endo visit today..and question about c-peptide

[rak1978]

For those of you who have been tolerant enough to read all of my confused posts about diabetes types, thanks!
I got some test results back today and I am no longer confused...hurray! I told the Dr. that for my own sanity, I needed to be told exactly what type I am if possible so that I can move on past this confused state of being. (poor guy...he's very patient with me) He said that I'm type 1. A little background...previously he has told me that I'm a little bit of a mix of both types, based on the fact that I have some insulin resistance, hence the 1.5 classification. I'm gonna stick with the 1.5 now that I understand more what is going on with my body.Here are my results...

Islet cell antibody: neg
GAD65 antibody: 33.2 (ref range 0.0-5.0)
C-peptide: .18 (ref range .81-3.85, fasting)
A1c: 7.0

My question is this...he said that he does not often run the cpetide test anymore and that it is pretty insignificant. He said that since I am on insulin, the results may be skewed. Is this true? He said that the only way to get a true picture of how much insulin one is actually making is to go off of insulin for a full 24 hrs and then run a fasting test. Obviously, this can't be done in someone who is insulin dependent. Anybody have any insight on this?

Thanks for reading!
Rachel

[Ategeler]

I have heard this too. Although,keep in mind a C peptide can differentiate b/w the insilin your body makes and the insulin you inject. The skewing comes in where the injected insulin can offset your body's need to produce insulin since you are aiding it from an outside source. Therefore, you might not get a true result of how much your body can actually produce. It won't produce as much as it potentially could b/c it doesn't think it has to. I know there are some others that could explain it better...I hope this helps a bit.

[rak1978]

I have heard this too. Although,keep in mind a C peptide can differentiate b/w the insilin your body makes and the insulin you inject. The skewing comes in where the injected insulin can offset your body's need to produce insulin since you are aiding it from an outside source. Therefore, you might not get a true result of how much your body can actually produce. It won't produce as much as it potentially could b/c it doesn't think it has to. I know there are some others that could explain it better...I hope this helps a bit.

Yes, that is what he said...you said it better. Thanks!
So, can anything really be concluded from my low result since I am on insulin already?
Just trying to figure out how to interpret these results.

[foxl]

Probably not. The exogenous insulin would suppress your production unless you went off it ... hopefully you still have more potential production than that ... and I figure with your nice A1c, you do.

[rak1978]

Probably not. The exogenous insulin would suppress your production unless you went off it ... hopefully you still have more potential production than that ... and I figure with your nice A1c, you do.

Hi Linda! Well, I wasn't all that impressed with an a1c of 7.
I'd like to be in the low 6's or 5's. Also, I take about 35-40 units of humalog a day on a moderately low carb diet to reach that number. My doc said that my insulin production is not really there.
Oh well! There are much worse problems to have. At least this can be remedied. Thank God for insulin! Insulin is our friend.

Rachel

[foxl]

... and someday it shall be my friend too ...

Rachel, how long have you been pumping?

[butterflykisses]

Personally I think they should do the C-peptide (and antibody tests) at diagnosis. But then what do I know. :cool:

[rak1978]

Personally I think they should do the C-peptide (and antibody tests) at diagnosis. But then what do I know. :cool:

I completely agree, although my case was a little tricky upon the initial diagnosis. I was newly pregnant, so while prenant I was treated as having gestational (did I mention that I had sugar in my urine on three seperate dr visits prior to becoming pregnant?!),then when I delivered and still had diabetes, they said probably type 2, then further tests revealed that I was actually 1 or 1.5. A firm, concrete diagnosis has been a long time coming. It wouldve been good even to have an a1c done at the initial diagnosis. But, I agree with you!

[rak1978]

... and someday it shall be my friend too ...

Rachel, how long have you been pumping?

it'll be two years in Oct. I was on mdi for three years before that.

[lorilei]

k...rak...i think your cpeptide may be confusing, but your gad is firm...you have high antibodies..but we will be pump buddies, no?

[rak1978]

k...rak...i think your cpeptide may be confusing, but your gad is firm...you have high antibodies..but we will be pump buddies, no?

the c-peptide, while skewed, still gave me some sort of mental confirmation. it was good for me to see the numbers on a paper. when are you going to take the plunge with the pump?
don't be scared :).

[Ategeler]

I agree with testing antibodies/cpeptide at diagnosis. I am just now getting these tests done and have known about type 1 for almost 3 years. Seems crazy to me!

rak1978- I am much like you in that I was misdiagnosed as GD during pregnancy until someone decided to test for GAD and came up positive. I think there are a lot more people like us out there than docs even realize!

[foxl]

But not C-pep at diagnosis if you are DKA, because glocotoxicosis will give you a false low .... :)

And after a DKA episode, beta cell function may return, gradually, up to 6 months later!