Approximately 95% of the human body’s total creatine is located in skeletal muscle and serum Cre can be served as a surrogate marker of skeletal muscle mass even in CKD patients16 The previous study revealed that visceral adipose tissue detected by CT scan was associated with CKD when defined using cystatin C estimating equations but not when using a Cre-based estimating Eq. 17 On the other hand, area of skeletal muscle and area of visceral fat were not identified as influential factors in the ML analysis. The gene discussed is CST3; the disease is chronic kidney disease.