Gout: a review of nonmodifiable and modifiable risk factors

Burden of gout among different WHO regions, 1990-2019: estimates from the global burden of disease study

The global incidence of gout has increased rapidly, likely secondary to the increase in the prevalence of conditions that predispose to gout, such as obesity. Depending on the population studied, the prevalence of gout ranges from less than 1 to 6.8%. Thus, gout can be a significant burden on healthcare systems. The objective of this study is to observe the trends in the incidence, prevalence, and disability-adjusted life years (DALYs) of gout between 1990 and 2019 globally and in the European Union (EU) 15+ nations. We extracted data from the Global Burden of Disease Study database based on the International Classification of Diseases (ICD) versions 10 and 9. Incidence, prevalence, and disability-adjusted life years (DALYs) were extracted for individual EU15+ countries and globally in males and females between 1990 and 2019. Joinpoint regression analysis was used to describe trends. Between 1990 and 2019, gout prevalence, incidence, and DALYs increased in both males (+ 21.42%, + 16.87%, + 21.49%, respectively) and females (+ 21.06%, + 18.75%, + 20.66%, respectively) globally. The United States of America had the highest increase in prevalence (males: + 90.6%; females + 47.1%), incidence (males: + 63.73%; females: + 39.11%) and DALYs (males: + 90.43%; females: + 42.75%). Incidence, prevalence, and DALYs from gout are increasing worldwide and in most of the EU15+ countries for males and females. Studies have reported the association of gout with comorbidities such as metabolic syndrome, diabetes mellitus, and cardiovascular disease. Health policies and resource allocation are required to increase awareness and modify risk factors globally.

Timely Shaver Treatment Removes Chronic Tophaceous Mass Improve Surgical Outcomes

Background: Current treatments with urate-lowering therapy (ULT) are effective for most patients with gout. However, approximately 10% of these patients do not respond well to ULT and develop chronic tophus lesions. Objective: This study aimed to evaluate the efficacy of surgery involving the shaver technique against chronic tophus lesions. Methods: This single-center, retrospective cohort study included 217 patients who had cumulatively undergone 303 shaver-assisted procedures between 2002 and 2018. Surgical outcomes were assessed in terms of the length of hospital stay (LOS) and wound healing time. Results: LOS and wound healing time were longer in patients with a preoperative tophus infection and lower extremity lesions than in those without infection and with upper extremity lesions (respectively, LOS: 12.7 vs. 8.6 days; wound healing time: 22.7 vs. 16.3 days). However, factors such as age, sex, body mass index, renal function, or uricemia level exerted no significant effect on surgical outcomes. Conclusion: Surgery involving the shaver technique should be performed before tophus infection. Clinical outcomes tend to be better for upper extremity lesions than for lower extremity lesions.

An update on the study of synovial fluid in the geriatric patient

BACKGROUND

The characteristics of synovial fluid (SF) in geriatric patients differ from those in younger patients. In Mexico, epidemiologic data on the incidence of different rheumatic diseases in geriatric patients are scarce.

OBJECTIVE

To describe the physical characteristics of geriatric SF and the prevalence of crystals in knee and other joint aspirates from patients with previously diagnosed joint disease.

MATERIALS AND METHODS

A retrospective study was performed with a baseline of 517 SF samples between 2011 and 2023. White blood cell count was performed by Neubauer chamber and crystals were identified by polarized light microscopy. Descriptive statistical analysis was performed and prevalence was reported as a percentage.

RESULTS

The mean age of the adults was 73.5±5.0 years, 54.4% were women and 45.6% were men. The mean SF volume was 6.3±9.5mL in older adults and 15.3±24.9mL in those younger than 65 years. The mean viscosity in older adults was 9.5±4.5mm and the mean leukocyte count was 7352±16,402leukocytes/mm3. Seventy percent of the older adults' SFs were referred to the laboratory for osteoarthritis (OA), with lower proportions for rheumatoid arthritis (RA) (14.6%) and gout (5.1%). Of the crystals observed in the geriatric population, 14.6% corresponded to monosodium urate crystals (CUM) and 18.9% to calcium pyrophosphate crystals (CPP).

CONCLUSIONS

The characteristics of LS in older adults were smaller volume, increased viscosity, and non-inflammatory. The main diagnoses were OA, RA, and gout. The crystal content of the SF of the geriatric population corresponded mainly to CPP.

Purine Metabolic Pathway Alterations and Serum Urate Changes after Oral Inosine Loading in Male Chinese Volunteers

BACKGROUND

Oral inosine loading is a new method to evaluate the effects of purine on urate metabolism. However, individuals respond differently to acute purine intake, and the effects on the metabolism of other purines remain to be explored.

METHODS

35 male participants are recruited. Participants received 500 mg of inosine orally after an overnight fast, and blood and urine samples are collected before and at various time points over 180 min after inosine administration.

RESULTS

The serum urate concentration is significantly different between the hyperuricemia (n = 14) and non-hyperuricemia (n = 16) groups before inosine intake, but there is no in urate change after inosine intake. When grouped according to the baseline estimated glomerular filtration rate (eGFR), the increase in urate level in the high-eGFR group is significantly higher than that in the low-eGFR group (p  =  0.047). The high-eGFR group showed higher levels of serum xanthine and xanthine oxidase (XOD), the key enzyme in urate synthesis, after inosine loading (p < 0.01).

CONCLUSIONS

The increase in urate level is positively related to eGFR after oral acute inosine administration, which may have been due to a higher level of XOD.

Single-nucleotide polymorphisms link gout with health-related lifestyle factors in Korean cohorts

Gout-a very painful inflammatory arthritis caused by the deposition of monosodium urate crystals in the joints-is influenced by several factors. We identified the association of single- nucleotide polymorphisms (SNPs) that link gout with health-related lifestyle factors using genomic data from the Korean Genome and Epidemiology Study. We conducted a genome-wide association study (GWAS) on 18,927 samples of 438 Korean patients with gout and 18,489 controls for the discovery stage. For the replication stage, another batch containing samples of 326 patients with gout and 2,737 controls were analyzed. Lastly, a meta-analysis was performed using these two cohorts. We analyzed the effects of health-related lifestyle factors, including eating habits, physical activity, drinking behavior, and smoking behavior, on gout. After identifying the association between GWAS-derived SNPs and health-related lifestyle factors, we confirmed the interaction between the polygenic risk score (PRS) and health-related lifestyle factors. We identified 15 SNPs related to gout, among which rs1481012 of ABCG2 located on chromosome 4 has been newly discovered (P = 2.46e-11). On examining the interaction between SNPs and health-related lifestyles, rs3109823-located in ABCG2-was found to be associated with smoking status. In addition, rs11936395-located in SLC2A9-was significantly associated with the average momentum of exercise per session, whereas rs11066325 located in PTPN11, showed a significant association with the number of exercise sessions per week, smoking status, drinking status, and amount of soju drink per session. rs9421589-located in FAM35A-was significantly associated with the duration of smoking. In addition, we verified that the association between PRS and duration of smoking affects gout. Thus, in this study, we identified novel SNPs that link gout with health-related lifestyle factors in the Korean population.

Risk of gout in Taiwan Biobank participants pertaining to their sex and family history of gout among first-degree relatives

BACKGROUND

Family history of gout and sex are independently associated with gout. However, there is a paucity of research regarding the joint role of both factors in gout pathogenesis. Therefore, we assessed the independent and combined association of family history of gout and sex with gout.

METHODS

Our analysis included 132,311 Taiwan Biobank (TWB)-enrolled individuals comprising 21,159 gout cases and 111,152 controls. We subcategorized the family history of gout as (1) both siblings and parents had gout), (2) only parents had gout, and (3) only siblings had gout.

RESULTS

Generally, sex (men compared to women) and family history of gout were independently associated with a higher risk of gout. The odds ratio (OR); 95% confidence interval (CI) was 9.175; 8.801-9.566 for sex, and 2.306; 2.206-2.410 for family history. For the subcategories 'both siblings and had gout,' 'only parents had gout,' and 'only siblings had gout,' the odds ratios (ORs); 95% confidence intervals (CIs) were 4.944; 4.414-5.538, 2.041; 1.927-2.161, and 2.162; 2.012-2.323, respectively. The interaction between sex and family history was significant (p value = 0.0001). After stratification by sex, family history of gout remained significantly associated with a higher risk of gout in both sexes, even though the odds ratios were higher in men. For the subcategories 'both siblings and parents had gout,' 'only parent had gout,' and 'only siblings had gout,' the corresponding ORs; 95% CIs were 6.279; 5.243-7.520, 2.211; 2.062-2.371, and 2.148; 1.955-2.361 in men and 4.199; 3.566-4.945, 1.827; 1.640-2.035, and 2.093; 1.876-2.336 in women. After integrating sex and family history (reference: women with no family history), the highest risk of gout was observed in men who had at least one parent and sibling with a history of gout (OR; 95% CI 55.774; 46.360-67.101).

