The economic burden of gout: A systematic review

Characteristics and Management of Uncontrolled Gout Prior to Pegloticase Therapy: A 2-year Claims Analysis

OBJECTIVE

Gout is a progressive form of arthritis that causes significant pain and disability. Patients with treatment-refractory (or uncontrolled) gout experience a higher prevalence and severity of comorbidities than those whose gout is controlled. Pegloticase is a recombinant PEGylated uricase indicated for the treatment of gout in patients refractory to conventional therapy. We evaluated the treatment journey of patients with chronic uncontrolled gout before initiation of pegloticase therapy.

METHODS

Using IQVIA's PharMetrics® Plus database, we conducted a retrospective observational analysis of adults with ≥ 1 pegloticase claim between April 1, 2011, and August 31, 2020. Demographics were assessed at baseline. Clinical outcomes, health care resource utilization (HCRU), and associated costs were compared over two 12-month periods (months 13-24 and 1-12) prior to the first pegloticase claim (index date).

RESULTS

The study included 408 patients. Prevalence of all gout-associated conditions increased between months 1-12 and 13-24 (P < 0.05 for all). The percentage of patients with tophi increased from 15.4% to 61.5%, the percentage with ≥ 1 flare increased from 49% to 84%, and mean number of flares per patient increased from 1.0 to 2.1 (P < 0.0001 for all). The frequency of all categories of HCRU except emergency department visits also increased (P < 0.0001 for all), as did gout-related healthcare utilization (P£0.005).

CONCLUSIONS

Patients with uncontrolled gout experienced an increase in the clinical burden of disease and HCRU in the 2 years before the initiation of pegloticase. Earlier patient identification and initiation of potentially effective therapy may help alleviate these burdens.

Exploring the associations and potential mediators between lipid biomarkers and the risk of developing gout: NHANES 2007-2018

BACKGROUND

Gout stands as a prevailing manifestation of inflammatory arthritis. While it is linked to several well-established risk factors, the associations between lipid profiles and the risk of gout remain unclear.

METHODS

This research involved National Health and Nutrition Examination Survey data (2007-2018). The cardiometabolic index, which incorporates the Triglycerides (TG)/High-density lipoprotein cholesterol (HDL) ratio and waist to height ratio (WHtR), was used to assess lipid profiles and metabolic health. Multivariate logistic regression analysis, propensity score matching, and mediation analyses were utilized to evaluate the associations of lipid profiles and the cardiometabolic index with the risk of developing gout.

RESULTS

Among 11,032 participants, each 1-unit increase in TG levels was associated with a 65% increase in the odds of developing gout before matching [1.65 (1.15-2.38), P = 0.007] and a 155% increase in the odds of developing gout after matching [2.55 (1.59-4.09), P = 0.007]. Each 1-unit increase in the cardiometabolic index was linked to an 81% increase in the odds of developing gout before matching [1.81 (1.22-2.70), P = 0.004] and a 215% increase in the odds of developing gout after matching [3.15 (1.84-5.40), P < 0.001]. The participants with HDL levels in the third quartile presented a 35% reduction in gout risk relative to those with HDL levels in the first quartile before matching [0.65 (0.46-0.92), P = 0.014] and a 51% reduction in gout risk after matching [0.49 (0.32-0.75), P < 0.001]. Mediation analyses revealed that BMI, WHtR, and homeostatic model assessment for insulin resistance (HOMA-IR) mediated the relationships between TG levels and the risk of developing gout at 18.75%, 24.28%, and 5.35%, respectively. For the association between HDL levels and the risk of developing gout, the mediating effects of BMI, WHtR, leukocytes, γ-glutamyltransferase (in those with HDL < 56 mmol/L), and HOMA-IR were 57.98%, 69.03%, 8.77%, 5.18%, and 11.14%, respectively.

CONCLUSION

This study reveals the relationship between lipid profiles and the risk of developing gout. Regularly checking TG and HDL levels and actively managing obesity, insulin resistance, oxidative stress and inflammation are important for lowering the risk of developing gout.

Knowledge, attitude, and practice toward hyperuricemia among healthcare workers in Shandong, China

Background

Hyperuricemia is a relatively common condition, with a prevalence of over 20% among the general population. Also, most patients initially present no symptoms. This study aimed to investigate the knowledge, attitude, and practice (KAP) toward hyperuricemia among healthcare workers in Shandong, China.

Methods

Healthcare workers were recruited in this cross-sectional study conducted in Shandong in December 2022. A self-designed questionnaire was used to collect demographic information and KAP data.

Results

A total of 372 questionnaires were distributed, and 216 (58.06%) valid questionnaires were collected from 131 physicians, 80 nurses, and five other healthcare workers. The participants had a mean score of 10.76 ± 2.53 (possible range: 0-14, 76.9%) and 31.94 ± 2.58 (possible range: 0-40, 79.9%) in knowledge and attitude, respectively. The physicians' and nurses' practice scores were 47.57 ± 5.34 (possible range: 0-55, 86.5%) and 30.06 ± 4.11 (possible range: 0-35, 85.9%), respectively. The attitude scores were independently associated with proactive practice in both physicians (P < 0.001) and nurses (P = 0.046).

Conclusion

This study found that healthcare workers in Shandong had adequate knowledge, positive attitudes, and proactive practices towards hyperuricemia. However, there is room for improvement in the attitudes of both physicians and nurses to achieve better practice.

Global, regional, and national burden of gout, 1990-2020, and projections to 2050: a systematic analysis of the Global Burden of Disease Study 2021

BACKGROUND

Gout is an inflammatory arthritis manifesting as acute episodes of severe joint pain and swelling, which can progress to chronic tophaceous or chronic erosive gout, or both. Here, we present the most up-to-date global, regional, and national estimates for prevalence and years lived with disability (YLDs) due to gout by sex, age, and location from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021, as well as forecasted prevalence to 2050.

METHODS

Gout prevalence and YLDs from 1990 to 2020 were estimated by drawing on population-based data from 35 countries and claims data from the USA and Taiwan (province of China). Nested Bayesian meta-regression models were used to estimate prevalence and YLDs due to gout by age, sex, and location. Prevalence was forecast to 2050 with a mixed-effects model.

FINDINGS

In 2020, 55·8 million (95% uncertainty interval 44·4-69·8) people globally had gout, with an age-standardised prevalence of 659·3 (525·4-822·3) per 100 000, an increase of 22·5% (20·9-24·2) since 1990. Globally, the prevalence of gout in 2020 was 3·26 (3·11-3·39) times higher in males than in females and increased with age. The total number of prevalent cases of gout is estimated to reach 95·8 million (81·1-116) in 2050, with population growth being the largest contributor to this increase and only a very small contribution from the forecasted change in gout prevalence. Age-standardised gout prevalence in 2050 is forecast to be 667 (531-830) per 100 000 population. The global age-standardised YLD rate of gout was 20·5 (14·4-28·2) per 100 000 population in 2020. High BMI accounted for 34·3% (27·7-40·6) of YLDs due to gout and kidney dysfunction accounted for 11·8% (9·3-14·2).

INTERPRETATION

Our forecasting model estimates that the number of individuals with gout will increase by more than 70% from 2020 to 2050, primarily due to population growth and ageing. With the association between gout disability and high BMI, dietary and lifestyle modifications focusing on bodyweight reduction are needed at the population level to reduce the burden of gout along with access to interventions to prevent and control flares. Despite the rigour of the standardised GBD methodology and modelling, in many countries, particularly low-income and middle-income countries, estimates are based on modelled rather than primary data and are also lacking severity and disability estimates. We strongly encourage the collection of these data to be included in future GBD iterations.

