Serum Uric Acid and the Risk of Incident and Recurrent Gout: A Systematic Review

Sodium-Glucose Cotransporter-2 Inhibitors vs Sulfonylureas for Gout Prevention Among Patients With Type 2 Diabetes Receiving Metformin

Importance

Sodium-glucose cotransporter type 2 inhibitors (SGLT2i) are a revolutionary treatment for type 2 diabetes (T2D) with cardiovascular, kidney, and serum urate-lowering benefits.

Objective

To compare risk of incident gout and rate of recurrent flares between patients with T2D initiating SGLT2i vs sulfonylurea, most common second-line glucose-lowering therapy, when added to metformin monotherapy.

Design, Setting, and Participants

This sequential, propensity score-matched, new-user comparative effectiveness study using target trial emulation framework included adults with T2D receiving metformin monotherapy in a Canadian general population database from January 1, 2014, to June 30, 2022.

Exposures

Initiation of SGLT2i vs sulfonylurea.

Main Outcomes and Measures

The primary outcome was incident gout diagnosis, ascertained by emergency department (ED), hospital, outpatient, and medication dispensing records. Secondary outcomes were gout-primary hospitalizations and ED visits and major adverse cardiovascular events (MACE), as well as recurrent flare rates among prevalent gout patients. Heart failure (HF) hospitalization was assessed as positive control outcome and osteoarthritis encounters as negative control. For target trial emulations, we used Cox proportional hazards and Poisson regressions with 1:1 propensity score matching (primary analysis) and overlap weighting (sensitivity analysis). The analysis was conducted from September to December, 2023.

Results

Among 34 604 propensity score matched adults with T2D initiating SGLT2i or sulfonylurea (20 816 [60%] male, mean [SD] age, 60 [12.4] years), incidence of gout was lower among SGLT2i initiators (4.27 events per 1000 person-years) than sulfonylurea initiators (6.91 events per 1000 person-years), with a hazard ratio (HR) of 0.62 (95% CI, 0.48-0.80) and a rate difference (RD) of -2.64 (95% CI, -3.99 to -1.29) per 1000 person-years. Associations persisted regardless of sex, age, or baseline diuretic use. SGLT2i use was also associated with fewer recurrent flares among gout patients (rate ratio, 0.67; 95% CI, 0.55-0.82; and RD, -20.9; 95% CI, -31.9 to -10.0 per 1000 person-years). HR and RD for MACE associated with SGLT2i use were 0.87 (95% CI, 0.77-0.98) and -3.58 (95% CI, -6.19 to -0.96) per 1000 person-years. For control outcomes, SGLT2i users had lower risk of HF (HR, 0.53; 95% CI, 0.38-0.76), as expected, with no difference in osteoarthritis (HR, 1.11; 95% CI, 0.94-1.34). Results were similar when applying propensity score overlap weighting.

Conclusions

In this population-based cohort study, the gout and cardiovascular benefits associated with SGLT2i in these target trial emulations may guide selection of glucose-lowering therapy in patients with T2D, at risk for or already with gout.

Diagnostic values of different musculoskeletal ultrasound signs, serum uric acid, and their combined detection for gouty arthritis

Objectives

The study aimed to investigate the diagnostic values of different musculoskeletal ultrasound (MSUS) signs, serum uric acid (SUA), and their combined detection for gouty arthritis (GA).

Patients and methods

In this retrospective study, 70 patients (62 males, 8 females; mean age: 46.1±14.1 years; range, 25 to 86 years) diagnosed with GA (the GA group) between August 2022 and March 2023 and 70 patients (54 females, 16 males; mean age: 49.0±14.1 years; range, 21 to 75 years) diagnosed with rheumatoid arthritis and osteoarthritis during the same period (the non-GA group) were included. The positive rate of MSUS signs and SUA in both groups was recorded to compare the differences. The correlations of MSUS signs and SUA with GA were analyzed using Spearman's rank correlation analysis. The diagnostic values of different MSUS signs, SUA, and their combined detection for GA were analyzed using a receiver operating characteristic, the area under the curve (AUC), sensitivity, specificity, and the Youden index.

Results

The positive rate of the double contour (DC) sign (chi-squared [χ2 ]=102.935, p<0.001), hyperechoic spots (χ2=56.395, p<0.001), bone erosions (χ2 =10.080, p<0.001), and SUA (χ2 =41.117, p <0.001) were higher in the GA group than in the non-GA group. The positive rate of the DC sign (rs=0.829, p=0.001), hyperechoic spots (rs=0.631, p<0.001), bone erosion (rs=0.268, p=0.001), and SUA (rs=0.542, p<0.001) were positively correlated with GA. Among the single-indicator measures, the DC sign exhibited the highest diagnostic value (AUC=0.907, sensitivity=81.4%, specificity=100%, p<0.001). Among the combined-indicator measures, the DC sign combined with SUA exhibited the highest diagnostic value (AUC=0.929, sensitivity=91.4%, specificity=94.3%, p<0.001), higher than DC sign detection alone.

Conclusion

The DC sign combined with SUA yielded a high diagnostic value and can thus provide a reliable basis for effectively and efficiently diagnosing GA.

Current updates for hyperuricemia and gout in age-related macular degeneration

The escalating prevalence of metabolic syndrome poses a significant public health challenge, particularly among aging populations, with metabolic dysfunctions contributing to pro-inflammatory states. In this review, we delved into the less recognized association between hyperuricemia (HUA), a manifestation of metabolic syndrome and a primary risk factor for gout, and age-related macular degeneration (AMD), a sight-threatening ailment predominantly affecting the elderly. In recent years, inflammation, particularly its involvement in complement pathway dysregulation, has gained prominence in AMD pathophysiology. The contradictory role of uric acid (UA) in intercellular and intracellular environments was discussed, highlighting its antioxidant properties in plasma and its pro-oxidant effects intracellularly. Emerging evidence suggests a potential link between elevated serum uric acid levels and choroid neovascularization in AMD, providing insights into the role of HUA in retinal pathologies. Various pathways, including crystal-induced and non-crystal-induced mechanisms, were proposed to indicate the need for further research into the precise molecular interactions. The implication of HUA in AMD underscores its potential involvement in retinal pathologies, which entails interdisciplinary collaboration for a comprehensive understanding of its impact on retina and related clinical manifestations.

Moving urate-lowering therapy in gout beyond guideline recommendations

The 'treat-to target serum urate strategy' when using urate-lowering therapy has been recommended by most specialist rheumatology societies for many years. An alternative "treat-to-avoid-symptoms" in gout has been suggested, albeit without a clear definition of what this means and how it might be implemented in clinical trials or clinical practice. This has hampered efforts to design clinical trials that compare the "treat-to-target [urate]" and "treat-to-avoid-symptoms" strategies in the long-term management of gout. In this review we consider the rationale for the treat-to-target urate strategy when using urate-lowering therapy, potential definitions of a "treat-to-avoid-symptoms" strategy, or perhaps what is not "treat-to-avoid-symptoms", and approaches that might address this uncertainty.

The association between gout flares and monosodium urate burden assessed using musculoskeletal ultrasound in patients with gout

Background

Ultrasound (US) has a high sensitivity in detecting monosodium urate (MSU) deposition in gout patients. However, the value of US in predicting gout flares has been reported only in a few monocentric studies.

Objective

To investigate the association between gout flares in the previous year and US-detected MSU burden using two different US scores.

Design

A retrospective study.

Methods

Patients with gout were consecutively recruited to undergo musculoskeletal US examinations of their knees, ankles, and feet. The score derived from Outcome Measure in Rheumatology (hereinafter referred to as MSU score) and musculoskeletal US features-based (hereinafter referred to as MSKF score) were used to quantify the MSU burden of gout. Odds ratios for frequent gout flares were calculated.

Results

We enrolled 1894 patients with gout (mean age: 45 years; gout duration: 5 years; males: 96.1%), experiencing a median of three flares over the past year. Of these, 428 (22.6%) patients reported frequent (⩾7) gout flares. The MSU and MSKF median scores were 6 and 9, respectively. For each five-point increase in MSU and MSKF score, the odds ratio of frequent gout flares increased 1.13-fold and 1.24-fold, respectively. The area under the curve (AUC) for the MSU and MSKF score was 0.635 [95% confidence interval (CI): 0.604-0.665] and 0.688 (95% CI: 0.659-0.718), respectively, (AUC difference 0.054, p value for AUC difference < 0.001).

Conclusion

The MSU and MSKF scores were significantly associated with the number of gout flares in the previous year. The MSKF score outperformed the MSU score in terms of frequent gout flare discrimination.

