Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) consensus statement regarding labels and definitions of disease states of gout

Systemic inflammation in asymptomatic hyperuricaemia with sonographic crystal deposits, including a comparison with normouricaemia and gout

OBJECTIVE

To describe the inflammatory profile of asymptomatic hyperuricaemia (AH) with ultrasound evidence of monosodium urate (MSU) crystals (AH-MSUpos), vs AH without deposits (AH-MSUneg), intercritical gout and normouricaemia.

METHODS

Based on serum urate levels, musculoskeletal ultrasound and history of flares, we divided 122 participants into four groups: normouricaemia, AH-MSUneg, AH-MSUpos and intercritical gout. We tested four ultrasound definitions for MSU deposition in AH: grade 2-3 (G2-3) double contour and/or tophi, G1-3 double contour and/or tophi, G1-3 Stewart scheme (double contour sign in knee cartilage and/or first metatarsophalangeal joint and/or tophi in first metatarsophalangeal joint) and G2-3 Stewart scheme. Serum acute phase reactants, cytokines, pyroptosis derivates and neutrophil-related proteins were measured and compared between groups. A linear regression model was fitted to correlate crystal and inflammatory burden (measured by ultrasound) with inflammatory markers in hyperuricaemics.

RESULTS

Rates of MSU deposition in AH ranged from 26.0% to 68.8%, depending on the definition used. Levels of CRP, leukocytes, IL-1RA, IL-6, sIL-6R, IL-18, TNF-α, TGF-β and galectin-3 were higher in hyperuricaemics vs normouricaemics. Sex, obesity and comorbidity scores influenced some comparisons. We saw no differences comparing AH-MSUposvs AH-MSUneg groups, except for higher calprotectin using G1-3 sonographic definitions and higher CRP and TGF-β when restricted to women and obese participants.

CONCLUSIONS

Hyperuricaemia is associated with substantial inflammation and some degree of active pyroptosis. Four different ultrasound definitions for AH with MSU deposits yielded similar findings, although we noted some differences in calprotectin, CRP, and TGF-β. Sex, obesity, and comorbidities influenced some inflammatory responses.

Time-course of tophus resolution on Dual-energy CT and ultrasound after 24months of a treat-to-target strategy: Results from GOUT-DECTUS study

OBJECTIVES

The main objective of the study was to evaluate the kinetics of tophus volume measured with dual-energy CT (DECT) and ultrasound (US) in patients with gout during their first 24months of treat-to-target (T2T) urate-lowering therapy.

METHODS

This was a prospective, multicenter, 24-month longitudinal pilot study including ULT-naïve patients with gout and US tophi. Clinical visits, and DECT and US scans of the knees and feet were performed at baseline, 6, 12 and 24months. The largest tophus identified by US was chosen as the index tophus. The primary outcome was the change in the absolute volume and relative change from baseline of the tophus index volume measured with US and with DECT at all timepoints, with their correlation assessed by the Spearman correlation coefficient (ρ).

RESULTS

A total of 55 patients (63.1 (12.3) years old, predominantly male (47/55 [85.5%]), with baseline serum urate levels of 8.73 mg/dL [7.93; 9.52] were included. Index tophus volume measured with US changed from median [inter-quartile range] 0.61 cm3 [0.30; 1.20] at baseline to 0.07 cm3 [0; 0.50] at month 24, and with DECT from 0.1 cm3 [0; 0.63] at baseline to 0 cm3 [0; 0] at month 24. Relative changes in index tophus volume measured with US and DECT were respectively -56% [-90; 0] and -96% [-100; -34] at M6, -84% [-100; -13] and -100% [-100; -89] at M12, and -96% [-100; -72] and -100% [-100; -100] at M24. The correlation for relative tophus volume change was weak at month 6 (ρ=0.39 [0.01; 0.74]) and moderate at months 12 (ρ=0.43 [-0.14; 0.82]) and 24 (ρ=0.42 [-0.01; 0.73]).

CONCLUSION

Complete tophus resolution is obtained at 24months of T2T in DECT but not in US, which provided a greater variability of volumetric assessments throughout follow-up.

Impact of gout flare on health-related quality of life: a multi-center cross-sectional study in Thailand

OBJECTIVE

Although the 5-level EQ-5D version (EQ-5D-5L) instrument has been used to determine health-related quality of life and health utility in gout, it is used in comparing health utility among gout flare (GF) and non-gout flare (non-GF) patients is still limited. This study aimed to compare health utility among GF and non-GF patients in Thailand.

METHODS

In this multi-center cross-sectional study, patients with GF and non-GF were interviewed for the EQ-5D5L and EQ-Visual Analog Scale (VAS) instruments by rheumatologists or trained research staffs. Patients with GF were subdivided into 2 subgroups (those who received no treatment and those who received treatment less than 48 h after GF episode).

RESULTS

Two hundred and sixteen patients (108 GF and 108 non-GF patients), males in 90.28%, were included. The gout disease duration was significantly longer in the non-GF than in the GF groups (median, 10 vs 5 years; p = 0.004). There was no difference in the tophi present between the two groups. When compared with the non-GF group, the GF patients significantly had low health utility (0.34 ± 0.36 vs. 0.89 ± 0.15, p < 0.001) and EQ-VAS score (54.73 ± 25.14 vs. 84.06 ± 13.38, p < 0.001). In the subgroup analysis of the non-GF group, there was insignificant health utility and EQ-VAS score between those with tophi and those without tophi (0.87 ± 0.14 vs. 0.90 ± 0.15, p = 0.124 and 83.36 ± 14.92 vs. 84.33 ± 12.83, p = 0.938, respectively).

CONCLUSION

This study found that GF clearly had a substantial impact on patients' quality of life. Targeted interventions in managing GF patients to improve their health outcomes are needed. Key Points • Patients with gout flare had lower health utility than those without gout flare. • The clinical significance of the utility and EQ-VAS was evaluated by the EQ-5D-5L instrument between gout flare and non-gout flare groups in Thai gouty patients. • Regarding the presence of tophi or disease duration, no significant differences in health utility and EQ-VAS were observed in the gout flare or non-gout flare group. • Targeted interventions for management of gout flare are needed to improve the health outcomes of gout flare patients.

Association between advanced lung cancer inflammation index and acute gouty arthritis in Dalian, China: a cross-sectional study

Introduction

Acute gouty arthritis (AGA) is an inflammatory joint disease. The advanced lung cancer inflammation index (ALI) evaluates inflammation. This study investigates the association between ALI and AGA.

Methods

We included 652 participants in this cohort study, dividing them into two groups: those with AGA and a control group without AGA. We employed logistic regression to examine the ALI-AGA relationship, using restricted cubic splines (RCS) to assess dose-response relationships, performing subgroup analyses, and conducting interaction tests. K-fold cross-validation was applied for model assessment. Receiver operating characteristic (ROC) curves were applied to visualize and compare the predictive value of ALI and other inflammatory indices for AGA.

Results

Among the 652 participants, the AGA group exhibited significantly lower ALI values compared to the control group. Multivariate logistic regression identified an inverse relationship between ALI and AGA. RCS analysis indicated an L-shaped non-linear relationship between ALI levels and AGA, with inflection points at an ALI of 23.38. Subgroup analyses showed no significant interactions between ALI levels and AGA after stratifying by age, hypertension, coronary heart disease (CHD), and diabetes (DM). The results from the ROC curves indicate that ALI may serve as a better predictor of AGA.

Conclusion

This cross-sectional study found a significant inverse correlation between ALI levels and AGA prevalence. Moreover, the ALI could serve as a more accurate diagnostic tool for AGA and offer a novel approach for further investigating the relationship between inflammation and AGA.

Systematic literature review on Calcium Pyrophosphate Deposition (CPPD) nomenclature: condition elements and clinical states- A Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) consensus project

OBJECTIVES

The Gout, Hyperuricaemia and Crystal-Associated Disease Network (G-CAN) has developed a calcium pyrophosphate deposition (CPPD) nomenclature project. This systematic literature review constituted its first step and aimed to provide a state-of-the-art analysis of the medical literature of the last 20 years.

METHODS

A systematic literature search was undertaken in the PubMed, Cochrane and Embase databases between 2000 and 2022, restricted to studies on humans and in the English language. Eight reviewers independently and manually extracted labels related to CPPD concepts, according to an a priori list generated by the authors: pathogenic conditions and pathogenic crystal labels, elementary imaging condition elements and asymptomatic and symptomatic condition states. For each concept, labels were analysed to determine their frequency.

RESULTS

Among the 2375 articles identified, 886 articles were included, of which 394 (44.5%) were case reports and 169 (19.0%) were scoping reviews. Overall, the most common labels used to designate the pathogenic condition were 'pseudogout' in 365/783 (46.6%), 'chondrocalcinosis' in 207/783 (26.4%) and 'calcium pyrophosphate deposition disease' in 181/783 (23.1%) occurrences. The most common abbreviation was 'CPPD' in 312/390 (80.0%), but with different meanings. CPPD clinical phenotypes were often described as 'pseudo-form' labels.

CONCLUSION

Those results demonstrate the heterogeneity of labels used to describe CPPD condition concepts, with wide variation in condition labels in the medical literature. This work provides the rationale and basis to achieve agreement about CPPD technical nomenclature.

