Increased cardiovascular mortality associated with gout: a systematic review and meta-analysis

Cardiovascular risk in inflammatory arthritis: rheumatoid arthritis and gout

The increased risk of cardiovascular morbidity and mortality in rheumatoid arthritis and gout has been increasingly acknowledged in past decades, with accumulating evidence that gout, just as with rheumatoid arthritis, is an independent cardiovascular risk factor. Although both diseases have a completely different pathogenesis, the underlying pathophysiological mechanisms in systemic inflammation overlap to some extent. Following the recognition that systemic inflammation has an important causative role in cardiovascular disease, anti-inflammatory therapy in both conditions and urate-lowering therapies in gout are expected to lower the cardiovascular burden of patients. Unfortunately, much of the existing data showing that urate-lowering therapy has consistent beneficial effects on cardiovascular outcomes in patients with gout are of low quality and contradictory. We will discuss the latest evidence in this respect. Cardiovascular disease risk management for patients with rheumatoid arthritis and gout is essential. Clinical guidelines and implementation of cardiovascular risk management in daily clinical practice, as well as unmet needs and areas for further investigation, will be discussed.

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.

Effects of Urate-Lowering Therapy on Risk of Hyperlipidemia in Gout by a Population-Based Cohort Study and on In Vitro Hepatic Lipogenesis-Related Gene Expression

Patients with gout are at a higher risk of cardiovascular disease, which is associated with hyperlipidemia. Management of gout in Taiwan is poor, and the association between urate-lowering therapy (ULT) among gout patients and hyperlipidemia is unclear. We conducted a retrospective cohort study using data from the Longitudinal Health Insurance Database (LHID) of Taiwan on new-onset gout patients and a comparison cohort without gout. A Cox proportional hazards model was used to analyze differences in the risk of hyperlipidemia between patients with and without gout after considering related comorbidities. We also examined the ULT medications on the hepatic expression of lipogenesis-related genes. After adjusting for potential confounders, the case group (44,413 patients) was found to have a higher risk of hyperlipidemia than the control cohort (177,652 patients) [adjusted hazards ratio (aHR) = 2.55]. Gout patients without antigout treatment had significantly higher risk of hyperlipidemia than the control cohort (aHR = 3.10). Among gout patients receiving ULT, except those receiving probenecid (aHR = 0.80), all had significantly lower risk of hyperlipidemia than gout patients without ULT (all aHR < 0.90). Using real-time polymerase chain reaction, we found that most of the antigout drugs decreased the expression of hepatic genes related to lipogenesis in differentiated HepaRG cells. These data indicate that these antigout drugs reduce hyperlipidemia in gout patients, partly via the reduction in expression of lipogenesis-related genes, leading to improved blood lipid profiles. We provide evidence of the strong association between gout and hyperlipidemia and highlight the need for appropriate treatment guidelines.

Gout Is Prevalent but Under-Registered Among Patients With Cardiovascular Events: A Field Study

Objectives: Gout is an independent cardiovascular (CV) risk factor with significant morbidity and mortality. We aimed to estimate the prevalence of gout, characteristics and management in a hospitalized population for CV disease, a topic that remains to be defined. Methods: An observational, descriptive, cross-sectional study was carried out in patients admitted for CV events in the Cardiology, Neurology, and Vascular Surgery units of a tertiary center. Patients were selected following a non-consecutive, systematic sampling. Data about CV disease and gout were obtained from face-to-face interviews and patients' records. Gout diagnosis was established using the 2015 ACR/EULAR clinical classification criteria. The registration rate of gout was assessed by auditing patients' records and hospital discharge reports of CV events from the units of interest in the previous 2 years. To predict the presence of gout, multivariate logistic regression models were built to study the possible explanatory variables. Results: Two hundred and sixty six participants were recruited, predominantly males (69.9%) and Caucasians (96.6%) with a mean age of 68 years. Gout was identified in 40 individuals; thus, the prevalence was 15.0% (95% CI 10.9-19.2%). In 35% of cases, the diagnosis was absent from patients' records. Gout was found in 1.4-2.6% of hospital discharge reports of CV events, also indicating under-registration. The disease was long-standing, but with low reported rates of flares, involved joints, and tophi. At admission, only half of the gout patients were on urate-lowering therapy, being 38.5% of them on serum urate <6 mg/dl. The only independent predictor of gout was the existence of previous hyperuricemia (median serum urate in previous 5 years ≥7 mg/dl), with an odds ratio of 2.9 (95% CI 1.2-7.1); if hyperuricemia is not included in the model, the only independent predictor was chronic kidney disease (odds ratio 3.0; 95% CI 1.4-6.6). Conclusion: Gout is highly prevalent among patients admitted for CV events, with significant lack of awareness and suboptimal management, despite being a well-established independent CV risk factor.

Effect of canakinumab on clinical and biochemical parameters in acute gouty arthritis: a meta-analysis

BACKGROUND

Targeted anti-IL-1β therapy may be a valuable option for the management of gouty arthritis. The present meta-analysis has evaluated the effect of canakinumab, an anti-IL-1β monoclonal antibody in gouty arthritis.

METHODS

A standard meta-analysis protocol was developed and after performing a comprehensive literature search in MEDLINE, Cochrane, and International Clinical Trial Registry Platform (ICTRP), reviewers assessed eligibility and extracted data from three relevant articles. A random-effects model was used to estimate the pooled effect size as the mean difference in Visual Analouge Scale (VAS) score, serum hsCRP, serum Amyloid A, and risk ratio for global assessment between the groups. Quality assessment was done using the risk of bias assessment tool and summary of findings was prepared using standard Cochrane methodology with GradePro GDT.

RESULTS

Treatment with canakinumab showed a mean reduction of VAS score by 14.59 mm [95% CI - 19.42 to - 9.77], serum hsCRP by 15.36 mg/L [95% CI 1.62-29.11], serum Amyloid A by 67.18 mg/L [95% CI 17.06-117.31], and improvement in patient global assessment (RR = 1.478; 95% CI 1.29-1.67) and physician global assessment (RR = 1.44; 95% CI 1.28-1.61). The probability that future studies may have a mean difference in VAS score less than zero has been calculated to be 27.3% using a cumulative distribution function (CDF) calculator.

CONCLUSION

This meta-analysis shows the beneficial effect of canakinumab over triamcinolone by reducing VAS score, serum hsCRP, serum amyloid A, and improvement in global assessments in acute gouty arthritis.

Comparative effectiveness of allopurinol and febuxostat for the risk of atrial fibrillation in the elderly: a propensity-matched analysis of Medicare claims data

AIMS

Gout is associated with a higher risk of atrial fibrillation (AF). Comparative effectiveness of allopurinol or febuxostat for reducing the AF risk is unknown, which was our study's main objective.

