Cardiovascular Safety of Febuxostat or Allopurinol in Patients with Gout

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

Assessment of Nonfatal Myocardial Infarction as a Surrogate for All-Cause and Cardiovascular Mortality in Treatment or Prevention of Coronary Artery Disease: A Meta-analysis of Randomized Clinical Trials

IMPORTANCE

Although nonfatal myocardial infarction (MI) is associated with an increased risk of mortality, evidence validating nonfatal MI as a surrogate end point for all-cause or cardiovascular (CV) mortality is lacking.

OBJECTIVE

To examine whether nonfatal MI may be a surrogate for all-cause or CV mortality in patients with or at risk for coronary artery disease.

DATA SOURCES

In this meta-analysis, PubMed was searched from inception until December 31, 2020, for randomized clinical trials of interventions to treat or prevent coronary artery disease reporting mortality and nonfatal MI published in 3 leading journals.

STUDY SELECTION

Randomized clinical trials including at least 1000 patients with 24 months of follow-up.

DATA EXTRACTION AND SYNTHESIS

Trial-level correlations between nonfatal MI and all-cause or CV mortality were assessed for surrogacy using the coefficient of determination (R2). The criterion for surrogacy was set at 0.8. Subgroup analyses based on study subject (primary prevention, secondary prevention, mixed primary and secondary prevention, and revascularization), era of trial (before 2000, 2000-2009, and 2010 and after), and follow-up duration (2.0-3.9, 4.0-5.9, and ≥6.0 years) were performed.

MAIN OUTCOMES AND MEASURES

All-cause or CV mortality and nonfatal MI.

RESULTS

A total of 144 articles randomizing 1 211 897 patients met the criteria for inclusion. Nonfatal MI did not meet the threshold for surrogacy for all-cause (R2 = 0.02; 95% CI, 0.00-0.08) or CV (R2 = 0.11; 95% CI, 0.02-0.27) mortality. Nonfatal MI was not a surrogate for all-cause mortality in primary (R2 = 0.01; 95% CI, 0.001-0.26), secondary (R2 = 0.03; 95% CI, 0.00-0.20), mixed primary and secondary prevention (R2 = 0.001; 95% CI, 0.00-0.08), or revascularization trials (R2 = 0.21; 95% CI, 0.002-0.50). For trials enrolling patients before 2000 (R2 = 0.22; 95% CI, 0.08-0.36), between 2000 and 2009 (R2 = 0.02; 95% CI, 0.00-0.17), and from 2010 and after (R2 = 0.01; 95% CI, 0.00-0.09), nonfatal MI was not a surrogate for all-cause mortality. Nonfatal MI was not a surrogate for all-cause mortality in randomized clinical trials with 2.0 to 3.9 (R2 = 0.004; 95% CI, 0.00-0.08), 4.0 to 5.9 (R2 = 0.06; 95% CI, 0.001-0.16), or 6.0 or more years of follow-up (R2 = 0.30; 95% CI, 0.01-0.55).

CONCLUSIONS AND RELEVANCE

The findings of this meta-analysis do not appear to establish nonfatal MI as a surrogate for all-cause or CV mortality in randomized clinical trials of interventions to treat or prevent coronary artery disease.

Xanthine oxidoreductase: A leading actor in cardiovascular disease drama

Cardiovascular diseases (CVD) are the leading cause of global mortality and their pathogenesis lies mainly in the atherosclerotic process. There are close connections linking oxidative stress and inflammation to endothelial dysfunction, atherosclerosis and, consequently, to CVD. This review focuses on the role of xanthine oxidoreductase (XOR) and its products on the development of chronic inflammation and oxidative stress, responsible for atheromatous plaque formation. Evidence is reported that an excessive level of XOR products favors inflammatory response and plaque development, thereby promoting major cardiovascular risk factors. Also, the relationship between hyperuricemia and hypertension as well as between XOR activity and CVD is confirmed. In spite of the increasing number of clinical studies investigating the output of cardiovascular patients treated with urate-lowering therapies (including uricosuric drugs, XOR inhibitors and recombinant uricase) the results are still uncertain. The inhibition of XOR activity appears more promising than just the control of uricemia level in preventing cardiovascular events, possibly because it also reduces the intracellular accumulation of urate, as well as the production of reactive oxygen species. However, XOR inhibition also reduces the availability of the multifaced mediator nitric oxide and, at present, can be recommended only in hyperuricemic patients.

Cardiovascular risk associated with allopurinol vs. benzbromarone in patients with gout

Aims 

With the high prevalence of gout and associated cardiovascular (CV) diseases, information on the comparative CV safety of individual urate-lowering drugs becomes increasingly important. However, few studies examined the CV risk of uricosuric agents. We compared CV risk among patients with gout who initiated allopurinol vs. benzbromarone.

Methods and results 

Using the Korean National Health Insurance claims data (2002–17), we conducted a cohort study of 124 434 gout patients who initiated either allopurinol (n = 103 695) or benzbromarone (n = 20 739), matched on propensity score at a 5:1 ratio. The primary outcome was a composite CV endpoint of myocardial infarction, stroke/transient ischaemic attack, or coronary revascularization. To account for competing risk of death, we used cause-specific hazard models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the outcomes comparing allopurinol initiators with benzbromarone. Over a mean follow-up of 1.16 years, 2258 patients developed a composite CV event. The incidence rate of the composite CV event was higher in allopurinol initiators (1.81 per 100 person-years) than benzbromarone (1.61 per 100 person-years) with a HR of 1.22 (95% CI 1.05–1.41). The HR for all-cause mortality was 1.66 (95% CI 1.43–1.93) among allopurinol initiators compared with benzbromarone.

Conclusion 

In this large population-based cohort of gout patients, allopurinol was associated with an increased risk of composite CV events and all-cause mortality compared to benzbromarone. Benzbromarone may reduce CV risk and mortality in patients with gout, although more studies are necessary to confirm our findings and to advance our understanding of the underlying mechanisms.

Association of Mutations Identified in Xanthinuria with the Function and Inhibition Mechanism of Xanthine Oxidoreductase

Xanthine oxidoreductase (XOR) is an enzyme that catalyzes the two-step reaction from hypoxanthine to xanthine and from xanthine to uric acid in purine metabolism. XOR generally carries dehydrogenase activity (XDH) but is converted into an oxidase (XO) under various pathophysiologic conditions. The complex structure and enzymatic function of XOR have been well investigated by mutagenesis studies of mammalian XOR and structural analysis of XOR-inhibitor interactions. Three XOR inhibitors are currently used as hyperuricemia and gout therapeutics but are also expected to have potential effects other than uric acid reduction, such as suppressing XO-generating reactive oxygen species. Isolated XOR deficiency, xanthinuria type I, is a good model of the metabolic effects of XOR inhibitors. It is characterized by hypouricemia, markedly decreased uric acid excretion, and increased serum and urinary xanthine concentrations, with no clinically significant symptoms. The pathogenesis and relationship between mutations and XOR activity in xanthinuria are useful for elucidating the biological role of XOR and the details of the XOR reaction process. In this review, we aim to contribute to the basic science and clinical aspects of XOR by linking the mutations in xanthinuria to structural studies, in order to understand the function and reaction mechanism of XOR in vivo.

