Gout, Hyperuricemia, and Crystal-Associated Disease Network Consensus Statement Regarding Labels and Definitions for Disease Elements in Gout

Investigating gout flares: beyond a definition

PURPOSE OF REVIEW

Gout flares are a paramount component of disease burden inflicted by gout onto the patient. Furthermore, they are included in the core domain set for long-term gout studies recognized by Outcome Measures in Rheumatology. Along with a validated classification criterion for gout, gout investigators have turned their efforts into defining and characterizing the gout flare. This brief review will summarize the efforts that have been done to define and characterize a gout flare in clinical studies.

RECENT FINDINGS

Recent findings include a validated definition of a gout flare that has been utilized in novel clinical studies, use of technology to monitor for gout flares and their effects on patient life, and qualitative analyses into the disease burden that a patient undergoes.

SUMMARY

Although guidelines for core outcome domains have been well established, there is question in methods of measuring and reporting gout flares in long-term trials. Furthermore, there is question as to the effectiveness of the agreed upon instruments' abilities to fully capture the disease burden experienced by patients with gout. A combination of outcome measurements including binary data (gout flare present or absent) along with a comprehensive measurement of disease burden over time would theoretically provide a more accurate description of the disease and serve as a basis for intervention development.

The Terminalia chebula Retz extract treats hyperuricemic nephropathy by inhibiting TLR4/MyD88/NF-κB axis

ETHNOPHARMACOLOGICAL RELEVANCE

Hyperuricemic nephropathy (HN) is a renal injury caused by hyperuricemia and is the main cause of chronic kidney disease and end-stage renal disease. ShiWeiHeZiSan, which is composed mainly of components of Terminalia chebula Retz. And is recorded in the Four Medical Tantras, is a typical traditional Tibetan medicinal formula for renal diseases. Although T. chebula has been reported to improve renal dysfunction and reduce renal cell apoptosis, the specific mechanism of the nephroprotective effects of T. chebula on HN is still unclear.

AIM OF THE STUDY

This study was conducted to evaluate the effects and specific mechanism of T. chebula extract on HN through network pharmacology and in vivo and in vitro experiments.

MATERIALS AND METHODS

Potassium oxalate (1.5 g/kg) and adenine (50 mg/kg) were combined for oral administration to establish the HN rat model, and the effects of T. chebula extract on rats in the HN model were evaluated by renal function indices and histopathological examinations. UPLC-Q-Exactive Orbitrap/MS analysis was also conducted to investigate the chemical components of T. chebula extract, and the potential therapeutic targets of T. chebula in HN were predicted by network pharmacology analysis. Moreover, the activation of potential pathways and the expression of related mRNAs and proteins were further observed in HN model rats and uric acid-treated HK-2 cells.

RESULTS

T. chebula treatment significantly decreased the serum uric acid (SUA), blood urea nitrogen (BUN) and serum creatinine (SCr) levels in HN rats and ameliorated renal pathological injury and fibrosis. A total of 25 chemical components in T. chebula extract were identified by UPLC-Q-Exactive Orbitrap/MS analysis, and network pharmacology analysis indicated that the NF-κB pathway was the potential pathway associated with the therapeutic effects of T. chebula extract on HN. RT‒PCR analysis, immunofluorescence staining and ELISA demonstrated that the mRNA and protein levels of TLR4 and MyD88 were significantly decreased in the renal tissue of HN rats after treatment with T. chebula extract at different concentrations, while the phosphorylation of P65 and the secretion of TNF-α and IL-6 were significantly inhibited. The results of in vitro experiments showed that T. chebula extract significantly decreased the protein levels of TLR4, MyD88, p-IκBα and p-P65 in uric acid-treated HK-2 cells and inhibited the nuclear translocation of p65 in these cells. In addition, the expression of inflammatory factors (IL-1β, IL-6 and TNF-α) and fibrotic genes (α-SMA and fibronectin) was significantly downregulated by T. chebula extract treatment, while E-cadherin expression was significantly upregulated.

CONCLUSION

T. chebula extract exerts nephroprotective effects on HN, such as anti-inflammatory effects and fibrosis improvement, by regulating the TLR4/MyD88/NF-κB axis, which supports the general use of T. chebula in the management of HN and other chronic kidney diseases.

Uptake of the Gout and Crystal Arthritis Network Consensus Statements for Gout Nomenclature

OBJECTIVE

In 2019, the Gout and Crystal Arthritis Network (G-CAN) published consensus statements for the nomenclature of disease elements and states in gout. The aim of this study was to determine adherence to the G-CAN consensus nomenclature statements since publication.

METHODS

American College of Rheumatology and EULAR conference abstracts were searched using online databases for the keywords 'gout,' 'urate,' 'uric acid,' 'hyperuricaemia,' 'tophus,' and/or 'tophi' before and after publication of the consensus statements (January 1, 2016 to December 31, 2017 and January 1, 2020 to December 31, 2021, respectively). Abstracts were manually searched for labels used to reference gout disease elements and states. Use of the G-CAN-agreed labels, as well as alternatives, were compared between the two time periods.

RESULTS

There were 988 abstracts included in the analysis: 596 in 2016 to 2017 and 392 in 2020 to 2021. Use of the agreed labels 'urate' and 'gout flare' increased between the two periods. There were 219 of 383 abstracts (57.2%) with the agreed label 'urate' in 2016 to 2017 compared with 164 of 232 (70.7%) in 2020 to 2021 (P = 0.001). There were 60 of 175 abstracts (34.3%) with the agreed label 'gout flare' in 2016 to 2017 compared with 57 of 109 (52.3%) in 2020 to 2021 (P = 0.003). Consistent with the G-CAN statement, use of the label 'chronic gout' reduced between the two time periods. There were 29 of 596 abstracts (4.9%) in 2016 to 2017 that used the label 'chronic gout' compared with 8 of 392 abstracts (2.0%) in 2020 to 2021 (P = 0.02).

CONCLUSION

Use of G-CAN-agreed gout labels has increased, but gout nomenclature remains imprecise. Additional efforts are needed to ensure consistent use of agreed nomenclature for gout in the scientific literature.

Identification of inhibitors from a functional food-based plant Perillae Folium against hyperuricemia via metabolomics profiling, network pharmacology and all-atom molecular dynamics simulations

Introduction

Hyperuricemia (HUA) is a metabolic disorder caused by purine metabolism dysfunction in which the increasing purine levels can be partially attributed to seafood consumption. Perillae Folium (PF), a widely used plant in functional food, has been historically used to mitigate seafood-induced diseases. However, its efficacy against HUA and the underlying mechanism remain unclear.

Methods

A network pharmacology analysis was performed to identify candidate targets and potential mechanisms involved in PF treating HUA. The candidate targets were determined based on TCMSP, SwissTargetPrediction, Open Targets Platform, GeneCards, Comparative Toxicogenomics Database, and DrugBank. The potential mechanisms were predicted via Gene Ontology (GO) and Kyoto Gene and Genome Encyclopedia (KEGG) analyses. Molecular docking in AutoDock Vina and PyRx were performed to predict the binding affinity and pose between herbal compounds and HUA-related targets. A chemical structure analysis of PF compounds was performed using OSIRIS DataWarrior and ClassyFire. We then conducted virtual pharmacokinetic and toxicity screening to filter potential inhibitors. We further performed verifications of these inhibitors' roles in HUA through molecular dynamics (MD) simulations, text-mining, and untargeted metabolomics analysis.

Results

We obtained 8200 predicted binding results between 328 herbal compounds and 25 potential targets, and xanthine dehydrogenase (XDH) exhibited the highest average binding affinity. We screened out five promising ligands (scutellarein, benzyl alpha-D-mannopyranoside, elemol, diisobutyl phthalate, and (3R)-hydroxy-beta-ionone) and performed MD simulations up to 50 ns for XDH complexed to them. The scutellarein-XDH complex exhibited the most satisfactory stability. Furthermore, the text-mining study provided laboratory evidence of scutellarein's function. The metabolomics approach identified 543 compounds and confirmed the presence of scutellarein. Extending MD simulations to 200 ns further indicated the sustained impact of scutellarein on XDH structure.

Conclusion

Our study provides a computational and biomedical basis for PF treating HUA and fully elucidates scutellarein's great potential as an XDH inhibitor at the molecular level, holding promise for future drug design and development.

Adherence to the Dietary Approaches to Stop Hypertension (DASH) and Serum Urate Concentrations: A Longitudinal Analysis from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

BACKGROUND

Increased serum urate (SU) and hyperuricemia (HU) are associated with chronic noncommunicable diseases and mortality. SU concentrations are affected by several factors, including diet, and are expected to rise with age. We investigated whether the Dietary Approaches to Stop Hypertension (DASH) diet alter this trend.

OBJECTIVE

The objective was to assess whether adherence to the DASH diet predicts a longitudinal change in SU concentrations and risk of HU in 8 y of follow-up.

