Elevation of Urate in Saliva and Serum of Patients with Knee Osteoarthritis

Background: Knee osteoarthritis (knee OA) is the most common joint disease and the leading cause of disability and has a considerable financial burden on the healthcare system. Objective: The aim of the present study was to evaluate urate in saliva and serum of knee OA. Methods: Serum and saliva urate levels of 30 knee OA and 30 healthy controls were evaluated in a cross-sectional study. Data were analysed by Student's t test, Pearson correlation test, and receiver operating characteristic. Results: The mean serum and both stimulated and unstimulated saliva urate levels were higher in the knee OA than that of the healthy group. WOMAC score positively correlated with serum (r = 0.485; p = 0.004), unstimulated saliva (r = 0.575; p = 0.001) and stimulated saliva (r = 0.453; p = 0.009) levels of urate. The serum level of urate significantly correlated with unstimulated (r = 0.442; p < 0.001) and stimulated (r = 0.563; p < 0.001) saliva urate levels. Serum and saliva urate had significant cutoff values (6.4, 4.9, and 3.3 mg/dL in serum, stimulated, and unstimulated saliva, respectively). Conclusion: In this study, urate in serum and saliva was increased in patients with knee OA and positively correlated with WOMAC.