Help with understanding Libre graph, pls?

[NoLongerACarbFiend]

Hi, Google has not been my friend with regard to this, so wonder if anyone could help me interpret my libre graph, as it doesn’t seem to reflect my actual scan readings, although the general ups and downs following eating and exercise is following a line I’d expect.

Right at the beginning of the graph there is a tail-off of a stress spike which reached 6.2 on scan and graph seemed to agree. Then after a very big lunch my reading was 7.8 but on the graph it looks more like high 6 (the upper limit is set at 7.8). Then at 6pm, just before dinner, I had a scan of 3.7 which again doesn’t show. Then after breakfast today I had a scan of 6 which isn’t showing, and has charted maybe 5.4. Its all got me a bit confused.

Also, is the saw-bone pattern on the graph ok? I’m used to the nice straight lines connecting the dots on the finger jab charts so all this variation is freaking me out a bit. I realise I’m holding my glucose between fairly tight parameters so I guess it doesn’t actually matter, but I somehow hadn’t expected minute by minute variations. I’ve only been using Libre for a few weeks and I’m self funding as I’m diet controlled. I do like the visibility it gives me, not just about what food does, but how I’m reacting to stress, insomnia and exercise, things I didn’t look at with only finger sticks. But at the same time I’m feeling a wee bit anxious about all the variation. I could ask the nurse but she’s already told me several times that all diet controlled T2s need is an annual HBA1C and that all testing does is increase anxiety.Any time in the past I’ve asked her to look at BG charts she’s basically just glanced, given a little smile and said ‘it’s fine’, so I’m not expecting any real help there. Thank you!

 

[Mrs HJG]

Hi @NoLongerACarbFiend If I say 'ignore the readings' I am doing an injustice to the Libre, but you can ignore the minutiae of the scan readings as you, like me, are not insulin dependent, and the Libre is not a realtime device. If you look at the graphs they are far more accurate than the scans.

If you click on the logbook you will see all your scan figures for the day, click on one, and then you will see where the actual levels went after the 15 minute delay from what Libre 'expects' you to be, as per the scans, to what you 'actually' were.

In my pictures - yesterday I got a reading of 3.4 when I was waiting for my daughter to come out of a party last night, (again not on insulin, so no worry), but I could see when I got home that I never actually went that low anyway; also at lunchtime and a few other times when testing yesterday the graph does not match the readings, ie. the scan dot is not on the line. This can go both higher or lower than the scan, and the faster your blood is changing, and with how the algorithm predicts you will be, it can make it feel inaccurate. There are bound to be others with a more eloquent explanations, but hope this makes sense.


The scaling on the graphs makes a big difference too, on my phone I am as ziggardy as it gets for a narrow range, but on the LibreView online, last picture, its a lot nicer and smoother as the time axis is longer.

Hope this helps

Obviously if the Libre is always different AND different to blood tests, give Abbot a ring, they will do a calc to see if the Libre is faulty, and send a replacement if so. For me the first half dozen Libre I had were a lot less accurate, and didn't last the 14 days, but have been better since; I don't know if our bodies get used to the 'intruder' or I had an unlucky batch.

Your graph looks great though - I would save the Libre money for shoe shopping! We all have to do what makes us feel better, in control or able to navigate the diabetes 'fun & games', so test, don't test, do what helps you.

 

[NoLongerACarbFiend]

Thank you so much! Feel a bit stupid that I never realised that clicking on the log book entries gave you more detail, but now that I have, I can see it gives lots more reassuring info. I also didn’t realise I can use the website and get a different view to what I see on the app. I’m normally quite tech-savvy so not sure how I ended up so clueless re this!

 

[becca59]

Libre offer online tutorials which are useful.

 

[Mrs HJG]

@NoLongerACarbFiend no worries - it's all trial and error, and most of what I know came with the Libre training I received from Abbot/NHS, which I guess you are not eligible for as a T2 self-funder - obviously it would be helpful for anyone who is paying for the privilege, but I think there are some on their website too - Good luck.

 

[Paule Foster]

Thank you so much! Feel a bit stupid that I never realised that clicking on the log book entries gave you more detail, but now that I have, I can see it gives lots more reassuring info. I also didn’t realise I can use the website and get a different view to what I see on the app. I’m normally quite tech-savvy so not sure how I ended up so clueless re this!

It took me a while to realise this as well so you are by no means the only one. I recommend you onto the Abbot website & request a call back https://www.freestyle.abbott/uk-en/support/callback.html
They are very helpful & patient in my experience & will talk you through & replace a sensor if you are concerned. I’ve had to have them help me reset my phone twice now in the last few months

 

[KennyA]

Hi, Google has not been my friend with regard to this, so wonder if anyone could help me interpret my libre graph, as it doesn’t seem to reflect my actual scan readings, although the general ups and downs following eating and exercise is following a line I’d expect.

