Freestyle Libre.

[Joybells]

I have been using Libre for some time but the bg results are consistently incorrect. They are around 25% lower than finger prick tests. The company has replaced the sensors free of charge several times. 1) Do other people have this problem? 2) would the Dexcom G6 be worth a try?

 

[Kaylz]

Are you well hydrated? Are you scanning 15 minutes after taking a BG finger prick reading? There are many that find it reads lower or higher than BG pricks but then they aren't expected to read exactly the same as they are reading different fluids xx

 

[Joybells]

Thanks Kaylz .Yes, I am well hydrated, and do leave 10 mins between Freestyle reading and finger prick tests. I understand about the two different fluids, but shouldn't the results be similar? Freestyle often shows a hypo, when I don't really have one. Joy

 

[Joybells]

Thanks Alannah, I am on insulin (4 times a day), and my BG results go up and down all the time. I didn't know you could calibrate the libre and will try to do that. It is interesting that you find Dexcom more accurate, I will have to think about the price though. I will leave 15-20 minutes between readings and see if that is better. Joy

 

[Robin]

You can calibrate the libre, which might be worth trying, but it also depends on what you are using it for

I didn't know you could calibrate the libre and will try to do that

I didn’t think you could. I know people who are using add on programs, like x-drip or whatever it’s called, can do something like that, but if you’re using the standard package, I don’t think it’s possible.

 

[helli]

A few things to bear in mind (as well as the 15 minute delay)
- Libre (and other CGMs) are least accurate during the first 24 to 48 hours as our arm gets use to having an alien object inserted. Many people do not activate their sensor straight away.
- Libre (and other CGMs) are most accurate between 4 and 8 mmol/l. Anything outside tis range should always be checked with finger pricks before making corrections.
- Libre is factory calibrated. Unfortunately, some of us seem to have different physiology to the guy in the factory (I call him"Factory Man"). The official apps and readers provide no mechanism for calibrating the readings but unofficial apps such as Glimp and xDrip use a different algorithm to convert interstitial fluid values to blood sugar values and incorporate calibration.

 

[trophywench]

Nah, definitely can't.

My first Libre 2 started lunchtime yesterday. I apparently had no increase in BG either from my lunchtime sandwich, the hot X bun in the afternoon or from the dish of spaghetti we both ate for tea. That's a bit odd really! Then of course I was hypo for several hours before bed and after I went, it says. Been telling me I'm hypo every day since I had the first sensor last year, Hours and hours and hours, the ambulance HQ not far down the road would all know my flippin name and my birthday - were that true!

 

[mark king]

When my local health body was looking at issuing the Libre one of their concerns was accuracy of the read out. It has already been said above about the delay dwell between readings for best accuracy and as helli says best accuracy is between 4 and 8.
I did do quite a lot of report finding and Finger prick and the Libre have a build reading allowed accuracy level of within 3%.
So on a bad day at the factory one could be bottom 3% and the other top 3% meaning you could have 6% different built into the comparison. This is not a big error but i believe the finger prick is preferred by the medical world despite them both having a build tolerance specification for variance.

Personally I don't see the point of using the same readings but running them through a different calculation to get a "better" more acceptable result unless that algorithm has been accepted by the manufacturer.

There does seem to be some questioning between the professionals on taking readings from blood and making the comparison with the interstitial fluid.

Finally the blood finger pricking system can be calibrated so it would be wise to make certain that it is in spec.

Now here's a question some of you more techy minded might know the answer to. This post has set me thinking -- HOW DOES THE LIBRE REFRESH ITS SAMPLE. I can see that when the Libre canula is inserted it would get a sample but how does it keep sampling?????? any one know. I'm thinking it must be some form of absorbing blotting wick that dangles in the fluid and not just a tube.

Regards

 

[helli]

@trophywench how long between inserting your Libre 2 and starting it?
I found my first Libre 2 sensor was less reliable than Libre 1 until the 3rd day.
And that was started 2 days after inserting.
I am not sure I will wear my next one for 5 days before starting it but I may give it 3 days to bed in instead of the 48 hours I usually give.

 

[trophywench]

I started it as soon as it let me, same as I always have the Libre 1, so I'm not going to base my overall impression of it on anything yet , but the trouble is there's always a gap - I never get full 24hr graphs for long periods, no idea how a person can do that whilst wearing two sensors because how the hell do you remember which arm the new one's in anyway! Often scan the wrong arm and get cross when the reader refuses to beep, then go Oh that's right it can't find it cos it ain't there! I'd have to think to remember where my pump cannula is at any given time - I'm simply not aware of it 99.9% of the time and why on earth would I wish to be? Hence if they are both 'started' and you happen to scan the new one instead of the old one or vice versa that's potentially even more confusing - esp when they don't match your BG anyway. No I don't leave 10-15 minutes between scans and BG tests - I'd never remember I intended to test my BG cos I'd be doing summat else by them like eg typing minutes for a Board meeting for a Ltd co I'm a director/co sec of or maybe reading medical info concerning a Health Charity I'm a Trustee of, or reading stuff about my own health or reading a book/watching a TV prog, or doing housework or cooking or family stuff!

