C peptide confusion

[SB.25]

Hello, I now have one of my tests results back (well sort of!). The tests are to ascertain if type 1 or 2.

The c peptide came back at 444 but the blood glucose at the time was 13.5. A note was put on it to say that the peptide was low for the blood glucose, so it has been sent to the lab for other tests (not sure which ones). The doctor said this would indicate type 1 as low peptide indicated type 1 and high indicated type 2.

I’ve tried online to see what the levels should be but I am really struggling to find any information.

I wondered if anyone had any insight into what levels should be at all?

4 other tests are still awaited including islet and GAD (I think).

Thanks for any help in advance!

 

[slip]

Any idea what that 444 measure is using?
Below from https://www.diabetes.co.uk/c-peptide-test.html the normal levels are tiny compared to your score. The only thing I can maybe think of is with BG at 13.5 they would expect the result to be say 1000 ng/ml????!

"C-peptide test results
C-peptide test results are classed within 3 ranges/values.

Normal range

• The normal range for a c-peptide test is: 0.51 to 2.72 nanograms per millilitre (ng/mL)
• This may also be expressed as: 0.17-0.90 nanomoles per litre (nmol/L)

The following information serves only as a guide. Your doctor should be able to advise you as to what the test results may indicate.

Low test result values
Low levels of c-peptide and high blood glucose levels could be an indicator of type 1 diabetes.

Low levels of both c-peptide and blood glucose could indicate liver disease, a severe infection or Addison’s disease.


High test result values
High levels of c-peptide with a low level of blood glucose could be an indication of insulin resistance, either type 2 diabetes or Cushing’s syndrome.

High levels of c-peptide but low blood glucose levels may be a result of insulinoma (a tumour of the pancreas) unless glucose lowering medication has influenced the result."

 

[DCUKMod]

@SB.25 - Do you have a print our of your test result, or access online to your medical records. They would usually quote the lab ranges on there?

There's a page here, on DCUK on the c-peptide testing, but the results seem to be being expressed differently: https://www.diabetes.co.uk/c-peptide-test.html

 

[SB.25]

@SB.25 - Do you have a print our of your test result, or access online to your medical records. They would usually quote the lab ranges on there?

There's a page here, on DCUK on the c-peptide testing, but the results seem to be being expressed differently: https://www.diabetes.co.uk/c-peptide-test.html

Hello,

No I don’t have the print out. I also found that the numbering system was different on everywhere I looked.... maybe I will have to go back to the docs to ask for a printout... the number I was given was definitely 444 and that’s what it said on the results back from the docs - although it did say ‘low peptide reading for blood glucose’...

 

[SB.25]

Any idea what that 444 measure is using?
Below from https://www.diabetes.co.uk/c-peptide-test.html the normal levels are tiny compared to your score. The only thing I can maybe think of is with BG at 13.5 they would expect the result to be say 1000 ng/ml????!

"C-peptide test results
C-peptide test results are classed within 3 ranges/values.

Normal range

• The normal range for a c-peptide test is: 0.51 to 2.72 nanograms per millilitre (ng/mL)
• This may also be expressed as: 0.17-0.90 nanomoles per litre (nmol/L)

The following information serves only as a guide. Your doctor should be able to advise you as to what the test results may indicate.

Low test result values
Low levels of c-peptide and high blood glucose levels could be an indicator of type 1 diabetes.

Low levels of both c-peptide and blood glucose could indicate liver disease, a severe infection or Addison’s disease.


High test result values
High levels of c-peptide with a low level of blood glucose could be an indication of insulin resistance, either type 2 diabetes or Cushing’s syndrome.

High levels of c-peptide but low blood glucose levels may be a result of insulinoma (a tumour of the pancreas) unless glucose lowering medication has influenced the result."

Yes that’s what I saw.... I’m not sure what measure they are using but it did have a note to say it was ‘low for blood glucose’.

I’ll have to get the measurements from the docs tomorrow as they don’t post them on the online access...

 

[DCUKMod]

About the only thing I found, referring to the sorts of numbers you have been told are here (only just found it): https://www.exeterlaboratory.com/test/c-peptide-plasma/

Did you just have the one vial of blood taken or did you have a vial taken, then had an injection, then a further vial of blood drawn? There seem to be two ways of doing the test.

I'm neither T1, nor an insulin user, so it's not something I have had to dig into for myself.

I wonder if @Diakat or @Juicyj are around.

 

[Diakat]

Hi @SB.25

When I had a c-peptide done my results were 0. Something so must be different units.
Agree that the low suggests T1.
Sorry not to be more use to you and how all is clarified soon.

 

[Daibell]

Hello,

No I don’t have the print out. I also found that the numbering system was different on everywhere I looked.... maybe I will have to go back to the docs to ask for a printout... the number I was given was definitely 444 and that’s what it said on the results back from the docs - although it did say ‘low peptide reading for blood glucose’...

Hi. Yes, every test lab appears to use a different result range for c-peptide; there isn't any standard. I would find out the range for your specific test and see where you are i.e. at or near the bottom T1 and at or near the top T2.

 

[SB.25]

Hi. Yes, every test lab appears to use a different result range for c-peptide; there isn't any standard. I would find out the range for your specific test and see where you are i.e. at or near the bottom T1 and at or near the top T2.