METHODS

Longitudinal analyses using baseline (2008-2010, aged 35-74 y), second (2012-2014), and third (2016-2018) visits data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). The inclusion criteria were having complete food frequency questionnaire (FFQ) and urinary sodium measurement, in addition to having SU measurement at the 1st visit and at least 1 of the 2 follow-up visits. For the HU incidence analyses, participants had also to be free from HU at baseline. The final samples included 12575 individuals for the SU change analyses and 10549 for the HU incidence analyses. Adherence to DASH diet was assessed as continuous value. HU was defined as SU>6.8 mg/dL and/or urate-lowering therapy use. Mixed-effect linear and Poisson regressions (incidence rate ratio [IRR] and 95% confidence interval [CI]) were used in the analyses, adjusted for confounders.

RESULTS

The mean age was 51.4 (8.7) y, and 55.4% were females. SU means (standard deviation) were 5.4 (1.4) at 1st visit, 5.2 (1.4) at 2nd visit, and 5.1(1.3) mg/dL at 3rd visit. The HU incidence rate was 8.87 per 1000 person-y. Each additional point in adherence to the DASH diet accelerated SU decline (P< 0.01) and lowered the incidence of HU by 4.3% (IRR: 0.957; 95% CI: 0.938,0.977) in adjusted model.

CONCLUSION

The present study findings reinforce the importance of encouraging the DASH diet as a healthy dietary pattern to control and reduce the SU concentrations and risk of HU.

Non-loading versus loading low-dose colchicine in acute crystal-associated arthritis: A double-blinded randomized controlled study

INTRODUCTION

This study aimed to compare the efficacy of non-loading versus loading low-dose colchicine in patients with acute crystal-associated arthritis.

MATERIALS AND METHODS

All in-patients who were admitted to Chiang Mai University Hospital with non-arthritis disease and developed acute crystal-associated arthritis during admission (within 48 h after arthritis onset) were invited to join this study. The patients were randomized into two groups. Patients in Group I (non-loading group) and Group II (loading group) received colchicine at 1.2 and 2.4 mg in the first 24 h, respectively. The primary outcome was the patients' pain response at 24 h after treatment.

RESULTS

Of 80 patients, 49 were acute gouty arthritis, and 31 acute calcium pyrophosphate (CPP) arthritis. The mean [95% CI] pain score was no different between Groups I and II at the baseline level (6.46[5.72-7.19] vs. 6.654[5.85-7.44], p = .867) and at 24 h (3.13[2.43-3.82] vs. 3.18[2.42-3.93], p = .907). The proportion of patients with ≥50% pain reduction was not different (57.50% vs. 55.00%, p = .822). Sensitivity analysis among patients with a baseline pain score of ≥4 showed the same pattern of response. Mild diarrhea was common and comparable in both groups. Subgroup analysis according to renal function (eGFR < 60 vs. ≥60 mL/min/1.73 m2 ) or type of crystals (acute gouty arthritis vs. acute CPP arthritis) also showed the same pattern of response.

CONCLUSION

Non-loading low-dose colchicine was as effective as loading low-dose colchicine in patients with acute crystal-associated arthritis, regardless of renal function or type of crystals.

Coinfection with Schistosoma mansoni Enhances Disease Severity in Human African Trypanosomiasis

Introduction

Human African trypanosomiasis (HAT) and schistosomiasis are neglected parasitic diseases found in the African continent. This study was conducted to determine how primary infection with Schistosoma mansoni affects HAT disease progression with a secondary infection with Trypanosoma brucei rhodesiense (T.b.r) in a mouse model.

Methods

Female BALB-c mice (6-8 weeks old) were randomly divided into four groups of 12 mice each. The different groups were infected with Schistosoma mansoni (100 cercariae) and Trypanosoma brucei rhodesiense (5.0 × 104) separately or together. Twenty-one days after infection with T.b.r, mice were sacrificed and samples were collected for analysis.

Results

The primary infection with S. mansoni significantly enhanced successive infection by the T.b.r; consequently, promoting HAT disease severity and curtailing host survival time. T.b.r-induced impairment of the neurological integrity and breach of the blood-brain barrier were markedly pronounced on coinfection with S. mansoni. Coinfection with S. mansoni and T.b.r resulted in microcytic hypochromic anemia characterized by the suppression of RBCs, hematocrit, hemoglobin, and red cell indices. Moreover, coinfection of the mice with the two parasites resulted in leukocytosis which was accompanied by the elevation of basophils, neutrophils, lymphocytes, monocytes, and eosinophils. More importantly, coinfection resulted in a significant elevation of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin, creatinine, urea, and uric acid, which are the markers of liver and kidney damage. Meanwhile, S. mansoni-driven dyslipidemia was significantly enhanced by the coinfection of mice with T.b.r. Moreover, coinfection with S. mansoni and T.b.r led to a strong immune response characterized by a significant increase in serum TNF-α and IFN-γ. T.b.r infection enhanced S. mansoni-induced depletion of cellular-reduced glutathione (GSH) in the brain and liver tissues, indicative of lethal oxidative damage. Similarly, coinfection resulted in a significant rise in nitric oxide (NO) and malondialdehyde (MDA) levels.

Conclusion

Primary infection with S. mansoni exacerbates disease severity of secondary infection with T.b.r in a mouse model that is associated with harmful inflammatory response, oxidative stress, and organ injury.

Hyperuricemia is accompanied by elevated peripheral CD4+ T cells

Hyperuricemia (HUA) makes a chronic inflammation status, which affects immune cells. The association between HUA and immune cells, such as monocytes and neutrophils, has been extensively studied. However, studies on HUA and lymphocytes are still limited. We selected 1543 healthy participants and 258 individuals with HUA to analyze the correlation between serum uric acid (SUA) levels and immune cells, and 98 healthy participants and 16 individuals with HUA were used to study the relationship between SUA levels and cytokine levels. Then, we used soluble UA to stimulate peripheral blood mononuclear cells in vitro and examined lymphocyte subset counts and activation by flow cytometry. The results revealed that the number of lymphocytes in the HUA group was significantly increased, particularly CD4+ T cell numbers, which were higher than those in the total population (P = 0.0019), females (P = 0.0142), and males (P = 0.0199) of the healthy control group. Concomitantly, interleukin (IL)-4 and IL-10 levels significantly increased in people with HUA (P = 0.0254; P = 0.0019). In vitro, soluble UA promoted the proliferation and activation of CD4+ T and CD19+ B cells. Thus, HUA is accompanied by elevated peripheral CD4+ T cells and may cause a Th2-dominant immune status.

Rapidly separating dissolving microneedles with sustained-release colchicine and stabilized uricase for simplified long-term gout management

Despite growing prevalence and incidence, the management of gout remains suboptimal. The intermittent nature of the gout makes the long-term urate-lowering therapy (ULT) particularly important for gout management. However, patients are reluctant to take medication day after day to manage incurable occasional gout flares, and suffer from possible long-term toxicity. Therefore, a safe and easy-to-operate drug delivery system with simple preparation for the long-term management of gout is very necessary. Here, a chitosan-containing sustained-release microneedle system co-loaded with colchicine and uricase liposomes were fabricated to achieve this goal. This microneedle system was confirmed to successfully deliver the drug to the skin and maintain a one-week drug retention. Furthermore, its powerful therapeutic potency to manage gout was investigated in both acute gouty and chronic gouty models. Besides, the drug co-delivery system could help avoid long-term daily oral colchicine, a drug with a narrow therapeutic index. This system also avoids mass injection of uricase by improving its stability, enhancing the clinical application value of uricase. In general, this two-drug system reduces the dosage of uricase and colchicine and improves the patient's compliance, which has a strong clinical translation.

Causal association between tea intake and risk for gout: a Mendelian randomization study

Background: Gout, an increasingly prevalent form of inflammatory arthritis, is caused by the accumulation of uric acid crystals in joints, resulting in severe pain, swelling and stiffness that adversely affect physical, mental and emotional wellbeing. The management of gout requires a combination of medication and lifestyle modifications. Recent studies suggest that tea intake may reduce the risk of developing gout; however, further research is needed to establish a causal relationship. Methods: In this study, we employed a bidirectional two-sample Mendelian randomization (MR) approach, utilizing genome-wide association study (GWAS) summary statistics, to investigate the causal association between increased tea intake and gout. We meticulously selected instrumental variables (IVs) based on rigorous criteria and employed five different MR methods. Heterogeneity was assessed using Cochran's Q statistic, and pleiotropy was evaluated using the MR Egger intercept and MR-PRESSO tests. Weak IVs were identified using F values. The Phenoscanner database was consulted to exclude single nucleotide polymorphisms associated with confounding factors or outcomes. Results: The study included one dataset related to tea intake (ukb-b-6066) and three datasets related to gout (ukb-b-12765, finn-b-M13_GOUT, and finn-b-GOUT_STRICT). Our forward MR analysis suggest a causal relationship between increased tea intake and reduced risk of gout in all three gout-related datasets [OR (95% CI): 0.9966 (0.9938-0.9993), p = 0.0167; 0.4842 (0.2683-0.8737), p-value = 0.0160; and 0.4554 (0.2155-0.9623), p = 0.0393, respectively]. The reveres MR showed increased risk of gout (ukb-b-12765) was significantly associated with low tea intake according to the IVW analysis [OR (95% CI): 0.0062 (0.0002-0.154), p = 0.0020]. However, this association was not observed in the Finn-b-M13_GOUT and Finn-b-GOUT_STRICT [OR (95% CI): 0.9992 (0.9909-1.0075), p = 0.8453 and OR (95% CI): 0.9996 (0.9932-1.0059), p = 0.8896, respectively]. No significant heterogeneity or potential pleiotropy was detected, and the possibility of weak IVs was also excluded. Conclusion: Our MR analysis suggest a causal relationship between genetically predicted tea intake and a decreased risk of gout. These findings underscore the potential advantages of increasing tea intake for preventing gout. However, further research is needed to validate these results and elucidate the underlying mechanisms.