CONCLUSION

Sex and family history of gout were independently and interactively associated with gout. Sex-wise, men had a higher risk of gout than women. Family history was associated with a higher risk of gout in both sexes, but men had a higher risk. Notably, men having both siblings and parents with gout had the highest risk of gout.

Association between Asymptomatic Hyperuricemia with Adiposity Indices: A Cross-Sectional Study in a Spanish Population

INTRODUCTION

New anthropometric indices have been developed as an alternative to body mass index (BMI) and waist circumference (WC) to assess body mass and visceral fat. Asymptomatic hyperuricemia is considered an independent cardiovascular risk factor. Currently, little is known about the relationship between asymptomatic hyperuricemia and several new anthropometric indices. This study aimed to assess the association between the presence of asymptomatic hyperuricemia and anthropometric indices, both novel and traditional.

METHODS

This study analyzed 1094 Spanish subjects who consecutively visited the cardiovascular risk consultation of the University Hospital San Pedro de Alcántara of Cáceres, Spain, between June 2021 and September 2022. Anthropometric measures, including traditional and novel indices, were determined. The asymptomatic hyperuricemia group was defined according to serum uric acid levels.

RESULTS

All the anthropometric indices studied, including new and traditional, were significantly greater among patients with asymptomatic hyperuricemia, except for WWI. In multiple linear regression analysis, serum uric acid levels were significantly correlated with BMI, WHR, WHtR, AVI, BAI, BRI, CUN-BAE, and WWI but not ABSI or CI. In the univariate analysis, all indices were associated with asymptomatic hyperuricemia (p < 0.05); however, only WHtR (adjusted OR: 2.93; 95% CI: 1.03-8.37; p = 0.044), AVI (adjusted OR: 1.46; 95% CI: 1.04-2.04; p = 0.026), and BRI (adjusted OR: 1.66; 95% CI: 1.19-2.32; p = 0.003) were significantly associated in multivariate analysis. Finally, WHtR, AVI, and BRI provided the largest AUCs.

CONCLUSIONS

Our findings showed that WHtR, AVI, and BRI were independently positively associated with asymptomatic hyperuricemia and could be good predictors.

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

Background

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

Methods

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

Results

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

Conclusion

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

Familial Risk of Gout and Interaction With Obesity and Alcohol Consumption: A Population-Based Cohort Study in Korea

OBJECTIVE

Population-based studies of the familial aggregation of gout are scarce, and gene/environment interactions are not well studied. This study was undertaken to evaluate the familial aggregation of gout as well as assess interactions between family history and obesity or alcohol consumption on the development of gout.

METHODS

Using the Korean National Health Insurance database, which includes information regarding familial relationships and risk factor data, we identified 5,524,403 individuals from 2002 to 2018. Familial risk was calculated using hazard ratios (HRs) with 95% confidence intervals (95% CIs) to compare the risk in individuals with and those without affected first-degree relatives. Interactions between family history and obesity/alcohol consumption were assessed on an additive scale using the relative excess risk due to interaction (RERI).

RESULTS

Individuals with a gout-affected first-degree relative had a 2.42-fold (95% CI 2.39, 2.46) increased risk of disease compared to those with unaffected first-degree relatives. Having both a family history of gout and being either overweight or having moderate alcohol consumption was associated with a markedly increased risk of disease, with HRs of 4.39 (95% CI 4.29, 4.49) and 2.28 (95% CI 2.22, 2.35), respectively, which exceeded the sum of their individual risks but was only statistically significant in overweight individuals (RERI 0.96 [95% CI 0.85, 1.06]). Obese individuals (RERI 1.88 [95% CI 1.61, 2.16]) and heavy drinkers (RERI 0.36 [95% CI 0.20, 0.52]) had a more prominent interaction compared to overweight individuals and moderate drinkers, suggesting a dose-response interaction pattern.

CONCLUSION

Our findings indicate the possibility of an interaction between gout-associated genetic factors and obesity/alcohol consumption.

Association between Dietary Acid Load and Hyperuricemia in Chinese Adults: Analysis of the China Health and Nutrition Survey (2009)

BACKGROUND

This study evaluates the association between dietary acid load (DAL) and hyperuricemia in Chinese adults.

METHODS

The China Health and Nutrition Survey (CHNS) in 2009 was used in this cross-sectional study. Potential renal acid load (PRAL) and net endogenous acid production (NEAP) were applied to estimate DAL. A multiple logistic regression model was used to test the relationship between DAL and hyperuricemia risk.

RESULTS

A total of 7947 participants were included in this study, of whom 1172 had hyperuricemia. The PRAL score was positively related to the prevalence of hyperuricemia, even when potential covariates were taken into account. In comparison with Q1, the ORs were 1.12 (95% CI, 0.92-1.38), 1.20 (95% CI, 0.97-1.47) and 1.42 (95% CI, 1.16-1.75) in Q2, Q3 and Q4. However, there was no significant relationship between NEAP scores and hyperuricemia. Every 10 g increase in energy-adjusted fat, protein and animal protein intakes caused a 10%, 17% and 18% increase in hyperuricemia risk, respectively (OR: 1.10, 95% CI: 1.04-1.16; OR: 1.17, 95% CI: 1.11-1.25; OR: 1.18, 95% CI: 1.12-1.24, respectively). An obvious linear correlation was also suggested by the restricted cubic spline.

CONCLUSIONS

Hyperuricemia risk was associated with higher PRAL among Chinese adults. This means that a diet low in PRAL scores could be a very valuable uric acid-lowering dietary pattern.

A randomized pilot trial assessing the reduction of gout episodes in hyperuricemic patients by oral administration of Ligilactobacillus salivarius CECT 30632, a strain with the ability to degrade purines

Introduction

Hyperuricemia and gout are receiving an increasing scientific and medical attention because of their relatively high prevalence and their association with relevant co-morbidities. Recently, it has been suggested that gout patients have an altered gut microbiota. The first objective of this study was to investigate the potential of some Ligilactobacillus salivarius strains to metabolize purine-related metabolites. The second objective was to evaluate the effect of administering a selected potential probiotic strain in individuals with a history of hyperuricemia.

Methods

Inosine, guanosine, hypoxanthine, guanine, xanthine, and uric acid were identified and quantified by high-performance liquid chromatography analysis. The uptake and biotransformation of these compounds by a selection of L. salivarius strains were assessed using bacterial whole cells and cell-free extracts, respectively. The efficacy of L. salivarius CECT 30632 to prevent gout was assessed in a pilot randomized controlled clinical trial involving 30 patients with hyperuricemia and a history of recurrent gout episodes. Half of the patients consumed L. salivarius CECT 30632 (9 log₁₀ CFU/day; probiotic group; n = 15) for 6 months while the remaining patients consumed allopurinol (100-300 mg/daily; control group; n = 15) for the same period. The clinical evolution and medical treatment received by the participants were followed, as well as the changes in several blood biochemical parameters.

Results

L. salivarius CECT 30632 was the most efficient strain for inosine (100%), guanosine (100%) and uric acid (50%) conversion and, therefore, it was selected for the pilot clinical trial. In comparison with the control group, administration of L. salivarius CECT 30632 resulted in a significant reduction in the number of gout episodes and in the use of gout-related drugs as well as an improvement in some blood parameters related to oxidative stress, liver damage or metabolic syndrome.

Conclusion

Regular administration of L. salivarius CECT 30632 reduced serum urate levels, the number of gout episodes and the pharmacological therapy required to control both hyperuricemia and gout episodes in individuals with a history of hyperuricemia and suffering from repeated episodes of gout.

Confirming Prior and Identifying Novel Correlates of Acute Calcium Pyrophosphate Crystal Arthritis

OBJECTIVE

To investigate previously identified and novel correlates of acute calcium pyrophosphate (CPP) crystal arthritis among well-characterized cases.

