Am I Type1/LADA/Undetermined?

Please refer to this thread: What type of insulin should I ask for?

My history is similar to Ashley. She states: negative antibodies, lowish c-peptide, postprandial spikes.

2 years ago, I went to my GP with concerns of diabetes. Test results back then: Hba1c was 4.6%, fasting 3.9 mmol/l.
Begged for OGTT. Got it. While low carbing took it, result: 13.2 mmol/l at 2 hours. Came down on my own at 3 hours.
Referral to endo. Repeat HbA1c, fasting, fructosamine, antibodies. All normal. C-peptide 0.68 (below reference range, normal fasting, so he did not care about low c-peptide). While on low carb, do OGTT again. Failed at 14.2 mmol/l at 2 hours, coming down to 3.9 mmol/l at 3.5 hours. Diagnosis: diabetes unlikely. Eat normal diet.

Current period: 2019 June, c-peptide (1.0) bottom reference range. hba1c 4.9%, fasting between 5-5.6 mmol/l. Still low carb. Decided to start ramping up carbs in mid-December. Tried with 15g at a time. What I saw was frequent spikes to 8 mmol/l, which lasts for around 2.5 hours, then comes down to below 6 mmol/l at around 3 hours. Went to another endo a few days ago. She said my c-peptide is too low (I found multiple studies with normal people having c-peptides around 1.0-1.4 ng/ml on keto). I told her 2 years ago I failed OGTT. She said one needs to eat 200g of carbs a day for a week before OGTT to get accurate result. I told her about antibodies that were negative. Asked if I should repeat them, she said ‘not necessary’. Can antibodies appear from being absent? I have not noticed my BG control getting worse, still getting similar fastings, postprandials and low carb diet manages condition OK. It has been 2 years, surely if something was attacking pancreas, I would experience obvious issues?

But I still have low c-peptide and postprandial spikes so that is what she focused on. In the end, she said: eat 150g of carbs for 2 weeks, come in to repeat OGTT. Diagnosis: suspected MODY diabetes. Problem is, there is not a strong family history for it. I asked her if reference ranges for c-peptide are from people eating normal diet, she said “yes”. So … for all I know, my pancreas outputs enough insulin to keep me between where my body wants it: 5.0-5.6 mmol/l fasting.

I think my plan is this: get records from previous endo, see why he considers me not diabetic. If it is not convincing, I go repeat antibodies tests again and go from there. Any thoughts?

You don’t have to have a family history for you to get type 1, type 2 or MODY diabetes, it just makes it more likely.

There are a few, it’s just rarer type 1’s that don’t have the antibodies but don’t make insulin either. My diabetic educator is one of them. Since you make some insulin for a while, when you eat low carb you can “last” for longer before needing insulin. Some type 1’s are known to make a little insulin for quite a while. Usually a type 1 needs insulin before 3 years but some have even lasted much longer than that. 40% of type 1/LADA’s are misdiagnosed as a type 2 at first, because it is a slow developing form.

I could be wrong but I believe a repeat of antibodies test will not be any different as antibodies can actually decrease over extended time. But there are a few antibody test other than the GAD one that is the most popular to test for. So you might check what tests antibody test/tests they did.


Here are antibodies tested 2 years ago: ICA, IA-2, GAD. He said they are negative.

I am missing ZnT8, IAA. I believe he did not test IAA because they are rare in adults. One of the websites I found say to not bother test for them in adults. ZnT8 he said ‘has issues’ and he did not test for that.

He said that my glucose spiked but started coming down spontaneously on its own. He also says it was caused by insulin resistance via low carbing and fasting. I personally don’t see me being insulin resistant. There would be no people with c-peptide below normal range and insulin resistant at the same time. In his report, he also claims I had hypoglycemia at 1 and 2 hour marks on OGTT which is another sloppy mistake to be honest.

He never mentioned MODY as well. But to be fair he is an old guy, worked as an endo for 30 years and probably seen enough to know his stuff. Current endo just recently finished her PhD so much less experienced.

The first Endo I had I asked if I could be type 1 as I had an uncle that had type 1. I was told no and he never tested me. I believe because I wasn’t skinny. I was misdiagnosed as a type 2 for over 8 years, luckily I was at least put on long acting insulin fairly early. This was supposedly a “good” endo. It wasn’t until I switched doctors who sent me to a new endo that she tested me immediately and I was diagnosed right. This turns out to be a common way of being diagnosed right.

