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Type 2 Fasting Insulin Levels

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Vagabond2020

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Location
Brooklyn, NYC
Type of diabetes
Type 2
Treatment type
Diet only
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Liars, cheats, bad hygiene
Have you ever had your fasting insulin levels tested? I think most physicians and endos overlook it, even thought it is just as important or even more so than fasting glucose? It tells you exactly how insulin resistant you are.
 
Yes I had mine tested about a year ago. Invaluable information. For the most part, HCPs are oblivious to its importance.
 
Antje77 said:
Why would testing insulin be better than the more usual C-peptide?
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I think c-peptide is better for getting an idea of reactions to food, but fasting insulin is more appropriate for measuring a baseline of overall metabolic health and for calculating HOMA-IR insulin resistance (along with a corresponding blood glucose measure). That is my understanding at least. I believe that fasting insulin is more suitable for type 2, where the aetiology is typically hyperinsulinemia. High circulating insulin after fasting overnight means you're in bad shape.
 
Vagabond2020 said:
My endo told me that c-peptide is important in diagnosing and evaluating T1, but not T2
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Wouldn't it be a good test to do before putting a T2 onto insulin? It would indicate whether you need extra insulin because of insulin resistance or because your body's insulin production is failing???
 
EllieM said:
Wouldn't it be a good test to do before putting a T2 onto insulin? It would indicate whether you need extra insulin because of insulin resistance or because your body's insulin production is failing???
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Absolutely but try and get any NHS doctor to test it is virtually impossible unless T1 isa real possibility. In my opinion it's why there are so many misdiagnoses of T1/LADA/MODY as T2..
 
EllieM said:
Wouldn't it be a good test to do before putting a T2 onto insulin? It would indicate whether you need extra insulin because of insulin resistance or because your body's insulin production is failing???
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Debatable perhaps. A low fasting insulin played against a high fasting glucose indicates an insulin deficiency. But the majority of T2 are likely to have high fasting insulin and high fasting glucose. Particularly those recently diagnosed. If the HOMA-IR indicates resistance (hyperinsulinemia) then the correct course of action is (should be) to reduce circulating insulin with diet. Adding more is not the correct way to manage insulin resistance. It will only make it exponentially worse.
 
It's been a while since I read up about this, so I may be completely wrong. But from what I understood, C-peptide is produced whenever insulin is produced (or is a result of producing insulin or such, anyway, they go together). C-peptide has a longer lifetime so it's more accurate than insulin level. I'm talking C-peptide from a blood test of course, not the 24 hour urine one.
I may try to find some literature to back up (or burn) my rather vague memories tomorrow.

I only asked because I wondered why people would value an insulin test as more useful than a venous C-peptide, going with what I remembered from what I've read about it. It's one of those thing that left me vaguely wondering what it's about whenever someone mentions an insulin test on the forum, this seemed a good thread to ask
 
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Perhaps they just meant the same thing?
 
I think C-peptide may be slightly more 'elastic'. Perhaps lag may be a factor, with CP lingering after the fact, and thus skewing measurements by not representing actual insulin vs. glucose in that precise moment? It's an indirect measurement. I imagine that to meaningfully and accurately calculate insulin resistance (HOMA-IR) you would need instantaneous and realtime measurement of both glucose and insulin, not a direct measurement of glucose and a laggy, indirect indication of insulin.

That's only my rudimentary understanding based on basic knowledge of the subject. It's an interesting one and I'd be keen to learn more about C-peptide.
 
I've never had a c-peptide test, so don't know what is involved, or how long it takes to come back?

Have had a self-funded fasting insulin test though. Used thriva.com.
My understanding of a fasting insulin test is that it gives a snapshot of my current insulin level - so is v useful to see if my insulin level is high or low after an overnight fast - which then informs me via the HOMA-IR calculation how much insulin resistance I have.

If I were made of money (actually the test isn't that expensive) it would be very interesting to do the test at different times of day and after different carb and non-carb food intake
Good excuse for a donut, eh?
Which would then enable me to learn whether my insulin resistance before and after 'normal' carb intake was the same as someone without my glucose dysregulation.

Yes, it is a very geeky and number crunchy speculation, but it would be brilliant to know exactly what was happening in response to carb intake. The rise and fall of blood glucose only tells a small part of the story, because I could find that my bg levels stay good on carb intake (because I can pump out lots of insulin but it only barely does the job, which means my IR rises). That would suggest that while I have bg under good control, my insulin resistance is still problematic, with the accompanying raised risk of metabolic syndrome and knock on health risks.

Here is a link to a youtube video where Ivor Cummins shows how undetected insulin resistance is the elephant in the room for many health issues we associate with modern life:

 
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Yes, I’ve had fasting insulin tested. My doctor is very obliging and runs it annually with my normal labs.
 
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yes, C-Peptide is a pro-insulin secreted in equimolar amounts as insulin. Insulin, as well know, gets taken up by receptors on the cell, and thus the amount left circulating (what is “left over” or “rejected”) is basically a good measure of how insulin sensitive you are - how many receptors take up the insulin. C-Peptide has a totally different biological function and pathway out of the body, plus as others have stated it degrades at a much slower rate, and therefore it’s considered a good measure of B cell secretion v insulin which measures usage - at that point in time, meaning how much your body is producing to keep BG at whatever level it is at the same time. So, to me, it’s not a matter of which is more useful, but rather of what you want to measure.

Many doctors will run it as an inexpensive test to help determine T1 v T2. My doctor ran mine upon diagnosis. Totally normal, and along with other clinical sign, it pointed to T2 without further expensive tests. She basically said “this means we try Metformin, diet and exercise and if those don’t work, then we keep investigating.” They worked (now minus the Met).
 
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Brunneria said:
I've never had a c-peptide test, so don't know what is involved, or how long it takes to come back?
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just a vial of blood, same as regular labs. Results are a quick - 1 day or longer depending upon typical lab times.
 
Dear Brunneria,
Was grateful to find your link to a question about insulin resistance, in another forum, where you quoted this link
https://www.docmuscles.com/does-long-term-ketosis-cause-insulin-resistance/
Nice reassuring article. But now on this forum page you mention thriva and I can't email them, and can't see an insulin home finger prick test listed at all. Any ideas ?
 

Hi @hooha

I am afraid that my access to Thriva (as a customer) is exactly the same as your access (as a new customer).
As a commercial website they will have a 'contact us' page somewhere on their website, so you could start by contacting them through that.

My own fasting insulin test through them was an add on to a standard package, but I don't remember the details, except that it was very reasonably priced.
 
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