Uric Acid in Inflammation and the Pathogenesis of Atherosclerosis

Hyperuricemia is a common metabolic syndrome. Elevated uric acid levels are risk factors for gout, hypertension, and chronic kidney diseases. Furthermore, various epidemiological studies have also demonstrated an association between cardiovascular risks and hyperuricemia. In hyperuricemia, reactive oxygen species (ROS) are produced simultaneously with the formation of uric acid by xanthine oxidases. Intracellular uric acid has also been reported to promote the production of ROS. The ROS and the intracellular uric acid itself regulate several intracellular signaling pathways, and alterations in these pathways may result in the development of atherosclerotic lesions. In this review, we describe the effect of uric acid on various molecular signals and the potential mechanisms of atherosclerosis development in hyperuricemia. Furthermore, we discuss the efficacy of treatments for hyperuricemia to protect against the development of atherosclerosis.

Effect of Topiroxostat on Brain Natriuretic Peptide Level in Patients with Heart Failure with Preserved Ejection Fraction: A Pilot Study

BACKGROUND

Various optimal medical therapies have been established to treat heart failure (HF) with reduced ejection fraction (HFrEF). Both HFrEF and HF with preserved ejection fraction (HFpEF) are associated with poor outcomes. We investigated the effect of topiroxostat, an oral xanthine oxidoreductase inhibitor, for HFpEF patients with hyperuricemia or gout.

METHODS

In this nonrandomized, open-label, single-arm trial, we administered topiroxostat 40-160 mg/day to HFpEF patients with hyperuricemia or gout to achieve a target uric acid level of 6.0 mg/dL. The primary outcome was rate of change in log-transformed brain natriuretic peptide (BNP) level from baseline to 24 weeks after topiroxostat treatment. The secondary outcomes included amount of change in BNP level, uric acid evaluation values, and oxidative stress marker levels after 24 weeks of topiroxostat treatment. Thirty-six patients were enrolled; three were excluded before study initiation.

RESULTS

Change in log-transformed BNP level was -3.4 ± 8.9% (p = 0.043) after 24 weeks of topiroxostat treatment. The rate of change for the decrease in BNP level was -18.0 (-57.7, 4.0 pg/mL; p = 0.041). Levels of uric acid and 8-hydroxy-2'-deoxyguanosine/creatinine, an oxidative stress marker, also significantly decreased (-2.8 ± 1.6 mg/dL, p < 0.001, and -2.3 ± 3.7 ng/mgCr, p = 0.009, respectively).

CONCLUSIONS

BNP level was significantly lower in HFpEF patients with hyperuricemia or gout after topiroxostat administration; however, the rate of decrease was low. Further trials are needed to confirm our findings.

Pharmacotherapy for gout

Background: Gout is a common disease that is mainly caused by hyperuricemia. Although it is relatively easy to treat, adherence to drug treatment and the rate at which treatment targets are met is low.Current Concepts: For the treatment of acute gout attack, colchicine, nonsteroidal anti-inflammatory drugs, and glucocorticoids can be used alone or in combination depending on the severity of symptoms. To prevent gout attacks, patients are started on colchicine prior to or concurrent with treatment with uric acid–lowering drugs. The treatment is maintained until serum uric acid levels have returned to normal, and the patient has had no acute attacks for three to six months. Ultimately, the symptoms of gout are controlled in the long term by treating the patient’s hyperuricemia. For this purpose, allopurinol, febuxostat, and benzbromarone are used, and the side effects and contraindications for each drug should be checked. The goal for the treatment of chronic gout is to maintain a serum uric acid concentration below 6.0 mg/dL.Discussion and Conclusion: Patients visit the emergency departments of hospitals for sudden gout attacks. However, gout is a chronic disease that requires the lifelong use of uric acid–lowering agents. Therefore, it is necessary to educate patients on a serum urate-based treat-to-target approach.

Role of asymptomatic hyperuricemia in the progression of chronic kidney disease and cardiovascular disease

Previous research has investigated whether hyperuricemia serves as an independent risk factor for cardiovascular and renal diseases. Hyperuricemia is defined as an abnormally high level of uric acid (UA; i.e., serum urate level > 6.8 mg/dL). Hyperuricemia has been considered a complication of chronic kidney disease (CKD). However, it seems to play a pathogenic role in the progression of renal diseases. There has been increasing focus on the link between hyperuricemia and CKD. The results of randomized controlled trials have implied independent associations between hyperuricemia and the progression of cardiovascular and renal morbidities. These associations may be mediated by renin-angiotensin system activation, nitric oxide synthase inhibition, and macrovascular/microvascular disease development. There remains controversy regarding the use of serum UA level as an indirect index of renal vascular disease. This literature review focuses on the role of asymptomatic hyperuricemia in the progression of CKD, as well as the association between hyperuricemia and cardiovascular disease. It also provides a general overview of the physiological metabolism of UA.

Assessing the Causal Relationships Between Insulin Resistance and Hyperuricemia and Gout Using Bidirectional Mendelian Randomization

OBJECTIVE

Hyperuricemia is closely associated with insulin resistance syndrome (and its many cardiometabolic sequelae); however, whether they are causally related has long been debated. We undertook this study to investigate the potential causal nature and direction between insulin resistance and hyperuricemia, along with gout, by using bidirectional Mendelian randomization (MR) analyses.

METHODS

We used genome-wide association data (n = 288,649 for serum urate [SU] concentration; n = 763,813 for gout risk; n = 153,525 for fasting insulin) to select genetic instruments for 2-sample MR analyses, using multiple MR methods to address potential pleiotropic associations. We then used individual-level, electronic medical record-linked data from the UK Biobank (n = 360,453 persons of European ancestry) to replicate our analyses via single-sample MR analysis.

RESULTS

Genetically determined SU levels, whether inferred from a polygenic score or strong individual loci, were not associated with fasting insulin concentrations. In contrast, genetically determined fasting insulin concentrations were positively associated with SU levels (0.37 mg/dl per log-unit increase in fasting insulin [95% confidence interval (95% CI) 0.15, 0.58]; P = 0.001). This persisted in outlier-corrected (β = 0.56 mg/dl [95% CI 0.45, 0.67]) and multivariable MR analyses adjusted for BMI (β = 0.69 mg/dl [95% CI 0.53, 0.85]) (P < 0.001 for both). Polygenic scores for fasting insulin were also positively associated with SU level among individuals in the UK Biobank (P < 0.001). Findings for gout risk were bidirectionally consistent with those for SU level.

CONCLUSION

These findings provide evidence to clarify core questions about the close association between hyperuricemia and insulin resistance syndrome: hyperinsulinemia leads to hyperuricemia but not the other way around. Reducing insulin resistance could lower the SU level and gout risk, whereas lowering the SU level (e.g., allopurinol treatment) is unlikely to mitigate insulin resistance and its cardiometabolic sequelae.

