Chronic kidney disease (CKD) is considered one of the most common risk factors for cardiovascular disease. Coronary artery calcification (CAC) is a potential mechanism that explains the association between renal function and cardiovascular mortality. We aimed to evaluate the association between renal function and CAC in apparently healthy Korean subjects.

A total of 23,617 participants in a health-screening program at Kangbuk Samsung Hospital were included in the study. Estimated glomerular filtration rate (eGFR) was assessed using the Cockcroft-Gault equation. Coronary artery calcium score (CACS) was measured via multidetector computed tomography. Subjects were divided into three groups according to the CKD Staging system with eGFR grade: stage 1, eGFR ≥90 mL/min/1.73 m²; stage 2, eGFR 60 to 89 mL/min/1.73 m²; and stage 3, eGFR 30 to 59 mL/min/1.73 m².

The mean age of the participants was 41.4 years and the mean eGFR was 103.6±21.7 mL/min/1.73 m². Hypertension and diabetes were noted in 43.7% and 5.5% of the participants, respectively. eGFR showed a weakly negative but significant association with CACS in bivariate correlation analysis (r=-0.076, P<0.01). Mean CACS significantly increased from CKD stage 1 to 3. The proportion of subjects who had CAC significantly increased from CKD stage 1 to 3. Although the odds ratio for CAC significantly increased from stage 1 to 3 after adjustment for confounding factors, this significance was reversed when age was included in the model.

In early CKD, renal function negatively correlated with the degree of CAC in Korean subjects. Age was the strongest effector for this association.