What Causes High Kidney Function Levels And Foul Odour During Urination?

I am a healthy 53 year old female. I recently had a ck-up and my doctor s ofc called to advise that my blood work looked good, other than my kidney function levels were high (I believe was the term). I asked what that meant....the nurse said drink more water. I am very active. I exercise and lift weights at least 5x/wk. However, I also drink between 69 and 115 ounces of water each day. I have noticed over the last cpl mos that my urine seems to smell very old . Not every time I go, but more often than not. Thoughts?