Blood meter giving weird readings

[Kaylz]

Target figures for post meal are under 8.5. If I had eaten a meal then the figures given would even be above that target. It seems to me that the inaccuracy of meters is a drawback. Can you imagine being stopped for speeding and telling the nice policeman that your speedometer was right plus of minus 15% for 95% of the time....

Not too much of a drawback, I'm managing well as are many other insulin dependants, you seem to be only testing BG, as insulin dependants meters basically have lives in their hands as we use them to estimate how much insulin we take, not enough or too much and it could be dangerous either away so I see them as pretty accurate xx

 

[Docb]

Hi @TinaD. I think you are being a bit hard on the portable blood glucose meter. It's a bit of a miracle that you can get a measurement at all and as @Kaylz reminds us, you cannot get much better than having the accuracy needed to adjust insulin doses for those with T1.

You need to use a meter for a while in order to establish the patterns associated with your blood glucose variations. Used well and wisely it is a brilliant tool for working out what foods give you what rises in blood glucose and to check whether changes in diet are sending things in the right direction. It is at its most useful if your HbA1c is above the diabetes diagnosis level and you are trying to get it down by adjustment of your diet. As a method for determining the status of your diabetes it is very limited. As a device for raising concerns where none should really exist it has vast potential!

So, unless you are getting highs heading for the twenties and lows never below 9, my thought is not to worry too much about the numbers and look for patterns. Look for things that are abnormal for you and you cannot do that until you establish what normality is. So keep testing, write all the numbers down against the meals you have eaten until you get a decent feel for what is going on.

By the way, I suggest you look up the regulations for the accuracy of speedometers. You might find that interesting! 😉

 

[Bruce Stephens]

It seems to me that the inaccuracy of meters is a drawback.

For those of us relying on insulin (and exercise, etc.) they're good enough. And more continuous systems (like Libre) are also OK (even though they're likely a bit less accurate): I don't care that much about individual values, I'm just aiming to keep within what Libre says is 3.9-10.0 for most of the time.

 

[pm133]

Good of you all to reply. If target range for Type 2 is between 4 to 7 before meals and you eat only 4g of carbs (green veggies) together with modest protein ration 3 hours before test one would hope to see something better. Dammit the figures are high for post meal. How can one get a handle on this beastly illness with such a coarse, inaccurate, analysis tool.

I'm newly diagnosed and found the inaccuracy of the machine very frustrating as well. I think the best approach is to ignore the individual readings and focus on the overall trend.
As an example, here's my results since diagnosis from a spreadsheet I designed:-


Along the horizontal axis are individual readings (wow nearly 300 already!!) clumped into groups of 4 spike for each day. Blood glucose readings in mmol/L are on the vertical column.

Individual readings are pretty much all over the place but hopefully you can see a clear trend to numbers averaging around 6.0 which is exactly where I want to be. Having that sort of comforting set of results, I can then start adding readings from 2 hours after eating and make sure (on a separate graph) those don't increase by more than 3.0 mmol/L on average.

The combination of both of those gives me comfort that I'm doing the best job I can at avoiding massive spikes and potential complications further down the line.

Hope this helps.

 

[pm133]

For those who are Type 2, I notice @TinaD is only taking in 4g carbs. Is there any chance her liver is dumping glucose to compensate for this ultra low amount because I'm struggling to understand why so few carbs would result in such large readings?

 

[Docb]

Hi @pm133. What you are doing is exactly what I am talking about when I suggest you look for patterns rather than focus on individual results. You can plot the results as a simple XY plot and you will get the same pattern. It is also helpful to calculate a running average and plot that as well, it will show trends much better.

Here is my plot from the data I have collected. The blue line is the raw data and the red line the running average. After the big fall, the first rise was due to changing medications and corrected by changing them back again. The other ups and downs are just part of the overall pattern although I was beginning to wonder about the last rise before it corrected itself.

 

[TinaD]

Hi @TinaD. I think you are being a bit hard on the portable blood glucose meter. It's a bit of a miracle that you can get a measurement at all and as @Kaylz reminds us, you cannot get much better than having the accuracy needed to adjust insulin doses for those with T1.

