritating as it is, I do find it useful for the 6 days it is reliable!

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No probs, Sophielouise, like I say, it takes a bit of time to get used to, I went through a lot of time with it saying, aargh, what's it doing, I don't trust it, but as time went by I sussed it out, bg started levelling out, got a blucon, then miaomiao, and started using the info from that to push out nice lines like this in the pic below with it (although it's T1, so it does still do fliers!).

Phone's charge is tanking just now, so will post tomorrow about the transmitters - they really sharpen libre up.

Mbaker said:

I asked a Libre rep at a recent APPG for Diabetes to have built in calibration, as according to the Libre on several occasions I have an estimated HbA1c of 21.

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Libre would benefit from per user calibration, but you're not going to turn a hundred billion market cap company round anytime soon on that, they're individually calibrating L2 instead of batch cal on L1 which might improve matters, but comes nowhere near the third party cal accuracy of xdrip via blucon/miaomiao.

These things are used primarily by T1s to monitor hour to hour changes in bg, some of which might result in really nasty hypos if we didn't have cgm. Accuracy of hba1c measured by cgm is irrelevant in this context. T1s look at the cgm line, the estimated a1c is just a bit of additional info. My last measured hospital a1c was 31, xdrip estimated it at 35, I was like, hmm, so what, I spend more time looking at the line, the delta, and after the event the tir, sd, median, etc. A1c on any of these things is just a passing glance.

(edited by mod to remove unnecessary remark)

Scott-C said:

Libre would benefit from per user calibration, but you're not going to turn a hundred billion market cap company round anytime soon on that, they're individually calibrating L2 instead of batch cal on L1 which might improve matters, but comes nowhere near the third party cal accuracy of xdrip via blucon/miaomiao.

These things are used primarily by T1s to monitor hour to hour changes in bg, some of which might result in really nasty hypos if we didn't have cgm. Accuracy of hba1c measured by cgm is irrelevant in this context. T1s look at the cgm line, the estimated a1c is just a bit of additional info. My last measured hospital a1c was 31, xdrip estimated it at 35, I was like, hmm, so what, I spend more time looking at the line, the delta, and after the event the tir, sd, median, etc. A1c on any of these things is just a passing glance.

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I would consider an initial HbA1c of 134 and several diabetes complications justification for wanting expected accuracy and a knowledge of what was going on. In addition I had discordance with my HbA1c and measurements (later proved). The estimated HbA1c was secondary to testing how foods affected my condition, and if I was getting spikes at all. I am aware of what Type 1's go through and would expect reciprocal understanding.

(edited by mod because of quoting an edited post)

I self fund, do not have a suitable phone and cannot afford extra gizmos. However, I am fortunate enough to find Libre very accurate. So accurate that I trust it when high or low and react accordingly. I didn’t in the early days, obsessively checking against my meter. Now if I check when high or low it is always bang on correct. I feel so confident that I rarely check bloods now. I know I am lucky, but just wanted to show the other side, people are always criticising it but that criticism does not apply for everyone. Just need to get it on prescription now-oh look a flying pig!!

Sophielouise said:

Thanks Scott, this was helpful. You’re right, it will take time. I don’t know what third party transmitters are so I guess I’ll look into that. Thank you! I just hope the strange readings won’t reflect badly on my trial when they decide if I can get it on prescription. Because as irritating as it is, I do find it useful for the 6 days it is reliable!

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Hi, Sophielouise, if you're interested in the transmitters, some links below about them.

Basically, they're small bits of electronics which sit on top of the libre sensor, read it every 5 mins then bluetooth the reading to a phone app. Because there's a reading every 5 mins, it turns it into "proper" cgm, so that you get a much more detailed graph than the "averaged" libre graph, so it's easier to identify trends and respond to them, you can also set hypo and hyper alerts at any level you want so the phone rings if you're going too high or low, and you can also "calibrate" by typing in a bg test number: this tightens up the accuracy a lot - libre reader might think it's 3.6 but if you've told the app that your bg at a particular point in time is 4.7, the app is going to interpet the raw number coming from the sensor as 4.7 instead of 3.6 and it'll then be able to interpret future numbers much more sensibly. It's usual to recalibrate once, maybe twice, a day as it can drift. I've gone for long periods with just 1 bg test a day, and I'm happy to bolus from it. With a good, well calibrated sensor, it's often only about 0.1 to 0.4 out.

The first commercial transmitter was the blucon, about £100 but not waterproof so needs to be taken on and off for showers, though they do have a waterproof version now as well. I used it for well over a year, it's looking a bit "beta-max" now compared to the newer one, but still has a price edge if money is an issue.

https://www.ambrosiasys.com/

The newer, sleeker (and waterproof) kid on the block is MiaoMiao. A bit more expensive at around £160. I've been using it for about 7 months now, it's reliable. They tweeted recently that a slimmer version 2 is coming out but noone knows when.

https://miaomiao.cool/


Both transmitters have their own inhouse phone apps for android and ios, but they're very basic.

If on android, xDrip+ is highly regarded, there's a lot of folks here using it, including me for almost 2 yrs now. It's an open source app, not regulated by any authority, so "use at own risk" but many do and do so safely. The folks behind it are basically part of #wearenotwaiting. When dexcom first came out, a lot of users liked it but thought it could have more useful features, so they basically reverse engineered it, came up with dexdrip and Nightscout, and it's developed from there into xDrip+. It is a bit of a leap of faith using an unregulated open source app, but, hey, it works and it works well.

https://github.com/NightscoutFoundation/xDrip/releases

https://jamorham.github.io/

If on ios, there's Spike, which was based on xDrip+. It's had a few issues with licensing from Apple, seems folks need to either buy a developer licence or renew the certificate each week, not been following it as I'm not using ios.

https://spike-app.com/


The combination of libre, transmitter and xDrip+ is a fantastic tool which have helped me a lot but they are still just tools and you need to learn how to use them properly. There's a couple of books about cgm which I found really useful, both on kindle:

Sugar Surfing, Stephen Ponder

Beyond Fingersticks..., William Lee Dubois

My general take on it after using cgm for about 3 yrs now is that things don't happen overnight, but as time goes by you'll have seen so many cgm traces and situations that you start seeing subtler things in the line and start to realise how small, small adjustments made at the right time, 1u here, 1 dextrotab there, really go a long way to steering things, and it becomes way easier to say, ok, this situation need x units, and all that, given time, just sort of naturally leads to smoother lines. Except for Saturday nights when there's some beer and fish and chips involved - still haven't figured those out!