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Standardization of p-creatinine assays and use of lean body mass allow improved prediction of calculated glomerular filtration rate in adults: A new equation

Nyman, U.; Björk, Jonas LU ; Sterner, Gunnar LU ; Back, S-E; Carlson, Joyce LU ; Lindström, Veronica LU ; Bakoush, Omran LU and Grubb, Anders LU (2006) In Scandinavian Journal of Clinical & Laboratory Investigation 66(6). p.451-468
Abstract
Objective. To evaluate the Cockcroft - Gault (CG) equation, using various body weight expressions, and the Sawyer equation in predicting glomerular filtration rate (GFR) using an enzymatic and zero-calibrated Jaffe plasma-creatinine assay, and to derive a new robust equation in adults. Material and methods. The CG weight measures included total, ideal and adjusted body weight (ABW; lowest of total and ideal) and two lean body mass (LBM) expressions, while the Sawyer equation is based primarily on LBM. Iohexol clearance was used to measure GFR. One derivation set (n = 436; enzymatic assay) was used to evaluate and bias-adjust existing equations when indicated, and to derive a new equation based on plasma-creatinine, age, gender and the body... (More)
Objective. To evaluate the Cockcroft - Gault (CG) equation, using various body weight expressions, and the Sawyer equation in predicting glomerular filtration rate (GFR) using an enzymatic and zero-calibrated Jaffe plasma-creatinine assay, and to derive a new robust equation in adults. Material and methods. The CG weight measures included total, ideal and adjusted body weight (ABW; lowest of total and ideal) and two lean body mass (LBM) expressions, while the Sawyer equation is based primarily on LBM. Iohexol clearance was used to measure GFR. One derivation set (n = 436; enzymatic assay) was used to evaluate and bias-adjust existing equations when indicated, and to derive a new equation based on plasma-creatinine, age, gender and the body weight measure yielding the best adjusted R-2. All equations were then validated in a separate set (n = 414; Jaffe assay). Results. The existing equations all performed similarly in both sets. Prediction errors of equations based on LBM showed no correlation with BMI. The CG(ABW) and Sawyer equations performed best. The new equation with LBM yielded the highest adjusted R-2. In the combined set (n = 850), its accuracy (86%/98% of estimates within 30%/50% of measured GFR) was significantly better than for the CGABW (79%/95%) and Sawyer equations (79%/93%) (p < 0.001) for each 30 mL/min GFR subgroup within +/- 30% and +/- 50%, except within +/- 30% > 120 mL/min. Prediction error did not correlate with BMI, age or gender. Conclusion. A new creatinine-based equation derived in a mainly Caucasian patient sample is a better predictor of GFR than CG-type equations irrespective of the body weight measure used or, if bias-adjusted, when using zero-calibrated creatinine assays. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
kidney, kidney disease, drug therapy, glomerular filtration rate, function tests, renal insufficiency
in
Scandinavian Journal of Clinical & Laboratory Investigation
volume
66
issue
6
pages
451 - 468
publisher
Informa Healthcare
external identifiers
  • pmid:17000553
  • wos:000240743500001
  • scopus:33749012540
ISSN
1502-7686
DOI
10.1080/00365510600902362
language
English
LU publication?
yes
id
077765c2-25ca-4adb-a722-4734d873743c (old id 389947)
date added to LUP
2007-08-20 11:29:22
date last changed
2019-03-27 03:07:39
@article{077765c2-25ca-4adb-a722-4734d873743c,
  abstract     = {Objective. To evaluate the Cockcroft - Gault (CG) equation, using various body weight expressions, and the Sawyer equation in predicting glomerular filtration rate (GFR) using an enzymatic and zero-calibrated Jaffe plasma-creatinine assay, and to derive a new robust equation in adults. Material and methods. The CG weight measures included total, ideal and adjusted body weight (ABW; lowest of total and ideal) and two lean body mass (LBM) expressions, while the Sawyer equation is based primarily on LBM. Iohexol clearance was used to measure GFR. One derivation set (n = 436; enzymatic assay) was used to evaluate and bias-adjust existing equations when indicated, and to derive a new equation based on plasma-creatinine, age, gender and the body weight measure yielding the best adjusted R-2. All equations were then validated in a separate set (n = 414; Jaffe assay). Results. The existing equations all performed similarly in both sets. Prediction errors of equations based on LBM showed no correlation with BMI. The CG(ABW) and Sawyer equations performed best. The new equation with LBM yielded the highest adjusted R-2. In the combined set (n = 850), its accuracy (86%/98% of estimates within 30%/50% of measured GFR) was significantly better than for the CGABW (79%/95%) and Sawyer equations (79%/93%) (p &lt; 0.001) for each 30 mL/min GFR subgroup within +/- 30% and +/- 50%, except within +/- 30% &gt; 120 mL/min. Prediction error did not correlate with BMI, age or gender. Conclusion. A new creatinine-based equation derived in a mainly Caucasian patient sample is a better predictor of GFR than CG-type equations irrespective of the body weight measure used or, if bias-adjusted, when using zero-calibrated creatinine assays.},
  author       = {Nyman, U. and Björk, Jonas and Sterner, Gunnar and Back, S-E and Carlson, Joyce and Lindström, Veronica and Bakoush, Omran and Grubb, Anders},
  issn         = {1502-7686},
  keyword      = {kidney,kidney disease,drug therapy,glomerular filtration rate,function tests,renal insufficiency},
  language     = {eng},
  number       = {6},
  pages        = {451--468},
  publisher    = {Informa Healthcare},
  series       = {Scandinavian Journal of Clinical & Laboratory Investigation},
  title        = {Standardization of p-creatinine assays and use of lean body mass allow improved prediction of calculated glomerular filtration rate in adults: A new equation},
  url          = {http://dx.doi.org/10.1080/00365510600902362},
  volume       = {66},
  year         = {2006},
}