Comparison of Serum Uric Acid in Major Depressive Disorder and Bipolar Disorder: a Retrospective Chart Review Study

Uric Acid as a Biomarker for Mood Disorders: A Comparative Study of Blood Uric Acid Levels Correlating With the Symptom Severity and Treatment Response

Background Bipolar affective disorder (BPAD) and major depressive disorder (MDD) are two mood disorders whose pathophysiology may involve the purinergic system. Elevated uric acid levels, associated with this system, can impact various behaviors in individuals affected by these conditions. In addition to genetic predisposition, blood uric acid levels can be impacted by various factors, including metabolic syndrome, the consumption of psychoactive medications, and other underlying kidney conditions such as gout. Objective The study aims to investigate the relationship between blood uric acid levels and mental health conditions, specifically BPAD subtypes (manic and depressive) and MDD. The study also examines changes in blood uric acid levels following treatment and evaluates the effectiveness of different treatment approaches in reducing uric acid levels. Methodology To be eligible to participate, individuals must have a confirmed diagnosis of BPAD (manic or depressive type) or MDD, according to the International Classification of Diseases (ICD-10). Blood uric acid levels were measured at both baseline and follow-up assessments. Symptoms were assessed weekly using standardized rating scales (Young Mania Rating Scale (YMRS) and Hamilton Rating Scale for Depression (HAM-D)) until treatment response was achieved, which was defined as a 50% reduction in initial scores on both scales. We used ANOVA to examine the differences among the three patient groups and paired sample t-tests to examine the changes in means before and after treatment conditions. Results A significant positive correlation was found between the severity of illness and serum uric acid levels across all three patient groups: those with BPAD-mania, BPAD-depression, and MDD. Notably, patients with BPAD-mania patients had significantly higher serum uric acid levels (5.2±0.9 mg/dL) compared to those with BPAD-depression (4.8±1.0 mg/dL) and MDD (4.0±1.1 mg/dL). After treatment, all patient groups exhibited a decrease in serum uric acid levels. The reduction in serum uric acid levels was pronounced in all patient groups, with decreases of 3.1±0.8 mg/dL in patients with BPAD-mania, 3.1±0.9 mg/dL in those with BPAD-depression, and 3.5±1.1 mg/dL in those with MDD. The study showed that the reduction in serum uric acid levels was significantly correlated with the severity of illness in patients with BPAD-mania, but not in those with BPAD-depression or MDD. Furthermore, the study found that treatment with lithium carbonate, sodium valproate, or carbamazepine was equally effective in reducing serum uric acid levels, regardless of the mood stabilizer used. Conclusion The study supports that dysfunction in the purine system might play a significant role in the development and progression of BPAD, suggesting that this phenomenon is not solely due to chronicity or medication exposure. This study also introduces a fresh perspective on the underlying biological processes that contribute to the development of BPAD and also sheds light on new treatment regimens targeting uric acid reduction in treating patients with bipolar disorder.

Comparison of Clinical Features, Serum Lipid, and Uric Acid Levels in Patients with Unipolar Depression and Bipolar Depression

Background

The level of uric acid and serum lipids has been suggested as a possible biomarker of bipolar disorder. We aimed to investigate the differences in clinical features and serum levels of lipids and uric acid in patients with bipolar depression or unipolar depression in order to distinguish them.

Methods

The clinical data of 53 patients with unipolar depression (unipolar group) and 61 patients with bipolar depression (bipolar group), who all met the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders-IV of the American Psychiatric Association, were compared with each other retrospectively. The serum levels of uric acid and lipids (including total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides) were measured after hospital admission. The Statistical Package for the Social Science version 22.0 software was used for statistical analysis, and logistic regression was employed to identify the susceptible factors of bipolar depression.

Results

Taking into account confounding factors, logistic regression analysis revealed that the high levels of uric acid (odds ratio = 1.016, P = .001) and low levels of triglycerides (odds ratio = 0.457, P = .025) were significantly correlated with bipolar depression.

Conclusion

It has been demonstrated from this study that individuals with bipolar depression have higher serum uric acid levels and lower triglyceride levels than unipolar depression ones. Therefore, serum levels of uric acid and triglycerides might have the potential to be the biomarkers for differential diagnosis between bipolar and unipolar depression.

Metabolic parameters as possible diagnostic predictors in first-episode psychosis: An exploratory retrospective cohort study

AIM

Patients in early phases of schizophrenia or mood disorders with psychotic symptoms have a wide array of metabolic abnormalities. We analysed the potential predictive value of uric acid (UA) levels and other metabolic parameters in first-episode psychosis patients to differentiate between non-affective and affective psychosis.

METHODS

Retrospective chart review of all patients referenced to a first-episode psychosis unit (n = 149), between 2012 and 2017, with available UA levels. Patients included (n = 37) were compared according to the follow-up diagnosis of schizophrenia or mood disorder.

RESULTS

Mood disorder patients presented higher UA levels (p = .030) and lower fasting blood glucose levels (p = .020) compared with schizophrenia patients. The remaining variables did not show significant intergroup differences.

CONCLUSIONS

Findings in this first-episode psychosis cohort support previous evidence suggesting higher UA levels as a predictor of affective psychosis and glucose dysfunction as predictive of schizophrenia. Further studies are needed to explore metabolic parameters as possible diagnostic predictors in first-episode psychosis.

Oxidative stress parameters and antioxidants in adults with unipolar or bipolar depression versus healthy controls: Systematic review and meta-analysis

BACKGROUND

To study differences in oxidative stress markers and antioxidants among patients with bipolar depression (BPD) and unipolar depression (UPD).

