T1Ds Misdiagnosed As T2

I like Kerri Sparling very much. T1 for 28 years, and dx when she was 6. She started her blog site several years ago. It is called “Six Until Me”. It is a great site. In 2012 she examined the problem of T1D’s who are misdiagnosed as T2. this happens very often when the dx occurs later in life. I have read about T1 being dx for people in their 80s. An organ can fail at any age, for so many reasons. So a pancreas can certainly fail in an older person. Why don’t doctors realize this??? Here is Kerri’s blog:


I’m one of the folks who were initially dx as T2 but turned out to be dx as T1 later. The time between the initial and final dx was almost 13 years which has recently gotten me to thinking I’m an unusual case. The confusing aspects for me are that I was dx in 2000 as T2 and was advised to control BGs with diet and exercise because at the time the severity of the BG spike during the dx tests weren’t bad. So for 10 years I “controlled” BGs with diet and exercise and saw the endo every 6 months to check A1C levels. During that time period my A1Cs never rose much above 6 until the second half of 2009 and exceeded 7 by late 2010. Over the next 3 years I tried Metformin, which did nothing but make me nauseous, Onglyza, which did even less and finally Victoza. Initially Victoza drove my A1C levels into the 5 range but that lasted only a few months then they rose back into the high 6s low 7s. The primary side effects I experienced with Victoza were bad nausea and a total loss of appetite. Finally, after losing close to 20lbs putting me at 155lbs, I had a discussion with the endo where she finally agreed to test for T1 markers. GAD came back negative but Insulin Antibodies were very positive (don’t remember the exact number) indicating T1. There are a couple factors that are still confusing me though. First, when we tested my insulin production the level came back at 13 after fasting overnight which is toward the bottom of the “normal” range of 10-20. So my system is still making insulin. Some of the research I’ve done leads me to think there is disagreement on what that number really indicates and where the “normal” range should be.
Second, the amount of insulin I use daily seems to be on the low side based on what I’ve read on this site. My daily average is ~26 units and my average daily carb intake is ~210 grams. I work as a software developer so I’m not very physically active and I seem to be very sensitive to the amount of insulin I use, just a little too much pushes me over the edge into a hypo.
After reading some of the stories here I don’t seem to fit in with the traditional T1s who suddenly stop producing insulin and deal with severe experiences when dx, nor do I fit the T2 scenario either where the oral meds actually work for a while and the amount of insulin used is much higher than I use. I work with a T2 who injects more for a single meal bolus than I use in almost 2 days.
I am happy the endo ran the tests and found what we did, now I have a pump which has helped a lot with my control (saw the endo today and my A1C went from 7.2 to 6.6), but I’m puzzled.
Maybe I need to stop trying to figure out the T1, T2 thing and just move forward with figuring out how to live with this beast. That part has gotten harder over the last couple years.

Edit: I guess I should add that I was dx at age 35 and am now 50.


It’s hard for me to be sure of specifics since my “T1 moment” happened a bit over 35 years ago.

I was initially diagnosed as a T2 … not what it was called back then, of course. But because my sister insisted, I went for a second opinion. As part of that I was given an oral glucose tolerance test which had not been done earlier. (I wonder if the OGTTs are still used? I never see anyone mention them as being part of their diagnosis.)

In addition to measuring my BG for the OGTT, they somehow also measured the amount of insulin in my blood. It was very obvious on the graph of the results that while my BG rose & peaked & then started a very slow decline, my insulin production stayed essentially constant.

The endo’s opinion was that I was only producing about half the insulin I actually needed. While my BG would eventually return to more normal levels so long as I didn’t do anything more to elevate it, I still needed supplemental insulin. In other words, though I might appear to fit all the criteria of a T2 when evaluated quickly and superficially, a closer, more insightful look at my actual insulin production indicated pretty clearly that I was/am T1 (LADA, I believe).