Risk of myocardial infarction and heart failure in gout patients: a systematic review and meta-analysis

BACKGROUND

Gout is a metabolic disease caused by decreased blood uric acid excretion and purine metabolism disorders. Long-term and persistent metabolic dysfunction gradually affects other organ functions and is the main factor inducing Myocardial Infarction (MI) and Heart Failure (HF), seriously affecting the health of patients. This study adopts a meta-analysis to analyze the risk of MI and HF in gout patients.

METHODS

Clinical research literature related to gout complicated with MI or HF was searched in databases such as PubMed, Embase, Web of Science, Cochrane Library, etc. through computer retrieval before March 2023. Literature content was carefully read and retrieved, and screening was conducted based on inclusion and exclusion criteria. Relevant data were extracted from the final screened literature, and a forest map was drawn using RevMan 5.3 software for meta-analysis.

RESULTS

After searching in various databases, 2519 articles were obtained. After screening, 8 articles were finally included for meta-analysis. Among the 22 included literature, 9 analyzed the risk of gout and MI, and heterogeneity tests showed P = 0.20 and I2 = 28%. Fixing effects analysis showed RR = 4.60, 95%CI = 4.39-4.82, and P < 0.001. Nine articles analyzed the risk of gout and HF, and heterogeneity tests showed that P = 0.13 and I2 = 37%. Fixing effects analysis showed RR = 2.71, 95%CI = 2.61-2.82, and P < 0.001. Eight studies compared the incidence of MI or HF between male gout and non-gout patients. Heterogeneity tests showed P = 0.21 and I2 = 28%, while fixing effects analysis showed RR = 1.98 and 95%CI = 1.89-2.01, with P < 0.001. Four articles statistically compared the incidence of MI or HF between female gout and non-gout patients. Heterogeneity tests showed P = 0.15 and I2 = 43%. Fixing effects analysis showed RR = 1.70, 95%CI = 1.57-1.83, and P < 0.001. Thirteen studies compared the incidence of MI or HF in gout patients of different genders. Heterogeneity tests showed P = 0.37 and I2 = 7%. Fixing effects analysis showed RR = 0.03, 95%CI = 0.03-0.03, and P < 0.001.

CONCLUSION

Compared to non-gout patients, gout patients are more prone to MI or HF and are not affected by gender. However, among gout patients, women have a higher risk of MI or HF than men.

The comprehensive role of dual-energy CT in gout as an advanced diagnostic innovation

Gout is a common and growing health concern globally, marked by the deposition of monosodium urate (MSU) crystals in joints and soft tissues. While diagnosis relies on synovial fluid analysis, it is limited by technical difficulties and a notable rate of false negatives. Over the past decade, dual-energy computed tomography (DECT) has emerged as a highly sensitive and less-invasive modality for detecting MSU crystals. DECT offers several advantages, including the ability to visualize both intra- and extra-articular MSU deposits and to monitor crystal burden over time. It also aids in treatment planning by accurately assessing the therapeutic response. However, sensitivity of DECT can be lower in early-stage gout, and artifacts can occasionally result in false positives. Recent studies have highlighted new values of using DECT, such as predicting future flares in gout patients. In this review, we focus on the comprehensive clinical utility of DECT and its potential pitfalls in the diagnosis and management of gout.

Baseline Dual-Energy Computed Tomography Urate Volume Predicts Fulfillment of Gout Remission After Two Years of Urate-Lowering Therapy

OBJECTIVE

This study aimed to identify variables that predict gout remission in people with erosive gout receiving urate-lowering therapy.

METHODS

We analyzed data from a two-year, double-masked randomized-controlled trial of people with erosive gout, randomized to a serum urate target of <0.20 mmol/L or <0.30 mmol/L using oral urate-lowering therapies. All participants had dual-energy computed tomography (DECT) scans of the feet and ankles at baseline. The proportion of participants achieving gout remission according to the 2016 preliminary gout remission criteria and simplified gout remission criteria (without the patient reported outcomes) was analyzed. Logistic regression models were used to evaluate predictors of gout remission in year 2.

RESULTS

The preliminary gout remission criteria were fulfilled in 11 of 97 participants (11%) at year 1 and 21 of 92 participants (23%) at year 2. The simplified criteria were fulfilled in 26 of 97 participants (27%) in year 1 and 40 of 92 participants (44%) in year 2. In multivariable regression models, baseline DECT monosodium urate crystal volume was the only significant independent predictor of gout remission at year 2, using either criteria. Each 1-cm3 increase in the baseline DECT monosodium urate crystal volume decreased the odds of fulfilling the 2016 preliminary gout remission criteria (odds ratio [OR] 0.65, 95% confidence interval [CI] 0.46-0.93; P = 0.02) and the simplified gout remission criteria (OR 0.57, 95% CI 0.41-0.78; P < 0.001).

CONCLUSION

In people with erosive gout on urate-lowering therapy, higher baseline DECT monosodium urate crystal volume is associated with lower odds of gout remission after two years of treatment, defined by either the preliminary gout remission criteria or simplified gout remission criteria.

Research hotspots and trends related to pain in gouty arthritis from 2014 to 2024: A bibliometric analysis

BACKGROUND

Gouty arthritis is a metabolic condition caused by disordered purine metabolism and elevated uric acid levels. This study adopts a bibliometric approach to analyze current research on pain in gouty arthritis and forecast future research trends.

METHODS

Retrieve relevant research on gouty arthritis pain in the Web of Science core collection database, screen literature, and use visualization software such as CiteSpace, Vosviewers, and R package "Bibliometrix" for analysis.

RESULTS

The total number of documents included was 1133, with 909 articles and 224 reviews. Between 2014 and 2024, there was an overall upward trend in the number of publications about pain in gouty arthritis, with the United States of America and China ranking first and second, respectively, in terms of publication volume. The UNIVERSITY OF ALABAMA BIRMINGHAM had the most publications, and Professor DALBETH N played a key role in this field. According to the keyword analysis, disease management and treatment, particularly methods for enhancing patients' quality of life and reducing symptoms, are research hotspots. For a deeper understanding, attention is also being paid to the epidemiology and pathological mechanisms of the disease. Emerging keywords such as "gut microbiota" and "urate-lowering therapies" indicate growing interest in the interrelationship between gut microbiota and gout, and the development of new treatment methods.

CONCLUSION

This bibliometric study reveals that research on gouty arthritis pain is actively developing. Current hot topics reflect investigations into the deeper pathological mechanisms of gouty arthritis and the development of new treatment methods, including urate-lowering therapies. There is also increasing attention on the role of gut microbiota in the disease. Despite limitations such as the preliminary nature of research methods and insufficient interdisciplinary collaboration, future research directions aim to improve the rigor of research design, strengthen international cooperation, promote unified treatment guidelines, and optimize the diagnosis and treatment of gouty arthritis with new technologies like artificial intelligence, precision medicine, and nanomedicine. This will drive the field towards a deeper scientific understanding, more effective treatment methods, and more comprehensive disease management, ultimately improving patients' prognosis and quality of life.

Preclinical gout is common in the patient with stage 3-5 chronic kidney disease. Relevance of musculoskeletal ultrasound

BACKGROUND

One in 10 patients with hyperuricemia may develop gout over time, with urate deposition sometimes asymptomatic. Recent reviews and guidelines support ultrasound (US) to assess asymptomatic hyperuricemic (AH) patients to detect gout lesions, showing double contour (DC) and tophus the highest specificities and positive predictive values. Hyperuricemia and gout are common in chronic kidney disease (CKD), especially with glomerular filtration rate (GFR) <60, and both are associated with worse prognosis, although treatment of AH in CKD is not yet recommended in all guidelines. US gout lesions have been found more frequently in AH (up to 35%) than in normouricemic (NU) patients, but evidence is scarce in CKD.

OBJECTIVES

To assess the prevalence of urate deposit in stages 3-5 CKD detected by US, and to investigate if there are differences between AH and NU patients.

METHODS

Multicenter cross-sectional study, recruiting patients aged ≥18 years with AH and stages 3-5 CKD in 4 hospitals. A comparator group of NU patients with stage 3-5 CKD was included.

EXCLUSION CRITERIA

previous diagnosis of gout, tophi. Hyperuricemia was defined as serum uric acid (sUA) >7 mg/dl, documented at least twice during the last 12 months. A standardized US exam of the knees and bilateral first metatarsophalangeal joints was performed to assess patients for DC/tophus as defined by OMERACT. Demographic, clinical and laboratory data were recorded. A descriptive analysis was performed using SPSS. Pre-clinical gout (PCG: DC and/or tophus) was considered as outcome variable. Chi-square and Fisher's exact test were used for qualitative variables, and Mann-Whitney U test for quantitative variables; significant threshold p < 0.05.

RESULTS

Fifty-three patients with stages 3-5 CKD (59.6% stage 3, 19.1% stage 4, 21.3% stage 5) were recruited, 38 AH (71.7%) and 15 NU. A higher prevalence of US findings was observed in HU patients compared to NU patients (DC 23.7% vs 13.3%, tophus 31.6% vs 26.7%, PCG 39.5% vs 33.3%), although the differences were not statistically significant. NU patients had CKD of longer duration than HU patients [11 (7.2-13.5) vs 6 (2-9.2) years; p = 0.02], with no differences in sex, age, comorbidities, or urate-lowering therapy (ULT) (66.7% vs 44.7%; p = 0.05) and other treatments. Seventy percent of NU patients with TRU had AH before starting treatment. In patients with tophi, we observed a trend towards shorter duration of CKD and shorter duration of treatment with ULT compared to those without tophi [3.5 (2-6.7) vs 7 (3-12) years; p = 0.05] and [22 (12-44) vs 39 (29-73) months; p = 0.08], respectively. This trend was also observed in PCG, but not in DC, first US sign to disappear after initiation of ULT. Ninety percent of patients (100% in non-dialyzed patients) with PCG had a median uricemia ≥5 mg/dl in the past 12 months.