FUNDING

Bill & Melinda Gates Foundation and the Global Alliance for Musculoskeletal Health.

Secular trend of gout incidence in the UK: an age-period-cohort analysis

OBJECTIVES

The incidence of gout in the UK appears to have declined since 2013; however, whether such a trend occurred across participants born in different years (ie, birth cohort) is unknown. We aimed to examine the effects of the birth cohort on gout incidence using an age-period-cohort (APC) model.

DESIGN

Cross-sectional study.

SETTING

Nationwide data from the UK primary care database.

PARTICIPANTS

Individuals between 30 and 89 years of age were included. We excluded individuals who had gout history when entering the database and individuals with less than 1 year of continuous follow-up between 1 January 1999 and 31 December 2019.

PRIMARY AND SECONDARY OUTCOME MEASURES

Gout was identified using READ codes assigned by general practitioners. The incidence of gout between 1999-2013 and 2011-2019 was analysed with APC model.

RESULTS

The incidence of gout between 1999 and 2013 increased with birth cohorts. Compared with those born in 1949-1953 (reference), the age-adjusted and period-adjusted rate ratios (RRs) of incident gout increased from 0.39 (95% CI 0.34 to 0.46) in participants born in 1910-1914 to 2.36 (95% CI 2.09 to 2.66) in participants born in 1979-1983 (p for trend <0.001). In contrast, the incidence of gout between 2011 and 2019 decreased with birth cohorts. Compared with those born in 1949-1953 (reference), the age-adjusted and period-adjusted RRs of incident gout declined from 2.75 (95% CI 2.30 to 3.28) in participants born in 1922-1926 to 0.75 (95% CI 0.65 to 0.87) in participants born in 1976-1980 but then increased slightly to 0.95 (95% CI 0.77 to 1.17) in participants born in 1985-1989.

CONCLUSIONS

The gout incidence between 1999 and 2013 in the UK increased with the birth cohorts and then decreased between 2011 and 2019 except for those born after 1980. Future monitoring is needed to help identify aetiological factors and guide preventive and treatment strategies for gout.

The Impact of Different Intensities of Physical Activity on Serum Urate and Gout: A Mendelian Randomization Study

Physical activity is a potential protective factor against gout, but the role of exercise intensity in this context remains unclear. To overcome the limitations of observational studies in causal inference, this study employed a two-sample Mendelian randomization approach to explore the impact of different genetically proxied/predicted intensities of physical activity on serum urate concentration and the incidence of gout. Our data related to physical activity, serum urate, and gout were obtained from the UK Biobank, the Global Urate Genetics Consortium (GUGC), and the FinnGen dataset, respectively. Walking was included as representative of typical low-intensity physical activity in the analysis, and the other two types were moderate and vigorous physical activities. The estimation methods we used included the inverse-variance-weighted (IVW) method, MR-Egger regression, weighted-median method, simple-mode method, and weighted-mode method. Sensitivity analyses involved Rucker's framework, Cochran's Q test, funnel plots, MR-PRESSO outlier correction, and leave-one-out analysis. We found suggestive evidence from the inverse-variance-weighted method that moderate physical activity was a potential factor in reducing the incidence of gout (OR = 0.628, p = 0.034), and this association became more substantial in our subsequent sensitivity analysis (OR = 0.555, p = 0.006). However, we observed no distinctive effects of physical activity on serum urate concentration. In conclusion, our study supports some findings from observational studies and emphasizes the preventive role of moderate physical activity against gout. Given the limitations of the existing datasets, we call for future reexamination and expansion of our findings using new GWAS data.

Global burden and epidemic trends of gout attributable to high body mass index from 1990 to 2019

Introduction

Gout is an inflammatory and metabolic disease characterized by arthritis and elevation of the serum uric acid (SUA) level. More and more studies have shown that high body mass index (BMI) has become one of the most important risk factors for gout.

Material and methods

We used the data of gout burden attributed to high body mass index (BMI) from global burden of disease (GBD) study 2019 to provide insights for reducing the global burden of gout.

Results

From 1990 to 2019, the prevalence and DALYs of gout caused by high BMI worldwide has been increasing. The burden of gout caused by high BMI is heavier in the elderly male group and regions with high SDI worldwide.

Conclusions

Our findings provide evidence for the burden of gout caused by high BMI. Developing a weight management plan and lifestyle habits for groups severely affected by gout will effectively reduce the global disease and economic burden.

All-cause and specific mortality in patients with gout: A systematic review and meta-analysis

OBJECTIVES

This meta-analysis aims to examine the general mortality risk and specific mortality risk of gout, as the incidence of the condition is on the rise but information on mortality rates remains uncertain.

METHOD

The researchers conducted a search of published cohort studies on gout and mortality using Medical subject headings and keywords in PubMed, EMBASE, and Cochrane Library databases from inception to September 2022. The quality of study was evaluated using the NOS scale. Statistical analysis was performed using STATA software (version 16.0). Publication bias was assessed using funnel plots and Egger's test.

RESULT

This meta-analysis included 11 cohort studies (2010-2022), covering 14,854,490 people with a follow-up time of 1.66-16 years. The pooled analysis shows increased risk of overall mortality [HR=1.23, 95 % CI (1.13-1.35), I2=96.4 %, P<0.001], cardiovascular mortality [HR=1.29, 95 % CI (1.13-1.48), I2=98.5 %, P<0.001], infection mortality [HR=1.24, 95 % CI (1.04-1.47), I2=88.5 %, P = 0.019], and digestive system disease mortality [HR=1.42, 95 % CI (1.13-1.80), I2=91.7 %, P = 0.003] in gout. Sensitivity and subgroup analysis support the findings, and publication bias was not evident.

CONCLUSION

The findings from our meta-analysis indicate that gout is associated with an increased risk of all-cause mortality, as well as mortality related to cardiovascular disease, infections, and digestive system diseases. This has important implications for clinical practice, nursing care of patients with gout, and guidance on lifestyle modifications to prevent adverse outcomes such as cardiovascular events, infections, and digestive disorders.

Cohort study investigating gout flares and management in UK general practice

BACKGROUND

Gout is the most common inflammatory arthritis and is almost exclusively managed in primary care, however the course and severity of the condition is variable and poorly characterised. This research aims improve understanding about the frequency of, and factors associated with, gout flares in the UK and characterise the factors associated with the initiation of ULT.

METHODS

Using the Clinical Practice Research Database, patients with a coded incident gout diagnosis without a prior prescription for urate-lowering therapy (ULT) were identified. Gout flares post diagnosis and ULT initiation were identified through prescribing and coded data. Patient characteristics, co-morbidities and co-prescribing were co-variants. Factors associated with gout flares and ULT initiation were analysed using cox-proportional hazard model and logistic regression.

RESULTS

Fifty-one thousand seven hundred eighty-four patients were identified: 18,605 (35.9%, 95%CI 35.5-36.3%) had experienced ≥ 1 recurrent flare, 17.4% (95%CI 17.1-17.8%) within 12 months of diagnosis. Male sex, black ethnicity, higher BMI, heart failure, CKD, CVD and diuretic use were associated with flares, with the highest HR seen with high serum urate levels (≥ 540 µmol/L HR 4.63, 95%CI 4.03-5.31). ULT initiation was associated with similar variables, although higher alcohol intake and older age were associated with lower odds of ULT initiation but were not associated with flares. ULT was initiated in 27.7% (95%CI 27.3-28.0%): 5.7% (95%CI 5.5-5.9%) within 12 months of diagnosis. ULT initiation rates were higher in patients with recurrent flares.