An artificial neural network model for evaluating the risk of hyperuricaemia in type 2 diabetes mellitus

Type 2 diabetes with hyperuricaemia may lead to gout, kidney damage, hypertension, coronary heart disease, etc., further aggravating the condition of diabetes as well as adding to the medical and financial burden. To construct a risk model for hyperuricaemia in patients with type 2 diabetes mellitus based on artificial neural network, and to evaluate the effectiveness of the risk model to provide directions for the prevention and control of the disease in this population. From June to December 2022, 8243 patients with type 2 diabetes were recruited from six community service centers for questionnaire and physical examination. Secondly, the collected data were used to select suitable variables and based on the comparison results, logistic regression was used to screen the variable characteristics. Finally, three risk models for evaluating the risk of hyperuricaemia in type 2 diabetes mellitus were developed using an artificial neural network algorithm and evaluated for performance. A total of eleven factors affecting the development of hyperuricaemia in patients with type 2 diabetes mellitus in this study, including gender, waist circumference, diabetes medication use, diastolic blood pressure, γ-glutamyl transferase, blood urea nitrogen, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting glucose and estimated glomerular filtration rate. Among the generated models, baseline & biochemical risk model had the best performance with cutoff, area under the curve, accuracy, recall, specificity, positive likelihood ratio, negative likelihood ratio, precision, negative predictive value, KAPPA and F1-score were 0.488, 0.744, 0.689, 0.625, 0.749, 2.489, 0.501, 0.697, 0.684, 0.375 and 0.659. In addition, its Brier score was 0.169 and the calibration curve also showed good agreement between fitting and observation. The constructed artificial neural network model has better efficacy and facilitates the reduction of the harm caused by type 2 diabetes mellitus combined with hyperuricaemia.

Electroacupuncture for acute gouty arthritis: a systematic review and meta-analysis of randomized controlled trials

Acute gouty arthritis (AGA) is a metabolic disorder in which recurrent pain episodes can severely affect the quality of life of gout sufferers. Electroacupuncture (EA) is a non-pharmacologic therapy. This systematic review aimed to assess the efficacy and safety of electroacupuncture in treating acute gouty arthritis. We searched eight Chinese and English databases from inception to July 30, 2023, and 242 studies were retrieved. Finally, 15 randomized controlled trials (n=1076) were included in a meta-analysis using Review Manager V.5.4.1. meta-analysis results included efficacy rate, visual rating scale (VAS) for pain, serum uric acid level (SUA), immediate analgesic effect, and incidence of adverse events. Electroacupuncture (or combined non-pharmacologic) treatment of AGA was significantly different from treatment with conventional medications (RR = 1.14, 95% confidence interval CI = 1.10 to 1.19, P < 0.00001). The analgesic effect of the electroacupuncture group was superior to that of conventional Western drug treatment (MD = -2.26, 95% CI = -2.71 to -1.81, P < 0.00001). The electroacupuncture group was better at lowering serum uric acid than the conventional western drug group (MD =-31.60, CI -44.24 to -18.96], P < 0.00001). In addition, electroacupuncture combined with Western drugs had better immediate analgesic effects than conventional Western drug treatment (MD = -1.85, CI -2.65 to -1.05, P < 0.00001). Five studies reported adverse events in the electroacupuncture group versus the drug group, including 19 cases of gastrointestinal symptoms and 6 cases of neurological symptoms (RR = 0.20, 95% CI = 0.04 to 0.88, P = 0.03).

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=450037, identifier CRD42023450037.

Screening, isolation, and activity evaluation of potential xanthine oxidase inhibitors in Poria Cum Radix Pini and mechanism of action in the treatment of gout disease

Poria Cum Radix Pini is a rare medicinal fungus that contains several potential therapeutic ingredients. On this basis, a particle swarm mathematical model was used to optimize the extraction process of total triterpenes from P. Cum Radix Pini, and xanthine oxidase inhibitors were screened using affinity ultrafiltration mass spectrometry. Meanwhile, the accuracy of the ultrafiltration assay was verified by molecular docking experiments and molecular dynamics analysis, and the mechanism of action of the active compounds for the treatment of gout was analyzed by enzymatic reaction kinetics and network pharmacology. A high-speed countercurrent chromatography method combined with the consecutive injection and the economical two-phase solvent system preparation using functional activity coefficient of universal quasichemical model (UNIFAC) mathematical model was developed for increasing the yield of target compound. In addition, dehydropachymic acid and pachymic acid were used as competitive inhibitors, and 3-O-acetyl-16alpha-hydroxydehydrotrametenolic acid and dehydrotrametenolic acid were used as mixed inhibitors. Then, activity-oriented separation and purification were performed by high-speed countercurrent chromatography combined with semi-preparative high-performance liquid chromatography and the purity of the four compounds isolated was higher than 90%. It will help to provide more opportunities to discover and develop new potential therapeutic remedies from health care food resources.

Serum uric acid was non-linearly associated with the risk of all-cause and cardiovascular death in individuals with coronary heart disease: a large prospective cohort study

Objective

To investigate the association of serum uric acid (SUA) with all-cause and cardiovascular death in individuals with coronary heart disease (CHD).

Methods

In this prospective cohort study, 1556 individuals from the National Health and Nutrition Examination Survey (1999-2015) were included in the analysis. Multivariate COX regression analysis, restricted cubic spline plot (RCS) and threshold effect were used to investigate the association between SUA and all-cause and cardiovascular death in individuals with CHD.

Results

In the fully adjusted model, when SUA was regarded as a continuous variable, it was closely associated with the risk of all-cause and cardiovascular death (P < 0.01). When all participants were divided into four groups according to the quartile of SUA, compared with Q1 group, only individuals in Q4 group had higher risk of all-cause and cardiovascular death (P = 0.002 and 0.034). The following subgroup analysis showed that the association between SUA and all-cause death risk was still statistically significant in individuals over 60 years old, male, with hypertension, without diabetes and with chronic kidney disease, while the association with cardiovascular death risk only persisted in individuals over 60 years old and male (P < 0.05). Further sensitivity analysis showed that SUA was still closely associated with all-cause and cardiovascular death, whether as a continuous variable or a classified variable (P = 0.007 and 0.044). RCS analysis revealed that SUA had a nonlinear association with all-cause and cardiovascular death risk (P for nonlinearity < 0.01). Threshold effect analysis showed that SUA below 345 umol/L was negatively associated with all-cause and cardiovascular death risk (P < 0.05), while SUA above 345 umol/L was positively associated with all-cause and cardiovascular death risk (P < 0.001), and the 2-piecewise regression model was better than the 1-line regression model (P for likelihood ratio test < 0.05).

Conclusion

SUA had a nonlinear association with all-cause and cardiovascular death risk in individuals with CHD.

Cohort study investigating gout flares and management in UK general practice

BACKGROUND

Gout is the most common inflammatory arthritis and is almost exclusively managed in primary care, however the course and severity of the condition is variable and poorly characterised. This research aims improve understanding about the frequency of, and factors associated with, gout flares in the UK and characterise the factors associated with the initiation of ULT.

METHODS

Using the Clinical Practice Research Database, patients with a coded incident gout diagnosis without a prior prescription for urate-lowering therapy (ULT) were identified. Gout flares post diagnosis and ULT initiation were identified through prescribing and coded data. Patient characteristics, co-morbidities and co-prescribing were co-variants. Factors associated with gout flares and ULT initiation were analysed using cox-proportional hazard model and logistic regression.

RESULTS

Fifty-one thousand seven hundred eighty-four patients were identified: 18,605 (35.9%, 95%CI 35.5-36.3%) had experienced ≥ 1 recurrent flare, 17.4% (95%CI 17.1-17.8%) within 12 months of diagnosis. Male sex, black ethnicity, higher BMI, heart failure, CKD, CVD and diuretic use were associated with flares, with the highest HR seen with high serum urate levels (≥ 540 µmol/L HR 4.63, 95%CI 4.03-5.31). ULT initiation was associated with similar variables, although higher alcohol intake and older age were associated with lower odds of ULT initiation but were not associated with flares. ULT was initiated in 27.7% (95%CI 27.3-28.0%): 5.7% (95%CI 5.5-5.9%) within 12 months of diagnosis. ULT initiation rates were higher in patients with recurrent flares.

CONCLUSION

Approximately one in six people with incident gout had a second flare within 12 months. Factors associated with flare recurrence and ULT initiation were similar, but ULT initiation occurred later after diagnosis than previously thought.

A liquid chromatography-tandem mass spectrometry method for comprehensive determination of metabolites in the purine pathway of rat plasma and its application in anti-gout effects of Lycium ruthenicum Murr

It has been proved that purine metabolites are implicated in various biological syndromes and disorders. Therefore, the realization of panoramic detection of purine metabolites will be of great significance to the pathogenesis of purine metabolic disorders. In the present study, an ultra-high performance liquid chromatography with tandem mass spectrometry method was developed for the comprehensive quantification of purine metabolites in rat plasma. The 17 purine metabolites were separated and quantified in the short running time of 15 min. The proposed method was strictly validated by applying SeraSub solution as a matrix and proved to be linear (R2 ≥ 0.9944), accurate (the recoveries of all analytes ranged from 85.3% to 103.0%, with relative standard deviation values ≤ 9.3%), and precise (the intra- and inter-day precisions were less than 10.8% and 12.4%, respectively). The method was then successfully applied to the qualification of the endogenous purine metabolites in acute gouty arthritis rats, as well as colchicine and anthocyanin-intervened rats. Results showed that uric acid, xanthine, hypoxanthine, and xanthine were considered the key factors of acute gouty arthritis. The established method and measurement of purines in rat plasma might help the investigation of the action mechanisms between purine disorders and related diseases.

Associations between vitamin C intake and serum uric acid in US adults: Findings from National Health and Nutrition Examination Survey 2011-2016

BACKGROUNDS

Dietary factors has been found to influence serum uric acid (SUA) levels. We further explored the associations between dietary and supplemental vitamin C intake and SUA in a large population-based study.

