Association between low-density lipoprotein cholesterol levels and serum uric acid to serum creatinine ratio in Chinese male gout patients.

This study aimed to evaluate the association between low-density lipoprotein cholesterol (LDL-C) and serum uric acid to serum creatinine (SUA/SCr) ratio in male gout patients at different BMIs. This real-world study included 956 male gout patients aged 18-83 years. We retrospectively analyzed the medical records of Chinese male gout patients from 2017 to 2019. The correlation between LDL-C and SUA/SCr was tested after adjusting for confounding factors. We found a nonlinear relationship between LDL-C and SUA/SCr in the whole study population. Stratification analysis showed that there was actually a nonlinear relationship between LDL-C and SUA/SCr in men with a BMI of 24-28, the inflection point of LDL-C was 1.8 mmol/L, when LDL-C was greater than 1.8 mmol/L, there was a positive correlation between LDL-C levels and SUA/SCr (ß = 0.67, 95% CI 0.35-0.98, P < 0.001). Moreover, LDL-C showed a significant positive correlation with SUA/SCr with a BMI of 28 or greater (ß = 0.30, 95% CI 0.05-0.55, P = 0.019). However, no association was found between LDL-C and SUA/SCr with a BMI of less than 24 (ß = 0.42, 95% CI - 0.03-0.86, P = 0.070). LDL-C levels were associated with SUA/SCr in Chinese male gout patients, but this correlation appeared inconsistent among different BMIs. Our findings suggest that LDL-C levels may be more noteworthy in overweight and/or obese male gout patients.

Large-scale cross-ancestry genome-wide meta-analysis of serum urate.

Hyperuricemia is an essential causal risk factor for gout and is associated with cardiometabolic diseases. Given the limited contribution of East Asian ancestry to genome-wide association studies of serum urate, the genetic architecture of serum urate requires exploration. A large-scale cross-ancestry genome-wide association meta-analysis of 1,029,323 individuals and ancestry-specific meta-analysis identifies a total of 351 loci, including 17 previously unreported loci. The genetic architecture of serum urate control is similar between European and East Asian populations. A transcriptome-wide association study, enrichment analysis, and colocalization analysis in relevant tissues identify candidate serum urate-associated genes, including CTBP1, SKIV2L, and WWP2. A phenome-wide association study using polygenic risk scores identifies serum urate-correlated diseases including heart failure and hypertension. Mendelian randomization and mediation analyses show that serum urate-associated genes might have a causal relationship with serum urate-correlated diseases via mediation effects. This study elucidates our understanding of the genetic architecture of serum urate control.

Serum Urate and Recurrent Gout.

Importance: Approximately 12 million adults in the US have a history of gout, but whether serum urate levels can help predict recurrence is unclear. Objective: To assess associations of a single serum urate measurement with subsequent risk of acute gout flares and subsequent risk of hospitalizations for gout among patients in the UK with a history of gout. Design, Setting, and Participants: This retrospective study included patients with a history of gout identified from the UK between 2006 and 2010 who were followed up through Primary Care Linked Data medical record linkage until 2017 and through the Hospital Episode Statistics database until 2020. Exposures: Serum urate levels at enrollment. Main Outcome and Measure: Rate of recurrent acute gout, ascertained by hospitalization, outpatient, and prescription/procedure records, and adjusted rate ratios using negative binomial regressions. Results: Among 3613 patients with gout (mean age, 60 years; 3104 [86%] men), 1773 gout flares occurred over a mean follow-up of 8.3 years. Of these, 1679 acute gout flares (95%) occurred in people with baseline serum urate greater than or equal to 6 mg/dL and 1731 (98%) occurred in people with baseline serum urate greater than or equal to 5 mg/dL. Rates of acute gout flares per 1000 person-years were 10.6 for participants with baseline urate levels less than 6 mg/dL, 40.1 for levels of 6.0 to 6.9 mg/dL, 82.0 for levels of 7.0 to 7.9 mg/dL, 101.3 for levels of 8.0 to 8.9 mg/dL, 125.3 for urate levels of 9.0 to 9.9 mg/dL, and 132.8 for levels greater than or equal to 10 mg/dL. Rate ratio of flares were 1.0, 3.37, 6.93, 8.67, 10.81, and 11.42, respectively, over 10 years (1.61 [1.54-1.68] per mg/dL). Rates of hospitalization per 1000 person-years during follow-up were 0.18 for those with baseline serum urate less than 6 mg/dL, 0.97 for serum urate of 6.0 to 6.9 mg/dL, 1.8 for serum urate of 7.0 to 7.9 mg/dL, 2.2 for serum urate of 8.0 to 8.9 mg/dL, 6.7 for serum urate of 9.0 to 9.9 mg/dL, and 9.7 for serum urate greater than or equal to 10 mg/dL. Rate ratios of hospitalization for gout, adjusting for age, sex, and race were 1.0, 4.70, 8.94, 10.37, 33.92, and 45.29, respectively (1.87 [1.57-2.23] per mg/dL). Conclusions and Relevance: In this retrospective study of patients with a history of gout, serum urate levels at baseline were associated with the risk of subsequent gout flares and rates of hospitalization for recurrent gout. These findings support using a baseline serum urate level to assess risk of recurrent gout over nearly 10 years of follow-up.

