Burden of gout among different WHO regions, 1990-2019: estimates from the global burden of disease study.

The global incidence of gout has increased rapidly, likely secondary to the increase in the prevalence of conditions that predispose to gout, such as obesity. Depending on the population studied, the prevalence of gout ranges from less than 1 to 6.8%. Thus, gout can be a significant burden on healthcare systems. The objective of this study is to observe the trends in the incidence, prevalence, and disability-adjusted life years (DALYs) of gout between 1990 and 2019 globally and in the European Union (EU) 15+ nations. We extracted data from the Global Burden of Disease Study database based on the International Classification of Diseases (ICD) versions 10 and 9. Incidence, prevalence, and disability-adjusted life years (DALYs) were extracted for individual EU15+ countries and globally in males and females between 1990 and 2019. Joinpoint regression analysis was used to describe trends. Between 1990 and 2019, gout prevalence, incidence, and DALYs increased in both males (+ 21.42%, + 16.87%, + 21.49%, respectively) and females (+ 21.06%, + 18.75%, + 20.66%, respectively) globally. The United States of America had the highest increase in prevalence (males: + 90.6%; females + 47.1%), incidence (males: + 63.73%; females: + 39.11%) and DALYs (males: + 90.43%; females: + 42.75%). Incidence, prevalence, and DALYs from gout are increasing worldwide and in most of the EU15+ countries for males and females. Studies have reported the association of gout with comorbidities such as metabolic syndrome, diabetes mellitus, and cardiovascular disease. Health policies and resource allocation are required to increase awareness and modify risk factors globally.

Clinical implications of persistent joint pain after gout flare.

OBJECTIVES: A subset of gout patients developed persistent joint pain after flares. Analysis of this clinical phenomenon may shed further light on the factors related to worsening gout and even provide clues to its pathogenesis. METHODS: We analyzed the clinical, laboratory, and ultrasound data of gout patients to explore the associations of these data with persistent joint pain after gout flares. RESULTS: A total of 1029 gout patients were included: 182 (17.7%) patients with persistent joint pain and 847 (82.3%) patients with nonpersistent joint pain. Patients with persistent joint pain had more total involved joints, more gout flares in the past year, and more joints with simultaneous gout flares (P<0.01). Among the ultrasound-detected lesions, patients with persistent joint pain had a higher incidence of tophus (36.4% vs. 21.1%) and bone erosion (18.6% vs. 8.6%) (P<0.05). Higher UA and lower TBil were found in patients with persistent joint pain (P<0.001). Hypertension (54.9% vs. 38.7%) and metabolic syndrome (58.8% vs. 46.4%) were both more frequent in patients with persistent joint pain (P<0.05). TBil was negatively correlated with the incidence of persistent joint pain (P<0.001, r=-0.190), UA values (P<0.001, r=-0.125), and metabolic syndrome scores (P<0.001, r=-0.192). A correlation curve was fitted using LOESS (locally weighted region). CONCLUSION: Persistent joint pain after gout flares is a marker of increased disease burden in gout. The significance of the level of total bilirubin for the exacerbation of gout deserves further study.

Associations of Circulating Biomarkers with Disease Risks: A Two-Sample Mendelian Randomization Study.

