The net clinical benefits of febuxostat versus allopurinol in patients with gout or asymptomatic hyperuricemia - A systematic review and meta-analysis

Cardiovascular safety of febuxostat versus allopurinol among the Asian patients with or without gout: A systematic review and meta-analysis

The cardiovascular (CV) safety of febuxostat compared to allopurinol for the treatment of hyperuricemia among Asian patients is uncertain. In this study, we conducted a systematic review and meta-analysis to compare the CV safety profiles of febuxostat with allopurinol in Asian patients with hyperuricemia. A total of 13 studies were included. On the basis of the pooled results of cohort studies, febuxostat users were at a significantly higher risk for acute coronary syndrome (ACS; hazard ratio [HR]: 1.06, 95% confidence interval [CI]: 1.03-1.09, p < 0.01), atrial fibrillation (HR: 1.19, 95% CI: 1.05-1.35, p < 0.01) than allopurinol users, whereas no significant difference between febuxostat and allopurinol existed for urgent coronary revascularization (HR: 1.07, 95% CI: 0.98-1.16, p = 0.13), and stroke (HR: 0.96, 95% CI: 0.91-1.01, p = 0.13). Nevertheless, that difference in results of acute decompensated heart failure (ADHF; HR: 0.73, 95% CI: 0.35-1.53, p = 0.40) and all-cause death (HR = 0.86, 95% CI: 0.49-1.51, p = 0.60) was not significant based on randomized controlled trials. In the Chinese subgroup, febuxostat could increase the risk of ADHF (HR: 1.22, 95% CI: 1.01-1.48, p < 0.05), CV death (HR: 1.25, 95% CI: 1.03-1.50, p < 0.05), and all-cause mortality (HR: 1.07, 95% CI: 1.01-1.14, p < 0.05) compared to allopurinol. In conclusion, the use of febuxostat, compared with allopurinol among Asian patients, was associated with a significantly increased risk of adverse CV events.

Effectiveness and safety of different doses of febuxostat compared with allopurinol in the treatment of hyperuricemia: a meta-analysis of randomized controlled trials

BACKGROUND

The prevalence of hyperuricemia has increased steadily with the continuous improvement of living standards. Some studies have reported the clinical effectiveness and safety of different doses of febuxostat in comparison with allopurinol in hyperuricemia treatment, but the sample sizes of the studies have been small, and the results have been inconsistent. We designed this meta-analysis to evaluate the effectiveness and safety of different doses of febuxostat compared with allopurinol in the treatment of hyperuricemia.

METHODS

The Cochrane Library, Embase, PubMed, Web of Science and ClinicalTrials.gov databases were searched to identify randomized controlled trials (RCTs) comparing the use of febuxostat and allopurinol for the treatment of hyperuricemia. The effectiveness and safety of different doses of febuxostat and allopurinol in treating hyperuricemia were assessed using meta-analysis.

RESULTS

A total of 11 randomized controlled trials were included in the meta-analysis. The results of the meta-analysis showed that the percentage of patients achieving serum uric acid levels of 6.0 mg/dL or less was higher among patients taking febuxostat (80 mg/d) than among patients taking allopurinol (200-300 mg/d) [RR = 1.79, 95% CI (1.55, 2.08), P < 0.00001]. However, there was no statistically significant difference in the percentage of patients achieving serum uric acid levels of 6.0 mg/dL or less between febuxostat (40 mg/d) and allopurinol (200-300 mg/d) [RR = 1.10, 95% CI (0.93, 1.31), P = 0.25]. There was also no statistically significant difference in the incidence of gout between the febuxostat (40 mg/d) and allopurinol (200-300 mg/d) [RR = 0.97, 95% CI (0.64, 1.49), P = 0.91] or between the febuxostat (80 mg/d) and allopurinol (200-300 mg/d) [RR = 1.13, 95% CI (0.81, 1.58), P = 0.48].No significant difference in the incidence of major adverse reactions as observed between the febuxostat (40 mg/d) and allopurinol (200-300 mg/d) [RR = 1.16; 95% CI (0.43, 3.16), P = 0.77] or between the febuxostat (80 mg/d) and allopurinol (200-300 mg/d) [RR = 1.06; 95% CI (0.79, 1.42), P = 0.70]. The incidence of adverse cardiovascular events did not differ significantly between the febuxostat (40 mg/d) and allopurinol (200-300 mg/d) [RR = 1.30; 95% CI (0.57, 2.95), P = 0.53] or between the febuxostat (80 mg/d) and allopurinol (200-300 mg/d) [RR = 1.79; 95% CI (0.74, 4.32), P = 0.20].

CONCLUSIONS

Febuxostat (80 mg/d) was associated with a higher percentage of patients achieving serum uric acid levels of 6.0 mg/dL or less than allopurinol (200-300 mg/d), however, febuxostat (80 mg/d) did not exhibit better efficacy in reducing the incidence of gout. More attention should be devoted to the adverse reactions caused by an increase in febuxostat doses.

