Contemporary Prevalence of Gout and Hyperuricemia in the United States and Decadal Trends: The National Health and Nutrition Examination Survey, 2007-2016

The Epidemiology and Genetics of Hyperuricemia and Gout across Major Racial Groups: A Literature Review and Population Genetics Secondary Database Analysis

Gout is an inflammatory condition caused by elevated serum urate (SU), a condition known as hyperuricemia (HU). Genetic variations, including single nucleotide polymorphisms (SNPs), can alter the function of urate transporters, leading to differential HU and gout prevalence across different populations. In the United States (U.S.), gout prevalence differentially affects certain racial groups. The objective of this proposed analysis is to compare the frequency of urate-related genetic risk alleles between Europeans (EUR) and the following major racial groups: Africans in Southwest U.S. (ASW), Han-Chinese (CHS), Japanese (JPT), and Mexican (MXL) from the 1000 Genomes Project. The Ensembl genome browser of the 1000 Genomes Project was used to conduct cross-population allele frequency comparisons of 11 SNPs across 11 genes, physiologically involved and significantly associated with SU levels and gout risk. Gene/SNP pairs included: ABCG2 (rs2231142), SLC2A9 (rs734553), SLC17A1 (rs1183201), SLC16A9 (rs1171614), GCKR (rs1260326), SLC22A11 (rs2078267), SLC22A12 (rs505802), INHBC (rs3741414), RREB1 (rs675209), PDZK1 (rs12129861), and NRXN2 (rs478607). Allele frequencies were compared to EUR using Chi-Square or Fisher’s Exact test, when appropriate. Bonferroni correction for multiple comparisons was used, with p < 0.0045 for statistical significance. Risk alleles were defined as the allele that is associated with baseline or higher HU and gout risks. The cumulative HU or gout risk allele index of the 11 SNPs was estimated for each population. The prevalence of HU and gout in U.S. and non-US populations was evaluated using published epidemiological data and literature review. Compared with EUR, the SNP frequencies of 7/11 in ASW, 9/11 in MXL, 9/11 JPT, and 11/11 CHS were significantly different. HU or gout risk allele indices were 5, 6, 9, and 11 in ASW, MXL, CHS, and JPT, respectively. Out of the 11 SNPs, the percentage of risk alleles in CHS and JPT was 100%. Compared to non-US populations, the prevalence of HU and gout appear to be higher in western world countries. Compared with EUR, CHS and JPT populations had the highest HU or gout risk allele frequencies, followed by MXL and ASW. These results suggest that individuals of Asian descent are at higher HU and gout risk, which may partly explain the nearly three-fold higher gout prevalence among Asians versus Caucasians in ambulatory care settings. Furthermore, gout remains a disease of developed countries with a marked global rising.

Serum Uric Acid Levels and Risk of Eight Site-Specific Cancers: A Mendelian Randomization Study

The relationship between serum uric acid (UA) levels and cancer risk remains controversial. Here, a two-sample Mendelian randomization analysis was performed to identify a causal effect of serum UA levels on cancer risk. Twenty-six single nucleotide polymorphisms strongly associated with serum UA levels were screened as genetic variants from large-scale meta-analysis data of a genome-wide association study of 110,347 European individuals. Genetic associations with eight common site-specific cancers were subsequently explored. A total of six Mendelian randomization methods were used to estimate the potential effect of serum UA levels on cancer risk, including random effects inverse variance weighting, fix effects inverse variance weighting, MR-Egger, median weighting, mode weighting, and simple mode analysis. Our primary random effects inverse variance weighted analysis revealed that no significant associations with cancers was found (all p > 0.05). Sensitivity analyses and additional analyses also showed similar pooled results. In conclusion, no significant causality between serum UA levels and cancer risk was evidenced.

The Management of Gout in Renal Disease

Gout, a debilitating inflammatory arthritis, currently affects more than 9 million Americans. Hyperuricemia, the laboratory abnormality associated with the development of gout, also occurs in a significant number of patients with chronic kidney disease (CKD), a condition that affects approximately 14% of the US population. Several recent studies have attempted to provide a definitive link between the presence of hyperuricemia and progression of CKD; however, the treatment of asymptomatic hyperuricemia in CKD is not supported by recent randomized controlled trials. The pharmacology of acute gout flares and urate lowering is complicated in patients who also have evidence of CKD, primarily because of an increased risk of medication toxicity. Recipients of kidney transplants are particularly at risk of debilitating gout and medication toxicity. We review the available data linking CKD, gout, and hyperuricemia, providing practice guidelines on managing gout in CKD patients and kidney transplant recipients. We advocate for much greater involvement of nephrologists in the management of gout in renal patients.

Management and Cure of Gouty Arthritis

Gout is the most common inflammatory arthritis in the United States. Gouty arthritis is associated with significant morbidity and mortality and is caused by hyperuricemia. Gout is effectively managed and potentially cured by decreasing the overall urate burden with serum urate-lowering therapy. When serum urate is maintained at less than 6.0 mg/dL urate deposition is resolved and gout can be cured. Unfortunately, owing to a lack of physician monitoring and dose escalation the majority of patients do not achieve these urate levels.

Meta-analysis of the correlation between serum uric acid level and carotid intima-media thickness

Objective

Recently, increasing epidemiological evidence has shown that there is a correlation between serum uric acid level (SUA) and carotid intima-media thickness (CIMT). This paper explored the relationship between them through meta-analysis.

Methods

PubMed, Cochrane Library, EMBASE, Web of Science and Google Scholar were searched to obtain literature. The keywords used to retrieve the literature were carotid intima thickness, intima-media thickness, carotid atherosclerosis, carotid stenosis, carotid artery, uric acid, blood uric acid, and hyperuricaemia. The retrieval time was from the establishment of the database through July 2020. Stata15.0 and RevMan5.3 software were used for statistical analysis. The standardized mean difference (SMD) and 95% confidence interval (95% CI) were calculated by a random effect model to estimate the correlation. Publication bias was assessed using the Begg and Egger tests. The stability of these results was evaluated using sensitivity analyses.

Results

Fifteen studies were included with a total sample size of 11382, including 7597 participants in the high uric acid group and 3785 in the control group, on the basis of the inclusion and exclusion criteria. According to the evaluation of the JBI scale, the literature was of high quality. The average age ranged from 42 to 74. Meta-analysis showed that CIMT in the high uric acid group was significantly higher than that in the control group (SMD = 0.53, 95% CI: [0.38, 0.68]), and the difference was significant (z = 6.98, P < 0.00001). The heterogeneity among the 15 articles was obvious (I² = 89%, P < 0.00001). Subgroup analysis by disease status illustrated a positive relationship between SUA and CIMT in healthy people and people with diseases. SUA was shown to be positively correlated with CIMT in people aged 45–60 years and ≥60 years by subgroup analysis by age. SUA was also found to be positively correlated with CIMT in a population with BMI>24 kg/m² by subgroup analysis by BMI. In addition, subgroup analysis of other risk factors for CIMT, including TC, SBP, DBP, triglycerides, and LDL-C, all showed a positive correlation between SUA and CIMT.

Conclusions

There is a significant correlation between serum uric acid level and carotid intima-media thickness, and a high concentration of serum uric acid is related to carotid artery intima-media thickness.