Circulating biomarkers play a pivotal role in personalized medicine, offering potential for disease screening, prevention, and treatment. Despite established associations between numerous biomarkers and diseases, elucidating their causal relationships is challenging. Mendelian Randomization (MR) can address this issue by employing genetic instruments to discern causal links. Additionally, using multiple MR methods with overlapping results enhances the reliability of discovered relationships. Here, we report an MR study using multiple methods, including inverse variance weighted, simple mode, weighted mode, weighted median, and MR-Egger. We use the MR-base resource (v0.5.6) from Hemani et al. 2018 to evaluate causal relationships between 212 circulating biomarkers (curated from UK Biobank analyses by Neale lab and from Shin et al. 2014, Roederer et al. 2015, and Kettunen et al. 2016 and 99 complex diseases (curated from several consortia by MRC IEU and Biobank Japan). We report novel causal relationships found by four or more MR methods between glucose and bipolar disorder (Mean Effect Size estimate across methods: 0.39) and between cystatin C and bipolar disorder (Mean Effect Size: -0.31). Based on agreement in four or more methods, we also identify previously known links between urate with gout and creatine with chronic kidney disease, as well as biomarkers that may be causal of cardiovascular conditions: apolipoprotein B, cholesterol, LDL, lipoprotein A, and triglycerides in coronary heart disease, as well as lipoprotein A, LDL, cholesterol, and apolipoprotein B in myocardial infarction. This Mendelian Randomization study not only corroborates known causal relationships between circulating biomarkers and diseases but also uncovers two novel biomarkers associated with bipolar disorder that warrant further investigation. Our findings provide insight into understanding how biological processes reflecting circulating biomarkers and their associated effects may contribute to disease etiology, which can eventually help improve precision diagnostics and intervention.

Gout: A Rapid Review of Presentation, Diagnosis and Management.

Gout is inflammatory arthritis caused by monosodium urate crystal deposition in articular and non-articular structures. Acute gout flares are often monoarticular/polyarticular involving lower extremity joints characteristically involving 1st metatarsophalangeal joint. However, gout flares can also be polyarticular, involving upper extremity joints, especially in patients with multiple comorbidities and contraindications to urate-lowering therapies (ULT). Risk factors exacerbating gout flares include obesity, high alcohol and purine-rich food consumption, and the use of diuretics. Diagnosis requires synovial fluid analysis with direct visualization of monosodium urate crystals. Acute flares are managed with steroids, non-steroidal anti-inflammatory drugs, or colchicine. Long-term management includes lifestyle modifications including a heavy emphasis on weight loss, avoidance of alcohol, purine-rich foods, and diuretics. ULT is indicated in patients with 2 or more gout flares/year, tophi, or radiographic evidence of gouty arthropathy. Although allopurinol is the first-line ULT agent, it does carry a risk of inducing severe cutaneous adverse reactions, especially in patients with chronic kidney disease and patients harboring the HLA-B*5801 allele. Other ULT agents include febuxostat and probenecid. ULT is usually titrated to achieve goal serum uric acid (SUA) levels below 6 mg/dL. However, in patients with tophi, a lower SUA target of less than 5 mg/dL should be implemented for prompt urate crystal dissolution.

Associations of oxidative balance score with hyperuricemia and gout among American adults: a population-based study.

Objective: The current study aimed to assess the relationships between oxidative balance score (OBS) and OBS subclasses (dietary and lifestyle OBS) with risks of hyperuricemia (HUA) and gout among American adults. Methods: Participants in the National Health and Nutrition Examination Survey from 2007 to 2018 were initially recruited and then the final sample was restricted to adults without missing values about serum uric acid, gout, OBS, and covariates. Rao-Scott adjusted chi-square test and analysis of variance were utilized to compare the baseline characteristics in adults of different quartiles of OBS, while the weighted stepped logistic regression models were used to explore the associations of overall, dietary, and lifestyle OBS with the risks of HUA and gout. Weighted restricted cubic spline analyses were conducted to explore the nonlinear dose-response associations. Results: The final sample consisted of 22,705 participants aged 20 years and older, which was representative of approximately 197.3 million non-institutionalized American adults. HUA and gout prevalence decreased with OBS quartiles. Compared with adults in the first quartile of OBS, those in the second (OR: 0.85, 95% CI: 0.72-0.99), third (OR: 0.71, 95% CI: 0.58-0.85), and fourth (OR: 0.48, 95% CI: 0.38-0.61) quartiles of OBS had reduced risks of hyperuricemia. Similarly, adults in the second (OR: 0.70, 95% CI: 0.51-0.97) quartile of OBS was associated with lower gout risk in comparison to adults in the lowest quartile. Regarding OBS subclasses, dietary and lifestyle OBS were both negatively correlated with the risk of HUA, and only higher lifestyle OBS was significantly associated with lower gout risk. Furthermore, the subgroup analyses and interaction effects also substantiated similar effects. Significant nonlinear dose-response relationships were observed between overall, dietary, and lifestyle OBS with HUA risk as well as that of lifestyle OBS with gout risk. Conclusion: This study strongly suggests the significant negative associations of OBS with HUA and gout in American adults and provides a dietary and lifestyle guideline to reduce the risks.

