Comparative effect of allopurinol and febuxostat on long-term renal outcomes in patients with hyperuricemia and chronic kidney disease: a systematic review

The efficacy of a low-dose combination of febuxostat and benzbromarone versus each drug used alone for the treatment of gout

Objective

The study focuses on comparing the efficacy of a low-dose combination of febuxostat and benzbromarone versus each drug used alone for the treatment of gout.

Methods

A prospective, randomized, open-labeled trial of men with gout and renal uric acid underexcretion was conducted. We randomly assigned 100 patients to either low-dose febuxostat or low-dose benzbromarone for initial treatment. 43 patients with complete data were analyzed in this study. The analysis of medication Treatment effects, Period effects and Patient-Within-Sequence effects for different treatment options was performed by cross-test ANOVA.

Result

The cross-trial analysis revealed no significant differences in the magnitude of uric acid decline among the three groups after treatment. Similarly, there were no statistically significant differences in blood lipid levels, CRP, CA724, eGFR, and ALT among the three groups post-treatment. The null model without participant-specific benefits was a linear mixed model for ALT, AST, eGFR, TC, TG, LDL, UA, CRP, CA724, and 24-h uric acid with age, BMI, treatment period and treatment as fixed factors, and the intercept as a random factor by participant. The results indicated no significant differences on relevant indicators among the three treatment regimens.

Conclusion

Our study did not identify a difference in the efficacy of reducing uric acid excretion in gout patients when comparing conventional dose febuxostat and benzbromarone monotherapy versus low-dose combination therapy.

Analysis of the efficacy of multidisciplinary integration based on 3D reconstruction technology for the treatment of gout stone

OBJECTIVE

This study investigates the efficacy of multidisciplinary fusion therapy based on 3D reconstruction technology for the treatment of gouty stone by comparing the efficacy of multidisciplinary fusion therapy with pharmacologic therapy.

METHODS

This study is a cohort study.Patients who underwent gout stone surgery at the Affiliated Hospital of Qingdao University from November 2020 to November 2022 were included in this study, totaling 85 to form the MDT surgery group, and matched among gout stone patients in the outpatient clinic during the same period to form the medication group. Patients in the 2 groups were followed up for 6 months to compare baseline and follow-up data.

RESULTS

Both groups experienced a decrease in uric acid levels and an increase in SF-36 scores during follow-up. After adjusting for confounders, multifactorial logistic regression showed that the uric acid attainment rate of patients in the MDT surgery group was 4.011 times higher than that of the drug group (OR: 4.011, 95% CI: 1.595, 10.086, P = 0.003); the proportion of patients with an increase in SF-36 in the MDT surgery group was 4.976 times higher than that of the drug group (OR: 4.976, 95% CI: 2.243, 11.040, P < 0.001); the proportion of patients treated with high-dose medication in the MDT surgery group was 1.8% of that of patients in the drug group (OR: 0.018, 95% CI: 0.002, 0.148, P < 0.001); and the proportion of patients in the MDT surgery group who developed frequent gout was 2.8% of that in the drug group (OR: 0.028 95% CI: 0.003, 0.2398, P = 0.001). the proportion of patients in the MDT surgery group who developed abnormal liver function was 0.317 times higher than that in the drug group (OR: 0.317, 95% CI: 0.121, 0.831, P = 0.019).

CONCLUSION

The multidisciplinary integration of 3D reconstructive techniques for gout stone treatment resulted in an increase in uric acid compliance, a decrease in the frequency of gout and the appearance of liver impairment; and a greater benefit in terms of improvement in the quality of life of the patients after treatment.

Bibliometric and visual assessment of research trends in the management of hyperuricemia (HUA)

OBJECTIVE

To analyze the development status and trend of related research in the health management of hyperuricemia and provide a theoretical basis for clinical treatment.

METHODS

A bibliometric analysis was conducted on hyperuricemia health management research data from 2000 to 2024 using the Web Science Core Collection database, PubMed, and SINOMED. A total of 789 articles were evaluated for specific characteristics, such as year of publication, journal, author, institution, country/region, reference, and keyword. The VOSviewer was used for co-author, co-occurrence, co-citation, and network visualization. Important sub-topics identified by bibliometric characteristics were discussed and reviewed.

RESULTS

The number of articles published in the last 24 years has generally followed a year-on-year trend, and the total number of papers published is increasing. Over 200 affiliations from 70 countries and regions contributed papers, and PLOS ONE has the highest number of linked publications. Dalbeth N, is the author with the most publications, with an H-index of 17. Hyperuricemia, gout, management, prevalence, allopurinol, risk, and other keywords were often used. Researchers formed mature teams, and the teams' study directions intersect and are comparable. However, these teams demonstrated a lack of communication and coordination.

