Determinants of the prevalence of gout in the general population: a systematic review and meta-regression

Gout and risk of venous thromboembolism: A systematic review and meta-analysis of cohort studies

BACKGROUND

The association between gout and venous thromboembolism (VTE) remains ambiguous, and the results of current studies are inconsistent. A systematic review and meta-analysis of cohort studies were conducted to comprehensively assess the associations between gout and VTE and its subtypes, deep venous thrombosis (DVT) and pulmonary embolism (PE).

METHODS

PubMed, Web of Science, Embase, Scopus, and the Cochrane Library databases were searched up to June 2021, to identify eligible cohort studies, reporting the association of gout with VTE and its subtypes. We pooled hazard ratios (HRs) with 95% confidence intervals (CIs). Subgroup analysis, sensitivity analysis, and publication bias tests were also conducted.

RESULTS

Five studies involving 642 632 individuals were included. Patients with gout had a statistically significantly higher risk of VTE (HR: 1.33; 95% CI: 1.21, 1.46; P < .001) compared with non-gout controls, and significant associations were also found between gout and DVT (HR: 1.40; 95% CI: 1.22, 1.62; P < .001) and PE (HR: 1.18; 95% CI: 1.07, 1.30; P = .001). Subgroup analysis showed this association in men (HR: 1.37; 95% CI: 1.14, 1.65; P = .001) and women (HR: 1.36; 95% CI: 1.21, 1.53; P < .001) were consistent (P = .980). Meta-regression analysis revealed publication year (P = .005) and quality of study (P = .006) contributed to heterogeneity.

CONCLUSIONS

In conclusion, our study provided evidence that gout was associated with the risk of VTE and its subtypes DVT and PE. However, more prospective and high-quality clinical evidence is required to confirm our findings.

Infected nasal gout tophus: A case report

Gout is a common form of inflammatory arthritis, characterized by the deposition of monosodium urate crystals. If chronically present and not adequately treated by serum urate reducers, gout tophi can develop at various locations. Here, we report the first infected gout tophus at the septal cartilage and nasal tip.

Cynarin suppresses gouty arthritis induced by monosodium urate crystals

The study is aimed to determine the effects of cynarin (Cyn) on mice with gouty arthritis (GA) induced by monosodium urate (MSU). We measured swelling in the hind paws of mice in vivo using Vernier calipers and ultrasound. The liver, kidney, and hind paws were stained with hematoxylin-eosin, and M1 type macrophages were detected in the hind paws using anti-F4/80 and anti-iNOS antibodies. The mRNA expression of inflammatory factors in bone marrow-derived macrophages (BMDMs) and in the hind paws was detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain containing 3 (NLRP3) inflammasomes and the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways were analyzed via western blotting. Cyn was detected in vitro using Cell Counting Kit-8 (CCK-8). Cyn treatment reduced hind paw swelling and M1 macrophage infiltration, suppressed the mRNA expression of inflammatory factors, and inhibited NLRP3 inflammasome activation in vivo, in addition to inhibiting the phosphorylation of IKKa/β, p65, and c-Jun NH 2-terminal kinase (JNK). Furthermore, Cyn exerted anti-inflammatory and anti-swelling effects in mice with GA by regulating the NF-κB and JNK pathways and NLRP3 inflammasomes.

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.

Association Between Use of Anti-gout Preparations and Dementia: Nested Case-Control Nationwide Population-Based Cohort Study

Objectives: Gout is the most common form of inflammatory arthritis and was found to be independently associated with incident dementia in the elderly. However, the associations between anti-gout preparations and dementia were not well-studied.

Methods: Data were collected from Taiwan's National Health Insurance Research Database (NHIRD). A 2005–2013 retrospective cohort study was conducted, and all investigated subjects were identified by International Statistical Classification of Diseases and Related Health Problems, 9th Revision, Clinical Modification. Conditional logistic regression was used to evaluate the odds ratio of dementia in relation to different gout preparations (benzbromarone, allopurinol, sulfinpyrazone, probenecid) and number of days of anti-gout preparation use, after adjustment for potential confounding variables.

Results: A total of 3,242 gout patients with and without dementia were selected from the NHIRD and included in the final analysis after 1:1 matching for age, gender, and diagnosis year of gout. In the anti-gout preparations, only use of Benzbromarone decreased the risk of dementia (adjusted OR, 0.81; 95% CI, 0.68–0.97). The result of the subgroup analysis revealed a trend toward a lower risk of dementia with longer use of benzbromarone. Use of benzbromarone for ≥180 days showed a significantly lower risk of dementia (adjusted OR, 0.72; 95% CI, 0.58–0.89). Moreover, the protective effect was more pronounced in males compared with females.

Conclusion: This cohort study reveals that gout patients taking benzbromarone are at a decreased risk of developing incident dementia, especially with longer use and in male. Further prospective trials are warranted to confirm our findings.

