Insulin resistanceTest?

[mrburden]

Hi,

I have been offered the possablility of a pancreas only transplant, having been taken off the SKP transplant list because my kidney output is now steady at about 38% for the last 2 years or so. However, the surgeon thinks that I may be "insulin resistant". This is because I take a higher than expected amount of insulin for my weight (a total of 168 units a day basal/bolas for 88kg).Although my diabetes consultant says that he is happy for me to have theop he can't understand what test the transplant team want him to perform to give a yes or no result. If I am resistant they are less likely to perform the transplant as there is more chance of a new pancreas overworking and then failing.
While I understand the idea of being insulin resistant, has anyone had a test to prove the fact or what level of resistance you have? What is the test called?
Thanks in advance,
MB :?

 

[viviennem]

Does he mean you should have an Oral Glucose Tolerance Test? I don't know how they could give this to a Type !. I suggest your doctor gets in touch with the consultant.

Viv 8)

 

[ebony321]

i thought insulin resistance was tested by using a glucose tolerance test but also comparing the amount of insulin along with the high glucose level? If your insulin resistant there would be ALOT more insulin than in someone who isn't insulin resistant because you need more insulin to tackle the glucose?

But being type 1 the insulin isn't released it's injected, and they already know how much insulin covers your glucose because you control your diabetes that way, by knowing how much insulin to give.

So if i am correct in how i think insulin resistance is looked at then it's completely pointless to do this for a type 1?

 

[viviennem]

In fact, following on from Ebony's comments, if your present pancreas is producing no insulin, I don't see how they could test you for insulin resistance until you've had your transplant.

Do you think you use an excessive amount of insulin at present, in comparison to what you eat?

The transplant surgeon should discuss this with a diabetic consultant, I think.

Viv 8)

 

[Patch]

There is a test - called the C-Peptide Test:

http://www.labtestsonline.org/understan ... /test.html

It won't actually measure your level of insulin resistance, but it will give you results that you can combine with any type of BG test to conclude your level of insulin resistance.

It's a bit like algebra - if you know how much insulin you're producing, and how high your BG is going, you can crudely calculate your level of insulin resistance...

I asked my GP about a C-Peptide test and he'd never even heard of it! :x

 

[ebony321]

There is a test - called the C-Peptide Test:

http://www.labtestsonline.org/understan ... /test.html

It won't actually measure your level of insulin resistance, but it will give you results that you can combine with any type of BG test to conclude your level of insulin resistance.

It's a bit like algebra - if you know how much insulin you're producing, and how high your BG is going, you can crudely calculate your level of insulin resistance...

I asked my GP about a C-Peptide test and he'd never even heard of it! :x

This is what i don't understand, As he is type 1 there will be little or no insulin produced so the test won't be useful for insulin resistance..

as the C-peptide test will show if any insulin is being produced, when insulin is being used artificially won't this interfere with the results?

i keep checking this post as i really want to know the answer as i feel slightly confused by what i think i know but i'm not sure :?

 

[Patch]

A C-Peptide test would be useful to a T1 - T1's can ALSO develop T2 (called Double Diabetes), where the patient becomes resistant to the insulin they are injecting.

I can't see that a pancreas transplant would be much use to someone with a high level of insulin resistance - so what if the pancreas isproducing insulin, but the body can't transport it into the cells due to insulin resistance?

Result = Weight gain.

 

[ebony321]

I still don't quite understand it..

I understand insulin resistance can be with any type of diabetes, but i don't understand why a c-peptide test is useful for type 1's as you already know how much insulin is required to control blood glucose levels as your injecting it?

I also think there is some sort of formula to work out what you insulin dose should be based on size and weight? i think i've read it here before...

Wouldn't the pancreas transplant be useful to get rid of the need for insulin therapy and then just treat the insulin resistance with oral medication?