Effect of Febuxostat versus Allopurinol on the Glomerular Filtration Rate and Hyperuricemia in Patients with Chronic Kidney Disease

Hyperuricemia is a risk factor for the progression of chronic kidney disease (CKD). We compared febuxostat versus allopurinol in the progression of CKD and hyperuricemia in 101 patients with Stage 3-4 CKD treated with febuxostat or allopurinol for at least 6 months for hyperuricemia (>7 mg/dL) between January 2012 and December 2016. Baseline characteristics, serum uric acid (SUA), serum creatinine, and estimated glomerular filtration rate (eGFR) at entry and 6 months were compared. The primary outcome was the decline in eGFR and the secondary outcomes were reductions in SUA and adverse events. Fifty-four were in the febuxostat group and 47 were in the allopurinol group. The baseline characteristics were comparable except for age. The mean dose of febuxostat and allopurinol was 43.70 ± 14.5 mg and 108.51 ± 40 mg, respectively. After 6 months, the median rate of decline in eGFR was 1.2 mL/min/1.73 m2 (IQR: 1.2, 5.5) in the febuxostat group and 3.1 mL/min/1.73 m2 (0.6, 6.2) in the allopurinol group, but this was not statistically significant (P = 0.136). The mean reduction in SUA was significantly better (P = 0.004) in the febuxostat group (3.9 ± 1.7 mg/dL) compared with the allopurinol group (2.1 ± 1.0 mg/dL). Both drugs had no serious adverse events. Febuxostat was better at reducing hyperuricemia than allopurinol, but there was no significant difference in the progression of CKD. Large randomized trials and long-term follow-up are necessary to see whether febuxostat has a favorable effect on the progression of CKD.

Identification of the Constituents of Ethyl Acetate Fraction from Smilax china L. and Determination of Xanthine Oxidase Inhibitory Properties

The aim of this work was to investigate the xanthine oxidase (XO)-inhibitory activity of ethanol extracts from Smilax china L. and to identify the active compounds in the ethyl acetate (EtOAc) fraction. Extraction of ethanol extracts from Smilax china L. and then ethanol extracts were concentrated, and the polyphenolic compounds were extracted with petroleum ether (PE), chloroform, EtOAc, n-butanol (n-BuOH), and residual ethanol fractions. Their effects on XO activity were then compared separately. The polyphenolic components of the EtOAc fraction were identified by HPLC and HPLC-mass spectrometry (HPLC-MS) analysis. Kinetic analysis demonstrated that all these extracts showed XO-inhibitory properties, and among them the EtOAc fraction had the strongest inhibitory effect (IC₅₀ = 101.04 μg/mL). The inhibitory constant (K_i) of the EtOAc fraction on XO activity was 65.20 μg/mL, showing excellent inhibition on XO in the competitive mode. Sixteen compounds were identified from the EtOAc fraction. The study demonstrates that the EtOAc fraction of Smilax china L. may be a potential functional food to inhibit XO activity.

Effect of febuxostat on adverse events and mortality in gout in Taiwan: An interrupted time series analysis

OBJECTIVES

To evaluate the influence of febuxostat on adverse events and mortality in gout.

METHODS

We retrospectively enrolled patients with newly diagnosed gout and prescribed urate-lowering therapy between 2006 and 2017 from the Taiwan National Health Insurance Database. These patients were divided into 2 groups: with and without comorbidities (n = 294 847 and 194 539). An interrupted time series analysis with adjustments for demographics, comorbidities, and comedication by propensity score-based stabilized weights was used to compare the trend of adverse events and mortality before vs after febuxostat was introduced in 2012.

RESULTS

The proportion of febuxostat use gradually increased from 0% in 2012 to 30% in those with comorbidities and 10% in those without comorbidities in 2017. Allopurinol use decreased from 30% in 2012 to 10% in 2017. The slope of the 1-year incidence rate of Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) (per 10 000 patients) significantly reduced after 2012 in those with and without comorbidities (-0.375 per quarter, P = .015 and -.253 per quarter, P = .049). The slope of the 3-year incidence rate of acute myocardial infarction (AMI) (per 1000 patients), percutaneous coronary intervention (PCI) (per 1000 patients), and all-cause mortality (per 100 patients) significantly increased after 2012 in those with comorbidities (+0.207 per quarter, P = .013; +.389 per quarter, P = .002; +.103 per quarter, P = .001).

CONCLUSIONS

Febuxostat may reduce SJS and TEN in all gout patients but increase AMI, PCI, and all-cause mortality in gout patients with comorbidities.

Hypouricemic and nephroprotective effects of palmatine from Cortex Phellodendri Amurensis: A uric acid modulator targeting Keap1-Nrf2/NLRP3 axis

ETHNOPHARMACOLOGICAL RELEVANCE

Palmatine (Pal) is a major bioactive alkaloid originated from ancient Chinese herbal medicine Cortex Phellodendri Amurensis (CPA), which has long been applied to treat hyperuricemia (HUA)-related diseases. Pal possesses potent anti-inflammatory and anti-oxidant effects against metabolic diseases. However, its potential beneficial effect against PO (potassium oxonate)/HX (hypoxanthine)-induced HUA remains elusive.

AIM OF THE STUDY

This study aimed to investigate the potential pharmacological effect and mechanism of Pal on PO/HX-induced HUA in mice.

MATERIAL AND METHODS

A mouse model of HUA was established by co-administration of PO/HX once daily for 7 consecutive days. The HUA mice were orally given three doses (25, 50 and 100 mg/kg) of Pal daily for a week. Febuxostat (Feb, 5 mg/kg) was given as a positive control. At the scheduled termination of the experiment, the whole blood, liver and kidney were collected for subsequent analyses. The concentrations of uric acid (UA), creatinine (CRE) and blood urea nitrogen (BUN), and activities of adenosine deaminase (ADA) and xanthine oxidase (XOD) were evaluated. Histopathological alterations of the kidney were detected by H&E staining. The inflammatory and oxidative stress status was detected by assay kits. Additionally, key proteins involved in the urate transporter, Keap1-Nrf2 and TXNIP/NLRP3 signaling pathways were evaluated by immunohistochemistry and Western blotting. Finally, molecular docking was employed to probe the binding characteristics of Pal and target proteins Keap1, NLRP3, URAT1 and HO-1.

