Reference intervals for serum creatinine with enzymatic assay and evaluation of four equations to estimate glomerular filtration rate in a healthy Chinese adult population

Background: With the wide usage of enzymatic assays to determine serum creatinine (Scr) in China, reference interval (RI) needs to be established. At the same time, the performance of Scr based equations to calculate estimated glomerular filtration rate (eGFR) in healthy Chinese adults has not been extensively investigated. Methods: This study has strictly followed the International Federation of Clinical Chemistry (IFCC) recommendations and the Clinical Laboratory Standards Institute (CLSI) C28-A2 document. A total number of 778 healthy Chinese adults (male 433, female 345) were enrolled in this study. Results: By nonparametric method, RIs for males were: <60 years, 58-93 mu mol/l and >60 years, 54-109 mu mol/l; RIs for females were: <60 years, 42-69 mu mol/l and >60 years, 43-83 mu mol/l. Modification of Diet in Renal Disease (MDRD) equation and MDRD for Japanese made the percentage of eGFR >90 ml/min/1.73 m(2) 31.7% and 4.9%; percentage of eGFR 60-89 ml/min/1.73 m(2) 65.2% and 64.0%, respectively. Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and CKD-EPI for Asian made the percentage of eGFR >90 ml/min/1.73 m(2) 89.2% and 94.0%; percentage of eGFR 60-89 ml/min/1.73 m(2) 10.3% and 5.7%, respectively. Conclusion: Scr RIs of healthy Chinese adults were found to be lower than those of Caucasians. Two MDRD equations underestimated GFR, while two CKD-EPI equations seemed to estimate a reasonable distribution of eGFR in healthy Chinese adult populations. (C) 2011 Elsevier B.V. All rights reserved.