You need to use a meter for a while in order to establish the patterns associated with your blood glucose variations. Used well and wisely it is a brilliant tool for working out what foods give you what rises in blood glucose and to check whether changes in diet are sending things in the right direction. It is at its most useful if your HbA1c is above the diabetes diagnosis level and you are trying to get it down by adjustment of your diet. As a method for determining the status of your diabetes it is very limited. As a device for raising concerns where none should really exist it has vast potential!

So, unless you are getting highs heading for the twenties and lows never below 9, my thought is not to worry too much about the numbers and look for patterns. Look for things that are abnormal for you and you cannot do that until you establish what normality is. So keep testing, write all the numbers down against the meals you have eaten until you get a decent feel for what is going on.

By the way, I suggest you look up the regulations for the accuracy of speedometers. You might find that interesting! 😉

Thanks Docb - I am doing exactly that - keeping a food diary, measuring frequently, and trying also to see if there is a pattern with my steroid dose which maximises its therapeutic effect 2-2.5 hours after taking it. Also because I am on a reducing steroid dose (32.5mg from today) and have dropped 12.6kg in weight I am contemplating the necessity of reducing other medications, in particular those related to high blood pressure and blood thinning. My fasting bloods are running mostly between 4.3 and 5.4 with only 9 tests over the past 28 days a little exceeding 5.4 (5.5 - 5.9). Found Greek yoghurt, which sadly I love, created a high (for me) and lingering post food spike so I am reduced to greens, protein and olive oil. GY is only 5g carbs to the 100g. Nuts also, another love, have exited the menu for the same reason as has fruit. Since dropping those elements I have left the upper teens and am getting mainly 9.1 to 11.6 with a few miraculous 7 and 8s. I shall be down to zero steroids in 12 months unless the palindromic arthritis and COPD flare and cripple me again. Sadly altho' the figures must look wonderful for other more serious diabetics my toes are going blue and I have bad oedema by nightfall. So I am anxious to get into remission if I can and find anomalous figures really irritating and stressful. The USA claims to have a more accurate one but it doesn't seem to be available here.

 

[grovesy]

Thanks Docb - I am doing exactly that - keeping a food diary, measuring frequently, and trying also to see if there is a pattern with my steroid dose which maximises its therapeutic effect 2-2.5 hours after taking it. Also because I am on a reducing steroid dose (32.5mg from today) and have dropped 12.6kg in weight I am contemplating the necessity of reducing other medications, in particular those related to high blood pressure and blood thinning. My fasting bloods are running mostly between 4.3 and 5.4 with only 9 tests over the past 28 days a little exceeding 5.4 (5.5 - 5.9). Found Greek yoghurt, which sadly I love, created a high (for me) and lingering post food spike so I am reduced to greens, protein and olive oil. GY is only 5g carbs to the 100g. Nuts also, another love, have exited the menu for the same reason as has fruit. Since dropping those elements I have left the upper teens and am getting mainly 9.1 to 11.6 with a few miraculous 7 and 8s. I shall be down to zero steroids in 12 months unless the palindromic arthritis and COPD flare and cripple me again. Sadly altho' the figures must look wonderful for other more serious diabetics my toes are going blue and I have bad oedema by nightfall. So I am anxious to get into remission if I can and find anomalous figures really irritating and stressful. The USA claims to have a more accurate one but it doesn't seem to be available here.

If you mean a US monitor they use differnt measurements, and most companies sell in US and here, but some models are only available in certain areas. What meter are you using?

 

[TinaD]

AgaMatrix Jazz

 

[grovesy]

I have not used that one myself but I think that one is commonly prescribed.
What was the US one that you think is more accurate?

 

[pm133]

Hi @pm133. What you are doing is exactly what I am talking about when I suggest you look for patterns rather than focus on individual results. You can plot the results as a simple XY plot and you will get the same pattern. It is also helpful to calculate a running average and plot that as well, it will show trends much better.

