Incidence and prevalence of gout in Western Sweden

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.

Course and predictors of work productivity in gout - results from the NOR-Gout longitudinal 2-year treat-to-target study

OBJECTIVES

In patients with gout there is a lack of longitudinal studies on the course of work productivity. We explored longitudinal changes in and predictors of work productivity over 2 years.

METHODS

Patients in the NOR-Gout observational study with a recent gout flare and serum urate (sUA) >360 µmol/l attended tight-control visits during escalating urate lowering therapy according to a treat-to-target strategy. From the Work Productivity and Activity Impairment (WPAI) questionnaire, scores for work productivity and activity impairment were assessed over 2 years together with the Beliefs about Medicines Questionnaire and a variety of demographic and clinical variables.

RESULTS

At baseline patients had a mean age of 56.4 years and 95% were males. WPAI scores at baseline were 5.0% work missed (absenteeism), 19.1% work impairment (presenteeism), 21.4% overall work impairment and 32.1% activity impairment. Work productivity and activity impairment improved during the first months, and remained stable at 1 and 2 years. Comorbidities were not cross-sectionally associated with WPAI scores at baseline, but predicted worse work impairment and activity impairment at year 1. The Beliefs about Medicines Questionnaire subscale with concerns about medicines at baseline independently predicted worse overall work impairment and worse activity impairment at year 1.

CONCLUSIONS

In patients with gout who were intensively treated to the sUA target, work productivity and activity impairment were largely unchanged and at 1 year predicted by comorbidities and patient concerns about medication.

Sex and country differences in gout: cross-country comparison between Sweden and the UK

OBJECTIVE

Compare characteristics, sex differences, and management of gout in Sweden and the UK.

METHOD

The results from two separate primary care gout surveys from Sweden and the UK were compared. Participants aged ≥18 years with gout were sent a questionnaire asking about lifestyle, gout characteristics, uratelowering therapy (ULT), comorbidities, disability, and disease impact. For sex comparison, participants were pooled across countries.

RESULTS

In total, 784 (80% male) participants from Sweden and 500 (87% male) from the UK were included. Swedish patients were significantly older at gout onset, mean (SD) age 72 (12) versus 63 (13) years, (p<0.0001), with more comorbidities, and more frequent use of ULT (48% vs 35%, p=0.0005, age-adjusted). Use of alcohol and diuretics was significantly more common among UK patients, who also reported a higher number of gout flares, mean (SD) 2.2 (1.7) versus 1.6 (3.6), (p=0.003) age-adjusted. Females with gout were older at gout onset, mean (SD) age 67 (13) versus 56 (15), (p<0.0001), more often obese, and reported higher use of diuretics. Furthermore, females reported greater impact of gout, more pain and physical limitations, whereas no sex differences were seen in ULT or flares.

CONCLUSIONS

In the UK, gout was more frequently associated with modifiable risk factors. People with gout in Sweden were more commonly taking ULT and had lower frequency of gout flares and impact of gout. Females with gout more commonly took diuretics, had higher body mass index, and reported greater physical disability, which should be considered when managing gout in women.

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

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

Health-related quality of life in gout, psoriatic arthritis, rheumatoid arthritis and ankylosing spondylitis, results from a cross-sectional survey in Western Sweden

OBJECTIVES

Inflammatory joint diseases (IJDs) substantially affect health-related quality of life (HRQoL). We aimed to compare HRQoL between patients with gout, psoriatic arthritis (PsA), rheumatoid arthritis (RA), and ankylosing spondylitis (AS): (i) overall; (ii) stratified by sex; and (iii) between women and men with the same IJD diagnosis.

METHOD

A survey including the RAND36-Item Health Survey for assessing HRQoL was sent to patients with a diagnosis of gout, PsA, RA, or AS, registered at a rheumatology clinic or primary care centre during 2015-2017. HRQoL was compared across IJDs. Because of age differences between diagnoses, age-matched analyses were performed.

RESULTS

In total, 2896/5130 (56.5%) individuals responded to the questionnaire. Of these, 868 had gout, 699 PsA, 742 RA, and 587 AS. Physical component summary (PCS) scores were more affected than mental component summary (MCS) scores for all diagnoses (PCS range: 39.7-41.2; MCS range: 43.7-48.9). Patients with gout reported better PCS scores than patients with PsA, RA, and AS, who reported similar scores in age-matched analysis. MCS scores were close to normative values for the general population and similar across IJDs. When comparing women and men with respective IJDs, women reported worse PCS (range, all IJDs: 34.5-37.4 vs 37.5-42.5) and MCS (PsA: 44.0 vs 46.8; RA: 46.1 vs 48.7) scores.

CONCLUSION

We found that patients with gout reported better PCS scores than patients with other IJDs, for whom the results were similar. Women reported overall worse PCS and MCS scores than men.

Gout in Dalarna, Sweden - a population-based study of gout occurrence and compliance to treatment guidelines

OBJECTIVE

This study aimed to describe the incidence and prevalence of gout, describe the use of allopurinol among prevalent gout cases, and determine persistence with allopurinol and degree of compliance with treat-to-target recommendations before and after the publication of Swedish national guidelines in 2016.

METHOD

Prospectively registered data on gout diagnoses and allopurinol prescriptions were used to calculate incidence and prevalence, and the proportion of prevalent patients on allopurinol. Gout patients starting allopurinol during 2013-2015 versus 2016-2018 were compared regarding persistence and compliance with treat-to-target principles.

RESULTS

The incidence of gout was 221-247 per 100 000 person-years during 2014-2019, prevalence in 2018 was 2.45%. Among prevalent cases, the proportion on allopurinol ranged from 21% to 25%. Allopurinol persistence was better for individuals starting therapy during 2016-2018 compared with 2013-2015 (45% vs 39%, p = 0.031), as were several outcomes related to treat-to-target principles, e.g. measuring baseline serum urate (SU) (84% vs 77%, p < 0.001), follow-up SU (50% vs 36%, p < 0.001), and the proportion of patients reaching an SU level < 360 µmol/L (45% vs 30%, p < 0.001).

CONCLUSION

Incidence and prevalence were slightly higher than in previous Swedish reports. Allopurinol use among prevalent gout patients did not increase during 2014-2019. Only a minor improvement in persistence was seen, and a moderate increase in compliance with guidelines, suggesting a need for improved management and extended patient involvement to increase and optimize the use of urate lowering therapy.

Gender differences in illness perceptions and disease management in patients with gout, results from a questionnaire study in Western Sweden

BACKGROUND

Aims were to examine gender differences in patients with gout with regard to a) self-reported gout severity, b) illness perceptions (IP), c) impact on daily activities and Quality of Life (QoL), d) advice from healthcare professionals, e) having changed dietary- or alcohol habits.

METHODS

Adult patients with gout identified in primary and secondary care in Sweden between 2015 and 2017 (n = 1589) were sent a questionnaire about demographics, gout disease severity, IP (using the Brief Illness Perception Questionnaire, (B-IPQ)) and disease management. T-tests, Chi square tests, ANalysis Of VAriance (ANOVA) and linear regression models were used for gender comparisons.

RESULTS

Eight hundred sixty-eight patients responded to the questionnaire. Women, n = 177 (20%), experienced more severe gout symptoms (p = 0.011), albeit similar frequencies of flares compared to men. Women experienced modest but significantly worse IP with regard to consequences, identity, concerns and emotional response (p < 0.05) as well as daily activities such as sleeping (p < 0.001) and walking (p = 0.042) and QoL (p = 0.004). Despite this and a higher frequency of obesity in women (38 vs 21%, P < 0.001) and alcohol consumption in men (p < 0.001), obese women had received significantly less advice regarding weight reduction (47 vs 65%, p = 0.041) compared to obese men. On the other hand, women reported having acted on dietary advice to a larger degree.

CONCLUSIONS

Despite only modestly worse gout severity and perception, women appear to have been given less information regarding self-management than men. These gender differences should be given attention and addressed in clinical care.