The prevalence of gout and hyperuricaemia in Australia: An updated systematic review

BACKGROUND

Gout continues to increase in prevalence in developed countries with Oceanic countries particularly affected. Both gout and hyperuricaemia are associated with the metabolic syndrome and its sequelae. Recently, the Australian Institute for Health and Welfare (AIHW) reported a prevalence rate of 0.8% which appeared incongruous with other published research. Thus, an updated systematic review was undertaken to review the literature on the prevalence of gout and hyperuricaemia in Australia from data published after 2011.

METHODS

A comprehensive, systematic search was conducted in MEDLINE, Embase and Web of Science in addition to relevant websites to identify research reporting the prevalence of gout and/or hyperuricaemia in Australia from May 2011 until June 2020. Crude gout and hyperuricaemia prevalence data was obtained and presented alongside case ascertainment, time-period, age range and stratified by gender if available.

RESULTS

118 full text articles were screened. 12 articles were included for analysis of gout prevalence. 4 articles were identified for the hyperuricaemia analysis. Wide variation in prevalence figures exist largely due study design and sample age range. Studies using a case definition of self-reported diagnosis of gout reported prevalence rates between 4.5% and 6.8%. The remaining studies used either electronic coding data from general practitioners or wastewater estimation of allopurinol consumption and documented adult prevalence rates between 1.5% and 2.9%. Prevalence increases with age, male sex and over time in keeping with global data. Hyperuricaemia prevalence ranged between 10.5% and 16.6% in Caucasian or an Australian representative population. AIHW estimates applied a chronic condition status, defined as current and lasted or expected to last more than six months, to cases of gout in the Australian National Health Survey. This likely results in an under-estimation in reported Australian gout prevalence rates.

CONCLUSIONS

Gout is highly prevalent in Australia compared to global comparisons and continues to increase over time. Hyperuricaemia prevalence is also high although contemporary data is limited.

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.

Diagnosis and management of gout by clinicians in Nepal: a web-based survey

Patients with gout in Nepal are usually attended by medical graduates, family medicine, internists, and orthopedic surgeons. The study aimed to evaluate knowledge, attitude, and practice (KAP) of point-of-care clinicians of Nepal regarding diagnosis and management of gout and assess the quality of treatment provided to the patients. A web-based descriptive, cross-sectional study was conducted among doctors managing gout patients. The questionnaire comprises 38 multiple choice questions; 9 questions for demographic data, 8, 11, and 10 questions each for knowledge, attitude, and practice, respectively. A pilot study was conducted to observe comprehensibility of the questionnaire before subjecting it to the participants. Ethical approval was obtained from review committee of National Center for Rheumatic diseases, Nepal. Simple descriptive statistics was used to describe the correct responses. Among 1200 clinicians invited, 32% (380) participated in the survey. Maximum respondents were of age group 25-45 years (82%) with majority being internists (43%). Although only 32% understood that the disease is not curable, knowledge regarding disease was acceptable in majority (60-90%). Around 83% denied attending any gout-related seminars and 34% denied being updated with the recent guidelines. The majority of postgraduates (72%) managed the cases themselves. Although there was acceptable practice accuracy on use of therapy for acute attacks (75%), target urate levels (57%), and use of urate-lowering agents (92%), they lacked in adequate screening of co-morbidities and initiation of long-term treatment. The point-of-care clinicians have adequate knowledge to diagnose and treat acute events. However, there is poor reflection in practice and frequent update of treatment guidelines is warranted.

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.

Comparative Study of Real-Life Management Strategies in Gout: Data From Two Protocolized Gout Clinics

OBJECTIVE

To compare outcomes of 2 gout clinics that implemented different treatment strategies.

METHODS

Patients newly diagnosed with gout and a follow-up of 9-15 months were included. Co-primary outcomes were the proportion of patients reaching a serum uric acid (UA) ≤0.36 mmoles/liter and free of flares. Secondary outcomes were the proportion of patients requiring treatment intensification and experiencing adverse events. One clinic adopted a strict serum UA (≤0.30 mmoles/liter target) strategy, with early addition of a uricosuric to allopurinol, and the other clinic adopted a patient-centered (PC) strategy emphasizing a shared decision based on serum UA and patient satisfaction with gout control. Independent t-tests or chi-square tests were used to test differences in outcomes, and logistic regressions were used to adjust the effect of the treatment center on outcomes for confounders.

RESULTS

In total, 126 and 86 patients had a follow-up mean ± SD of 11.3 ± 1.8 versus 11.1 ± 1.9 months. In the UA strategy, 105 of 126 patients (83%) compared to 63 of 86 (74%) in the PC strategy (P = 0.10) reached the threshold of ≤0.36 mmoles/liter; and 58 of 126 (46%) versus 31 of 86 (36%) were free of flares (P = 0.15). In the UA strategy, 76 of 126 patients (60%) were on allopurinol monotherapy compared to 63 of 86 (73%) in the PC strategy (P = 0.05), yet the number of adverse events was not different (n = 25 [20%] versus n = 20 [23%]; P = 0.55). Adjusting for confounders did not substantially change these associations.

CONCLUSION

A strict UA strategy resulted in a nonsignificantly higher proportion of patients reaching a serum UA ≤0.36 mmoles/liter and being free of flares. This result was accomplished with significantly more therapy intensification. The small sample size plays a role in the significance of results.

