Independent impact of gout on the risk of diabetes mellitus among women and men: a population-based, BMI-matched cohort study

Relationship between gout, hyperuricemia, and obesity-does central obesity play a significant role?-a study based on the NHANES database

BACKGROUND

Our objective was to evaluate how various measures of obesity, such as body mass index(BMI), body roundness index(BRI), and weigh adjusted waist index(WWI), influence urate levels, prevalence of gout and to compare the disparities among these obesity indicators.

METHODS

By analyzing the 2001-2018 National Health and Nutrition Examination Survey (NHANES), we assessed the relationship between BMI, WWI, and BRI indices and urate levels, hyperuricemia, and the prevalence of gout. Smoothed curve fitting was used to determine whether there was a nonlinear relationship between BMI,WWI, and BRI indices and urate levels, hyperuricemia, and the prevalence of gout, and threshold effects analysis was used to test this relationship. We also used ROC curves to determine the diagnostic efficacy of BMI, WWI, and BRI on the prevalence of hyperuricemia and gout.

RESULTS

The study incorporated a total of 29,310 participants aged over 20 years, out of which 14,268 were male. Following the adjustment for the pertinent confounding factors, it was observed that higher levels of BMI, WWI, and BRI were significantly associated with a gradual and dose-dependent increase in urate levels. In the sensitivity analysis, each unit increment in BMI, WWI, and BRI levels exhibited an 8%, 72%, and 26% respective elevation in the risk of hyperuricemia, as well as a 5%, 31%, and 15% respective increase in the risk of gout. Dose-response curves provided evidence of a linear positive correlation between BMI, WWI, BRI, and urate levels, as well as the prevalence of hyperuricemia and gout. Based on the response from the ROC curve, overall, the diagnostic efficacy of BRI for hyperuricemia and gout surpasses that of BMI.

CONCLUSION

The central obesity indices WWI and BRI levels are superior to BMI in detecting the prevalence of urate levels, hyperuricemia, and gout, and although a clear causal relationship has not yet been established, it is important to recognize the impact of central obesity on uric acid levels and to give it due attention.

Association of visceral adipose tissue with gout: Observational and Mendelian randomization analyses

BACKGROUND

The causal relationship between visceral adipose tissue (VAT) and gout is still unclear. We aimed to examine the potential association between them using observational and Mendelian randomization (MR) analyses.

METHODS

In the observational analyses, a total of 11,967 participants (aged 39.5 ± 11.5 years) were included from the National Health and Nutrition Examination Survey. Logistic regression models were used to investigate the association between VAT mass and the risk of gout. In two-sample MR analyses, 211 VAT mass-related independent genetic variants (derived from genome-wide association studies in 325,153 UK biobank participants) were used as instrumental variables. The random-effects inverse-variance weighted (IVW) method was used as the primary analysis. Additional sensitivity analyses were also performed to validate our results.

RESULTS

Observational analyses found that an increase in VAT mass (per standard deviation) was associated with a higher risk of gout after controlling for confounding factors (odds ratio [OR] = 1.27, 95% confidence intervals [CI] = 1.11-1.45). The two-sample MR analyses demonstrated a causal relationship between increased VAT mass and the risk of gout in primary analyses (OR = 1.78, 95% CI = 1.57-2.03). Sensitivity analyses also showed similar findings, including MR-Egger, weighted median, simple mode, weighted mode, and leave-one-out analyses.

CONCLUSIONS

Observational analyses showed a robust association of VAT mass with the risk of gout. Meanwhile, MR analyses also provided evidence of a causal relationship between them. In summary, our findings suggested that targeted interventions for VAT mass may be beneficial to prevent gout.

Exploring the Multifaceted Nexus of Uric Acid and Health: A Review of Recent Studies on Diverse Diseases

The prevalence of patients with hyperuricemia or gout is increasing worldwide. Hyperuricemia and gout are primarily attributed to genetic factors, along with lifestyle factors like consuming a purine-rich diet, alcohol and/or fructose intake, and physical activity. While numerous studies have reported various comorbidities linked to hyperuricemia or gout, the range of these associations is extensive. This review article focuses on the relationship between uric acid and thirteen specific domains: transporters, genetic factors, diet, lifestyle, gout, diabetes mellitus, metabolic syndrome, atherosclerosis, hypertension, kidney diseases, cardiovascular diseases, neurological diseases, and malignancies. The present article provides a comprehensive review of recent developments in these areas, compiled by experts from the Young Committee of the Japanese Society of Gout and Uric and Nucleic Acids. The consolidated summary serves to enhance the global comprehension of uric acid-related matters.

Causal Association Between Tea Consumption and Gout: A Mendelian Randomization Study

OBJECTIVE

Evidence from prospective studies on the consumption of tea and risk of gout is conflicting and limited. We aimed to investigate the potential causal effects of tea intake on gout using Mendelian randomization (MR).

METHODS

Genome-wide association studies in UK Biobank included 349 376 individuals and successfully discovered single-nucleotide polymorphisms linked to consumption of one cup of tea per day. Summary statistics from the Chronic Kidney Disease Genetics consortium included 13 179 cases and 750 634 controls for gout. Two-sample MR analyses were used to evaluate the relationship between tea consumption and gout risk. The inverse-variance weighted (IVW) method was used for primary analysis, and sensitivity analyses were also conducted to validate the potential causal effect.

RESULTS

In this study, the genetically predicted increase in tea consumption per cup was associated with a lower risk of gout in the IVW method (OR: 0.90; 95% CI: 0.82-0.98). Similar results were found in weighted median methods (OR: 0.88; 95% CI: 0.78-1.00), while no significant associations were found in MR-Egger (OR: 0.89; 95% CI: 0.71-1.11), weighted mode (OR: 0.80; 95% CI: 0.65-0.99), and simple mode (OR: 1.01; 95% CI: 0.75-1.36). In addition, no evidence of pleiotropy was detected by MR-Egger regression (P=0.95) or MR-PRESSO analysis (P=0.07).

CONCLUSION

This study provides evidence for the daily consumption of an extra cup of tea to reduce the risk of gout.

Comparison Between Early-Onset and Common Gout: A Systematic Literature Review

INTRODUCTION

Gout is an inflammatory, metabolic disease associated with a high comorbidity burden including cardiovascular disease, hypertension, type 2 diabetes, hyperlipidemia, renal disease, and metabolic syndrome. Approximately 9.2 million Americans have gout, making prognosis and treatment outcome predictors highly important. About 600,000 Americans have early-onset gout (EOG), generally defined as first gout attack at ≤ 40 years of age. However, data on EOG clinical features, comorbidity profile, and treatment response are sparse; this systematic literature review provides insight.

METHODS

PubMed and American College of Rheumatology (ACR)/European Alliance of the Associations for Rheumatology (EULAR) abstract archives were searched for early-onset gout, "early onset gout," and ("gout" AND "age of onset"). Duplicate, foreign language, single case report, older (before 2016), and irrelevant/data insufficient publications were excluded. The age of diagnosis categorized patients as having common gout (CG, generally > 40 years) or EOG (generally ≤ 40 years). Applicable publications were extensively reviewed/discussed among authors for inclusion/exclusion consensus.

RESULTS

A total of 283 publications were identified, with 46 (35 articles, 10 abstracts) reviewed and 17 (12 articles, 5 abstracts) ultimately included. Eleven reported clinical characteristics, with 6 EOG-CG retrospective/cross-sectional comparisons. Gout diagnosis preceded cardiometabolic comorbidity and renal comorbidities were less prevalent in EOG than CG patients. EOG patients had more severe disease (more gout flares, polyarticular disease), higher pre-therapy serum urate (SU), and worse oral urate-lowering therapy response. Genetics-focused publications reported higher incidences of dysfunctional urate transporter mutations in EOG patients.

CONCLUSIONS

This review suggests that EOG is more recalcitrant to urate-lowering therapy, is associated with urate transporter defects, and carries heavy disease burden. Therefore, early rheumatology referral and urate-lowering in a treat-to-target fashion may benefit EOG patients. Interestingly, EOG patients had fewer cardiometabolic comorbidities at diagnosis than CG patients, presenting a potential "window of opportunity" to attenuate cardiometabolic comorbidity development with SU control. Preventing gout-related suffering and health burden is particularly important in these young EOG patients who will live with gout and its sequelae for decades.

