title: Evaluation of serum creatinine- and cystatin C-based equations for the estimation of glomerular filtration rate in a Chinese population.
abstract: OBJECTIVE
  This study aimed to evaluate the applicability of a selection of glomerular filtration rate (GFR) estimating equations based on serum creatinine (SCr) and serum cystatin C in a Chinese population.
  
  
  METHODS
  Estimated GFR values from 10 equations were compared with reference GFR (rGFR) from the (99m)Tc-DTPA renal dynamic imaging method. The study enrolled 569 Chinese participants (41.5% women, 53.5 ± 16.9 years, range 19-92 years), with mean rGFR 74.80 ± 26.10 (range 9.8-146.8 ml/min/1.73 m(2)).
  
  
  RESULTS
  Bland-Altman analysis illustrated that the 95% agreement limits of all the equations surpassed the acceptable tolerance (<60 ml/min/1.73 m(2)), of which the MacIsaac equation was the closest one, reaching 71.7 ml/min/1.73 m(2). Linear regression analysis also demonstrated a consistent result. When assessed in all participants, the accuracy of the six equations reached and exceeded the acceptable level (≥70%), of which the Shanghai and MacIsaac equations gained more accuracy than others. When compared in subgroups, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), MacIsaac and Cockcroft-Gault (CG) equations were optimal for rGFR stages ≥ 90 ml/min/1.73 m(2), 30-89 ml/min/1.73 m(2) and < 30 ml/min/1.73 m(2), respectively.
  
  
  CONCLUSIONS
  The results demonstrated that further improvement is needed for the selected 10 equations. Not all the cystatin C equations were superior to SCr equations. They have their own applicability at various GFR levels. At present, the CKD-EPI, MacIsaac and CG equations may be applied to evaluate GFR in normal, mild to moderate and severe kidney function, respectively.
authors.affiliation: Division of Nephrology, Department of Geriatrics, School of Public Health, Nanjing Medical University, Nanjing, PR China.
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Pei
authors.forename: Juan
authors.initials: J
authors.lastname: He
authors.forename: Qiao
authors.initials: Q
authors.lastname: Liu
authors.forename: Bei
authors.initials: B
authors.lastname: Zhu
authors.forename: Li-Hua
authors.initials: LH
authors.lastname: Bao
authors.forename: Chen-Jing
authors.initials: CJ
authors.lastname: Yan
authors.forename: Jian-Qing
authors.initials: JQ
authors.lastname: Wu
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D044466:Asian People; D015415:Biomarkers; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011866:Radioisotope Renography; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis*; D016284:Technetium Tc 99m Pentetate
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine; D016284:Technetium Tc 99m Pentetate