Effects of xanthine oxidase inhibitors on cardiovascular disease in patients with gout: a cohort study

Managing Gout in Patients with Metabolic Syndrome

Gout is characterized by monosodium urate (MSU) crystal deposition secondary to hyperuricemia. Gout is associated with metabolic syndrome (MetS) and its related comorbid conditions such as cardiovascular disease (CVD). Major advances have been made in the comprehension of the link between MetS and gout. Despite observational studies suggesting an association between MetS-related conditions and hyperuricemia, there is no proof of causality. Most studies using Mendelian randomization did not find hyperuricemia as a causal factor for MetS-related conditions. In contrast, these conditions were found associated with hyperuricemia, which suggests a reverse causality. Among patients with gout, this high CVD risk profile implies the need for systematic screening for MetS-related conditions. Most international guidelines recommend systematic screening for and care of CVD and related risk factors in patients with gout. Some anti-hypertensive agents, such as losartan and calcium channel blockers, are able to decrease serum urate (SU) levels. However, there are potential interactions between gout management therapies and the treatment of metabolic diseases. Some data suggest that anti-inflammatory drugs used for gout flare treatment, such as colchicine or canakinumab, might have benefits for CVD. Regarding the impact of urate-lowering therapies on CVD risk, recent studies found a similar CVD safety profile for allopurinol and febuxostat. Finally, sodium-glucose cotransporter-2 inhibitors are promising for gout because of their ability to decrease SU levels and risk of recurrent flares. In this review, we focus on the clinical challenge of managing MetS in patients with gout, particularly older patients with co-medications.

Prediction of renal and cardiometabolic outcomes in gout during urate-lowering therapy by sonography

OBJECTIVES

To assess whether the extent of monosodium urate (MSU) crystal deposition estimated by ultrasound could predict renal and cardiometabolic events during urate-lowering therapy (ULT).

METHODS

A prospective study on gout patients from two referral centers initiating ULT who underwent baseline ultrasound and were followed for 1 year. Ultrasound scans assessed six joints for double-contour (DC) signs and tophi. A five-point change (mL/min/1.73 m2 ) in the glomerular filtration rate at month 12 (M12) was considered significant. Outcomes of interest were renal function degraded versus improved and a composite cardiometabolic outcome (new hypertension, diabetes, atherosclerotic disease, and cardiovascular death). Homogeneity analyses and Cox regression models were performed.

RESULTS

One hundred sixty patients were recruited. At baseline, 81.1% of patients (n = 129) showed sonographic tophi with a mean number of 1.4 joints (±1.3) with a DC sign. At M12, 18 patients (11.3%) were lost to follow-up. The serum urate (SU) target (<6.0 mg/dL) was reached in 86 patients (69.9%). Regarding renal function, 15.9% of patients showed improvement, while in 31.0% it degraded. Fourteen new cardiometabolic events occurred in 12 patients. Neither the DC sign nor tophi showed any significant impact on the outcomes of interest. Baseline SU level was higher in those with renal improvement but not with renal decline, while achieving the SU target protected against new cardiometabolic events (HR = 0.2; 95% CI: 0.05-0.81).

CONCLUSIONS

Sonographic MSU crystal burden was unhelpful in predicting renal and cardiometabolic events during the first year of ULT. Reaching the SU target prevented cardiometabolic events, while its benefit in preserving/improving renal function is unclear.

Ten Years Milestones in Xanthine Oxidase Inhibitors Discovery: Febuxostat-Based Inhibitors Trends, Bifunctional Derivatives, and Automatized Screening Assays

Xanthine oxidase (XO) is an enzyme involved in the oxidative process of hypoxanthine and xanthine to uric acid (UA). This process also produces reactive oxygen species (ROS) as byproducts. Both UA and ROS are dangerous for human health, and some health conditions trigger upregulation of XO activity, which results in many diseases (cancer, atherosclerosis, hepatitis, gout, and others) given the worsened scenario of ROS and UA overproduction. So, XO became an attractive target to produce and discover novel selective drugs based on febuxostat, the most recent XO inhibitor out of only two approved by FDA. Under this context, high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) have been successfully applied to rapidly and easily screen for bioactive compounds, isolated or in complex natural matrixes, that act as enzyme inhibitors through the use of an immobilized enzyme reactor (IMER). This article’s goal is to present advances comprising febuxostat-based XO inhibitors as a new trend, bifunctional moieties capable of inhibiting XO and modulating ROS activity, and in-flow techniques employing an IMER in HPLC and CE to screen for synthetic and natural compounds that act as XO inhibitors.

Folic acid and zinc improve hyperuricemia by altering the gut microbiota of rats with high-purine diet-induced hyperuricemia

A high-purine diet can cause hyperuricemia and destroy the microbial composition of the gut microbiota. Both folic acid and zinc significantly reduce uric acid levels and alleviate hyperuricemia. However, whether the underlying mechanisms are associated with the regulation of the gut microbiota remain unknown. To explore alterations of the gut microbiota related to folic acid and zinc treatment in rats with hyperuricemia in our study. A hyperuricemic rat model was established with a high-purine diet. The effects of folic acid and zinc on uric acid levels were evaluated. Alterations of the gut microbiota related to hyperuricemia and the treatments were evaluated by sequencing using the Illumina MiSeq system. The results demonstrated that uric acid levels dropped observably, and the activities of adenosine deaminase (ADA) and xanthine oxidase (XOD) were downregulated after folic acid or zinc intervention. 16S rRNA gene sequencing-based gut microbiota analysis revealed that folic acid and zinc enhanced the abundance of probiotic bacteria and reduced that of pathogenic bacteria, thus improving intestinal barrier function. PICRUST analysis indicated that folic acid and zinc restored gut microbiota metabolism. These findings indicate that folic acid and zinc ameliorate hyperuricemia by inhibiting uric acid biosynthesis and stimulating uric acid excretion by modulating the gut microbiota. Thus, folic acid and zinc may be new and safe therapeutic agents to improve hyperuricemia.

A glance into the future of gout

Gout is characterized by monosodium urate (MSU) crystal deposits in and within joints. These deposits result from persistent hyperuricaemia and most typically lead to recurrent acute inflammatory episodes (gout flares). Even though some aspects of gout are well characterized, uncertainties remain; this upcoming decade should provide further insights into many of these uncertainties. Synovial fluid analysis allows for the identification of MSU crystals and unequivocal diagnosis. Non-invasive methods for diagnosis are being explored, such as Raman spectroscopy and imaging modalities. Both ultrasound and dual-energy computed tomography (DECT) allow the detection of MSU crystals; this not only provides a mean of diagnosis, but also has furthered gout knowledge defining the presence of a preclinical deposition in asymptomatic hyperuricaemia. Scientific consensus establishes the beginning of gout as the beginning of symptoms (usually the first flare), but the concept is currently under review. For effective long-term gout management, the main goal is to promote crystal dissolution treatment by reducing serum urate below 6 mg/dL (or 5 mg/dL if faster crystal dissolution is required). Current urate-lowering therapies' (ULTs) options are limited, with allopurinol and febuxostat being widely available, and probenecid, benzbromarone, and pegloticase available in some regions. New xanthine oxidase inhibitors and, especially, uricosurics inhibiting urate transporter URAT1 are under development; it is probable that the new decade will see a welcomed increase in the gout therapeutic armamentarium. Cardiovascular and renal comorbidities are common in gout patients. Studies determining whether optimal treatment of gout will positively impact these comorbidities are currently lacking, but will hopefully be forthcoming. Overall, the single change that will most impact gout management is greater uptake of international rheumatology society recommendations. Innovative strategies, such as nurse-led interventions based on these recommendations have recently demonstrated treatment success for people with gout.

