Epidemiology of gout

Mechanism of flavonoids in the treatment of gouty arthritis (Review)

The present review expounds the advancements in the application and mechanisms of flavonoids in gouty arthritis, highlighting their significance in managing the disease. Gouty arthritis is among the most common and severe inflammatory diseases, caused by hyperuricemia and the deposition of sodium urate crystals in the joints and surrounding tissues, posing a serious threat to human life and health. Flavonoids, extracted from various herbs, have attracted significant attention due to their efficacy in improving gouty arthritis. The present study systematically reviews the in vivo studies and in vitro animal studies on flavonoids from herbal medicines for the treatment of gouty arthritis that have been previously published in the PubMed, ScienceDirect, Google Scholar and China National Knowledge Infrastructure databases between 2000 and 2023. The review of the literature indicated that flavonoids can improve gouty arthritis through multiple mechanisms. These include lowering xanthine oxidase activity, inhibiting uric acid (UA) synthesis, regulating UA transporters to promote UA excretion, reducing the inflammatory response and improving oxidative stress. These mechanisms predominantly involve regulating the NOD‑like receptor 3 inflammasome, the Toll‑like receptor 4/myeloid differentiation factor 88/nuclear factor‑κB signaling pathway, and the levels of UA transporter proteins, namely recombinant urate transporter 1, glucose transporter 9, organic anion transporter (OAT)1 and OAT3. Various flavonoids used in traditional Chinese medicine hold therapeutic promise for gouty arthritis and are anticipated to pave the way for novel pharmaceuticals and clinical applications.

The effect of exercise rehabilitation with exergames combined with ice therapy in the treatment of obese patients with gout: protocol for a clinical trial

BACKGROUND

Gout remains a leading cause of inflammatory arthritis worldwide, and the main risk factor for gout is persistent hyperuricemia. The clinical management of gout is mostly drug-based, and other treatment options are often ignored. This research proposal will explore whether exergames combined with ice therapy can help patients with gout to lose weight, relieve pain, improve the range of movement, improve quality of life, decrease uric acid level, decrease kinesiophobia and improve mental health of patients with gout.

METHODS

This experiment will use a two-arm randomized controlled design. The study setting is at the Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia (USM). Obese patients with gout (N = 30) will be randomly assigned to the control group (receive an exergames intervention) and intervention group (receive an exergames intervention combined with ice therapy). The outcomes measurement will be conducted before (baseline) and after intervention (4 weeks). Then, it will be followed up at 12 weeks.

DISCUSSION

To our knowledge, no study has investigated the effect of exergames and ice therapy among gout patients. This study is expected to demonstrate that exercise rehabilitation facilitated by exergames with ice therapy is more effective in gout management compared to a conventional rehabilitation intervention.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2300070029). Registered on 31 March 2023.

Lipidomics Analysis Deepen Understanding the Molecular Mechanisms in a Gouty Model Induced by Combination of MSU Crystals Injection and High-Fat Diet Feeding and the Intervention Mechanisms of Allopurinol

Background

Gouty arthritis (GA) is a common inflammatory disease caused by deposition of monosodium urate (MSU) crystals in diarthrodial joints. GA attacks commonly involved in joint with red, swollen, heat and pain, and often happened in unilateral foot-first metatarsophalangeal. Accumulated studies have proved that lipids play critical roles in biological processes and lipids biomarkers can substitute for the diagnosis of various diseases.

Methods

Herein, shotgun lipidomics was used to quantitatively analyze serum lipidomes of a gouty model which was induced by injecting MSU crystals and feeding high-fat diet with/without treatment with allopurinol. Meanwhile, ELISA kit was used to detect mouse serum levels of inflammatory cytokines (eg, tumor necrosis factor-α, interleukin 1 beta) and HE staining was used to observe the infiltration of inflammatory cells in the foot pad.

Results

A total of 9 types of serum lipids were detected in lipidomics by shotguns, and the result of NMDS' analysis demonstrated significant differences in lipids profiles between the control and model group. It is worth noting that lipid abnormality in GA (such as Ceramide (Cer), sphingomyelin (SM), 4-hydroxyalkenals (HNE), phosphatidylinositol (PI), ethanolamine glycerophospholipid (PE), etc.) is related with phospholipid and energy metabolism, and allopurinol treatment could correct the aberrant metabolism of lipid to some extent.

Conclusion

Our results indicated that various aberrant lipid metabolisms were present in the established gouty model, and allopurinol treatment could relief this aberrant metabolism of lipids to some degree.

Glucagon-Like Peptide 1 Receptor Agonists in Patients With Inflammatory Arthritis or Psoriasis: A Scoping Review

ABSTRACT

Obesity is a proinflammatory state associated with increased disease severity in various types of inflammatory arthritis. Weight loss is associated with improved disease activity in certain forms of inflammatory arthritis such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA). We conducted a scoping review summarizing the literature evaluating the effect of glucagon-like peptide 1 (GLP-1) receptor agonists on weight and disease activity in patients with inflammatory arthritis or psoriasis. MEDLINE, PubMed, Scopus, and Embase were searched for publications evaluating the role of GLP-1 analogs in RA, PsA, psoriasis, axial spondyloarthritis, systemic lupus erythematosus, systemic sclerosis, gout, and calcium pyrophosphate deposition disease. Nineteen studies were included: 1 gout study, 5 RA studies (3 basic science, 1 case report, and 1 longitudinal cohort), and 13 psoriasis studies (2 basic science, 4 case reports, 2 combined basic science/clinical studies, 3 longitudinal cohorts, and 2 randomized controlled trials). No psoriasis study reported on PsA outcomes. Basic science experiments demonstrated weight-independent immunomodulatory effects of GLP-1 analogs through inhibition of the NF-κB pathway (via AMP-activated protein kinase phosphorylation in psoriasis and prevention of IκBα phosphorylation in RA). In RA, improved disease activity was reported. In psoriasis, 4 of 5 clinical studies demonstrated significant improvements in Psoriasis Area Severity Index and weight/body mass index with no major adverse events. Common limitations included small sample sizes, short follow-up periods, and lack of control groups. GLP-1 analogs safely cause weight loss and have potential weight-independent anti-inflammatory effects. Their role as an adjunct in patients with inflammatory arthritis and obesity or diabetes is understudied, warranting future research.

The impact of two dietary patterns on hyperuricemia in adults: A meta analysis of observational studies

BACKGROUND

Hyperuricemia (HUA) is a crucial factor contributing to some chronic diseases among adults. In past observational literatures, scholars have debated the effectiveness of dietary pattern on HUA and inconsistencies exist. Given this condition, the study aimed to provide a comparative assessment of the relation between dietary pattern and HUA risk and offer implications to policy makers.

METHODS

A systematic research was undertaken in PubMed, Web of Science, Cochrane, Embase, Medicine, ScienceDirect and Medline to identify observational studies examining the effect of dietary pattern on HUA, and search period was from past to January 2022. Meta analysis was applied by using the Stata version 11.0 software.

RESULTS

A total of 34,583 adults from 8 observational studies, 45,525 adults from 6 observational studies were included to examine the effectiveness of "healthy" and "meat/western" dietary patterns on HUA risk respectively. The findings suggested that "healthy" dietary pattern significantly decreased the HUA risk (OR = 0.73; 95% CI: 0.61-0.88) both in Eastern countries (OR = 0.79; 95% CI: 0.64-0.98) and Western countries (OR = 0.53; 95% CI: 0.30-0.92) while the "Meat/Western" pattern increased the HUA possibilities (OR = 1.26; 95% CI: 1.17-1.37). Stratified analysis exhibited that "healthy" pattern reduced HUA risk in adults was more effective in cohort study (OR = 0.79; 95% CI: 0.72-0.86).

CONCLUSIONS

This study's findings highlighted the potential benefit of healthy dietary pattern in decreasing HUA risk. Accordingly, implementing policy makers of countries should enhance to appeal adults to keep a healthy diet, offer financial support to low-income staff, or provide guidelines for adult's dietary behavior changes.