CONCLUSIONS

This study highlights research hotspots, global cooperation models, and emerging frontiers in hyperuricemia, focusing on uric acid control, disease screening, health education, and epidemiological investigation in hyperuricemia-associated complications over the past two decades. However, there is still a lack of standardized management processes and systems, and the communication between research teams needs to be enhanced. Key Points • The study analyzed hyperuricemia health management research data from 2000 to 2024 using the Web Science Core Collection database, PubMed, and SINOMED, evaluating 789 articles and discussing key sub-topics using VOSviewer. • Over 200 articles from 70 countries, including PLOS ONE, have been published over the past 24 years, focusing on hyperuricemia, gout, management, prevalence, allopurinol risk, etc. • Our study outlines research hotspots, global cooperation models, and emerging hyperuricemia frontiers, emphasizing the need for standardized management processes and improved communication between research teams.

Comparison of the therapeutic effects of febuxostat combined with a low-purine diet and allopurinol combined with a low-purine diet on the improvement of gout patients

OBJECTIVE

To compare the clinical efficacy of febuxostat combined with a low-purine diet versus allopurinol combined with a low-purine diet in the treatment of gout.

METHODS

In this prospective controlled trial, 98 gout patients admitted to our hospital from February 2021 to December 2022 were enrolled as study subjects. Patients were randomly assigned to the study group (febuxostat combined with a low-purine diet) and the control group (allopurinol combined with a low-purine diet), with 49 patients in each group. The therapeutic effect was evaluated based on joint function and serum uric acid levels after treatment, and classified into three levels: markedly effective, effective, and ineffective. The levels of inflammatory factors, including tumor necrosis factor-a (TNF-a), cytokine interleukin-1beta (IL-1β), and interleukin (IL)-18 (IL-18), were collected. The Numeric Rating Scale (NRS) was used to assess the degree of pain in patients. Clinical indicators before and 6 months after treatment were compared between the two groups.

RESULTS

There was no statistically significant difference in age and gender between the two groups. After 6 months of treatment, the effective rate in the study group (48 cases, 97.96%) was higher than that in the control group (42 cases, 85.71%), with a statistically significant difference (p = .027). At the same time, the study group had significantly lower levels of serum uric acid (162.39 μmol/L ± 17.23 μmol/L vs. S198.32 μmol/L ± 18.34 μmol/L, p < .001), creatinine (87.39 mmol/L ± 9.76 mmol/L vs. 92.18 mmol/L ± 9.27 mmol/L, p = .014), total cholesterol (3.65 mmol/L ± 0.65 mmol/L vs. 4.76 mmol/L ± 0.73 mmol/L, p < .001), and triglycerides (1.76 mmol/L ± 0.32 mmol/L vs. 2.28 mmol/L ± 0.41 mmol/L, p < .001) compared to the control group, with statistically significant differences (p < .05). After treatment, the levels of inflammatory factors and degree of pain in the study group were significantly lower than those in the control group (all p < .05). During the treatment process, the incidence of adverse reactions in the study group (2 cases, 4.08%) was lower than that in the control group (9 cases, 18.37%), with a statistically significant difference (p = .025).

CONCLUSION

Febuxostat combined with a low-purine diet can reduce inflammatory factors and alleviate the degree of pain in gout patients, significantly improving their clinical symptoms.

Timing of Initiation of Xanthine Oxidase Inhibitors Based on Serum Uric Acid Level Does Not Predict Renoprognosis in Patients with Preserved Kidney Function

Background: Despite recent evidence of remaining possibility that early initiation of xanthine oxidase inhibitors (XOIs) is beneficial in renoprognosis for patients with stage 2 or less chronic kidney disease (CKD), no evidence is available regarding the difference in renoprognosis based on serum uric acid (sUA) levels at the initiation of XOIs among patients with preserved kidney function. Methods: New XOI initiators were divided into quartiles based on baseline sUA. Primary outcome was the composite incidence of a significant estimated glomerular filtration rate (eGFR) decline (≥40% decline in eGFR from baseline or development of eGFR <30 mL/1.73 m2/min) or all-cause death within 5 years. Results: After excluding inapplicable patients, 1170 XOI initiators were analyzed (mean ± standard deviation age: 68 ± 14.3 years; sUA: 10.6 ± 1.15 mg/dL). On overall median [interquartile range (IQR)] follow-up of 824 (342, 1576) days, incidence rate of the primary outcome was 287 per 1000 person-years for 5 years. Although the nonadjusted model showed a dose-response association between baseline sUA level and the outcome, the adjusted model showed no significant association. Adjusted hazard ratios (95% confidence interval) of the second, third, and fourth quartiles of baseline sUA with the composite outcome within 5 years compared to the first quartile were 1.00 (0.78, 1.29), 1.00 (0.80, 1.30), and 1.02 (0.80, 1.32), respectively. Conclusions: Early initiation of XOIs did not predict a significant benefit on renoprognosis even among the population with preserved kidney function. The validity of initiating XOIs with the aim of improving renoprognosis based on sUA is questionable.