Cardiovascular risk and mortality in patients with hyperuricemia treated with febuxostat or allopurinol: a retrospective nation-wide cohort study in Austria 2014-2017

Patients with hyperuricemia and gout are at an increased risk for cardiovascular (CV) disease. Inhibition of the xanthine oxidase with allopurinol or febuxostat have become the mainstay for urate lowering therapy. However, it has been suggested that febuxostat increases the risk for CV mortality as compared to allopurinol. The aim of this retrospective cohort study was to assess the CV risk among patients with febuxostat or allopurinol therapy. Patients who initiated urate lowering therapy with febuxostat or allopurinol between 2014 and 2017 were selected from the drug reimbursement database of the Austrian health insurances funds. The primary CV endpoint was a composite of angina pectoris, nonfatal myocardial infarction, nonfatal subarachnoid or cerebral hemorrhage, nonfatal ischemic stroke, or death from any cause. In total, 28.068 patients (62.1% male) with a mean age of 71 years were included. 7.767 initiated febuxostat treatment and 20.301 received allopurinol. The incidence rate per 100 patient-years of the composite primary endpoint was 448 (febuxostat) and 356 (allopurinol) with a corresponding adjusted hazard ratio (HR) of 0.58 (95% CI 0.53–0.63) for allopurinol vs. febuxostat initiators. Similar HR were found for secondary endpoints including all-cause mortality [0.61 (95% CI 0.55–0.68)] and separate analyses of cardiac events [0.48 (95% CI 0.38–0.61)] and ischemic stroke [0.47 (95% CI 0.36–0.61)]. Data from this Austrian population-based study suggests that febuxostat initiators are at an increased risk for nonfatal CV events or death from any cause as compared to those with allopurinol. This is consistent with CV concerns of other trials, which limited the broad therapeutic use of febuxostat.

Managing Cardiovascular Risk in Patients with Rheumatic Disease

Individuals with rheumatoid arthritis, systemic lupus erythematosus, or gout have increased risk of cardiovascular disease (CVD) compared with the general population. This risk relates to a combination of traditional cardiovascular risk factors and disease-specific factors. Screening for CVD is important because CVD contributes to significant morbidity and mortality. Management includes tight control of disease activity to reduce inflammation, but with care to minimize use of nonsteroidal anti-inflammatory drugs and prolonged courses of high-dose corticosteroids. Traditional cardiovascular risk factors should be managed with a combination of lifestyle interventions and pharmacotherapy. The decision to start antihypertensive and lipid-lowering therapy should be based on individual CVD risk.

Association between serum urate level and carotid atherosclerosis: an insight from a post hoc analysis of the PRIZE randomised clinical trial

Objectives

Elevated serum urate (SU) levels are associated with arterial atherosclerosis and subsequent cardiovascular events. However, an optimal therapeutic target SU level for delaying atherosclerotic progression in patients with hyperuricaemia remains uncertain. The aim of this analysis was to assess an association between changes in SU level and carotid intima–media thickness (IMT) to examine whether an optimal SU concentration exists to delay atherosclerotic progression.

Methods

This was a post hoc analysis of the PRIZE (programme of vascular evaluation under uric acid control by xanthine oxidase inhibitor, febuxostat: multicentre, randomised controlled) study of Japanese adults with asymptomatic hyperuricaemia. The primary endpoint of this analysis was an association between changes in SU levels and mean common carotid artery IMT (CCA-IMT) after 24 months of febuxostat treatment.

Results

Among subjects treated with febuxostat (n=239), a total of 204 who had both data on SU and mean CCA-IMT at baseline and 24 months were included in this analysis. The mean baseline SU level was 7.7±1.0 mg/dL, and febuxostat treatment significantly reduced SU concentrations at 24 months (estimated mean change ‒3.051 mg/dL, 95% CI ‒3.221 to ‒2.882). A multivariable linear regression analysis revealed that a reduction in SU level was associated with changes in mean CCA-IMT values at 24 months (p=0.025). In contrast, the achieved SU concentrations were not associated with changes in mean CCA-IMT at 24 months.

Conclusion

A greater reduction in SU, but not its achieved concentrations, may be associated with delayed progression of carotid IMT in patients with asymptomatic hyperuricaemia treated with febuxostat.

Trial registration number

UMIN000012911

Reduced Risk of Sepsis and Related Mortality in Chronic Kidney Disease Patients on Xanthine Oxidase Inhibitors: A National Cohort Study

Background

Advanced chronic kidney disease (CKD) patients are at higher risk of sepsis-related mortality following infection and bacteremia. Interestingly, the urate-lowering febuxostat and allopurinol, both xanthine oxidase inhibitors (XOis), have been suggested to influence the sepsis course in animal studies. In this study, we aim to investigate the relationship between XOis and infection/sepsis risk in pre-dialysis population.

Methods

Pre-dialysis stage 5 CKD patients with gout were identified through the National Health Insurance Research Database (NHIRD) in Taiwan from 2012 to 2016. Outcomes were also compared with national data.

Results

In our nationwide, population-based cohort study, 12,786 eligible pre-dialysis stage 5 CKD patients were enrolled. Compared to non-users, febuxostat users and allopurinol users were associated with reduced sepsis/infection risk [hazard ratio (HR), 0.93; 95% confidence interval (CI), 0.87–0.99; P = 0.0324 vs. HR, 0.92; 95% CI, 0.86–0.99; P = 0.0163]. Significant sepsis/infection-related mortality risk reduction was associated with febuxostat use (HR, 0.68; 95% CI, 0.52–0.87). Subgroup analysis demonstrated preference of febuxostat over allopurinol in sepsis/infection-related mortality among patients younger than 65 years of age, stain users, non-steroidal anti-inflammatory drug non-users, and non-diabetics. There was no significant difference in major adverse cardiac and cerebrovascular event (MACCE) risk between users and non-users while reduced risk of all-cause mortality was observed for XOi users.

Conclusions

Use of XOi in pre-dialysis stage 5 CKD patients may be associated with reduced risk of sepsis/infection and their related mortality without increased MACCE and overall mortality.

Reduced Incidence of Stroke in Patients with Gout Using Benzbromarone

Gout is strongly associated with the incidence of atherosclerotic events, including stroke and myocardial infarction. Considering the increased prevalence of stroke in the population with gout, the aim of this study was to evaluate the effects of benzbromarone, a uricosuric agent, on the incidence of stroke in the population with gout. We used data from the Taiwanese National Health Insurance Registration Database (NHIRD). The benzbromarone user cohort included 15,143 patients; each patient was age- and sex-matched with one non-user randomly selected from the population with gout. Cox proportional hazard regression analysis was conducted to estimate the effects of benzbromarone on the incidence of stroke in the population with gout. The incidence of stroke was significantly lower in benzbromarone users than in benzbromarone non-users. The HR for the incidence of stroke was lower in male benzbromarone users than in non-users. An analysis of three age groups (<40, 40–59, and ≥60 years) indicated that the HRs in those aged 40–59 years and ≥60 years were significantly lower among benzbromarone users than non-users. In the population with gout, the incidence of stroke was lower in benzbromarone users than in benzbromarone non-users.

Allopurinol to reduce cardiovascular morbidity and mortality: A systematic review and meta-analysis

Aims

To compare the effectiveness of allopurinol with no treatment or placebo for the prevention of cardiovascular events in hyperuricemic patients.

Methods and results

Pubmed, Web of Science and Cochrane library were searched from inception until July 2020. Randomized controlled trials (RCT) and observational studies in hyperuricemic patients without significant renal disease and treated with allopurinol, versus placebo or no treatment were included. Outcome measures were cardiovascular mortality, myocardial infarction, stroke, or a combined endpoint (CM/MI/S). For RCT’s a random effects meta-analysis was performed. For observational studies a narrative synthesis was performed. Of the original 1995 references we ultimately included 26 RCT’s and 21 observational studies. We found a significantly reduced risk of combined endpoint (Risk Ratio 0.65 [95% CI] [0.46 to 0.91]; p = 0.012) and myocardial infarction (RR 0.47 [0.27 to 0.80]; p = 0.01) in the allopurinol group compared to controls. We found no significant effect of allopurinol on stroke or cardiovascular mortality. Of the 15 observational studies with sufficient quality, allopurinol was associated with reduced cardiovascular mortality in 1 out of 3 studies that reported this outcome, myocardial infarction in 6 out of 8, stroke in 4 out of 7, and combined end-point in 2 out of 2. Cardiovascular benefit was only observed when allopurinol therapy was prolonged for more than 6 months and when an appropriate allopurinol dose was administered (300 mg or more/day) or sufficient reduction of serum urate concentration was achieved (<0.36 mmol/l).