RESULTS

Administration of Pal substantially decreased the elevated kidney weight, lowered UA, CRE and BUN levels, and attenuated abnormal histopathological alterations. Meanwhile, treatment with Pal also dramatically lowered hepatic XOD and ADA activities. Besides, Pal treatment effectively mitigated the renal inflammatory and oxidative stress markers. Further mechanistic investigation indicated Pal distinctly downregulated the protein levels of GLUT9 and URAT1, while up-regulated the expression levels of OAT1 and ABCG2. Pal also restored Nrf2 activation, promoted subsequent expression of anti-oxidative enzymes, and downregulated the expressions of TXNIP, NLRP3, apoptosis-associated speck-like (ASC), caspase-1, IL-1β and IL-18. Molecular docking analysis also indicated Pal firmly bound with Keap1, NLRP3, URAT1 and HO-1.

CONCLUSIONS

These findings indicated that Pal exhibited favorable anti-HUA effect via modulating the expressions of transporter-related proteins and suppressing XOD activity. Furthermore, Pal also alleviated HUA-induced kidney injury, which was at least partially related to restoring Keap1-Nrf2 pathway and inhibiting TXNIP/NLRP3 inflammasome. Our investigation was envisaged to provide experimental support for the traditional application of CPA and CPA-containing classical herbal formulas in the management of HUA-related diseases and might provide novel dimension to the clinical application of Pal.

Fabrication and In Vitro Evaluation of Febuxostat Tablet for Obtaining Biphasic Drug Release Profile

Aim and Objective The primary aim of the present investigation was to adopt the concept of quality by design (QbD) for developing Febuxostat matrix tablets containing a novel combination of polyethylene oxide (PEO), pre-gelatinized starch (PGS) and lactose for obtaining biphasic drug release. Experimental work Febuxostat-containing matrix tablets were prepared by direct compression using 32 full factorial designs. The tablets were prepared with varying amounts of PEO WSR 301 to PGS and lactose to obtain the desired release pattern. The chosen responses were cumulative % drug released at 1, 6 and 12 hours. The evaluation of tablets was done for pre and post-compressional parameters. Compared with the marketed tablet, the optimized formulations were selected based on in vitro drug release. Dose dumping was checked in the dissolution medium containing up to 40% alcohol. Result and discussion The results of the dissolution study indicated that the batch containing a 1:1 ratio of PEO WSR 301 and PGS (15 mg each) and 20 mg of Lactose showed fast initial drug release to imitate the pharmacological action followed by sustained drug release effect. The use of Lactose facilitated immediate drug release, while PEO WSR 301 and PGS exhibited the opposite effect on cumulative drug release. The results of the 32 Factorial design revealed that the concentration of Lactose is a critical parameter. Dose dumping was not observed in the alcoholic dissolution medium. Kinetic equations were fitted to the dissolution data after 1 hour of the dissolution study. Conclusion The type (soluble or swellable) and the concentration of excipients (low or high) dictate the tablets' drug release. The study's outcome revealed that the most critical material attribute is the amount of lactose. The novel combination of PEO, PGS and lactose can bypass existing patents and give more industrial applicability.

Cardiovascular safety of febuxostat and allopurinol in patients with gout: A meta-analysis

Background: Gout is a common disease and is usually treated with uric acid-lowering drugs (the most commonly used of which are febuxostat and allopurinol). However, the cardiovascular safety of febuxostat and allopurinol is still controversial. The purpose of our study is to evaluate the cardiovascular safety of the two drugs in patients with gout using one-stage and two-stage meta-analysis. Methods: PubMed, Embase, CBM, CNKI, WanFang, Central, and VIP were searched from inception to 30 January 2022. Randomized controlled trials which evaluated the cardiovascular safety of febuxostat or allopurinol for treating patients with gout were included. Based on the Kaplan-Meier curves of the two studies, individual patient data (IPD) were extracted and reconstructed. We used time-varying risk ratios (RRs) to summarize time-to-event outcomes, and the RRs of MACE incidence, cardiovascular mortality, and all-cause mortality were calculated by a multi-level flexible hazard regression model in 1-stage meta-analyses. p values were calculated using a log-rank test. At the same time, using the reconstructed IPD, we performed 2-stage meta-analyses to inform the quantitative estimates of time-specific relative risks at the six time points (1 , 2, 3, 4, 5, and 6 years) based on a random-effects model. Results: Two RCTs with 12,318 participants were included. In the incidence of major adverse cardiovascular events between the two regimens, there was no significant difference [RR = 0.99 (95% CI, 0.89-1.11), p = 0.87]; at the same time, there was no significant difference in cardiovascular mortality [RR = 1.17 (95% CI, 0.98-1.40),p = 0.08] or all-cause mortality [RR = 1.03 (95% CI, 0.91-1.17),p = 0.62]. In terms of 2-stage meta-analyses, there was no significant difference in any outcomes at any time point (moderate-to low-certainty evidence). Conclusion: In patients without atherosclerotic disease, febuxostat likely has a similar cardiovascular profile to allopurinol. However, in patients with a history of cardiovascular disease, allopurinol treatment is associated with less cardiovascular mortality as compared with febuxostat. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/#loginpage, identifier PROSPERO, CRD42022325656.