The Impact of Urate-Lowering Therapy in Post-Myocardial Infarction Patients: Insights from a Population-Based, Propensity Score-Matched Analysis

The role of urate‐lowering therapy (ULT) for the primary prevention of cardiovascular (CV) events has been widely discussed, but its evidence for the secondary prevention of myocardial infarction (MI) is limited. Therefore, we conduct a population‐based, propensity score‐matched cohort study to investigate the CV outcomes among patients with post‐MI with and without ULT. A total of 19,042 newly diagnosed in‐hospital patients with MI were selected using the Taiwan National Health Insurance Database between January 1, 2005, and December 31, 2016. After 1:1 propensity score matching with covariates, patients with MI with (n = 963) and without (n = 963) ULT were selected for further analysis. The primary outcome was the all‐cause mortality and the secondary outcomes were composite CV outcomes, including hospitalization for recurrent MI, stroke, heart failure, and cardiac arrhythmias. ULT users were associated with lower all‐cause mortality (adjusted hazard ratio (adjHR), 0.67; 95% confidence interval (CI), 0.51–0.87) compared to the ULT nonusers. In addition, ULT users had a significantly lower risk of recurrent MI, which needed revascularization by percutaneous coronary intervention or coronary artery bypass grafting (adjHR, 0.67; 95% CI, 0.53–0.86) than the ULT nonusers. The primary and secondary outcomes were not different between patients with post‐MI who received uricosuric agents and xanthine oxidase inhibitors. The anti‐inflammatory effect of ULT plays an essential role in MI management. From a real‐world setting, this study shows that ULT is associated with the lower risk of all‐cause mortality in patients with post‐MI. In addition, the result shows the possible lower incidence of repeat revascularization procedures in the ULT users.

Serum uric acid is associated with incident metabolic syndrome independent of body shape index and body roundness index in healthy individuals

BACKGROUND AND AIMS

Elevated serum uric acid (SUA) levels, body shape index (BSI) and body roundness index (BRI) were associated with incident metabolic syndrome (MetS). We aimed to investigate the relationship among the SUA level, BSI, and BRI on the incidence of MetS.

METHODS AND RESULTS

We retrospectively included 6221 healthy individuals from annual health exams at our hospital between 2016/1/1 and 2016/12/31. We defined hyperuricemia as SUA levels greater than 7 mg/dl in men and 6 mg/dl in women and MetS according to the contemporary definition. The study cohort included 6221 healthy individuals with an overall incidence rate of MetS of 9.8%. Compared with the normouricemic group, the hyperuricemic group had a greater incidence of MetS (17.2% vs. 9.6%, P < 0.001). After full adjustment for confounders, the SUA level was significantly associated with incident MetS in addition to body mass index (BMI) (adjusted OR [aOR]: 1.161, 95% CI: 1.071-1.259, P < 0.001), BRI (aOR: 1.196, 95% CI: 1.104-1.296, P < 0.001), and BSI (aOR: 1.297, 95% CI: 1.200-1.403, P < 0.001). Regarding the anthropometric indices, BMI and BRI were independent predictors of incident MetS, but the BSI lost its significant association in multivariate logistic regression analyses. In sensitivity analyses, various thresholds of elevated SUA levels remained associated with incident MetS.

CONCLUSION

We showed a dose-response effect of SUA on incident MetS independent of BMI, BRI and BSI in healthy individuals. Future studies can use SUA levels to stratify cardiometabolic risk in healthy individuals.

CLINICAL TRIALS

ClinicalTrials.gov with the identification number NCT03473951.

Hyperuricemia and Its Association With Ischemic Stroke

Elevated serum uric acid (SUA) levels have been associated with an increased risk of cardiovascular (CV) disease and acute ischemic stroke (AIS) as well as many other medical conditions. AIS is a CV complication that is the second most common cause of mortality worldwide. It results from reduced blood flow to the brain by means of thrombosis, embolism, or systemic hypoperfusion. Studies have demonstrated an association between SUA levels and CV events, with a significant dose-response relationship between elevated SUA levels and stroke risk. Since the relationship between SUA levels and AIS risk has been established, studies are also being conducted in order to evaluate whether antihyperuricemic drugs can lower this risk. Allopurinol use in hyperuricemic patients has been shown to decrease the risk of major CV events, which include AIS. This narrative review aims to investigate the role of SUA as an independent risk factor for AIS along with the proposed biological mechanisms by thoroughly appraising research findings from relevant full-text articles and abstracts indexed in PubMed and the Cochrane Library. In this literature, we will be discussing hyperuricemia, AIS, the association between the two, and the use of antihyperuricemic medications on stroke prognosis. This review will also shed new light on studies that have begun to provide insight into the predictive role of hyperuricemia in AIS.

Treatment advances in gout

The purpose of gout treatment is to alleviate symptoms of flares, prevent flares from recurring by lowering serum urate, and minimize structural joint damage and functional impairment. In recent years, several new medications to treat gout have been developed, and novel agents continue to be investigated, in addition to several long-established treatments. Although a number of effective therapies are available, optimal management and outcomes are frequently not achieved due to physician under prescribing of urate-lowering therapy (ULT) and poor adherence with therapy when it is prescribed. This article reviews recent developments in the management of gout with reference to recently published clinical guidelines, outlines some important questions regarding the safety and efficacy of particular agents, and remaining gaps in our knowledge about the most effective strategies for using currently available treatments.

Allopurinol attenuates oxidative injury in rat hearts suffered ischemia/reperfusion via suppressing the xanthine oxidase/vascular peroxidase 1 pathway

Allopurinol, a xanthine oxidase (XO) inhibitor, is reported to alleviate myocardial ischemia/reperfusion (I/R) injury by reducing the production of reactive oxygen species (ROS). As an XO-derived product, H2O2 can act as a substrate of vascular peroxidase 1 (VPO1) to induce the generation of hypochlorous acid (HOCl), a potent oxidant. This study aims to explore whether the XO/VPO1 pathway is involved in the anti-oxidative effects of allopurinol on the myocardial I/R injury. In a rat heart model of I/R, allopurinol alleviated I/R oxidative injury accompanied by decreased XO activity, XO-derived products (H2O2 and uric acid), and VPO1 expression (mRNA and protein). In a cardiac cell model of hypoxia/reoxygenation (H/R), allopurinol or XO siRNA reduced H/R injury concomitant with decreased XO activity, VPO1 expression as well as the XO and VPO1-derived products (H2O2, uric acid, and HOCl). Although knockdown of VPO1 could also exert a beneficial effect on H/R injury, it did not affect XO activity, XO expression, and XO-derived products. Based on these observations, we conclude that the novel pathway of XO/VPO1 is responsible for, at least partly, myocardial I/R-induced oxidative injury, and allopurinol exerted the cardioprotective effects on myocardial I/R injury via inhibiting the XO/VPO1 pathway.

Management of gout in chronic kidney disease: a G-CAN Consensus Statement on the research priorities

Gout and chronic kidney disease (CKD) frequently coexist, but quality evidence to guide gout management in people with CKD is lacking. Use of urate-lowering therapy (ULT) in the context of advanced CKD varies greatly, and professional bodies have issued conflicting recommendations regarding the treatment of gout in people with concomitant CKD. As a result, confusion exists among medical professionals about the appropriate management of people with gout and CKD. This Consensus Statement from the Gout, Hyperuricemia and Crystal-Associated Disease Network (G-CAN) discusses the evidence and/or lack thereof for the management of gout in people with CKD and identifies key areas for research to address the challenges faced in the management of gout and CKD. These discussions, which address areas for research both in general as well as related to specific medications used to treat gout flares or as ULT, are supported by separately published G-CAN systematic literature reviews. This Consensus Statement is not intended as a guideline for the management of gout in CKD; rather, it analyses the available literature on the safety and efficacy of drugs used in gout management to identify important gaps in knowledge and associated areas for research.