Using intravoxel incoherent motion imaging to evaluate uric acid-induced renal injury and efficacy after treatment

OBJECTIVES

To validate the feasibility of intravoxel incoherent motion imaging (IVIM) for monitoring renal injury and uric acid-lowering efficacy in a rat model of hyperuricaemia.

METHODS

A total of 92 rats were analysed and categorized into 4 groups: control (CON), hyperuricaemia (HUA), allopurinol intervention (ALL), and combined intervention (COM). Eight rats were randomly selected from each group and underwent IVIM scanning on days 0, 1, 3, 5, 7, and 9. Quantitative magnetic resonance values (D, D*, and f values) measured from the different renal anatomical regions. Quantitative histopathological analysis was performed to assess renal tubular injury using neutrophil gelatinase-associated lipocalin (NGAL), and renal fibrosis using alpha-smooth-muscle-actin (α-SMA). Pearson's correlation analysis was used to determine the correlation between IVIM-derived parameters and the expression of NGAL and α-SMA.

RESULTS

The D values of the HUA, ALL, and COM groups generally showed a downward trend over time, and this fluctuation was most significant in the HUA group. The D values showed significant intergroup differences at each point, whereas only a few discrepancies were found in the D* and f values. In addition, the renal D value was negatively correlated with the positive staining rates for NGAL and α-SMA (P < .05), except for the lack of correlation between Dos and α-SMA (P > .05).

CONCLUSION

IVIM could be a noninvasive and potential assessment modality for the evaluation of renal injury induced by hyperuricaemia and its prognostic efficacy.

ADVANCES IN KNOWLEDGE

IVIM could be a surrogate manner in monitoring renal damage induced by hyperuricaemia and its treatment evaluation.

Gout therapeutics and drug delivery

Gout is a common inflammatory arthritis caused by persistently elevated uric acid levels. With the improvement of people's living standards, the consumption of processed food and the widespread use of drugs that induce elevated uric acid, gout rates are increasing, seriously affecting the human quality of life, and becoming a burden to health systems worldwide. Since the pathological mechanism of gout has been elucidated, there are relatively effective drug treatments in clinical practice. However, due to (bio)pharmaceutical shortcomings of these drugs, such as poor chemical stability and limited ability to target the pathophysiological pathways, traditional drug treatment strategies show low efficacy and safety. In this scenario, drug delivery systems (DDS) design that overcome these drawbacks is urgently called for. In this review, we initially describe the pathological features, the therapeutic targets, and the drugs currently in clinical use and under investigation to treat gout. We also comprehensively summarize recent research efforts utilizing lipid, polymeric and inorganic carriers to develop advanced DDS for improved gout management and therapy.

The Stiff Joint: Comparative Evaluation of Monotherapy and Combination Therapy With Urate Lowering Agents in Managing Acute Gout

Gout, an extremely painful form of arthritis, is triggered by the innate immune system's response to the accumulation of monosodium urate crystals in specific joints and surrounding tissues. This condition is characterized by recurring episodes of excruciating arthritis flares, interspersed with periods of disease quiescence. Over time, gout can result in disability, tophi formation, and severe pain. The treatment of gout is centered around two main objectives: alleviating inflammation and pain during acute gout attacks and long-term management to reduce serum urate levels and mitigate the risk of future attacks. Addressing inflammation and pain during acute attacks is often complicated by various factors, including underlying health conditions commonly associated with gout, such as hypertension, chronic kidney disease, cardiovascular disease, and diabetes mellitus. Moreover, gout patients are frequently older and have multiple coexisting health issues, necessitating complex medication regimens. Given the rising prevalence of gout and its associated comorbidities, there's a growing demand for improved treatment options. While existing treatments effectively manage gout in some patients, a significant portion, particularly those with comorbidities, face contraindications to these treatments and require alternative approaches. Innovative medications are required to enhance gout treatment, especially for individuals with concurrent health conditions. These considerations underscore the importance of reviewing both monotherapy and combination therapy approaches for acute gout treatment.