Efficacy and safety of urate-lowering agents in asymptomatic hyperuricemia: systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Asymptomatic hyperuricemia was found to be associated with increased cardiovascular disease risk but the potential benefits of urate-lowering therapy (ULT) remain controversial. We conducted a systematic review and network meta-analysis (NMA) with frequentist model to estimate the efficacy and safety of ULT in asymptomatic hyperuricemia.

METHODS

MEDLINE, Embase, and Scopus were searched without language restrictions. Randomized controlled trials (RCT) of adults with asymptomatic hyperuricemia were eligible if they compared any pair of ULTs (i.e., allopurinol, febuxostat, probenecid, benzbromarone, sulfinpyrazone, rasburicase, lesinurad, and topiroxostat) and placebo or no ULT, and had outcomes of interest, including composite renal events, major adverse cardiovascular events, serum urate levels, estimated glomerular filtration rate (eGFR), systolic blood pressure, and adverse events.

RESULTS

NMA with frequentist approach was applied to estimate relative treatment effects, i.e., risk ratio (RR) and mean difference (MD). A total of 23 RCTs were eligible. NMA identified beneficial effects of ULT on composite renal events and eGFR but not for other outcomes. Allopurinol and febuxostat had significantly lower composite renal events than placebo (RR 0.39, 95% confidence interval [CI] 0.23 to 0.66, and RR 0.68, 95% CI 0.46 to 0.99, respectively). Both treatments also resulted in significantly higher eGFR than placebo (MD 3.69 ml/min/1.73 m², 95% CI 1.31 to 6.08, and MD 2.89 ml/min/1.73 m², 95% CI 0.69 to 5.09, respectively). No evidence of inconsistency was identified.

CONCLUSIONS

Evidence suggests that allopurinol and febuxostat are the ULTs of choice in reducing composite renal events and improving renal function.

TRIAL REGISTRATION

This study was registered with PROSPERO: CRD42019145908. The date of the first registration was 12^th November 2019.

Effects of uric acid-lowering therapy in patients with essential arterial hypertension

OBJECTIVES

Asymptomatic hyperuricemia (AHU) is elevated serum uric acid (UA) without symptoms. This study aimed to determine the effects of AHU treatment with allopurinol on selected hypertension-mediated organ damage (HMOD) indices in patients with uncomplicated essential arterial hypertension (AH).

METHODS

Patients aged 30-70 years with AHU and AH grade 1-2 with adequate blood pressure (BP) control, without previous urate-lowering therapy (ULT), were divided into two groups: (a) ULT (receiving allopurinol) and (b) control (age- and sex-matched patients without ULT). Both received a UA-lowering diet. BP (office, 24 h and central), echocardiographic parameters, carotid intima-media thickness (IMT) and lab tests [high-sensitivity C-reactive protein (hs-CRP)] were measured at baseline and at 6 months follow-up.

RESULTS

Of 100 participants, 87 (44 ULT, 43 controls) completed the study. At 6 months follow-up, there was a greater reduction in serum UA concentration in the ULT group than in the control group. Patients receiving allopurinol had significant reductions in office systolic and diastolic BP, central systolic BP, pulse pressure, IMT (0.773 ± 0.121 vs. 0.752 ± 0.13 mm, P = 0.044) and hs-CRP (3.36 ± 2.73 vs. 2.74 ± 1.91 mg/L, P = 0.028) compared to controls. Multivariate regression analysis revealed the independent relationship between reduction in IMT and UA lowering (P < 0.026).

CONCLUSION

In patients with AH and AHU, treatment with allopurinol leads to improvement in BP control and reduction in HMOD intensity, in particular IMT. The decrease in hs-CRP concentration associated with ULT may have a beneficial effect on a patient's long-term prognosis.

Hypouricemic, hepatoprotective and nephroprotective roles of oligopeptides derived from Auxis thazard protein in hyperuricemic mice

The oligopeptides derived from Auxis thazard protein (ATO) are a class of small peptides with molecular weight <1 kDa and good bioactivity. This paper aimed to explore the hypouricemic, hepatoprotective, and nephroprotective effects of ATO and its potential mechanisms in hyperuricemia in mice induced by potassium oxonate. The results showed that ATO significantly reduced serum UA, serum creatinine levels, inhibited XOD and ADA activities in the liver (p < 0.05), and accelerated UA excretion by downregulating the gene expression of renal mURAT1 and mGLUT9 and upregulating the gene expression of mABCG2 and mOAT1. ATO could also reduce the levels of liver MDA, increase the activities of SOD and CAT, and reduce the levels of IL-1β, MCP-1 and TNF-α. Histological analysis also showed that ATO possessed hepatoprotective and nephroprotective activities in hyperuricemic mice. Thus, ATO could reduce the serum UA level in hyperuricemic mice by decreasing UA production and promoting UA excretion from the kidney, suggesting that ATO could be developed as a dietary supplement for hyperuricemia treatment.

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.

Serum Uric Acid: A Murderer or Bystander for Cardiac-related Mortality?