METHODS

The cross-sectional study included 6308 participants (3146 males and 3162 females) aged ≥20 years from the National Health and Nutrition Examination Survey (NHANES) 2011-2016 in the United States. The dietary vitamin C was log-transformed for statistical analysis. Hyperuricemia was defined as SUA concentrations >420 umol/L in males or >360 umol/L in females. The associations of dietary vitamin C and supplemental vitamin C with SUA levels and hyperuricemia risk were evaluated using weighted linear regression models and weighted multivariate logistic regression models, and a subgroup analysis stratified by gender was also conducted.

RESULTS

In this large-scale database study, there was a negative association between dietary vitamin C (log transformed) and SUA levels in US adults (β = -7.27, 95% CI: -11.58, -2.97). The inverse relationship existed among males but not females (P for interaction = 0.02). There was inverse correlation between dietary vitamin C (log transformed) and hyperuricemia risk (OR = 0.68, 95% CI: 0.57, 0.81), especially in males compared to females determined through an interaction test (P = 0.04). There were no associations between supplemental vitamin C and SUA levels (β = 1.00 (95% CI: -4.44, 6.44) or hyperuricemia risk (OR = 0.98 (95% CI: 0.78, 1.24). High-dosage supplemental vitamin C (>300 mg) and hyperuricemia risk were not associated (OR = 1.04, 95% CI: 0.69, 1.56).

CONCLUSIONS

This study demonstrated that there were negative associations between dietary vitamin C and SUA levels and hyperuricemia risk among US adults. The inverse correlations between dietary vitamin C and hyperuricemia risk were more significant in males compared to females. There were no associations between supplemental vitamin C and SUA levels or hyperuricemia risk.

The Effect of Decrease in Serum Urate for the Risk of Gout Flares During Urate-Lowering Therapy Initiation Among Chinese Male Gout Patients: A Prospective Cohort Study

Purpose

Higher baseline serum urate or higher initial urate-lowering medication dose increased risk of gout flares during urate-lowering therapy (ULT) initiation. The decrease in serum urate may play a crucial role in this process. Therefore, we aim to explore the relationship between decrease in serum urate and the risk of gout flares during ULT initiation.

Patients and Methods

A 12-week prospective cohort study of Chinese male gout patients was conducted at Shandong Provincial Clinical Research Center for Immune Diseases and Gout in China. Patients were grouped by baseline serum urate (7-7.9 mg/dL, 8-8.9 mg/dL and ≥9 mg/dL). All patients received febuxostat 20 mg daily during weeks 0-4, then escalated to 40mg during weeks 4-12 if serum urate >6mg/dL. The main outcomes were the number of gout flares and the decrease in serum urate. Poisson regression was performed.

Results

A total of 282 participants were enrolled, of whom 260 completed (84, 87 and 89 in each group) from March 2021 to December 2021. A 44.2% of all participants experienced at least one gout flare. In the multivariate Poisson regression 1, Δ serum urate 0-12 weeks (IRR 1.184, 95% CI, 1.062-1.320; P=0.002), the number of gout flares before treatment 1 year (1.017, 1.010-1.024; P<0.001) and tophus (1.580, 1.023-2.440; P=0.039) were independently associated with the number of gout flares. While in the multivariate Poisson regression 2, baseline serum urate (1.256, 1.050-1.503; P=0.013) and the number of gout flares before treatment 1 year (1.014, 1.007-1.022; P<0.001) were independently associated with the number of gout flares, Δ serum urate 0-12 weeks (1.055, 0.923-1.207; P=0.433) was no longer a risk factor.

Conclusion

ULT-induced gout flares depend on the degree of decrease in serum urate, which is affected by baseline serum urate. Higher baseline serum urate and greater decrease in serum urate lead to higher risk of gout flares.

Epidemiology and risk factors associated with gout control among adult Asians: a real-world retrospective cohort study

Background

Gout is associated with significant morbidity and mortality, yet suboptimal gout control remains a problem globally. Identifying the risk factors associated with poor gout control among patients in primary care allows targeted interventions to improve their clinical management. This study aimed to determine the prevalence of poor gout control and its associated demographic and clinical factors among urbanized community-dwelling Asian patients.

Methods

This retrospective study was based on data extracted from the electronic medical records of 8 public primary care clinics in Singapore. Patients with a diagnostic code of gout who had 2 or more visits between 1st January 2018 and 31st December 2019 were included in the analysis. Data extracted included: demographics, anthropological measurements, comorbidities, serum uric acid levels and medication prescription. A patient is defined to have poor gout control if they suffer two or more acute gout attacks within a year. Chi-Squared test was used for categorical parameters. For continuous variables, univariate logistic regression analysis was first performed. Significant factors (p ≤ 0.1) were then included in the logistics regression model to account for confounders.

Results

A total of 7,970 patients and 24,624 visits were included in the analysis. The prevalence of poorly controlled gout was 28.2% (n = 2,244/7,970); only 46.3% of them (n = 1,039/2,244) were prescribed allopurinol and 13.4% (n = 301/2,244) were taking doses ≥300 mg. Using logistic regression, factors associated with poor gout control were: male gender [adjusted OR (AOR) =1.66, p < 0.001], Malay ethnicity (AOR = 1.27, p = 0.007), congestive heart failure (AOR = 1.64, p = 0.037). Patients prescribed allopurinol (AOR = 1.52, p < 0.001), NSAIDs (AOR = 2.76, p < 0.001) and corticosteroids (AOR = 2.83, p < 0.001) were more likely to have poorly-controlled gout.

Conclusion

Nearly 30% of patients had poor gout. Interventions should focus on male and Malay patients and those with congestive cardiac failure.

Korean guidelines for the management of gout

Gout is the most common form of arthritis, with the prevalence increasing worldwide. The present treatment guidelines provide recommendations for the appropriate treatment of acute gout, management during the inter-critical period, and prevention of chronic complications. The guidelines were developed based on evidence-based medicine and draft recommendations finalized after expert consensus. These guidelines are designed to provide clinicians with clinical evidence to enable efficient treatment of gout.

Comparative Effectiveness of Sodium-Glucose Cotransporter-2 Inhibitors for Recurrent Gout Flares and Gout-Primary Emergency Department Visits and Hospitalizations : A General Population Cohort Study

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2is) decrease serum urate levels, but whether this translates into prevention of recurrent flares among patients with gout and gout-primary emergency department (ED) visits or hospitalizations is unknown.

OBJECTIVE

To compare gout flares and cardiovascular events among patients with gout initiating SGLT2is versus dipeptidyl peptidase 4 inhibitors (DPP-4is), another second-line glucose-lowering agent not associated with serum urate levels or cardiovascular risk.

DESIGN

Propensity score-matched, new-user cohort study.

SETTING

General population database from 1 January 2014 to 30 June 2022.

PARTICIPANTS

Patients with gout and type 2 diabetes.

MEASUREMENTS

The primary outcome was recurrent gout flare counts ascertained by ED, hospitalization, outpatient, and medication dispensing records. Secondary outcomes included myocardial infarction and stroke; genital infection (positive control) and osteoarthritis encounter (negative control) were also assessed. Poisson and Cox proportional hazards regressions were used with 1:1 propensity score matching (primary analysis) and overlap weighting (sensitivity analysis).

RESULTS

After propensity score matching, the flare rate was lower among SGLT2i initiators than DPP-4i initiators (52.4 and 79.7 events per 1000 person-years, respectively), with a rate ratio (RR) of 0.66 (95% CI, 0.57 to 0.75) and a rate difference (RD) of -27.4 (CI, -36.0 to -18.7) per 1000 person-years. The corresponding RR and RD for gout-primary ED visits and hospitalizations were 0.52 (CI, 0.32 to 0.84) and -3.4 (CI, -5.8 to -0.9) per 1000 person-years, respectively. The corresponding hazard ratio (HR) and RD for myocardial infarction were 0.69 (CI, 0.54 to 0.88) and -7.6 (CI, -12.4 to -2.8) per 1000 person-years; the HR for stroke was 0.81 (CI, 0.62 to 1.05). Those who initiated SGLT2is showed higher risk for genital infection (HR, 2.15 [CI, 1.39 to 3.30]) and no altered risk for osteoarthritis encounter (HR, 1.07 [CI, 0.95 to 1.20]). Results were similar when propensity score overlap weighting was applied.

LIMITATION

Participants had concurrent type 2 diabetes.

CONCLUSION

Among patients with gout, SGLT2is may reduce recurrent flares and gout-primary ED visits and hospitalizations and may provide cardiovascular benefits.

PRIMARY FUNDING SOURCE

National Institute of Arthritis and Musculoskeletal and Skin Diseases.

Elevated serum CA72-4 predicts gout flares during urate lowering therapy initiation: a prospective cohort study

OBJECTIVE

Gout flares during urate-lowering therapy (ULT) initiation are common, but predictors of these flares are poorly understood. The aim of this study was to determine whether serum CA72-4 is an independent predictor for gout flares during ULT initiation.

METHODS

A prospective cohort study was conducted between March 2021 and January 2022. Men with gout, at least one gout flare in the past year, and at least three serum CA72-4 measurements in the previous six months were enrolled. Participants were grouped according to their highest recorded serum CA72-4 levels (above or within the normal range). All participants took oral febuxostat 20 mg daily without flare prophylaxis therapy, and attended face-to-face visits every four weeks until 24 weeks. The incidence of gout flare was compared between the two groups. Backward stepwise logistic regression analyses were used to identify risk factors associated with flares. Receiver operating characteristic curve analysis was used to evaluate prediction efficacy.

