Cross-sectional and longitudinal associations between serum uric acid and metabolic syndrome

Elevated uric acid level and metabolic syndrome in Non-Hispanic Black American adults

Objectives

To ascertain the direct and indirect link between elevated uric acid (eUA) and metabolic syndrome (MetSyn) in Non-Hispanic Black (NHB) American adults.

Design

Structural equation modeling (SEM) was used to disentangle the U.S. National Health and Nutritional Examination Survey (2015-2018 NHANES) dataset and investigate the connection between eUA and components of MetSyn as per the criteria from the National Cholesterol Education Program (NCEP) Adult Treatment Panel III. The association between eUA and MetSyn was determined using odds ratios from sex-specific multivariable logistic regression analysis. The analysis was adjusted for age, physical activity, alcohol use, and smoking. SEM coefficients were used to measure the strength of the link between eUA and MetSyn components.

Results

NHB American men with eUA had 1.41-fold greater odds of MetSyn, and NHB American women with eUA had 2.70-fold greater odds of MetSyn after adjusting for confounding factors. Elevated uric acid was more strongly and directly linked to abdominal obesity (β = 0.320, p < 0.01) in NHB American men, and with abdominal obesity (β = 0.423, p < 0.01), dyslipidemia (β = 0.151, p < 0.01) and hypertension (β = 0.121, p < 0.01) in NHB American women than between eUA and other components of MetSyn.

Conclusions

This study's finding linking eUA to MetSyn components in NHB American adults needs reaffirmation through a robust prospective study design. If validated, eUA could help predict and prevent MetSyn in NHB American adults.

Hyperuricemia and its related diseases: mechanisms and advances in therapy

Hyperuricemia, characterized by elevated levels of serum uric acid (SUA), is linked to a spectrum of commodities such as gout, cardiovascular diseases, renal disorders, metabolic syndrome, and diabetes, etc. Significantly impairing the quality of life for those affected, the prevalence of hyperuricemia is an upward trend globally, especially in most developed countries. UA possesses a multifaceted role, such as antioxidant, pro-oxidative, pro-inflammatory, nitric oxide modulating, anti-aging, and immune effects, which are significant in both physiological and pathological contexts. The equilibrium of circulating urate levels hinges on the interplay between production and excretion, a delicate balance orchestrated by urate transporter functions across various epithelial tissues and cell types. While existing research has identified hyperuricemia involvement in numerous biological processes and signaling pathways, the precise mechanisms connecting elevated UA levels to disease etiology remain to be fully elucidated. In addition, the influence of genetic susceptibilities and environmental determinants on hyperuricemia calls for a detailed and nuanced examination. This review compiles data from global epidemiological studies and clinical practices, exploring the physiological processes and the genetic foundations of urate transporters in depth. Furthermore, we uncover the complex mechanisms by which the UA induced inflammation influences metabolic processes in individuals with hyperuricemia and the association with its relative disease, offering a foundation for innovative therapeutic approaches and advanced pharmacological strategies.

Association between serum uric acid levels and diabetic peripheral neuropathy in type 2 diabetes: a systematic review and meta-analysis

Background

The evidence supporting a connection between elevated serum uric acid (SUA) levels and diabetic peripheral neuropathy (DPN) is controversial. The present study performed a comprehensive evaluation of this correlation by conducting a systematic review and meta-analysis of relevant research.

Method

PubMed, Web of Science (WOS), Embase, and the Cochrane Library were searched for published literature from the establishment of each database to January 8, 2024. In total, 5 cohort studies and 15 cross-sectional studies were included, and 2 researchers independently screened and extracted relevant data. R 4.3.0 was used to evaluate the included literature. The present meta-analysis evaluated the relationship between SUA levels and the risk of DPN in type 2 diabetes (T2DM) by calculating the ratio of means (RoM) and 95% confidence intervals (CIs) using the method reported by JO Friedrich, and it also analyzed continuous outcome measures using standardized mean differences (SMDs) and 95% CIs to compare SUA levels between DPN and non-DPN groups. Funnel plot and Egger's test were used to assess publication bias. Sensitivity analysis was conducted by sequentially removing each study one-by-one.

Results

The meta-analysis included 20 studies, with 12,952 T2DM patients with DPN and 16,246 T2DM patients without DPN. There was a significant correlation between SUA levels and the risk of developing DPN [odds ratio (OR) = 1.23; 95% CI: 1.07-1.41; p = 0.001]. Additionally, individuals with DPN had higher levels of SUA compared to those without DPN (SMD = 0.4; 95% CI: -0.11-0.91; p < 0.01).

Conclusion

T2DM patients with DPN have significantly elevated SUA levels, which correlate with a heightened risk of peripheral neuropathy. Hyperuricemia (HUA) may be a risk indicator for assessing the risk of developing DPN in T2DM patients.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO, identifier CRD42024500373.

Association of serum uric acid with hypertriglyceridemia in children and adolescents: a cross-sectional study

BACKGROUND

Uric acid (UA), a liver-derived metabolite, is intimately tied to metabolic disorders. Although ample research underscores its connection with hypertriglyceridemia (HTG), studies focusing on adolescents remain limited. To fill the gaps in epidemiology,this study focused on analyzing the relationship between the levels of uric acid and HTG in a demographic sample comprising adolescents from the United States.

METHODS

In this study, a total of 4,435 participants through the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2020. The exposure variable was serum uric acid (SUA), the effect variable was HTG, and the covariates included demographic, questionnaire, physical examination and laboratory indicators. We utilized weighted logistic regression and meticulous subgroup evaluations to discern the intrinsic link between SUA and HTG. Stratified analyses augmented the validation of this association, while smooth curve fitting probed for potential nonlinear correlations.

RESULTS

The study included 4,435 participants. Male adolescents exhibit elevated SUA levels. After adjusting for all variables, the weighted multiple logistic regression model revealed that SUA was positively correlated with HTG risk (OR = 1.006, 95% CI: 1.005-1.007). This relationship was consistent across the three tertiles group of SUA (T1: OR = 1.006 [95% CI: 1.005-1.007]; T2: OR = 1.006 [95% CI: 1.005-1.007]; T3: OR = 1.004 [95% CI: 1.003-1.006]; P for trend < 0.001). Stratified analyses confirmed that the positive correlation between SUA and HTG risk was significant, irrespective of sex, age or race.

CONCLUSIONS

In American children and adolescents aged 12 to 18 years, there was a pronounced association between SUA and HTG. SUA could serve as a risk indicator for HTG. It is recommended that children diagnosed with HTG should be regularly tested for SUA levels. In addition, it is recommended that SUA be included in the comprehensive care of children diagnosed with HTG.

Investigating the nexus of metabolic syndrome, serum uric acid, and dementia risk: a prospective cohort study

BACKGROUND

The global dementia prevalence is surging, necessitating research into contributing factors. We aimed to investigate the association between metabolic syndrome (MetS), its components, serum uric acid (SUA) levels, and dementia risk.