Trends in the prevalence of kidney stones in the United States from 2007 to 2016

The overall prevalence of kidney stones (KS) in the US rose from 3.2% in 1980 to 10.1% in 2016, but the trends in important subgroups have not been reported. We examined the prevalence trends of KS in subgroups of age, sex and race in the US and identified relevant laboratory factors associated with a history of KS using National Health and Nutrition Examination Survey (NHANES) data. We conducted a cross-sectional study among 28,209 US adults aged ≥ 20 years old in the NHANES from 2007 to 2016. We calculated the prevalence of a self-reported history of KS by using weights and standardized to the 2010 US Census population. We also compared relevant laboratory values according to the history of KS. The prevalence of KS decreased from 8.7% in 2007-2008 to 7.2% in 2011-2012 but then increased to 9.0% in 2013-2014 and 10.1% in 2015-2016. However, the overall prevalence of KS increased over 2007-2016 (p-trend = 0.02). Prevalence of KS among men was higher than women. Among men aged 20-79, there were significant quadratic trends in the prevalence of KS. Whereas, the prevalence of KS increased as a linear trend among women aged 20-59 years over 2007-2016. There were no consistent trends in the prevalence of KS by race. The prevalence trend of KS among non-Hispanic whites was 9.8% from 2007 to 2010 then dropped to 7.9% in 2011-2012 and increased to 10.6% in 2013-2014 and 12.1% in 2015-2016. A similar trend was also observed among non-Hispanic blacks. Among Hispanic, the prevalence of KS was 7.6% in 2007-2008 and 7.4% in 2009-2010 and then fluctuated over the next several time periods. For non-Hispanic Asians, the range was 4.4-4.6%. Regarding relevant laboratory factors, after adjusting for sex, race, age, BMI, smoking status, alcohol drinking, history of diabetes and gout, urine albumin-creatinine ratio and serum osmolality were independently associated with the history of KS in women and men. In conclusion, there was substantial variability in KS prevalence across individual 2-year time periods. This variation of period-specific prevalence values emphasizes the importance of looking at long-term trends and using more than a single 2-year cycle in analyses to increase the precision of the estimate. However, there was an overall increase in the prevalence of KS over 2007-2016.

The visceral fat area to leg muscle mass ratio is significantly associated with the risk of hyperuricemia among women: a cross-sectional study

BACKGROUND

A significant positive association was found in previous studies among obesity, visceral fat accumulation, and hyperuricemia. The purpose of this study was to explore the association between the ratio of visceral fat area to leg muscle mass (VFA-to-LMM) and hyperuricemia, and verify the role of gender differences in the association.

METHODS

A total of 3393 (43.3% are men) participants from Tianjin Union Medical Center-Health Management Center were recruited for this cross-sectional study. The VFA-to-LMM ratio was used as the independent variable. Hyperuricemia, a serum uric acid level ≥ 416 μmol/L in men and in menopausal women and ≥ 357 μmol/L in premenopausal women, was used as the dependent variable. Multiple logistic regression analysis was used to estimate the odds ratio and the 95% confidence interval between the VFA-to-LMM ratio and hyperuricemia.

RESULTS

The overall prevalence of hyperuricemia was 14.8% (8.9% in women, and 22.5% in men). After adjustment by age, smoking status (for males), menopause status (for females), drinking status, exercise frequency, blood pressure, alanine aminotransferase, fasting plasma glucose, triglycerides, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, creatinine, and history of diseases, a strong positive association was found between the VFA-to-LMM ratio and hyperuricemia in both men (4th vs. 1st quartile 1.60, 95%CI: 1.03-2.49) and women (4th vs. 1st quartile 5.22, 95%CI: 2.44-12.56). After additional adjustment by BMI, there was still a significant positive association in women (4th vs. 1st quartile 2.57, 95%CI: 1.06-6.77). The results of subgroup analysis showed that pre-menopausal women (4th vs. 1st quartile OR: 3.61) have a higher risk of hyperuricemia than postmenopausal women (4th vs. 1st quartile OR: 1.94) with the increase of the VFA-to-LMM ratio. Besides, the interaction analysis results showed the highest risk of hyperuricemia when VFA and LMM were both in the highest quantile (OR: 11.50; 95% CI: 4.86-31.98).

CONCLUSION

The VFA-to-LMM ratio was positively associated with the risk of hyperuricemia in women after adjustment by confounders. Pre-menopausal women have a higher risk of hyperuricemia than postmenopausal women with the increase of the VFA-to-LMM ratio. In addition, the highest risk of hyperuricemia was demonstrated when both VFA and LMM were at the highest quartile.

Identification of Gout Flares in Chief Complaint Text Using Natural Language Processing

Many patients with gout flares treated in the Emergency Department (ED) often do not receive optimal continuity of care after an ED visit. Thus, developing methods to identify patients with gout flares in the ED and referring them to appropriate outpatient gout care is required. While Natural Language Processing (NLP) has been used to detect gout flares retrospectively, it is much more challenging to identify patients prospectively during an ED visit where documentation is usually minimal. We annotate a corpus of ED triage nurse chief complaint notes for the presence of gout flares and implement a simple algorithm for gout flare ED alerts. We show that the chief complaint alone has strong predictive power for gout flares. We make available a de-identified version of this corpus annotated for gout mentions, which is to our knowledge the first free text chief complaint clinical corpus available.

Asymptomatic hyperuricemia: is it really asymptomatic?

PURPOSE OF REVIEW

Hyperuricemia is highly prevalent, affecting approximately 38 million individuals in the United States. However, the significance of asymptomatic hyperuricemia - hyperuricemia in the absence of gout - continues to be debated.

RECENT FINDINGS

Asymptomatic hyperuricemia results in monosodium urate crystal deposition in tissues, which may promote chronic inflammation. Intracellularly, hyperuricemia inhibits the master regulator adenosine monophosphate (AMP)-associated protein kinase and may condition innate immune responses through durable epigenetic modifications. At the population level, asymptomatic hyperuricemia is associated with multiple comorbidities, including hypertension, chronic kidney disease, coronary artery disease, and diabetes; limitations of these studies include that most are retrospective and some do not rigorously distinguish between asymptomatic hyperuricemia and gout. Treatment studies suggest that urate lowering may reduce the risk of incidence or progression of some of these comorbidities; unfortunately, many of these treatment studies are small or flawed, and not all study results are consistent.

SUMMARY

Accumulating evidence suggests that asymptomatic hyperuricemia contributes to the comorbidities with which it associates and that proper asymptomatic hyperuricemia treatment may reduce future risk. Additional prospective trials are needed to definitely establish causality and support decision-making as to whether, and which patients with asymptomatic hyperuricemia would warrant urate-lowering treatment.

The Efficacy and Mechanism of Chinese Herbal Medicines in Lowering Serum Uric Acid Levels: A Systematic Review

Background. Chinese herbal medicines are widely used to lower serum uric acid levels. However, no systemic review summarizes and evaluates their efficacies and the underlying mechanisms of action. Objectives. To evaluate the clinical and experimental evidences for the effectiveness and the potential mechanism of Chinese herbal medicines in lowering serum uric acid levels. Methods. Four electronic databases PubMed, Wed of Science, the Cochrane Library and Embase were used to search for Chinese herbal medicines for their effects in lowering serum uric acid levels, dated from 1 January 2009 to 19 August 2020. For clinical trials, randomized controlled trials (RCTs) were included; and for experimental studies, original articles were included. The methodological quality of RCTs was assessed according to the Cochrane criteria. For clinical trials, a meta-analysis of continuous variables was used to obtain pooled effects. For experimental studies, lists were used to summarize and integrate the mechanisms involved. Results. A total of 10 clinical trials and 184 experimental studies were included. Current data showed that Chinese herbal medicines have promising clinical efficacies in patients with elevated serum uric acid levels (SMD: −1.65, 95% CI: −3.09 to −0.22; p = 0.024). There was no significant difference in serum uric acid levels between Chinese herbal medicine treatments and Western medicine treatments (SMD: −0.13, 95% CI: −0.99 to 0.74; p = 0.772). Experimental studies revealed that the mechanistic signaling pathways involved in the serum uric acid lowering effects include uric acid synthesis, uric acid transport, inflammation, renal fibrosis and oxidative stress. Conclusions. The clinical studies indicate that Chinese herbal medicines lower serum uric acid levels. Further studies with sophisticated research design can further demonstrate the efficacy and safety of these Chinese herbal medicines in lowering serum uric acid levels and reveal a comprehensive picture of the underlying mechanisms of action.

