Utility of saliva as a sample to assess renal function and estimated glomerular filtration rate.

Diagnosis of renal diseases by assessing renal parameters in saliva. Biochemical investigations using serum form important component of monitoring patients with renal disease. Utility of saliva, in diagnosis and monitoring of patients with renal disease and for calculation of estimated glomerular filtration rate (eGFR), was studied. Sixty patients with renal disease and sixty ageand sex-matched healthy controls were studied. Urea, creatinine, sodium, potassium, uric acid, calcium, and phosphorus were measured in both serum and saliva. eGFR was calculated using salivary creatinine. Data were expressed as mean ± standard deviation. Comparison and correlation between groups were assessed by Student's t -test and Pearson correlation, respectively. Bland-Altman plot, mountain plot, and intra-class correlation coefficient were used to test agreement. A P P = 0.001) and creatinine, sodium, calcium, and uric acid levels were lower ( P = 0.001) in saliva compared to serum in both patients and controls. Positive correlation was observed between serum and salivary urea and creatinine ( P 6 mmol/L) and creatinine (>14.6 μmol/L) and eGFR calculated from salivary creatinine can be used to identify patients with renal disease.