Got Antibody Test Results Back

Hi everyone, If you've read my few posts, you know I saw an endo last week who wanted to test me for antibodies b/c I seemed to fit the LADA profile moreso than T2 (underweight, 40 yrs. old, family and personal history of autoimmune disease, normal BP/cholesterol).... WELL, the antibody tests came back negative. She tested GAD, ICA, and IA-2A--all negative. GAD <1.0 (0.0-1.5), IA-2A .8 (<1.0), ICA Negative (Negative: <1:1). My FBG the morning of the test was 85. It was higher when I woke up (110), but I didn't get to the lab until I was up for 2 hrs. (Does that matter?). My c-peptide was 1.6 (range 1.1-4.4) and my insulin was 3.4 (range 2.6-24.9). Do my c-peptide and insulin levels seem on the low side?

I just can't believe that I'm early pre-diabetic for T2 with my particular profile, but I guess if there are no antibodies, that's just what it is.

Thanks for all your input and support these last few weeks! :)

EDIT: I spoke with my endo this afternoon, after I saw the lower C-peptide number (she had just left a voicemail this morning saying the antibody tests were negative and emailed the results to me). She said she has not ruled out Type 1 yet. I mentioned the 10% of T1s who don't test positive on the 3 antibody tests I had done and she said Why don't we go ahead and test you for zinc transporter (ZnT8) and IAA? (I know--I'm very lucky with this endo!). So, back to the lab tomorrow! She said it may also be that I'm not showing antibodies yet b/c it's so early. I thought once you started having abnormal BG, and it was T1, that you'd show antibodies at that time?

If the ZnT8 and IAA come back negative, I wonder if I should ask for the OGTT?? She hasn't even mentioned that yet.

Antibodies are only one of many factors that can aid in the T1 determination.

Most (all?) of us old-timers were diagnosed without blood tests at all. In fact only in the past few decades has blood tests been part of diabetes diagnosis. I myself did urine testing for so long, I am sometimes surprised that urine testing is so out-of-fashion and irrelevant for diagnosis today.

Even with the most thorough antibody panels, something like 10% of newly diagnosed T1's still aren't showing antibodies.

Regarding your FBG numbers... does 85 or 110 count as "diabetic" today? Those often fall in the "normal" range of my lab paperwork. We all know there's a lot more than just FBG, but I'm not sure just a single random 85 or 110 would lead to any diabetes diagnosis, either T1 or T2.

No matter what it's called, it sounds like you are getting excellent detailed help and testing real early on, and that's great!

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Hey, Tim. Thanks for your reply. My FBG has been running 110-116 the last 2 months, which is considered "pre-diabetic." My PP numbers with a decent amount of carbs (30g +) has been running 160-216 at 1hr and 130-150 at 2hrs. So, elevated, but not horrible.

I'm keeping the possibility of T1 in the back of my mind b/c I just fit that profile so much more than T2 (although I know there is no typical in D!).

Before I had my test, my Endo told me the antibodies tests weren't a cut and dry T-1 vs T-2 diagnosis, she said in some cases people are evolving Type 1's or something in between. She actually ordered the test because I asked for it. For me it did come back positive for both and about a month later I had to start insulin therapy. I had much better blood sugar control when I was able to manage diabetes with oral meds, diet and exercise.

I'm not an expert in C-peptides, but your C-peptide number would certainly tend towards the "low insulin production" conclusion rather than the "high insulin resistance" conclusion.

Of course if you have been going low-carb, this will also lower your C-peptide and insulin assays.

I have been involved in some research programs, where a prerequisite to "being full blown T1" was pretty much zero C-peptide.

We all have to remember that we are all much more than our lab tests :-).

The antibody tests are helpful in diagnosing T1/LADA, but only 85-90% of T1s test positive for one or more of the three antibodies. I recently had the antibody tests, all negative. My c-peptide at the time was low. My endo continues to support my use of an intensive insulin regime which is the typical treatment for T1. But I remain with a diagnosis of T2. And in truth, after years of trying to figure out exactly what kind of diabetes I have, I have accepted that I may just never be sure. And in the end, it really doesn't matter. All that matters is that I am able to get the treatment I need to stay healthy. As to what label is given to me I just don't care.

And please rejoice. It is actually good to not be diagnosed with T1. It does sounds like you are diabetic, but you do have the promise of being able to manage things with diet and exercise without immediately facing medication and insulin. That is really, really good news.

Thanks again, Tim. I eat around 160g carbs a day. I think that's on the lower end, but not truly low-carb (is that right?). I wonder if it's enough to make a difference?

I'm definitely not a full-blown diabetic at this stage, so I wasn't expecting zero C-peptide, but a little surprised it was near the bottom of the range.

Thanks for the encouragement. :)

Hi Graceymomma! Thanks for sharing your experience--that's interesting.

Thanks, Brian. Glad to hear your endo supports your insulin use. I've read your story and you've been through a lot!

As an update: I spoke with my endo today (she had just left a voice mail this morning with the antibody results and her secretary emailed the actual results which is when I got my numbers, so I called her back...) She said she has not ruled out Type 1. I mentioned the 10% of people who do not test positive on the major 3 antibody tests and she said, You may be one of those 10% so why don't we test for zinc transporter and IAA? (I got very lucky with this endo, I know!) She also said maybe I'm just not showing antibodies yet. It's obvious that whatever is going on, I've caught it early.

I will certainly be happy if it's not T1. I understand the ramifications of that diagnosis. I'll keep doing the diet and exercise thing and hope for the best.

Thanks again! :)

I have never tested positive for an antibody related to diabetes in the 12 years I have had T1.
I tested positive in 2008, the only time, for a rheumatoid arthritis antibody and I've had that since 1992.
I think there's a lot more to be learned. Wait a century.

I have been Treated as a Type 2 for almost 9 years. I use the max of metformin, 2550 mg and my control is OK. But my HbA1 c is always in the high 6’s no matter how good my bgs are. I am a thin, 114 pounds and have started to see diabetic complicatiins. I have been dx’d with Retinopothy and Diabetic Macular Edema. Last week I had surgery to remove a breast lump and the pathology report said it was a rare diabetic condition called Diabetic Mastopathy. It is mainky seen in long time type 1’s with poor control. My Endo teested me for GAD and it came back normal. My C-peptide was 1.1 with a fasting of 151. My fadtings at home are normally around 100-115. I normally do a low carb diet but I carbed up for a week or so before the test. I don’t think my ENDO will make a LADA dx. I am afraid I will be dx’d with more complications and want to prevent that. Are there any other tests I should ask for?

I think @Melitta describes them all in this post

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Thank you. I am surprised my ENDO didn’t recommend the tests besides the GAD.

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