Don't know of feline figures, wolf.
I have what is termed 'chronic kidney disease' with a creatine level of 180-ish, and all I 'get' is monitored once a year to make sure it hasn't gone up. Consultant told me some years ago that I'd probably die of heart failure of some sort before I died of kidney failure! (I liked his bluntness...)
Hope it's not more serious, and hope it's not your cat whose got kidney problems - far more serious in a cat than a human.
BillB