Association between oxidative balance score and risk of gout: The NHANES cross-sectional study, 2007-2018.

BACKGROUND: The Oxidative Balance Score (OBS) is a systematic tool to assess the effects of diet and lifestyle in relation to oxidative stress. The association between OBS and gout has not been reported previously. We conducted a cross-sectional study to investigate the complex association between OBS and gout in US adults. METHODS: In all, 10 492 participants were included in this study. The exposure variable was OBS, which was scored by 16 dietary and four lifestyle factors. Multivariate logistic regression, subgroup analysis, and restricted cubic spline (RCS) regression were used to analyze the association between OBS and gout. RESULTS: Compared with the lowest OBS quartile group (Q1), the multivariate corrected odds ratio (OR) (95% confidence interval [C]) for the highest quartile of OBS (Q4) was 0.72 (0.52-1.00) (p = .13 for trend); furthermore, the RCS showed a negative linear relationship between OBS and gout (p-nonlinear = .606). CONCLUSION: In conclusion, the risk of gout is higher with high OBS. The prevalence of gout decreased with higher OBS. Diabetes may alter this negative correlation.

Unraveling the pathological biomineralization of monosodium urate crystals in gout patients.

Crystallization of monosodium urate monohydrate (MSU) leads to painful gouty arthritis. Despite extensive research it is still unknown how this pathological biomineralization occurs, which hampers its prevention. Here we show how inflammatory MSU crystals form after a non-inflammatory amorphous precursor (AMSU) that nucleates heterogeneously on collagen fibrils from damaged articular cartilage of gout patients. This non-classical crystallization route imprints a nanogranular structure to biogenic acicular MSU crystals, which have smaller unit cell volume, lower microstrain, and higher crystallinity than synthetic MSU. These distinctive biosignatures are consistent with the template-promoted crystallization of biotic MSU crystals after AMSU at low supersaturation, and their slow growth over long periods of time (possibly years) in hyperuricemic gout patients. Our results help to better understand gout pathophysiology, underline the role of cartilage damage in promoting MSU crystallization, and suggest that there is a time-window to treat potential gouty patients before a critical amount of MSU has slowly formed as to trigger a gout flare.

Causal impact of human blood metabolites and metabolic pathways on serum uric acid and gout: a mendelian randomization study.

Objective: Hyperuricaemia and gout are common metabolic disorders. However, the causal relationships between blood metabolites and serum urate levels, as well as gout, remain unclear. A systematic evaluation of the causal connections between blood metabolites, hyperuricemia, and gout could enhance early screening and prevention of hyperuricemia and gout in clinical settings, providing novel insights and approaches for clinical treatment. Methods: In this study, we employed a bidirectional two-sample Mendelian randomization analysis utilizing data from a genome-wide association study involving 7,286 participants, encompassing 486 blood metabolites. Serum urate and gout data were sourced from the Chronic Kidney Disease Genetics consortium, including 288,649 participants for serum urate and 9,819 African American and 753,994 European individuals for gout. Initially, LDSC methodology was applied to identify blood metabolites with a genetic relationship to serum urate and gout. Subsequently, inverse-variance weighting was employed as the primary analysis method, with a series of sensitivity and pleiotropy analyses conducted to assess the robustness of the results. Results: Following LDSC, 133 blood metabolites exhibited a potential genetic relationship with serum urate and gout. In the primary Mendelian randomization analysis using inverse-variance weighting, 19 blood metabolites were recognized as potentially influencing serum urate levels and gout. Subsequently, the IVW p-values of potential metabolites were corrected using the false discovery rate method. We find leucine (IVW P FDR = 0.00004), N-acetylornithine (IVW P FDR = 0.0295), N1-methyl-3-pyridone-4-carboxamide (IVW P FDR = 0.0295), and succinyl carnitine (IVW P FDR = 0.00004) were identified as significant risk factors for elevated serum urate levels. Additionally, 1-oleoylglycerol (IVW P FDR = 0.0007) may lead to a substantial increase in the risk of gout. Succinyl carnitine exhibited acceptable weak heterogeneity, and the results for other blood metabolites remained robust after sensitivity, heterogeneity, and pleiotropy testing. We conducted an enrichment analysis on potential blood metabolites, followed by a metabolic pathway analysis revealing four pathways associated with serum urate levels. Conclusion: The identified causal relationships between these metabolites and serum urate and gout offer a novel perspective, providing new mechanistic insights into serum urate levels and gout.