While you may be at the low end of normal as far as a fasting AM insulin level “snapshot”, I wonder if your body can provide much beyond this background “maintenance” level? Was that ever explored or discussed?

As I say, my experience was all quite some time in the past. None of the doctors I have seen since then has ever revisited that initial testing to get a guess on how much, if any, insulin my body may still produce. I am personally curious about this, of course. But looking into it further never seems to come up as a topic for discussion during my doctor visits. :no_mouth:

I was diagnosed as a Type 2 when I was 35 (20 years ago) but I remember having really bad, of what I know now was diabetes, symptoms in my late 20’s. I struggled with diet and medications, then switched to insulin, was called “non-compliant” - a word I hate, but I was. At age 50 (on my b-day!) I ended up in the ER with DKA, then suffered a mild heart attack and kidney failure due to massive dehydration. My endo then says I’m a 1. I think we did a c-peptide test but I think I will have it done again - it’s been awhile. So I am assuming I am a 1 - I’m now on a pump and a CGM, but if I wasn’t on the pump and still MDI and I hadn’t eaten all day and never took a shot, I would go low, so is that Type 1?


Can’t seem to quote from your post, not sure why.
Yes, my endo and I discussed the question of why my morning insulin was “normal”, her answer was that I can’t make enough to cover my needs but I still make some. She also said my system will probably lose the ability to make any as time progresses.
We haven’t explored the question further. I anticipate there would be little useful information gathered that would change the diagnosis or the treatment so it won’t happen.
It really is just a point of curiosity for me, being a software engineer I’m intrigued by puzzles, especially those I can’t solve. :smile:

It was an OGTT test used for my initial dx. I drank a super sweet orange soda, then gave urine and blood samples every 30 minutes for 2 1/2 hrs. I don’t remember if my blood insulin level was monitored but I know they tracked my blood and urine glucose levels. If I remember correctly my BGs topped out at ~250 in about 1 hr but didn’t drop below 200 in the 2 hr window. This showed I was diabetic. Later that week I visited an endo (not the one I see now) who summarily pronounced I was T2 with no other tests performed.

If they had monitored your insulin level during the OGTT then I don’t see how they could have misdiagnosed you as a T2. IMO it should be routine to do this, since it’s really easy to mistakenly diagnose a T1 as a T2 based simply on the results of the BG from the OGTT. The BG results from producing insufficient insulin would look the same as having insulin resistance, wouldn’t they?

But my impression is that measuring the insulin levels during an OGTT is not typical. I am pretty sure it was only done in my case because the endo I saw was particularly interested in differentiating between T1s & T2s. I believe he was actually one of the first in the late 70s and early 80s to explore T2 being a consequence of insulin resistance.

I keep wondering if I still have my copy of that OGTT laying hidden under a pile of stuff somewhere. If I do I hope I can find it and scan it so I can post it. For nostalgic purposes. :blush:

I hope you folks are reading the replies to Kerri’s blog. Some of them are very interesting, and so are the replies being made here.

I participated in the Joslin Medalist Study in 2009. I was given an OGTT test as part of my workup there. They took blood tests every 30 minutes for two hours, like one of you mentioned. My BG kept rising and never decreased at all. I was over 300 after two hours. I had not been allowed any insulin except for my basal insulin since the previous evening. The fact that my BG never decreased showed I was not making any insulin, and a C-peptide test confirmed that, it was less than 0.1. What is most noteworthy is that many medalists showed a BG decreasing after two hours, indicating they were still producing some insulin. That is very significant since all of the 1000+ participants in the Study have been type 1 for 50+ years. We can no longer assume that T1D’s do not produce some insulin, no matter how long they live.

