Evaluation of Individual Cardiovascular Risk in Pre-Dialysis CKD Patients by Using the Ratio of Calcium-Phosphorus Product to Estimated Glomerular Filtration Rate (Ca×P/eGFR)

Background: Chronic kidney disease (CKD) patients have an increased risk of cardiovascular disease (CVD), necessitating effective risk assessment methods. This study evaluates the calcium-phosphorus product (Ca×P) to estimated glomerular filtration rate (Ca×P/eGFR) ratio as a potential biomarker for predicting CV risk in pre-dialysis CKD patients. Methods: Eighty-four CKD patients in stages G1 - G4, according to the KDIGO criteria, were classified into CVD (n = 43) and non-CVD (n = 41) groups. Biochemical parameters, including serum creatinine (SCr), blood urea nitrogen (BUN), calcium (Ca), inorganic phosphate (Pi), parathyroid hormone (PTH), alkaline phosphatase (ALP), Ca×P, eGFR, and the Ca×P/eGFR ratio, were measured and calculated. Statistical analyses were performed to identify predictors of CV risk and evaluate the diagnostic reliability of the Ca×P/eGFR ratio for predicting the risk. Results: Significant differences were observed in SCr, BUN, eGFR (p < 0.001) and the Ca×P/eGFR ratio (p = 0.007) between the groups. Regression analysis indicated the Ca×P/eGFR ratio as a significant CVD risk predictor (p = 0.012, OR = 1.206, 95% CI: 1.042-1.395). Receiver Operating Characteristic (ROC) curve analysis revealed an AUC of 0.751 (p < 0.001, 95% CI: 0.645–0.857), with sensitivity and specificity of the method 74.4% and 70.7%, respectively. Significant correlations were found between the Ca×P/eGFR ratio and SCr, BUN, UA, Ca, Pi, PTH, and ALP. Conclusions: The Ca×P/eGFR ratio is a significant predictor of CVD risk in pre-dialysis CKD patients, suggesting its integration into routine evaluations could improve CV risk stratification and management.