Cystatin C-based estimated GFR and albuminuria are independently associated with all-cause and CVD mortality in Korean population: The Dong-gu Study

Abstract

Objective: To assess the associations among the estimated glomerular filtration rate (eGFR), albumin to creatinine ratio (ACR), and all-cause and CVD mortality rate and to compare the performances of eGFR_MDRD, eGFR_CKD-EPI, and eGFR_cys using receiver operating characteristic (ROC) analysis in Korean adults aged ≥ 50 years.

Methods: Of the 9,260 subjects who participated in the baseline survey of a prospective longitudinal study conducted in Korea, 9,009 (men: 3,574 (39.7%); women: 5,435 (60.3%)) were included in this analysis after the exclusion of 217 subjects with missing eGFR and 34 subjects with missing ACR data.

Main outcome measure: The associations of eGFR and ACR with all-cause and CVD mortality were investigated using Cox proportional hazards models that included sex, age, waist circumference, smoking, alcohol intake, degree of physical activity, hypertension, diabetes, systolic blood pressure, log-HbA_1c, total cholesterol, log-triglyceride, log-HDL and log-ACR or eGFR.

Results: After adjustment for covariates, independent associations were found between all-cause mortality and the eGFR_cys (mL/min per 1.73 m²) [HR 1.23, 95% confidence interval (CI) 1.05-1.43 for 60-89 vs. ≥ 90; HR 1.87, 95% CI 1.49-2.34 for 45-59 vs. ≥ 90; HR 2.38, 95% CI 1.77-3.20 for 30-44 vs. ≥ 90; HR 2.82, 95% CI 1.89-4.23 for <30 vs. ≥ 90] and ACR (μg/mg creatinine) [HR 1.09, 95% CI 0.88-1.34 for Q2 vs. Q1; HR 1.34, 95% CI 1.10-1.63 for Q3 vs. Q1; HR 1.49, 95% CI 1.22-1.81 for Q4 vs. Q1]. In addition, independent associations of CVD mortality with the eGFR_cys and ACR were significant. In the comparison of eGFR performance, the ROC-plot AUC for all-cause mortality was significantly greater for the eGFR_cys than for the eGFR_MDRD and eGFR_CKD-EPI.

Conclusion: The eGFR_cys and ACR were associated independently with all-cause and CVD mortality after adjustment for covariates, including the eGFR_cys and ACR. In addition, the ROC-plot AUC for all-cause mortality was greater for the eGFR_cys than for the eGFR_MDRD and eGFR_CKD-EPI in Korean adults aged ≥ 50 years.

Keywords: Albuminuria; Creatinine; Cystatin C; Glomerular Filtration Rate; Mortality.