Double checking with as blood glucose meter

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HalfpipMarathon

Well-Known Member
Relationship to Diabetes
Type 2
I switched my receiver back on this evening and 30 mins later I had a reading of 9.9 then it jumped to 10.9 so I decided to check with a finger prick and got a reading of 8.0. I then had a high glucose alert of 11.3 but finger prick 8.7! Just don't get it, do I go with Dexcom or my blood glucose meter?

The whole point for me of using Dexcom One or Libre 2 is/was to avoid finger pricking but if I am going to have to double check every time I get a high reading because my feeling doesn't match the reading it defeats the object.

I have decided to stop the sensor and have took it off but I am having difficulty removing the transmitter.

I have a spare transmitter and another sensor but I am not sure what to do with them.
 
How do those levels relate to when and what you ate.
What sort of meals are you having when you have recorded the high levels that you are worried about.
 
Leadinglights said:
How do those levels relate to when and what you ate.
What sort of meals are you having when you have recorded the high levels that you are worried about.
Click to expand...
Apologies for the late reply.

Most of the time I know why I am high but other times not so even when I know what food I have had. I don't keep a food diary as that is too much association with dieting something I left behind years ago.

I test to ensure that I am in range most of the time. While this might not be what most people do we all manage our diabetes differently.

I'm not on insulin or medication that might cause hypos ,so testing to see how food affects my blood glucose is not much point for me as I don't need to adjust an insulin dose in response to what my bg might be because I don't take it .

Maybe like some have suggested I need to not let my anxiety take over as stress can affect blood glucose which is a catch 22: I am anxious about a high reading so it remains high or rises in response to my anxiety.

I have not abandoned Dexcom One completely. I have the transmitter and a spare plus a sensor. I'm may return to it later on.

Someone told me you can wear a Libre 2 on your tummy if it works where's the harm just because Abbotts found back of the arm gave best results doesn't mean it is the same for everyone. I may try Libre on my tummy and compare it to the readings from before on my arm.
 
I found these sensors (Libre) to vary a lot from blood tests, so I ignored the actual reading and used the trends. I would see a value of 8 and the blood test would be 5, especially towards the end of the two weeks. I've used about 5 of them and the pattern is always the same - start off quite different to finger tests, then go fairly similar for a week, and then start to drift quite a lot. I saw a rise up to 10 when I had some oats (Which quickly came back down again) but it scared me so much I stopped eating oats.

There are a lot more variables with sensors: the filament inserted in the arm contains an enzyme and this might be fouled while it's in the body and become less effective as time goes on. It's also measuring a different fluid and there's a time lag they try to compensate for by using some maths... I also find the readings change a lot when they got warm/cold.

As you aren't injecting or taking any medication that can cause an instant improvement, I'd just ignore the value and look at how the graph rises and falls in response to food/exercise/stress/etc and what happens during the night. I found out that I don't see any rise during the night, just a flatline until I got up and had breakfast, which saw a slight rise.

I doubt I'll use them again, as I am pretty sure what I can/can't handle now and they're expensive. I know a T1 who uses them and finds them absolutely indispensable for keeping his BG within range. For most of us T2s they are just more an information gathering device and useful when 'starting out'.
 
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HalfpipMarathon said:
I test to ensure that I am in range most of the time. While this might not be what most people do we all manage our diabetes differently.

I'm not on insulin or medication that might cause hypos ,so testing to see how food affects my blood glucose is not much point for me as I don't need to adjust an insulin dose in response to what my bg might be because I don't take it .
Click to expand...

You may not be able to adjust insulin or medication, but you can adjust foods for next time.

Using the information sensors give you after a meal to see whether the carbohydrates in it (or the portion size) worked well for you.

I guess it’s just adjusting from the other end - you don’t have the medication to adjust, so you adjust the food instead.

Like the other day when you saw that there was a bit of BG chaos after McD - so it’s good to keep those are rare treats like you do, because your body struggled with that meal.

When you see readings that are higher than you’d like after meals, consider what you ate, and try a smaller portion or some sort of swap next time.

Maybe this would reduce your anxiety, because you’d be actively using the information week by week, rather than it just stressing you out?
 
T
harbottle said:
I found these sensors (Libre) to vary a lot from blood tests, so I ignored the actual reading and used the trends. I would see a value of 8 and the blood test would be 5, especially towards the end of the two weeks. I've used about 5 of them and the pattern is always the same - start off quite different to finger tests, then go fairly similar for a week, and then start to drift quite a lot. I saw a rise up to 10 when I had some oats (Which quickly came back down again) but it scared me so much I stopped eating oats.

There are a lot more variables with sensors: the filament inserted in the arm contains an enzyme and this might be fouled while it's in the body and become less effective as time goes on. It's also measuring a different fluid and there's a time lag they try to compensate for by using some maths... I also find the readings change a lot when they got warm/cold.

As you aren't injecting or taking any medication that can cause an instant improvement, I'd just ignore the value and look at how the graph rises and falls in response to food/exercise/stress/etc and what happens during the night. I found out that I don't see any rise during the night, just a flatline until I got up and had breakfast, which saw a slight rise.