Disseminated Cutaneous Tophi in a Patient with Chronic Tophaceous Gout and Renal Impairment: A Case Report of a Rare Manifestation of Gout

BACKGROUND Gout is a metabolic disease characterized by deposition of monosodium urate (MSU) crystals called tophi. The typical location of tophi is in the joint and will chronically damage the joint. However, there is a rare atypical dermatologic manifestation of tophi that occur extensively in the skin. CASE REPORT A 46-year-old male presented with acute pain in multiple joints. He had a history of gouty arthritis with recurrence attacks, in the past 2 years ago. Over time, he had gradual eruption of multiple tophi and multiple yellowish nodules under his skin which sometimes would ulcerate. Laboratory value showed creatinine 2.3 mg/dL and uric acid 11.5 mg/dL. Ultrasound of the kidney showed nephrocalcinosis appearance. Urate crystal was identified in skin biopsy of the nodules. We diagnosed the patient with chronic tophaceous gout with extensive cutaneous involvement. Given the renal impairment, we gave methylprednisolone 3 doses of 8 mg for 5 days then tapered off, colchicine 0.5 mg every other day and allopurinol 1 dose of 100 mg. The patient had dramatic improvement of his pain and is now being followed up regularly. CONCLUSIONS We describe a rare and severe extensive cutaneous manifestation in a chronic tophaceous gout patient.

Characteristics of the Urinary Microbiome From Patients With Gout: A Prospective Study

The role of host microbes in the pathogenesis of several diseases has been established, and altered microbiomes have been related to diseases. However, the variability of the urinary microbiome in individuals with gout has not been evaluated to date. Therefore, we conducted the present prospective study to characterize the urinary microbiome and its potential relation to gout. Urine samples from 30 patients with gout and 30 healthy controls were analyzed by Illumina MiSeq sequencing of the 16S rRNA hypervariable regions, and the microbiomes were compared according to alpha-diversity indices, complexity (beta diversity) with principal component analysis, and composition with linear discriminant analysis effect size. The most significantly different taxa at the phylum and genus levels were identified, and their potential as biomarkers for discriminating gout patients was assessed based on receiver operating characteristic (ROC) curve analysis. Compared with the healthy controls, there was a dramatic decrease in microbial richness and diversity in the urine of gout patients. The phylum Firmicutes and its derivatives (Lactobacillus_iners, Family_XI, and Finegoldia), the phylum Actinobacteria and its derivatives (unidentified_Actinobacteria, Corynebacteriales, Corynebacteriale, Corynebacterium_1, and Corynebacterium_tuberculostearicum), and the genera Prevotella and Corynebacterium_1 were significantly enriched in the urine of gout patients. ROC analysis indicated that the top five altered microbial genera could be reliable markers for distinguishing gout patients from healthy individuals. These findings demonstrate that there are specific alterations in the microbial diversity of gout patients. Thus, further studies on the causal relationship between gout and the urinary microbiome will offer new prospects for diagnosing, preventing, and treating gout.

Rapid Gout Detection Method and Kit

Gout is a form of arthritis characterized by buildup of uric acid in synovial fluid, which causes severe swelling and can harm joints, tendons, and other tissues. It affects approximately 4% of the United States population, or approximately 8.3 million people nationwide and is therefore a topic of epidemiologic consideration due to its prevalence. Gout is typically diagnosed via polarized microscopy of arthroscopically-aspirated synovial fluid, which is a costly, time-consuming, labor-intensive, and technically complex procedure, warranting a simpler and less complex method for diagnosis. Here, we propose and validate a colorimetric method which is based on the ability of uric acid to reduce silver nitrate. We also assessed how the colorimetric change can be accelerated by changing the concentration of silver nitrate or adding different silver catalysts, as well as develop a matrix bed for improved handling and ease of use. When translated to the clinic, this diagnostic method for gout will have the potential to increase diagnostic efficiency and accelerate patient care at the bedside.

Tophaceous gout of the middle ear

We present a very rare case of tophaceous gout of the middle ear causing conductive hearing loss, with special emphasis on Computed Tomography presentation.

Gout, flares, and allopurinol use: a population-based study

BACKGROUND

There is a paucity of community-based data regarding the prevalence and impact of gout flares as these may often be self-managed. The aim of this study was to determine the prevalence of self-reported gout and gout flares, the use of urate-lowering therapy (ULT), and the association of gout flares with health-related quality of life (HRQoL) in a large community sample. Covariate associations with flare frequency and allopurinol use were also examined.

METHODS

The South Australian Health Omnibus Survey is an annual, face-to-face population-based survey. Data collected in the 2017 survey included self-reported medically diagnosed gout, allopurinol use (first-line ULT in Australia), and gout attacks (flares) in the last 12 months, in addition to sociodemographic variables and health-related quality of life (HRQoL, SF-12). Data were weighted to the Australian Bureau of Statistics 2016 census data to reflect the South Australian population. Participants 25 years and over (n = 2778) were included in the analysis.

