Elevation of Uric Acid in Serum and Saliva of Patients with Bipolar Disorder

Background: Bipolar Disorder (BD) is a fairly common serious mental illness. A definitive and reliable biomarker remains elusive despite extensive exploration of various serum markers, brain scans, and genetic variants for diagnostic utility in BD. Reports indicate that serum uric acid levels are elevated in BD. This study aimed to determine whether salivary uric acid levels, as a non-invasive method, change in the same way as serum levels in these individuals. Methods: In a cross-sectional study, 28 patients aged 18 to 65 with BD based on DSM-5 diagnostic criteria were referred to teaching hospitals of Aja University of Medical Sciences in Tehran, and a control group consisting of 28 healthy individuals of the same gender and age entered the study. The serum and salivary uric acid levels were measured photometrically, and the data were analyzed by Unpaired Student’s t-test using SPSS software. Results: The mean concentration of serum and unstimulated saliva uric acid was significantly higher in patients than in healthy individuals, and the cut-off point for serum was 6.4 mg/dL with a sensitivity of 79% and a specificity of 68%, and for saliva, it was 3.3 mg/dL with 65% sensitivity and 61% specificity Conclusion: It seems that the amount of salivary uric acid increases in patients with BD, which may be used as an auxiliary biomarker for monitoring and diagnosis of the disease.