CONCLUSION

We found a significant prevalence of asymptomatic urate deposition in patients with stage 3-5 CKD, mostly in subjects with median uricemia ≥5 mg/dl in the last 12 months. Early diagnosis of PCG by musculoskeletal US in CKD may allow earlier introduction and optimization of ULT. This will probably contribute to slowing down the progression of this pathology, which makes it essential to promote collaboration between Nephrology and Rheumatology.

Computed tomography-current status and future directions for arthritis imaging

Applications of computed tomography (CT) in arthritis imaging have rapidly expanded in recent years due to ongoing technical developments. Dual-energy CT (DECT) has become indispensable in clinical practice, particularly for diagnosing gouty arthritis and assessing bony structural changes. Technological innovations such as low-dose CT and state-of-the-art reconstruction algorithms reduce radiation exposure while maintaining image quality and short acquisition times. This review explores the growing role of CT in arthritis imaging. Recent innovations have extended DECT's utility beyond gout diagnosis to the detection of inflammatory changes in various arthritic conditions. Postprocessing techniques such as the generation of subtraction images and iodine maps provide valuable insights into tissue perfusion and inflammatory activity, crucial for arthritis management. DECT can distinguish calcium from uric acid crystals, facilitating the differential diagnosis of various crystal arthropathies in a variety of clinical settings. This ability is particularly valuable in distinguishing between different clinical conditions in patients with inflammatory joint changes within a single imaging examination. Moreover, the advent of four-dimensional CT promises a better assessment of dynamic joint instabilities and ligament injuries, especially in the wrist. Overall, DECT offers a comprehensive approach to arthritis imaging, from the detection of structural changes to the assessment of active inflammation in joints and tendons. Continuous advances in CT technology, including photon-counting CT, hold promise for further improving diagnostic accuracy and expanding the role of CT in arthritis imaging and therapy monitoring.

Prevalence of crystal deposits in asymptomatic hyperuricemia according to different scanning definitions: A comparative study

BACKGROUND/AIM

The appropriate sonographic protocol for assessing urate crystal deposits in asymptomatic hyperuricemia (AH) is undefined, as well as how the choice would impact on deposit rates and accompanying sonographic, clinical and laboratory features.

METHODS

Patients with AH (serum urate ≥7 mg/dL) underwent musculoskeletal ultrasound of 10 locations for OMERACT elementary gout lesions (double contour [DC] signs, tophi, aggregates). Different definitions for AH with deposits were applied, varying according to deposits (any deposits; only DC and/or tophi); gradation (any grade; only grade 2-3 deposits), location (10 locations; 4-joint scheme including knees and 1MTPs; >1 location with deposits), or pre-defined definitions (DC sign in femoral condyles/1MTP and/or tophi in 1MTP). We evaluated crystal deposits rates and compared between other sonographic features, clinical and laboratory variables.

RESULTS

Seventy-seven participants with AH showed a median 1 location (IQR 0-2) with tophi, 1 (IQR 1-2) with aggregates, and 0 locations (IQR 0-1) with DC sign. The deposition rate ranged from 23.4% (in >1 location with grade 2-3 DC or tophi) to 87.0% (in any deposit in all 10 locations). Accompanying inflammation - assessed by a positive power-Doppler (PD) signal - and erosions were found in 19.5% and 28.4% of participants, respectively. Positive PD signal was better discriminated by criteria requiring grade 2-3 or >1 location with lesions. Erosions and the different clinical and laboratory variables were similar among protocols.

CONCLUSION

Rates of sonographic deposition in AH varied dramatically among studied protocols, while some could discriminate accompanying inflammation, all highlighting the need for a validated, consensus-based definition.

Updates in Ultrasound in Rheumatology

BACKGROUND

The purpose of the authors' narrative review was to outline the current literature regarding the use of ultrasound in main rheumatic disorders and summarize the updates, specifically about rheumatoid arthritis, psoriatic arthritis, and crystal-induced arthropathies.

METHODS

The authors searched on PubMed for articles discussing the major updates regarding the role of ultrasound in the previously mentioned rheumatic conditions.

RESULTS

The authors have provided the updated definitions, new criteria, and diagnostic scores.

CONCLUSIONS

In rheumatology's dynamic landscape, this review provides valuable insights for researchers and clinicians on ultrasound's role in improving patient care and outcomes in rheumatic diseases.

Hyperuricemia and its related diseases: mechanisms and advances in therapy

Hyperuricemia, characterized by elevated levels of serum uric acid (SUA), is linked to a spectrum of commodities such as gout, cardiovascular diseases, renal disorders, metabolic syndrome, and diabetes, etc. Significantly impairing the quality of life for those affected, the prevalence of hyperuricemia is an upward trend globally, especially in most developed countries. UA possesses a multifaceted role, such as antioxidant, pro-oxidative, pro-inflammatory, nitric oxide modulating, anti-aging, and immune effects, which are significant in both physiological and pathological contexts. The equilibrium of circulating urate levels hinges on the interplay between production and excretion, a delicate balance orchestrated by urate transporter functions across various epithelial tissues and cell types. While existing research has identified hyperuricemia involvement in numerous biological processes and signaling pathways, the precise mechanisms connecting elevated UA levels to disease etiology remain to be fully elucidated. In addition, the influence of genetic susceptibilities and environmental determinants on hyperuricemia calls for a detailed and nuanced examination. This review compiles data from global epidemiological studies and clinical practices, exploring the physiological processes and the genetic foundations of urate transporters in depth. Furthermore, we uncover the complex mechanisms by which the UA induced inflammation influences metabolic processes in individuals with hyperuricemia and the association with its relative disease, offering a foundation for innovative therapeutic approaches and advanced pharmacological strategies.

Managing Gout in Patients with Metabolic Syndrome

Gout is characterized by monosodium urate (MSU) crystal deposition secondary to hyperuricemia. Gout is associated with metabolic syndrome (MetS) and its related comorbid conditions such as cardiovascular disease (CVD). Major advances have been made in the comprehension of the link between MetS and gout. Despite observational studies suggesting an association between MetS-related conditions and hyperuricemia, there is no proof of causality. Most studies using Mendelian randomization did not find hyperuricemia as a causal factor for MetS-related conditions. In contrast, these conditions were found associated with hyperuricemia, which suggests a reverse causality. Among patients with gout, this high CVD risk profile implies the need for systematic screening for MetS-related conditions. Most international guidelines recommend systematic screening for and care of CVD and related risk factors in patients with gout. Some anti-hypertensive agents, such as losartan and calcium channel blockers, are able to decrease serum urate (SU) levels. However, there are potential interactions between gout management therapies and the treatment of metabolic diseases. Some data suggest that anti-inflammatory drugs used for gout flare treatment, such as colchicine or canakinumab, might have benefits for CVD. Regarding the impact of urate-lowering therapies on CVD risk, recent studies found a similar CVD safety profile for allopurinol and febuxostat. Finally, sodium-glucose cotransporter-2 inhibitors are promising for gout because of their ability to decrease SU levels and risk of recurrent flares. In this review, we focus on the clinical challenge of managing MetS in patients with gout, particularly older patients with co-medications.

Review: The Role of Dual-Energy Computed Tomography in Detecting Monosodium Urate Deposits in Vascular Tissues

PURPOSE OF REVIEW

To highlight novel findings in the detection of monosodium urate deposits in vessels using dual energy computed tomography, and to discuss the potential clinical implications for gout and hyperuricemia patients.

RECENT FINDINGS

Gout is an independent risk factor for cardiovascular disease. However, classical risk calculators do not take into account these hazards, and parameters to identify patients at risk are lacking. Monosodium urate measured by dual energy computed tomography is a well-established technology for the detection and quantification of monosodium urate deposits in peripheral joints and tendons. Recent findings also suggest its applicability to identify vascular urate deposits. Dual energy computed tomography is a promising tool for detection of cardiovascular monosodium urate deposits in gout patients, to better delineate individuals at increased risk for cardiovascular disease.

The value of musculoskeletal ultrasound in predicting gout flares in index joints: A prospective cohort study of people with gout starting urate-lowering therapy

OBJECTIVES

To evaluate whether ultrasound findings of monosodium urate (MSU) crystal deposition predict frequent gout flares in index joints over 12 months.

METHODS

This single-center study enrolled people with at least one gout flare involving the MTP1, ankle or knee joint. The most painful or most frequently joint was identified as index joint for analysis. All participants were started on urate-lowering therapy and had an ultrasound scan of the index joints at the baseline visit. OMERACT scores (for tophus, double contour sign and aggregates) were used to analyze whether ultrasound scores predicted frequent (≥2) gout flares in the index joint over 12 months.