RESULTS

The prevalence of gout was 6.5% (95%CI 5.5, 7.5). Amongst participants with gout, 37.1% (95%CI 29.6, 45.3) reported currently using allopurinol, while 23.2% (95%CI 16.9, 21.0) reported prior use (38% discontinuation rate). Frequent flares (≥ 2 in the last year) were reported by 25% of participants with gout and were more likely with younger age, higher body mass index, and current allopurinol use (p < 0.05). The frequency of gout flares was associated with a lower physical HRQoL (p = 0.012). Current allopurinol use was reported by 51% of participants with frequent gout flares.

CONCLUSION

Flares were frequently reported by people with gout in the community. Gout flares were associated with reduced physical HRQoL. Almost one half of people with frequent gout flares were not receiving allopurinol, and current allopurinol use was associated with frequent gout flares, suggesting undertreated disease and suboptimal use of ULT. Determining covariate associations with flares and ineffective allopurinol use may identify means of improving treatment and reducing flares.

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.

Overview of changes in RMD epidemiology and outcome development in the last 10 years

Epidemiological studies have been affected by environmental (or technological and societal) changes in the last 10 years, such as the emergence of registries, big data and machine learning algorithms, epigenetics, data protection regulations or a more solid presence of the patient perspective in outcomes research. As a consequence we, epidemiologists, are facing challenges in the design, conduct, and analysis of the studies, as well as on the interpretation of the results. Not everything that is new may be better than the old ways of doing epidemiology. In this article, we will review pros and cons of new technologies and regulations on epidemiological research, as well as ways to tackle obstacles and co-living of old and new methods.

Outcomes following laparoscopic Roux-en-Y gastric bypass (LRYGB) vary by sex: Analysis of 83,059 women and men with morbid obesity

BACKGROUND

Previously we have reported variation in pre-operative clinical characteristics between women and men undergoing laparoscopic roux-en-Y gastric bypass (LRYGB). However, variation by sex in post-operative outcomes following LRYGB has not been investigated.

METHODS

Pre-operative data was compared to follow-up data at 12 months after surgery on 83,059 patients from the Surgical Review Corporation's BOLD database. Data included age, weight, BMI, and 31 obesity-related medical conditions.

RESULTS

Men had increased weight, actual weight lost, and BMI. Women had higher rates of gastrointestinal and mental health disorders. Men failed to resolve cardiopulmonary/vascular and metabolic derangements, abdominal hernia, and were more functionally impaired than women.

CONCLUSIONS

Overall, women may benefit more from LRYG than men, as their pre-operative conditions showed greater improvement at 12 months post-op. This advance knowledge may aid LRYGB planning and improve outcomes.

Gout prevalence and predictors of urate-lowering therapy use: results from a population-based study

Background

Gout has an increasing global prevalence. Underutilization of urate-lowering therapy (ULT) is thought to be common, via both suboptimal dosing and poor medication adherence. The aims of this study were to determine the prevalence of self-reported gout and the key predictors of ULT use in those with gout in a representative population survey in South Australia.

Methods

Data were obtained from the Spring 2015 South Australian Health Omnibus Survey, a multilevel, systematic, survey in a representative population sample involving face-to-face interviews (n = 3005). This study analyzed responses from respondents aged ≥ 25 years (n = 2531) about self-reported gout, ULT use, sociodemographic factors, lifestyle factors, and comorbidities, using survey weighting. Univariate and subsequent adjusted logistic regression analyses on self-reported gout were performed. ULT use was divided into three categories (never use, prior use, and current use) and these data were analyzed using a multinomial logistic regression model.

Results

Self-reported gout prevalence was 6.8% (95% CI 5.8, 7.9). The mean age of respondents with gout was 64 years (standard deviation 16) and 82% were male. As expected, older age, male gender, lower socioeconomic status (SES), and higher body mass index (BMI) were associated with gout, as were high alcohol consumption, current smoking, other forms of arthritis, and hypertension or hypercholesterolemia medication, after adjustment for sociodemographic variables. Two thirds of respondents with gout reported ULT use (36% current; 29% previous) with only 55% continuing treatment. Predictors of ULT use included male gender, low SES, and concomitant cholesterol-lowering therapy. Respondents with gout with a higher BMI were more likely to remain on ULT.

Conclusions

Despite gout being a common, potentially disabling joint disease, only 55% of respondents with gout in this study adhered to ULT. Identification of key predictors of ULT use will provide guidance on prescribing strategy in clinical practice and on the quality of gout care in the community.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1633-9) contains supplementary material, which is available to authorized users.

Gout as a risk factor for osteoporosis: epidemiologic evidence from a population-based longitudinal study involving 108,060 individuals

Is gout a risk factor for future osteoporosis? This large population-based study comprising two matched groups of individuals with and without gout demonstrates that patients with gout have a 20% increase in the risk of developing osteoporosis in future through an 8-year follow-up.

INTRODUCTION

To examine if gout is associated with an increased risk of osteoporosis.

