Blood levels of uric acid, bilirubin, and albumin in individuals with major depressive disorder and bipolar disorder: A comparative retrospective analysis

Jiangjing Dai^1,2Qingling Li¹Yang Xu¹Biqiong Ren^1,3*

• ¹Hunan University of Chinese Medicine, Changsha, China
• ²The Central Hospital of Shaoyang, Shaoyang, Hunan, China
• ³Department of Psychiatry, Second People's Hospital of Hunan Province, Changsha, Hunan Province, China

Background:Serum uric acid, total bilirubin, and albumin are key antioxidants in peripheral blood, which can indirectly indicate the extent of oxidative stress. However, research on the association between differences in these parameters and the diagnosis and treatment of major depressive disorder and bipolar disorder is still limited. This study aimed to investigate differences in the levels of peripheral blood antioxidants(UA, TBIL, and Alb), as well as their clinical applicability in patients with MDD and BD at different disease episodes.Methods:This study retrospectively analyzed inpatients with MDD and BD from the psychiatric department. All patients were diagnosed in accordance with the International Classification of Diseases, 10th Edition (ICD-10) criteria. These cases were extracted from the database of Hunan Provincial Brain Hospital, covering the period from January 2023 to December 2023. All clinical data of the patient group were retrieved from medical records. Detailed data of the healthy controls(HC) group were obtained from employees of a state-owned public institution who underwent physical examinations at the hospital's physical examination center. Ultimately, 72 patients with MDD, 140 patients with BD, and 78 HC were included.Findings: 1. Patients with MDD and BD exhibited significantly lower TBIL and Alb levels compared to controls(P < 0.0001). Notably, MDD patients had reduced UA levels, whereas BD patients showed elevated UA levels, with the highest levels detected during manic episodes of BD.Alb has substantial diagnostic value in differentiating MDD from BD. 3. Among MDD patients, those with a hospitalization duration of ≤ 15 days had higher UA levels than those with > 15 days(P=0.0392), with a negative correlation observed(r = 0.28). In BD patients, those with a hospitalization duration of ≤ 15 days had lower UA, TBIL, and Alb levels than those with > 15 days(P=0.0213, P=0.0285, P=0.0481), and UA levels showed a positive correlation(r=0.19). 4.BD patients with major depressive episodes who were on antidepressants had a significantly longer hospitalization duration than those not on antidepressants(P<0.0001).Differences in antioxidant levels underscore the distinctions in oxidative stress between MDD and BD, indicating potential quantitative biomarkers for clinical diagnosis, differential diagnosis, and prognostic prediction, while also providing valuable insights for further mechanistic studies.