The gut microbiota as a target to control hyperuricemia pathogenesis: Potential mechanisms and therapeutic strategies

Hyperuricemia (HUA) is a metabolic disorder caused by abnormal uric acid (UA) metabolism, which is a complex physiological process involving multiple organs (liver, kidney, and intestine). Although UA metabolism in the liver and kidneys has been elucidated, only a few studies have focused on the process in the intestine. With our growing knowledge of the effects of gut microorganisms on health, the gut microbiota has been identified as a new target for HUA treatment. In this review, the relationship between HUA and the gut microbiota is elucidated, and anti-hyperuricemia mechanisms targeting the intestine are discussed, such as the promotion of purine and UA catabolism by the gut microbiota, increases in UA excretion by the gut microbiota and its metabolites, regulation of UA absorption or secretion in the intestinal tract by certain transporters, and the intestinal inflammatory response to the gut microbiota. Additionally, probiotics (Bifidobacteria and Lactobacilli) and prebiotics (polyphenols, peptides, and phytochemicals) with UA-lowering effects targeting the intestinal tract are summarized, providing reference and guidance for further research.

Prevalence of Hyperuricemia and the Use of Allopurinol in Older Poles-Results from a Population-Based PolSenior Study

BACKGROUND

Our study analyzes the frequency and risk factors of hyperuricemia and the use of allopurinol in a representative cohort of the older Polish adult population.

METHODS

The analysis was a part of a cross-sectional PolSenior study on aging in Poland. The complete medication data were available in 4873 out of 4979 community dwelling respondents aged 65 and over. Serum uric acid concentrations were evaluated in 4028 participants (80.9% of the cohort).

RESULTS

Hyperuricemia was observed in 28.2% of women and 24.7% of men. Ten risk factors of hyperuricemia were selected based on multivariable LASSO logistic regression analysis. Nine factors showed significant odds ratios: eGFR < 60 mL/min/1.73 m2 (OR = 4.10), hypertriglyceridemia (OR = 1.88), obesity (OR = 1.75), heart failure (1.70), CRP > 3.0 mg/dL (OR = 1.64), coronary artery disease (OR = 1.30), use of loop-diuretics (OR = 4.20), hydrochlorothiazide (OR = 2.96), and thiazide-like diuretics (OR = 2.81). Allopurinol was used by 2.8% of men and 1.8% of women. The therapy was considered effective in 46.7% of men and 53.3% of women.

CONCLUSIONS

Hyperuricemia was present in 23.1% (95% CI: 21.8-24.4) of the older Polish population. The frequency of hyperuricemia increases with age, reaching 30.5% in men and 33.7% in women aged 90 years or more. Chronic kidney disease, obesity, heart failure, hypertriglyceridemia, and the use of diuretics were the strongest risk factors for hyperuricemia in older adults. The treatment with allopurinol was ineffective in more than half of participants.

Asymptomatic Hyperuricemia and Metabolically Unhealthy Obesity: A Cross-Sectional Analysis in the Tianning Cohort

OBJECTIVE

The relationship between obesity and hyperuricemia has been demonstrated by many studies. However, whether or to what extent metabolic condition influents the association between obesity and hyperuricemia was not clear. Here, we aimed to examine the association between obese-metabolic phenotype and hyperuricemia in a large sample of Chinese adults.

METHODS

According to BMI and metabolic syndrome, obese-metabolic phenotype was defined as metabolically unhealthy obesity (MUO), metabolically healthy obesity (MHO), metabolically unhealthy non-obesity (MUNO) and metabolically healthy non-obesity (MHNO)in the Tianning cohort (N=5072). We conducted a cross-sectional analysis between obese-metabolic phenotype and hyperuricemia, followed by a Mendelian Randomization analysis using GWAS summary data to confirm the causality between uric acid and BMI.

RESULTS

The average level of serum UA showed 41.87-higher μmol/L in participants with MHO (β=41.87, P<0.001) and 63.18-higher μmol/L in participants with MUO (β=63.18, P<0.001), compared to those with MHNO. Compared to participants with MHNO, those with MUO had the highest likelihood to have hyperuricemia (OR=4.56, P<0.001), followed by those with MHO (OR=3.32, P<0.001). Mendelian randomization analysis indicated that uric acid was more likely to be a consequence of BMI (β=0.059, P=6.54×10^-154).

CONCLUSION

MUO, in comparison with MHO, was significantly associated with hyperuricemia in Chinese adults.

RBP4 Is Associated With Insulin Resistance in Hyperuricemia-Induced Rats and Patients With Hyperuricemia

OBJECTIVE

Hyperuricemia (HUA) is strongly associated with abnormal glucose metabolism and insulin resistance (IR). However, the precise molecular mechanism of HUA-induced IR is still unclear. Retinol binding protein 4 (RBP4) has been shown to induce IR in type 2 diabetes mellitus. This study was designed to clarify the relationship between RBP4 and HUA-induced IR and its potential mechanisms.

METHODS

Patients with HUA were collected to detect the levels of plasma RBP4 and clinical biochemical indicators. Rats were fed with 10% high yeast and oteracil potassium (300 mg/kg) via intraperitoneal injection once daily for eight weeks, and gavage with adenine (100 mg/kg) once daily from the fifth week to induce the HUA model. Glucose consumption testing was performed to determine the capacity of glucose intake and consumption in 3T3-L1 adipocytes. Real-time polymerase chain reaction (RT-PCR) and western blot were used to detect the mRNA and protein level of RBP4 and insulin receptor substrate-phosphatidylinositol 3-kinase-active protein kinase (IRS/PI3K/Akt) signaling pathway-related proteins.

RESULTS

The levels of plasma RBP4 in both HUA patients and HUA rat models were significantly higher than that in the control groups. The level of plasma RBP4 was positively correlated with plasma uric acid, creatinine, fasting insulin, IR index, total cholesterol and triglyceride levels in patients with HUA. In HUA rats, the level of plasma RBP4 was positively correlated with plasma uric acid, IR index, and triglycerides. HUA rats also exhibited IR. After inhibition of RBP4 expression, the phosphorylation levels of the IRS/PI3K/Akt signaling pathway were increased, and IR was significantly improved.

CONCLUSION

HUA induced IR both in vitro and in vivo. RBP4 may be involved in HUA-induced IR by inhibiting IRS/PI3K/Akt phosphorylation. Our findings may provide a new insight for the treatment of IR caused by HUA.

The comparative effect of exposure to various risk factors on the risk of hyperuricaemia: diet has a weak causal effect

BACKGROUND

Prevention of hyperuricaemia (HU) is critical to the prevention of gout. Understanding causal relationships and relative contributions of various risk factors to hyperuricemia is therefore important in the prevention of gout. Here, we use attributable fraction to compare the relative contribution of genetic, dietary, urate-lowering therapy (ULT) and other exposures to HU. We use Mendelian randomisation to test for the causality of diet in urate levels.

METHODS

Four European-ancestry sample sets, three from the general population (n = 419,060) and one of people with gout (n = 6781) were derived from the Database of Genotypes and Phenotypes (ARIC, FHS, CARDIA, CHS) and UK Biobank. Dichotomised exposures to diet, genetic risk variants, BMI, alcohol, diuretic treatment, sex and age were used to calculate adjusted population and average attributable fractions (PAF/AAF) for HU (≥0.42 mmol/L [≥7 mg/dL]). Exposure to ULT was also assessed in the gout cohort. Two sample Mendelian randomisation was done in the UK Biobank using dietary pattern-associated genetic variants as exposure and serum urate levels as outcome.

RESULTS

Adherence to dietary recommendations, BMI (< 25 kg/m²), and absence of the SLC2A9 rs12498742 urate-raising allele produced PAFs for HU of 20 to 24%, 59 to 69%, and 57 to 64%, respectively, in the three non-gout cohorts. In the gout cohort, diet, BMI, SLC2A9 rs12498742 and ULT PAFs for HU were 12%, 49%, 48%, and 63%, respectively. Mendelian randomisation demonstrated weak causal effects of four dietary habits on serum urate levels (e.g. preferentially drinking skim milk increased urate, β = 0.047 mmol/L, P = 3.78 × 10^-8). These effects were mediated by BMI, and they were not significant (P ≥ 0.06) in multivariable models assessing the BMI-independent effect of diet on urate.