METHODS AND RESULTS

We used the 5% Medicare Beneficiary cohort (≥65 years) from 2006 to 2012 to identify people with a new filled prescription for allopurinol or febuxostat, with a baseline period of 365 days without respective medication and without AF. We used 5:1 propensity-matched Cox regression analyses to assess whether allopurinol use differed from febuxostat use regarding the hazard ratio (HR) of incident AF. We found 25 732 eligible episodes in 23 135 beneficiaries. Of these, 2311 incident allopurinol or febuxostat use episodes (9%) ended in incident AF with crude incidence rates of 8.0 and 10.5 per 100 person-years, respectively. In propensity-matched analyses, compared with allopurinol, febuxostat was associated with higher HR of AF, 1.25 [95% confidence interval (CI) 1.05-1.48]. Compared with allopurinol <200 mg/day, febuxostat 80 mg/day was associated with significantly higher HR of AF, 1.62 (95% CI 1.16-2.27), but not febuxostat 40 mg/day or higher allopurinol doses. Compared with 1-180 days of allopurinol use, febuxostat use for 1-180 days was associated with significantly higher HR of AF, 1.36 (95% CI 1.10-1.67), but longer durations were not.

CONCLUSION

Febuxostat was associated with a higher risk of AF compared with allopurinol in older adults. Increased AF risk was noted with febuxostat 80 mg/day dose and was most evident in the first 6 months of use. These findings need replication.

An exploratory cross-sectional study of subclinical vascular damage in patients with polymyalgia rheumatica

The aim of the study was to investigate the presence of subclinical vascular damage in polymyalgia rheumatica (PMR). We enrolled PMR patients having major cardiovascular risk factors (MCVRF) and, as controls, patients with MCVRF. All underwent: color Doppler ultrasound to evaluate the common carotid intima-media thickness (IMT), the anterior–posterior abdominal aortic diameter (APAD), and the prevalence of carotid artery stenosis; the cardio-ankle vascular index (CAVI) to measure arterial stiffness together with the ankle-brachial index (ABI) to investigate the presence of lower-extremity peripheral arterial disease. Finally, we measured the serum levels of adipocytokines implicated in vascular dysfunction. As a result, 48 PMR and 56 MCVRF patients were included. An increase of IMT (1.07/0.8–1.2 vs 0.8/0.8–1.05; p = 0.0001), CAVI (8.7/7.8–9.3 vs 7.6/6.9–7.8; p < 0.0001) and APAD values (21.15/18.1–25.6 vs 18/16–22; p = 0.0013) was found in PMR patients with respect to controls. No differences were reported in the prevalence of carotid artery stenosis or ABI values between the two groups. A significant correlation between IMT and CAVI in PMR and MCVRF subjects (r² = 0.845 and r² = 0.556, respectively; p < 0.01) was found. Leptin levels (pg/mL; median/25th–75th percentile) were higher in PMR than in MCVRF subjects (145.1/67–398.6 vs 59.5/39.3–194.3; p = 0.04). Serum levels of adiponectin (ng/mL) were higher in PMR patients (15.9/10.65–24.1 vs 6.1/2.8–22.7; p = 0.01), while no difference in serum levels of resistin (ng/mL) was found between PMR and MCVRF subjects (0.37/0.16–0.66 vs 0.26/0.14–1.24). Our study shows an increased subclinical vascular damage in PMR patients compared to those with MCVRF, paving the way for further studies aimed at planning primary cardiovascular prevention in this population.

Dual-Energy Computed Tomography Detection of Cardiovascular Monosodium Urate Deposits in Patients With Gout

Importance

The prevalence of gout has increased in recent decades. Several clinical studies have demonstrated an association between gout and coronary heart disease, but direct cardiovascular imaging of monosodium urate (MSU) deposits by using dual-energy computed tomography (DECT) has not been reported to date.

Objective

To compare coronary calcium score and cardiovascular MSU deposits detected by DECT in patients with gout and controls.

Design, Setting, and Participants

This prospective Health Insurance Portability and Accountability Act-compliant study included patients with gout and controls who presented to a rheumatologic clinic from January 1, 2017, to November 1, 2018. All consecutive patients underwent DECT to assess coronary calcium score and MSU deposits in aorta and coronary arteries. In addition, cadavers were assessed by DECT for cardiovascular MSU deposits and verified by polarizing microscope. Analysis began in January 2017.

Main Outcomes and Measures

Detection rate of cardiovascular MSU deposits using DECT in patients with gout and control group patients without a previous history of gout or inflammatory rheumatic diseases.

Results

A total of 59 patients with gout (mean [SD] age, 59 [5.7] years; range, 47-89 years), 47 controls (mean [SD] age, 70 [10.4] years; range, 44-86 years), and 6 cadavers (mean [SD] age at death, 76 [17] years; range, 56-95 years) were analyzed. The frequency of cardiovascular MSU deposits was higher among patients with gout (51 [86.4%]) compared with controls (7 [14.9%]) (χ2 = 17.68, P < .001), as well as coronary MSU deposits among patients with gout (19 [32.2%]) vs controls (2 [4.3%]) (χ2 = 8.97, P = .003). Coronary calcium score was significantly higher among patients with gout (900 Agatston units [AU]; 95% CI, 589-1211) compared with controls (263 AU; 95% CI, 76-451; P = .001) and also significantly higher among 58 individuals with cardiovascular MSU deposits (950 AU; 95% CI, 639-1261) compared with 48 individuals without MSU deposits (217 AU; 95% CI, 37-397; P < .001). Among 6 cadavers, 3 showed cardiovascular MSU deposits, which were verified by polarizing light microscope.

Conclusion and Relevance

Dual-energy computed tomography demonstrates cardiovascular MSU deposits, as confirmed by polarized light microscopy. Cardiovascular MSU deposits were detected by DECT significantly more often in patients with gout compared with controls and were associated with higher coronary calcium score. This new modality may be of importance in gout population being at risk from cardiovascular disease.

The Complex Relationship Between Serum Uric Acid, Endothelial Function and Small Vessel Remodeling in Humans

AIMS

The relationship between serum uric acid (SUA) and microvascular remodeling in humans remains largely unexplored. We assessed whether SUA provides additional information on the severity of microvascular remodeling than that obtained from the European Heart Score (HS), the patterns of microvascular remodeling associated with changes in SUA levels and the mediation by endothelial function and nitric oxide (NO) availability on this relationship.

METHODS

A total of 162 patients included in the microvascular dataset of the Italian Society of Hypertension with available information on SUA, media-to-lumen (M/L) ratio, media cross-sectional area (MCSA), endothelial function, NO availability and HS were included in the analysis. The top tertile of M/L ratio and MCSA were used to define severe microvascular remodeling.

RESULTS

A U-shaped association was observed between SUA and both M/L ratio and MCSA. Adjustment for HS did not affect these associations. SUA was able to reclassify a significant number of subjects without, and with, severe M/L ratio and MCSA remodeling over the HS alone. The microvascular remodeling associated with SUA levels presented a predominant hypertrophic pattern. SUA was inversely associated with endothelial function and NO availability. Structural equation modeling analysis controlling for the HS suggested that the association of SUA with M/L ratio and MCSA was mediated through changes in endothelial function and NO availability.

CONCLUSIONS

The addition of SUA to the HS improves the identification of subjects with greater microvascular remodeling. The relationship between SUA and microvascular remodeling is mediated by endothelial function and NO availability.

