Is there anyway I can find out if I have T1 or T2 diabetes?

I was diagnosed about 2 months ago with diabetes but my Dr. isnt sure if its T1 or T2. I had gestational Diabetes almost 2 years ago. I am 21 years old and I’m mexican. diabetes also runs in my family. My Dr. first gave me Metformin but it wasnt doing anything but making me sick. now I take 4 insulin shots a day, lantus and humalog and I count carbs and try to excersie daily. I guess it doent matter either way if its T1 or T2 but I would like to know. is there a test that can be done to find out what it is? my Dr doent seen concerned about the type.

Hi Crystalee, I’m in the same boat as you. I’m unsure which Type I actually am. (I think I might be T1.5) Oral meds worked “ok” for me for about 18 months, then after being maxed out on them, they began not working. I’ve been taking insulin now since this past Feb.

Yes, there are a couple of tests they can do to help determine. The C-Peptide test which will show if you are or are not naturally producing any insulin, and whether that is a large or small amount. And also the GAD 65 test that tests for anti-bodies. I think tho that not everyone has the anti-bodies, so that is not exactly conclusive. (I’m still a bit confused on all of that myself)

As far as it making a difference or not. I guess that would depend. But since you are already on insulin and it is working, no I don’t see what difference it would make. I’m like you tho, it would just be nice to know! Won’t make a difference in my treatment whatsoever. But still, I want to know! ;0)

Right, a positive antibody test shows Type 1. A negative antibody test doesn’t not show Type 1. The reason is that antibody levels can vary over time in one person, so a test at any given time may or may not show them. Also, the tests aren’t 100% accurate; a “negative” result will show “below” a detectable value, instead of zero. I think the chance of them showing up on the test goes down the longer you’ve had Type 1. Still, good idea to get it anyway, along with the C-peptide.

How much insulin are you using? That will give you a very good idea.

Type 2s usually use a lot more insulin for the same amount of carbs as do Type 1s, though there are also some forms of diabetes that people can get which are called Type 2, but use very little insulin.

The important thing is that a classic Type 2 is insulin resistant, so even if they produce insulin it takes a huge amount to lower the blood sugar. A type 1 usually is not insulin resistant.

If you are using Lantus, a typical Type 2 dose of lantus might range anywhere from 30 units for a very small person to 100 units a day.

Type 1s might use anywhere from 12 units a day up to the 20s.

With meal time insulin, the ratio of insulin to carb for a type 1 might be 1/15, for a Type 2 1/5 or less.

So if you know whether or not you are insulin resistant, that can give you a clue.

I had the C-Peptide test and my level was high, which usually means that you’re not Type 1. However, I later had the antibody tests done and was positive for islet cell antibodies, but only just. 5 or over is considered abnormal and my level was exactly 5. It was important for me to be diagnosed as Type 1 because my fasting and 2 hour BG numbers were too low to be diagnosed any other way and it was necessary for insurance purposes. So if you do get testing, I suggest you ask for all the antibody tests, not just the GAD even though that is the most common one to have. Also, the number of different types of antibodies and the levels indicate how advanced your diabetes is. I think the antibody levels start low, then get higher and eventually go lower when your pancreas has less or no insulin secretion.

I take 13 units of Lantus in the morning. they started me on 10units but my morning levels were still too high so now I’m on 13. I occationally have highs in the morning but I think it has more to do with forgeting my bedtime snack. I may go to 14 but I think I may give myself lows if I push it.

meal times I have 5 units of humalog and eat 30-45 carbs. my sugars are usally really good during the day.

going to have to talk to Dr about getting these test done. thanks for your info everyone. :slight_smile:

same conundrum here, crystalee. i think i am type 2, and so does my endo, but she will be running blood tests on me very soon to check out my pancreas function and stuff. i am going to ask her what kind of tests she will be running.

when i was warded it sounds like she did a C-peptide test on me, and it turned out my pancreas had 1% of its function. i’ve had my insulin dosage cut twice though. jenny, i don’t really understand the insulin bit. i take 20 units of humulin 30/70 a day. it’s a mix of NPH and regular insulin and is good for about 16 hours before it wears off.

i feel the same as melissa & crystalee…i’m really looking forward to some answers! i had this weird dream though, that i was at my endo’s office and she told me i have type 1. interesting hmmm.


That sure sounds like a Type 1 dose to me.

The genetic forms of non-insulin resistant diabetes are rarer, but they do occur (I have one), and they use similar doses, but you would only consider testing for something like that if you didn’t find any markers for autoimmune diabetes.

Are there other autoimmune diseases in your family, or a strong history of Type 1?


The mix is a pretty old fashioned form of insulin and one that makes it very tough to get good control because you can’t match the insulin to your food.

More modern insulin regimens involve separating the background insulin --the basal which is slow and keeps a level going at all times–with the meal time insulin which is injected before a meal and is supposed to match the carb intake.

I have written up various oddball forms of diabetes on my web site. discusses LADA and its diagnosis. discusses the genetic forms of diabetes often misdiagnosed as type 2.

Since putting the MODY page up, I have heard from so many people with it that I am starting to think it is far more common than doctors realize. It can be very tough to diagnose because many of us have normal or near normal fasting blood sugars most of our lives combined with extremely high post-meal blood sugars that get missed by testing that only includes fasting blood tests.

interestingly enough, my control is actually pretty excellent if i do say so myself. i rarely spike higher than 8.0mmol when i test post-prandial unless i happily overdose on carb (which i don’t) , and my fasting sugars have always been between 4-5mmol since i was discharged from hospital. i’d say my body’s quite receptive to this insulin. i’ve had my dosage cut twice and i only take 20 units in total everyday. i can’t possiby know what this means…but in any case i will ask my endo about a basal/bolus routine as it sounds like those on such a routine have good control. but that all depends on what my blood work shows because she says she will take it from there. i’m really hoping to get a blood test soon though!

Those are amazingly good numbers, so probably you don’t need to change anything at this point!

I dont think so. both my parents have reletives with diabetes but since they doent have the money to take care of it or dont know they dont know what type. its something they have ignored. some reletives have died from complications but we never knew whaty type it was they had.

at my meeting with the support group other diabetics all told me I need to see an endocrinologist. that they think its crazy that my Dr isnt trying to find out if I have T1 or T2. she hasnt even refered me to an endo. so that what I’m gonna have to do. I’m gonna call my diabetes nurse ask her, then my Dr. thanks for all the help!!

i really think my endo suspects type 2 now. she mentioned metformin yesterday but hasn’t decided to put me on it until she confirms it is type 2. feeling a little scared now though. i’m due for a c-peptide test next week along with a few other tests like a lipids panel and a renal panel. i expect my endo is going to check out my pancreas function and take it from there. i’m not due for a GAD test though. on second thought i should’ve asked for one. but if my pancreas isn’t functioning at all, or much, then she might send me for that.

i’m confused again though. it seems that i am always confused! i was thinking about it last night and this question popped up into my mind. type 2 diabetes is characterized by insulin resistance (and correct me if i’m wrong…) and so if i’m on insulin and i have type 2 diabetes, wouldn’t i need quite a lot of it instead of my current 20 units a day? but on the other hand, if my doctor has cut my total dosage by about half since diagnosis, wouldn’t that suggest that my pancreas is recovering and starting to produce insulin?

now i know that none of us are doctors. maybe we should coerce a doctor into joining this site and start an ask the doc forum. hah!

T1 LADA perhaps? Seems likely to me. Worth seeing an Endo and finding out for sure.