Anyone negative for GAD but positive for other antibodies?

I’m thinking of the next step to take and wondering if anyone else may have had a similar experience. I’ve been experiencing large blood sugar swings for the past few months. I bought a glucometer and measured readings that go as low as 50 and as high as the 200’s. I paid out of pocket to see an Endo (not health insurance, so this has been an expensive journey). He was very short and ordered a fasting glucose test and hba1c. Here are my lab results:

Fasting glucose: 90
Hba1c: 5.1

All normal so far, but I know something is up with my blood sugar. So I took the 2 hour OGTT at a lab and got this:
Fasting: 83
1 hour: 233
2 hour: 91 (looks like I went back to normal, but I got big hypo symptoms and at the 3rd hour I checked and was 50)
Obviously that 50 isn’t on the lab report so if needed, I may retake the 3 hour one to document that.

I found a lab to test my GAD 65 without a referral. I got my results today. Under 5.0 (it doesn’t give me an exact #. I’m at a bit of a loss on the next step). I’m in my mid-20’s and a slim male, so I’d be shocked if it’s Type 2. Perhaps it’s not diabetes at all but something else messing with me. I have an upcoming appt with the endo again, but every appt is over $200 so I’m hesitant and thinking I should just get another test done on my own first, before I spend money on a $200+ visit just to have him order a test and schedule another $200 visit to review it.
With the symptoms and results I have, what makes the most sense here as to what to test next? I’m thinking of paying to do a full antibody test (IAA, IA2, etc) and rescheduling my follow up with my Endo to be after those results. What else could I be experiencing if it’s not diabetes related?

A 1-hour glucose of 233 mg/dL on an oral glucose tolerance test is not normal. Unfortunately, most clinicians focus on glucose only and should also measure insulin levels during an OGTT.

Dr. Joseph Kraft observed that high insulin levels on an OGTT dependably indicated a future diabetes diagnosis. Our bodies have an incredible ability to keep important measures like glucose in range even as diabetes emerges. What happens with many people is their insulin levels rise to an abnormally high level and often are able to keep the glucose levels within range for a time, sometimes years.

It looks like your body no longer has this ability but it was able to rein in the glucose at the two-hour mark. While your body was working hard to pull down that 233 number, it over-produced insulin and that over-production not only returned your glucose level into the normal range but overshot its mark and drove you into hypoglycemia. There’s a name for this phenomenon: reactive hypoglycemia. I experienced a few episodes like this during the year before I was diagnosed with type 1 diabetes.

Listen to your inner common sense that there’s something wrong with your glucose metabolism. If I were you, I would try to get another OGTT that includes an Insulin assay. Both glucose and insulin are measured at specific intervals following drinking a specific amount of glucose. I suspect that your body is over-producing insulin but in a delayed fashion.

A healthy pancreas produces insulin in two phases. In the first phase, it releases a large amount of stored insulin in response to a rapid increase of blood glucose caused by a meal. The second phase of insulin release is an elevated secretion over time that cleans up glucose the first phase may have missed. It appears that your first phase insulin is impaired and your second phase insulin is over-responding due to the high level of glucose you’re experiencing.

Most clinicians are unfamiliar with an OGTT that includes an insulin assay but you might as well ask. If you want more details about this test, here’s a YouTube video that features Dr. Kraft. This is not new science. Dr. Kraft performed thousands of these assays back in the '70s and '80s.

Don’t let clinician ignorance stall your effort to get a diagnosis. Responding early to any diagnosis almost always opens up treatment opportunities that foreclose when you delay. Good luck going forward. Welcome to TuD!

This is a concise summary of what Dr. Kraft observed and may apply to your case.


Thank you so much. Even though it’s painful on the wallet, I’m going to spend the money on testing. I’m going to do the full antibody panel and look into getting my insulin tested too. What is your opinion on the c peptide test?

It is possible, and if early stage, can be treated easily with low cost metformin. Had a similar post recently by young person, slim, being diagnosed after fasting insulin test. You may want to get that test.

I was diagnosed at 21 but for months before I had low blood sugar symptoms but I didn’t understand them. My legs went all tingly when I exercised and sometimes went weird when u walked.
I just ate and I was ok. Then the more obvious symptoms began and I got extreme thirst and urination. I went to urgent care and he told me likely type 2 and I should watch my carb intake.
Severe tiredness and blurred vision ensued. I went to the hospital.
I was in DKA by the time I got to the hospital.
Sometimes type 1 works like that, where your pancreas over reacts to hi sugars before it gives up the ghost.
They did t have the antibody test back then but I had a very low c peptide. And I was still sick with the Cocksackie B virus that commonly triggers type 1.
I was also very underweight.

