C Peptide

[ainiabdul]

Since I was diagnosed almost 3 years ago, I have never been tested for C Peptide level. My doctor never told me what type of diabetes I have. As a treatment he put me on insulin right away. When I asked him why this treatment, he told me it was a better option than medication. I was very new to diabetes then and took it the way it was.

Recently as I am learning more about the condition I got to learn about c peptide. So I independently got myself tested for this as I was very curious of my level. The result came back today. Mine is 0.3 and normal level is ranging from 0.5-7.0 (?).

Does anyone here know about this?
What does that mean if I have low level of c peptide? Could I be falling into type 1 category? Should I be taking islet autoantibody test to confirm this?

Thank you!

 

[SB.25]

Hiya, I have had both c peptide and GAD tests done.

I have an appointment next week with my consultant to discuss results but.....

I understand that c peptide is produced at same time as insulin but lasts longer in the body. So it gives a good indicator of how much insulin you are producing naturally. If it’s low, it’s likely you are not producing enough insulin so could suggest type 1. If you are producing lots of c peptide it would suggest you could be type 2 and are ‘insulin resistant’.

The GAD test looks for antibodies associated with ‘killing’ beta cells in the pancreas and therefore if you have these it’s likely type 1. Saying that, I think up to 25% of type 1 do not have these antibodies.

I think most of the time both tests are done together to get better results.

 

[Daibell]

Hi. I agree with @SB.25. Your low c-peptide implies T1 so the GP was probably right to put you on insulin. I was on tablets for years and was refused insulin until my BS went far too high. You are in some ways lucky to have a pro-active GP. The GAD test may or may not be positive and a negative implies nothing as beta cell death can be caused by different antibodies and viruses.

 

[SimonCrox]

Hiya, I have had both c peptide and GAD tests done.

I have an appointment next week with my consultant to discuss results but.....

I understand that c peptide is produced at same time as insulin but lasts longer in the body. So it gives a good indicator of how much insulin you are producing naturally. If it’s low, it’s likely you are not producing enough insulin so could suggest type 1. If you are producing lots of c peptide it would suggest you could be type 2 and are ‘insulin resistant’.

The GAD test looks for antibodies associated with ‘killing’ beta cells in the pancreas and therefore if you have these it’s likely type 1. Saying that, I think up to 25% of type 1 do not have these antibodies.

I think most of the time both tests are done together to get better results.

Totally agree (I would never be patronising). The pancrreatic beta cells make c-peptide and insulin at the same time, so c-peptide is a measure of insulin made by the person, rather than insulin injected. Hence really handy in insulin treated patients, or in hypoglycaemic patients whose hypoglycaemia is not obviously due to anti-diabetic treatment.
Best wishes

 

[ringi]

Regardless of the type of diabetes, slowly reducing card and adjusting the inslin as you go, can show if you need inslin. I expect you have type1 or LADA, but your result of 0.3 shows your body is making a little inslin, someone with fully developed type1 would get a lower result.

 

[SimonCrox]

Regardless of the type of diabetes, slowly reducing card and adjusting the inslin as you go, can show if you need inslin. I expect you have type1 or LADA, but your result of 0.3 shows your body is making a little inslin, someone with fully developed type1 would get a lower result.

It appears that some folk with T1DM do make a bit of insulin for a long time (assuming that the diagnosis of T1DM is correct in this study, which it probably is cos the c-peptides were not in the normal range:-

http://care.diabetesjournals.org/content/diacare/early/2017/06/13/dc16-2121.full.pdf

Guess this is why the antibody tests are also done, but not as straightforward as I thought

best wishes