Conclusions

Data from RCT’s and observational studies indicate that allopurinol treatment reduces cardiovascular risk in patients with hyperuricemia. However, the quality of evidence from RCTs is low to moderate. To establish whether allopurinol lowers the risk of cardiovascular events a well-designed and adequately powered randomized, placebo-controlled trial is needed in high-risk patients with hyperuricemia.

Systematic review registration

PROSPERO registration CRD42018089744

Uricemia in the acute phase of myocardial infarction and its relation to long-term mortality risk

Aim: Although uric acid has antioxidant effects, hyperuricemia has been established as an indicator of increased cardiovascular mortality in various patient populations. Treatment of asymptomatic hyperuricemia in patients with acute myocardial infarction (MI) is not routinely recommended, and the efficacy of such treatment in terms of cardiovascular risk reduction remains doubtful. Materials & methods: In a prospective cohort study, we followed 5196 patients admitted for a MI between 2006 and 2018. We assessed the relationship between baseline uricemia and the incidence of all-cause death and cardiovascular mortality and the effect of long-term allopurinol treatment. Hyperuricemia was defined as serum uric acid >450 μmol/l in men and >360 μmol/l in women. Results: In the entire cohort, the 1-year all-cause and cardiovascular mortality rates were 8 and 7.4%, and the 5-year rates were 18.3 and 15.3%, respectively. Using a fully adjusted model, hyperuricemia was associated with a 70% increased risk of both all-cause death and cardiovascular mortality at 1 year, and the negative prognostic value of hyperuricemia persisted over the 5-year follow-up (for all-cause death, hazard risk ratio = 1.45 [95% CI: 1.23-1.70] and for cardiovascular mortality, hazard risk ratio = 1.52 [95% CI: 1.28-1.80], respectively). Treatment of asymptomatic hyperuricemia with allopurinol did not affect mortality rates. Conclusion: Hyperuricemia detected in patients during the acute phase of an MI appears to be independently associated with an increased risk of subsequent fatal cardiovascular events. However, hyperuricemia treatment with low-dose allopurinol did not prove beneficial for these patients.

Allopurinol and cardiovascular events: Time-related biases in observational studies

OBJECTIVE

Several observational studies reported that allopurinol, an effective treatment for gout, was associated with important reductions in cardiovascular events, with calls for large randomized trials, though some results were conflicting. We assessed the extent of time-related biases in these observational studies.

METHODS

We searched the literature for all observational studies reporting on allopurinol and cardiovascular events, focusing on two time-related biases. Time-related confounding bias results from studies using cohorts of patients all exposed to allopurinol, with comparisons based on episodes of allopurinol discontinuation, where confounding factors are not updated over follow-up time. Immortal time bias arises from the exposure misclassification of periods of cohort follow-up during which the outcome under study cannot occur.

RESULTS

We identified 12 studies, of which eight were affected by time-related confounding bias or immortal time bias, while the remaining four studies avoided these biases. The studies affected by time-related confounding bias resulted in significant reductions in the incidence of cardiovascular events with allopurinol use (pooled hazard ratio 0.88; 95% CI: 0.85-0.92), as did the studies affected by immortal time bias (pooled hazard ratio 0.79; 95% CI: 0.72-0.87). The four studies that avoided these biases resulted in a pooled hazard ratio of 1.07 (95% CI: 0.91-1.25).

CONCLUSIONS

Observational studies reporting significantly reduced incidence of cardiovascular events with allopurinol use were affected by time-related biases. Overall, studies that avoided these biases did not find a protective effect. The ALL-HEART randomised trial will provide important and accurate evidence on the potential effectiveness of allopurinol on cardiovascular outcomes.

Managing Cardiovascular Risk in Patients with Rheumatic Disease

Individuals with rheumatoid arthritis, systemic lupus erythematosus, or gout have increased risk of cardiovascular disease (CVD) compared with the general population. This risk relates to a combination of traditional cardiovascular risk factors and disease-specific factors. Screening for CVD is important because CVD contributes to significant morbidity and mortality. Management includes tight control of disease activity to reduce inflammation, but with care to minimize use of nonsteroidal anti-inflammatory drugs and prolonged courses of high-dose corticosteroids. Traditional cardiovascular risk factors should be managed with a combination of lifestyle interventions and pharmacotherapy. The decision to start antihypertensive and lipid-lowering therapy should be based on individual CVD risk.

Comparative cardiovascular risk in users versus non-users of xanthine oxidase inhibitors and febuxostat versus allopurinol users

OBJECTIVES

The aim of this study is to determine major adverse cardiovascular events (MACE) and all-cause mortality comparing between xanthine oxidase inhibitors (XOIs) and non-XOI users, and between allopurinol and febuxostat.

METHODS

This is a retrospective cohort study of gout patients prescribed anti-hyperuricemic medications between 2013 and 2017 using a territory-wide administrative database. XOI users were matched 1:1 to XOI non-users using propensity scores. Febuxostat users were matched 1:3 to allopurinol users. Subgroup analyses were conducted based on colchicine use.

RESULTS

Of the 13 997 eligible participants, 3607 (25.8%) were XOI users and 10 390 (74.2%) were XOI non-users. After propensity score matching, compared with non-users (n = 3607), XOI users (n = 3607) showed similar incidence of MACE (hazard ratio [HR]: 0.997, 95% CI, 0.879, 1.131; P>0.05) and all-cause mortality (HR = 0.972, 95% CI 0.886, 1.065, P=0.539). Febuxostat (n = 276) users showed a similar risk of MACE compared with allopurinol users (n = 828; HR: 0.672, 95% CI, 0.416, 1.085; P=0.104) with a tendency towards a lower risk of heart failure-related hospitalizations (HR = 0.529, 95% CI 0.272, 1.029; P=0.061). Concurrent colchicine use reduced the risk for all-cause mortality amongst XOI users (HR = 0.671, 95% 0.586, 0.768; P<0.001).

CONCLUSION

In gout patients, XOI users showed similar risk of MACE and all-cause mortality compared with non-users. Compared with allopurinol users, febuxostat users showed similar MACE and all-cause mortality risks but lower heart failure-related hospitalizations.

Serum uric acid and incident atrial fibrillation: A systematic review and dose-response meta-analysis

The exposure-effect association between serum uric acid and atrial fibrillationis not well known. We conduct a meta-analysis to quantitatively examine the exposure-effect relationship between serum uric acid and atrial fibrillation. Prospective studies (including cohort or nested case-control) that reported the serum uric acid and atrial fibrillation were identified through electronic searches using EMBASE, PubMed, and the Cochrane Library database. The exposure-effect analysis was performed using a stage robust error meta-regression. Eleven studies were included, with a total of 6831 cases of atrial fibrillation among 527 908 individuals. Both the highest (risk ratio (RR), 1.9; 95% confidence interval (CI), 1.64-2.23; I2  = 0%) and intermediate (RR, 1.36; 95% CI, 1.16-1.59; I2  = 36%) level of serum uric acid were associated with increased risks of atrial fibrillation compared to the patients with the lowest level of serum uric acid. In the exposure-effect analysis, for each 1 mg/dL increase in serum uric acid level, the incidence of atrial fibrillation increased by 21% (RR, 1.21; 95% CI, 1.12-1.32; I2  = 78%). Furthermore, a significant positive linear relationship between serum uric acid and the risk of atrial fibrillation, Pnonlinearity  = 0.47 was found. The exposure-effect analysis demonstrated that serum uric acid over 5.0 mg/dL significantly increased the risk of atrial fibrillation. There was a positive linear association between serum uric acid and risk of atrial fibrillation, both in subjects with noruricaemia and hyperuricaemia. More studies are needed to explore the impact of serum uric acid reduction on the incidence of atrial fibrillation.