In this issue of The Journal of Rheumatology, Colantonio, et al ¹ conducted a case-cohort study from the REGARDS study to evaluate whether the association between serum uric acid (SUA) and sudden cardiac death, and between SUA and incident coronary heart disease (CHD) events, is confounded by SLC2A9 single-nucleotide polymorphisms (SNPs). Incident CHD events were the composites of nonfatal myocardial infarction (MI) or CHD deaths.

Effects of Macroporous Resin Extract of Dendrobium officinale Leaves in Rats with Hyperuricemia Induced by Fructose and Potassium Oxonate

AIM AND OBJECTIVE

Fructose, as a ubiquitous monosaccharide, can promote ATP consumption and elevate circulating uric acid (UA) levels. Our previous studies confirmed that the macroporous resin extract of Dendrobium officinale leaves (DoMRE) could reduce the UA level of rats with hyperuricemia induced by a high-purine diet. This study aimed to investigate whether DoMRE had a UA-lowering effect on rats with hyperuricemia caused by fructose combined with potassium oxonate, so as to further clarify the UA-lowering effect of DoMRE, and to explore the UA-lowering effect of DoMRE on both UA production and excretion.

MATERIALS AND METHODS

Rats with hyperuricemia induced by fructose and potassium oxonate were administered with DoMRE and vehicle control, respectively, to compare the effects of the drugs. At the end of the experiment, the serum uric acid (SUA) and creatinine (Cr) levels were measured using an automatic biochemical analyzer, the activities of xanthine oxidase (XOD) were measured using an assay kit, and the protein expression of urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), and ATP-binding cassette superfamily G member 2 (ABCG2) were assessed using immunohistochemical and western blot analyses. Hematoxylin and eosin staining was used to assess the histological changes in the kidney, liver, and intestine.

RESULTS

Rats with hyperuricemia were induced by fructose and potassiumFructose and potassium induced hyperuricemia in rats. Meanwhile, the activities of XOD were markedly augmented, the expression of URAT1 and GLUT9 was promoted, and the expression of ABCG2 was reduced, which were conducive to the elevation of UA. However, exposure to DoMRE reversed these fructose- and potassium oxonate-induced negative alternations in rats. The activities of XOD were recovered to the normal level, reducing UA formation; the expression of URAT1, ABCG2, and GLUT9 returned to the normal level, resulting in an increase in renal urate excretion.

CONCLUSION

DoMRE reduces UA levels in rats with hyperuricemia induced by fructose combined with potassium oxonate by inhibiting XOD activity and regulating the expression of ABCG2, URAT1, and GLUT9. DoMRE is a potential therapeutic agent for treating hyperuricemia through inhibiting UA formation and promoting UA excretion.

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.

Molecular Dockings and Molecular Dynamics Simulations Reveal the Potency of Different Inhibitors against Xanthine Oxidase

Xanthine oxidase (XO), which can catalyze the formation of xanthine or hypoxanthine to uric acid, is the most important target of gout. To explore the conformational changes for inhibitor binding, molecular dockings and molecular dynamics simulations were performed. Docking results indicated that three inhibitors had similar pose binding to XO. Molecular dynamics simulations showed that the binding of three inhibitors influenced the secondary structure changes in XO. After binding to the inhibitor, the peptide Phe798-Leu814 formed different degrees of unhelix, while for the peptide Glu1065-Ser1075, only a partial helix region was formed when allopurinol was bound. Through the protein structure analysis in the simulation process, we found that the distance between the active residues Arg880 and Thr1010 was reduced and the distance between Glu802 and Thr1010 was increased after the addition of inhibitors. The above simulation results showed the similarities and differences of the interaction between the three inhibitors binding to the protein. MM-PBSA calculations suggested that, among three inhibitors, allopurinol had the best binding effect with XO followed by daidzin and puerarin. This finding was consistent with previous experimental data. Our results can provide some useful clues for further gout treatment research.

Xanthine oxidase inhibitory activity and antihyperuricemic effect of Moringa oleifera Lam. leaf hydrolysate rich in phenolics and peptides

ETHNOPHARMACOLOGICAL RELEVANCE

Moringa oleifera Lam. leaf (MOL), a rich source of protein and phenolics, was traditionally used to treat various diseases including headaches, fevers, sore throat and dyslipidemia. Recently, MOL was reported to possess antioxidant, anti-dyslipidemia and hepato-renal protective activities, indicating that MOL could become a potential agent to improve metabolic disorders associated with hyperuricemia. The antihyperuricemic effect of MOL hydrolysate (MOLH) with high contents of phenolics and peptides remains unknown.

AIM OF THE STUDY

The aim of this study is to investigate xanthine oxidase (XO) inhibitory activity of MOLH, to clarify phenolic and peptide profiles of MOLH, and to evaluate possible mechanism underlying the antihyperuricemic effect of MOLH.

MATERIALS AND METHODS

MOLH was prepared by enzymatic hydrolysis using commercial trypsin. XO inhibitory activity was determined by XO reaction-UPLC-MS coupling method. The chemical profiles of the phenolic and peptide fractions of MOLH were determined by UPLC-QTOF-MS/MS. The antihyperuricemic effect of MOLH was evaluated in a potassium oxonate-induced hyperuricemic rat model at doses of 200 and 500 mg/kg. Serum uric acid (UA), urea nitrogen, creatinine (CRE), triglyceride (TG), total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol levels, serum XO activity, liver malondialdehyde (MDA) equivalent level, renal tumor necrosis factor-α and interleukin-1β levels, and protein expression of renal urate-anion transporter 1, glucose transporter 9 and ATP-binding cassette transporter G2 were determined.