I immediately went on insulin. R and Nph. That’s another nightmare story, but after a few months my insulin needs leveled off. And it became predictable
Doctors like to jump on type 2 for some reason.
If I were you I would get a doctor who knows diabetes well and can help you get the tests you need.
You don’t want to walk around with high sugars like that.
Best of luck to you.
I have some old Minimed sensors and a transmitter if you want them to monitor your sugars. Technically you need a script but you use them for research purposes.

That’s the first thing I thought of too was Reactive Hypoglycemia. Just be careful it’s not the beginning of type 1 either.
Here are some threads that talk about it.

I also included a link of blood tests for type 1. A c-peptide might yield some information, It’s a production of insulin test. If it’s low or low normal it’s a sign of type 1, high or high normal it’s a sign of type 2. This one keeps trending lower or higher over time of progression of type 1 or type 2. With a type 1 you slowly stop producing enough insulin, With a type 2 your body keeps trying to produce more than normal to compensate for not utilizing insulin well.

1 Like

I’ll let you read the details in the thread I started, but this sounds kind of similar to what I’m experiencing, except so far I haven’t tested positive for any antibodies. I’ve been sticking to a moderate carb diet for over a year and was still having problems with reactive lows and nighttime lows. I’m now on a low carb diet and that’s helped a lot, but I still have these weird blood sugar patterns when I do eat carbs. It usually looks like an M. My blood sugar goes up (it’s not spiking like it was before I moved to low-moderate carb diet), goes down, goes back up and then back down again all within an hour. Sometimes, it peaks three times. Clearly my pancreas is having a hard time knowing how much insulin to produce. I still don’t have any answers for how to manage this or what it is exactly, so other than trying to stay low carb enough to not tax my pancreas I don’t have much to recommend. I would like to have another OGTT done with insulin measurements, but my endocrinologists have not wanted to let me do that.

I’m currently trying to take acarbose with carbs to see if it helps, but I haven’t had any success so far. :confused:

Just sharing an update!
I’m still waiting on my results from the full antibody test. I did however take the fasting c-peptide test. I got 0.66 (reference 0.8-3.85). This is pretty affirming to me for the symptoms I’ve been having. I hope my doctor considers this.
Just waiting on the full antibody report now.

1 Like

Your c peptide test is very much depndant on weather or not you were fasting. Although still low a c peptide at .6 looks like an early stage. Mine has been non detectable since about a year after diagnosis, and believe it or not my control was easier when I finally went to zero.

I was fasting. But after doing some researching, it looks like that number doesn’t always mean something unless it’s at 0. Still, it does help a little. Thanks!

That’s not true, it means a lot. Because if you were a type 2, it would never be so low. You produce extra insulin as a type 2. So it pretty much eliminates type 2.

Plus I don’t know of any “normal” person testing below the normal ranges. As a type 1, you still make some insulin for a while, but not enough. The number slowly dwindles over time and that time varies but can be up to 8 years plus even. So you don’t reach .0 for potentially a long length of time.

1 Like

Thank you! Interpreting c-peptide results is one of those things that I’ve read some people explain a little differently

I got partial results back on the antibodies test.
Negative for IAA and IA2. Still waiting on GAD65 and ZnT8. I already know I’m negative on GAD from a prior test. I’m just mentally preparing for the next step if I am negative on ZnT8 but we’ll see.

I’m going to see my doctor and share all my results. Based on my impression from reading most people’s stories online, I’m worried he may just say I’m fine and send me on my way, when I’m clearly dealing wth fluctuations from 50 to 200 mg/dl. Whatever my real issue is, whether it’s LADA or not or something else, I’m really looking to get to the bottom of it so I can go back to normal life. I’m curious if anyone has advice in case the antibodies test is fully negative. Maybe the doctor will help with more specific testing or give a diagnosis b/c of the 200+ on the OGTT; I’m just anxious if not.
To save you some time scrolling –
Normal Hba1c and fasting blood glucose.
OGTT - 233 at 1 hour, 91 at 2 hour, then all the way to 50 at 3rd hour (hour 3 recorded on glucose monitor though. May redo OGTT as a 3 hr test though).
C-peptide 0.66. Antibodies negative.
IF this is LADA, looks like it would be in the very early stages? I just don’t want to live this way and wait/see if it gets worse or worst case down the road dka before getting the medical help to fix it.