METHODS

In this case-control study, we identified cases of acute CPP crystal arthritis using a validated algorithm (positive predictive value 81%) applied in the Partners HealthCare electronic health record (EHR). Cases were matched to general patient controls on the year of first EHR encounter and index date. Prespecified potential correlates included sex, race, and comorbidities and medications previously associated with CPP deposition/acute CPP crystal arthritis in the literature. We estimated odds ratios (ORs) and 95% confidence intervals using conditional logistic regression models adjusted for demographic characteristics, comorbidities, medications prescribed in the past 90 days, health care utilization, and multimorbidity score.

RESULTS

We identified 1,697 cases matched to 6,503 controls. Mean ± SD age was 73.7 ± 11.8 years, 56.7% were female, 80.8% were White, and 10.3% were Black. All prespecified covariates were more common in cases than controls. Osteoarthritis (OR 3.08), male sex (OR 1.35), rheumatoid arthritis (OR 2.09), gout (OR 2.83), proton pump inhibitors (OR 1.94), loop diuretics (OR 1.60), and thiazides (OR 1.46) were significantly associated with acute CPP crystal arthritis after full adjustment. Black race was associated with lower odds for acute CPP crystal arthritis compared to White race (OR 0.47).

CONCLUSION

Using a validated algorithm to identify nearly 1,700 patients with acute CPP crystal arthritis, we confirmed important correlates of this acute manifestation of CPP deposition. This is the first study to report higher odds for acute CPP crystal arthritis among males.

Research Progress on the Relationship between Dietary Patterns and Hyperuricemia

As the final metabolite of purine metabolism, uric acid is critically associated with human health. The serum uric acid level is regulated by diet and the metabolic capacity of the human body. The impaired control of uric acid metabolism and excretion is associated with the increased level of serum uric acid, which ultimately results in hyperuricemia. Hyperuricemia is the "fourth-highest" after hypertension, hyperglycemia, and hyperlipidemia. With progress made in the relationship between diet and hyperuricemia, different dietary patterns and lifestyles have been discussed, such as exercise, the amount intake of meat, seafood, supplements with omega-3 fatty acids, sugar-sweetened soft drinks and energy drinks, and lower-fat-containing foods as well as drinking beer, wine, and spirits in the present article. This study demonstrated that a lower risk of hyperuricemia is substantially correlated with higher baseline adherence to MeDiet, and plant polyphenols can combat hyperuricemia by blocking xanthine oxidase.

Prevalence of Hyperuricemia and Associated Factors Among Type 2 Diabetic Patients in Jordan

Background

Previous studies showed variable estimate of the prevalence of hyperuricemia in patients with type 2 diabetes mellitus (T2DM). The prevalence of hyperuricemia and associated risk factors in Jordanian patients with T2DM is largely unknown. Therefore, this study aimed to determine the prevalence of hyperuricemia and its associated factors in Jordanian patients with T2DM.

Methods

A cross-sectional study was conducted on 655 patients with T2DM. A structured questionnaire was used to collect socio-demographic data. In addition, records of the study subjects were reviewed to obtain other clinical data. Weight, height, and waist circumference were measured, and body mass index was calculated. Lipid profile, serum uric acid and glycated haemoglobin were analysed. The study was conducted in accordance with the Declaration of Helsinki. An informed written consent was obtained from each participant. The confidentiality of the information was assured and only used for scientific purposes.

Results

Overall, the prevalence of hyperuricemia was 28.1%. Female gender (OR: 2.37; 95%, CI: 1.63–3.45), intake of angiotensin-converting enzyme (ACE) and angiotensin-II receptor blockers (ARBs) (OR: 1.68; 95%, CI: 1.12–2.50), intake of β-blockers (OR: 2.20; 95%, CI: 1.51–3.22), increased waist circumference (OR: 3.17; 95%, CI: 1.39–7.22) and family history of hyperuricemia (OR: 2.56; 95%, CI: 1.57–4.16) were associated with increased odds of hyperuricemia.

Conclusion

Hyperuricemia was high among type 2 diabetic patients, and screening test will be useful for those patients.

The study of correlation between nomogram prediction of uric acid and different chemotherapy regimens in breast cancer patients

Background

High levels of serum uric acid (SUA) are associated with a poor survival rate of breast cancer. Meanwhile, a sharp increase in SUA after chemotherapy may lead to tumor lysis syndrome (TLS). We created and validated a nomogram to help doctors better manage the patient's SUA level ahead of time in this study.

Methods

From July 2012 to June 2021, 206 patients with breast cancer undergoing chemotherapy participated in the study. They are randomly divided into training set (n=137) and validation set (n=69). Univariate and multivariate logistic regression analysis was used to screen the independent predictors of the risk of elevated uric acid in the whole training set data. The receiver operating characteristic (ROC) curve and decision curve assessed the accuracy and clinical application value of nomogram.

Results

We confirmed that body mass index (BMI), age, menopause, EC-T chemotherapy (epirubicin-cyclophosphamide followed by paclitaxel) and THP + C-T (pirarubicin-cyclophosphamide followed by paclitaxel) are independent risk factors for high SUA. We established a nomogram for high SUA risk prediction to help clinicians make individualized choice of chemotherapy regimen. In the training cohort, the area under the ROC curve (AUC) showed statistical accuracy (AUC =0.796). Decision curve analysis proved the clinical value of the nomogram.

Conclusions

This nomogram can be used to calculate the specific likelihood of high SUA in patients with breast cancer undergoing chemotherapy with different chemotherapy options.

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

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

Thirty-Day Hospital Readmissions for Acute Gout in the United States: Analysis of the Nationwide Readmission Database

BACKGROUND/OBJECTIVE

The aims of this study were to describe the rates and characteristics of nonelective 30-day readmission among adult patients hospitalized for acute gout and to assess predictors of readmission.

METHODS

We analyzed the 2017 Nationwide Readmission Database. Gout hospitalizations were identified using the International Classification of Diseases, Tenth Revision, Clinical Modification code. Hospitalizations for adult patients were included. We excluded planned or elective readmissions. We utilized χ2 tests to compare baseline characteristics between readmissions and index hospitalizations. We used multivariate Cox regression to identify independent predictors of readmissions.

RESULTS

A total of 11,727 index adult hospitalizations with acute gout listed as the principal diagnosis were discharged alive and included. One thousand five hundred ninety-four (13.6%) readmissions occurred within 30 days. Acute gout was the most common reason for readmission. Readmissions had higher inpatient mortality (2.4% vs 0.1%, p < 0.0001), greater mean age (68.1 vs 67.0 years, p = 0.021), and longer hospital length of stay (5.9 vs 3.8 days, p < 0.0001) compared with index hospitalizations. Charlson Comorbidity Index scores of ≥2 (score 2: adjusted hazards ratio [AHR], 1.67; p = 0.001; score ≥3: AHR, 2.08; p < 0.0001), APR-DRG (All Patients Refined Diagnosis Related Groups) severity levels ≥2 (level 2: AHR, 1.43; p = 0.044; level 3: AHR, 1.83; p = 0.002; level 4: AHR, 2.38; p = 0.002), admission to metropolitan hospital (AHR, 1.83; p = 0.012), atrial fibrillation (AHR, 1.31; p = 0.004), and anemia (AHR, 1.30; p = 0.001) were significantly associated with 30-day readmissions.

CONCLUSIONS

Acute gout readmissions were associated with worse outcomes compared with index hospitalizations. Charlson Comorbidity Index scores ≥2, APR-DRG severity levels ≥2, admission to metropolitan hospital, atrial fibrillation, and anemia were significant predictors of readmission.

Monocyte to high-density lipoprotein cholesterol ratio and serum uric acid in Chinese adults: a cross-sectional study

BACKGROUND

Previous studies have shown that the monocyte to high-density lipoprotein cholesterol (HDL-C) ratio (MHR) is a predictor of various diseases such as coronary heart disease, diabetic microangiopathy, and metabolic syndrome. However, there are few scientific reports on the correlation between MHR and serum uric acid. The objective of this report is to explore the relationship between MHR and serum uric acid in Chinese adults.

METHODS

This cross-sectional study included 646 participants from southwest China who underwent a health examination at the Health Management Center of Deyang People's Hospital. The examination included blood pressure readings, routine blood tests (lipid, fasting glucose, serum transaminase, and serum uric acid levels), and various standardized questionnaires. We employed a generalized additive model and smoothed curve fitting to explore the relationship between MHR and serum uric acid levels. We then performed subgroup analyses to investigate the robustness of this relationship.