METHODS

Data sources. Electronic MEDLINE/PubMed/Cochrane Library/Scopus/TripDatabase database search until 30/06/2021.

STUDY SELECTION

Included were articles comparing antioxidant or oxidative stress markers between adults with BPD or UPD and healthy controls (HCs).

DATA EXTRACTION

Two authors extracted data independently. Random effects meta-analysis, calculating standardized mean differences for results from ≥3 studies.

RESULTS

Oxidative stress markers reported in 40 studies -1 published repeatedly- (UPD, studies = 30 n = 3072; their HCs, n = 2856; BPD, studies = 11 n = 393; their HCs, n = 540; with 1 study reporting on both UPD and BPD) included thiobarbituric acid reactive substances (TBARS), antioxidant uric acid and antioxidant-enhancing enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GPX). Compared with HCs, UPD and BPD were associated with significantly higher levels of TBARS, without differences between UPD and BPD (P = 0.11). Compared with HCs, UPD and BPD did not differ regarding the activity of the CAT (P = 0.28), SOD (P = 0.87) and GPX (P = 0.25) enzymes. However, uric acid levels were significantly higher vs HCs in BPD than in UPD among adult patients (P = 0.004). Results were heterogenous, which, for some parameters, decreased after stratification by the blood source (serum, plasma red blood cells, whole blood).

LIMITATIONS

The main limitations are the small number of studies/participants in the BPD subgroup, and heterogeneity of the results.

SUMMATIONS

Both BPD and UPD may be associated with an impaired oxidative stress balance, with significantly higher uric acid levels vs. HCs in UPD than in BPD.

The Purinergic System as a Target for the Development of Treatments for Bipolar Disorder

The neurobiological and neurochemical mechanisms underlying the pathophysiology of bipolar disorder are complex and not yet fully understood. From circadian disruption to neuroinflammation, many pathways and signaling molecules are important contributors to bipolar disorder development, some specific to a disease subtype or a cycling episode. Pharmacological agents for bipolar disorder have shown only partial efficacy, including mood stabilizers and antipsychotics. The purinergic hypothesis for bipolar disorder emerges in this scenario as a promising target for further research and drug development, given its role in neurotransmission and neuroinflammation that results in behavioral and mood regulation. Here, we review the basic concepts of purinergic signaling in the central nervous system and its contribution to bipolar disorder pathophysiology. Allopurinol and novel P2X7 receptor antagonists are promising candidates for treating bipolar disorder. We further explore currently available pharmacotherapies and the emerging new purinergic targets for drug development in bipolar disorder.

Uric acid levels in adult patients with severe eating disorders

OBJECTIVE

To investigate serum uric acid (UA) levels in patients with extreme forms of eating disorders, at admission and discharge, following weeks of nutritional rehabilitation and weight restoration.

METHOD

This observational study enrolled 160 patients diagnosed with anorexia nervosa restricting subtype (AN-R), AN binge-purge subtype (AN-BP), or avoidant restrictive food intake disorder (ARFID). Serum UA levels were drawn on admission and discharge.

RESULTS

Most of the cohorts were admitted with serum UA levels on the lower end of normal. Mean serum uric level for women was 4.3 mg/dl (SD: 2.3). Patients diagnosed with AN-BP had significantly higher UA levels on admission compared to patients with AN-R and ARFID; p < .0001, η²  = 0.13. High UA levels positively correlated with purging and admission serum blood urea nitrogen (r = .5, p = .009).

DISCUSSION

Serum UA levels tended to be in the low-normal range in most patients with severe AN-R, but not in AN-BP. However, levels did increase with nutritional intake and weight gain. There may be clinical value in checking UA levels on admission for patients with eating disorders.

Salivary Uric Acid: A Noninvasive Wonder for Clinicians?

This review is a summary of the modern-day approach and recent trend in the determination of uric acid in the saliva of humans and its use in diagnosis by clinicians. Uric acid, which is the end product obtained from the breakdown of purine nucleotides, is an important biomarker associated with various conditions. Uric acid is found in various body fluids, such as serum, plasma, and urine. It can be used as an important tool for various diseases, such as gout and hyperuricemia, or conditions that are associated with increased oxidative stress. Recently, there has been an emergence of studies that have utilized uric acid concentrations measured in the saliva and studied its association with various diseases. Salivary uric acid can prove to be a noninvasive method to provide a diagnosis of serious illness. A raised uric acid level in the saliva can be associated with cancer, human immunodeficiency virus (HIV) infection, gout, and hypertension. A reduced level of salivary uric acid on the other hand can be a marker for Alzheimer's disease, progression of multiple sclerosis, and impairment of cognition. Online search databases, including Google Scholar, Scopus, PubMed, and Web of Science, were searched, and articles that were published before September 2021 based on salivary uric acid analysis were analyzed for this review. Uric acid is an essential biomarker that has antioxidant properties. Assessment of salivary uric acid levels was found to be essential in conditions such as cancer, metabolic syndrome, neurological conditions, psychiatric conditions, human immunodeficiency virus, and gout and in monitoring treatment of hyperuricemia. Although having importance in diagnosis and therapeutic monitoring, salivary uric acid analysis has not gained enough popularity due to limitations such as saliva collection and sample processing issues. With proper education and standardization, salivary uric acid analysis can be used as a cost-effective and noninvasive tool for getting a clue about antioxidant biomarker concentration in saliva and hence various diseases associated with oxidative stress.