CONCLUSIONS

Diet has a relatively minor role in determining serum urate levels and HU. In gout, the use of ULT was the largest attributable fraction tested for HU.

Associations of Serum Uric Acid with Clustering of Cardiovascular Risk Factors and a 10-Year Atherosclerotic Cardiovascular Disease Risk Score in Jiangsu Adults, China

PURPOSE

The relationship between serum uric acid (SUA) and Chinese characteristic 10-year atherosclerotic cardiovascular disease (ASCVD) risk score has not been well evaluated in Chinese populations. Aims of this cross-sectional study were to describe the correlation between SUA level and clustering of prevalent cardiovascular risk factors (CRFs) including overweight, central obesity, hypertension, diabetes and dyslipidemia, as well as the Chinese 10-year ASCVD risk score in adults from Jiangsu Province located in Eastern China.

PATIENTS AND METHODS

A total of 7700 adults from 12 cities in Jiangsu Province were selected through multi-stage stratified cluster random sampling method in 2015. Face-to-face interviews, physical examinations and laboratory examinations were carried out to collect the information of the participants. Multivariate logistic analysis was used to analyze the relationship between SUA quartiles and various CVD risk factors. The nonlinear analysis was conducted to evaluate the relationship between SUA levels and the China-PAR 10-year ASCVD risk scores.

RESULTS

The prevalence of hyperuricemia was 13.3% in all of the participants. By adjusting potential confounders, significant correlations were found between the SUA level and the overweight, central obesity, hypertension and dyslipidemia in both males and females. The clustering of CRFs was different across SUA quantiles (χ ²=607.685, P<0.001). After Gamma trend test (P < 0.001) and ordered logistic regression analysis, it was found out that with the increase of SUA quantiles, prevalent CRFs gradually gathered in both males and females. Furthermore, sex-specific difference was identified between SUA and 10-year ASCVD risk scores.

CONCLUSION

The accumulation of CRFs increased with elevated SUA levels, whereas it was different between genders in the relationship between SUA and 10-year ASCVD risk scores. Tailored strategies should be taken when it came to males and females in managing SUA.

Association between Lipid Profiles and Serum Urate: A Cross-Sectional Study in Southwestern China

OBJECTIVE

The relationship between lipid profiles and serum urate has not been fully investigated. This study aims to investigate the sex- and age-specific association between lipid profiles and serum urate.

METHODS

This was a cross-sectional study involving 122,351 participants aged 18-99 years from a check-up centre in Southwestern China. Generalized additive models and smooth curve fitting were conducted to explore the association between components of lipid profiles and serum urate. Furthermore, multivariate linear and logistic regression models were also performed.

RESULTS

In generalized additive models, the fitted smoothing curves showed that serum urate fluctuated in a small range with total cholesterol, LDL-C, or HDL-C raising. After adjusting for confounders, the differences in serum urate progressively increased with raising serum triglycerides quartiles. The likelihood (odds ratio, OR) for developing serum urate > 420 μmol/L significantly increased in the highest quartile of triglycerides than in the lowest quartile, in hypertriglyceridemia than in normal triglycerides, and with 1 mmol/L increment in triglycerides in all sex- and age-specific groups. Furthermore, the increased OR (95% confidence interval) was higher in females than in males compared with their respective controls.

CONCLUSIONS

Serum urate and the likelihood for developing serum urate >420 μmol/L increased with triglycerides raising. Females were in a higher likelihood for developing serum urate >420 μmol/L than males with raising triglycerides. With changes in total cholesterol, LDL-C, or HDL-C, serum urate fluctuated in a small range.

HSP60 Regulates Monosodium Urate Crystal-Induced Inflammation by Activating the TLR4-NF-κB-MyD88 Signaling Pathway and Disrupting Mitochondrial Function

Acute gout is an inflammatory response induced by monosodium urate (MSU) crystals. HSP60 is a highly conserved stress protein that acts as a cellular "danger" signal for immune reactions. In this study, we aimed to investigate the role and molecular mechanism of HSP60 in gout. HSP60 expression was detected in peripheral blood mononuclear cells (PBMCs) and plasma of gout patients. The effect and molecular mechanism of HSP60 in gout were studied in MSU crystals treatment macrophages and C57BL/6 mice. JC-1 probe and MitoSOX Red were used to measure the mitochondrial membrane potential (MMP) and mitochondrial reactive oxygen species (mtROS). HSP60 expression was significantly upregulated in the PBMCs and sera of patients with acute gout (AG) compared to those with intercritical gout (IG) or healthy controls (HCs). MSU crystals induced the expression and secretion of HSP60 in the macrophages. HSP60 knockdown or overexpression affects TLR4 and MyD88 expression, IκBα degradation, and the nuclear localization of NF-κB in MSU crystal-stimulated inflammation. Further, HSP60 facilitates MMP collapse and mtROS production and activates the NLRP3 inflammasome in MSU crystal-stimulated macrophages. In MSU crystal-induced arthritis mouse models pretreated with HSP60 vivo-morpholino, paw swelling, myeloperoxidase (MPO) activity, and inflammatory cell infiltration significantly decreased. Our study reveals that MSU crystal stimulates the expression of HSP60, which accelerates the TLR4-MyD88-NF-κB signaling pathway and exacerbates mitochondrial dysfunction.

27-Hydroxycholesterol regulates human SLC22A12 gene expression through estrogen receptor action

The excretion and reabsorption of uric acid both to and from urine are tightly regulated by uric acid transporters. Metabolic syndrome conditions, such as obesity, hypercholesterolemia, and insulin resistance, are believed to regulate the expression of uric acid transporters and decrease the excretion of uric acid. However, the mechanisms driving cholesterol impacts on uric acid transporters have been unknown. Here, we show that cholesterol metabolite 27‐hydroxycholesterol (27HC) upregulates the uric acid reabsorption transporter URAT1 encoded by SLC22A12 via estrogen receptors (ER). Transcriptional motif analysis showed that the SLC22A12 gene promoter has more estrogen response elements (EREs) than other uric acid reabsorption transporters such as SLC22A11 and SLC22A13, and 27HC‐activated SLC22A12 gene promoter via ER through EREs. Furthermore, 27HC increased SLC22A12 gene expression in human kidney organoids. Our results suggest that in hypercholesterolemic conditions, elevated levels of 27HC derived from cholesterol induce URAT1/SLC22A12 expression to increase uric acid reabsorption, and thereby, could increase serum uric acid levels.

The prevalence of gout and hyperuricaemia in Australia: An updated systematic review

BACKGROUND

Gout continues to increase in prevalence in developed countries with Oceanic countries particularly affected. Both gout and hyperuricaemia are associated with the metabolic syndrome and its sequelae. Recently, the Australian Institute for Health and Welfare (AIHW) reported a prevalence rate of 0.8% which appeared incongruous with other published research. Thus, an updated systematic review was undertaken to review the literature on the prevalence of gout and hyperuricaemia in Australia from data published after 2011.

METHODS

A comprehensive, systematic search was conducted in MEDLINE, Embase and Web of Science in addition to relevant websites to identify research reporting the prevalence of gout and/or hyperuricaemia in Australia from May 2011 until June 2020. Crude gout and hyperuricaemia prevalence data was obtained and presented alongside case ascertainment, time-period, age range and stratified by gender if available.

RESULTS

118 full text articles were screened. 12 articles were included for analysis of gout prevalence. 4 articles were identified for the hyperuricaemia analysis. Wide variation in prevalence figures exist largely due study design and sample age range. Studies using a case definition of self-reported diagnosis of gout reported prevalence rates between 4.5% and 6.8%. The remaining studies used either electronic coding data from general practitioners or wastewater estimation of allopurinol consumption and documented adult prevalence rates between 1.5% and 2.9%. Prevalence increases with age, male sex and over time in keeping with global data. Hyperuricaemia prevalence ranged between 10.5% and 16.6% in Caucasian or an Australian representative population. AIHW estimates applied a chronic condition status, defined as current and lasted or expected to last more than six months, to cases of gout in the Australian National Health Survey. This likely results in an under-estimation in reported Australian gout prevalence rates.

