1. Estimating glomerular filtration rates by use of both cystatin C and standardized serum creatinine avoids ethnicity coefficients in Asian patients with chronic kidney disease.
- Author
-
Teo BW, Xu H, Wang D, Li J, Sinha AK, Shuter B, Sethi S, and Lee EJ
- Subjects
- Aged, Chronic Disease, Cross-Sectional Studies, Female, Humans, Kidney Diseases ethnology, Male, Middle Aged, Reference Standards, Asian People, Creatinine blood, Cystatin C blood, Glomerular Filtration Rate, Kidney Diseases physiopathology, White People
- Abstract
Background: The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is most accurate for estimating glomerular filtration rate (GFR) but requires an adjustment for African-American patients. Estimation equations are also improved with the use of serum cystatin C combined with standardized creatinine. Combination equations have been derived by the CKD-EPI and Chinese investigators. We investigated whether these cystatin C-based equations improve estimation adequately, so that adjustments for ethnicity are not required in a multiethnic Asian population with chronic kidney disease (CKD)., Methods: This was a cross-sectional study of 232 stable CKD patients who underwent GFR measurements using 3-sample plasma clearances of (99m)Tc-DTPA, and for whom serum cystatin C and creatinine were quantified., Results: For all patients, the median biases with cystatin C equations were generally greater than with the CKD-EPI equation, and precision and root mean square error (RMSE) were not significantly better. However, the combination serum creatinine and cystatin C equation improved the precision, RMSE, and percentage of estimated GFR to within 15% and 30% of the measured GFR (57.3% vs 50.0%, 88.4% vs 82.8%, respectively). The derived ethnicity coefficients for the combination equation were all >1 (1.009-1.082) but small, suggesting that coefficients are not required. The Chinese-specific equations were more biased and performed more poorly than the CKD-EPI equation., Conclusions: The use of a cystatin C and creatinine combination equation for estimating GFR in a multiethnic Asian population with CKD does not require ethnicity coefficients because the derived coefficients are very close to each other.
- Published
- 2012
- Full Text
- View/download PDF