RESULTS

The phenolic and peptide fractions played key roles in inhibiting XO activity and blocking uric acid production. Five flavonoids and sixteen polypeptides were identified in the phenolic and peptide fractions of MOLH, respectively. MOLH (200 and 500 mg/kg) could effectively reduce the serum UA level of hyperuricemic rats (p < 0.001) by regulation of serum XO activity (p < 0.05 at 200 mg/kg, p < 0.01 at 500 mg/kg) and renal urate transporters. Besides, MOLH could improve metabolic disorders associated with hyperuricemia by its multiple actions on liver MDA (p < 0.001), serum CRE (p < 0.05 at 500 mg/kg) and serum TG (p < 0.001).

CONCLUSION

The results provided scientific evidence that MOLH rich in phenolics and peptides ameliorated hyperuricemia and metabolic disorders. This study validated the potential use of MOLH for regulation of hyperuricemia.

Elevated serum uric acid is associated with incident hypertension in the health according to various contemporary blood pressure guidelines

BACKGROUND AND AIMS

Elevated serum uric acid (SUA) is associated with hypertension according to its traditional definition. We investigated the association between SUA and incident hypertension according to the European Society of Cardiology (ESC) and American Society of Cardiology (ACC) guidelines.

METHODS AND RESULTS

In this retrospective cohort study, we enrolled 10,537 healthy individuals ≥30 years old who underwent a routine annual health examination with office blood pressure recorded at our hospital in 2016; of the participants, 7349 repeated the exam in 2017. According to the ESC and ACC guidelines, hypertension was defined as office BP ≥ 140/90 mmHg or ≥130/80 mmHg. Hyperuricemia (HUA) was defined as SUA ≥7 mg/dL in men and ≥6 mg/dL in women. The hypertension incidence was 5.8% among 6378 individuals in the ESC cohort and 19% among 4330 individuals in the ACC cohort. Incident hypertension was significantly more common in the hyperuricemic group than in the normouricemic group (ESC: 8.6% vs. 4.7%, P < 0.001; ACC: 25.5% vs. 16.9%, P < 0.001). In the fully adjusted multivariate logistic regression analyses, each increase in SUA was associated with an increase in incident hypertension risk (ESC: adjusted OR: 1.167, 95% CI: 1.061-1.284, P = 0.001; ACC: adjusted OR: 1.125, 95% CI: 1.044-1.213, P = 0.002). The association can be explained by a significant correlation of baseline SUA with the BP in the following year (r = 0.24, P < 0.001 for baseline SUA and SBP in the following year; r = 0.239, P < 0.001 for baseline SUA and DBP in the following year).

CONCLUSION

Elevated SUA was associated with incident hypertension in healthy individuals according to various contemporary BP guidelines (ClinicalTrials.gov: NCT03473951).

CLINICAL TRIALS

ClinicalTrials.gov with the identification number of NCT03473951.

Is Febuxostat Use Associated With Increased Risk of Cardiovascular Disease Events? The Answer Is Crystal Clear

Gout is the most common inflammatory arthritis1, historically poorly managed, and is arguably the only one of the inflammatory arthritides that is curable with appropriate urate-lowering therapy (ULT)2. Whereas febuxostat has been shown to be a more effective ULT3, allopurinol has been the cornerstone of treatment for decades; however, allopurinol is problematic in the elderly, those with renal impairment, and those who carry the HLA-B*5801 antigen who are primarily of Asian origin.

Therapeutic Strategies for the Treatment of Chronic Hyperuricemia: An Evidence-Based Update

This article aims to critically review the evidence on the available therapeutic strategies for the treatment of hyperuricemia. For this reason, several papers were reviewed. Xanthine oxidase inhibitors are the safest and most effective uric acid lowering drugs for the management of chronic hyperuricemia, while the efficacy of uricosuric agents is strongly modulated by pharmacogenetics. Emergent drugs (lesinurad, peglotidase) were found to be more effective for the acute management of refractory hyperuricemia, but their use is supported by a relatively small number of clinical trials so that further well-designed clinical research is needed to deepen their efficacy and safety profile.

Clinical Effects of Xanthine Oxidase Inhibitors in Hyperuricemic Patients

This review aims to critically present the available clinical evidence supporting the treatment of chronic hyperuricemia with xanthine oxidase inhibitors. For this reason, the studies published on uric acid (UA)-lowering drugs in the English language from 2000 to August 2019 have been carefully reviewed. The terms "serum uric acid," "xanthine oxidase," "allopurinol," "febuxostat," and "topiroxostat" were incorporated into an electronic search strategy, alone and in combinations, in both MEDLINE (National Library of Medicine, Bethesda, MD) and the Cochrane Register of Controlled Trials (The Cochrane Collaboration, Oxford, UK). Even if new urate-lowering drugs seem of particular efficacy for acute treatment of refractory hyperuricemia, their use is supported by relatively small clinical evidence. On the contrary, large long-term clinical trials have demonstrated that xanthine oxidase inhibitors (XOIs, namely, allopurinol and febuxostat) are effective, safe, and relatively well-tolerated in most of the patients. They have mainly been tested in the elderly, in patients affected by chronic diseases such as heart failure and cancer, and in patients taking a large number of drugs, confirming their safety profile. Recent data also show that they could exert some positive effects on vascular health, renal function, and glucose metabolism. Their cost is also low. In conclusion, XOIs remain the first choice of UA-lowering drug for chronic treatment.