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.

Cardiovascular safety risks associated with gout treatments

INTRODUCTION

Uric acid is the final byproduct of purine metabolism. The loss of the enzyme that hydrolyzes uric acid to allantoin was lost, leading to a decrease in uric acid excretion and its further accumulation. The buildup of uric acid leads to damage in different organ systems, including the cardiovascular system. With the increasing burden of cardiovascular disease worldwide, a growing body of evidence has addressed the relationship between urate, cardiovascular outcomes, and gout medication cardiovascular safety. Areas covered: We discuss the most common gout therapies used for the reduction of serum urate and management of gout flares in different observational and clinical trials and their effects on different aspects of cardiovascular disease. We selected the most representative clinical studies that evaluated cardiovascular outcomes with each gout therapy as well as recommendation given by the most representative guidelines from Rheumatology societies for the management of gout.

EXPERT OPINION

The treatment of gout reduces joint damage and it can also lessen CV morbidity. Allopurinol shows CV safety profile when compared to other ULTs. Evidence supporting CV safety with the use of colchicine and IL-1 agents is promising and research needs to be conducted to further assess this outcome.

Cardio-renal protective effect of the xanthine oxidase inhibitor febuxostat in the 5/6 nephrectomy model with hyperuricemia

Although hyperuricemia has been shown to be associated with the progression of cardiovascular disorder and chronic kidney disease (CKD), there is conflicting evidence as to whether xanthine oxidase (XO) inhibitors confer organ protection besides lowering serum urate levels. In this study, we addressed the cardio-renal effects of XO inhibition in rodent CKD model with hyperuricemia. Sprague-Dawley rats underwent 5/6 nephrectomy and received a uricase inhibitor oxonic acid for 8 weeks (RK + HUA rats). In some rats, a XO inhibitor febuxostat was administered orally. Compared with control group, RK + HUA group showed a significant increase in albuminuria and renal injury. Febuxostat reduced serum uric acid as well as urinary albumin levels. Histological and immunohistochemical analysis of the kidney revealed that febuxostat alleviated glomerular, tubulointerstitial, and arteriolar injury in RK + HUA rats. Moreover, in the heart, RK + HUA showed individual myofiber hypertrophy and cardiac fibrosis, which was significantly attenuated by febuxostat. We found that renal injury and the indices of cardiac changes were well correlated, confirming the cardio-renal interaction in this model. Finally, NF-E2-related factor 2 (Nrf2) and the downstream target heme oxygenase-1 (HO-1) protein levels were increased both in the heart and in the kidney in RK + HUA rats, and these changes were alleviated by febuxostat, suggesting that tissue oxidative stress burden was attenuated by the treatment. These data demonstrate that febuxostat protects against cardiac and renal injury in RK + HUA rats, and underscore the pathological importance of XO in the cardio-renal interaction.

Efficacy and safety of urate-lowering treatments in patients with hyperuricemia: A comprehensive network meta-analysis of randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Hyperuricemia (HUA) and gout are considerable public health problems because of their increasing incidence and interactions with other diseases. We aimed to evaluate the efficacy and safety of urate-lowering therapies (ULTs) for patients.

METHODS

A systematic literature review was conducted, and a network meta-analysis was performed on the included studies using the Markov Chain Monte Carlo simulation method and a Bayesian statistical framework. We calculated surface under the cumulative ranking curve (SUCRA) values and performed clustered ranking to combine the efficacy and safety results.

RESULTS

Twenty-two randomized controlled studies were identified for the efficacy analysis, and 20 studies were identified for the safety analysis. Compared with the placebo, the ULTs were efficient and safe. Febuxostat 120 mg/d and allopurinol 200 mg/d had the highest SUCRA scores for efficacy and safety, respectively. Clustered ranking results showed that febuxostat 120 mg/d was the best in terms of efficacy and safety, topiroxostat 120/160 mg/d was similar to febuxostat 80 mg/d in terms of efficacy but safer, and allopurinol was not inferior to topiroxostat.

WHAT IS NEW AND CONCLUSION

Febuxostat had the best efficacy and safety results among the tested agents, and topiroxostat and allopurinol appeared to have fewer adverse events.

Febuxostat does not delay progression of carotid atherosclerosis in patients with asymptomatic hyperuricemia: A randomized, controlled trial

BACKGROUND

An elevated level of serum uric acid (SUA) is associated with an increased risk of cardiovascular disease. Pharmacological intervention with urate-lowering agents, such as the conventional purine analogue xanthine oxidase (XO) inhibitor, allopurinol, has been used widely for a long period of time in clinical practice to reduce SUA levels. Febuxostat, a novel non-purine selective inhibitor of XO, has higher potency for inhibition of XO activity and greater urate-lowering efficacy than conventional allopurinol. However, clinical evidence regarding the effects of febuxostat on atherosclerosis is lacking. The purpose of the study was to test whether treatment with febuxostat delays carotid intima-media thickness (IMT) progression in patients with asymptomatic hyperuricemia.

METHODS AND FINDINGS

The study was a multicenter, prospective, randomized, open-label, blinded-endpoint clinical trial undertaken at 48 sites throughout Japan between May 2014 and August 2018. Adults with both asymptomatic hyperuricemia (SUA >7.0 mg/dL) and maximum IMT of the common carotid artery (CCA) ≥1.1 mm at screening were allocated equally using a central web system to receive either dose-titrated febuxostat (10-60 mg daily) or as a control-arm, non-pharmacological lifestyle modification for hyperuricemia, such as a healthy diet and exercise therapy. Of the 514 enrolled participants, 31 were excluded from the analysis, with the remaining 483 people (mean age 69.1 years [standard deviation 10.4 years], female 19.7%) included in the primary analysis (febuxostat group, 239; control group, 244), based on a modified intention-to-treat principal. The carotid IMT images were recorded by a single sonographer at each site and read in a treatment-blinded manner by a single analyzer at a central core laboratory. The primary endpoint was the percentage change from baseline to 24 months in mean IMT of the CCA, determined by analysis of covariance using the allocation adjustment factors (age, gender, history of type 2 diabetes, baseline SUA, and baseline maximum IMT of the CCA) as the covariates. Key secondary endpoints included changes in other carotid ultrasonographic parameters and SUA and the incidence of clinical events. The mean values (± standard deviation) of CCA-IMT were 0.825 mm ± 0.173 mm in the febuxostat group and 0.832 mm ± 0.175 mm in the control group (mean between-group difference [febuxostat - control], -0.007 mm [95% confidence interval (CI) -0.039 mm to 0.024 mm; P = 0.65]) at baseline; 0.832 mm ± 0.182 mm in the febuxostat group and 0.848 mm ± 0.176 mm in the control group (mean between-group difference, -0.016 mm [95% CI -0.051 mm to 0.019 mm; P = 0.37]) at 24 months. Compared with the control group, febuxostat had no significant effect on the primary endpoint (mean percentage change 1.2% [95% CI -0.6% to 3.0%] in the febuxostat group (n = 207) versus 1.4% [95% CI -0.5% to 3.3%] in the control group (n = 193); mean between-group difference, -0.2% [95% CI -2.3% to 1.9%; P = 0.83]). Febuxostat also had no effect on the other carotid ultrasonographic parameters. The mean baseline values of SUA were comparable between the two groups (febuxostat, 7.76 mg/dL ± 0.98 mg/dL versus control, 7.73 mg/dL ± 1.04 mg/dL; mean between-group difference, 0.03 mg/dL [95% CI -0.15 mg/dL to 0.21 mg/dL; P = 0.75]). The mean value of SUA at 24 months was significantly lower in the febuxostat group than in the control group (febuxostat, 4.66 mg/dL ± 1.27 mg/dL versus control, 7.28 mg/dL ± 1.27 mg/dL; mean between-group difference, -2.62 mg/dL [95% CI -2.86 mg/dL to -2.38 mg/dL; P < 0.001]). Episodes of gout arthritis occurred only in the control group (4 patients [1.6%]). There were three deaths in the febuxostat group and seven in the control group during follow-up. A limitation of the study was the study design, as it was not a placebo-controlled trial, had a relatively small sample size and a short intervention period, and only enrolled Japanese patients with asymptomatic hyperuricemia.

