C peptide result: 1.2 ng/mL

Recent C peptide result came back as 1.2 ng/mL. My Endo, who is new (due to insurance plan), wants to verify with antibody tests. It seems like a reasonable idea. According to the internet, 0.5 - 2 ng/ml is the normal range of c peptides. I am puzzled by my c peptide # of 1.2. Does it mean that I’m ‘normal’? My A1C is 5.8,; am using Dexcom G6.

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The c peptide level is not meaningful without comparing it to your blood sugar at the same moment… if your blood sugar is high and your c peptide is normal or low it can mean insulin deficiency.

If c pep is high and your bg is normal or high it can mean insulin resistance

It becomes even sketchier of a measure when you’re taking exogenous insulin—- which isn’t reflected in your c pep level, but if you’re artificially replacing your bodies insulin with synthetic, the measure of your body’s insulin becomes less meaningful

Highly overrated lab… generally only has value to distinguish between type 1 and type 2 at initial diagnosis… and to determine if type 1 patients have residual insulin production—- which clearly you do

I’d be be willing to bet if you jacked your bg up to 300 and did a c pep lab it wouldn’t change much, when it should be like 15 at that point in a functioning metabolism

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The antibody tests won’t harm anything, and if they weren’t run when you were diagnosed they could be useful to strong arm insurance in case they try to reclassify your diabetes type and coverage.

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My BG at the time of the blood test, fasting, was 98. Dr. said that the injected insulin should not affect c peptide number.
The antibodies test results and c peptide, hopefully, will provide a consistent picture of what’s going on.

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Unfortunately, it won’t

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My c-peptide at diagnosis was 1.1. That simply indicated I was still making some insulin. The antibody tests proved that this was diabetes of autoimmune origin, i.e., Type 1. That’s important for insurance reimbursement of the things that Type 1 folks need but that may be considered by insurance companies to be “mere conveniences not medically necessary” for Type 2 folks.

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Yeah… and with that comes the risk that if no antibody tests come back positive (and they don’t always) and your fasting c pep is “normal” you could be setting yourself up for arguement with a pbm about if insulin is necessary

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That’s a scary thought. Do you recommend to avoid antibody testing?

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No, I’d recommend doing whatever tests a doctor recommends, I’d just not convince oneself that the results might lead to any clarity or simplification in ones life

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Yes and no…

You can inject all the insulin in the world and it will not increase your c peptide lab… however insulin injected can certainly lower your bodies natural demand for its own insulin, thus resulting in a lower reading than it otherwise would be…

That’s why it’s really only particularly useful at initial diagnosis

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I was thinking about that ^ too…

If my body has the ability to produce insulin, and I inject insulin, would my body think that it doesn’t need to generate my own insulin. Will my pancreas become ‘lazy’?

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I haven’t heard of that. Maybe the opposite. I vaguely think there may have been a rumor that taking insulin might help preserve some pancreas function for a while longer.

A glance at Effects of beta-cell rest on beta-cell function: a review of clinical and preclinical data - PMC suggests that there may be some support for that rumor, but I haven’t looked carefully.

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Out of curiousity, how much basal are you taking?

I’d suspect probably not very much? And perhaps a disproportionately large amount of bolus in comparison?

There’s a whole lot more than just being able to “make insulin”

There’s also the need to dump a whole lot of it into the bloodstream rather quickly, (like a bolus) which is often where people with LADA see not happening as it should for a long time

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could you be MODY?

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I don’t know. What are the symptoms of MODY? Is a definitive test for it?

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I’ve been taking 6 units of Tresiba. My nighttime BG are all horizontal. There are no sudden rises, or drops. My endo thinks that I can increase definitely to 7 units, and wait and see, and maybe 8 units. Yes, how did you guess about the bolus?!! :slightly_smiling_face: My bolus, Novolog, for a lunch or dinner, can range from 3 to 9+. I’ve used 12u Afrezza. I’ve also used 8u cartridges hour after hour for about 3 hours after fried pork cutlet and rice. That was frustrating.

What does it mean that I seem to be using many more units for bolus than basal?

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Doesn’t surprise me at all.

What would be considered a “therapuetic” basal dose of insulin for you would be somewhere around 30-35u… (I guessed a weight to come up with that). not that that really means anything it’s just where they’d WAG your basal to be as a t1.

But what you can glean from that is that you produce essentially almost enough insulin on your own for basal needs, have very little ability to increase that amount on demand the way it should when you eat. With LADA that can go on that way for a long, long time… hopefully forever.

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Several strains of mody can be identified with genetic testing, others can’t … which is incredibly expensive, generally not covered by insurance, and doesn’t really satisfy anything but getting you the mody merit badge… I went through the whole runaround and it was a total waste of time and frustration… not something I’d recommend as a productive use of your time unless your doc feels it’s necessary

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My weight is 85 pounds. I cannot imagine taking 30-35 units basal. I used Levemir, 5 in morning 5 at night many years ago.

Before I began basal, my fasting BG was trending up over the years 110, 120, 130’s. That was about 10-15 years ago…About 30 years ago, during my OGTT, first 1-2 hours, very high BG’s. IIRC over 200. Eventually after 4th or 5th hour, my BG did come down. Does it sound like I have no first phase insulin? My husband jokes with me and says that my pancreas is slow, and very delayed. It’s true- it’s delayed like 7-8+ hours.

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Well… I guessed 125 so I was way off

But anway 85 lbs /2.2 ~38 kg x.6 = ~23 u estimated bolus for a fully insulinopenic person (not an exact science by any means) but when you compare it to your “normal” fasting c pep, disproportionally large bolus doses, and very minimal basal dose it does seem to paint a pretty clear picture

Yeah that’s exactly what it sounds like, I can never remember which they call first vs second phase so I just avoided the terms…

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