Therapeutics in rheumatology and the kidney

The field of rheumatology has advanced significantly in recent years to provide rheumatologists with an extensive array of medications to combat rheumatic joint conditions. In contrast to an older era, when NSAIDs and other nephrotoxic agents were the mainstay of treatment, modern DMARDs vary considerably in their nephrotoxic potential and their use is not always precluded in populations with pre-existing chronic kidney disease (CKD). This review will explore in detail the safety and efficacy profiles of medications used to treat rheumatologic disease, specifically in the setting of CKD. Specifically, we discuss both traditional agents used, i.e. NSAIDs, CSs and conventional synthetic DMARDs, as well as novel biologic DMARDs and targeted synthetic DMARDs. Anti-gout prescribing in CKD is also reviewed. We aim to provide practical guidance to rheumatologists, nephrologists and general physicians when prescribing these medications in the setting of CKD.

Association of hyperuricemia with cardiovascular diseases: current evidence

The aim of the present study is to present a historical and unified perspective on the association of serum uric acid (SUA) in the cause of cardiovascular diseases (CVDs). The association of hyperuricemia (HUC) with CVD begun to be appreciated in the middle 1950s and early 1990s when clinical evidence was shown on the association of HUC with CVD. However, this association was disputed by several investigators including the Framingham group and by professional societies, like the American Heart Association and the American Society of Hypertension. This dispute was weakened or reversed by later studies, which showed a positive association of HUC with CVD, CHD, HF, CKD, and stroke, mediated by several risk factors, both molecular such as, oxidative stress, inflammatory stress, insulin resistance, and endothelial dysfunction, as well as clinical factors such as, atherosclerosis, hypertension, metabolic syndrome, and type 2 diabetes mellitus. The great majority of recent studies show a positive association of HUC with CVDs, and CKD. However, the cutoff of the damaging levels of SUA have not been established as yet. The European Society of Hypertension (ESH) Treatment Guidelines have proposed a cutoff level of SUA for CVD > 7 mg/dl for men and > 6 mg/dl for women. In contrast, the URRAH study has shown a SUA level of 4.7 mg/dl for all-cause mortality and 5.6 mg/dl for CV mortality. These levels are lower than the SUA levels proposed by the ESH, which are consistent with HUC. For a better understanding of this association, a Medline search of the English literature was conducted between 2015 and 2022 and 44 pertinent papers were selected. These papers together with collateral literature will be discussed in this review.

Risk factors and management of hyperuricemia after renal transplantation

Hyperuricemia (HUA) is a common complication after renal transplantation. Currently, there is no uniform consensus on factors which increase the risk for and treatment of HUA in renal transplant recipients. The purpose of this review is to summarize current and proposed risk factors and strategies to manage HUA after renal transplantation in order to assist renal function protection and prolong graft survival time.

Febuxostat Improves Uric Acid Levels and Renal Function in Patients with Chronic Kidney Disease and Hyperuricemia: A Meta-Analysis

Background. Uric acid nephropathy, also known as hyperuricemia nephropathy or gouty nephropathy, is characterized by uric acid crystal deposition and inflammatory cell infiltration. Herein, we aimed to demonstrate the role of febuxostat on uric acid levels and renal function in patients with chronic kidney disease and hyperuricemia. Methods. Eight databases included were searched for clinical randomized controlled trials. Meanwhile, the confidence interval (CI) of either relative risk or mean difference was set to 95%. Besides, the heterogeneity of the research results is tested by $I^2$ . Results. Ten studies were ultimately included in this meta-analysis. All of them were considered to be random controlled trials. 10 studies reported the serum uric acid of the test group and the control group, which was significantly lower (SMD: -146.44, 95% Cl: -195.96, -86.93, and $P<0.01$ ) than the control group, EGFR (SMD: 3.21, 95% Cl: 1.17, 5.25, and $P<0.01$ ), serum creatinine (SMD: -15.27, 95% Cl: -20.75, -9.79, and $P<0.01$ ), serum urea nitrogen (SMD: -2.37, 95% Cl: -3.31, -1.61, and $P<0.01$ ), and adverse reactions (OR: 0.74, 95% Cl: 0.32, 1.68, and $P=0.47$ ). Conclusion. The results of this study suggest that febuxostat may be effective in patients with CKD with HUA, as evidenced by serum uric acid, creatinine, urea nitrogen, and EGFR. However, large sample, multicenter, low risk of bias clinical studies, as well as basic medical research, are needed.

