C-Peptide

[Injecto]

Hey, what do you people know about C-Peptide results?

I can't seem to find much on the net at all.

For example:

What's the normal range for a Non-Diabetic?

What is "pmol/L"?

What does the result really mean?

etc....

Any help, including links, is very much appreciated.

[cheryl]

I don't know if I can be much help, but I was discussing my issue's to a friend of mine, that has diabetes, I met him in another forum. Well, anyway, we were talking c-peptide, his is .5 so that is 100% type 1, ok, well he said his lab results said on his paper that a normal is 1.1-5, I don't know if that is normal or that is to determine if your officially a type 1 or I am not sure. because my results last year were a 2, so he was shocked, and told me that maybe all the advice and books I am reading is not going to help me......I don't know what to think about the whole situation personally, all I know is that I need to take insulin in order to eat......lol....................but It is nice to know the number to see where you are at.........

cheryl

[soso]

C- peptide is a left-over from insulin production (i think it stands for connecting peptitide) so therefore they can estimate your insulin production capability from the levels of c-pep in the blood..
A mole is an amount of a substance that contains a large number (6 followed by 23 zeros) of molecules or atoms. A picomole is one-trillionth of a mole.
I don't know what the normal levels are per se.. I hae been tested twice and each time it was done on a different scale, however the lab had the normal ranges in brackets so I could see where I was on that scale. The first time I was in the middle and told by my endo that I had a marginal amount of insulin, later I was right at the bottom of the scale (albeit a different scale) 270-1270 and I was 299, I went on to insulin a couple of months later..however, I only use it at meals, so I clearly still have enough of my own to run basel..
ss
edited to say

if c-pep is higher than the normal range this indicates insulin resistence as the pancreas is super producing to try to get the glucose into the cells..If it is low though, it could still be T2 just at a later stage and beta cells dying or worn out. So very low T1 very high T2 as a simple definition.

[cheryl]

Hey soso,

Cool your on here on this one too, if a c-peptide is in what they consider a normal range how does it determine your type 2 if the insulin you do inject your not really that resistant to it.....oh well so confusing to me, I am so wondering why I actually really care because I still will always need insulin but sometimes myself I wonder why if I follow a type 2 diet per say I am requiring less and less insulin myself.....kind of mind boggling, I dropped my doses yet again actually last night now I am down to about 12 units of Lantus and let's just say at the moment 1:20 ratio I am totally confused lol.......but oh well there is no need to worry I guess, I'll just stick with what keeps the numbers either lower or stable lol

Cheryl

[Injecto]

Soso, very interesting indeed.

Here's why I ask. I got my C-Pep result back and I was at 384 pmol/L, and the lab sheet says between 350 - 1500 is "normal". Which of course starts to make you think that, well, I'm I'm normal I must not be diabetic (that, coupled with the fact that my TDD is very very low right now(7-9 Units/day including bolus'), but trust me, if I don't bolus, and on those occasions where I stop the pump, my BGs definately go up. I've shot up to 12s and 15s only after an hour of stopping my pump, so therefore I'm obviously "not" normal i.e. healthy.

[soso]

Injecto
Perhaps we were separated at birth......
Except for the pump bit, I am just the same.... It looks like you are about the same level on the c-pep scale as I am(or was)
I use 2 u per meal (novorapid) and eat 16-20 carb that seems to work out very well, often have to eat a bit extra on long hikes, but day to day a ratio of 1/10 works well for me..fbg is usually mid 4's since insulin was 5.8 or more before. If I take more insulin and eat more carbs, it is fine for my 2 hr pp but I can guarantee I will be low at 3 hrs..I do that sometimes anyway, but after the 2 yrs without insulin (and 30g or less carb per day)I am pretty happy with 20g carb per meal now. Do you have to turn your pump on and off a lot? I would love the slow delivery of a pump, but I am self employed so the cost would be prohibitive... my last A1c was 4.9 so I feel pretty safe for now anyway..last time I did a test before insulin I had 25 g carb as whole grain cereal (3/4 cup) and was 13.7 at 75 mins..ouch.
ss

[soso]

Hi Cheryl
I have seen your posts here recently, when I am in lurk mode..lol...