Relationship between serum uric acid levels and different types of atrial fibrillation: An updated meta-analysis

AIM

Increasing evidence supports the hypothesis that high serum uric acid (SUA) levels are related to atrial fibrillation (AF). However, the incidence of AF in patients with hyperuricemia and SUA levels in different types of AF is not entirely clear. This meta-analysis was designed to evaluate the relationship between SUA and incidence of AF, and the variation in SUA levels in different types of AF.

DATA SYNTHESIS

Relevant reports were searched for in Embase, PubMed and the Cochrane Library. A fixed-effects model combining relative risk (RR) and the corresponding 95% confidence interval (95% CI) was used to evaluate the correlation between SUA and AF. The standardized mean differences (SMDs) of SUA values were calculated using a random-effects model to evaluate the differences in SUA levels among different types of AF. A total of 31 studies with 504,958 participants were included in this research. The results from 8 cohort studies showed that high SUA levels significantly increased the incidence of AF [RR (95% CI): 1.92 (1.68-2.20); P < 0.01]. The results from 29 studies revealed that SUA levels elevated in patients with AF [SMD (95% CI): 0.55 (0.43-0.66); P < 0.001]. Meanwhile, SUA levels in new-onset AF [SMD (95%CI): 0.24 (0.10-0.38); P = 0.001], paroxysmal AF [SMD (95%CI): 0.52 (0.33-0.72); P < 0.001] and persistent AF [SMD (95%CI): 1.23 (0.98-1.48); P < 0.001] were significantly higher than that in patients without AF.

CONCLUSIONS

High SUA levels had an obvious correlation with the occurrence rate of AF. In addition, SUA levels were significantly different among patients with new-onset, paroxysmal and persistent AF.

Hyperuricemia in Patients With Coronary Artery Disease and Its Association With Disease Severity

The biochemical background of coronary artery disease (CAD) has been intensively explored in the past several decades. Previous clinical investigations have demonstrated the association of non-traditional risk factors, such as hyperuricemia, with CAD. Studies have shown that increased serum uric acid (SUA) was associated with an increased risk of adverse cardiovascular (CV) outcomes in patients with CAD. While the exact pathophysiological mechanisms leading to increased risk are still unknown, it has been postulated that hyperuricemia leads to endothelial dysfunction, oxidative metabolism, and platelet adhesiveness and aggregation, leading to CAD. Moreover, previous studies have shown that hyperuricemia is an independent risk factor for CAD. However, the correlation between high SUA levels and the severity of CAD remains unclear. The purpose of this review was to elucidate the association of hyperuricemia to CAD severity and to determine the effect of urate-lowering therapy (ULT) on CAD. A search of PubMed up to June 24, 2021, was carried out by the reviewers. From the findings, hyperuricemia stands as an independent risk factor for CAD, and CAD patients treated with ULT had improved CV outcomes and reduced mortality. Therefore, while SUA level is valuable in predicting an augmented risk of CAD and anticipating worse outcomes, ULT has promising cardioprotective effects.

Hyperuricemia and Progression of Chronic Kidney Disease: A Review from Physiology and Pathogenesis to the Role of Urate-Lowering Therapy

The relationship between hyperuricemia, gout, and renal disease has been investigated for several years. From the beginning, kidney disease has been considered a complication of gout; however, the viewpoints changed, claiming that hypertension and elevated uric acid (UA) levels are caused by decreased urate excretion in patients with renal impairment. To date, several examples of evidence support the role of hyperuricemia in cardiovascular or renal diseases. Several mechanisms have been identified that explain the relationship between hyperuricemia and chronic kidney disease, including the crystal effect, renin-angiotensin-aldosterone system activation, nitric oxide synthesis inhibition, and intracellular oxidative stress stimulation, and urate-lowering therapy (ULT) has been proven to reduce renal disease progression in the past few years. In this comprehensive review, the source and physiology of UA are introduced, and the mechanisms that explain the reciprocal relationship between hyperuricemia and kidney disease are reviewed. Lastly, current evidence supporting the use of ULT to postpone renal disease progression in patients with hyperuricemia and gout are summarized.

Inulin-type prebiotics reduce serum uric acid levels via gut microbiota modulation: a randomized, controlled crossover trial in peritoneal dialysis patients

PURPOSE

Increased levels of uric acid (UA), which is mainly excreted through the kidneys, are independently associated with higher mortality in end-stage renal disease (ESRD) patients. The uricolysis of gut microbiota plays an important role in extrarenal excretion of UA. This study aimed to examine the effect of inulin-type prebiotics (a type of fermentable dietary fiber) on intestinal microbiota modulation and serum UA levels in ESRD patients.

METHODS

Continuous ambulatory peritoneal dialysis (CAPD) patients were recruited to a randomized, double-blind, placebo-controlled crossover trial of 12-week inulin-type prebiotics. Participants were visited before and after treatment with prebiotics or placebo. Serum UA levels, dietary purine intake, serum xanthine oxidase (XO) activity, daily "renal excretion" of UA, and fecal UA degradation capability were measured at each visit. Fecal metagenomic analysis was conducted to assess microbial composition and function.

RESULTS

Sixteen participants (mean age = 37 y; 10 men and 6 women) completed the trial, and 64 specimens were analyzed. The average concentration of serum UA decreased by approximately 10% in the prebiotic intervention group in comparison to the placebo group (p = 0.047) without an increase in daily "renal excretion" of UA via urine and dialysate. There were no significant changes in purine intake or activity of XO. Notably, enhanced fecal UA degradation was observed after prebiotic intervention (p = 0.041), and the ratio of Firmicutes/Bacteroidetes, which was positively associated with fecal UA degradation, increased in the prebiotic period (p = 0.032). Furthermore, prebiotics enriched purine-degrading species in the gut microbiota, including unclassified_o_Clostridiales, Clostridium sp. CAG:7, Clostridium sp. FS41, Clostridium citroniae, Anaerostipes caccae, and Clostridium botulinum.

CONCLUSIONS

Inulin-type prebiotics is a promising therapeutic candidate to reduce serum UA levels in renal failure patients, and this urate-lowering effect could possibly be attributed to intestinal microbial degradation of UA.

TRIAL REGISTRY

This study was registered at the Chinese Clinical Trials Registry ( http://www.chictr.org.cn/ ), registration ID: ChiCTR-INR-17013739, registration date: 6th Dec 2017.

