Testing the association of serum uric acid levels with behavioral and clinical characteristics in subjects with major affective disorders: A cross-sectional study.

Previous research has hypothesized a role for serum uric acid as a marker of mental disorders and related behaviors, possibly due to its link with purinergic transmission and antioxidant activity. We tested the association of serum uric acid levels with specific behavioral and clinical characteristics in 99 individuals suffering from major affective disorders. Subjects were assessed and interviewed using the Kessler Psychological Distress Scale, the Columbia-Suicide Severity Rating Scale, the Modified Overt Aggression Scale, and the Barratt Impulsiveness Scale. We found that psychological distress and suicidal ideation severity were associated with lower uric acid serum levels. On the other hand, verbal aggression and history of violence were associated with higher levels of serum uric acid. However, according to linear regression analyses, there were no behavioral and clinical characteristics independently associated with serum uric acid. Serum uric acid levels were influenced by creatinine and BMI, as well as, possibly, by white blood cells count and gender. Despite some limitations, these results suggest that no behavioral / clinical features are associated with variations of serum uric acid, which rather seem attributable to specific biochemical and metabolic parameters. Nevertheless, the role of purinergic system in different mental disorders and behavioral abnormalities, deserves further research.

Exploring the association between bipolar disorder and uric acid: A mediation analysis.

OBJECTIVE: Recent evidence shows that bipolar disorder might be associated with a purinergic system dysfunction. This study aimed at (i) testing the association between bipolar disorder and uric acid serum levels, and (ii) clarifying whether this relationship is mediated by metabolic syndrome and other relevant metabolic parameters. METHODS: Patients consecutively admitted to a Mental Health Inpatient Unit, with a diagnosis of bipolar disorder or other severe mental disorders, and an appropriate healthy control sample, were included in this cross-sectional, exploratory study. We performed linear regression analyses, to explore factors associated with uric acid levels, and formal tests of mediation to assess mediating effect of candidate variables. RESULTS: 176 individuals with mental disorders and 89 healthy controls met inclusion criteria. Bipolar disorder was the only diagnostic subgroup significantly associated with increased uric acid levels. Furthermore, male gender, metabolic syndrome, as well as abdominal circumference and triglycerides levels, had a significant effect on uric acid. Relevant mediation analyses showed that the estimated effect between bipolar disorder and uric acid levels was only partially mediated by metabolic abnormalities. CONCLUSION: This study suggests a direct association between bipolar disorder and uric acid levels, only partially mediated by metabolic abnormalities. It seems consistent with results of previous studies highlighting a purinergic dysfunction in bipolar disorder and the role that purinergic modulators, lowering uric acid levels, could have in clinical practice.