Evaluation of Glomerular Filtration Rate by Prediction Equation in the Elderly.
- Author:
Yong Su LEE
1
;
Kyu Beck LEE
;
Hyun Young LHEE
;
Hyang KIM
;
Seung Ho RYU
;
Jung Mi BARK
Author Information
1. Department of Internal Medicine, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Korea. kyubeck.lee@samsung.com
- Publication Type:Original Article
- Keywords:
Glomerular filtration rate;
Cockcroft-Gault;
MDRD;
Cystatin C;
Elderly
- MeSH:
Female;
Male;
Humans;
Sensitivity and Specificity
- From:Korean Journal of Nephrology
2006;25(5):745-752
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: The glomerular filtration rate (GFR) is considered the best overall index for the level of renal function and is estimated commonly by the creatinine-based, Cockcroft-Gault (CG) equation or the Modification of Diet Disease Study (MDRD) equation indirectly. Recently, cystatin C has been reported as a new endogenous marker of GFR. To predict the decrease of renal function in the elderly, we measured standard GFR (EDTA-GFR) by (51)Cr- EDTA and attempted to compare the result with CG, MDRD, and cystatin C equation for accuracy. METHODS: Sixty-three elderly persons (28 men, 35 women:mean age 70, range 65-78) who underwent health screening, were measured for plasma creatinine, cystatin C and EDTA-GFR. RESULTS: The CG and MDRD equations performed better than the cystatin C equation with an accuracy of within 30% (68 and 67%, respectively, versus 37%) and 50% (98 and 94%, respectively, versus 72%) of EDTA-GFR. The coefficient of determination (R2) of each estimated equation was 0.08 (p=0.03) in CG, 0.06 (p=0.04) in MDRD, and 0.07 (p=0.04) in cystatin C equation. Analysis of ROC curves with EDTA-GFR 60 mL/min/1.73m2 showed that each estimated equation was inadequate for the diagnosis of chronic kidney disease (sensitivity and specificity, 73% and 65% in CG, and 68% and 65% in MDRD, respectively). CONCLUSION: In the elderly, CG or MDRD equation was more accurate than cystatin C equation. Nevertheless, problems remain in the assessment of GFR using these equations and caution is particularly necessary in the diagnosis of chronic kidney disease with calculated estimates of GFR<60 mL/ min/1.73m2 in the elderly.
