Gout and hyperuricemia in young people

Association between the combination of the triglyceride-glucose index and obesity-related indices with hyperuricemia among children and adolescents in China

BACKGROUND

The prevalence of hyperuricemia (HUA) among Chinese children and adolescents is a significant public health concern. Triglyceride-glucose (TyG) is recognized as a reliable biomarker in predicting insulin resistance, a condition associated with various metabolic disorders. Nevertheless, research on the association between TyG and its obesity-related indices with HUA among children and adolescents in China is limited.

METHODS

This study utilized data from the 2017 Chinese National Nutrition and Health Surveillance of Children and Lactating Mothers. TyG, TyG-BMI, TyG-WC, and TyG-WHtR were calculated based on participants' fasting blood glucose, triglycerides, and measured height, weight, and waist circumference. Multivariable logistic regressions were used to assess the relationships between TyG and its obesity-related indices with HUA in children and adolescents. Receiver Operating Characteristic curves were constructed to compare the predictive power of these indicators. Furthermore, we conducted a stratified analysis based on sex and age. Restricted cubic spline curves were used to illustrate the dose-response relationship of TyG, TyG-BMI, TyG-WC, and TyG-WHtR with HUA in children and adolescents. The sensitivity analysis included 1:1 propensity score matching with a caliper value of 0.02 and adjustments to the diagnostic criteria for HUA.

RESULTS

After adjusting for all covariables, multivariable logistic regression analysis indicated that the fourth quartiles of TyG (OR: 1.33, 95% CI: 1.14-1.54, P < 0.001), TyG-BMI (OR: 1.43, 95% CI: 1.14-1.79, P = 0.002), TyG-WC (OR: 1.76, 95% CI: 1.42-2.19, P < 0.001), and TyG-WHtR (OR: 1.92, 95% CI: 1.66-2.21, P < 0.001) were significantly associated with higher odds of HUA, compared to the lowest quartile. Stratified analyses identified a significant interaction between sex and TyG-BMI, TyG-WC, and TyG-WHtR. Compared to the first quartile, the highest quartile of TyG-BMI, TyG-WC and TyG-WHtR among male participants exhibited a stronger association with HUA(Male: TyG-BMI: OR = 1.82, 95%CI: 1.28-2.59; TyG-WC: OR = 1.87, 95%CI: 1.31-2.67; TyG-WHtR: OR = 2.07, 95%CI: 1.68-2.54).

CONCLUSIONS

This study identified a significant association between TyG and related obesity indices with HUA in children and adolescents in China. Furthermore, stronger associations of TyG-BMI, TyG-WC, and TyG-WHtR with HUA were observed, particularly in males.

Age and gender-specific reference intervals for uric acid level and hyperuricemia in children with Down syndrome

BACKGROUND

The association between Down syndrome (DS) and hyperuricemia has been described for a long time. The cut-off points for hyperuricemia should be determined as the upper limits of the uric acid (UA) level according to age- and gender-specific reference UA values prepared for children with DS.

METHODS

This study included 238 children (140 males and 98 females) with DS, below 21 years of age, who visited our medical center from May 1991 to June 31, 2018. Laboratory data were used to calculate the reference UA levels according to age and gender. We also inquired about the relationship between hyperuricemia and the presence of other diseases and other laboratory findings in children with DS. Fourteen patients had already been definitively diagnosed and treated. The UA data from these cases were excluded from the analysis.

RESULTS

The UA levels were significantly higher in all age groups among individuals with DS in comparison with the general population. Newly established reference values revealed 55 patients with hyperuricemia. The prevalence of hyperuricemia in males and females was 25.0% (35/140) and 20.4% (20/98), respectively. The number of hyperuricemia cases increased rapidly after 10 years of age. The UA levels were closely correlated with hemoglobin (Hb) values, creatinine, and total bilirubin, which are closely associated with dehydration in children with DS.

CONCLUSIONS

These reference levels could help to evaluate hyperuricemia candidates who should be carefully monitored and treated with uric-acid-lowering drugs in the future.

Efficacy and safety of febuxostat in Japanese paediatric patients with hyperuricaemia including gout: Phase 2, single arm, open‒label, multicentre studies

OBJECTIVES

Urate-lowering efficacy and safety of febuxostat was evaluated in paediatric patients with hyperuricaemia including gout.

METHODS

A Phase 2 study of febuxostat in paediatric patients aged 6-18 years with hyperuricaemia including gout was conducted. We evaluated the proportion of patients achieving serum uric acid (sUA) level ≤6.0 mg/dl at Week 26, and long-term safety and efficacy at Week 52. We also considered efficacy stratified by renal function.

RESULTS

Thirty patients (10 at <40 kg and 20 at ≥40 kg) were enrolled. Twenty-four were males, 29 had asymptomatic hyperuricaemia, and 1 had gout. Age was 8 to 18 years. Of these, 63.3% (95% confidence interval 43.9-80.1%) achieved a sUA level of ≤6.0 mg/dl at Week 26. sUA level (mean ± standard deviation) was 5.55 ± 0.87 mg/dl, reduced from 9.01 ± 1.23 mg/dl at baseline. Febuxostat efficacy appeared similar for mild to moderate renal dysfunction and with normal renal function. There were no major safety issues.

CONCLUSIONS

In paediatric patients with hyperuricaemia including gout, febuxostat showed long-term, well-controlled urate-lowering efficacy with no major safety issues. Findings suggest that no dose adjustment is required for paediatric patients with mild to moderate renal dysfunction.

Effect of the Intake of Solid Block Dairy Products Like Cheese on Serum Uric Acid in Children: A Preliminary Mechanistic Investigation

OBJECTIVE

This study aimed to investigate the relationship between the intake of solid block dairy products like cheese and serum uric acid levels, along with its potential physiological mechanisms.

METHODS

Data for our study were obtained from the Chinese Children and Lactating Women Nutrition and Health Surveillance. Generalized linear models and restricted cubic splines were employed to analyze the relationship between the intake of solid block dairy products like cheese and serum uric acid levels. Two-sample Mendelian randomization (TSMR) analysis was conducted to infer causality, based on a large sample size and robust methodology. Gene Ontology (GO) enrichment analysis was also performed to identify potential biological pathways.