What are the core recommendations for gout management in first line and specialist care? Systematic review of clinical practice guidelines

BACKGROUND

Gout is the most common inflammatory arthritis, increasing in prevalence and burden. Of the rheumatic diseases, gout is the best-understood and potentially most manageable condition. However, it frequently remains untreated or poorly managed. The purpose of this systematic review is to identify Clinical Practice Guidelines (CPG) regarding gout management, evaluate their quality, and to provide a synthesis of consistent recommendations in the high-quality CPGs.

METHODS

Gout management CPGs were eligible for inclusion if they were (1) written in English and published between January 2015-February 2022; focused on adults aged ≥ 18 years of age; and met the criteria of a CPG as defined by the Institute of Medicine; and (2) were rated as high quality on the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument. Gout CPGs were excluded if they required additional payment to access; only addressed recommendations for the system/organisation of care and did not include interventional management recommendations; and/or included other arthritic conditions. OvidSP MEDLINE, Cochrane, CINAHL, Embase and Physiotherapy Evidence Database (PEDro) and four online guideline repositories were searched.

RESULTS

Six CPGs were appraised as high quality and included in the synthesis. Clinical practice guidelines consistently recommended education, commencement of non-steroidal anti-inflammatories, colchicine or corticosteroids (unless contraindicated), and assessment of cardiovascular risk factors, renal function, and co-morbid conditions for acute gout management. Consistent recommendations for chronic gout management were urate lowering therapy (ULT) and continued prophylaxis recommended based on individual patient characteristics. Clinical practice guideline recommendations were inconsistent on when to initiate ULT and length of ULT, vitamin C intake, and use of pegloticase, fenofibrate and losartan.

CONCLUSION

Management of acute gout was consistent across CPGs. Management of chronic gout was mostly consistent although there were inconsistent recommendations regarding ULT and other pharmacological therapies. This synthesis provides clear guidance that can assist health professionals to provide standardised, evidence-based gout care.

TRIAL REGISTRATION

The protocol for this review was registered with Open Science Framework (DOI https://doi.org/10.17605/OSF.IO/UB3Y7 ).

Activation of NRF2 Signaling Pathway Delays the Progression of Hyperuricemic Nephropathy by Reducing Oxidative Stress

Hyperuricemia (HUA)-induced oxidative stress is a crucial contributor to hyperuricemic nephropathy (HN), but the molecular mechanisms underlying the disturbed redox homeostasis in kidneys remain elusive. Using RNA sequencing, together with biochemical analyses, we found that nuclear factor erythroid 2-related factor 2 (NRF2) expression and nuclear localization levels were increased in early HN progression and then gradually declined below the baseline level. We identified the impaired activity of the NRF2-activated antioxidant pathway as a driver of oxidative damage in HN progression. Through nrf2 deletion, we further confirmed aggravated kidney damage in nrf2 knockout HN mice compared with HN mice. In contrast, the pharmacological agonist of NRF2 improved kidney function and alleviated renal fibrosis in mice. Mechanistically, the activation of NRF2 signaling reduced oxidative stress by restoring mitochondrial homeostasis and reducing NADPH oxidase 4 (NOX4) expression in vivo or in vitro. Moreover, the activation of NRF2 promoted the expression levels of heme oxygenase 1 (HO-1) and quinone oxidoreductase 1 (NQO1) and enhanced the antioxidant capacity of cells. Furthermore, the activation of NRF2 ameliorated renal fibrosis in HN mice through the downregulation of the transforming growth factor-beta 1 (TGF-β1) signaling pathway and ultimately delayed the progression of HN. Collectively, these results suggested NRF2 as a key regulator in improving mitochondrial homeostasis and fibrosis in renal tubular cells by reducing oxidative stress, upregulating the antioxidant signaling pathway, and downregulating the TGF-β1 signaling pathway. The activation of NRF2 represents a promising strategy to restore redox homeostasis and combat HN.

Outcome reporting in randomized trials in gout: A systematic scoping review from the OMERACT gout working group assessing the uptake of the core outcome set

OBJECTIVE

The selection and reporting of core outcome measures in clinical trials is essential for patients, researchers, and healthcare providers for clinical research to have an impact on healthcare. In this systematic scoping review, we aimed to quantify the extent to which gout clinical trials are collecting and reporting data in accordance with the core outcome domains from Outcome Measures in Rheumatology (OMERACT) published in 2009 applicable for both acute and chronic trials and evaluate the reporting according to the core domains before and after the 2009 OMERACT endorsement.

METHODS

We searched multiple databases PubMed, EMBASE, the Cochrane Library including the Cochrane Central Register of Controlled Trials (CENTRAL), and Cochrane Database of Systematic Reviews (CDSR) and www.

CLINICALTRIALS

gov for randomized controlled trials (RCTs) allocating people with gout versus an active pharmacological gout treatment or a control comparator (no date limitation). We extracted the data in accordance with the core outcome sets, focusing individually on core outcome domains and the core outcome measurements for acute and chronic trials, respectively. In this study 'Acute trials' reflect studies that describe interventions for short term management of gout flares, and 'chronic trials' describe interventions for long-term urate lowering therapy in the management of gout.

RESULTS

From 8,522 records identified in the database search, 134 full text papers were reviewed, and 71 trials were included, of which 36 were acute and 35 were chronic. Only 3 of 36 (8%) acute trials reported all five core domains and none of the 35 included chronic trials reported all 7 core domains. In the acute trials, twenty-seven unique measurement instruments across the 5 core domains were identified. For chronic trials there were 31 unique measurement instruments used across the 7 core domains. Serum urate was reported in 100% of the chronic trials and gout flares in 80%. However, other core domains were reported in <30% of chronic trials. In particular the patient-important domains such as HR-QOL, patient global assessment and activity limitations were rarely reported. A broad variety of different measurement instruments were used to assess each endorsed core domain, a minority of trials used the OMERACT endorsed instruments. For acute trials, the number reporting on all core domains was consistently low and no change was detected before and after the endorsement of the core domains in 2009. None of the included chronic trials reported on all 7 endorsed core domains at any time.

CONCLUSION

In this study we found a low adherence with the intended endorsed (i.e., core) outcome domains for acute and chronic gout studies which represents a poor uptake of the global OMERACT efforts for the minimum of what should be measured in clinical trials. In addition, there is a significant variation in how the OMERACT endorsed outcome domains have been measured. This systematic review demonstrates the need for continuous encouragement among gout researchers to adhere to OMERACT core domains as well as further guidance on outcome measurements reporting.

REGISTRATION

Prospero: CRD42019151316.

Rutin ameliorates gout via reducing XOD activity, inhibiting ROS production and NLRP3 inflammasome activation in quail

Gout is a metabolic disease affected by monosodium urate (MSU) deposition, which is directly related to hyperuricemia. Recent reports on the prevalence and incidence of gout have been widely circulated worldwide. Currently, the anti-gout drugs in clinical practice are mainly small-molecule synthetic drugs, and the effectiveness and safety are limited. Reducing uric acid and inhibiting inflammation are the focused areas of drug research and development on gout. Rutin, a natural flavonoid, has been reported to alleviate inflammation in various diseases. However, whether rutin exerts protective effects on gout remains to be elucidated. This study used quails without urate oxidase as experimental animals to induce endogenous gout models through a high purine diet. We confirmed that quail in the model group developed gout symptoms at 30 days of the experiment. And the targets of uric acid metabolism, oxidative stress level, and NLRP3 inflammasome were dysregulated in quails. Rutin treatment improves gout and reduces inflammatory expression in quail. We further confirmed that rutin treatment reduced XOD activity and uric acid levels in quail. And rutin inhibited ROS production, restored oxidative stress balance, inhibited NLRP3 inflammasome activation, and exerted anti-inflammatory effects. We extracted and identified the fibroblast-like synoviocytes (FLS) for the first time. The results showed that rutin could reduce ROS production and NLRP3 inflammasome activation of FLS after uric acid stimulation. In conclusion, our findings underscore that rutin may be a gout protective agent by reducing XOD activity, inhibiting ROS production and NLRP3 inflammasome activation. Meanwhile, this study also provides an available animal model for the research drugs of gout.