CONCLUSION

Approximately one in six people with incident gout had a second flare within 12 months. Factors associated with flare recurrence and ULT initiation were similar, but ULT initiation occurred later after diagnosis than previously thought.

Potential clinical value of serum interleukin-41 levels in patients with acute gout

BACKGROUND

Gout is a common metabolic rheumatic disease, and there have been no reports on the serum levels of interleukin (IL)-41 in gout patients. The purpose of this study was to therefore determine the expression of IL-41 in the serum of gout patients.

METHODS

Eighty-one participants were enrolled in this study, including 34 patients with acute gout, 27 gout patients in remission, and 20 healthy controls (HCs). Baseline data were obtained through interviews and laboratory parameters were acquired via blood sample testing. We measured serum IL-41 concentrations with an enzyme-linked immunosorbent assay, and executed Spearman's correlation analysis to investigate the correlation between IL-41 and other parameters, and the diagnostic value for IL-41 was demonstrated using a receiver operating characteristic curve. Multivariate analysis was conducted by adopting logistic regression.

RESULTS

Serum IL-41 concentrations in acute-gout patients were higher than those in HCs and there was no significant difference in serum IL-41 levels between remission gout patients and HCs. In addition, IL-41 was positively correlated with white blood cell count, erythrocyte sedimentation rate, and C-reactive protein and serum amyloid A concentrations, while it was negatively correlated with triglyceride levels. IL-41 showed good diagnostic value for gout, and the combination of IL-41 and uric acid produced a superior diagnostic value. We also noted that IL-41 was an independent risk factor for acute gout.

CONCLUSIONS

This study revealed that serum IL-41 was elevated in patients with acute gout, and suggests that IL-41 may constitute a novel diagnostic marker for acute gout.

Analysis of Metabolites in Gout: A Systematic Review and Meta-Analysis

(1) Background: Many studies have attempted to explore potential biomarkers for the early detection of gout, but consistent and high levels of evidence are lacking. In this study, metabolomics was used to summarize the changes of metabolites in the literature and explore the potential value of metabolites in predicting the occurrence and development of gout. (2) Methods: We searched the databases including the EMBASE, the Cochrane Library, PubMed, Web of Science, VIP Date, Wanfang Data, and CNKI, and the screening was fulfilled on 30 July 2022. The records were screened according to the inclusion criteria and the risk of bias was assessed. Qualitative analysis was performed for all metabolites, and meta-analysis was performed for metabolite concentrations using random effects to calculate the Std mean difference and 95% confidence interval. (3) Results: A total of 2738 records were identified, 33 studies with 3422 participants were included, and 701 metabolites were identified. The qualitative analysis results showed that compared with the healthy control group, the concentration of 56 metabolites increased, and 22 metabolites decreased. The results of the meta-analysis indicated that 17 metabolites were statistically significant. (4) Conclusions: Metabolites are associated with gout. Some specific metabolites such as uric acid, hypoxanthine, xanthine, KYNA, guanosine, adenosine, creatinine, LB4, and DL-2-Aminoadipic acid have been highlighted in the development of gout.

Treat-to-target urate-lowering therapy and hospitalizations for gout: results from a nationwide cohort study in England

OBJECTIVE

To investigate associations between treat-to-target urate-lowering therapy (ULT) and hospitalizations for gout.

METHODS

Using linked Clinical Practice Research Datalink and NHS Digital Hospital Episode Statistics data, we described the incidence and timing of hospitalizations for flares in people with index gout diagnoses in England from 2004-2020. Using Cox proportional hazards and propensity models, we investigated associations between ULT initiation, serum urate target attainment, colchicine prophylaxis, and the risk of hospitalizations for gout.

RESULTS

Of 292 270 people with incident gout, 7719 (2.64%) had one or more hospitalizations for gout, with an incidence rate of 4.64 hospitalizations per 1000 person-years (95% CI 4.54, 4.73). There was an associated increased risk of hospitalizations within the first 6 months after ULT initiation, when compared with people who did not initiate ULT [adjusted Hazard Ratio (aHR) 4.54; 95% CI 3.70, 5.58; P < 0.001]. Hospitalizations did not differ significantly between people prescribed vs not prescribed colchicine prophylaxis in fully adjusted models. From 12 months after initiation, ULT associated with a reduced risk of hospitalizations (aHR 0.77; 95% CI 0.71, 0.83; P < 0.001). In ULT initiators, attainment of a serum urate <360 micromol/l within 12 months of initiation associated with a reduced risk of hospitalizations (aHR 0.57; 95% CI 0.49, 0.67; P < 0.001) when compared with people initiating ULT but not attaining this target.

CONCLUSION

ULT associates with an increased risk of hospitalizations within the first 6 months of initiation but reduces hospitalizations in the long term, particularly when serum urate targets are achieved.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION

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

Epidemiology and treatment-related concerns of gout and hyperuricemia in Korean

Gout is the most common form of inflammatory arthritis that affects mainly middle-aged men, and there is clear evidence of an association between hyperuricemia and the risk for gout. Increasing prevalence of gout and hyperuricemia has been reported in many countries. The prevalence of gout and hyperuricemia are constantly increasing in Korea with the patients at risk for developing a variety of comorbidities. Although there have been studies on the association between gout or serum uric acid level and several neurodegenerative diseases, cancer, and cardiovascular mortality, the causal relationship between gout and these comorbidities are still unclear. The associations of substantial economic burden with hyperuricemia, gout attack, and suboptimal treatment are well known. Gout is a disease that requires lifelong management including lifestyle modification. However, gout is poorly managed worldwide although effective urate-lowering drugs exist. In this review, we addressed epidemiological studies and treatment-related problems in the Korean population with gout or hyperuricemia to obtain the best clinical outcomes and reduce their medical burden.

Global, regional and national burdens of gout in the young population from 1990 to 2019: a population-based study

OBJECTIVE

To use data from the Global Burden of Disease (GBD) Study 2019 to report the global, regional and national rates and trends of annual incidence, point prevalence and years lived with disability (YLD) for gout in adolescents and young adults aged 15-39 years.

METHODS

We conducted a serial cross-sectional study of gout burden in the young population aged 15-39 years using data from GBD Study 2019. We extracted rates per 100 000 population of incidence, prevalence and YLD of gout, then calculated their average annual percentage changes (AAPCs) at the global, regional and national level between 1990 and 2019 by sociodemographic index (SDI).

RESULTS

The global gout prevalent cases in individuals aged 15-39 years was 5.21 million in 2019, with the annual incidence substantially increasing from 38.71 to 45.94 per 100 000 population during 1990-2019 (AAPC 0.61, 95% CI 0.57 to 0.65). This substantial increase was observed in all SDI quintiles (low, low-middle, middle, high-middle and high) and every age subgroup (15-19, 20-24, 25-29, 30-34 and 35-39 years). Males accounted for 80% of the gout burden. High-income North America and East Asia were facing a substantial increase in gout incidence and YLD simultaneously. Elimination of high body mass index can reduce 31.74% of the gout YLD globally in 2019, which varied from 6.97% to 59.31% regionally and nationally.

CONCLUSION

Gout incidence and YLD in the young population grew simultaneously and substantially in both developed and developing countries. Improving representative national-level data on gout, interventions for obesity and awareness in young populations are strongly suggested.

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

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

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.

