JDRF convened a workshop of international experts in November 2019 to address adult-onset Type 1 diabetes challenges, and a new research article in the November 2021 issue of Diabetes Care (“Adult-Onset Type 1 Diabetes – Current Understanding and Challenges”) summarizes findings and proposals from that workshop. tackles the problems experienced by those diagnosed with Type 1 diabetes as adults, and suggests a roadmap to better understand, diagnose, and care for adults with Type 1 diabetes. The authors propose an approach to correctly diagnose people with adult-onset T1D, they discuss knowledge gaps and areas of focus, and their goal is to improve the management of adults presenting with Type 1 diabetes. Here are key takeaways:
• Worldwide, over half of all new-onset Type 1 diabetes cases occur in adults.
• The classification of Type 1 diabetes includes all individuals with evidence of autoimmunity, regardless of disease development (rapid or slowly progressive) or other features such as obesity.
• There is a substantial risk that a person with adult-onset Type 1 diabetes will be misdiagnosed (the authors list five underlying causes for misdiagnosis, including the “lack of awareness that the onset of Type 1 diabetes is not limited to children”).
• The authors recommend measurement of autoantibodies at the time of diagnosis, including IAA, IA-2, GAD, and ZnT8. They also recommend measurement of c-peptide.
• The authors state, “In individuals who have [been misdiagnosed], additional stress derives from conflicting messages about the nature of their diabetes.”
• A cornerstone of the authors’ roadmap is “a renewed emphasis on the careful consideration of the underlying etiology of diabetes in every adult presenting with diabetes.” In other words, assess the etiology of the person’s diabetes, don’t assume Type 2 in an adult.
• One of the knowledge gaps that the authors identify is the problem of diagnosis and misclassification, and the authors say, “there is a need to build a diagnostic decision tree to aid in diabetes classification.”
Adult-onset Type 1 diabetes: current understanding and challenges
Surprising that there isn’t one already !!!
Kind of sad that they are so late late in starting to make this move. We’ve known for a long time that the number of adult onset T1s is actually high and misdiagnosis is a serious issue. I think the typical experience is for doctors to assume they are a T2, and then as things progress they prescribe insulin in addition to the T2 meds. Then when they have poor outcomes they blame the patient.
The diagnostic decision tree should probably be to test the “type 2 diabetic” for low insulin production and antibodies before making the diagnosis that they are type 2. In my case, I read Dr Bernstein’s book, went low carb, and got on insulin when that didn’t solve things. My metformin was causing highs and lows which I found be testing 10+ times a day, and then I demanded to get tested for T1. When my endo refused, I switched endos and while they didn’t believe me, they were will to at least give me the tests which I passed (or failed) with flying colors. This was 7 years ago.
Yeeeaaahhhh…
Even after a 20 day hospital stay from DKA, wasn’t tested for T1, wasn’t explained what LADA was, was sort of shoved out.
Was never told if the DKA was from all the medicines they changed me to (Rybelsus, Jardiance, etc.)
The “joy” of being told my numbers were bad because I wasn’t trying hard enough. Still makes me mad — and these were leading diabetes specialists, too.
I know, but there isn’t. Such a strange thing that this has been ignored, despite the fact that huge numbers of people have been misdiagnosed, received the wrong treatment, and suffered needlessly.
Until this article came out, I felt like I was the only person in the US that was trying to bring attention to adult-onset Type 1 and the need for correct diagnosis and treatment. So thankful that some true experts are working on it! And thanks to JDRF for sponsoring the workshop that was the seed.
I was diagnosed with “juvenile diabetes” 40 years ago and don’t have any known T1 antibodies today. I wasn’t tested for antibodies at time of diagnosis - the extreme DKA with ketotic breath, and having a piece of test-tape dipped into my urine instantly turn jet black, was enough back then!
Would this proposed classification scheme, if I had to be “re-diagnosed” today, put me into T1, even though I didn’t pass the “evidence of autoimmunity” test?