Gout of feet and ankles in different stages: The potentiality of a new semiquantitative DECT scoring system in monitoring urate deposition

The purpose of this study was to investigate the diagnostic performance of a novel semi-quantitative dual-energy computed tomography (DECT) scoring system in monitoring urate deposition. This study included 287 patients with gout. All patients underwent ankle/foot DECT scans. DECT scores at different stages were compared and their diagnostic efficacies evaluated. Associations between DECT scores and clinical variables were evaluated. Gouts with positive DECT results in early, middle, and late stages were 78.5 %, 81.4 %, and 95.8 %, respectively (all P > .05). The total and ankle/midfoot DECT scores at different stages significantly increased with disease duration (all P < .05). DECT scores of 4 regions excluding the first metatarsophalangeal joint in early and middle stages were lower than those in late stage (all P < .05). DECT scores achieved excellent diagnostic performance for differentiating gout in early stage from middle and late stages (area under the curve, 0.923 and 0.949), with high sensitivity, specificity, positive predictive value, and negative predictive value (all > 85 %). Total DECT score was highly positively correlated with the volume of urate crystals (R = 0.873, P < .001). Disease duration, serum uric acid level, bone erosion, and Achilles tendon involvement significantly affected total DECT scores (all P < .01). In conclusion, longer disease duration, higher serum uric acid levels, bone erosion, and Achilles tendon involvement were closely associated with total DECT scores. DECT scoring system may be an invaluable tool for gout diagnosis owing to its high detection efficacy and a surrogate method to evaluate the amount of urate crystals and erosion of surrounding tissues.

Endothelial injury and inflammation in patients with hyperuricemic nephropathy at chronic kidney disease stages 1-2 and 3-4

BACKGROUND

Endothelial injury and inflammation are the main pathological changes in hyperuricemic nephropathy (HN); however, they have not been assessed in patients in the early, middle, and late phases of HN.

AIM

To investigate endothelial injury and inflammatory conditions between patients with HN at chronic kidney disease (CKD) stages 3-4 and CKD 1-2.

METHODS

This study enrolled 80 patients (49 and 31 with HN at CKD stage 1-2 and 3-4, respectively) from the Department of Nephrology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine between July 2021 and January 2022. Plasma levels of heparan sulfate, endocan, oxidized low-density lipoprotein (Ox-LDL), E-selectin, soluble intercellular adhesion molecule-1 (slCAM1), interleukin (IL)-1β, and IL-6 and urine levels of lipocalin-type prostaglandin D synthase (L-PGDS), IL-1β, and IL-6 were measured using enzyme-linked immunosorbnent assay.

RESULTS

Comparison between patients with HN at CKD 1-2 and those with HN at CKD 3-4 showed that age and disease course were significant factors (P < 0.001 and P < 0.010, respectively). There were no statistical differences in sex, heart rate, body mass index, and systolic and diastolic blood pressures. The incidence of hypertension was also significant (P = 0.03). Plasma levels of heparin sulfate (P < 0.001), endocan (P = 0.034), E-selectin (P < 0.001), slCAM1 (P < 0.001), IL-1β (P = 0.006), and IL-6 (P = 0.004) and the urine levels of L-PGDS (P < 0.001), IL-1β (P = 0.003), and IL-6 (P < 0.001) were high in patients with HN at CKD 3-4 than in those with HN at CKD 1-2. The difference in plasma Ox-LDL levels was not significant (P = 0.078).

CONCLUSION

Vascular endothelial injury and inflammation were higher in patients with HN at CKD3-4 than at CKD 1-2. Plasma heparin sulfate and slCAM1 levels are synergistic factors for CKD staging in HN.

Does seasonality of the microbiota contribute to the seasonality of acute gout flare?

Gout, the most common inflammatory arthritis worldwide, is an auto-inflammatory metabolic disease that leads to monosodium urate crystal deposition. Hyperuricaemia is a significant risk factor for the development of gout; however, hyperuricaemia alone is not sufficient to induce gout.Gout flares have circadian rhythms. Gout flares vary during the day and have strong seasonality, with flares being more common in the spring. The reasons for the predominance of flares in the spring are unclear since serum urate (SU) levels show seasonal variation; however, SU levels are highest in the summer.Immune function varies significantly throughout the year, with enhanced immune responses increasing during the winter. In addition, chronic disruption of circadian rhythms is associated with metabolic syndrome and diseases driven by metabolism. The most telling example relates to Xanthine oxidase (XOD/XDH). The analysis of XOD/XDH established its circadian regulation and demonstrated that inhibition of the activity of XOD is characterised by distinct, crossregulating diurnal/seasonal patterns of activity.The gastrointestinal microbiota of gout patients is highly distinct from healthy individuals. In a small series of gout patients, Bacteroides caccae and Bacteroides xylanisolvens were found to be enriched. Bacteroidales levels were highest during the spring and summer, and loading values were highest in the spring.Our review discusses gout's circadian rhythm and seasonality, possible influences of the microbiome on gout due to our new knowledge that Bacteroidales levels were highest during spring when gout is most common, and potential opportunities for treatment based on our current understanding of this interaction.

Lacticaseibacillus rhamnosus Fmb14 prevents purine induced hyperuricemia and alleviate renal fibrosis through gut-kidney axis

Hyperuricemia is a critical threat to human health, and conventional medical treatment only aims to treat acute gouty arthritis. Purine diet-mediated chronic hyperuricemia and related syndromes are neglected in clinical therapeutics. In this study, the prevention ability of Lacticaseibacillus rhamnosus Fmb14, screened from Chinese yogurt, was evaluated in chronic purine-induced hyperuricemia (CPH) mice. After 12 weeks of Fmb14 administration, serum uric acid (SUA) in CPH mice decreased by 36.8 %, from 179.1 to 113.2 µmol/L, and the mortality rate decreased from 30 % to 10 %. The prevention role of Fmb14 in CPH was further investigated, and the reduction of uric acid by Fmb14 was attributed to the reduction of XOD (xanthine oxidase) in the liver and URAT1 in the kidney, as well the promotion of ABCG2 in the colon. Fmb14 administration Increased ZO-1 and Occludin expression in the colon and decreased fibrosis degree in the kidney indicated that Fmb14 administration had preventive effects through the gut-kidney axis in CPH. In specific, Fmb14 administration upregulated the diversity of gut microbiota, increased short-chain fatty acids (SCFA) by 35 % in colon materials and alleviated the inflammatory response by reducing biomarkers levels of IL-1β, IL-18 and TNF-α at 11.6 %, 21.7 % and 26.5 % in serum, compared to CPH group, respectively. Additionally, 16 S rRNA sequencing showed 31.5 % upregulation of Prevotella, 20.5 % and 21.6 % downregulation of Ruminococcus and Suterella at the genus level, which may be a new gut microbial marker in hyperuricemia. In conclusion, Fmb14 ameliorated CPH through the gut-kidney axis, suggesting a new strategy to prevent hyperuricemia.

Tea (Camellia sinensis) Ameliorates Hyperuricemia via Uric Acid Metabolic Pathways and Gut Microbiota

Hyperuricemia (HUA) is a metabolic disease that threatens human health. Tea is a healthy beverage with an abundance of benefits. This study revealed the uric acid-lowering efficacy of six types of tea water extracts (TWEs) on HUA in mice. The results revealed that under the intervention of TWEs, the expression of XDH, a key enzyme that produces uric acid, was significantly downregulated in the liver. TWE treatment significantly upregulated the expression of uric acid secretion transporters ABCG2, OAT1, and OAT3, and downregulated the expression of uric acid reabsorption transporter URAT1 in the kidney. Furthermore, HUA-induced oxidative stress could be alleviated by upregulating the Nrf2/HO-1 pathway. The intervention of TWEs also significantly upregulated the expression of the intestinal ABCG2 protein. On the other hand, TWE intervention could significantly upregulate the expression of intestinal ABCG2 and alleviate HUA by modulating the gut microbiota. Taken together, tea can comprehensively regulate uric acid metabolism in HUA mice. Interestingly, we found that the degree of fermentation of tea was negatively correlated with the uric acid-lowering effect. The current study indicated that tea consumption may have a mitigating effect on the HUA population and provided a basis for further research on the efficacy of tea on the dosage and mechanism of uric acid-lowering effects in humans.

Tea and its components reduce the production of uric acid by inhibiting xanthine oxidase

Background

The health benefits of tea are as diverse including the reduction of uric acid levels. Xanthine oxidase is the most directly mediated enzyme in the production of uric acid.

Objective

To explore the inhibitory effects of different teas and its main bioactive components on the production of uric acid.

Design

Experimental study. The experiments were conducted in vitro using human immortalized normal liver cell line HL-7702 (L-02).

Results

The inhibition of the xanthine oxidase activities and the expression level of xanthine dehydrogenase mRNA stimulated in the hyperuric hepatocyte cell model showed that the unfermented green tea and th1e lightly fermented yellow tea, white tea, and oolong tea significantly stronger than the highly fermented black tea and dark tea. The main bioactive compound, gallic acid, showed the strongest inhibitory effect on uric acid production, followed by tea polyphenols and theaflavins.

Discussion

All teas exhibited significant inhibition of xanthine oxidase activities, and the degree of fermentation of tea may be inversely proportional to its ability to inhibit the production of uric acid. Compared with tea polyphenols rich in tea, gallic acid may be a more potential uric acid-lowering component.

Conclusion

In this article, we first compared the effects of six traditional Chinese tea made from a single variety in stabilizing the synthesis of uric acid and found that the lighter the fermentation, the greater the potential for inhibiting the production of uric acid. Furthermore, we analyzed the inhibitory effects of its main biochemical active ingredients and found that the inhibitory effects of polyphenols rich in lightly fermented tea were significantly stronger than caffeine rich in highly fermented tea. Our findings will be helpful for people to choose a proper tea for alleviating hyperuricemia and provide a scientific basis for uric acid-lowering tea processing.