Imaging of Rheumatic Diseases Affecting the Lower Limb.

Imaging methods capable of detecting inflammation, such as MR imaging and ultrasound, are of paramount importance in rheumatic disease management, not only for diagnostic purposes but also for monitoring disease activity and treatment response. However, more advanced stages of arthritis, characterized by findings of cumulative structural damage, have traditionally been accomplished by radiographs and computed tomography. The purpose of this review is to provide an overview of imaging of some of the most prevalent inflammatory rheumatic diseases affecting the lower limb (osteoarthritis, rheumatoid arthritis, and gout) and up-to-date recommendations regarding imaging diagnostic workup.

Virtual noncontrast images reveal gouty tophi in contrast-enhanced dual-energy CT: a phantom study.

BACKGROUND: Dual-energy computed tomography (DECT) is useful for detecting gouty tophi. While iodinated contrast media (ICM) might enhance the detection of monosodium urate crystals (MSU), higher iodine concentrations hamper their detection. Calculating virtual noncontrast (VNC) images might improve the detection of enhancing tophi. The aim of this study was to evaluate MSU detection with VNC images from DECT acquisitions in phantoms, compared against the results with standard DECT reconstructions. METHODS: A grid-like and a biophantom with 25 suspensions containing different concentrations of ICM (0 to 2%) and MSU (0 to 50%) were scanned with sequential single-source DECT using an ascending order of tube current time product at 80 kVp (16.5-220 mAs) and 135 kVp (2.75-19.25 mAs). VNC images were equivalently reconstructed at 80 and 135 kVp. Two-material decomposition analysis for MSU detection was applied for the VNC and conventional CT images. MSU detection and attenuation values were compared in both modalities. RESULTS: For 0, 0.25, 0.5, 1, and 2% ICM, the average detection indices (DIs) for all MSU concentrations (35-50%) with VNC postprocessing were respectively 25.2, 36.6, 30.9, 38.9, and 45.8% for the grid phantom scans and 11.7, 9.4, 5.5, 24.0, and 25.0% for the porcine phantom scans. In the conventional CT image group, the average DIs were respectively 35.4, 54.3, 45.4, 1.0, and 0.0% for the grid phantom and 19.4, 17.9, 3.0, 0.0, and 0.0% for the porcine phantom scans. CONCLUSIONS: VNC effectively reduces the suppression of information caused by high concentrations of ICM, thereby improving the detection of MSU. RELEVANCE STATEMENT: Contrast-enhanced DECT alone may suffice for diagnosing gout without a native acquisition. KEY POINTS: • Highly concentrated contrast media hinders monosodium urate crystal detection in CT imaging • Virtual noncontrast imaging redetects monosodium urate crystals in high-iodinated contrast media concentrations. • Contrast-enhanced DECT alone may suffice for diagnosing gout without a native acquisition.

Lower plasma linoleic acids as a risk factor for gout: an integrated analysis of population-based cohort and genetic data.