TRIAL REGISTRATION NUMBER

INPLASY: INPLASY202290034.

Causal Relationship between Gut Microbiota and Gout: A Two-Sample Mendelian Randomization Study

Gout is a form of prevalent and painful inflammatory arthritis characterized by elevated serum urate (SUA) levels. The gut microbiota (GM) is believed to influence the development of gout and SUA levels. Our study aimed to explore the causal relationship between GM composition and gout, as well as SUA levels, utilizing a two-sample Mendelian Randomization (MR) approach. A total of 196 GM taxa from five levels were available for analysis. We identified five taxa associated with SUA levels and 10 taxa associated with gout. In reverse MR analysis, we discovered that gout affected the composition of five GM taxa, while SUA levels influenced the composition of 30 GM taxa. Combining existing research, our study unveiled a potential negative feedback loop between phylum Actinobacteria and SUA levels, establishing connections with gout. We also proposed two novel associations connecting GM taxa (genus Faecalibacterium and genus Prevotella9), SUA levels, and gout. These findings provide compelling evidence of causal relationships between specific GM taxa with SUA levels and gout, contributing valuable insights for the treatment of gout.

The Impact of Label Changes (Boxed Warning) on Real-World Febuxostat Utilization in Patients with Gout: A Cross-Sectional Drug Utilization Study

INTRODUCTION

This drug utilization study evaluated the impact of 2019 label changes on real-world febuxostat utilization among patients with gout. We describe the numbers and proportions of patients initiating febuxostat as new users (allopurinol-naïve) or prevalent new users (prior allopurinol use) and data on febuxostat users with established cardiovascular disease (CVD) morbidities before, during, and after the 2019 label changes.

METHODS

This descriptive, non-interventional, cross-sectional study used data from two large administrative claims databases in the United States, the IQVIA PharMetrics Plus database and the Optum Research Database (ORD). The study population included patients with gout initiating febuxostat on or after June 1, 2016. Data were collected on febuxostat and allopurinol use, established CVD morbidities, comorbidities of interest, concomitant medications, and patient demographics.

RESULTS

In both databases, the total number of febuxostat users and proportion of patients who initiated febuxostat as new users both decreased during the study period. Of 13,848 patients in the PharMetrics Plus cohort, 42.7% were new users of febuxostat and 57.3% were prevalent new users. In the ORD cohort, 40.5% of the 10,198 patients were new users and 59.5% were prevalent new users. The most common established CVD morbidities in the 12 months prior to initiation of febuxostat were diabetes mellitus, ischemic heart disease, and heart failure/cardiomyopathy.

CONCLUSIONS

Although the benefit-risk profile for febuxostat is considered favorable for the treatment of hyperuricemia in certain patients with gout, real-world febuxostat utilization decreased during the study period, presumably in response to the label change.

Gout therapeutics and drug delivery

Gout is a common inflammatory arthritis caused by persistently elevated uric acid levels. With the improvement of people's living standards, the consumption of processed food and the widespread use of drugs that induce elevated uric acid, gout rates are increasing, seriously affecting the human quality of life, and becoming a burden to health systems worldwide. Since the pathological mechanism of gout has been elucidated, there are relatively effective drug treatments in clinical practice. However, due to (bio)pharmaceutical shortcomings of these drugs, such as poor chemical stability and limited ability to target the pathophysiological pathways, traditional drug treatment strategies show low efficacy and safety. In this scenario, drug delivery systems (DDS) design that overcome these drawbacks is urgently called for. In this review, we initially describe the pathological features, the therapeutic targets, and the drugs currently in clinical use and under investigation to treat gout. We also comprehensively summarize recent research efforts utilizing lipid, polymeric and inorganic carriers to develop advanced DDS for improved gout management and therapy.

The landscape of pathophysiology guided therapeutic strategies for gout treatment

INTRODUCTION

Gout is a common autoinflammatory disease caused by hyperuricemia with acute and/or chronic inflammation as well as tissue damage. Currently, urate-lowering therapy (ULT) and anti-inflammatory therapy are used as first-line strategies for gout treatment. However, traditional drugs for gout treatment exhibit some unexpected side effects and are not suitable for certain patients due to their comorbidity with other chronic disease.

AREAS COVERED

In this review, we described the pathophysiology of hyperuricemia and monosodium urate (MSU) crystal induced inflammatory response during gout development in depth and comprehensively summarized the advances in the investigation of promising ULT drugs as well as anti-inflammatory drugs that might be safer and more effective for gout treatment.

EXPERT OPINION

New drugs that are developed based on these molecular mechanisms exhibited great efficacy on reduction of disease burden both in vitro and in vivo, implying their potential for clinical application. Moreover, hyperthermia also showed regulation effect on MSU crystals formation and the signaling pathways involved in inflammation.

Management of Gout in the Hand and Wrist

Gout, or monosodium urate deposition disease, is the most common form of inflammatory arthritis that affects almost 4% of adults in the United States.Medical management involves lifestyle modifications and urate-lowering therapy to reduce the frequency of gout flares, decrease the tophi size, and improve upper extremity function. Goals for surgical management of gout include functional optimization, symptomatic treatment, and cosmetic restoration.This article focuses on the medical and surgical treatment of the common manifestations of gout in the upper extremity including tophi, tenosynovitis, joint contractures, neural compression, and arthropathy.

The Effects of Gout Following total Knee Arthroplasty: A Retrospective Analysis

BACKGROUND

The prevalence of gout is increasing along with the number of total knee arthroplasties (TKA) performed annually. The purpose of this study was to evaluate the incidence of gout following TKA in patients who had a previous history of gout and to determine if it is associated with an increased rate of postoperative joint complications.

METHODS

Patients who did and did not have a preoperative diagnosis of gout and underwent a primary TKA were identified from a national database. The gout patients were matched 1:1 to patients who did not have gout and rates of postoperative gout diagnoses within 2 years of surgery were compared. Complication rates at mean 1 and 2 years were then compared for both patient cohorts using multivariable logistic regressions. A total of 17,463 patients with a prior diagnosis of gout were matched with 17,463 controls.

RESULTS

There were 53.8% of patients who had previous gout and had a recurrence of gout within 2 years versus 3.6% of controls (Odds Ratios [OR]: 30.86). At mean 1-year, patients who had gout were significantly more likely to experience prosthetic joint infections (PJIs) and revision procedures. At mean 2 years, gout patients were at increased risk of prosthetic loosening, PJI, revision, and incision and debridement procedures.

CONCLUSION

This study suggests that patients who had a prior diagnosis of gout are significantly more likely to experience recurrent episodes of gout after TKA. Gout attacks after TKA are associated with an increase in the rate of joint complications.

LEVEL OF EVIDENCE

Level III.

Infected nasal gout tophus: A case report

Gout is a common form of inflammatory arthritis, characterized by the deposition of monosodium urate crystals. If chronically present and not adequately treated by serum urate reducers, gout tophi can develop at various locations. Here, we report the first infected gout tophus at the septal cartilage and nasal tip.

Gouty Tophi Encompassing Retained Suture Material 7 Years After Achilles Tendon Rupture Repair

CASE

We report the case of a 32-year-old male patient with no history of gout who developed gouty tophi encompassing retained suture material 7 years after initial repair of a ruptured Achilles tendon. The patient had a posterior ankle mass concerning for abscess. Monosodium urate crystals were identified, and uric acid level was elevated at the time of irrigation and debridement.

CONCLUSION

Surgical site gout is a rare but important phenomenon to recognize in the treatment of patients with Achilles tendon repairs, particularly in patients with a history of abscess, infection, or collections localized to retained suture material.