Anti-hyperuricemic and Anti-inflammatory Effects of Marantodes pumilum as Potential Treatment for Gout

Marantodes pumilum (Primulaceae) has been used in Malaysian folk medicine to help women regain strength after delivery and for “sickness in the bones.” It was previously revealed that its extracts inhibited xanthine oxidase (XO) activity in vitro. The leaves and roots of M. pumilum var. alata (MPA), var. pumila (MPP), and var. lanceolata (MPL) were individually extracted in ethanol (80%). The anti-hyperuricemic activity was initially assessed by XO inhibition with a spectrophotometric in vitro assay. The most active extract was further investigated on hyperuricemic rat model induced by potassium oxonate to determine serum uric acid levels and liver XO effect. The in vitro anti-inflammatory activity was carried out on monosodium urate (MSU) crystal-induced pro-inflammatory cytokines (i.e., interleukin (IL)1α, IL-1β, IL-6, IL-8, and tumor necrosis factor (TNF)-α) secretion using human peripheral blood mononuclear cells and ELISA technique, and prostaglandin E₂ (PGE₂)secretion using radioimmunoassay. The active extract was then investigated on gout-induced inflammation with MSU crystals to determine pro-inflammatory cytokines and PGE₂ secretion levels in the synovial fluid of rat knee joint. Quantitative analysis using validated HPLC was performed on the extracts to determine presence of bioactive flavonoids. The findings revealed that extract of MPP leaves gave the highest inhibitory activity on XO (IC₅₀ 130.5 μg/mL) compared to other extracts tested. However, all extracts possessed significantly lower activity compared to allopurinol (IC₅₀ 0.13 μg/mL). Oral administration of MPP leaf extract (200 mg/kg) significantly reduced serum uric acid level in hyperuricemic rats in time-dependent manner to the baseline level and it was as effective as allopurinol (5 mg/kg). The extract also inhibited liver XO activity (25%) compared to allopurinol (45%). In vitro anti-inflammatory assay showed that extract of MPP roots inhibited MSU crystals-induced secretion of IL-1α, IL-1β, IL-8, TNF-α, and PGE₂ with IC₅₀ values of 36, 25, 38, 18, and 46 μg/mL, respectively. Oral administration of the MPP root extract (200 mg/kg) significantly decreased IL-1α, IL-1β, IL-6, TNF-α, and PGE₂ levels in rat’s synovial fluid as effective as indomethacin. There were no significant body weight changes of all experimental animals. MPP extracts showed presence of myricetin, quercetin and kaempferol. Myricetin was detected with values of 0.2 and 0.6 mg/g for root and leaf extracts, respectively. The anti-hyperuricemic of MPP leaf and anti-inflammatory of MPP root indicated that MPP may be promising for complementary therapy of gout.

Correlation between Gout and Coronary Heart Disease in Taiwan: A Nationwide Population-Based Cohort Study

Background

Gout is the most common inflammatory arthritis in adult males. Patients with gout are at a higher risk of coronary heart disease (CHD). This study aimed to investigate the correlation between gout and CHD.

Methods

This was a retrospective cohort study that used data from the Longitudinal Health Insurance Database of Taiwan. The study subjects were 46,140 patients with new-onset gout during 2003-2010. To avoid selection bias, we used propensity score matching. A Cox proportional hazard model was used to analyze differences in the risk of CHD between patients with and without gout after controlling for related variables.

Results

The patients with gout had a higher risk of CHD than the patients without gout [adjusted hazards ratio (HR) = 1.34, 95% confidence interval (CI): 1.23-1.45]. The risk of CHD increased with older age. Other related factors for CHD included gender (female vs. male, adjusted HR = 0.86, 95% CI: 0.79-0.93), hypertension (adjusted HR = 1.53, 95% CI: 1.42-1.65), hyperlipidemia (adjusted HR = 1.18, 95% CI: 1.07-1.29), and diabetes mellitus (adjusted HR = 1.24, 95% CI: 1.13-1.36).

Conclusions

We found correlations between gout and CHD and other influencing factors including hypertension, hyperlipidemia, and diabetes mellitus. We also found that gender and age were associated with CHD.

Dietary Interventions for Gout and Effect on Cardiovascular Risk Factors: A Systematic Review

Gout is one of the most prevalent inflammatory rheumatic disease. It is preceded by hyperuricemia and associated with an increased risk for cardiovascular disease, both related to unhealthy diets. The objective of this systematic review is to better define the most appropriate diet addressing both disease activity and traditional cardiovascular risk factors in hyperuricemic patients. We included clinical trials with patients diagnosed with hyperuricemia or gout, investigating the effect of dietary interventions on serum uric acid (SUA) levels, gout flares and—if available—cardiovascular risk factors. Eighteen articles were included, which were too heterogeneous to perform a meta-analysis. Overall, the risk of bias of the studies was moderate to high. We distinguished four groups of dietary interventions: Calorie restriction and fasting, purine-low diets, Mediterranean-style diets, and supplements. Overall, fasting resulted in an increase of SUA, whilst small (SUA change +0.3 to −2.9 mg/dL) but significant effects were found after low-calorie, purine-low, and Mediterranean-style diets. Studies investigating the effect on cardiovascular risk factors were limited and inconclusive. Since Mediterranean-style diets/DASH (Dietary Approach to Stop Hypertension) have shown to be effective for the reduction of cardiovascular risk factors in other at-risk populations, we recommend further investigation of such diets for the treatment of gout.

Fine mapping and identification of serum urate loci in American Indians: The Strong Heart Family Study

While studies have reported genetic loci affecting serum urate (SU) concentrations, few studies have been conducted in minority populations. Our objective for this study was to identify genetic loci regulating SU in a multigenerational family-based cohort of American Indians, the Strong Heart Family Study (SHFS). We genotyped 162,718 single nucleotide polymorphisms (SNPs) in 2000 SHFS participants using an Illumina MetaboChip array. A genome-wide association analysis of SU was conducted using measured genotype analysis approach accounting for kinships in SOLAR, and meta-analysis in METAL. Our results showed strong association of SU with rs4481233, rs9998811, rs7696092 and rs13145758 (minor allele frequency (MAF) = 25-44%; P < 3 × 10-14) of solute carrier family 2, member 9 (SLC2A9) and rs41481455, rs2231142 and rs1481012 (MAF = 29%; p < 3 × 10-9) of ATP-binding cassette protein, subfamily G, member 2 (ABCG2). Carriers of G alleles of rs9998811, rs4148155 and rs1481012 and A alleles of rs4481233, rs7696092 and rs13145758 and rs2231142 had lower SU concentrations as compared to non-carriers. Genetic analysis of SU conditional on significant SLC2A9 and ABCG2 SNPs revealed new loci, nucleobindin 1 (NUCB1) and neuronal PAS domain protein 4 (NPAS4) (p <6× 10-6). To identify American Indian-specific SNPs, we conducted targeted sequencing of key regions of SLC2A9. A total of 233 SNPs were identified of which 89 were strongly associated with SU (p < 7.1 × 10-10) and 117 were American Indian specific. Analysis of key SNPs in cohorts of Mexican-mestizos, European, Indian and East Asian ancestries showed replication of common SNPs, including our lead SNPs. Our results demonstrate the association of SU with uric acid transporters in a minority population of American Indians and potential novel associations of SU with neuronal-related genes which warrant further investigation.

