Type 2 C peptide test

[Flora123]

I need a test but I haven’t been given any instructions. Anything I should or shouldn’t eat? Or should it be fasted? Anything to make it accurate! Thanks.

 

[TashT1]

I’ve just dropped my test off at the hospital. Likewise I had no instructions & had to phone the diabetes team.

Is it a blood test or urine?

 

[DCUKMod]

@Flora123 - These might be helpful:

https://www.diabetes.co.uk/c-peptid...e test is,whether you have insulin resistance.

https://labtestsonline.org.uk/tests/c-peptide

https://privatebloodtests.co.uk/products/private-blood-test-for-insulin-c-peptide-in-blood

Seems like for a blood test, fasting is consistently required.

For urine:

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

https://www.webmd.com/diabetes/what-is-c-peptide-test#1-4

https://www.nbt.nhs.uk/severn-pathology/requesting/test-information/c-peptide-creatinine-ratio

Seems for a urine test, it's less clear really.

 

[TashT1]

For the urine test I had to
- collect a red top sample bottle
- eat a ‘good’ meal (I just ate slightly more than normal)
- wait 2hrs then do the sample

If you don’t have the red top sample bottle you need to collect one from the hospital/ diabetes team.

 

[Flora123]

I’ve just dropped my test off at the hospital. Likewise I had no instructions & had to phone the diabetes team.

Is it a blood test or urine?

Blood

 

[Daibell]

Hi. C-Peptide blood tests are usually done fasting but not always

 

[Flora123]

Hi. C-Peptide blood tests are usually done fasting but not always

But does it matter either way?

 

[KK123]

But does it matter either way?

Hi Flora, I don't know for sure whether it matters but I was told to fast for mine. They said the reason was that if I had eaten then my body would respond by producing an amount of insulin which would mean the C peptide level would match it, so when they checked the C Peptide level it would be showing 'higher' than normal because of the eaten meal. They wanted to check what my body was producing without a meal, the basal if you like. x

 

[Flora123]

Hi Flora, I don't know for sure whether it matters but I was told to fast for mine. They said the reason was that if I had eaten then my body would respond by producing an amount of insulin which would mean the C peptide level would match it, so when they checked the C Peptide level it would be showing 'higher' than normal because of the eaten meal. They wanted to check what my body was producing without a meal, the basal if you like. x

Thank you. Oh dear. Having a meal with a couple of glasses of wine. Will the wine make a difference? Maybe I should postpone my test...

 

[KK123]

Thank you. Oh dear. Having a meal with a couple of glasses of wine. Will the wine make a difference? Maybe I should postpone my test...

That made me smile, to be honest if they haven't been absolutely clear or TOLD you to fast then you can probably assume that it's not a fasting one. They usually make it quite clear about the fasting otherwise it's a wasted test. x

 

[Jam&Scones]

When I had mine both done I was not told to fast, but now I know more about this next time I am going to double-confirm with the doctor. I would suggest taking note of what you ate and when at least for 24 hours - in that way you can view the results based on the time the test was taken and check with the Doctor when the results come back.

 

[ert]

But does it matter either way?

I had a fasting one, and one where I drank a bottle of Lucozade before the test. I produced the same amount of insulin for both tests, which meant my BS's went above 30 mmol/L on the non-fasting. I had no phase 1 insulin response.