Topics

Insulin Testing


Eleanor Kellon, VMD
 

This study found that insulin testing of samples taken into an EDTA plasma tube (purple top) showed significantly lower levels than serum (red top) or heparin (green top) samples. Best stability when testing is going to be delayed beyond 3 days is heparinized samples.

https://pubmed.ncbi.nlm.nih.gov/31617618/

If you are using Cornell's ACTH/insulin/leptin panel the sample will be EDTA unless the vet also draws a separate serum sample and requests that be used for insulin.

Bottom Line: Use serum or heparin tubes for insulin testing. Varying sample type between tests will not give you accurate results.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001


LJ Friedman
 

I forwarded this message to my vet requesting heparin  tubes to use for a future testing. I’m wondering why we’re getting so much research of things that we need to change up lately?  Of course, thank you so much for posting
--
LJ Friedman  Nov 2014 Vista,   Northern  San Diego, CA

Jesse and majestic ‘s Case History 
Jesse's Photos

 


LJ Friedman
 


-- Vet. replied back that he’s been using the red tops. So I guess that’s, better than purple.?  assuming  heparin is preferred over red? 

LJ Friedman  Nov 2014 Vista,   Northern  San Diego, CA

Jesse and majestic ‘s Case History 
Jesse's Photos

 


Sherry Morse
 

LJ,

As per Dr. Kellon's note if testing is going to be delayed Heparin is the best option.




LJ Friedman
 

What is meant by delayed?  most samples usually arrive frozen so what does a delay mean?
--
LJ Friedman  Nov 2014 Vista,   Northern  San Diego, CA

Jesse and majestic ‘s Case History 
Jesse's Photos

 


Sherry Morse
 

I would take it to mean if there's a delay in transit or you send the sample and it arrives on an off day (Cornell only does insulin testing on Monday, Wednesday and Thursday) you have less to worry about using a red or heparin tube.

As per the study:
Results: An overall effect of time, tube type and temperature was identified (P = .01, P = 0.001, and P = 0.001, respectively). Serum and heparinized samples had similar concentrations for 3 days at 20°C and 8 days at 4°C; however, after 3 days at 20°C, heparinized samples had significantly higher insulin concentrations (P = .004, P = .03, and P = .03 on consecutive days).
Conclusions and clinical importance: These results suggest an ideal protocol to determine insulin concentrations involves using serum or heparinized samples with analysis occurring within 3 days at 20°C or 8 days at 4°C.
 
20°C=68°F
4°C=39.2°F
--

Thanks,
Sherry and Scutch (and Scarlet over the bridge)
EC Primary Response

PA 2014

https://ecir.groups.io/g/CaseHistory/files/Sherry%20and%20Scutch_Scarlet/Scutch%20Case%20History.pdf

https://ecir.groups.io/g/CaseHistory/album?id=78891

 


riggslippert@...
 

Thank you, Dr. Kellon, for highlighting this study.  I find it interesting in light of multiple paired results on my horses in which the EDTA samples (run at Cornell) were consistently higher than the serum samples (run at Idexx).  I'm not sure if the same types of assays (RIA vs CLIA) are used in both labs.  Do you have any idea why Cornell continues to indicate that either sample type can be used for the insulin assay?  Has anyone run paired samples (EDTA and serum) at Cornell?  It was also surprising how stable the serum samples were, in spite of the delay in separating them.
--
Aunna
October 2018
Oakland County, Michigan, USA
Cadet Case History:  https://ecir.groups.io/g/CaseHistory/files/Aunna%20and%20Cadet
Ruger Case History:  https://ecir.groups.io/g/CaseHistory/files/Aunna%20and%20Ruger

Cadet Photo Album:  https://ecir.groups.io/g/CaseHistory/album?id=84102




Kim Rice <kimberztaz@...>
 

That is a very interesting result.  Thank you Dr. Kellon.
--
Kim R, Lafayette, CA  2019
https://ecir.groups.io/g/CaseHistory/files/Kim%20and%20Shomee


Maria Duran
 

So, Dr. Kellon just to understand, for ACTH is best EDTA tube, then spinned and cooled and for insulin is best to draw blood into a red top tube, cool it and then send it to the lab?

--
María Durán Navarro 
Dec 2017
Madrid (Spain)

Plutón´s Case History
Plutón´s Photo Album
_._,_._,_


Lorna Cane
 

Not Dr. Kellon,Maria, but here is Cornell :

https://www.vet.cornell.edu/animal-health-diagnostic-center/testing/protocols/equine-ppid

  1. EDTA plasma is specifically needed for ACTH testing.  Draw blood into an EDTA collection tube (lavender or purple-top tube). Gently invert the specimen several times to mix blood and anti-coagulant and then chill sample (refrigerator/cooler/etc.).

Scroll down for more,and for Insulin testin protocol....red top.


--

Lorna  in Eastern  Ontario
2002
Check out FAQ : https://www.ecirhorse.org/FAQ.php


Kelli Land
 

Thank you Dr. Kellon.  We will be doing the cornel metabolic panel on him this week.... he is eating better this week now ,,,, and more life to him. I think he maybe have been depressed with his pasture pal passing as well. He has another horse to hang with but this is a youngster and a bit of kid still. I live in an area that it is hard to get appropriate feed. Small community feed stores won't carry more then what they feel will sell.... even with a commitment. I had totally dropped his feed to pellets only ,, no forage due to his dental health and recommendations of our equine dentist. He right now is happy with getting a bit of forage and no Bermuda pellets,, plus  increased his LMF SR low carb....since that is a complete feed. I also added brewers yeast recently as well.  