METHODS

We conducted a nationwide population-based retrospective matched-cohort study. Two matched cohorts (n = 36,458 with gout and 71,602 without gout) assembled and recruited from the Longitudinal Health Insurance Dataset containing 1 million subjects. Exclusion criteria were missing data, age < 20 years, short follow-up period, and pre-existing osteoporosis. Both cohorts were followed up until incident osteoporosis, death, or the end of the study. Person-year data and incidence rates were evaluated. A multivariable Cox model was used to derive an adjusted hazard ratio (aHR) after controlling for socioeconomic proxy, geographical difference, glucocorticoid and allopurinol exposure, various prespecified medical conditions, and comorbidities.

RESULTS

Men comprised 72.8% of the cohorts. With a follow-up of 183,729 and 359,900 person-years for the gout and non-gout cohorts, 517 and 811 incidents of osteoporosis occurred, respectively, after excluding osteoporosis incidents in the first 3 years of follow-up. The cumulative incidence of osteoporosis was statistically higher in the gout cohort than in the non-gout cohort, at 3.3 versus 2.1% (P = 0.0036, log-rank). Our Cox model showed a 1.2-fold increase in the incidence of osteoporosis in the gout cohort, with an aHR of 1.2 (95% confidence interval, 1.06-1.35).

CONCLUSIONS

This first population-based epidemiologic study supports the hypothesis that compared with individuals without gout; those with gout have a modest increase in the risk of developing osteoporosis in future.

Gout Classification Criteria: Update and Implications

Gout is the most common inflammatory arthritis, with a rising prevalence and incidence worldwide. There has been a resurgence in gout research, fueled, in part, by a number of advances in pharmacologic therapy for gout. The conduct of clinical trials and other observational research in gout requires a standardized and validated means of assembling well-defined groups of patients with gout for such research purposes. Recently, an international collaborative effort that involved a data-driven process with state-of-the art methodology supported by the American College of Rheumatology and the European League Against Rheumatism led to publication of new gout classification criteria.

Risk of infections in patients with gout: a population-based cohort study

To investigate the risk of various types of infections (pneumonia and urinary tract infection (UTI)), and infection-related mortality in patients with gout compared with population-based controls. A retrospective cohort study was conducted using data from the UK Clinical Practice Research Datalink (CPRD). All patients with a first diagnosis of gout and aged >40 years between January 1987-July 2014, were included and matched with up to two controls. Time-varying Cox proportional hazards models were used to estimate the risk of infections and mortality. 131,565 patients and 252,763 controls (mean age: 64 years, 74% males, mean follow-up of 6.7 years) were included in the full cohort. After full statistical adjustment, the risk of pneumonia was increased (adj. HR 1.27, 95% CI 1.18 to 1.36), while the risk of UTI (adj. HR 0.99, 95% CI 0.97 to 1.01) was similar in patients compared to controls. No differences between patients and controls were observed for infection-related mortality due to pneumonia (adj. HR 1.03, 95% CI 0.93 to 1.14) or UTI (adj. HR 1.16, 95% CI 0.98 to 1.37). In conclusion, patients with gout did not have decreased risks of pneumonia, UTI or infection-related mortality compared to population-based controls.

Gout in immigrant groups: a cohort study in Sweden

Our aim was to study the association between country of birth and incidence of gout in different immigrant groups in Sweden. The study population included the whole population of Sweden. Gout was defined as having at least one registered diagnosis in the National Patient Register. The association between incidence of gout and country of birth was assessed by Cox regression, with hazard ratios (HRs) and 95% confidence intervals (95% CI), using Swedish-born individuals as referents. All models were conducted in both men and women, and the full model was adjusted for age, place of residence in Sweden, educational level, marital status, neighbourhood socio-economic status and co-morbidities. The risk of gout varied by country of origin, with highest estimates, compared to Swedish born, in fully adjusted models among men from Iraq (HR 1.82, 95% CI 1.54-2.16), and Russia (HR 1.69, 95% CI 1.26-2.27), and also high among men from Austria, Poland, Africa and Asian countries outside the Middle East; and among women from Africa (HR 2.23, 95% CI 1.50-3.31), Hungary (HR 1.98, 95% CI 1.45-2.71), Iraq (HR 1.76, 95% CI 1.13-2.74) and Austria (HR 1.70, 95% CI 1.07-2.70), and also high among women from Poland. The risk of gout was lower among men from Greece, Spain, Nordic countries (except Finland) and Latin America and among women from Southern Europe, compared to their Swedish counterparts. The increased risk of gout among several immigrant groups is likely explained by a high cardio-metabolic risk factor pattern needing attention.

Progression rate of ankylosing spondylitis in patients with undifferentiated spondyloarthritis: A systematic review and meta-analysis

BACKGROUND

The idea that undifferentiated spondyloarthritis (uSpA) represents the early undifferentiated stage of ankylosing spondylitis (AS) and other well-defined SpA subtypes is well known. The gist of this study is to assess the rate estimate of patients with uSpA evolved to AS during long-term follow-up.

METHODS

A systematic search was implemented to identify pertinent articles. The primary outcome was the rate estimate that patients with uSpA fulfilling the diagnosis of AS according to the modified New York criteria during follow-up. The rate estimate and corresponding 95% confidence interval (95%CI) were pooled by the random-effects model in STATA 11.0 software. Meta-regression analyses were adopted to explore the sources of heterogeneity. The quality assessment was conducted by the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and the Begg test and the Egger test were applied to assess publication bias.