Gout Pharmacotherapy in Cardiovascular Diseases: A Review of Utility and Outcomes

Hyperuricemia and gout have been linked to an increased risk for cardiovascular (CV) disease, stroke, hypertension, heart failure, and chronic kidney disease, possibly through a proinflammatory milieu. However, not all the drugs used in gout treatment improve CV outcomes; colchicine has shown improved CV outcomes in patients with recent myocardial infarction and stable coronary artery disease independent of lipid-lowering effects. There is resurging interest in colchicine following publication of the COLCOT, LoDoCo, LoDoCo2, LoDoCo-MI trials, and COLCORONA trial which will shed light on its utility in COVID-19. Our aim is to review the CV use of colchicine beyond pericardial diseases, as well as CV outcomes of the available gout therapies, including allopurinol and febuxostat. The CARES trial and its surrounding controversies, which lead to the US FDA ‘black box’ warning on febuxostat, in addition to the recent FAST trial which contradicts this and finds febuxostat to be non-inferior, are discussed in this paper.

Molecular Biological and Clinical Understanding of the Pathophysiology and Treatments of Hyperuricemia and Its Association with Metabolic Syndrome, Cardiovascular Diseases and Chronic Kidney Disease

Uric acid (UA) is synthesized mainly in the liver, intestines, and vascular endothelium as the end product of an exogenous purine from food and endogenously from damaged, dying, and dead cells. The kidney plays a dominant role in UA excretion, and the kidney excretes approximately 70% of daily produced UA; the remaining 30% of UA is excreted from the intestine. When UA production exceeds UA excretion, hyperuricemia occurs. Hyperuricemia is significantly associated with the development and severity of the metabolic syndrome. The increased urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) expression, and glycolytic disturbances due to insulin resistance may be associated with the development of hyperuricemia in metabolic syndrome. Hyperuricemia was previously thought to be simply the cause of gout and gouty arthritis. Further, the hyperuricemia observed in patients with renal diseases was considered to be caused by UA underexcretion due to renal failure, and was not considered as an aggressive treatment target. The evidences obtained by basic science suggests a pathogenic role of hyperuricemia in the development of chronic kidney disease (CKD) and cardiovascular diseases (CVD), by inducing inflammation, endothelial dysfunction, proliferation of vascular smooth muscle cells, and activation of the renin-angiotensin system. Further, clinical evidences suggest that hyperuricemia is associated with the development of CVD and CKD. Further, accumulated data suggested that the UA-lowering treatments slower the progression of such diseases.

Interventions for tophi in gout

BACKGROUND

Tophi develop in untreated or uncontrolled gout. This is an update of a Cochrane Review first published in 2014.  OBJECTIVES: To assess the benefits and harms of non-surgical and surgical treatments for the management of tophi in gout.

SEARCH METHODS

We updated the search of Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase databases to 28 August 2020.

SELECTION CRITERIA

We included all published randomised controlled trials (RCTs) or controlled clinical trials examining interventions for tophi in gout in adults.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included one trial in our original review. We added four more trials (1796 participants) in this update. One had three arms; pegloticase infusion every two weeks (biweekly), monthly pegloticase infusion (pegloticase infusion alternating with placebo infusion every two weeks) and placebo. Two studies looked at lesinurad 200 mg or 400 mg in combination with allopurinol. One trial studied lesinurad 200 mg or 400 mg in combination with febuxostat. One trial compared febuxostat 80 mg and 120 mg to allopurinol. Two trials were at unclear risk of performance and detection bias due to lack of information on blinding of participants and personnel. All other trials were at low risk of bias. Moderate-certainty evidence (downgraded for imprecision; one study; 79 participants) showed that biweekly pegloticase resolved tophi in 21/52 participants compared with 2/27 on placebo (risk ratio (RR) 5.45, 95% confidence interval (CI) 1.38 to 21.54; number needed to treat for a benefit (NNTB) 3, 95% CI 2 to 6). Similar proportions of participants receiving biweekly pegloticase (80/85) had an adverse event compared to placebo (41/43) (RR 0.99, 95% CI 0.91 to 1.07). However, more participants on biweekly pegloticase (15/85) withdrew due to an adverse event compared to placebo (1/43) (RR 7.59, 95% CI 1.04 to 55.55; number needed to treat for a harm (NNTH) 7, 95% CI 4 to 16). More participants on monthly pegloticase (11/52) showed complete resolution of tophi compared with placebo (2/27) (RR 2.86, 95% CI 0.68 to 11.97; NNTB 8, 95% CI 4 to 91). Similar numbers of participants on monthly pegloticase (84/84) had an adverse event compared to placebo (41/43) (RR 1.05, 95% CI 0.98 to 1.14). More participants on monthly pegloticase (16/84) withdrew due to adverse events compared to placebo (1/43) (RR 8.19, 95% CI 1.12 to 59.71; NNTH 6, 95% CI 4 to 14). Infusion reaction was the most common reason for withdrawal. Moderate-certainty evidence (2 studies; 103 participants; downgraded for imprecision) showed no clinically significant difference for complete resolution of target tophus in the lesinurad 200 mg plus allopurinol arm (11/53) compared to the placebo plus allopurinol arm (16/50) (RR 0.40, 95% CI 0.04 to 4.57), or in the lesinurad 400 mg plus allopurinol arm (12/48) compared to the placebo plus allopurinol arm (16/50) (RR 0.79, 95% CI 0.42 to 1.49). An extension study examined lesinurad 200 mg or 400 mg in combination with febuxostat, or placebo (low-certainty evidence, downgraded for indirectness and imprecision). Participants on lesinurad in the original study continued (CONT) on the same dose. Lesinurad 400 mg plus febuxostat may be beneficial for tophi resolution; 43/65 in the lesinurad 400 mg CONT arm compared to 38/64 in the lesinurad 200 mg CONT arm had tophi resolution (RR 1.11, 95% CI 0.85 to 1.46). Lesinurad 400 mg plus febuxostat may result in no difference in adverse events; 57/65 in the lesinurad 400 mg CONT arm had an adverse event compared to 50/64 in lesinurad 200 mg CONT arm (RR 1.12, 95% CI 0.96 to 1.32). Lesinurad 400 mg plus febuxostat may result in no difference in withdrawals due to adverse events; 10/65 participants in the lesinurad 400 mg CONT arm withdrew due to an adverse event compared to 10/64 participants in the lesinurad 200 mg CONT arm (RR 0.98, 95% CI 0.44 to 2.20). Lesinurad 400 mg plus febuxostat may result in no difference in mean serum uric acid (sUA), which was 3 mg/dl in the lesinurad 400 mg CONT group compared to 3.9 mg/dl in the lesinurad 200 mg CONT group (mean difference -0.90, 95% CI -1.51 to -0.29). Participants who were not on lesinurad in the original study were randomised (CROSS) to lesinurad 200 mg or 400 mg, both in combination with febuxostat. Low-certainty evidence downgraded for indirectness and imprecision showed that lesinurad 400 mg (CROSS) may result in tophi resolution (17/34) compared to lesinurad 200 mg (CROSS) (14/33) (RR 1.18, 95% CI 0.70 to 1.98). Lesinurad 400 mg in combination with febuxostat may result in no difference in adverse events (33/34 in the lesinurad 400 mg CROSS arm compared to 27/33 in the lesinurad 200 mg (CROSS); RR 1.19, 95% CI 1.00 to 1.41). Lesinurad 400 mg plus febuxostat may result in no difference in withdrawals due to adverse events, 5/34 in the lesinurad 400 mg CROSS arm withdrew compared to 2/33 in the lesinurad 200 mg CROSS arm (RR 2.43, 95% CI 0.51 to 11.64). Lesinurad 400 mg plus febuxostat results in no difference in sUA (4.2 mg/dl in lesinurad 400 mg CROSS) compared to lesinurad 200 mg (3.8 mg/dl in lesinurad 200 mg CROSS), mean difference 0.40 mg/dl, 95% CI -0.75 to 1.55.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence showed that pegloticase is probably beneficial for resolution of tophi in gout. Although there was little difference in adverse events when compared to placebo, participants on pegloticase had more withdrawals due to adverse events. Lesinurad 400 mg plus febuxostat may be beneficial for tophi resolution compared with lesinurad 200 mg plus febuxostat; there was no difference in adverse events between these groups. We were unable to determine whether lesinurad plus febuxostat is more effective than placebo. Lesinurad (400 mg or 200 mg) plus allopurinol is probably not beneficial for tophi resolution, and there was no difference in adverse events between these groups. RCTs on interventions for managing tophi in gout are needed, and the lack of trial data is surprising given that allopurinol is a well-established treatment for gout.