The Role of the "Anti-Inflammatory" Couple for the Management of Hyperuricemia With Deposition

INTRODUCTION

Gout is the most prevalent inflammatory crystal arthropathy worldwide and is a chronic disease requiring strict, lifelong adherence to drug therapy and healthy lifestyles. Gout has a heavy burden on the patient's sexual health, owing to the associated inflammatory status, long-term complications, and chronic pain; however, the effects of gout also extend to the partner's sexual health.

AIMS

We aimed to investigate how the presence of a partner could influence the complex interaction between risk factors for sexual dysfunctions in gout in order to define novel strategies to improve sexual health and disease management.

METHODS

Clinical and experimental data on the role of the couple in chronic diseases, as well as on the association between gout and sexual health, were searched through Pubmed.

MAIN OUTCOME MEASURES

Evidence from studies describing how the presence of a couple and leveraging sexual health can improve management and clinical outcomes for chronic diseases.

RESULTS

Treatment adherence can improve the sexual health of gout patients and their partners; likewise, by leveraging sexual health, it would be possible to promote better health-seeking behaviors, ultimately improving gout management.

CLINICAL IMPLICATIONS

Promoting awareness of the sexual health relevance of gout can potentially be a pivotal strategy to improve disease management and prevent the progression of sexual dysfunctions from subclinical to overt forms.

STRENGTHS AND LIMITATIONS

Identifying a bidirectional association between sexual health and disease management paves the way for improved disease control and can potentially prevent the development of sexual dysfunctions in couples affected by gout. However, the relevance of the couple has not been adequately addressed in gout management, and most evidence comes from other chronic diseases.

CONCLUSION

Improving gout management results in better sexual health, and vice-versa promoting better sexual health can improve disease control for gout. The presence of a partner improves the behavioral well-being of gout patients, with beneficial effects on both sexual health and gout management. Sansone A, Reisman Y, Meto S, et al. The Role of the "Anti-Inflammatory" Couple for the Management of Hyperuricemia With Deposition. Sex Med 2022;10:100562.

Exploring the mechanism of action of dapansutrile in the treatment of gouty arthritis based on molecular docking and molecular dynamics

Purpose: Dapansutrile is an orally active β-sulfonyl nitrile compound that selectively inhibits the NLRP3 inflammasome. Clinical studies have shown that dapansutrile is active in vivo and limits the severity of endotoxin-induced inflammation and joint arthritis. However, there is currently a lack of more in-depth research on the effect of dapansutrile on protein targets such as NLRP3 in gouty arthritis. Therefore, we used molecular docking and molecular dynamics to explore the mechanism of dapansutrile on NLRP3 and other related protein targets.

Methods: We use bioinformatics to screen active pharmaceutical ingredients and potential disease targets. The disease-core gene target-drug network was established and molecular docking was used for verification. Molecular dynamics simulations were utilized to verify and analyze the binding stability of small molecule drugs to target proteins. The supercomputer platform was used to measure and analyze the binding free energy, the number of hydrogen bonds, the stability of the protein target at the residue level, the radius of gyration and the solvent accessible surface area.

Results: The protein interaction network screened out the core protein targets (such as: NLRP3, TNF, IL1B) of gouty arthritis. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that gouty arthritis mainly played a vital role by the signaling pathways of inflammation and immune response. Molecular docking showed that dapansutrile play a role in treating gouty arthritis by acting on the related protein targets such as NLRP3, IL1B, IL6, etc. Molecular dynamics was used to prove and analyze the binding stability of active ingredients and protein targets, the simulation results found that dapansutrile forms a very stable complex with IL1B.

Conclusion: We used bioinformatics analysis and computer simulation system to comprehensively explore the mechanism of dapansutrile acting on NLRP3 and other protein targets in gouty arthritis. This study found that dapansutrile may not only directly inhibit NLRP3 to reduce the inflammatory response and pyroptosis, but also hinder the chemotaxis and activation of inflammatory cells by regulating IL1B, IL6, IL17A, IL18, MMP3, CXCL8, and TNF. Therefore, dapansutrile treats gouty arthritis by attenuating inflammatory response, inflammatory cell chemotaxis and extracellular matrix degradation by acting on multiple targets.

Separating the effects of childhood and adult body size on inflammatory arthritis: a Mendelian randomisation study

OBJECTIVES

Using Mendelian randomisation (MR), we examined whether childhood body size affects risk of rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), gout and systemic lupus erythematosus (SLE) after accounting for the effect of adult body size.

METHODS

Genetic instruments for childhood (age 10 years) and adult body size were derived using data from 453 169 individuals from the UK Biobank study (313 and 580 variants respectively), which have been previously validated using body mass index data from three independent populations. Genome-wide association data comprised 22 350 RA, 9069 AS, 3609 PsA, 13 179 gout and 5201 SLE cases. For each outcome, we conducted univariable MR to estimate the total effects of childhood and adult body size, and multivariable MR to examine the independent effect of childhood body size after accounting for adult body size.

RESULTS

Genetically predicted childhood body size had a total effect on risk of PsA (OR 2.18 per change in body size category; 95% CI 1.43 to 3.31), gout (OR 2.18; 95% CI 1.43 to 3.31) and SLE (OR 2.44; 95% CI 1.14 to 5.22), but not RA (OR 0.95; 95% CI 0.70 to 1.29) or AS (OR 0.96; 95% CI 0.61 to 1.52). After accounting for adult body size, the direct effect of childhood body size was little changed for PsA (OR 1.92; 1.14 to 3.25) and SLE (OR 2.69; 1.24 to 5.87) but was attenuated for gout (OR 1.40; 95% CI 0.94 to 2.09).

CONCLUSIONS

Our findings suggest that, for PsA and SLE, the risk conferred from having a larger body size during childhood may not be fully reversable even when a healthy size is achieved in adulthood.

En Masse Excision and Curettage for Periarticular Gouty Tophi of the Hands

BACKGROUND

Despite increasing disease prevalence, there remains a paucity of data examining surgical treatments for gouty tophi. This article assesses en masse excision and curettage of articular tophi involving the hands and shows that carefully planned and precisely executed surgery can consistently alleviate pain, preserve function, and enhance the aesthetics of afflicted hands.

METHODS

A retrospective review was conducted of all consecutive patients who underwent surgical excision of tophaceous deposits from the upper extremity. All patients had an established diagnosis of gout and had been treated with urate-lowering medication. All tophi were substantive in size and were causing significant digital joint dysfunction and disfigurement with variable skin ulcerations.

RESULTS

The study group included 12 patients with 24 tophaceous deposits excised from the metacarpal and interphalangeal joints; 2 deposits were also concomitantly excised from the wrist and 2 from the elbow. The study group included 8 men and 4 women, with an average age of 67 years. Follow-up evaluation ranged from 2 to 15 years. All patients underwent successful tophus excision with restoration of tendon excursion and joint mobility without wound complications. All regained high levels of function, and all reported satisfaction with their outcome. On follow-up for as long as 15 years, recurrence has not been observed and secondary surgery has not proved necessary.

CONCLUSIONS

This study indicates that surgical excision of articular tophi of the hands can provide long-term improvement in function and aesthetics with minimal risk of wound complications or recurrence.

Association of dietary patterns with blood uric acid concentration and hyperuricemia in northern Chinese adults

Background

Studies have shown that a direct association exists between the diet and blood uric acid concentrations. However, works on the association of dietary patterns with blood uric acid concentrations and hyperuricemia remain limited. 

Objective

This study aims to evaluate the association of dietary patterns with blood uric acid concentrations and hyperuricemia.

Methods

The relationship between dietary patterns and hyperuricemia was explored through a nutritional epidemiological survey in China (n = 4855). Three statistical methods, including principal component analysis, reduced rank regression (RRR), and partial least squares regression, were used to extract dietary patterns. General linear regression and logistic regression analyses were utilized to explore the relationship of dietary patterns with blood uric acid concentrations and hyperuricemia.