CONCLUSIONS

Gout is highly prevalent in Australia compared to global comparisons and continues to increase over time. Hyperuricaemia prevalence is also high although contemporary data is limited.

Beyond Arthritis: Understanding the Influence of Gout on Erectile Function: A Systematic Review

OBJECTIVE

To review the evidence suggesting a significant association between gout and erectile dysfunction (ED) and evaluate possible underlying pathways that may explain this relationship.

METHODS

English medical literature was searched from January 1, 2010, to January 1, 2020, for randomized or quasi-randomized controlled trials, cross-sectional studies, case-cohort studies, or meta-analysis evaluating the relationship between gout and ED.

RESULTS

All nine gout studies included in the study found a significant association between gout and ED. ED pathophysiology in gout involves hyperuricemia, increased reactive oxygen species, decreased nitric oxide synthesis, and low-grade inflammation.

CONCLUSION

The findings of this review suggest that the effect of urate-lowering therapy on the incidence of ED in gout patients should be studied. Additionally, we propose that all gout patients should be assessed for ED.

Gicht: aktuelle Epidemiologie, Komorbiditäten, Komplikationen und sozioökonomische Konsequenzen

Die Gicht gehört neben der rheumatoiden Arthritis zu den häufigsten Ursachen von Gelenkentzündungen. Als metabolisch bedingte Erkrankung geht sie meist mit Hyperurikämie und der Ablagerung von Uratkristallen in Gelenken, Sehnen und Weichteilgeweben einher, wodurch Entzündungszustände ausgelöst werden können. Die Gichtarthritis tritt weltweit insbesondere in den Industrieländern mit steigender Prävalenz auf (weltweit 0,6%), wobei die größte Häufigkeit bei den Maoris in Ozeanien (bis zu 10%) gemessen wurde. In Deutschland tritt die Gicht altersabhängig mit einer Prävalenz von 1,63% auf, wobei Männer ungefähr dreimal so häufig wie Frauen betroffen sind. Kardiovaskuläre und vor allem renale Komorbiditäten können zu vermehrten Komplikationen und einer erhöhten Sterblichkeit von Patienten mit Gicht führen. Grundsätzlich haben Gichtpatienten eine erhöhte Mortalität im Vergleich zur Gesamtbevölkerung. Die zunehmende Inzidenz führt zu steigenden Gesundheitskosten, besonders durch vermehrte Hospitalisierungen. Darüber hinaus wurden bei Gichtpatienten mehr Arbeitsunfähigkeitstage sowie reduzierte Erwerbsfähigkeit mit entsprechenden volkswirtschaftlichen Konsequenzen nachgewiesen.

Degree of blood pressure control and the risk of new-onset hyperuricemia in treated hypertensive patients

Background

The relationship between blood pressure (BP) control and the risk of new-onset hyperuricemia remains uncertain. We aimed to examine the association between degree of time-averaged on-treatment BP control and new-onset hyperuricemia in general hypertensive patients.

Methods

A total of 10,617 hypertensive patients with normal uric acid (UA) concentrations (<357 µmol/L) at baseline were included from the UA Sub-study of the China Stroke Primary Prevention Trial (CSPPT). Participants were randomized to receive a double-blind daily treatment of enalapril 10 mg and folic acid 0.8 mg or enalapril 10 mg alone. BP measurements were taken every three months after randomization. The primary outcome was new-onset hyperuricemia, defined as a UA concentration ≥417 µmol/L in men or ≥357 µmol/L in women at the exit visit.

Results

Over a median of 4.4 years, 1,664 (15.7%) participants developed new-onset hyperuricemia. Overall, there was a significantly positive association between time-averaged on-treatment diastolic BP (DBP) and new-onset hyperuricemia (per 10 mmHg increment; OR 1.13; 95% CI: 1.02–1.26). Consistently, a significantly higher risk of new-onset hyperuricemia was found in participants with time-averaged on-treatment DBP ≥82.9 mmHg (median) (vs. <82.9 mmHg; 17.3% vs. 14.1%; OR 1.25; 95% CI: 1.10–1.44). Furthermore, the lowest new-onset hyperuricemia risk (12.1%) was found in those with both time-averaged on-treatment SBP (median: 138.3 mmHg) and DBP below the median (P-interaction=0.023). The results were similar for time-averaged DBP during the first 12- or 24-month treatment period, or in the analysis using propensity scores. Furthermore, a non-significant higher risk of new-onset hyperuricemia was observed in participants with time-averaged on-treatment SBP ≥120 mmHg (vs. <120 mmHg; OR 1.61; 95% CI: 0.88–2.97).

Conclusions

A tight DBP control of <82.9 mmHg was associated with lower risk of new-onset hyperuricemia among hypertensive patients without hyperuricemia.

Cardiometabolic Risk Factors and Preclinical Target Organ Damage Among Adults in Ghana: Findings From a National Study

Background

Although sub‐Saharan Africa has a high prevalence of cardiovascular diseases (CVDs), there remains a lack of systematic and comprehensive assessment of risk factors and early CVD outcomes in adults in sub‐Saharan Africa.

Methods and Results

Using a stratified multistage random sampling method, we recruited 1106 men and women, aged >18 years, from the general population in Ghana to participate in a national health survey from 2016 to 2017. In Ghanaian adults, the age‐standardized prevalence of known CVD risk factors was 15.1% (95% CI, 12.9%–17.3%) for obesity, 6.8% (95% CI, 5.1%–8.5%) for diabetes mellitus, 26.1% (95% CI, 22.9%–29.4%) for hypertension, and 9.3% (95% CI, 7.1%–11.5%) for hyperuricemia. In addition, 10.1% (95% CI, 7.0%–13.2%) of adults had peripheral artery disease, 8.3% (95% CI, 6.7%–10.0%) had carotid thickening, 4.1% (95% CI, 2.9%–5.2%) had left ventricular hypertrophy, and 2.5% (95% CI, 1.5%–3.4%) had chronic kidney disease. Three CVD risk factors appeared to play prominent roles in the development of target organ damage, including obesity for peripheral artery disease (odds ratio [OR], 2.22; 95% CI, 1.35–3.63), hypertension for carotid thickening (OR, 1.92; 95% CI, 1.22–3.08), and left ventricular hypertrophy (OR, 5.28; 95% CI, 2.55–12.11) and hyperuricemia for chronic kidney disease (OR, 5.49; 95% CI, 2.84–10.65).

Conclusions

This comprehensive health survey characterized the baseline conditions of a national cohort of adults while confirming the prevalence of CVD risk factors, and early CVD outcomes have reached epidemic proportions in Ghana. The distinct patterns of risk factors in the development of target organ damage present important challenges and opportunities for interventions to improve cardiometabolic health among adults in Ghana.

Characteristics, Comorbidities, and Potential Consequences of Uncontrolled Gout: An Insurance-Claims Database Study

INTRODUCTION

Gout is a common, progressive, systemic inflammatory arthritis caused by hyperuricemia. Current guidelines recommend that serum uric acid (sUA) levels be maintained below 6.0 mg/dl to minimize acute gout attacks, tophi development, and long-term joint and organ damage. This study examined the influence of uncontrolled gout on post-diagnosis comorbidities and medication use.

METHODS

The Humana Research Database (2007-2016, commercial insurance and Medicare) was searched (PearlDiver tool) for patients who had a gout diagnosis code, claims data for at least 6 months before and after diagnosis, and at least 90 days of continuous urate-lowering therapy within 1 year of diagnosis. Patients with controlled (all sUA measurements < 6.0 mg/dl) and uncontrolled (all sUA measurements ≥ 8.0 mg/dl) gout were further examined and compared to better understand the influence of uncontrolled gout on post-diagnosis comorbidities, medication use, and reasons for seeking medical care.