Katsuwonus pelamis Peptide and its Complexes Protect Zebrafish and Mice From Hyperuricemia Through Promoting Kidney Excretion of Uric Acid and Inhibiting Liver Xanthine Oxidase Activity

Katsuwonus pelamis peptide and its complexes have the effect of lowering uric acid (UA)-levels. To identify the effect and possible mechanisms, different concentrations of Katsuwonus pelamis peptide and its complexes were administered to the zebrafish and mice hyperuricemia models, and the UA level was measured. Meanwhile, the hyperuricemic mice were treated orally at 0.83, 1.67, and 5.00 mg/g body weight for 7 days with Katsuwonus pelamis peptide and the complexes groups, separately. The levels of serum UA (SUA), urinary UA (UUA), serum creatinine (SCR), blood urine nitrogen (BUN), and xanthine oxidase (XOD) activities were detected in each group. The results showed that the Katsuwonus pelamis peptide (125 μg/ml) and its complexes (83.3 and 250 μg/ml) effectively reduced UA level in zebrafish with hyperuricemia (p < 0.05). The Katsuwonus pelamis peptide at high concentration (5.00 mg/g) decreased the SUA level, SCR level, BUN level, and hepatic XOD activity, and the complexes (1.67 and 5.00 mg/g) significantly reduced the SUA level and hepatic XOD activity (p < 0.05) in the hyperuricemic mice. In addition, in a hyperuricemic mouse model, the UUA level was increased after treatment with Katsuwonus pelamis peptide and its complexes at high concentrations (p < 0.05). The total therapeutic effects in the Katsuwonus pelamis peptide complex group were better than those in the Katsuwonus pelamis peptide group. Thus, Katsuwonus pelamis peptide and its complexes may possibly be used to prevent hyperuricemia via promoting urate secretion and inhibiting XOD activity production.

Efficacy of Urate-Lowering Therapy in Patients With Chronic Kidney Disease: A Network Meta-Analysis of Randomized Controlled Trials

PURPOSE

The goal of this study was to systematically review the efficacy and safety of urate-lowering therapy in patients with chronic kidney disease (CKD).

METHODS

PubMed, the Cochrane Central Registration of Controlled Trials, and EMBASE databases and several websites were electronically searched to collect randomized clinical trials on the efficacy of urate-lowering therapy in CKD from inception to December 31, 2020. The key primary end points were uric acid or estimated glomerular filtration rate (eGFR) levels; the safety end points were death, renal event, cardiovascular event, and gastrointestinal event. A Bayesian network meta-analysis was conducted with the use of ADDIS and R software.

FINDINGS

A total of 17 randomized clinical trials involving 2059 patients were included. The results of network meta-analysis showed that urate-lowering therapy could reduce urate levels in patients with CKD. Febuxostat was the most effective treatment in lowering urate levels according to the rank probability. Urate-lowering therapy has the tendency to delay the decline of eGFR, but the difference was not statistically significant. Ranking probability showed that benzbromarone, febuxostat, and allopurinol ranked higher than placebo in reducing the decline of eGFR. There were no statistically significant differences between groups in the incidence of all adverse effects.

IMPLICATIONS

All urate-lowering therapies could reduce the urate level in patients with CKD, but the benefit of such therapy in renal disease is still unclear. PROSPERO identifier: CRD42020222601.

Enhancement of oral bioavailability and anti-hyperuricemic activity of aloe emodin via novel Soluplus®-glycyrrhizic acid mixed micelle system

The objective of this study was to fabricate a novel drug delivery system using Soluplus® (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer) and glycyrrhizic acid to improve solubility, bioavailability, and anti-hyperuricemic activity of aloe emodin (AE). The AE-loaded mixed micelles (AE-M) were prepared by thin-film hydration method. The optimal AE-M contained small-sized (30.13 ± 1.34 nm) particles with high encapsulation efficiency (m/m, %) of 90.3 ± 1.08%. The release rate of AE increased in the micellar formulation than that of free AE in the four media (DDW, pH 7.0; phosphate buffer solution, pH 7.4; phosphate buffer solution, pH 6.8; and hydrochloric acid aqueous solution, pH 1.2). In comparison to free AE, the pharmacokinetic study of AE-M showed that its relative oral bioavailability increased by 3.09 times, indicating that mixed micelles may promote gastrointestinal absorption. More importantly, AE-M effectively reduced uric acid level by inhibiting xanthine oxidase (XOD) activity in model rats. The degree of ankle swelling, serum levels of interleukin (IL)-1, and IL-6-related inflammatory factors levels all decreased in the gouty arthritis model established via monosodium urate (MSU) crystals. Taken together, the AE-M demonstrated the potential to improve the bioavailability, anti-hyperuricemic activity, and anti-inflammation of AE.