RESULTS

Among all types of dairy products, a significant negative association with serum uric acid levels was observed only for the intake of solid block dairy products like cheese, regardless of covariate adjustment (β = -0.182, p < 0.001). TSMR results supported a negative causal relationship between cheese intake and serum uric acid levels (β = -0.103, 95% CI: -0.149 to -0.057; p = 0.002). The JAK-STAT signaling pathway and autophagy regulation were identified as potential physiological mechanisms underlying this relationship.

CONCLUSIONS

The intake of solid block dairy products like cheese was found to result in decreased levels of serum uric acid, with potential mechanisms involving the JAK-STAT signaling pathway and the regulation of autophagy.

Clinical characteristics of adolescent-onset gout in Chinese: A hospital-based cross-sectional study

OBJECTIVE

Adolescent-onset gout has a greater impact on the lives and health of patients than adult-onset gout. However, there is a relative lack of clinical information on adolescent-onset gout. Hence, we analyzed a Chinese cohort.

METHODS

We studied clinical features of 9,003 Chinese patients. Gout onset age of 12 - 19 years is defined as adolescent-onset group (AG), 20 - 40 years as early-onset group (EG), and 41 - 64 years as late-onset group (LG). Multivariable regression analysis evaluated factors associated with recurrent flares, serum urate (SU) levels, and underexcretion type in AG.

RESULTS

Compared with EG and LG, the AG had higher SU levels [AG: 9.5 (2.2) mg/dL, EG: 8.6 (2.1) mg/dL, LG: 7.73 (2.0) mg/dL, P < 0.001], higher percentage of positive family history of gout (AG: 41.8 %, EG: 29.6 %, LG: 24.6 %, P < 0.001), underexcretion type (AG: 62.4 %, EG: 62.5 %, LG: 58.8 %, P = 0.04), recurrent flares (AG: 78.1 %, EG: 70.3 %, LG: 68.9 %, P = 0.01). Urate-lowering therapy (ULT) initiated [OR 6.58 (95 % CI 1.35 - 32.00)] and hypercholesterolemia [OR 4.16 (95 % CI 1.28 - 13.53)] were associated with recurrent flares. eGFR was identified to be a significant variable of increasing SU levels [beta -0.24 (95 % CI -0.04 to -0.01)]. Hypertriglyceridemia [OR 0.35 (95 % CI 0.17 - 0.71)] was related to underexcretion type.

CONCLUSION

Adolescent-onset gout patients had clinically distinctive features with higher SU levels, BMI, positive gout family history, underexcretion type and recurrent flares. These specific populations were less likely to achieve ULT target, requiring more clinical attention.

Interleukin-41 as a biomarker of the anti-inflammatory response associated with hyperuricemia

BACKGROUND

Interleukin (IL)-41 is a recently discovered secreted protein that is expressed in a variety of tissues, and it is associated with several immune and metabolic diseases. However, IL-41 has not been studied in hyperuricemia (HUA).

METHODS

Forty-four HUA patients and 44 healthy controls (HCs) were included in this study, and we collected theirgeneral and biochemical parameters, including white blood cell, neutrophil, lymphocyte, and platelet counts, mean platelet volume, platelet distribution width, serum creatinine, blood urea nitrogen, fasting blood glucose, total triglyceride, total cholesterol, high-density lipoprotein, low-density lipoprotein, total protein, albumin, alkaline phosphatase, gamma-glutamyltransferase, and hemoglobin concentration. The level of serum IL-41 was determined using an enzyme-linked immunosorbent assay. Multivariate logistic regression analysis was exploited to identify the independent risk factors associated with HUA, and the clinical diagnostic value of IL-41 was analyzed by applying the receiver operating characteristic (ROC) curve. We assessed the association between IL-41 and clinical parameters with Spearman's rank correlation.

RESULTS

Circulating IL-41 levels were significantly higher in HUA patients than in the HCs group (460.3 pg/mL vs. 261.3 pg/mL, respectively; P < 0.001). The area under the ROC curve (AUC) for IL-41 in HUA patients was 0.7443 (with a cut-off value of 311.055 pg/mL, a sensitivity of 68.18 %, and a specificity of 72.73 %), while the AUC for IL-41 combined with the platelet count was 0.8109. Correlation analysis revealed that the circulating IL-41 level was positively correlated with age in HCs and HUA patients.

CONCLUSIONS

We herein demonstrated that serum IL-41 was elevated in HUA patients and that it may constitute a novel biomarker of anti-inflammatory response related to HUA.

Association between the dietary inflammatory index and gout in the National Health and Nutrition Examination Survey 2007-2018

Objective

The aim of our study was to investigate whether the Dietary Inflammatory Index (DII) correlated with gout in American adults.

Method

The study used data from the 2007-2018 National Health and Nutrition Examination Survey, with 27,710 adults participating. Initially, multivariable analysis was performed, with controls for covariates, to assess the link of DII and gout. Then, restricted cubic splines (RCS) were applied to model the nonlinear relationship of DII and gout. Furthermore, propensity score matching (PSM) as a further study of potential relationships was established. Eventually, subgroup analysis was performed.

Result

Participants within the highest DII quartile would be more susceptible to increased risk of gout in the univariate regression model (Q4 vs. Q1, OR = 1.31, CI: 1.05-1.63). Additionally, a positive correlation was detected between gout risk and DII after adjusting on drinking, smoking, gender, race, age, and BMI. Based on RCS analysis, we observed that the risk of gout raised sharply as DII values increased, then flattened, and increased sharply again when the DII was greater than approximately 2.5. After performing the PSM, it was observed that DII correlated in a positive way to the presence of gout on a fully adjusted multivariable model. Subgroup analysis revealed that the link of DII and gout showed no statistical significance in females, blacks, Mexicans, nor in the population that smoked.

Conclusion

Greater degrees of pro-inflammation correlate with a higher risk of gout and might be a predisposing factor for gout. Hence, tactics fostering an anti-inflammatory diet for preventing and improving gout in adults should be regarded.

Combining body mass index and waist height ratio to assess the relationship between obesity and serum uric acid levels in adolescents

Background

The study aims to explore the relationship between obesity and serum uric acid in adolescents by combining body mass index and waist height ratio.

Methods

475 adolescents in our study were classified as normal weight without central obesity (NW), normal weight but central obesity (NWCO), overweight or obesity without central obesity (OB) and overweight or obesity with central obesity (OBCO). Odds ratios (OR) and 95% confidence intervals (CI) for hyperuricemia were calculated using a logistic regression model. The dose-response association between obesity indicators and serum uric acid were explored by restricted cubic spline model.