RESULTS

A total of 5473 and 1358 patients met inclusion and classification criteria for the controlled and uncontrolled groups, respectively. Identified comorbidities in both groups included hypertension, hyperlipidemia, diabetes, cardiovascular disease, and chronic kidney disease (CKD). However, the uncontrolled group was more likely to have diabetes, CKD, and cardiovascular disease (including heart failure and atrial fibrillation). Additionally, CKD tended to be more advanced in the uncontrolled gout population (Stage 4-5: 34.6 vs. 22.2%). Overall opioid use was higher in uncontrolled patients.

CONCLUSIONS

The current study identified differences between controlled and uncontrolled gout patients, including usage of medication, severity of CKD, and prevalence of CKD, diabetes, and heart disease.

Anti-Hyperuricemic Effects of Astaxanthin by Regulating Xanthine Oxidase, Adenosine Deaminase and Urate Transporters in Rats

This study was designed to investigate the effects and underlying mechanisms of Astaxanthin (AST) on high-fructose-induced hyperuricemia (HUA) from the perspectives of the uric acid (UA) synthesis and excretion in rat models. Following six weeks of a 10% fructose diet, the level of serum UA effectively decreased in the AST groups as compared to the model group. The enzymatic activities of xanthine oxidase (XOD) and adenosine deaminase (ADA) were significantly inhibited, and the mRNA expression levels of XOD and ADA significantly decreased after the AST administration. These results suggested that the AST reduced UA synthesis by inhibiting the mRNA expressions and enzyme activities of XOD and ADA, thereby contributing to HUA improvement. On the hand, the relative expressions of the mRNA and protein of kidney reabsorption transport proteins (GLUT9 and URAT1) were significantly down-regulated by AST, while that of the kidney secretion proteins (OAT1, OAT3 and ABCG2) were significantly up-regulated by AST. These results indicated that the AST promoted UA excretion by regulating the urate transport proteins, and thus alleviated HUA. This study suggested that the AST could serve as an effective alternative to traditional medicinal drugs for the prevention of fructose-induced HUA.

Beyond Medical Treatment: Surgical Treatment of Gout

PURPOSE OF REVIEW

Medical treatment with urate-lowering therapy (ULT) is efficacious. A recent publication suggested that surgery in gout is more prevalent than previously reported. This revelation led us to review what is known about surgical treatment of gout.

RECENT FINDINGS

The Google Scholar database (January 1, 2014-January 1, 2020) found 104 publications with a total of 169 gout patients, with an average disease duration of 6.7 years. Most (68%) were not on ULT. The mean pre-operative serum urate levels were 9.19 mg/dL. One hundred thirteen patients underwent tophi excision, while in 33 patients, tophi were found during surgery. The majority of the surgeries were performed in Asia and Europe. Most patients were not taking ULT at the time of surgery, leading to hyperuricemia. This can result in tophi reformation post-surgery. The role of surgery should be a last-line treatment and until recently has only been demonstrated through case reports.

Estimation of Primary Prevention of Gout in Men Through Modification of Obesity and Other Key Lifestyle Factors

IMPORTANCE

The population impact of modifying obesity and other key risk factors for hyperuricemia has been estimated in cross-sectional studies; however, the proportion of incident gout cases (a clinical end point) that could be prevented by modifying such factors has not been evaluated.

OBJECTIVE

To estimate the proportion of incident gout cases that could be avoided through simultaneous modification of obesity and other key risk factors.

DESIGN, SETTING, AND PARTICIPANTS

The Health Professionals Follow-up Study is a US prospective cohort study of 51 529 male health professionals enrolled in 1986 and followed up through questionnaires every 2 years through 2012. Self-reported gout cases were confirmed through June 2015. Clean and complete data used for this analysis were available in June 2016, with statistical analyses performed from July 2016 to July 2019.

EXPOSURES

From data collected in the validated questionnaires, men were categorized to low-risk groups according to combinations of the following 4 factors: normal body mass index (BMI [calculated as weight in kilograms divided by height in meters squared]; <25), no alcohol intake, adherence to Dietary Approaches to Stop Hypertension (DASH)-style diet (highest quintile of DASH diet score), and no diuretic use.

MAIN OUTCOMES AND MEASURES

Population attributable risks (PARs) for incident gout meeting the preliminary American College of Rheumatology survey criteria, overall and stratified by BMI.

RESULTS

We analyzed 44 654 men (mean [SD] age, 54.0 [9.8] years) with no history of gout at baseline. During 26 years of follow-up, 1741 (3.9%) developed incident gout. Among all participants, PAR for the 4 risk factors combined (BMI, diet, alcohol use, and diuretic use) was 77% (95% CI, 56%-88%). Among men with normal weight (BMI <25.0) and overweight (BMI 25.0-29.9), we estimated that more than half of incident gout cases (69% [95% CI, 42%-83%] and 59% [95% CI, 30%-75%], respectively) may have been prevented by the combination of DASH-style diet, no alcohol intake, and no diuretic use. However, among men with obesity (BMI ≥30), PAR was substantially lower and not significant (5% [95% CI, 0%-47%]).

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that addressing excess adiposity and other key modifiable factors has the potential to prevent the majority of incident gout cases among men. Men with obesity may not benefit from other modifications unless weight loss is addressed.

Hyperuricemia in Kidney Disease: A Major Risk Factor for Cardiovascular Events, Vascular Calcification, and Renal Damage

Kidney disease, especially when it is associated with a reduction in estimated glomerular filtration rate, can be associated with an increase in serum urate (uric acid), suggesting that hyperuricemia in subjects with kidney disease may be a strictly secondary phenomenon. Mendelian randomization studies that evaluate genetic scores regulating serum urate also generally have not found evidence that serum urate is a causal risk factor in chronic kidney disease. Nevertheless, this is countered by a large number of epidemiologic, experimental, and clinical studies that have suggested a potentially important role for uric acid in kidney disease and cardiovascular disease. Here, we review the topic in detail. Overall, the studies strongly suggest that hyperuricemia does have an important pathogenic role that likely is driven by intracellular urate levels. An exception may be the role of extracellular uric acid in atherosclerosis and vascular calcification. One of the more striking findings on reviewing the literature is that the primary benefit of lowering serum urate in subjects with CKD is not by slowing the progression of renal disease, but rather by reducing the incidence of cardiovascular events and mortality. We recommend large-scale clinical trials to determine if there is a benefit in lowering serum urate in hyperuricemic subjects in acute and chronic kidney disease and in the reduction of cardiovascular morbidity and mortality in subjects with end-stage chronic kidney disease.

Molecular Pathophysiology of Uric Acid Homeostasis

Uric acid, the end product of purine metabolism, plays a key role in the pathogenesis of gout and other disease processes. The circulating serum uric acid concentration is governed by the relative balance of hepatic production, intestinal secretion, and renal tubular reabsorption and secretion. An elegant synergy between genome-wide association studies and transport physiology has led to the identification and characterization of the major transporters involved with urate reabsorption and secretion, in both kidney and intestine. This development, combined with continued analysis of population-level genetic data, has yielded an increasingly refined mechanistic understanding of uric acid homeostasis as well as greater understanding of the genetic and acquired influences on serum uric acid concentration. The continued delineation of novel and established regulatory pathways that regulate uric acid homeostasis promises to lead to a more complete understanding of uric acid-associated diseases and to identify new targets for treatment.

Pathophysiology of hyperuricemia and its clinical significance - a narrative review

Hyperuricemia, i.e. increased serum uric acid (UA) concentration, is a common problem in clinical practice. While there are clear guidelines concerning management of symptomatic hyperuricemia in acute conditions such as gout, urolithiasis or acute urate nephropathy, less is known about their secondary prevention. Moreover, despite the ongoing debate on the role of UA in the pathogenesis of chronic kidney disease, hypertension, cardiovascular disease and heart failure, the management of asymptomatic hyperuricemia in patients with these chronic conditions is still mainly up to physicians' judgement. Individual considerations should always be taken into account when prescribing urate-lowering therapy. In this narrative review study, we attempt to present current trends concerning treatment of patients with either symptomatic or asymptomatic hyperuricemia in the light of the available knowledge on the role of hyperuricemia in the development of gout, renal, cardiovascular and other diseases.