CONCLUSIONS

In Japanese patients with asymptomatic hyperuricemia, 24 months of febuxostat treatment did not delay carotid atherosclerosis progression, compared with non-pharmacological care. These findings do not support the use of febuxostat for delaying carotid atherosclerosis in this population.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trial Registry UMIN000012911.

Enzymatic Bioautographic Methods

Enzymatic bioautography enables the detection of enzyme inhibitors absorbed on a thin-layer chromatography plate. Therefore, it is an assay format that is particularly useful for the detection of inhibitors present in complex mixtures. The inhibition properties of compounds separated by thin-layer chromatography can be directly analyzed to produce an inhibition profile. Here, we describe the conditions to detect inhibitor of the enzymes xanthine oxidase and β-glucosidase immobilized on agar gel.

Risk of Acute Myocardial Infarction Among New Users of Allopurinol According to Serum Urate Level: A Nested Case-Control Study

Objectives: To test the hypothesis that allopurinol reduces the risk of acute myocardial infarction (AMI) in hyperuricemic patients and to assess whether the effect is dependent on dose, duration and serum uric acid (SUA) level attained after treatment. Methods: Nested case-control study over the period 2002–2015. From a cohort of patients aged 40–99 years old, we identified incident AMI cases and randomly selected five controls per case, matched for exact age, sex and index date. Adjusted odds ratios (AOR) and 95% CI were computed through unconditional logistic regression. Only new users of allopurinol were considered. Results: A total of 4697 AMI cases and 18,919 controls were included. Allopurinol use was associated with a reduced risk of AMI mainly driven by duration of treatment (AOR ≥180 days = 0.71; 95% CI: 0.60–0.84). Among long-term users (≥180 days), the reduced risk was only observed when the SUA level attained was below 7 mg/dL (AOR_{<6 mg/dL} = 0.64; 95% CI: 0.49–0.82; AOR_6–7mg/dL = 0.64; 95%CI:0.48-0.84); AOR_>7mg/dL = 1.04; 95% CI: 0.75–1.46; p for trend = 0.001). A dose-effect was observed but faded out once adjusted for the SUA level attained. The reduced risk of AMI occurred in both patients with gout and patients with asymptomatic hyperuricemia. Conclusions: The results confirm a cardioprotective effect of allopurinol which is strongly dependent on duration and SUA level attained after treatment.

Computational Analysis and Synthesis of Syringic Acid Derivatives as Xanthine Oxidase Inhibitors

BACKGROUND

Xanthine oxidase (XO; EC 1.17.3.2) has been considered as a potent drug target for the cure and management of pathological conditions prevailing due to high levels of uric acid in the bloodstream. The role of xanthine oxidase has been well established in the generation of hyperuricemia and gout due to its important role in catalytic oxidative hydroxylation of hypoxanthine to xanthine and further catalyses of xanthine to generate uric acid. In this research, syringic acid, a bioactive phenolic acid was explored to determine the capability of itself and its derivatives to inhibit xanthine oxidase.

OBJECTIVE

The study aimed to develop new xanthine oxidase inhibitors from natural constituents along with the antioxidant potential.

METHODS

In this report, we designed and synthesized syringic acid derivatives hybridized with alcohol and amines to form ester and amide linkage with the help of molecular docking. The synthesized compounds were evaluated for their antioxidant and xanthine oxidase inhibitory potential.

RESULTS

Results of the study revealed that SY3 produces very good xanthine oxidase inhibitory activity. All the compounds showed very good antioxidant activity. The enzyme kinetic studies performed on syringic acid derivatives showed a potential inhibitory effect on XO ability in a competitive manner with IC50 value ranging from 07.18μM-15.60μM and SY3 was revealed as the most active derivative. Molecular simulation revealed that new syringic acid derivatives interacted with the amino acid residues SER1080, PHE798, GLN1194, ARG912, GLN 767, ALA1078 and MET1038 positioned inside the binding site of XO. Results of antioxidant activity revealed that all the derivatives showed very good antioxidant potential.

CONCLUSION

Molecular docking proved to be an effective and selective tool in the design of new syringic acid derivatives .This hybridization of two natural constituents could lead to desirable xanthine oxidase inhibitors with improved activity.

Assessment of Cardiovascular Risk in Older Patients With Gout Initiating Febuxostat Versus Allopurinol: Population-Based Cohort Study

BACKGROUND

Hyperuricemia and gout are associated with an increased risk of cardiovascular disease. Xanthine oxidase inhibitors, allopurinol and febuxostat, are the mainstay of urate-lowering treatment for gout and may have different effects on cardiovascular risk in patients with gout.

METHODS

Using US Medicare claims data (2008-2013), we conducted a cohort study for comparative cardiovascular safety of initiating febuxostat versus allopurinol among patients with gout ≥65 years of age. The primary outcome was a composite end point of hospitalization for myocardial infarction or stroke. Secondary outcomes were individual end points of hospitalization for myocardial infarction, stroke, coronary revascularization, new and recurrent heart failure, and all-cause mortality. We used propensity score matching with a ratio of 1:3 to control for confounding. We estimated incidence rates and hazard ratios for primary and secondary outcomes in the propensity score-matched cohorts of febuxostat and allopurinol initiators.

RESULTS

We included 24 936 febuxostat initiators propensity score-matched to 74 808 allopurinol initiators. The median age was 76 years, 52% were male, and 12% had cardiovascular disease at baseline. The incidence rate per 100 person-years for the primary outcome was 3.43 in febuxostat and 3.36 in allopurinol initiators. The hazard ratio for the primary outcome was 1.01 (95% CI, 0.94-1.08) in the febuxostat group compared with the allopurinol group. Risk of secondary outcomes including all-cause mortality was similar in both groups, except for a modestly decreased risk of heart failure exacerbation (hazard ratio, 0.94; 95% CI, 0.91-0.99) in febuxostat initiators. The hazard ratio for all-cause mortality associated with long-term use of febuxostat (>3 years) was 1.25 (95% CI, 0.56-2.80) versus allopurinol. Subgroup and sensitivity analyses consistently showed similar cardiovascular risk in both groups.

CONCLUSIONS

Among a cohort of 99 744 older Medicare patients with gout, overall there was no difference in the risk of myocardial infarction, stroke, new-onset heart failure, coronary revascularization, or all-cause mortality between patients initiating febuxostat compared with allopurinol. However, there seemed to be a trend toward an increased, albeit not statistically significant, risk for all-cause mortality in patients who used febuxostat for >3 years versus allopurinol for >3 years. The risk of heart failure exacerbation was slightly lower in febuxostat initiators.

Clinical Characteristics of Early-Onset Gout in Outpatient Setting

Objective

The objective of this study is to investigate the clinical characteristics and treatment of patients with early-onset gout.

Methods

We retrospectively reviewed 327 adult patients with a first diagnosis of gout from 2008 to 2016 using the database of a multispecialty group practice in New England. Patients were classified into the following groups: age 30 years or younger at first diagnosis (group 1), age 31-40 years (group 2), and age over 40 years (group 3). The clinical characteristics and treatment of gout were compared among the three groups.

