Confused with readings.

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Bullet1954

Bullet1954

Member
Relationship to Diabetes
Type 2
hi all,
Male type2 on tablets. Recently had my medication increased and started checking bloods, pre Breakfast, Lunch and Evening meal, then before bed.

AM
160mg Gliclazide
2 x 500mg Metformin

PM
160mg Gliclazide
2 x 500mg Metformin

What is confusing me are readings. E.g.: one night before bed, reading 7, medication before breakfast then test blood before I eat and gone up to 8.1,

Another occurrence, at bedtime 4.1, tested my blood in the morning, was 4.3, had my gliclazide then retested before I had my breakfast and again gone up to 5.1.

What I'm failing to understand is how after I have my Gliclazide the readings go up instead of down before I eat?

Any advice
Thanks
Glenn.
 
Weird isn't it! My advice, after about a year of testing, is simply collect the numbers for a couple of weeks and not worry too much about things, that is if you do not get many very highs (greater than 10) or very lows (less than 4).

Lots of things affect the instantaneous blood glucose level in your blood and you need quite a lot of readings before you can detect patterns that you can relate to specific changes. Makes things much harder if you are doing other things, such as changing diet and taking more exercise, as well as taking pills.

A couple of points... Are you any good with spreadsheets? If so, then start to put your numbers into one from the beginning. You are taking quite a lot of gliclazide and getting readings below 5. Normal advice is not to drive with readings below 5 because if you get a drop then you could go below 4 without knowing and that is not a good thing. It's one of the factors to take into account when taking gliclazide. I would add test before you drive to your schedule and keep some jelly babies handy to push your BG up if you find yourself in the 4's.

It will all make sense eventually!
 
Hello @Bullet1954

Welcome to the forum!

I think there are two things here. One is the accuracy of home blood glucose monitors, and the likely homogenous nature of blood itself. Essentially small differences are almost inevitable between fingers and even in the same finger between strips beside capillary blood is unlikely to be 100% the same all over the body at any one moment, and strips can it be assumed to react 100% identically to samples every time.

Small differences of 0.5mmol/L I generally think of as being more or less the same.

The other thing you seem to be observing is Dawn Phenomenon (or its cousin Feet Hit The Floor). This is the hormone response to ‘fire up the boilers’ in the early hours or just after rising which dates back to our cave dwelling ancestors.

Many people find their BG rises overnight with no food consumed. Some find a small low carb snack before bed helps, though this is more for BG boosts around 3am. Like you, I dont find my BG rises until I’ve actually got out of bed.
 
Interesting Mike, thanks for the info. Sometimes when I wake up I test before and after medication. If before I'm eg; 4.1 and I have to have my Gliclizide before my breakfast I fear that it will push me below 4 and towards hypo. That's when it seems irrational that after the mess it can go up before eating, instead of down.
Glenn
 
Docb said:
Weird isn't it! My advice, after about a year of testing, is simply collect the numbers for a couple of weeks and not worry too much about things, that is if you do not get many very highs (greater than 10) or very lows (less than 4).

Lots of things affect the instantaneous blood glucose level in your blood and you need quite a lot of readings before you can detect patterns that you can relate to specific changes. Makes things much harder if you are doing other things, such as changing diet and taking more exercise, as well as taking pills.

A couple of points... Are you any good with spreadsheets? If so, then start to put your numbers into one from the beginning. You are taking quite a lot of gliclazide and getting readings below 5. Normal advice is not to drive with readings below 5 because if you get a drop then you could go below 4 without knowing and that is not a good thing. It's one of the factors to take into account when taking gliclazide. I would add test before you drive to your schedule and keep some jelly babies handy to push your BG up if you find yourself in the 4's.

It will all make sense eventually!
Click to expand...
Docb said:
Weird isn't it! My advice, after about a year of testing, is simply collect the numbers for a couple of weeks and not worry too much about things, that is if you do not get many very highs (greater than 10) or very lows (less than 4).

Lots of things affect the instantaneous blood glucose level in your blood and you need quite a lot of readings before you can detect patterns that you can relate to specific changes. Makes things much harder if you are doing other things, such as changing diet and taking more exercise, as well as taking pills.

A couple of points... Are you any good with spreadsheets? If so, then start to put your numbers into one from the beginning. You are taking quite a lot of gliclazide and getting readings below 5. Normal advice is not to drive with readings below 5 because if you get a drop then you could go below 4 without knowing and that is not a good thing. It's one of the factors to take into account when taking gliclazide. I would add test before you drive to your schedule and keep some jelly babies handy to push your BG up if you find yourself in the 4's.

It will all make sense eventually!
Click to expand...
 
Bullet1954 said:
Interesting Mike, thanks for the info. Sometimes when I wake up I test before and after medication. If before I'm eg; 4.1 and I have to have my Gliclizide before my breakfast I fear that it will push me below 4 and towards hypo. That's when it seems irrational that after the mess it can go up before eating, instead of down.
Glenn
Click to expand...

if you are waking at 4.1 it seems that your meds could well need an adjustment as @Docb says.

