Can salivary creatinine and urea levels be used to diagnose chronic kidney disease in children as accurately as serum creatinine and urea levels? A case-control study

• Published in: Renal failure 2017-01, Vol.39 (1), p.452-457
• Main Author: Renda, Rahime
• Format: Article
• Language: English
• Subjects: Adolescent; Biochemical analysis; Case-Control Studies; Child; Children; chronic kidney disease; Clinical Study; Creatinine; Creatinine - analysis; Creatinine - blood; Female; Humans; Kidney diseases; Kidney Function Tests; Male; Renal Insufficiency, Chronic - blood; Renal Insufficiency, Chronic - diagnosis; ROC Curve; Saliva; Saliva - chemistry; Serum; Urea; Urea - analysis; Urea - blood
• ISSN: 0886-022X; 1525-6049
• DOI: 10.1080/0886022X.2017.1308256

Background and aim: Children with chronic kidney disease (CKD) develop many metabolic changes in blood that often necessitate frequent biochemical analysis. Serum analysis is an invasive and painful procedure. It would be highly beneficial if a noninvasive alternative process to serum analysis in children were identified. Saliva can be collected noninvasively, repeatedly, and without the use of healthcare personnel. The aims of this study were to compare serum and salivary urea and creatinine levels in children with CKD and healthy controls, and to determine if salivary creatinine and urea levels can be used to diagnose CKD in children as accurately as serum creatinine and urea levels. Materials and methods: This case-control study included 35 children with CKD and 28 healthy children as controls. Saliva and blood samples were collected for measurement of urea and creatinine levels. The urea and creatinine levels in serum and saliva in the CKD and control groups were compared using the independent samples Mann-Whitney U test. Correlations between the serum and salivary urea and creatinine levels were determined using Pearson's correlation coefficient. Receiver operating characteristic analysis was used to assess the diagnostic performance of salivary creatinine and cutoff values were identified. Results: In the CKD group, the mean salivary creatinine level was 0.45 mg/dL and the mean salivary urea level was 0.11 mg/dL, versus 28.83 mg/dL and 21.78 mg/dL, respectively, in the control group. Stage 4 and 5 CKD patients had a mean salivary urea level of 31.35 mg/dL, as compared to 17.78 mg/dL in the control group. Serum urea and creatinine, and salivary creatinine were significantly higher in the CKD patients (regardless of disease stage) than in the controls (p