Potential Association of Osteoporosis and Not Osteoporotic Fractures in Patients with Gout: A Longitudinal Follow-Up Study

Health issues associated with gout and increased occurrence of osteoporosis or fractures have been raised; however, the results are elusive. Herein, we explored the possible link between gout and incident osteoporosis/osteoporotic fractures based on long-term follow-up nationwide data. This study enrolled 16,305 patients with gout and 65,220 controls who were matched by propensity score at a 1:4 ratio on the basis of sex, age, income, and residence from the Korean National Health Insurance Service-Health Screening Cohort database (2002−2015). A Cox proportional hazard model was employed to identify the relevance between gout and incident osteoporosis/fractures, following adjustment for various covariates. In the follow-up period, osteoporosis developed in 761 individuals with gout and 2805 controls (incidence rates: 8.0 and 7.3/1000 person-years, respectively), and each osteoporotic fracture in the distal radius (2.8 vs. 2.7/1000 person-years), hip (1.3 vs. 1.3/1000 person-years), and spine (4.5 vs. 4.5/1000 person-years) occurred in gout and control groups, respectively. After adjustment, the gout group presented an 11% higher development of osteoporosis (95% confidence interval = 1.02−1.20) than the controls (p = 0.011). Subgroup analyses maintained the augment of incident osteoporosis in sufferers with gout, particularly in either men or <60 years. However, no such relevance was identified between gout and incident osteoporotic fractures at any site. In conclusion, gout may result in a slightly elevated likelihood of developing osteoporosis, and not osteoporotic fractures, in the Korean population.

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.

Trend dynamics of gout prevalence among the Chinese population, 1990-2019: A joinpoint and age-period-cohort analysis

Background

The burden of gout is increasing worldwide, which places a heavy burden on society and healthcare systems. This study investigates the independent effects of age, period, and cohort on the gout prevalence from 1990 to 2019 in China, compares these effects by gender and then predicts the future burden of gout over the next decade.

Methods

The data were obtained from the Global Burden of Disease (GBD) study in 2019. Joinpoint regression model was employed to calculate the annual percentage change (APC) in gout prevalence, and the age-period-cohort analysis was utilized to estimate the independent effects of age, period, and cohort. ARIMA model was extended to predict the gout epidemic in 2020-2029.

Results

In 2019, there were 16.2 million cases of gout in China, with an age-standardized prevalence rate (ASPR) of 12.3‰ and 3.9‰ in men and women, respectively. During 1990-2019, the ASPR of gout was increasing significantly, with an average APC of 0.9%. The periods of 2014-2017 and 2001-2005 were "joinpoint" for men and women (APC: 6.3 and 5.6%). The age-period-cohort analyses revealed that the relative risk (RR) of developing gout increased with age, peaking at 70-74 years in men (RR_age(70-74) = 162.9) and 75-79 years in women (RR_age(75-79)=142.3). The period effect trended upward, with a more rapid increase in women (RR_period(2019) = 2.31) than men (RR_period(2019) = 2.23). The cohort effect generally peaked in the earlier cohort born in 1905-1909 for both sexes. Gout prevalence showed a strong positive correlation with the consumption of meat and aquatic products (r_meat = 0.966, r_{aquaticproducts} = 0.953). Within 2029, the ASPR of gout was projected to be 11.7‰ and 4.0‰ in men and women, respectively.

Conclusion

The prevalence of gout is increasing at an alarming rate in China; thus, it is necessary to provide targeted health education, regular screening, and accessible urate-lowering therapy healthcare to prevent and protect against gout in China, particularly in older women.

Environmental factors and risk of gout

Gout is a chronic disease with inflammatory arthritis caused by monosodium urate (MSU) crystals deposition, an elevated serum urate level (hyperuricaemia) is the critical factor leading to MSU crystals deposition and promoting the progression of gout. The onset and development of gout is generally the result of multiple factors, such as diet, heredity and environmental factors. Although genetics and diet are thought to play as major factors, a growing body of research evidence has highlighted that environmental factors also play a significant role in the onset and exacerbation of gout. Recent studies have shown that air pollutants such as particulate matter, sulfur dioxide (SO₂) and carbon monoxide (CO) may increase the risk of hospitalizations for gout, and that the changes in temperature and humidity may affect uric acid (UA) levels. There is also seasonal trend in gout. It has been demonstrated that environmental factors may induce or accelerate the production and release of pro-inflammatory mediators, causing an unbalance oxidative stress and systemic inflammation, and then participating in the overall process or a certain link of gout. Moreover, several environmental factors have shown the ability to induce the production urate and regulate the innate immune pathways, involving in the pathogenesis of gout. Nevertheless, the role of environmental factors in the etiology of gout remains unclear. In this review, we summarized the recent literatures and aimed to discuss the relationship between environmental factors (such as microclimate, season, ambient/indoor air pollution and extreme weather) and gout. We further discussed the inflammatory mechanisms of environmental factors and gout and the comprehensive effects of environmental factors on gout. We also made a prospect of the management and treatment of gout, with special consideration to environmental factors associated with gout.

Soluplus®-based dissolving microarray patches loaded with colchicine: towards a minimally invasive treatment and management of gout

Considered as one of the most common inflammatory arthritis, gout is characterised by a sudden onset of severe joint pain. As the first-line drug of choice used in treating acute gout, colchicine (CLC) is hindered by poor gastrointestinal permeability as well as unfavourable gastrointestinal side effects. Herein, we present, for the first time, the preparation of microarray array patches (MAPs) made of a polymeric solubiliser, Soluplus®, loaded with CLC for its systemic delivery. The fabricated MAPs displayed acceptable mechanical properties and were capable of being inserted into the skin to a depth of ≈500 μm in full thickness ex vivo neonatal porcine skin, as evidenced by optical coherence tomography. In vitro dermatokinetic studies utilising full thickness neonatal porcine skin demonstrated that the CLC-loaded MAPs delivered CLC across all skin strata, resulting in a delivery efficiency of 73% after 24 hours. Furthermore, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and cell proliferation assays along with LIVE/DEAD™ staining on the 3T3-L1 cell line showed that the MAP formulation displayed minimal toxicity, with acceptable biocompatibility. Lastly, the anti-inflammatory properties of the formulation were evaluated using a THP-1 macrophage cell line. It was shown that treatment of THP-1 macrophages that are exposed to lipopolysaccharide (LPS) with CLC-loaded MAPs caused a significant (p < 0.05) reduction of TNF-α production, a pro-inflammatory cytokine typically associated with the early onset of acute gout. Accordingly, CLC-loaded MAPs could represent a new minimally-invasive alternative strategy for management of acute gout.

Gout and Hospital Admission for Ambulatory Care-Sensitive Conditions: Risks and Trajectories

OBJECTIVE

To investigate the risks and trajectories of hospital admission for ambulatory care-sensitive conditions (ACSCs) in gout.

METHODS

Among individuals aged 35 years to 85 years residing in Skåne, Sweden, in 2005, those with no doctor-diagnosed gout during 1998 to 2005 (n = 576,659) were followed from January 1, 2006, until a hospital admission for an ACSC, death, relocation outside Skåne, or December 31, 2016. Treating a new gout diagnosis (International Classification of Diseases, 10th revision, code M10) as a time-varying exposure, we used Cox proportional and additive hazard models to estimate the effects of gout on hospital admissions for ACSCs. We investigated the trajectory of hospital admissions for ACSCs from 3 years before to 3 years after gout diagnosis using generalized estimating equations and group-based trajectory modeling in an age-and sex-matched cohort study.