Single photon emission computed tomography/computed tomography imaging of gouty arthritis: A new voice

Gouty arthritis, often referred to simply as gout, is a disorder of purine metabolism characterized by the deposition of monosodium urate monohydrate (MSU) crystals in multiple systems and organs, especially in joints and their surrounding soft tissue. Gout is a treatable chronic disease, and the main strategy for effective management is to reverse the deposition of MSU crystals by uric acid reduction, and to prevent gout attacks, tophi deposition and complications, and thereby improve the quality of life. However, the frequent association of gout with other conditions such as hypertension, obesity, cardiovascular disease, diabetes, dyslipidemia, chronic kidney disease (CKD) and kidney stones can complicate the treatment of gout and lead to premature death. Here, we review the use of medical imaging techniques for studying gouty arthritis with special interest in the potential role of single photon emission computed tomography (SPECT)/computed tomography (CT) in the clinical management of gout and complications (e.g., chronic kidney disease and cardiovascular disease).

Increased Metallothionein-1 Associated with Gout Activity and Tophi

BACKGROUND AND AIMS

Gout is a chronic self-limiting inflammatory arthritis. An increase in metallothionein-1 (MT-1) has been reported in rheumatoid arthritis and osteoarthritis, and it attenuates inflammation and the pathology of diseases. This study aims to detect MT-1 levels in patients with gout and to explore its correlation with disease activity, clinical indexes, and inflammatory cytokines.

METHODS

The expression of MT-1 messenger RNAs (mRNAs) and protein levels in patients with gout were measured using real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Correlations between MT-1 and clinical indexes or inflammatory mediators were analyzed using Spearman's correlation test.

RESULTS

Compared with healthy controls (HCs, n = 43), patients with active gout (n = 27) showed higher levels of MT-1 mRNA in peripheral blood mononuclear cells and protein in serum, particularly those with tophi. No significant difference in serum MT-1 levels was observed among patients with inactive gout, HCs, and patients with hyperuricemia without gout. Furthermore, no significant difference was observed between patients with gout with kidney damage and HCs. In addition, serum interleukin (IL)-1β, IL-6, and IL-8 levels were significantly increased in patients with active gout, particularly in those with tophi. The serum MT-1 level was positively correlated with C-reactive protein, as well as with IL-1β, IL-6, and IL-18.

CONCLUSION

The higher levels of MT-1 were found in patients with gout, which were correlated with disease activity and gout related pro-inflammatory cytokines. Indicating MT-1 may serve as a new marker for predicting disease activity.Abbreviations: IL-1β: Interleukin 1β; MT-1: Metallothionein-1; CRP: C-Reactive Protein; ROS: Reactive Oxygen Species; IL-10: Interleukin 10; TGF-β: Transforming Growth Factor Beta.

Professionals’ perspectives on existing practice and conditions for nurse-led gout care based on treatment recommendations: a qualitative study in primary healthcare

Background

Gout affects nearly 2 % of the population and is associated with repeated painful flares of arthritis. Preventive urate-lowering therapy is widely available, but only one third of patients receive adequate treatment. Lack of knowledge among healthcare professionals and patients within primary healthcare are implicated as partial explanations for this undertreatment. Nurse-led care has proved to be an effective model when treating patients with gout, but there is a need for more knowledge about factors that can be expected to influence the future implementation of such care. The aim of this study was to describe factors influencing existing gout care in primary healthcare and the conditions for a future implementation of nurse-led gout care based on national treatment recommendations.

Methods

In this qualitative study, focus group discussions with 56 nurses and physicians and individual interviews with eight managers were conducted at nine primary healthcare units in central Sweden. A deductive qualitative content analysis based on the main constructs of the framework Integrated Promoting Action on Research Implementation in Health Services was followed by an inductive analysis within the frames of the main constructs: innovation, recipients and context.

Results

Gout-related contacts with primary healthcare was described as being patient initiated, diagnostics was in some respects complex and nurse-led care was experienced as a favourable primary healthcare model in general (innovation). Gout was seen as a low-priority condition with acute flares and there was inadequate knowledge of gout, including preventive treatment (recipients). Primary healthcare was perceived as having a holistic but fragmented responsibility for gout care, recommendations against keeping waiting lists complicated follow-up appointments and a need for motivation and support when introducing new practices was emphasised (context).

Conclusion

In this study, investigating the perspective of professionals, several factors were found to influence existing gout care. It will be crucial to target these factors in the development of a future implementation strategy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-022-01677-z.

Fluctuation and change of serum urate levels and flares in gout: results from the NOR-Gout study

A gout attack may evolve after a purine-rich diet or alcohol and after starting urate-lowering therapy (ULT). The relationships between fluctuation and change in serum urate (SU) with the occurrence of flares were investigated in this study. In the prospective NOR-Gout study, gout patients with increased SU and a recent flare were treated to target with ULT over 1 year, with follow-up at year 2 with SU and flare as outcomes. SU and flares were assessed at both monthly and 3-monthly intervals until target SU was reached. Fluctuation over periods and changes in SU between two time points were assessed and compared in patients with and without flares. At year 1, 186 patients completed follow-up (88.2%) and 173 (82.0%) at year 2. Mean age (SD) at baseline was 56.4 (13.7) years, disease duration was 7.8 (7.6) years, and 95.3% were men. The first-year SU fluctuation and change were related to flare occurrence during year 1 (both p < 0.05). High fluctuation with an absolute sum of all SU changes during the first 9 months was related to flares over 3-month periods (all p < 0.05), and high fluctuation during the first 3 months was related to flares in months 3-6 (p = 0.04). Monthly and high SU changes or again reaching higher SU levels > 360 µmol/l were not related to flares. Fluctuation and change in SU were related to flare occurrence during the first year of ULT, while changes between visits and reaching SU levels > 360 µmol/L were not related to flares. Key Points • Urate-lowering therapy seeks to achieve a treatment target and prevent gout flares, and changes in serum urate are related to gout flares. • Fluctuation and changes in serum urate were associated with gout flares, suggesting that fluctuation in serum urate is unfavourable during gout treatment. • During urate-lowering therapy in gout in clinical practice, fluctuation of serum urate, for example, due to lack of adherence, should be observed and avoided.

Mapping Knowledge Structure and Global Research Trends in Gout: A Bibliometric Analysis From 2001 to 2021

Background

The incidence and prevalence of gout have been steadily increasing globally, which has resulted in gout research attracting consistently increased attention. This study aimed to visualize the knowledge structure and research trends in gout research through bibliometrics to help understand the future development of basic and clinical research.

Methods

Articles and reviews on gout from 2001 to 2021 were extracted from the Web of Science Core Collection database. CiteSpace and VOSviewer software were used to visualize the knowledge network of countries, institutions, authors, references, and keywords in this field. SPSS and Microsoft Excel software were used for curve fitting and correlation analysis.

Results

A total of 3,259 articles and reviews were included. The number of publications about gout significantly increased yearly. Publications were mainly concentrated in North America, Europe, Oceania, and East Asia. The USA contributed most with 1,025 publications, followed by China and New Zealand. After adjusting for publications by population size and Gross Domestic Product (GDP), New Zealand ranked in the first place. GDP and international collaboration were significantly correlated with scientific productivity for gout research. University of Auckland and Professor Dalbeth Nicola were the most prolific institutions and influential authors, respectively. Rheumatology was the most productive journal for gout research. Gout research hotspots have shifted over time in the following order: clinical features, pathological mechanisms, complications, gouty arthritis, epidemiology, and dual-energy computed tomography to drug clinical trials, which can be observed from the keyword analysis and co-cited reference cluster analysis.

Conclusions

This study found that research on gout is flourishing. The development and experimentation of drugs for the prevention and treatment of gouty arthritis would be the focus of current research and developmental trends in future research.

Prevalence and risk factors of hyperuricemia and gout: a cross-sectional survey from 31 provinces in mainland China

Background and Objetives

Hyperuricemia (HUA) and gout seriously influence patients’ quality of life. The current study was performed to investigate the prevalence of HUA and gout and the related risk factors in Chinese adults.

Methods

Data were collected from the National Survey of Thyroid Disorders and Diabetes (the Thyroid Disease, Iodine Status, and Diabetes National Epidemiological survey [TIDE]), a cross-sectional investigation conducted during 2015–2017. Using a random, multistage, and stratified sampling strategy, a representative sample (78,130 participants aged 18 years and above) was selected from the general population in 31 provinces of mainland China. The weighted prevalence rates of HUA and gout were calculated, and the related risk factors were analyzed.