RESULTS

Sixteen papers were finally included in this study after screening 1299 citations. The pooled rate of patients with uSpA progression to AS synthesized from the 16 papers was 0.323 (95%CI 0.257-0.389). Subgroup analysis based on the length of follow-up showed that the rate at the time-point of 5, 8, and 10 years follow-up was 0.220 (95%CI 0.110-0.330), 0.291 (95%CI 0.257-0.325), and 0.399 (95%CI 0.190-0.608), respectively; while the rate in Asia, Europe, and Latin America was 0.367 (95%CI 0.282-0.452), 0.228 (95%CI 0.066-0.390), and 0.269 (95%CI 0.209-0.329), respectively. Meta-regression analysis indicated that the length of follow-up alone accounts for 45.23% of the total heterogeneity. Nearly half of the papers scored fair quality and none publication bias was identified based on the Begg test and the Egger test. Further, line chart describes an obviously increased trend for the patients with uSpA fulfilling the diagnosis of AS over time.

CONCLUSION

The progression rate of patients with uSpA evolved into AS was variable in different time-point, this variation can mostly be explained by the length of follow-up. Thus, more studies with similar time point of follow-up are needed to clarify the full spectrum of uSpA.

Construct Validity of Radiographs of the Feet to Assess Joint Damage in Patients with Gout

OBJECTIVE

To investigate construct validity of radiographic damage of the feet in gout.

METHODS

Radiographs of the feet were scored using the Sharp/van der Heijde method. Factors associated with damage were investigated by a negative binomial model, and contribution of damage to health by linear regressions.

RESULTS

Age, disease duration, serum uric acid, and tophi were associated with being erosive and erosion score. Tophi were associated with joint space narrowing. Erosions were associated (β 0.47, 95% CI 0.09-0.84) with physical function, but damage was not associated with overall physical health.

CONCLUSION

Our results support construct validity for radiographs of the feet when assessing joint damage in gout.

Prevalence and incidence of gout in southern Sweden from the socioeconomic perspective

OBJECTIVES

To estimate the prevalence and cumulative incidence of gout in southern Sweden with respect to socioeconomic status.

METHODS

Among residents of Skåne region in the year 2013 (total population 1.3 million), adult persons (age 18 years +) who between 1998 and 2013 received a diagnosis of gout (International Classification of Disease 10th Edition (ICD-10) code M10) by any physician were identified using the Skåne Healthcare Register. We calculated the point prevalence by end of 2013 and annual cumulative incidence in 2013 standardised to the whole Skåne population according to sex, individual information on occupation (white collar/blue collar), income (low/middle/high) and level of education (primary school/high school/university).

RESULTS

The crude 2013 point prevalence of gout and 2013 cumulative incidence (95% CI) were 1.69% (1.66% to 1.71%) and 24 cases per 10 000 persons (23-25), respectively. Compared to women, men had higher point prevalence (2.44% (2.40% to 2.49%) vs 0.96% (0.93% to 0.98%)) and higher annual cumulative incidence (33 cases per 10 000 (32-35)) versus 15 (14-16)). These figures increased with higher age but decreased with higher level of education, being the lowest in individuals with a university degree. Persons with middle income had highest point prevalence and cumulative incidence of gout, while those with white collar occupations had the lowest.

CONCLUSIONS

Gout is the most common inflammatory arthritis in southern Sweden with a prevalence of ∼1.7% in the adult population. There is a socioeconomic gradient with more gout present in the lower level of education and with more manual labour.

The Direct Economic Burden of Gout in an Elderly Canadian Population

Objective.

To estimate the direct healthcare cost and resource use from the public payer perspective between patients with incident gout and matched gout-free patients in Ontario.

Methods.

Patients with incident gout aged ≥ 66 with uninterrupted Ontario Health Insurance Plan (OHIP) coverage in the 1-year baseline period were included in the study. Patients with gout were indexed at first gout diagnosis or prescription over the study period April 1, 2008, to March 31, 2014. Gout-free patients with no gout diagnosis within history were matched (up to 5:1) to each patient with gout. Linked medical records were analyzed until end of study, death, or OHIP ineligibility. Bang and Tsiatis adjusted healthcare costs and resource use were compared using bootstrap p-values and 95% CI.

Results.

A total of 29,894 patients with gout and 148,231 gout-free patients were included in the study. Patients were 56% male, had a median Adjusted Clinical Group healthcare resource use band of moderate morbidity, and had a median age of 75–79 years. Baseline comorbidities were similar between groups except for renal disease. Analyzing 5-year total healthcare costs, patients with gout ($44,297) incurred a significantly higher average healthcare cost compared to gout-free patients ($33,965), for an incremental cost of $10,332 (95% CI $9617–$11,039; p < 0.01). Similar trends were observed in all individual healthcare component cost and use metrics.

Conclusion.