Results

The highest serum uric acid level and the OR for hyperuricemia were found in the OBCO group, regardless of sex. After controlling for waist height ratio, the risk of hyperuricemia increased with increasing body mass index in boys and girls. The restricted cubic spline model showed that boys had higher ORs for hyperuricemia at the 25th and 75th percentiles of body mass index than for waist height ratio and girls had a higher OR for hyperuricemia than waist height ratio at the 25th percentile of body mass index.

Conclusions

Hyperuricemia in adolescence was not only associated with the overweight or obesity in BMI, but with the combination of overweight or obesity in BMI and central obesity in WHtR. However, in boys and girls, the increased risk of hyperuricemia associated with elevated body mass index was significantly better than that of waist height ratio.

Identifying the intervention mechanisms of polydatin in hyperuricemia model rats by using UHPLC-Q-Exactive Orbitrap mass spectroscopy metabonomic approach

Introduction

Polydatin is a biologically active compound found in mulberries, grapes, and Polygonum cuspidatum, and it has uric acid-lowering effects. However, its urate-lowering effects and the molecular mechanisms underlying its function require further study.

Methods

In this study, a hyperuricemic rat model was established to assess the effects of polydatin on uric acid levels. The body weight, serum biochemical indicators, and histopathological parameters of the rats were evaluated. A UHPLC-Q-Exactive Orbitrap mass spectrometry-based metabolomics approach was applied to explore the potential mechanisms of action after polydatin treatment.

Results

The results showed a trend of recovery in biochemical indicators after polydatin administration. In addition, polydatin could alleviate damage to the liver and kidneys. Untargeted metabolomics analysis revealed clear differences between hyperuricemic rats and the control group. Fourteen potential biomarkers were identified in the model group using principal component analysis and orthogonal partial least squares discriminant analysis. These differential metabolites are involved in amino acid, lipid, and energy metabolism. Of all the metabolites, the levels of L-phenylalanine, L-leucine, O-butanoylcarnitine, and dihydroxyacetone phosphate decreased, and the levels of L-tyrosine, sphinganine, and phytosphingosine significantly increased in hyperuricemic rats. After the administration of polydatin, the 14 differential metabolites could be inverted to varying degrees by regulating the perturbed metabolic pathway.

Conclusion

This study has the potential to enhance our understanding of the mechanisms of hyperuricemia and demonstrate that polydatin is a promising potential adjuvant for lowering uric acid levels and alleviating hyperuricemia-related diseases.

The Hong Kong Society of Rheumatology consensus recommendations for the management of gout

Gout is one of the most common noncommunicable diseases in Hong Kong. Although effective treatment options are readily available, the management of gout in Hong Kong remains suboptimal. Like other countries, the treatment goal in Hong Kong usually focuses on relieving symptoms of gout but not treating the serum urate level to target. As a result, patients with gout continue to suffer from the debilitating arthritis, as well as the renal, metabolic, and cardiovascular complications associated with gout. The Hong Kong Society of Rheumatology spearheaded the development of these consensus recommendations through a Delphi exercise that involved rheumatologists, primary care physicians, and other specialists in Hong Kong. Recommendations on acute gout management, gout prophylaxis, treatment of hyperuricemia and its precautions, co-administration of non-gout medications with urate-lowering therapy, and lifestyle advice have been included. This paper serves as a reference guide to all healthcare providers who see patients who are at risk and are known to have this chronic but treatable condition.

Musculoskeletal pain is prevalent in Chinese medical and dental students: A cross-sectional study

Objectives

Musculoskeletal pain (MSP) is a major reason for consultation in primary care and is becoming increasingly prevalent among medical students. There is little research on the current situation of MSP among Chinese medical and dental students. Data on the analysis of risk factors related to MSP are also limited. The objectives of this study were to investigate the prevalence and characteristics of MSP among Chinese medical and dental students and to explore the risk factors for MSP and students' intent to seek medical treatment.

Methods

An anonymous, internet-based, cross-sectional, open survey was distributed to medical and dental students at Fujian Medical University, Fuzhou, China. Data on the demographic information and characteristics of MSP were collected and analyzed. In addition to descriptive statistics, logistic regression was used to analyze significant risk factors contributing to MSP.

Results

A total of 1,178 students responded to the survey (response rate = 79.6%), including 722 medical students and 456 dental students. The age ranged from 16 to 24. There were 553 male students and 625 female students. A total of 523 students reported neck pain (NP, 44.4%), 361 students reported low back pain (LBP, 30.6%), and 182 students reported joint pain (JP, 15.4%). Sixty-six students (5.6%) simultaneously suffered from NP, LBP, and JP. The prevalence of NP (49.1 vs. 41.4%, P = 0.01), LBP (34.6 vs. 28.1%, P = 0.02), and JP (20.2 vs. 12.5%, P < 0.001) was significantly higher in dental students than in medical students. The prevalence of MSP was significantly different among the academic years for NP and LBP (P = 0.02 and P < 0.001, respectively). Univariate and multivariate regression analyses demonstrated that female sex, PSS-10 score, and major of stomatology were risk factors for MSP. Medical and dental students' intention to seek treatment for MSP was low and was significantly associated with the severity of pain.

Conclusions

The prevalence of MSP in Chinese medical and dental students is high, especially for NP and LBP, and is significantly higher in dental students than in medical students. The prevalence of NP and LBP were significantly different among academic grades. Female sex, PSS-10 score, and major of stomatology were risk factors for MSP. Students' intent to seek treatment for MSP was very low and was determined by the severity of pain.

Profiling of Serum Oxylipins Identifies Distinct Spectrums and Potential Biomarkers in Young People with Very Early Onset Gout

Objective

Oxylipins modulate inflammation via complex pathways. The oxylipin profile in gout remains unexplored. In this study, we systemically profiled oxylipins in young men and identified new oxylipin biomarkers for clinical use in differentiating gout from hyperuricemia.

Methods

Oxylipin profiling was performed in 90 men (30 very early onset gout, 30 asymptomatic HU (HU) and 30 normouricemia (NU), all aged &lt;20 years) divided into discovery and validation sample sets. The dataset was analyzed based on orthogonal projection to latent structure-discriminant analysis (OPLS-DA). Correlation network and pathway enrichment were conducted to reveal potential oxylipin-involved pathways of gout. Candidate oxylipins were further evaluated and optimized in the validation cohort, and differential oxylipin biomarkers combined with or without serum urate were applied to construct diagnosis models.