METHODS

Our prospective study comprised 466,788 participants without pre-existing MetS from the UK Biobank. We confirmed dementia diagnoses based on the ICD-10 criteria (F00-03). To evaluate the dementia risk concerning MetS, its components, and SUA levels, we applied Cox proportional hazards models, while adjusting for demographic factors.

RESULTS

Over a median follow-up of 12.7 years, we identified 6845 dementia cases. Individuals with MetS had a 25% higher risk of all-cause dementia (hazard ratio [HR] = 1.25, 95% confidence interval [CI] = 1.19-1.31). The risk increased with the number of MetS components including central obesity, dyslipidemia for high-density lipoprotein (HDL) cholesterol, hypertension, hyperglycemia, and dyslipidemia for triglycerides. Particularly for those with all five components (HR = 1.76, 95% CI = 1.51-2.04). Dyslipidemia for HDL cholesterol, hypertension, hyperglycemia, and dyslipidemia for triglycerides were independently associated with elevated dementia risk (p < 0.01). MetS was further linked to an increased risk of all-cause dementia (11%) and vascular dementia (VD, 50%) among individuals with SUA levels exceeding 400 μmol/L (all-cause dementia: HR = 1.11, 95% CI = 1.02-1.21; VD: HR = 1.50, 95% CI = 1.28-1.77).

CONCLUSIONS

Our study provides robust evidence supporting the association between MetS, its components, and dementia risk. These findings emphasize the importance of considering MetS and SUA levels in assessing dementia risk, offering valuable insights for prevention and management strategies.

Identification of inhibitors from a functional food-based plant Perillae Folium against hyperuricemia via metabolomics profiling, network pharmacology and all-atom molecular dynamics simulations

Introduction

Hyperuricemia (HUA) is a metabolic disorder caused by purine metabolism dysfunction in which the increasing purine levels can be partially attributed to seafood consumption. Perillae Folium (PF), a widely used plant in functional food, has been historically used to mitigate seafood-induced diseases. However, its efficacy against HUA and the underlying mechanism remain unclear.

Methods

A network pharmacology analysis was performed to identify candidate targets and potential mechanisms involved in PF treating HUA. The candidate targets were determined based on TCMSP, SwissTargetPrediction, Open Targets Platform, GeneCards, Comparative Toxicogenomics Database, and DrugBank. The potential mechanisms were predicted via Gene Ontology (GO) and Kyoto Gene and Genome Encyclopedia (KEGG) analyses. Molecular docking in AutoDock Vina and PyRx were performed to predict the binding affinity and pose between herbal compounds and HUA-related targets. A chemical structure analysis of PF compounds was performed using OSIRIS DataWarrior and ClassyFire. We then conducted virtual pharmacokinetic and toxicity screening to filter potential inhibitors. We further performed verifications of these inhibitors' roles in HUA through molecular dynamics (MD) simulations, text-mining, and untargeted metabolomics analysis.

Results

We obtained 8200 predicted binding results between 328 herbal compounds and 25 potential targets, and xanthine dehydrogenase (XDH) exhibited the highest average binding affinity. We screened out five promising ligands (scutellarein, benzyl alpha-D-mannopyranoside, elemol, diisobutyl phthalate, and (3R)-hydroxy-beta-ionone) and performed MD simulations up to 50 ns for XDH complexed to them. The scutellarein-XDH complex exhibited the most satisfactory stability. Furthermore, the text-mining study provided laboratory evidence of scutellarein's function. The metabolomics approach identified 543 compounds and confirmed the presence of scutellarein. Extending MD simulations to 200 ns further indicated the sustained impact of scutellarein on XDH structure.

Conclusion

Our study provides a computational and biomedical basis for PF treating HUA and fully elucidates scutellarein's great potential as an XDH inhibitor at the molecular level, holding promise for future drug design and development.

Serum uric acid to high-density lipoprotein ratio as a novel indicator of inflammation is correlated with the presence and severity of metabolic syndrome: A large-scale study

INTRODUCTION

We investigated the association of serum uric acid to high-density lipoprotein ratio (UHR) with the presence and severity of metabolic syndrome (MetS) among MASHAD cohort participants.

METHODS

In this cross-sectional study, according to International Diabetes Federation criteria, the cohort participants were divided into MetS (+) and MetS (-) groups. MetS (+) were classified into Group 1 (those with 3 MetS criteria), Group 2 (those with 4 MetS criteria) and Group 3 (those with 5 MetS criteria). UHR was compared among the groups.

RESULTS

Data related to 9637 subjects including 3824 MetS (+) and 5813 MetS (-) were analysed. The mean UHR was significantly higher (p < .001) in the MetS (+) group compared with the MetS (-) group. UHR increased as the MetS severity increased (p < .001). ROC analysis revealed that UHR greater than 9.5% has 89.07% sensitivity and 77.03% specificity in differentiating MetS (-) from MetS (+) subjects.

CONCLUSION

Among MASHAD cohort study participants, a significant association between UHR and MetS was found. Furthermore, there is an increase in UHR as the severity of MetS increases. Registration number of MASHAD cohort study: 85134.

The association between serum uric acid and hypertriglyceridemia: evidence from the national health and nutrition examination survey (2007-2018)

Background

Accumulating evidence suggests that elevated serum uric acid (SUA) may be a risk factor for hypertriglyceridemia (HTG). However, the epidemiological evidence for the association between SUA and HTG is limited. This article aimed to use the data from National Health and Nutrition Examination Survey (NHANES) (2007-2018) database to bridge the research gap.

Methods

This cross-sectional study used data from 10027 adults involved in NHANES from 2007-2018. We designed the exposure variable as SUA and the outcome variable as HTG. The covariates included demographics, questionnaires, laboratory, and examination information. Weighted logistic regression and subgroup analysis were used to explore the independent association between SUA and HTG. Furthermore, interaction tests were also carried out to evaluate the strata differences. Generalized additive models (GAM), smooth curve fittings, and threshold effect analysis were applied to examine the non-linear relationship.

Results

A total of 10027 participants were included, of which 3864 were HTG participants and 6163 were non-HTG participants. After fully adjusting for confounders, weighted multiple logistic regression models revealed a 77% increase in the risk of HTG when each unit of log2-SUA increased. There was also a positive association between elevated log2-SUA and developed risk of HTG in the quartile (Q) groups (Q1 OR: 1.00; Q2 OR: 1.17 [95%CI: 0.95,1.45]; Q3 OR: 1.43 [95%CI: 1.16,1.78]; Q4 OR: 1.68 [95%CI: 1.36,2.08]. The subgroup analysis results remained consistent across strata, with a strong positive correlation between SUA and HTG. Interaction tests showed no dependence on physical activity (PA), gender, BMI, smoking status, alcohol intake, hypertension, and diabetes for this positive association between log2-SUA and HTG (all p for interaction >0.05). The participants' age may impact the strength of the association between SUA and HTG (p for interaction <0.05).