Results

The weighted prevalence rates of HUA and gout in Chinese adults were 17.7% and 3.2%, respectively. The prevalence of HUA in males linearly decreased with age, while the prevalence in females showed the opposite trend (both P for trend < 0.01). The prevalence rate of gout exhibited a rising tendency with age in both genders (both P for trend < 0.05). The HUA and gout prevalence rates in males were the highest in Han and Tibetan nationalities, respectively. Logistic regression analysis showed that the morbidities of HUA and gout were differentially associated with age, residence location, nationality, smoking, and other complicating metabolic diseases in the two genders.

Conclusions

There are relatively high prevalence rates of gout and HUA in China, which is currently a developing country. Reducing their burden has become an urgent issue for Chinese people.

Allopurinol Initiation and All-Cause Mortality Among Patients With Gout and Concurrent Chronic Kidney Disease : A Population-Based Cohort Study

BACKGROUND

Two recent randomized clinical trials of escalating doses of allopurinol for the progression of chronic kidney disease (CKD) reported no benefits but potentially increased risk for death. Whether the risk could occur in patients with gout and concurrent CKD remains unknown.

OBJECTIVE

To examine the relation of allopurinol initiation, allopurinol dose escalation, and achieving target serum urate (SU) level after allopurinol initiation to all-cause mortality in patients with both gout and CKD.

DESIGN

Cohort study.

SETTING

The Health Improvement Network U.K. primary care database (2000 to 2019).

PARTICIPANTS

Patients aged 40 years or older who had gout and concurrent moderate-to-severe CKD.

MEASUREMENTS

The association between allopurinol initiation and all-cause mortality over 5-year follow-up in propensity score (PS)-matched cohorts was examined. Analysis of hypothetical trials were emulated: achieving target SU level (<0.36 mmol/L) versus not achieving target SU level and dose escalation versus no dose escalation for mortality over 5-year follow-up in allopurinol initiators.

RESULTS

Mortality was 4.9 and 5.8 per 100 person-years in 5277 allopurinol initiators and 5277 PS-matched noninitiators, respectively (hazard ratio [HR], 0.85 [95% CI, 0.77 to 0.93]). In the target trial emulation analysis, the HR of mortality for the achieving target SU level group compared with the not achieving target SU level group was 0.87 (CI, 0.75 to 1.01); the HR of mortality for allopurinol in the dose escalation group versus the no dose escalation group was 0.88 (CI, 0.73 to 1.07).

LIMITATION

Residual confounding cannot be ruled out.

CONCLUSION

In this population-based data, neither allopurinol initiation, nor achieving target SU level with allopurinol, nor allopurinol dose escalation was associated with increased mortality in patients with gout and concurrent CKD.

PRIMARY FUNDING SOURCE

Project Program of National Clinical Research Center for Geriatric Disorders.

Association between perinatal factors and future risk for gout-a nested case-control study

Background

Increased level of urate is the strongest risk factor for gout development but since only a minority of hyperuricemics are affected by gout, other pathogenic factors must be considered. Low birth weight is associated with future morbidities causing hyperuricemia, such as diabetes and renal disease. The purpose of this study was to investigate if, and to what extent, maternal and perinatal factors, including birth weight, are associated with future risk of being diagnosed with gout.

Methods

A population-based retrospective nested case-control registry study based on regional and national health care registers in Sweden. All incident cases of gout born in 1973 and onward who had received ≥1 diagnosis of gout from 2000 through 2019 in the region of western Sweden were included. Up to 5 non-gout controls were matched to each case by age, sex, and county at the year of first gout diagnosis. A range of maternal, gestational, and perinatal factors were analyzed for their potential association to future gout development. This included the health of the mother, gestational length, birth weight, number of siblings, and congenital malformations.

Results

Maternal diabetes, any congenital malformation, and being small for gestational age were factors that significantly increased the risk for future gout development, odds ratio (95% CI) 3.1 (1.3 to 7.4) (p=0.01), 1.33 (1.04 to 1.7) (p=0.02), and 1.75 (1.3 to 2.3) (p<.0001), respectively.

Conclusions

In this study, maternal diabetes and being small for gestational age increased the risk for future gout development in young adults. As of today, these conditions are becoming more prevalent and may contribute to the ongoing gout epidemic. These results require both confirmation and further delineation of underlying mechanisms.

Identification of Inflammation-Related Biomarker Pro-ADM for Male Patients With Gout by Comprehensive Analysis

Objective

Gout is a local inflammatory disease caused by the deposition of monosodium urate (MSU) crystals in joints or adjacent tissues. When some gout occurs without hyperuricemia, or its clinical symptoms and signs are not typical, the diagnosis of gout will be delayed, so there is an urgent need to find a new biomarker to predict and diagnose of gout flare. Our research attempts to find the key genes and potential molecular mechanisms of gout through bioinformatics analysis, and collected general data and blood biochemical samples of patients with gout and healthy, then analyzed and compared the expression of factors regulated by key genes.

Method

GSE160170 were downloaded from GEO database for analysis. The data were normalized to identify the differentially expressed genes (DEGs), then GO and KEGG enrichment analysis were applied. Protein-protein interaction (PPI) networks and hub genes between DEGs were identified. Then collect general information and blood samples from male patients with acute gout, hyperuricemia and healthy. ELISA method was used to detect pro-ADM levels of different groups, and the data was input into SPSS statistical software for analysis.

Result

We identified 266 DEGs (179 up-regulated and 87 down-regulated) between gout patients and healthy controls. GO analysis results show that DEGs are mostly enriched in inflammatory response, growth factor activity, cytokine activity, chemokine activity, S100 protein binding and CXCR chemokine receptor binding. KEGG pathway analysis showed that DEGs are mainly related to Chemokine signaling pathway and Cytokine-cytokine receptor interaction. ADM, CXCR1, CXCR6, CXCL3, CCL3, CCL18, CCL3L3, CCL4L1, CD69, CD83, AREG, EREG, B7RP1, HBEGF, NAMPT and S100B are the most important hub genes in the PPI network. We found that the expression of pro-ADM in the gout group and hyperuricemia group was higher than that in the healthy group, and the difference was statistically significant.

Conclusion

In this study, a series of bioinformatics analyses were performed on DEGs to identify key genes and pathways related to gout. Through clinical verification, we found that pro-ADM can be used as an inflammation-related biomarker for acute attacks of gout, providing new ideas for the diagnosis and treatment of gout.

Genetic assessment of hyperuricemia and gout in Asian, Native Hawaiian, and Pacific Islander subgroups of pregnant women: biospecimens repository cross-sectional study

Background

Gout, an inflammatory condition, is characterized by the precipitation of monosodium urate crystals (MSU) in or around distal joints. The latter is caused by chronic hyperuricemia (HU)—high urate levels in the blood. Genetic variations in urate transporters play a significant role in determining urate levels within the human body, rendering some racial and ethnic groups more or less susceptible to developing either HU or gout. This study aims to estimate the frequencies of HU and gout risk alleles in Asian, Native Hawaiian, and Pacific Islander subgroups, using biorepository DNA samples.

Methods

The biospecimens repository at the University of Hawai’i provided DNA samples of consented post-partum women of Japanese, Filipino, Korean, Native Hawaiian, Samoan, and Marshallese descent. The DNA was previously extracted from maternal blood and genotyped at the Genomics and Bioinformatics Shared Resource, Cancer Center (Honolulu, HI). Nine urate genes: ABCG2, SLC2A9, SLC16A9, GCKR, SLC22A11, SLC22A12, LRR16A, PDZK1, and SLC17A1, were selected due to their significant association with HU and gout risk. Hardy–Weinberg Equilibrium (HWE) for genotype frequencies was assessed, using the Chi-Square test with p < 0.006 for statistical significance. Allele frequencies in our study were then compared to EUR from the 1000 Genomes Project Database Phase III, using Chi-square or Fisher's exact test, when appropriate. Bonferroni correction for multiple comparisons was used, with p < 0.006 for statistical significance.