Contributing Factors of Diabetes Mellitus among Patients with Gout (Results of the Long-Term Prospective Study)

It is assumed that the risk of developing type 2 diabetes mellitus (T2DM) in patients with gout is influenced by both generally accepted risk factors and factors related to gout. The aim of the study was to evaluate the impact of various risk factors for T2DM in patients with gout. A total of 444 patients (49 women, 395 men) ≥18 years old with gout and without DM were included. The duration of observation was 5.66 [2.69; 7.64] years. To identify the factors associated with the risk of developing T2DM, multivariate logistic regression was used, which included sex; T2DM in relatives; insufficient physical activity; unbalanced diet; age  ≥ 45 years; ≥4 attacks per year; presence of tophi; BMI ≥30 kg/m2; allopurinol, febuxostat, glucocorticoids, diuretics, metformin, colchicine; GFR < 60 mL/min/1.73 m2; serum uric acid level (sUA) ≥ 420 µmol/L and  ≥ 480 µmol/L. T2DM developed in 108 (24.3%) patients. According to the multivariate model, the presence of ≥4 attacks of arthritis per year increased the risk of T2DM (OR = 5.23; 95% CI: 2.98-9.19; p = 0.0001); presence of tophi (OR = 2.61; 95% CI: 1.50-4.54; p = 0.001); sUA ≥ 480 µmol/L (OR = 2.26; 95% CI: 1.02-5.00; p = 0.144); diuretics (OR = 2.35; 95% CI: 1.19-4.64; p = 0.014). Febuxostat (OR = 0.31; 95% CI: 0.11-0.84; p = 0.022) and metformin (OR = 0.49; 95% CI: 0.21-1.16; p = 0.107) reduced the risk of developing T2DM. Risk of T2DM in patients with gout is associated with high incidence of arthritis attacks, MK ≥ 480 μmol/L, hypertension, diuretic use, and febuxostat and metformin reduces risk.

Gout and Diet: A Comprehensive Review of Mechanisms and Management

Gout is well known as an inflammatory rheumatic disease presenting with arthritis and abnormal metabolism of uric acid. The recognition of diet-induced systemic metabolic pathways have provided new mechanistic insights and potential interventions on gout progression. However, the dietary recommendations for gouty patients generally focus on food categories, with few simultaneous considerations of nutritional factors and systemic metabolism. It is worthwhile to comprehensively review the mechanistic findings and potential interventions of diet-related nutrients against the development of gout, including purine metabolism, urate deposition, and gouty inflammation. Although piecemeal modifications of various nutrients often provide incomplete dietary recommendations, understanding the role of nutritional factors in gouty development can help patients choose their healthy diet based on personal preference and disease course. The combination of dietary management and medication may potentially achieve enhanced treatment effects, especially for severe patients. Therefore, the role of dietary and nutritional factors in the development of gout is systematically reviewed to propose dietary modification strategies for gout management by: (1) reducing nutritional risk factors against metabolic syndrome; (2) supplementing with beneficial nutrients to affect uric acid metabolism and gouty inflammation; and (3) considering nutritional modification combined with medication supplementation to decrease the frequency of gout flares.

The Interaction Between Dietary Fructose and Gut Microbiota in Hyperuricemia and Gout

With the worldwide epidemics of hyperuricemia and associated gout, the diseases with purine metabolic disorders have become a serious threat to human public health. Accumulating evidence has shown that they have been linked to increased consumption of fructose in humans, we hereby made a timely review on the roles of fructose intake and the gut microbiota in regulating purine metabolism, together with the potential mechanisms by which excessive fructose intake contributes to hyperuricemia and gout. To this end, we focus on the understanding of the interaction between a fructose-rich diet and the gut microbiota in hyperuricemia and gout to seek for safe, cheap, and side-effect-free clinical interventions. Furthermore, fructose intake recommendations for hyperuricemia and gout patients, as well as the variety of probiotics and prebiotics with uric acid-lowering effects targeting the intestinal tract are also summarized to provide reference and guidance for the further research.

Association between Clinical Use of Colchicine and Risk of Type 2 Diabetes Mellitus among Gouty Patients: A Nationwide Cohort Study

Background: Gout is the most common form of inflammatory arthritis in adults. Even though a link between gouty arthritis and type 2 diabetes mellitus (T2DM) has been reported, there is a limited understanding of the association between the anti-inflammatory agent colchicine and the risk of T2DM. This aim of this study was to assess the association between the use of colchicine and the risk of T2DM in an Asian cohort. Methods: A retrospective cohort study was conducted using the National Health Insurance Research Database (NHIRD) in Taiwan from 2000 to 2013. The study cohorts comprised 3841 gouty patients using colchicine (the exposed cohort) and 7682 gouty patients not using colchicine (the unexposed -cohort). The primary outcome was incident DM. The hazard ratios (HRs) and 95% confidence intervals (CIs) derived from a Cox proportional regression model were used to assess the association between colchicine use and the risk of diabetes. Results: The cumulative incidence of T2DM was significantly lower in the exposed cohort (18.8%) than in the unexposed cohort (25.0%). The risk of T2DM was significantly lower in colchicine users than in non-users (adjusted HR, 0.74; 95% CI, 0.36–0.87). The inverse relationship between colchicine use and diabetes risk remained consistent across sex and age groups. Conclusions: This cohort study provides longitudinal evidence that the use of colchicine is associated with a reduced risk of T2DM. This conclusion, however, needs to be interpreted cautiously given the lack of body mass index data in the NHIRD. Further studies are needed to determine the clinical implications of this study.

Arthritis is associated with an increased risk of incident diabetes in Chinese adults: A nationwide cohort study and updated meta-analysis

AIMS

To prospectively examine the association between arthritis and type 2 diabetes (T2D) in the Chinese population and confirm this association through a comprehensive meta-analysis of cohort studies.

METERIALS AND METHODS

Data were from the China Health and Retirement Longitudinal Study which was started in 2011-2013 and followed up in 2013-2014 and 2015-2016. Arthritis was defined as self-reported physician diagnosis at baseline, and incident T2D was determined by self-reported physician diagnosis, fasting blood glucose ≥7.0 mmol/L or glycosylated haemoglobin ≥6.5% during the follow-ups. Cox proportional hazards regression models were used to assess the association between arthritis and risk for T2D. A meta-analysis was conducted to pool our effect estimate and those from other cohort studies using a random-effects model.

RESULTS

Eleven thousand four hundred and eight participants (47.9% men; mean age: 59.3 years) were included in final analyses. During a 4-year follow-up, 981 participants reported incident T2D. Compared with individuals without arthritis, those with arthritis at baseline had an 18% higher risk for incident T2D (multivariable-adjusted hazard ratio: 1.18; 95% confidence interval: 1.04, 1.34). In the meta-analysis of 13 cohort studies including ours, a total of 2,473,514 participants were included with 121,851 incident diabetes. The pooling HR was 1.32 (95% CI: 1.21, 1.44) for the association between arthritis and diabetes.

CONCLUSION

Arthritis was associated with an increased risk of incident diabetes in Chinese adults, and the positive association was confirmed in the meta-analysis of cohort studies. Our work can inform clinical trials to assess the effectiveness of arthritis treatments in reducing risk of diabetes.

Excess comorbidities in gout: the causal paradigm and pleiotropic approaches to care

Gout is a common hyperuricaemic metabolic condition that leads to painful inflammatory arthritis and a high comorbidity burden, especially cardiometabolic-renal (CMR) conditions, including hypertension, myocardial infarction, stroke, obesity, hyperlipidaemia, type 2 diabetes mellitus and chronic kidney disease. Substantial advances have been made in our understanding of the excess CMR burden in gout, ranging from pathogenesis underlying excess CMR comorbidities, inferring causal relationships from Mendelian randomization studies, and potentially discovering urate crystals in coronary arteries using advanced imaging, to clinical trials and observational studies. Despite many studies finding an independent association between blood urate levels and risk of incident CMR events, Mendelian randomization studies have largely found that serum urate is not causal for CMR end points or intermediate risk factors or outcomes (such as kidney function, adiposity, metabolic syndrome, glycaemic traits or blood lipid concentrations). Although limited, randomized controlled trials to date in adults without gout support this conclusion. If imaging studies suggesting that monosodium urate crystals are deposited in coronary plaques in patients with gout are confirmed, it is possible that these crystals might have a role in the inflammatory pathogenesis of increased cardiovascular risk in patients with gout; removing monosodium urate crystals or blocking the inflammatory pathway could reduce this excess risk. Accordingly, data for CMR outcomes with these urate-lowering or anti-inflammatory therapies in patients with gout are needed. In the meantime, highly pleiotropic CMR and urate-lowering benefits of sodium-glucose cotransporter 2 (SGLT2) inhibitors and key lifestyle measures could play an important role in comorbidity care, in conjunction with effective gout care based on target serum urate concentrations according to the latest guidelines.