RESULTS

Gout was associated with a 41% increased rate of hospital admission for ACSCs (hazard ratio 1.41, 95% CI 1.35-1.47), corresponding to 121 (95% CI 104-138) more hospital admissions for ACSCs per 10,000 person-years compared with those without gout. Our trajectory analysis showed that higher rates of hospital admission for ACSCs among persons with gout were observed from 3 years before to 3 years after diagnosis, with the highest prevalence rate ratio (2.22, 95% CI 1.92-2.53) at the 3-month period after diagnosis. We identified 3 classes with distinct trajectories of hospital admissions for ACSCs among patients with gout: almost none (88.5%), low-rising (9.7%), and moderate-sharply rising (1.8%). The Charlson Comorbidity Index was the most important predictor of trajectory class membership.

CONCLUSION

Increased risk of hospital admissions for ACSCs in gout highlights the need for better management of the disease through outpatient care, especially among foreign-born, older patients with comorbidities.

Modifiable Factors and Incident Gout Across Ethnicity Within a Large Multiethnic Cohort of Older Adults

OBJECTIVE

Gout disproportionately affects older Pacific Islander and Black populations relative to White populations. However, the ethnic-specific determinants remain understudied within these groups, as well as within other ethnicities. We examined gout incidence and associations with behavioral factors, including diet, alcohol, and smoking, within a large multiethnic population of older adults from the Multiethnic Cohort Study, which linked prospective cohort data to Medicare gout claims between 1999-2016.

METHODS

Using samples of Black (n = 12,370), Native Hawaiian (n = 6459), Japanese (n = 29,830), Latino (n = 17,538), and White (n = 26,067) participants, we conducted multiple Cox regressions, producing hazard ratios (HRs) and 95% CIs.

RESULTS

Relative to White individuals, Native Hawaiians had the highest risk of gout (HR 2.21, 95% CI 2.06-2.38), followed successively by Black and Japanese participants, whereas Latino individuals had a lower risk of gout (HR 0.78, 95% CI 0.73-0.83). Alcohol use was associated with an increased risk, with significantly greater effects observed among Japanese participants drinking ≥ 3 drinks per day (HR 1.46, 95% CI 1.27-1.66), or > 5 beers per week (HR 1.29, 95% CI 1.17-1.43), compared to White individuals (P_interaction < 0.001). Former smokers with ≥ 20 pack-years had an increased risk (HR 1.14, 95% CI 1.06-1.22). Higher dietary quality was associated with a decreased gout risk, with the largest effect observed among White participants (HR_Q5vsQ1 0.84, 95% CI 0.79-0.90), whereas vitamin C was weakly associated with a decreased risk of gout only among Japanese individuals (HR 0.91, 95% CI 0.85-0.98).

CONCLUSION

Overall, notable ethnic differences were observed in both gout risk and associations with modifiable behavioral factors. Our findings offer crucial insights that may improve precision in preventing and managing gout.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Thirty-Day Hospital Readmissions for Acute Gout in the United States: Analysis of the Nationwide Readmission Database

BACKGROUND/OBJECTIVE

The aims of this study were to describe the rates and characteristics of nonelective 30-day readmission among adult patients hospitalized for acute gout and to assess predictors of readmission.

METHODS

We analyzed the 2017 Nationwide Readmission Database. Gout hospitalizations were identified using the International Classification of Diseases, Tenth Revision, Clinical Modification code. Hospitalizations for adult patients were included. We excluded planned or elective readmissions. We utilized χ2 tests to compare baseline characteristics between readmissions and index hospitalizations. We used multivariate Cox regression to identify independent predictors of readmissions.

RESULTS

A total of 11,727 index adult hospitalizations with acute gout listed as the principal diagnosis were discharged alive and included. One thousand five hundred ninety-four (13.6%) readmissions occurred within 30 days. Acute gout was the most common reason for readmission. Readmissions had higher inpatient mortality (2.4% vs 0.1%, p < 0.0001), greater mean age (68.1 vs 67.0 years, p = 0.021), and longer hospital length of stay (5.9 vs 3.8 days, p < 0.0001) compared with index hospitalizations. Charlson Comorbidity Index scores of ≥2 (score 2: adjusted hazards ratio [AHR], 1.67; p = 0.001; score ≥3: AHR, 2.08; p < 0.0001), APR-DRG (All Patients Refined Diagnosis Related Groups) severity levels ≥2 (level 2: AHR, 1.43; p = 0.044; level 3: AHR, 1.83; p = 0.002; level 4: AHR, 2.38; p = 0.002), admission to metropolitan hospital (AHR, 1.83; p = 0.012), atrial fibrillation (AHR, 1.31; p = 0.004), and anemia (AHR, 1.30; p = 0.001) were significantly associated with 30-day readmissions.

CONCLUSIONS

Acute gout readmissions were associated with worse outcomes compared with index hospitalizations. Charlson Comorbidity Index scores ≥2, APR-DRG severity levels ≥2, admission to metropolitan hospital, atrial fibrillation, and anemia were significant predictors of readmission.

Incidence, Prevalence, and Burden of Gout in the Veterans Health Administration

OBJECTIVE

To determine the prevalence, incidence, and burden of gout in the Veterans Health Administration (VHA) from 2005 to 2014.

METHODS

We used national VHA data from January 1999 to December 2014 to determine the annual incidence and prevalence of gout in the VHA. Gout burden to the VHA was determined by the proportion of patients with an encounter related to gout. Rates of urate-lowering therapy (ULT) and opiate use were determined annually. Characteristics of those with and without gout were compared using 2014 data.

RESULTS

From 2005 to 2014, gout prevalence in the VHA increased from 4.2% to 5.8%, while disease incidence ranged from 5.8 to 7.4 cases per 1,000 patient-years. Gout prevalence was highest among men, older patients, and non-Hispanic black patients. During 2014, 4.0% of all inpatient or outpatient encounters and 1.3% of hospitalizations were gout related. Administration of ULT remained stable over the 10-year period, with 46% of gout patients receiving ULT in 2014. In contrast, 16.4% of prevalent gout patients were receiving a weak opioid in 2014, nearly doubling the prescription rate of weak opioids in 2005, while the use of stronger opioids did not change significantly over this period. Patients with gout had greater comorbidity and health care utilization than patients without gout.

CONCLUSION

The burden posed by gout in the VHA is considerable and increased between 2005 and 2014. While the use of ULT has remained stable, the use of opioid therapy has increased among patients with gout.

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.

Prevalence of gout in the adult general population in Spain: Estimating the proportion of undiagnosed cases

OBJECTIVE

To estimate the prevalence of gout in Spain.

METHODS

Cross-sectional, population-based study of people aged 20 years or older. First, randomly selected individuals were contacted by telephone and rheumatic disease screening questionnaires were conducted. If the first screening was positive, medical records were then reviewed and/or a phone questionnaire was conducted by a rheumatologist, followed by an appointment if necessary. Newly diagnosed cases had to fulfil the ACR/EULAR 2015 criteria. To calculate the prevalence and its 95% CI, the sample design was taken into account and weighing was calculated according to age, sex and geographic origin.

RESULTS

In all, 4916 individuals were included, 1361 had a positive screening result for gout (59 of them reported a prior diagnosis). Of these, 51 were classified as missing and 95 were classified as gout cases. An additional case was detected through a positive screening for fibromyalgia and Sjögren's syndrome, although a previous gout diagnosis was confirmed by a review of the medical records. Of the 96 gout cases, 31 (32%) were de novo diagnoses. The estimated weighted prevalence of gout was 2.4% (95% CI 1.95-2.95), with a higher prevalence in men (4.55% [95%CI 3.65-5.65]) than women (0.38% [95%CI 0.19-0.76]).

