There were no diabetes "types" when I was diagnosed in 1945. All people diagnosed with diabetes were treated with insulin taken from pigs and cows. That crude form of insulin gave me back my health. In the years 1936-1939 it was discovered that there were two types of diabetes, but it was not until 1959 that the labels Type 1 and Type 2 were attached. Oral drugs for Type 2 diabetics were introduced in the years 1955-1956.
Now, in current times, we are seeing more and more people with characteristics of both type 1 and type 2 diabetes. These individuals have "double diabetes". This occurs when:
1. A person with type 1 diabetes becomes overweight and develops the basic feature of type 2 diabetes – insulin resistance (IR). Typically, the type 1 diabetic would then use a type 2 medication to help control the IR. Insulin would still be necessary as well.
2. A person with type 2 diabetes has one of the key features of type 1 – the presence of antibodies in the blood against the insulin producing beta cells of the pancreas causing a decrease in the body's ability to produce insulin. The decreased insulin production can then lead to the type 2 diabetic becoming insulin dependent. These individuals still use their type 2 medication for their IR.
So double diabetics may have initially been either type 1, or type 2. Once they have become double diabetics they have IR, they are using insulin, and they are using a medicine (usually metformin) for their IR. I have several type 1 friends, and type 2 friends, who are double diabetics. Some of my type 2 friends are using a pump and a CGM.
In the 1990s I stopped using animal insulins, and began using synthetic insulins. I began gaining weight, even though I was following a much healthier diet, and eating fewer carbs. The only thing that had changed was my insulin. I have read many reports that say the synthetic insulins cause our cells to store fat. Maybe that was the reason for my weight gain, but I did not know that information until much later. I had never been more than five pounds above my ideal weight (185) until the 1990s. By the year 1997 I weighed 242 pounds. That was a net gain of 57 pounds. A lower carb intake and plenty of exercise did not seem to help at that time.
Finally, in 1998, I was diagnosed with insulin resistance. I had several relatives with Type 2 diabetes, and it seems likely I had the Type 2 gene. The gene and the weight gain are likely the explanation for my insulin resistance. In the early 2000s I reduced my daily carb intake, increased my amount of exercise, and lost 34 pounds. I initially used avandia for my IR, but started using metformin starting in early 2011. Using metformin for one year has been very good for me. That medication has helped many diabetics lose weight. I have lost an additional nineteen pounds, and am presently only four pounds above my ideal weight. Despite the weight loss, I still have IR. Metformin, eating an average of 140-150 carbs per day, and getting lots of exercise is keeping me in good health. My A1c's are typically below 6.0, and except for some mild nerve damage, I do not have any diabetes complications. Double diabetes can be controlled, and my health is just as good now as it was before I became a double diabetic.