1. Get the Diabetes Forum App for your phone - available on iOS and Android.
    Dismiss Notice
  2. Guest, we'd love to know what you think about the forum! Take the Diabetes Forum Survey 2020 »
    Dismiss Notice
  3. Diabetes Forum should not be used in an emergency and does not replace your healthcare professional relationship. Posts can be seen by the public.
    Dismiss Notice
  4. Guest, stay home, stay safe, save the NHS. Stay up to date with information about keeping yourself and people around you safe here and GOV.UK: Coronavirus (COVID-19). Think you have symptoms? NHS 111 service is available here.
    Dismiss Notice
Dismiss Notice
Find support, ask questions and share your experiences. Join the community »

C peptide test

Discussion in 'Type 1 Diabetes' started by wiserkurtious, Jan 23, 2019.

  1. wiserkurtious

    wiserkurtious Type 1 · Well-Known Member

    Messages:
    368
    Likes Received:
    328
    Trophy Points:
    103
    Hi guys long time no hear :) So I went to see my consultant today and it wen t pretty well.He's put me forward for the 2 week libra trial which I'm over the moon about,also wants me to take a c peptide test through my urine.So here's my problem,I've the instructions on how to do the test but wondering will taking insulin with my morning meal after the result???he didn t mention anything regarding not taking my dose with meal so should I presume that I should go on as normal.and hope you's all been well and had a merry xmas :)))))))))))))))))))
     
  2. db89

    db89 Type 1 · Well-Known Member

    Messages:
    1,138
    Likes Received:
    1,707
    Trophy Points:
    198
    Hi @wiserkurtious, good to hear from you again (and good news about your Libre trial! :)).
    So far as I understand it c-peptide can't be affected by injected insulin as it's a byproduct of natural insulin production from beta cells in the pancreas. It can be either a fasting or non-fasting test, however, so did your consultant tell you which to do?
     
    • Like Like x 2
    • Agree Agree x 1
  3. EllsKBells

    EllsKBells Type 1 · Well-Known Member

    Messages:
    365
    Likes Received:
    320
    Trophy Points:
    123
    Hi @wiserkurtious so this may be a bit more technical than you want, if so apologies. Basically, endogenous insulin (insulin made by the beta cells in the pancreas) doesn't start out as insulin, it starts out as a molecule called preproinsulin, then proinsulin. A series of cleavage steps happens, with bits getting chopped off until you get the final product, insulin. The C-peptide is one of those bits that gets chopped off (from the c terminal end of the protein, hence its name - biologists seem to be selectively imaginative). Injectable (exogenous) insulin doesn't have all these extra bits to be cleaved off, so there will be no c-peptide from it, so the only c-peptide the test will measure is what your own body is (or is not) producing.

    Hope that helps!
     
    • Informative Informative x 4
    • Like Like x 3
    • Agree Agree x 1
  4. wiserkurtious

    wiserkurtious Type 1 · Well-Known Member

    Messages:
    368
    Likes Received:
    328
    Trophy Points:
    103
    **** good information there ty very much
     
  5. wiserkurtious

    wiserkurtious Type 1 · Well-Known Member

    Messages:
    368
    Likes Received:
    328
    Trophy Points:
    103
    told to pee in a pot 2 hours after eating me morning meal the get the pee sample in asap
     
  6. wiserkurtious

    wiserkurtious Type 1 · Well-Known Member

    Messages:
    368
    Likes Received:
    328
    Trophy Points:
    103
    hope you guys are well
     
  7. tim2000s

    tim2000s Type 1 · Expert
    Retired Moderator

    Messages:
    8,914
    Likes Received:
    11,773
    Trophy Points:
    198
    @wiserkurtious I'd add one thing though. WHile it can't be detected in a test, exogenous insulin does reduce the amount of insulin the body needs to produce, as it reduces glucose levels. If you are doing an unfasted test, I'd expect you to not take insulin to give your body the best possible chance to counter a rising glucose level and produce c-peptides.

    I am aware of a friend who also did a fasted C-Peptide test and he was told to disable his pump and wait for six hours before the test, to give the body a change to react to whatever his glucose level was, as injected insulin inhibits this process.
     
    • Like Like x 1
    • Informative Informative x 1
  8. bulkbiker

    bulkbiker Type 2 · Oracle

    Messages:
    16,379
    Likes Received:
    11,306
    Trophy Points:
    298
  9. slip

    slip Type 1 · Well-Known Member

    Messages:
    3,524
    Likes Received:
    5,385
    Trophy Points:
    198
    @EllsKBells I wanted to press 'informative' and 'winner' at the same time but I don't have 2 mice to click! And @tim2000s as well for his explanation to! Brilliant info.
     
    • Like Like x 1
  10. wiserkurtious

    wiserkurtious Type 1 · Well-Known Member

    Messages:
    368
    Likes Received:
    328
    Trophy Points:
    103
    I wasn t told any of this from my consultant,nurse or the instructions they sent me home with so I'm now hoping that I haven t messed up
     
  • Meet the Community

    Find support, connect with others, ask questions and share your experiences with people with diabetes, their carers and family.

    Did you know: 7 out of 10 people improve their understanding of diabetes within 6 months of being a Diabetes Forum member. Get the Diabetes Forum App and stay connected on iOS and Android

    Grab the app!
  • Tweet with us

  • Like us on Facebook