Abstract
BACKGROUND: Individuals with chronic kidney disease (CKD) are at substantial risk for cardiovascular mortality, but the risk associated with specific glomerular filtration rates (GFRs) is unknown. The objective of this study was to investigate the relationship between level of kidney function and the risk of cardiovascular mortality in a diverse population. METHODS AND RESULTS: This was a nonconcurrent cohort study of 34,982 ambulatory patients. Kidney function was entered into the model as a time-dependent variable to minimize misclassification and allow for improved estimate of the effect of decreasing GFR on cardiovascular mortality. The adjusted hazard ratio for cardiovascular mortality was 1.00 (95% CI 0.93-1.06) with an estimated GFR (eGFR) of 45-59; 1.77 (95% CI 1.65-1.89) with an eGFR 30-44; 3.75 (95% CI 3.47-4.06) with an eGFR 15-29, and 3.83 (95% CI 3.40-4.33) with an eGFR <15. CONCLUSION: We demonstrate a graded risk of cardiovascular mortality with decreasing GFR, with a marked increase with an eGFR <45 ml/min/1.73 m(2). These data also suggest that the availability of eGFR to physicians has had little impact on reducing the cardiovascular risk facing individuals with CKD. Our findings further highlight the public health significance of CKD and the importance of its early identification and management to reduce cardiovascular mortality.