There's still a lot more in my life than bloomin diabetes! MY Diabetes has to fit in with me and I only have time to worry about it when it ain't being sensible! Then I always WILL invest the time and effort. If I don't find the Libre to be of much more help than it has been so far, I'll just stop using it. No point anyone chucking money down the drain whether it's the NHS or me.

 

[Joybells]

Wow, I have never joined in a forum before this one, and I have learnt such a lot from reading your messages. Many thanks for all the advice folks. By the way, what is a Bertie course? Now I have to decide whether or not to continue with the Freestyle.....

 

[Robin]

Wow, I have never joined in a forum before this one, and I have learnt such a lot from reading your messages. Many thanks for all the advice folks. By the way, what is a Bertie course? Now I have to decide whether or not to continue with the Freestyle.....

It’s an online carb counting course aimed at Type 1 insulin users.

Home - BERTIE Key Learning

www.keylearning.bertieonline.org.uk

 

[SB2015]

Hi @Joybells

I always inserted my Libre1 the day before I wanted to activate it, as it seemed to take a day to settle in. Recently switched to CGM and wondering whether I will need to do the same, but just using the two hour warm up that is set by the system at present.

If I do a finger prick in quick succession in two different fingers I would get a discrepancy between the readings. I guess none of our fluids have exactly the same amount of glucose in at any one time. The Libre is certainly a massive learning tool for patterns, ease of checking during exercise and working out timings of ore bolus for meals.

I haven’t tried a Libre 2 so I am interested to read people’s experience of these.

 

[helli]

@trophywench you cannot start two sensors at the same time.
if you try to scan an unstarted sensor it will warn you and give you a chance to start it with a second scan. That is more than enough to remind me that it was the wrong one and save the wasted unreliable first 2 days of a new sensor.

to be honest my problem is usually getting too used to scanning an arm. For the first couple of days with a new sensor, I tend to scan an empty arm 🙄

As for waiting 15 minutes to check with finger pricks, my understanding is the Libre app will predict 15 minutes ahead to avoid this need. If your blood sugars are changing fast, this prediction will be wrong and Libre will correct when it catches up. This is why some people notice a reading which appears to disappera later.

So no need to interrupt your important charity work.

 

[everydayupsanddowns]

Some people find some sensor chemistries suit them better than others I think. So some will prefer Libre1 over Libre2... or Dex over Medtronic... or whatever.

I had great parity between BG fingersticks and Libre 1 initially (15 minute lag... reading different fluids etc etc) generally between 0.5-1ish different. Unfortunately when they rejigged the Libre1 algorithm to improve things that didn’t suit my body so well, and it became mostly 1-2ish... which I found a frustratingly large difference in usability terms.

Libre2 however I found excellent for 2 sensors, and quite dodgy for one.

Dexcom G6 I feel I can rely on entirely, and barely fingerstick much at all when wearing one. But again I have had one dodgy Dex sensor.

So Indon’t think there is ever going to be a system that is right for you all the time. You just need to find one that gives you useful flow of data most of the time. 🙂

 

[Spozkins]

@trophywench how long between inserting your Libre 2 and starting it?
I found my first Libre 2 sensor was less reliable than Libre 1 until the 3rd day.
And that was started 2 days after inserting.
I am not sure I will wear my next one for 5 days before starting it but I may give it 3 days to bed in instead of the 48 hours I usually give.

Sorry, just to be clear, you're putting the new sensor into your arm days before activating it?

 

[helli]

Sorry, just to be clear, you're putting the new sensor into your arm days before activating it?

Yes. I put my next sensor on my "other" arm one or two days before my current sensor expires.
Then, when it is time to start it, my body is used to the alien filament and it has less affect on my blood sugar readings.
If I start a sensor the day it is inserted, the first couple of days of readings are unreliable so my sensor is only useful for 12 rather than 14 days.

 

[Spozkins]

Yes. I put my next sensor on my "other" arm one or two days before my current sensor expires.
Then, when it is time to start it, my body is used to the alien filament and it has less affect on my blood sugar readings.
If I start a sensor the day it is inserted, the first couple of days of readings are unreliable so my sensor is only useful for 12 rather than 14 days.

Ah I thought it was the sensor adjusting after being "activated". I had no idea it was the body adjusting. Thanks for clarifying that.