I don't understand my labs

I've just been diagnosed as a diabetic on 2 April. At time of diagnosis, fasting glucose levels were pushing 400 pretty hard. A1C was over 11. I had lost about 15-20 lbs from my healthy weight by the time I saw the doctor (I am not overweight normally)

Initially, I assume because of my age (29) the family doctor I saw (I was away from home on an extended business trip) told me it was type 2 and put me on metformin immediately. My first set of labs came back with low insulin levels and low C-peptide-- at that point the doctor changed his diagnosis to type 1 and had me stop the metformin and start a MDI routine with Lantus and Novolog. This has brought my glucose levels into normal ranges, and actually I've had to reduce my insulin doses significantly due to glucose levels trending too low. At this point I'm only taking 8 units of Lantus each day, and 20:1 carb ratio with meals for the novolog. It's my understanding that this is a very small dose for a full grown man.

So up until yesterday I believed I was a newly diagnosed type 1 enjoying the temporary "honeymoon period."

Yesterday some new labs came back for auto-antibodies. These results bewilder me, which I assume if due to my lack of understanding; My GAD autoantibodies were elevated at 3.6. Insulin and islet cell autoantibodies tested negative.

If I am type 1, wouldn't I have islet cell antibodies? Isn't that the whole issue with type 1? My doctor basically says he can't definitively say one type or another at this point, and indicates I might be able to wean myself off the insulin and onto oral meds if my glucose levels stay as stable as they have been lately.

I just don't understand. Does anyone have any wisdom to share?

I run a laboratory that runs these tests.
I have seen this before in type 1 Diabetes. Sometimes the antibodies show up later in tests.
There is often a lag time in the levels required to get a positive test.
Your other symptoms are classic LADA TYPE 1. The immune response is often smaller and takes longer to effectivly wipe out the islet cells.
The fact that you are very sensitive to insulin suggests that the type 1 diagnosis is correct, also low C- peptide suggests the same.
SOmetimes patients do not fit easily into one category.

Often Newly diagnosed Type 1s and Latent Autoimmune diabetics (1.5) have a lot of back and forth issues with sugars. I would wait 6 months to a year more and have a new antibodies test done.
Many adult onset type 1 diabetics are typed and retyped a few times before an accurate and reflective diagnosis can be found.

I think it is best to use the meds that work for you no matter what type you are. There are plenty of Type 2s that use insulin anyway.
After some time has gone by it may be more clear to your doctor and you what type you are and the best course of action is.

Welcome to the club I guess ( no one really wants to be in it )
I was diagnosed as type 1 when I was 21. I never had the antibody test because I do not think it was avalilable back then. The rest sounds very similar to your experience.

Read some of the posts in the TYPE 1.5 section and I bet you will find many who have had the same or similar experiences as you.

I think it does not matter at all. The low C-peptide shows that your beta cells are gone. Why bother how this has happened?

I do not like that your doctor is talking about going off insulin. It is current knowledge that exogenous insulin helps to preserve some of the beta cells. The minimal input from these cells will give you smaller spikes and little amounts of amylin. Most long time T1 diabetics without complications have managed to keep some residual beta cells (Joslin Medalist Studies). Healthy beta cells can produce 20 units per hour. If just one unit per hour will be left this will have tremendous effects on the quality of your blood glucose control for the years to come. Thus I would stay on even small amounts of insulin to keep the burden away from these cells. Please do yourself a favour and do not believe in going off insulin or switching to oral meds. This would just put you in a high risk of going into DKA which is very dangerous and harmful.

Well, the diagnosis of T1 diabetes is a bit murky and still subject to some interpretation. In general, being positive to one or more antibodies and being insulin deficient (low c-peptide) is sufficient to diagnose T1. However, only 85-90% of T1 diabetics test positive for any antibodies, so perhaps 1 in 10 would fail to be diagnosed by that strict criteria. Further complicating the matters, about 15-20% of T2 diabetics test positive for one or more antibodies and most T2s have lost significant portions of their insulin production capabilities by the time they are diagnosed.

