I have a question about C-peptide level


I am happy i could join this group! :)

i am T2 (well diagnosed as non insulin dependant diabetic) and i have had my C-peptide also tested just recently. I can only go with my results to the doctor in October…and what i am wondering, if my C-peptide is too low? I am on oral medication now. Thank you for your reply

my fasting BG is now 96 mg/dl
insuline: 2,43 mIU/l
Hemoglobine A1c%: 3,86 %
C-peptide: 0,71 ng/ml (there is a "-" between it and written that the reference would be between: 0,78-5,19)

I'm assuming you mean .71? That is low, but it isn't a matter of "too low" or "just right" it is a matter of what it means diagnostically. That low a c-peptide is often more indicative of Type 1 than Type 2. Have you had antibody testing?

I'm a bit puzzled by the commas in your results. Are you saying your A1C is 3.86?? that doesn't make much sense and you wouldn't be diagnosed as diabetic with a number that low.

Hi Zoe,

thank you for your reply!
Yeah, it means .71 (i am in Europe and we have it here on the paper written 0,71 )

Yeah my A1C is now 3.86% but before i also had once 4.1%. I do not know why is it so low..
Well i was diagnosed diabetic when my fasting BG was 126.54 mg/dl and i also had before OGTT test and then i had 216 mg/dl after drinking the 75 gramm "sugar drink". Well actually on my paper is only written "non insulin dependant diabetes" so maybe i am not totally diagnosed yet T1 or T2, i got this diagnostic only this May. (before i had IGT).

No, i never had antibody testing. They do it if a c-peptide is low?

No, antibody testing is done if there is a question if the person is Type 1 or Type 2. C-peptide is also used to determine Type and as I said one that low is often indicative of Type 1. But only antibody testing is definitive. With an A1C that low I'm not even sure why you are taking medication. I would think diet and exercise would be sufficient. Are you overweight? Unless you are Type 1, then it is a whole different story.

Thank you for the information about the antibody testing! :)
I also wonder about my medicaction, i hope that my doctor will tell me that i do not need it anymore. I think i had to start taking it because on my OGTT test also my insuline levels were very high, i was checked 5 tiimes in every 30 minutes, and they kept rising all the time by 50 mIU/l and so by the 120 minutes i had a level of insuline 200 mIU/l with still higher BG level.
No, i am not overweight, and another problem of mine is that i can not gain weight, 1 year ago i was like 117 pounds, now i am 99 pounds and my BMI is 16

Do you have any other autoimmune diseases, like thyroid?

I have ypothyroidism (but not Hashimoto), was diagnosed last December and have been taking for it also medication. Actually with this problem i think i should gain weight, but i was never overweight. But i have hair loss and i am often tired so i guess that is causing it.
And i also have PCOs.

Ok, my strong guess then is that you are Type 1. Type 1 is an autoimmune condition, and people with one autoimmune condition often have others. Also you are thin. And your c-peptide is quite low. I would request your doctor to do antibody testing. You might have to push for it. Many doctors don't think adults get Type 1. They are wrong. It's really important you get the correct diagnosis and treatment. You seem to have caught it early which is good, but if you are Type 1, oral meds are a waste of time and money.

Thank you for the information.
(I guess if i had family member my grandpa on my mother`s side T1 then it is also a factor to make it more possible?).
I will request for this antibody test at my next doctor appointment in October or do it at a private lab.
So T1 can also develope slower? (like in my case).

The positive thing since i am doing the treatment (the medicine, diet and exercise) is that my terrible migraine i had for like nearly 7 years (like every week at least one time) has almost gone, i get it like every 1,5 months or so but that is all. I also heard that my high insuline level could also have caused that.

Thank you again for your helpful informations! :)

Yes, family members are also a factor. And yes, Type 1 can develop slowly, it's called LADA, Latent autoimmune diabetes in adults. I was misdiagnosed type 2 and did fine on oral meds for 15 months until my blood sugars started to rise and I figured out I was type 1. Some people go longer than that.

I was diagnosed as a "type 2" diabetic with a similar c peptide and a fasting blood sugar of 126 as well. I was rediagnosed as type 1 (LADA) and put on insulin 14 months later.

I will read now on the internet about LADA, thank you for pointing this out Zoe. I am sorry you were misdiagnosed first :(

Thank you for the reply LiL MaMa!
Then maybe i am in the same shoes as you, though my fasting BG was now lower (96), but i had before fasting 126.54 mg/dl and also a few months ago 120.6 mg/dl and 115.2 mg/dl (but that time my c-peptide level and insuline level were not tested)