Comparison of Rates of Lower Extremity Amputation in Patients With and Without Gout in the US Department of Veterans Affairs Health System

Importance

Cardiometabolic and other risk factors could render patients with gout more likely to undergo lower extremity amputation (LEA).

Objective

To examine the rate of and factors associated with LEA in patients with gout.

Design, Setting, and Participants

In this matched cohort study using national administrative data, multivariable Cox proportional hazards regression models were used to examine the associations of gout with LEA. In analyses limited to patients with gout, attributes of serum urate control and treatment with urate-lowering therapy were examined as factors associated with LEA. This study included patients who used US Department of Veterans Affairs services from January 1, 2000, to July 31, 2015. Patients with gout were identified using diagnostic codes and matched with up to 10 controls by age, sex, and year of benefit enrollment. Data analysis was performed from January 26, 2021, to September 3, 2021.

Exposures

Gout classification served as the primary independent variable of interest. In analyses limited to patients with gout, factors associated with serum urate control and urate-lowering therapy were examined.

Main Outcomes and Measures

Overall LEA, as well as toe, transmetatarsal, below-the-knee, and above-the-knee amputation.

Results

This cohort study included 5 924 918 patients, 556 521 with gout (mean [SD] age, 67 [12] years; 550 963 (99.0%) male; 88 853 [16.0%] Black non-Hispanic; 16 981 [4.3%] Hispanic/Latinx; 345 818 [62.1%] White non-Hispanic; 80 929 [14.5%] with race and ethnicity data missing; and 23 940 [4.3%] classified as other) and 5 368 397 without gout (mean [SD] age, 67 [12] years; 5 314 344 [99.0%] male; 558 464 [10.4%] Black non-Hispanic; 204 291 [3.0%] Hispanic/Latinx; 3 188 504 [59.4%] White non-Hispanic; 1 257 739 [23.4%)] with race and ethnicity data missing; and 159 399 [3.0%] classified as other). Compared with patients without gout, patients with gout were more likely to undergo amputation, an increased rate that remained after adjustment (adjusted hazard ratio, 1.20; 95% CI, 1.16-1.24) and was highest for below-the-knee amputation (adjusted hazard ratio, 1.59; 95% CI, 1.39-1.81). In those with gout, poor serum urate control (mean >7 mg/dL during the preceding year) was associated with a 25% to 37% increase in the rate of amputation. In contrast, treatment with urate-lowering therapy was not associated with the LEA rate.

Conclusions and Relevance

In this matched cohort study, patients with gout were more likely to undergo LEA. This increase was independent of other comorbidities that have been associated with amputation, including diabetes and peripheral vascular disease. Serum urate control was independently associated with the LEA rate, suggesting the possibility that lower extremity amputation may be preventable in some patients.

Improved joint and patient-reported health assessments with pegloticase plus methotrexate co-therapy in patients with uncontrolled gout: 12-month exploratory outcomes of the MIRROR open-label trial

BACKGROUND

Uncontrolled/refractory gout patients are recalcitrant/intolerant to oral urate-lowering therapies (ULTs), experiencing frequent gout flares, functionally limiting tophi, and low quality of life. Pegloticase lowers urate, but anti-pegloticase antibodies limit urate-lowering efficacy and increase infusion reaction (IR) risk. Immunomodulator + pegloticase co-administration may improve treatment response rates, with 79% of MIRROR open-label trial (MIRROR-OL, pegloticase + oral methotrexate) participants meeting 6-month response criteria. Exploratory outcomes from MIRROR-OL are described here.

METHODS

Adults with uncontrolled gout (serum urate [SU] ≥ 6 mg/dL and ULT-intolerance/recalcitrance or functionally limiting tophi) were included. Oral methotrexate (15 mg/week) was administered 4 weeks before and during pegloticase treatment (biweekly 8 mg infusion, ≤ 52 weeks). Exploratory outcomes included change from baseline (CFB) in number of affected joints, Health Assessment Questionnaires (HAQs), and Gout Global Assessments.

RESULTS

Fourteen patients received ≥ 1 pegloticase infusion, with 13 included in 52-week analyses (1 enrolled before treatment-extension amendment, exited at 24 weeks). Three patients prematurely exited due to SU rise; 10 completed 52-week evaluations (8 completed 52 weeks of co-therapy, 2 completed 24 weeks [met treatment goals]). At 52 weeks, SU averaged 1.1 ± 2.5 mg/dL, with improvements in HAQ pain and health (CFB: - 33.6 and - 0.7, respectively), Patient and Physician Global Assessments (CFB: - 4.6 and - 5.7, respectively), and joint involvement (CFB: - 5.6, - 8.4, - 6.0 tender, swollen, tophi-affected joints, respectively). Two patients underwent dual-energy computed tomography, showing concomitant monosodium urate volume reductions. All patients had ≥ 1 AE, with 92.9% experiencing acute flare. One mild IR ("cough") occurred and no new safety signals were identified.

CONCLUSION

Pegloticase + methotrexate co-therapy resulted in sustained SU-lowering with meaningful improvements in clinical measures, urate burden, and patient-reported outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03635957).

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.

Genetic Predisposition to Type 2 Diabetes and Insulin Levels Is Positively Associated With Serum Urate Levels

PURPOSE

Previous epidemiological evidence showed that type 2 diabetes (T2D) is related with gout. However, the causality and the direction of this association are still not definitely elucidated. We investigated bidirectional associations of T2D and glycemic traits with serum urate concentrations and gout using a Mendelian randomization approach.

METHODS

Summary statistics from the large-scale genomewide association studies conducted for T2D (Ncase = 62 892, Ncontrol = 596 424), fasting glucose (N = 133 010), fasting insulin (N = 133 010), hemoglobin A1c (N = 123 665), homeostasis model assessment of insulin resistance (N = 46 186), urate (N = 110 347), and gout (Ncase = 2115, Ncontrol = 67 259) among participants of European ancestry were analyzed. For each trait of interest, independent genomewide significant (P < 5 × 10-8) single nucleotide polymorphisms were selected as instrumental variables. The inverse-variance weighted method was used for the primary analyses.

RESULTS

Genetic predisposition to higher risk of T2D [beta = 0.042; 95% confidence interval (CI) = 0.016-0.068; P = 0.002] and higher levels of fasting insulin (beta = 0.756; 95% CI = 0.408-1.102; P = 1.96e-05) were significantly associated with increased serum urate concentrations. Moreover, we found suggestively significant evidence supporting a causal role of fasting insulin on risk of developing gout (odds ratio = 3.06; 95% CI = 0.88-10.61; P = 0.078). In the reverse direction analysis, genetic predisposition to both urate and gout were not associated with T2D or any of 4 glycemic traits being investigated.

CONCLUSIONS

This study provides supportive evidence on causal associations of T2D and fasting insulin with serum urate concentrations and a suggestive association of fasting insulin with risk of gout. Future research is required to examine the underlying biological mechanisms on such relationships.

Prevalence and Risk Factors Associated with Hyperuricemia in the Pearl River Delta, Guangdong Province, China

Background

In China, the prevalence of HUA in the Pearl River Delta (PRD) region of Guangdong Province has not been extensively investigated. Therefore, this study investigated the prevalence of HUA and its related factors among people aged 20–99 years in nine cities in the PRD.

Materials and Methods

We selected 6491 health check participants from 9 cities in the PRD and collected participants’ anthropometric and biochemical test results for a cross-sectional study. We included 6491 participants and assessed their blood pressure (BP), body mass index (BMI), total cholesterol (TC), triglycerides (TG), glucose (Glu) and serum uric acid (UA) to analyze the regional prevalence of HUA and its related factors. HUA was indicated when fasting serum UA level was >420 μmol/L in men and >360 μmol/L in women.