CONCLUSION

EPISER2016 is the first population-based study to estimate the prevalence of gout in Spain. Undiagnosed patients accounted for a substantial proportion of cases, highlighting the need for population-approaches when estimating the prevalence of infra-diagnosed diseases. Reliable national approaches are key to obtaining accurate estimates of diseases to better aid healthcare and workforce planning.

The GOUT-36 prediction rule for inpatient gout flare in people with comorbid gout: derivation and external validation

OBJECTIVES

To develop and validate a gout flare risk stratification tool for people with gout hospitalised for non-gout conditions.

METHODS

The prediction rule for inpatient gout flare was derived from a cohort of 625 hospitalised people with comorbid gout from New Zealand. The rule had four items: (1) no pre-admission GOut flare prophylaxis, (2) no pre-admission Urate-lowering therapy, (3) Tophus and (4) pre-admission serum urate >0.36 mmol/l within the previous year (GOUT-36 rule). Two or more items are required for the classification of high risk for developing inpatient gout flare. The GOUT-36 rule was validated in a prospective cohort of 284 hospitalised people with comorbid gout from Thailand and China.

RESULTS

The GOUT-36 rule had a sensitivity of 75%, specificity of 67% and AUC of 0.71 for classifying people at high risk for developing inpatient gout flare. Four risk groups were developed: low (no items), moderate (one item), high (two items) and very high risk (three or four items). In a population with frequent (overall 34%) in-hospital gout flare, 80% of people with very high risk people developed flare, while 11% of low-risk people had inpatient flare.

CONCLUSION

GOUT-36 rule is simple and sensitive for classifying people with high risk for inpatient gout flare. The rule may help inform clinical decision and future research on the prevention of inpatient gout flare.

Gout Flare Burden, Diagnosis, and Management: Navigating Care in Older Patients with Comorbidity

Gout is the most common form of inflammatory arthritis, and its incidence is highest in middle-aged and older patients. Adding to the diagnostic complexity, up to 50% of patients aged > 65 years present atypically, with subacute oligo- or polyarticular flares. Comorbidity and polypharmacy, common in older populations, affect real-world treatment decisions in gout management, and no specific guidelines are available to address these issues in these at-risk groups. Despite the growing public health burden posed by gout, suboptimal management has led to increased morbidity and substantial healthcare utilization and cost burden, as reflected by an increased incidence of emergency department visits and hospitalizations in recent years. Colchicine, nonsteroidal anti-inflammatory drugs, or glucocorticoids (oral, intraarticular, or intramuscular) should be considered as first-line agents for gout flare management. Urate-lowering therapy, with the goal of lowering and maintaining serum urate concentrations at < 6 mg/dL (< 360 μmol/L), is recommended to achieve optimal outcomes, including regression of tophi, reduction (or elimination) of flares, and reductions in total urate burden. In this review, we summarize the current burden posed by gout and discuss best practices in its diagnosis and management, focusing on best practices in the context of gout flare in older patients with comorbid conditions.

Gout

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

Reporting quality of clinical practice guidelines regarding gout and hyperuricemia according to the RIGHT checklist: systematic review

BACKGROUND

The Reporting Items for Practice Guidelines in Healthcare (RIGHT) checklist was used to assess the reporting quality of 2009-2019 clinical practice guidelines (CPGs) regarding gout and hyperuricemia, aimed to improve the reporting quality of future guidelines.

METHODS

We searched PubMed, the Chinese Biomedical Literature database, the Wanfang Database, and the China National Knowledge Infrastructure from January 2009 to June 2019 for guidelines regarding gout and hyperuricemia. We also searched the websites of guideline development organizations (the Guidelines International Network, the National Institute for Health and Clinical Excellence, the American College of Rheumatology, and the European League Against Rheumatism (EULAR)). Furthermore, supplementary guidelines reported in included articles were systematically searched, as well as Google Scholar.

RESULTS

Seventeen guidelines were included, of which one was in Chinese and 16 were in English. The mean reporting rate of the 35 items specified was 14.9 (42.5%); only five CPGs (29.4%) had a reporting rate >50%. Of the 35 items, three were very frequently reported. The reporting proportion of the seven domains (basic information, background, evidence, recommendations, review and quality assurance, funding and declaration and management of interests, and other information) were 64.7%, 36.8%, 50.6%, 42.9%, 8.82%, 33.8%, and 31.4%, respectively.

CONCLUSION

The reporting quality of the present guidelines for gout and hyperuricemia is relatively poor. We suggest that the RIGHT reporting checklist should be used by CPG developers to ensure higher reporting quality of future guidelines.

The Efficacy and Mechanism of Chinese Herbal Medicines in Lowering Serum Uric Acid Levels: A Systematic Review

Background. Chinese herbal medicines are widely used to lower serum uric acid levels. However, no systemic review summarizes and evaluates their efficacies and the underlying mechanisms of action. Objectives. To evaluate the clinical and experimental evidences for the effectiveness and the potential mechanism of Chinese herbal medicines in lowering serum uric acid levels. Methods. Four electronic databases PubMed, Wed of Science, the Cochrane Library and Embase were used to search for Chinese herbal medicines for their effects in lowering serum uric acid levels, dated from 1 January 2009 to 19 August 2020. For clinical trials, randomized controlled trials (RCTs) were included; and for experimental studies, original articles were included. The methodological quality of RCTs was assessed according to the Cochrane criteria. For clinical trials, a meta-analysis of continuous variables was used to obtain pooled effects. For experimental studies, lists were used to summarize and integrate the mechanisms involved. Results. A total of 10 clinical trials and 184 experimental studies were included. Current data showed that Chinese herbal medicines have promising clinical efficacies in patients with elevated serum uric acid levels (SMD: −1.65, 95% CI: −3.09 to −0.22; p = 0.024). There was no significant difference in serum uric acid levels between Chinese herbal medicine treatments and Western medicine treatments (SMD: −0.13, 95% CI: −0.99 to 0.74; p = 0.772). Experimental studies revealed that the mechanistic signaling pathways involved in the serum uric acid lowering effects include uric acid synthesis, uric acid transport, inflammation, renal fibrosis and oxidative stress. Conclusions. The clinical studies indicate that Chinese herbal medicines lower serum uric acid levels. Further studies with sophisticated research design can further demonstrate the efficacy and safety of these Chinese herbal medicines in lowering serum uric acid levels and reveal a comprehensive picture of the underlying mechanisms of action.

Gout in China, 1990-2017: the Global Burden of Disease Study 2017

OBJECTIVE

The aim of the study was to estimate the gout burden and risk factors in China from 1990 to 2017.

STUDY DESIGN

The Global Burden of Disease (GBD) Study uses various analytical tools and a diverse set of data sources to generate comparable estimates of deaths and mortality rates broken down by age, sex, cause, year, and geography.

METHODS

We used the results from the GBD Study 2017 to compare disability-adjusted life years (DALYs), prevalence, incidence, and risk factors of gout in China. The median of the percentage change and 95% uncertainty intervals were determined for the period between 1990 and 2017.

RESULTS

The age-standardized DALY rate, prevalence, and incidence increased 6.92%, 6.88%, and 6.16%, respectively, in China from 1990 to 2017. Although the rates of gout both globally and in China were increasing, the range of change for males in China was larger than that of the global level. All risk factors combined accounted for 30.04% of gout DALYs in 2017. The leading risk factors for gout DALYs were high body mass index and impaired kidney function, and the proportion of high body mass index increased significantly from 10.67% to 24.31%, whereas the proportion of impaired kidney function remained basically unchanged.