Conclusion

There is a positive association between SUA and HTG in US adults. Considering that SUA may be a risk factor for HTG, individuals diagnosed with HTG should prioritize the daily management of SUA as part of their comprehensive care.

Association between dyslipidaemia and the risk of hyperuricaemia: a six-year longitudinal cohort study of elderly individuals in China

BACKGROUND

Despite abundant evidence linking dyslipidaemia to an increased risk of hyperuricaemia, the exact association between each component of dyslipidaemia and hyperuricaemia remains controversial. Thus, the objective of this research was to examine the correlation between dyslipidaemia and its components, as well as hyperuricaemia in Chinese people over the age of 60.

METHODS

In this study, 4018 participants over 60 years without hyperuricaemia were investigated from 2014 to 2020. The association between each dyslipidaemia component and hyperuricaemia was evaluated employing Cox proportional hazards models. This research conducted further stratified and sensitivity analyses to assess the potential relationship.

RESULTS

A total of 1155 participants suffered from hyperuricaemia (28.75%) at the time of the 6-year follow-up survey. In multivariable-adjusted analyses, compared to participants with normal lipid levels, those with dyslipidaemia had 1.28 times the risk (95% confidence interval 1.12 to 1.47) of experiencing hyperuricaemia. The hazard ratios (HR) (95% CI) comparing high TC, high TG, high LDL-C, and low HDL-C of dyslipidaemia with the regular group were 0.99 (0.72 to 1.37), 1.30 (1.07 to 1.57), 1.02 (0.70 to 1.50), and 1.20 (1.00 to 1.44), respectively. There was a nonlinear dose-response between TG, HDL-C, and serum uric acid (SUA).

CONCLUSIONS

Dyslipidaemia and its two distinct types, high TG and low HDL-C, increased hyperuricaemia incidence in this prospective cohort. Further research should be undertaken to investigate the possible reverse causality between different components of dyslipidaemia and hyperuricaemia.

Association between metabolic syndrome and uric acid: a systematic review and meta-analysis

This systematic review and meta-analysis aim to provide the best evidence on the association between metabolic syndrome (MetS) and uric acid (UA) by determining the size of the effect of this biomarker on MetS. The review protocol is registered with PROSPERO (CRD42021231124). The search covered the PubMed and Scopus databases. Methodological quality was assessed with the STROBE tool, overall risk of bias with RevMan (Cochrane Collaboration) and quality of evidence with Grade Pro. Initially, 1582 articles were identified. Then, after excluding duplicates and reviewing titles and abstracts, 1529 articles were excluded from applying the eligibility criteria. We included 43 papers (56 groups) comparing UA concentrations between subjects 91,845 with MetS and 259,931 controls. Subjects with MetS had a higher mean UA of 0.57 mg/dl (95% CI 0.54-0.61) (p < 0.00001). Given the heterogeneity of the included studies, the researchers decided to perform subgroups analysis. Men with MetS have a higher UA concentration mg/dl 0.53 (95% CI 0.45-0.62, p < 0.00001) and women with MetS 0.57 (95% CI 0.48-0.66, p < 0.00001) compared to subjects without MetS. Assessment of UA concentration could provide a new avenue for early diagnosis of MetS, as a new biomarker and the possibility of new therapeutic targets.

Cross-sectional association between gamma-glutamyl transferase and hyperuricaemia: the China Multi-Ethinic Cohort (CMEC) study

OBJECTIVES

Several studies have demonstrated the association between gamma-glutamyl transferase (GGT) and hyperuricaemia, but little is known about such relation in less-developed ethnic minority regions.

DESIGN

We cross-sectionally analysed data from the China Multi-Ethnic Cohort (Yunnan region).

SETTING

Cross-sectional study.

PARTICIPANTS

22 020 participants aged 30-79 years from Han ethnicity, Yi ethnicity and Bai ethnicity.

OUTCOMES

The serum level of uric acid, GGT and other metabolic parameters were tested. Weight, height and blood pressure were measured. Smoking, drinking, ethnicity, education and medical history were obtained from questionnaires.

RESULTS

In the crude model, compared with the lowest quintile, the second, third, fourth and fifth quintiles of serum GGT exhibited a positive association with hyperuricaemia risk (OR=1.69, 2.90, 4.34 and 7.70, 95% CI=1.42 to 2.01, 2.47 to 3.42, 3.71 to 5.09 and 6.60 to 8.98, respectively, p-trend<0.0001). In fully adjusted model, compared with the lowest quintile, the second, third, fourth and fifth quintiles of serum GGT also exhibited a positive association with hyperuricaemia risk (OR=1.26, 1.68, 2.02 and 3.02, 95% CI=1.04 to 1.51, 1.40 to 2.00, 1.69 to 2.42 and 2.51 to 3.64, respectively, p-trend<0.0001). Logistic regression model was conducted separately in ethnic groups. Compared with first quintile, the highest GGT level were related to higher risk of hyperuricaemia in three ethnic groups (OR (95% CI): 2.89 (2.26 to 3.68), 2.81 (1.93 to 4.11) and 3.04 (1.91 to 4.84) for Han, Yi and Bai ethnicity, respectively, p-trend <0.0001). The relationship between GGT and hyperuricaemia was also observed in different age groups or gender groups.

CONCLUSIONS

High serum GGT level was related to a higher risk of hyperuricaemia in less-developed ethnic minority regions in China.

Non-alcoholic fatty liver disease: correlation with hyperuricemia in a European Mediterranean population

OBJECTIVES

Non-alcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS) are two pathologies that intersect each other. It was found that there is an association between MetS/NAFLD and hyperuricemia. The aim of our study was to demonstrate this association in a European Mediterranean population.

METHODS

We compared 236 patients with NAFLD to 218 patients without NAFLD. We assessed laboratory metabolic parameters (serum uric acid - SUA, fasting glucose, triglycerides, total cholesterol, etc.) and the presence or absence of MetS in a retrospective, cross-sectional, case-control manner.

RESULTS

Analysis of the two main variables in study showed a moderate direct correlation (p< 0.01; Pearson coefficient 0.443) between SUA and NAFLD. Evaluation for SUA quartiles showed a decreased risk of NAFLD for the first and second quartiles (OR Q1 = 0.20; OR Q2 = 0.59), but increased for the third and fourth quartiles (OR Q3 = 2.22; OR Q4 = 6.97). In females, the risk of NAFLD was less compared to males for the first three quartiles of SUA, but it was more than double for the fourth quartile (OR Q1 0.21 vs 0.16; OR Q2 0.82 vs 0.45; OR Q3 2.50 vs 2.26; OR Q4 4.50 vs 9.83). In the NAFLD group, hyperuricemia was significantly correlated with sex, obesity, hypertension, and with the number of components of the MetS. In the Control group, SUA directly correlated with age, diabetes, and ALT, but not with obesity.

CONCLUSION

We have found a significant correlation between NAFLD and hyperuricemia. The higher SUA levels accompanied the risk of NAFLD.