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

Background

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

Methods

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

Results

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

Conclusions

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

Failure to reach uric acid target of <0.36 mmol/L in hyperuricaemia of gout is associated with elevated total and cardiovascular mortality

Objective

To determine the impact of achieving serum uric acid (sUA) of <0.36 mmol/L on overall and cardiovascular (CV) mortality in patients with gout.

Methods

Prospective cohort of patients with gout recruited from 1992 to 2017. Exposure was defined as the average sUA recorded during the first year of follow-up, dichotomised as ≤ or >0.36 mmol/L. Bivariate and multivariate Cox proportional hazards models were used to determine mortality risks, expressed HRs and 95% CIs.

Results

Of 1193 patients, 92% were men with a mean age of 60 years, 6.8 years' disease duration, an average of three to four flares in the previous year, a mean sUA of 9.1 mg/dL at baseline and a mean follow-up 48 months; and 158 died. Crude mortality rates were significantly higher for an sUA of ≥0.36 mmol/L, 80.9 per 1000 patient-years (95% CI 59.4 to 110.3), than for an sUA of <0.36 mmol/L, 25.7 per 1000 patient-years (95% CI 21.3 to 30.9). After adjustment for age, sex, CV risk factors, previous CV events, observation period and baseline sUA concentration, an sUA of ≥0.36 mmol/L was associated with elevated overall mortality (HR=2.33, 95% CI 1.60 to 3.41) and CV mortality (HR=2.05, 95% CI 1.21 to 3.45).

Conclusions

Failure to reach a target sUA level of 0.36 mmol/L in patients with hyperuricaemia of gout is an independent predictor of overall and CV-related mortality. Targeting sUA levels of <0.36 mmol/L should be a principal goal in these high-risk patients in order to reduce CV events and to extend patient survival.

Genetic association between adiposity and gout: a Mendelian randomization study

Objective

To investigate whether overall obesity (as measured by BMI) and abdominal obesity (as measured by waist-to-hip ratio adjusted for BMI) are associated with gout risk and serum urate concentrations using Mendelian randomization.

Methods

Single nucleotide polymorphisms associated with BMI (n = 97) and waist-to-hip ratio adjusted for BMI (n = 49) were analysed for association with gout risk in 2115 gout cases and 67 259 controls, and with serum urate concentrations in 110 347 individuals from the Global Urate Genetics Consortium.

Results

Genetically higher BMI, but not waist-to-hip ratio adjusted for BMI, was positively associated with risk of gout and serum urate concentrations. Each standard deviation (about 4.6 kg/m2) increase in genetically predicted BMI was associated with an odds ratio of gout of 2.24 (95% CI 1.70, 2.95; P = 8.4 × 10-9) and with a 0.30 mg/dl (95% CI 0.25, 0.35; P = 1.6 × 10-36) increase in serum urate concentrations.

Conclusion

These findings provide support that overall obesity may be a risk factor for gout and is associated with higher serum urate concentrations.

Urate-lowering treatment and risk of total joint replacement in patients with gout

Objectives

To examine whether gout is an independent risk factor for total joint replacement (TJR) and whether urate-lowering treatment (ULT) reduces this risk.

Methods

Using the Taiwan National Health Insurance database and the UK Clinical Practice Research Datalink, 74 560 Taiwan patients and 34 505 UK patients with incident gout were identified and age and sex matched to people without gout. Cox proportional hazards models and condition logistic regression were used to examine the risk of TJR in gout patients and the association between cumulative defined daily dose (cDDD) of ULT and TJR.

Results

The prevalence rates of TJR in the patients at the time of diagnosis of gout and in people without gout were 1.16% vs 0.82% in Taiwan and 2.61% vs 1.76% in the UK. After a gout diagnosis, the incidence of TJR was higher in the patients with gout compared with those without (3.23 vs 1.91 cases/1000 person-years in Taiwan and 6.87 vs 4.61 cases/1000 person-years in the UK), with adjusted HRs of 1.56 (95% CI 1.45, 1.68) in Taiwan and 1.14 (1.05, 1.22) in the UK. Compared with patients with gout with <28 cDDD ULT, the adjusted ORs for TJR were 0.89 (95% CI 0.77, 1.03) for 28-90 cDDD, 1.03 (0.85, 1.24) for 90-180 cDDD and 1.12 (0.94, 1.34) for >180 cDDD ULT in Taiwan. In the UK, the respective ORs were 1.09 (0.83, 1.42), 0.93 (0.68, 1.27) and 1.08 (0.94, 1.24).

Conclusion

This population-based study provides evidence from two nation populations that gout confers significant TJR risk, which was not reduced by current ULT.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Presence of tophi is a predictive factor of arterial stiffness in patients with gout

The objective of this study is to determine whether the presence of tophi could predict an increase in arterial stiffness. Between June 2017 and June 2018, the augmentation index (AI) was measured using SphygmoCor^® for patients with gout who visited the Jeju National University Hospital in South Korea. Patients were divided into the following groups: group with tophi and group without tophi. Medical records, laboratory data, and AI were retrospectively analyzed. One hundred and twenty patients with gout or participated in the study, with most (96.7%) of the patients being male. The mean duration of the disease was 7.0 years. At the time of the examination, 99 patients (82.5%) were treated with a uric acid-lowering agent. Of the total patients, 24 (19.7%) had tophi. Patients with tophi were significantly older (60.2 ± 11.6 years vs. 53.8 ± 13.0 years, p = 0.031), had longer disease duration (13.0 ± 6.5 years vs 5.5 ± 5.4 years, p < 0.001), and higher AI@75 (28.7 ± 7.8 vs 20.9 ± 10.0, p = 0.001) than those without tophi. In the multiple linear regression analysis, tophi was shown to be a significant predictor of high AI (p = 0.040). The presence of tophi is a predictor of increased arterial stiffness in patients with gout. Therefore, more strict control of cardiovascular disease risk factors is needed in the treatment of patients with tophi.

Uric acid and the cardio-renal effects of SGLT2 inhibitors

Sodium/glucose co-transporter-2 (SGLT2) inhibitors, which lower blood glucose by increasing renal glucose elimination, have been shown to reduce the risk of adverse cardiovascular (CV) and renal events in type 2 diabetes. This has been ascribed, in part, to haemodynamic changes, body weight reduction and several possible effects on myocardial, endothelial and tubulo-glomerular functions, as well as to reduced glucotoxicity. This review evaluates evidence that an effect of SGLT2 inhibitors to lower uric acid may also contribute to reduced cardio-renal risk. Chronically elevated circulating uric acid concentrations are associated with increased risk of hypertension, CV disease and chronic kidney disease (CKD). The extent to which uric acid contributes to these conditions, either as a cause or an aggravating factor, remains unclear, but interventions that reduce urate production or increase urate excretion in hyperuricaemic patients have consistently improved cardio-renal prognoses. Uric acid concentrations are often elevated in type 2 diabetes, contributing to the "metabolic syndrome" of CV risk. Treating type 2 diabetes with an SGLT2 inhibitor increases uric acid excretion, reduces circulating uric acid and improves parameters of CV and renal function. This raises the possibility that the lowering of uric acid by SGLT2 inhibition may assist in reducing adverse CV events and slowing progression of CKD in type 2 diabetes. SGLT2 inhibition might also be useful in the treatment of gout and gouty arthritis, especially when co-existent with diabetes.

