I think you should know that diabetes affects the kidney. Diabetic kidney disease, also known as Diabetic nephropathy, is one of the key specific complication of diabetes. Thirty to Fifty percent of people who had kidney failure are found to be diabetic.
Blood sugar if not controlled and if it grows high, over a period of time, produces functional and later structural changes in the kidneys. But the unfortunate fact is, the changes that occur in the kidney is not clinically visible or traceable to the treating doctor. Only when the kidney function is severely affected and the disease has reached an irreversible stage, the symptoms are shown in the patient.