I doubt I'll use them again, as I am pretty sure what I can/can't handle now and they're expensive. I know a T1 who uses them and finds them absolutely indispensable for keeping his BG within range. For most of us T2s they are just more an information gathering device and useful when 'starting out'.
Click to expand...
Thank you for your reply.

When you say ignore the value do you mean just glance at it then look at the graph? I had a graph on my Dexcom One receiver but it is not the same as looking at a daily graph on Libre 2. I only used Libre 2 for TIR if I was over 7% I was happy. Dexcom One on receiver only gives me 3-day average.

I have tried to take the readings at face value as that is what it is at that moment in time. I managed with Libre but not sure about Dexcom One. It's good not having to scan but not sure about constant change in my bg. I could just not have alerts and look at it before or 2hrs after food.

I'm taking a break from Libre and Dexcom One atm while I decide which I am going to stick with.
 
HalfpipMarathon said:
Thank you. Part of me feels why were cgms/flash gms invented if one still has to finger prick. All the cgms etc say no finger pricking but as an aside say finger prick if reading doesnt match. A bit of a mixed message.
Click to expand...

I get what you’re saying, but for me, as a Type 1, my Libre 2 allows me to adjust my pump basal rates more easily (eg I can look at the overnight graph to help me), it allows me to judge whether to do an after-meal correction (I look at the Libre arrows), and it has alarms which not only help me prevent very high sugars and ketones, but also make me sleep better because I know the alarm will sound if I’m heading for a hypo.

I think the problem is that they’re mis-sold a bit. Yes, it can reduce the number of fingerpricks (eg when I was pregnant, I’d have to do 14-18 tests a day to keep in range and reduce any risk to my baby) but that’s just an added bonus most of the time. For a few people like children or workers in specific industries, it will be more important, but largely it’s just a nice extra that’s given my poor fingers a rest. I’d never think of that as a main reason for a Libre or CGM.
 
HalfpipMarathon said:
Part of me feels why were cgms/flash gms invented if one still has to finger prick.
Click to expand...
I think replacing finger pricks just isn't that important for most of us. Getting readings 24 hours a day (including times when I wasn't thinking about using a test strip) is the important value. So we can see what happened overnight, and when we take a reading we can see the nearby graph so can get an idea of how fast it's changing and in which direction. Those are really helpful, and test strips can't practically provide them.

And the differences you note (10.9 and 8.0, 11.3 and 8.7) while they're a bit annoying they're really not going to change what I do a whole lot. If (well, when) my Libre says 3.5 and a test strip says 6.2, that's significant and if it stayed that far out I'd be replacing the sensor (and reporting it).
 
HalfpipMarathon said:
I switched my receiver back on this evening and 30 mins later I had a reading of 9.9 then it jumped to 10.9 so I decided to check with a finger prick and got a reading of 8.0. I then had a high glucose alert of 11.3 but finger prick 8.7! Just don't get it, do I go with Dexcom or my blood glucose meter?

The whole point for me of using Dexcom One or Libre 2 is/was to avoid finger pricking but if I am going to have to double check every time I get a high reading because my feeling doesn't match the reading it defeats the object.

I have decided to stop the sensor and have took it off but I am having difficulty removing the transmitter.

I have a spare transmitter and another sensor but I am not sure what to do with them.
Click to expand...
I’ve had same issues with libre 2 and fingerpricks being different. My libre 2 is not warning me of hypos early enough and when I double check with finger prick I’m already hypo. Thinking of changing to Dexcom 1.
Hope your issues resolving
 
Unfortunately, I think you have too high an expectation from CGM be it Libre or Dexcom. They won't be as accurate as a finger prick and part of the discrepancy is that they are reading two different things. Your meter is reading Blood Glucose and your sensor is reading the level of glucose in your interstitial fluid. These 2 things are linked but not the same and each system has an algorithm built into it to try to convert the interstitial fluid reading to a glucose reading, but everyone's body is slightly different so these algorithms will work better for some people than others. The readings of 8 and 10.9 are close enough and both pairs of readings indicate that your levels are rising ie your BG went from 8.0 to 8.7 and your Dexcom went from 10.9 to 11.3 so they are both showing that your levels are rising so the Dexcom is telling you that you are at the top end of your range and levels are rising.... could this have been within an hour after eating something? That would explain why it is rising. If you wanted to do something about that, you could go for a walk or do some other exercise to help bring it down again or not worry about it because it is perfectly normal or levels to spike after a meal even for non diabetics as long as it goes back down promptly. Also CGM will be less likely to correspond closely to BG readings when your levels are changing rapidly, which it sounds like they were when you replaced the transmitter. You really need to compare CGM and BG readings when levels are stable, not when they are changing.

I don't have experience of Dexcom, but for me, Libre 1 is almost always 1 whole mmol lower than a finger prick, so if it says 3.5 I am usually 4.5 and if it says 8.6 I'm probably nearer 10 and above 10 it become a little less accurate still. I can happily work with that and I just keep it in my mind when I come to dose my insulin or need a hypo treatment. If I am driving, I usually have to double check with a finger prick.