RESULTS

A total of 193 completed the study (79 with high CA72-4; 114 with normal CA72-4). The cumulative incidence of at least one gout flare was 48.1% (62.1% in the high CA72-4 group, 38.4% in the normal CA72-4 group, P = 0.001), and recurrent (≥2) flares was 33.0% (47.1% in the high CA72-4 group, 23.2% in the normal CA72-4, P < 0.001). High CA72-4, disease duration, intra-articular tophus size, glucose, high-density lipoprotein-cholesterol and ESR were independent risk factors for gout flares. Serum CA72-4 alone predicted recurrent flares with an area under the curve of 0.63 (95% CI = 0.54, 0.71), and 0.78 (95% CI = 0.71, 0.85) when combined with other independent variables.

CONCLUSION

High serum CA72-4 predicts the risk of gout flares during ULT initiation.

TRIAL REGISTRATION

ChiCTR; https://www.chictr.org.cn/; ChiCTR2100043573.

Korean guidelines for the management of gout

Gout is the most common form of arthritis, with the prevalence increasing worldwide. The present treatment guidelines provide recommendations for the appropriate treatment of acute gout, management during the inter-critical period, and prevention of chronic complications. The guidelines were developed based on evidence-based medicine and draft recommendations finalized after expert consensus. These guidelines are designed to provide clinicians with clinical evidence to enable efficient treatment of gout.

Transdermal delivery of allopurinol to acute hyperuricemic mice via polymer microneedles for the regulation of serum uric acid levels

Allopurinol (AP) is widely used to treat hyperuricemia which may cause severe side effects upon oral administration. Alternative means for the treatment of hyperuricemia are demanded to simultaneously facilitate drug absorption, patient compliance, and fewer side effects. In this study, a new polymer microneedle (MN) system was developed for the transdermal delivery of AP to acute hyperuricemic mice. This study aims to achieve the controllable regulation of serum uric acid (SUA) levels with fewer side effects compared with oral administration. The matrix of polymer MNs consisted of polyvinylpyrrolidone (PVP) and polycaprolactone (PCL), in which the rapid dissolution of PVP offers a rapid dissolution of AP into the blood and the biodegradability of PCL resulting in a sustainable drug release behavior. An in vivo study demonstrated that the AP-loaded MN system can effectively reduce the SUA levels as oral administration with lower side effects, which will be conducive to reducing the adverse reactions and improving the bioavailability of AP. This MN-mediated strategy can facilitate transcutaneous hyperuricemia treatment and provide a new alternative for the exploration of clinical treatment of hyperuricemia and improvement of patient compliance.

TGF-β is elevated in hyperuricemic individuals and mediates urate-induced hyperinflammatory phenotype in human mononuclear cells

BACKGROUND

Soluble urate leads to a pro-inflammatory phenotype in human monocytes characterized by increased production of IL-1β and downregulation of IL-1 receptor antagonist, the mechanism of which remains to be fully elucidated. Previous transcriptomic data identified differential expression of genes in the transforming growth factor (TGF)-β pathway in monocytes exposed to urate in vitro. In this study, we explore the role of TGF-β in urate-induced hyperinflammation in peripheral blood mononuclear cells (PBMCs).

METHODS

TGF-β mRNA in unstimulated PBMCs and protein levels in plasma were measured in individuals with normouricemia, hyperuricemia and gout. For in vitro validation, PBMCs of healthy volunteers were isolated and treated with a dose ranging concentration of urate for assessment of mRNA and pSMAD2. Urate and TGF-β priming experiments were performed with three inhibitors of TGF-β signalling: SB-505124, 5Z-7-oxozeaenol and a blocking antibody against TGF-β receptor II.

RESULTS

TGF-β mRNA levels were elevated in gout patients compared to healthy controls. TGF-β-LAP levels in serum were significantly higher in individuals with hyperuricemia compared to controls. In both cases, TGF-β correlated positively to serum urate levels. In vitro, urate exposure of PBMCs did not directly induce TGF-β but did enhance SMAD2 phosphorylation. The urate-induced pro-inflammatory phenotype of monocytes was partly reversed by blocking TGF-β.

CONCLUSIONS

TGF-β is elevated in individuals with hyperuricemia and correlated to serum urate concentrations. In addition, the urate-induced pro-inflammatory phenotype in human monocytes is mediated by TGF-β signalling. Future studies are warranted to explore the intracellular pathways involved and to assess the clinical significance of urate-TGF-β relation.

Linear and non-linear Mendelian randomization analyses of sex-specific associations between sleep duration and hyperuricemia

Background

Observational studies have suggested a potential non-linear association between sleep duration and hyperuricemia. However, the causal nature and sex-specific differences are poorly understood. We aimed to determine the shape of sex-specific causal associations between sleep duration and hyperuricemia in the UK Biobank.

Methods

Logistic regression was used to investigate the observational association between self-reported sleep duration and hyperuricemia among 387,980 white British participants (mean age: 56.9 years and 46.0% males). Linear and non-linear Mendelian Randomization (MR) analyses were performed to assess the causal association between continuous sleep duration and hyperuricemia. The causal effects of genetically predicted short (<7 h) and long (>8 h) sleep durations on hyperuricemia were further estimated, respectively.

Results

Traditional observational analysis suggested U- and J-shaped associations between sleep duration and hyperuricemia in females and males, respectively. Linear MR did not support the causal effect of sleep duration on hyperuricemia. Non-linear MR demonstrated an approximately U-shaped causal association between continuous sleep duration and hyperuricemia in overall participants and females, but not in males. Genetically predicted short sleep duration was significantly associated with hyperuricemia in females (OR [95% CI]: 1.21 [1.08–1.36]; P = 0.001), but not in males (1.08 [0.98–1.18]; P = 0.137). By contrast, genetically predicted long sleep duration was not significantly associated with the risk of hyperuricemia in either females or males.

Conclusion

Genetically predicted short sleep duration is a potential causal risk factor for hyperuricemia for females but has little effect on males. Long sleep duration does not appear to be causally associated with hyperuricemia.

Prevalence of hyperuricemia in patients with severe obesity and the relationship between serum uric acid and severe obesity: A decade retrospective cross-section study in Chinese adults

Objective

Undoubtedly, the relationship between serum uric acid (SUA) and obesity is less data for Chinese patients with obesity. This study aimed to examine the prevalence of hyperuricemia (HUA) and the association between SUA and patients with obesity.

Methods

All participants were categorized as overweight, obesity I, obesity II, and obesity III. In addition, based on SUA concentration, the participants were stratified into four quartiles. The authors used descriptive analysis, independent t-test, ANOVA, correlation analysis, and multiple linear regression models to verify the SUA level and obesity among Chinese adults.

Results

Overall, the estimated prevalence of HUA was 69.8%. In the BMI categories, the prevalence of HUA was 5.1% in overweight, 15.2% in obesity I, 16.9% in obesity II, and 32.5% in obesity III. Correlation analysis shows that SUA is strongly correlated with BMI, waist circumference (WC), and hip circumference (HC). Multiple linear regression analysis shows that high density-lipoprotein cholesterol (HDL-C) is a protective predictor of serum uric acid levels in patients with obesity. Compared with the overweight, obesity I, obesity II, and obesity III were more likely to have higher levels in the SUA levels.

Conclusion

We mainly showed that the serum uric acid levels in Chinese patients with severe obesity declined slightly as age increased.

Critical appraisal of serum urate targets in the management of gout

Gout management involves two broad aspects: treatment of gout flares to provide rapid symptomatic relief and long-term urate-lowering therapy to lower serum urate sufficiently to prevent gout flares from occurring. All of the major rheumatology societies recommend a target serum urate of <5 mg/dl (<0.30 mmol/l) or <6 mg/dl (<0.36 mmol/l), both of which are below the point of saturation for urate and therefore lead to monosodium urate crystal dissolution. In this Review, we describe the rationale for treat-to-target urate approach in the long-term management of gout and the current evidence and controversy around the appropriate serum urate targets.

Gout as a Risk Factor for Age-Related Macular Degeneration in Taiwanese Adults-A Population-Based Study in Taiwan

The relationship between gout and age-related macular degeneration (AMD) was suggested in previous literature but has yet to be accepted fully among physicians. This study aimed to explore the effect of gout on the development of age-related macular degeneration in Taiwan. A retrospective cohort study was conducted using Taiwan's National Health Insurance Database that includes a 2-million-persons dataset. The crude hazard ratio, Kaplan-Meier plot, and separate cox proportional hazard ratio were utilized to demonstrate the effect of gout on the development of age-related macular degeneration. The crude hazard ratio for gout patients developing AMD was 1.55 and the adjusted hazard ratio 1.20. In conclusion, gout is a risk factor for developing AMD, and achieving good disease management is therefore essential for preventing AMD from occurring.

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).

Reference range of serum uric acid and prevalence of hyperuricemia: a cross-sectional study from baseline data of ELSA-Brasil cohort

Background

Most of the few studies that have established reference ranges for serum uric acid (SUA) have not taken into account factors which may interfere with its levels and followed rigorous laboratory quality standards. The aim of this study was to establish reference ranges for SUA and determine the prevalence of hyperuricemia.