Results

In discovery stage 21 differential oxylipins between the gout vs HU comparisons and 14 differential oxylipins between the gout vs NU comparisons were discovered. Correlation network analysis was performed and 14(S)-HDHA（14S-hydroxy-4Z, 7Z, 10Z, 12E, 16Z, 19Z-docosahexaenoic acid）was identified as a hub metabolite in both comparisons. Seven down-regulated oxylipins in gout vs HU group and five down-regulated oxylipins in gout vs NU group were validated. Diagnostic models were constructed with the above oxylipins, with 14(S)-HDHA alone acquiring area under the curve (AUC) 1 (95%CI, 1–1) in both comparisons.

Conclusion

Young men with very early onset gout have distinct oxylipin spectrums, especially those derived from AA (arachidonic acid), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Differential oxylipins could serve as candidate serum biomarkers in differentiating gout from hyperuricemia.

Lactobacillus paracasei X11 Ameliorates Hyperuricemia and Modulates Gut Microbiota in Mice

Hyperuricemia (HUA) is the presence of excessive uric acid (UA) in blood, which leads to an increased risk of chronic kidney disease and gout. Probiotics have the potential effect of alleviating HUA. The purpose of this study was to screen probiotics with UA-lowering activity and explore the underlying mechanism. The UA-lowering activity of 20 lactic acid bacteria strains was investigated in vitro, and the effect of candidate probiotics on UA metabolism was evaluated using the HUA Balb/c mouse model. The results showed that Lactobacillus paracasei X11 had excellent UA-lowering activity in vitro, which could degrade nucleotides and nucleosides completely within 30 min, and the degradation rates of purine and trioxypurine could reach 83.25% and 80.42%, respectively. In addition, oral administration of L. paracasei X11 could reduce serum UA by 52.45% and inhibit renal proinflammatory cytokine IL-1β by 50.69%, regulating adenosine deaminase (ADA), xanthine oxidase (XOD), and transporter expression (GLUT9, NPT1, and URAT1) to a normal level. Moreover, it could restore the ratio of Bacteroidetes to Firmicutes (Bac/Firm ratio) and showed a positive effect on the recovery of the intestinal microbiota. These findings provided fundamental information about the UA-lowering properties of probiotics, which suggested that L. paracasei X11 had the potential to be developed as a novel probiotic strain to ameliorate HUA.

Clinical features of gout in adult patients with type Ia glycogen storage disease: a single-centre retrospective study and a review of literature

Background

This study aimed to explore the clinical features of gout in adult patients with glycogen storage disease type Ia (GSD Ia).

Methods

Ninety-five adult patients with GSD Ia admitted to Peking Union Medical College Hospital were retrospectively analysed. A clinical diagnosis of GSD Ia was confirmed in all patients through gene sequencing. All patients had hyperuricaemia; 31 patients complicated with gout were enrolled, and 64 adult GSD Ia patients with asymptomatic hyperuricaemia were selected as a control group during the same period. Clinical characteristics were analysed and compared between the two groups.

Results

Thirty-one of the 95 patients had complications of gout (median age, 25 years; 11 (35.5%) females). All 31 patients had hepatomegaly, abnormal liver function, fasting hypoglycaemia, hyperuricaemia, hyperlipaemia, and hyperlacticaemia. A protuberant abdomen, growth retardation, recurrent epistaxis, and diarrhoea were the most common clinical manifestations. Among these 31 patients, 10 patients (32.3%) had gout as the presenting manifestation and were diagnosed with GSD Ia at a median time of 5 years (range, 1–14) after the first gout flare. The median age of gout onset was 18 years (range, 10–29). Fifteen of the 31 GSD Ia-related gout patients were complicated with gouty tophi, which has an average incidence time of 2 years after the first gouty flare. The mean value of the maximum serum uric acid (SUA) was 800.5 μmol/L (range, 468–1068). The incidence of gout in adult GSD Ia patients was significantly associated with the initial age of regular treatment with raw corn starch, the proportion of urate-lowering therapy initiated during the asymptomatic hyperuricaemic stage, maximum SUA level, and mean cholesterol level.

Conclusions

Determination of GSD Ia should be performed for young-onset gout patients with an early occurrence of gouty tophi, especially in patients with hepatomegaly, recurrent hypoglycaemia, or growth retardation. Early detection and long-term regulatory management of hyperuricaemia, in addition to early raw corn starch and lifestyle intervention, should be emphasized for GSD Ia patients in order to maintain good metabolic control.

Trial registration

Retrospectively registered.

Urate-lowering therapy for gout and asymptomatic hyperuricemia in the pediatric population: a cross-sectional study of a Japanese health insurance database

BACKGROUND

Our previous research showed that uric acid lowering therapy (ULT) for gout and hyperuricemia is being prescribed for pediatric patients even though these drugs have not been approved for use in children. However, the actual clinical situation has not been clearly elucidated. In this paper, we provide an in-depth look at the details of actual clinical practice.

METHODS

This retrospective cross-sectional study accessed health insurance data for 696,277 children from April 2016 through March 2017 to identify pediatric patients with gout or asymptomatic hyperuricemia, calculate the proportion of patients prescribed ULTs, and analyze population characteristics. Adherence and mean dose for febuxostat and allopurinol, the most commonly prescribed drugs, were also analyzed.

RESULTS

Among children with gout or asymptomatic hyperuricemia, we found that 35.1% (97/276) were prescribed ULT. This proportion increased with age, especially among males. By comorbidity, ULT was prescribed to 47.9% (46/96) of patients with kidney disease, 41.3% (26/63) for cardiovascular disease, 40.0% (6/15) for Down syndrome, and 27.1% (32/118) for metabolic syndrome. In patients with kidney disease, febuxostat was prescribed more than twice as frequently as allopurinol (28 vs. 12). Median values for the medication possession ratio (MPR) of febuxostat and allopurinol were 70.1 and 76.7%, respectively, and prescriptions were continued for a relatively long period for both drugs. Both drugs were prescribed at about half the adult dose for patients 6-11 years old and about the same as the adult dose for patients 12-18 years old.

CONCLUSIONS

This study showed that the continuous management of serum uric acid is being explored using off-label use of ULT in pediatric patients with gout or asymptomatic hyperuricemia in Japan. Drug selection is based on patient characteristics such as sex, age, and comorbidities, and pediatric dosage is based on usage experience in adults. To develop appropriate pediatric ULT, clinical trials are needed on the efficacy and safety of ULT in the pediatric population.