3β,23-Dihydroxy-12-ene-28-ursolic Acid Isolated from Cyclocarya paliurus Alleviates NLRP3 Inflammasome-Mediated Gout via PI3K-AKT-mTOR-Dependent Autophagy

Gout is regarded as a painful inflammatory arthritis induced by the deposition of monosodium urate crystals in joints and soft tissues. Nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome-mediated IL-1β production plays a crucial role in the pathological process of gout. Cyclocarya paliurus (CP) tea was found to have an effect on reducing the blood uric acid level of people with hyperuricemia and gout. However, its medicinal ingredients and mechanism for the treatment of gout are still unclear. Thus, this study was designed to investigate the effects of the active triterpenoids isolated from C. paliurus on gout and explore the underlying mechanism. The results showed that compound 2 (3β,23-dihydroxy-12-ene-28-ursolic acid) from C. paliurus significantly decreased the protein expression of IL-1β, caspase-1, pro-IL-1β, pro-caspase-1, and NLRP3. Furthermore, the production of ROS in the intracellular was reduced after compound 2 treatment. However, ROS agonist rotenone remarkably reversed the inhibitory effect of compound 2 on the protein expression of NLRP3 inflammasome. Additionally, the expression level of LC3 and the ratio of LC3II/LC3I were increased, but the expression level of p62 was suppressed by compound 2 whereas an autophagy inhibitor 3-methyladenine (3-MA) significantly abolished the inhibitory effects of compound 2 on the generation of ROS and the protein expression of NLRP3 inflammasome. Moreover, compound 2 could ameliorate the expression ratio of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR. Interestingly, mTOR activator MHY-1485 could block the promotion effect of compound 2 on autophagy regulation and inhibitory effect of compound 2 on induction of ROS and IL-1β. In conclusion, these findings suggested that compound 2 may effectively improve NLRP3 inflammasome-mediated gout via PI3K-AKT-mTOR-dependent autophagy and could be further investigated as a potential agent against gout.

Prevention of kidney function decline using uric acid-lowering therapy in chronic kidney disease patients: a systematic review and network meta-analysis

INTRODUCTION

Several previous studies have suggested that uric acid-lowering therapy (ULT) can slow the progression of chronic kidney disease (CKD). Although crucial for CKD patients, few studies have evaluated the effects of different ULT medications on kidney function. This systematic review summarizes evidence from randomized controlled trials (RCTs) regarding the effects of ULT on kidney function.

METHOD

We performed a systematic search of PubMed, MEDLINE, Embase, Scopus, and the Cochrane Library up to September 2021 to identify RCTs in CKD patients comparing the effects of ULT on kidney function with other ULT medications or placebo. A network meta-analysis was performed to compare each ULT indirectly. The primary outcome was a change in estimated glomerular filtration rate (eGFR) from baseline.

RESULTS

Ten studies were selected with a total of 1480 patients. Topiroxostat significantly improved eGFR and reduced the urinary albumin/creatinine ratio compared to placebo (mean difference (MD) and 95% confidence interval [95% CI]: 1.49 [0.08; 2.90], P = 0.038 and 25.65% [13.25; 38.04], P < 0.001, respectively). Although febuxostat did not show a positive effect overall, it significantly improved renal function (i.e., eGFR) in a subgroup of CKD patients with hyperuricemia (MD [95% CI]: 0.85 [0.02; 1.67], P = 0.045). Allopurinol and pegloticase did not show beneficial effects.

CONCLUSIONS

Topiroxostat and febuxostat may have better renoprotective effects in CKD patients than other ULT medications. Further large-scale, long-term studies are required to determine whether these effects will lead, ultimately, to reductions in dialysis induction and major adverse cardiovascular events. Key Points • This study is the first network meta-analysis comparing the nephroprotective effects of ULT in CKD patients. • Topiroxostat and febuxostat showed better renoprotective effects in CKD patients than other ULT medications. • Heterogeneity was low in this study, suggesting consistency of results.

Effect of uric acid-lowering therapy on renal function in patients with chronic kidney disease: a systematic review and meta-analysis

Background

Whether uric acid (UA)-lowering therapy (ULT) is effective in reducing the progression of renal dysfunction in patients with chronic kidney disease (CKD) remains controversial. Since several advances have been made in therapies for hyperuricemia, including novel xanthine oxidoreductase (XOR) inhibitors, we conducted a systematic review to clarify the effectiveness of ULT in preserving renal function among CKD patients.

