Once upon a time, diabetic kidney disease was rare. Diabetes tended to either: occur so severely that death resulted from DKA or occur in elderly persons (or at the least, elderly for their time) who tended to die of infectious disease before kidney disease could catch up with them.
In December 1936, Clifford Wilson (1906-1997) and Paul Kimmelstiel (1900-1970) published a paper about kidney disease in the American Journal of Pathology called Intercapillary Lesions in the Glomeruli of the Kidney, describing kidney disease (with intercapillary lesions in the glomeruli) that primarily occurred in diabetics who also had hypertension and kidney disease signs and symptoms such as albuminuria and edema. They speculated that diabetes might be the cause.
As an aside, the current wikipedia article mistakenly cites a different article by these two authors as the paper that first described diabetic nephropathy, but in fact their article on benign and malignant hypertension's only mention of diabetes is in noting that a small portion of autopsies showed pancreatic lesions.
Wilson and Kimmelstiel's description of diabetic kidney disease earned them the naming of the major type of diabetic nephropathy- Wilson-Kimmelstiel Disease.
However, it should be noted that the first paper mentioning that kidney changes could be seen in some diabetics was published in 1854.
Today, diabetic nephropathy is a major cause of death for type 1 diabetics; in some populations, it is the top cause but in most groups it ranks #2 or #3.
Landmark Papers in Nephrology, ed John Feehally et al. 2013