CONCLUSIONS

The age-standardized DALY rate, prevalence, and incidence in China have increased progressively since 1990. Increasing attention on body weight management should be prioritized for controlling the rising prevalence of gout in the young and middle-aged population.

Perfluoroalkyl acids, hyperuricemia and gout in adults: Analyses of NHANES 2009-2014

BACKGROUND

Previous studies have reported a positive association of perfluoralkyl acids (PFAAs), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), with hyperuricemia. The objective of the study is to investigate whether there is an association between concurrent serum levels of several PFAAs and gout, serum uric acid (SUA) or hyperuricemia in the U.S. adult population as represented by the National Health and Nutrition Examination Survey (NHANES) 2009-2014 sample (n = 4917). The PFAAs investigated include PFOA, perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorohexane sulfonic acid (PFHxS) and PFOS.

METHODS

This cross-sectional study used multivariate logistic regressions to analyze the association of single PFAAs with hyperuricemia and self-reported gout; the association with SUA was analyzed by multivariate linear regression. Analyses were adjusted for race/ethnicity, age, sex, education, alcohol consumption, smoking, serum cotinine, BMI, diabetes, hypertension, chronic kidney disease, and SUA (for gout only).

RESULTS

Higher quartile values of serum PFOA and PFHxS were associated with increased odds of self-reported gout. There was a positive association of SUA with increased levels of PFOA, PFNA, PFOS, PFHxS and PFDA. Higher quartile values of PFOA, PFNA, and PFHxS were associated with higher odds of hyperuricemia.

CONCLUSIONS

In this population-based cross-sectional analysis, we found an association between selected PFAAs and self-reported gout. We also confirmed previous reports of an association between several PFAAs and hyperuricemia. Our study suggests that exposure to PFAAs may be a risk factor for hyperuricemia and gout.

Out-of-pocket spending among a cohort of Australians living with gout

OBJECTIVE

To measure the direct and indirect out-of-pocket (OOP) costs borne by Australians with gout.

METHODS

A cross-sectional, Australia-wide, web-based survey was conducted over 12 months between May 2017 and April 2018. Participants were recruited via advertisements in doctors' clinics and healthcare organizations' websites, and social media platforms such as Facebook and Twitter. Survey questions collected information about participants' OOP spending on direct medical and non-medical gout-related healthcare costs. Participant demographics, gout status, healthcare sought, workdays lost to due gout and health-related quality of life were also collected.

RESULTS

Seventy-nine patients with gout completed the survey; 70 (89%) were male, and on average were 56 (SD 16) years of age and had gout for 14 (SD 12) years. For this cohort, the median total OOP direct medical cost was AU$200 per year (interquartile range [IQR]: AU$60-AU$570). Sixty (76%) people with gout reported being affected by gout during work; however, only 0.25 (IQR: 0-3) days of work (approximately $60) were lost due to gout in a year. Nine percent (n = 7) of participants experienced cost-related treatment attrition and 33% reported economic hardship (n = 26). Participants who experienced economic hardship or cost-related treatment attrition had higher median total gout-related direct costs than those who did not.

CONCLUSION

In Australia, gout has an OOP financial cost and reduces work productivity. The presence of cost-related treatment attrition among people with gout indicates that financial costs may be a significant barrier to seeking treatment for a subset of patients with gout.

Cost-effectiveness of allopurinol versus febuxostat in the treatment of gout patients: A systematic review

Background: In recent years, increased longevity, poor dietary habits, and the rising prevalence of metabolic syndrome and hypertension have increased the prevalence of gout. Gout significantly increases direct and indirect costs and reduces the quality of life. Allopurinol and febuxostat are the most commonly used drugs for reducing uric acid levels and controlling this disease with different cost-effectiveness. The present systematic review compares the cost-effectiveness of these drugs. Methods: This was a systematic review of economic evaluations. Cochrane CENTRAL, Web of Science, PubMed, Embase, and the Cost-Effectiveness Analysis (CEA) Registry were searched up to April 30, 2018, based on the specific search strategy of each database. Keywords used in the search include gout, cost-effectiveness, allopurinol, and febuxostat in MeSH and free-text forms. Screening of identified studies, data extraction, and quality assessment were done independently by 2 reviewers. The quality of studies was assessed based on Drummond Checklist. Finally, a qualitative analysis was done to analyze the results. Results: A total of 94 studies were identified through database search and the review of references. After screening the titles, abstracts, and full-texts, 6 economic evaluations were included in the review. The majority of the studies had been conducted in the US using the Markov model, within a 5-year horizon, and from the payer's perspective, with the quality of life as a measure of effectiveness. In most studies, the incremental cost-effectiveness ratios (ICERs) of febuxostat per quality-adjusted life year (QALY) were below the threshold (10 000$/QALY and 30 000€/QALY). Conclusion: Febuxostat has been shown to be more cost-effective than allopurinol in all treatment sequences in studies that have used uric acid levels as the measure of effectiveness. Furthermore, in studies with the quality of life as the measure of effectiveness, febuxostat has been shown to be very cost-effective as the second-line treatment.

Trends of venous thromboembolism risk before and after diagnosis of gout: a general population-based study

OBJECTIVE

To estimate the overall risk and the temporal trend of venous thromboembolism (VTE), deep vein thrombosis (DVT), and pulmonary embolism (PE) before and after gout diagnosis in an incident gout cohort compared with the general population.

METHODS

We conducted a matched cohort study using a province-wide population-based administrative health database in Canada. We calculated incidence rates (IRs) and multivariable adjusted hazard ratios (HRs) for the risk of VTE, DVT and PE before and after gout diagnosis.

RESULTS

Among 130 708 incident individuals with gout (64% male, mean age 59 years), 2071 developed VTE, 1377 developed DVT and 1012 developed PE. IRs per 1000 person-years for gout were 2.63, 1.74 and 1.28 compared with 2.03, 1.28 and 1.06 for non-gout, respectively. The fully adjusted HRs (95% CI) for VTE, DVT and PE were 1.22 (1.13, 1.32), 1.28 (1.17, 1.41) and 1.16 (1.05, 1.29). For the pre-gout period, the fully adjusted HRs (95% CI) were 1.51 (1.38, 1.64), 1.55 (1.40, 1.72) and 1.47 (1.31, 1.66) for VTE, DVT and PE. During the third, second and first years preceding gout, the fully adjusted HRs for VTE were 1.44, 1.56 and 1.62. During the first, second, third, fourth and fifth years after gout, the fully adjusted HRs were 1.63, 1.29, 1.33, 1.28 and 1.22. Similar trends were also seen for DVT and PE.

CONCLUSION

Increased risks of VTE, DVT and PE were found both before and after gout diagnosis. The risk increased gradually before gout, peaking in the year prior to diagnosis, and then progressively declined. Gout-associated inflammation may contribute to venous thrombosis risk.

Assessing the Quality of Global Clinical Practice Guidelines on Gout Using AGREE II Instrument

OBJECTIVE

The aim of this study was to assess the quality of global clinical practice guidelines (CPGs) on gout.

METHODS

We systematically searched MEDLINE, CBM (Chinese Biomedical Literature database), GIN (Guidelines International Network), NICE (National Institute for Health and Clinical Excellence), NGC (National Guideline Clearinghouse), WHO (World Health Organization), SIGN (Scottish Intercollegiate Guidelines Network), DynaMed, UpToDate, and Best Practice databases from their inception until January 2017 to identify and select CPGs related to gout. Two reviewers independently assessed the eligible gout CPGs using the AGREE II instrument.