Methods

In this systematic review, the MEDLINE database was searched up to June 2019. We included complete randomized controlled trials comparing renal events between adult non-dialyzed CKD patients, defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2, with and without ULTs. Changes in eGFR were expressed as the mean difference (MD). The incidence of dichotomous outcomes was expressed as a risk ratio. This review was performed using the predefined protocol published in PROSPERO (CRD 42019140346).

Results

Eleven studies with 4277 CKD patients were included. Drugs used in the intervention groups of all studies were XOR inhibitors (allopurinol, febuxostat or topiroxostat). Although patients with ULT tended to show superior preservation of eGFR as compared to those without ULT, no significant differences were identified (MD, 2.52; 95% confidence interval, − 0.15 to 5.18). In subgroup analysis, the use of allopurinol was associated with superior preservation of eGFR, whereas the newer XOR inhibitors, febuxostat and topiroxostat, showed no significant effects on eGFR changes. Neither incidence of end-stage kidney disease nor treatment-emergent adverse events differed significantly between groups.

Conclusions

The present systematic review and meta-analysis suggested that CKD patients with ULT tend to show superior eGFR preservation as compared to patients without ULT, but further studies are needed to verify the renoprotective effects of ULT.

Effectiveness of Drug Treatments for Lowering Uric Acid on Renal Function in Patients With Chronic Kidney Disease and Hyperuricemia: A Network Meta-Analysis of Randomized Controlled Trials

Background: Hyperuricemia is very common in patients with chronic kidney disease (CKD); the role of hyperuricemia in the occurrence and progression of kidney disease remains an interesting and unresolved issue for nephrologists, and whether urate-lowering therapy (ULT) is warranted in CKD patients is still in controversy. To summarize and compare the clinical outcomes and adverse events (AEs) of three common ULT drugs, we performed a systematic review and network meta-analysis of randomized clinical trials (RCTs). Method: PubMed, MEDLINE, Clinical Trials.gov, EMBASE, and the Cochrane Central Register of Controlled Trials electronic databases were searched. The network meta-analysis was performed using the "gemtc 0.8-7" and its dependent packages in R software. The primary outcome was the change of renal function and uric acid; creatinine, proteinuria, blood pressure, and adverse events were assessed as the secondary outcomes. Results: 16 RCTs involving 1,943 patients were included in the final network analysis. Febuxostat, allopurinol, and benzbromarone were not found to exert superior effects over placebo upon renoprotective effect. With respect to lowering urate, the three drugs showed to be statistically superior to placebo, while febuxostat could better lower urate than allopurinol (MD: -1.547; 95% CrI: -2.473 to -0.626). It is also indicated that febuxostat was superior to placebo at controlling blood pressure, while no differences were observed when allopurinol and benzbromarone were compared to placebo. These results are stable in subgroup analysis. Conclusion: There is insufficient evidence to support the renoprotective effects of the three urate-lowering agents in CKD patients with hyperuricemia; febuxostat shows a tendency to be superior to allopurinol on lowering the decline of eGFR and increment of proteinturia, but the difference does not reach a statistical significance. Regarding its urate-lowering effect, febuxostat appears to be a satisfactory alternative to allopurinol and benzbromarone, and can control blood pressure better.

Hyperuricemia, urate-lowering therapy, and kidney outcomes: a systematic review and meta-analysis

BACKGROUND

Contradictory evidence exists for association of hyperuricemia and kidney function. To investigate the association of hyperuricemia and kidney function decline (hyperuricemia question) and effect of urate-lowering therapies (ULTs) on kidney function (ULT question), we performed a systematic review and meta-analysis.

METHODS

MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and CINAHL were searched from inception to July 2020. We selected observational studies for the hyperuricemia question and controlled trials for the ULT question. Two investigators independently assessed study eligibility and abstracted the data. Risk of bias was assessed using the Newcastle-Ottawa Scale and Cochrane risk of bias tool. Meta-analysis was done using the inverse variance method and random effect model. We estimated odds ratio (OR), hazard ratio (HR), risk ratio (RR), and the mean difference (MD). Evidence certainty was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

Of 12,037 studies screened, 131 studies with 3,414,226 patients were included. Hyperuricemia was associated with a significant risk of rapid estimated glomerula filtration rate (eGFR) decline ⩾3 ml/min per 1.73 m2 per year (OR 1.38, 95% CI 1.20-1.59; low certainty), albuminuria (OR/HR 1.94, 95% CI 1.34-2.79; very low certainty), chronic kidney disease (OR/HR 2.13, 95% CI 1.74-2.61; very low certainty), and kidney failure (HR 1.53, 95% CI 1.18-1.99; very low certainty). Compared with control, ULT use for ⩾1 year was associated with significantly more improved eGFR (MD 1.81 ml/min per 1.73 m2, 95% CI 0.26-3.35; very low certainty), serum creatinine (MD -0.33 mg/dl, 95% CI -0.47 to -0.19; low certainty), and proteinuria (MD -5.44 mg/day, 95% CI -8.49 to -2.39; low certainty), but no difference in kidney failure.