Results

After adjusting for potential confounding factors, the score for the plant-based dietary pattern was found to be negatively correlated with blood uric acid levels (β =  − 3.225) and that for the animal dietary pattern was discovered to be directly correlated with blood uric acid levels (β = 3.645). The participants in the highest quartile of plant-based dietary pattern scores were at a low risk of hyperuricemia (OR = 0.699; 95% CI: 0.561–0.870, P < 0.05), whereas those in the highest quartile of animal dietary pattern scores were at a high risk of hyperuricemia (OR = 1.401; 95% CI: 1.129–1.739, P < 0.05). The participants in the third quartile of scores for the RRR dietary pattern, which was characterized by the relatively high intake of poultry, sugary beverages, and animal organs and the low intake of desserts and snacks, had a significantly higher risk of hyperuricemia than those in the first quartile of scores for the RRR dietary pattern (OR = 1.421; 95% CI: 1.146–1.763, P < 0.05).

Conclusions

Our research indicated that plant-based dietary pattern analyzed by PCA was negatively associated with blood uric acid concentrations, while animal-based dietary pattern was directly associated with blood uric acid concentrations. The RRR dietary pattern may have the potential to induce elevations in blood uric acid concentrations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-022-00789-7.

Polysaccharide extract from Isatidis Radix inhibits multiple inflammasomes activation and alleviate gouty arthritis

The polysaccharide extract from Isatidis Radix exhibits potent antiinflammatory and antiviral activities, but the mechanism of Isatidis Radix polysaccharide (IRP) remains obscure. Herein, we reported that IRP blocked the activation of nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome, leading to the inhibiting of caspase-1 cleavage and IL-1β secretion. Mechanistically, IRP did not inhibit NLRP3 inflammasome through suppressing mitochondrial reactive oxygen species (mtROS) production. However, IRP can significantly suppress the oligomerization of apoptosis-associated speck-like protein (ASC) and subsequently block the formation of inflammasome. Next, we evaluate the role of IRP in monosodium urate (MSU)-induced gout in vivo which is a NLRP3-associated disease. We also observed that oral administration of IRP can reduce the increased ankle thickness and the secretion of IL-1β, IL-18, IL-6, TNF-α and MPO of the mouse ankle joints caused by MSU crystals. Furthermore, flow cytometry analysis highlighted a significant modulation of T helper 17 cells (Th17)/regulatory T cells (Treg) following IRP treatment in MSU induced gout. Overall, our findings suggest that IRP has comprehensive and potent antiinflammatory effects and provide a reasonable therapeutic strategy in preventing inflammasome-associated diseases, such as inflammatory gouty arthritis.

Cardiovascular risk and mortality in patients with hyperuricemia treated with febuxostat or allopurinol: a retrospective nation-wide cohort study in Austria 2014-2017

Patients with hyperuricemia and gout are at an increased risk for cardiovascular (CV) disease. Inhibition of the xanthine oxidase with allopurinol or febuxostat have become the mainstay for urate lowering therapy. However, it has been suggested that febuxostat increases the risk for CV mortality as compared to allopurinol. The aim of this retrospective cohort study was to assess the CV risk among patients with febuxostat or allopurinol therapy. Patients who initiated urate lowering therapy with febuxostat or allopurinol between 2014 and 2017 were selected from the drug reimbursement database of the Austrian health insurances funds. The primary CV endpoint was a composite of angina pectoris, nonfatal myocardial infarction, nonfatal subarachnoid or cerebral hemorrhage, nonfatal ischemic stroke, or death from any cause. In total, 28.068 patients (62.1% male) with a mean age of 71 years were included. 7.767 initiated febuxostat treatment and 20.301 received allopurinol. The incidence rate per 100 patient-years of the composite primary endpoint was 448 (febuxostat) and 356 (allopurinol) with a corresponding adjusted hazard ratio (HR) of 0.58 (95% CI 0.53–0.63) for allopurinol vs. febuxostat initiators. Similar HR were found for secondary endpoints including all-cause mortality [0.61 (95% CI 0.55–0.68)] and separate analyses of cardiac events [0.48 (95% CI 0.38–0.61)] and ischemic stroke [0.47 (95% CI 0.36–0.61)]. Data from this Austrian population-based study suggests that febuxostat initiators are at an increased risk for nonfatal CV events or death from any cause as compared to those with allopurinol. This is consistent with CV concerns of other trials, which limited the broad therapeutic use of febuxostat.

Differential gene expression of ABCG2, SLC22A12, IL-1β, and ALPK1 in peripheral blood leukocytes of primary gout patients with hyperuricemia and their comorbidities: a case-control study

Background

The ABCG2, SLC22A12, and ALPK1 genes have been strongly associated with dysfunction of urate metabolism in patients with gout, but it is unknown how these transporters are expressed in patients with acute or chronic gout. Our objectives were to: (a) analyze the gene expression of urate transporters and of inflammation genes in peripheral blood from gout patients and controls; (b) determine whether the metabolic profile of gout patients can influence the gene expression profile and the expression of urate transporters, ABCG2 and SLC22A12, and inflammation molecules, ALPK1 and IL-1β, in peripheral blood leukocytes from gout patients; (c) compare them with their metabolic profile and the gene expression of people without gout and without hyperuricemia.

Methods

A total of 36 chronic and acute patients and 52 controls were recruited, and ABCG2, SLC22A12, IL-1β, and ALPK1 gene expression was evaluated by quantitative real-time PCR. Correlations of gene expression with clinical and laboratory parameters of patients were also analyzed.

Results

IL-1β was significantly increased in peripheral blood mononuclear cells (PBMCs) of patients compared with their polymorphonuclear leukocytes white blood cells (PMNLs, p < 0.05). A significant increase in ABCG2 and IL-1β was found in PMNLs from patients compared to controls (p < 0.05). Correlations of gene expression in patients were found with levels of serum uric acid (sUA), serum creatinine, C-reactive protein (CRP), triglycerides, body mass index (BMI), kidney disease, hypertension, and metabolic syndrome.

Conclusions

Our data suggest that leukocytes of patients respond to the presence of hyperuricemia and comorbidities, expressing ABCG2 and IL-1β genes differentially compared to normouricemic and nondisease states. Hyperuricemia, dyslipidemia, and obesity probably stimulate the differential gene expression of peripheral blood leukocytes (neutrophils and monocytes), even in an asymptomatic state.

Are the levels of uric acid associated with biometeorological conditions?

Hyperuricemia is an independent risk factor for renal and cardiovascular diseases and is closely associated with gout episodes. It is caused, inter alia, by nutritional habits and genetic factors, and also displays seasonal variability conditioned by meteorological factors. The impact of meteorological factors, including both cold and heat stress, on the human physiology is presented based on the Universal Thermal Climate Index (UTCI) - a biometeorological index derived from an analysis of human thermal balance. The aim of our study was to establish whether seasonal variations significantly affect routinely measured urine acid (UA) levels and could eventually support the clinical decision making process, as well as assessing whether UTCI values are correlated with UA levels in blood serum. This work presents a retrospective epidemiological study of data collected in Olsztyn (Poland). Study material comprised 54,536 results of ambulatory tests measuring UA levels, performed during the period 2016-2019. The analysis concerned correlations between UA and the ages of female and male subjects as well as existing biometeorological conditions as represented by UTCI values in an annual cycle. UA levels in females were found to be lower (4.94 ± 1.37 SD) as compared to those of males (6.13 ± 1.43 SD) and demonstrated a strong positive correlation with age. UA values differed significantly (p < 0.05) on days characterized by cold stress and heat stress, for the oldest age group. UA levels were found to differ depending on the season, but these relationships were not statistically significant, except for significantly higher UA levels in females in autumn (p < 0.001). However, there was an evident difference in population UA levels under cold stress conditions (lower) and heat stress conditions (higher) in the elderly. The UTCI is an adequate predictor of population variations in UA levels since it takes into account the variability of local meteorological conditions.