Low or lower normal on c peptide is a sign of type 1, high normal or high is a sign of type 2.
Type 1’s can develop insulin resistance, they just can’t make more insulin to try to compensate for it like a type 2 does.

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Right, but did you test positive for antibodies at that new endo?

Yes I tested positive for antibodies and the c peptide showed I wasn’t making insulin.

Do you remember which ones were Ab+?

I tested positive or (H) on GAD65 and something called Insulin autoantibody
I tested as under any detectable amount of C-Peptide

25 years ago at age 52, I was diagnosed T2. I don’t recall any details but I assume it was based on my age and high A1c. Started on Metformin and after two years graduated to insulin (Novolog 70/30 and Lantus.) I do recall that about ten years ago my quarterly c-peptide results started to come in at<0.01. Eight years ago, I started on an insulin pump and CGM.

I still exhibit indications of insulin resistance; however, I am currently being treated as a T1. Does it matter what I am classified as as long as my treatment is effective?

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No, it really does not matter what you are classified as long as your treatment get the results you are happy with. I am treated at Joslin - Boston and after about 30 years there, they are still scratching their head and trying to type me. My diabetes does not fit the profile of any other diabetic in their facility.

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The most important thing is to get treated properly, that is usually one reason you would want to know if you are type 1 or type 2.

In my case Humalog was added to my Lantus as a “type 2”, (years later) but since I thought I was type 2, I would skip insulin shots thinking I would let my body deal with it. Most type 2’s still make some insulin and I would argue it would be very rare as a type 2 to not make any insulin. They just released the results that only 6% of type 2’s are deficient in insulin and that is deficient, not not making any. I don’t believe I remember the study stating how many stopped completely.

And that little bit of insulin that a type 2 makes usually saves them from DKA, allows them to respond with glucogen when needed so they don’t hypo with severe consequences etc. So it is different. Plus as a type 1, insurance is better about covering our tech etc so it helps as a label in coverage in that respect.

And I would argue that as a type 2 they usually don’t do any testing unless some kind of flag eventually goes up. As my A1C went up and I was sent to the first endo I was still never tested for anything they just kept wanting to add drugs that made me sick, that endo isn’t even the one that added a fast acting insulin into the mix. How often do they test for c peptide in your standard type 2? Probably not until everything else is failing and you are starting to get sick and even then?. Maybe you get lucky and get a “good” doctor, but I hadn’t and I was in a major metropolitan area not far from Loma Linda teaching hospital and a major medical school. You would have thought he would have been, well better at his job?

In the OP’s case it is a frustrating problem for him. What is going on? Will it last or will I keep making some minuscule amount of insulin, maybe more later or was it caused by an event or medication??? I’m not sure what he wants to know but getting diabetes takes a little bit to sink in and then you want to fix it. Well a lot of people can “fix” type 2 if they follow certain changes, but there is no fixing type 1 and I argue it’s better to know if you can what type you have.

So I would argue that yes in a lot of cases it’s helpful to know, because then you are likely to get the proper care.

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Over last 2 years, there was zero reduction in me handling low carb diet. I still get same postprandials, though on some days they go higher than usual and it looks like my pancreas works worse on these days. My A1c is <5% throughout 2 years since failed OGTT, fasting is in high normal (5.0-5.6) which is normal due to low carb diet. c-peptide seems to indicate that: I am on low carb diet (so pancreas is happy to pump less insulin as indicated by multiple studies I found studies of healthy insulin sensitive people having c-peptide 1.0-1.2 ng/ml just like I am). Reference ranges are made for people who eat SAD diet and are not mostly healthy, insulin-sensitive young people.

Here you can see how low c-peptides go on low carb diet in normal people, sometimes below reference range:
These are ref ranges for low carb people who are insulin sensitive. Any low c-peptide like that would raise eyebrows for an endo but the main point is: is it accompanied by high BG? No? Then this is all insulin needed to keep BG normal in fasted state.

The situation changes if I add carbs. On some days I eat around 15g of carbs in 70% chocolate and spike a bit, on others like yesterday I barely increase or even decrease. My doctors keep telling me that it is not diabetes (maybe just crappy pancreas and it will wear out over time) yet. They tell me to add back complex carbs, see how much I can handle, try to break ketosis and repeat OGTT.