Efficacy and safety of lesinurad for the treatment of hyperuricemia in gout

The aim of this review is to present current evidence about the efficacy and safety of lesinurad in combination with xanthine oxidase inhibitors (XOIs) in the treatment of hyperuricemia in patients with gout. Gout is the most common inflammatory form of arthritis. It is caused by an elevated concentration of serum uric acid (UA) that leads to the formation of monosodium urate crystals in joints and different tissues. The goal of therapy is to maintain serum UA levels at <6 mg/dL (0.36 mmol/L), to prevent the formation and deposition of monosodium urate crystals, and to dissolve existing crystals. Lesinurad, a new uricosuric, increases renal urate excretion by selectively inhibiting the renal uric acid transporter 1 (URAT1). Lesinurad is indicated in adults, in combination with a XOI, for the adjunctive treatment of hyperuricemia in patients with gout (with or without tophi) who have not achieved target serum UA levels with an adequate dose of a XOI alone. With the combination strategy, serum UA targets could be reached with the consequence of inhibiting formation of new crystals and promoting dissolution of existing crystals and, therefore, inducing improvement of outcomes such as flares and tophi. The approval of lesinurad was based on data from three pivotal phase III studies (CLEAR 1, CLEAR 2, and CRYSTAL). These clinical studies assessed lesinurad 200 and 400 mg doses. As only lesinurad 200 mg/day dose was finally approved and commercialized, it will be the focus of this paper. In the pivotal clinical trials, the target serum UA level was achieved by significantly more patients in lesinurad 200 mg plus allopurinol group (CLEAR 1 and CLEAR 2 trials) or lesinurad 200 mg plus febuxostat group (CRYSTAL study) compared with patients who received either XOI alone. In these trials, the safety profile of lesinurad 200 mg plus a XOI was comparable to allopurinol or febuxostat alone. Lesinurad, in combination with a XOI, is an effective and safe treatment that covers unmet needs in adults with gout who have not achieved target serum UA levels with a XOI alone.

[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.

Validity and reliability of the Gout Impact Scale in a multi-ethnic Asian population

OBJECTIVES

The emphasis on capturing patient-reported outcomes (PRO) is increasing, but gout-specific PRO are lacking. We evaluated the reliability and validity of the 24-item Gout Impact Scale (GIS) of the Gout Assessment Questionnaire 2.0 (GAQ2.0) in a multi-ethnic Asian population.

METHODS

Participants with gout in an academic medical center in Singapore completed the GIS which comprises five scales. Confirmatory factor analyses (CFA) were performed. Known-groups validity, divergent validity and internal consistency were evaluated.

RESULTS

We analyzed data of 267 participants (mean [SD] age 52.2 [16.08] years, 92.1% men and 76.0% Chinese). CFA based on the original GIS factor structure had good model fit based on Tucker-Lewis Index (TLI) of 0.946 but not when based on Root Mean Square Error Of Approximation (RMSEA), which was 0.123 (90% CI: 0.116-0.130). Internal consistency of GIS exceeded 0.7 in all except one scale, consistent with previous studies. Hypotheses related to known-groups validity were largely supported. Scores were significantly higher (ie greater impact) for participants reporting at least some problem on the EQ-5D-3L anxiety/ depression item across all GIS scales. Correlations between RAND-36 Physical Functioning (PF) scale and all five scales in the GIS were poor (Spearman rank correlation coefficients: -0.2355 to 0.0426), implying that GIS does not measure impact of gout on physical health.

CONCLUSION

The GIS is valid and reliable for assessing gout-specific psychosocial functioning in a multi-ethnic Asian population.

Therapy with canakinumab for gout

A significant part of patients with gout has contraindications to taking nonsteroidal anti-inflammatory drugs, colchicine and glucocorticoids. Such therapy is often ineffective, particularly in patients with the severe tophaceous gout what hampers treatment of acute arthritis attack assuming the need for other methods of therapy. During the last years several medications have been introduced the mechanism of anti-inflammatory action of which is associated with inhibition of interleukin 1 (IL1) playing a key role in the development of acute gouty arthritis. To date, the most well-studied and the only registered drug for relief of acute arthritis attack is canakinumab, recommended for use in situations where other therapy options are unacceptable. Despite these limitations, the use of IL1 inhibitors, in particular canakinumab, seems promising due to the high efficiency of the drug, the ability to use it in patients with comorbid diseases, as well as a favorable effect on the risk of cardiovascular disease.

Comorbidities in polymyalgia rheumatica: a systematic review

BACKGROUND AND AIM

Comorbidities are known to exist in many rheumatological conditions. Polymyalgia rheumatica (PMR) is a common inflammatory rheumatological condition affecting older people which, prior to effective treatment, causes severe disability. Our understanding of associated comorbidities in PMR is based only on case reports or series and small cohort studies. The objective of this study is to review systematically the existing literature on the comorbidities associated with PMR.

METHODS

MEDLINE, EMBASE, PsycINFO and CINAHL databases were searched for original observational research from inception to November 2016. Papers containing the words 'Polymyalgia Rheumatica' OR 'Giant Cell Arteritis' OR the terms 'PMR' OR 'GCA' were included. Article titles were reviewed based on pre-defined criteria by two reviewers. Following selection for inclusion, studies were quality assessed using the Newcastle-Ottawa tool and data were extracted.

RESULTS

A total of 17,329 papers were reviewed and 41 were incorporated in this review, including three published after the search took place. Wide variations were found in study design, comorbidities reported and populations studied. Positive associations were found between PMR diagnosis and stroke, cardiovascular disease, peripheral arterial disease, diverticular disease and hypothyroidism. Two studies reported a positive association between PMR and overall malignancy rate. Seven studies reported an association between PMR and specific types of cancer, such as leukaemia, lymphoma, myeloproliferative disease and specified solid tumours, although nine studies found either no or negative association between cancer and PMR.

CONCLUSION

Quantification of the prevalence of comorbidities in PMR is important to accurately plan service provision and enable identification of cases of PMR which may be more difficult to treat. This review highlights that research into comorbidities in PMR is, overall, methodologically inadequate and does not comprehensively cover all comorbidities. Future studies should consider a range of comorbidities in patients with a validated diagnosis of PMR in representative populations.