TRIAL REGISTRATION

UMIN000036029 .

Design and Optimization of Febuxostat-loaded Nano Lipid Carriers Using Full Factorial Design

Objectives

This work aims to develop nanostructured lipid carriers (NLCs) to improve the oral bioavailability of febuxostat (FEB).

Materials and Methods

High shear homogenization, a well-known technique, followed by bath sonication with slight modifications was used to prepare FEB-loaded NLCs using oleic acid as liquid lipid and stearic acid as solid lipid. A total of 3² full factorial design was utilized to examine the effect of 2 independent variables, namely, X1 (liquid to solid lipid ratio) and X2 (surfactant concentration) on the Y1 (particle size) and Y2 (% entrapment efficiency) of the drug. The prepared NLCs were evaluated for particle size, polydispersity index, zeta potential, and (%) entrapment efficiency.

Results

The drug's highest solubility was found in the stearic (solid lipid) and oleic acid (liquid lipid), which were further chosen for NLC preparation. Result of the present study showed an increase in entrapment efficiency and a decrease in particle size with the increase in liquid lipid to solid lipid ratio. With increased surfactant concentration, a small particle size is observed. The optimized formulation's particle size and (%) entrapment efficiency was found to be 99 nm and 80%, respectively. The formulations' zeta potential and polydispersity index were found within the range. Compared to plain drug suspension, the optimized formulation showed higher drug release, which may be due to the presence of the higher amount of liquid lipid. The particles shown in the transmission electron microscopy were round in shape and have smooth surface. Stability studies showed that the NLC formulation can be stored for a longer time period under room condition.

Conclusion

FEB-loaded NLC were successfully prepared using full 3² factorial design, and can be further used for oral delivery of FEB for gout treatment.

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.

Real-world treatment of gout and asymptomatic hyperuricemia: A cross-sectional study of Japanese health insurance claims data

OBJECTIVES

To assess gout and asymptomatic hyperuricemia in Japan and review treatment conditions.

METHODS

This retrospective cross-sectional study analyzed the prevalence of hyperuricemia and gout, and characteristics and treatment of patients with those conditions, using Japanese health insurance claims and medical check-up data collected from April 2016 through March 2017.

RESULTS

Among 2,531,383 persons registered in the database, 1.1% (men 1.9%, women <0.1%) were diagnosed with gout and 2.6% (4.1%, 0.4%) with asymptomatic hyperuricemia. Medical check-ups showed 13.4% (19.6%, 1.0%) of patients with hyperuricemia (serum uric acid [sUA] > 7.0 mg/dL). Urate-lowering therapy (ULT) was prescribed for 80.7% of patients identified with gout and 72.4% identified with asymptomatic hyperuricemia. ULT adherence was satisfactory, but most patients were treated with low-dose ULT. Less than half of patients receiving ULT achieved the sUA target (≤6.0 mg/dL). In gout patients, the incidence of gout flare was 47.8% (0.74 flares/person-year).

CONCLUSIONS

Although hyperuricemia prevalence is similar in Japan and worldwide, gout is comparatively rare in Japan. Gout and asymptomatic hyperuricemia are often treated with low-dose ULT, and many patients fail to reach target sUA, suggesting that gout management is suboptimal in Japan. Patients would benefit from stricter focus on a treat-to-target approach for gout management.

Serum Metabolic Profiling Analysis of Gout Patients Treated with Traditional Chinese Medicine Tongfengtai Granules Based on Gas Chromatography-Mass Spectrometry

Gout has become a public health problem that seriously threatens human health. Traditional Chinese medicines (TCMs) have a long history of treating gout and have some advantages compared with the conventional medicines. Compound TCM Tongfengtai granules are gradually being used for clinical treatment of gout, but its mechanism is still unclear. The purpose of this study was to explore the metabolic profiling of serum from gout patients before and after treatment with Tongfengtai granules and identify the differential metabolites and related metabolic pathways. A total of 40 gout patients hospitalized in Shenzhen Traditional Chinese Medicine Hospital from 2018 to March 2019 were recruited in the current study, and serum samples from these patients before and after treatment with Tongfengtai granules were collected. Gas chromatography-mass spectrometry (GC-MS) assay was used to identify serum metabolites. The OPLS-DA VIP method was used to screen for potential metabolic biomarkers, and MetaboAnalyst 4.0 was used to identify related metabolic pathways. The result showed that there was a significant difference in the concentrations of six metabolites in the serum after treatment: D-galactose, lactic acid, 3-hydroxybutyric acid, D-pyran (type) glucose, alanine, and L-isoleucine. Except D-pyran (type) glucose, the serum concentrations of the other five metabolites were all significantly reduced. Besides, pathway enrichment analysis found that these potential metabolic biomarkers were mainly involved in lactose degradation and the glucose-alanine cycle. Thus, the serum metabolic profiling of gout patients treated with Tongfengtai granules changed, and the differential metabolites and related metabolic pathways might provide clues for understanding the mechanism of Tongfengtai granules.

Unraveling the genetic causes in large pedigrees with gout by whole‑exome sequencing

Gout is a common type of inflammatory arthritis that is clinically and genetically heterogeneous. The genetic aetiology remains unclear, and mainly relies on previous genome-wide association studies focused on sporadic cases. The present study aimed to identify the genetic basis of gout in three families using whole-exome sequencing (WES). WES was performed in the probands, and family members were involved in the co-segregation analysis. In total, three deleterious rare or novel missense mutations were identified in ATP-binding cassette super-family G member 2 (ABCG2), protein kinase CGMP-dependent 2 (PRKG2) and adrenoceptor β3 (ADRB3) genes in three different families. In addition, certain gout-associated candidate genes were revealed to be shared among the co-expression and protein-protein interaction (PPI) networks of ABCG2, PRKG2 and ADRB3. Furthermore, the disease ontology analysis of the genes present in the co-expression network exhibited significant (P<0.05) enrichment in hyperuricemia, gout, cardiovascular system disease and metabolic disease. In addition, genes involved in the PPI network were significantly enriched in the purine nucleoside monophosphate biosynthetic process, urate transport and biological processes associated with glycose metabolism. Collectively, to the best of our knowledge, the present study was the first to use WES to identify three candidate rare or novel deleterious mutations in three families with gout. The present results provided novel insights that may improve the current understanding of the molecular genetic basis underlying gout. Importantly, the present results may facilitate the improvement of clinical diagnosis and the development of novel personalized therapies.