Finding Teff around my area is near impossible,, however there are some places south of me or north of me to buy if I don't want to travel 2-4 hours to go get it. Feed stores just wont bring it in. Timothy is also hard to find,,, and again I can travel a bit to get it. These are not favorite options since quantity only makes it affordable and reasonable, and I don't have enough storage to put up 80 bales of hay right now, only a few at a time.
I know Teff pellets are made up in Oregon, but again I cant convince any feed store in Cali to even carry the stuff. argg frustrating for sure.

I have been soaking the orchard alfalfa,,,, until we work thru this problem. My memory from last year this time of year after I increased his pergolide to the fall winter dose he did this as well but not as bad and not loosing weight. It seemed to happen very quickly. Such my concern.  I am working on the case paper ,,,, to get uploaded to the site as we speak. It made me feel a bit better when he was eating better over the weekend,,, and he was not dogging about. We actually did a trail ride locally and he was in the lead single footing down the trail with bouncy ears with his gaiting friends in tow.

One product I can get locally is Chaffe hay. The feed store that will carry my LMF feed was sharing info on the product and my needs as I was pushing again for the teff pellets/hay/timothy pellets/cubes. Chaffe promotes the benefits well, but their analysis is hard to put into perspective to what other feeds have to offer. It seems palatable as I tried a sample and he did eat after walking away from it initially. I am reading about it... but I did not see it as one of the approved feeds on the list from the website.

I am also researching the compounded formulas. I get it why prascend is recommended over compounded pergolide. In asking about the compounded formulas,,, I like the mini melt tabs. That has been the hardest part of treating this horse... as we all know hates the taste so I mix it with a bit of pellets before he gets his feed so I see he gets it. however when he wasn't feeling so good I was out of town and the other horse went down so Who know if the was getting it correctly with the house sitter I would hope so.... but...
I found the cost more reasonable with the compounded formula so going to work thru what I have and move to the compounded formula. Crap 3 times amount of medicine for the same cost  no brainer..... I always thought doing the compounded way was not the best but that was early days when it was only liquid and it was harder to manage the liquid formula and shelf stability was short lived. So very excited. In the mean time I am going to try taking  the pills a i have and grind them up to put in a capsule and see if that works better in getting it in his body. 

So again thank you for your direction and ideas ,,, and a great website... I was on it when we started this journey 5 years ago. but had put it away ,,,, maybe a older and wiser has made it stick more in my brain..... It certainly is helping me now.

of course i will keep chugging on his case file,,, and get it uploaded when done... it was a bit daunting when I started it,,, but working thru it... 

thank you 

Kelli Land, RVT

On Monday, October 26, 2020, 08:29:11 AM PDT, Eleanor Kellon, VMD <drkellon@...> wrote:


This study found that insulin testing of samples taken into an EDTA plasma tube (purple top) showed significantly lower levels than serum (red top) or heparin (green top) samples. Best stability when testing is going to be delayed beyond 3 days is heparinized samples.

https://pubmed.ncbi.nlm.nih.gov/31617618/

If you are using Cornell's ACTH/insulin/leptin panel the sample will be EDTA unless the vet also draws a separate serum sample and requests that be used for insulin.

Bottom Line: Use serum or heparin tubes for insulin testing. Varying sample type between tests will not give you accurate results.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001


--

--

Kelli L. in CA 2020


Sherry Morse
 

Hi Kelli,

I would suggest contacting Chaffe hay's manufacturer directly and ask them for the guaranteed analysis including ESC and starch numbers so you know if it's safe to feed to your guy.

As far as the mini-melt tabs.  They are not necessarily the best form of pergolide.  We've had a few members use them with varying levels of success.  Most members prefer to use the capsules which can either be dissolved in water and syringed or put into a treat and fed directly to the horse.  If you're counting on putting the medication into grain and it being eaten there is always a chance that not all of it is going into the horse.





Eleanor Kellon, VMD
 

Maria,

Yes on the tube types. Both should  be spun/separated  before sending and ACTH should be frozen.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001


Maria Duran
 

Thank you Dr. Kellon.

--
María Durán Navarro 
Dec 2017
Madrid (Spain)

Plutón´s Case History
Plutón´s Photo Album
_._,_._,_


Eva
 

LJ - as a former IDEXX manager I would recommend sending both the RTT and GTT with the date, time, name on each tube.  The lab will select the most appropriate sample.  They could even run both if needed.
--
Eva and Anske
October 2017 Corvallis OR
Case History Anske 2009 Friesian Mare https://ecir.groups.io/g/CaseHistory/files/Eva%20and%20Anske


Eleanor Kellon, VMD
 

Aunna,

CLIA is an immunoassay just like RIA but with a different indicator (light emission vs radioactivity).  CLIA is reported to give lower results than RIA https://pubmed.ncbi.nlm.nih.gov/28124389/ . I don't know what assay Idexx uses (have asked but didn't get an answer). That paper is less than a year old so  maybe Cornell hasn't been investigated further yet; don't know but  I'll ask! They use a Millipore human RIA.
--
Eleanor in PA

www.drkellon.com 
EC Owner 2001