Clinical and Experimental Nephrology

, Volume 11, Issue 1, pp 41–50

Estimation of glomerular filtration rate by the MDRD study equation modified for Japanese patients with chronic kidney disease

Authors

    • Department of NephrologyOsaka University Graduate School of Medicine
  • Masaru Horio
    • Department of Functional Diagnostic ScienceOsaka University Graduate School of Medicine
  • Kosaku Nitta
    • Fourth Department of MedicineTokyo Women's University of Medicine
  • Kunihiro Yamagata
    • Department of Nephrology, Institute of Clinical Medicine, Graduate School of Comprehensive Human SciencesUniversity of Tsukuba
  • Kunitoshi Iseki
    • Dialysis UnitUniversity Hospital of The Ryukyus
  • Shigeko Hara
    • Health Medical CenterToranomon Hospital
  • Nobuyuki Ura
    • Second Department of Internal MedicineSapporo Medical University School of Medicine
  • Yutaka Kiyohara
    • Department of Environmental Medicine, Graduate School of Medical SciencesKyushu University
  • Hideki Hirakata
    • Nephrology and Dialysis CenterFukuoka Red Cross Hospital
  • Tsuyoshi Watanabe
    • Third Department of MedicineFukushima Medical University
  • Toshiki Moriyama
    • Healthcare CenterOsaka University
  • Yasuhiro Ando
    • Department of NephrologyJichi Medical School
  • Daiki Inaguma
    • Tosei Hospital
  • Ichiei Narita
    • Division of Nephrology and RheumatologyNiigata University
  • Hiroyasu Iso
    • Department of Public HealthOsaka University Graduate School of Medicine
  • Kenji Wakai
    • Aichi Cancer Institute
  • Yoshinari Yasuda
    • Department of NephrologyNagoya University Graduate School of Medicine
  • Yusuke Tsukamoto
    • Syuwa General Hospital
  • Sadayoshi Ito
    • Division of Nephrology, Endocrinology and Vascular MedicineTohoku University Graduate School of Medicine
  • Hirofumi Makino
    • Department of Medicine and Clinical ScienceOkayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences
  • Akira Hishida
    • First Department of MedicineHamamatsu University School of Medicine
  • Seiichi Matsuo
    • Department of NephrologyNagoya University Graduate School of Medicine
ORIGINAL ARTICLE

DOI: 10.1007/s10157-006-0453-4

Cite this article as:
Imai, E., Horio, M., Nitta, K. et al. Clin Exp Nephrol (2007) 11: 41. doi:10.1007/s10157-006-0453-4

Abstract

Background

Accurate estimation of the glomerular filtration rate (GFR) is crucial for the detection of chronic kidney disease (CKD). In clinical practice, GFR is estimated from serum creatinine using the Modification of Diet in Renal Disease (MDRD) study equation or the Cockcroft-Gault (CG) equation instead of the time-consuming method of measured clearance for exogenous markers such as inulin. In the present study, the equations originally developed for a Caucasian population were tested in Japanese CKD patients, and modified with the Japanese coefficient determined by the data.

Methods

The abbreviated MDRD study and CG equations were tested in 248 Japanese CKD patients and compared with measured inulin clearance (Cin) and estimated GFR (eGFR). The Japanese coefficient was determined by minimizing the sum of squared errors between eGFR and Cin. Serum creatinine values of the enzyme method in the present study were calibrated to values of the noncompensated Jaffé method by adding 0.207 mg/dl, because the original MDRD study equation was determined by the data for serum creatinine values measured by the noncompensated Jaffé method. The abbreviated MDRD study equation modified with the Japanese coefficient was validated in another set of 269 CKD patients.

Results

There was a significant discrepancy between measured Cin and eGFR by the 1.0 × MDRD or CG equations. The MDRD study equation modified with the Japanese coefficient (0.881 × MDRD) determined for Japanese CKD patients yielded lower mean difference and higher accuracy for GFR estimation. In particular, in Cin 30–59 ml/min per 1.73 m2, the mean difference was significantly smaller with the 0.881 × MDRD equation than that with the 1.0 × MDRD study equation (1.9 vs 7.9 ml/min per 1.73 m2; P <?0.01), and the accuracy was significantly higher, with 60% vs 39% of the points deviating within 15%, and 97% vs 87% of points within 50%, respectively (both P <?0.01). Validation with the different data set showed the correlation between eGFR and Cin was better with the 0.881 × MDRD equation than with the 1.0 × MDRD study equation. In Cin less than 60 ml/min per 1.73 m2, the accuracy was significantly higher, with 85% vs 69% of the points deviating within 50% (P <?0.01), respectively. The mean difference was also significantly smaller (P <?0.01). However, GFR values calculated by the 0.881 × MDRD equation were still underestimated in the range of Cin over 60 ml/min per 1.73 m2.

Conclusions

Although the Japanese coefficient improves the accuracy of GFR estimation of the original MDRD study equation, a new equation is needed for more accurate estimation of GFR in Japanese patients with CKD stages 3 and 4.

Key words

Serum creatinineInulin clearanceGlomerular filtration rateChronic kidney disease

Copyright information

© Japanese Society of Nephrology 2007