RESULTS

Frequent flares were significantly higher in those with ultrasound findings in all index joints (MTP1: tophus: 85.0% vs 46.0%, P < 0.001, aggregates: 78.8% vs 59.0%, P < 0.01; ankle: tophus: 54.6% vs 20.8%, P < 0.001; aggregates: 60.0% vs 35.9%, P < 0.05; knee: tophus: 68.4% vs 28.6%, P < 0.05). For the MTP1, for each 1-point increase in tophus score, the odds of frequent gout flares increased by 5.19 [(95%CI: 1.26-21.41), 7.91 [(95%CI: 2.23-28.14), and 13.79 [(95%CI: 3.79-50.20)] fold respectively. For the ankle, a tophus score of 3 markedly improved the prediction of the frequent flares [OR= 9.24 (95%CI=2.85-29.91)]. Semi-quantitative sum scores were associated with frequent flares with an OR (95%CI) of 13.66 (3.44-54.18), P < 0.001 at the MTP1, 7.05 (1.98-25.12), P < 0.001 at the ankle.

CONCLUSION

Ultrasound features of MSU crystal deposition at the MTP1 and knee predict subsequent risk of frequent gout flares in the same joints following initiation of urate-lowering therapy, with the highest risk in those with high tophus scores.

Projected Health and Economic Burden of Comorbid Gout and Chronic Kidney Disease in a Virtual US Population: A Microsimulation Study

INTRODUCTION

Gout, a common comorbidity of chronic kidney disease (CKD), is associated with high morbidity and healthcare utilization. However, a large proportion of gout remains undermanaged or untreated which may lead to worse patient outcomes and greater healthcare costs. This study estimates the present and future health and economic burden of controlled and uncontrolled gout in a virtual United States (US) CKD population.

METHODS

A validated microsimulation model was used to project the burden of gout in patients with CKD in the USA through 2035. Databases were utilized to build a virtual CKD population of "individuals" with controlled or uncontrolled gout. Modelling assumptions were made on the basis of the literature, which was sparse in some cases. Health and economic outcomes with the current care (baseline) scenario were evaluated, along with potential benefits of urate-lowering intervention scenarios.

RESULTS

The prevalence of comorbid gout and CKD in the USA was projected to increase by 29%, from 7.9 million in 2023 to 9.6 million in 2035 in the baseline scenario. Gout flares, tophi, and comorbidity development were also projected to increase markedly through 2035, with the economic burden of gout in the CKD population subsequently increasing from $38.9 billion in 2023 to $47.3 billion in 2035. An increased use of oral urate-lowering therapies in undermanaged patients, and pegloticase use in patients refractory to oral urate-lowering therapies were also project to result in 744,000 and 353,000 fewer uncontrolled gout cases, respectively, by 2035. Marked reductions in complications and costs ensued.

CONCLUSIONS

This study projected a substantial increase in comorbid gout and CKD. However, improved use of urate-lowering interventions could mitigate this growth and reduce the health and economic burdens of gout.

2023 EULAR recommendations on imaging in diagnosis and management of crystal-induced arthropathies in clinical practice

OBJECTIVE

To formulate evidence-based recommendations and overarching principles on the use of imaging in the clinical management of crystal-induced arthropathies (CiAs).

METHODS

An international task force of 25 rheumatologists, radiologists, methodologists, healthcare professionals and patient research partners from 11 countries was formed according to the EULAR standard operating procedures. Fourteen key questions on the role of imaging in the most common forms of CiA were generated. The CiA assessed included gout, calcium pyrophosphate deposition disease and basic calcium phosphate deposition disease. Imaging modalities included conventional radiography, ultrasound, CT and MRI. Experts applied research evidence obtained from four systematic literature reviews using MEDLINE, EMBASE and CENTRAL. Task force members provided level of agreement (LoA) anonymously by using a Numerical Rating Scale from 0 to 10.

RESULTS

Five overarching principles and 10 recommendations were developed encompassing the role of imaging in various aspects of patient management: making a diagnosis of CiA, monitoring inflammation and damage, predicting outcome, response to treatment, guided interventions and patient education. Overall, the LoA for the recommendations was high (8.46-9.92).

CONCLUSIONS

These are the first recommendations that encompass the major forms of CiA and guide the use of common imaging modalities in this disease group in clinical practice.

Hyperuricemia and intravenous fat emulsion are risk factors for gout flares during active gastrointestinal bleeding: a case control study

OBJECTIVE

It is well-established that patients with a history of gout are more susceptible to experiencing gastrointestinal bleeding. Gout flare during active gastrointestinal bleeding poses a significant challenge due to the gastrointestinal side effects of anti-inflammatory therapy. This study sought to investigate the risk factors associated with gout flares during episodes of gastrointestinal bleeding.

METHODS

We conducted a retrospective observational study involving 94 patients who experienced active gastrointestinal bleeding and had a history of gout. This study was conducted at Jinhua Municipal Central Hospital from January 2019 to October 2022. We collected and recorded demographic information and clinical characteristics.

RESULTS

Among the gout flare patients, hyperuricemia and intravenous fat emulsion therapy were more prevalent compared to those who remained stable (81.6% vs. 57.8% and 46.9% vs. 24.4%, p < 0.05). Multivariate logistic regression analysis revealed that both hyperuricemia (odds ratio 2.741, 95% CI 1.014-7.413, p = 0.047) and intravenous fat emulsion therapy (odds ratio 2.645, 95% CI 1.046-6.686, p = 0.040) were independent predictors of gout flares. Furthermore, gout attacks occurred sooner in patients receiving intravenous fat emulsion therapy compared to those not receiving it (median: 4 days (interquartile range: 2) vs. median: 5 days (interquartile range: 2.25), p = 0.049).

CONCLUSION

Our study revealed a high incidence of gout flares during episodes of active gastrointestinal bleeding, with patients undergoing intravenous fat emulsion therapy and those with hyperuricemia being at increased risk.

Describing calcium pyrophosphate deposition: undoing the tower of Babel!

PURPOSE OF REVIEW

In 1977, McCarty astutely observed, 'The variety of names suggested for the condition associated with deposits of calcium pyrophosphate dihydrate crystals is exceeded only by the variations of its clinical presentation'. Fast forward to 2024, a standardized nomenclature for calcium pyrophosphate deposition (CPPD) is still lacking. This review aims to delineate the challenges in characterizing CPPD through nomenclature and imaging.

RECENT FINDINGS

Despite the effort of nomenclature standardization in 2011 by the EULAR, confusion persists in the literature and clinical practice, with pseudo-forms and obscure abbreviations. The Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN) has launched a project to redefine CPPD nomenclature and formulate a user-friendly language for effective communication with patients and other stakeholders. Additionally, recent advancements in imaging, have shed light on various aspects of the disorder.

SUMMARY

Almost 60 years from the first description of a clinical manifestation related to calcium pyrophosphate crystals, a common language describing the disorder is still lacking. A redefined CPPD nomenclature, together with lay-friendly terminology, would significantly contribute to the uniformity of CPPD research, enhance public understanding and awareness and improve doctor-patient communication and therefore disease outcomes. Imaging can provide deep insights into CPPD elements, promoting comprehension of this disorder.

The association between gout flares and monosodium urate burden assessed using musculoskeletal ultrasound in patients with gout

Background

Ultrasound (US) has a high sensitivity in detecting monosodium urate (MSU) deposition in gout patients. However, the value of US in predicting gout flares has been reported only in a few monocentric studies.

Objective

To investigate the association between gout flares in the previous year and US-detected MSU burden using two different US scores.

Design

A retrospective study.

Methods

Patients with gout were consecutively recruited to undergo musculoskeletal US examinations of their knees, ankles, and feet. The score derived from Outcome Measure in Rheumatology (hereinafter referred to as MSU score) and musculoskeletal US features-based (hereinafter referred to as MSKF score) were used to quantify the MSU burden of gout. Odds ratios for frequent gout flares were calculated.

Results

We enrolled 1894 patients with gout (mean age: 45 years; gout duration: 5 years; males: 96.1%), experiencing a median of three flares over the past year. Of these, 428 (22.6%) patients reported frequent (⩾7) gout flares. The MSU and MSKF median scores were 6 and 9, respectively. For each five-point increase in MSU and MSKF score, the odds ratio of frequent gout flares increased 1.13-fold and 1.24-fold, respectively. The area under the curve (AUC) for the MSU and MSKF score was 0.635 [95% confidence interval (CI): 0.604-0.665] and 0.688 (95% CI: 0.659-0.718), respectively, (AUC difference 0.054, p value for AUC difference < 0.001).

Conclusion

The MSU and MSKF scores were significantly associated with the number of gout flares in the previous year. The MSKF score outperformed the MSU score in terms of frequent gout flare discrimination.

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.

Effect and mechanism of aqueous extract of Chinese herbal prescription (TFK) in treating gout arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

With the rapid development of China's economic level, great changes have taken place in people's diet structure, gout has become a common disease that puzzles people's health, seriously affects the realization of China's "Healthy China" strategic goal. Gouty arthritis (GA) is a common joint disease caused by chronic purine metabolism disorder. Currently, drugs used to treat GA are allopurinol and colchicine. However, these drugs can only temporarily relieve the clinical symptoms of GA with significant side effects. More and more basic and clinical studies have confirmed that Traditional Chinese medicine has definite curative effect on GA.

AIM OF THE STUDY

To elucidate the potential molecular mechanism of Tongfengkang (TFK) in the treatment of GA, and to provide experimental basis for the search and development of efficient and low-toxicity Chinese medicine for GA treatment.