Association of Gout With Long-Term Cardiovascular Outcomes Among Patients With Obstructive Coronary Artery Disease

Background Epidemiological studies demonstrating a relationship between gout and cardiovascular disease are older and predate modern cardiovascular preventive therapy. We assessed the contemporary association between gout and cardiovascular disease in patients with obstructive coronary artery disease. Methods and Results Data were from the Duke Databank for Cardiovascular Diseases, which followed up patients undergoing cardiac catheterization with obstructive coronary artery disease at Duke University Medical Center (1998-2013). We assessed the relationship between gout diagnosis at baseline or during follow-up and the primary composite outcome of cardiovascular death, myocardial infarction, or stroke, adjusting for differences in baseline clinical factors. Secondary end points included cardiovascular death and all-cause mortality. New, postbaseline, gout diagnosis was included as a time-dependent covariate. Among 17 201 patients, 1406 (8.2%) had baseline gout and a high burden of cardiovascular risk factors, but high rates of optimal medical therapy. Over a median follow-up of 6.4 years, gout diagnosis at time of catheterization was not associated with the primary outcome (hazard ratio [95% confidence interval], 1.05 [0.96-1.15]; P=0.31) or cardiovascular death (hazard ratio [95% confidence interval], 1.10 [0.99-1.22]; P=0.08), but was associated with increased all-cause mortality (hazard ratio [95% confidence interval], 1.13 [1.05-1.23]; P=0.002). After including new, postbaseline, gout diagnosis, the instantaneous risk of the primary outcome was significantly associated with prior gout diagnosis (hazard ratio [95% confidence interval], 1.15 [1.07-1.25]; P=0.0004). Conclusions A clinical history of gout is associated with worse outcomes in a contemporary population of patients with obstructive coronary artery disease. This increased risk exists despite high levels of optimal baseline cardiovascular disease medical therapy, suggesting that residual cardiovascular risk is not addressed by standard medical therapy.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Ultrasonographic assessment of joint pathology in type 2 diabetes and hyperuricemia: The Fremantle Diabetes Study Phase II

AIMS

The prevalence and consequences (articular and extra-articular) of hyperuricemia in type 2 diabetes, especially when asymptomatic (ASH), are incompletely understood. The aim of this study was to use ultrasonography to assess pathology associated with monosodium urate deposition in the joints of well-characterized hyperuricemic patients with type 2 diabetes.

METHODS

A subset of 101 participants (mean age 70.4 years, 59.8% males, median diabetes duration 14.6 years) with hyperuricemia (fasting serum uric acid ≥0.42 mmol/L) from the community-based observational Fremantle Diabetes Study Phase II were assessed by ultrasound for signs of intra-articular urate deposition and inflammation in 14 joints at increased risk of involvement in patients with gout.

RESULTS

Most participants had evidence of crystal deposition comprising aggregates (59.4%), tophi (19.8%) or a double contour sign (27.7%), and 37% had a power Doppler signal indicative of inflammation in at least one joint. There was no difference between the prevalence of these abnormalities in those with ASH (n = 60) versus participants with a history of gout (n = 41; P ≥ 0.15). There was no association between a history of ischemic heart disease (reported by 17.8% of participants) and either any abnormality on joint ultrasound or inflammatory changes assessed by power Doppler (P ≥ 0.41).

CONCLUSIONS

Joint inflammation and/or urate deposition were present in the majority of community-based patients with type 2 diabetes and hyperuricemia regardless of whether there was a history of gout. Given the potential consequences of chronic inflammation for joint damage and extra-articular complications such as cardiovascular disease, these data have potential clinical implications.

Impact of diuretics on the urate lowering therapy in patients with gout: analysis of an inception cohort

Background

Diuretics have been associated with impaired response and refractoriness in gout, but whether this effect is still present with new urate-lowering drugs (ULD) and treat-to-target strategies is unknown. The aim of the present study was to assess the impact of the diuretics on the response to ULD in patients with gout. 

Methods

This was a retrospective analysis of an inception cohort. Participants were classified according to the type of ULD prescribed. We analysed the maximal dose of ULD (primary outcome variable), serum urate (SU) reduction, and the achievement of different SU targets (6 mg/dL, 5 mg/dL, and 4 mg/dL), according to the type of ULD prescribed and use of diuretics (loop and/or thiazide). We adjusted for confounders using multiple linear regression analysis.

Results

We included 245 patients: 208 treated with allopurinol (66 on diuretics, 31.7%), 35 with febuxostat (19 on diuretics, 57.6%), and 2 with benzbromarone. Significantly fewer participants in the allopurinol plus diuretics subgroup achieved SU levels of less than 5 mg/dL, but we found no other significant differences in SU targets associated with diuretics. Regarding the maximum ULD dose, a simple linear regression suggested an inverse relationship with diuretics (beta = − 0.125, p = 0.073), but this did not hold in the multivariable analysis (beta = − 0.47, p = 0.833). There was no association with febuxostat (beta = − 0.116, p = 0.514).

Conclusion

Diuretics do not appear to have a significant impact on managing gout.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1559-2) contains supplementary material, which is available to authorized users.

Gouty arthritis: decision-making following dual-energy CT scan in clinical practice, a retrospective analysis

To establish whether dual-energy CT (DECT) is a diagnostic tool, i.e., associated with initiation or discontinuation of a urate lowering drug (ULD). Secondly, to determine whether DECT results (gout deposition y/n) can be predicted by clinical and laboratory variables. Digital medical records of 147 consecutive patients with clinical suspicion of gout were analyzed retrospectively. Clinical data including medication before and after DECT, lab results, and results from diagnostic joint aspiration and DECT were collected. The relationship between DECT results and clinical and laboratory results was evaluated by univariate regression analyses; predictors showing a p < 0.10 were entered in a multivariate logistic regression model with the DECT result as outcome variable. A backward stepwise technique was applied. After the DECT, 104 of these patients had a clinical diagnosis of gout based on the clinical judgment of the rheumatologist, and in 84 of these patients, the diagnosis was confirmed by demonstration of monosodium urate (MSU) crystals in synovial fluid (SF) or by positive DECT. After DECT, the current ULD was modified in 33 (22.4%) of patients; in 29 of them, ULD was started and in 1 it was intensified. Following DECT, the current ULD was stopped in three patients. In the multivariable regression model, cardiovascular disease (OR 3.07, 95% CI 1.26-7.47), disease duration (OR 1.008, 95% CI 1.001-1.016), frequency of attack (OR 1.23, 95% CI 1.07-1.42), and creatinine clearance (OR 2.03, 95% CI 0.91-1.00) were independently associated with positive DECT results. We found that the DECT result increases the confidence of the prescribers in their decision to initiation or discontinuation of urate lowering therapy regimen in of mono- or oligoarthritis. It may be a useful imaging tool for patients who cannot undergo joint aspiration because of contraindications or with difficult to aspirate joints, or those who refuse joint aspiration. We also suggest the use of DECT in cases where a definitive diagnosis cannot be made from signs, symptoms, and MSU analysis alone.

Update on colchicine, 2017

Colchicine is an ancient medication that is currently approved for the treatment of gout and FMF. However, colchicine has a wide range of anti-inflammatory activities, and studies indicate that it may be beneficial in a variety of other conditions. This paper reviews the evidence for the well-established use of colchicine in gout, as well as several other rheumatic diseases. In addition, we highlight the potential benefit of colchicine in cardiac disease, including coronary artery disease in patients both with and without gout.

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.

Uric acid in the pathogenesis of metabolic, renal, and cardiovascular diseases: A review

The association between uric acid (UA) on one side and systemic hypertension (Htn), dyslipidemia, glucose intolerance, overweight, fatty liver, renal disease and cardiovascular disease (CVD) on the other side is well recognized. However, the causal relationship between UA and these different clinical problems is still debatable. The recent years have witnessed hundreds of experimental and clinical trials that favored the opinion that UA is a probable player in the pathogenesis of these disease entities. These studies disclosed the strong association between hyperuricemia and metabolic syndrome (MS), obesity, Htn, type 2 diabetes mellitus (DM), non-alcoholic fatty liver disease, hypertriglyceridemia, acute kidney injury, chronic kidney disease (CKD), coronary heart disease (CHD), heart failure and increased mortality among cardiac and CKD patients. The association between UA and nephrolithiasis or preeclampsia is a non-debatable association. Recent experimental trials have disclosed different changes in enzyme activities induced by UA. Nitric oxide (NO) synthase, adenosine monophosphate kinase (AMPK), adenosine monophosphate dehydrogenase (AMPD), and nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase are affected by UA. These changes in enzymatic activities can lead to the observed biochemical and pathological changes associated with UA. The recent experimental, clinical, interventional, and epidemiologic trials favor the concept of a causative role of UA in the pathogenesis of MS, renal, and CVDs.

