Cystatin C and Creatinine Concentrations are Uninformative Biomarkers of Sarcopenia: A Cross-Sectional NHANES Study

Differences in creatinine and cystatin C-based estimates of glomerular filtration rate (eGFRDiff = eGFRCr – eGFRCysC) may reflect differences in muscle mass. We sought to determine if eGFRDiff (1) reflects lean mass, (2) identifies sarcopenic individuals beyond estimates based on age, BMI, and sex; and (3) demonstrates associations differently in those with and without chronic kidney disease (CKD).