The Association with Subclinical Thyroid Dysfunction and Uric Acid

The relationship between subclinical thyroid dysfunction and uric acid was not well established. This study aimed to determine if subclinical thyroid dysfunction is associated with hyperuricemia risk and to evaluate the levels of uric acid in patients with different forms of subclinical thyroid dysfunction. A systematic search was conducted in 4 databases to obtain relevant studies on subclinical thyroid dysfunction (subclinical hyperthyroidism and subclinical hypothyroidism) and uric acid. The standardized mean difference (SMD) or odds ratio (OR) and 95% confidence interval (95% CI) were used for evaluation, and the sensitivity analysis was conducted. Publication bias was estimated by funnel plot, Egger's test, and Begg's test. A total of 73 studies were included in this meta-analysis. The results demonstrated that serum levels of uric acid in patients with subclinical hypothyroidism were significantly higher than those of controls and patients with subclinical hyperthyroidism. Patients with subclinical thyroid dysfunction had a higher prevalence of hyperuricemia compared with normal clinical thyroid function. Subclinical thyroid dysfunction was associated with the prevalence of hyperuricemia. Different types of subclinical thyroid dysfunction had varied effects on serum levels of uric acid.

Can biomarkers be used to improve diagnosis and prediction of metabolic syndrome in childhood cancer survivors? A systematic review

Childhood cancer survivors (CCS) are at increased risk to develop metabolic syndrome (MetS), diabetes, and cardiovascular disease. Common criteria underestimate adiposity and possibly underdiagnose MetS, particularly after abdominal radiotherapy. A systematic literature review and meta-analysis on the diagnostic and predictive value of nine newer MetS related biomarkers (adiponectin, leptin, uric acid, hsCRP, TNF-alpha, IL-1, IL-6, apolipoprotein B (apoB), and lipoprotein(a) [lp(a)]) in survivors and adult non-cancer survivors was performed by searching PubMed and Embase. Evidence was summarized with GRADE after risk of bias evaluation (QUADAS-2/QUIPS). Eligible studies on promising biomarkers were pooled. We identified 175 general population and five CCS studies. In the general population, valuable predictive biomarkers are uric acid, adiponectin, hsCRP and apoB (high level of evidence), and leptin (moderate level of evidence). Valuable diagnostic biomarkers are hsCRP, adiponectin, uric acid, and leptin (low, low, moderate, and high level of evidence, respectively). Meta-analysis showed OR for hyperuricemia of 2.94 (age-/sex-adjusted), OR per unit uric acid increase of 1.086 (unadjusted), and AUC for hsCRP of 0.71 (unadjusted). Uric acid, adiponectin, hsCRP, leptin, and apoB can be alternative biomarkers in the screening setting for MetS in survivors, to enhance early identification of those at high risk of subsequent complications.

Dose-response association between serum uric acid levels and incident hypertension: a systematic review and meta-analysis of 17 prospective cohort studies of 32 thousand participants

BACKGROUND

Various magnitudes of the risk of incident hypertension (IHTN) have been reported to be associated with increased serum uric acid (SUA) levels in observational studies, however, whether a dose-response relation exists is unclear. We aimed to quantitatively evaluate the SUA-IHTN association.

METHODS

We searched the PubMed and Embase databases for relevant articles published prior to 21 October 2019. Random-effects models were used to estimate the summary relative risks (RRs) and 95% confidence intervals (CIs) of the IHTN risk in relation to SUA levels. We used restricted cubic splines to model the dose-response association between SUA levels and IHTN.

RESULTS

A total of 17 articles (17 prospective cohort studies) including 321,716 adults and 65,890 IHTN cases were identified. The pooled RR was 1.10 (95% CI 1.07-1.13; I²=90.7%; n = 17) per 1 mg/dL change in the SUA level. In addition, we found evidence of a linear and positive dose-response association between SUA levels and IHTN (P_{non-linearity} = 0.069). The results of the subgroup and sensitivity analyses were consistent with those of the primary analysis.

CONCLUSION

These data suggested that people with higher SUA levels had a higher IHTN risk. SUA levels need to be controlled to reduce or eliminate the risk of IHTN associated with SUA levels. Clinical trial studies or diagnostic studies are needed to determine the optimal cut-off point for SUA.

Causal Associations of Urate With Cardiovascular Risk Factors: Two-Sample Mendelian Randomization

Background

Mendelian Randomization (MR) studies show conflicting causal associations of genetically predicted serum urate with cardiovascular risk factors (i.e., hypertension, diabetes, lipid profile, and kidney function). This study aimed to robustly investigate a causal relationship between urate and cardiovascular risk factors considering single nucleotide polymorphisms (SNPs) as instrumental variables using two-sample MR and various sensitivity analyses.

Methods

Data on SNP-urate associations were taken from the Global Urate Genetics Consortium and data on SNP-cardiovascular risk factor associations were taken from various consortia/UK Biobank. SNPs were selected by statistically and biologically driven approaches as instrumental variables. Various sensitivity analyses were performed using different MR methods including inverse variance weighted, MR-Egger, weighted median/mode, MR-PRESSO, and the contamination mixture method.

Results

The statistically driven approach showed significant causal effects of urate on HDL-C and triglycerides using four of the six MR methods, i.e., every 1 mg/dl increase in genetically predicted urate was associated with 0.047 to 0.103 SD decrease in HDL-C and 0.034 to 0.207 SD increase in triglycerides. The biologically driven approach to selection of SNPs from ABCG2, SLC2A9, SLC17A1, SLC22A11, and SLC22A12 showed consistent causal effects of urate on HDL-C from all methods with 0.038 to 0.057 SD decrease in HDL-C per 1 mg/dl increase of urate, and no evidence of horizontal pleiotropy was detected.

Conclusion

Our study suggests a significant and robust causal effect of genetically predicted urate on HDL-C. This finding may explain a small proportion (7%) of the association between increased urate and cardiovascular disease but points to urate being a novel cardiac risk factor.

Differences in Clinical and Dietary Characteristics, Serum Adipokine Levels, and Metabolomic Profiles between Early- and Late-Onset Gout

This study aimed to identify differences in clinical and dietary characteristics, serum adipokine levels, and metabolomic profiles between early- and late-onset gout. Eighty-three men with gout were divided into an early-onset group (n = 38, aged < 40 years) and a late-onset group (n = 45, aged ≥ 40 years). Dietary and clinical information was obtained at baseline. Serum adipokines, including adiponectin, resistin, leptin, and plasminogen activator inhibitor-1 (PAI-1), were quantified by a Luminex multiplex immunoassay. Metabolite expression levels in plasma were measured in 22 representative samples using metabolomics analysis based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Average body mass index, rate of consumption of sugar-sweetened beverages, and serum uric acid levels were significantly higher in the early-onset group (p < 0.05), as was the PAI-I concentration (105.01 ± 42.45 ng/mL vs. 83.76 ± 31.16 ng/mL, p = 0.013). Changes in levels of metabolites mostly involved those related to lipid metabolism. In the early-onset group, acylcarnitine analog and propylparaben levels were downregulated and negatively correlated with the PAI-1 concentration whereas LPC (22:6) and LPC (18:0) levels were upregulated and positively correlated with the PAI-1 concentration. Dietary and clinical features, serum adipokine concentrations, and metabolites differed according to whether the gout is early-onset or late-onset. The mechanisms of gout may differ between these groups and require different treatment approaches.

