i am a 77 year old man with diabetes under control last a1c was 6.2i have serum creatinine of 1.6 and estimated gfr of 45.i never had protein in my urine and last 2 microalbumin tests were normal.the doctor said i am stage 3 kidney desease.they dont seem to think normal microalbunin is important just that damn gfr.anyway how nuch kidney function do i have left?read a reasuring article that said most elderly people that have stage 3 kidney damage/stay at stage 3 and dont progress to further kidney damage.is this true