Comparison of estimated glomerular filtration rate by the chronic kidney disease epidemiology collaboration (CKD-EPI) equations with and without Cystatin C for predicting clinical outcomes in elderly women

Wai H Lim; Joshua R Lewis; Germaine Wong; Robin M Turner; Ee M Lim; Peter L Thompson; Richard L Prince

doi:10.1371/journal.pone.0106734

Comparison of estimated glomerular filtration rate by the chronic kidney disease epidemiology collaboration (CKD-EPI) equations with and without Cystatin C for predicting clinical outcomes in elderly women

PLoS One. 2014 Sep 29;9(9):e106734. doi: 10.1371/journal.pone.0106734. eCollection 2014.

Authors

Wai H Lim¹, Joshua R Lewis², Germaine Wong³, Robin M Turner⁴, Ee M Lim⁵, Peter L Thompson⁶, Richard L Prince²

Affiliations

¹ University of Western Australia School of Medicine and Pharmacology, Sir Charles Gairdner Hospital Unit, Perth, Australia; Department of Renal Medicine, Sir Charles Gairdner Hospital, Perth, Australia.
² University of Western Australia School of Medicine and Pharmacology, Sir Charles Gairdner Hospital Unit, Perth, Australia; Department of Endocrinology and Diabetes, Sir Charles Gairdner Hospital, Perth, Australia.
³ Centre for Kidney Research, Children's Hospital at Westmead, Sydney, Australia; School of Public Health, Sydney Medical School, The University of Sydney, Sydney, Australia.
⁴ School of Public Health, The University of New South Wales, Sydney, Australia.
⁵ Department of Renal Medicine, Sir Charles Gairdner Hospital, Perth, Australia; PathWest, Sir Charles Gairdner Hospital, Perth, Australia.
⁶ Department of Cardiovascular Medicine, Sir Charles Gairdner Hospital, Perth, Australia.

Abstract

Background: Reduced estimated glomerular filtration rate (eGFR) using the cystatin-C derived equations might be a better predictor of cardiovascular disease (CVD) mortality compared with the creatinine-derived equations, but this association remains unclear in elderly individuals.

Aim: The aims of this study were to compare the predictive values of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)-creatinine, CKD-EPI-cystatin C and CKD-EPI-creatinine-cystatin C eGFR equations for all-cause mortality and CVD events (hospitalizations±mortality).

Methods: Prospective cohort study of 1165 elderly women aged>70 years. Associations between eGFR and outcomes were examined using Cox regression analysis. Test accuracy of eGFR equations for predicting outcomes was examined using Receiver Operating Characteristic (ROC) analysis and net reclassification improvement (NRI).

Results: Risk of all-cause mortality for every incremental reduction in eGFR determined using CKD-EPI-creatinine, CKD-EPI-cystatin C and the CKD-EPI-creatinine-cystatic C equations was similar. Areas under the ROC curves of CKD-EPI-creatinine, CKD-EPI-cystatin C and CKD-EPI-creatinine-cystatin C equations for all-cause mortality were 0.604 (95%CI 0.561-0.647), 0.606 (95%CI 0.563-0.649; p = 0.963) and 0.606 (95%CI 0.563-0.649; p = 0.894) respectively. For all-cause mortality, there was no improvement in the reclassification of eGFR categories using the CKD-EPI-cystatin C (NRI -4.1%; p = 0.401) and CKD-EPI-creatinine-cystatin C (NRI -1.2%; p = 0.748) compared with CKD-EPI-creatinine equation. Similar findings were observed for CVD events.

Conclusion: eGFR derived from CKD-EPI cystatin C and CKD-EPI creatinine-cystatin C equations did not improve the accuracy or predictive ability for clinical events compared to CKD-EPI-creatinine equation in this cohort of elderly women.

Publication types

Comparative Study
Randomized Controlled Trial
Research Support, Non-U.S. Gov't

MeSH terms

Aged
Biomarkers / blood*
Cystatin C / blood*
Female
Glomerular Filtration Rate*
Humans
Kidney Failure, Chronic / epidemiology
Kidney Failure, Chronic / physiopathology*
Prospective Studies
ROC Curve

Substances

Biomarkers
Cystatin C

Grants and funding

Dr. Lewis was supported by Raine Medical Research Foundation Priming Grant and Dr. Turner was supported by National Health and Medical Research Council (NHMRC) program grant #633003 to the Screening & Test Evaluation Program. The authors had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. The study was supported by Kidney Health Australia, Healthway Health Promotion Foundation of Western Australia and by project grants 254627, 303169 and 572604 from the National Health and Medical Research Council of Australia. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.