Results

Our study involved 1059 post-partum women 18-year-old or older who self-reported their respective race and ethnicity, including Asian, Native Hawaiian, and Pacific Islander ancestry. The Asian subgroups included Japanese, Filipino, and Korean. The Pacific Islander subgroups included Marshallese and Samoan. None of the study participants had a history of gout. We excluded the PDZK1 gene from the final analysis due to its deviation from HWE (p < 0.006) across all the population subgroups, with eight loci remaining for cross-subgroup comparisons. Compared to EUR, the genetic polymorphism frequencies were significantly different-8/8 in Japanese, 6/8 in Korean, 6/8 in Filipino, 8/8 in Samoan, 6/8 in Native Hawaiian, and 6/8 in Marshallese. HU and gout risk alleles indices were 8, 6, 5, 5, 4, and 4 in Japanese, Filipino, Korean, Samoan, Marshallese, and Native Hawaiian, respectively. The percentage of cumulative risk alleles was 100% in both Japanese and Filipino, followed by 83.5% in Korean.

Conclusions

Compared to EUR, Asian subgroups, particularly Japanese, Filipino, and Korean, had the highest percentage of the cumulative uric acid risk alleles. These results could partly explain the increased risk of developing gout among some Asian ancestral subgroups compared to EUR.

Role of microRNA alternation in the pathogenesis of gouty arthritis

Gouty arthritis is a common inflammatory disease. The condition is triggered by a disorder of uric acid metabolism, which causes urate deposition and gout flares. MicroRNAs are a class of conserved small non-coding RNAs that bind to the 3' untranslated region (UTR) of mRNA and regulate the expression of a variety of proteins at the post-transcriptional level. In recent years, attention has been focused on the role of miRNAs in various inflammatory diseases, including gouty arthritis. It is thought that miRNAs may regulate immune function and inflammatory responses, thereby influencing the onset and progression of the disease. This article mainly reviewed the roles of miRNAs in the pathogenesis of gouty arthritis and prospected their potential as diagnostic and prognostic relevant biomarkers and as possible therapeutic targets.

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.

12-month results from the real-life observational treat-to-target and tight-control therapy NOR-Gout study: achievements of the urate target levels and predictors of obtaining this target

OBJECTIVES

Gout is often not adequately treated, and we aimed to apply urate lowering treatment (ULT) combined with individual information to achieve target serum urate (sUA) in clinical practice, and to identify predictors of achievement of this sUA target.

METHODS

Patients with a recent gout flare and sUA >360 µmol/L (>6 mg/dL) were consecutively included in a single-centre study and managed with a treat-to-target approach combining nurse-led information about gout with ULT. All patients were assessed with tight controls at baseline, 1, 2, 3, 6, 9 and 12 months including clinical examination, information on demographics, lifestyle, self-efficacy and beliefs about medicines. The treatment target was sUA <360 µmol/L and multivariable logistic regression was used to identify predictors of target attainment with ORs and 95% CIs.

RESULTS

Of 211 patients (mean age 56.4 years, disease duration 7.8 years, 95% males), 186 completed the 12-month study. Mean sUA levels decreased from baseline mean 500 to 311 µmol/L at 12 months with 85.5% achieving the treatment target. Alcohol consumption at least weekly versus less frequently (OR 0.14; 95% CI 0.04 to 0.55) as well as beliefs in overuse of medicines (OR per unit 0.77; 95 CI 0.62 to 0.94) decreased the chance of reaching the treatment target, while higher self-efficacy for arthritis symptoms (OR 1.49 per 10 units; 95% CI 1.09 to 2.05) increased the likelihood.

CONCLUSIONS

This study shows that target sUA can be achieved with ULT in most patients. Less self-reported alcohol consumption, low beliefs in overuse of medicines and higher self-efficacy are associated with treatment success.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Two-year reduction of dual-energy CT urate depositions during a treat-to-target strategy in gout in the NOR-Gout longitudinal study

OBJECTIVES

There is a lack of large longitudinal studies of urate deposition measured by dual-energy computed tomography (DECT) during urate lowering therapy (ULT) in people with gout. We explored longitudinal changes in DECT urate depositions during a treat-to-target strategy with ULT in gout.

METHODS

Patients with a recent gout flare and serum-urate (sUA) >360 µmol/l attended tight-control visits during escalating ULT. The treatment target was sUA <360 µmol/l, and <300 µmol/l if presence of tophi.A DECT scanner (General Electric Discovery CT750 HD) acquired data from bilateral forefeet and ankles at baseline and after one and two years. Images were scored in known order, using the semi-quantitative Bayat method, by one experienced radiologist who was blinded to serum urate and clinical data. Four regions were scored: the first metatarsophalangeal (MTP1) joint, the other joints of the toes, the ankles and midfeet, and all tendons in the feet and ankles.

RESULTS

DECT was measured at baseline in 187 of 211 patients. The mean (S.D.) serum urate level (μmol/l) decreased from 501 (80) at baseline to 311 (48) at 12 months, and 322 (67) at 24 months.DECT scores at all locations decreased during both the first and the second year (p< 0.001 for all comparisons vs baseline), both for patients achieving and not achieving the sUA treatment target.

CONCLUSIONS

In patients with gout, urate depositions in ankles and feet as measured by DECT decreased both in the first and the second year, when patients were treated using a treat-to-target ULT strategy.

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.

The Epidemiology and Genetics of Hyperuricemia and Gout across Major Racial Groups: A Literature Review and Population Genetics Secondary Database Analysis

Gout is an inflammatory condition caused by elevated serum urate (SU), a condition known as hyperuricemia (HU). Genetic variations, including single nucleotide polymorphisms (SNPs), can alter the function of urate transporters, leading to differential HU and gout prevalence across different populations. In the United States (U.S.), gout prevalence differentially affects certain racial groups. The objective of this proposed analysis is to compare the frequency of urate-related genetic risk alleles between Europeans (EUR) and the following major racial groups: Africans in Southwest U.S. (ASW), Han-Chinese (CHS), Japanese (JPT), and Mexican (MXL) from the 1000 Genomes Project. The Ensembl genome browser of the 1000 Genomes Project was used to conduct cross-population allele frequency comparisons of 11 SNPs across 11 genes, physiologically involved and significantly associated with SU levels and gout risk. Gene/SNP pairs included: ABCG2 (rs2231142), SLC2A9 (rs734553), SLC17A1 (rs1183201), SLC16A9 (rs1171614), GCKR (rs1260326), SLC22A11 (rs2078267), SLC22A12 (rs505802), INHBC (rs3741414), RREB1 (rs675209), PDZK1 (rs12129861), and NRXN2 (rs478607). Allele frequencies were compared to EUR using Chi-Square or Fisher’s Exact test, when appropriate. Bonferroni correction for multiple comparisons was used, with p < 0.0045 for statistical significance. Risk alleles were defined as the allele that is associated with baseline or higher HU and gout risks. The cumulative HU or gout risk allele index of the 11 SNPs was estimated for each population. The prevalence of HU and gout in U.S. and non-US populations was evaluated using published epidemiological data and literature review. Compared with EUR, the SNP frequencies of 7/11 in ASW, 9/11 in MXL, 9/11 JPT, and 11/11 CHS were significantly different. HU or gout risk allele indices were 5, 6, 9, and 11 in ASW, MXL, CHS, and JPT, respectively. Out of the 11 SNPs, the percentage of risk alleles in CHS and JPT was 100%. Compared to non-US populations, the prevalence of HU and gout appear to be higher in western world countries. Compared with EUR, CHS and JPT populations had the highest HU or gout risk allele frequencies, followed by MXL and ASW. These results suggest that individuals of Asian descent are at higher HU and gout risk, which may partly explain the nearly three-fold higher gout prevalence among Asians versus Caucasians in ambulatory care settings. Furthermore, gout remains a disease of developed countries with a marked global rising.

Gicht: aktuelle Epidemiologie, Komorbiditäten, Komplikationen und sozioökonomische Konsequenzen

Die Gicht gehört neben der rheumatoiden Arthritis zu den häufigsten Ursachen von Gelenkentzündungen. Als metabolisch bedingte Erkrankung geht sie meist mit Hyperurikämie und der Ablagerung von Uratkristallen in Gelenken, Sehnen und Weichteilgeweben einher, wodurch Entzündungszustände ausgelöst werden können. Die Gichtarthritis tritt weltweit insbesondere in den Industrieländern mit steigender Prävalenz auf (weltweit 0,6%), wobei die größte Häufigkeit bei den Maoris in Ozeanien (bis zu 10%) gemessen wurde. In Deutschland tritt die Gicht altersabhängig mit einer Prävalenz von 1,63% auf, wobei Männer ungefähr dreimal so häufig wie Frauen betroffen sind. Kardiovaskuläre und vor allem renale Komorbiditäten können zu vermehrten Komplikationen und einer erhöhten Sterblichkeit von Patienten mit Gicht führen. Grundsätzlich haben Gichtpatienten eine erhöhte Mortalität im Vergleich zur Gesamtbevölkerung. Die zunehmende Inzidenz führt zu steigenden Gesundheitskosten, besonders durch vermehrte Hospitalisierungen. Darüber hinaus wurden bei Gichtpatienten mehr Arbeitsunfähigkeitstage sowie reduzierte Erwerbsfähigkeit mit entsprechenden volkswirtschaftlichen Konsequenzen nachgewiesen.

