Can you change from Type 2 to Type 1?

I've always wondered if when a person that has Type 2 diabetes ends up going on insulin, no longer producing any of their own,when medications no longer help etc. if they are then considered Type I?

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Normally, the only way a type 2 diabetic becomes a type 1 diabetic is because of a mis diagnosis. Type 2 diabetes is triggered by obesity, a lack of exercise, increased age and to some degree, genetic predisposition. Type 2 diabetics have create enough insulin but their bodys are resistant to it. With type 1 diabetes, the body make little to no insulin at all. Of course with all diseases, there are exceptions to the rule, but overall (to my knowledge) a correctly diagnosed type 2 diabetic can not become a type 1 diabetic.

If anyone knows anything to contradict this, please chime in.

I had a friend who was diagnosed as a Type 2 in the 1980s. She took pills for a while and finally had to take insulin but still treated as a Type 2. A few years ago she was hospitalized because of Neuropathy, the Muscular Skeletal type and she couldn’t walk. Anyway, she was rediagnosed as being Type 1.5.

Chris and Betty have more or less summed it up. A T2 cannot become a T1 over time unless he was misdiagnosed in the first place. The reason why T2s may need to go on insulin jabs is the fact that the become so resistant to insulin over time that synthetic insulin must be injected into their systems to cope with processing glucose and such.

Type 2 diabetes can also be caused by medication. That is how I got diabetes. I have to take insulin because the oral medications made me so sick

The names T1 and T2 are about the cause of diabetes - T1 has to have the antibodies, T2 the insulin resistance. T1 is a total lack of insulin production, T2 is overproduction but not so good at putting it in the right places. The cause is what matters when it comes to naming Diabetes. (Not forgetting, of course, LADA as a slower form of T1, MODY, etc…).

There are plenty of cases of people being misdiagnosed… I’m one of them! But I didn’t ‘progress’ from T2 to T1, I was just incorrectly diagnosed T2 and had a year of mess until I was finally found to be a LADA T1.

If a T2 goes on insulin then they’re still a T2. If a T1 develops insulin resistance they’re still T1, although some people use the term ‘double diabetes’ so I guess in some way it’s possible to have both at once.

Cody, I don’t think oral meds are the cause of diabetes. Oral diabetes pills can have severe side effects on people, but I don’t think they make you get the condition.

I am getting a settlement next month from Eli Lilly

Thanks for the clarification. I thought you were referring to oral diabetes medicine like Metformin, Januvia and so on. Hope all goes well with your settlement!

I was orginally on Metformin and it made me really sick which is why they switched me to insulin.

I was initially diagnosed with type 2 (by a general doctor), treated with oral meds (actos, avandia, glucophage, etc. etc.) and eventually found to have all the signs of type 1 (by an endo) and switched over to Lantus first, eventually Lantus and Novolog (now using only Novolog, since I got on the pump).

If you haven’t been tested for antibodies, I recommend you do, so as to establish what you really have.


You are mistaken, but it is understandable why, since the “information” you cite is often printed in the media.

People with Type 2 have typically lost from 50% to 80% of their beta cells AT DIAGNOSIS. Because of the rotten medical treatment they receive, which leaves them with blood sugars that spend hours each day over 200 mg/dl, the rest of their beta cells succumb to “glucose toxity” and die.

Ten years after diagnosis, many Type 2s have almost no functional beta cells left.

It is true that people with Type 2 START OUT making more insulin than normal, because they are insulin resistant, but though their insulin resistance continues, the amount of insulin they are able to make declines.

Eventually they have only a tiny bit of insulin being produced. Unfortunately, ignorant doctors do not prescribe insulin for most Type 2s early enough to support their remaining beta cells.

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Also worth pointing out that a significant number of people with insulin resistant Type 2 ALSO have antibodies. Different studies give different numbers but it is somewhere between 6 and 9%.

So much of what you hear about Type 2 is out of date and wrong, but it just keeps getting repeated!

I believe what you say is true Jenny because, now the ADA is saying that T2s should start on insulin earlier then they do. I’ve believed for a long time that T2s should be on insulin. My theory is that because doctors take so long to put them on insulin that physical damage is being continually caused because of constant highs for long periods of time.

T1 was thought not to produce insulin and the Pancreas but now there is a test (C-Peptide), which determins who is T1 or T2. In Type 1 we produce but not of any use. The determination for T1 is 0.5 anything over that is considered T2.

I still have C-Peptide (1.7) but I am diagnosed Type 1 because I have antibodies to my islet cells. I don’t have insulin resistance. In England Type 2s who need insulin are called Type 1, but my understanding is that if the cause of your diabetes is insulin resistance you are Type 2 and if it is lack of insulin due to autoimmune disease you are Type 1. However, adult onset Type 1s like me may still produce some insulin and therefore have C-peptide.

How do you know if you are insulin resistant anyway? I’ve spent the last couple months thinking of whether I show any of that.

If you are taking insulin, your insulin-carb ratio might be 1-10 or 1-15. If you have insulin resistance, you have to take much more. I don’t know how you figure it out if you are not taking insulin.

I previously took mixed insulin, but I didn’t take very much - just 20 units a day. Even on Metformin, I’ve been hitting 4-6mmol post prandial. I guess this is another question I’ll take down to ask my endo next month…


There really is NO way to determine if you are insulin resistant without trying insulin.

I plugged my pre-insulin c-peptide numbers into the IR calculator you can find online and came up saying that I was significantly insulin resistant, but once I started insulin I found out that I wasn’t. That is because the calculator is making some assumptions that don’t work out if, you, like me, have near normal basal insulin secretion and no post-meal secretion.

When I wasn’t on insulin Metformin didn’t do much for my blood sugars, though it stopped me from gaining weight while eating at a low calorie level. I didn’t see a huge difference in my blood sugars with insulin when I stopped metformin, but I did start to pack on weight again, so I’m back on it.