Elevated Serum Uric Acid and Cardiovascular Disease: A Review and Potential Therapeutic Interventions

Several landmark studies found a relationship between elevated serum uric acid (SUA) levels and cardiovascular disease (CVD). In fact, the association between hyperuricemia and hypertension (HTN), coronary artery disease (CAD), and heart failure (HF) is currently well-established. While the mechanism linking hyperuricemia and CVD is not fully known, a systemic inflammatory response by the host is believed to play a role. With the goal of decreasing the morbidity and mortality of CVD in patients with hyperuricemia, the focus has now turned to properly optimizing a medication regimen for this patient population. Recent studies have shown that controlling underlying inflammation can, in fact, lead to better cardiovascular outcomes for populations with acute and chronic coronary disease. In this paper, we will discuss the current state of understanding on the association of hyperuricemia and cardiovascular disease. Furthermore, we will look into the most recent clinical trials showing the effects anti-inflammatory medications have on both decreasing and recovering from cardiovascular events. We will conclude with a discussion on, given the information mentioned above, how to properly optimize a medication regimen in patients with elevated SUA levels with a focus on decreasing the morbidity and mortality associated with CVD.

Periarticular calcifications

Periarticular calcification and ossification is a frequent finding on imaging and may sometimes pose a diagnostic challenge. The differential diagnoses for this radiological finding are wide and can be classified into broad groups such as idiopathic, developmental, trauma, burns, infection, tumor, connective tissue disease, crystalline, metabolic, vascular, and foreign bodies. With careful consideration of the clinical and imaging findings as well as awareness of mimickers of periarticular mineralization, the list of differential diagnoses can be narrowed down. This article aims to review the clinical-radiologic findings of periarticular calcified or ossified lesions with relevant imaging illustrations.

Gout As a Predictor of Total Knee Arthroplasty Outcomes and Costs

Gout is the most common inflammatory arthritis and affects approximately 4% of the U.S. population. As the prevalence of gout and the number of total knee arthroplasties (TKAs) performed continue to increase, the literature on TKA in patients with gout remains scant. The purpose of this study was to evaluate the outcomes of patients with gout following TKA at a population level, that is, how patient with gout fair after TKA. We hypothesized that patients with gout have higher rates of complications and higher costs compared with controls. A case-control study was designed to evaluate two cohorts of Medicare patients who underwent TKA whose only distinguishing feature was the presence or absence of gout. Matching was performed to decrease confounding at a 1:1 ratio based on age, gender, and Charlson comorbidity index (CCI), (10-year survival predictor). The Medicare standard analytical files were queried through International Classification of Disease and current procedural terminology codes. A total of 15,238 patients were evaluated with 7,619 in each cohort. There were no age, gender, or CCI differences and 57.4% were females. Day of surgery and 90-day post-surgery costs were both significantly greater in those with gout (p < 0.001 for both). Multivariate analysis revealed that gout patients had increased odds of infection (odds ratio [OR] 1.229, p = 0.019), cardiac arrest (OR 1.354, p = 0.002), pneumonia (OR 1.161, p < 0.001), hematoma (OR 1.204, p = 0.002), and development of capsulitis (OR 1.208, p = 0.012). Nonetheless these patients had a decreased risk of pulmonary emboli (OR 0.835, p = 0.016). Our results support our hypothesis that patients with gout have higher rates of postoperative complications and increased day of surgery and 90-day costs of care after TKA. Given the high prevalence of gout in the United States, additional study on the utility of preoperative gout optimization for TKA patients is warranted. The level of evidence of this study is III, and it is a retrospective case-control study.

Operative Management of Gouty Tophi in the Region of the Olecranon: A Case Series

Background

Tophaceous gout affecting the olecranon region can result in local discomfort, skin ulceration, secondary infection, and considerable disability if left untreated. However, there are limited reports of outcomes, including postoperative complications and recurrence after surgical excision of tophaceous gout deposits at the elbow. The aim of this study is to present our surgical technique and minimum one-year outcomes after surgical excision of tophaceous gout involving the elbow.

Methods

A retrospective chart review was performed on all patients from a single surgeon's practice who underwent surgical excision of gouty tophi of the elbow between January 2016 and December 2019. The indications for surgical excision of tophi included failure of medical management, presence of skin ulceration, and/or large gouty tophi. The relevant data pertaining to patient demographics, preoperative findings, intraoperative findings, surgical pathology reports, and short-term postoperative complications were collected through retrospective chart review. Patients were subsequently contacted for a follow-up telehealth visit to assess recurrence of gouty tophi, functional outcomes, and range of motion (ROM) measurements.

Results

Six male patients underwent 7 total procedures (1 bilateral elbow) during the study period. The mean age of the cohort at the time of surgery was 56.0 ± 7.1 years (range: 45.3-63.5). The mean size of the swelling in 2 maximum dimensions was 5.8 × 3.4 cm. There were no intraoperative or immediate postoperative wound complications. There was no recurrence of gouty tophi at a mean follow-up time of 30.8 months (range: 14.0-43.5). Patients reported physiologic ROM (mean flexion-extension arc of 2°-134°) with no pain at final follow-up.

Conclusion

Surgical treatment of tophaceous gout of the elbow is associated with a low risk of wound complication and recurrence.

Efficacy and Safety of Acupuncture Combined with Herbal Medicine in Treating Gouty Arthritis: Meta-Analysis of Randomized Controlled Trials

Background

Gouty arthritis is a common metabolic disease caused by long-term purine metabolism and elevated serum uric acid. In recent years, the incidence of gouty arthritis has been increasing year by year. As an effective method for treating gouty arthritis, acupuncture combined with herbal medicine has been widely used in clinical practice. However, the evidence for the treatment needs to be evaluated through systematic review and meta-analysis. Methods. The Cochrane Library, PubMed, Web of Science, EMBASE, China CBM database, Clinical Trials, CNKI, China Wanfang database, and VIP information database were searched from the establishment of each database to March 2021. Randomized controlled trials (RCTs) were included in the study, and the therapeutic effects of acupuncture combined with herbal medicine versus conventional therapy, or acupuncture combined with herbal medicine versus anti-inflammatory drugs, or acupuncture combined with herbal medicine versus acupuncture/herbal medicine alone were compared in the subjects with gouty arthritis. Two authors screened all references, assessed the risk of bias, and independently extracted the data. The binary outcome was summarized using 95% confidence intervals (CIs) and risk ratios (RRs). The overall quality of the evidence was assessed with hierarchy, and meta-analysis was performed with a random-effects model.

Results

A total of 14 randomized controlled trials (1,065 participants, 540 treatment groups, and 525 control groups) with treatment courses of 5 to 21 days were included. Acupuncture combined with herbal medicine and acupuncture was compared in three trials, acupuncture combined with herbal medicine and conventional therapy was compared in 14 of them, and acupuncture combined with herbal medicine and anti-inflammatory drugs was compared in 8 of them. The clinical efficacy (clinical symptoms, serological tests, and visual analogue scale (VAS) results) was significantly improved in the acupuncture combined with herbal medicine treatment group (P=0.0005, 95% CI 0.03 to 0.13; 687 participants; 8 trials), and the efficacy in reducing uric acid was also better (P < 0.00001; 95% CI −102.89, −68.37; 100 participants; 2 trials; evidence with moderate quality). The effect of acupuncture combined with herbal medicine was better than that of acupuncture alone (RR 1.22, 95%CI 1.06 to 1.41; 139 participants; 3 trials), the effect of acupuncture combined with herbal medicine was better than that of herbal medicine alone (RR 1.31 95%CI 1.08 to 1.57, 100 participants, 2 trials, evidence with moderate quality), and the effect of acupuncture combined with herbal medicine was better than that of colchicine (P = 0.02, RR 1.14 95%CI 1.02 to 1.27, 2 trials, evidence with moderate quality). The incidence of adverse events was considerably different between the two groups, and the acupuncture combined with herbal medicine group was significantly superior to the control group in terms of adverse events (P < 0.00001; 95% CI (0.08 to 0.32)).

