Serum Creatinine and Creatinine-to-calcium Ratio as Superior Predictors of Chronic Kidney Disease in the Pakistani Population

Abstract

Chronic kidney disease (CKD) poses a significant public health challenge. This study assessed the kidney function markers in 140 CKD patients to evaluate their variations and diagnostic utility across various demographic and clinical parameters. ANOVA revealed significant differences in the serum phosphate (F=3.307, P=0.040) and calcium (F=3.643, P=0.029) levels, while no significant group differences were noted in the creatinine (F=0.987, P=0.375) and uric acid levels (F=1.273, P=0.283). Post hoc analysis indicated significant differences in the calcium (mean difference=0.62, P=0.022) and phosphate (mean difference=1.64, P=0.032) levels between patients aged 30~50 and >50 years. A sex-based comparison showed higher uric acid levels in females (8.16 mg/dL) than in males (7.97 mg/dL), and a significant sex–age interaction for creatinine (F=3.806, P=0.025). Receiver operating characteristic curve analysis revealed strong diagnostic performance for creatinine (AUC=0.810, 95% CI: 0.74~0.87) and the creatinine-to-calcium ratio (AUC=0.812, 95% CI: 0.74~0.88), whereas the uric acid, calcium, and phosphate levels had lower discriminative power. These findings highlight the relevance of integrating age, sex, and comorbidity burden in CKD diagnoses and underscore the superior predictive value of creatinine-related markers.