MATERIALS AND METHODS

Aqueous extract of TFK (AETFK) were determined by liquid phase high resolution mass spectrometry and the possible effective constituents were screened out. Acute GA model rats were established to detect the anti-inflammatory and detumification effects of AETFK on GA and explore the potential mechanism. The effect of AETFK on serum uric acid and urinary uric acid levels in acute GA rats was determined by automatic biochemical analyzer, and the effect of AETFK on the expression of acute GA-related immunoinflammatory factors were determined by protein thermal fluorescence chip. The effect of AETFK on the concentration of neutrophils in the joint fluid of acute GA rats were determined by Reichs-Giemsa staining. The effect of AETFK on macrophage activation was detected by ELISA. In order to further investigate the mechanism of AETFK in the treatment of GA, a rat model of hyperuricemia was established to detect the effect of AETFK on the level of uric acid in hyperuricemia model rats. Biochemical indexes of liver and kidney and hematoxylin-eosin staining (HE) were used to evaluate the effects of AETFK on the organs, and to preliminatively evaluate the safety of ventilation confufang.

RESULTS

Compared with the model group, the joint swelling degree of GA rats in AETFK treatment group were significantly reduced, and the levels of blood uric acid and urine uric acid were also significantly decreased. Protein thermal fluorescence microarray results showed that the levels of gout - related inflammatory factors in GA rats in AETFK treatment group were significantly lower than those in control group. Reichsen-giemsa staining and ELISA showed that AETFK could reduce the activation of macrophages and the accumulation of neutrophils in the joint fluid. The results of liver and kidney biochemical indexes and HE staining showed that no obvious tissue damage was observed in the organs of rats treated with AETFK.

CONCLUSIONS

AETFK not only has significant anti-inflammatory effects on GA, but also can significantly reduce the level of blood uric acid in GA rats, without obvious toxic and side effects. These effects may be related to AETFK's inhibition of neutrophil enrichment and macrophage activation during early inflammation.

Consensus statement on the management of patients with asymptomatic hyperuricemia in general medical practice

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The Role of Ultrasound Semi-Quantitative Scoring in the Diagnosis and Assessment of Gout and Hyperuricemia

OBJECTIVES

To develop an ultrasound semi-quantitative scoring system for the diagnosis and evaluation of gout and hyperuricemia.

METHODS

This study included 348 male patients: 81 patients with asymptomatic hyperuricemia, 182 patients with gout, and 85 patients with other arthritis. Clinical data were collected, ultrasound was detected, gout activity score was calculated to assess disease activity, and statistical analysis was performed.

RESULTS

Monosodium urate crystal deposition and subclinical arthritis were detected in 17 patients with asymptomatic hyperuricemia, with lesions concentrated in the metatarsophalangeal joint, ankle and peroneus-longus and brevis at rate of 91.8%. Gout was significantly higher than non-gouty arthritis in crystal scores (sum scores of double contour, aggregates, and tophi), but not in inflammation scores (sum scores of synovial hypertrophy, power Doppler [PD] activity, and tenosynovitis) and bone erosion. The optimal cut-off score for the diagnosis of gout by the crystal score was 2. The sensitivity, specificity, and AUC were 95.4%, 97.1%, and .965, respectively. Gout flare had higher inflammation scores than intercritical gout, while bone erosion scores were lower than intercritical gout. The active gout patients had higher ultrasound scores of tophi, bone erosion, and PD activity than the remission group (P < .001). The sensitivity, specificity and area under the receiver operating characteristic curve (AUC) for the identification with high disease activity gout by ultrasound semi-quantitative composite score were 76.2%, 84.2%, and .812, respectively.

CONCLUSION

Ultrasound helps early identification of patients at risk in asymptomatic hyperuricemia. Ultrasound semi-quantitative scoring allows for more objective and accurate assessment of gout lesions, correlates with disease activity, and helps in the diagnosis and assessment of gout.

Improving the accuracy of automated gout flare ascertainment using natural language processing of electronic health records and linked Medicare claims data

BACKGROUND

We aimed to determine whether integrating concepts from the notes from the electronic health record (EHR) data using natural language processing (NLP) could improve the identification of gout flares.

METHODS

Using Medicare claims linked with EHR, we selected gout patients who initiated the urate-lowering therapy (ULT). Patients' 12-month baseline period and on-treatment follow-up were segmented into 1-month units. We retrieved EHR notes for months with gout diagnosis codes and processed notes for NLP concepts. We selected a random sample of 500 patients and reviewed each of their notes for the presence of a physician-documented gout flare. Months containing at least 1 note mentioning gout flares were considered months with events. We used 60% of patients to train predictive models with LASSO. We evaluated the models by the area under the curve (AUC) in the validation data and examined positive/negative predictive values (P/NPV).

RESULTS

We extracted and labeled 839 months of follow-up (280 with gout flares). The claims-only model selected 20 variables (AUC = 0.69). The NLP concept-only model selected 15 (AUC = 0.69). The combined model selected 32 claims variables and 13 NLP concepts (AUC = 0.73). The claims-only model had a PPV of 0.64 [0.50, 0.77] and an NPV of 0.71 [0.65, 0.76], whereas the combined model had a PPV of 0.76 [0.61, 0.88] and an NPV of 0.71 [0.65, 0.76].

CONCLUSION

Adding NLP concept variables to claims variables resulted in a small improvement in the identification of gout flares. Our data-driven claims-only model and our combined claims/NLP-concept model outperformed existing rule-based claims algorithms reliant on medication use, diagnosis, and procedure codes.

The Effect of Decrease in Serum Urate for the Risk of Gout Flares During Urate-Lowering Therapy Initiation Among Chinese Male Gout Patients: A Prospective Cohort Study

Purpose

Higher baseline serum urate or higher initial urate-lowering medication dose increased risk of gout flares during urate-lowering therapy (ULT) initiation. The decrease in serum urate may play a crucial role in this process. Therefore, we aim to explore the relationship between decrease in serum urate and the risk of gout flares during ULT initiation.

Patients and Methods

A 12-week prospective cohort study of Chinese male gout patients was conducted at Shandong Provincial Clinical Research Center for Immune Diseases and Gout in China. Patients were grouped by baseline serum urate (7-7.9 mg/dL, 8-8.9 mg/dL and ≥9 mg/dL). All patients received febuxostat 20 mg daily during weeks 0-4, then escalated to 40mg during weeks 4-12 if serum urate >6mg/dL. The main outcomes were the number of gout flares and the decrease in serum urate. Poisson regression was performed.

Results

A total of 282 participants were enrolled, of whom 260 completed (84, 87 and 89 in each group) from March 2021 to December 2021. A 44.2% of all participants experienced at least one gout flare. In the multivariate Poisson regression 1, Δ serum urate 0-12 weeks (IRR 1.184, 95% CI, 1.062-1.320; P=0.002), the number of gout flares before treatment 1 year (1.017, 1.010-1.024; P<0.001) and tophus (1.580, 1.023-2.440; P=0.039) were independently associated with the number of gout flares. While in the multivariate Poisson regression 2, baseline serum urate (1.256, 1.050-1.503; P=0.013) and the number of gout flares before treatment 1 year (1.014, 1.007-1.022; P<0.001) were independently associated with the number of gout flares, Δ serum urate 0-12 weeks (1.055, 0.923-1.207; P=0.433) was no longer a risk factor.

Conclusion

ULT-induced gout flares depend on the degree of decrease in serum urate, which is affected by baseline serum urate. Higher baseline serum urate and greater decrease in serum urate lead to higher risk of gout flares.

Gout Remission as a Goal of Urate-Lowering Therapy: A Critical Review

Urate-lowering therapies for the management of gout lead to a reduction in serum urate levels, monosodium urate crystal deposition, and the clinical features of gout, including painful and disabling gout flares, chronic gouty arthritis, and tophi. Thus, disease remission is a potential goal of urate-lowering therapy. In 2016, preliminary gout remission criteria were developed by a large group of rheumatologists and researchers with expertise in gout. The preliminary gout remission criteria were defined as: serum urate < 0.36 mmol/L (6 mg/dL); an absence of gout flares; an absence of tophi; pain due to gout < 2 on a 0-10 scale; and a patient global assessment < 2 on a 0-10 scale over a 12-month period. In this critical review, we describe the development of the preliminary gout remission criteria, the properties of the preliminary gout remission criteria, and clinical studies of gout remission in people taking urate-lowering therapy. We also describe a future research agenda for gout remission.

Ultrasonography in the prediction of gout flares: a 12-month prospective observational study

OBJECTIVES

To evaluate whether US findings indicating MSU deposits and US-detected inflammation (i.e. power Doppler signal) predict gout flares over 12 months.

METHODS

Gout patients on urate-lowering therapy for at least the preceding 6 months were enrolled consecutively in this 12-month prospective, observational, single-centre study. A nested case-control analysis was performed. Cases were participants with at least one flare in the follow-up period, while controls did not self-report any gout flare. The US assessment included elbows, wrists, second MCP joints, knees, ankles, and first MTP joints. The US findings indicating MSU deposits [i.e. aggregates, double contour (DC) sign and tophi] were identified as present/absent according to the Outcome Measure in Rheumatology definitions. Power Doppler signal was scored semiquantitatively. Summated scores were calculated for each US finding.