Unique Considerations for the Management of Gout in the Hmong Population: Examining Tertiary Encounters at a Large Regional Health Care System

OBJECTIVE

To evaluate demographic characteristics, care encounters, comorbidities, and clinical differences in Hmong and non-Hmong patients with gout.

METHODS

Using retrospective chart review, all inpatient encounters (Hmong versus non-Hmong) were reviewed from 2014 to 2017. Acute or chronic gout was the primary or secondary diagnosis for the encounter.

RESULTS

Hmong gout patients were on average 11 years younger than non-Hmong patients, but after adjustment for age, sex, and type of encounter, they had similar rates of hypertension, diabetes mellitus, and heart disease. Hmong patients had significantly decreased renal function at the time of presentation; the odds ratio of chronic kidney disease for Hmong patients was 2.33 versus 1.48 for non-Hmong patients (P < 0.05), the mean creatinine level was 3.3 mg/dl versus 2.0 mg/dl (β = 1.35, P < 0.001), and the glomerular filtration rate was 44.8 ml/minute versus 49.3 ml/minute (β = -6.95, P < 0.001). Hmong gout patients were more likely to use emergency care versus elective or urgent care, they were less likely to be using medications for the treatment of gout prior to admission (32.3% versus 58.2%), and the length of hospital stay was increased (8.8 versus 5.2 days; P < 0.05).

CONCLUSION

Hmong gout patients who had a tertiary care encounter were 11 years younger than non-Hmong patients with similar rates of comorbidities but had worse renal function despite the age differences. They were more likely to use emergency services, to be insured through Medicaid, and not to use preventive medications for gout prior to their encounter. Intensive efforts are needed in the Hmong population for culturally appropriate preventive care management of gout along with diabetes mellitus, hypertension, heart disease, and kidney disease.

Individualized homeopathic medicines and Urtica urens mother tincture in treatment of hyperuricemia: an open, randomized, pragmatic, pilot trial

OBJECTIVES

The quality of management of hyperuricemia has remained sub-optimal owing to unavoidable toxicities, limitations, and dearth of novel advances. Homeopathy has remained under-researched in hyperuricemia. We investigated the clinical effectiveness of three treatment regimens - individualized homeopathy (IH), Urtica urens mother tincture (UUMT), and both (IH + UUMT) along with lifestyle modifications in a sample of 90 patients with hyperuricemia.

METHODS

An open, randomized (1:1:1), 3 parallel arms (IH, UUMT, and IH + UUMT), pragmatic trial was conducted at National Institute of Homoeopathy, Kolkata. Outcome measures were serum uric acid (primary), Gout Assessment Questionnaire version 2 (GAQ2, secondary), and Measure Yourself Medical Outcome Profile version 2 (MYMOP2, secondary); all measured at baseline, and after 3 and 6 months. Intention- to-treat sample was analyzed to detect group differences by unpaired t tests.

RESULTS

Attrition rate was 8.9% (IH: 3, UUMT: 3, IH + UUMT: 2). Groups were comparable at baseline. Reductions in serum uric acid over 3 months were comparatively higher (p=0.057) in the UUMT group than others, however, the differences were narrowed over 6 months (p=0.119). Per protocol analysis of serum uric acid level revealed similar trend of significantly higher reduction in the UUMT group than the other two (3 months: p=0.001; 6 months: p=0.007). No significant differences existed in reductions of GAQ2 scores among the three groups. Few significant differences were detected in MYMOP scores over 3 months favoring IH against others (symptom 2, p=0.001 and wellbeing score, p=0.002), and also over 6 months favoring IH + UUMT against others (symptom 1, p<0.001).

CONCLUSION

Although all three therapies showed similar improvements, the IH + UUMT group had more positive direction of effects than IH or UUMT alone; however, no definite conclusion could be arrived at. Further trials are warranted with larger sample size. Trial registration: CTRI/2018/05/014026.

Prevalence of gout and asymptomatic hyperuricemia in the pediatric population: a cross-sectional study of a Japanese health insurance database

Background

Although gout is rare in children, chronic sustained hyperuricemia can lead to monosodium urate deposits progressing to gout, just as in adults. This study assessed prevalence and characteristics of gout and asymptomatic hyperuricemia, and incidence of gouty arthritis in the pediatric population, using data from Japanese health insurance claims. The diagnosis and treatment of pediatric gout and hyperuricemia were analyzed, and specific characteristics of those patients were assessed. Since Japanese guidelines recommend treatment with uric acid lowering drugs for asymptomatic hyperuricemia as well as for gout, these data were also used to investigate the real-world use of uric acid lowering drugs in a pediatric population.

Methods

This cross-sectional study was based on a 2016–2017 Japanese health insurance claims database, one of the largest epidemiology claims databases available in Japan, which included 356,790 males and 339,487 females 0–18 years of age. Outcomes were measured for prevalence, patient characteristics, treatment with uric acid lowering drugs for gout and asymptomatic hyperuricemia, and prevalence and incidence of gouty arthritis. Because uric acid can be elevated by some forms of chemotherapy, data from patients under treatment for malignancies were excluded from consideration.

Results

Total prevalence of gout and asymptomatic hyperuricemia in 0–18 year-olds was 0.040% (276/696,277 patients), with gout prevalence at 0.007% (48/696,277) and asymptomatic hyperuricemia at 0.033% (228/696,277). Prevalence of gout and asymptomatic hyperuricemia was highest in adolescent males, at 0.135% (176/130,823). The most common comorbidities for gout and asymptomatic hyperuricemia were metabolic syndrome at 42.8% (118/276) and kidney disease at 34.8% (96/276). Of the patients diagnosed with gout or asymptomatic hyperuricemia, 35.1% (97/276) were treated with uric acid lowering drugs. Gouty arthritis developed in 43.8% (21/48) of gout patients during the study, at an incidence of 0.65 flares/person-year.

Conclusions

Even the pediatric population could be affected by asymptomatic hyperuricemia, gout, and gouty arthritis, and uric acid lowering drugs are being used in this population even though those drugs have not been approved for pediatric indications. Such off-label use may indicate a potential need for therapeutic agents in this population.

Trial registration

UMIN000036029.

Gout management and outcomes during the COVID-19 pandemic: a cross-sectional internet survey

Aim:

We aimed to assess the gout management during the COVID-19 pandemic.

Methods:

We assessed medication use, healthcare utilization, gout-specific health-related quality of life (HRQoL) on the Gout Impact Scale (GIS), psychological distress using the patient health questionnaire-4 (PHQ-4), and resilience in people with self-reported physician-diagnosed gout during the COVID-19 pandemic in a cross-sectional Internet survey.

Results:

Among the 122 survey respondents with physician-diagnosed gout, 82% were prescribed urate-lowering therapy (ULT) and 66% were taking ULT daily; mean age was 54.2 years [standard deviation (SD), 13.8], 65% were male, and 79% were White. More regular use of gout medication was reported during the COVID-19 pandemic: allopurinol, 44%; colchicine, 37%; non-steroidal anti-inflammatory drugs, 36%. Gout flares were common: 63% had ⩾1 gout flare monthly; 11% went to emergency room/urgent care; and 2% were hospitalized with gout flares. Between 41% and 56% of respondents reported more difficulty with gout management and related functional status related to COVID-19; 17–37% had difficulty with healthcare access for gout. HRQOL deficits were evident for gout concern overall, 79.4 (SD, 25); unmet gout treatment need, 64.5 (SD, 27.1); and gout concern during flare, 67.3 (SD, 27.1); but less so for gout medication side effects, 48.9 (SD, 27.4). Psychological distress was moderate in 19% and severe in 15% (mild, 22%; normal, 45%). Resilience score on Connor–Davidson Resilience Scale (CD-RISC2) was 5.6 (SD, 1.8; range 0–8). Compared with no/mild psychological distress, moderate–severe psychological distress during the COVID-19 pandemic was significantly associated with more difficulty getting gout medication filled (p = 0.02), flares treated (p = 0.005), and receiving gout education (p = 0.001).

