Abstract MP073: Combining Multiple Kidney Markers to Predict Future Risk of Clinical Outcomes: The Atherosclerosis Risk in Communities (ARIC) Study
Background There is substantial interest in investigating how multiple chronic kidney disease (CKD) markers combine to predict risk, in particular using eGFR by cystatin C (eGFRcys) as a supplement to traditional CKD markers, eGFR by creatinine (eGFRcr) and albumin: creatinine ratio (ACR).
Methods We followed 10,268 participants for a median of 11.2 years. Participants were classified into 8 categories: (1) no CKD by any marker (reference); CKD by either (2) eGFRcr or (3) eGFRcys (<60 ml/min/1.73 m2) or (4) ACR (≥30 mg/g) only; CKD by both (5) eGFRcys and eGFRcr or (6) eGFRcys and ACR or (7) eGFRcr and ACR; and (8) CKD by all 3 markers. Cox proportional hazard models were used to estimate hazard ratios.
Results Risk increased with the number of markers indicating CKD. eGFRcr<60 alone (ACR and eGFRcys normal) was associated with increased risk of ESRD but not other outcomes [mortality: 0.95 (0.7, 1.2); coronary heart disease: 0.9 (0.6, 1.2); heart failure: 0.9 (0.6, 1.2); acute kidney injury: 1.3 (0.9, 2.0)] compared to individuals without CKD by any marker. In contrast, eGFRcys <60 alone was associated with increased risk of all outcomes except coronary heart disease. When all three markers were abnormal, risk was higher compared to when combination of eGFRcr and ACR were abnormal, particularly for ESRD [ESRD: 109.2 (66.3, 179.9) vs. 12.2 (4.6, 32.2)]. More markers indicating CKD were associated with higher risk for each of the five outcomes examined after adjustment for covariates (Table).
Conclusions Cystatin C is a useful confirmatory marker in those with eGFRcr<60 to predict future risk of mortality, cardiovascular and kidney outcomes, particularly in the absence of albuminuria (i.e., when creatinine is the only criterion used to define CKD). Cystatin C may be used as a supplement to traditional CKD markers when more precise information about risk is needed.
- © 2012 by American Heart Association, Inc.