[Hyperuricemia, gout and high cardiovascular risk - how to manage them in clinical practice]

In recent years, the relationship of hyperuricemia and gout with a high risk of cardiovascular disease has been widely discussed. Therefore, it is important to systematically examine patients in order to diagnose comorbidities, among which cardiovascular disease and its complications occupy a leading place and consider mandatory treatment of patients with hyperuricemia and gout with high cardiovascular risk with lowering drugs, which fully reflects the provisions of the latest European recommendations for the management and treatment of patients with gout.

Clinical characteristics of patients under 40 years old with early-onset hyperuricaemia: a retrospective monocentric study in China

OBJECTIVE

To investigate the clinical characteristics of patients with early-onset hyperuricaemia (HUC).

METHODS

A retrospective study using data from the Second Affiliated Hospital of Soochow University was conducted. 623 patients with HUC were divided into early-onset group and late-onset group. Another 201 healthy subjects ≤40 years old were regarded as control group. The data of physical measurements and biochemistry test were collected. Clinical data of early-onset group were compared with late-onset group and control group by analysis of variance (ANOVA) and χ² test. Principal component analysis (PCA) was applied. Logistic regression was used to identify the clinical factors correlated with patients with early-onset HUC.

RESULTS

The patients of early-onset group had different body mass index (BMI), serum albumin, alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP), gamma-glutamyltransferase (GGT), creatinine (Cr), triglyceride (TG), total cholesterol (TC), low density lipoprotein (LDL), TG/high density lipoprotein (HDL) ratio, HDL and percentage of males, hypertension (HBP) as well as fatty liver compared with healthy people in the control group. Early-onset group patients had different albumin, ALT, fasting blood glucose, Cr, percentage of males and HBP compared with late-onset group patients. PCA identified four significant patterns including PC1 (labelled 'TG and HDL'), PC2 (labelled 'fatty liver and liver enzymes'), PC3 (labelled 'TC and LDL') and PC4 (labelled 'AKP'). The results of univariate and multivariate logistic regression analysis showed that BMI, HBP and albumin were correlative factors for early onset of HUC when the patients with early-onset and late-onset HUC were involved, while gender, BMI, PC1, PC2 and PC4 were correlative factors for early-onset HUC when the early-onset and control groups were involved.

CONCLUSION

This study described a group of patients with early-onset HUC with distinct clinical features. Gender, BMI, 'TG and HDL', 'fatty liver and liver enzymes' and 'AKP' have higher values than HBP, type 2 diabetes mellitus and 'TC and LDL' in patients under 40 years old with early-onset HUC.

The Effects of Ginsenosides and Anserine on the Up-Regulation of Renal Aquaporins 1–4 in Hyperuricemic Mice

Hyperuricemia is a metabolic disease of the kidney that results in decreased uric acid excretion. Here, we aimed to investigate the effects of ginsenosides and anserine on hyperuricemia and the expression of aquaporin (AQP) 1–4, which are indicators of renal excretion. Ginsenosides and anserine were administered separately or together after the establishment of hyperuricemia with adenine in BALB/c mice. Renal function indexes such as serum uric acid, creatinine, and urea nitrogen were measured in each group of mice, and the expression of AQP1–4 in renal tissues was detected. Serum uric acid and urea nitrogen were decreased in the ginsenoside and the anserine +UA groups. Meanwhile, the uric acid excretion and clearance rate were clearly increased in the co-treatment +UA group ([Formula: see text].05). Moreover, ginsenosides or anserine ginsenosides or anserine alone and treatment with both increased the expression of AQP1–4; however, the synergistic effects were more significantly enhanced ([Formula: see text].01). We provide the first reported evidence that ginsenosides and anserine have synergistic effects on uric acid excretion. The improvement in renal function in hyperuricemic mice after treatment with ginsenosides and anserine may result from up-regulation of AQP1–4 expressions.

Clinical Characteristics of Early-Onset Gout in Outpatient Setting

Objective

The objective of this study is to investigate the clinical characteristics and treatment of patients with early-onset gout.

Methods

We retrospectively reviewed 327 adult patients with a first diagnosis of gout from 2008 to 2016 using the database of a multispecialty group practice in New England. Patients were classified into the following groups: age 30 years or younger at first diagnosis (group 1), age 31-40 years (group 2), and age over 40 years (group 3). The clinical characteristics and treatment of gout were compared among the three groups.

Results

We identified 87 patients in group 1 and 140 patients in group 2. Group 3 included 100 patients randomly chosen from the 7216 patients with a first diagnosis at age over 40 years. Patients within group 1 had significantly higher serum uric acid (sUA) levels at the time of diagnosis and a more prominent family history of gout. Younger patients (groups 1 and 2) had a significantly higher body mass index than patients over 40 years of age (group 3). A substantial number of younger patients also had hypertension or hyperlipidemia. The majority of younger patients met the 2012 American College of Rheumatology (ACR) guidelines for initiating urate-lowering therapy (ULT) on the basis of frequency of gout attacks, whereas the majority of patients over 40 years of age met the guidelines for ULT on the basis of chronic kidney disease. Patients over 40 years of age were more likely to achieve an sUA level less than 6.0 mg/dl.

Conclusion

Patients with a first diagnosis of gout at age 40 years or younger frequently had cardiovascular risk factors and were less likely to achieve an sUA level less than 6.0 mg/dl compared with patients over 40 years of age who were treated in routine clinical practice. Clinicians should be aware that patients with early-onset gout may be an undertreated population with poor adherence to ULT and increased risk of recurrent gout and cardiovascular diseases.

Patients With Early-Onset Gout and Development of Earlier Severe Joint Involvement and Metabolic Comorbid Conditions: Results From a Cross-Sectional Epidemiologic Survey

OBJECTIVE

Little is known of the clinical features and comorbidity profile of patients presenting with early-onset gout (EOG), although international guidelines recommend rapid treatment after diagnosis. The objective of this study was to assess specific characteristics and comorbidities of patients with gout who had an early onset.

METHODS

Patients from a cross-sectional French national cohort who experienced their first gout flare before age 40 years were included in the EOG group and compared to patients with an onset after age 40 years, the common gout group.