Association between baseline and changes in serum uric acid and incident metabolic syndrome: a nation-wide cohort study and updated meta-analysis

BACKGROUND

To prospectively examine the associations of baseline serum uric acid (SUA) and SUA changes with incident metabolic syndrome (MetS) and update the evidence through a meta-analysis.

METHODS

Our analyses were based on the China Health and Retirement Longitudinal Study from 2011-2012 to 2015-2016. The exposures were baseline SUA and SUA changes, and the outcome was incident MetS assessed in 2015-2016. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). A meta-analysis was conducted to synthesize evidence from all cohort studies on the same topic.

RESULTS

Of 3779 participants (47.2% men; mean age: 59.5 years) without MetS, 452 participants developed MetS after a follow-up of 4 years. Compared to the lowest quartiles, the adjusted ORs (95% CIs) for MetS were 1.08 (0.77-1.50), 1.32 (0.95-1.82), and 1.55 (1.12-2.16) for three higher quartiles of baseline SUA, and 1.23 (0.89-1.71), 1.39 (1.00-1.93), and 1.89 (1.38-2.58) for three higher quartiles of SUA changes. Each increment of 1 mg/dL of baseline SUA level was associated with 19% higher odds of MetS (adjusted OR 1.19; 95% CI 1.07-1.33). In the meta-analysis of 24 cohort studies among 140,913 participants, the pooled relative risk (95% CI) was 1.32 (1.25-1.40) for the highest versus lowest SUA category, and 1.15 (1.09-1.21) for each 1 mg/dL increase in the SUA level.

CONCLUSIONS

Both baseline SUA and longitudinal SUA changes were positively associated with risk of MetS among middle-aged and elderly Chinese, which was supported by findings from a comprehensive meta-analysis across multiple populations. SUA levels might need to be monitored closely for subsequent risk of MetS in clinical practice.

Association of serum uric acid with thyroid function in health check-up participants

Background

The relationship of uric acid (UA) with the thyroid function among healthy individuals remains unclear. We aimed to examine the relationship between UA contents and thyroid hormone levels in healthy Chinese individuals.

Methods

This was a cross-sectional study of 1186 Chinese adults (736 men and 450 women) who underwent a health check-up at the Huadong Hospital Affiliated to Fudan University (Shanghai, China) between January 1, 2010 and July 31, 2018. Clinical and thyroid hormone levels were compared in different UA groups (in male and menopause women groups, MG1: UA < 5 mg/dL; MG2: 5 mg/dL ≤ UA< 7 mg/dL; and MG3: UA ≥ 7 mg/dL; in female groups, FG1 to FG3 represent the UA levels of <4 mg/dL, 4 mg/dL ≤ UA< 6 mg/dL, and ≥6 mg/dL, respectively). In addition, natural cubic spline regression, together with Pearson correlation analysis, was performed in investigating the correlation of UA with thyroid hormones.

Results

After adjusting for confounding factors, low levels of UA (for males, UA < 5.30 mg/dL; for females, UA < 4.05 mg/dL) were negatively correlated with free triiodothyronine (FT3) both in men and women. UA levels between 4.83 and 6.06 mg/dL may act to protect FT3 in women, while UA levels between 6.39 and 7.09 mg/dL may protect FT3 in men. FT3 levels of low-range UA group reduced compared with mid-range UA and the high-range UA groups in both men and women.

Conclusions

Our results provide epidemiologic evidence to support the negative correlation between low UA contents and FT3 in the Chinese Han population, suggesting that the reduced UA contents may serve as the risk factor to predict poor thyroid function in Chinese individuals.

Association between serum uric acid and major chronic diseases among centenarians in China: based on the CHCCS study

BACKGROUND

This study aims to analyze the distribution of serum uric acid (SUA) level based on more than 1000 centenarians and to explore the association with three common diseases including hypertension, diabetes and dyslipidemia.

METHODS

All the 1002 centenarians from the CHCCS were included. Household survey was conducted.

RESULTS

The mean SUA level of centenarians was 329.04 ± 97.75 μmol/L and the prevalence of hyperuricemia in centenarians was 26.5%. There was no statistical difference in the distribution of SUA levels among centenarians with or without hypertension/diabetes. For dyslipidemia, there was an independent positive association. The risk of dyslipidemia among those with hyperuricemia was 1.646 (95%CI: 1.078-2.298) compared with those who didn't have hyperuricemia. By comparing different subtypes of dyslipidemia, hyperuricemia was positively associated with hypertriglyceridemia and low-density lipoprotein cholesterolemia, with the corresponding ORs of 2.553 (95%CI: 1.282-5.083) and 1.927 (95%CI: 1.273-2.917) respectively, while there was no statistically significant association with hypercholesterolemia 0.998 (95%CI: 0.574-1.732).

CONCLUSIONS

There was no relation between SUA with hypertension or diabetes, while there was independently and positively association with hypertriglyceridemia and low-density lipoprotein cholesterolemia. The health benefits of controlling SUA in centenarians still require evidence based on prospective studies.

Temporal relationship between body mass index and uric acid and their joint impact on blood pressure in children and adults: the Bogalusa Heart Study

OBJECTIVE

This study aimed to examine the temporal relationship between body mass index (BMI) and uric acid (UA), and their joint effect on blood pressure (BP) in children and adults.

METHODS

The longitudinal cohorts for temporal relationship analyses consisted of 564 and 911 subjects examined twice 5-14 years apart from childhood to adulthood. The cross-sectional cohorts for mediation analyses consisted of 3102 children and 3402 nondiabetic adults. Cross-lagged panel analysis models were used to examine the temporal relationship between BMI and UA, and mediation analysis models the mediation effect of UA on the BMI-BP association.

RESULTS

After adjusting for age, race, sex and follow-up years in children, and additionally smoking and alcohol drinking in adults, the path coefficients (standardized regression coefficients) from baseline BMI to follow-up UA (0.145 in children and 0.068 in adults) were significant, but the path coefficients from baseline UA to follow-up BMI (0.011 in children and 0.016 in adults) were not. In mediation analyses, indirect effects through UA on the BMI-systolic BP association were estimated at 0.028 (mediation effect = 8.8%) in children and 0.033 (mediation effect = 13.5%) in adults (P < 0.001 for both). Direct effects of BMI on systolic BP (0.289 in children and 0.212 in adults) were significant. The mediation effect parameters did not differ significantly between Blacks and Whites.