Lactic acid bacteria strains relieve hyperuricaemia by suppressing xanthine oxidase activity via a short-chain fatty acid-dependent mechanism

Globally, the incidence of hyperuricaemia is steadily increasing. The evidence increasingly suggests an association between hyperuricaemia and the gut microbiota, which may enable the development of a novel therapeutic approach. We studied the effects of treatment with lactic acid bacteria (LAB) on hyperuricaemia and their potential underlying mechanisms. A mouse model of hyperuricaemia was generated by oral gavage with hypoxanthine and intraperitoneal injections of potassium oxonate for 2 weeks. The anti-hyperuricaemic activities of 10 LAB strains relative to allopurinol as a positive drug control were investigated in the mouse model. Lactobacillus rhamnosus R31, L. rhamnosus R28-1 and L. reuteri L20M3 effectively reduced the uric acid (UA) concentrations in serum and urine and the xanthine oxidase (XOD) activity levels in serum and hepatic tissue in mice with hyperuricaemia. These strains also reversed the elevated lipopolysaccharide (LPS) concentration, hepatic inflammation and slight renal injury associated with hyperuricaemia. A correlation analysis revealed that UA-reducing LAB strains promoted short-chain fatty acid (SCFA) production to suppress serum and hepatic XOD activity by increasing the abundances of SCFA production-related gut bacterial taxa. However, the UA-reducing effects of LAB strains might not be mediated by purine degradation. In summary, L. rhamnosus R31, L. rhamnosus R28-1 and L. reuteri L20M3 relieved hyperuricaemia in our mouse model by promoting SCFA production in a purine degradation-independent manner. Our findings suggest a novel therapeutic approach involving LAB strains for hyperuricaemia.

Changing paradigms in the management of gout

The incidence and prevalence of gout have increased, as have comorbid obesity, diabetes mellitus, hypertension, chronic kidney and cardiovascular disease. Gout is now the commonest type of inflammatory arthritis despite availability of safe, effective and potentially 'curative' urate-lowering drugs. Modern imaging studies show that gout is a chronic inflammatory crystal deposition disorder even at the first acute attack and they illuminate the need to eliminate urate crystals by continuing reduction of the serum urate below its solubility threshold. Clinical outcomes, adherence to therapy and quality of gout care in primary care and hospital practice can be greatly improved by better use of allopurinol and flare prophylaxis, greater patient engagement, education and follow-up, and by nurse-led models of care that employ a 'treat-to-target' principle (SUA< 360 or 300µmol/l). Advances in understanding the physiology and genetic control of urate transport in the kidney and gut have led to novel, more selective uricosuric drugs, and basic research on mediators of urate crystal-induced inflammation has pointed to alternative therapeutic targets for treating and preventing gout flares. Current guidelines for the management of gout and indications for the use of some more recently introduced drugs; febuxostat, lesinurad, pegloticase and interleukin-1 antagonists are also briefly reviewed.

Hyperuricemia, the heart, and the kidneys - to treat or not to treat?

Background

Hyperuricemia is a state in which the serum levels of uric acid are elevated. As such it has a pronounced effect on vascular and renal function with their consequences, while also showing some antioxidant effects that show to be beneficial.

Summary

Hyperuricemia has shown to have a J-shaped relationship with mortality, is frequently associated with development and progression of heart and kidney disease, and is correlated with malnutrition-inflammation-atherosclerosis syndrome, although several Mendelian studies have failed to show an association with morbidity and mortality. Hyperuricemia is usually associated with gout flares and tophi development but can also present as asymptomatic hyperuricemia. It is still uncertain whether asymptomatic hyperuricemia is an independent risk factor for cardiovascular or renal disease and as such its treatment is questionable.

Key messages

Some possible tools for future decision making are the use of noninvasive techniques such as pulse wave analysis, urinary sediment analysis, and joint ultrasound, which could help identify individuals with asymptomatic hyperuricemia that could benefit from urate lowering therapy most.

Simiao Wan attenuates monosodium urate crystal-induced arthritis in rats through contributing to macrophage M2 polarization

ETHNOPHARMACOLOGICAL RELEVANCE

Simiao Wan (SMW) is a classical traditional Chinese medicine (TCM) prescription to empirically treat gouty arthritis (GA) in TCM clinical practice. However, the potential mechanisms of SMW on GA are not fully evaluated.

AIM OF STUDY

The aim of this study is to investigate the role of macrophage polarization in the anti-GA activity of SMW.

MATERIALS AND METHODS

Rats were intragastricly treated with SMW for consecutive 7 days. On day 6, monosodium urate (MSU) crystal-induced arthritis (MIA) in the ankle joint was prepared. Paw volume, gait score and histological score were measured. Levels of interleukin (IL)-1β and IL-10 in serum were detected by enzyme-linked immunosorbent assay. Expressions of inducible nitric oxide synthase (iNOS), arginase (Arg)-1, phosphorylated (p)-p65, inhibitor of nuclear factor (NF)-κB (IκB)α, p-signal transducer and transcription activator (STAT)3 and p-Janus kinase (JAK)2 in synovial tissues were determined by Western blot.

RESULTS

The elevated paw volume, gait score and histological score in MIA rats were significantly decreased by SMW treatment. Meanwhile, SMW significantly decreased the IL-1β level and increased the IL-10 level in serum of MIA rats. Furthermore, SMW reduced the expressions of iNOS, p-p65 and enhanced the expressions of Arg-1, IκBα, p-STAT3 and p-JAK2 in synovial tissues of MIA rats.

CONCLUSIONS

The results suggest that SMW attenuates the inflammation in MIA rats through promoting macrophage M2 polarization.