Results

Overall prevalence of HUA in our cohort was 34.05%; prevalence was higher in men than in women (41.53% vs 26.14%, P < 0.001). Characteristics associated with HUA were hypertension (odds ratio (OR), 5.506; 95% confidence interval (CI), 4.402–6.889), higher body mass index (BMI; OR: 1.746; 95% CI: 1.560–1.954), age 31–40 years (OR: 0.829; 95% CI: 0.706–0.973), age 61–70 years (OR: 1.434; 95% CI: 1.194–1.722) and age ≥71 years (OR: 1.742; 95% CI: 1.397–2.173). In all subjects, serum UA was positively correlated with Glu, TG and TC. After we adjusted for age, BMI and BP, multivariate logistic regression analysis showed that HUA risk factors were high TC (OR: 1.770; 95% CI: 1.459–2.147) and TG (OR: 1.961; 95% CI: 1.632–2.357) in men; and high Glu (OR: 1.508; 95% CI: 1.084–2.099), TC (OR: 1.341; 95% CI: 1.084–1.660) and TG (OR: 1.680; 95% CI: 1.290–2.187) in women.

Conclusion

The prevalence of HUA was relatively high in the PRD of Guangdong Province. Relevant governmental bodies should focus on early diagnosis, early treatment and early intervention.

Identification of the urine and serum metabolomics signature of gout

OBJECTIVE

Gout is the most common inflammatory arthritis and the worldwide incidence is increasing. By revealing the metabolic alterations in serum and urine of gout patients, the first aim of our study was to discover novel molecular biomarkers allowing for early diagnosis. We also aimed to investigate the underlying pathogenic pathways.

METHODS

Serum and urine samples from gout patients (n = 30) and age-matched healthy controls (n = 30) were analysed by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) to screen the differential metabolites and construct a diagnostic model. Next, the model was verified and optimized in the second validation cohort (n = 100). The pathways were illustrated to understand the underlying pathogenesis of gout.

RESULTS

In general, serum metabolomics demonstrated a clearer distinction than urine metabolomics. In the discovery cohort, 40 differential serum metabolites were identified that could distinguish gout patients from healthy controls. Among them, eight serum metabolites were verified in the validation cohort. Through regression analysis, the final model consisted of three serum metabolites-pyroglutamic acid, 2-methylbutyryl carnitine and Phe-Phe-that presented optimal diagnostic power. The three proposed metabolites produced an area under the curve of 0.956 (95% CI 0.911, 1.000). Additionally, the proposed metabolic pathways were primarily involved in purine metabolism, branched-chain amino acids (BCAAs) metabolism, the tricarboxylic acid cycle, synthesis and degradation of ketone bodies, bile secretion and arachidonic acid metabolism.

CONCLUSION

The metabolomics signatures could serve as an efficient tool for early diagnosis and provide novel insights into the pathogenesis of gout.

Characteristics, Comorbidities, and Potential Consequences of Uncontrolled Gout: An Insurance-Claims Database Study

INTRODUCTION

Gout is a common, progressive, systemic inflammatory arthritis caused by hyperuricemia. Current guidelines recommend that serum uric acid (sUA) levels be maintained below 6.0 mg/dl to minimize acute gout attacks, tophi development, and long-term joint and organ damage. This study examined the influence of uncontrolled gout on post-diagnosis comorbidities and medication use.

METHODS

The Humana Research Database (2007-2016, commercial insurance and Medicare) was searched (PearlDiver tool) for patients who had a gout diagnosis code, claims data for at least 6 months before and after diagnosis, and at least 90 days of continuous urate-lowering therapy within 1 year of diagnosis. Patients with controlled (all sUA measurements < 6.0 mg/dl) and uncontrolled (all sUA measurements ≥ 8.0 mg/dl) gout were further examined and compared to better understand the influence of uncontrolled gout on post-diagnosis comorbidities, medication use, and reasons for seeking medical care.

RESULTS

A total of 5473 and 1358 patients met inclusion and classification criteria for the controlled and uncontrolled groups, respectively. Identified comorbidities in both groups included hypertension, hyperlipidemia, diabetes, cardiovascular disease, and chronic kidney disease (CKD). However, the uncontrolled group was more likely to have diabetes, CKD, and cardiovascular disease (including heart failure and atrial fibrillation). Additionally, CKD tended to be more advanced in the uncontrolled gout population (Stage 4-5: 34.6 vs. 22.2%). Overall opioid use was higher in uncontrolled patients.

CONCLUSIONS

The current study identified differences between controlled and uncontrolled gout patients, including usage of medication, severity of CKD, and prevalence of CKD, diabetes, and heart disease.

Effect modification of hyperlipidemia and hypertension on the association between type 2 diabetes and gout

AIMS

We evaluated the association between type 2 diabetes and gout by a retrospective cohort study.

METHODS

Data of 17,259 male and 18,318 female patients with type 2 diabetes were retrieved for the 1998-2010 period. These patients were matched to a comparison group (n=34,518 and n=36,636, respectively) in a 1:2 ratio by age and region.

RESULTS

We found that patients with type 2 diabetes after adjustment for hyperlipidemia and hypertension had a lower risk of incident gout than the matched population (incidence rate ratio, men: 0.39 [95% CI: 0.36-0.42]; women: 0.78 [0.72-0.84]). Specifically, type 2 diabetes alone without hyperlipidemia and hypertension was associated with a reduced risk of incident gout in men (adjusted relative risk [RR]: 0.29, 95% CI: 0.22-0.39), but not in women (0.86, 95% CI: 0.55-1.36). We found that insulin users with hyperlipidemia and hypertension associated with risk of incident gout and no sex-specific differences were noted (adjusted RR, men: 1.28 [95% CI: 1.11-1.48]; women: 1.32 [95% CI: 1.14-1.53]). Specifically, insulin users alone without hyperlipidemia and hypertension were not statistically significantly associated with gout risk (P≥.0954).

CONCLUSIONS

The results of this study indicated that hyperlipidemia and hypertension modified the association between type 2 diabetes and gout.

Risk of Cancer in Middle-aged Patients With Gout: A Nationwide Population-based Study in Korea

OBJECTIVE

Gout is reportedly associated with a higher incidence of cancer. However, patients with gout tend to have several cancer-related factors including obesity, smoking, and alcohol consumption; thus, the precise association between gout and cancer risk remains unclear. We aimed to investigate the risk of cancer in Korean patients with gout.

METHODS

Based on the Korea Health Insurance Service database, the subjects comprised patients aged 41-55 years with gout newly diagnosed between 2003 and 2007. We used a multivariable-adjusted Cox proportional hazards model in gout patients and a 1:2 ratio for the matched controls by age, sex, and index year.

RESULTS

We compared 4176 patients with gout with 8352 controls. The mean age and follow-up duration were 48.8 years and 10.1 years in both groups. Overall cancer risk was significantly different between gout patients and controls (HR 1.224, 95% CI 1.073-1.398). The all-cause mortality (HR 1.457, 95% CI 1.149-1.847) and cancer mortality (HR 1.470, 95% CI 1.020-2.136) were higher in patients with gout. In the subgroup analysis, the cancer risks of the stomach (HR 1.710, 95% CI 1.221-2.395), head and neck (HR 1.850, 95% CI 1.071-3.196), and hematologic or lymphoid organ (HR 2.849, 95% CI 1.035-7.844) were higher in patients with gout.

CONCLUSION

Patients aged 41-55 years with gout have a higher risk of cancer and all-cause and cancer mortality compared with the general population. Therefore, special attention should be paid to higher cancer risk and mortality in these patients who are diagnosed in middle age.

Association between Gout, Urate-Lowering Therapy, and Risk of Developing Type 2 Diabetes Mellitus: A Nationwide Population-Based Retrospective Cohort Study

Gout is the most prevalent inflammatory arthritis in adults. Although the link between gout and type 2 diabetes mellitus (T2DM) has been documented, our understanding of the association between urate-lowering therapy (ULT) among gout patients and T2DM development remains poor. We included 69,326 patients with new-onset gout in 2000-2011. Each case was matched randomly with 1 patient without gout during the study period, and 69,326 patients were recognized as the comparison cohort. A Cox proportional hazard regression model was used to analyze differences in the risk of T2DM development between patients with and without gout after considering related comorbidities. After adjusting for potential confounders, the case group had a higher risk of T2DM than the control cohort (adjusted hazard ratio (aHR) = 1.30, 95%confidence interval (CI) = 1.24-1.38; P < 0.001). Gout patients without appropriate ULT had significantly higher risk of T2DM development than the control cohort (aHR = 1.39; 95%CI = 1.30-1.48; P < 0.001). Among gout patients, those receiving ULT excluding probenecid (aHR = 0.80; 95%CI = 0.64-1.00), all had significantly lower risk of T2DM than gout patients without ULT (all aHR < 0.90; all P < 0.001). In this study, we found that gout increased the risk of T2DM; however, patients with any ULT exhibited a lower risk of T2DM than gout patients without any ULT (all aHR < 0.90, P < 0.001; excluding probenecid).