CONCLUSIONS

Changes in BMI precede alterations in UA, and the BMI-BP association is in part mediated through BMI-related increase in UA both in children and in adults. These findings have implications for addressing mechanisms of obesity hypertension beginning in early life.

Microvascular Reactivity in Hypertensive Patients with High Body Adiposity

Fundamento:

Diversos índices antropométricos têm sido propostos para determinar a associação entre excesso de peso e fatores de risco cardiovascular.

Objetivo:

Avaliar a relação entre adiposidade corporal e reatividade microvascular em pacientes hipertensos sob terapia anti-hipertensiva.

Métodos:

Pacientes hipertensos tratados de 40 a 70 anos foram submetidos à avaliação de índices antropométricos: conicidade (IC), adiposidade corporal (IAC), adiposidade visceral (IAV) e relação cintura-estatura (RCE). Os participantes foram divididos pelos tercis de percentual de gordura (%G) obtido pela bioimpedância elétrica (BIA) e submetidos a teste de reatividade microvascular (laser speckle contrast image), medida da velocidade da onda de pulso (VOP). O valor de p < 0,05 foi considerado estatisticamente significativo.

Resultados:

A variação da área sob a curva (ASC) da perfusão cutânea foi inferior no tercil superior (97 ± 57% vs. 67 ± 36%; p = 0,027). O %G apresentou correlação significativa com RCE (r = 0,77; p < 0,001), IAV (r = 0,41; p = 0,018), IC (r = 0,60; p < 0,001) e IAC (r = 0,65; p < 0,001) nos homens e somente com RCE (r = 0,55; p < 0,001) e IAC (r = 0,60; p < 0,001) nas mulheres. Na regressão linear, a ASC mostrou associação independente com o %G (β =–3,15; p = 0,04) nas mulheres e com a glicemia (β = –1,15; p = 0,02) nos homens. Não houve diferença nas medidas de VOP.

Conclusão:

Os índices antropométricos de obesidade foram mais associados ao %G nos homens. A maior adiposidade corporal foi relacionada com menor reatividade microvascular, o que foi mais evidente nas mulheres. Não houve diferença na rigidez arterial, o que pode ter sido influenciado pelo tratamento anti-hipertensivo.

Association between serum uric acid levels and dyslipidemia in Chinese adults: A cross-sectional study and further meta-analysis

This study aimed to investigate the association of serum uric acid (SUA) levels with dyslipidemia and its components and to further explore the age- and gender-specific association of SUA levels with dyslipidemia in Chinese adults.A cross-sectional study was performed among 8642 adults who underwent health examinations. A meta-analysis covering 17 studies was conducted to confirm the results.The prevalence of hyperuricemia and dyslipidemia was 9.25% and 20.44%, respectively. Participants with hyperuricemia had higher prevalence of dyslipidemia than those without hyperuricemia (34.42% vs 19.01%, P < .005). Compared with participants with SUA in the first quintile, the odds ratio (OR) (95% confidence interval) of dyslipidemia in the second, third, fourth, and fifth quintiles of SUA were 1.095 (0.901-1.332), 1.582 (1.315-1.904), 2.095 (1.752-2.505), and 3.212 (2.702-3.818), respectively. Subgroup analysis showed that SUA quintiles were significantly correlated with the likelihood of dyslipidemia in females aged > 50 years and in males, but not in females aged ≤50 years. The meta-analysis also showed that hyperuricemia increased the likelihood of dyslipidemia and the pooled OR for the highest uric acid level vs the lowest uric acid level was 1.84 (1.49-2.28).SUA levels are significantly associated with dyslipidemia, and this association is impacted by age and gender.

Hepatocyte-Specific Ablation or Whole-Body Inhibition of Xanthine Oxidoreductase in Mice Corrects Obesity-Induced Systemic Hyperuricemia Without Improving Metabolic Abnormalities

Systemic hyperuricemia (HyUA) in obesity/type 2 diabetes facilitated by elevated activity of xanthine oxidoreductase (XOR), which is the sole source of uric acid (UA) in mammals, has been proposed to contribute to the pathogenesis of insulin resistance/dyslipidemia in obesity. Here, the effects of hepatocyte-specific ablation of Xdh, the gene encoding XOR (HXO), and whole-body pharmacologic inhibition of XOR (febuxostat) on obesity-induced insulin resistance/dyslipidemia were assessed. Deletion of hepatocyte Xdh substantially lowered liver and plasma UA concentration. When exposed to an obesogenic diet, HXO and control floxed (FLX) mice became equally obese, but systemic HyUA was absent in HXO mice. Despite this, obese HXO mice became as insulin resistant and dyslipidemic as obese FLX mice. Similarly, febuxostat dramatically lowered plasma and tissue UA and XOR activity in obese wild-type mice without altering obesity-associated insulin resistance/dyslipidemia. These data demonstrate that hepatocyte XOR activity is a critical determinant of systemic UA homeostasis, that deletion of hepatocyte Xdh is sufficient to prevent systemic HyUA of obesity, and that neither prevention nor correction of HyUA improves insulin resistance/dyslipidemia in obesity. Thus, systemic HyUA, although clearly a biomarker of the metabolic abnormalities of obesity, does not appear to be causative.

NLRP3 inflammasome and lipid metabolism analysis based on UPLC-Q-TOF-MS in gouty nephropathy

To determine the differences in plasma metabolism between healthy patients and patients with hyperuricaemia and gouty nephropathy, the present study identified differentially expressed metabolites associated with gouty nephropathy. Furthermore, the NLRP3 inflammasome signalling pathway in gouty nephropathy was explored, and the mechanism of hyperuricaemia-induced renal damage. Adult male patients examined between July 2016 and June 2017 were selected as the patient cohort for the present study from the Affiliated Bao'an Hospital of Shenzhen, Southern Medical University (Shenzhen, China). These patients were divided into three groups of 30 patients each: Control, hyperuricaemia and gouty nephropathy groups. The expression levels of NLRP3, ASC and caspase-1 mRNA and protein were detected in peripheral blood mononuclear cells, and the plasma levels of IL-1β and IL-18. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used to determine differential levels of metabolites between patients from different groups, in order to identify potential biomarkers. The expression of the NLRP3 inflammasome in peripheral blood mononuclear cells, and the levels of IL-1β and IL-18 in the plasma were increased in the gouty nephropathy group compared with the control and hyperuricaemia groups. In addition, 46 metabolites were identified as potential plasma metabolic biomarkers that were able to distinguish gouty nephropathy from hyperuricaemia. The majority of these metabolites were involved in lipid metabolism, in particular the activity of phospholipase A2 and β-oxidation. These data indicated that lipid metabolism and the NLRP3 inflammasome serve a pivotal role in gouty nephropathy. In addition, the results suggested that lipids may mediate the progression of gouty nephropathy through the activity of phospholipase A2, β-oxidation and activation of the NLRP3 inflammasome.