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My C-pep test comes back saying < .05 (basically undetectable) but I have been called a T2 and a T1 buy other doctors.I’m extremely insulin resistant now but it could be caused buy some of the medication I take post major organ transplant. I have never cared about what others think. When I was first Dx they gave me pills but my BG never came down until they gave me some insulin…when they first tested my BG it was 800 mg/dL, they gave me pills and for the next few days it was still 800mg/dL, I do not remember anyone running any other test on me for 15 years then someone did a GAD and it was positive but 5 years later a different doctor ran several antibody tests and they where all negative. I don’t think it’s always just an easy test or two away from a diagnoses…but one thing all of my doctors have figured out is that I cannot live without insulin and suffer from DK if I don’t get enough of it…

JohnG, it’s my understanding that both GAD and C-Peptide need to be run. For whatever reason, it’s one or the other that reveals the dx. Having negative in one, does not mean negative in both. For your gee whiz :wink:

Well I have tested negative for C-pep <.05 and positive for GAD65…and today if they test me I’m Negative C-pep and Negative to GAD65 plus I’m insulin resistant… so what does that tell you…am I a T1 or a T2…??? C-peptide is just a indicator that tells us if we make some of our own insulin or not. And If it’s zero you could be a T1 or a T2 with a worn out pancreas. The antibody tests can also be tricky, I have tested both positive and negative during different stages of my Diabetic life. So someone who has been called a T2 for 30 years may no longer present antibody’s even though they may have early in there Bêtes career…:wink: It does not change the fact that we are insulin dependent and suffer from DK if we go without insulin. And to even confuse things more…there are type2’s that can also suffer from DK.

My brother and I are both insulin dependent and as different as black & white. The only thing we have in common is we both use insulin and the commonality stops there…none of our children, mom, or dad have diabetes…

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I was misdiagnosed as a type 2 at 22 years old in June of 2013. Like for months I suffered, because I was only getting higher (like the weeks before I started insulin I was getting almost all over 240 mg/dL readings while eating basically no carbs and basically no food period) and the metformin seemed to be doing nothing other than make me have the worst farts in the entire universe. I got to an endocrinologist, and he really helped me. While I am probably the only person here right now who’s not had the testing , I’d say it’s pretty clear in how my diabetes works that I’m not a type 2. I’m not resistant to insulin, I’m quite sensitive to it (my period and activity reduces my insulin so much because then I get SUPER sensitive). I also have never had any known extremes, but my diagnosis blood sugar was 249 mg/dL and I was basically at fasting , so I have no doubt I was in the 500+ range and never knew it. I knew all along I was a type 1, the more I read about it, the more I knew it. Sure, I could get the lab testing, but I feel it’d confirm the obvious.

I asked that my insulin also be checked during my OGTT. On a graph my insulin level started low and had a very slow gradual incline with the highest level coming at the end of the test, this pattern was considered indicative of T1 by several studies I looked at that tracked both insulin and glucose during OGTTs. I’m not sure why they don’t routinely check both?

The way diabetes is diagnosed needs to be overhauled if you ask me, many people are misdiagnosed with T2 because of age, or are not diagnosed and treated at all and are simply considered pre-diabetic. I had many post meal values over 200, weight loss (my BMI was 18) polyuria, and I spilled ketones when over 200 but because my fasting and A1c were ok I was told by one endo I wasn’t diabetic, a couple said I was pre-diabetic, one admitted he had no idea what was going on (I also had CGM documented reactive hypoglycemia) and he said I should go to the Mayo Clinic…finally one endo said early onset LADA. My PCP let me try NovoLog for post meal spikes and after only 5 weeks of insulin therapy I’m now apparently honeymooning, gaining weight and I’m feeling better and able to maintain decent control with diet alone for the time being. I hope to try Afrezza when I need insulin again.

Perhaps you are proof that medicine is not all science, and the art of medicine has to come into play. I worry that medical students and residents are not taught that part.

