Article Type

Original Study


Objectives This study was carried out to explore the changes and clinical significance of urea and creatinine in saliva in patients with chronic kidney disease (CKD) and provide a noninvasive, quick, accurate, and reliable test for diagnosing kidney disease. Background Monitoring of markers in saliva instead of serum is advantageous because saliva collection is a noninvasive, simple, and inexpensive approach. Measurement of biomarkers in saliva may be an effective alternative method for monitoring the effectiveness of hemodialysis. Patients and methods Urea and Cr in the saliva and serum were collected from both healthy individuals and CKD patients and measured with a biochemical analyzer. Fifty individuals participated in this study, divided into 40 patients with CKD and 10 apparent healthy controls. Results The concentrations of urea and Cr in both saliva and serum were positively correlated in healthy individuals and CKD patients. The levels of saliva urea and Cr in CKD patients were significantly higher than those of healthy individuals (P < 0.05). Saliva urea and Cr concentrations of middle-stage and late-stage CKD patients were higher than those of healthy people and early-stage CKD patients (P < 0.05). Areas under the curve of the receiver operating characteristic of saliva creatinine and urea and serum creatinine and urea were, respectively, 0.876, 0.796, 0.942, and 0.922 and specificity was 80, 80, 90, and 80, respectively. Conclusion The levels of urea and Cr in saliva and serum are closely related. The concentration of saliva urea and Cr can reflect renal damage, monitor the kidney function of CKD patients, and help in the diagnosis of middle-stage and late-stage CKD. It is a simple, noninvasive, and quick method.