Research Article

Assessment of Salivary Creatinine and Urea as Non-Invasive Alternatives to Serum Markers in Healthy Individuals

Abstract

Background: Conventional methods for assessing renal function, which rely on serum urea and creatinine, are invasive and can lead to patient compliance issues. Saliva offers a non-invasive alternative, but the correlation between serum and salivary markers in healthy individuals remains unclear. Aim: This study aimed to quantify and compare the concentrations of urea and creatinine in serum and unstimulated whole saliva in a cohort of apparently healthy students, thereby assessing the potential of salivary markers as non invasive alternatives. Methods: A cross-sectional study was conducted on 60 apparently healthy students. Paired blood and unstimulated whole saliva samples were collected. Urea was estimated using the enzymatic Urease-Berthelot method, and creatinine was measured using the kinetic Jaffe’s method. Data were analyzed using T-tests for comparison of means and Pearson’s correlation (r), with p < 0.05 considered significant. Results: Mean blood urea (3.00 mmol/L) was not significantly different from mean salivary urea (2.50 mmol/L) (p > 0.05). Mean blood creatinine (186.20 umol/L) was significantly higher than mean salivary creatinine (59.20 umol/L) (p < 0.05). Neither urea (r = -0.1, p > 0.05) nor creatinine (r = -0.05, p > 0.05) showed a statistically significant correlation between blood and saliva concentrations. Conclusion: The non-significant difference between mean blood and salivary urea concentrations suggests that salivary urea holds potential as a reliable non-invasive marker for further validation in populations with renal disease. The lack of correlation is likely a statistical consequence of the narrow reference range in the healthy study population.