@windyshores
The best marker for kidney function is a Cystantin C test. Other than Medicare, some insurance companies do not cover this test. My nephrologist tells me that she is not so concerned about the creatinine eGFR as many are bodybuilders or exercise a great deal to get lean muscle mass. Ideally, she says both tests should be about the same eGFR. You are in good hands if your Cystatin C is high. Incidentally, I read somewhere that Cystatin C is in the high 90s percentile for accuracy of kidney disease as opposed to creatinine eGFR which is in the 60s. Interesting!