RESULTS

Eighty-one gout participants were enrolled, and 71 completed the study. Thirty (42.3%) of 71 participants experienced at least one flare over 12 months, with a median of 2.0 flares. Cases had a greater US burden of MSU deposits (6.7 ± 4.7 vs 2.9 ± 2.6, P = 0.01) and power Doppler signal (3.73 ± 3.53 vs 0.82 ± 1.44, P < 0.01) than controls, at baseline. The baseline US scores indicating MSU deposits and US-detected inflammation were significantly associated with the occurrence (total MSU score, adjusted odds ratio:1.75, 95% CI: 1.26, 2.43; power Doppler score, adjusted odds ratio: 1.63, 95% CI: 1.12, 2.40) and the number (total MSU score, adjusted incidence risk ratio: 1.17, 95% CI: 1.08, 1.26; power Doppler score, adjusted incidence risk ratio: 1.29, 95% CI: 1.19, 1.40) of flares over 12 months in multivariate analyses.

CONCLUSIONS

Baseline US findings indicating MSU deposits and US-detected inflammation are independent predictors of gout flares over 12 months.

The Burden of Gout and Its Attributable Risk Factors in the Middle East and North Africa Region, 1990 to 2019

OBJECTIVE

This study reported the burden of gout and its attributable risk factors in the Middle East and North Africa (MENA) region between 1990 and 2019 by age, sex, and sociodemographic index (SDI).

METHODS

Data on the prevalence, incidence, and years lived with disability (YLD) due to gout were obtained from the Global Burden of Disease 2019 study for the 21 countries in the MENA region, from 1990 to 2019.

RESULTS

In 2019, the regional age-standardized point prevalence and annual incidence rates of gout were 509.1 and 97.7 per 100,000 population, which represent a 12% and 11.1% increase since 1990, respectively. Moreover, in 2019 the regional age-standardized YLD rate was 15.8 per 100,000 population, an 11.7% increase since 1990. In 2019, Qatar and Afghanistan had the highest and lowest age-standardized YLD rates, respectively. Regionally, the age-standardized point prevalence of gout increased with age up to the oldest age group, and it was more prevalent among males in all age groups. In addition, there was an overall positive association between SDI and the burden of gout between 1990 and 2019. In 2019, high BMI (46.1%) was the largest contributor to the burden of gout in the MENA region.

CONCLUSION

There were large intercountry variations in the burden of gout, but in general, it has increased in MENA over the last 3 decades. This increase is in line with the global trends of gout. However, the age-standardized YLD rate change was higher in MENA than at the global level.

Overnutrition-induced gout: An immune response to NLRP3 inflammasome dysregulation by XOD activity increased in quail

Background

Gout is a progressive metabolic disease closely related to hyperuricemia and urate deposition, with an increasing prevalence and incidence across the globe. Recent studies have shown that the pathological process of gout includes two stages: asymptomatic hyperuricemia and MSU crystal deposition. However, the immune response during the development of hyperuricemia to gouty arthritis is not fully elucidated.

Methods

Thus, an overnutrition-induced whole-course gout model was established to clarify the immune response and pathological changes in the development from hyperuricemia to gouty arthritis. The quails without urate oxidase were used as experimental animals. And we confirmed that uric acid metabolic targets were changed when quails were in the asymptomatic hyperuricemia stage.

Results

When the quail showed gout symptoms, the NLRP3 inflammasome was activated, and the expressions of IL-1β, TNF-α, IL-6, IL-8, and IL-18 were significantly increased. The relationship between the uric acid metabolism target and the NLRP3 inflammasome may be the critical immune response between hyperuricemia and gouty arthritis. Our data showed that, in the process of gout disease, the expression of xanthine oxidase (XOD) has been increasing, which increases the level of uric acid, disrupts the balance of oxidative stress, generates a large amount of ROS, activates the NLRP3 inflammasome, and release IL-1β. Treatment with the XOD inhibitor can reduce uric acid, restore the body's degree of peroxidative damage and antioxidant capacity, and inhibit NLRP3 inflammasome and IL-1β. In vitro, we extracted and identified primary fibroblast-like synoviocytes (FLS) from quail for the first time. Stimulating FLS with uric acid also caused ROS release and NLRP3 inflammasome activation. However, treatment with an XOD inhibitor prevented all these responses in FLS.

Conclusion

Our results indicate that the immune response between the uric acid metabolism target XOD and NLRP3 inflammasomes plays a crucial role in developing hyperuricemia to gouty arthritis, and inhibition of both XOD and NLRP3 inflammasomes may be an effective treatment for avoiding the development of asymptomatic hyperuricemia to MSU crystal deposition. Meanwhile, this study also provides an advantageous animal model for pathological mechanisms and research and development drugs for gout.

A glance into the future of gout

Gout is characterized by monosodium urate (MSU) crystal deposits in and within joints. These deposits result from persistent hyperuricaemia and most typically lead to recurrent acute inflammatory episodes (gout flares). Even though some aspects of gout are well characterized, uncertainties remain; this upcoming decade should provide further insights into many of these uncertainties. Synovial fluid analysis allows for the identification of MSU crystals and unequivocal diagnosis. Non-invasive methods for diagnosis are being explored, such as Raman spectroscopy and imaging modalities. Both ultrasound and dual-energy computed tomography (DECT) allow the detection of MSU crystals; this not only provides a mean of diagnosis, but also has furthered gout knowledge defining the presence of a preclinical deposition in asymptomatic hyperuricaemia. Scientific consensus establishes the beginning of gout as the beginning of symptoms (usually the first flare), but the concept is currently under review. For effective long-term gout management, the main goal is to promote crystal dissolution treatment by reducing serum urate below 6 mg/dL (or 5 mg/dL if faster crystal dissolution is required). Current urate-lowering therapies' (ULTs) options are limited, with allopurinol and febuxostat being widely available, and probenecid, benzbromarone, and pegloticase available in some regions. New xanthine oxidase inhibitors and, especially, uricosurics inhibiting urate transporter URAT1 are under development; it is probable that the new decade will see a welcomed increase in the gout therapeutic armamentarium. Cardiovascular and renal comorbidities are common in gout patients. Studies determining whether optimal treatment of gout will positively impact these comorbidities are currently lacking, but will hopefully be forthcoming. Overall, the single change that will most impact gout management is greater uptake of international rheumatology society recommendations. Innovative strategies, such as nurse-led interventions based on these recommendations have recently demonstrated treatment success for people with gout.

Lowering and Raising Serum Urate Levels: Off-Label Effects of Commonly Used Medications

Drug-induced hyperuricemia and gout present an increasingly prevalent problem in clinical practice. Herein, we review the urate-lowering or urate-raising effects of commonly used agents. We performed a PubMed search using the terms gout, urate, and medication, along with the specific agents/classes described herein. Reports were reviewed until 2022, and original studies were considered if they primarily or secondarily reported the effects of 1 or more drugs on serum urate level. Previous reviews were assessed for references to additional studies that described urate-altering effects of medications. Urate-changing drugs are summarized regarding their magnitude of effect, mechanism of action, and clinical significance. Potentially urate-lowering drugs include angiotensin II receptor blockers, calcium channel blockers, high-dose aspirin and salicylates, some nonsalicylate nonsteroidal anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, sodium-glucose cotransporter 2 inhibitors, statins, and fenofibrate. Potentially urate-increasing drugs discussed include diuretics, β-blockers, insulin, pyrazinamide, ethambutol, calcineurin inhibitors, low-dose aspirin, testosterone, and lactate. In patients who have or are at risk for hyperuricemia or gout, an increased awareness of drugs that affect serum urate level may allow for prescribing that effectively treats the indicated problem while minimizing adverse effects on hyperuricemia and gout.

Zhengqing fengtongning sustained-release tablets prevents gout flares in the process of ULT: A randomized, positive control, double-blind, double-simulation, multicenter trial

INTRODUCTION

When initiating urate-lowering therapy, using anti-inflammatory prophylaxis therapy for at least 3 to 6 months is strongly recommended. Previous studies have found that zhengqing fengtongning sustained-release tablets (sinomenine) can improve inflammation in the acute phase of gout; however, the efficacy of urate-lowering therapy in reducing frequency of acute flares still needs to be investigated. The aim of the present study is to explore the efficacy and safety of sinomenine for prophylaxis of acute flares when initiating urate-lowering therapy.

METHODS AND ANALYSIS

This randomized, placebo-controlled, double-blinded trial will include a total of 210 gout patients who meet the study criteria. The patients will be randomized (1:1) to the test group and the control group. The intervention is planned to be performed for 12 weeks with a follow-up of 12 weeks. All patients would be administered febuxostat (40 mg/d) and concomitant anti-inflammatory prophylaxis therapy. Sinomenine and colchicine placebo are administered in the sinomenine group, sinomenine placebo and colchicine are administered in the colchicine group. The primary outcome is the rate of acute gout flares in subjects within 12 weeks of the treatment period. The secondary outcomes include the times of acute gout flares and the duration of each acute flares within 12 weeks; the compliance rate in patients whose UA levels ≤6.0 mg/dL (360 μmol/L) at the weekend of 2nd, 4th, 8th, and 12th week in each group; the proportion of patients with ≥1 and ≥2 gout flares within 12 weeks; average visual analogue scale/score pain score during gout flares; and the oral dose of etoricoxib will be used to control the onset of acute flares within 12 weeks.

ETHICS AND DISSEMINATION

The Institutional Medical Ethics Committee have approved the trial protocol. We plan to publish the results of this study in a peer-reviewed journal.

TRIAL REGISTRATION

ChiCTR, ChiCTR2100045114, Registered 8 April 2021 http://www.chictr.org.cn/showproj.aspx?proj=124688.