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Hi Richard,

I think the whole training for diabetes & diabetes diagnosis needs an overhaul for sure. I went to so many docs it is unbelievable I wasn’t diagnosed long before dka. Even then I was at first semi misdiagnosed as 1.5 with some type 2 and not hospitalized. It was very twilight zone and crazy. My “misdiagnosis” didn’t last long due to ending up in hospital 2.5 days later. I wonder what would have happened if I had been diagnosed earlier, I guess I will never know but I think I would’ve been diagnosed type 1 eventually and it wouldn’t have taken years. I had gad and c peptide done in the icu and c peptide also at my diagnosis but my doc never gave me the results for the first one. I think he was planning to put me on insulin anyway depending on how bg responded to metformin.

Even now I have had some docs demonstrate to me that they don’t understand that I have to stay on insulin. Some have asked if I’m sure it’s type 1 and one tried to suggest maybe I could get off my “meds”, after discussing my history which says to me they really have no clue. I can’t believe I’ve had to set some straight on this basic fact. I went to see a neurologist recently who immediately told me that mostly children are type 1. I’m not sure why she felt the need to tell me that and even if it were true it wasn’t relevant to why I was there.

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Hello meee. Lol, I feel like I am talking to myself. I have read about so many situations like yours. So many people are diagnosed as T2 because they are older or they are overweight. You and I know that T1 can occur with people irregardless of their age or weight. Too many doctors do not realize thi, so they do not have the C-peptide and GAD tests done. Some endos do not seem to have this awareness about T1D’s. My first two endos did not understand much about my diabetes management. I agreed to do what they anted, and then went home and did what I knew would work best. We need the doctors who will write scripts for us, otherwise I would not be seeing an endo. I am glad you are now correctly diagnosed.


Lorraine, a few years ago a doctor who teaches at a medical school wrote an article. He said that the graduates at that school have very little exposure to diabetes knowledge, and they are not equipped to always correctly diagnose and treat people with diabetes.

Our friend that’s an expert in LADA @Melitta could explain this a lot better than me, but it’s entirely possible to test autoantibody positive then negative later on. If you test autoantibody positive at one time , it’s very likely you’re a type 1. Especially if you have very little to no insulin production (which your c-peptide pretty much tells me and should tell a doctor you make basically no insulin) . It’s also possible for a type 1 to have insulin resistance from what I understand, it often seems to happen to people who’ve had diabetes for a long time, but I would never rule it out as just something you have going on now that may go away or just how your diabetes is.

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Good thing Richard to do what you know works best :smile: I will not let go of my endo who treated me in the hospital and knows my whole history first hand, I really worry about having to start all over with someone else.

A year after I had half of my pancreas removed in a Whipple operation, I suddenly had terribly high BG. I went to an endo and he mindlessly assumed I had type 2, because of my age, and practically in his sleep wrote out a prescription for metfornin. I said - I HAD MY PANCREAS REMOVED. Don’t you think you should test my C-peptide? I managed to get a blood test prescription from him, and took those results to another endo, who immediately put me on insulin. What always scares me when these things happen is, what about people who don’t constantly google and research their symptoms and diseases as I compulsively do – they can go for years with the wrong diagnosis and treatment!


While I am sympathetic to the issues of misdiagnosis of T1 the issue is much more far reaching. An article in the Washington Post “Misdiagnosis is more common than drug errors or wrong-site surgery” highlighted some key issues. Most notably:

Diagnoses that are missed, incorrect or delayed are believed to affect 10 to 20 percent of cases

If you follow the source of this figure it is from a paper entitled “Overconfidence as a cause of diagnostic error in medicine.”

Think about it. Most doctors get 10-20% of their diagnoses wrong across the board. Somebody with diabetes walks in the door. They don’t even have to look up at the patient and they can wave their hand and diagnose the patient with 90% accuracy as Type 2. That is better than they do on average. Obviously when you couple that with them being arrogant and overconfident then we have the current situation.

ps. And in fact you don’t get diagnosed as Type 2 you get diagnosed as “Diabetes of unknown cause.” That is the whole problem.