CONCLUSION

Hyperuricemia is associated with worsening eGFR, albuminuria, chronic kidney disease, and kidney failure. ULT use for ⩾1 year may improve kidney function.

REGISTRATION

The protocol was registered at PROSPERO database, CRD42015013859.

Managing hyperuricemia and gout in chronic kidney disease: a clinical conundrum

PURPOSE OF REVIEW

There is controversy regarding the impact of hyperuricemia on the progression of chronic kidney disease (CKD), and gout remains sub optimally managed in this population. We discuss the prescribing of drugs for the treatment of gout in patients with CKD.

RECENT FINDINGS

There is a lack of consensus from expert guidelines, and prescribers have concerns regarding the risk of adverse reactions from medicines used to treat gout. These situations appear to contribute to suboptimal management of gout in this cohort. Recent data have challenged the role of urate lowering therapy (ULT) in the management of asymptomatic hyperuricemia in CKD.

SUMMARY

ULT should be commenced in all patients with severe, recurrent disease, tophaceous gout and evidence of joint damage. Most international guidelines recommend a treat-to-target approach for the management of gout. In CKD, ULT should be started at low dose with up titration adjusted to serum urate levels, rather than being based on the creatinine clearance. If patients fail first-line therapy, alternative agents are utilized, the specific agent depending on ease of access, burden of disease and other comorbidities. This approach should be incorporated into routine practice to ensure optimal treatment of gout in CKD. More research is required to investigate whether treatment of asymptomatic hyperuricemia has clinical benefits.

Treating Hyperuricemia: The Last Word Hasn't Been Said Yet

Gout as well as asymptomatic hyperuricemia have been associated with several traditional cardiovascular risk factors and chronic kidney disease. Both in vitro studies and animal models support a role for uric acid mediating both hemodynamic and tissue toxicity leading to glomerular and tubule-interstitial damage, respectively. Nevertheless, two recent well designed and carried out trials failed to show the benefit of allopurinol treatment on kidney outcomes, casting doubts on expectations of renal protection by the use of urate lowering treatment. With the aim of providing possible explanations for the lack of effect of urate lowering treatment on chronic kidney disease progression, we will critically review results from all available randomized controlled trials comparing a urate-lowering agent with placebo or no study medication for at least 12 months and report renal clinical outcomes.

Purification, identification, and computational analysis of xanthine oxidase inhibitory peptides from kidney bean

Hyperuricemia is related to plenty of diseases, seriously damaging human health. Current clinical drugs used to treat hyperuricemia have many adverse effects. In this study, kidney bean hydrolysate (KBH) was found to exert high xanthine oxidase inhibitory (XOI) activity. Compared to KBH (50.31 ± 2.73%), XOI activities of three fractions (M_w <5 kDa, M_w <3 kDa, M_w  < 1 kDa) by ultrafiltration were higher and increased to 58.58 ± 3.57%, 59.34 ± 1.78%, and 55.05 ± 5.00%, respectively (P < 0.05). A total of 69 peptides were identified by HPLC-ESI-MS/MS and analyzed binding affinities with XO with the help of molecular docking. AVDSLVPIGR, DWYDIK, LDNLLR, ISPIPVLK, ISSLEMTR showed well binding affinities with XO and DWYDIK presented the highest XOI activity (68.63 ± 5.07%) among five synthetic peptides (P < 0.05). Additionally, visual analysis results indicated that DWYDIK was pushed into the hydrophobic channel and formed hydrogen bonds with pivotal amino acids of xanthine oxidase. Overall, KBH could be a promising candidate as anti- hyperuricemia functional food. PRACTICAL APPLICATION: This research initially revealed that kidney bean peptides could significantly inhibit the activity of xanthine oxidase, indicating kidney bean peptides could be a treatment for hyperuricemia. Kidney bean peptides may have commercial potentials as a safer alternative with few side effects to drugs.

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.