The absolute risk of gout by clusters of gout-associated comorbidities and lifestyle factors-30 years follow-up of the Malmö Preventive Project

Background

Gout is predicted by a number of comorbidities and lifestyle factors. We aimed to identify discrete phenotype clusters of these factors in a Swedish population-based health survey. In these clusters, we calculated and compared the incidence and relative risk of gout.

Methods

Cluster analyses were performed to group variables with close proximity and to obtain homogenous clusters of individuals (n = 22,057) in the Malmö Preventive Project (MPP) cohort. Variables clustered included obesity, kidney dysfunction, diabetes mellitus (DM), hypertension, cardiovascular disease (CVD), dyslipidemia, pulmonary dysfunction (PD), smoking, and the use of diuretics. Incidence rates and hazard ratios (HRs) for gout, adjusted for age and sex, were computed for each cluster.

Results

Five clusters (C1–C5) were identified. Cluster C1 (n = 16,063) was characterized by few comorbidities. All participants in C2 (n = 750) had kidney dysfunction (100%), and none had CVD. In C3 (n = 528), 100% had CVD and most participants were smokers (74%). C4 (n = 3673) had the greatest fractions of obesity (34%) and dyslipidemia (74%). In C5 (n = 1043), proportions with DM (51%), hypertension (54%), and diuretics (52%) were highest. C1 was by far the most common in the population (73%), followed by C4 (17%). These two pathways included 86% of incident gout cases. The four smaller clusters (C2–C5) had higher incidence rates and a 2- to 3-fold increased risk for incident gout.

Conclusions

Five distinct clusters based on gout-related comorbidities and lifestyle factors were identified. Most incident gout cases occurred in the cluster of few comorbidities, and the four comorbidity pathways had overall a modest influence on the incidence of gout.

Global, regional and national burden of gout, 1990-2017: a systematic analysis of the Global Burden of Disease Study

OBJECTIVES

The burden of gout has been increasing globally. However, little is known about the global, regional and national distribution and time trend of this disease. We present a comprehensive analysis of the Global Burden of Disease Study 2017 on gout burden estimates for 195 countries or territories between 1990 and 2017.

METHODS

Age-standardized prevalence and disability-adjusted life-years of gout were reported between 1990 and 2017 in 195 countries and territories, and associations between these estimates and sociodemographic index (SDI) were further explored. Total and annual percent change between 1990 and 2017 were calculated to quantify the time trends of gout burden.

RESULTS

Age-standardized prevalence rates (95% uncertainty interval) per 100 000 persons were 790.90 (706.10-881.90) and 253.49 (225.69-284.02) in 2017 in males and females, respectively. The annual percent change in age-standardized prevalence (males, 0.22%; females, 0.38%) and disability-adjusted life-years (males, 0.21%; females, 0.38%) of gout increased every year from 1990 to 2017, globally. The highest increase was detected in high-SDI countries, especially in high-income North America. A non-linear association was observed between burden of gout and SDI, with the lowest estimates of gout burden when SDI value was about 0.6. High BMI was the leading risk factor for the burden of gout.

CONCLUSION

These study results suggest a globally rising trajectory of gout burden between 1990 and 2017. More effective interventions, such as detailed and intensive dietary managements and other prevention strategies for reducing obesity, should be carried out to reverse this trend, especially in females and high-SDI countries.

Ultrasound shows rapid reduction of crystal depositions during a treat-to-target approach in gout patients: 12-month results from the NOR-Gout study

OBJECTIVES

As ultrasound is sensitive for detecting crystal depositions in patients with gout, our objectives were to explore the main locations for depositions and the extent of dissolution of depositions during a treat-to-target approach with urate lowering treatment (ULT) in patients with gout.

METHODS

Patients with a recent flare of gout were consecutively included in this single-centre study and managed by a treat-to-target approach with ULT. All patients were assessed at baseline, 3, 6 and 12 months including bilateral ultrasound examinations of joints/tendons/entheses of hands, elbows, knees, ankles and feet. A new semiquantitative scoring system of 0-3 of elementary lesions (double contour (DC), tophi and aggregates) was applied to quantify the amount of depositions during the follow-up.

RESULTS

209 of the patients were evaluated with ultrasound at baseline (mean (SD) age 56.4 (13.8) years and disease duration 7.9 (7.7) years, 95.2% men). The serum urate levels decreased from baseline to 12 months (mean (SD) 500 (77) to 312 (49) µmol/L) (p<0.001)). The first metatarsophalangeal joint was the most frequent location for all the elementary lesions and erosions were associated with higher levels of crystal depositions. From baseline to 12 months, mean sum scores decreased for DC (4.3 to 1.3), tophi (6.5 to 3.8) and aggregates (9.3 to 6.7) (p<0.001 for all), with DC being most sensitive to change.

CONCLUSIONS

The ultrasound scoring system for crystal depositions was sensitive to change and showed that a treat-to-target approach with ULT resulted in significant reductions of all the depositions, most extensively for DC.

Global epidemiology of gout: prevalence, incidence, treatment patterns and risk factors

Gout is the most common inflammatory arthritis and occurs when hyperuricaemia, sustained elevation of serum urate levels resulting in supersaturation of body tissues with urate, leads to the formation and deposition of monosodium urate crystals in and around the joints. Recent reports of the prevalence and incidence of gout vary widely according to the population studied and methods employed but range from a prevalence of <1% to 6.8% and an incidence of 0.58-2.89 per 1,000 person-years. Gout is more prevalent in men than in women, with increasing age, and in some ethnic groups. Despite rising prevalence and incidence, suboptimal management of gout continues in many countries. Typically, only a third to half of patients with gout receive urate-lowering therapy, which is a definitive, curative treatment, and fewer than a half of patients adhere to treatment. Many gout risk factors exist, including obesity, dietary factors and comorbid conditions. As well as a firmly established increased risk of cardiovascular disease and chronic kidney disease in those with gout, novel associations of gout with other comorbidities have been reported, including erectile dysfunction, atrial fibrillation, obstructive sleep apnoea, osteoporosis and venous thromboembolism. Discrete patterns of comorbidity clustering in individuals with gout have been described. Increasing prevalence and incidence of obesity and comorbidities are likely to contribute substantially to the rising burden of gout.

Educational inequalities in all-cause and cause-specific mortality among people with gout: a register-based matched cohort study in southern Sweden

Background

Gout is the most common inflammatory arthritis with a rising prevalence around the globe. While educational inequalities in incidence and prevalence of gout have been reported, no previous study investigated educational inequality in mortality among people with gout. The aim of this study was to assess absolute and relative educational inequalities in all-cause and cause-specific mortality among people with gout in comparison with an age- and sex-matched cohort free of gout in southern Sweden.

Methods

We identified all residents aged ≥30 years of Skåne region with doctor-diagnosed gout (ICD-10 code M10, n = 24,877) during 1998–2013 and up to 4 randomly selected age- and sex-matched comparators free of gout (reference cohort, n = 99,504). These were followed until death, emigration, or end of 2014. We used additive hazards models and Cox regression adjusted for age, sex, marital status, and country of birth to estimate slope and relative indices of inequality (SII/RII). Three cause-of-death attribution approaches were considered for RII estimation: “underlying cause”, “any mention”, and “weighted multiple-cause”.

Results

Gout patients with the lowest education had 1547 (95% CI: 1001, 2092) more deaths per 100,000 person-years compared with those with the highest education. These absolute inequalities were larger than in the reference population (1255, 95% CI: 1038, 1472). While the contribution of cardiovascular (cancer) mortality to these absolute inequalities was greater (smaller) in men with gout than those without, the opposite was seen among women. Relative inequality in all-cause mortality was smaller in gout (RII 1.29 [1.18, 1.41]) than in the reference population (1.46 [1.38, 1.53]). The weighted multiple-cause approach generally led to larger RIIs than the underlying cause approach.

