what is your meter telling you?

I think almost all meters are used with whole blood. Most are probably human rather than animal meters.

But the question is are they calibrated to give results as glucose amounts in whole blood or as the equivalent glucose amounts in plasma? Older ones probably give the former, but I'm told that most newer ones do the latter.

Most meters are plasma calibrated now, including my own (the Accu-Chek Performa). My Accu-Chek Performa still consistently reads 20 points lower than both the AlphaTRAK 2 (which I also own) and the serum analyzer at our vet ~ and that is at my cat's remission BG levels. With higher BG levels, the difference would be greater. The Accu-Chek is also the most accurate of the human meters I've tried.

So rest assured, you can safely follow UQ's Table 3A with your plasma calibrated human meter.

dbdb said:

I think almost all meters are used with whole blood. Most are probably human rather than animal meters.

But the question is are they calibrated to give results as glucose amounts in whole blood or as the equivalent glucose amounts in plasma? Older ones probably give the former, but I'm told that most newer ones do the latter.

Does it matter?

Yes if you are using any protocol based on Roomp and Rand, which I suspect most protocols are. For example if using the former type of meter you should reduce the Lantus/glargine dose immediately if your cats drops once below 40 mg/dL but if the latter type the figure at which you should reduce immediately is 70. (To assist, 40 is 2.2 mmol/L and 70 is 4.5).

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emphasis is mine. opinion expressed is that of dbdb.



fwiw, recent comments re: glucose meters made by Kirsten (the Roomp in the Roomp and Rand Protocol) can be found in their entirety here:
Glucometer Accuracy Problems Acknowledged By FDA, Industry. amongst other things, Kirsten wrote:

Kirsten said:

When I mention that FDMB has been using the TR protocol "as is" for at least 5 years with plasma-calibrated meters and it works very well, these members just reiterated that they personally measured something different.... Sigh.

The most I would be willing to say, is to be careful with the AlphaTrak and also be careful with meters that have actually failed in the linked study.

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I'm confused. Are you suggesting that when we use a human meter, and we read "X" on the meter, that it's really 30 points lower than we think it is?

If so, I don't think that's true. I've seen cats read below 40 fairly frequently. If somebody gets a 37, is the BG really 7? That defies logic, doesn't it? Wouldn't that cat be in a coma?

Thanks, Jill.
I don't think I'm quite qualified to differ with Kirsten. She knows a lot more about managing FD and the TR protocol than 99% of the people in world probably do.

Blood Glucose Meter for Cats
Facts:
Blood has two constituents, the red and white blood cells and the liquid (serum). Blood plasma is blood serum without the clotting factor
The blood glucose value obtained via laboratory analysis is the glucose level in the serum/plasma constituents of blood
The glucose is in both the serum and red-blood cells (RBC) themselves. However, the distribution of glucose is different between humans and cats (and dog too)1
In Humans 58% is in plasma/serum and 42% in RBCs
In cats 93% is in plasma/serum and 7% in RBCs
In dogs 87.5 % in plasma/serum and 12.5% in RBCs.
The point-of-use blood glucose meters (the ones we use at home) all use whole blood.2 However, what specific blood glucose they measure varies with the manufacturer. Some manufacturers only measure the glucose in the serum/plasma. Others lyse (disrupt the cell walls of the RBCs) and thus mix the glucose that was in the RBC into the liquid and thus measure total glucose. The meters then correct/adjust the reading to be equivalent to human blood plasma
Discussion:
Since the glucose distribution is different n humans and cats/dogs the resulting BG valve obtained from the human meters will be different that lab values and animal-calibrated meters. Also, some manufacturer's meters will be much different that lab values for animals depending upon which method (lyse cells or only use plasma/serum) they use to measure glucose.

Animal calibrated meters correct the value to be equivalent to lab values.

What clouds any BGs obtained from hand-held meter si that they are only accurate to +/- 20 %. That includes the animal-calibrated meter. Also, do not confuse accuracy with reproducibility. It is expected that one meter with one lot of tests strips to be relatively repeatable, that is if you use the same drop of blood, you BG value will be much close than +/- 20%

References:
1. WHY DO YOU NEED A SPECIES SPECIFIC METER?
http://www.alphatrakmeter.com/alphatrak ... cific.html
2. Glucose Meters: A Review of Technical Challenges to Obtaining Accurate Results
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2769957/

Apologies if I had this wrong, it may be that for the purposes of R&R there are three types of meter - the old human whole blood calibrated for blood, the now common human whole blood calibrated for plasma and the obscure feline calibrated meter. Perhaps only the third type is to use table 3B? In which case the 2nd type would use table 3A but just add 10% to the figures in the table?