RESULTS

After adjusting for confounders (age, sex, body mass index, systolic blood pressure, diastolic blood pressure, aspartate transaminase, alanine aminotransferase, fasting glucose, total cholesterol, low-density lipoprotein, smoking, drinking, and exercise status), MHR was found to be positively correlated with serum uric acid levels (P < 0.001). The smoothing curve showed an approximately linear correlation between MHR and serum uric acid levels, and the linear correlation coefficient was 146.74 (95% CI 96.16-197.33, P < 0.0001). The subgroup analyses showed that the effect of MHR on serum uric acid levels was smaller in occasional smokers and smokers than in nonsmokers (P = 0.0194).

CONCLUSION

MHR was significantly and positively correlated with serum uric acid levels. Additionally, the effect of MHR on serum uric acid levels was lower in the individuals who smoked more.

Association between non-optimal temperature and hospitalizations for gout in Anqing, China: a time-series analysis

Previous studies have found that non-optimal temperature influences the development of gout, but the results have been inconsistent. The present study aimed to explore the effects of high temperature and high temperature variation on hospitalizations for gout in Anqing, China. We collected daily data on air pollutants, meteorological factors, and hospitalizations for gout between 1January 2016 and 31 December 2020 in Anqing City, China. We used Poisson generalized linear regression model and a distributed lag non-linear model (DLNM) to explore the relationship of high temperature, diurnal temperature range (DTR), and temperature change between neighboring days (TCN) with hospitalizations for gout. Stratified analysis by gender (male, female) and age (<65 years, ≥65 years) was conducted. Hospitalizations for gout attributed to high temperature, high DTR, and high TCN were also quantified. A total of 8675 hospitalized patients with gout were reported during the study period. We observed that exposure to high temperature was linked with an increased risk of hospitalizations for gout (lag 0, RR: 1.081, 95% confidence interval (CI): 1.011, 1.155). Exposure to high DTR was also associated with increased risk of hospitalizations for gout (lag9, RR: 1.017, 95% CI: 1.001,1.035). A large drop in temperature between neighboring days was associated an increased risk of hospitalizations for gout (lag 0-2 days, RR: 1.234, 95% CI: 1.017, 1.493). Stratified analysis results revealed that older adults and men were more sensitive to high-level DTR exposure than their counterparts. Nearly 15% of hospitalizations for gout could be attributable to high temperature (attributable fraction: 14.93%, 95% CI: 5.99%, 22.11%). This study suggests that high temperature and high temperature variation may trigger hospitalizations for gout, indicating that patients with gout need to take proactive actions in the face of days with non-optimal temperature.

Hyperuricemia is associated with secondary hyperparathyroidism in patients with chronic kidney disease

PURPOSE

Hyperuricemia is common among patients with chronic kidney disease (CKD). In the general population, hyperuricemia is associated with secondary hyperparathyroidism (SHPT), in a mechanism that involves vitamin D metabolism. Data for patients with CKD, however, are scarce. We aimed to evaluate the relationship between hyperuricemia and mineral and bone metabolism, particularly hyperparathyroidism.

METHODS

This is a retrospective study that included 922 adult patients with stages 3, 4, or 5 CKD, not on dialysis. Clinical, demographic, and biochemical data were collected from charts and included uric acid, parathyroid hormone (PTH), 25(OH)-vitamin D, calcium, phosphate, renal function (estimated glomerular filtration rate-eGFR), and medications such as allopurinol, furosemide, and cholecalciferol. SHPT was defined as PTH > 65 pg/ml.

RESULTS

Our patients were mostly Caucasian women, with a mean age of 64 ± 16 years. SHPT and hyperuricemia were observed in 70% and 62.4% of patients, respectively. Patients with SHPT presented higher levels of uric acid (7.2 ± 1.8 vs. 6.6 ± 1.7 mg/dL, p = 0.0001) and a higher frequency of hyperuricemia (66% vs. 33%, p = 0.0001). Patients with hyperuricemia were mostly female, with lower eGFR, higher phosphate, and higher PTH. The risk of hypovitaminosis D was higher among patients with SHPT (69.7% vs. 53.1%, p = 0.0001). Hyperuricemia remained independently associated with hyperparathyroidism, (p = 0.033) even after adjustments for eGFR, calcium, phosphate, hypovitaminosis D, and use of allopurinol, calcitriol, furosemide, and cholecalciferol.

CONCLUSION

Hyperuricemia seems to be a contributing factor for SHPT in patients with CKD. The mechanisms behind this finding have yet to be elucidated.

Evolving Role of Dual-Energy CT in the Clinical Workup of Gout: A Retrospective Study

Background: Dual-energy CT (DECT) allows noninvasive detection of monosodium urate (MSU) crystal deposits and has become incorporated into the routine clinical evaluation for gout at many institutions over the past decade. Objective: To compare two time periods over the past decade in terms of radiologists' interpretations of DECT examinations performed for the evaluation of gout and subsequent clinical actions. Methods: This retrospective study included 100 consecutive adult patients who underwent DECT to evaluate for gout in each of two periods (periods beginning in March 2013 and September 2019). Examinations in 2013 used a second-generation DECT scanner (140 kV with 0.4 mm tin filter), and in 2019 used a third-generation DECT scanner (150 kV with 0.6 mm tin filter) that provides improved spectral separation. Original DECT reports were classified as positive, negative, or equivocal for MSU crystals indicative of gout. Joint aspirations occurring after the DECT examinations were recorded based on medical record review. A single radiologist performed a post hoc retrospective blinded image review, classifying examinations as positive, negative, or equivocal. Results: In 2013, 44.0% of DECT examinations were interpreted as positive, 23.0% as negative, and 33.0% as equivocal; in 2019, 37.0% were interpreted as positive, 47.0% as negative, and 16.0% as equivocal (p<.001). The frequency of joint aspiration after DECT was 14.0% in 2013 versus 2.0% in 2019 (p=.002), and after DECT examinations with negative interpretations was 17.4% in 2013 versus 2.1% in 2019 (p=.02). In post hoc assessment by a single radiologist, the distribution of interpretations in 2013 was positive in 49.0%, negative in 22.0%, and equivocal in 29.0%, and in 2019 was positive in 39.0%, negative in 50.0%, and equivocal in 11.0% (p<.001). Conclusion: When comparing DECT examinations performed for gout in 2013 and 2019, the frequency of equivocal interpretations was significantly lower in 2019, possibly related to interval technologic improvements. Negative examinations were less frequently followed by joint aspirations in 2019, possibly reflecting increasing clinical acceptance of the DECT results. Clinical Impact: The findings indicate an evolving role for DECT in the evaluation of gout following an institution's routine adoption of the technology for this purpose.

Hyperuricemia: Features of the Diet

The association of hyperuricemia (HU) with cardiovascular disease (CVD), diabetes, metabolic syndrome, and kidney disease has been demonstrated in numerous studies. НU is the main pathogenetic factor in the development of gout and is associated with an increase in overall and cardiovascular mortality. НU is included in the list of factors determining cardiovascular risk. According to epidemiological studies, there is a high prevalence of HU in the world and its increase in recent decades. A number of factors have been identified that contribute to the increased risk of НU. Non-modifiable factors include gender, age, genetic factors, and modifiable factors include diet and lifestyle. Nutritional unbalances, increased life expectancy, increased prevalence of obesity, and increased use of drugs (especially diuretics) are seen as contributing factors to the rise in НU. The review was carried out to summarize the available information on the effect of dietary habits, individual foods and nutrients on serum uric acid (SUA) levels and the risk of developing HU. The review presents the results of scientific studies demonstrating the relationship of НU with the consumption of foods rich in purines (offal, red meat, fish, seafood, legumes), alcohol consumption, drinks sweetened with fructose, coffee, dairy products, vegetables and fruits. Diet correction is an important and necessary step in the prevention and treatment of НU. The article reviews the basic principles of dietary management in HU and provides dietary recommendations for patients. For effective prevention and treatment of НU, a mandatory correction of the diet is required.