Well, the real fact is, unless you are totally out of c-pep or up over the top of the scale, it doesn't necessarily tell you anything... I suppose it's possible that others with lower levels do fine on it..My dh has explained bell curves and normal ranges to me and while I can see the sense, it doesn't mean if you fall within normal range you have no problem...it might mean that, but it doesn't definately mean that..you only have to look at some of the diagnosis stories to see how different drs interpret test results. my prego sis had a gtt come back as normal (shes had gd before) she got a meter and was 8.2 after a modest meal..is she gd? perhaps not, but that's not a great bg either...more testing will tell..
So, a lower c-pep accompanied by high pp readings and high A1c to me would indicate a slow onset T1 diabetes esp if the person was normal weight and exercised. I have tried a lot of exercise and not seen a big difference in my numbers, whereas you hear T2 say how they adjust diet and get more exercise and wonderful things happen... I feel we have to find our own way and make it work for us, docs sort of just pass through our lives..we have to live it...
ss

[cheryl]

Oh I definately agree with you, I don't think I want to find out anything differently then what I am used to but it would make me understand more of why I fit differently then certain type 1's, I guess right now that is hard to explain, but, if I eat anything and I mean anything and this is the honest truth, that wouldn't be part of a type 2 diet, for example the white bread and other things, my ratio's do not work, I have resistance to my insulin for a day or so, then back down to going low and having to drop my insulin requirements more...........I wish there was an explanation for that, cause I see people dosing for subway and a piece of cake and cookies and hit it right on target, I cannot do that period, I will be off for days............it doesn't make any sense to me......I know I heard a change in diet means less insulin, but when you want to cheat once and actually eat something then I am off for a while not just for that one cheat thing I mean a couple of days and my resistance is awful.....then when I stick with my diet I don't have much resistance at all strange to me I am a little mind boggled but oh well it is just a jealousy thing I guess, cause if I ate a tv dinner or anything processed my sugars are awful, but I can eat more carbs like oatmeal with fruit and be perfect really strange to me......but I guess, I just won't cheat anymore lol...........

Cheryl

[kgm0612]

Here's a link explaining C-Peptide from Web MD. Go to page #2 for an explanation of values.

C-Peptide (http://diabetes.webmd.com/C-Peptide)


Karen

[soso]

Thanks Karen, that's interesting...I had never read about the c-pep stimulation test before...that sounds like a good test for those of us still wondering...how to get the health service to agree to it though....hmmmm.
ss

[Injecto]

Thanks for the link Karen. I'm just confused by my result. I'm in the "normal" range so when the link discusses "low" Cpep with high BG as being Type 1, do they mean low as in lower then the normal range, or is my level considered low too?

[lilituc]

Thanks for the link Karen. I'm just confused by my result. I'm in the "normal" range so when the link discusses "low" Cpep with high BG as being Type 1, do they mean low as in lower then the normal range, or is my level considered low too?

Injecto, my c-peptide was previously in the "normal" range, but I'm still a Type 1. I have LADA, though. If you're still making insulin way after diagnosis, it's possible that you have it. Eventually the ability to produce insulin goes away.

IOH latent autoimmune diabetes (lada) diagnosis chart (http://www.isletsofhope.com/diabetes/symptoms/lada_chart_1.html)

The other possibility I can think of is MODY, which is a genetic form of diabetes.

IOH Symptoms, Information Maturity Onset Diabetes of the Young (MODY) (http://www.isletsofhope.com/diabetes/symptoms/maturity_onset_diabetes_mody_1.html)

[poodlebone]

I had a c-peptide test run a little less than 2 years ago. My CDE ordered it, I think because she didn't believe I was Type 1 as I was very overweight at the time.

I don't know what my result wasm - she told me but I had never heard of the test before so it didn't mean much. She also ordered the antibody test. I asked her what the results meant and she said it meant I had a huge number of antibodies, made absolutely no insulin, and was definitely Type 1.

[June91]

I've been wondering about C-peptide in Type 1 in general... It does definitely prove that no natural insulin is present. But that does not necessarily mean that:

a) The beta cells are dead - they could be malfunctioning or unresponsive, much like a broken thermostat;

b) That beta cells are even malfunctioning - it could be that the insulin they produce is immediately recognized as a foreign body (for example due to a fault in the immune system) and destroyed.

Hopefully someone with a better knowledge of chemistry can clarify this, but I think there's still no method to prove any of the above for certain.