One- and 2-year flare rates after treat-to-target and tight-control therapy of gout: results from the NOR-Gout study

OBJECTIVES

To explore the frequency and predictors of flares over 2 years during a treat-to-target strategy with urate-lowering therapy (ULT) in patients with gout.

METHODS

In the treat-to-target, tight control NOR-Gout study patients started ULT with escalating doses of allopurinol. Flares were recorded over 2 years. Baseline predictors of flares during months 9-12 in year 1 and during year 2 were analyzed by multivariable logistic regression.

RESULTS

Of 211 patients included (mean age 56.4 years, disease duration 7.8 years, 95% males), 81% (150/186) of patients experienced at least one gout flare during the first year and 26% (45/173) during the second year. The highest frequency of flares in the first year was seen during months 3-6 (46.8% of patients). Baseline crystal depositions detected by ultrasound and by dual-energy computed tomography (DECT) were the only variables which predicted flares both during the first period of interest at months 9-12 (OR 1.033; 95% CI 1.010-1.057, and OR 1.056; 95% CI 1.007-1.108) and also in year 2. Baseline subcutaneous tophi (OR 2.42, 95% CI 1.50-5.59) and prior use of colchicine at baseline (OR 2.48, 95% CI 1.28-4.79) were independent predictors of flares during months 9-12, whereas self-efficacy for pain was a protective predictor (OR 0.98 per unit, 95% CI 0.964-0.996).

CONCLUSIONS

In patients with gout, flares remain frequent during the first year of a treat-to-target ULT strategy, especially during months 3-6, but are much less frequent during year 2. Baseline crystal depositions predict flares over 2 years, supporting ULT early during disease course.

TRIAL REGISTRATION

ACTRN12618001372279.

OAT10/SLC22A13 Acts as a Renal Urate Re-Absorber: Clinico-Genetic and Functional Analyses With Pharmacological Impacts

Dysfunctional missense variant of organic anion transporter 10 (OAT10/SLC22A13), rs117371763 (c.1129C>T; p.R377C), is associated with a lower susceptibility to gout. OAT10 is a urate transporter; however, its physiological role in urate handling remains unclear. We hypothesized that OAT10 could be a renal urate re-absorber that will be a new molecular target of urate-lowering therapy like urate transporter 1 (URAT1, a physiologically-important well-known renal urate re-absorber) and aimed to examine the effect of OAT10 dysfunction on renal urate handling. For this purpose, we conducted quantitative trait locus analyses of serum urate and fractional excretion of uric acid (FE_UA) using samples obtained from 4,521 Japanese males. Moreover, we performed immunohistochemical and functional analyses to assess the molecular properties of OAT10 as a renal urate transporter and evaluated its potential interaction with urate-lowering drugs. Clinico-genetic analyses revealed that carriers with the dysfunctional OAT10 variant exhibited significantly lower serum urate levels and higher FE_UA values than the non-carriers, indicating that dysfunction of OAT10 increases renal urate excretion. Given the results of functional assays and immunohistochemical analysis demonstrating the expression of human OAT10 in the apical side of renal proximal tubular cells, our data indicate that OAT10 is involved in the renal urate reabsorption in renal proximal tubules from urine. Additionally, we found that renal OAT10 inhibition might be involved in the urate-lowering effect of losartan and lesinurad which exhibit uricosuric effects; indeed, losartan, an approved drug, inhibits OAT10 more strongly than URAT1. Accordingly, OAT10 can be a novel potential molecular target for urate-lowering therapy.

Gout. What's up doc?

A considerable improvement in the knowledge of gout has taken place in the 2decades of the XXIth century. Definitions of disease, estate, and clinical situations, along with a new nomenclature, have been agreed. More importantly, the concept of gout as a "curable" or "controllable" disease has been settled. We know for the first time its prevalence in Spain. Factors associated to disease, the genetics that condition the predisposition to develop hyperuricemia and the structure and functions of the transportome complex that control the renal and intestinal handling of urate have been examined. Imaging techniques have come to support diagnosis. Different primary therapeutic targets have been defined depending on the burden of disease, and targets for secondary prevention considered. We know how to best prescribe available medications and prevent the risk of adverse events. Finally, we have understood the importance of adherence, education, and empower patients during treatment instead of blaming them.

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.

Update of the current role of ultrasound in asymptomatic hyperuricemia. A systematic literature review

Ultrasound (US) is a recognized imaging modality for the assessment of gout. Recently it is being explored for its potential role in the evaluation of subjects with asymptomatic hyperuricemia (AH). Preliminary reports demonstrated the presence of monosodium urate (MSU)-crystal deposits including aggregates, double contour sign and/or tophi in both intra-articular and periarticular tissues of AH individuals. Although these results are exciting, the value and potential application of US in AH remain to be clearly delineated. In this systematic literature review, we aim to summarise the recent publications regarding the role of US in the assessment of AH. We analyzed possible application of US in the daily clinical practice and its future clinical and research potential in the evaluation of AH individuals.

Non-steroidal anti-inflammatory drugs for acute gout

BACKGROUND

Gout is an inflammatory arthritis resulting from the deposition of monosodium urate crystals in and around joints. Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat acute gout. This is an update of a Cochrane Review first published in 2014.

OBJECTIVES

To assess the benefits and harms of non-steroidal anti-inflammatory drugs (NSAIDs) (including cyclo-oxygenase-2 (COX-2) inhibitors (COXIBs)) for acute gout.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase for studies to 28 August 2020. We applied no date or language restrictions.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) and quasi-RCTs comparing NSAIDs with placebo or another therapy for acute gout. Major outcomes were pain, inflammation, function, participant-reported global assessment, quality of life, withdrawals due to adverse events, and total adverse events.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

We included in this update 28 trials (3406 participants), including 5 new trials. One trial (30 participants) compared NSAIDs to placebo, 6 (1244 participants) compared non-selective NSAIDs to selective cyclo-oxygenase-2 (COX-2) inhibitors (COXIBs), 5 (712 participants) compared NSAIDs to glucocorticoids, 13 compared one NSAID to another NSAID (633 participants), and single trials compared NSAIDs to rilonacept (225 participants), acupuncture (163 participants), and colchicine (399 participants). Most trials were at risk of selection, performance, and detection biases. We report numerical data for the primary comparison NSAIDs versus placebo and brief results for the two comparisons - NSAIDs versus COX-2 inhibitors and NSAIDs versus glucocorticoids. Low-certainty evidence (downgraded for bias and imprecision) from 1 trial (30 participants) shows NSAIDs compared to placebo. More participants (11/15) may have a 50% reduction in pain at 24 hours with NSAIDs than with placebo (4/15) (risk ratio (RR) 2.7, 95% confidence interval (CI) 1.1 to 6.7), with absolute improvement of 47% (3.5% more to 152.5% more). NSAIDs may have little to no effect on inflammation (swelling) after four days (13/15 participants taking NSAIDs versus 12/15 participants taking placebo; RR 1.1, 95% CI 0.8 to 1.5), with absolute improvement of 6.4% (16.8% fewer to 39.2% more). There may be little to no difference in function (4-point scale; 1 = complete resolution) at 24 hours (4/15 participants taking NSAIDs versus 1/15 participants taking placebo; RR 4.0, 95% CI 0.5 to 31.7), with absolute improvement of 20% (3.3% fewer to 204.9% more). NSAIDs may result in little to no difference in withdrawals due to adverse events (0 events in both groups) or in total adverse events; two adverse events (nausea and polyuria) were reported in the placebo group (RR 0.2, 95% CI 0.0, 3.8), with absolute difference of 10.7% more (13.2% fewer to 38% more). Treatment success and health-related quality of life were not measured. Moderate-certainty evidence (downgraded for bias) from 6 trials (1244 participants) shows non-selective NSAIDs compared to selective COX-2 inhibitors (COXIBs). Non-selective NSAIDs probably result in little to no difference in pain (mean difference (MD) 0.03, 95% CI 0.07 lower to 0.14 higher), swelling (MD 0.08, 95% CI 0.07 lower to 0.22 higher), treatment success (MD 0.08, 95% CI 0.04 lower to 0.2 higher), or quality of life (MD -0.2, 95% CI -6.7 to 6.3) compared to COXIBs. Low-certainty evidence (downgraded for bias and imprecision) suggests no difference in function (MD 0.04, 95% CI -0.17 to 0.25) between groups. Non-selective NSAIDs probably increase withdrawals due to adverse events (RR 2.3, 95% CI 1.3 to 4.1) and total adverse events (mainly gastrointestinal) (RR 1.9, 95% CI 1.4 to 2.8). Moderate-certainty evidence (downgraded for bias) based on 5 trials (712 participants) shows NSAIDs compared to glucocorticoids. NSAIDs probably result in little to no difference in pain (MD 0.1, 95% CI -2.7 to 3.0), inflammation (MD 0.3, 95% CI 0.07 to 0.6), function (MD -0.2, 95% CI -2.2 to 1.8), or treatment success (RR 0.9, 95% CI 0.7 to 1.2). There was no difference in withdrawals due to adverse events with NSAIDs compared to glucocorticoids (RR 2.8, 95% CI 0.5 to 14.2). There was a decrease in total adverse events with glucocorticoids compared to NSAIDs (RR 1.6, 95% CI 1.0 to 2.5).