Excess Uric Acid Induces Gouty Nephropathy Through Crystal Formation: A Review of Recent Insights

Uric acid (UA) is the final product of purine metabolism in the human body, and impaired purine metabolism can increase the uric acid in serum, finally resulting in hyperuricemia (HUA). Current evidences suggest that urates might have antioxidant properties under certain circumstances, but most evidences suggest that urates promote inflammation. Hyperuricemia leads to the formation of urate crystals, which might be recognized as a red flag by the immune system. Such a response stimulates macrophage activation, leads to the activation of NOD-like receptor protein 3 (NLRP3) inflammasome vesicles, and ultimately the production and liberation of interleukin-1b (IL-1b) and interleukin-18 (IL-18), which can mediate inflammation, apoptosis and necroinflammation and cause an inflammatory cascade response. The kidney is one of the most commonly affected organs in HUA, which promotes the development of chronic kidney disease (CKD) by damaging endothelial cells, activating the renin-angiotensin system (RAS), and promoting inflammatory responses. Pharmacological interventions and lifestyle modifications are the primary means for controlling gout and lowering UA. The febuxostat is safe for CKD patients in the UA lowering therapy. Although dialysis can reduce UA levels, the application of drug is also necessary for dialysis patients. This article reviews the synthesis and metabolism of UA, etiology of HUA, the relationship between HUA and kidney disease, the treatment of gout and gouty nephropathy (GN).

Russian Society for the Prevention of Noncommunicable Diseases (ROPNIZ). Alimentary-dependent risk factors for chronic non-communicable diseases and eating habits: dietary correction within the framework of preventive counseling. Methodological Guidelines

The methodological guidelines are developed as a practical document for medical specialists working in the field of preventive medicine, in order to expand and improve the provision of this type of medical service to the adult population. The methodological guidelines include an informational and informative part for medical specialists and a practical part for patients, presented in the format of memos, contain the main sections-healthy nutrition, correction of eating habits, issues of modifying the diet for the main alimentary-dependent risk factors for chronic non-communicable diseases, such as arterial hypertension, obesity, disorders of lipid, carbohydrate and purine metabolism, a decrease in bone mineral density. They are intended for medical specialists working in the field of prevention, for doctors and secondary medical personnel of offices and departments of medical prevention, public health and medical prevention centers, healthy lifestyle specialists, teachers of medical educational institutions, for specialists who develop and implement educational programs for patients, as well as for medical specialists of a therapeutic profile.

A Study of Metabolic Parameters in Patients with Gout: A Single Center Study from Nepal

BACKGROUND AND AIMS

To study the prevalence of deranged metabolic parameters in patients with gout.

METHODS

This was a prospective, cross-sectional observational study conducted at a tertiary level rheumatology center in Nepal. Patients over 18 years and diagnosed as gout using the ACR/EULAR 2015 classification criteria were included in the study. Known cases of chronic kidney disease, liver disease and heart diseases were excluded. Baseline demographic data along with records of weight, waist circumference, lipid profile, glucose profile, blood pressure measurement, serum uric acid level and inflammatory markers were taken. Diagnosis of metabolic syndrome (MS) was made according to the National Cholesterol Education Program criteria. Approval was obtained from the ethical review board of the National Center for Rheumatic Diseases.

RESULTS

A total of 523 patients with gout were enrolled in the study, out of which 97.0% were male. The mean age at diagnosis was 49.1±12.8 years. Most of the patients were overweight with a mean BMI of 27.0±3.6 kg/m2. About 8.1% had preexisting diabetes mellitus, 24.6% had hypertension, 5.1% had hypothyroidism and 45.1% had dyslipidemia. Patients fulfilling 2 out of 5 criteria of MS were 60.6% whereas 30.6% fulfilled 3 out of 5 criteria.

CONCLUSION

Gout was commonly observed in middle-aged men. The prevalence of metabolic syndrome and its components was high in patients with gout. Management of gout should also include screening and management of the metabolic syndrome.

Sugar-sweetened soft drinks consumption and risk of hyperuricemia: Results of the ELSA-Brasil study

BACKGROUND AND AIMS

The prospective association between sugar-sweetened beverages consumption and hyperuricemia is controversial. The aim was to investigate the association of the consumption of sugar-sweetened soft drinks and unsweetened fruit juices with the incidence of hyperuricemia and the levels of serum uric acid in the participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

METHODS AND RESULTS

Longitudinal analysis in ELSA-Brasil participants (baseline 2008-2010 and follow-up 2012-2014). The sample consisted of 10,072 civil servants (35-74 years, both sexes). The consumption of beverages estimated by a food frequency questionnaire (baseline) was divided into five categories: nonconsumption and quartiles (≥0.1 mL/day). Hyperuricemia was defined as uric acid ≥7.0 mg/dL (men) and ≥5.7 mg/dL (women). Poisson regression with robust variance and multiple linear regression were tested. The average consumption of soft drinks was 84 ± 191 mL/day in men and 42 ± 128 mL/day in women. After 4 years of follow-up, the higher consumption of soft drinks (men: 401 ± 303 mL/day; women: 390 ± 290 mL/day) increased the relative risk of hyperuricemia by 30% (men) and 40% (women), and was associated with increased mean uric acid (men: β = 0.14 mg/dL; 95% CI 0.41-0.24; women: β = 0.11 mg/dL; 95% CI 0.00-0.21). The consumption of unsweetened juice was not associated with hyperuricemia.

CONCLUSION

High consumption of sugar-sweetened soft drinks is associated with an increased relative risk of hyperuricemia and elevated serum uric acid levels in Brazilian adults.

The biology of urate

Urate is the end-product of the purine metabolism in humans. The dominant source of urate is endogenous purines and the remainder comes through diet. Approximately two thirds of urate is eliminated via the kidney with the rest excreted in the feces. While the transporter BCRP, encoded by ABCG2, has been found to play a role in both the gut and kidney, SLC22A12 and SLC2A9 encoding URAT1 and GLUT9, respectively, are the two transporters best characterized. Only 8-12% of the filtered urate is excreted by the kidney. Renal elimination of urate depends substantially on specific transporters, including URAT1, GLUT9 and BCRP. Studies that have assessed the biologic effects of urate have produced highly variable results. Although there is a suggestion that urate may have anti-oxidant properties in some circumstances, the majority of evidence indicates that urate is pro-inflammatory. Hyperuricemia can result in the formation of monosodium urate (MSU) crystals that may be recognized as danger signals by the immune system. This immune response results in the activation of the NLRP3 inflammasome and ultimately in the production and release of interleukin-1β, and IL-18, that mediate both inflammation, pyroptotic cell death, and necroinflammation. It has also been demonstrated that soluble urate mediates effects on the kidney to induce hypertension and can induce long term epigenetic reprogramming in myeloid cells to induce "trained immunity." Together, these sequelae of urate are thought to mediate most of the physiological effects of hyperuricemia and gout, illustrating this biologically active molecule is more than just an "end-product" of purine metabolism.

Older age and diclofenac are associated with increased risk of upper gastrointestinal bleeding in gout patients

Background

Gouty arthritis is a disease of global burden in which defective metabolism of uric acid causes arthritis. Gouty arthritis or medications used for its treatment may lead to uric acid-associated complications such as upper gastrointestinal bleeding (UGIB) and renal impairment.

Methods

In this cross-sectional study with retrospective record review, 403 established gouty arthritis patients were recruited to determine the incidence of UGIB and associated factors among gout patients who were on regular nonsteroidal anti-inflammatory drugs (NSAIDs).

Results

The mean age of the 403 gouty arthritis patients was 55.7 years old and the majority (n = 359/403; 89.1%) were male. The incidence of UGIB among gouty arthritis patients who were on NSAIDs was 7.2% (n = 29/403). Older age (p < 0.001), diclofenac medication (p = 0.003), pantoprazole medication (p = 0.003), end-stage renal failure (ESRF) (p = 0.007), smoking (p = 0.035), hypertension (p = 0.042) and creatinine (p = 0.045) were significant risk factors for UGIB among the gouty arthritis patients in univariable analysis. Older age (p = 0.001) and diclofenac medication (p < 0.001) remained significant risk factors for UGIB among the gouty arthritis patients in multivariable analysis.

Conclusions

Age and diclofenac were significantly associated with UGIB among patients with gouty arthritis on regular NSAIDs, indicating that these factors increased the risks of developing UGIB in gout patients. Hence, these high-risk groups of gouty arthritis patients should be routinely monitored to avoid the potential onset of UGIB. Our data also suggest that diclofenac should be prescribed for the shortest duration possible to minimize the risk of developing UGIB in gout patients.

Association Between Dietary Intake and Serum Uric Acid Levels in Kidney Transplant Patients

OBJECTIVES

The aim of this study was to evaluate the association between dietary intake and uric acid (UA) levels in kidney transplant patients (KTPs).