Optimal Cut-off Point of Waist to Height Ratio in Beijing and Its Association with Clusters of Metabolic Risk Factors

A host of studies found waist-to-height ratio (WHtR) having higher diagnostic value than other abdominal obesity anthropometric indicators for metabolic disorders. But the cut-off points are still not consistent. This study was aimed to explore the optimal cut-off point of WHtR in Chinese population and identify the association between WHtR and cluster of metabolic risk factors. In total, 13379 Han adults (7553 men and 5726 women) from over 40 institutions who took physical examination in Xuanwu Hospital of Capital Medical University between January 2014 and January 2015 were involved in this cross-sectional study. Subjects with two or more components of metabolic syndrome (MetS) were considered to have multiple risk factors. Optimal cut-off points of WHtR for cluster of metabolic risk factors were analyzed by receiver operating characteristic (ROC) curve analysis. The optimal cut-off points of WHtR were 0.51 for men and 0.49 for women. People with elevated WHtR had higher levels of metabolic risk factors. And the prevalence of individual and clusters of 5 risk factors were all higher among WHtR-defined abdominal obesity people than in normal subjects. The optimal cut-off points of WHtR were 0.51 for men and 0.49 for women. In conclusion, people with elevated WHtR are susceptible to cluster of metabolic risk factors.

Hypertriglyceridaemic waist is associated with hyperuricaemia and metabolic syndrome in rheumatoid arthritis patients

BACKGROUND

/Aim: The hypertriglyceridaemic waist (HTGW) phenotype has been described and suggested in general population as a cardiovascular risk marker. The aim of the present study was to evaluate the HTGW phenotype as a marker related to HUC and MetS in rheumatoid arthritis (RA).

MATERIALS AND METHODS

This was a cross-sectional study was designed in 250 RA Mexicans patients. The HTGW phenotype was defined as elevated waist circumference and elevated triglyceride concentration. Logistic regression analysis was used to evaluate the association between the HTGW phenotype, HUC and MetS in its traditional NCEP/ATPIII versions and modified (HTGWm and MetSm).

RESULTS

The prevalence of HTGW and HTGWm it was 20.4% and 32%, respectively. All patients with HTGW presented MetS (P < 0.001), and in a multivariate model, the HTGW phenotype was the marker most closely related to HUC in comparison to components of MetS.

CONCLUSION

The HTGW may represent a marker for screening of cardiometabolic risk in RA patients, so in clinical practice can be implemented as a low-cost marker in the evaluation of the patient regardless of clinical characteristics of disease.

Metabolic syndrome and cancer risk: The role of xanthine oxidoreductase

Obesity and related pathologies such as diabetes and metabolic syndrome are associated with chronic inflammation and cancer. The serum level of xanthine oxidoreductase (XOR) is correlated to obesity-associated metabolic disorders. XOR can play a role in the pathogenesis of both metabolic syndrome and cancer through the inflammatory response and the oxidative stress elicited by the products of its activity. The reactive oxygen and nitrogen species and the uric acid derived from XOR concur to the development of hypertension, dyslipidemia and insulin resistance and participate in both cell transformation and proliferation, as well as in the progression and metastasis process. Despite the availability of different drugs to inhibit in vivo XOR activity, the complexity of XOR inhibition effects should be carefully considered before clinical application, save in the case of symptomatic hyperuricemia.

•

Metabolic syndrome (MS) increases the risk of cancer development.

•

Xanthine oxidoreductase (XOR) plays a role in both MS and cancer.

•

Uric acid, ROS and RNS produced by XOR cause inflammation and oxidative stress.

•

Inflammation and oxidative stress contribute to the pathogenesis of MS and cancer.

•

XOR activity can be pharmacologically controlled.

Association of hyperuricemia with metabolic syndrome among university workers: sex and occupational differences

BACKGROUND

The relationship between metabolic syndrome (MetS) and hyperuricemia is not fully understood.

OBJECTIVE

To examine the association of hyperuricemia with MetS and the component of MetS that is mostly influenced by hyperuricemia among university workers.

METHODS

Anthropometric measurements, blood pressure, glucose, lipid profiles, renal function tests were measured in 1198 male and 1075 female (22-60 years old) workers on annual medical examination.

RESULTS

Hyperuricemia was 3-fold higher in males (odds ratio, OR, 2.938, 95% confidence interval, CI, 1.909-4.522, P<0.01) than females after adjustment for age, body mass index (BMI) and renal function. Overall, individuals with hyperuricemia were 3.9-fold likely to have MetS OR, 3.903; CI (2.439-6.245), P<0.01, and dyslipidemia, 2.5 times (OR, 2.501; 95% CI, 1.776-3.521, P<0.01) after adjustment for age, BMI, sex and renal function. However, no associations were found in individuals with hypertension (OR, 1.427; 95% CI, 0.996-2.205, P=0.052) and hyperglycemia (OR, 1.476; 95% CI, 0.989-2.202, P=0.057). Administrative work positively associated (OR, 1.895; 95% CI, 1.202-2.925, P<0.05) with hyperuricemia in males and not females.

CONCLUSION

Male workers with hyperuricemia, especially those working in administration were at risk of metabolic syndrome. It is important to screen, prevent and treat metabolic syndrome in individuals diagnosed with hyperuricemia at the workplace.

Baseline and changes in serum uric acid independently predict 11-year incidence of metabolic syndrome among community-dwelling women

INTRODUCTION

Metabolic syndrome (MetS) is associated with an increased risk of major cardiovascular events. In women, increased serum uric acid (SUA) levels are associated with MetS and its components. However, whether baseline and changes in SUA predict incidence of MetS and its components remains unclear.

METHODS

The subjects comprised 407 women aged 71 ± 8 years from a rural village. We have identified participants who underwent a similar examination 11 years ago, and examined the relationship between baseline and changes in SUA, and MetS based on the modified criteria of the National Cholesterol Education Program's Adult Treatment Panel (NCEP-ATP) III report.

RESULTS

Of these subjects, 83 (20.4%) women at baseline and 190 (46.7%) women at follow-up had MetS. Multiple linear regression analysis was performed to evaluate the contribution of each confounding factor for MetS; both baseline and changes in SUA as well as history of cardiovascular disease, low-density lipoprotein cholesterol, and estimated glomerular filtration ratio (eGFR) were independently and significantly associated with the number of MetS components during an 11-year follow-up. The adjusted odds ratios (ORs) (95% confidence interval) for incident MetS across tertiles of baseline SUA and changes in SUA were 1.00, 1.47 (0.82-2.65), and 3.11 (1.66-5.83), and 1.00, 1.88 (1.03-3.40), and 2.49 (1.38-4.47), respectively. In addition, the combined effect between increased baseline and changes in SUA was also a significant and independent determinant for the accumulation of MetS components (F = 20.29, p < 0.001). The ORs for incident MetS were significant only in subjects with age ≥ 55 years, decline in eGFR, and no baseline MetS.