For a T1, the minimum suggested BG in the mornings is 5, because lower than that comes with an increased risk of long periods of undetected hypoglycaemia where the cortisol output from the liver dips during the night, coupled with a lower counterregulatory hormone response (people with long term T1 often don’t get hypo symptoms so much overnight).

I would assume 5 I’m waking would be a much safer level for T2s on hypoglycaemic (BG lowering) meds too.
 
Hi

Yes thanks for that, maybe I'm expecting too much and been to observing. I didn't realise until I went for pre op assessment for double hip replacements there was a problem really until they returned my bloods and deferred the ops because they were 90 which convert to 10.4 and was told unless they lower to below 70 (8.6) at least they won't operate.

A change in the meds and most reading are between 22 and 49 (4.2/6.6) before meals throughout the day. Averages having come down to about 51, so, I'm heading the right way, I'm below there 70 and heading towards the suggested 48(6.5)
 
Bullet1954 said:
A change in the meds and most reading are between 22 and 49 (4.2/6.6) before meals throughout the day. Averages having come down to about 51, so, I'm heading the right way, I'm below there 70 and heading towards the suggested 48(6.5)
Click to expand...

I’m a little confused by the way you are posting those numbers @Bullet1954 and wonder whether you might be mixing up some of the BG results which are interlinked, but not interchangeable.

The results you get from your meter at home are in mmol/L. These are ‘spot checks’. The level of glucose in your blood at one moment in time.

The 90/10.4 and 70/8.6 seem likely to be HbA1c levels expressed in new units and the old ones which some HCPs are more familiar with (a bit like metres vs feet and inches). This isn’t a direct measure of glucose, it is a measure of the way that glucose in the bloodstream has affected red blood cells. The higher the circulating glucose value, the more red blood cells are affected, so it’s a ‘sort of’ measure of glucose values over the last 120 days (the lifespan of red blood cells).

These are 90mmol/mol (10.4%) and 70mmol/mol (8.6%). It’s important to recognise that the % values relate to the percentage of haemoglobin in a sample that has been affected by excess glucose in the bloodstream rather than measuring the glucose itself. So 8.6% doesn’t equate to a spot check (or even average of spot checks!) of 8.6mmol/L fingersticks. This has long confused people, and is one of the benefits of moving to the international standard of mmol/mol for HbA1c because the numbers are clearly different.

Hope that makes some kind of sense!
 
A bit more on the numbers... The 90 number you mention will be your HBA1c which is got from a blood sample sent to a lab, and they want you to get that below 70 before they will do your hips. 70 is still in the red zone as far as getting complications from your diabetes is concerned so hip op not withstanding you should be aiming to get that down in the longer term. Target is normally below 48.

How do these numbers square with the readings from your meter? First off is that they are actually measuring different things - that's why the numbers are so different. The HBA1c gives you a measure of your long term blood glucose control, not by measuring the free glucose in your blood, but by looking at how much has got attached to your haemoglobin. The blood glucose readings from your meter actually tell you how much glucose there is in the drop of blood on your finger and as Mike says, its affected by all sorts of things and goes up and down like a fiddlers elbow. However, the average of the readings you get from your meter is related to HBA1c but there is a bit of debate about how you get from one to the other. There are various conversion factors about.

Lets pick apart your target for the op of below 70(8.6). I interpret this as 70 is the HBA1c they are looking for, and they are suggesting this equates to an average spot reading of 8.6. That's a bit lower than the conversion I have been using would give, but as I say the factor you use depends on where you look. If the surgeons are happy with it then go with it, its erring on the good side as far as your diabetes is concerned. One thing for sure is that you are going to hit your below 70 target if your spot readings are mostly in single figures.

Just seen that Mike has posted again.... hope this has clarified and not confused things.
 
Docb said:
I interpret this as 70 is the HBA1c they are looking for, and they are suggesting this equates to an average spot reading of 8.6.
Click to expand...

Actually, as Mike says, they're both HbA1c: 70 mmol/mol = 8.6%
 
Eddy Edson said:
Actually, as Mike says, they're both HbA1c: 70 mmol/mol = 8.6%
Click to expand...

Doh! Looks like I was not thinking wide enough - thanks Eddy.

Anyway the principal holds, the average of your spot readings will say something about the HBA1c measurement you will get and getting that average into single figures should get you comfortably below the 70 value that the surgeons are looking for.
 
everydayupsanddowns said:
if you are waking at 4.1 it seems that your meds could well need an adjustment as @Docb says.

For a T1, the minimum suggested BG in the mornings is 5, because lower than that comes with an increased risk of long periods of undetected hypoglycaemia where the cortisol output from the liver dips during the night, coupled with a lower counterregulatory hormone response (people with long term T1 often don’t get hypo symptoms so much overnight).

I would assume 5 I’m waking would be a much safer level for T2s on hypoglycaemic (BG lowering) meds too.
Click to expand...
I did think it's a bit low but I feel ok with it, just a bit apprehensive I suppose.
 
everydayupsanddowns said:
I’m a little confused by the way you are posting those numbers @Bullet1954 and wonder whether you might be mixing up some of the BG results which are interlinked, but not interchangeable.

