C peptite

I just had my c peptites testes. The result was 1.1 and the lab considers values 1.1 - ? “normal”. My last test was 5 years ago and it was 0.6. I am confused now, I thought the C peptite helps determine what kind of diabetes you have, a low one type 1 and a high one typ 2. So how do my results “improve” and go from low to normal? Wouldn’t that mean I have no diabetes? I am just wondering if there is an error in the lab…

Hi Christine,
I had 1.45 which was considered on the end of low normal. I’m on a pump and use 50 units a day and 6 foot 1" 180 lbs never more than 10lbs + - with no anti bodies… so it puts me in type 2 per my endo @ Joslin. Go figure… I’ve given up trying to define type 1 or 2. Just working on keeping my A1C under 6.5 if I can do this none of the rest matters. Well maybe ; )

Was it a fasting C-peptide or was it with a glucose challenge?

a fasting C peptite

What type were you diagnosed as? If you are possibly LADA our pancreas tends to work in fits and starts, so you could be having an insulin spurt. Also, perhaps some more tech savy person would know, but I wonder if that is little enough of a difference that it could just be accounted for by different labs?

Zoe, yes I am a LADA .
Dave, thanks for giving me the correct spelling.

Unless you are a type 1, the fasting c-peptide may not tell you much, it really depends on your fasting blood sugar. If your fasting blood sugar is pretty much 80 mg/dl and you are insulin sensitive your basal insulin requirements are probably pretty low and your corresponding c-peptide will come in pretty low even if you are non-diabetic. The c-peptide does tell you something when you have an elevated fasting blood sugar or you measure it with a glucose challenge (the so called stimulated c-peptide). If you are type 1, your c-peptide will likely come in very low (out of reference range) or even zero. Surprisingly, many type 1s still retain some residual insulin production, just far to little to be useful. Your own test pretty much says nothing without knowing the conditions of the test.

If you have a high fasting blood sugar and a low c-peptide, that indicates insulin deficiency.

if you have a high fasting blood sugar and a high c-peptide, that indicates insulin resistance.

If you have a low fasting blood sugar then your c-ceptide probably won’t tell you much.

Even more confusing is that if you are using insulin, your natural insulin production may be suppressed so it may even tell you less than nothing.

ah ok,thanks bsc!:slight_smile: I had a high fasten BC and a c-peptide at the low end of the reference range, that’s what confused me. Last time I also had a high fasten BC and a very low c-peptide that’s why I am really confused. I hope my Endo can explain it at my next visit in 2 month…

The normal range is 1.1 to 5.0 ng/ml according to my last test.
The 1.1 is on the low side of normal.
The govt requires less then 0.7 to pay for pump supplies on medicare.
If you scored a 0.6 a year ago, then you are a type 1. I doubt a type 1 can get better. Probably the Lab made an error after all a nanogram is very small number. The test however should be done while the BG is less then 200 or so since the Glucose possibly throws off the test. I think that the peptide is produce as a byproduct of the production of insulin by the pancreas.