RESULTS

We evaluated 15 CPGs published between 2007 and 2017, produced by 13 different developers. Quality of evidence and strength of recommendations were presented in 14 (93%) and 13 (87%) CPGs, respectively. The mean scores (±SD) for each AGREE II domain were as follows: (i) scope and purpose: 75% (±17%), (ii) stakeholder involvement: 39% (±19%), (iii) rigor of development: 43% (±17%), (iv) clarity and presentation: 82% (±14%), (v) applicability: 31% (±12%), and (vi) editorial independence: 23% (±29%).

CONCLUSIONS

The quality of gout CPGs was suboptimal, and various incompatible grading systems of quality of evidence and strength of recommendations were used. The use of a standardized international grading system is essential to ensure high methodological quality of gout CPGs. Tools such as AGREE II could substantially improve the development and update of future gout CPGs.

Cichorium intybus L. Extract Suppresses Experimental Gout by Inhibiting the NF-κB and NLRP3 Signaling Pathways

BACKGROUND

The production and maturation of interleukin (IL)-1β, regulated by the NF-κB and NLRP3 signaling pathways, lie at the core of gout. This study aimed to evaluate the antigout effect of Cichorium intybus L. (also known as chicory) in vivo and in vitro.

METHODS

A gout animal model was established with monosodium urate (MSU) crystal injections. Rats were orally administered with chicory extract or colchicine. Levels of ankle edema, inflammatory activity, and IL-1β release were observed. Several essential targets of the NF-κB and NLRP3 signaling pathways were detected. Primary macrophages were isolated to verify the antigout mechanism of chicory extract as well as chicoric acid in vitro.

RESULTS

Improvements of swelling degree, inflammatory activity, and histopathological lesion in MSU-injected ankles were observed in the treatment with chicory extract. Further, the chicory extract significantly decreased IL-1β release by suppressing the NF-κB and NLRP3 signaling pathways in gout rats. Similar to the in vivo results, IL-1β release was also inhibited by chicory extract and chicoric acid, a specific effective compound in chicory, through the NF-κB and NLRP3 signaling pathways.

CONCLUSION

This study suggests that chicory extract and chicoric acid may be used as promising therapeutic agents against gout by inhibiting the NF-κB and NLRP3 signaling pathways.

Gout is not associated with the risk of fracture: a meta-analysis

BACKGROUND

Numerous quantitatively based studies measuring the association between gout and the risk of fractures remain inconclusive. In order to determine whether gout could increase the risk of fractures, a meta-analysis was performed systematically.

METHODS

Electronic databases, MEDLINE/PubMed, Embase, and Cochrane Library were systematically searched to identify studies evaluating the association of gout and the risk of fractures. No restrictions on language, publication date, or journal of publication were imposed. Meta-analysis was performed to pool the outcome estimates of interest such as fracture incidence, fracture risk, and fracture risk in different sites and at different time points in the follow-up period.

RESULTS

Screening determined that seven studies involving a total of 684,964 participants (151,002 in the gout group and 533,962 in the control group) were deemed viable for inclusion in the meta-analysis. The results of the analysis showed that gout would not significantly have a relatively higher risk of any fracture (RR = 1.11, 95% CI 0.98-1.26). Subgroup analysis showed consistent results for sexuality (female: RR = 1.13, 95% CI 0.93-1.37; male: RR = 0.99, 95% CI 0.91-1.07) and several occurring sites (humerus, wrist, vertebra, hip, upper limbs, and lower limbs). Additionally, the results demonstrated that urate-lowering drugs prescribed early during disease had neither adverse nor beneficial effect on the long-term risk of fractures (RR = 0.89, 95% CI 0.76-1.05).

CONCLUSIONS

This meta-analysis confirmed that gout was not associated with an increased risk of fractures. Urate-lowering drugs prescribed early during the course of disease had neither adverse nor beneficial effect on the long-term risk of fractures.

Second-line treatment with lesinurad and allopurinol versus febuxostat for management of hyperuricemia: a cost-effectiveness analysis for Spanish patients

INTRODUCTION/OBJECTIVES

Lesinurad, in combination with allopurinol, has been approved for treatment of patients with gout which do not reach therapeutic serum urate target with xanthine oxidase inhibitors monotherapy. The study aimed to assess the incremental cost-effectiveness ratio of adding lesinurad to allopurinol as second-line therapy, compared to febuxostat for patients with gout in Spain.

METHOD

A Markov model representing disease evolution was used to estimate the lifetime accumulated cost and benefits in terms of quality-adjusted-life-year (QALY). Patients could either continue with second-line treatment with lesinurad (200 mg/daily) plus allopurinol (400 mg/daily) or febuxostat (80 mg/daily) switch to allopurinol monotherapy (271 mg/daily) in case of intolerance or discontinue treatment. The treatment's efficacy captured in the transition probabilities between health states were derived from CLEAR and EXCEL trials. Quality of life related to gout severity and flare frequency was considered by means of utilities. The total cost estimation (€, 2019) included drug acquisition cost, disease monitoring, and flare management cost. Unitary local costs derived from databases and literature. A 3% annual discount rate was applied for cost and outcomes.

RESULTS

Lesinurad plus allopurinol provided higher QALYs (14.79) than febuxostat (14.69). Total accrued cost/patient was lower with lesinurad and allopurinol (€50,631.51) versus febuxostat (€56,698.64). Lesinurad plus allopurinol resulted more effective and less costly (dominant option) versus febuxostat.

CONCLUSIONS

Lesinurad plus allopurinol therapy compared with febuxostat seems an effective option for the management of hyperuricemia in patients who did not reach serum urate target to previous allopurinol monotherapy, associated to cost-savings for the Spanish Health System.Key Points• Lesinurad, in combination with allopurinol, has been recently authorized as second-line treatment of hyperuricemia in gout patients.• Lesinurad plus allopurinol provided higher effectiveness in terms of quality-adjusted-life-years (14.79) than febuxostat (14.69).• Lesinurad plus allopurinol resulted less costly (total cost/per patient) compared with febuxostat.• Lesinurad plus allopurinol resulted a dominant option compared with febuxostat.

Are Target Urate and Remission Possible in Severe Gout? A Five-year Cohort Study

OBJECTIVE

Determine the proportion of patients achieving target serum urate (SU), defined as < 6 mg/dl for patients with non-severe gout and < 5 mg/dl for patients with severe gout, as well as the proportion of patients achieving remission after 5 years of followup.

METHODS

Patients from the Gout Study Group (GRESGO) cohort were evaluated at 6-month intervals. Demographic and clinical data were obtained at baseline. Visits included assessments of serum urate, flares, tophus burden, health-related quality of life using the EQ-5D, activity limitations using the Health Assessment Questionnaire adapted for gout, and pain level and patient's global assessment using visual analog scales. Treatment for gout and associated diseases was prescribed according to guidelines and available drugs.

RESULTS

Of 500 patients studied, 221 had severe gout (44%) and 279 had non-severe gout (56%) at baseline. No significant differences were observed across the study in percentages of severe gout versus non-severe gout patients achieving SU 6 mg/dl or 5 mg/dl. The highest proportion of patients achieving target SU (50-70%) and remission (39%) were found after 3-4 years of followup. In the fifth year, these proportions decreased and 28% of the patients were in remission, but only 40 patients remained in the study. None of the patients with severe gout achieved remission.

CONCLUSION

In patients with severe gout, target SU was hard to achieve and remission was not possible. The main obstacles for target SU and gout remission include poor medication adherence, persistent tophi, and loss to followup.