Method

Cross-sectional study including 15,100 participants (all sample) aged 35 to 74 years from baseline data of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicentric cohort of volunteer civil servants from five universities and one research institute located in different regions of Brazil. It was established a reference sample excluding participants with factors that directly influence SUA levels: glomerular filtration rate lower than 60 ml/min, excessive alcohol intake, use of diuretics, aspirin, estrogen or urate-lowering therapy. SUA was measured using the uricase method and following rigorous international quality standards. Reference ranges were defined as values between percentiles 2.5 (P2.5) and 97.5 (P97.5) of SUA distribution in the reference sample, stratified by sex. Hyperuricemia was defined as SUA ≥ 7 mg/100 ml in the all sample.

Results

The reference sample was composed of 10,340 individuals (55.3% women, median age 50 years). Reference ranges (P2.5 to P97.5) for SUA were: 4.0 to 9.2 mg/100 ml for men and 2.8 to 6.9 mg/100 ml for women. Sex was a major determinant for SUA levels (median [IQR], mg/100 ml: 6.1 [5.3–7.0] for men versus 4.5 [3.9–5.3] for women, p < 0.001). Higher levels of SUA were found in patients with higher BMI. Higher age had (a modest) influence only for women. The prevalence of hyperuricemia for all sample (N = 15,100) was 31.9% (95% confidence interval [CI] 30.8–33.0%) in men and 4.8% (95% CI 4.3–5.3%) in women.

Conclusion

SUA reference ranges were 4.0 to 9.2 mg/100 ml for men and 2.8 to 6.9 mg/100 ml for women. Prevalence of hyperuricemia was 31.9% in men and 4.8% in women. Updated SUA reference ranges and prevalence of hyperuricemia are higher nowadays and might be used to guide laboratories and the screening for diseases related to SUA.

Comparison of Benzbromarone and Allopurinol on Primary Prevention of the First Gout Flare in Asymptomatic Hyperuricemia

Objectives. Whether uric acid-lowering agent use in asymptomatic hyperuricemia can reduce the development of the first gout flare remains unsettled. The goal of the present research was to test the efficacy of benzbromarone and allopurinol on primary prevention of the first gout flare in persons with asymptomatic hyperuricemia in Taiwan. Methods. One observational cohort study was constructed to examine the 2001−2015 dataset adapted from the National Health Insurance Program of Taiwan containing the claims data of 2 million beneficiaries. Asymptomatic hyperuricemia was considered as individuals on uric acid-lowering therapy who did not have gout flares. Individuals aged 20−84 without gout flares who had the use of benzbromarone alone were assigned into a benzbromarone group. Individuals ages 20−84 without gout flares who had the use of allopurinol alone were assigned into an allopurinol group. The final study included 6111 pairs of 1:1 propensity score-matched individuals from both benzbromarone and allopurinol groups. The end point was assigned as individuals who were newly diagnosed with their first gout flare. The incidence rate of the first gout flare was estimated between the benzbromarone and allopurinol groups. A Cox proportional hazards regression model was applied to explore the hazard ratio and 95% confidence interval of the first gout flare related to benzbromarone use and allopurinol use. Results. The incidence rate of the first gout flare was lower in the benzbromarone group compared with an allopurinol group (3.29 versus 5.46 per 1000 person-months, incidence rate ratio = 0.60 and 95% confidence interval = 0.56−0.64). After adjustment for co-variables, the adjusted hazard ratio of the first gout flare was 0.63 (95% confidence interval = 0.59−0.68, p < 0.001) for the benzbromarone group when compared with the allopurinol group. Conclusion. People with asymptomatic hyperuricemia taking benzbromarone have a lower hazard of developing their first gout flare when compared with those taking allopurinol. Based on the medication safety, the therapeutic effects and the low price, with oral administration once daily, we suggest that benzbromarone should be the first drug of choice if clinicians are treating asymptomatic hyperuricemia.

One- and 2-year flare rates after treat-to-target and tight-control therapy of gout: results from the NOR-Gout study

OBJECTIVES

To explore the frequency and predictors of flares over 2 years during a treat-to-target strategy with urate-lowering therapy (ULT) in patients with gout.

METHODS

In the treat-to-target, tight control NOR-Gout study patients started ULT with escalating doses of allopurinol. Flares were recorded over 2 years. Baseline predictors of flares during months 9-12 in year 1 and during year 2 were analyzed by multivariable logistic regression.

RESULTS

Of 211 patients included (mean age 56.4 years, disease duration 7.8 years, 95% males), 81% (150/186) of patients experienced at least one gout flare during the first year and 26% (45/173) during the second year. The highest frequency of flares in the first year was seen during months 3-6 (46.8% of patients). Baseline crystal depositions detected by ultrasound and by dual-energy computed tomography (DECT) were the only variables which predicted flares both during the first period of interest at months 9-12 (OR 1.033; 95% CI 1.010-1.057, and OR 1.056; 95% CI 1.007-1.108) and also in year 2. Baseline subcutaneous tophi (OR 2.42, 95% CI 1.50-5.59) and prior use of colchicine at baseline (OR 2.48, 95% CI 1.28-4.79) were independent predictors of flares during months 9-12, whereas self-efficacy for pain was a protective predictor (OR 0.98 per unit, 95% CI 0.964-0.996).

CONCLUSIONS

In patients with gout, flares remain frequent during the first year of a treat-to-target ULT strategy, especially during months 3-6, but are much less frequent during year 2. Baseline crystal depositions predict flares over 2 years, supporting ULT early during disease course.

TRIAL REGISTRATION

ACTRN12618001372279.

Colchicine prophylaxis is associated with fewer gout flares after COVID-19 vaccination

Objectives

COVID-19 vaccination often triggers a constellation of transitory inflammatory symptoms. Gout is associated with several comorbidities linked to poor outcomes in COVID-19, and gout flares can be triggered by some vaccinations. We analysed the risk of gout flares in the first 3 months after COVID-19 vaccination with inactivated virus, and whether colchicine can prevent gout flares following post-COVID-19 vaccination.

Methods

A clinical delivery population-based cross-sectional study was conducted in the Gout Clinic at the Affiliated Hospital of Qingdao University between February and October 2021. Study participants were selected using a systematic random sampling technique among follow-up patients with gout. We collected data, including vaccinations and potential risk factors, using a combination of interviews, health QR codes and medical records. Logistic regression was used to adjust for covariates.

Results

We enrolled 549 gout participants (median age 39 years, 84.2% vaccinated). For the 462 patients who received COVID-19 vaccine, 203 (43.9%) developed at least one gout flare in the 3 months after vaccination. Most of these flares were experienced within 1 month after the first (99/119 (83.2%)) or second (70/115 (60.9%)) dose of vaccine. Compared with unvaccinated participants, COVID-19 vaccination was associated with higher odds of gout flare within 3 months (adjusted OR 6.02; 95% CI 3.00 to 12.08). Colchicine use was associated with 47% less likelihood of postvaccine gout flare.

Conclusion

COVID-19 vaccination was associated with increased odds of gout flare, which developed mainly in month 1 after each vaccine dose, and was negatively associated with colchicine prophylaxis.

Development of a patient decision aid for the initiation of urate-lowering therapy in gout patients

Aim

Shared decision-making improves patients’ experiences with care, satisfaction with management decisions and possibly health outcomes. This study describes the development of a decision aid (DA) that supports patients with gout and their physicians in a face-to-face clinical setting to (a) decide whether or not to (re)start urate-lowering therapy (ULT) and (b) agree on the preferred ULT.

Methods

Recommendations of the International Patient Decision Aid Standards group guided the development. A steering group of experts in gout and health services research specified the scope. Nominal group technique meetings were organised in which patients ranked the importance of preidentified potential characteristics/attributes of ULT and discussed further needs regarding the DA. A literature search was conducted to collect evidence on gout outcomes with and without ULT. Subsequently, the DA prototype was designed and adjusted using feedback from the steering group and results of cognitive debriefing interviews among five gout patients.

Results

The final DA consists of six pages. First, the DA clarifies the decision at stake and describes gout including its risk factors, the role of lifestyle and treatment of flares. Next, risk of future flares with and without ULT in relation to serum uric acid levels is described and visualised. Relevant attributes of ULT are presented in an option grid distinguishing first-line and second-line ULT. Finally, patients’ believes and preferences are explicitly addressed before making the shared decision.

Conclusion

This study provides initial support for usability of a DA for gout patients eligible for starting ULT.

Tolerable upper intake level for dietary sugars

Following a request from five European Nordic countries, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was tasked to provide scientific advice on a tolerable upper intake level (UL) or a safe level of intake for dietary (total/added/free) sugars based on available data on chronic metabolic diseases, pregnancy-related endpoints and dental caries. Specific sugar types (fructose) and sources of sugars were also addressed. The intake of dietary sugars is a well-established hazard in relation to dental caries in humans. Based on a systematic review of the literature, prospective cohort studies do not support a positive relationship between the intake of dietary sugars, in isocaloric exchange with other macronutrients, and any of the chronic metabolic diseases or pregnancy-related endpoints assessed. Based on randomised control trials on surrogate disease endpoints, there is evidence for a positive and causal relationship between the intake of added/free sugars and risk of some chronic metabolic diseases: The level of certainty is moderate for obesity and dyslipidaemia (> 50-75% probability), low for non-alcoholic fatty liver disease and type 2 diabetes (> 15-50% probability) and very low for hypertension (0-15% probability). Health effects of added vs. free sugars could not be compared. A level of sugars intake at which the risk of dental caries/chronic metabolic diseases is not increased could not be identified over the range of observed intakes, and thus, a UL or a safe level of intake could not be set. Based on available data and related uncertainties, the intake of added and free sugars should be as low as possible in the context of a nutritionally adequate diet. Decreasing the intake of added and free sugars would decrease the intake of total sugars to a similar extent. This opinion can assist EU Member States in setting national goals/recommendations.