Update on gout management: what is old and what is new

PURPOSE OF REVIEW

The global burden of gout is rising, as are the prevalence of associated comorbidities, all-cause mortality and societal costs. In this review, we discuss recent advances in epidemiology and treatment strategies for gout.

RECENT FINDINGS

Genetic factors and obesity are prominent contributors to hyperuricemia and gout, while dietary factors contribute to less variance in serum urate, though can still have some contribution to population attributable risk. A consensus statement by the Gout, Hyperuricemia and Crystal-Associated Disease Network outlined appropriate terminology regarding gout, which will aid in communication about various aspects of the disease. The 2020 American College of Rheumatology gout guideline offers comprehensive evidence-based recommendations for the management of hyperuricemia using urate-lowering therapy, prophylaxis when initiating urate-lowering therapy, treatment of gout flare and adjunctive management strategies. There is improved understanding of risk factors for allopurinol hypersensitivity syndrome and well tolerated use of allopurinol in chronic kidney disease. Trial data have provided new insights regarding cardiovascular risk with febuxostat. Several new drug therapies are being tested for both urate-lowering efficacy and gout flare management.

SUMMARY

Although there have been significant advances in understanding of risk factors and treatment approaches, gout remains suboptimally managed. There is substantial need for improving gout management efforts and gout education among patients and clinicians.

The potential of probiotics in the amelioration of hyperuricemia

Hyperuricemia is a common disease caused by metabolic disorders or the excessive intake of high-purine foods. Persistent hyperuricemia in extreme cases induces gout, and asymptomatic hyperuricemia is probably linked to other metabolic diseases, such as hypertension. The typical damage caused by asymptomatic hyperuricemia includes inflammation, oxidative stress and gut dysbiosis. Probiotics have broad potential applications as food additives, not as drug therapies, in the amelioration of hyperuricemia. In this review, we describe novel methods for potential hyperuricemia amelioration with probiotics. The pathways through which probiotics may ameliorate hyperuricemia are discussed, including the decrease in uric acid production through purine assimilation and XOD (xanthine oxidase) inhibition as well as enhanced excretion of uric acid production by promoting ABCG2 (ATP binding cassette subfamily G member 2) activity, respectively. Three possible probiotic-related therapeutic pathways for alleviating the syndrome of hyperuricemia are also summarized. The first mechanism is to alleviate the oxidation and inflammation induced by hyperuricemia through the inhibition of NLRP3 inflammasome, the second is to restore damaged intestinal epithelium barriers and prevent gut microbiota dysbiosis, and the third is to enhance the innate immune system by increasing the secretion of immunoglobulin A (sIgA) to resist the stimulus by hyperuricemia. We propose that future research should focus on superior strain resource isolation and insight into the cause-effect mechanisms of probiotics for hyperuricemia amelioration. The safety and effects of the application of probiotics in clinical use also need verification.

Model-based cost-effectiveness analyses comparing combinations of urate lowering therapy and anti-inflammatory treatment in gout patients

Objectives

To assess the cost-effectiveness of various combinations of urate lowering therapy (ULT) and anti-inflammatory treatment in the management of newly diagnosed gout patients, from the Dutch societal perspective.

Methods

A probabilistic patient-level simulation estimating costs and quality-adjusted life years (QALYs) comparing gout and hyperuricemia treatment strategies was performed. ULT options febuxostat, allopurinol and no ULT were considered. Flare treatments naproxen, colchicine, prednisone, and anakinra were considered. A Markov Model was constructed to simulate gout disease. Health states were no flare, and severe pain, mild pain, moderate pain, or no pain in the presence of a flare. Model input was derived from patient level clinical trial data, meta-analyses or from previously published health-economic evaluations. The results of probabilistic sensitivity analyses were presented using incremental cost-effectiveness ratios (ICERs), and summarized using cost-effectiveness acceptability curves (CEACs). Scenario analyses were performed.

Results

The ICER for allopurinol versus no ULT was €1,381, when combined with naproxen. Febuxostat yielded the highest utility, but also the highest costs (€4,385 vs. €4,063 for allopurinol), resulting in an ICER of €25,173 when compared to allopurinol. No ULT was not cost-effective, yielding the lowest utility. For the gout flare medications, comparable effects on utility were achieved. Combined with febuxostat, naproxen was the cheapest option (€4,404), and anakinra the most expensive (€4,651). The ICER of anakinra compared to naproxen was €818,504. Colchicine and prednisone were dominated by naproxen.

Conclusion

Allopurinol and febuxostat were both cost-effective compared to No ULT. Febuxostat was cost-effective in comparison with allopurinol at higher willingness-to-pay thresholds. For treating gout flares, colchicine, naproxen and prednisone offered comparable health economic implications, although naproxen was the favoured option.

Prevalence of asymptomatic hyperuricemia and its association with prediabetes, dyslipidemia and subclinical inflammation markers among young healthy adults in Qatar

AIM

The aim of this study is to investigate the prevalence of asymptomatic hyperuricemia in Qatar and to examine its association with changes in markers of dyslipidemia, prediabetes and subclinical inflammation.

METHODS

A cross-sectional study of young adult participants aged 18 - 40 years old devoid of comorbidities collected between 2012 and 2017. Exposure was defined as uric acid level, and outcomes were defined as levels of different blood markers. De-identified data were collected from Qatar Biobank. T-tests, correlation tests and multiple linear regression were all used to investigate the effects of hyperuricemia on blood markers. Statistical analyses were conducted using STATA 16.

RESULTS

The prevalence of asymptomatic hyperuricemia is 21.2% among young adults in Qatar. Differences between hyperuricemic and normouricemic groups were observed using multiple linear regression analysis and found to be statistically and clinically significant after adjusting for age, gender, BMI, smoking and exercise. Significant associations were found between uric acid level and HDL-c p = 0.019 (correlation coefficient -0.07 (95% CI [-0.14, -0.01]); c-peptide p = 0.018 (correlation coefficient 0.38 (95% CI [0.06, 0.69]) and monocyte to HDL ratio (MHR) p = 0.026 (correlation coefficient 0.47 (95% CI [0.06, 0.89]).

CONCLUSIONS

Asymptomatic hyperuricemia is prevalent among young adults and associated with markers of prediabetes, dyslipidemia, and subclinical inflammation.

Traditional Chinese Herbal Medicine Plays a Role in the Liver, Kidney, and Intestine to Ameliorate Hyperuricemia according to Experimental Studies

In the last few decades, hyperuricemia has drawn increasing attention owing to its global prevalence. Observational surveys have manifested that there is a relation between hyperuricemia and increased risks of hypertension, chronic kidney disease, cardiovascular events, metabolic disorders, end stage renal disease, and mortality. As alternatives, Traditional Chinese medicinal herbs have demonstrated concrete effects in mitigating hyperuricemia in different experiments. Researchers have made efforts to investigate the role of herbal medicine in attenuating hyperuricemia. This review focuses on traditional Chinese herbal medicines that have been reported to ameliorate hyperuricemia in experimental studies.

Gout during the SARS-CoV-2 pandemic: increased flares, urate levels and functional improvement

Introduction

Gout is the most common inflammatory arthritis, but was not considered in most COVID-19 and rheumatic diseases reports. Our aim was to describe changes in clinical data, treatment, function and quality of life for gout patients during COVID-19 pandemic.

Methods

Prospective, descriptive and analytical study of 101 consecutive gout (ACR/EULAR 2015) patients from our clinic evaluated during pandemic by phone call (n=52) or phone call + face-to-face (n=68) that accepted to participate. Variables are demographics, clinical and treatment data, HAQ, EQ5D questionnaires and COVID-19-related data. Patients were divided in two groups: flare (n=36) or intercritical gout (n=65) also; available pre-pandemic data was obtained from 71 patients. Statistical analyses are X², paired t-test and Wilcoxon test.

Results

Included gout patients were males (95.8%), mean (SD) age 54.7 (10.7) years and disease duration 16.4 (9.8) years; 90% received allopurinol, 50% colchicine as prophylaxis and 25% suspended ≥ 1 medication. Comparison of pre-pandemic vs pandemic data showed > flares (4.4% vs 36%, p=0.01), more flares in the last 6 months: 0.31 (0.75) vs 1.71 (3.1), (p=0.004 and > urate levels: 5.6 (1.7)vs 6.7 (2.2) mg/dL, p=0.016. Unexpectedly, function and quality-of-life scores improved: HAQ score 0.65 (2.16) vs 0.12 (0.17), p= 0.001. Seven patients were COVID-19-confirmed cases; they had significantly more flares, higher urate levels and lower allopurinol doses and two died.

Conclusions

In gout patients, flares were 9 times more frequent during pandemic also, they had increased urate levels but led to an unexpected improvement in HAQ and functionality scores. Resilience and lifestyle changes in gout during COVID-19 pandemic require further studies.