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.

[Independent risk factors for severe cardiovascular events in male patients with gout: Results of a 7-year prospective study]

AIM

To determine risk factors for severe cardiovascular (CV) events (CVEs) in male patients with crystal-verified gout.

SUBJECTS AND METHODS

251 male patients with crystal-verified gout were prospectively followed up in 2003 to 2013. The mean follow-up period was 6.9±2.0 years. New severe CVE cases and deaths were recorded. Logistic regression was used to analyze the impact of traditional and other risk factors and allopurinol use on the risk for severe CVEs.

RESULTS

32 patients died during the follow-up period. Severe CVEs were recorded in 58 (23.1%) patients; CVE deaths were notified in 22 (8.8%) patients. The risk of all severe CVEs was high for hypertension, increased serum high-sensitivity C-reactive protein (hs-CRP) level (>5 mg/l), ≥ stage III chronic kidney disease (CKD) (glomerular filtration rate, <60 ml/min/1.73 m2), alcohol intake (>20 g/day), coronary heart disease (CHD), and a family history of premature CHD. The risk of fatal CVEs was highest for elevated serum hs-CRP level, ≥ stage III CKD, a family history of premature CHD, hypercholesterolemia, upper quartile of serum uric acid levels (>552 µmol/l), and regular intake of allopurinol.

CONCLUSION

In addition to the traditional risk factors of CV catastrophes, the presence of chronic inflammation and the impact of high serum uric acid levels may explain the high frequency of CV catastrophes.

Gout and subsequent erectile dysfunction: a population-based cohort study from England

Background

An association has been suggested between gout and erectile dysfunction (ED), however studies quantifying the risk of ED amongst gout patients are lacking. We aimed to precisely determine the population-level absolute and relative rate of ED reporting among men with gout over a decade in England.

Methods

We utilised the UK-based Clinical Practice Research Datalink to identify 9653 men with incident gout age- and practice-matched to 38,218 controls. Absolute and relative rates of incident ED were calculated using Cox regression models. Absolute rates within specific time periods before and after gout diagnosis were compared to control using a Poisson regression model.

Results

Overall, the absolute rate of ED post-gout diagnosis was 193 (95% confidence interval (CI): 184–202) per 10,000 person-years. This corresponded to a 31% (hazard ratio (HR): 1.31 95%CI: 1.24–1.40) increased relative risk and 0.6% excess absolute risk compared to those without gout. We did not observe statistically significant differences in the risk of ED among those prescribed ULT within 1 and 3 years after gout diagnosis. Compared to those unexposed, the risk of ED was also high in the year before gout diagnosis (relative rate = 1.63 95%CI 1.27–2.08). Similar findings were also observed for severe ED warranting pharmacological intervention.

Conclusions

We have shown a statistically significant increased risk of ED among men with gout. Our findings will have important implications in planning a multidisciplinary approach to managing patients with gout.

Cost Comparison of Urate-Lowering Therapies in Patients with Gout and Moderate-to-Severe Chronic Kidney Disease

BACKGROUND

Patients with chronic kidney disease (CKD) are at increased risk for developing gout and having refractory disease. Gout flare prevention relies heavily on urate-lowering therapies such as allopurinol and febuxostat, but clinical decision making in patients with moderate-to-severe CKD is complicated by significant comorbidity and the scarcity of real-world cost-effectiveness studies.

OBJECTIVE

To compare total and disease-specific health care expenditures by line of therapy in allopurinol and febuxostat initiators after diagnosis with gout and moderate-to-severe CKD.

METHODS

A retrospective observational cohort study was conducted to compare mean monthly health care cost (in 2012 U.S. dollars) among gout patients with CKD (stage 3 or 4) who initiated allopurinol or febuxostat. The primary outcome was total mean monthly health care expenditures, and the secondary outcome was disease-specific (gout, diabetes, renal, and cardiovascular disease [CVD]) expenditures. Gout patients (ICD-9-CM 274.xx) aged ≥ 18 years with concurrent CKD (stage 3 or 4) were selected from the MarketScan databases (January 2009-June 2012) upon allopurinol or febuxostat initiation. Patients were followed until disenrollment, discontinuation of the qualifying study agent, or use of the alternate study agent. Patients initiating allopurinol were subsequently propensity score-matched (1:1) to patients initiating febuxostat. Five generalized linear models (GLMs) were developed, each controlling for propensity score, to identify the incremental costs (vs. allopurinol) associated with febuxostat initiation in first-line (without prior allopurinol exposure) and second-line (with prior allopurinol exposure) settings.

RESULTS

Propensity score matching yielded 2 cohorts, each with 1,486 patients (64.6% male, mean [SD] age 67.4 [12.8] years). Post-match, 74.6% of patients had stage 3 CKD; 82.9% had CVD; and 42.1% had diabetes. The post-match sample was well balanced on numerous comorbidities and medication exposures with the following exception: 50.0% of febuxostat initiators were treated in the second-line setting; that is, they had baseline exposure to allopurinol, whereas only 4.2% of allopurinol initiators had baseline exposure to febuxostat. Unadjusted mean monthly cost was $1,490 allopurinol and $1,525 febuxostat (P = 0.809). GLM results suggest that first-line febuxostat users incurred significantly (P = 0.009) lower cost than allopurinol users ($1,299 vs. $1,487), whereas second-line febuxostat initiators incurred significantly (P = 0.001) higher cost ($1,751 vs. $1,487). Febuxostat initiators in both settings had significantly (P < 0.001) higher gout-specific cost, due to higher febuxostat acquisition cost. Increased gout-specific cost in the first-line febuxostat cohort was offset by significantly (P < 0.001) lower CVD ($288 vs. $459) and renal-related cost ($86 vs. $216). There were no significant differences in either renal or CVD costs (adjusted) between allopurinol initiators treated almost exclusively in the first-line setting and second-line febuxostat patients.

CONCLUSIONS

Gout patients with concurrent CKD, initiating treatment with febuxostat in a first-line setting, incurred significantly less total cost than patients initiating allopurinol during the first exposure to each agent. Conversely, patients treated with second-line febuxostat following allopurinol incurred significantly higher total cost than patients initiating allopurinol. There was no significant difference in total cost between the agents across line of therapy. Although study findings suggest the potential for CVD and renal-related savings to offset febuxostat's higher acquisition cost in gout patients with moderate-to-severe CKD, this is the first such retrospective evaluation. Future research is warranted to both demonstrate the durability of study findings and to better elucidate the mechanism by which associated cost offsets occur.