Conclusions

The efficacy of acupuncture combined with herbal medicine was better than conventional drug therapy in treating gouty arthritis. The study results must be interpreted with caution due to the high or unclear risk of bias of the trials included in the study. PROSPERO registration number: CRD42020202544. INPLASY registration number: 202090006.

Epigenome-wide association study of serum urate reveals insights into urate co-regulation and the SLC2A9 locus

Elevated serum urate levels, a complex trait and major risk factor for incident gout, are correlated with cardiometabolic traits via incompletely understood mechanisms. DNA methylation in whole blood captures genetic and environmental influences and is assessed in transethnic meta-analysis of epigenome-wide association studies (EWAS) of serum urate (discovery, n = 12,474, replication, n = 5522). The 100 replicated, epigenome-wide significant (p < 1.1E-7) CpGs explain 11.6% of the serum urate variance. At SLC2A9, the serum urate locus with the largest effect in genome-wide association studies (GWAS), five CpGs are associated with SLC2A9 gene expression. Four CpGs at SLC2A9 have significant causal effects on serum urate levels and/or gout, and two of these partly mediate the effects of urate-associated GWAS variants. In other genes, including SLC7A11 and PHGDH, 17 urate-associated CpGs are associated with conditions defining metabolic syndrome, suggesting that these CpGs may represent a blood DNA methylation signature of cardiometabolic risk factors. This study demonstrates that EWAS can provide new insights into GWAS loci and the correlation of serum urate with other complex traits.

Inosine induces acute hyperuricaemia in rhesus monkey (Macaca mulatta) as a potential disease animal model

CONTEXT

The uric acid metabolism pathway is more similar in primates and humans than in rodents. However, there are no reports of using primates to establish animal models of hyperuricaemia (HUA).

OBJECTIVES

To establish an animal model highly related to HUA in humans.

MATERIALS AND METHODS

Inosine (75, 100 and 200 mg/kg) was intraperitoneally administered to adult male rhesus monkeys (n = 5/group). Blood samples were collected over 8 h, and serum uric acid (SUA) level was determined using commercial assay kits. XO and PNP expression in the liver and URAT1, OAT4 and ABCG2 expression in the kidneys were examined by qPCR and Western blotting to assess the effects of inosine on purine and uric acid metabolism. The validity of the acute HUA model was assessed using ulodesine, allopurinol and febuxostat.

RESULTS

Inosine (200 mg/kg) effectively increased the SUA level in rhesus monkeys from 51.77 ± 14.48 at 0 h to 178.32 ± 14.47 μmol/L within 30 min and to peak levels (201.41 ± 42.73 μmol/L) at 1 h. PNP mRNA level was increased, whereas XO mRNA and protein levels in the liver were decreased by the inosine group compared with those in the control group. No changes in mRNA and protein levels of the renal uric acid transporter were observed. Ulodesine, allopurinol and febuxostat eliminated the inosine-induced elevation in SUA in tested monkeys.

CONCLUSIONS

An acute HUA animal model with high reproducibility was induced; it can be applied to evaluate new anti-HUA drugs in vivo and explore the disease pathogenesis.

Characteristics of monosodium urate crystal deposition in the foot in the different stages of gout by dual-energy computed tomography

OBJECTIVE

To compare the characteristics of monosodium urate (MSU) crystal deposition at specific anatomical sites of the foot detected by dual-energy computed tomography in patients with different stages of gout.

MATERIALS AND METHODS

This study included 101 patients with gout, 64 had early gout (<3 years) and 37 had late gout (>3 years). We retrospectively compared the total volumes of MSU crystals, the detection rates, and the morphology of MSU crystals at specific anatomical sites in the foot of the patients with different gout durations.

RESULTS

The total volume of MSU crystals in patients with early gout was significantly smaller than that in patients with late gout (P < 0.05). The detection rates and morphology of MSU crystals in the anterior calf tendons, ankle joints, tarsometatarsal joints, and metatarsophalangeal joints differed significantly between the patients with early and late gout (P < 0.05). There were no significant differences in the detection rates of submillimeter MSU crystals at the other specific anatomical sites, except for the tendons of the anterior calf, the ankle joint, and the metatarsal joint (P > 0.05). The submillimeter MSU crystal deposition was most common in the tendons of the posterior calf, the proportions in patients with early gout and late gout were 85.9% and 70.3%. Only submillimeter deposition existed in 52 patients (81.3%) with early gout and 11 patients (29.7%) with late gout at all sites of the foot.

CONCLUSION

Dual-energy computed tomography detection of submillimeter MSU crystal deposits in the foot is of great significance for the diagnosis of gout, especially along tendons.

Clinical Association between Gout and Parkinson's Disease: A Nationwide Population-Based Cohort Study in Korea

Background and Objectives: This retrospective cohort study aimed to investigate the association between gout and Parkinson’s disease (PD) in Korea. Materials and Methods: Overall, 327,160 patients with gout and 327,160 age- and sex-matched controls were selected from the Korean National Health Insurance Service (NHIS) database. PD incidence was evaluated by reviewing NHIS records during the period from 2002 to 2019. Patients with a diagnosis of gout (International Classification of Diseases-10 (ICD-10), M10) who were prescribed medications for gout, including colchicine, allopurinol, febuxostat, and benzbromarone for at least 90 days were selected. Patients with PD who were assigned a diagnosis code (ICD-G20) and were registered in the rare incurable diseases (RID) system were extracted. Results: During follow-up, 912 patients with gout and 929 control participants developed PD. The incidence rate (IR) of overall PD (per 1000 person-years) was not significantly different between both groups (0.35 vs. 0.36 in gout and control groups, respectively). The incidence rate ratio (IRR) was 0.98 (95% CI: 0.89–1.07). The cumulative incidence of PD was not significantly different between the groups. No association between gout and PD was identified in univariate analysis (HR = 1.00, 95% CI: 0.91–1.10, p = 0.935). HR increased significantly with old age (HR = 92.08, 198, and 235.2 for 60–69 years, 70–79 years, and over 80 years, respectively), female sex (HR = 1.21, 95% CI: 1.07–1.37, p = 0.002), stroke (HR = 1.95, 95% CI: 1.76–2.16, p < 0.001), and hypertension (HR = 1.16, 95% CI: 1.01–1.34, p = 0.04). Dyslipidemia exhibited an inverse result for PD (HR = 0.6, 95% CI: 0.52–0.68, p < 0.001). Conclusions: This population-based study did not identify an association between gout and PD. Age, female sex, stroke, and hypertension were identified as independent risk factors for PD, and dyslipidemia demonstrated an inverse result for PD.

Advances in Experimental and Clinical Research of the Gouty Arthritis Treatment with Traditional Chinese Medicine

Gouty arthritis (GA) is a multifactorial disease whose pathogenesis is utterly complex, and the current clinical treatment methods cannot wholly prevent GA development. Western medicine is the primary treatment strategy for gouty arthritis, but it owns an unfavorable prognosis. Therefore, the prevention and treatment of GA are essential. In China, traditional Chinese medicine (TCM) has been adopted for GA prevention and treatment for thousands of years. Gout patients are usually treated with TCM according to their different conditions, and long-term results can be achieved by improving their physical condition. And TCM has been proved to be an effective method to treat gout in modern China. Nevertheless, the pharmacological mechanism of TCM for gout is still unclear, which limits its spread. The theory of prevention and treatment of gout with TCM is more well acknowledged in China than in abroad. In this article, Chinese herbs and ancient formula for gout were summarized first. A total of more than 570 studies published from 2004 to June 2021 in PubMed, Medline, CNKI, VIP, Web of Science databases and Chinese Pharmacopoeia and traditional Chinese books were searched; the current status of TCM in the treatment of GA was summarized from the following aspects: articular chondrocyte apoptosis inhibition, antioxidative stress response, inflammatory cytokine levels regulation, uric acid excretion promotion, immune function regulation, uric acid reduction, and intestinal flora improvement in subjects with gout. The literature review concluded that TCM has a specific curative effect on the prevention and treatment of GA, particularly when combined with modern medical approaches. However, lacking a uniform definition of GA syndrome differentiation and the support of evidence-based medicine in clinical practice have provoked considerable concern in previous studies, which needs to be addressed in future research.

