Assessment and Correlation of Urea and Creatinine Levels in Saliva and Serum of Patients with Chronic Kidney Disease, Diabetes and Hypertension-A Research Study

Introduction: Serum urea and creatinine are most widely accepted parameters to assess Chronic Kidney Disease (CKD) status as well as to assess renal status in susceptible diabetic and hypertensive subjects. Aim: To assess and correlate the serum and salivary urea and creatinine levels of CKD, diabetes mellitus and hypertensive subjects. Materials and Methods: This cross-sectional study was done on 120 subjects involving 30 CKD, 30 diabetic, 30 hypertensive subjects and 30 healthy controls. After collection of saliva and blood samples, urea was analyzed by enzymatic calorimetric method and creatinine by Jaffe's method. Kruskal Wallis test and Mann Whitney U test were used for comparison between different groups and correlations between serum and salivary parameters were evaluated by applying Spearman's correlation test. The p-value <0.05 was considered statistically significant. Results: The median serum and salivary urea and creatinine levels were highest in CKD group followed by diabetic, hypertensive groups and controls. The correlation coefficient for serum urea and salivary urea was 0.977 and for serum creatinine and salivary creatinine was 0.976, with p-value <0.001. Conclusion: This study showed that there is a significant positive relationship between salivary and serum urea and creatinine. Thus, salivary urea and creatinine levels can be used non-invasively to detect serum urea and creatinine levels respectively in renal disease and diabetic and hypertensive nephropathic cases.