hi, i am not 100% about this but in my experience if the nurse is referring to a low number it is possibly your eGFR test, which you really want to be above 60, anything lower indicates kidney disease, and i believe any lower than 15 is kidney failure. Mine fluctuates continously between 40 and 65 - and i believe many diabetics are on medications like ACE inhibitors to help prevent damage to the kidneys. I was told things like keeping good diabetic control, low bp etc all help.