Management of oxidative stress and inflammation in cardiovascular diseases: mechanisms and challenges

Cardiovascular diseases (CVDs) have diverse physiopathological mechanisms with interconnected oxidative stress and inflammation as one of the common etiologies which result in the onset and development of atherosclerotic plaques. In this review, we illustrate this strong crosstalk between oxidative stress, inflammation, and CVD. Also, mitochondrial functions underlying this crosstalk, and various approaches for the prevention of redox/inflammatory biological impacts will be illustrated. In part, we focus on the laboratory biomarkers and physiological tests for the evaluation of oxidative stress status and inflammatory processes. The impact of a healthy lifestyle on CVD onset and development is displayed as well. Furthermore, the differences in oxidative stress and inflammation are related to genetic susceptibility to cardiovascular diseases and the variability in the assessment of CVDs risk between individuals; Omics technologies for measuring oxidative stress and inflammation will be explored. Finally, we display the oxidative stress-related microRNA and the functions of the redox basis of epigenetic modifications.

Comparing the Effects of Febuxostat and Allopurinol in an Animal Model of Metabolic Syndrome

INTRODUCTION

Recent studies highlighted the association of hyperuricemia and metabolic syndrome (MS). The aim of this study was to compare the beneficial effects of febuxostat versus allopurinol on the biochemical changes that occur in MS.

METHODS

Forty adult male Sprague Dawley albino rats were used in the study. Insulin resistance and MS were induced by administration of a high-fructose diet for 8 weeks. Follow-up of changes in weight, blood pressure, serum biochemical parameters, serum antioxidant catalase, and glutathione peroxidase activities was done. At the end of the study, animals were sacrificed, and the thoracic aorta was isolated for in vitro study of the endothelial integrity.

RESULTS

Allopurinol and febuxostat treatment induced significant reduction in body weight, systolic blood pressure, blood glucose, insulin, lipids, and improved kidney functions and endothelial integrity compared to nontreated rats. Febuxostat was more effective than allopurinol in normalizing serum fasting glucose, uric acid, catalase, and glutathione peroxidase activities.

CONCLUSION

Xanthine oxidase inhibitors ameliorated the effects of MS. Febuxostat was mildly superior to allopurinol in lowering serum fasting glucose, lipids, uric acid, and antioxidant enzyme activities.

Therapeutic approaches in the treatment of gout

Gout is a disease in which the metabolic condition hyperuricemia leads to the formation of monosodium urate crystals, which provoke acute and chronic inflammatory responses through activation of the innate immune system. Recent advances in our knowledge of gout pathogenesis have emphasized the role of the kidneys in urate handling, the evolutionary loss of uricase as a necessary precondition for hyperuricemia, and the central role of IL-1ß in the pathogenesis of gouty inflammation. These, and other advances, have shaped our current strategies for managing gout. Here, we review the most current, evidence-based gout management approaches, including treating acute flares, addressing gout through the long-term regulation of serum urate, and prophylaxis against gouty flares during urate lowering.

The association between urate-lowering therapies and treatment-related adverse events, liver damage, and major adverse cardiovascular events (MACE): A network meta-analysis of randomized trials

PURPOSE

Hyperuricemia is a common disease that may lead to gout, renal damage, and cardiovascular events. Oral medication is the main treatment for hyperuricemia patients when lifestyle intervention fails. An evaluation of the safety of various urate-lowering therapies (ULTs) is integral to clinical decision-making. We constructed a network meta-analysis (NMA) to evaluate the safety of oral ULTs.

METHODS

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched up to April 1, 2021, for randomized controlled trials that examined the safety of ULTs. The language restriction was English. The three outcomes used to assess the safety of uric acid lowering medications were treatment-related adverse events, liver damage, and major adverse cardiovascular events (MACE).

RESULTS

Thirty-two trials enrolling 23,868 individuals were included in the study. In terms of treatment-related adverse events, there were no statistically significant differences between five uric acid lowering medications and placebo: allopurinol (risk ratio (RR): 1.08; 95% credible interval (CrI): 0.91, 1.29), febuxostat (RR: 1.05; 95% CrI: 0.89, 1.25), lesinurad (RR: 1.19; 95% CrI: 0.85, 1.67), lesinurad combined with xanthine oxidase inhibitor (XOI, RR: 1.05; 95% CrI: 0.83, 1.32), and topiroxostat (RR: 1.01; 95% CrI: 0.83, 1.23). Topiroxostat likely increases risk of liver damage (RR: 2.65; 95%CI: 1.24, 5.70; NNH: 33.40) as compared with placebo. With regard to MACE, there were no statistically significant differences between three uric acid lowering medications and placebo: allopurinol (RR: 0.63; 95% CrI: 0.36, 1.34), febuxostat (RR: 0.69; 95% CrI: 0.38, 1.66), and lesinurad combined with XOI (RR: 0.56; 95% CrI: 0.23, 1.85). The rankings of different interventions were depicted by cumulative ranking curve (SUCRA).

CONCLUSIONS

Through NMA, we provide some evidence for the safety of ULTs. We found no statistically significant differences in their effects on treatment-related adverse events and MACE. However, topiroxostat likely increases the risk of liver damage.

Uric acid as a cardiorenal mediator: pathogenesis and mechanistic insights

Introduction: The role of serum uric acid as a connector in cardiorenal interactions has been long debated and studied extensively in the past decade. Epidemiological, and clinical data suggest that hyperuricemia may be an independent risk factor as well as a strong predictor of morbidity and mortality in cardiovascular diseases (CVD) and renal diseases. New data suggesting that urate lowering therapies may improve outcomes in cardiovascular diseases have generated interest.Areas Covered: This review attempts to summarize the pathophysiological mechanisms by which hyperuricemia causes cardiorenal dysfunction. It also provides a summary of the recent evidence for urate lowering therapies and the possible underlying mechanisms which lead to cardiovascular benefits. This was a narrative review with essential references or cross references obtained via expert opinion.Expert Opinion: Emphasis on newer drugs that address the cardio-renal metabolic axis and the relation to their effects on uric acid may help further elucidate underlying mechanisms responsible for their cardiovascular and renal benefits. Once these benefits are well established, we will be able to come up with guidelines for targeting hyperuricemia. This can potentially lead to a change in clinical practice and can possibly lead to improved cardiovascular and renal outcomes.

Cardiovascular Safety of Febuxostat and Allopurinol in Hyperuricemic Patients With or Without Gout: A Network Meta-Analysis

Background: Hyperuricemia is a common metabolic disease and has become a public health problem because of its increasing prevalence and association with comorbidities. Allopurinol and febuxostat are recommended as the first-line treatments for hyperuricemia and gout. But cardiovascular safety between febuxostat and allopurinol is still controversial. The purpose of this study is to compare the cardiovascular safety of XOIs and placebo in hyperuricemic patients with or without gout. Methods: PubMed, Embase via OVID, Cochrane Library, CNKI, Wanfang, and VIP were searched from their earliest records to February 8th 2021. ClinicalTrials.gov was also searched for unpublished data. The reference lists of included studies and relevant review articles investigating the cardiovascular safety of XOIs in hyperuricemia patients are screened for potentially eligible studies. Randomized controlled trials (RCTs) evaluating allopurinol (100~900 mg/d), febuxostat (20~120 mg/d), or placebo for hyperuricemia were included. The outcomes were incidence of MACE, non-fatal MI, non-fatal stroke, and cardiovascular death. We conducted a Bayesian random-effects network meta-analysis on the included randomized controlled trials using the Markov Chain Monte Carlo simulation method. The grading of recommendations assessment, development, and evaluation (GRADE) approach was used to assesses the certainty of the evidence. Results: Ten RCTs with 18,004 participants were included. The network estimates showed that there was no significant difference observed among febuxostat, allopurinol, and placebo regarding outcomes. The certainty of the evidence ranged from very low to moderate. The probabilities of rankings and SUCRA showed that compared to placebo, febuxostat, and allopurinol might prevent adverse cardiovascular events. Conclusion: Febuxostat is not associated with increasing risk of adverse cardiovascular events compared to allopurinol; and compared to placebo, whether febuxostat and allopurinol reduce the risk of adverse cardiovascular events remains uncertain.

