TY - JOUR
T1 - Understanding estimated glomerular filtration rate
T2 - Implications for identifying chronic kidney disease
AU - Rule, Andrew D.
PY - 2007/5
Y1 - 2007/5
N2 - PURPOSE OF REVIEW: Glomerular filtration rate (GFR) can be estimated using serum markers such as serum creatinine (SCr) or cystatin C. This review presents new insights into estimated GFR based on theory, validation studies, SCr assay standardization, cystatin C, and longitudinal comparison with measured GFR. RECENT FINDINGS: The estimation of GFR by SCr differs in health and in chronic kidney disease (CKD) due to differences in GFR range and in creatinine production between these two populations. Among populations with normal baseline GFR, there is a more rapid decline in measured GFR than in SCr-based estimated GFR. While elevated SCr is specific for CKD, other disease processes may lead to elevated cystatin C. Validation is improved by refitting equation coefficients to compare populations, recognizing the asymmetry between estimated GFR and measured GFR, and using residual plots instead of Bland-Altman plots to assess bias. SUMMARY: As a screening test, SCr should be interpreted as a marker of CKD probability in the context of the patient's clinical presentation. Measured GFR or creatinine clearance may be helpful in high-risk patients with normal SCr levels. GFR estimating equations should be reserved for patients with identified CKD. Standardized SCr and cystatin C assays are needed.
AB - PURPOSE OF REVIEW: Glomerular filtration rate (GFR) can be estimated using serum markers such as serum creatinine (SCr) or cystatin C. This review presents new insights into estimated GFR based on theory, validation studies, SCr assay standardization, cystatin C, and longitudinal comparison with measured GFR. RECENT FINDINGS: The estimation of GFR by SCr differs in health and in chronic kidney disease (CKD) due to differences in GFR range and in creatinine production between these two populations. Among populations with normal baseline GFR, there is a more rapid decline in measured GFR than in SCr-based estimated GFR. While elevated SCr is specific for CKD, other disease processes may lead to elevated cystatin C. Validation is improved by refitting equation coefficients to compare populations, recognizing the asymmetry between estimated GFR and measured GFR, and using residual plots instead of Bland-Altman plots to assess bias. SUMMARY: As a screening test, SCr should be interpreted as a marker of CKD probability in the context of the patient's clinical presentation. Measured GFR or creatinine clearance may be helpful in high-risk patients with normal SCr levels. GFR estimating equations should be reserved for patients with identified CKD. Standardized SCr and cystatin C assays are needed.
KW - Cystatin C
KW - Estimating equations
KW - Glomerular filtration rate
KW - Serum creatinine
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U2 - 10.1097/MNH.0b013e328057de8b
DO - 10.1097/MNH.0b013e328057de8b
M3 - Review article
C2 - 17420668
AN - SCOPUS:34247240950
SN - 1062-4821
VL - 16
SP - 242
EP - 249
JO - Current opinion in nephrology and hypertension
JF - Current opinion in nephrology and hypertension
IS - 3
ER -