RESULTS

A total of 120 patients were included in the EOG group (mean ± SD age 49.5 ± 11.9 years) and 865 patients in the common gout group (mean ± SD age 64.4 ± 10.1 years). Patients with EOG more often presented with a history of polyarticular flares (P < 0.01), but had similar frequency of flares (P = 0.16), gout arthropathy (P = 0.79), and tophi (P = 0.53). Prevalence of each item comprising metabolic syndrome did not differ between groups. In patients with EOG, all cardiovascular comorbidities were diagnosed after gout onset. Greater age, low high-density lipoprotein, and excessive alcohol intake were associated in multivariate analysis with the common gout group, while a familial history of gout, longer duration of urate-lowering treatment, higher serum uric acid levels, and metabolic syndrome were associated with the EOG group.

CONCLUSION

Patients with EOG developed slightly more severe joint involvement and earlier metabolic disorders than patients with common gout.

Hyperuricemia in Children and Adolescents: Present Knowledge and Future Directions

Recent evidence suggests that hyperuricemia is an important condition in children and adolescents, particularly in association with noncommunicable diseases. This review aims to summarize our current understanding of this condition in pediatric patients. An analysis of serum uric acid reference values in a healthy population indicates that they increase gradually with age until adolescence, with differences between the sexes arising at about 12 years of age. This information should be taken into consideration when defining hyperuricemia in studies. Gout is extremely rare in children and adolescents, and most patients with gout have an underlying disease. The major causes of hyperuricemia are chronic conditions, including Down syndrome, metabolic or genetic disease, and congenital heart disease, and acute conditions, including gastroenteritis, bronchial asthma (hypoxia), malignant disorders, and drug side effects. The mechanisms underlying the associations between these diseases and hyperuricemia are discussed, together with recent genetic information. Obesity is a major cause of hyperuricemia in otherwise healthy children and adolescents. Obesity is often accompanied by metabolic syndrome; hyperuricemia in obese children and adolescents is associated with the components of metabolic syndrome and noncommunicable diseases, including hypertension, insulin resistance, dyslipidemia, and chronic kidney disease. Finally, strategies for the treatment of hyperuricemia, including lifestyle intervention and drug administration, are presented.

Renal excretion is a cause of decreased serum uric acid during acute gout

AIMS

To evaluate the fluctuation of serum uric acid (SUA) during acute gout (AG) and explore its potential mechanisms.

METHODS

Data such as SUA, urinary uric acid and 24-hour uric acid urinary excretion were collected from 126 patients diagnosed with gout and were analyzed.

RESULTS

Serum uric acid was negatively correlated with age in gout patients, and significantly elevated in patients aged ≤50 years. Twenty-four-hour uric acid urinary excretion was affected by SUA, creatinine clearance, age, body mass index and urine volume. In contrast, clearance of uric acid and fractional excretion of uric acid (FEur) were more stable. SUA was significantly downregulated during acute attacks. Of the AG patients, 34.92% had detected SUA <420 μmol/L. Clearance of uric acid and FEur were notably increased in patients during acute attacks, especially in patients with SUA <420 μmol/L.

CONCLUSION

This study demonstrated that the level of SUA was remarkably upregulated in young gout patients. Therefore, early onset of gout should be considered of great importance. SUA was downregulated during acute gouty arthritis, which might be associated with increased urinary excretion of uric acid.

Prevalence and correlates of hyperuricemia in the middle-aged and older adults in China

Hyperuricemia, the physiological prerequisite for gout, is linked to the presence and severity of multiple comorbidities that affect longevity and well-being. By using the baseline data from the China Health and Retirement Longitudinal Study, a nationally representative survey, the prevalence of hyperuricemia in general middle-aged and older Chinese was estimated. The potential effects of health behaviours and comorbidities on hyperuricemia were also explored. In 2010, the prevalence of hyperuricemia among middle-aged and older Chinese was 6.4%. Hyperuricemia was more prevalent in males than in females (7.9% vs. 4.9%). The risk of hyperuricemia increased with advanced age in both sexes. In males, current drinking, obesity and dyslipidemia were positively associated with hyperuricemia, whereas singles males and males living in North China were with lower odds of having hyperuricemia. For females, being single, at a higher economic level, living in the Southwest China, smoking, obesity, diabetes, hypertension and dyslipidemia were all significant risk factors for hyperuricemia, but females living in North China and Northwest China were with a lower hyperuricemia prevalence than females in East China. Therefore, hyperuricemia in China was not as prevalent as in developed countries, its prevalence varied greatly according to demographic, socioeconomic, and geographic factors.

2016 updated EULAR evidence-based recommendations for the management of gout

BACKGROUND

New drugs and new evidence concerning the use of established treatments have become available since the publication of the first European League Against Rheumatism (EULAR) recommendations for the management of gout, in 2006. This situation has prompted a systematic review and update of the 2006 recommendations.

METHODS

The EULAR task force consisted of 15 rheumatologists, 1 radiologist, 2 general practitioners, 1 research fellow, 2 patients and 3 experts in epidemiology/methodology from 12 European countries. A systematic review of the literature concerning all aspects of gout treatments was performed. Subsequently, recommendations were formulated by use of a Delphi consensus approach.

RESULTS

Three overarching principles and 11 key recommendations were generated. For the treatment of flare, colchicine, non-steroidal anti-inflammatory drugs (NSAIDs), oral or intra-articular steroids or a combination are recommended. In patients with frequent flare and contraindications to colchicine, NSAIDs and corticosteroids, an interleukin-1 blocker should be considered. In addition to education and a non-pharmacological management approach, urate-lowering therapy (ULT) should be considered from the first presentation of the disease, and serum uric acid (SUA) levels should be maintained at<6 mg/dL (360 µmol/L) and <5 mg/dL (300 µmol/L) in those with severe gout. Allopurinol is recommended as first-line ULT and its dosage should be adjusted according to renal function. If the SUA target cannot be achieved with allopurinol, then febuxostat, a uricosuric or combining a xanthine oxidase inhibitor with a uricosuric should be considered. For patients with refractory gout, pegloticase is recommended.

CONCLUSIONS

These recommendations aim to inform physicians and patients about the non-pharmacological and pharmacological treatments for gout and to provide the best strategies to achieve the predefined urate target to cure the disease.