The development and evaluation of dose-prediction tools for allopurinol therapy (Easy-Allo tools).

AIMS: Dose escalation at the initiation of allopurinol therapy can be protracted and resource intensive. Tools to predict the allopurinol doses required to achieve target serum urate concentrations would facilitate the implementation of more efficient dose-escalation strategies. The aim of this research was to develop and externally evaluate allopurinol dosing tools, one for use when the pre-urate-lowering therapy serum urate is known (Easy-Allo1) and one for when it is not known (Easy-Allo2). METHODS: A revised population pharmacokinetic-pharmacodynamic model was developed using data from 653 people with gout. Maintenance doses to achieve the serum urate target of <0.36 mmol L-1 in >80% of individuals were simulated and evaluated against external data. The predicted and observed allopurinol doses were compared using the mean prediction error (MPE) and root mean square error (RMSE). The proportion of Easy-Allo predicted doses within 100 mg of the observed was quantified. RESULTS: Allopurinol doses were predicted by total body weight, baseline urate, ethnicity and creatinine clearance. Easy-Allo1 produced unbiased and suitably precise dose predictions (MPE 2 mg day-1 95% confidence interval [CI] -13-17, RMSE 91%, 90% within 100 mg of the observed dose). Easy-Allo2 was positively biased by about 70 mg day-1 and slightly less precise (MPE 70 mg day-1 95% CI 52-88, RMSE 131%, 71% within 100 mg of the observed dose). CONCLUSIONS: The Easy-Allo tools provide a guide to the allopurinol maintenance dose requirement to achieve the serum urate target of <0.36 mmol L-1 and will aid in the development of novel dose-escalation strategies for allopurinol therapy.

Estimation of adherence to urate-lowering therapy in people living with gout using Australia's Pharmaceutical Benefits Scheme and patient-reported dosing.

AIMS: The aim of this study was to estimate adherence to urate-lowering therapy (ULT), predominately allopurinol, from Australia's Pharmaceutical Benefits Scheme (PBS) claims database in association with (1) patient-reported doses and (2) World Health Organization's (WHO) defined daily doses (DDD), namely, allopurinol (400 mg/day) or febuxostat (80 mg/day). METHODS: Proportion of days covered (PDC) was calculated in 108 Gout App (Gout APP) trial participants with at least two recorded ULT dispensings in an approximately 12-month period before provision of intervention or control apps. Adherence was defined as PDC ≥80%. We measured the correlation between the two methods of calculating PDC using a Wilcoxon signed rank test. Agreement between ULT-taking status (self-reports) and ULT-dispensed status (PBS records) was tested with Cohen's kappa (κ), and positive and negative percent agreement. RESULTS: Allopurinol was prescribed in 93.5% of participants taking ULT. Their self-reported mean daily dose (SD) was 291 (167) mg/day. Mean PDC (SD) for allopurinol was 83% (21%) calculated using self-reported dose, and 63% (24%) using WHO's DDD. Sixty-three percent of allopurinol users were identified as adherent (PDC ≥80%) using self-reported dose. There was good agreement between self-reported ULT use and PBS dispensing claims (κ = 0.708, P < .001; positive percent agreement = 90%, negative percent agreement = 82%). CONCLUSIONS: Participant-reported allopurinol daily doses, in addition to PBS dispensing claims, may enhance confidence in estimating PDC and adherence compared to using DDD. This approach improves adherence estimations from pharmaceutical claims datasets for medications where daily doses vary between individuals or where there is a wide therapeutic dose range.