Association of Specific Comorbidities with Monosodium Urate Crystal Deposition in Urate-Lowering Therapy-Naive Gout Patients: A Cross-Sectional Dual-Energy Computed Tomography Study

(1) Background: To determine which factors are associated with the volume of monosodium urate (MSU) crystal deposition quantified by dual-energy computed tomography (DECT) in urate-lowering therapy (ULT)-naive gout patients. (2) Methods: In this multicenter cross-sectional study, DECT scans of knees and feet/ankles were prospectively obtained from ULT-naive gout patients. Demographic, clinical (including gout history and comorbidities), and biological data were collected, and their association with DECT MSU crystal volume was analyzed using bivariate and multivariate analyses. A second bivariate analysis was performed by splitting the dataset depending on an arbitrary threshold of DECT MSU volume (1 cm³). (3) Results: A total of 91 patients were included. In the bivariate analysis, age (p = 0.03), gout duration (p = 0.003), subcutaneous tophi (p = 0.004), hypertension (p = 0.02), diabetes mellitus (p = 0.05), and chronic heart failure (p = 0.03) were associated with the total DECT volume of MSU crystal deposition. In the multivariate analysis, factors associated with DECT MSU volumes ≥1 cm³ were gout duration (odds ratio (OR) for each 10-year increase 3.15 (1.60; 7.63)), diabetes mellitus (OR 4.75 (1.58; 15.63)), and chronic heart failure (OR 7.82 (2.29; 31.38)). (4) Conclusion: Specific comorbidities, particularly chronic heart failure and diabetes mellitus, are more strongly associated with increased MSU crystal deposition in knees and feet/ankles than gout duration, regardless of serum urate level.

THE ROLE OF NT PRO-BNP IN THE EVALUATION OF DIABETIC PATIENTS WITH HEART FAILURE

CONTEXT

The prevalence of patients with concomitant heart failure (HF) and diabetes mellitus (DM) is high.

OBJECTIVE

To analyze the role of NT-pro-BNP levels in the evaluation of diabetic patients with heart failure.

DESIGN

Retrospective comparative cohort study.

SUBJECTS AND METHODS

A total of 174 patients admitted to our Cardiology Department, previously diagnosed with HF, were enrolled. Among these patients, 47.7% had DM. HF was defined according to the 2016 ESC criteria. The NT-pro BNP levels above 126 pg/mL indicate a high probability of heart failure.

RESULTS

In diabetic patients there were significant correlations between NT-pro-BNP values and the following parameters: hemoglobin (rho=-0.28, p=0.01), hematocrit (rho= -0.27, p=0.014), total cholesterol (rho= -0.21, p=0.048), triglycerides (rho= -0.283, p=0.01), ejection fraction (rho= -0.465, p<0.0001), end-diastolic volume (rho= 0.253, p= 0.026), end-systolic volume (rho= 0.29 p=0.01). Only the following 3 parameters: ejection fraction (p= 0.0009), hemoglobin (p= 0.0092) and triglycerides (p= 0.0380) were independent predictive factors for elevated NT-pro-BNP values.

CONCLUSION

In diabetic heart failure patients, the value of NT-pro-BNP holds a pivotal role in the evaluation of their overall status, facilitating the establishment of correct management and follow-up.

Diabetes Mellitus Is Associated with a Lower Risk of Gout: A Meta-Analysis of Observational Studies

AIMS

Although several epidemiological studies have investigated the relationship between diabetes mellitus (DM) and the risk of gout, the results are inconsistent. Therefore, we systematically retrospected available observational studies to clarify the impact of DM on the risk of gout.

METHODS

Embase, PubMed, Cochrane Library, Scopus, Web of Science, and China National Knowledge Infrastructure were searched for relevant articles from inception to 2 March 2020. The quality of the included studies was assessed using the Newcastle-Ottawa Quality Assessment Scale. The multivariate adjusted relative risks (aRR) and corresponding 95% confidence intervals (CI) were pooled based on a random-effect model. Cochran's Q test and I ² were used to evaluate heterogeneity.

RESULTS

Five studies involving 863,755 participants were included in our meta-analysis. DM was associated with a lower risk of gout (aRR: 0.66; 95% CI: 0.59 to 0.73) but had a high heterogeneity (I ² = 89.2%). Metaregression analysis revealed that the types of DM were the source of heterogeneity. Subgroup analysis by types of DM showed that the risk of gout was significantly lower in type 1 DM (T1DM) (aRR: 0.42; 95% CI: 0.28 to 0.63) than in type 2 DM (T2DM) (aRR: 0.72; 95% CI: 0.70 to 0.74). Furthermore, when stratified according to gender in DM, sex-specific association was found. The inverse association was observed in males only (aRR: 0.57; 95% CI: 0.43 to 0.77) and not in females (aRR: 0.96; 95% CI: 0.87 to 1.05). Further stratified based on glycated hemoglobin (HbA1c) levels in DM, raised A1C levels were associated with a reduced risk of gout in patients with DM.

CONCLUSIONS

This meta-analysis indicated that DM was related to a lower risk of gout, and the protective effect of DM on the risk of gout was stronger in males, T1DM, or DM with high HbA1c levels. However, more prospective cohort studies are required to confirm these results.

Gout and risk of diabetes mellitus: meta-analysis of observational studies

To determine the prevalence of diabetes mellitus (DM) in people with gout, and investigate the relationship between gout and the occurrence of DM. Systematic review and meta-analysis of epidemiological studies. Data sources: MEDLINE, Web of Science, EMBASE and CINAHL databases, hand-searched reference lists, citation history and contact with authors. Eligibility criteria: cohort, case-control or cross-sectional studies which examined the occurrence of DM amongst adults with gout (with or without gout group) in primary care or general population samples. Prevalence and risk estimate meta-analyses were performed using a random-effects model. A total of 23 identified studies matched the inclusion criteria, reporting on a total of 575 284 gout patients. Meta-analyses revealed that the prevalence of DM in gout patients was 16% (95% CI, 14-18%, I² = 99.8%) according to clinical interviews. In the subgroup analysis, the prevalence of DM was higher in the female population (18%, 95%CI 2.7-33.3%) than the male population (12.6%, 95%CI 8.2-17.1%). As age increased, the incidence of diabetes in gout population increased. DM is commonly found among patients with gout. Patients with gout should be actively screened for DM and its consequences.

Relationship between Gout and Diabetes Mellitus after Acute Pancreatitis: A Nationwide Cohort Study

OBJECTIVE

After acute pancreatitis, individuals often have low-grade inflammation, and subsequently develop metabolic sequelae such as post-pancreatitis diabetes mellitus (PPDM). Although numerous studies have investigated the relationship between gout and type 2 diabetes, little is known about the relationship between gout and PPDM. The aim was to investigate the associations between gout and PPDM.

METHODS

Using nationwide pharmaceutical dispensing data linked to hospital discharge data in New Zealand, gout and PPDM were identified among individuals after first episode of acute pancreatitis between January 1, 2007, and December 31, 2015. Multivariable Cox regression analyses were conducted, adjusting for age, sex, ethnicity, social deprivation index, alcohol consumption, tobacco smoking, comorbidities, medications (glucocorticoids, statins, and estrogens), and characteristics of acute pancreatitis.

RESULTS

A total of 10,117 individuals were included in the analysis of risk for gout and 9471 in the analysis of risk for PPDM. PPDM was significantly associated with a higher risk of gout in the overall cohort (adjusted HR 1.88, 95% CI 1.15-3.06) and women (2.72, 95% CI 1.31-5.65), but not in men (1.42, 95% CI 0.73-2.78). Preexisting gout was significantly associated with a higher risk of PPDM in the overall cohort (adjusted HR 1.58, 95% CI 1.04-2.41) and women (2.66, 95% CI 1.29-5.49), but not in men (1.31, 95% CI 0.78-2.20).

CONCLUSION

The relationship between gout and PPDM is bidirectional in the post-pancreatitis setting. A history of gout is a risk factor of PPDM, particularly in women.

The association of gout with an increased risk of hypertension and diabetes mellitus among stroke survivors in New Zealand: A cross-sectional study using routinely collected electronic health data

Background

There is a paucity of data relating to the association of gout with the occurrence of hypertension and diabetes mellitus in patients with stroke. This study aimed to determine the association of gout with the risk of hypertension and diabetes mellitus in a cohort of stroke patients from Auckland, Aotearoa New Zealand.

