Negative antibodies but low stimulated c-peptide?

Hey all,

So I was diagnosed last August as being diabetic. I was basically DKA on arrival. I'm 31, no family history and bmi of 20.

I've had tests for antibodies (GAD, IA2, ZnT8) and all have been negative.

I've also had a stimulated c-peptide (i.e. drink a can of coke, bring glucose levels to ~15 and then have a blood test). This showed detectable but low c-peptide (360 pmol).
In the letter from the consultant with the results, they said that my diagnosis remains unclear but i would be managed as a type 1.

In terms of medication im on insulin and use lyumjev for fast acting and getting really good results. I'm very much on top of my blood sugars and have a recent a1c of 5.0% (31mmol). I'm guessing that part of the reason i'm able to easily manage this is because I still have some insulin production. My a1c on diagnosis was 95 mmol.

Has anyone had a similar history and might be able to offer any further possible explanations and causes? My next appointment with the endo is 6 months away and im a bit confused as to what the future holds.

Thanks.

EllieM said:

What's your insulin ratio like? The problem with antibodies is that a negative antibody proves nothing but if you were T2 I'd expect you to need lots of insulin for your carbs.

And of course there are other types of diabetes (Mody, T3s) which I'd hope your endo has ruled out.

(I'm straight childhood T1 so don't have a similar history but am applying some logic. And no this is not a diagnosis).

And some people just don't ever fit into a neat diagnostic box.

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My ratio is roughly 1 unit per 10g. I haven't discussed mody or type3 with my endo, but ive only had a single appointment unfortunately due to staffing issues.

Antje77 said:

I was rediagnosed T1 (LADA) from having been diagnosed as T2 for two years. My rediagnosis was based on C-peptide being low but not near zero, and on needing insulin very quickly after diagnosis despite cutting carbs.
I had only the GAD antibodies tested, which were negative. My endo said she could have the other antibodies tested if I really wanted to but because it wouldn't really make a difference we decided not to.

Not all T1's have antibodies present, and some have had them tested more than once to have them appear or disappear.
Having diabetes plus antibodies means a T1 diagnosis, not having a positive result for antibodies does not mean it's not T1.

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Seeing as my antibodies are negative, i'm curious what this means for natural insulin production levels going forward. Mine are clearly reduced at the moment, but if they stay at this level i'd be happy. I think it is making it a lot easier for me to manage my blood sugars.

I haven't noticed any real change in the amount of insulin i've needed in the last 9 months (since i was diagnosed). Hoping it stays this way.