Meantime I've removed the following from my original post, in case it applies only to human v feline meters and not human whole blood v human plasma calibrated as I first thought.

Does it matter?

Yes if you are using any protocol based on Roomp and Rand, which I suspect most protocols are. For example if using the former type of meter [calibrated for whole blood] you should reduce the Lantus/glargine dose immediately if your cats drops once below 40 mg/dL but if the latter type [calibrated for plasma] the figure at which you should reduce immediately is 70. (To assist, 40 is 2.2 mmol/L and 70 is 4.5).

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For the very few (I imagine) people using feline calibrated meters the "figure at which you should reduce immediately " remains at 70 instead of 40, as above.

There also remains, only relevant to feline meters users, what seems to me a typo in table 3B, this is the subject of another post http://felinediabetes.com/FDMB/viewtopic.php?f=28&t=98026 and I have asked Rand about it.

JC & Balki said:

Most meters are plasma calibrated now, including my own (the Accu-Chek Performa). My Accu-Chek Performa still consistently reads 20 points lower than both the AlphaTRAK 2 (which I also own) and the serum analyzer at our vet ~ and that is at my cat's remission BG levels. With higher BG levels, the difference would be greater. The Accu-Chek is also the most accurate of the human meters I've tried.

Click to expand...

I understand why your alpha trax 2 reads higher than your plasma calibrated Acc-Check - your alpha trak 2 is a feline calibrated meter. Presumably your vets serum analyzer is also feline calibrated?

But for old human blood calibrated versus newer human plasma calibrated the R&R paper says "Measurements from meters calibrated for human blood which provide plasma equivalent
values are approximately 10% higher."
Another source says the same "The difference is that plasma numbers read about 10 - 12% higher than the older whole blood numbers." http://www.joslin.org/info/plasma_glucose_meters_and_whole_blood_meters.html

You were suggesting that people should be following the feline calibrated meter table (3B) with their human plasma calibrated meters. Hence, my comment.

Yes, just factor in the 10% for table 3A if you are worried.

My meter is telling me that Wink is still OTJ after 3 months on a ultra low carb canned food diet.

I think that some caretakers can't see the forest from the trees.

not see the forest for the trees
to pay too much attention to details and not understand the general situation not see the wood for the trees Company officials were so involved in the talks, they couldn't see the forest for the trees and didn't realize their employees were willing to strike.

<a href="http://idioms.thefreedictionary.com/not+see+the+forest+for+the+trees">not see the forest for the trees</a>

I agree with Larry, some caretakers get way too caught up in meter accuracy, and let's face it, they all have a 20%error anyway. Asides avoiding the "lite" and "true" meters i would just pick a meter that works in the price range that you are comfortable with, with the least amount of blood possible and leave it at that.

I've been doing this 'sugar dance' for six and a half years with Bertie, and there have been a couple of times during that period when I really, really, really wanted to know which meter was going to give me the most accurate results. I must have experimented in those periods with half a dozen different meters (including the Alphatrak). It's funny how a need to know something can suddenly get a hold of you and become uber important. I'm sure I lost sleep over it. Really....

I couldn't find the answers I wanted. I'm not even sure those answers 'exist'. I admit it: It was frustrating. But I got over it. Twice... And I went back to my trusty One Touch Ultra meter, and I went back to observing trends in my cat's blood glucose levels...

My meter may not give me the most accurate blood glucose readings in the entire cosmos (but you never know - maybe it does! :shock: ) But the information my meter gives me is sufficient to manage my cat's diabetes pretty well. And many cats have gone into remission using these (and similar) meters.

For the time being I'm a happy bunny. And I hope I don't get another of those 'really, really, really needing to know the precise/exact/'real' blood glucose level' episodes, because they're sort of 'painful' and can drive you completely barmy...

I'm grateful to Hope ('and Baby') for sending me her meter experiment results the last time I 'got my knickers in a twist' about this (Note: for our Aussie members that would be 'getting my panties in a bunch'). (And Hope, if this happens to me again maybe you can just click 'Resend'.... ;-) :lol: )

Eliz

PS. Loving that poll idea. Didn't know we could do that sort of thing here. Ideas for other polls are already trickling into my consciousness; for example: 'How do you reward yourself for a busy day's hometesting?' - Chocolate? Ice cream? Wine? Relaxing bubble bath? Other? All of the above...? ;-)