AUTHORS' CONCLUSIONS

Low-certainty evidence from 1 placebo-controlled trial suggests that NSAIDs may improve pain at 24 hours and may have little to no effect on function, inflammation, or adverse events for treatment of acute gout. Moderate-certainty evidence shows that COXIBs and non-selective NSAIDs are probably equally beneficial with regards to improvement in pain, function, inflammation, and treatment success, although non-selective NSAIDs probably increase withdrawals due to adverse events and total adverse events. Moderate-certainty evidence shows that systemic glucocorticoids and NSAIDs probably are equally beneficial in terms of pain relief, improvement in function, and treatment success. Withdrawals due to adverse events were also similar between groups, but NSAIDs probably result in more total adverse events. Low-certainty evidence suggests no difference in inflammation between groups. Only low-certainty evidence was available for the comparisons NSAID versus rilonacept and NSAID versus acupuncture from single trials, or one NSAID versus another NSAID, which also included many NSAIDs that are no longer in clinical use. Although these data were insufficient to support firm conclusions, they do not conflict with clinical guideline recommendations based upon evidence from observational studies, findings for other inflammatory arthritis, and expert consensus, all of which support the use of NSAIDs for acute gout.

Gut Microbiota Characterization in Patients with Asymptomatic Hyperuricemia: probiotics increased

Asymptomatic hyperuricemia (AH) is an early stage of gout. Emerging evidence shows that the intestinal microbiota is related to gout. However, the relationship between AH and the intestinal microbiota is poorly understood. Therefore, the aim of the current study was to explore the possible correlation between AH and intestinal flora. We compared the intestinal microbial communities of AH (45 cases) and healthy subjects (45 cases) by 16S rRNA gene sequencing and clustering analysis on the incorporated population. Intestinal-type clustering can be divided into two groups, and significant differences in the proportion of AH are found among different bowel types. Alpha diversity indices were higher in the AH group than in the control group, and beta diversity indices also showed significant differences. A total of 19 genera were found different between the AH group and the control group. Compared with the control group, some probiotics are increased in the AH population. Two groups were ranked by importance of bacteria. We found the different bacteria partially coincided with the important bacteria, and the joint diagnosis level of the important bacteria was good. Conclusion: There were significant differences in the composition of intestinal biota between AH patients and healthy subjects. Some probiotics increased in AH.

Denosumab did not improve computerized tomography erosion scores when added to intensive urate-lowering therapy in gout: Results from a pilot randomized controlled trial

BACKGROUND/PURPOSE

Disordered osteoclast activity has been implicated in the pathogenesis of gouty bone erosion. We sought to determine if the addition of denosumab (a monoclonal antibody targeting the receptor activator of nuclear factor kappa-B ligand - RANKL) to intensive urate-lowering therapy (ULT) improves gouty bone erosion.

METHODS

Open-label, parallel-group pilot randomized controlled trial in which 20 participants with gout with at least one confirmed conventional radiographic foot bone erosion were assigned in a 1:1 allocation to receive denosumab (60 mg subcutaneous every 6 months) added to intensive ULT (serum urate ≤5 mg/dL or 300 µmol/L at the time of randomization and continued for the duration of the study), or intensive ULT alone. The primary outcome was the change in the bilateral foot and ankle computed tomography (CT) bone erosion score from baseline to 12 months, assessed by an experienced musculoskeletal radiologist blinded to study assignment. Secondary outcomes included change in serum C-terminal telopeptide (CTX), and patient reported outcomes of pain and function.

RESULTS

Although serum CTX declined markedly in the denosumab/ULT group compared with the ULT alone group, there was no interval change in CT erosion score in either the denosumab/ULT or ULT alone group after one year of follow-up. Other secondary outcomes did not differ between groups. There were two severe adverse events: One patient developed atrial fibrillation (on denosumab/ULT) and another atrial flutter (on ULT alone).

CONCLUSIONS

In this pilot study, denosumab did not offer additional benefit to intensive urate lowering therapy for gouty bone erosion.

The role of dual energy computed tomography in the differentiation of acute gout flares and acute calcium pyrophosphate crystal arthritis

Objectives

To analyse the diagnostic impact of dual energy computed tomography (DECT) in acute gout flares and acute calcium pyrophosphate (CPP) crystal arthritis when compared to the gold standard of arthrocentesis with compensated polarised light microscopy. Microscopy results were also compared to musculoskeletal ultrasound (MUS), conventional radiographs, and the suspected clinical diagnosis (SCD).

Methods

Thirty-six patients with a suspected gout flare (n = 24) or acute CPP crystal arthritis (n = 11, n = 1 suffered from neither) who received a DECT and underwent arthrocentesis were included. Two independent readers assessed DECT images for signs of monosodium urate crystals or calcium pyrophosphate deposition.

Results

Sensitivity of DECT for gout was 63% (95% CI 0.41–0.81) with a specificity of 92% (0.41–0.81) while sensitivity and specificity for acute CPP arthritis were 55% (0.23–0.83) and 92% (0.74–0.99), respectively. MUS had the highest sensitivity of all imaging modalities with 92% (0.73–0.99) and a specificity of 83% (0.52–0.98) for gout, while sensitivity and specificity for acute CPP crystal arthritis were 91% (0.59–1.00) and 92% (0.74–0.99), respectively.

Conclusion

DECT is an adequate non-invasive diagnostic tool for acute gout flares but might have a lower sensitivity than described by previous studies. Both MUS and SCD had higher sensitivities than DECT for acute gout flares and acute CPP crystal arthritis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10067-021-05949-4.

Management of gout in chronic kidney disease: a G-CAN Consensus Statement on the research priorities

Gout and chronic kidney disease (CKD) frequently coexist, but quality evidence to guide gout management in people with CKD is lacking. Use of urate-lowering therapy (ULT) in the context of advanced CKD varies greatly, and professional bodies have issued conflicting recommendations regarding the treatment of gout in people with concomitant CKD. As a result, confusion exists among medical professionals about the appropriate management of people with gout and CKD. This Consensus Statement from the Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN) discusses the evidence and/or lack thereof for the management of gout in people with CKD and identifies key areas for research to address the challenges faced in the management of gout and CKD. These discussions, which address areas for research both in general as well as related to specific medications used to treat gout flares or as ULT, are supported by separately published G-CAN systematic literature reviews. This Consensus Statement is not intended as a guideline for the management of gout in CKD; rather, it analyses the available literature on the safety and efficacy of drugs used in gout management to identify important gaps in knowledge and associated areas for research.

Characteristic dysbiosis in gout and the impact of a uric acid-lowering treatment, febuxostat on the gut microbiota

Gut dysbiosis is suggested to play a critical role in the pathogenesis of gout. The aim of our study was to identify the characteristic dysbiosis of the gut microbiota in gout patients and the impact of a commonly used uric acid-lowering treatment, febuxostat on gut microbiota in gout. 16S ribosomal RNA sequencing and metagenomic shotgun sequencing was performed on fecal DNA isolated from 38 untreated gout patients, 38 gout patients treated with febuxostat, and 26 healthy controls. A restriction of gut microbiota biodiversity was detected in the untreated gout patients, and the alteration was partly restored by febuxostat. Biochemical metabolic indexes involved in liver and kidney metabolism were significantly associated with the gut microbiota composition in gout patients. Functional analysis revealed that the gut microbiome of gout patients had an enriched function on carbohydrate metabolism but a lower potential for purine metabolism, which was comparatively enhanced in the febuxostat treated gout patients. A classification microbial model obtained a high mean area under the curve up to 0.973. Therefore, gut dysbiosis characterizings gout could potentially serve as a noninvasive diagnostic tool for gout and may be a promising target of future preventive interventions.

Variation in serum urate levels in the absence of gout and urate lowering therapy

BACKGROUND

Previous studies have noted significant variation in serum urate (sUA) levels, and it is unknown how this influences the accuracy of hyperuricemia classification based on single data points. Despite this known variability, hyperuricemic patients are often used as a control group in gout studies. Our objective was to determine the accuracy of hyperuricemia classifications based on single data points versus multiple data points given the degree of variability observed with serial measurements of sUA.

METHODS

Data was analyzed from a cross-over clinical trial of urate-lowering therapy in young adults without a gout diagnosis. In the control phase, sUA levels used for this analysis were collected at 2-4 week intervals. Mean coefficient of variation for sUA was determined, as were rates of conversion between normouricemia (sUA ≤6.8 mg/dL) and hyperuricemia (sUA > 6.8 mg/dL).

RESULTS

Mean study participant (n = 85) age was 27.8 ± 7.0 years, with 39% female participants and 41% African-American participants. Mean sUA coefficient of variation was 8.5% ± 4.9% (1 to 23%). There was no significant difference in variation between men and women, or between participants initially normouricemic and those who were initially hyperuricemic. Among those initially normouricemic (n = 72), 21% converted to hyperuricemia during at least one subsequent measurement. The subgroup with initial sUA < 6.0 (n = 54) was much less likely to have future values in the range of hyperuricemia compared to the group with screening sUA values between 6.0-6.8 (n = 18) (7% vs 39%, p = 0.0037). Of the participants initially hyperuricemic (n = 13), 46% were later normouricemic during at least one measurement.

CONCLUSION

Single sUA measurements were unreliable in hyperuricemia classification due to spontaneous variation. Knowing this, if a single measurement must be used in classification, it is worth noting that those with an sUA of < 6.0 mg/dL were less likely to demonstrate future hyperuricemic measurements and this could be considered a safer threshold to rule out intermittent hyperuricemia based on a single measurement point.

TRIAL REGISTRATION

Data from parent study ClinicalTrials.gov Identifier: NCT02038179 .

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.