Right at the beginning of the graph there is a tail-off of a stress spike which reached 6.2 on scan and graph seemed to agree. Then after a very big lunch my reading was 7.8 but on the graph it looks more like high 6 (the upper limit is set at 7.8). Then at 6pm, just before dinner, I had a scan of 3.7 which again doesn’t show. Then after breakfast today I had a scan of 6 which isn’t showing, and has charted maybe 5.4. Its all got me a bit confused.

Also, is the saw-bone pattern on the graph ok? I’m used to the nice straight lines connecting the dots on the finger jab charts so all this variation is freaking me out a bit. I realise I’m holding my glucose between fairly tight parameters so I guess it doesn’t actually matter, but I somehow hadn’t expected minute by minute variations. I’ve only been using Libre for a few weeks and I’m self funding as I’m diet controlled. I do like the visibility it gives me, not just about what food does, but how I’m reacting to stress, insomnia and exercise, things I didn’t look at with only finger sticks. But at the same time I’m feeling a wee bit anxious about all the variation. I could ask the nurse but she’s already told me several times that all diet controlled T2s need is an annual HBA1C and that all testing does is increase anxiety.Any time in the past I’ve asked her to look at BG charts she’s basically just glanced, given a little smile and said ‘it’s fine’, so I’m not expecting any real help there. Thank you! View attachment 59175

That looks pretty good to me. You see the quick (but very limited) rise after your lunch and a fairly rapid return to baseline, which is what you want.

Your system responds to lots of stimuli and changes, not just food, and our livers are constantly adjusting glucose levels in response to what they think we might need, so you should expect variation. Actually, I think I've never seen a flat or nearly flat line libre graph for a single day's readings - that might take some doing.

I suspect that one of the other issues is that CGM have not been around for long and there isn't a great deal of experience on what "normal" variation over the course of a day looks like. I've read accounts from non-diabetic people trying out a CGM and panicking because their blood glucose levels are rising and falling.

It's a bit like your heart rate/blood pressure not always being the same - they test it while you're sitting down, but you'd expect it to rise during exercise or times of stress and fall afterwards. If they didn't rise, you might be in trouble.

 

[Deleted member 527103]

I suspect that one of the other issues is that CGM have not been around for long

Only since 1999!

Affordable CGM are more recent but until now they have mostly been used by people with Type 1 diabetes.
I am sure there are studies on people without diabetes- how else would we have knowledge of what to aim for?

What few people seem to understand is that there are known limitations. They are repeated many times on fora such as this but rarely shared by Abbott or DSNs.
The first that many people forget is what I have seen described as "insertion trauma" - the first day or two after insertion could be out due to the affect of having an alien object in your arm. This is why it is often suggested to apply the sensor a day or two before activating. This may be the issue that the OP is seeing. I know mine can be a random number generator if I don't get it time to bed in.

 

[KennyA]

Only since 1999!

Affordable CGM are more recent but until now they have mostly been used by people with Type 1 diabetes.
I am sure there are studies on people without diabetes- how else would we have knowledge of what to aim for?

What few people seem to understand is that there are known limitations. They are repeated many times on fora such as this but rarely shared by Abbott or DSNs.
The first that many people forget is what I have seen described as "insertion trauma" - the first day or two after insertion could be out due to the affect of having an alien object in your arm. This is why it is often suggested to apply the sensor a day or two before activating. This may be the issue that the OP is seeing. I know mine can be a random number generator if I don't get it time to bed in.

But CGMs have not been around in the general community until very recently, which was my point about there not being a great understanding about what normal/non-diabetic etc BG variations looked like.

OP's graph says that the sensor has three days left so I think it's unlikely to be a bedding in issue.

 

[KennyA]

The attached graph shows the distribution of blood glucose (as HbA1c results) in a non-diabetic population of just under 3,000 Dutch adults taken for the Lifelines study:

About Lifelines

Lifelines is a large, multigenerational cohort study that includes over 167,000 participants (10%) from the northern population of the Netherlands. We included participants from three generations,...

www.lifelines.nl

The Lifelines study is interesting in itself, as is the similar HUNT study for Norway. This is a link to a paper on one aspect of HUNT:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3303886/

These are HbA1c figures - I have never seen anything (but would like to) where similar numbers of non-diabetic people have taken fingerprick readings over a prolonged period of time, which might give some sort of comparison with what diabetic fingerprickers see daily. I guess the patchy non-diabetic CGM info is all there is at the minute, but that's a very self-selected and certainly biased sample.