Recent research papers naming 4 antibodies (e.g. Autoantibodies in Type 1 Diabetes | Johns Hopkins Diabetes Guide and https://www.jci.org/articles/view/14257 ) say that while up to 90% of T1’s diagnosed in the past few years were tested for antibodies and found to have them, I fear the new JDRF definition may exclude up to 10% of recently diagnosed T1’s, who were tested but didn’t show signs of any known T1 antibodies.
Even though they’re using terminology that was intended specifically to eliminate the age association. That was the whole POINT of “Type” instead of juvenile vs mature age of onset. My doctor told me about it in 1983, though it hadn’t been officially adopted yet, so my chart still says “juvenile.” And yet you still get actual, trained medical professionals saying “You can’t have Type 1, you’re too old”!!! The actual term they’re using is supposed to tell them not to make that judgment, but hey, “type” is just another word for “juvenile” amirite? Makes my head explode.
Same here and you voice my concerns as well. With the addition that I’m coming up to transitioning to Medicare from my wife’s private insurance (she’s retiring) and I still have some live beta cells and my c-pep may not be low enough to qualify me for the insulin pump I’ve been using for 15 years. I’ve been on insulin since the day I was dx’d in 1983, but hey, maybe I coulda been doing it all with pills ‘n’ exercise that whole time! Ya think?
To be fair to Melitta and JDRF, the part she was posting says T1 “includes” those who test positive for antibodies, but that little excerpt doesn’t by itself exclude you and me.
Several times a year we get some very young person who says they were skinny and/or recent extreme weight loss, in ER for DKA and spent several weeks being stabilized with insulin and the yet their doc says they are doc says they are T2 because of a The presence of C-peptide or lack of antibodies in a blood test. To me (and you too, I would hazard) this so closely matches our personal stories except that in your and my cases 35+ years ago the doc made the right call, and in the more modern case the newbie poster’s modern doc made the wrong call and discharged them on oral T2 medications and the advice to lose weight. At least to me it’s obviously T1 and the guy should be on insulin.
In early cases of adult T1, c-peptide can be low OR mid-range normal. All it means is that the T1 was caught early.
In the case of no antibodies found, that is usually when the DM has been going on for a while (very slow onset), beta cells have been substantially compromised, and the assault on them has receded. I am sure that there are other markers that have not been discovered as yet. For some reason, very little research is being done on T1 by anyone but pharma and their research is purely for money-making gadgetry. Of course, that is my opinion exclusively and others may disagree, some vehemently.
Good points @Tim12 and @DrBB. If you read the entire paper, you see that the authors don’t address the 10% of Type 1’s who aren’t autoantibody positive, but they do identify that T-cell activation is another way to ID Type 1. Also, they say that autoantibodies are good for IDing new-onset Type 1, but that c-peptide is better at IDing longstanding Type 1. Another significant recent publication is “The Management of Type 1 Diabetes in Adults. A Consensus Report by the ADA and EASD.” ADA/EASD Consensus Report In that publication, the authors state, “if there is a clinical suspicion of T1D, the individual should be treated with insulin,” and “The absence of autoantibodies does not exclude T1D, since approximately 5-10% of White European people with new-onset T1D have negative islet autoantibodies.”
There might be auto antibodies that are not yet discovered.
I was diagnosed with type1/Juvenile onset. That was 34 years ago when they were transitioning the terms.
I had a bracelet that said “sugar diabetes” that they gave me in the hospital. It was a cheap fake gold metal ID bracelet.
Sugar diabetes. That is so incredibly odd. I know there is diabetes insipidus, but I don’t think they were differentiating that. I think it meant type1, not type2. But who knows.
I was positive for 2 auto antibodies a few years ago.
Isn’t the big difference, whether or not you’re making insulin?
Perhaps a better differentiation would be tendency to go into a state of ketoacidosis if deprived of supplemental insulin. The early stages of Type 1 of course would be problematic since there may be an indolent onset wth some residual beta cell activity. There are certainly “Type 2” people who will and then there are others who don’t. (I’d personally trade in a heartbeat: if by exercise and avoiding certain foods my blood glucose normalized, rather than constantly chasing elusive goals and the roller coaster that even a pump can’t completely stop.)