Trends in Prevalence of Gout Among US Asian Adults, 2011-2018.

Importance: Gout disparities among Black individuals in the US have recently been explained by socioclinical factors; however, no information is available among Asian individuals living in Western countries, despite their disproportionately worsening metabolic health. Objective: To determine the prevalence of gout and serum urate concentrations according to race and ethnicity and to explore the association of social determinants of health and clinical factors. Design, Setting, and Participants: This is a population-based, cross-sectional analysis. Data from a nationally representative sample of US adults were obtained from the National Health and Nutrition Examination Survey (NHANES) (2011-2018) in which Asian race data were collected (primary). Data from the UK Biobank (2006-2021) were used for replication of the Asian vs White differences. Data analysis was performed from December 2021 to September 2022. Main Outcomes and Measures: Race-specific gout prevalence and serum urate levels. Results: A total of 22 621 participants from NHANES (2011-2018) were included in the analysis (mean [SD] age, 49.8 [17.8] years; 10 948 male participants [48.4%]). In 2017 to 2018, gout affected 12.1 million US individuals, with its crude prevalence increasing from 3.6% (95% CI, 2.8%-4.5%) in 2011 to 2012 to 5.1% (95% CI, 4.2%-5.9%) in 2017 to 2018 (P for trend = .03); this trend was no longer significant after age adjustment (P for trend = .06) or excluding Asian individuals (P for trend = .11). During the same period, age- and sex-adjusted prevalence among Asian Americans doubled from 3.3% (95% CI, 2.1%-4.5%) to 6.6% (95% CI, 4.4%-8.8%) (P for trend = .007) to numerically exceed all other racial and ethnic groups in 2017 to 2018, with age- and sex-adjusted odds ratio (ORs) of 1.61 (95% CI, 1.03-2.51) and a socioclinical factor-adjusted multivariable OR of 2.62 (95% CI, 1.59-4.33) for Asian vs White individuals. The latest age- and sex-adjusted gout prevalence among US individuals aged 65 years and older was 10.0% among White individuals and 14.8% among Asian individuals (including 23.6% of Asian men). Serum urate concentrations also increased between 2011 and 2018 among US Asian individuals (P for trend = .009). The Asian vs White disparity was also present in the UK Biobank. Conclusions and Relevance: The findings of this study suggest that the prevalence of gout among Asian individuals numerically surpassed that for all other racial and ethnic groups in 2017 to 2018. This Asian vs White disparity did not appear to be associated with socioclinical factors.

Up-regulation of HSPA1A and HSPA1B in the blood of tophi patients and its clinical significance.