So in the end, you depend strongly on the doctor to make a good diagnosis. In your case, with a quick onset, only 29 years of age and not overweight, things were pretty clear cut. A 50 year old rubenesque woman with high blood sugars and low insulin levels might well suffer through a year or two of arguments with her doctor about a proper diagnosis.

In the end, maintaining blood sugars as close to normal as possible will be the most important goal. If you can do that with small amounts of insulin, even better. But have others have said, it would be a miracle to do so. I personally never was satisfied with my diagnosis and I "chose" to start insulin early, specifically to do what Holger described. I want to keep my blood sugars controlled so that I can preserve any remaining insulin production and make my life a lot easier.

Hi Abellseaman: If you are positive for GAD antibodies, then you have Type 1 autoimmune diabetes. The diagnosis of autoimmune diabetes is based on presence of any one (or more) of the antibodies (GAD, ICA, IA-2, Zn8, t-reactive cell) being present. You sound like you have classic adult-onset Type 1 diabetes. I agree with Holger: use the insulin (you may need very little during the honeymoon period, and you can keep the honeymoon going for a LONG time with tight control) and don't think that Type 2 meds will work for you. Best of luck!

Some here take the antibody tests as holy gospel definitive proof of something.

I don't.

It is not at all unusual for a T1 or a LADA T1 to have multpile tests run (GAD, Insulin antibodies, islet cell antibodies) and maybe only one or maybe even none have the expected results for a T1. There is no definitive catch-all test. What they do is apply a battery of tests and even then many T1's have no antibodies.

Your doc is treating you like a T1 and I'm sure he's 100% correct.

You are a carbon copy of what I went through, although I didn’t get any of the antibody tests because of what others are saying, what does it matter. If you go to my page and you can read my discussions, a lot of people answered a lot of the questions you probably had on my early posts.

I actually was on insulin about to your level, then slowly decreased it to absolutely none. EVeryone here warned me not to go off insulin, but I did, and my blood sugars stayed pretty good for about a week. I wear a CGM so I could see what was happening. AFter a week the same meals started making bigger spikes and lasting longer. A lot of honeymooners, like you and I, need only one type of insulin, either the basal or the bolus. It’s just a matter of figuring out with one you need. Once you get your levels to normal levels, basal test to see if you need that. I found that when I was on MDI, I could take 2 units daily, and even that would drop me during the basal test. I then did a basal test using no basal, and my sugars stayed steady. I found that my body just needed help with the bolus insulin to handle meals. Once my bs levels return to normal after meals, my body can handle keeping it there. They say you know you are coming out of your honeymoon when your wake up readings are consistently getting higher. For me, I have been waking up in the 100-110 range ever since I went to the bolus-only routine.

Good points, Tim. Abellseaman did have the antibody tests run, so I was responding to that. But in fact as you say they are not necessary. I just see that so many adult-onset Type 1s are misdiagnosed as having Type 2, strictly based on age not etiology. Positive antibody tests can help a person get a correct diagnosis and correct treatment (exogenous insulin) in that case.

In hindsight, I am not entirely certain my docor meant entirely taking me off insulin, he may have been referring to just decreasing my basal dose down to zero and continuing with the mealtime bolus. Thanks for all the replies, the picture is coming much more clear. Now if anyone could answer my previous forum post about merchant mariner medical clearance, I'd be able to relax a little.

I too struggled with my diagnosis in the beginning. Just curious, did the Metformin have any effect on your blood sugar? Metformin essentially helps reduce insulin resistance (it works in other ways as well). If it didn't bring your blood sugar down within a day or two, I think it's safe to say you're not insulin resistant.

I have to commend your doctor for at least taking the effort to figure it out.

I was only on the metformin (500mg 2x day) for about 2 days without insulin... It didn't seem to help. Then I continued it with lantus for a few more days before the first doctor I was seeing said I could discontinue it.

My understanding from my T2 friends is that at that dose, it should've had an effect in that time.

I actually think he got some pretty clear answers right here!