Conclusions

Our register-based matched cohort study showed that low level of education was associated with increased mortality among gout patients. Although the magnitude of relative inequality was smaller in people with gout compared with those without, the absolute inequalities were greater reflecting a major mortality burden among those with lower education.

Gout: state of the art after a decade of developments

This review article summarizes the relevant English literature on gout from 2010 through April 2017. It emphasizes that the current epidemiology of gout indicates a rising prevalence worldwide, not only in Western countries but also in Southeast Asia, in close relationship with the obesity and metabolic syndrome epidemics. New pathogenic mechanisms of chronic hyperuricaemia focus on the gut (microbiota, ABCG2 expression) after the kidney. Cardiovascular and renal comorbidities are the key points to consider in terms of management. New imaging tools are available, including US with key features and dual-energy CT rendering it able to reveal deposits of urate crystals. These deposits are now included in new diagnostic and classification criteria. Overall, half of the patients with gout are readily treated with allopurinol, the recommended xanthine oxidase inhibitor (XOI), with prophylaxis for flares with low-dose daily colchicine. The main management issues are related to patient adherence, because gout patients have the lowest rate of medication possession ratio at 1 year, but they also include clinical inertia by physicians, meaning XOI dosage is not titrated according to regular serum uric acid level measurements for targeting serum uric acid levels for uncomplicated (6.0 mg/dl) and complicated gout, or the British Society for Rheumatology recommended target (5.0 mg/dl). Difficult-to-treat gout encompasses polyarticular flares, and mostly patients with comorbidities, renal or heart failure, leading to contraindications or side effects of standard-of-care drugs (colchicine, NSAIDs, oral steroids) for flares; and tophaceous and/or destructive arthropathies, leading to switching between XOIs (febuxostat) or to combining XOI and uricosurics.

Cause-Specific Mortality in Gout: Novel Findings of Elevated Risk of Non-Cardiovascular-Related Deaths

OBJECTIVE

To examine cause-specific mortality beyond cardiovascular diseases (CVDs) in patients with gout compared to the general population.

METHODS

We included all residents of Skåne (Sweden) age ≥18 years in the year 2002. Using the Skåne Healthcare Register, we identified subjects with a new diagnosis of gout (2003-2013) and matched each person with gout with 10 comparators free of gout, by age and sex. We used information on the underlying cause of death from the Swedish Cause of Death Register (through December 31, 2014) to estimate hazard ratios (HRs, with 95% confidence intervals [95% CIs]) of mortality for specific causes of death in a multi-state Cox model, with adjustment for potential confounders.

RESULTS

Among 832,258 persons, 19,497 had a new diagnosis of gout (32% women) and were matched with 194,947 comparators. Subjects with gout had higher prevalence of chronic kidney disease, metabolic disease, and CVD. Gout was associated with 17% increased hazard of all-cause mortality overall (HR 1.17 [95% CI 1.14-1.21]), 23% in women (HR 1.23 [95% CI 1.17-1.30]), and 15% in men (HR 1.15 [95% CI 1.10-1.19]). In terms of cause-specific mortality, the strongest associations were seen in the relationship of gout to the risk of death due to renal disease (HR 1.78 [95% CI 1.34-2.35]), diseases of the digestive system (HR 1.56 [95% 1.34-1.83]), CVD (HR 1.27 [95% CI 1.22-1.33]), infections (HR 1.20 [95% CI 1.06-1.35]), and dementia (HR 0.83 [95% CI 0.72-0.97]).

CONCLUSION

Several non-CV causes of mortality are increased in persons with gout, emphasizing the need for improved management of comorbidities.

Contemporary Prevalence of Gout and Hyperuricemia in the United States and Decadal Trends: The National Health and Nutrition Examination Survey, 2007-2016

OBJECTIVE

To estimate the current prevalence rates and decadal trends of gout and hyperuricemia in the US, as well as the prevalence of urate-lowering therapy (ULT) among gout patients, using 2007-2016 data from a nationally representative survey of American men and women (the National Health and Nutrition Examination Survey [NHANES]).

METHODS

Using data from 5,467 participants in the NHANES 2015-2016, we estimated the most recent prevalence rates of gout and hyperuricemia. When the NHANES was conducted, all participants were asked about their history of gout (as diagnosed by a health professional) and medication use. Hyperuricemia was defined as having a serum urate level of >7.0 mg/dl in men and >5.7 mg/dl in women. We examined decadal trends in these estimates using data from the NHANES 2007-2016 and investigated ULT usage trends using the NHANES 2007-14 (the most recent data available to date).

RESULTS

In 2015-2016, the prevalence of gout was 3.9% among adults in the US (9.2 million people), with 5.2% [5.9 million] in men and 2.7% [3.3 million] in women. Mean serum urate levels were 6.0 mg/dl in men and 4.8 mg/dl in women, and hyperuricemia prevalence rates were 20.2% and 20.0%, respectively. The prevalence rates of gout and hyperuricemia remained stable between 2007 and 2016 (P for trend > 0.05). The prevalence of ULT use among patients with gout was 33% in 2007-2014 and remained stable over time (P for trend > 0.05).

CONCLUSION

In this nationally representative survey sample of adults in the US, the prevalence rates of gout and hyperuricemia remained substantial, albeit unchanged, between 2007 and 2016. Despite these rates, only one-third of gout patients were receiving ULT.

An evaluation of gout visits in the United States for the years 2007 to 2011

Background

This study analyzed visits for and factors associated with gout and gout medication treatment trends for the years 2007–2011 in the United States given the introduction of febuxostat, the first new treatment option for gout in over 40 years, which was introduced to the market in 2009.

Methods

This study was a retrospective, cross-sectional, observational study of patients age 20 and older seen by providers who participated in the National Ambulatory Medical Care Survey (NAMCS), the National Hospital Ambulatory Medical Care Survey Outpatient Department (NHAMCS-OPD) or Emergency Department (NHAMCS-ED) in the United States. The outcome of interest was visits for gout diagnosis and visits where a gout medication was prescribed.

Results

Approximately 1.2% of visits had a diagnosis of gout. There was a significant increase in the percentage of visits with a diagnosis of gout in years 2009–2011 compared to 2007–2008, which remained after adjusting for covariates of interest. Groups more likely to have a visit with gout included those ≥65 and 45–64 (both as compared to those 20–44), the African-American and ‘Other’ race groups (as compared to Caucasians) and those on a diuretic. Groups less likely to have a visit with gout included females, Hispanic/Latinos, those with insurance type of ‘Other’ and Medicaid (both as compared to private insurance) and visits to a hospital emergency setting (as compared to physician’s office visits).

Conclusion

Although there was a significant increase in visits where gout is diagnosed across study years, the overall percentage of visits with a gout diagnosis is low in the US population. Treatment trends over the study years has remained consistent, with the introduction of febuxostat appearing to have little impact for the study years through 2011.

Incident gout and chronic Kidney Disease: healthcare utilization and survival

Background

Uncontrolled gout can cause significant joint and organ damage and has been associated with impairments in quality of life and high economic cost. Gout has also been associated with other comorbid diseases, such as chronic kidney disease. The current study explored if healthcare resource utilization (HRU) and survival differs between patients with incident gout in the presence or absence of chronic kidney disease (CKD).

Methods

Clalit Health Services (CHS) data were used to conduct a retrospective population-based cohort study of incident gout between 1/1/2006–31/12/2009. Incident cases of gout were identified and stratified by CKD status and by age group (< 55 and 55+ years). CKD status was defined as a pre-existing diagnosis of chronic kidney disease, chronic renal failure, kidney transplantation, or dialysis at index date. Demographic and clinical characteristics, as well as healthcare resource use, were reported.

Results

A total of 12,940 incident adult gout patients, with (n = 8286) and without (n = 4654) CKD, were followed for 55,206 person-years. Higher rates of HRU were observed for gout patients with CKD than without. Total annual hospital admissions for patients with gout and CKD were at least 3 times higher for adults < 55 (mean = 0.51 vs 0.13) and approximately 1.5 times higher for adults 55+ (mean = 0.46 vs 0.29) without CKD. Healthcare utilization rates from year 1 to year 5 remained similar for gout patients < 55 years irrespective of CKD status, however varied according to healthcare utilization by CKD status for gout patients 55+ years. The 5-year all-cause mortality was higher among those with CKD compared to those without CKD for both age groups (HR_{< 55 years} = 1.65; 95% CI 1.01–2.71; HR_{55+ years} = 1.50; 95% CI 1.37–1.65).