Clinical characteristics of early- and late-onset gout: A cross-sectional observational study from a Chinese gout clinic

A retrospective cross-sectional study using data from an outpatient clinic in China was conducted to investigate the clinical features of early-onset gout patients.All patients diagnosed with gout were asked about clinical characteristics of their gout and comorbid diseases. Patients presenting with acute flares were asked about common triggers before the flare. "Early-onset" gout was defined as onset of gout before 40 years and "late-onset" as onset ≥40 years. Major joint involvement, flare frequency before presentation, the cumulative number of involved joints, proportions of tophi complications at presentation, flare triggers, as well as any metabolic, cardiovascular, cerebrovascular, and renal comorbidities, were compared between the 2 groups.A total of 778 gout patients were enrolled in this study, including 449 (57.7%) in the early-onset group and 329 (42.3%) in the late-onset group. Compared with the late-onset gout patients, the early-onset gout patients had a higher proportion of ankle/mid-foot involvement (62.8% vs 48.2%, P < 0.001), more frequent flares before presentation (11.2 ± 1.17 vs 6.97 ± 1.03 times per year, P = 0.01), higher cumulative number of involved joints (5.2 ± 0.26 vs 3.8 ± 0.26, P < 0.001), and more likely to have alcohol consumption as a flare trigger (65.2% vs 53.9%, P = 0.03); whereas early-onset gout patients had fewer metabolic, cardiovascular, cerebrovascular, or renal complications.Early- and late-onset gout patients had different clinical features. Early-onset seems to be influenced more by lifestyle, while late-onset patients have more complications because of comorbidities.

Biosensors Incorporating Bimetallic Nanoparticles

This article presents a review of electrochemical bio-sensing for target analytes based on the use of electrocatalytic bimetallic nanoparticles (NPs), which can improve both the sensitivity and selectivity of biosensors. The review moves quickly from an introduction to the field of bio-sensing, to the importance of biosensors in today's society, the nature of the electrochemical methods employed and the attendant problems encountered. The role of electrocatalysts is introduced with reference to the three generations of biosensors. The contributions made by previous workers using bimetallic constructs, grouped by target analyte, are then examined in detail; following which, the synthesis and characterization of the catalytic particles is examined prior to a summary of the current state of endeavor. Finally, some perspectives for the future of bimetallic NPs in biosensors are given.

Treatment and prevention of gout

Gout is a disorder of purine metabolism that primarily occurs in adult males. Elevated plasma uric acid concentrations (hyperuricemia) cause deposits of urate crystals in joint spaces causing severe, repeated attacks of arthritis.

Metabolic syndrome, diabetes, and hyperuricemia

PURPOSE OF REVIEW

To explore the causal relationship between metabolic syndrome, type 2 diabetes and hyperuricemia.

RECENT FINDINGS

The prevalence of hyperuricemia in male adults with metabolic syndrome was increased and a large difference in prevalence of metabolic syndrome also existed in those with hyperuricemia compared with normouricemia. Even in those with normouricemia, higher serum uric acid levels were associated with metabolic syndrome. Serum uric acid was an independent risk factor for incident diabetes, and evidence showed that the patients with both gout and type 2 diabetes exhibited a mutual inter-dependent effect on higher incidences. Furthermore, obese patients often demonstrated insulin resistance and adipose tissue macrophage with low-grade inflammation, which is suggested to be the major contributor. Although alcohol intake is considered a risk for developing hyperuricemia, moderate alcohol intake showed a lower risk for developing type 2 diabetes and insulin resistance. Hyperinsulinemia reduces renal excretion of uric acid on the proximal tubular of the kidney leading to hyperuricemia, which has deleterious effects on endothelial function and on nitric oxide bioavailability, thus causing hyperinsulinemia.

SUMMARY

We found evidence to suggest that insulin resistance plays a potentially key role in the causal relationship between metabolic syndrome, type 2 diabetes and hyperuricemia. Furthermore, it is likely that hyperuricemia and insulin resistance share a bidirectional causal effect.

Investigation on hyperuricemia in children with obesity or various pediatric disorders

The present study aims at investigating the frequency and characteristics of hyperuricemia in both obese and sick children. First, we established our own reference values for serum uric acid (UA), since UA values are highly dependent upon age. In the analysis of 328 samples consisting of six different age groups: <1, 1-3, 4-6, 7-9, 10-12, and 13-15 years, the mean values for UA were found to increase significantly with an increase of age. A significant sex difference was observed only in the age group of 13-15 years. Hyperuricemia was defined as the values over the mean value plus 2 standard deviations for each age group. Next, we examined the frequency of hyperuricemia in 1,687 obese children aged 6-15 years and its relation to metabolic syndrome (MetS). A total of 328 children (19.4%) were found to have hyperuricemia. Among them, 98 children (29.9%) had MetS, whereas 197 (14.5%) out of 1,359 children without hyperuricemia had MetS. Finally, the frequency of hyperuricemia in sick patients was investigated using 13,675 samples from 9,405 patients. Hyperuricemia was seen in 348 (3.7%) patients after excluding redundant samples. The number of patients with hyperuricemia was higher in males than in females. The most common disorder causing hyperuricemia was gastroenteritis, followed by respiratory tract infection and cardiac diseases. This first comprehensive study of childhood hyperuricemia is useful for considering its relationship with hyperuricemia and life-style-related disorders occurring in adulthood.

The role of serum uric acid in cardiovascular disease in type 2 diabetic and non-diabetic subjects: a narrative review

The role of serum uric acid (UA) as a marker or risk factor of cardiovascular disease (CVD) is still controversial. The strong association of serum UA with established risk factors such as hypertension, Type 2 diabetes, dyslipidemia, and chronic kidney disease makes it difficult to establish a direct causal role of serum UA in the development and progression of CVD. The main aims of this review are: 1) to briefly summarize the most relevant studies concerning the association of serum UA with hypertension, chronic kidney disease, CVD events, and death both in patients without diabetes and in those with Type 2 diabetes; and 2) to briefly discuss the putative underlying mechanisms that link serum UA to adverse CVD outcomes. A search was conducted to identify relevant studies in the major electronic databases (MEDLINE and EMBASE, from January 1990 to December 2010) using Medical Subjects Headings and keywords. Collectively, by reviewing the published data in the literature, it emerges that serum UA may exert a number of potentially adverse cardiovascular effects. Nevertheless, the prognostic role of elevated serum UA level as a causal risk factor of adverse CVD outcomes remains still controversial, especially in patients with Type 2 diabetes. At this time, the treatment of asymptomatic hyperuricemia for the primary prevention of CVD is not recommended.