Or is the issue that the insulin resistance would put the pancreas under pressure resulting in high chance of the transplant failing?

so many questionnnssss

 

[phoenix]

There are direct tests of insulin sentitivity/resistance. These are used in research but I've never heard of anyone having them because they're expensive and not normally justified.
They must be available in the UK because there are research projects that use them.
There are other indirect methods, most of which I don't think would really work with T1.
http://www.endotext.org/diabetes/diabet ... tes12.html

I agree your diabetes consultant needs to ask what test , presumably they have something in mind

 

[mrburden]

There is a test - called the C-Peptide Test:

http://www.labtestsonline.org/understan ... /test.html

It won't actually measure your level of insulin resistance, but it will give you results that you can combine with any type of BG test to conclude your level of insulin resistance.

It's a bit like algebra - if you know how much insulin you're producing, and how high your BG is going, you can crudely calculate your level of insulin resistance...

I asked my GP about a C-Peptide test and he'd never even heard of it! :x

This is what i don't understand, As he is type 1 there will be little or no insulin produced so the test won't be useful for insulin resistance..

as the C-peptide test will show if any insulin is being produced, when insulin is being used artificially won't this interfere with the results?

i keep checking this post as i really want to know the answer as i feel slightly confused by what i think i know but i'm not sure :?

Thanks for the replies. Although I have quoted the above, all of the replies cover exactly what my consultant has said to me. The C-Peptide test will only show that there is a level of insulin in my blood because I put it there and I can control the results of that test be how much I inject.
For other reasons I have been keeping a food diary over the last 6 weeks and I can see that I do use more insulin than other people compared to my overall carb intake. I have worked out that I need a ratio of about 2.25 units of bolus for each carb portion, as well as 112 units of basal each day. However, I still get some random BS readings of 12 or more.That alone suggests that there may be some resistance occurring. But as has been pointed out, the only way to know what level of resistance I have would be after a transplant. There is a chance that they want me to be admitted to have IV glucose & insulin to establish an exact ratio but, as my consultant says, it will not be much more accurate than the figures I have already worked out myself.
He is now talking to the transplant team and, hopefully, they may be able to decide how they want to play it. I'll post any info as I find out...

 

[mrburden]

Or is the issue that the insulin resistance would put the pancreas under pressure resulting in high chance of the transplant failing?

so many questionnnssss

Yes that is the transplant team's main worry here.
The other (unconnected) worry is that having just the pancreas rather than a kidney too (the SKP option) may cause the kidneys to go into shock and fail as a result of the op. Then I'd end up needing a kidney from a different donor and twice the problems in regard to the anti-rejection drugs

 

[ebony321]

ah right, so it is very important to look into insulin resistance first.

I would have thought the transplant team would know which route to take to assess all the pro's and con's on just doing the pancreas transplant?

 

[mrburden]

ah right, so it is very important to look into insulin resistance first.

I would have thought the transplant team would know which route to take to assess all the pro's and con's on just doing the pancreas transplant?

Well, I think they know what they want to know (if you follow) but I don't think they know how they will get the answer! They don't seem to be able to tell the consultant exactly what test they need him to perform as they haven't asked for a test by name.
I don't think that the option of a "pancreas only" is a usual choice. My consultant has had patients who have had the SKP or kidney only, but this has caught him out a bit I think.
Maybe others who have had this done could throw some light on the situation...please!

 

[ebony321]

wish i could give you a definate answer

I know there has been one or two members that have had kidney and pancreas transplants as i remember talking in a thread once, but that was a while ago so i'm not sure if those members still visit the forum.

 

[mrburden]

Hi All,
I thought it may interest people to hear an update to this thread.

My diabetes specialist wrote to me and said that, having spoken to some of his colleagues form around the country, none can think of a better way to test for insulin resistance (in a diabetic on insulin injections) than noting the total amount of insulin dose compared to carb intake. But since my level of insulin is obviously quite high (Total of 160+ units per day) a blood test for glucose and C-peptide, straight after breakfast, will be the way ahead. So after that I will know whether I am producing any insulin of my own, thus adding to the already high doses I give myself... yet that still won't be a conclusive answer as to whether I can have a pancreas transplant or not!