Febuxostat Attenuates the Induction of Vascular Cell Adhesion Protein 1 by TNF-α in Human Umbilical Vein Endothelial Cells

In a randomized trial, higher all-cause and cardiovascular mortality was observed in treatment with febuxostat than with allopurinol in patients with coexisting gout and serious cardiovascular conditions. In this study, we focus on an intervention of febuxostat or allopurinol as an anti-inflammatory treatment to reduce the transcription of nuclear factor-kappa B (NF-κB) and production of relevant inflammatory factors. We evaluated the effect of febuxostat on vascular cell adhesion protein 1 (VCAM-1) induction in cultured human umbilical vein endothelial cells (HUVECs). Cells were exposed to tumor necrosis factor (TNF)-α (10 ng/mL) treatment for 24 h. Febuxostat or allopurinol (0.1–100 μM) was added to the bath medium 15 min before TNF-α treatment. VCAM-1 levels in HUVECs increased after 24-h TNF-α treatment (<i>n</i> = 4). Febuxostat and allopurinol significantly suppressed VCAM-1 induced by treatment with TNF-α in a dose-dependent manner (<i>p</i> &#x3c; 0.05, <i>n</i> = 4). Furthermore, these drugs suppressed the NF-κB protein levels in the nucleus 4 h after TNF-α treatment (<i>n</i> = 3 or 4). Our results suggest that TNF-α induces VCAM-1 production via NF-κB, which can be blocked by febuxostat or allopurinol. The effect of febuxostat treatment on cardiovascular events may be associated with protection against the infiltration of lymphocytes or monocytes through VCAM-1 induction in inflamed endothelial cells such as arterial sclerosis.

Serum Uric Acid may be Associated with Left Ventricular Diastolic Dysfunction in Military Individuals

INTRODUCTION

We investigated the correlation and association between serum uric acid (SUA) and left ventricular diastolic dysfunction (LVDD) criteria in military individuals.

MATERIAL AND METHODS

We prospectively enrolled military individuals who visited our hospital for evaluation of electrocardiographic abnormalities detected at an annual health exam between January 1, 2018 and December 31, 2019. Hyperuricemia was defined as an SUA level ≥7 mg/dL in men and ≥6 mg/dL in women. The definitions of LVDD criteria and LV hypertrophy were according to contemporary echocardiographic guidelines.

RESULTS

The study included 268 individuals (89% male), with a mean age of 32.9 ± 7.6 years and SUA of 6.1 ± 1.3 mg/dL. The hyperuricemic (n = 74) and normouricemic (n = 194) groups had no significant differences in lifestyle choices and baseline characteristics. Serum uric acid correlated weakly with heart size parameters (r = 0.354, P < .001 for left atrial diameter and r = 0.146, P = .017 for left ventricular mass index (LVMI) and average E/e' >14 (r = 0.204, P = .001). The hyperuricemic group had higher LVMI (87.6 g/m2 vs. 81.8 g/m2, P = .022), septal e' velocity <7 cm/s (14.9% vs. 5.2%, P = .019), lateral e' velocity <10 cm/s (27.0% vs. 11.3%, P = .003), and average E/e' >14 (4.1% vs. 0%, P = .020) values than the normouricemic group. In multivariate logistic regression analyses, SUA was significantly associated with septal e' velocity <7 cm/s (adjusted HR: 2.398; 95% CI, 1.427-4.030; P = .001).

CONCLUSION

Elevated SUA was significantly associated with the presence of LVDD criteria, namely, septal e' velocity <7, in military individuals. Maintaining SUA levels within normal limits may prevent the development of LVDD.

The Association of Febuxostat Compared With Allopurinol on Blood Pressure and Major Adverse Cardiac Events Among Adult Patients With Hyperuricemia: A Meta-analysis

Increased uric acid levels have been known to be associated with different cardiovascular and renal diseases. Over the past few years, several studies have examined the role of urate-lowering therapy (ULT) in hypertension and major adverse cardiac events (MACE) and suggest a potential role of elevated serum uric acid as an independent cardiovascular risk factor. This meta-analysis was done to determine the association of 2 ULTs commonly used in clinical practice (febuxostat vs. allopurinol) on hypertension and MACE and resolve the conflicting results of the outcomes of earlier studies. Randomized controlled trials comparing febuxostat versus allopurinol published with outcomes on blood pressure, all-cause mortality, myocardial infarction (MI), and stroke were searched through PubMed, Google Scholar, and Cochrane database. A total of 10 studies were subsequently included in the meta-analysis. Pooled analysis of the mean differences (MD) were done for the outcomes on blood pressure (systolic and diastolic) and risk ratios (RRs) for the outcomes on MACE with corresponding 95% confidence intervals (CIs). Pooled analysis of studies on hyperuricemic patients showed that febuxostat 40 mg has no significant difference compared with allopurinol 100/300 mg with respect to diastolic (MD, -0.56 with 95% CI of -4.28 to 3.15) and systolic blood pressure (MD, 0.30 with 95% CI of -3.33 to 3.93). No significant differences were also noted on all-cause mortality (RR, 1.18 with 95% CI of 0.99-1.41), MI (RR, 0.92 with 95% CI of 0.72-1.18), and stroke (RR, 1.05 with 95% CI of 0.77-1.43). The results of this meta-analysis showed that the 2 ULTs (febuxostat vs. allopurinol) have no significant association with respect to blood pressure among adult patients with hyperuricemia. No significant association was also noted of either ULT with all-cause mortality, MI, and stroke.

