Serum Cystatin C(Cys-C) has been proposed as a marker of glomerular filtration rate(GFR). Serum creatinine (creatinine) is widely used to estimate the glomerular filtration rate, but its tubular secretion, dependence on muscle mass, alteration in some inflammatory diseases, and analytical interferences can limit its utility. Thus, Cys-C has been proposed as a novel biomarker of kidney function.