Hiya,

I got the rest of my anti body tests today which has confirmed it’s not type 1. So now I’m back at square 1....

The next stage they want to investigate is whether I am MODY. Due to the fact I have minimal risk factors for type 2 (being only 26, active, BMI of 21, no other health problems). Alternatively I may just be an odd type 2!

I don’t think at this stage it’s really going to effect my treatment as I already have some nightly slow release insulin.

And so the saga continues.......

 

[Diakat]

Hiya,

I got the rest of my anti body tests today which has confirmed it’s not type 1. So now I’m back at square 1....

The next stage they want to investigate is whether I am MODY. Due to the fact I have minimal risk factors for type 2 (being only 26, active, BMI of 21, no other health problems). Alternatively I may just be an odd type 2!

I don’t think at this stage it’s really going to effect my treatment as I already have some nightly slow release insulin.

And so the saga continues.......

Did they say not type 1? Just because not all T1s test positive for the GAD antibodies...

 

[slip]

oh yeah diakat is correct about 25% of T1s fail the GAD test.

 

[SB.25]

Did they say not type 1? Just because not all T1s test positive for the GAD antibodies...

Hi, they said I don’t have any of the type 1 anti bodies - so they are ruling it out.....

I’m waiting on my consultant to call me back to discuss next steps as it was just my GP who called up with the blood results.

However the GP did seem to think it’s likely MODY....

Very frustrating not having a correct diagnosis, but trying to stay positive...

 

[SB.25]

oh yeah diakat is correct about 25% of T1s fail the GAD test.

Oh I didn’t realise this.....

If this is the case then how else can they diagnose T1?

 

[Diakat]

Oh I didn’t realise this.....

If this is the case then how else can they diagnose T1?

Sometimes it is slight guesswork as they don’t test for all possible antibodies. So things like body type, presentation of symptoms eg quick onset, weight loss, DKA. And how you respond to treatment.

MODY has a genetic test I think, don’t know much about that.

 

[SB.25]

Sometimes it is slight guesswork as they don’t test for all possible antibodies. So things like body type, presentation of symptoms eg quick onset, weight loss, DKA. And how you respond to treatment.

MODY has a genetic test I think, don’t know much about that.

Thanks for the information. I will raise this with the consultant when I have my meeting with him.

Just seems like my diagnosis has been a complete u-turn since yesterday being told it’s likely type 1 to today it defiantly not being type 1 at all!

 

[DCUKMod]

Thanks for the information. I will raise this with the consultant when I have my meeting with him.

Just seems like my diagnosis has been a complete u-turn since yesterday being told it’s likely type 1 to today it defiantly not being type 1 at all!

@SB.25 - I'd probably urge you, as others have also said, not count anything out yet.

Yes, for T1s, and for t2s, there are some classic cases, who make diagnosis easy, but there are also many, many who don't quite tick all the boxes, one way or another, and some who don't appear to tick any diagnostic boxes, yet are what they are (whether T1 or T2).

My only suggestion would be that even if, at some time in the future, it is decreed you are T2, I would be trying very, very hard to keep the relationship with your consultant open, because of the annomolies you see to present with. There are many on her for whom their true diagnosis only becomes clear, some way down the line in both directions. Once a person is decreed T2 and sent back to GP care, they can sometimes find it very hard to be re-referred to specialist diabetes care, which can hamper a formal re-diagnosis.

I'd say that for now, the important things is to get your blood sugars into a safe range where you not in danger due to very high t blood sugars, or wild fluctuations, and can have a quality of life. Aside from all else, that will help you plain old feel better.

 

[SB.25]

@SB.25 - I'd probably urge you, as others have also said, not count anything out yet.

Yes, for T1s, and for t2s, there are some classic cases, who make diagnosis easy, but there are also many, many who don't quite tick all the boxes, one way or another, and some who don't appear to tick any diagnostic boxes, yet are what they are (whether T1 or T2).

My only suggestion would be that even if, at some time in the future, it is decreed you are T2, I would be trying very, very hard to keep the relationship with your consultant open, because of the annomolies you see to present with. There are many on her for whom their true diagnosis only becomes clear, some way down the line in both directions. Once a person is decreed T2 and sent back to GP care, they can sometimes find it very hard to be re-referred to specialist diabetes care, which can hamper a formal re-diagnosis.

I'd say that for now, the important things is to get your blood sugars into a safe range where you not in danger due to very high t blood sugars, or wild fluctuations, and can have a quality of life. Aside from all else, that will help you plain old feel better.

Thank you so much for your kind words and support.

I must say I have been extremely impressed with my care to date from the NHS - including the A&E department I went to after 3 weeks of being dizzy, my GP surgery where I have been seen by 3 doctors and 2 nurses, the consultants who have spoken to me over the phone, the consultant I met in person and the diabetic nurses who have been calling me every now and again just for a catch up. My pharmacist has also been very good including ordering in my type of insulin, giving me a sharps box when the doctor forgot to prescribe one and also chasing up my doctors for prescriptions. I know many people don’t get as much attention as me (bearing in mind I was only diagnosed 1st November) and I am very grateful for all of their care.

The DSN I spoke to today asked me to increase my insulin further to try to get the levels even more under control but they are much better than on my initial diagnosis.

Hopefully when I see my consultant again we can talk further to decide the next plan or action to get to the bottom of the diagnosis.