Key Points • COVID-19 pandemic is associated with 4 times more flares in gout patients. • Increased flares were also seen in previously well-controlled gout patients. • Increased serum urate levels were also found in gout patients during pandemic. • In our gout clinic, 8/101 patients were diagnosed as COVID-19+, and two of them died.

Dietary supplements for chronic gout

BACKGROUND

Dietary supplements are frequently used for the treatment of several medical conditions, both prescribed by physicians or self administered. However, evidence of benefit and safety of these supplements is usually limited or absent.

OBJECTIVES

To assess the efficacy and safety of dietary supplementation for people with chronic gout.

SEARCH METHODS

We updated the original search by searching CENTRAL, MEDLINE, Embase, CINAHL, and four trials registers (August 2020). We applied no date or language restrictions. We also handsearched the abstracts from the 2010 to 2019 American College of Rheumatology and European League against Rheumatism conferences, and checked the references of all included studies.

SELECTION CRITERIA

We considered all published randomised controlled trials (RCTs) or quasi-RCTs that compared dietary supplements with no supplements, placebo, another supplement, or pharmacological agents for adults with chronic gout for inclusion. Dietary supplements included, but were not limited to, amino acids, antioxidants, essential minerals, polyunsaturated fatty acids, prebiotic agents, probiotic agents, and vitamins. The major outcomes were acute gout flares, study withdrawal due to adverse events (AEs), serum uric acid (sUA) reduction, joint pain reduction, participant global assessment, total number of AEs, and tophus regression.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

Two previously included RCTs (160 participants) met our inclusion criteria; we did not identify any new trials for this update. As these two trials evaluated different diet supplements (enriched skim milk powder (SMP) and vitamin C) with different outcomes (gout flare prevention for enriched SMP, and sUA reduction for vitamin C), we reported the results separately. One trial (120 participants), at unclear risk of selection and detection bias, compared SMP enriched with glycomacropeptides (GMP) with un-enriched SMP, and with lactose, over three months. Participants were predominantly men, aged in their 50s, who had severe gout. The results for all major outcomes were imprecise, except for pain. None of the results were clinically significant. The frequency of acute gout attacks, measured as the number of flares per month, decreased in all three groups over the three-month study period. The effects of enriched SMP (SMP/GMP/G600) compared with the combined control groups (SMP and lactose powder) at three months in terms of mean number of gout flares per month were not clinically significant (mean (standard deviation (SD)) flares per month: 0.49 (1.52) in SMP/GMP/G60 group versus 0.70 (1.28) in the control groups; absolute risk difference: mean difference (MD) -0.21 flares per month, 95% confidence interval (CI) -0.76 to 0.34; low-quality evidence). The number of withdrawals due to adverse effects was similar between groups (7/40 in SMP/GMP/G600 group versus 11/80 in control groups; (risk ratio (RR) 1.27, 95% CI 0.53 to 3.03); there were 4% more withdrawals in the SMP/lactose groups (10% fewer to 18% more; low-quality evidence). Serum uric acid reduction was similar across groups (mean (SD) -0.025 (0.067) mmol/L in SMP/GMP/G60 group versus -0.010 (0.069) in control groups; MD -0.01, 95% CI -0.04 to 0.01; low-quality evidence). Pain from self-reported gout flares (measured on a 10-point Likert scale) improved slightly more in the GMP/G600 SMP group compared with controls (mean (SD) -1.97 (2.28) in SMP/GMP/G600 group versus -0.94 (2.25) in control groups; MD -1.03, 95% CI -1.89 to -0.17). This was an absolute reduction of 10% (95% CI 20% to 1% reduction; low-quality evidence), which may not be of clinical relevance. The risk of adverse events was similar between groups (19/40 in SMP/GMP/G600 group versus 39/80 in control groups; RR 0.97, 95% CI 0.66 to 1.45); the absolute risk difference was 1% fewer adverse events (1% fewer to 2% more), low-quality evidence). Gastrointestinal events such as nausea, flatulence and diarrhoea were the most commonly reported adverse effects. Data for participant global assessment were not available for analysis; the study did not report tophus regression. One trial (40 participants), at high risk of selection, performance, and detection bias, compared vitamin C alone with allopurinol, and with allopurinol plus vitamin C, in a three-arm study. We only included data from the vitamin C versus allopurinol comparison in this review. Participants were predominantly middle-aged men, and their severity of gout was representative of gout in general. Allopurinol reduced sUA levels more than vitamin C (MD 0.10 mmol/L, 95% CI 0.06 to 0.15), low-quality evidence. The study reported no adverse events; none of the participants withdrew due to adverse events. The study did not assess the rate of gout attacks, joint pain reduction, participant global assessment, or tophus regression.

AUTHORS' CONCLUSIONS

While dietary supplements may be widely used for gout, this review found no high-quality that supported or refuted the use of glycomacropeptide-enriched skim milk powder or vitamin C for adults with chronic gout.

Association of Sodium-Glucose Transport Protein 2 Inhibitor Use for Type 2 Diabetes and Incidence of Gout in Taiwan

IMPORTANCE

The use of sodium-glucose transport protein 2 (SGLT2) inhibitors is currently a standard intervention in patients with type 2 diabetes (T2DM) and exerts favorable pleiotropic effects to consistently lower blood urate levels. However, to date, no association between SGLT2 inhibitor use and the incidence of gout have been established.

OBJECTIVE

To investigate whether prescribed SGLT2 inhibitors are associated with lower gout incidence in patients with T2DM.

DESIGN, SETTING, AND PARTICIPANTS

In a cohort study, all patients with incident T2DM in Taiwan National Health Institution databases between May 1, 2016, and December 31, 2018, were retrospectively analyzed. As a comparator, patients using dipeptidyl peptidase 4 (DPP4) inhibitors were included. A total of 47 905 individuals receiving an SGLT2 inhibitor and 183 303 receiving a DPP4 inhibitor were evaluated, along with 47 405 pairs of patients using an SGLT2 inhibitor or DPP4 inhibitor in 1:1 propensity score-matched analyses. Data analysis was conducted from April 1 to June 30, 2021.

MAIN OUTCOMES AND MEASURES

A gout diagnosis was based on the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and the International Statistical Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM). Multiple Cox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% CIs.

RESULTS

In total, 231 208 patients with T2DM were included in the population; 113 812 individuals (49.22%) were women, and the mean (SD) age was 61.53 (12.86) years. The overall gout incidence was 20.26 per 1000 patient-years for SGLT2 inhibitor users and 24.30 per 1000 patient-years for DPP4 inhibitor users. When potential risk factors were adjusted in the propensity score-matched population, use of SGLT2 inhibitors was associated with a lower risk of gout (HR, 0.89; 95% CI, 0.82-0.96) compared with DPP4 inhibitors, particularly for patients receiving dapagliflozin (HR, 0.86; 95% CI, 0.78-0.95). A sensitivity analysis, performed when a gout diagnosis was ascertained using the ICD-9-CM or ICD-10-CM code with gout-related medication, also showed a significantly lower risk for gout incidence of 15% with SGLT2 inhibitors (HR, 0.85; 95% CI, 0.74-0.97). Subgroup analysis indicated that SGLT2 inhibitor benefits in patients with T2DM to achieve a lower gout risk were not different across subgroups.

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that patients with T2DM who are receiving SGLT2 inhibitors may have a lower risk for gout compared with those receiving DPP4 inhibitors.

The challenge of gout flare measurement

Gout flares are central to the patient experience of gout and are included in the Outcome Measures in Rheumatology (OMERACT) core outcome domain set for long-term gout studies. Although a valid definition for gout flare has been developed, there is no consensus around how flare outcomes are measured and reported in long-term clinical studies. Current methods of flare measurement, which are centered on measuring flares as a binary outcome (i.e., present vs absent), do not reflect the variable pattern of flares over time, nor the multidimensional patient experience of gout flares which include factors related to pain severity, functional disability, impact on family and social life, and psychological wellbeing. This review will discuss the importance and challenges of gout flare measurement.

'It's just a great muddle when it comes to food': a qualitative exploration of patient decision-making around diet and gout

Objective

Our aim was to understand whether, why and how patients choose to modify their diets after developing gout.

Methods

We conducted an inductive thematic secondary analysis of qualitative data from 43 interviews and four focus groups with UK participants with gout (n = 61).

Results

Participants commonly initiated dietary changes as part of a self-management strategy for gout. Reasons for making such dietary changes included: desperation; a desire for control; and belief that it would be possible to achieve successful management through diet alone; but not weight loss. Participants who did not make changes or who reverted to previous dietary patterns did so because: they believed urate-lowering therapy was successfully managing their gout; medication allowed normal eating; they did not find ‘proof’ that diet would be an effective treatment; or the dietary advice they found was unrealistic, unmanageable or irrelevant. Dietary modification was patient led, but patients would have preferred the support of a health-care professional. Beliefs that diet could potentially explain and modify the timing of flares gave patients a sense of control over the condition. However, the belief that gout could be controlled through dietary modification appeared to be a barrier to acceptance of management with urate-lowering therapy.

Conclusions

Perceptions about gout and diet play a large role in the way patients make decisions about how to manage gout in their everyday lives. Addressing the reasons why patients explore dietary solutions, promoting the value of urate-lowering therapy and weight loss and drawing on strong evidence to communicate clearly will be crucial in improving long-term clinical management and patient experience.

Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) common language definition of gout

Objective

To develop a Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) common language definition of gout, with the goal of increasing public understanding and awareness, and ensure consistent and understandable messages about gout.

Methods

A G-CAN working group that included patients, physicians and nongovernmental organisation (NGO) representatives was formed to develop a common language definition of gout for use with the public, media, healthcare providers and stakeholders. A literature search and interviews with patients, healthcare workers and stakeholders informed development of the definition. Following consultation with G-CAN members and partners, the definition was endorsed by the G-CAN board.

Results

The G-CAN common language definition of gout describes the epidemiology, pathophysiology, symptoms and impact, risk factors, comorbidities, management and healthcare and workforce considerations. Detailed information is provided to support the content of the definition. After the publication of the English-language version, the definition will be available for translation into other languages by G-CAN members.

Conclusion

G-CAN has developed a concise and easily understandable statement describing gout in language that can be used in conversations with the lay public, media, NGOs, funders, healthcare providers and other stakeholders.

Higher Serum Urate Levels Are Associated With an Increased Risk for Sudden Cardiac Death

OBJECTIVE

To determine the association of serum urate (SU) levels with sudden cardiac death and incident coronary heart disease (CHD), separately, among adults without a history of CHD.

METHODS

We conducted a case-cohort analysis of Black and White participants aged ≥ 45 years enrolled in the REason for Geographic And Racial Differences in Stroke (REGARDS) study without a history of CHD at baseline between 2003 and 2007. Participants were followed for sudden cardiac death or incident CHD (i.e., myocardial infarction [MI] or death from CHD excluding sudden cardiac death) through December 31, 2013. Baseline SU was measured in a random sample of participants (n = 840) and among participants who experienced sudden cardiac death (n = 235) or incident CHD (n = 851) during follow-up.

RESULTS

Participants with higher SU levels were older and more likely to be male or Black. The crude HR (95% CI) per 1 mg/dL higher SU level was 1.26 (1.14-1.40) for sudden cardiac death and 1.17 (1.09-1.26) for incident CHD. After adjustment for age, sex, race, and cardiovascular risk factors, the HR (95% CI) per 1 mg/dL higher SU level was 1.19 (1.03-1.37) for sudden cardiac death and 1.05 (0.96-1.15) for incident CHD. HRs for sudden cardiac death were numerically higher among participants aged 45-64 vs ≥ 65 years, without vs with diabetes, and among those of White vs Black race, although P values for effect modification were all ≥ 0.05.

CONCLUSION

Higher SU levels were associated with an increased risk for sudden cardiac death but not with incident CHD.

Gout

Gout is a common and treatable disease caused by the deposition of monosodium urate crystals in articular and non-articular structures. Increased concentration of serum urate (hyperuricaemia) is the most important risk factor for the development of gout. Serum urate is regulated by urate transporters in the kidney and gut, particularly GLUT9 (SLC2A9), URAT1 (SLC22A12), and ABCG2. Activation of the NLRP3 inflammasome by monosodium urate crystals with release of IL-1β plays a major role in the initiation of the gout flare; aggregated neutrophil extracellular traps are important in the resolution phase. Although presenting as an intermittent flaring condition, gout is a chronic disease. Long-term urate lowering therapy (eg, allopurinol) leads to the dissolution of monosodium urate crystals, ultimately resulting in the prevention of gout flares and tophi and in improved quality of life. Strategies such as nurse-led care are effective in delivering high-quality gout care and lead to major improvements in patient outcomes.

Managing hyperuricemia and gout in chronic kidney disease: a clinical conundrum

PURPOSE OF REVIEW

There is controversy regarding the impact of hyperuricemia on the progression of chronic kidney disease (CKD), and gout remains sub optimally managed in this population. We discuss the prescribing of drugs for the treatment of gout in patients with CKD.

RECENT FINDINGS

There is a lack of consensus from expert guidelines, and prescribers have concerns regarding the risk of adverse reactions from medicines used to treat gout. These situations appear to contribute to suboptimal management of gout in this cohort. Recent data have challenged the role of urate lowering therapy (ULT) in the management of asymptomatic hyperuricemia in CKD.

SUMMARY

ULT should be commenced in all patients with severe, recurrent disease, tophaceous gout and evidence of joint damage. Most international guidelines recommend a treat-to-target approach for the management of gout. In CKD, ULT should be started at low dose with up titration adjusted to serum urate levels, rather than being based on the creatinine clearance. If patients fail first-line therapy, alternative agents are utilized, the specific agent depending on ease of access, burden of disease and other comorbidities. This approach should be incorporated into routine practice to ensure optimal treatment of gout in CKD. More research is required to investigate whether treatment of asymptomatic hyperuricemia has clinical benefits.

LncRNAs Landscape in the patients of primary gout by microarray analysis

To determine the expression profile and clinical significance of long non-coding RNAs (lncRNAs) in peripheral blood mononuclear cells (PBMCs) of patients with primary gout and healthy control subjects. Human lncRNA microarrays were used to identify the differentially expressed lncRNAs and mRNAs in primary gout patients (n = 6) and healthy control subjects (n = 6). Bioinformatics analyses were performed to predict the roles of differently expressed lncRNAs and mRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect the expression levels of 8 lnRNAs in 64 primary gout patients and 32 healthy control subjects. Spearman’s correlation was used to analyze the correlation between these eight lncRNAs and the laboratory values of gout patients. A receiver operating characteristic (ROC) curve was constructed to evaluate the diagnostic value of the lncRNAs identified in gout. The microarray analysis identified 1479 differentially expressed lncRNAs (879 more highly expressed and 600 more lowly expressed), 862 differentially expressed mRNAs (390 more highly expressed and 472 more lowly expressed) in primary gout (fold change > 2, P < 0.05), respectively. The bioinformatic analysis indicated that the differentially expressed lncRNAs regulated the abnormally expressed mRNAs, which were involved in the pathogenesis of gout through several different pathways. The expression levels of TCONS_00004393 and ENST00000566457 were significantly increased in the acute gout flare group than those in the intercritical gout group or healthy subjects (P<0.01). Moreover, inflammation indicators were positive correlated with TCONS_00004393 and ENST00000566457 expression levels. The areas under the ROC curve of ENST00000566457 and NR-026756 were 0.868 and 0.948, respectively. Our results provide novel insight into the mechanisms of primary gout, and reveal that TCONS_00004393 and ENST00000566457 might be as candidate targets for the treatment of gout flare; ENST00000566457 and NR-026756 could effectively discriminate between the gout and the healthy control groups.

Which factors predict discordance between a patient and physician on a gout flare?

OBJECTIVE

To investigate the factors associated with discordance between patient and physician on the presence of a gout flare.

METHODS

Patients' self-reports of current gout flares were assessed with the question, 'Are you having a gout flare today?' which was then compared with a concurrent, blinded, physician's assessment. Based on agreement or disagreement with physicians on the presence of a gout flare, flares were divided into concordant and discordant groups, respectively. Within the discordant group, two subgroups-patient-reported flare but the physician disagreed and physician-reported flare but the patient disagreed-were identified. The factors associated with discordance were analysed with multivariable logistic regression analysis.

RESULTS

Of 268 gout flares, 81 (30.2%) flares were discordant, with either patient or physician disagreeing on the presence of a flare. Of the discordant flares, in 57 (70.4%) the patient reported a flare but the physician disagreed. In multivariable logistic regression analysis adjusted for demographics, disagreement among patients and physicians on the presence of a gout flare was associated with lower pain scores at rest [odds ratio (OR) for each point increase on 0-10 point pain scale 0.81 (95% Wald CI 0.73, 0.90), P < 0.0001] and less presence of joint swelling [OR 0.24 (95% CI 0.10, 0.61), P = 0.003] or joint warmth [OR 0.39 (95% CI 0.20, 0.75), P = 0.005].

CONCLUSION

Although patients and physicians generally agree about the presence of gout flare, discordance may occur in the setting of low pain scores and in the absence of swollen or warm joints.

Gouty Involvement of Foot and Ankle: Beyond Flares

The foot and ankle are common locations of deposition of monosodium urate (MSU) crystals, as indicated by the clinical manifestations presented by patients with gout, which are not limited to the acute inflammation of the big toe. We present a narrative literature review aimed to update the gout involvement of foot and ankle and how it affects the quality of life. Cumulative reports indicate that gout, even at the non-tophaceous stage, could cause pain, gait impairment and limit the mobility at lower limbs. These patients may present difficulties in some activities of daily living such as choosing footwear, thus leading to an impaired quality of life. Gout is a curable disease by dissolving MSU crystals but remains unclear how this could modify some of these foot and ankle manifestations, especially when structural damage has already occurred. Furthermore, a collaboration between rheumatologists and podiatrists seems helpful to understand, relieve these symptoms and improve the quality of life in gouty patients.

Crystal deposition measured with dual-energy computed tomography: association with mortality and cardiovascular risks in gout

Objectives

To determine whether the volume of monosodium urate (MSU) crystal deposition measured with dual-energy CT (DECT) is predictive of short-term mortality and development of cardiovascular comorbidities and diabetes mellitus.