I can understand that there isn’t clinical value in putting everyone on a pump and the costs are significant.
Give me Metformin any day. Didn’t you hear, it’s the elixir of long life? 
Many (if not most) T1s are still making some insulin when diagnosed. Otherwise the honeymoon phase wouldn’t exist. Even for prototypical juvenile presentations like mine (10 years old, high ketones, blood glucose 750, thirst/urination/weightloss, presumably in or heading rapidly toward DKA), I still produced enough insulin to have a honeymoon period for a year or so once I was on insulin.
I was 39 when I moved to a new city and wanted to find a physician. So I booked an appointment and he asked, ‘Why didn’t you tell me you were diabetic?’ (Back then, they did a urine test for diabetes, not a blood test, and my urine had sugar.) He immediately diagnosed me as Type II, and back then, the drugs for Type II did not extend life expectancy: you died from the side effects, not from complications, but your life expectancy was not extended until Glucophage. So he told me, ‘Diet and exercise,’ but my sugars remained high. I think he finally gave me oral meds, but my sugars remained high. Finally, he referred me to an endocrinologist who had to say I had a kind of Type II where I needed exactly twice as much insulin as my body was producing, so he put me on insulin, and also ordered a glucose tolerance test, where they measure both glucose and insulin levels. A Type II will see a sharp rise in both blood glucose and insulin levels. A Type I who is not already taking insulin will see blood glucose rise even higher than it was, but no insulin response. A Type I who is taking insulin will see that the insulin level is a straight line. The endocrinologist lied that was my own insulin, measured by C-peptide. Note that, if he said the primary care physician had misdiagnosed me, I might sue, and the primary responsibility of every physician working for a clinic must be to their employers, not their patients. But he put me on an insulin regime that kept my HbA1C at a reasonable level, so his lie to protect the clinic didn’t really hurt me. And the primary care physician referred me to an endocrinologist before any real damage had been done.
Today, new patients are sent for a fasting blood sugar. And many older diabetics are diagnosed and treated as Type II when they are really Type I. The standard tests are glucose tolerance and C-Peptide, both of which clearly indicate if one is Type I or Type II, but many now prefer the newer, more expensive antibody tests, which do not always prove Type I. And many physicians, like my own primary care physician, do not bother with any tests for Type I or Type II, they diagnose based on the age of the newly diagnosed diabetic.
But c-pep (testing for if your body produces much insulin) in conjunction should find almost all of them. My recollection was that something like 15% of T2’s were actually misdiagnosed T1s in some study a couple decades ago.
Regardless of what one thinks of Dr Bernstein, his book really explained this stuff well when I (late onset T1) was first diagnosed as a T2 over a decade ago, and it was probably why I was able to figure it out relatively quickly.
I’m more surprised that insurance companies aren’t taking a lead if only to watch out for the high hospitalization costs.
My “holiday” in the ICU was roughly $250k. Now, there’s ongoing kidney monitoring, long-term complications, etc.
I still have some insulin production so my C-peptide is too high to qualify for a pump on Medicare. I was misdiagnosed as Type 2 at age 52. Finally asked for antibody testing and had just made the cutoff for islet cell antibodies. I think it was greater than 5. More recent testing didn’t show any measurable antibodies. My first endo said my glucose tolerance test was normal because my BG was 175 for 90 minutes and then went down to 120 at 2 hours.
I originally didn’t show as having antibodies when I was tested by my internal medicine doctor, and that was the only test she knew to run. She didn’t know about the GAD testing thus she assumed I could not have type 1 due to that test result. Thankfully my BG went high enough and a visit to the ER and subsequent Endo visit caught the type 1. I do have them now strangely enough (antibodies, that is). Hearing people stories though about endocrinologist not catching it is very depressing to me!!!