Cumulative Serum Uric Acid and Its Time Course Are Associated With Risk of Myocardial Infarction and All-Cause Mortality

Background Serum uric acid (SUA) has been demonstrated as a risk factor for myocardial infarction (MI) and all-cause mortality; however, the impact of cumulative SUA (cumSUA) remains unclear. We aimed to investigate the association of cumSUA with MI risk and all-cause mortality, and to further explore the effects of SUA accumulation time course. Methods and Results The study enrolled 53 463 participants without a history of MI, and these participants underwent 3 examinations during 2006 to 2010. cumSUA from baseline to the third examination was calculated, multiplying mean values between consecutive examinations by time intervals between visits. Cox models estimated hazard ratios (HRs) and 95% CIs of MI and all-cause mortality for cumSUA quartiles, hyperuricemia exposure duration, and SUA accumulation time course. During a median follow-up of 7.04 years, 476 incident MIs and 2692 deaths occurred. In the fully adjusted model, a higher MI risk was observed in the highest cumSUA quartile (HR, 1.48; 95% CI, 1.10-1.99), in participants with longer hyperuricemia exposure duration (HR, 1.71; 95% CI, 1.06-2.73), and in participants with cumSUA≥median and a negative slope (HR, 1.58; 95% CI, 1.18-2.11). Similar associations persisted for all-cause mortality. Conclusions The risk of MI and all-cause mortality increased with higher cumSUA and was affected by the SUA accumulation time course. Early SUA accumulation contributed more to MI risk and all-cause mortality than later SUA accumulation with the same overall cumulative exposure, emphasizing the importance of optimal SUA control early in life.

Correlation analysis of low-level serum uric acid and cardiovascular events in patients on peritoneal dialysis

Background

The impact of serum uric acid (SUA) on development of cardiovascular disease (CVD) in patients undergoing peritoneal dialysis (PD) remains controversial, especially the impact of hypouricemia (HUA) on CVD. The aim of our study was to investigate the influence of low-level SUA on cardiovascular (CV) events in PD patients.

Methods

A retrospective cohort study was conducted.728 PD patients from February 1, 2010 to May 31, 2019 were enrolled. All demographic and laboratory data were collected at baseline and 6 months after PD treatment. The study cohort was divided into four groups according to SUA level (μmol/L) after 6 months of PD: Group1 (< 360), Group2 (360–420), Group3 (420–480), Group4 (≥ 480). The clinical characteristics of each group were analyzed. With Group2 as reference, logistic regression analysis was performed to investigate the correlation between SUA levels and risk of CV events in patients undergoing PD. Use Kaplan–Meier method to generate CV events risk graph.

Results

728 patients were enrolled in this study, including 403 (55.4%) males and 325 (44.6%) females, with an average age of 48.66 ± 13.98 years; of which 158 (21.7%) patients developed CV events. Multivariate COX regression showed that after adjusting for multiple clinical factors, Group1 (HR = 1.92, 95% CI 1.17–3.15, P = 0.01), Group3 (HR = 1.89, 95% CI 1.13–3.15, P = 0.015), and Group4 (HR = 2.38, 95% CI 1.35–4.19, P = 0.003) are all independent risk factors for developing CV events. The Kaplan–Meier risk curve of CV events showed that the risk of CV events in the Group1, Group3 and Group4 were significantly higher (Log-Rank = 12.67; P = 0.005). Restricted cubic spline (RCS) showed that SUA level is non-linearly associated with the risk of CV events, showing an U-shaped curve (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\chi_{4}^{2}$$\end{document}χ42=13.3 P = 0.01).

Conclusions

Our study suggested that patients with SUA level less than 360 μmol/L also exhibited the higher risk for developing CV events, an U-shaped association between SUA level and risk of CV events in patients undergoing PD. Both SUA levels below 360 μmol/L and above 420 μmol/L were found to be significant risk factors for developing CV events in patients undergoing long-term PD.

Cardiovascular safety of febuxostat compared to allopurinol for the treatment of gout: A systematic and meta-analysis

The cardiovascular safety of febuxostat compared to allopurinol for the treatment of gout remains equivocal. Febuxostat had a better safety outcome compared with allopurinol. In this systematic review and meta-analysis, we searched MEDLINE and Embase for articles published between March 1, 2000 and April 4, 2021, without any language restrictions. We did a systematic review and meta-analysis of included clinical trials to evaluate the cardiovascular safety of febuxostat compared to allopurinol for treatment of chronic gout. Two reviewers independently selected studies, assessed study quality, and extracted data. Risk ratios were calculated with random effects and were reported with corresponding 95% confidence intervals (CI). From 240 potentially relevant citations, 224 papers were excluded; 16 studies were ultimately included in the analysis. Febuxostat had a better safety outcome compared with allopurinol，which was the composite of urgent coronary revascularization (OR: 0.84, 95% CI: 0.77-0.90, p < .0001) and stroke (OR: 0.87, 95% CI: 0.79-0.97, p = .009). However, that difference was not found in nonfatal myocardial infarction (OR: 0.99, 95% CI: 0.80-1.22, p = .91), cardiovascular related mortality (OR: 0.98, 95% CI: 0.69-1.38, p = .89) and all-cause mortality (OR: 0.93, 95% CI: 0.75-1.15, p = .52). No significant differences in cardiovascular related mortality and all-cause mortality were observed across any subgroup. This meta-analysis adds new evidence regarding the cardiovascular safety of febuxostat in patients. Initiation of febuxostat in patients was not associated with an increased risk of death or serious cardiovascular related adverse events compared with allopurinol.

Gout

Gout is a common and treatable disease caused by the deposition of monosodium urate crystals in articular and non-articular structures. Increased concentration of serum urate (hyperuricaemia) is the most important risk factor for the development of gout. Serum urate is regulated by urate transporters in the kidney and gut, particularly GLUT9 (SLC2A9), URAT1 (SLC22A12), and ABCG2. Activation of the NLRP3 inflammasome by monosodium urate crystals with release of IL-1β plays a major role in the initiation of the gout flare; aggregated neutrophil extracellular traps are important in the resolution phase. Although presenting as an intermittent flaring condition, gout is a chronic disease. Long-term urate lowering therapy (eg, allopurinol) leads to the dissolution of monosodium urate crystals, ultimately resulting in the prevention of gout flares and tophi and in improved quality of life. Strategies such as nurse-led care are effective in delivering high-quality gout care and lead to major improvements in patient outcomes.