The clinical efficacy of urate-lowering therapy in acute gout: a meta-analysis of randomized controlled trials

An updated systematic review and meta-analysis of randomised controlled trials on the effects of urate-lowering therapy initiation during a gout flare

BACKGROUND

There is uncertainty about the optimal time to start urate-lowering therapy (ULT) in the setting of a gout flare. The aim was to perform a systematic review and meta-analysis of randomised controlled trials (RCTs) assessing the effects of ULT initiation during a gout flare.

METHODS

This systematic review was conducted in accordance with PRISMA methodology. MEDLINE, EMBASE and The Cochrane Library were searched for studies published between database inception to 1 March 2023. RCTs published in English that examined ULT initiation during a gout flare in adults ≥18 years were included. The quality of included studies was assessed using the revised Cochrane Risk of Bias tool 2.0. Data were extracted for the following outcomes: patient-rated pain score, duration of gout flare, recurrent gout flares, time to achieve target serum urate, adherence to ULT, patient satisfaction with treatment and adverse events. Meta-analyses were performed using Review Manager v5.4. This study is registered on PROSPERO, number CRD42023404680.

RESULTS

A total of 972 studies were identified and of these, six RCTs met the criteria for inclusion in the analysis. Three studies were assessed as having high risk of bias, one study as having some concerns, and two studies as having low risk of bias. In total, there were 445 pooled participants; 226 participants randomised to early initiation of ULT and 219 to placebo or delayed initiation of ULT. Allopurinol was used in three studies, febuxostat in two studies and probenecid in one study. Few participants (n = 62, 13.9 %) had tophaceous gout. Participants with renal impairment were excluded from most studies. There were no differences in patient-rated pain scores at baseline, days 3-4, days 7-8, day 10 or days 14-15 (p ≥ 0.42). Additionally, there was no significant difference in time to resolution of gout flare (standardised mean difference 0.77 days; 95 % CI -0.26 to 1.79; p = 0.14) or the risk of recurrent gout flare in the subsequent 28 to 30 days (RR 1.06; 95 % CI 0.59 to 1.92; p = 0.84). Adverse events were similar between groups. The included studies did not report time to achieve target serum urate, long-term adherence to ULT, or patient satisfaction with treatment.

CONCLUSION

There appears to be no evidence for harm or for benefit to initiating ULT during a gout flare. These findings have limited applicability to patients with tophaceous gout, or those with renal impairment.

Uric acid en route to gout

Gout and hyperuricemia (HU) have generated immense attention due to increased prevalence. Gout is a multifactorial metabolic and inflammatory disease that occurs when increased uric acid (UA) induce HU resulting in monosodium urate (MSU) crystal deposition in joints. However, gout pathogenesis does not always involve these events and HU does not always cause a gout flare. Treatment with UA-lowering therapeutics may not prevent or reduce the incidence of gout flare or gout-associated comorbidities. UA exhibits both pro- and anti-inflammation functions in gout pathogenesis. HU and gout share mechanistic and metabolic connections at a systematic level, as shown by studies on associated comorbidities. Recent studies on the interplay between UA, HU, MSU and gout as well as the development of HU and gout in association with metabolic syndromes, non-alcoholic fatty liver disease (NAFLD), and cardiovascular, renal and cerebrovascular diseases are discussed. This review examines current and potential therapeutic regimens and illuminates the journey from disrupted UA to gout.

Efficacy and Safety of Qinpi Tongfeng Formula in the Treatment of Acute Gouty Arthritis: A Double-Blind, Double-Dummy, Multicenter, Randomized Controlled Trial

Objective

Traditional Chinese medicine (TCM) has certain curative effect against acute gouty arthritis (AGA), but it lacks high-quality evidence-based studies. In this randomized controlled trial, we try to evaluate the clinical efficacy and safety of Qinpi Tongfeng Formula (QPTFF) in the treatment of AGA.

Methods

One hundred and fourteen patients with AGA (damp heat accumulation syndrome) who met the inclusion and exclusion criteria were randomly divided into treatment group and control group in a ratio of 1 : 1. Patients in the treatment group were treated with QPTFF, and patients in the control group were treated with diclofenac sodium sustained-release tablets for 7 days. The primary outcome measure was the change in visual analog scale (VAS) score for pain from the baseline to day 8. The secondary outcome measures were joint symptom score, TCM syndrome score, total effective rate, pain cure rate, complete pain relief time, patient satisfaction score, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum uric acid level. The safety outcome measures were routine blood test, urinalysis, liver function including alanine aminotransferase and aspartate aminotransferase, renal function including blood urea nitrogen and serum creatinine, and the rate of treatment-related adverse events (TRAEs).