The results you get from your meter at home are in mmol/L. These are ‘spot checks’. The level of glucose in your blood at one moment in time.

The 90/10.4 and 70/8.6 seem likely to be HbA1c levels expressed in new units and the old ones which some HCPs are more familiar with (a bit like metres vs feet and inches). This isn’t a direct measure of glucose, it is a measure of the way that glucose in the bloodstream has affected red blood cells. The higher the circulating glucose value, the more red blood cells are affected, so it’s a ‘sort of’ measure of glucose values over the last 120 days (the lifespan of red blood cells).

These are 90mmol/mol (10.4%) and 70mmol/mol (8.6%). It’s important to recognise that the % values relate to the percentage of haemoglobin in a sample that has been affected by excess glucose in the bloodstream rather than measuring the glucose itself. So 8.6% doesn’t equate to a spot check (or even average of spot checks!) of 8.6mmol/L fingersticks. This has long confused people, and is one of the benefits of moving to the international standard of mmol/mol for HbA1c because the numbers are clearly different.

Hope that makes some kind of sense!
Click to expand...
Yes it does seem to make things clearer.
 
Docb said:
A bit more on the numbers... The 90 number you mention will be your HBA1c which is got from a blood sample sent to a lab, and they want you to get that below 70 before they will do your hips. 70 is still in the red zone as far as getting complications from your diabetes is concerned so hip op not withstanding you should be aiming to get that down in the longer term. Target is normally below 48.

How do these numbers square with the readings from your meter? First off is that they are actually measuring different things - that's why the numbers are so different. The HBA1c gives you a measure of your long term blood glucose control, not by measuring the free glucose in your blood, but by looking at how much has got attached to your haemoglobin. The blood glucose readings from your meter actually tell you how much glucose there is in the drop of blood on your finger and as Mike says, its affected by all sorts of things and goes up and down like a fiddlers elbow. However, the average of the readings you get from your meter is related to HBA1c but there is a bit of debate about how you get from one to the other. There are various conversion factors about.

Lets pick apart your target for the op of below 70(8.6). I interpret this as 70 is the HBA1c they are looking for, and they are suggesting this equates to an average spot reading of 8.6. That's a bit lower than the conversion I have been using would give, but as I say the factor you use depends on where you look. If the surgeons are happy with it then go with it, its erring on the good side as far as your diabetes is concerned. One thing for sure is that you are going to hit your below 70 target if your spot readings are mostly in single figures.

Just seen that Mike has posted again.... hope this has clarified and not confused things.
Click to expand...
Yes, thanks for that, there seems to be a lot of information around but it seems a lot should be taken with a pinch of salt. With the Anaesthetist saying he would allow <70 it at least gave me a target, using my meter my averages are showing 50% which I'm pleased about and will endeavour to carry on trying to get as fit as possible fir the ops.
 
Bullet1954 said:
With the Anaesthetist saying he would allow <70 it at least gave me a target, using my meter my averages are showing 50% which I'm pleased about
Click to expand...

Where are you getting 50% from Bullet?
 
Bullet1954 said:
On the converter I have where it shows such as the average 6.5 = 48 etc etc
Click to expand...

Ah OK. That's not right then.

Neither of those numbers are fingerstick/test strip numbers. They are two ways of reporting HbA1c (lab test from blood drawn from your arm).

HbA1c of 48mmol/mol used to be recorded as 6.5%.

HbA1c of 50mmol/mol used to be recorded as 6.7%

Neither of those are the same as the 6.7 you might see on your BG meter.

If you want a *vague* estimate of HbA1c from your meter average you can use:

HbA1c = (averageBG+2.52)/1.583

But you'd have to know that you were capturing all the highs and lows with enough 'weight' in your frequency of checking (so that twenty minutes of 4.8 doesn't counteract 4 hours of 12.5 etc etc). Plus there isn't a mathematical conversion between fingerstick BG and HbA1c as they are completely different things.

Sorry it's all a bit mind boggling!

Your best bet is to aim for an average BG below 7mmol/L and to try to keep between 4mmol/L and 9mmol/L for as much of the day as you can manage. If you do that your HbA1c should fallt nicely into range. 🙂
 
So are you saying if my finger prick returns 6.7 and I use the sum 6.7 + 2.5/ 1.583 the figure would be nearer to 5.81 which would be more like 40mmol/mol and not 50 as my conversion chart shows. If so that take me closer to my target of <70 and closer to the average 6.5 or am I confusing myself more lol.
 
Bullet1954 said:
So are you saying if my finger prick returns 6.7 and I use the sum 6.7 + 2.5/ 1.583 the figure would be nearer to 5.81 which would be more like 40mmol/mol and not 50 as my conversion chart shows. If so that take me closer to my target of <70 and closer to the average 6.5 or am I confusing myself more lol.
Click to expand...

Yes that’s roughly right. The formula is an approximation, and it’s hard to get a completely accurate average BG from fingersticks. There are a bunch of those conversion estimates and the that one always read a little low for me - so I’d expect around 42-48mmol/L-ish
 
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