Cystatin C Is Not More Sensitive Than Creatinine for Detecting Early Renal Impairment in Patients With Diabetes

Am J Kidney Dis. 2001 Aug;38(2):310-6. doi: 10.1053/ajkd.2001.26096.

Abstract

This study evaluated serum cystatin C as a potential new marker of glomerular filtration rate (GFR) in 49 patients who had steady-state diabetes with early renal impairment. We determined the correlation between GFR measured by chromium 51-labeled EDTA and levels of serum cystatin C, serum creatinine, serum beta(2)-microglobulin, endogenous creatinine clearance, and Cockcroft formula. Sensitivity and specificity for the diagnosis of renal failure, defined as a GFR less than either 80 or 60 mL/min/1.73 m(2), were calculated by receiver operating characteristic (ROC) curves for creatinine, cystatin C, and beta(2)-microglobulin. Finally, we compared mean values of these three serum parameters in patients grouped according to GFR using the two definitions of renal failure. Correlation coefficients with GFR were -0.77 for serum creatinine level, -0.65 for serum cystatin C level, -0.71 for serum beta(2)-microglobulin level, +0.56 for endogenous creatinine clearance, and +0.69 for Cockcroft formula (all P < 0.001). With a cutoff value of 60 mL/min/1.73 m(2), areas under the ROC curve were 0.972 for beta(2)-microglobulin, 0.925 for cystatin C, and 0.916 for creatinine levels. With a cutoff value of 80 mL/min/1.73 m(2), these were 0.838 for beta(2)-microglobulin, 0.780 for cystatin C, and 0.905 for creatinine levels (P = not significant between parameters). These results were not altered after the exclusion of patients (n = 8) with a serum creatinine level greater than 1.41 mg/dL. When patients were classified into three groups according to GFR (group 1, >80 mL/min/1.73 m(2); group 2, 60 to 80 mL/min/1.73 m(2); group 3, <60 mL/min/1.73 m(2)), mean values of serum parameters in the three groups were statistically different (P < 0.0001) except between groups 1 and 2 for cystatin C and beta(2)-microglobulin. With patients classified into two groups (GFR > or < 80 mL/min/1.73 m(2)), mean values for each parameter were statistically different (P < 0.001). Sensitivity, specificity, and positive and negative predictive values for serum creatinine and serum cystatin C levels were very close for both definitions of renal failure. Serum cystatin C is not better than serum creatinine or serum beta(2)-microglobulin levels for estimating GFR in patients with steady-state diabetes using ROC curves or other validation tests.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Biomarkers / blood
  • Creatinine / blood*
  • Cystatin C
  • Cystatins / blood*
  • Diabetes Mellitus, Type 1 / complications*
  • Diabetes Mellitus, Type 2 / complications*
  • Diabetic Nephropathies / blood
  • Diabetic Nephropathies / diagnosis*
  • Diabetic Nephropathies / etiology
  • Female
  • Glomerular Filtration Rate
  • Humans
  • Male
  • Middle Aged
  • ROC Curve
  • Sensitivity and Specificity
  • beta 2-Microglobulin / blood

Substances

  • Biomarkers
  • CST3 protein, human
  • Cystatin C
  • Cystatins
  • beta 2-Microglobulin
  • Creatinine