I'm a male 50 and recently had blood tests with EGFR of 56. 2 other tests have 59 then 55. Going back through 10 years of results I've never been over 74. No symptoms. Had ultrasound on kidneys and perfect for shape, size, and blood flow.
Creatinine slightly high at 1.38. Rest of values are perfect. Non drinker health nut. Needless to say this freaked me out a bit.
After research, research and more research. (Remember kind of freaked out) I guess the EGFR is a calculation using age and other factors along with creatinine levels.
Creatinine levels can be higher in people with a lot of muscle from what I gather. Example: So if I'm 282lbs at 50 years old but my BF is 13% it means I have quite a bit of muscle and the EGFR may not be very accurate. I read I should actually be looking to get a Cystatin 3 Blood Test. It isn't as prone to false calculations with people with muscle mass or people that eat meat.
Anyone else come across a similar issue? Anyone with low EGFR but may have high muscle % and have this issue? Anyone get a Cystatin 3 blood test? Results?