I am still struggling to understand what you gain from CGM if you don't do anything with the information, like take some exercise when your levels are going higher than you would like, or keep a food diary and modify what you eat to prevent it going so high next time.
It seems a huge expense for no real benefit and lots of anxiety!

How long have you been using the Dexcom One? You can't expect it to give you a 7 day average if you haven't been using it for 7 days or maybe I am misunderstanding you?
 
bridge said:
I’ve had same issues with libre 2 and fingerpricks being different. My libre 2 is not warning me of hypos early enough and when I double check with finger prick I’m already hypo. Thinking of changing to Dexcom 1.
Hope your issues resolving
Click to expand...

What do you have your Low alarm set to? I’ve set mine higher so that I can hopefully get advance notice of any drops.
 
bridge said:
I’ve had same issues with libre 2 and fingerpricks being different. My libre 2 is not warning me of hypos early enough and when I double check with finger prick I’m already hypo. Thinking of changing to Dexcom 1.
Hope your issues resolving
Click to expand...
Thank you. I'm taking a break from Libre and Dexcom One atm.

I will go back to either one at some point.
 
HalfpipMarathon said:
T

Thank you for your reply.

When you say ignore the value do you mean just glance at it then look at the graph? I had a graph on my Dexcom One receiver but it is not the same as looking at a daily graph on Libre 2. I only used Libre 2 for TIR if I was over 7% I was happy. Dexcom One on receiver only gives me 3-day average.

I have tried to take the readings at face value as that is what it is at that moment in time. I managed with Libre but not sure about Dexcom One. It's good not having to scan but not sure about constant change in my bg. I could just not have alerts and look at it before or 2hrs after food.

I'm taking a break from Libre and Dexcom One atm while I decide which I am going to stick with.
Click to expand...

I just looked at the graph to see what the bumps (And valleys) were like when I ate, and the lows when I exercised/slept.
I didn't bother with alarms or anything else like time in range. I just liked to see it staying pretty flat, regardless of the values.

The readings aren't going to be as accurate as finger pricks, and finger pricks aren't as accurate as lab equipment.

The last one I used I pretty much stopped scanning.
 
rebrascora said:
Unfortunately, I think you have too high an expectation from CGM be it Libre or Dexcom. They won't be as accurate as a finger prick and part of the discrepancy is that they are reading two different things. Your meter is reading Blood Glucose and your sensor is reading the level of glucose in your interstitial fluid. These 2 things are linked but not the same and each system has an algorithm built into it to try to convert the interstitial fluid reading to a glucose reading, but everyone's body is slightly different so these algorithms will work better for some people than others. The readings of 8 and 10.9 are close enough and both pairs of readings indicate that your levels are rising ie your BG went from 8.0 to 8.7 and your Dexcom went from 10.9 to 11.3 so they are both showing that your levels are rising so the Dexcom is telling you that you are at the top end of your range and levels are rising.... could this have been within an hour after eating something? That would explain why it is rising. If you wanted to do something about that, you could go for a walk or do some other exercise to help bring it down again or not worry about it because it is perfectly normal or levels to spike after a meal even for non diabetics as long as it goes back down promptly. Also CGM will be less likely to correspond closely to BG readings when your levels are changing rapidly, which it sounds like they were when you replaced the transmitter. You really need to compare CGM and BG readings when levels are stable, not when they are changing.

I don't have experience of Dexcom, but for me, Libre 1 is almost always 1 whole mmol lower than a finger prick, so if it says 3.5 I am usually 4.5 and if it says 8.6 I'm probably nearer 10 and above 10 it become a little less accurate still. I can happily work with that and I just keep it in my mind when I come to dose my insulin or need a hypo treatment. If I am driving, I usually have to double check with a finger prick.

I am still struggling to understand what you gain from CGM if you don't do anything with the information, like take some exercise when your levels are going higher than you would like, or keep a food diary and modify what you eat to prevent it going so high next time.
It seems a huge expense for no real benefit and lots of anxiety!

How long have you been using the Dexcom One? You can't expect it to give you a 7 day average if you haven't been using it for 7 days or maybe I am misunderstanding you?
Click to expand...
Firstly I didn't change the transmitter not sure where you get that from. I removed the sensor with transmitter from my abdomen. I may try again but I won't be advertising the fact.

Secondly I know that cgms or flash gm (Libre 2) measure different things. Surely if Libre 2 for example showed 10 and you didn't feel like a 10 you finger prick. Makes no sense to check this way if reading on libre is 7 for example just my opinion.

Thirdly I know Libre or Dexcom One or any other cgm aren't perfect and the way they work for individuals will be different.

Where have I said that I am not going to do anything. Sometimes I can't do anything even if I wanted to ie too late in the evening.

You get out what you put in. I'm sorry you are struggling to understand what I gain from a cgm but as above you have assumed I am not going to do anything and even if I didn't, as you said it's perfectly normal for levels to spike after a meal say an hour, thats up to me

I set up the receiver and applied the sensor and transmitter on 10/11 but it didn't give me a reading until 2hrs warm up had finished.

I removed the Dexcom One sensor and transmitter yesterday evening so 7 days unless you don't count the day I set it up.
 
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