Genetic risk of hyperuricemia in hypertensive patients associated with antihypertensive drug therapy: a longitudinal study

Elevated serum uric acid (UA) level has been shown to be influenced by multiple genetic variants, but it remains uncertain how UA‐associated variants differ in their influence on hyperuricemia risk in people taking antihypertensive drugs. We examined a total of 43 UA‐related variants at 29 genes in 1840 patients with hypertension from a community‐based longitudinal cohort during a median 2.25‐year follow‐up (including 1031 participants with normal UA, 440 prevalent hyperuricemia at baseline, and 369 new‐onset hyperuricemia). Compared with the wild‐type genotypes, patients carrying the SLC2A9 rs3775948G allele or the rs13129697G allele had decreased risk of hyperuricemia, while patients carrying the SLC2A9 rs11722228T allele had increased risk of hyperuricemia, after adjustment for cardiovascular risk factors and correction for multiple comparisons; moreover, these associations were modified by the use of diuretics, β‐blockers, or angiotensin converting enzyme inhibitors. The rs10821905A allele of A1CF gene was associated with increased risk of hyperuricemia, and this risk was enhanced by diuretics use. The studied variants were not observed to confer risk for incident cardiovascular events during the follow‐up. In conclusion, the genes SLC2A9 and A1CF may serve as potential genetic markers for hyperuricemia risk in relation to antihypertensive drugs therapy in Chinese hypertensive patients.

The Influence of Serum Uric Acid on the Brain and Cognitive Dysfunction

Uric acid is commonly known for its bad reputation. However, it has been shown that uric acid may be actively involved in neurotoxicity and/or neuroprotection. These effects could be caused by oxidative stress or inflammatory processes localized in the central nervous system, but also by other somatic diseases or systemic conditions. Our interest was to summarize and link the current data on the possible role of uric acid in cognitive functioning. We also focused on the two putative molecular mechanisms related to the pathological effects of uric acid-oxidative stress and inflammatory processes. The hippocampus is a prominent anatomic localization included in expressing uric acid's potential impact on cognitive functioning. In neurodegenerative and mental disorders, uric acid could be involved in a variety of ways in etiopathogenesis and clinical presentation. Hyperuricemia is non-specifically observed more frequently in the general population and after various somatic illnesses. There is increasing evidence to support the hypothesis that hyperuricemia may be beneficial for cognitive functioning because of its antioxidant effects but may also be a potential risk factor for cognitive dysfunction, in part because of increased inflammatory activity. In this context, gender specificities must also be considered.

Association between serum urate and flares in people with gout and evidence for surrogate status: a secondary analysis of two randomised controlled trials

BACKGROUND

Use of serum urate as a treatment target and outcome measure has become controversial in view of the 2017 American College of Physicians guidelines, which advocated a treat-to-symptom rather than a treat-to-target serum urate approach to gout management. The relevance of serum urate as a treatment target measure implies that achievement of target serum urate is causally associated with improvement in patient-important outcomes such as reduction in the number of gout flares. The aim of this study was to assess the causal relationship between achieving target serum urate and the occurrence of gout flares.

METHODS

We analysed individual patient-level data from two randomised trials on urate-lowering therapies in people with gout conducted in Nottingham, UK, and New Zealand. We included participants randomly assigned to immediate dose escalation in the New Zealand study and all participants in the Nottingham study (a nurse-led gout care group and a general practitioner-led usual care group). Individuals who on average achieved a serum urate concentration less than 6 mg/dL (0·36 mmol/L) based on data at 6, 9, and 12 months post-baseline were defined as serum urate responders. The primary outcome was the proportion of participants having at least one gout flare, and the secondary outcome was the mean number of flares per participant per month, from 12 to 24 months after baseline, compared between serum urate responders and non-responders. In adjusted logistic regression models, serum urate at baseline, previous flare history (in the year preceding study entry), presence of tophi at baseline, and, for the Nottingham dataset, the original randomisation group, were included as covariates. The Nottingham study was registered with ClinicalTrials.gov, NCT01477346. The New Zealand study was registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000845932.

FINDINGS

From the combined individual data from both trials, we identified 343 serum urate responders and 245 serum urate non-responders. Significantly fewer serum urate responders had a gout flare than did serum urate non-responders between 12 and 24 months (91 [27%] of 343 vs 156 [64%] of 245; adjusted odds ratio [OR] 0·29 [95% CI 0·17 to 0·51], p<0·0001). The mean number of flares per participant per month between 12 and 24 months was significantly lower in serum urate responders than in serum urate non-responders (adjusted mean difference -1·41 [95% CI -1·77 to -1·04], p<0·0001). This association was independent of the original randomised treatment allocation.

INTERPRETATION

Achieving an average serum urate concentration less than 6 mg/dL is associated with an absence of gout flares and a reduction in the number of flares in the subsequent 12 months in people with gout. These results support a treat-to-target serum urate approach in the management of gout.

FUNDING

None.

Establishment of sex difference in circulating uric acid is associated with higher testosterone and lower sex hormone-binding globulin in adolescent boys

Men have higher circulating levels of uric acid than women. This sex difference is suspected to be a result of suppressive effects of estradiol on uric acid. If so, estradiol would be inversely associated with circulating uric acid. This study aimed to test this hypothesis. This cross-sectional study included 9472 participants (weighted sample size of 184,342,210) aged 12-80 years from the 2013 to 2016 US National Health and Nutrition Examination Survey. Associations of sex hormones with uric acid were analyzed using weighted least squares regression, adjusting for demographic characteristics, lifestyle risk factors, and comorbidities. Neither free nor bioavailable estradiol was inversely associated with circulating uric acid in adolescent boys or girls, or adult men or women, or perimenopausal women after full adjustment. The sex difference in uric acid was established during adolescence as a result of a dramatic increase in uric acid in adolescent boys. During adolescence, the increase in estradiol in girls over time was accompanied by a relatively unchanged level of uric acid. All three fractions of estradiol (free, bioavailable, and total) were positively associated with uric acid in adolescent boys and girls after full adjustment. In adolescent boys, all three fractions of testosterone were positively associated with serum uric acid, and sex hormone-binding globulin was inversely associated with uric acid after full adjustment. These results suggest that estradiol is not inversely associated with circulating uric acid in adolescents and the establishment of sex difference in circulating uric acid during adolescence is associated with higher testosterone and lower sex hormone-binding globulin in adolescent boys.

Different Food Sources of Fructose-Containing Sugars and Fasting Blood Uric Acid Levels: A Systematic Review and Meta-Analysis of Controlled Feeding Trials

BACKGROUND

Although fructose as a source of excess calories increases uric acid, the effect of the food matrix is unclear.

OBJECTIVES

To assess the effects of fructose-containing sugars by food source at different levels of energy control on uric acid, we conducted a systematic review and meta-analysis of controlled trials.

METHODS

MEDLINE, Embase, and the Cochrane Library were searched (through 11 January 2021) for trials ≥ 7 days. We prespecified 4 trial designs by energy control: substitution (energy-matched replacement of sugars in diets); addition (excess energy from sugars added to diets); subtraction (energy from sugars subtracted from diets); and ad libitum (energy from sugars freely replaced in diets) designs. Independent reviewers (≥2) extracted data and assessed the risk of bias. Grading of Recommendations, Assessment, Development, and Evaluation was used to assess the certainty of evidence.

RESULTS

We included 47 trials (85 comparisons; N = 2763) assessing 9 food sources [sugar-sweetened beverages (SSBs), sweetened dairy, fruit drinks, 100% fruit juice, fruit, dried fruit, sweets and desserts, added nutritive sweetener, and mixed sources] across 4 energy control levels in predominantly healthy, mixed-weight adults. Total fructose-containing sugars increased uric acid levels in substitution trials (mean difference, 0.16 mg/dL;  95% CI:  0.06-0.27 mg/dL;  P = 0.003), with no effect across the other energy control levels. There was evidence of an interaction by food source: SSBs and sweets and desserts increased uric acid levels in the substitution design, while SSBs increased and 100% fruit juice decreased uric acid levels in addition trials. The certainty of evidence was high for the increasing effect of SSBs in substitution and addition trials and the decreasing effect of 100% fruit juice in addition trials and was moderate to very low for all other comparisons.

CONCLUSIONS

Food source more than energy control appears to mediate the effects of fructose-containing sugars on uric acid. The available evidence provides reliable indications that SSBs increase and 100% fruit juice decreases uric acid levels. More high-quality trials of different food sources are needed. This trial was registered at clinicaltrials.gov as NCT02716870.

Association of eating out frequency and other factors with serum uric acid levels and hyperuricemia in Chinese population

PURPOSE

A significant shift in meal pattern with frequent eating out was closely associated with multiple chronic outcomes, but with limited evidence on hyperuricemia. We aimed to explore the associations between eating out and serum uric acid (SUA) as well as hyperuricemia.