Following onset of gout, patients in Ontario incur significantly greater healthcare costs and resource use compared to matched gout-free patients. Alternative gout management strategies should be investigated to reduce the incremental burden of gout borne by the Ontario healthcare system.

Prevalence of Gout in the Adult Population of France

OBJECTIVE

To estimate adult gout prevalence in France.

METHODS

We used a previously established phone questionnaire that allowed for classifying patients as gouty or nongouty by 2 logistic regression models and 1 classification and regression tree (CART) model, the sensitivity and specificity of which were all more than 80%. The full questionnaire was administered by phone to subjects who acknowledged present or past nontraumatic acute pain in a peripheral joint, the others being classified as nongouty. A random sample of adults residing in France was derived from the national telephone directory (home and mobile) by the quota method and further redressed to match the French population. The target size for the interview survey conducted in March and June 2013 was 10,000 participants.

RESULTS

We interviewed 10,026 participants. All 3 models (2 logistic regression models and a CART model) converged to an estimated gout prevalence of 0.9%. This prevalence was lower than that estimated by self-reporting only (3.7% [95% confidence interval 3.3-4.1]). The prevalence was higher for men than women and increased with age but did not differ by area of France.

CONCLUSION

Gout prevalence in the adult population of France in 2013 was estimated at 0.9%. Studies using self-reporting only might overestimate the prevalence.

Knowledge, illness perceptions and stated clinical practice behaviour in management of gout: a mixed methods study in general practice

The objective of the present study is to explore knowledge, illness perceptions and stated practice behaviour in relation to gout in primary care. This is a mixed methods study among 32 general practitioners (GPs). The quantitative assessment included the Gout Knowledge Questionnaire (GKQ; range 0–10; better) and Brief Illness Perceptions Questionnaire (BIPQ; nine items, range 0–10; stronger). Structured individual interviews obtained further qualitative insight into knowledge and perceptions, in the context of daily practice. Among 32 GPs, 18 (56.3 %) were male, mean age 44.4 years (SD 9.6) and mean working experience 17.1 years (SD 9.7). Median score [interquartile ranges (IQR)] on the GKQ was 7.8 [6.7–8.9] and 9.0 [8.0–10.0], when presented as open or multiple-choice questions, respectively. The BIPQ (median; [IQR]) revealed that gout was seen as a chronic disease (8.0; [7.0–9.0]), affecting life and emotions moderately (6.5; [5.0–7.0]), having many severe symptoms (8.0; [7.0–9.0]) and in which treatment could be very helpful (8.0; [7.0–9.0]). Further interviews revealed large variation in specific aspects of knowledge and about gaps concerning indications for uric acid-lowering therapy (UALT), duration of UALT, target serum uric acid (sUA) level or duration of prophylactic treatment. Finally, patients’ adherence was not checked systematically. Specific knowledge gaps and discrepancies between perceptions and stated practice behaviour were identified, which might hamper effective management of this well-treatable disease. Improving evidence on the rationale and effectiveness of treatment targets and adherence interventions, tailoring guidelines to general practice and intensification of implementation of guidelines in primary health care seem to be needed.

Epidemiology and health-related services

PURPOSE OF REVIEW

This article presents recent epidemiologic contributions focusing on gout-related conditions, especially if controversial, to find plausible, despite hypothetical, mechanistic explanations from the clinician perspective.

RECENT FINDINGS

The prevalence of gout is increasing, but it is only partially clear that the incidence may be increasing as well. Direct associations of gout with increased risk of diabetes, black races, neurodegenerative disorders, and sugar-enriched foods have been recently questioned. A negative association with smoking has been reported, and new evidence shows that the impact of diet may be independent of obesity. Kidney disease and diuretics have been confirmed to be associated with gout, whereas new data on aging and menopause have come to challenge apparently established disease mechanisms. Regarding treatments, increase in bladder cancer associated with chronic allopurinol use has been reported, and the positive effect of urate-lowering treatment on cardiovascular events has been contested.

SUMMARY

Epidemiological data in gout-related conditions are still evolving and claim for future cohort or intervention studies to prove causality. Controversies in epidemiological results fertilize the ground for studies to prove mechanisms and causality and provides a unique opportunity for clinical intervention to improve outcomes, especially with regard to treatments.

Gout and its comorbidities in the total population of Stockholm

OBJECTIVE

Study of prevalence of gout with concomitant diseases.

METHODS

Study population included all living persons in Stockholm County, Sweden, on January 1st 2013 (N=2,124,959). A diagnosis of gout was identified during 2013-2014, with information of diabetes mellitus and insulin resistance, hypertension, chronic heart failure, chronic kidney disease, alcohol abuse, and malignancies. Age-adjusted odds ratios (ORs) with 95% confidence intervals (95% CI) for women and men with gout, using individuals without gout as referents, were calculated.