Background: Gout is a nutrition-related, highly prevalent inflammatory arthritis with undesirable effects on the quality of life. The relationships between circulating fatty acids (FAs) and gout remain poorly understood. Method: We included 268 174 participants with plasma FAs measured using nuclear magnetic resonance at the baseline (2006-2010) from the UK Biobank, of which 15 194 participants had repeated measures of FAs between 2012 and 2013. Cox proportional hazards models were used to assess the association of the baseline and longitudinal changes in relative levels of plasma FAs (% total FAs) with incident gout. Mendelian randomization (MR) analyses were conducted to assess the potential causality of the examined association. Results: Over a median follow-up of 12.8 years, 5160 incident cases of gout occurred. Baseline polyunsaturated fatty acids (PUFAs), n-6 PUFAs, and linoleic acids (LAs) were inversely associated with incident gout (all P-trend values < 0.0001). Baseline monounsaturated fatty acids (MUFAs), n-3 PUFAs, and docosahexaenoic acids (DHAs) were positively associated with incident gout (all P-trend values < 0.0001). Longitudinal increments of n-6 PUFAs and LAs were associated with a lower risk of subsequent gout, whereas an increment of n-3 PUFAs was associated with a higher risk. In two-sample MR analyses, genetically determined higher levels of PUFAs, n-6 PUFAs, and LAs were associated with a decreased risk of gout (all P values < 0.05). Conclusions: Our findings consistently indicate a causal relationship of elevated levels of n-6 PUFAs, especially LAs, with a reduced risk of gout.

Diastolic and systolic blood pressure and gout: a Mendelian randomization study.

Background: Although there is solid epidemiological evidence supporting the connection between hypertension and gout, little has been said about the relationship between diastolic and systolic blood pressure and gout, the causal relationship and direction associated are uncertain, so we aim to research the causal relationship between diastolic and systolic blood pressure and gout. Methods: We conducted a two-sample Mendelian randomization (MR) analysis to assess the causal effect between 2 blood pressure phenotypes (including diastolic blood pressure and systolic blood pressure) and 5 gout phenotypes (including gout, drug-induced gout, idiopathic gout, unspecified gout, and strictly defined gout) using genome-wide association study statistics. The inverse variance weighting method was used to generate the main results, while sensitivity analyses using MR-Egger, weighted median, Cochran's Q test, Egger intercept test, and leave-one-out analysis, were performed to assess the stability and reliability of the results. Results: After the screening, we found a causal relationship between diastolic blood pressure and gout, idiopathic gout, unspecified gout, and strictly defined gout, and a causal relationship between systolic blood pressure and gout, idiopathic gout, unspecified gout, and strictly defined gout. Conclusion: From a genetic predisposition, controlling blood pressure may reduce the risk of gout.

Structural basis for urate recognition and apigenin inhibition of human GLUT9.

Urate, the physiological form of uric acid and a potent antioxidant in serum, plays a pivotal role in scavenging reactive oxygen species. Yet excessive accumulation of urate, known as hyperuricemia, is the primary risk factor for the development of gout. The high-capacity urate transporter GLUT9 represents a promising target for gout treatment. Here, we present cryo-electron microscopy structures of human GLUT9 in complex with urate or its inhibitor apigenin at overall resolutions of 3.5 Å and 3.3 Å, respectively. In both structures, GLUT9 exhibits an inward open conformation, wherein the substrate binding pocket faces the intracellular side. These structures unveil the molecular basis for GLUT9's substrate preference of urate over glucose, and show that apigenin acts as a competitive inhibitor by occupying the substrate binding site. Our findings provide critical information for the development of specific inhibitors targeting GLUT9 as potential therapeutics for gout and hyperuricemia.

Benefits of uric acid-lowering medication after bariatric surgery in patients with gout.

