The clinical value of cystatin C in the assessment of renal injury of patients with chronic kidney disease at the early and middle stage

Objective To explore the clinical value of cystatin C (Cys C) in the assessment of renal injury of patients with chronic kidney disease at the early and middle stage.Methods A total of 221 patients with CKD stage 1-3 were enrolled in this study.Serum Cys C,serum creatinine (SCr),blood urea nitrogen (BUN),serum uric acid (BUA) and albumin (Alb) were tested,and compared with estimated glomerular filtration rate (GFR) based on MDRD formula.Results Serum Cys C increased while GFR decreased in different groups,the level of serum Cys C and GFR were significantly different(P0.05).Serum Cys C was positively correlated with SCr (r=0.650,P=0.000),BUN (r=0.631,P=0.000) and BUA(r=0.309,P=0.000),and negatively correlated with GFR(r=-0.717,P=0.000).The percentage of patients with elevating level of Cys C with CKD at stage 2 and stage 3 were 32.8% and 70%,respectively,while with the increasing level of SCr were 0 and 58.4%,respectively(P0.05).The AUCROC for Cys C and SCr were 0.853 and 0.924,respectively.An increase of AUCROC (0.940) was observed when combined Cys C with SCr.Conclusions Cys C is a sensitive marker to detect mild and middle renal insufficiency.Combination of the used of Cys C and SCr as the indicator may improve the diagnostic efficacy for patients with chronic kidney disease at the early and middle stage.