Conclusions

The current study suggests important differences exist in patient characteristics and outcomes among patients with gout and CKD. Healthcare utilization differed between sub-populations, age and comorbidities, over the study period and the 5-year mortality risk was higher for gout patients with CKD, regardless of age. Future work should explore factors associated with these outcomes and barriers to gout control in order to enhance patient management among this high-risk subgroup.

The association between gout and cardiovascular disease in patients with atrial fibrillation

Objective

Gout is a sign of a disturbed metabolism and associated with atrial fibrillation (AF) and other cardio-vascular diseases. Our aim was to study associations between gout and cardiovascular co-morbidities in patients with AF.

Methods

The study population included all adults (n=12,283) ≥45 years diagnosed with AF visiting 75 primary care centers in Sweden 2001-2007. Logistic regression was used to calculate odds ratios with 95% confidence intervals (CIs) for the associations between prevalent gout and cardiovascular co-morbidities. In subsamples we studied incident congestive heart failure (CHF) and ischemic stroke (IS), excluding patients with earlier registered specific diagnosis, using Cox regression (to estimate hazard ratios (HR) with 95% CIs).

Results

Gout was significantly and positively associated with CHF, obesity and diabetes among men and women, and among men also with hypertension and coronary heart disease. Prevalent gout was negatively associated with incident IS (HR and 95% CI: 0.64, 0.49-0.82; 0.50, 0.39-0.64) in both full model (adjusted for sex, age, socio-economic factors and comorbidities) and CHA₂DS₂-VASc model (adjusted for CHA₂DS₂-VASc, sex and age). Adding gout to full model increased Harrell's C by 1% in CHA₂DS₂-VASc model.

Conclusions

In this clinical setting we found gout to be associated with most cardiometabolic diseases except cerebrovascular diseases, and with decreased risk of IS, with gout adding significantly to the predictive value compared to CHA₂DS₂-VASc without gout included.

U. A, Adeeb F, Fraser AD, Stack AG. Prevalence and treatment of gout among patients with chronic kidney disease in the Irish health system: A national study

Background

Gout is a common inflammatory arthritis associated with adverse clinical outcomes. Under treatment is common in the general population. The aim of this study was to determine the prevalence of gout and its treatment among patients with chronic kidney disease (CKD).

Methods

We conducted a multi-centre cross sectional study of patients (n = 522) who attended specialist nephrology clinics in Ireland. Standardized data collection tool recorded clinical characteristics and medication use at clinic visits and kidney function was assessed with standardised creatinine measurements and Estimated Glomerular Filtration Rate (eGFR). The prevalence of gout and the corresponding use of urate lowering therapies (ULT) were determined. Multivariate logistic regression explored correlates of gout expressed as Odds Ratios (OR) and 95% Confidence Intervals (CI) adjusting for demographic and clinical characteristics.

Results

Overall prevalence of gout was 16.6% and increased significantly from 7.5% in Stage 1–2 CKD to 22.8% in stage 4–5 CKD, P< 0.005. Prevalence increased with age (P < 0.005) and was higher in men than women (19.1% versus 10.3% P< 0.005). Overall, 67.9% of gout patients with CKD were treated with ULT, and the percentage increased with advancing stage of CKD from 55.6% in Stage 1–2 to 77.4% in Stage 4–5, P<0.005. Multivariable modelling identified men (vs women), OR, 1.95 (0.95–4.03), serum albumin, OR 1.09 (1.02–1.16) per 1 g/L lower, poorer kidney function, OR 1.11 (1.01–1.22) per 5 ml/min/1.73m² lower, and rising parathyroid hormone levels, OR 1.38 (1.08–1.77) per 50 pg/ml higher as disease correlates.

Conclusions

Gout is common in CKD and increases with worsening kidney function in the Irish health system. Over two thirds of patients with gout were receiving ULT, increasing to 77% of patients with advanced CKD. Greater awareness of gout in CKD, its treatment and the effectiveness of treatment strategies should be vigorously monitored to improve patient outcomes.

Secular trends in the incidence and prevalence of gout in Denmark from 1995 to 2015: a nationwide register-based study

Objective

To investigate temporal trends in the incidence and prevalence of gout in the adult Danish population.

Methods

Using the nationwide Danish National Patient Registry, we calculated the number of incident gout patients (per 100 000 person-years) within each 1 year period from 1995 to 2015 and the prevalence of gout in 2000 and 2015. Further, we calculated age- and gender-specific incidence rates of gout from 1995 to 2015.

Results

We identified a total of 45 685 incident gout patients (72.9% males) with a mean age of 65 years (s.d. 16) at diagnosis. In both genders, an increase in age-standardized incidence rates was observed from 32.3/100 000 (95% CI 30.7, 33.9) in 1995 to 57.5/100 000 (95% CI 55.6, 59.5) in 2015 (P < 0.001). Similar trends were observed for 8950 cases diagnosed in rheumatology departments. We likewise observed an increase in the prevalence of gout from 0.29% (95% CI 0.29, 0.30) in 2000 to 0.68% (95% CI 0.68, 0.69) in 2015.

Conclusions

The annual incidence rate of gout increased by almost 80% in Denmark between 1995 and 2015. The prevalence increased by nearly 130% between 2000 and 2015. Reasons for this are unknown but may include an increase in risk factors (e.g. obesity, diabetes mellitus), longer life expectancy and increased awareness of the disease among patients and/or health professionals.

Recognition of gout in rheumatoid arthritis: A case report

RATIONALE

Rheumatoid arthritis (RA) and gout are common rheumatic diseases. However, their coexistance has been rarely reported. Here in, we describe a case of a middle aged Chinese woman having RA complicated with atypical gout on both the knee joints.

PATIENT CONCERNS

A 44-year-old Chinese woman complained of swelling and tenderness of multiple joints since 10 months. She had a positive rheumatoid factor and high titers of anti-CCP antibody. She was diagnosed with RA, and commenced on methotrexate, leflunomide, and methylprednisolone. Her symptoms of pain and swelling over interphalangeal and wrists joints subsided except the knee joints. She was started with treat to target treatment (TTT) for RA and rest of her medications was adjusted accordingly. Surprisingly, her symptoms did not improve ever after the addition of a biologic agent, tumor necrosis factor (TNF)-α receptor antagonist.

DIAGNOSIS

Presence of urate crystals in the synovium was viewed under polarization microscope which was extracted from one of the knee joint. Hence, we established the diagnosis of RA complicated with gout.

INTERVENTIONS

We commenced her on TNF-α receptor antagonist, colchicines, and febuxostat.

OUTCOMES

Her symptoms of pain and swelling improved significantly on both the knees and no longer recurred.

LESSONS

Coexistence of RA and gout has been rarely reported as it is not frequently seen in clinical practice. Hence, when patients with RA with oligoarthritis repeatedly do not respond to TTT, a standard antirheumatism treatment, the possibility of RA complicating with gout should be rule out.

Increasing trend of asymptomatic hyperuricemia under treatment with urate-lowering drugs in Japan

Objectives: To describe recent trends in the prevalence of gout and asymptomatic hyperuricemia regarding urate-lowering treatment (ULT) in Japan. Methods: A database of health insurance claims managed by the Japan Medical Data Center was used to estimate the annual prevalence of gout and asymptomatic hyperuricemia during 2010-2014. ULT was evaluated for status of the two diseases during the same period. The significance of time trends was evaluated by Cochrane-Armitage trend test. Results: The prevalence of physician-diagnosed gout in men aged 20-64 years was 1.54% (95% CI: 1.49%-1.58%) in 2010, with a slight but significant (p < 0.001) annual increase, up to 1.66% (95% CI: 1.62%-1.71%) in 2014. In women, gout prevalence was somewhat constant about 0.09% during 2010-2014. Among male patients with gout, 78% received ULT. The prevalence of male patients with asymptomatic hyperuricemia in the same age range, who received ULT, increased significantly from 1.77% (95% CI: 1.72%-1.81%) to 2.14% (95% CI: 2.09%-2.19%) during 2010-2014 (p < 0.001). Conclusion: Gout prevalence in adult men in Japan has increased significantly in recent years. The prevalence of asymptomatic hyperuricemia under ULT has also increased significantly and was higher than that of gout.