METHODS

A total of 29,597 participants were recruited from the Henan Rural Cohort Study. A validated food frequency questionnaire (FFQ) was used to collect dietary data, including the frequency of eating out. Linear regression models were used to examine the association of eating-out frequency with SUA and BMI. Logistic regression and restricted cubic spline were performed to assess the association and dose-response relationship between eating-out frequency and hyperuricemia. The mediation effect of BMI between eating out and the risk of hyperuricemia was evaluated.

RESULTS

Eating out was significantly associated with higher SUA levels in the total population and males (P < 0.001). Multivariate-adjusted odds ratios (ORs) with 95% confidence interval (CIs) of hyperuricemia were 1.26 (1.09, 1.46) for the total population and 1.18 (1.00, 1.40) for males (≥ 7 times/week vs 0 time/week). A non-linear positive dose-response relationship between eating-out frequency and hyperuricemia was observed. Furthermore, BMI played a partial mediating role in the relationship between eating out frequency and hyperuricemia, which explained 30.7% in the total population and 44.8% in males.

CONCLUSION

Our findings indicated that eating out was associated with increased SUA levels and elevated hyperuricemia risk in rural China, especially in males. Moreover, the relationship was partly mediated by BMI.

CLINICAL TRIALS

ChiCTR-OOC-15006699 (2015-07-06).

Function of Uric Acid Transporters and Their Inhibitors in Hyperuricaemia

Disorders of uric acid metabolism may be associated with pathological processes in many diseases, including diabetes mellitus, cardiovascular disease, and kidney disease. These diseases can further promote uric acid accumulation in the body, leading to a vicious cycle. Preliminary studies have proven many mechanisms such as oxidative stress, lipid metabolism disorders, and rennin angiotensin axis involving in the progression of hyperuricaemia-related diseases. However, there is still lack of effective clinical treatment for hyperuricaemia. According to previous research results, NPT1, NPT4, OAT1, OAT2, OAT3, OAT4, URAT1, GLUT9, ABCG2, PDZK1, these urate transports are closely related to serum uric acid level. Targeting at urate transporters and urate-lowering drugs can enhance our understanding of hyperuricaemia and hyperuricaemia-related diseases. This review may put forward essential references or cross references to be contributed to further elucidate traditional and novel urate-lowering drugs benefits as well as provides theoretical support for the scientific research on hyperuricemia and related diseases.

Gout

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

Sex-Specific Association of Uric Acid and Kidney Function Decline in Taiwan

An elevated serum urate concentration is associated with kidney damage. Men’s uric acid levels are usually higher than women’s. However, postmenopausal women have a higher risk of gout than men, and comorbidities are also higher than in men. This study examined the sex differences in the relationship between hyperuricemia and renal progression in early chronic kidney disease (CKD) and non-CKD, and further examined the incidence of CKD in non-CKD populations among patients over 50 years of age. We analyzed 1856 women and 1852 men participating in the epidemiology and risk factors surveillance of the CKD database. Women showed a significantly higher risk of renal progression and CKD than men within the hyperuricemia group. After adjusting covariates, women, but not men resulted in an hazard ratio (HR) for developing renal progression (HR = 1.12; 95% CI 1.01–1.24 in women and HR = 1.03; 95% CI 0.93–1.13 in men) and CKD (HR = 1.11; 95% CI 1.01–1.22 in women and HR = 0.95; 95% CI 0.85–1.05 in men) for each 1 mg/dL increase in serum urate levels. The association between serum urate levels and renal progression was stronger in women. Given the prevalence and impact of kidney disease, factors that impede optimal renal function management in women and men must be identified to provide tailored treatment recommendations.

Reporting quality of clinical practice guidelines regarding gout and hyperuricemia according to the RIGHT checklist: systematic review

BACKGROUND

The Reporting Items for Practice Guidelines in Healthcare (RIGHT) checklist was used to assess the reporting quality of 2009-2019 clinical practice guidelines (CPGs) regarding gout and hyperuricemia, aimed to improve the reporting quality of future guidelines.

METHODS

We searched PubMed, the Chinese Biomedical Literature database, the Wanfang Database, and the China National Knowledge Infrastructure from January 2009 to June 2019 for guidelines regarding gout and hyperuricemia. We also searched the websites of guideline development organizations (the Guidelines International Network, the National Institute for Health and Clinical Excellence, the American College of Rheumatology, and the European League Against Rheumatism (EULAR)). Furthermore, supplementary guidelines reported in included articles were systematically searched, as well as Google Scholar.

RESULTS

Seventeen guidelines were included, of which one was in Chinese and 16 were in English. The mean reporting rate of the 35 items specified was 14.9 (42.5%); only five CPGs (29.4%) had a reporting rate >50%. Of the 35 items, three were very frequently reported. The reporting proportion of the seven domains (basic information, background, evidence, recommendations, review and quality assurance, funding and declaration and management of interests, and other information) were 64.7%, 36.8%, 50.6%, 42.9%, 8.82%, 33.8%, and 31.4%, respectively.

CONCLUSION

The reporting quality of the present guidelines for gout and hyperuricemia is relatively poor. We suggest that the RIGHT reporting checklist should be used by CPG developers to ensure higher reporting quality of future guidelines.

Incident gout and weight change patterns: a retrospective cohort study of US adults

BACKGROUND

Although the relationship between obesity and incident gout has been clarified, the influence of weight changes during the transition from early adulthood to midlife and the different weight change patterns in specific age ranges on the incidence of gout in later life remain unknown. Therefore, we aimed to investigate the association between weight change patterns across adulthood and incident gout.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES), we categorized individuals into four weight change patterns: those who remained obese (stable obese), those who moved from a non-obese body mass index (BMI) to an obese BMI (gaining), those who moved from an obese BMI to a non-obese BMI (losing), and those who remained non-obese (stable non-obese). Incident gout reflected its occurrence over the 10-year follow-up from the recalled midlife weight measure to the time of this survey. Hazard ratios (HRs) and 95% confidence intervals relating weight change patterns to incident gout over the 10-year follow-up period were calculated using Cox models adjusted for covariates. The hypothetical population attributable fraction (PAF) for the weight change patterns was calculated.

RESULTS

Among our sample of adults aged 40-74 years at their midlife weight measure (n = 11,079), 320 developed gout. The highest risk of incident gout was found for participants with the stable obese pattern (HR 1.84; 1.08-3.14) and not for participants who remained stable non-obese during adulthood. Moreover, gaining weight was a significant risk factor for incident gout (HR 1.65; 1.19-2.29). No significant associations were found between losing weight change patterns and the risk of gout during the study period. If participants who gained weight had become non-obese during the 10-year follow-up, an estimated 3.2% (95% CI 0-6.3) of observed gout cases could have been averted. In addition, if the population had maintained a normal BMI, 32.9% (95% CI 18.2-44.9) cases could have been prevented during the 10 years.

CONCLUSIONS

Gaining weight over adulthood was associated with an increased risk of gout. These findings have highlighted that maintaining non-obese weight and weight loss across adulthood is essential for the prevention and treatment of gout in adult life.

Gender-Specific Inverse Associations Between Beans Intake, Serum Urate Levels, and Hyperuricemia: A Cross-Sectional Analysis Based on the Henan Rural Cohort Study

Background and Aims: Beans are rich in purines, which are important substances that lead to elevated serum urate, especially exogenous purines. Few studies were conducted to assess the relationship between beans intake and serum urate or hyperuricemia, especially in rural people. The purpose of this study was to validate the association by gender in the rural Chinese population.

Methods: A total of 38,855 participants aged 18–79 years old were enrolled from the Henan Rural Cohort Study (Registration number: ChiCTR-OOC-15006699). Dietary data were collected using a validated food frequency questionnaire (FFQ). Linear regression models and logistic regression models were used to examine the associations between beans intake and serum urate levels or hyperuricemia. Restricted cubic spline regression was performed to display the dose–response relationship.

Results: In multivariate-adjusted linear regression, an inverse correlation was found between beans intake and serum urate level (the highest quartile Q4 vs. the bottom quartile Q1) in both men (P = 0.008) and women (P < 0.001). Per 10-g increment in beans intake was associated with 0.30 μmol/L decreased concentration of serum urate in men and 0.71 μmol/L in women. The multivariate-adjusted odds ratios (ORs) of hyperuricemia were 0.83 (0.71, 0.97) in men and 0.73 (0.63, 0.84) in women (Q4 vs. Q1). Per 10-g increment in beans intake created a 1% decreased risk of hyperuricemia in men and 3% in women. The cubic spline suggested a risk reduction for hyperuricemia with increasing intake of beans.

Conclusion: A higher beans intake was associated with a lower serum urate level and a reduced risk of hyperuricemia in both sexes, and the association was more pronounced in women.

