March 8, 2008
Other
Question from India:
Can decreased creatinine clearance with normal S.Creatine and BUN can still be related to non-kidney disease? Can decreased muscle movement (sedentary lifestyle or lack of physical activities/exercise, etc.) or variations in normal muscular tone be relevant to decreased creatinine clearance? If so, can it still be normal?
Answer:
It is not so much muscle tone as it is muscle mass. Therefore, as older individuals age, and as their muscle mass goes down and produces less creatine, the serum creatinine may not reflect true clearance. A lot of the laboratories in the U.S. are going to cystatin C as the marker for renal function in chronic renal failure. It is a serum test that very accurately reflects kidney function with progressive renal failure.
JTL