Do Type-1 and Type-2 Diabetes have a common origin?

We are constantly being told that there is a diabetes epidemic. No question there. The numbers are absolutely staggering. But there are inconsistencies in the picture given us.

100 years ago, both types were quite rare. But today they are both growing exponentially. This growth type strongly suggests some commonality between the 2 types.

There are overweight people that can't develop T2 diabetes no matter how hard they seem to try. People that have been very obese for most of their adult life. On the other hand there are thin, active people that develop T2 diabetes, some before middle age.

Scientists are gradually changing their tune. No longer is T2 diabetes always preventable, rather it can be significantly delayed. This leads to the conclusion that being overweight is just one component of the cause.

No explanation is presented for the exponential growth of T1 diabetes. Only that it's being looked at. At this time there is no known way of preventing it. It's become more and more like a lottery with an ever increasing chance of winning.

Type 1.5 has recently joined in and raises interesting questions. We now have T1.5 diabetics diagnosed in their early 20's. People that can manage on oral drugs at least for a lengthy initial period.

Either we are polluting our genetic pool or else we are poisoning our environment and food. When the final answer is found, we have to hope that it's not too late to fix the problem. Otherwise we have truly created an awful monster of huge proportions.

Looking at the other side of the coin... there are so many diabetics today compared to 100 years ago, in large part because treatment has turned the diagnosis has turned from a death sentence into a chronic disease. And diabetics are living much longer than ever before. 100 years ago an insulin-dependent diabetic usually died weeks after diagnosis (no insulin available). Today there are several that have lived 75 years thanks to insulin. Huge win.

Apples and oranges. The diagnosis thresholds have changed a lot in the past few decades. Diabetes for millenia was defined as "sugar in urine". How many people diagnosed in the past decade were diagnosed way before they ever started spilling sugar in urine? Probably most.

And until recently we didn't even have T1 and T2 defined. It was "juvenile-onset" and "adult-onset". Many "juvenile onset" diabetics never grew into adulthood even after the discovery of insulin. It would be wrong to assume that it was ever a one-to-one map from "juvenile and adult onset" into "T1 and T2", but it is easy to fall into the trap of think it's a one-to-one map.

You might want to read this. The source is the American Diabetes Association.
It's quite long and I haven't totally absorbed it yet. But it does contain some very interesting statistics.

The Rise of Childhood Type 1 Diabetes in the 20th Century
http://diabetes.diabetesjournals.org/content/51/12/3353.full