Results

105 patients with 53 in the treatment group and 52 in the control group completed the 7-day treatment. There was no significant difference between two groups in demographic characteristics, VAS score for pain, joint symptom score, TCM syndrome score, ESR, CRP, and serum uric acid level before enrollment at baseline (based on both the full analysis set (FAS) and per protocol set (PPS), P > 0.05). The 95% confidence interval of the difference between the eighth and first VAS score for pain of the two groups was (−0.57, 0.42) in FAS and (−0.48, 0.47) in PPS. The lower bound of both FAS and PPS is greater than the bound value of −0.7. On day 8, there was no significant difference between the two groups in joint symptom score, TCM syndrome score, total effective rate, pain cure rate, complete pain relief time, patient satisfaction score, ESR, and CRP (FAS and PPS, P > 0.05). The serum uric acid level and TRAEs in the treatment group were significantly lower than those in the control group (FAS and PPS, P < 0.05).

Conclusions

QPTFF could alleviate the symptoms of patients with AGA, which is not inferior to diclofenac sodium sustained-release tablets in analgesic. Moreover, QPTFF overmatches diclofenac sodium sustained-release tablets in decreasing serum uric acid level and TRAEs. Therefore, the results provide reliable foundation for QPTTF in the treatment of AGA. Trial Registration. This study protocol was registered in Chinese Clinical Trial Registry (registration number: ChiCTR2100050638).

The effect of initiation of urate-lowering treatment during a gout flare on the current episode: a meta-analysis of randomized controlled trials

OBJECTIVE

The objective was to evaluate whether initiation of urate-lowering treatment (ULT) during an acute gout flare prolonged the current episode.

METHODS

A comprehensive search of MEDLINE and Web of Science databases was conducted from their inception to 15 March 2021. Five randomized controlled trials (RCTs) with 381 patients met the inclusion criteria. Standardized mean difference (SMD), odds ratio (OR), and 95% confidence interval (CI) were used for estimating the clinical efficacy of ULT in acute gout.

RESULTS

There was no statistical difference in days to resolution (intent-to-treat analysis) (SMD, 0.68; 95% CI - 0.42 to 1.78; I², 49%; p = 0.22), the pain visual analogue score (VAS) by day 10 (SMD, - 0.07; 95% CI - 0.30 to 0.16; I², 0%; p = 0.53), C-reactive protein (CRP) from day 7 to 10 (SMD, - 1.14; 95% CI - 5.63 to 3.36; I², 55%; p = 0.62), erythrocyte sedimentation rate (ESR) from day 7 to 10 (SMD, - 2.51; 95% CI - 5.46 to 0.45; I², 0%; p = 0.10) and the recurrence of gout flares within 28-30 days (OR 0.78; 95% CI 0.29 to 2.09; I², 0%; p = 0.62).

CONCLUSION

Initiation of ULT during an acute gout flare did not prolong the duration of the flare. However, larger sample size studies are needed to confirm this finding. Trial registration number PROSPERO (CRD42021234581).

Why Does Hyperuricemia Not Necessarily Induce Gout?

Hyperuricemia is a risk factor for gout. It has been well observed that a large proportion of individuals with hyperuricemia have never had a gout flare(s), while some patients with gout can have a normuricemia. This raises a puzzle of the real role of serum uric acid (SUA) in the occurrence of gout flares. As the molecule of uric acid has its dual effects in vivo with antioxidant properties as well as being an inflammatory promoter, it has been placed in a delicate position in balancing metabolisms. Gout seems to be a multifactorial metabolic disease and its pathogenesis should not rely solely on hyperuricemia or monosodium urate (MSU) crystals. This critical review aims to unfold the mechanisms of the SUA role participating in gout development. It also discusses some key elements which are prerequisites for the formation of gout in association with the current therapeutic regime. The compilation should be helpful in precisely fighting for a cure of gout clinically and pharmaceutically.