The risk of clinically diagnosed gout by serum urate levels: results from 30 years follow-up of the Malmö Preventive Project cohort in southern Sweden

Background

Hyperuricemia (HU) is in the causal pathway for developing clinical gout. There are few population-based assessments of the absolute and relative risk of clinically diagnosed incident gout in subjects with HU. We aimed to explore the long-term risk of developing incident gout among asymptomatic adults with different levels of serum urate (SU).

Methods

Malmö Preventive Project was a population-based screening program for cardiovascular risk factors, alcohol abuse, and breast cancer in Malmö, Sweden. The study population was screened between 1974 and 1992. At baseline, subjects were assessed with a questionnaire, physical examination, and laboratory tests. Follow-up ended at first gout diagnosis, death, moving from area, or December 31, 2014. Incident gout (using ICD10 codes) was diagnosed based on national registers for specialized inpatient and outpatient care, and from 1998 onward in the Skåne Healthcare Register including primary healthcare. Incidence rates, absolute risk, hazard ratios (HRs) and potentially associated factors were analyzed by baseline SU levels, i.e. normal levels (≤ 360 μmol/L); 361–405 (levels below tissue solubility of SU), and > 405 (HU), overall, and by sex.

Results

Overall, 1275 individuals [3.8%; 1014 men (4.5%) and 261 women (2.4%)] of the 33,346 study participants (mean age: 45.7 (SD: 7.4), 67% men), developed incident gout during follow-up (mean 28.2 years). Of those with HU, 14.7% of men and 19.5% of women developed gout. Compared to subjects in the lowest SU category, the age-adjusted HR in men increased from 2.7 to 6.4, and in women from 4.4 to 13.1 with increasing baseline SU category, and with a statistically significant interaction of sex (p < 0.001). Body mass index, estimated glomerular filtration rate (negative), triglycerides, alcohol risk behavior (only in men), and comorbidities such as hypertension, cardiovascular disease, and diabetes were strongly associated with SU at baseline in both sexes.

Conclusions

The absolute risk for developing clinically diagnosed gout over 30 years in middle-aged subjects was 3.8%, and increased progressively in both men and women in relation to baseline SU. This risk increase was significantly higher in women than in men, whereas the associations between baseline risk markers and SU levels were similar in both sexes.

Goals of gout treatment: a patient perspective

To assess the goals of gout treatment from a patient perspective, a convenience sample of consecutive patients with doctor-diagnosed gout seen at a community-based outpatient clinic were invited. Sex-stratified nominal groups were conducted until saturation was achieved. Responses were collected verbatim, discussed, and rank-ordered by each participant. Thirty-six patients with doctor-diagnosed gout participated in 12 nominal groups: 6 male only, 5 female only, and 1 group with both. Mean age was 61.9 years (SD, 12.3); mean gout duration was 13.3 years (SD, 12.5); 53% were men, 64% African-American, 42% retired, 47% currently married, 87% were using either allopurinol and/or febuxostat, and 40% had had no gout flares in the last 6 months. The top 5 treatment goals accounted for 91% of all votes and included the following: (1) prevent and better manage flare-ups and improve function (25%), (2) eliminate flare-ups/disease remission (30%), (3) diet and activity modification/lifestyle change (13%), (4) patient education and public awareness (12%), and (5) medication management and minimization of side effects (11%). When examining the top-rated concern for each nominal group, the first two goals were nominated by four groups each, diet/activity modification and medication management by 1 group each, and patient education by 3 groups. There were no differences evident by sex in top-ranked treatment goal. People with gout identified and rank-ordered treatment goals relevant to them. Providers of gout care need to be cognizant of these goals. Disease management concordant with these treatment goals might lead to a more satisfied, informed patient.

Gout and the risk of incident atrial fibrillation in older adults: a study of US Medicare data

Objective

To assess the association of gout with new-onset atrial fibrillation (AF) in the elderly.

Methods

We used the 5% Medicare data from 2005 to 2012 to assess whether a diagnosis of gout was associated with incident AF. We used multivariable Cox regression adjusted for demographics, Charlson-Romano comorbidity index, common cardiovascular medications, allopurinol and febuxostat use, to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

Among 1 647 812 eligible people, 9.8% had incident AF. The mean age was 75 years, 42% were male, 86% were white and the mean Charlson-Romano index score was 1.52. We noted 10 604 incident AF cases in people with gout and 150 486 incident AF cases in people without gout. The crude incidence rates of AF in people with and without gout were 43.4 vs 16.3 per 1000 patient-years, respectively. After multivariable-adjustment, gout was associated with a higher HR of incident AF, 1.92 (95% CI 1.88 to 1.96), with minimal attenuation of HR in sensitivity models that replaced the Charlson-Romano index score with a categorical variable, HR was 1.91 (95% CI 1.87 to 1.95). In another model that adjusted for AF-specific risk factors including hypertension, hyperlipidaemia and coronary artery disease and individual Charlson-Romano index comorbidities, the HR was slightly attenuated at 1.71 (95% CI 1.67 to 1.75). Older age, male sex, white race and higher Charlson-Romano index score were each associated with higher hazard of incident AF.

Conclusion

A diagnosis of gout almost doubled the risk of incident AF in the elderly. Future studies should explore the pathogenesis of this association.

Managing Gout Flares in the Elderly: Practical Considerations

Gout is common in the elderly, affecting an estimated 4.7 million people aged > 60 years in the USA alone. The incidence and prevalence of gout increases, and male predisposition to gout reduces, with increasing age. The elderly have more comorbidities, and gout manifests differently, with more frequent involvement of knees, ankles, and wrists at disease onset, systemic upset, and tophi. Comorbidities and polypharmacy make the management of gout flares challenging in this population. Intra-articular corticosteroid injection remains the treatment of choice for accessible joints, oral prednisolone is preferred over low-dose colchicine, and non-steroidal anti-inflammatory drugs (NSAIDs) are best avoided. Xanthine oxidase inhibitors (XOI) remain the first-line treatment for hyperuricemia in the elderly. Arhalofenate, an emerging uricosuric anti-inflammatory drug, prevents gout flares while reducing serum urate. It may be particularly relevant in the treatment of gout in the elderly as they are unable to tolerate long-term colchicine for flare prophylaxis and frequently have contraindications to corticosteroids and NSAIDs. However, given its modest urate-lowering effect, it can only be used in combination with an XOI, and the safety and efficacy of this drug has not been examined in the elderly or in those with chronic kidney disease. Diuretics and beta-blockers should be discontinued where feasible, whereas low-dose aspirin can be continued if otherwise indicated.

Burden of gout in the Nordic region, 1990-2015: findings from the Global Burden of Disease Study 2015

OBJECTIVE

To explore the burden of gout in the Nordic region, with a population around 27 million in 2015 distributed across six countries.

METHOD

We used the findings of the 2015 Global Burden of Diseases study to report prevalence and disability associated with gout in the Nordic region.

RESULTS

From 1990 to 2015, the number of prevalent gout cases rose by 30% to 252 967 [95% uncertainty interval (UI) 223 478‒287 288] in the Nordic region. In 2015, gout contributed to 7982 (95% UI 5431‒10 800) years lived with disability (YLDs) in the region, an increase of 29% (95% UI 24‒35%) from 1990. While the crude YLD rate of gout increased by 12.9% (95% UI 7.8‒18.1%) between 1990 and 2015, the age-standardized YLD rate remained stable. Gout was ranked as the 63rd leading cause of total YLDs in the region in 2015, with the highest rank in men aged 55-59 years (38th leading cause of YLDs). The corresponding rank at the global level was 94. Of 195 countries studied, four Nordic countries [Greenland (2nd), Iceland (12th), Finland (14th), and Sweden (15th)] were among the top 15 countries with the highest age-standardized YLD rate of gout.

CONCLUSION

The burden of gout is rising in the Nordic region. Gout's contribution to the total burden of diseases in the region is more significant than the global average. Expected increases in gout burden owing to population growth and ageing call for stronger preventive and therapeutic strategies for gout management in Nordic countries.