Methods

Patients with a diagnosis of gout having had baseline DECT scans of their knees and feet to measure the volume of MSU crystal deposition were included to undergo a follow-up visit. Risk factors for mortality and a composite variable (onset of any cardio-metabolic event) were examined using multivariable Cox models.

Results

A total of 128 patients aged 66.1 (14.0) years with gout durations of 11.4 (10.4) years were included; most were naïve of urate lowering therapy (61.7%), with a follow-up visit at 24 (12, 36) months. Baseline serum urate (SU) level was 7.44 (2.29) mg/dl and DECT volume of MSU crystals was 0.2 (0, 0.9) cm3. A total of 14 patients died during follow-up, 6/14 from a cardiovascular cause, and 17 patients presented a new cardio-metabolic comorbidity. Factors associated with mortality risk were baseline DECT volume of MSU crystals [hazard ratio (HR) 1.02, 95% CI: 1.002, 1.03] and baseline SU level (HR 1.04, 95% CI: 1.003, 1.06). DECT volume of MSU crystals was the only factor associated with the onset of cardio-metabolic comorbidities with a HR of 1.014 (95% CI: 1.001, 1.03).

Conclusions

Volume of MSU crystals measured with DECT is a biomarker for the risk of developing new cardio-metabolic diseases and for all-cause mortality.

Alterations in the Serum Urate Concentrations after Bariatric Surgery: a Short-Term Prospective Observational Study

BACKGROUND

Bariatric surgery is associated with a reduced incidence of hyperuricaemia during the long follow-up time. However, few studies have elucidated the alterations in serum urate (SU) levels in the short-term post-surgery period.

PURPOSE

To identify the alterations in SU concentrations in individuals with obesity at 1 week, 1 month, and 3 months after bariatric surgery and determine the risk factors for alterations during the first 3 post-surgery months.

METHODS

Thirty-four patients were enrolled. Pre- and post-operative variables were collected at baseline and at each follow-up point. A paired t-test was applied to investigate the relationship between the major parameters. A linear mixed model was performed to analyse the variations of SU concentrations with time.

RESULTS

Compared with baseline levels, SU levels significantly increased at 1 week, then declined significantly at 1 month after surgery (P < 0.05). At the 3-month follow-up, a significant decrease in SU levels was detected compared with that in baseline levels (P < 0.001). In univariate regression analysis, age, sex, weight, body mass index, triglyceride (TG), total cholesterol (TC), creatinine (Cr), and medications were all risk factors for alterations in SU concentrations post-surgery. In the final model, sex, weight, Cr, age, TC, Cr * age, and Cr * TC were established.

CONCLUSIONS

Surgeons should be cognizant of the significant increase in SU levels in the first postoperative week. Alterations in SU concentrations during the first 3 post-operative months were associated with sex, age, weight, Cr, and TC levels at baseline.

The Role of Soluble Uric Acid in Modulating Autophagy Flux and Inflammasome Activation during Bacterial Infection in Macrophages

Autophagy is a homeostatic process that regulates and recycles intracellular structures and is a host defense mechanism that facilitates bacterial clearance. Uric acid in plasma is a major antioxidant but in certain conditions acts as an inflammatory danger signal. The aim of this study is to investigate the effect of soluble uric acid on autophagy and the inflammatory responses in macrophages during bacterial infection. Herein, we employed murine RAW264.7 macrophages that express uricase enzyme and human THP-1 cells that are uricase-deficient. Three different strains of Staphylococcus aureus and two different strains of Klebsiella pneumoniae were used to infect macrophages in presence and absence of soluble uric acid. We found that soluble uric acid enhanced autophagy flux in infected macrophages. We observed that IL-1β increased during bacterial infection but decreased when macrophages were co-stimulated with bacteria and uric acid. In contrast to IL-1β, soluble uric acid did not affect TNFα release and there were no dramatic differences when macrophages were infected with S. aureus or K. pneumoniae. In conclusion, uric acid enhances autophagy flux during bacterial infection, consequently reducing inflammasome activation in macrophages. Understanding the effect of uric acid on the interplay between autophagy and inflammation will facilitate therapeutic design.

An update on gout diagnosis and management for the primary care provider

Gout is the most common inflammatory arthritis in the US, affecting 3.9% of the population. Although many effective gout therapies are available for acute flares and chronic management, it is suboptimally treated worldwide, and recurrent gout flares can cause significant pain and irreversible joint damage.

Gout Is Prevalent but Under-Registered Among Patients With Cardiovascular Events: A Field Study

Objectives: Gout is an independent cardiovascular (CV) risk factor with significant morbidity and mortality. We aimed to estimate the prevalence of gout, characteristics and management in a hospitalized population for CV disease, a topic that remains to be defined. Methods: An observational, descriptive, cross-sectional study was carried out in patients admitted for CV events in the Cardiology, Neurology, and Vascular Surgery units of a tertiary center. Patients were selected following a non-consecutive, systematic sampling. Data about CV disease and gout were obtained from face-to-face interviews and patients' records. Gout diagnosis was established using the 2015 ACR/EULAR clinical classification criteria. The registration rate of gout was assessed by auditing patients' records and hospital discharge reports of CV events from the units of interest in the previous 2 years. To predict the presence of gout, multivariate logistic regression models were built to study the possible explanatory variables. Results: Two hundred and sixty six participants were recruited, predominantly males (69.9%) and Caucasians (96.6%) with a mean age of 68 years. Gout was identified in 40 individuals; thus, the prevalence was 15.0% (95% CI 10.9-19.2%). In 35% of cases, the diagnosis was absent from patients' records. Gout was found in 1.4-2.6% of hospital discharge reports of CV events, also indicating under-registration. The disease was long-standing, but with low reported rates of flares, involved joints, and tophi. At admission, only half of the gout patients were on urate-lowering therapy, being 38.5% of them on serum urate <6 mg/dl. The only independent predictor of gout was the existence of previous hyperuricemia (median serum urate in previous 5 years ≥7 mg/dl), with an odds ratio of 2.9 (95% CI 1.2-7.1); if hyperuricemia is not included in the model, the only independent predictor was chronic kidney disease (odds ratio 3.0; 95% CI 1.4-6.6). Conclusion: Gout is highly prevalent among patients admitted for CV events, with significant lack of awareness and suboptimal management, despite being a well-established independent CV risk factor.

The Frequency of Axial Deposition in Korean Patients With Gout at a Tertiary Spine Center

Objectives: This study aimed to describe the frequency of axial deposition (axial gout) and determine the associated factors in patients with gout who presented to a spine clinic in Korea.

Methods: We enrolled 95 Korean patients who visited our spine center from March 2012 to February 2016 and who had been previously diagnosed with gout and had available computed tomography (CT) images of the vertebral columns. Axial gout was defined as the presence of erosions or tophi in the vertebral endplate or facet joint. The clinical and laboratory data of these patients were retrieved from medical records.

Results: Out of 95 patients, 15 [15.8%; 95% confidence interval (CI), 9.4–25.0%] had a conventional CT evidence suggestive of axial gout. In these 15 patients, 12 (80%) had lumbar spine involvement (95% CI, 51.4–94.7%). Fifteen patients had erosions of the vertebral column, and two presented with tophi that exhibited erosive changes of the facet joints. The presence of axial gout was not associated with the patients' age, duration of gout, laboratory findings, inflammatory back pain symptoms, identification of monosodium urate crystals in the peripheral joints, current use of urate-lowering drugs, hypertension, and end-stage renal disease; however, there was a significant association with the presence of diabetes (P = 0.008).

Conclusions: The frequency of axial deposition in Korean patients with gout and spinal symptoms was 15.8%, with the lumbar region being the most commonly involved section of the spine. In addition, diabetes was associated with evidence of axial gout on imaging.

Management of Gout in the United States: A Claims-based Analysis

Objective

Gout is the most common inflammatory arthritis in the United States. Although numerous guidelines exist for the management of gout, they are not routinely implemented. This study evaluated the real‐world practice patterns in gout patients using large administrative claims databases.

Methods

An analysis of patients diagnosed with gout from October 2015 to November 2018 was carried out using the Symphony Integrated Dataverse and Truven Marketscan administrative claims databases. Patients were identified as having gout if they were more than18 years of age and had 2 or more primary gout diagnoses on different days, separated by 3 or more months. Patients were further identified as having either acute gout or advanced forms of gout including chronic nontophaceous, tophaceous, and uncontrolled gout. Percent and frequency of serum urate testing, rheumatology specialist visits, prescriptions for urate lowering therapies (ULTs), and emergency room (ER) visits for gout flares were evaluated.

Results

We identified 1 162 747 gout patients. Gout patients were seen most frequently by internists and family medicine practitioners. Neither urate testing nor prescriptions for ULTs were uniform. Patients with acute gout were infrequently seen by rheumatologists, whereas rheumatologist care progressively increased in patients with advanced gout. The frequency of serum urate testing and prescriptions for ULTs significantly increased, whereas the frequency of ER visits decreased in gout patients seen by a rheumatologist.

Conclusion

Measurement of serum urate and prescriptions for ULTs are not consistent in gout patients. Rheumatologist care increases the frequency of urate measurement and ULT prescriptions and may also improve outcomes for gout patients.