Results

We identified 87 patients in group 1 and 140 patients in group 2. Group 3 included 100 patients randomly chosen from the 7216 patients with a first diagnosis at age over 40 years. Patients within group 1 had significantly higher serum uric acid (sUA) levels at the time of diagnosis and a more prominent family history of gout. Younger patients (groups 1 and 2) had a significantly higher body mass index than patients over 40 years of age (group 3). A substantial number of younger patients also had hypertension or hyperlipidemia. The majority of younger patients met the 2012 American College of Rheumatology (ACR) guidelines for initiating urate-lowering therapy (ULT) on the basis of frequency of gout attacks, whereas the majority of patients over 40 years of age met the guidelines for ULT on the basis of chronic kidney disease. Patients over 40 years of age were more likely to achieve an sUA level less than 6.0 mg/dl.

Conclusion

Patients with a first diagnosis of gout at age 40 years or younger frequently had cardiovascular risk factors and were less likely to achieve an sUA level less than 6.0 mg/dl compared with patients over 40 years of age who were treated in routine clinical practice. Clinicians should be aware that patients with early-onset gout may be an undertreated population with poor adherence to ULT and increased risk of recurrent gout and cardiovascular diseases.

Cardiovascular Risks of Probenecid Versus Allopurinol in Older Patients With Gout

BACKGROUND

Patients with gout are at an increased risk of cardiovascular (CV) disease including myocardial infarction (MI), stroke, and heart failure (HF).

OBJECTIVES

The authors conducted a cohort study to examine comparative CV safety of the 2 gout treatments-probenecid and allopurinol-in patients with gout.

METHODS

Among gout patients ≥65 years of age and enrolled in Medicare (2008 to 2013), those who initiated probenecid or allopurinol were identified. The primary outcome was a composite CV endpoint of hospitalization for MI or stroke. MI, stroke, coronary revascularization, HF, and mortality were assessed separately as secondary outcomes. The authors estimated the incidence rate and hazard ratio of the primary and secondary outcomes in the 1:3 propensity score-matched cohort of probenecid and allopurinol initiators.

RESULTS

A total of 9,722 probenecid initiators propensity score-matched to 29,166 allopurinol initiators with mean age of 76 ± 7 years, and 54% males were included. The incidence rate of the primary composite endpoint of MI or stroke per 100 person-years was 2.36 in probenecid and 2.83 in allopurinol initiators with a hazard ratio of 0.80 (95% confidence interval: 0.69 to 0.93). In the secondary analyses, probenecid was associated with a decreased risk of MI, stroke, HF exacerbation, and mortality versus allopurinol. These results were consistent in the subgroup analyses of patients without baseline CV disease or those without baseline chronic kidney disease.

CONCLUSIONS

In this large cohort of 38,888 elderly gout patients, treatment with probenecid appears to be associated with a modestly decreased risk of CV events including MI, stroke, and HF exacerbation compared with allopurinol.

Association between allopurinol and cardiovascular outcomes and all-cause mortality in diabetes: A retrospective, population-based cohort study

AIM

To assess the association between allopurinol and mortality and cardiovascular outcomes in an allopurinol-treated diabetes cohort.

MATERIALS AND METHODS

We conducted a population-based retrospective cohort study in Ontario, Canada. Eligible subjects were ≥ 66 years old with diabetes and a first prescription for allopurinol between 1 April, 2002 and 31 March, 2012 and were followed until 31 March, 2016. The primary outcome was a composite: all-cause mortality, non-fatal cardiovascular event (myocardial infarction, revascularization procedure, or stroke) or congestive heart failure (CHF). Secondary outcomes were components of the primary outcome and pneumonia as a negative tracer. Allopurinol was modelled as time-varying exposed versus unexposed, daily dose category and cumulative dose using sex-specific multivariable Cox proportional hazards models.

RESULTS

Over a median follow-up of 4.65 years (interquartile range 1.79-7.81), 16 266/23 103 males and 10 571/15 313 females experienced the primary outcome. Allopurinol was associated with a reduction in the primary outcome [adjusted hazard ratios (aHR) 0.77 (95% confidence interval 0.75-0.80) and 0.81 (0.78-0.84) for males and females, respectively], driven by marked reductions in all-cause mortality and modest reductions in cardiovascular events/CHF. There was no effect of cumulative allopurinol dose on any outcome, and allopurinol was also associated with reduced risk of pneumonia in males [aHR 0.88 (0.83, 0.93)].

CONCLUSIONS

Allopurinol was associated with reduced mortality and cardiovascular outcomes. However, lack of cumulative dose effect and a positive tracer outcome in males suggests residual bias. Future research assessing whether allopurinol prevents vascular complications in diabetes requires a clinical trial.

Management of complex gout in clinical practice: Update on therapeutic approaches

Increasing therapeutic options are available for gout management. Anti-inflammatory agents are used in the acute management of gout flares, and interleukin-1 inhibitors are effective for those unable to take conventional anti-inflammatory treatments. Lowering of serum urate remains the cornerstone of effective long-term management. Allopurinol is the first-line urate-lowering therapy, and a gradual dose-escalation strategy to serum urate target is recommended. Febuxostat and lesinurad have been approved more recently. In a large cardiovascular outcomes trial, higher all-cause and cardiovascular mortality was observed with febuxostat than with allopurinol. Lesinurad should be co-prescribed with a xanthine oxidase inhibitor, and close monitoring of kidney function is required. Evidence for non-pharmacological management is limited, but personalised lifestyle modification may reduce associated cardiovascular risk. In this review, we discuss current principles in the gout management paradigm, consider strategies for managing complex, clinical scenarios, and review emerging therapies.

Hypersensitivity and Cardiovascular Risks Related to Allopurinol and Febuxostat Therapy in Asians: A Population-Based Cohort Study and Meta-Analysis

The safety of newer xanthine oxidase inhibitor febuxostat compared to allopurinol remains unclear. To compare the risks of allopurinol hypersensitivity and febuxostat hypersensitivity and cardiovascular diseases (CVDs) in Asians, we conducted a population-based cohort study enrolling patients receiving allopurinol or febuxostat from Chang Gung Memorial Hospital Health System across Taiwan during 2012-2016 and further performed a meta-analysis incorporating two recent studies. Among the 61,539 users, a corresponding 12,007 and 5,680 patients were identified as new users. The overall incidence of febuxostat hypersensitivity was significantly lower than allopurinol hypersensitivity (0.2 vs. 2.7 per 1,000 new users; P < 0.001). There were 33 allopurinol-hypersensitivity reactions (including 18 severe cutaneous adverse drug reactions), and only one patient developed febuxostat-maculopapular exanthema. Moreover, febuxostat did not statistically increase the risk of CVD (hazard ratio (HR), 1.16; P = 0.152) and related death (HR, 1.49; P = 0.496) compared to allopurinol. The result of the meta-analysis also showed a consistent result. In conclusion, the incidence and severity of febuxostat-hypersensitivity are lower than with allopurinol. Febuxostat did not show an increased risk of CVD and related death.

The dose-response effects of uric acid on the prevalence of metabolic syndrome and electrocardiographic left ventricular hypertrophy in healthy individuals

BACKGROUND AND AIM

Hyperuricemia (HUA) is associated with the prevalence of metabolic syndrome (MetS) and cardiovascular risks in various populations. HUA is also able to induce cardiomyocyte hypertrophy in mouse models. However, the dose-response effects of serum uric acid (SUA) on the prevalence of MetS and electrocardiographic left ventricular hypertrophy (LVH) are unclear.

METHODS AND RESULTS

We retrospectively collected data from 18,932 individuals who underwent an annual health examination between 1/1/2016 and 12/31/2016. We excluded those with systemic diseases or missing questionnaires. The primary study endpoints were the prevalence of MetS and LVH, which were defined by the criteria for the Taiwanese population and the "SPRINT" trial. The cohort consisted of 17,913 individuals with a mean age of 31.2 years (SD 7.4) and a mean body mass index of 24.6 kg/m² (SD 3.6); 87.1% of the individuals were men. The prevalence rates of HUA, MetS, and LVH were 29.5%, 9.4%, and 0.32%, respectively, in the overall study population. The HUA group was predominantly male and had significantly poorer lifestyle choices and greater laboratory cardiometabolic biomarker values than did the normouricemic group. However, the frequencies of physical activity were comparable between the two groups. After adjusting for confounders, SUA was associated with MetS (OR:1.473, 95% CI:1.408-1.540, P < 0.001) and LVH (OR:1.301, 95% CI:1.064-1.591, P = 0.01).