Methods

A cross-sectional study was conducted among stroke survivors in South and East Auckland, New Zealand from the years 2010 to 2014. Electronic health record data were collected and analysed using Statistical Package for Social Science version 23. Multivariate logistic regression modelling adjusted for age, gender, and ethnicity was conducted to determine the association of gout with the risk of hypertension and diabetes mellitus in patients discharged with a diagnosis of stroke.

Results

The age-, gender-, and ethnicity-adjusted odds ratio for having hypertension and diabetes mellitus among stroke survivors with gout history were 3.25 (95% confidence interval 1.32–8.03) and 1.94 (95% confidence interval 1.12–3.36), respectively. Māori stroke survivors with gout history had the highest risk of having diabetes mellitus with age- and gender-adjusted odds ratio of 5.10 (95% confidence interval 1.90–18.93).

Conclusion

The findings from this study suggest gout may be independently associated with an increased risk of hypertension and diabetes mellitus in patients with stroke. Māori who are the indigenous population of New Zealand show a greater risk of diabetes mellitus associated with a gout diagnosis compared to other populations. This finding highlights the importance of the need for further research with Māori stroke survivors and other indigenous populations.

Cardiovascular Risk in Type 2 Diabetic Patients With Asymptomatic Hyperuricemia and Gout

Aim: To study the differences in cardiovascular risk between type 2 diabetic and non-diabetic patients with asymptomatic hyperuricemia and gout using the Framingham Risk Score (FRS) and complex multimodal ultrasonography.

Patients and methods: A total of 201 patients participated, divided into two groups: 1/ patients with asymptomatic hyperuricemia (n = 52), and 2/ patients with gout (n = 149). FRS was determined as well as ultrasound parameters, independent predictors of cardiovascular risk: left atrial size (LA), intima-media thickness (IMT) and common carotid artery resistive index (CCARI).

Results: The patients in the two groups were age-matched and conventional cardiovascular risk factors were equally distributed. In the asymptomatic hyperuricemia group, 12 patients (23.1%) had diabetes. In this group, there was no difference in FRS between diabetic and non-diabetic individuals. However, diabetic patients had larger LA, thicker intima-media and higher CCARI. In the gout group 18 subjects (12%) had diabetes, but the FRS, LA, IMT and CCARI values were similar among diabetic and non-diabetic patients. Furthermore, when gout subjects were subdivided according to the presence of tophi, we found that the subgroup having gouty tophi and diabetes had larger LA (p = 0.014) compared to those with gouty tophi without diabetes.

Conclusion: In diabetic patients with asymptomatic hyperuricemia and gouty tophi, a more complex approach for estimation of cardiovascular risk is needed. Our work suggests that diabetes and tophi might potentiate their action on the cardiovascular system.

[Comorbidity in gout and hyperuricemia: prevalence, causes, prospects of urate lowering therapy]

Nowadays, there is increased interest in the connection of gout and asymptomatic hyperuricemia with comorbid conditions such as diabetes mellitus, cardiovascular diseases, hypertension, chronic kidney disease and other. Studies conducted over the past few decades suggest that not only gout, but also asymptomatic hyperuricemia can significantly worsen the prognosis in patients with cardiovascular diseases, as the deposition of urate crystals can be both an immediate cause and a factor in the progression of renal failure. In that way, the timely appointment of urate - lowering therapy and achieving the target serum uric acid level can not only affect joint damage, but also can significantly slow the progression of life - threatening comorbid conditions.

Consumption of 100% Tart Cherry Juice Reduces Serum Urate in Overweight and Obese Adults

BACKGROUND

Gout is a frequently occurring, complex rheumatologic form of inflammatory arthritis caused by the accumulation of serum uric acid (sUA) and deposition of uric acid crystals in the joints and tissues of the body. Hyperuricemia is also a significant independent risk factor for all-cause and cardiovascular morbidity and mortality and is associated with hypertension, diabetes, obesity, and osteoarthritis. However, patient adherence to prescribed urate-lowering therapies ranges from 20% to 70%, suggesting that other additional strategies, such as dietary intervention with specific, efficacious foods or beverages, may be necessary to mitigate the risk of arthritis, as well as other comorbidities. Tart cherry juice (TCJ) has been used for decades by some for gout based largely on anecdotal evidence of its efficacy and its antioxidant and anti-inflammatory properties.

OBJECTIVES

We designed this study to test the effect of TCJ on uricemia, lipidemia, glycemia, and inflammation in at-risk overweight and obese humans with a specific hypothesis that TCJ consumption would reduce sUA concentrations.

METHODS

In this randomized, placebo-controlled crossover study, we recruited overweight and obese participants with body mass index (BMI) >25.0 kg/m2 (n = 26, 18 women/8 men, 41 ±11 y; BMI 31.3 ± 6.0; 12 obese, 14 overweight) to consume 240 mL/d (8 oz/d) of either TCJ or placebo beverage, for 4 wk each with a 4-wk intervening washout period followed by 4 wk of the alternate beverage.

RESULTS

TCJ significantly reduced sUA concentration by 19.2% (P < 0.05) and reduced by 19.4% (P = 0.09) and 6.3% (P = 0.08) proinflammatory high-sensitivity C-reactive protein and monocyte chemoattractant protein-1, respectively. The participants in this study displayed risk ratios indicating increased cardiovascular disease risk and insulin resistance but no differences in the pre- and postintervention groups of either placebo or TCJ groups.

CONCLUSION

Collectively, the data suggest that 100% TCJ reduces sUA concentrations, mitigating hyperuricemia associated with gouty arthritis. This trial was registered at clinicaltrials.gov as NCT03636529.

Associations between urate-lowering therapy and the risk of type 2 diabetes mellitus

Background

Gout is independently associated with increased risk of type 2 diabetes mellitus (T2DM). Urate-lowering therapy (ULT) might be beneficial in lowering the risks of T2DM. Therefore, we conducted a nested case-control study to evaluate the associations between ULT and T2DM.

Methods

This study retrieved the data of 29,765 gout patients from the period of 1998–2010 by using data from Taiwan’s National Health Insurance Research Database. Controls (n = 59,530) were matched at a 1:2 ratio by age, sex, and region. Multivariate Cox proportional hazards regression were performed to examine the dose-dependent relationship between ULT and T2DM.

Results

The adjusted Hazard ratio (HR) for the association of T2DM with allopurinol or benzbromarone exposure was 1.17 (95% confidence interval (CI) 1.07–1.28) and1.09 (95% CI 1.03–1.15), respectively. The HR for the cumulative allopurinol dose was 0.87 (95% CI 0.71–1.07) for patients with dose ≤1.3 mg/day and was 1.31 (95% CI 1.13–1.52) for those with a dose >15.2 mg/day. Similarly, the HR for the cumulative benzbromarone dose was 0.85(95% CI 0.75–0.96) for patients with a dose ≤1.3 mg/day and 1.42 (95% CI 1.30–1.55) for patients with a dose>9.4 mg/day, respectively. Moreover, the average exposure dose of >100 mg/day for allopurinol and >100 mg/day for benzbromarone was associated with a 1.28-fold (95% CI 1.11–1.48) and 1.47-fold (95% CI 1.23–1.76) T2DM risk respectively. The HR for patients in aged >50 years group with cumulative dose ≤1.3 mg/day of allopurinol or benzbromarone had lower risk of T2DM (HR = 0.74, 95% CI 0.58–0.94 for allopurinol; HR = 0.79, 95% CI 0.69–0.90 for benzbromarone).

Conclusion

Gout patients with prolonged ULT and a high dose of ULT were associated with a significant increase in T2DM risk. Although gout patients with age greater than 50 years and a lower dose of ULT may be beneficial in lowering T2DM risk, further clinical studies need to be confirmed these associations.

Prevalence and characteristics of metabolic syndrome in gout patients in a hospital setting in sub-Saharan Africa

BACKGROUND

Evidence from epidemiological studies suggests an important association between gout and the metabolic syndrome (MetS). However, to the best of our knowledge, prevalence of metabolic syndrome in gout has not been reported in sub-Saharan African (SSA) settings.

OBJECTIVES

The aim of this study was to determine the prevalence and characteristics of MetS in gout in a SSA population.