Management of hyperuricemia in asymptomatic patients: A critical appraisal

While there is consensus on starting urate-lowering therapy (ULT) in cases of symptomatic hyperuricemia, the frequent condition of asymptomatic hyperuricemia (AH) remains a challenge due to differences in the findings of studies that have addressed the issue. Uric acid has anti-oxidant properties, but high levels predispose to gout and may play a role in metabolic syndrome. We systematically evaluated randomized controlled trials (RCTs) addressing ULT in patients with AH, to assess the current evidence. We found broad heterogeneity among the studies (13 RCTs), in terms of study design and population, making findings challenging to interpret and generalize; hard end-points were not assessed. Allopurinol is often prescribed for AH despite the fact that its use is not backed by conclusive evidence from prospective RCTs, nor is it recommended by the guidelines. Its potential benefits, in terms of absolute risk reduction, must be weighed against its potential for harm since it can trigger severe adverse hypersensitivity reactions, sometimes even fatal. RCTs with hard end-points are needed to assess the risk/benefit of lowering uric acid in subjects with AH, particularly as secondary prevention for cardiovascular risk and in patients with different degrees of renal disease. To date, particularly after the result from the CARES trial, preventive treatment of asymptomatic and non-severe hyperuricemia is not recommended.

Construction and expression of recombinant uricase‑expressing genetically engineered bacteria and its application in rat model of hyperuricemia

At present, the treatment of hyperuricemia is designed primarily to decrease the production of uric acid using xanthine oxidase inhibitors; however, the therapeutic effect is not satisfactory. Therefore, the key to the successful treatment of hyperuricemia is to increase the excretion of uric acid. The aim of present study was to construct uricase-expressing genetically engineered bacteria and analyze the effects of these engineered bacteria on the lowering of uric acid levels in a rat model of hyperuricemia. The uricase expression vector was constructed by gene recombination technology and transfected into Escherichia coli. The expression and activity of uricase were analyzed by SDS-PAGE analysis and Bradford assay. The water consumption, food intake, body weight, eosinophil count and intestinal histology, in addition to the levels of serum uric acid (SUA) and allantoin in the feces of the rats, were assessed. The intestinal contents of the rats were analyzed by 16S rDNA sequencing technology. The results demonstrated that uricase-expressing genetically engineered bacteria secreted active uricase. All rats exhibited a natural growth trend during the entire experiment, and the SUA of hyperuricemic rats treated with uricase-expressing engineered bacteria was significantly decreased. In conclusion, these results indicate that uricase secreted by recombinant uricase-expressing genetically engineered bacteria served an important role in decreasing SUA levels in a rat model of hyperuricemia.

Patent highlights, August-September 2019

A snapshot of recent noteworthy developments in the patent literature of relevance to pharmaceutical and medical research and development.

Spectrum and dosing of urate-lowering drugs in a large cohort of chronic kidney disease patients and their effect on serum urate levels: a cross-sectional analysis from the German Chronic Kidney Disease study

Background

Despite a plethora of studies on the effect of urate-lowering therapy (ULT) in patients with chronic kidney disease (CKD), current guidelines on the treatment of hyperuricaemia and gout vary, especially concerning the need for dose adjustment of allopurinol, whose main metabolite is accumulating with declining renal function. Data on allopurinol dosing and its relationship to renal function, co-medication and sex and the resulting urate level in large cohorts are missing.

Methods

We studied a subgroup of 2378 patients of the German Chronic Kidney Disease (GCKD) study to determine prescription patterns of ULT among CKD patients under nephrological care and the relationship of ULT dose to urate levels. Prescription and dosing of ULT were manually abstracted from the patient’s paper charts at the baseline visit, in which all currently used medications and their dosing were recorded.

Results

In this cohort, 39.6% were women, the mean estimated glomerular filtration rate (eGFR) was 51.3 ± 19.3 mL/min/1.73 m² and the mean age was 59.0 ± 12.4 years. Of the 2378 examined patients, 666 (28.0%) received ULT. The dose of ULT was available for 572 patients. The main ULT agent was allopurinol (94.4%), followed by febuxostat (2.9%) and benzbromarone (2.6%). Of the 540 patients who used allopurinol with a reported daily dose, 480 had an eGFR <60 mL/min/1.73 m² and 320 had an eGFR <45 mL/min/1.73 m², 31.5% of the latter (n = 101) received a dose >150 mg/day, the recommended maximal dose for this level of eGFR. The prescribed dose was not related to eGFR: the median eGFR for patients taking 100, 150 and 300 mg/day was 40 [interquartile range (IQR) 32–49], 43 (34–52) and 42 (35–54) mL/min/1.73 m², respectively. Patients with lower doses of allopurinol had higher serum urate levels than patients with higher (than recommended) allopurinol doses. Sex, alcohol intake, eGFR, use of diuretics and treatment with allopurinol were independent determinants of serum urate levels in multivariate regression analysis.

Conclusions

The most frequently used drug to lower serum urate levels in this CKD cohort was allopurinol. Even in patients regularly seen by nephrologists, the dose of allopurinol is often not adjusted to the current eGFR. Patients with higher ULT doses achieved better control of their serum urate levels. Lowering of serum urate in CKD patients requires balancing potential adverse effects of allopurinol with suboptimal control of serum urate levels.