Crystalline-Induced Arthropathy Following Total Knee Replacement

Gout rarely occurs in the setting of prior total joint replacement. It can present as an acute or chronic painful joint that may mimic prosthetic joint infection with further similarities found on physical examination and initial workup. Elevated leukocyte count, erythrocyte sedimentation rate, and C-reactive protein are common to both conditions. The confirmatory test to distinguish infection versus inflammatory arthropathy is joint aspiration with crystal or micro-organism identification microscopically. Establishing proper diagnosis is important in guiding appropriate treatment, which may prevent the unnecessary removal of implants. The current study includes a review of the literature and presents a case of bilateral gouty arthropathy after total knee arthroplasty.

Where Epigenetics Meets Food Intake: Their Interaction in the Development/Severity of Gout and Therapeutic Perspectives

Gout is the most frequent form of inflammatory arthritis in the world. Its prevalence is particularly elevated in specific geographical areas such as in the Oceania/Pacific region and is rising in the US, Europe, and Asia. Gout is a severe and painful disease, in which co-morbidities are responsible for a significant reduction in life expectancy. However, gout patients remain ostracized because the disease is still considered "self-inflicted", as a result of unhealthy lifestyle and excessive food and alcohol intake. While the etiology of gout flares is clearly associated with the presence of monosodium urate (MSU) crystal deposits, several major questions remain unanswered, such as the relationships between diet, hyperuricemia and gout flares or the mechanisms by which urate induces inflammation. Recent advances have identified gene variants associated with gout incidence. Nevertheless, genetic origins of gout combined to diet-related possible uric acid overproduction account for the symptoms in only a minor portion of patients. Hence, additional factors must be at play. Here, we review the impact of epigenetic mechanisms in which nutrients (such as ω-3 polyunsaturated fatty acids) and/or dietary-derived metabolites (like urate) trigger anti/pro-inflammatory responses that may participate in gout pathogenesis and severity. We propose that simple dietary regimens may be beneficial to complement therapeutic management or contribute to the prevention of flares in gout patients.

Anti-Hyperuricemic and Uricosuric Potential of Berberis vulgaris in Oxonate-Induced Hyperuricemic Rats

Hyperuricemia is a metabolic disorder with characteristic elevated serum uric acid. Recently, several plant-based medicines are being used for the treatment of hyperuricemia. The study aimed to find the hypouricemic potential of Berberis vulgaris in in-vitro and in-vivo study models. In in-vitro studies, xanthine oxidase inhibition assay was performed to evaluate IC₅₀ value and capsule absorbance of the drug, respectively. For in-vivo experiment, the study comprised 15 groups of rats. In-vitro results revealed that significant xanthine oxidase inhibition was shown by Berberis vulgaris with an IC₅₀ value of 272.73±.3 μg/mL. Similarly, oral administration of Berberis vulgaris with dosages of 250 and 500 mg/kg decreased serum and liver uric acid levels significantly in a dose- and time-dependent manner in oxonate-induced hyperuricemic rats. Furthermore, 3-day and 7-day administration of Berberis vulgaris showed more potential compared to 1-day administrations. The present study indicated marked hypouricemic effects of Berberis vulgaris in rats. Due to caveat of the small sample size, a firm assumption of the hypouricemic effect of Berberis vulgaris cannot be made. However, extensive study is needed to find out the exact molecular mechanism involved and to translate its effects into clinical trials for the further validation of the results.

Association of urate-lowering drugs with the risk of future urolithiasis in patients with gout: A population-based nested case-control study

BACKGROUND

Patients with gout have an increased risk of urolithiasis and usually need urate-lowering therapy (ULT) for the prevention of disease progression. However, there is a paucity of clinical data regarding the risk of future urolithiasis in ULT users.

METHODS

This nested case-control study was performed using the Taiwan National Health Insurance Research Database. The aim of this study was to examine whether ULT (xanthine oxidase inhibitors [XOIs] or uricosuric agents) is associated with risk of future urolithiasis in patients with gout. Data were collected from January 2000 to December 2012.

RESULTS

This study included 2307 case patients and 2307 matched controls. Case patients had gout that developed into urolithiasis, and control patients had gout but were not diagnosed with urolithiasis during the study period. Patients had a mean age of 56.3 years at diagnosis of gout, and 83.2% were male patients. No association was detected between use of XOIs or uricosuric agents and risk of future urolithiasis. Furthermore, there was no significant difference in the risk of future urolithiasis in patients exposed to various cumulative days of XOI or uricosuric prescriptions.

CONCLUSION

The present study provides evidence that neither XOIs nor uricosuric agents are associated with risk of future urolithiasis in patients with gout. Before the availability of more clinical evidence, ensuring high fluid intake and prospective monitoring of urolithiasis development are still important for uricosuric agent users.

An update of genetics, co-morbidities and management of hyperuricaemia

Hyperuricaemia (HU) caused by disorders of purine metabolism is a metabolic disease. A number of epidemiological reports have confirmed that HU is correlated with multiple disorders, such as chronic kidney diseases, cardiovascular disease and gout. Recent studies showed that the expression and functional changes of uric acid transporters, including URAT1, GLUT9 and ABCG2, were associated with HU. Moreover, a large number of genome-wide association studies have shown that these transporters' dysfunction leads to HU. In this review, we describe the recent progress of aetiology and related transporters of HU, and we also summarise the common co-morbidities possible mechanisms, as well as the potential pharmacological and non-pharmacological treatment methods for HU, aiming to provide new ideas for the treatment of HU.

Dietary and Lifestyle-Centered Approach in Gout Care and Prevention

PURPOSE OF REVIEW

We aim to provide a comprehensive review of the available literature to inform dietary recommendations for patients with gout and hyperuricemia that have the potential to simultaneously lower serum urate and reduce gout morbidity while addressing gout's cardiometabolic comorbidities holistically.

RECENT FINDINGS

The global burden of gout is rising worldwide, particularly in developed nations as well as in women. Patients with gout are often recommended to follow a low-purine (i.e., low-protein) diet to avoid purine-loading. However, such an approach may lead to increased consumption of unhealthy carbohydrates and fats, which in turn contributes to metabolic syndrome and subsequently raises serum urate levels and leads to adverse cardiovascular outcomes. On the other hand, several well-established diets for cardiometabolic health, such as the Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets, in combination with weight loss for those who are overweight or obese, also have beneficial effects on relevant gout endpoints. It is important to recognize not only the direct effect of diet on hyperuricemia and gout, but its mediated effect through obesity and insulin resistance. Thus, several preeminent healthy dietary patterns that have proven benefits in cardiometabolic health have the power to holistically address not only gout morbidity but also its associated comorbidities that lead to premature mortality among patients with gout.

Unravelling the mysteries of gout by multimodality imaging

Gout is a common inflammatory arthritis that manifests as an aggregate of variably symptomatic monosodium urate crystals (MSU) in the joints and surrounding tissues in addition to multisystem involvement such as genitourinary and cardiovascular systems. In recent decades, there has been a documented increase in the prevalence and incidence of gout. Risk factors for gout include obesity, dietary influences, hypertension, renal impairment, and diuretic use. A prompt diagnosis followed by uric acid lowering treatment prior to the onset of bone destruction is the goal in any suspected case of gout. Advanced imaging modalities, such as dual energy computed tomography (DECT) and ultrasonography (US), employed for the diagnosis of gout are each accompanied by advantages and disadvantages. Conventional radiography (CR), although useful in visualizing joint erosions and mineralization, is limited in its ability to diagnose gout flare. Although synovial fluid aspiration remains the gold standard for MSU crystal visualization, less-invasive imaging modalities are preferred to avoid potential complications. DECT and US in particular are useful in the diagnosis of gout. In this review, we will discuss the current state and role of imaging in the detection of gout.