METHODS

A cross-sectional study was performed with 113 KTPs. Dietary intake assessment was carried out thorough two 24-hour dietary recalls using the 5-step multiple pass method. We evaluated the intake of energy, carbohydrate, total protein, animal protein, vegetable protein, total fat, saturated fat, trans fat, monounsaturated fat, polyunsaturated fat, omega-3 and omega-6 fatty acids, cholesterol, total sugar, added sugars, total fiber, insoluble fiber, soluble fiber, alcohol, caffeine, fructose, glucose, lactose, sucrose, vitamin A, vitamin C, vitamin E, and calcium. The intake of several food groups (portions) was also evaluated. Hyperuricemia was classified as >7.0 and >6 mg/dL for men and women, respectively.

RESULTS

In odds ratio analyses, the individuals who ingested more vegetable protein (g/kg) and caffeine (mg) presented lower chance to have hyperuricemia. In linear regression, animal protein (g) intake was positively associated (β = 0.011, P = .048), while vegetable protein (g/kg) intake was inversely associated (β = -2.45, P = .047) with serum UA. However, after a multiple linear regression including vegetable and animal protein intakes together, only vegetable protein intake remained associated with UA. The intake of other nutrients and portions of food groups was not associated with UA. All the analyses were adjusted for sex, age, hypertension, body mass index, glomerular filtration rate, use of medicines, and caloric intake misreporting.

CONCLUSIONS

Vegetable protein and caffeine intakes were inversely associated with UA in KTPs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Associations of Amino Acid and Acylcarnitine Profiles With Incident Hyperuricemia in Middle-Aged and Older Chinese Individuals

OBJECTIVE

Little is known about how metabolic perturbations are linked to hyperuricemia in the general population. Therefore we aimed to examine metabolomics profiles in relation to uric acid change and incident hyperuricemia.

METHODS

This study included 1,621 community-dwelling Chinese participants ages 50-70 years without hyperuricemia at baseline, with a mean duration of follow-up of 6 years. A total of 56 metabolites (22 amino acids and 34 acylcarnitines) at baseline were quantified by gas or liquid chromatography coupled to mass spectrometry. Annual change in uric acid was calculated, and incident hyperuricemia was defined as plasma uric acid >420 μmoles/liter in men and >360 μmoles/liter in women.

RESULTS

The mean ± SD annual change in uric acid was 9.6 ± 12.1 μmoles/liter and the incidence of hyperuricemia was 23.1% (375 of 1,621). After adjustment for conventional risk factors, 9 metabolites (cysteine, glutamine, phenylalanine, threonine, and long-chain acylcarnitines C14:1OH, C18, C18:2, C20, and C20:4) were significantly associated with uric acid change (Bonferroni corrected P < 0.05) and with incident hyperuricemia (relative risks ranged from 1.14 to 1.21 per SD increment of metabolites; P < 0.05). A network analysis showed significant associations between the module containing long-chain acylcarnitines and incident hyperuricemia. Moreover, levels of these 9 metabolites were specifically correlated with intake of foods, including red and processed meat or soy products.

CONCLUSION

Plasma cysteine, glutamine, phenylalanine, threonine, and long-chain acylcarnitines are positively associated with incident hyperuricemia. The levels of these metabolites may be partially driven by intakes of meat and soy products that are associated with hyperuricemia.

Breaking the vicious circle of diet, malnutrition and oral health for the independent elderly

Aging impairs senses, mastication, oral status and function, causing nutritional needs and diet insufficiencies. The present needs of independent older adults suggest that health research and oral health care should shift from reductionist disease management to integral and personal treatment plans, including lifestyle, psychological, nutritional and oral health coaching approaches. Dentists and other medical professionals that work in the field of gerodontology should be educated on the macro and micronutrient needs of the elderly and incorporate certain nutritional plans early in the life of their patients with their approval and cooperation, in order to postpone tooth loss and masticatory impairment. Old recipes such as the Mediterranean diet should be kept as a base for all the elderly and be enriched in a customized interpersonal way from the dentist as well as the medical professional according to the specific needs of one's oral and general health status. In this nonsystematic review paper, the basic aspects of the vicious cycle of nutrition and oral health status are discussed and suggestions of major nutrients' influence and needs for independent elders are reported. Based on the scientific data collected, suggestions are made for the food industry for better quality and dosage of foods for this category of individuals. Such strategies can be a whole new area of interest for the food industry in order to obtain better quality of food packaging for the independent OA with accepted texture, odor, colors, macronutrients and micronutrients' consistency and in specific portions.

Wastewater-based estimation of the prevalence of gout in Australia

Allopurinol, a first-line gout treatment drug in Australia, was assessed as a wastewater-based epidemiology biomarker of gout via quantification of the urinary metabolite, oxypurinol in wastewater. The in-sewer stability of oxypurinol was examined using laboratory-scale sewer reactors. Wastewater from 75 wastewater treatment plants across Australia, covering approximately 52% (12.2 million) of the country's population, was collected on the 2016 census day. Oxypurinol was quantified in the wastewater samples and population-weighted mass loads calculated. Pearson and Spearman rank-order correlations were applied to investigate any link between allopurinol, other selected wastewater biomarkers, and socio-economic indicators. Oxypurinol was shown to be stable in sewer conditions and suitable as a WBE biomarker. Oxypurinol was detected in all wastewater samples. The estimated consumption of allopurinol ranged from 1.9 to 32 g/day/1000 people equating to 4.8 to 80 DDD/day/1000 people. The prevalence of gout across all tested sewer catchments was between 0.5% to 8%, with a median of 2.9% nationally. No significant positive correlation was observed between allopurinol consumption and alcohol consumption, mean age of catchment population, remoteness or higher socioeconomic status. There was a significant positive correlation with selective analgesic drug use. Wastewater analysis can be used to study gout prevalence and can provide additional insights on population level risk factors when triangulated with other biomarkers.

Triglycerides and Total Cholesterol Concentrations in Association with Hyperuricemia in Chinese Adults in Qingdao, China

Objective

To assess the association between triglycerides (TG), total cholesterol (TC) and hyperuricemia (HUA) in the general Chinese population.

Methods

A population-based cross-sectional survey included 9680 participants aged 35–74 years in 2006 and 2009 in Qingdao, China. TG, TC and uric acid (UA) were measured. The logistic regression model was performed to estimate the association between TG, TC, and HUA with an odds ratio (OR) and 95% confidence intervals (CI). Meanwhile, age stratification analysis (<55 years group and ≥55 years group) was performed to evaluate whether age potentially affects the association between TG, TC and HUA using multivariable logistic regression.

Results

Higher TG and TC showed significantly increased HUA prevalence in both men and women (P_trend all <0.05). Multivariate logistic regression indicated that borderline high TG (OR: 1.68, 95% CI: 1.31, 2.15 and HTG (OR: 2.98, 95% CI: 2.39, 3.72) indicated increased risk for HUA in men, and borderline high TG (OR: 2.09; 95% CI: 1.68,2.62); HTG (OR: 3.62; 95% CI: 2.90,4.51), borderline high TC (OR: 2.09, 95% CI: 1.68, 2.62) and HTC (OR: 3.62, 95% CI: 2.90, 4.51) showed significant association with HUA in women after adjusted age, school years, marital status, geographic division, personal monthly income, BMI and HDL-C. Age stratification analyses demonstrated that the association between TG and HUA was stronger in males aged ≥55 years and female aged <55 years, and the association between TC and HUA was stronger in both gender aged <55 years.

Conclusion

This large cross-sectional study focusing on the association between single indictor of blood lipid as exposure and HUA as outcome on the east coast of China for the first time. From a sample of Chinese adults, this study demonstrated that elevated TG in men and women and TC in women were associated with increased HUA prevalence.