So, for now things are ok. But people who claim in the comments that cause is not important to determine…I have zero idea why you think so. One: current doctor thinks MODY. MODY can be treated without insulin, why would someone be treated with insulin then? Or, just yesterday I talked with a guy whose doctors determined that pancreas issue is caused by portal nerve damage, which is a signaling problem to release insulin. Ever heard of that? Probably not. He had high A1c, it went down with 100g of carb a day to normal ranges. The main life changes were weightlifting, proper sleep. Making nervous system work better and hence pancreas respond better to glucose…

So knowing the cause is important.

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After 30 years of being diabetic, I have no idea (beyond possible educated guesses at a world renowned diabetes clinic) of the cause of my diabetes and frankly I really don’t care. Sure, over time I have taken every test under the sun and will continue to take new tests from a curiosity standpoint but the only thing that is important to me and the only thing that should really be important to anyone is to follow a food, exercise and medication dosing plan that keeps their diabetes in a range they are happy with.

Doubt this will help you but I got tested for MODY and came up negative for I think 13 of the known variants? My current A1C is 5.1 (up from previous 4.9 which disappoints me a bit because I always wonder does that mean it’s getting worse). My endo says she isn’t sure what I have but has some patients with LADA that didn’t require insulin for over 15 years.

I did my own stimulated c-peptide test (maybe something you want to try) and got a 6.2 with a glucose reading of 180. I did another and got glucose 130, c peptide 3.1 and insulin 14.

I still spike high (170/180s) if I eat super carby things so I do keto and try to keep all readings under 120. I read something that there are over 5 variants of diabetes and I am sure there are even more out there. I belong to a LADA FB group and there are several women who have the exact same experience I do. We all have normal fastings and fairly good A1Cs but spike high if we eat carb heavy meals (editing to add and all antibody negative/negative for MODY). There is an article about someone who doesn’t have diabetes and wore a CGM and had significant spikes eating oatmeal though and she linked to a Stanford study where many participants spiked with eating cornflakes but I looked at the raw data and my spikes are much higher than the dataset.

But for me I have sort of given up figuring out “what I have” - I just keep on checking my levels, eating low carb and trying my best not to obsess about things (thanks to @Sam19 for being a great sounding board - appreciate it).


^ fan mail. Love it. Enjoyed talking with you :grin:


Thanks. I appreciate your input. Question. Any digestion problems, say digesting fats? Also, I am not sure what reference ranges for antibodies mean but main were in-range…what I don’t get is why is there a range. Same for various thyroid antibodies. I have some antibodies not a lot. But I do. Shouldn’t a healthy person have 0 antibodies?

I don’t have digestion problems - I know fried carbs are my #1 enemy of all carbs where I will have a delayed and then extended significant spike but I think that it’s probably the fat delaying it. I can eat fat and no carbs pretty well but try to still not eat a huge amount of fat and huge amount of protein or that’s another extended (but not significant) spike.

My results all show for both thyroid and any of the suite of LADA antibodies that I am below the threshold of the test. For example my GAD is <5 so could I have 1-4 I guess but that’s probably not the sensitivity of the test. What do yours look like?

Anti IA-2 0.74 (0.0-1.0) but all sources online actually say that a number much higher is considered positive, so … shrug.
GAD <0.16 (0.0-1.0) shows much higher number for positive here as well.
ICA - negative

Then a bunch of antibodies:
Tissue Transglutaminase IgA 0.5 (0 -10)
Immunoglobulin IgA 1.75 (0.7 - 4.0)
Thyroid receptor Ab 0.4 (0 - 0.8)
Thyroglubulin Ab 16.5 (0 - 115)
Thyroid Peroxidase Ab <9 (0 - 33)

Just curious have you ever had your TSH, T3, T4 tested? My endo said thyroid levels can impact your glucose as well.

As a note, my OGTT 1 hour results are similar to yours (both times I’ve done it). My endo did give me a prescription of metformin ER if I wanted to take it and see how it would affect me but I still haven’t started it yet.

Yeah, normal ranges, but FT3 on low side. Was told it is because thyroid needs more vitamin D and also keto does not agree with me too much.

What are your c-peptide levels fasting?