Conclusion:

Healthcare gaps, psychological distress, and HRQoL deficits were commonly reported by people with gout during the COVID-19 pandemic. Interventions to address these challenges for people with gout during the COVID-19 pandemic are needed.

Global, regional and national burden of gout, 1990-2017: a systematic analysis of the Global Burden of Disease Study

OBJECTIVES

The burden of gout has been increasing globally. However, little is known about the global, regional and national distribution and time trend of this disease. We present a comprehensive analysis of the Global Burden of Disease Study 2017 on gout burden estimates for 195 countries or territories between 1990 and 2017.

METHODS

Age-standardized prevalence and disability-adjusted life-years of gout were reported between 1990 and 2017 in 195 countries and territories, and associations between these estimates and sociodemographic index (SDI) were further explored. Total and annual percent change between 1990 and 2017 were calculated to quantify the time trends of gout burden.

RESULTS

Age-standardized prevalence rates (95% uncertainty interval) per 100 000 persons were 790.90 (706.10-881.90) and 253.49 (225.69-284.02) in 2017 in males and females, respectively. The annual percent change in age-standardized prevalence (males, 0.22%; females, 0.38%) and disability-adjusted life-years (males, 0.21%; females, 0.38%) of gout increased every year from 1990 to 2017, globally. The highest increase was detected in high-SDI countries, especially in high-income North America. A non-linear association was observed between burden of gout and SDI, with the lowest estimates of gout burden when SDI value was about 0.6. High BMI was the leading risk factor for the burden of gout.

CONCLUSION

These study results suggest a globally rising trajectory of gout burden between 1990 and 2017. More effective interventions, such as detailed and intensive dietary managements and other prevention strategies for reducing obesity, should be carried out to reverse this trend, especially in females and high-SDI countries.

An update on gout diagnosis and management for the primary care provider

Gout is the most common inflammatory arthritis in the US, affecting 3.9% of the population. Although many effective gout therapies are available for acute flares and chronic management, it is suboptimally treated worldwide, and recurrent gout flares can cause significant pain and irreversible joint damage.

Pharmacologic Management of Gout in Patients with Cardiovascular Disease and Heart Failure

Gout is the most common inflammatory arthritis and is often comorbid with cardiovascular disease (CVD). Hyperuricemia and gout are also independent risk factors for cardiovascular events, worsening heart failure (HF), and death. The recommended treatment modalities for gout have important implications for patients with CVD because of varying degrees of cardiovascular and HF benefit and risk. Therefore, it is critical to both manage hyperuricemia with urate-lowering therapy (ULT) and treat acute gout flares while minimizing the risk of adverse cardiovascular events. In this review, the evidence for the safety of pharmacologic treatment of acute and chronic gout in patients with CVD and/or HF is reviewed. In patients with CVD or HF who present with an acute gout flare, colchicine is considered safe and potentially reduces the risk of myocardial infarction. If patients cannot tolerate colchicine, short durations of low-dose glucocorticoids are efficacious and may be safe. Nonsteroidal anti-inflammatory drugs should be avoided in patients with CVD or HF. The use of canakinumab and anakinra for acute gout flares is limited by the high cost, risk of serious infection, and relatively modest clinical benefit. For long-term ULT, allopurinol, and alternatively probenecid, should be considered first-line treatments in patients with CVD or HF given their safety and potential for reducing cardiovascular outcomes. An increased risk of cardiovascular death and HF hospitalization limit the use of febuxostat and pegloticase as ULT in this population. Ultimately, the selection of agents used for acute gout management and long-term ULT should be individualized according to patient and agent cardiovascular risk factors.

Recent advances in fructose intake and risk of hyperuricemia

With the widespread popularity of hyperuricemia, it has become a severe threat to human public health. Accumulating evidence suggests that dietary fructose has a close relationship with hyperuricemia, but the role of fructose intake in hyperuricemia remains unclear. Hyperuricemia is characterized by excessive production and deposition of urate crystals. Metabolism of fructose leads to the increased serum concentration of urate. In this review, we depict an update of fructose consumption worldwide and the epidemiology of hyperuricemia and summarize the progress in studying the relationship between fructose intake and the risk of hyperuricemia. This review highlights the metabolic process of fructose in the liver, small intestine, and kidney. Furthermore, we discuss molecular insights on fructose metabolism to reveal the underlying mechanism of fructose metabolism. Additionally, we elaborate on the effect of fructose metabolism on hyperuricemia to deeply understand the pathogenesis of hyperuricemia caused by fructose intake. Fructose consumption has a close correlation with an enhanced risk of developing hyperuricemia. More prospective studies are inevitable to understand the role of fructose intake in the development of hyperuricemia.

Urate in fingernail represents the deposition of urate burden in gout patients

Urate in the fingernails of gout patients and healthy volunteers was successfully detected by high-performance liquid chromatography (HPLC) with ultraviolet (UV) in our previous research. This study aimed to further investigate whether nail urate could be a proxy for the burden of monosodium urate (MSU) crystals deposits in gout. To this end, we conducted a study in two parts. Firstly, we successfully detected urate in the nail by HPLC-UV and evaluated nail urate concentrations in control subjects and patients with gout. As expected, we found that levels of nail urate were significantly higher in patients with gout than in healthy controls, and the nail urate level was significantly correlated with the volume of MSU crystals deposits measured by dual-energy CT (DECT). Secondly, we found that nail urate can reflect changes in urate levels in the body during urate lowering therapy through a 3-month follow-up study. Our results provide the possibility of quantification of urate in human fingernails as a non-invasive alternative for assessing MSU crystals deposits in gout.

Use of electronic recruitment methods in a clinical trial of adults with gout

BACKGROUND/AIMS

Electronic-based recruitment methods are increasingly utilized in clinical trials to recruit and enroll research participants. The cost-effectiveness of electronic-based methods and impact on sample generalizability is unknown. We compared recruitment yields, cost-effectiveness, and demographic characteristics across several electronic and traditional recruitment methods.

METHODS

We analyzed data from the diet gout trial recruitment campaign. The diet gout trial was a randomized, controlled, cross-over trial that examined the effects of a dietary approaches to stop hypertension (DASH)-like diet on uric acid levels in adults with gout. We used four electronic medical record and four non-electronic medical record-based recruitment methods to identify and recruit potentially eligible participants. We calculated the response rate, screening visit completion rate, and randomization rate for each method. We also determined cost per response, the screening, and randomization for each method. Finally, we compared the demographic characteristics among individuals who completed the screening visit by recruitment method.

RESULTS

Of the 294 adults who responded to the recruitment campaign, 51% were identified from electronic medical record-based methods. Patient portal messaging, an electronic medical record-based method, resulted in the highest response rate (4%), screening visit completion rate (37%), and randomization rate (21%) among these eight methods. Electronic medical record-based methods ($60) were more cost-effective per response than non-electronic medical record-based methods ($107). Electronic-based methods, including patient portal messaging and Facebook, had the highest proportion of White individuals screened (52% and 60%). Direct mail to non-active patient portal increased enrollment of traditionally under-represented groups, including both women and African Americans.

CONCLUSION

An electronic medical record-based recruitment strategy that utilized the electronic medical record for participant identification and postal mailing for participant outreach was cost-effective and increased participation of under-represented groups. This hybrid strategy represents a promising approach to improve the timely execution and broad generalizability of future clinical trials.

Gender and Ethnic Inequities in Gout Burden and Management

Although effective and low-cost urate-lowering therapy has been available for decades, inequities in gout management exist. Despite high impact of disease, rates of urate-lowering therapy prescription are low in women, in African-Americans in the United States, in Māori (Indigenous New Zealanders), and in Pacific peoples living in Aotearoa/New Zealand. Social determinants of health, barriers to accessing the health care system, health literacy demands, stigmatization, and bias contribute to inequities in gout burden and management. Approaches that focus on building health literacy and delivering culturally safe care lead to improved outcomes in gout, and offer important solutions to achieve health equity.