Minimally Invasive Embedding of Saturated MSU Induces Persistent Gouty Arthritis in Modified Rat Model

Introduction

Animal models are valid for in vivo research on the pathophysiological process and drug screening of gout arthritis. Intra-articular injection of monosodium urate (MSU) is the most common method, while stable MSU deposition enveloped by inflammatory cells was rarely reported.

Objective

To develop a modified gouty arthritis rat model characterized by intra-articular MSU deposition and continuous joint pain with a minimally invasive method.

Method

A total of twenty-four rats were randomly allocated into six groups. Three intervention groups of rats received intra-articular MSU embedment. Sham groups received pseudosurgeries with equal normal saline (NS). Gross parameters and pathological features of synovium harvested from anterior capsule were estimated. Mechanical pain threshold tests were conducted over a 96-hour period postoperatively. Moreover, quantitative immunofluorescence was conducted to assess tissue inflammation.

Result

After MSU embedding, rats got more persistent arthritic symptoms as well as tissue MSU deposition. More significant synovial swelling was detected in the MSU group compared to sham groups (P < 0.025). Behavioral tests showed that the embedding of MSU resulted in prolonged mechanical hyperalgesia during 2 hours to 96 hours postoperatively (P < 0.05). MSU depositions enveloped by inflammatory cells that express IL-1β and TNF-α were detected in embedding groups. Quantitative immunofluorescence suggested that the frequencies of MSU interventions upregulated expression of proinflammatory factors including IL-1β and TNF-α (P < 0.05).

Conclusion

A minimally invasive method was developed to establish modified rat model of intra-articular MSU deposition. This model was proved to be a simple reproducible method to mimic the pathological characteristics of persistent gouty arthritis.

Association Between Chinese Herbal Medicine Therapy and the Risk of Chronic Kidney Disease in Gout Patients

Background: Chinese herbal medicine (CHM) has been nationally and globally used in treating gout for over a millennium. The potential relationship between the incidence of chronic kidney disease (CKD) in gout patients and CHM therapy is unclear. Thus, this study aimed to provide some evidence regarding the relationship between CHM therapy and the occurrence of CKD in gout patients.

Methods: We used data from the National Health Insurance Research database (NHIRD) in Taiwan. In this population-based nested case-control study, all participants were identified by International Classification of Diseases, Ninth Revision (ICD-9). Conditional logistic regression was used to calculate the odds ratio (OR) of the risk of CKD in gout patients treated with CHM therapy.

Results: Data on 1718 gout patients with CKD and 1:1 matched 1718 gout patients without CKD were collected for analysis. The results showed that CHM therapy in gout patients did not increase the risk of developing CKD (adjusted OR = 1.01; 95% confidence interval [CI]: 0.86–1.18; p > 0.05). Moreover, CHM therapy in gout patients for >365 days did not increase the incidence of CKD (adjusted OR = 1.30; 95% CI: 0.90–1.88; p = 0.162).

Conclusion: Traditional CHM therapy does not increase the incidence of CKD in gout patients.

Machine Learning Prediction Models for Chronic Kidney Disease Using National Health Insurance Claim Data in Taiwan

Chronic kidney disease (CKD) represents a heavy burden on the healthcare system because of the increasing number of patients, high risk of progression to end-stage renal disease, and poor prognosis of morbidity and mortality. The aim of this study is to develop a machine-learning model that uses the comorbidity and medication data obtained from Taiwan's National Health Insurance Research Database to forecast the occurrence of CKD within the next 6 or 12 months before its onset, and hence its prevalence in the population. A total of 18,000 people with CKD and 72,000 people without CKD diagnosis were selected using propensity score matching. Their demographic, medication and comorbidity data from their respective two-year observation period were used to build a predictive model. Among the approaches investigated, the Convolutional Neural Networks (CNN) model performed best with a test set AUROC of 0.957 and 0.954 for the 6-month and 12-month predictions, respectively. The most prominent predictors in the tree-based models were identified, including diabetes mellitus, age, gout, and medications such as sulfonamides and angiotensins. The model proposed in this study could be a useful tool for policymakers in predicting the trends of CKD in the population. The models can allow close monitoring of people at risk, early detection of CKD, better allocation of resources, and patient-centric management.

Studies on effect of Tongfengxiaofang in HUM model mice using a UPLC-ESI-Q-TOF/MS metabolomic approach

Hyperuricemia (HUM) is a major risk factor for the development of gout. The traditional Chinese medicine (TCM) complex prescription Tongfengxiaofang (TFXF) is composed of a variety of TCMs. To study the therapeutic effect of TFXF on HUM mice and the mechanisms by which it exerts a therapeutic effect, the biochemical indices were measured and qPCR technique was used. In addition, plasma metabolomics analysis was carried out based on UPLC-Q-TOF/MS to evaluate the characteristics of the metabolic spectrum changes. TFXF significantly downregulated the contents of uric acid, urea nitrogen and creatinine in serum and the concentration of xanthine oxidase in liver of HUM mice. In addition, TFXF significantly inhibited the overexpression of uric acid transporter 1 and glucose transporter 9 and upregulated the expression of organic anion transporter 1 in the kidney. A total of 152 metabolites were identified and 11 key biomarkers were further selected from these pathways to understand the mechanism of TFXF on the arginine biosynthesis, galactose metabolism, pyrimidine metabolism, glycerophospholipid metabolism, tryptophan metabolism and the citrate cycle (TCA cycle). The results of this confirmed the effect of TFXF on HUM and revealed the metabolic activity mechanism.

Analysis of Wistar Rats Submitted to a Gout Model, Treated with Double Cryotherapy Protocol

Gout arthritis commonly affects joint regions by deposition of crystals, promoting functional damage mainly during periods of exacerbation. Cryotherapy is a commonly used resource to contain inflammatory processes, however, its use during a gout crisis is not yet well understood. Therefore, the objective was to evaluate the parameters of Wistar rats submitted to an experimental gout model and treated with dual cryotherapy protocol. Twenty-one male Wistar rats were used, separated into three groups: control group (CG), lesion group (LG), and lesion + cryotherapy group (LCG). Gout model induction was through intra-articular injection, with urate crystal solution, in the right knee and cryoimmersion treatment was performed for 20 minutes at a temperature of 5° ± 2°C. Seven evaluations and two treatment moments were performed, and the following parameters were analyzed: joint edema, grip strength, joint disability, motor function, and leukocyte migration through synovial lavage. In the statistical analysis we used SPSS 20.0 with Generalized Linear Models, with least significant difference posttest, always with 5% significance level. The treatment reduced edema, promoted strength recovery, and was effective in reducing total leukocytes in the synovial fluid. No difference was observed between the injured groups for joint disability and motor function. Cryotherapy promoted edema reduction and increased pelvic limb grip strength in Wistar rats during the acute period.

Serum Uric Acid Levels and Risk of Eight Site-Specific Cancers: A Mendelian Randomization Study

The relationship between serum uric acid (UA) levels and cancer risk remains controversial. Here, a two-sample Mendelian randomization analysis was performed to identify a causal effect of serum UA levels on cancer risk. Twenty-six single nucleotide polymorphisms strongly associated with serum UA levels were screened as genetic variants from large-scale meta-analysis data of a genome-wide association study of 110,347 European individuals. Genetic associations with eight common site-specific cancers were subsequently explored. A total of six Mendelian randomization methods were used to estimate the potential effect of serum UA levels on cancer risk, including random effects inverse variance weighting, fix effects inverse variance weighting, MR-Egger, median weighting, mode weighting, and simple mode analysis. Our primary random effects inverse variance weighted analysis revealed that no significant associations with cancers was found (all p > 0.05). Sensitivity analyses and additional analyses also showed similar pooled results. In conclusion, no significant causality between serum UA levels and cancer risk was evidenced.