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C-Peptide testing. Should I stop meds B4 test?

miahara

Well-Known Member
Messages
1,019
Location
Tayside
Type of diabetes
Type 3c
Treatment type
Insulin
I’m shortly having a C-Peptide test as I’ve queried my T2 diagnosis and suspect I may be LADA or T1.

I’m currently taking gliclazide, a sulphonylurea which as far as I understand, pushes my pancreas into producing insulin. Now, to my non-medical mind if the test is to accurately assess insulin production it ought to be done without any artificial boost by the gliclazide and I ought to stop the medication a day or so before the test. I queried this with my GP and she said to keep taking the medication. I think she’s wrong.

What are your views?

I was diagnosed T2 three years ago (an underweight diabetic) and at first the gliclazide, and LCHF had a significant impact on my BG and HbA1c, and at one stage I was considered as being in remission with HbA1c 46mmol/l in January this year. However over the year my HbA1c levels have risen considerably and my last test it was 61 mmol/l (7.7 %) and going by my own finger prick tests over the past few months my next test will produce a much higher result. I rather suspect that my pancreas has been pushed to exhaustion by the medication.
 
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Hi @miahara, If you type "C-peptide test "into the search box upper right on diabetes.co.uk Home screen information on the C-peptide test appears.
It mentions that the person being tested is likely to be asked to stop their oral diabetes medication prior to the test so you are right to be questioning about this in your case. Injected insulin does not contain C-peptide so does not interfere with the test result.
It also mentions a fast for 8 to 10 hours before the test. And that occasionally a 24 hour urine collection is used to test for C-peptide. Sometimes to stimulate the pancreas gland to release insulin, an injection of glucagon is used.
At labtestsonline.au - it points out that liver and kidney problems may influence the test result.
Best Wishes on the test helping to find out what your diabetes diagnosis/category is !
 
In your shoes I would want to get specialist assistance by a real low carb Doctor, as I think gliclazide over works the pancreas, yours may need a rest.

I can't diagnose, but I can say what I would do in your place. I would go low Keto and OMAD. My rationale would be to rest the pancreas in 2 ways - 1 hit a day and time. If this worked I would then do 3 day fasting once a month to rejuvenate cells and encourage repair.
 
It depends on the questions being asked.

For example if you keep taking the drugs, the test will show if need insulin as well or instead of the drugs you are on at present. A low result would point towards inslin being a good option, a very high result could point towards drugs that reduce inslin resistance.
 
I can only talk from a T1 perspective but I have to fast for 12 hours prior to the rest, but take any fast acting and hold off taking the slow release too.

Have they done blood tests for antibodies?
 
Hi. I can't remember if I stopped my Met & Glic before my C-peptide test but it probably wouldn't do any harm to stop it for day or so just before and then re-start afterwards. As others have said you can have the test when taking insulin. Taking the Gliclazide might skew the results slightly as it prods the pancreas to produce more insulin. When I had my test I was on 320mg Glic and it no longer worked so had probably burned out my pancreas anyway! Ref anti-body tests they can be useful but a negative result doesn't mean not T1 as there are various causes for beta cell failure such as viruses.
 
Circuspony said:
I can only talk from a T1 perspective but I have to fast for 12 hours prior to the rest, but take any fast acting and hold off taking the slow release too.

Have they done blood tests for antibodies?
Click to expand...
Why do you have to fast ive never been told to do this
 
Question ....

Gliclazide makes the pancreas secrete more insulin, but does this happen continuously all day, or only after we have eaten? In other words, does it work to increase our natural basal insulin or not?

If not, then fasting for lots of hours before the test should mean the Glic isn't doing any work at that time.

Probably a very stupid question.
 
Hi
I also have doubt LADA I have to do the test C-peptide
Because I find a big problem in controlling my blood sugar Especially when eating bread my body completely fails but When I eat 25 grams of white sugar I do not find a problem
I seem to be a diabetic patient [hyperInterest] I am sorry to use this term probably not in English
 


This type of medicine works for up to a week
But it seems to burn the remaining cells of the pancreas
 
Gliclazide has 2 main modes of action
gliclazide has several modes of action affecting first and seond phase insulin production, peripheral insulin sensitivity and hepatic glucose production / release
https://www.ncbi.nlm.nih.gov/pubmed/1794262
http://www.japsonline.com/admin/php/uploads/253_pdf.pdf
 
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HICHAM_T2 said:
Because I find a big problem in controlling my blood sugar Especially when eating bread my body completely fails but When I eat 25 grams of white sugar I do not find a problem
Click to expand...

Why do you think this could mean you are a LADA? If you are LADA you would almost certainly react to the sugar.
 
HICHAM_T2 said:
This type of medicine works for up to a week
But it seems to burn the remaining cells of the pancreas
Click to expand...
In terms of long term use, Ive been on it for 22years without any problems
In terms of individual doses, the half life of gliclazide is around 11 hours with the peak effect of the drug being at 4-9 hours after ingestion
 

Am I reading it correctly that it mostly stimulates the pancreas to produce insulin after eating. (first and second phases) The other bits and bobs are by-products for want of a better description? (Or perhaps I need a glass of wine. ) If that is the case, then if there is no food taken, it won't be stimulating the pancreas and is therefore OK to take before a test??
 
Not really sure - If i still drank, Id join you with the vino!
 
HICHAM_T2 said:
I often do not like things that do not seem logical but I will say
You may be lucky who knows
Click to expand...
My medics agree that I am not typical of people diagnosed as T2
 
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