Higher than normal serum creatinine means damaged kidney function. Creatinine is a production of your body, if the kidney functions normally, the crreatinine will stay in a normal range. When it goes higher, it means the kidney can't metabolize it normally. The damaged kidney function is eventually developing into kidney failure, the key is to start treatment at an early stage, so as to slow down the progression. Kidney health is largely linked to diabetes. A1C 7.5% is in the diabetes range. So the first thing to do is to take your diabetes medicine or insulin regularly, make sure the blood sugar (before meal, after meal, bedtime) are all well managed, meaning less than 130 before meal, less than 180 after meal, less than 140 bedtime. If you have the meds for kidney, start to take them. If not, try to drink more water.