Meter Variance

Long story short, I've done a lot of testing with different meters and different strips and on myself, and have been getting very different results. I know the advice is, pick a meter and stick with it, but what I tested today has me very confused and concerned.

With the same drop of feline blood, I tested with:

1. AlphaTrak2 meter with an AT2 strip (code 37 per bottle): 413
2. FreeStyle Lite meter with FreeStyle strip (no code needed): 288

Now I know that human meter is going to read lower than the AT2, but 413 vs. 288 is a pretty big difference.

 

Everyone says that the difference between a pet and human meter is going to be greater at higher numbers. You could have also tried the FreeStyle strip in the AlphaTrak meter. There are people here that use those strips to save cost. I have seen some comparisons that have been done, and I think using the FreeStyle strips in the AlphaTrak might get you closer to the AlphaTrak number.

There are so many posts here on the topic of meter variances, human/pet meter comparisons, etc. You could search and read until you pass out. You can really fall down the rabbit hole with this. Take the advice, pick a meter and stick with it.

 

The freestyle lite reads low for human meters afaik, and I found comparable differences to the vet's meter (though at lower numbers than those).

I have an old one touch ultra mini that I use on the rare occasion to double check a low number- it reads closer to the at2. I havent had it at the vet for direct compare though.

 

Oh, believe me, I searched and read all the posts. Multiple times. I've tried testing with the different strips in the different meters, I've tried different codes, I've tried testing on myself. I also have the InsulinX strips which I've tried in the AT2 meter, and when I tested with the same drop of blood, I got a > 30% variance. Other posters seem to have gotten much more consistent readings than I have.

My concern is just that everyone says it's dangerous to be up in the reds/blacks for an extended period. But on a human meter, he'd be in the yellows/pinks.

 

While numbers in the black/red are high no matter which meter you use, the spreadsheet colouring was geared to the human meter readings on the US scale of measure in increments of 100 points. This alters the "colour" picture a bit when using a pet meter and/or for those who use a different scale of BG measure (mg (US) vs. mmol (World)) so the type of meter does need to be acknowledged when interpreting the meaning of each of the colours. Human meters will only read to approx. 500 while the AT2 meter reads to 700 before you simply get a HI on the screen.

A human meter is a totally safe alternative to the pet meter but will not produce readings equivalent to those from the vet's office. In most cases they will be lower and the difference will be larger at high BG and less so at lower range BG. Human meters have been used for cats much longer than pet meters which were developed later.

I agree with FurBabiesMama....pick a meter and stick with it. Any meter is going to give you the tool you need to get Hogan's BG under better control and to keep him safe.

 

thank you for this. All the back and forth about pet meters vs. human is confusing and concerning. I get that Alpha Trak strips are horrendously expensive - I use insulinx strips with mine and am comfortable with that for now. My vet prefers that I use AT so when I send her a spreadsheet she knows what she's looking at. It seems to me that things get dicey in the numbers under 200 or so. Can't experts (including vets) agree on don't shoot and hypo/take action numbers for each? THanks, I'm just trying to learn!

 

Vets are dealing with a lot of folks who do not home test so they quite often will aim to keep kitty in less than optimal, but decent BG range simply for safety sake. Even when folks are home testing, vets often (usually) do not want to pass the baton to the caregiver when it comes to making dosing decisions so they set what they deem to be reasonable no shoot levels based on their own experience and comfort levels.
No shoot/take action numbers here are based on years of experience following methods/protocols used here and those numbers differ depending on what insulin is being used. Those limits can be adjusted once one has enough data to thoroughly understand how their kitty reacts to insulin (ECID).
It isn't a one size fits all proposition when it comes to giving insulin and therefore there is likely to always be some variation in setting shoot/don't shoot and take action BG levels.

 

My inclination would be to switch to the human meter for three reasons:

(1) I would think human meters have tighter controls than the pet meters. I know the pet meters are just rebranded human meters with different programming, but maybe how the manufacturer deals with quality control could be different based on whether it's intended for humans or for pets.
(2) The psychological factor of lower numbers for me.
(3) I feel like his clinical signs have vastly improved since switching his food and starting insulin, and that's not reflected in the numbers.

But then I think using the Alphatrack2 will make my vet more comfortable with my test results. Like many of you, I am trying to keep the balance between listening to my vet and doing what I think is best based on home testing.

So I keep going round and round and round, and using three times the number of strips required . I'd like to switch to a less-expensive strip in the AT2, but don't have the confidence in the numbers yet when doing so. I do see that once you get closer to "normal" numbers, the variance is much slighter.

For example, I tested myself last night (not with the same drop of blood - had to alternate between two spots on same finger), and the numbers are all fairly reflective of what we've been told - the AT2 will be ~20 points higher than human.

1. AT2 meter with AT2 strip (code 37): 117
2. AT2 meter with InsulinX strip (code 37): 135
3. Freestyle Lite meter with FS Lite strip: 94
4. Freestyle Lite meter with AT2 strip: 79
5. Freestyle Lite meter with InsulinX strip: 85

So I probably just need to stop trying to "solve" this problem and let it go. Like the song I really am my own worst enemy, though at least I found out I'm not diabetic

Thank you MrWorfMen's Mom for always replying despite having answered this exact same question a million times before.

 

Thanks, that makes a lot of sense. I'm lucky in that my vet actually suggested I join this forum when Sammy was first diagnosed 3 months ago. I think that now she realizes that I'm following protocols and advice from here rather than hers, and in fact I've not sent her a spreadsheet in a month. I do want her to be available if we need her, and will schlep Sammy in for a check up when requested. Her initial dosing advice did not comply with folks here so eventually I just morphed over to SLGS. She is conservative, probably for the reasons you mention. Her no shot number for AT is 250. As we get lower numbers I'll make decisions about that and dosing based on advice from here, her advice, and my growing confidence in knowing my cat and his data. But I will stick with my AT for now and quit worrying about scores from human ones. I so appreciate the help!

 

The difference will not be the same for every reading. There is no linear or % difference that will explain the number of points between the two meter readings. Cat blood and human blood are different and all meters are designed to give a plasma equivalent reading based on the assumption that the blood being tested has a certain % of glucose in the plasma. That is why the human meter reads lower than a pet meter when testing cat blood.

Species Glucose Concentration in
........................RBCs ...............Plasma
Human -----------42% ---------------58%
Feline --------------7% ---------------93%

The no shoot recommendations on this site are based on the use of a human meter. I did a substantial amount of comparison testing between human and pet meters and your vet's recommendation seems totally reasonable to me.

 

Very interesting! Thanks so much for the info, much appreciated as always!

 

Adding another voice saying what others have already said -- there's no real formula comparing a human meter to a pet meter, and it's much further off at higher numbers. 413 vs. 288 is totally consistent with my own experience, so both meters are probably functioning correctly. I have an AlphaTrak2 and a human meter that I normally use just to check for ketones, but I tried it for BG, and I got a similarly wide spread.

I stuck with the AlphaTrak2 despite the cost of the strips so my vet would be more willing trust my numbers. Plus, even the human meters that say they only need a little drop of blood do seem to require more than the AlphaTrak2, so I find it much easier to use.

 

When I was discussing meters with my vet, I had no idea there would be such a difference. It concerned him, so I looked into it and emailed him. I told him the normal glucose parameters according to my meter, and that it was normal for it to read lower than the at2. He was good with that.