METHOD

After prior ethical clearance, we carried out a cross-sectional study involving gout patients in a referral hospital in Douala-Cameroon. Metabolic syndrome was defined using International Diabetes Foundation criteria. Associations between variables were assessed using logistic regression.p <  0.05 was considered significant.

RESULTS

On 174 gout patients (48.3% females) who consented to participate in the study, the median (IQR) age was 55.00 (14.25) years, and the median (IQR) duration of gout was 7.5 (10.0) years. Prevalence of metabolic syndrome was 54.6% (95% CI: 47.9%-62.8%). One hundred and forty-seven (84.5%) participants had central obesity, 62 (35.6%) raised triglycerides, 79 (45.4%) reduced HDL-C, 129 (74.1%) raised blood pressure, and 85 (48.9%) had raised fasting plasma glucose. On logistic regression analyses, gout patients with metabolic syndrome significantly had a higher body mass index (OR: 1.09, 95% CI: 1.02-1.17), and higher levels of serum uric acid (OR: 1.02, 95% CI: 1.01-1.04).

CONCLUSIONS

About 1 out of every 2 gout patients in this population have metabolic syndrome. These gout patients with metabolic syndrome significantly have a higher body mass index, and higher levels of serum uric acid. Cohort studies are required to clearly establish the direction of the relationship between gout and metabolic syndrome.

Effects of pharmacological reversal of hyperuricemia on features of the metabolic syndrome in patients with gouty arthritis

Hyperuricemia has been associated in epidemiological studies with the development of obesity, hypertension, insulin resistance and type 2 diabetes. Nevertheless, it remains unclear whether lowering of serum uric acid (UA) alters any of the features of the metabolic syndrome. In this prospective study (ClinicalTrials.gov identifier: NCT01654276), 24 patients with gouty arthritis and hyperuricemia were treated for 6 months with the xanthine oxidase inhibitor febuxostat to lower serum UA to <6 mg/dL. Measurements of 24 hours ambulatory blood pressure (ABP) and serum and urine markers of the metabolic syndrome were measured at baseline and at the end of 6 months of febuxostat. The study population consisted of 18 men and 6 women, 18 of which completed the baseline and 6 months visits. Serum UA decreased significantly from 8.7±1.5 mg/dL at baseline to 4.4±1.1 mg/dL at 6 months (P<0.0001). During that time frame, there was no significant change in body mass index, systolic or diastolic blood pressure measured by 24 hours ABP monitor, serum glucose, insulin or homeostatic model assessment for insulin resistance, serum total and high-density lipoprotein-cholesterol, serum triglycerides or urine pH (P>0.05 for all). There was no correlation between parameters of the metabolic syndrome and the decline in serum UA or serum UA achieved at study end. In conclusion, in patients with gouty arthritis, UA lowering with febuxostat below 6 mg/dL had no significant impact on features of the metabolic syndrome.

Clinical characteristics associated with subcutaneous tophi formation in Chinese gout patients: a retrospective study

The objective of this study is to analyze clinical characteristics associated with the formation of subcutaneous tophi among Chinese gout patients. It was a retrospective outpatient cohort study. Five thousand six hundred ninety-three gout patients treated at the Affiliated Hospital of Qingdao University from March 2011 to February 2016 were included and divided into the tophus group and non-tophus group according to the presence of megascopic tophus. Relevant clinical information and biochemical parameters were analyzed to identify potential risk factors for the incidence of subcutaneous tophi. There are significant difference (P < 0.05) between the tophus and non-tophus groups in gender, family history, exercise, incidence of obesity, hypertension, renal dysfunction, kidney stone, coronary heart disease, and upper limb joint involvement. Between the two groups, significant difference (P < 0.01) was detected in the onset age (43.80 ± 13.82 years vs. 45.40 ± 13.77 years), duration of disease (10.28 ± 7.54 years vs. 5.11 ± 6.06 years), number of joint involved (3.11 ± 2.15 vs. 1.81 ± 1.35), systolic pressure (138.53 ± 19.46 mmHg vs. 133.87 ± 17.93 mmHg), diastolic pressure (89.55 ± 12.73 mmHg vs. 87.48 ± 11.77 mmHg), serum uric acid (487.15 ± 120.13 μmol/L vs. 458.89 ± 119.04 μmol/L), creatinine (93.87 ± 54.19 μmol/L vs. 85.51 ± 37.71 μmol/L), and creatinine clearance rate (Ccr) (93.05 ± 48.7 mL/min vs. 106.61 ± 51.76 mL/min). Logistic regression analysis suggests that duration of disease, number of joints involved, involvement of upper limb joints, kidney stones, diastolic pressure, and serum uric acid are associated with the subcutaneous tophi formation, while exercise and obesity are protective factors. The present study has identified several clinical parameters (such as duration of disease, involvement of upper limb joints, involved joints, kidney stone, hypertension) as risk factors for the incidence of subcutaneous tophi, which provides insights into the treatment and prevention of tophus.

Work disability in gout: a population-based case–control study

Objectives

To examine the extent and cost of work disability among patients with gout compared with matched population controls and to analyse predictors of work disability.

Methods

A regional cohort study using data from Swedish national and regional registries from January 2000 through December 2012, including 4571 patients with gout of working age, with a first recorded diagnosis of gout in the years 2003–2009 and 22 482 population controls, matched by age, sex and place of residence. Differences in baseline characteristics (educational level, income, previous employment and comorbidities) and the number of work-loss days (absenteeism) due to sick leave and disability pension for 3 years after identification were calculated. Predictors for new-onset work absenteeism (>90 days/year) in a subset were determined by conditional logistic regression.

Results

Patients with gout (median age 53 years) had significantly more comorbidities, lower income and lower level of education than matched controls. The average work absentee rate during the 3-year follow-up period was higher among patients with gout than controls, 22% and 14%, respectively (P<0.0001). New-onset absenteeism was in multivariate analyses significantly predicted by gout (OR 1.47; 95% CI 1.23 to 1.75). Other variables independently related to new-onset absenteeism were education ≤12 years, previous unemployment and history of sick leave, in addition to several comorbidities (renal disease, cardiovascular disease, alcohol abuse and obesity).

Conclusions

Gout is associated with substantially higher work absenteeism and costs for society due to productivity loss, after adjusting for associated comorbidities and socioeconomic differences. Whether more intensive treatment of gout is cost-effective needs to be addressed in future studies.

An association of smoking with serum urate and gout: A health paradox

BACKGROUND

The potential effect of cigarette smoking on levels of serum urate and risk of gout has been considered by a large number of studies, either as the primary variable of interest or as a covariate.

METHODS

Here we systematically review the published evidence relating to the relationship of smoking with serum urate, hyperuricaemia, and gout.

RESULTS

Many studies have reported that smoking reduces serum urate, however, the evidence has not been conclusive with other studies pointing to the opposite or no effect. It has also been suggested that smoking reduces the risk of gout, although there is some evidence to contradict this finding.

CONCLUSION

A consensus has yet to be reached as to the effect of smoking on serum urate levels and the risk of gout.

Prevalence and associations of gout and hyperuricaemia: results from an Australian population-based study

BACKGROUND

Despite gout and hyperuricaemia being major comorbid health issues worldwide, there is a knowledge gap regarding their impact in the Australian community.

AIMS

To determine the prevalence and associations of self-reported medically diagnosed gout and hyperuricaemia in an Australian population-based cohort.

METHODS

The North West Adelaide Health Study is a longitudinal cohort study consisting of three stages of data collection. Each stage comprised a self-complete questionnaire, clinic assessment and computer-assisted telephone interview. In Stage 3 (2008-2010), participants were asked if a doctor had ever diagnosed them with gout. Additional data included demographics, comorbidities, laboratory data and Short Form 36 (SF-36). Participants were defined as having gout if they had self-reported medically diagnosed gout or were taking any gout-specific medication (allopurinol, colchicine, probenecid). Hyperuricaemia was defined as a serum uric acid (SUA) level >0.42 mmol/L in men and >0.34 mmol/L in women.

RESULTS

The overall prevalence of gout was 5.2%. Males were significantly more likely to have gout than females (8.5 vs 2.1%, P < 0.001). The overall prevalence of hyperuricaemia was 16.6%, with being male again identified as a significant risk factor (17.8 vs 15.4%, P < 0.01). Both gout and hyperuricaemia were associated with male sex, body mass index and renal disease after multivariable adjustment. There was no significant difference reported in quality of life (mean SF-36) scores in participants with gout compared to unaffected individuals.