CONCLUSION

We demonstrated that the dose-response effects of SUA are associated with the prevalence of MetS and electrocardiographic LVH in healthy individuals from Taiwan. Based on this evidence, future studies should investigate urate-lowering therapy and cardiovascular benefits in individuals with HUA (ClinicalTrials.gov number NCT03473951).

Urinary tungsten and incident cardiovascular disease in the Strong Heart Study: An interaction with urinary molybdenum

BACKGROUND

Tungsten (W) interferes with molybdenum (Mo) binding sites and has been associated with prevalent cardiovascular disease (CVD). We evaluated if (1) W exposure is prospectively associated with incident CVD and (2) the association between urinary W levels and incident CVD is modified by urinary Mo levels.

METHODS

We estimated multi-adjusted hazard ratios (HRs) for incident CVD outcomes by increasing W levels for 2726 American Indian participants in the Strong Heart Study with urinary metal levels measured at baseline (1989-1991) and CVD events ascertained through 2008.

RESULTS

Increasing levels of baseline urinary W were not associated with incident CVD. Fully-adjusted HRs (95% CIs) of incident CVD comparing a change in the IQR of W levels for those in the lowest and highest tertile of urinary Mo were 1.05 (0.90, 1.22) and 0.80 (0.70, 0.92), respectively (p-interaction = 0.02); for CVD mortality, the corresponding HRs were 1.05 (0.82, 1.33) and 0.73 (0.58, 0.93), respectively (p-interaction = 0.03).

CONCLUSIONS

The association between W and CVD incidence and mortality was positive although non-significant at lower urinary Mo levels and significant and inverse at higher urinary Mo levels. Although prior cross-sectional epidemiologic studies in the general US population found positive associations between urinary tungsten and prevalent cardiovascular disease, our prospective analysis in the Strong Heart Study indicates this association may be modified by molybdenum exposure.

Alterations of the Gut Microbiome Associated With the Treatment of Hyperuricaemia in Male Rats

Hyperuricaemia is an important risk factor for many diseases including gout, hypertension, and type II diabetes. The gut microbiota is associated with hyperuricaemia and has also been demonstrated to play significant roles in the effects of drug therapy. This study used Illumina MiSeq sequencing to explore alterations of the gut microbiome associated with allopurinol and benzbromarone treatment in the male rat with hyperuricaemia. After drug treatment, both allopurinol and benzbromarone caused an increase of the genera Bifidobacterium and Collinsella and a decrease of the genera Adlercreutzia and Anaerostipes. In addition, allopurinol and benzbromarone caused respective unique changes in genera. The genera Bilophila, Morganella, and Desulfovibrio specifically decreased due to allopurinol treatment. Decreased Butyricimonas and Ruminococcus and increased Proteus were caused by benzbromarone treatment. The PICRUST analysis indicated that allopurinol renovated the disorder of nucleotide metabolism and benzbromarone renovated the disorder of lipid metabolism in the gut microbiota of male rats with hyperuricaemia. These findings demonstrated that the gut microbiota may be altered by the treatment of hyperuricaemia with allopurinol and benzbromarone in male rats. Such alterations of the gut microbiota could be considered as indicators of the effectiveness of drug therapy.

An evaluation of longitudinal changes in serum uric acid levels and associated risk of cardio-metabolic events and renal function decline in gout

OBJECTIVE

Gout patients have a high burden of co-morbid conditions including diabetes mellitus (DM), chronic kidney disease (CKD), and cardiovascular disease (CVD). We sought to evaluate the association between changes in serum uric acid (SUA) levels over time and the risk of incident DM, CVD, and renal function decline in gout patients.

METHODS

An observational cohort study was conducted among enrollees of private health insurance programs in the US between 2004 and 2015. Gout patients were included on the index date of a SUA measurement ≥6.8 mg/dl. The exposure of interest was cumulative change in SUA levels from baseline. Hazard ratios (HR) and 95% confidence intervals (CI) for incident DM, incident CVD, and renal function decline (≥30% reduction in glomerular filtration rate) were derived using marginal structural models with stabilized inverse probability weights accounting for baseline confounders (age, gender, co-morbidities, co-medications) and time-varying confounders (serum creatinine, blood urea nitrogen, glycated hemoglobin).

RESULTS

Among 26,341 patients with gout, the average age was 62, 75% were men, and the median baseline SUA was 8.6 mg/dl (interquartile range 7.7 to 9.5). The incidence rates/100 person-years (95% CI) were 1.63 (1.51-1.75) for DM, 0.77 (0.70-0.84) for CVD, and 4.32 (4.14-4.49) for renal function decline. The adjusted HR (95% CI) per 3 mg/dl reduction in SUA, corresponding on average to achieving the target level of <6 mg/dl in this population, was 1.04 (0.92-1.17) for DM, 1.07 (0.89-1.29) for CVD, and 0.85 (0.78-0.92) for renal function decline.

CONCLUSIONS

Reduction in SUA in patients with gout may be associated with a reduced risk of renal function decline, but not with DM or CVD.

Xanthine oxidase inhibitors for prevention of cardiovascular events: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Xanthine oxidase inhibitors (XOI), classified as purine-like (allopurinol and oxypurinol) and non-purine (febuxostat and topiroxostat) XOI, present antioxidant properties by reducing the production of reactive oxygen species derived from purine metabolism. Oxidative stress is an important factor related to endothelial dysfunction and ischemia-reperfusion injury, and may be implicated in the pathogenesis of heart failure, hypertension, and ischemic heart disease. However, there is contradictory evidence regarding the possible cardiovascular (CV) protective effect exerted by XOI. Our objective is to compare the incidence of major adverse cardiovascular events (MACE), mortality, total (TCE) and specific CV events in randomized controlled trials (RCTs) testing XOI against placebo or no treatment.

METHODS

PubMed, EMBASE, Web of Science, Cochrane Central, Lilacs databases were searched from inception to Dec 30 2016, along with hand searching. RCTs including exclusively adult individuals, lasting ≥ 4 weeks, with no language restriction, were eligible. Independent paired researchers selected studies and extracted data. Considering the expected rarity of events, Peto and DerSimonian/Laird odds ratios (OR), the latter in case of heterogeneity, were used for analysis. Random-effects meta-regression was used to explore heterogeneity.

RESULTS

The analysis of MACE included 81 articles (10,684 patients, 6434 patient-years). XOI did not significantly reduce risk of MACE (ORP = 0.71, 95% CI 0.46-1.09) and death (0.89, 0.59-1.33), but reduced risk of TCE (0.60, 0.44-0.82; serious TCE: 0.64, 0.46 to 0.89), and hypertension (0.54, 0.37 to 0.80). There was protection for MACE in patients with previous ischemic events (0.42, 0.23-0.76). Allopurinol protected for myocardial infarction (0.38, 0.17-0.83), hypertension (0.32, 0.18-0.58), TCE (0.48, 0.31 to 0.75, I2 = 55%) and serious TCE (0.56, 0.36 to 0.86, I2 = 44%). Meta-regression associated increasing dose of allopurinol with higher risk of TCE and serious TCE (P < 0.05). Accordingly, lower doses (≤ 300 mg/day) of allopurinol reduced the risk of TCE, unlike higher doses. Non-purine-like XOI did not significantly reduce or increase the risk of adverse CV events, but confidence intervals were wide. Quality of evidence was generally low to moderate.

