Multicenter Study of Creatinine- and/or Cystatin C-Based Equations for Estimation of Glomerular Filtration Rates in Chinese Patients with Chronic Kidney Disease

Abstract

Objective To establish equations for the estimation of glomerular filtration rates (eGFRs) based on serum creatinine (SCr) and/or serum cystatin C (SCysC) in Chinese patients with chronic kidney disease (CKD), and to compare the new equations with both the reference GFR (rGFR) and the literature equations to evaluate their applicability.Methods The 788 Chinese CKD patients were randomly divided into two groups, the training group and the testing group, to establish new eGFR-formulas based on serum CysC and to validate the established formulas, respectively. 99mTc-DTPA clearance (as the rGFR), serum Cr, and serum CysC were determined for all patients, and GFR was calculated using the Cockcroft-Gault equation (eGFR1), the MDRD formula (eGFR2), the CKD-EPI formulas (eGFR3, eGFR4), and the Chinese eGFR Investigation Collaboration formulas (eGFR5, eGFR6). The accuracy of each eGFR was compared with the rGFR.Results The training and testing groups' mean GFRs were 50.84±31.36 mL/min/1.73 m2 and 54.16±29.45 mL/min/1.73 m2, respectively. The two newly developed eGFR formulas were fitted using iterative computation: and . Significant correlation was observed between each eGFR and the rGFR. However, proportional errors and constant errors were observed between rGFR and eGFR1, eGFR2, eGFR4, eGFR5 or eGFR6, and constant errors were observed between eGFR3 and rGFR, as revealed by the Passing & Bablok plot analysis. The Bland-Altman analysis illustrated that the 95% limits of agreement of all equations exceeded the previously accepted limits of <60 mL/min •1.73 m2, except the equations of eGFR7 and eGFR8.Conclusion The newly developed formulas, eGFR7 and eGFR8, provide precise and accurate GFR estimation using serum CysC detection alone or in combination with serum Cr detection. Differences in detection methods should be carefully considered when choosing literature eGFR equations to avoid misdiagnosis and mistreatment.

Applicability of estimating glomerular filtration rate equations in pediatric patients: comparison with a measured glomerular filtration rate by iohexol clearance

“…2 The combined equation is commonly employed in adult hospitals as the method for eGFR in adults, replacing the popular MDRD eGFR. 24,25 Similarly to others in adults and children, we found that all three combined (Scr with Scys) equations outperformed equations that used the Scr or Scys, alone.…”

Estimating glomerular filtration rate by serum creatinine or/and cystatin C equations: An analysis of multi‐centre Chinese subjects

“…Chinese investigators have proposed a series of GFR estimation equations based on serum creatinine or/and cystatin C in recent years . Yet, only limited data exist outside the development cohort regarding their application in Chinese individuals.…”

“…22 Chinese investigators have proposed a series of GFR estimation equations based on serum creatinine or/and cystatin C in recent years. [4][5][6][7] Yet, only limited data exist outside the development cohort regarding their application in Chinese individuals. In our previous study, CKD-EPIscr-cys achieved ideal performance in overall population while Mascr and Mascr-cys equations appeared more biased and less accurate.…”

“…Analogous to different epidemiological studies in other countries, the CKD prevalence was reported to be 10.8% in China, equivalent to 119.5 million CKD patients. 1 To find an accurate, convenient, and reproducible GFR-estimating method, a series of GFR-estimation equations utilizing cystatin C instead of, or in addition to, creatinine have been proposed by the CKD-EPI collaboration (CKD-EPIscr, 2 CKD-EPIcys 3 and CKD-EPIscr-cys 3 equations) and Chinese investigators (Mascr, 4 Peiscr, 5 Macys, 6 Fengcys, 7 Mascr-cys 6 and Fengscr-cys 7 equations). These equations, however, are not fully validated in the Chinese population outside of their original development population, and the question exists whether GFR estimation is improved using cystatin C based equations.…”

A comparison of the effects of ketamine and remifentanil on renal functions in coronary artery bypass graft surgery

“…Gold standard procedures for measurement of GFR (inulin, iohexol, 51Cr-EDTA, 99mTc-DTPA and 125I-iothalamate clearance) are timeconsuming, have side effects for patient or expensive. 11,12 Estimated GFR (eGFR) formulas have been developed and used in more than 80% of clinical laboratories in the United States because of the aforementioned problems. 13 The most common formulas used in the calculation of eGFR include MDRD and recently CKD-EPI equations.…”