Estimation of GFR by different creatinine- and cystatin-C-based equations in anorexia nervosa.
BACKGROUND
Patients with anorexia nervosa (AN) are at high risk of renal failure. Glomerular filtration rate (GFR) is overestimated when estimated by the creatinine-based equations. We have studied the accuracy and precision of cystatin C-based equations.


METHODS
27 AN patients were included. GFR was measured with the chromium-51-ethylenediaminetetraacetate (51Cr-EDTA) method. We have compared the accuracy and precision of creatinine-based equations (MDRD and Cockcroft) with those of different new cystatin C-based equations.


RESULTS
The creatinine-based equations overestimate measured GFR, especially the MDRD study equation. All the cystatin C-based equations also overestimate measured GFR. The Cockcroft and Gault formula and the cystatin C-based equation published by Rule have the best accuracy and precision, but these last performances remain unsatisfactory.


CONCLUSIONS
Both creatinine and cystatin C-based equations strongly overestimate measured in patients with AN.
Delanaye
P
P
Department of Nephrology-Dialysis, University of Liège, CHU Sart Tilman, Liège, Belgium. pierre_delanaye@yahoo.fr
Cavalier
E
E
Radermecker
R P
RP
Paquot
N
N
Depas
G
G
Chapelle
J-P
JP
Scheen
A J
AJ
Krzesinski
J-M
JM
D000293:Adolescent; D000328:Adult; D000856:Anorexia Nervosa / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D003937:Diagnosis, Differential; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009391:Nephelometry and Turbidimetry; D011379:Prognosis; D051437:Renal Insufficiency / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013057:Spectrum Analysis; D055815:Young Adult
D055316:Cystatin C; D003404:Creatinine