CONCLUSIONS

Purine-like XOI may reduce the incidence of adverse CV outcomes. However, higher doses of allopurinol (> 300 mg/day) may be associated with loss of CV protection.

Serum uric acid as a potential marker for heart failure risk in men on antihypertensive treatment: The British Regional Heart Study

The role of serum uric acid (SUA) as a prognostic marker for incident heart failure (HF) in hypertensive subjects is uncertain. We have prospectively examined the relationship between SUA and incident HF in 3440 men aged 60–79 years separately in those on and not on antihypertensive treatment who were followed up for a mean period of 15 years. Men on SUA lowering drugs and those with history of HF or myocardial infarction were excluded. There were 260 incident HF cases. The men were divided into three groups of SUA concentrations/levels (< 350, 350–410 and > 410 μmol/L). Raised SUA was associated with significantly increased risk of HF in men on antihypertensive treatment (N = 949) but not in those without (N = 2491) (p = 0.003 for interaction). In men on antihypertensive treatment those with hyperuricemia (> 410 μmol/L) had the most adverse biological risk profile for HF including the highest rates of atrial fibrillation and renal dysfunction and the highest mean level of BMI, c-reactive protein and cardiac function (cardiac troponin T). Treated hypertensive men with SUA levels > 410 μmol/L showed an increase in risk of HF of more than twofold compared to those on treatment with levels < 350 μmol/L even after adjustment for lifestyle characteristics and biological risk factors [adjusted hazard ratio 2.26 (1.23,4.15)]. SUA improved prediction of HF beyond routine conventional risk factors (p = 0.02 for improvement in c-statistics). SUA as a marker of increased xanthine oxidase activity may be a useful prognostic marker for HF risk in older men on antihypertensive treatment.

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Raised serum uric acid (SUA) is associated with increased risk of heart failure in older men on antihypertensive treatment

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Treated hypertensive men with raised SUA have the most adverse risk profile for heart failure including underlying ischaemia

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Monitoring of SUA in older hypertensive patients may identify high risk patients who would benefit from further investigation

Major Cardiovascular Events in Patients with Gout and Associated Cardiovascular Disease or Heart Failure and Chronic Kidney Disease Initiating a Xanthine Oxidase Inhibitor

BACKGROUND

Several observational studies and meta-analyses have suggested that treating hyperuricemia in patients with gout and moderate or severe chronic kidney disease (CKD) may improve renal and cardiovascular (CV) outcomes.

OBJECTIVE

To evaluate the impact of initiating allopurinol or febuxostat treatment on major CV events in patients with gout, preexisting CV disease (CVD) or heart failure (HF), and stage 3 or 4 CKD in a real-world setting.

METHODS

Patients with gout (aged >18 years) who initiated allopurinol or febuxostat treatment between 2009 and 2013 after a diagnosis of stage 3 or 4 CKD and CVD-including coronary artery disease (CAD), cerebrovascular disease, and peripheral vascular disease (PVD)-or HF were selected from the MarketScan databases. The major CV events included CAD-specific, cerebrovascular disease-specific, and PVD-specific events. Cox proportional hazards modeling identified the predictors of major CV events in aggregate, and of CAD, cerebrovascular disease, and PVD events, individually.

RESULTS

During follow-up, 2426 patients (370 receiving febuxostat and 2056 receiving allopurinol; 63% male; mean age, 73 years) had 162 major CV events (3.8% in those receiving febuxostat vs 7.2% in those receiving allopurinol; P = .015). The rates of major CV events per 1000 person-years were 51.8 (95% confidence interval [CI], 28-87) in patients initiating febuxostat and 99.3 (95% CI, 84-117) among those initiating allopurinol. Overall, 49.4% of patients had a CAD event, 32.5% had a PVD event, and 23.5% had a cerebrovascular disease-specific event. Febuxostat initiation was associated with a significantly lower risk for a major CV event versus patients who initiated allopurinol (hazard ratio, 0.52; P = .02), driven in large part by lower PVD-specific events (P = .026).

CONCLUSION

Patients with moderate-to-severe CKD and CVD or HF who initiated febuxostat treatment had a significantly lower rate of major CV events than patients who initiated allopurinol.

Cardiovascular effects of urate-lowering therapies in patients with chronic gout: a systematic review and meta-analysis

Objectives

To determine if urate-lowering treatment (ULT) in gout can reduce cardiovascular (CV) outcomes.

Methods

Randomized trials were searched for treatment with ULT in gout. Eligible trials had to report CV safety of a ULT. Potential medications included allopurinol, febuxostat, pegloticase, rasburicase, probenecid, benzbromarone, sulphinpyrazone, losartan, fenofibrate and sodium-glucose linked transporter 2 inhibitors.

Results

A total of 3084 citations were found, with 642 duplicates. After the primary screen, 35 studies were selected for review. Several trials did not report CV events. Six were not randomized controlled trials (RCTs). Four studies reported no events in either intervention arm while the other four had 40 events in the febuxostat group ( n = 3631) and 5 in allopurinol group ( n = 1154). Overall, the pooled analysis did not show a significant difference between the two [febuxostat vs allopurinol: relative risk (RR) 1.69 (95% CI 0.54, 5.34), P = 0.37]. CV events did not decrease over time. Comparing shorter studies (<52 weeks) to longer ones did not reveal any statistical differences. However, in long-term studies with febuxostat vs allopurinol, results were nearly significant, with more CVE occurring with febuxostat treatment. Comparing any ULT to placebo (eight studies, n = 2221 patients) did not demonstrate a significant difference in non-Anti-Platelet Trialists' Collaboration events [any ULT vs placebo: RR 1.47 (95% CI 0.49, 4.40), P = 0.49] or all-cause mortality [any ULT vs placebo: RR 1.45 (95% CI 0.35, 5.77), P = 0.60].

Conclusion

RCT data do not suggest differences in CV events among ULTs in gout. Trials had few events despite high-risk patients being enrolled and may have been too short to show CV reduction by controlling inflammatory attacks and lowering uric acid.

Lesinurad, a Selective Uric Acid Reabsorption Inhibitor, in Combination With Febuxostat in Patients With Tophaceous Gout: Findings of a Phase III Clinical Trial

OBJECTIVE

To investigate the efficacy and safety of lesinurad in combination with febuxostat in a 12-month phase III trial in patients with tophaceous gout.

METHODS

Patients with serum urate (UA) ≥8.0 mg/dl (≥6.0 mg/dl with urate-lowering therapy) and ≥1 measurable target tophus were given febuxostat 80 mg/day for 3 weeks before randomization to receive lesinurad (200 or 400 mg daily) or placebo in addition to the febuxostat. The primary end point was the proportion of patients achieving a serum UA level of <5.0 mg/dl (month 6). The key secondary end point was the proportion of patients with complete resolution of ≥1 target tophus (month 12). Other end points included the percentage change in total target tophi area. Safety assessments included adverse events and laboratory data.

RESULTS

Patients (n = 324) were predominantly male, with a mean age of 54.1 years. Significantly more patients achieved the serum UA target by month 6 with the addition of lesinurad 400 mg (76.1%; P < 0.0001), but not 200 mg (56.6%; P = 0.13), to the febuxostat therapy as compared with febuxostat alone (46.8%). At all other time points, significantly more patients in the lesinurad 200 mg group achieved the serum UA target. The number of patients with complete tophus resolution was not different between groups. Treatment with lesinurad (200 mg and 400 mg) plus febuxostat reduced the total target tophi area as compared with febuxostat alone (50.1% and 52.9% versus 28.3%, respectively; P < 0.05). Safety was generally comparable with that of febuxostat alone, except for higher rates of predominantly reversible elevations in the serum creatinine level, particularly with lesinurad 400 mg.

CONCLUSION

Treatment with lesinurad in combination with febuxostat demonstrated superior lowering of serum UA levels as compared with febuxostat alone, with clinically relevant added effects on tophi and an acceptable safety profile with lesinurad 200 mg in patients with tophaceous gout warranting additional therapy.