eGFR and coronary artery calcification in chronic kidney disease

Area of Science:

• Nephrology
• Cardiology
• Biomarkers

Background:

• The relationship between estimated glomerular filtration rate (eGFR) and coronary artery calcification (CAC) in predialysis chronic kidney disease (CKD) is not fully understood.
• CKD affects millions globally, increasing cardiovascular risk.

Purpose of the Study:

• To investigate the association between eGFR, calculated using various equations, and CAC in Korean predialysis CKD patients.
• To determine which eGFR equation provides the best prediction for CAC in this population.

Main Methods:

• A cross-sectional study of 1533 predialysis CKD patients from the KNOW-CKD cohort.
• eGFR was calculated using four equations: MDRD (eGFRMDRD), CKD-EPI creatinine (eGFRCr), CKD-EPI cystatin C (eGFRCys), and CKD-EPI creatinine-cystatin (eGFRCrCys).
• Coronary artery calcium score (CACS) was measured, with CAC defined as CACS >100.

Main Results:

• CAC was present in 21.8% of patients and was more common in lower eGFR groups (P < 0.001).
• Decreasing eGFRCrCys showed a gradual increase in CACS (P for trend = 0.034).
• Lower eGFRCrCys or eGFRCys levels were associated with increased odds of CAC. The adjusted OR for CAC with eGFR <30 mL/min/1.73 m² vs. eGFR ≥90 mL/min/1.73 m² was 2.64 (95% CI, 1.09-3.60) using eGFRCrCys.
• Only eGFRCrCys significantly improved CAC prediction models without eGFR (P = 0.046).

Conclusions:

• A gradual and independent association exists between reduced eGFR and CAC in Korean predialysis CKD patients.
• The eGFRCrCys equation demonstrated superior predictive performance for CAC compared to other tested equations in this cohort.