OBJECTIVE: Poorly treated gout can cause tophi, which can lead to serious and potentially fatal complications. This study aimed to find the potential diagnostic value of blood levels of HSPA1A and HSPA1B for tophi patients. METHODS: 58 tophi patients and 61 healthy controls were enrolled in this study, and the whole venous blood samples of all subjects were collected for microarray analysis to identify differentially expressed genes associated with tophi. Meanwhile, KEGG and GO analysis were used to filtrate the enriched different expression genes. The mRNA expression levels of HSPA1A, as well as HSPA1B, were measured by the RT-qPCR method, the correlation between which and the severity of the disease were analyzed. Finally, the receiver operating characteristics curve (ROC) analysis has been performed to the diagnostic value of HSPA1A as well as HSPA1B. RESULTS: Bioinformatic analysis results suggested that both HSPA1A and HSPA1B are abnormally expressed in tophi. Then, it was observed that HSPA1A and HSPA1B were dramatically increased in the blood samples of tophi patients compared with healthy controls and were further linked with the severity of tophi. Moreover, the area under the curve (AUC) of HSPA1A for the diagnosis of ACI was 0.8999 (95% confidence interval (CI), 0.8338 to 0.9661) while of HSPA1B was 0.9093 (95% confidence interval (CI), 0.8550 to 0.9635), suggesting that blood level of HSPA1A, as well as HSPA1B, are sensitive markers to distinguish tophi patients from the healthy people. CONCLUSION: HSPA1A and HSPA1B were over-expressed in the blood of tophi patients and may be potential diagnostic markers for tophi.

Model-based cost-effectiveness analyses comparing combinations of urate lowering therapy and anti-inflammatory treatment in gout patients.

OBJECTIVES: To assess the cost-effectiveness of various combinations of urate lowering therapy (ULT) and anti-inflammatory treatment in the management of newly diagnosed gout patients, from the Dutch societal perspective. METHODS: A probabilistic patient-level simulation estimating costs and quality-adjusted life years (QALYs) comparing gout and hyperuricemia treatment strategies was performed. ULT options febuxostat, allopurinol and no ULT were considered. Flare treatments naproxen, colchicine, prednisone, and anakinra were considered. A Markov Model was constructed to simulate gout disease. Health states were no flare, and severe pain, mild pain, moderate pain, or no pain in the presence of a flare. Model input was derived from patient level clinical trial data, meta-analyses or from previously published health-economic evaluations. The results of probabilistic sensitivity analyses were presented using incremental cost-effectiveness ratios (ICERs), and summarized using cost-effectiveness acceptability curves (CEACs). Scenario analyses were performed. RESULTS: The ICER for allopurinol versus no ULT was €1,381, when combined with naproxen. Febuxostat yielded the highest utility, but also the highest costs (€4,385 vs. €4,063 for allopurinol), resulting in an ICER of €25,173 when compared to allopurinol. No ULT was not cost-effective, yielding the lowest utility. For the gout flare medications, comparable effects on utility were achieved. Combined with febuxostat, naproxen was the cheapest option (€4,404), and anakinra the most expensive (€4,651). The ICER of anakinra compared to naproxen was €818,504. Colchicine and prednisone were dominated by naproxen. CONCLUSION: Allopurinol and febuxostat were both cost-effective compared to No ULT. Febuxostat was cost-effective in comparison with allopurinol at higher willingness-to-pay thresholds. For treating gout flares, colchicine, naproxen and prednisone offered comparable health economic implications, although naproxen was the favoured option.

Associations between serum urate and telomere length and inflammation markers: Evidence from UK Biobank cohort.

Objective: Hyperuricemia and gout have become gradually more common. The effect of serum urate on organism aging and systematic inflammation is not determined. This study aims to evaluate whether serum urate is causally associated with cellular aging markers and serum inflammation markers. Methods: A Mendelian randomization study was performed on summary-level data from the largest published genome-wide association studies. Single nucleotide polymorphisms with a genome-wide significance level were selected as instrumental variables for leukocyte telomere length (LTL), and serum soluble makers of inflammation (CRP, IL-6, TNF-α, and IGF-1). Standard inverse variance weighted (IVW) method was used as the primary statistical method. The weighted median, MR-Egger regression, and MR-PRESSO methods were used for sensitivity analysis. Results: An inverse causal association of genetically predicted serum urate levels and LTL was found using IVW method (OR: 0.96, 95%CI 0.95, 0.97; ß=-0.040; SE=0.0072; P=4.37×10-8). The association was also supported by MR results using MR-Egger method and weighted median method. The MR-PRESSO analysis and leave-one-out sensitivity analysis supported the robustness of the combined results. In terms of other aging-related serum biomarkers, there was no evidence supporting a causal effect of serum urate on CRP, IL-6, TNF-α, or IGF-1 levels. Conclusions: Serum urate levels are negatively associated with telomere length but are not associated with serum soluble indicators of inflammation. Telomere length may be a critical marker that reflects urate-related organismal aging and may be a mechanism in the age-related pathologies and mortality caused by hyperuricemia.