CONCLUSION

The prevalence of gout and hyperuricaemia is high in the South Australian population. This study emphasises the need for optimal diagnosis and management of gout in Australia.

Use of large healthcare databases for rheumatology clinical research

PURPOSE OF REVIEW

Large healthcare databases, which contain data collected during routinely delivered healthcare to patients, can serve as a valuable resource for generating actionable evidence to assist medical and healthcare policy decision-making. In this review, we summarize use of large healthcare databases in rheumatology clinical research.

RECENT FINDINGS

Large healthcare data are critical to evaluate medication safety and effectiveness in patients with rheumatologic conditions. Three major sources of large healthcare data are: first, electronic medical records, second, health insurance claims, and third, patient registries. Each of these sources offers unique advantages, but also has some inherent limitations. To address some of these limitations and maximize the utility of these data sources for evidence generation, recent efforts have focused on linking different data sources. Innovations such as randomized registry trials, which aim to facilitate design of low-cost randomized controlled trials built on existing infrastructure provided by large healthcare databases, are likely to make clinical research more efficient in coming years.

SUMMARY

Harnessing the power of information contained in large healthcare databases, while paying close attention to their inherent limitations, is critical to generate a rigorous evidence-base for medical decision-making and ultimately enhancing patient care.

Impact of comorbidities on gout and hyperuricaemia: an update on prevalence and treatment options

Gout, the most prevalent inflammatory arthritis worldwide, is associated with cardiovascular and renal diseases, and is an independent predictor of premature death. The frequencies of obesity, chronic kidney disease (CKD), hypertension, type 2 diabetes, dyslipidaemias, cardiac diseases (including coronary heart disease, heart failure and atrial fibrillation), stroke and peripheral arterial disease have been repeatedly shown to be increased in gout. Therefore, the screening and care of these comorbidities as well as of cardiovascular risk factors are of outmost importance in patients with gout. Comorbidities, especially CKD, and drugs prescribed for their treatment, also impact gout management. Numerous epidemiological studies have shown the association of asymptomatic hyperuricaemia with the above-mentioned diseases and cardiovascular risk factors. Animal studies have also produced a mechanistic approach to the vascular toxicity of soluble urate. However, causality remains uncertain because confounders, reverse causality or common etiological factors might explain the epidemiological results. Additionally, these uncertainties remain unsolved despite recent studies using Mendelian randomisation or therapeutic approaches. Thus, large randomised placebo-controlled trials are still needed to assess the benefits of treating asymptomatic hyperuricaemia.

Serum Uric Acid and the Risk of Incident and Recurrent Gout: A Systematic Review

OBJECTIVE

Lowering serum uric acid (SUA) levels can essentially cure gout; however, this is not widely practiced. To summarize epidemiologic evidence related to this causal link, we conducted a systematic review of the published literature reporting the association between SUA level and incident and recurrent gout (i.e., gout flares).

METHODS

We systematically searched Medline, EMBASE, and the Cochrane Database of Systematic Reviews using separate search strategies for incident gout and recurrent gout. We screened 646 abstracts to identify 8 eligible articles reporting gout incidence and 913 abstracts to identify 18 articles reporting recurrent gout.

RESULTS

For both gout incidence and recurrence, a graded trend was observed where the risk was increased with higher SUA levels. Gout incidence rates per 1000 person-years from population-based studies ranged from 0.8 (SUA ≤ 6 mg/dl) to 70.2 cases (SUA ≥ 10 mg/dl). Recurrent gout risk in clinical cohorts ranged from 12% (SUA ≤ 6 mg/dl) to 61% (SUA ≥ 9 mg/dl) among those receiving urate-lowering therapy (ULT), and 3.7% (SUA 6-7 mg/dl) to 61% (SUA > 9.3 mg/dl) after successful ULT. Retrospective database studies also showed a graded relationship, although the strength of the association was weaker. Studies reporting mean flares or time-to-flare according to SUA showed similar findings.

CONCLUSION

This systematic review confirms that higher SUA levels are associated with increased risk of incident and recurrent gout in a graded manner. Although few prospective cohorts have evaluated incident and recurrent gout according to SUA, the existing evidence underscores the need to treat to SUA targets, as recommended by the American College of Rheumatology and the European League Against Rheumatism.

Association Between Gout and Incident Type 2 Diabetes Mellitus: A Retrospective Cohort Study

OBJECTIVE

We investigated the association between gout and the risk of type 2 diabetes mellitus.

METHODS

Population-based representative insurance (outpatient and inpatient) claims data of 29,765 patients with gout and 59,530 controls without gout (1:2 case:control ratio) between 1998 and 2010 in Taiwan were identified. The association between gout and type 2 diabetes was evaluated using the Cox proportional hazards model. Moreover, the combined effects of sex and incident gout on the risk of type 2 diabetes were estimated.

RESULTS

In total, 3940 patients (13.24%) with gout and 6334 controls (10.64%) developed type 2 diabetes in the follow-up period. Multivariate analyses revealed a significant association between gout and type 2 diabetes. Compared with the control group, the adjusted hazard ratios (95% confidence intervals) for type 2 diabetes were 1.62 (1.54-1.70) in men, 1.97 (1.81-2.14) in women, and 1.70 (1.62-1.77) overall. The multiplicative interaction was β = 0.18 and P = .0001, suggesting a positive interaction between sex and incident gout. Moreover, compared with men without gout, a significantly higher risk of type 2 diabetes was noted in women without gout (adjusted relative risk [95% confidence interval], 1.17 [1.10-1.24]), men with gout (1.11 [1.06-1.16]), and women with gout (1.47 [1.37-1.57]) (P for interaction = .0058).

CONCLUSIONS

Gout is a strong and independent risk factor for type 2 diabetes, and female patients with gout are at a higher risk of type 2 diabetes than are male patients with gout.

Sex differences regarding the amelioration of wrinkles due to skin dryness by the administration of tranexamic acid

Tranexamic acid (trans-4-aminomethylcyclohexanecarboxylic acid) exerts an amelioration effect on wrinkle formation due to skin dryness. We examined the sex differences in this effect. We administered tranexamic acid (750mg/kg/day) orally for 20 consecutive days to male and female Naruto Research Institute Otsuka Atrichia (NOA) mice, which naturally develop skin dryness. In the treated female mice, the amelioration effect on the wrinkle score, deterioration of transepidermal water loss (TEWL), capacitance, and decrease in the expression of collagen type I was stronger than in the male treated mice. Furthermore, the level of β-endorphin in the plasma and the expression of β-endorphin, μ-opioid receptor, and macrophages in the dorsal skin increased after the administration of tranexamic acid, and this increase was higher in female mice than in males. In addition, the macrophage production was increased by the administration of tranexamic acid in the ovary but did not change after administration in the testes. A histological examination revealed that these macrophages produce the β-endorphin, clarifying the source of the elevated levels. The amelioration effect in the female treated mice was decreased by the administration of clophosome (a macrophage inhibitor) to a degree that did not markedly differ from the effect observed in the male treated mice. These results suggest that the amelioration effect on wrinkles is stronger in female NOA mice than in males and that β-endorphin produced by macrophages plays an important role in this sex difference.

Bidirectional Association between Diabetes and Gout: the Singapore Chinese Health Study

We aimed to prospectively investigate the bidirectional association between type 2 diabetes (T2D) and gout. We analyzed follow-up data from the Singapore Chinese Health Study, when self-reports of diagnosed diabetes and gout were enquired at follow-ups I and II. Individuals who participated in both follow-ups and were free of cardiovascular disease or cancer at follow-up I were included. For T2D to gout (analysis I), prevalent gout were further excluded (final n = 31,137). For gout to T2D (analysis II), prevalent diabetes were excluded (final n = 28,668). Cox regression models were used to estimate relative risks (RRs). In the analysis I, the RR of diabetes to incident gout (682 cases) was 0.77 (95% CI 0.60–0.97). In the analysis II, the RR of gout to incident diabetes (2223 cases) was 1.36 (1.12–1.63), but became insignificant after adjustment for hypertension and BMI (1.00; 0.83–1.21). The gout to diabetes association was modified by BMI (P_interaction = 0.04) and hypertension (P_interaction = 0.007), and it was marginally significant in adults with BMI<24 while significant among non-hypertensive participants, but not in their counterparts. In conclusion, our results suggest that diabetes is associated with a lower risk of incident gout, while gout is positively related to diabetes among normal weight and non-hypertensive adults.

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.