RESULTS

Age-adjusted odds of co-morbidities among individuals with gout vs. those without gout were: diabetes mellitus and insulin resistance 3.97 (95% CI 3.65-4.31) in women and 1.88 (95% CI 1.78-1.99) in men; hypertension 4.02 (95% CI 3.69-4.37) in women and 3.21 (95% CI 3.06-3.37) in men; chronic heart failure 4.72 (95% CI 4.31-5.19) in women and 2.84 (95% CI 2.66-3.04) in men; chronic kidney disease 2.08 (95% CI 1.50-2.87) in women and 2.39 (95% CI 2.15-2.66) in men; alcohol abuse 8.98 (95% CI 8.15-9.80) in women and 4.38 (95% CI 4.10-4.69) in men; and malignancies 1.32 (95% CI 1.17-1.48) in women and 1.13 (95% CI 1.06-1.21) men.

CONCLUSION

Gout is a warning sign for concomitant diseases, e.g. alcoholism, diabetes, cardiovascular diseases, and cancer. KEY MESSAGES.

Health and Utilities in Patients With Gout Under the Care of a Rheumatologist

OBJECTIVE

To compare limitations in health between Dutch patients with gout and the general population and to determine factors influencing societal and patient values for health as assessed with different utility approaches.

METHODS

A cross-sectional study was done among 110 patients with gout under the care of a rheumatologist, with patients completing the EuroQol 5-domain instrument (EQ-5D), the EQ-5D visual analog scale (EQ-5D VAS), and the Short Form 6-dimensions health survey (SF-6D). Scores on EQ-5D domains were compared with age- and sex-matched general population data. Agreement between utility measures was assessed using the intraclass correlation coefficient (ICC). Mixture modeling was used to assess factors associated with the different approaches to assess utility.

RESULTS

Compared to the general population, gout patients reported more limitations in mobility (66% versus 12%), self-care (24% versus 8%), daily activities (49% versus 24%), and pain (76% versus 45%), but equal anxiety/depressive symptoms (18% versus 19%). For patients with gout, utilities were reduced: the mean, median, and interquartile range, respectively, were 0.74, 0.81, and 0.69-0.84 for EQ-5D, 0.69, 0.67, and 0.59-0.81 for SF-6D, and 66, 70, and 57-77 for EQ-5D VAS. ICC agreement between each pair of utilities was only moderate (0.52-0.59). Only minor differences were seen in the type of variables associated with each utility approach, with worse Health Assessment Questionnaire scores, cardiovascular disease (CVD), gout concern, and gout pain consistently associated with lower utility. The strength of contribution of these variables, however, differed among the 3 approaches.

CONCLUSION

Patients with gout experience substantially impaired health compared to the general population. Although absolute values of utility varied between instruments and perspectives, functional disability, CVD, and higher gout impact contributed to utility independently of which instrument was used.

An Observational Study of Gout Prevalence and Quality of Care in a National Australian General Practice Population

Objective.

The central strategy for effective gout management is longterm urate-lowering therapy to maintain the serum urate at a level below 0.36 mmol/l. We sought to determine the prevalence of gout and the quality of care in a national Australian general practice population.

Methods.

Data were from general practice point-of-care electronic records over a 5-year period (n = 1,479,449). Information was collected on patients with gout according to a validated definition. All patients who visited the same general practices over the study period formed the denominator group. We determined the estimated prevalence of gout, the frequency of allopurinol prescription, and serum urate testing, and the percentage of patients achieving a target serum urate level.

Results.

The crude prevalence of gout in this general practice population was 1.54% (95% CI 1.52–1.56). Prevalence in men was 2.67% and in women 0.53%. Prevalence increased with age in both men and women (4.90%, 95% CI 4.82–4.99, in men > 65 yrs). Allopurinol was prescribed to 57% of patients with gout during the 5 years of the study. Only 55% of patients with gout had their serum urate tested at any time during the 5-year study period. A target serum urate concentration of < 0.36 mmol/l at any time during the 5-year study period was documented in 22.4% of all people with gout.

Conclusion.

Gout is managed poorly in Australian primary care, with low levels of allopurinol prescribing and serum urate testing. Collectively, these factors probably contribute to low achievement of serum urate targets.

Global epidemiology of gout: prevalence, incidence and risk factors

Gout is a crystal-deposition disease that results from chronic elevation of uric acid levels above the saturation point for monosodium urate (MSU) crystal formation. Initial presentation is mainly severely painful episodes of peripheral joint synovitis (acute self-limiting 'attacks') but joint damage and deformity, chronic usage-related pain and subcutaneous tophus deposition can eventually develop. The global burden of gout is substantial and seems to be increasing in many parts of the world over the past 50 years. However, methodological differences impair the comparison of gout epidemiology between countries. In this comprehensive Review, data from epidemiological studies from diverse regions of the world are synthesized to depict the geographic variation in gout prevalence and incidence. Key advances in the understanding of factors associated with increased risk of gout are also summarized. The collected data indicate that the distribution of gout is uneven across the globe, with prevalence being highest in Pacific countries. Developed countries tend to have a higher burden of gout than developing countries, and seem to have increasing prevalence and incidence of the disease. Some ethnic groups are particularly susceptible to gout, supporting the importance of genetic predisposition. Socioeconomic and dietary factors, as well as comorbidities and medications that can influence uric acid levels and/or facilitate MSU crystal formation, are also important in determining the risk of developing clinically evident gout.