Estimating glomerular filtration rate in diabetes: a comparison of cystatin-C- and creatinine-based methods.
OBJECTIVE
We compared the predictive performance of a GFR based on serum cystatin C levels with commonly used creatinine-based methods in subjects with diabetes.


METHODS
In a cross-sectional study of 251 consecutive clinic patients, the mean reference (plasma clearance of (99m)Tc-diethylene-triamine-penta-acetic acid) GFR (iGFR) was 88+/-2 ml min(-1) 1.73 m(-2). A regression equation describing the relationship between iGFR and 1/cystatin C levels was derived from a test population (n=125) to allow for the estimation of GFR by cystatin C (eGFR-cystatin C). The predictive performance of eGFR-cystatin C, the Modification of Diet in Renal Disease 4 variable formula (MDRD-4) and Cockcroft-Gault (C-G) formulas were then compared in a validation population (n=126).


RESULTS
There was no difference in renal function (ml min(-1) 1.73 m(-2)) as measured by iGFR (89.2+/-3.0), eGFR-cystatin C (86.8+/-2.5), MDRD-4 (87.0+/-2.8) or C-G (92.3+/-3.5). All three estimates of renal function had similar precision and accuracy.


CONCLUSIONS
Estimates of GFR based solely on serum cystatin C levels had the same predictive potential when compared with the MDRD-4 and C-G formulas.
Macisaac
R J
RJ
Endocrine Centre and the Department of Medicine, Austin Health and University of Melbourne, Heidelberg Repatriation Hospital, Level 2, Centaur Building, Heidelberg West, VIC, 3081, Australia. r.macisaac@unimelb.edu.au
Tsalamandris
C
C
Thomas
M C
MC
Premaratne
E
E
Panagiotopoulos
S
S
Smith
T J
TJ
Poon
A
A
Jenkins
M A
MA
Ratnaike
S I
SI
Power
D A
DA
Jerums
G
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003404:Creatinine / Q000032:analysis*; D003430:Cross-Sectional Studies; D055316:Cystatin C; D015891:Cystatins / Q000032:analysis*; D005919:Glomerular Filtration Rate; D006801:Humans; D008875:Middle Aged; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D003404:Creatinine