Here is my plot from the data I have collected. The blue line is the raw data and the red line the running average. After the big fall, the first rise was due to changing medications and corrected by changing them back again. The other ups and downs are just part of the overall pattern although I was beginning to wonder about the last rise before it corrected itself.

View attachment 15366

Agreed. I also have a graph of daily averages and can do running averages of both sets of data if needed.

 

[TinaD]

I am ashamed to say I cannot recall! Didn't note it down - it exceeded the 95% of the time and had a lesser window of + and -. I shot off to Amazon but no joy.

 

[everydayupsanddowns]

The ISO specifications and chart at the bottom of this post show the allowable variations for BG meters - with some quite wide variations

Useful links for people new to diabetes

These links provide useful information, particularly to those newly-diagnosed. You can also browse the Recommended Books and Links sections for further information :) Contents: Type 1 Section Insulin Pumps Section Type 2 Section General Help and Information Section Complications and screening...

forum.diabetes.org.uk

And I agree that it is a limitation of the tecnnology... but also that it is a sufficiently accurate data feed to manage diabetes day to day, while realising that variation happens, and that perfection is impossible.

Incidentally I was under the impression that speedometers were allowed an 10% margin of error, so that you were unlikely to be convicted of speeding if clocked at 22mph in a 20 zone or 77mph on the motorway?

 

[everydayupsanddowns]

AgaMatrix Jazz

The Jazz doesn’t do very well in this lineup I’m afraid (though the comparison is a few years old)

Why Checking Postprandial Glucose Is Important

Checking your blood sugar levels two hours after a meal — the postprandial glucose (PPG) test — can be a key component of successful diabetes management.

www.diabetesdaily.com

Many folks here find the SD Gluco Navii or Spirit Tee2 give them good performance at affordable strip cost

 

[SweetGuy]

This morning's debacle: 8.6 before breakfast. Two hours after 18.6. I'm asking for a recount lol.

 

[grovesy]

This morning's debacle: 8.6 before breakfast. Two hours after 18.6. I'm asking for a recount lol.

What did you have for breakfast and did you recheck the 18.6?

 

[SweetGuy]

What did you have for breakfast and did you recheck the 18.6?

A bowl of Shreddies (I know) and a bacon, egg and fried tomato sandwich. It's dropped back to 8.7 now (over four hours post). I get the biggest spike after breakfast but that was the worst for a while.

 

[grovesy]

A bowl of Shreddies (I know) and a bacon, egg and fried tomato sandwich. It's dropped back to 8.7 now (over four hours post). I get the biggest spike after breakfast but that was the worst for a while.

At least you recognize the problem.

 

[TinaD]

The ISO specifications and chart at the bottom of this post show the allowable variations for BG meters - with some quite wide variations

Useful links for people new to diabetes

These links provide useful information, particularly to those newly-diagnosed. You can also browse the Recommended Books and Links sections for further information :) Contents: Type 1 Section Insulin Pumps Section Type 2 Section General Help and Information Section Complications and screening...

forum.diabetes.org.uk

And I agree that it is a limitation of the tecnnology... but also that it is a sufficiently accurate data feed to manage diabetes day to day, while realising that variation happens, and that perfection is impossible.

Incidentally I was under the impression that speedometers were allowed an 10% margin of error, so that you were unlikely to be convicted of speeding if clocked at 22mph in a 20 zone or 77mph on the motorway?

"1General speed limit for restricted roads.
(1)It shall not be lawful for a person to drive a motor vehicle on a restricted road at a speed exceeding 30 miles per hour." Any such leeway would therefore be discretionary - a decision that prosecution int he particular case would not serve the public good or Mr Plod and colleague deciding they were up to quota and would rather go for doughnuts. You are not prosecuted because your speedo is wrong but because there is extraneous evidence of the offence. I gatehr that the problem with glucose meters is that they deal with whole blood not just plasma and have to rely on an algorithm to make some sort of allowance for the other parts of the blood than the plasma. I still think plus or minus 15% is poor - would you sell your £1m house for £850k? Interestingly Estate Agents/valuers are allowed 15% leeway...

 

[everydayupsanddowns]

A bowl of Shreddies (I know)...

All Cereal Is Evil TM