Ever Use of E-Cigarettes Among Adults in the United States: A Cross-Sectional Study of Sociodemographic Factors

E-cigarette use among adolescents is well-documented, but less is known about adult users of e-cigarettes. The purpose of this study was to examine associations between sociodemographic factors and e-cigarette use in a nationally representative sample of adults in the United States. Cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) for years 2015-2016 were analyzed to assess e-cigarette use among 5989 adults aged ≥18 years. Multivariable logistic regression was conducted to examine associations between the sociodemographic exposures of age, sex, race, marital status, education level, employment status, and poverty-income ratio and the outcome of e-cigarette use. The weighted prevalence of ever use of e-cigarettes was 20%. Compared with adults aged ≥55 years, odds of e-cigarette use were 4.77 times (95% confidence interval [CI] = 3.63-6.27) higher among ages 18 to 34 years and 2.16 times (95% CI = 1.49-3.14) higher among ages 35 to 54 years. Higher odds of e-cigarette use were observed among widowed/divorced/separated participants compared with those who were married/living with a partner, among participants with less than high school (odds ratio [OR] = 1.47; 95% CI = 1.08-2.00) or high school/general educational development (GED) education (OR=1.41; 95% CI = 1.12-1.77) compared with those with college degrees/some college, and among those with incomes below the poverty level (OR=1.31; 95% CI = 1.01-1.69) compared with above the poverty level. For non-smokers of conventional cigarettes, higher odds of e-cigarette use were observed among males compared with females, Mexican Americans/Other Hispanics compared with non-Hispanic whites, and non-working participants compared with those who were working. Overall findings indicate that individuals who are widowed/divorced/separated, individuals with lower education, and with incomes below the poverty level are likely to report ever use of e-cigarettes. As increasing evidence demonstrates negative health consequences, e-cigarette initiation may ultimately contribute to additional smoking-related health inequalities even among non-smokers of conventional cigarettes.

The prevalence of gout and hyperuricemia in middle-aged and elderly people in Tibet Autonomous Region, China: A preliminary study

OBJECTIVE

Gout and hyperuricemia are common public health problem. There has been no epidemiological survey of gout and hyperuricemia in Tibet Autonomous Region, the southwest of China. Therefore, we estimated the prevalence of gout and hyperuricemia in Luoma Town, Naqu City, Tibet Autonomous Region of China.

METHODS

A population-based cross-sectional survey was conducted among 1458 residents of Luoma Town, Tibet Autonomous Region, age ≥40 years. We used questionnaires in face-to-face interviews, anthropometric measurements and serum uric acid test. Hyperuricemia was defined as serum uric acid level ≥7 mg/dl in men and ≥6 mg/dl in women. The definition of gout in this study was on the basis of new 2015ACR/EULAR classification criteria.

RESULTS

Nine hundred eighty-nine participants completed all items of gout and 818 participants attended to be taken blood samples for serum UA levels test. The overall crude prevalence of gout and hyperuricemia was 0.30% and 1.83% respectively. It was more prevalent in men than in women (2.86% vs 0.75%, P = .034) in hyperuricemia group. Tibetan had a lower age-standardized prevalence of gout 0.26% (95% confidence interval (CI): 0%-0.60%) and hyperuricemia 2.05% (95% confidence interval (CI): 0.99%-3.44%) compared with the China Health and Retirement Longitudinal Study results.

CONCLUSION

This is the first large-scale population-based survey to demonstrate the prevalence of gout and hyperuricemia of the middle-aged and elderly population in Tibet Autonomous Region, China. The prevalence of gout and hyperuricemia is relatively lower than other places in China, and that might be influenced by ethnicity, genetic and environment factors. These findings will be useful for the future researches and health care strategies.

Dietary Interventions for Gout and Effect on Cardiovascular Risk Factors: A Systematic Review

Gout is one of the most prevalent inflammatory rheumatic disease. It is preceded by hyperuricemia and associated with an increased risk for cardiovascular disease, both related to unhealthy diets. The objective of this systematic review is to better define the most appropriate diet addressing both disease activity and traditional cardiovascular risk factors in hyperuricemic patients. We included clinical trials with patients diagnosed with hyperuricemia or gout, investigating the effect of dietary interventions on serum uric acid (SUA) levels, gout flares and—if available—cardiovascular risk factors. Eighteen articles were included, which were too heterogeneous to perform a meta-analysis. Overall, the risk of bias of the studies was moderate to high. We distinguished four groups of dietary interventions: Calorie restriction and fasting, purine-low diets, Mediterranean-style diets, and supplements. Overall, fasting resulted in an increase of SUA, whilst small (SUA change +0.3 to −2.9 mg/dL) but significant effects were found after low-calorie, purine-low, and Mediterranean-style diets. Studies investigating the effect on cardiovascular risk factors were limited and inconclusive. Since Mediterranean-style diets/DASH (Dietary Approach to Stop Hypertension) have shown to be effective for the reduction of cardiovascular risk factors in other at-risk populations, we recommend further investigation of such diets for the treatment of gout.

The coexistence of gout in ankylosing spondylitis patients: a case control study

Ankylosing spondylitis (AS) and gout are common inflammatory arthropathies. It had been claimed previously that the two conditions rarely coexist. The aim of this study was to compare the prevalence of gout in a population of AS patients to its prevalence in the general population. To conduct this population-based case-control study, data of adult patients with a physician diagnosis of AS were retrieved from the database of the largest health-care provider organization in Israel, Clalit Health Services. For each patient with AS, five age- and sex-matched subjects without AS were randomly selected from the same database. Different parameters including the existence of gout, hypertension, body mass index, socioeconomic status, and smoking were evaluated in both the AS and the control groups. The study included 3763 patients with AS and 19,214 controls. The proportion of gout in the AS group was higher than in the control group: 73 subjects in the AS group had gout, while only 107 subjects in the non-AS group had gout (1.94% and 0.56%, respectively, OR 3.53, P < 0.001). Logistic regression adjusting for possible confounding variables found that AS was independently associated with gout (OR 1.41, P = 0.037). Our study suggests that gout is not less common in AS patients in comparison with the general population, and that it might even be more common in AS patients.

Uric Acid and Plant-Based Nutrition

Plant-based diets (PBDs) are associated with decreased risk of morbidity and mortality associated with important noncommunicable chronic diseases. Similar to animal-based food sources (e.g., meat, fish, and animal visceral organs), some plant-based food sources (e.g., certain soy legume products, sea vegetables, and brassica vegetables) also contain a high purine load. Suboptimally designed PBDs might consequently be associated with increased uric acid levels and gout development. Here, we review the available data on this topic, with a great majority of studies showing reduced risk of hyperuricemia and gout with vegetarian (especially lacto-vegetarian) PBDs. Additionally, type of ingested purines, fiber, vitamin C, and certain lifestyle factors work in concordance to reduce uric acid generation in PBDs. Recent limited data show that even with an exclusive PBD, uric acid concentrations remain in the normal range in short- and long-term dieters. The reasonable consumption of plant foods with a higher purine content as a part of PBDs may therefore be safely tolerated in normouricemic individuals, but additional data is needed in hyperuricemic individuals, especially those with chronic kidney disease.

ABCG2 gene polymorphism rs2231142 is associated with gout comorbidities but not allopurinol response in primary gout patients of a Chinese Han male population

Background

One common ATP-binding cassette subfamily G member 2 (ABCG2) gene variant, which is encoded by the single nucleotide polymorphism (SNP) rs2231142, was identified to take an essential part in gouty arthritis. However, the relationship between rs2231142, gout comorbidities and therapeutic effect of allopurinol in Chinese Han male population is still unclear. Wherefore, this study explored into the association between ABCG2 SNP rs2231142 affecting common comorbidities and the therapeutic effect of allopurinol in Chinese Han male gout patients.

Results

ABCG2 SNP rs2231142 and the gout comorbidities including nephrolithiasis and CKD were associated (P = 0.014 and P = 0.026). Group CKD stage = 1 were significantly different from those in group CKD stage≥2 regarding genotypes of ABCG2 gene polymorphism, while they were not significantly different from those in group CKD stage≥3. Meanwhile, the genotypes of rs2231142 and allopurinol response were not significantly associated (P = 0.588).

Conclusions

ABCG2 rs2231142 may predict the risk of kidney comorbidities for Chinese Han male gout patients, but not allopurinol response.

Gout in males: a possible role for COMT hypomethylation

OBJECTIVE

Gout is a common inflammatory disease, and the prevalence of gout in men is significantly higher than in women. Catechol-O-methyltransferase (COMT) regulates dopamine activity and metabolism, thereby participating in the uric acid metabolism, which in turn affects the occurrence of gout. Our study aimed to investigate the association between COMT methylation and gout in men.

METHODS

This study involved 57 male gout patients and 103 age-matched healthy men. We used quantitative methylation-specific polymerase chain reaction (qMSP) to determine DNA methylation levels in the blood. The COMT methylation level was represented by the percentage of methylation reference (PMR).

RESULTS

Our results showed that COMT methylation levels were significantly lower in gout patients than in the control group (median PMR 9.50 vs 31.34, p = 3E-5). The area under the curve (AUC) was 0.701 (95% CI 0.611-0.790, p = 2.7E-5) with a sensitivity of 68% and a specificity of 68.4%.