Regular pre-admission urate-lowering therapy and serum urate testing are associated with a shorter hospital length of stay in people with gout: A nation-wide population-based cohort study.

OBJECTIVE: This study aims to explore the association between inpatient gout flare-related variables and the length of stay (LOS) in hospitalized people with comorbid gout. METHODS: Using data from the Aotearoa/New Zealand national data collections, this cohort study included adults with comorbid gout who were admitted to publicly funded hospitals during 2017 for reasons other than gout. The primary outcome was LOS. Association between 20 variables and the LOS was explored using two generalized linear models. Directed acyclic graph (DAG) was constructed to evaluate the causal relationship between pre-admission urate lowering therapy (ULT) and LOS. RESULTS: The cohort included 36 047 admissions. We identified five variables associated with shorter LOS (pre-admission regular urate-lowering therapy (ULT), serum urate testing, male gender, Maori ethnicity and low-dose aspirin) and seven variables associated with longer LOS (M3 multimorbidity index, acute admission, operation, loop diuretics, potassium-sparing diuretics, NSAIDs, and age). Regular ULT had the strongest impact on shorter LOS (10% shorter). The model estimated an additional four days of hospitalization if the patient had multiple variables associated with longer LOS. DAG suggested a causal relationship between regular ULT and LOS under the condition that all unobserved confounders affected only ULT use, with no impact on in-hospital gout flares and/or LOS except through its influence on ULT use or as mediator of confounders that were observed. CONCLUSION: We have identified a set of gout flare-related variables found to be associated with LOS in hospitalized people with comorbid gout. Pre-admission ULT may help reduce the LOS in such patients.

Epigenome-wide association study of serum urate reveals insights into urate co-regulation and the SLC2A9 locus.

Elevated serum urate levels, a complex trait and major risk factor for incident gout, are correlated with cardiometabolic traits via incompletely understood mechanisms. DNA methylation in whole blood captures genetic and environmental influences and is assessed in transethnic meta-analysis of epigenome-wide association studies (EWAS) of serum urate (discovery, n = 12,474, replication, n = 5522). The 100 replicated, epigenome-wide significant (p < 1.1E-7) CpGs explain 11.6% of the serum urate variance. At SLC2A9, the serum urate locus with the largest effect in genome-wide association studies (GWAS), five CpGs are associated with SLC2A9 gene expression. Four CpGs at SLC2A9 have significant causal effects on serum urate levels and/or gout, and two of these partly mediate the effects of urate-associated GWAS variants. In other genes, including SLC7A11 and PHGDH, 17 urate-associated CpGs are associated with conditions defining metabolic syndrome, suggesting that these CpGs may represent a blood DNA methylation signature of cardiometabolic risk factors. This study demonstrates that EWAS can provide new insights into GWAS loci and the correlation of serum urate with other complex traits.

Distribution of bony erosions in feet and performance of two bone erosion scores: A dual-energy computed tomography study of 61 patients with gout.

