C peptide interpretation

I don’t know much about c peptide results myself, however a bit more information might be helpful to those that know more than me. Firstly what unit of measurement is your c peptide result quoted as? Also a little background as to why your c peptide has been tested. Have you had symptoms of diabetes? Have you had a high HbA1c result indicating that you are diabetic?

Last Resort said:

Hi,

Can someone help me to interpret my test results please?

C peptide is 1105

I don't know the levels of this result as I wasn't told. Does it mean I am type 2?

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The result appears to be pmol/L. due to its magnitude. The results supports you are producing enormous amounts of extra insulin and type 2.
https://www.exeterlaboratory.com/test/c-peptide-plasma/
What was the reasoning behind obtaining a c-peptide test?

rosemaree said:

Hey @Last Resort, when and what did you eat before the blood test? And do you know what your blood glucose level at the time was?

My c-peptide was normal/low according to the standard values, but it also wasn't fasting and my blood sugar was at 20 mmol, so it has been hard to get a proper answer about it. I had antibodies though so was diagnosed LADA. There really are so many other factors at play, it is possible for a type 2 to have diminished c-peptide but that is usually after some years of having diabetes/being uncontrolled.

You'll need to get a proper diagnosis / interpretation of your results from a doctor, but from what I understand of the info you have shared you seem to have a slightly low c-peptide!

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The levels are really high. Don't get the ranges given by the laboratory with the cut off for diagnosis. These ranges are just the levels the laboratory can detect.

Last Resort said:

Hi,

Fasting levels are 260-1270
After meal levels are 3000-9000

Mine blood test wasn't done fasting.

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These are not normal ranges, it's just the levels the laboratory can detect. Non-fasting above 250 pmol/l supports type 2. Your levels were 1105 which are really, really abnormally high.

https://www.exeterlaboratory.com/test/c-peptide-plasma/

It would be helpful if you can confirm the units. I suggest you speak to a medical professional.

rosemaree said:

Hey @ert what do you mean by these are just the levels the labs can detect?

The range they gave - Fasting levels 260-1270, After meal levels 3000-9000 - can be found as reference ranges for pmol/l, and if their test came back as 1105 not fasting, that would indicate their levels are lower than the given range.

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You misunderstand the diagnosis process. It's listed here in from Exeter University below. My c-peptide as a type 1 is 60 pmol/l. Levels as high as 3000 pmol/l are extremely high. The laboratories differ in their sensitivity test ranges for c-peptide but it's not a diagnosis. The cut off is 200 pmol/l for a c-peptide test for severe insulin deficiency on a simulated test. The issue is that some laboratories can't test for type 1's as their test ranges aren't sensitive enough. That's the problem with buying a random c-peptide test and not going through a specialist diabetes consultant.
https://www.exeterlaboratory.com/test/c-peptide-plasma/

Here is a good calculator to change between the units;
https://unitslab.com/node/111

I find it very irritating that they use different pmol nmol ‘s I still don’t know what my test result used, why if it went to Exeter would they use different methods of describing the same thing?

Can I please remind you all that forum rules specifically state that we can't diagnose on the forums, and this thread seems to be a good example of why this is the case.

Yes, a high cpeptide generally goes with T2 and a low one with T1, but the units and reference ranges seem to vary with the labs, and though @Last Resort has said he wasn't fasting, he hasn't said exactly when the test was in relation to a meal...
Plus T2s can have low cpeptide after many years because their pancreases are exhausted, and I'm guessing, if it's not fasting, the cpeptide will also vary a bit by diet. And there are other types of diabetes than T1 and T2: MODY, T3c etc etc.

He needs to take the test result to a doctor (if it was a private one) or wait for the doctor's analysis, if it was a public one. ) He hasn't even stated whether her blood sugars are high yet...

@Last Resort , do you have a recent hba1c to go with that cpeptide test? My understanding (disclaimer I am not a doctor) is that a cpeptide result is just part of the diagnostic process. (Though as a long term T1 I am pretty confident that mine is 0 and I would be dead without my best friend insulin. )

EllieM said:

(Though as a long term T1 I am pretty confident that mine is 0 and I would be dead without my best friend insulin. )

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You should move back to the UK Ellie, we get our own meds here, no need to borrow from our friends.






I’ll get my coat

Fenn said:

I find it very irritating that they use different pmol nmol ‘s I still don’t know what my test result used, why if it went to Exeter would they use different methods of describing the same thing?

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It's a general interpretation of c-peptide results listed through the Exeter link I posted. (It's not just other laboratory with different results.) Exeter University conducted the MODY trials and genetic testing for diabetes, and the of type 1's back to type 2 based on c-peptide results using these general results in the link. These cut offs are what my specialist team used to diagnose me using a c-peptide test. This is why it's important to involve a medical professional.