Salivary creatinine is a promising noninvasive biomarker for chronic kidney disease: a case-control study

Chronic kidney disease (CKD) is associated with irreversible and progressive renal dysfunction. Our study aimed to assess whether salivary creatinine can be used as an alternative noninvasive biomarker for serum creatinine. Hence, a case-control study was conducted at Al-Gadarif Hospital for kidney disease in Eastern Sudan. The study included 40 hemodialysis patients as a case group and 40 healthy individuals as a control group. Significantly higher serum and salivary creatinine levels were reported in the case group (10.9±2.65 mg/dL; 2.2±1.3 mg/dL) than in the control group (0.88±0.15 mg/dL; 0.23±0.14 mg/dL). The serum and salivary creatinine levels were significantly higher in males (8.6±5.4 mg/dL; 1.7±1.5 mg/dL) than in the females (3.6±4.2 mg/dL; 0.83±1.1 mg/dL) in the patient group. Age was significantly correlated with serum (r=0.68, p=0.001) and salivary creatinine (r=0.48, p=0.001) in CKD patients. A significantly strong positive correlation was reported between serum and salivary creatinine. The sensitivity and specificity of salivary and serum creatinine were 100%. Therefore, our study revealed that salivary creatinine may serve as a potential noninvasive biomarker in CKD patients.