BACKGROUND/PURPOSE: Patients with gout are at risk for increased serum uric acid (SUA) levels and gout attacks in the short term after undergoing bariatric surgery, and the purpose of this study was to evaluate the benefits of short-term treatment with uric acid-lowering medication after bariatric surgery for the control of gout attacks and SUA levels in patients with gout. METHODS: 71 patients who underwent SG from January 2020 to December 2022 were prospectively included. These patients were diagnosed with hyperuricemia before surgery and had a history of gout attacks. Patients were classified into a drug-treatment group (DTG, n = 32) and a non-drug-treatment group (NDTG, n = 39) according to whether they took uric acid-lowering medication after surgery. Changes in the number of gout attacks, body mass index (BMI), and SUA levels at 1 week, 1 month, 3 months, and 6 months after bariatric surgery were measured in both groups. RESULTS: In the DTG, 22 patients (68.8%) experienced an increase in SUA within 1 week, 3 patients (9.4%) had an acute attack of gout within the first month, and no patients had a gout attack thereafter. In the NDTG, 35 patients (89.7%) experienced an increase in SUA within 1 week, 7 patients (17.9%) had an acute gout attack within the first month, and 4 patients (10.3%) experienced gout attacks between month 1 and month 3 postoperatively. Both groups were free of gout attacks between the 3rd and 6th postoperative month and showed a significant decrease in SUA and BMI by the sixth month. CONCLUSION: In patients with gout, continued use of uric acid-lowering medication after bariatric surgery is beneficial in reducing the number of gout attacks and the risk of rising SUA.

Concomitant septic and crystal arthropathy: a single-centre 10-year retrospective observational study in New Zealand.

AIM: To quantify and characterise patients with coexistent septic arthritis (SA) and crystal arthritis (CA) (SACA) in an emergency department (ED) setting. METHODS: A single-centre, retrospective, 10-year observational study was conducted at a major referral centre. Patients with a positive joint aspirate for CA or SA carried out in ED, were included. The Newman criteria were utilised to define SA. RESULTS: Of the 567 patients included in the final analysis, 427 had CA and 140 had a final diagnosis of SA. Twenty-three point six percent of patients diagnosed with SA had concomitant CA, while 7.2% of patients diagnosed with CA had concomitant SA. The greatest predisposing factors for SACA were previous history of gout, rheumatoid arthritis, being immunocompromised or having joint metalware. Synovial fluid (SF) white cell count (WCC) showed excellent predictive capability for joint infection with the area under the receiver operating characteristic curves (AUROCs) of 0.81 and 0.87 for SA and SACA respectively. The receiver operating characteristic curves (ROCs) reported a SF WCC cutoff of 32,000/mm3 allowed for 100% sensitivity and approximately 50% specificity. CONCLUSIONS: SACA remains a small but important sub-group of patients at risk of misdiagnosis of CA alone. SF WCC of 32,000/mm3 may be a better cutoff than the traditionally accepted 50,000/mm3, possibly warranting inpatient admission for investigation and management of presumed SA.

Urate-lowering therapy in patients with hyperuricemia and heart failure: A retrospective cohort study using the UK Clinical Practice Research Datalink.

BACKGROUND: Elevated serum uric acid (sUA) is associated with heart failure (HF). HYPOTHESIS: Urate-lowering therapy (ULT) in HF is associated with lower risk of HF hospitalization (hHF) and mortality. METHODS: Data on patients with HF and gout or hyperuricemia in the Clinical Practice Research Datalink database linked to the Hospital Episode Statistics and the Office for National Statistics in the United Kingdom were analyzed. Risks of hHF and all-cause mortality or cardiovascular-related mortality by ULT exposure (ULT initiated within ≤6 months of gout or hyperuricemia diagnosis) were analyzed in a propensity score-matched cohort using adjusted Cox proportional hazards regression models. RESULTS: Of 2174 propensity score-matched pairs, patients were predominantly male, aged >70 years, with mean ± standard deviation sUA 9.3 ± 1.8 (ULT-exposed) and 9.4 ± 1.9 mg/dL (ULT-unexposed). At 5 years, ULT-exposed patients had a 43% lower risk of hHF or all-cause mortality (adjusted hazard ratio [HR]: 0.57; 95% confidence interval [CI]: 0.51-0.65) and a 19% lower risk of hHF or cardiovascular-related mortality (adjusted HR: 0.81; 95% CI: 0.71-0.92) versus no ULT exposure. CONCLUSION: ULT was associated with reduced risk of adverse clinical outcomes in patients with HF and gout or hyperuricemia over 5 years.