Gicht – auch eine Frage des Lebensstiles

Mit steigenden Harnsäurewerten steigt das Risiko einer Gicht. Da die Harnsäure-Homöostase von zahlreichen Lebensstilfaktoren beeinflusst wird, ist das Auftreten einer Gicht fast immer auch mit der Lebensweise assoziiert. Lange schon ist bekannt, dass die Zufuhr purinreicher Lebensmittel (z. B. Fleisch, Meeresfrüchte) über vermehrte Harnsäurebildung aus exogen zugeführten Purinen zu Gichtanfällen führen kann. Auch Fruktose-haltige Getränke haben über einen vermehrten Abbau von ATP bei der Verstoffwechslung von Fruktose eine Hyperurikämie zur Folge, wogegen bei vermehrter Alkoholzufuhr und Adipositas eine verminderte renale Harnsäureausscheidung für die Hyperurikämie ursächlich ist. Einige Lebensmittel (z. B. Milch, Kaffee) scheinen einen harnsäuresenkenden Effekt zu haben und können Patienten explizit empfohlen werden. Mit Blick auf den Lebensstil spielen jedoch nicht nur Ernährungsfaktoren (Lebensmittel) eine wichtige Rolle. So kommt es beim aktuell sehr populären Heilfasten durch die entstehende Ketose und häufig gleichzeitig zu geringer Flüssigkeitszufuhr zu einer verminderten Harnsäureausscheidung über die Niere und konsekutiv Harnsäureanstieg. Auch Extremsport wie Marathon stellt aufgrund der katabolen Stoffwechsellage (Ketose) und hohen mechanischen Belastung (Mikrotraumata) bereits arthrotisch vorgeschädigter Gelenke einen Risikofaktor für das gehäufte Auftreten von Gichtanfällen dar. Patienten mit einer Hyperurikämie sollten als Basismaßnahme immer über eine mögliche Ernährungsumstellung beraten werden, zumal die Hyperurikämie eng mit dem metabolischen Syndrom assoziiert ist, häufigen Stoffwechselkrankheiten wie Diabetes mellitus, Hyperlipidämien und Adipositas, die ebenfalls durch eine Lebensstilmodifikation günstig zu beeinflussen sind. Eine manifeste (langjährige) Gicht kann allerdings durch eine alleinige Ernährungsumstellung nur selten erfolgreich behandelt werden. Der Zusammenhang zwischen Lebensstil und Gicht ist seit Jahrhunderten bekannt. Leider beschränken sich die wenigen Studien zu diesem Thema meist auf epidemiologische Erhebungen, über die in dieser Arbeit eine Übersicht gegeben werden soll.

Uric acid preconditioning alleviated doxorubicin induced JNK activation and Cx43 phosphorylation associated cardiotoxicity via activation of AMPK-SHP2 signaling pathway

Background

Doxorubicin is an anthracycline antibiotic, which is effective for treating various malignancies such as leukemias and lymphomas. However, its serious cumulative dose-dependent cardiotoxicity limits its clinical application. Previous studies have shown that doxorubicin-associated cardiotoxicity is closely related to adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK). Uric acid is known to exert a strong antioxidant function and moderate protection on the nerves. However, its cardioprotective properties have not been established. This study aimed to investigate the potential effect of uric acid preconditioning on doxorubicin-induced cardiotoxicity and the involvement of AMPK signaling in this process.

Methods

An acute cardiotoxicity model of doxorubicin was established by intraperitoneal injection of a single dose of doxorubicin (20 mg/kg) in mice. Uric acid (62.5, 125, and 250 mg/kg) was intragastrically administered to mice one day before doxorubicin treatment and then continuously administered every 24 h for 8 consecutive days. The mortality rate and weight of the mice were recorded every day. Electrocardiograms (ECG) and serum biochemicals were detected with an ECG instrument and enzyme-linked immunosorbent assay kit (Elisa) respectively. A real-time cell analyzer (RTCA) was used to investigate the cytotoxicity of doxorubicin in vitro. Cell signaling was assayed by western blotting.

Results

Uric acid (125 mg/kg) preconditioning increased the survival rate and body weight of doxorubicin-treated mice. Uric acid also effectively alleviated prolongation of the doxorubicin-induced QT interval, slowed heart rate, and reduced the plasma levels of aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) in plasma in mice. Moreover, uric acid strongly activated AMPK and Src homology 2 domain-containing protein tyrosine phosphatase (SHP2), inhibiting doxorubicin-induced expression phosphorylated-c-Jun N-terminal kinases (JNK) and phosphorylated-connexin 43 (Cx43) in vitro and in vivo and effectively reversing the doxorubicin-induced decreased viability of H9C2 myocardial cells in vitro.

Conclusions

We demonstrated that uric acid preconditioning alleviated doxorubicin-induced cardiotoxicity through the AMPK-SHP2-JNK-Cx43 signaling pathway.

High Serum Uric Acid Was a Risk Factor for Incident Asthma: An Open Cohort Study

Background

Several cross-sectional studies have suggested an association between SUA and asthma. However, few studies have investigated this relationship longitudinally. Although SUA is an independent risk factor for chronic kidney disease and cardiovascular diseases, its contribution to incident asthma remains uncertain.

Objective

To determine whether a high SUA was a risk factor for adult incident asthma.

Methods

By using health care data from the Shandong multicenter health check-up, 76,369 participants, aged 20 to 79 years, were identified who had an SUA determination with a mean follow-up period of 3.73±2.21 years. Multivariate modeling employed Cox proportional hazards models to verify the association between SUA and incident asthma by adjusting age, BMI, smoking habits, drinking habits, and asthma-like diseases.

Results

A total of 51,389 individuals were included in the analysis. Cut-off values of SUA able to discriminate asthma status were identified by means of maximally selected rank statistics in the whole participants (≥376.80umol/L), women (≥314.45umol/L), and men (≥376.80umol/L). Multivariate Cox regression analyses adjusted for covariates (age, body mass index (BMI), smoking habit, drinking habit, and asthma-like disease) identified an independent association between SUA and incident asthma in the whole participants (hazard ratio (HR) 2.92, 95% confidence intervals (CI), 1.76–4.48, P=0.00) and men (HR 3.02, 95% CI 1.70–5.39, P=0.00), but not in women.

Conclusion

The results of the current study confirmed that high SUA was an independent risk factor for incident asthma after adjustment of potential covariates and suggested that a cut-off value related to incident asthma could be identified only in men.

Association between serum uric acid and spirometric pulmonary function in Korean adults: The 2016 Korea National Health and Nutrition Examination Survey

BACKGROUND

A limited number of epidemiological studies have investigated the association between serum uric acid and pulmonary function in the general population. However, the results have been inconclusive.

OBJECTIVES

This study was performed to investigate the association between serum uric acid and spirometric pulmonary function in general population.

METHODS

Among the 8,150 participants who participated in the 2016 Korea National Health and Nutrition Examination Survey, 2,901 participants were analyzed in this study. Subjects were divided into four groups according to forced vital capacity (FVC)% predicted or forced expiratory volume in 1 second (FEV1) % predicted quartiles. Participants in the lowest quartile of FVC % predicted and FEV1% predicted were compared to those in the remaining quartiles according to age, education level, household income, smoking status, alcohol consumption, aerobic exercise, obesity, hypertension, diabetes, renal impairment, serum uric acid, and hyperuricemia. Multivariable logistic regression analyses were used to calculate the odds ratio (OR) of hyperuricemia for participants in the lowest quartile of FVC% and FEV1 predicted, with above covariates.

RESULTS

In women, hyperuricemia was associated with lowest quartile of FVC% predicted (OR 1.71, 95% CI 1.06-2.75, p = 0.027) and FEV1 predicted (OR 1.70, 95% CI 1.06-2.74, p = 0.028) respectively, serving as above confounding variables. In men, hyperuricemia (OR 1.54, 95% CI 1.07-2.22, p = 0.021) was associated with the lowest quartile of FEV1% predicted, not FVC% predicted. According to median age, in women, age ≥ 56 years old with hyperuricemia was associated with lowest quartile of FVC% predicted (OR 1.85, 95% CI 1.04-3.28, p = 0.037) and FEV1% predicted (OR 1.99, 95% CI 1.11-3.75, p = 0.021), respectively. In men, age ≥ 56 years old with hyperuricemia was associated with lowest quartile of FEV1% predicted (OR 1.75, 95% CI 1.05-2.94, p = 0.033), not FCV% predicted.

CONCLUSIONS

Hyperuricemia was associated with lowest quartile of FEV1% or FVC% predicted in Korean general population. This correlation between hyperuricemia and low pulmonary function was more pronounced in women and older age.

Association of urate deposition shown by ultrasound and frequent gout attacks

BACKGROUND

There are few data demonstrating the association between urate burden assessed by ultrasound (US) and gout flares. The aim of this study was to determine the association of urate deposition shown by US and frequent gout attacks.

MATERIALS AND METHODS

Patients with gout were divided into two groups according to the frequency of gout attacks in the previous 12 months: frequent (>2 attacks) and infrequent (0-2 attacks). Urate deposition in the hands, knees, and feet was assessed by US.

RESULTS

Overall, 106 patients were enrolled in this study, of whom 32 (30.1%) had had frequent gout attacks (>2 attacks) in the previous 12 months (the average number of gout attacks was 4.7, range 3-12). Those with frequent gout attacks had significantly longer gout duration, a higher serum urate level, and more urate deposition shown by US than those with infrequent gout attacks (P < 0.05). In both univariate and logistic regression analyses, frequent gout attacks were correlated with gout duration, serum urate level, and urate deposition as shown by US (P < 0.05).

CONCLUSION

These findings indicate that urate deposition shown by US is independently associated with frequent gout attacks. Special attention should be given to the prevention of flares in patients with an initially high urate burden as assessed by US.