OBJECTIVES: To assess the distribution of bone erosions and two erosion scores in the feet of patients with gout and analyze the association between erosion scores and monosodium urate (MSU) crystal deposition using dual-energy computed tomography (DECT). MATERIALS AND METHODS: We included all patients who underwent DECT of both feet between 2016 and 2019 in our radiology department, with positive detection of MSU deposits. Data on sex, age, treatment, serum urate, and DECT urate volumes were obtained. CT images were analyzed to score bone erosions in 31 sites per foot by using the semi-quantitative method based on the Rheumatoid Arthritis MRI Scoring (RAMRIS) system and the Dalbeth-simplified score. Reproducibility for the two scores was calculated with intraclass correlation coefficients (ICCs). Correlations between clinical features, erosion scores and urate crystal volume were analyzed by the Spearman correlation coefficient (r). RESULTS: We studied 61 patients (mean age 62.0 years); 3,751 bones were scored. The first metatarsophalangeal joint and the midfoot were the most involved in terms of frequency and severity of bone erosions. The distribution of bone erosions was not asymmetrical. The intra- and inter-observer reproducibility was similar for the RAMRIS and Dalbeth-simplified scores (ICC 0.93 vs 0.94 and 0.96 vs 0.90). DECT urate volume was significantly correlated with each of the two erosion scores (r = 0.58-0.63, p < 0.001). There was a high correlation between the two scores (r = 0.96, p < 0.001). CONCLUSIONS: DECT demonstrates that foot erosions are not asymmetric in distribution and predominate at the first ray and midfoot. The two erosion scores are significantly correlated with DECT urate volume. An almost perfect correlation between the RAMRIS and Dalbeth-simplified scores is observed.

Uric Acid in Inflammation and the Pathogenesis of Atherosclerosis.

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

Decrease in Serum Urate Level Is Associated With Loss of Visceral Fat in Male Gout Patients.

Objective: To clarify the relationship between serum urate (SU) decrease and visceral fat area (VFA) reduction in patients with gout. Methods: We retrospectively analyzed 237 male gout patients who had two sets of body composition and metabolic measurements within 6 months. Subjects included had all been treated with urate-lowering therapy (ULT) (febuxostat 20-80 mg/day or benzbromarone 25-50 mg/day, validated by the medical record). All patients were from the specialty gout clinic of The Affiliated Hospital of Qingdao University. The multiple linear regression model evaluated the relationship between change in SU [ΔSU, (baseline SU) - (final visit SU)] and change in VFA [ΔVFA, (baseline VFA) - (final visit VFA)]. Results: ULT resulted in a mean (standard deviation) decrease in SU level (464.22 ± 110.21 µmol/L at baseline, 360.93 ± 91.66 µmol/L at the final visit, p <0.001) accompanied by a decrease in median (interquartile range) VFA [97.30 (81.15-118.55) at baseline, 90.90 (75.85-110.05) at the final visit, p < 0.001]. By multiple regression model, ΔSU was identified to be a significant determinant variable of decrease in VFA (beta, 0.302; p = 0.001). Conclusions: The decrease in SU level is positively associated with reduced VFA. This finding provides a rationale for clinical trials to affirm whether ULT promotes loss of visceral fat in patients with gout.

Implementation Status of Liver Function Tests for Monitoring Benzbromarone-Induced Hepatotoxicity: An Epidemiological Survey Using the Japanese Claims Database.

A major adverse effect of benzbromarone is hepatotoxicity. Therefore, periodic liver function tests are required at least for the first 6 months of benzbromarone administration. However, it is not clear whether the relevant blood tests are implemented appropriately. Here, we performed a cross-sectional survey of the implementation status of liver function tests in patients who were newly prescribed benzbromarone, using the Japanese large claims database. Male patients who were newly prescribed benzbromarone from January 2010 to December 2016 were included. We targeted patients who continued benzbromarone during the observation period (up to 180 d from the start of administration). The primary endpoint was the proportion of patients in whom periodic liver function tests were implemented. A periodic liver function test was defined as one or more liver function tests performed during both 1-90 and 91-180 d of initial benzbromarone administration. We labeled the tests as a "periodic test" or "non-periodic test" based on whether periodic liver function tests were performed or not, respectively. Furthermore, factors influencing non-periodic test were analyzed. Periodic testing was implemented only in 28.7% of patients. Additionally, factors such as number of hospital beds ≤19 (compared to 100-199 beds) and duration of the first prescription of benzbromarone were associated with non-periodic testing. Our study revealed that periodic liver function tests are not performed sufficiently in Japan. Thus, clinicians prescribing benzbromarone should be educated about the test. Our blood-test-based approach should be applied to other drugs and countries in future research.