CONCLUSION

Our study found that there was a significant correlation between COMT hypomethylation and the risk of gout in males, and this provides an epigenetic mechanism of COMT in gout. COMT hypomethylation might be used as a potential diagnostic biomarker for gout in the future.

Associations of multiple exposures to persistent toxic substances with the risk of hyperuricemia and subclinical uric acid levels in BIOAMBIENT.ES study

Hyperuricemia is becoming a serious public health issue, which is highly influenced by environmental factors, although there is still controversial information on the potential influence of the exposure to Persistent Toxic Substances (PTSs) in the general population. In this study we aimed to assess the association. PTS exposure with uric acid homeostasis in a sample of the Spanish population. Participants were recruited during 2009-2010 in all the main geographical areas of Spain. Exposure to 34 PTSs was estimated by chemical analyses of serum levels of 6 Polychlorinated Biphenyls (PCBs, n = 950), 13 Organochlorine Pesticides (OCPs, n = 453), 6 Perfluoroalkyl Substances (PFAs, n = 755), 7 Polybrominated Diphenyl Ethers (PBDEs, n = 365), urinary Cadmium (n = 926), and Lead in whole blood (n = 882). The two study outcomes were defined as the prevalence of hyperuricemia in the study population and uric acid levels, the latter only in individuals with no previous diagnosis of hyperuricemia. Statistical analyses were performed by means of binomial logistic regression and linear regression, and mixture effects were screened using Weighted Quantile Sum Regression (WQS). Serum concentrations of γ-HCH, o,p´-DDE, PCB-138, PCB-153, PFOA, and urinary Cadmium were associated with an increased risk of hyperuricemia, while PBDE-153 showed an inverse association with the effect. Furthermore, exposure to Cadmium, PCB-138, and to PCB-153 was positively associated with uric acid levels. Results were consistent after lipid adjustment or standardization. WQS analyses revealed a major contribution of PCB-153 within the PCB mixture on both the risk of hyperuricemia and uric acid levels. Sensitivity analyses were performed by adjusting for dietary habits, fasting glucose and estimated glomerular filtration rate. Overall, we found novel associations between human exposure to mixtures of PTSs and disturbances in uric acid homeostasis. However, we cannot completely rule out potential residual confounding effect or reversed-causality related to the cross-sectional design.

Reuniting overnutrition and undernutrition, macronutrients, and micronutrients

Over-nutrition and its late consequences are a dominant theme in medicine today. In addition to the health hazards brought on by over-nutrition, the medical community has recently accumulated a roster of health benefits with obesity, grouped under "obesity paradox." Throughout the world and throughout history until the 20^th century, under-nutrition was a dominant evolutionary force. Under-nutrition brings with it a mix of benefits and detriments that are opposite to and continuous with those of over-nutrition. This continuum yields J-shaped or U-shaped curves relating body mass index to mortality. The overweight have an elevated risk of dying in middle age of degenerative diseases while the underweight are at increased risk of premature death from infectious conditions. Micronutrient deficiencies, major concerns of nutritional science in the 20^th century, are being neglected. This "hidden hunger" is now surprisingly prevalent in all weight groups, even among the overweight. Because micronutrient replacement is safe, inexpensive, and predictably effective, it is now an exceptionally attractive target for therapy across the spectrum of weight and age. Nutrition-related conditions worthy of special attention from caregivers include excess vitamin A, excess vitamin D, and deficiency of magnesium.

Biochemical Characterization of Kluyveromyces lactis Adenine Deaminase and Guanine Deaminase and Their Potential Application in Lowering Purine Content in Beer

Excess amounts of uric acid in humans leads to hyperuricemia, which is a biochemical precursor of gout and is also associated with various other disorders. Gout is termed as crystallization of uric acid, predominantly within joints. The burden of hyperuricemia and gout has increased worldwide due to lifestyle changes, obesity, and consumption of purine-rich foods, fructose-containing drinks, and alcoholic beverages. Some of the therapies available to cure gout are associated with unwanted side-effects and antigenicity. We propose an attractive and safe strategy to reduce purine content in beverages using enzymatic application of purine degrading enzymes such as adenine deaminase (ADA) and guanine deaminase (GDA) that convert adenine and guanine into hypoxanthine and xanthine, respectively. We cloned, expressed, purified, and biochemically characterized both adenine deaminase (ADA) and guanine deaminase (GDA) enzymes that play important roles in the purine degradation pathway of Kluyveromyces lactis, and demonstrate their application in lowering purine content in a beverage. The popular beverage beer has been selected as an experimental sample as it confers higher risks of hyperuricemia and gout. Quantification of purine content in 16 different beers from the Indian market showed varying concentrations of different purines. Enzymatic treatment of beer samples with ADA and GDA showed a reduction of adenine and guanine content, respectively. These enzymes in combination with other purine degrading enzymes showed marked reduction in purine content in beer samples. Both enzymes can work at 5.0–8.0 pH range and retain >50% activity at 40°C, making them good candidates for industrial applications.

The prevalence of hyperuricemia and its correlates in Ganzi Tibetan Autonomous Prefecture, Sichuan Province, China

Background

Hyperuricemia is a common and serious public health problem. There has been no broad epidemiological survey of hyperuricemia in China, especially in Tibetan area. This study was therefore investigated the prevalence of hyperuricemia and its correlated factors among people aged 18–85 years in Ganzi Tibetan Autonomous Prefecture, Sichuan Province, China.

Methods

We carried out a cross-sectional study among 3093 participants in Ganzi Tibetan Autonomous Prefecture using questionnaires in face-to-face interviews, anthropometric measurements and biochemical tests. We included 1416 subjects with complete data including serum uric acid and medical history to analyze the prevalence of hyperuricemia and correlated factors. Hyperuricemia was defined as a fasting serum uric acid level higher than 420 μmol/L in men and 360 μmol/L in women.

Results

The overall crude prevalence of hyperuricemia was 37.2%, and was greater in men than women (41% vs 34.4%, P = 0.011). The age-adjusted prevalence was 33.0%. Characteristics linked to hyperuricemia were farmers-herdsmen (OR: 1.749, 95% CI: 1.022–2.992), low to moderate education level (low OR:1.57, 95% CI: 1.102–2.237; moderate OR: 1.86, 95% CI: 1.167–2.963), current drinking (OR: 1.795, 95% CI: 1.193–2.702), hypertension (OR: 1.48, 95% CI: 1.091–2.006), higher body mass index (1 unit increase) (OR: 1.116, 95% CI: 1.077–1.156) and higher serum creatinine (1 unit increase) (OR: 1.046, 95% CI: 1.034–1.059). Serum uric acid was positively related to triglycerides and total cholesterol and negatively related to high density lipoprotein cholesterol in all subjects. Hyperuricemia was a risk factor for high triglyceride ((OR: 2.13, 95% CI: 1.156–3.9266) and high total cholesterol (OR: 2.313, 95% CI: 1.364–3.923) in men and for high low-density lipoprotein cholesterol (OR: 2.696, 95% CI: 1.386–5.245) in women.

Conclusion

There is a high prevalence of hyperuricemia in Ganzi Tibetan Autonomous Prefecture. The government needs to prevent and manage hyperuricemia in this area.

Association Between Alcohol Consumption and Nocturnal Leg Cramps in Patients Over 60 Years Old: A Case-Control Study

PURPOSE

Nocturnal leg cramps are a specific kind of cramps affecting almost one-half of patients aged 60 years and older. They reduce patients' quality of sleep and have a negative impact on their quality of life. The aim of this study was to evaluate the association between nocturnal leg cramps and the consumption of alcoholic beverages in patients aged 60 years and older attending general practices.

METHODS

Case-control study with a Bayesian approach for sensitivity analysis. Participants were voluntary ambulatory patients aged 60 years and older consulting their family doctor. They were recruited in 67 general practices across the Alsace region. Cases (patients having cramps), were matched with controls (patients free from cramps) for age, sex, medical history, and medications known to trigger cramps. Alcohol consumption was assessed through a standardized food frequency questionnaire.

RESULTS

We found an association between the global consumption of alcoholic beverages and nocturnal leg cramps (OR = 6.5, 95% credibility interval, 1.68-38.05; posterior probability 99.82%).

CONCLUSION

We identified an association between alcohol consumption and nocturnal leg cramps among patients aged 60 years and older attending general practices. These findings have implications for the prevention of cramps.