My diabetes educator has what they still consider type 1. She is negative on all the antibody tests but she doesn’t make insulin. It is pretty rare. I don’t know how long it took her to develop it. But for some reason the pancreas decides to stop making insulin and they don’t have a clue as to why a good deal of the time. Sometimes it’s obvious, constant pancreatitis or trauma to the pancreas, but other times it’s not.

How old are you.? Because thee is a sub type of diabetes In older people where you are not insulin resistant and you are not having an auto immune response. Where your insulin production simply starts waining. Generally those people go on type 2 meds until they can’t produce enough and add insulin.

I meant to mention this in my last post and forgot. It may be worth doing a google search for “lean diabetes”. I was reading about it recently and it seems to be more common among men than women.

After reading what you said about your c-peptide I was also curious to look back at some of my lab work. Before I went to a low/moderate carb diet, my c-peptide was 1.5. My most recent blood work on the low/moderate carb diet is 2.2. :thinking: I’m not sure if that means anything but it’s something my brain has been chewing on anyway.

Followed back up with my Endo today.
He looked at everything and said that I’m good to go. I asked him questions and he said that the one hour mark of the OGTT doesn’t matter at all (even if it’s over 200). No comment on me dropping to 50 at the third hour. I’m skeptical because I just don’t feel like a non-diabetic should ever hit 230 (on a lab test at that, not the glucometer). He subtly implied I shouldn’t have paid for an OGTT because of the normal hba1c. He said he never recommends the OGTT.

I mean, if I don’t have LADA or any other problem, then hooray. That would be ideal. But it has me feeling pretty hopeless with my symptoms, which I don’t feel like are normal in healthy adults. It doesn’t change the fact that I’m constantly dehydrated, going to the bathroom constantly (like every 15 minutes at night when I’m trying to sleep, which is pretty embarrassing for others in the house to notice). I’m a tough guy so I don’t mind pushing through symptoms but the high’s and low’s are actually debilitating to me actually being able to do my job at work or even enjoying my personal life when I’m with other people. I’ll just go low carb / no sugar (which hopefully helps) and continue checking my symptoms.

He referred me to a a doctor in internal medicine. I’ll go with that recommendation and talk to that doctor. I think I’ll do some research to see if I can find an expert in LADA in my area. The guy I saw does actually seem like he’s probably a great doctor for his patients, but unaware of early LADA symptoms. (By the way, to answer someone’s question here. I’m 26. Also: 150 lb, low BMI, don’t eat junk food, exercise a few times a week)

1 Like

Don’t get discouraged! I’ve encountered the same issue with doctors. Unfortunately most doctors don’t have protected time for keeping up with current medical literature so they’re practicing with knowledge from at least 20 years ago. It might be worth trying to go to a doctor at a university hospital. They get protected time for that and may be more knowledgeable in less common or less well known diseases like LADA.

1 Like

I was misdiagnosed for over 8 years. I had a GP that told me medication wouldn’t work at all if I was a type 1, ??? I had an endo say I wasn’t type 1. Neither had me tested. It wasn’t until I switched doctors and the new doctor sent me to a new endo that I was tested and properly diagnosed.

Time and time again I heard similiar stories for all sorts of different conditions of people going to a different doctor and finally getting diagnosed right. I know of one guy with severe digestive issues that saw over 5 GI doctors. Another one I will always remember is a guy that his mom had shaking arms, but not Parkinsons. She saw many different specialists at Kaiser and no one knew why. He had heard about a really good doctor outside the group he decided to take her to. The doctor goes, I know what this is and you get rid of it by a small implant. So he went back to Kaiser and said his mom needs this surgery so you need to approve an outside surgery.

Kaiser’s response was we have someone that specializes in that surgery…but not one doctor she saw knew what the condition even was. They say 80% of what a doctor learns in school becomes obsolete in 5 years. I still had a chiro tell me 5 years ago I could cure my type 1 because I didn’t get it as a child.

Unfortunately searching out an answer can be very disheartening. You get told that everything is good enough but you know something is wrong because it’s not normal. It can cost money and time too.

I heard Joslin is doing phone consults? I think? They are specialists in diabetes, it could be worth checking into. @CJ114 never got an answer as to what was causing his problems though. @pink_chiffon 's idea of a university hospital might help. Endos are in short supply and immediately hit with a huge amount of patients. There are some diabetes groups out there too that they don’t really know that much about.


The doctor in internal medicine I was referred to ended up being great. He actually listened and when I brought up LADA, he was pretty educated in that and MODY. He’s having me take more tests. Regardless, I’m so relieved to be talking to a doctor that listens and believes me. Especially since for some people it takes years.

Thank you everyone for all the feedback and support here. It has truly helped.