Got my metabolic panel back and creatinine is flagged over range again, second time now, and the eGFR came out low alongside it. Im sitting around 240lb, lift heavy 5 days a week, been on creatine for years and eat a ton of protein daily. Doctor took one look and started talking about kidney function which put the wind up me a bit. Is this actually my kidneys packing in or is it just the muscle mass and the creatine throwing the number off? Anyone else big get flagged for this and how did you actually work out whether it was real or not?