DISCLOSURES

No outside funding supported this study. Turpin is an employee of Takeda Pharmaceuticals U.S.A. Mitri and Wittbrodt were employees of Takeda Pharmaceuticals U.S.A. at the time of this study. Tidwell and Schulman are employees of Outcomes Research Solutions, consultants to Takeda Pharmaceuticals U.S.A. All authors contributed to the design of the study and to the writing and review of the manuscript. All authors read and approved the final manuscript. Tidwell and Schulman collected the data, and all authors participated in data interpretation.

Asymptomatic hyperuricemia is not an independent risk factor for cardiovascular events or overall mortality in the general population of the Busselton Health Study

Background

To investigate the impact of uric acid (UA) levels on cardiovascular disease and mortality at a population level.

Methods

Prospective analysis of baseline serum UA measurement and 15 year follow-up data from the Busselton Health Survey (n = 4,173), stratified by existence or absence of baseline cardiovascular disease. Outcomes were ascertained from state-wide hospital discharge and mortality registries. Cox regression produced adjusted hazard ratios (HR) for UA level as continuous and categorical (low, medium, high) predictor for cardiovascular events (CVE) and mortality. Gout was defined as a patient’s self-reported history of gout.

Results

After age and gender adjustment each 0.1 mmol/L rise in UA level was associated with increased mortality (HR 1.19, CI 1.04–1.36), cardiovascular mortality (HR 1.27, CI 1.03–1.57) and first CVE (HR 1.28, CI 1.13–1.44) in participants with no history of CVE. Adjustment for behavioural and biomedical risk factors of cardiovascular disease attenuated these associations. Results for participants with a history of CVE and for a subset of 1,632 participants using UA levels (2–6 measurements) averaged over time were similar. The overall prevalence of hyperuricemia was 10.7%. When stratified by history of gout, UA level was significantly associated with increased risk of cardiovascular mortality only in participants with a history of CVE (HR 2.13, CI 1.03–4.43).

Conclusions

Despite the considerable prevalence of hyperuricemia in 10.7% of the population, single or time averaged measures of UA were not independently predictive of incident cardiovascular disease or mortality. Hyperuricemia did associate with an increased risk of cardiovascular death only in participants with gout and existing cardiovascular disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-016-0421-1) contains supplementary material, which is available to authorized users.

Comorbidity Burden in Trial-Aligned Patients with Established Gout in Germany, UK, US, and France: a Retrospective Analysis

Introduction

Patients with gout have numerous comorbidities. We aimed to estimate the prevalence and incidence rates of renal and cardiovascular morbidities in trial-aligned patients with established gout in Germany (DE), the United Kingdom (UK), the United States (US), and France (FR).

Methods

This longitudinal cohort study used retrospective data from IMS Disease Analyzer™ (DE, FR), Clinical Practice Research Datalink–Hospital Episode Statistics (UK), and IMS’ PharMetrics Plus database linked with outpatient laboratory results (US). Included patients were ≥18 years at index date (January 1, 2010; all dates +1 year for FR), with continuous enrollment during the pre-index year, had “prevalent established gout” determined by data in the pre-index year, and ≥1 documented visit after index date; additional inclusion/exclusion criteria were aligned with recent gout clinical trials. Look-back for comorbidity prevalence extended to January 1, 2003 (US: January 1, 2009). Follow-up for incidence extended from index date to at most March 26, 2013 (FR: May 31, 2014). Events of interest were identified by diagnostic codes and/or laboratory data.

Results

The trial-aligned cohorts included 35,118 (DE), 24,607 (UK), 121,591 (US), and 17,338 (FR) patients. Among renal conditions, baseline diagnosis of chronic kidney disease/renal failure was most prevalent in the UK followed by DE; abnormal serum creatinine was most prevalent in the UK. Hypertension was the most prevalent cardiovascular diagnosis in all countries, followed by ischemic heart disease (IHD) and myocardial infarction. Incidence rates (per 100 patient-years) for new/worsening renal impairment ranged from 1.67 (DE) to 4.34 (US) and for nephrolithiasis diagnosis from 0.31 (FR) to 3.79 (US). The incidence rates for hypertension diagnosis were highest among cardiovascular-related events, ranging from 3.23 (UK) to 20.27 (US), followed by IHD.

Conclusions

Patients with established gout such as those included in gout trials have a high burden of established morbidity and new diagnoses of morbid events. Consideration of comorbidities, which greatly exacerbate disease burden, is important in gout management.

Funding

AstraZeneca.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-016-0346-1) contains supplementary material, which is available to authorized users.

Greater Wound and Renal Complications in Gout Patients Undergoing Total Joint Arthroplasty

BACKGROUND

Little is known about total joint arthroplasty (TJA) outcomes in gout patients. The purpose of this study was to compare adverse events between gout and nongout patients who underwent primary TJA.

METHODS

Using our institutional database and medical records review, a retrospective case-control study was conducted. From 2000 to 2012, a total of 482 gout TJA patients were matched with nongout TJA patients in a 1:1 ratio. Length of stay, complications, 90-day emergency room visits, and 90-day readmissions in these patients were compared.

RESULTS

Gout patients had greater wound healing problems (12.2% vs 5.0%, P = .001) and renal complications (8.9% vs 3.1%, P = .0003) compared with nongout patients. There were no significant differences between gout and nongout patients in terms of mean length of hospital stay (3.82 vs 3.17 days, P = .11) and 90-day emergency room visits (5.6% vs 3.5%, P = 1.00). Subgroup analysis showed that 90-day readmission rates were higher in gout patients who underwent total hip arthroplasty compared with those in nongout THA patients (6.8% vs 2.1%, P = .02).

CONCLUSION

Gout patients undergoing TJA have greater wound healing problems and renal complications. Surgeons should be cognizant of fluid management, renal monitoring and wound issues and should be cautious when treating TJA gout patients.

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.

Association between allopurinol use and hip fracture in older patients

BACKGROUND

Allopurinol reduces oxidative stress and interacts with purinergic signalling systems important in bone metabolism and muscle function. We assessed whether allopurinol use was associated with a reduced incidence of hip fracture in older people.

METHODS

Analysis of prospective, routinely-collected health and social care data on patients undergoing health and social work assessment in a single geographical area over a 12year period. Exposure to allopurinol was derived from linked community prescribing data, and hospitalisation for hip fracture and comorbid disease was derived from linked hospitalisation data. Fine and Gray modelling was used to model time to hip fracture accounting for the competing risk of death, incorporating previous use of allopurinol, cumulative exposure to allopurinol as a time dependent variable, and covariate adjustments.

RESULTS

17,308 patients were alive at the time of first social work assessment without previous hip fracture; the mean age was 73years. 10,171 (59%) were female, and 1155 (8%) had at least one exposure to allopurinol. 618 (3.6%) sustained a hip fracture, and 4226 (24%) died during a mean follow-up of 7.2years. In fully-adjusted analyses, each year of allopurinol exposure conferred a hazard ratio of 1.01 (95% CI 0.99, 1.02; p=0.37) for hip fracture and 1.00 (0.99, 1.01; p=0.47) for death. Previous use of allopurinol conferred a hazard ratio of 0.76 (0.45, 1.26; p=0.28) for hip fracture and 1.13 (0.99, 1.29; p=0.07) for death.

CONCLUSION

Greater cumulative use of allopurinol was not associated with a reduced risk of hip fracture or death in this cohort.