CONCLUSIONS

These results suggested that combined assessment of baseline and changes in SUA levels provides increased information for incident MetS, independent of other confounding factors in community-dwelling women.

The role of xanthine oxidoreductase and uric acid in metabolic syndrome

Xanthine oxidoreductase (XOR) could contribute to the pathogenesis of metabolic syndrome through the oxidative stress and the inflammatory response induced by XOR-derived reactive oxygen species and uric acid. Hyperuricemia is strongly linked to hypertension, insulin resistance, obesity and hypertriglyceridemia. The serum level of XOR is correlated to triglyceride/high density lipoprotein cholesterol ratio, fasting glycemia, fasting insulinemia and insulin resistance index. Increased activity of endothelium-linked XOR may promote hypertension. In addition, XOR is implicated in pre-adipocyte differentiation and adipogenesis. XOR and uric acid play a role in cell transformation and proliferation as well as in the progression and metastatic process. Collected evidences confirm the contribution of XOR and uric acid in metabolic syndrome. However, in some circumstances XOR and uric acid may have anti-oxidant protective outcomes. The dual-face role of both XOR and uric acid explains the contradictory results obtained with XOR inhibitors and suggests caution in their therapeutic use.

Low serum uric acid concentration augments insulin effects on the prevalence of metabolic syndrome

AIM

Insulin and uric acid were shown affect the prevalence of Metabolic Syndrome (MetS), but no studies examine their interaction. Therefore, we conducted this study to determine their biological interaction in subjects from central Mexico.

METHODS

433 subjects were enrolled for a cross-sectional study. MetS was defined according to the Harmonizing Definition. Hyperuricemia was defined as ≥7.0 mg/dL in males and ≥5.8 mg/dL in females. Hyperinsulinemia was defined as ≥11.0 μU/mL. Pearson correlation coefficient (r) was calculated to determine the association between uric acid or insulin and MetS. Logistic regression was used to determine the risk (odds ratio) of developing MetS. Biological interactions were determined by the PROCESS Macro and Anderson's method.

RESULTS

Insulin and uric acid levels were elevated in MetS positive group (p < .05) and correlated with the number of MetS components (r = 0.276 and r = 0.166, p < .001, respectively). The interaction between uric acid and insulin was associated with the number of MetS components (PROCESS Model 1, interaction coefficient = -0.009, 95%CI: -0.017 to -0.001, p = .036). Johnson-Neyman analysis suggests the interaction is lost when uric acid concentration increased >7.0 mg/dL. When the cohort was separated by hyperinsulinemia and hyperuricemia, there was a significant risk of developing MetS for subjects with hyperuricemia (odds ratio = 2.3; 95%CI: 1.1-4.8, p < .05), hyperinsulinemia (odds ratio = 3.1; 95%CI: 1.9-4.9, p < .05), or both (odds ratio = 7.4; 95%CI: 3.2-17.2, p < .05); however, there was no multiplicative or additive interaction.

CONCLUSION

Here, we show that uric acid and insulin augments the prevalence of MetS; however, no biological interaction was determined for hyperuricemia and hyperinsulinemia.

Association between serum gamma-glutamyl transferase and serum uric acid levels in Chinese females: A cross-sectional study

OBJECTIVE

To investigate the association between serum gamma-glutamyl transferase (GGT) levels and serum uric acid levels in middle-aged and elderly Chinese females.

METHODS

A cross-sectional population survey was performed in Luzhou, China (2014). Questionnaires, physical examinations and biochemical tests were conducted. Finally, we included 2486 females who were > 40 years old as participants. Multiple linear regression analysis was used to estimate the association of serum acid levels and other variables. Serum GGT levels were divided into four groups using the 25th, 50th and 75th percentiles as cut-off points. Finally, binary logistic regression analysis was used to investigate the association of different serum GGT quartiles with the risk of hyperuricemia.

RESULTS

The prevalence of hyperuricemia was 25.1% in the studied population and gradually increased across the serum GGT quartiles (P < 0.05). Binary logistic regression analysis showed that compared with subjects in the lowest quartile of serum GGT levels, the adjusted odds ratio (ORs) for uric acid in the highest quartile was 2.34 (95% confidence interval (CI), 1.68-3.28, P < 0.001),after corrections for TG, TC, HDL-C, LDL-C, creatinine (CR), GGT, AST, ALT, fasting plasma glucose (FPG), postprandial 2-h plasma glucose, hemoglobin A1c(HbA1c), age, BMI, SBP, DBP, waist-to-hip ratio and neck circumference (NC).

CONCLUSIONS

The serum GGT level is associated with hyperuricemia in middle-aged and elderly Chinese females.

Lipidomics to investigate the pharmacologic mechanisms of ginkgo folium in the hyperuricemic rat model

Hyperuricemia caused by purine metabolic abnormalities is reported to have close correlation with lipid metabolic disorders. Ginkgo folium, a frequently-used lipid-lowering medicine, has significant anti-hyperuricemia effects. However, it is poorly known about the interaction between lowering uric acid and regulation of lipid metabolic disorders. In this study, hyperuricemic rat model was induced by orally administration with fructose. Ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) combined with pattern recognition approaches were used to determine different lipid metabolites in serum of control group, model group, and different doses of ginkgo folium groups. Principal component analysis (PCA) was applied to analyze the MS data to assess the establishment of model, partial least squares-discriminate analysis (PLS-DA) and independent samples T-test were performed to indicate the differences between different groups of rats and to find biomarkers. Metabolomics pathway analysis (MetPA) was introduced to reveal the pharmacologic mechanisms of ginkgo folium. 19 potential biomarkers associated with hyperuricemia were found. After intervened by ginkgo folium, these biomarkers were returning to normal level. Among these biomarkers, 13 lipid biomarkers were significantly reversed. Ginkgo filum can lower uric acid via adjusting back the level of PCs and LPCs, which suggested that its treatment mechanisms may be related to reducing the activity of PLA2. In sum, the lipidomics analysis in the system level have enhanced our understanding to pathogenesis of hyperuricemia and the results suggested that ginkgo folium could alleviate the abnormal metabolic status of hyperuricemia. These results demonstrated a new mechanism for lowering uric acid, which was helpful to the early treatment for hyperuricemia.

An observational study on the relationship between serum uric acid and hypertension in a Northern Chinese population aged 45 to 59 years

Little is known about the relationship serum uric acid (SUA) and hypertension in Chinese population. Therefore, the aim of this study was to determine the association between SUA and hypertension in a northern Chinese population. The participants were a group of 1730 Chinese adults aged 45 to 59 years in Shandong Province, who were recruited from the Linyi Nutrition and Health Survey (2015-2016). Hypertension was defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg. Hyperuricemia was defined as SUA >420 μmol/L (7.0 mg/dL) for men and >360 μmol/L (6.0 mg/dL) for women. All anthropometric measurements and biochemical data were collected following standard protocols. Multivariate logistic regression analysis was used to examine the association between SUA and hypertension with adjustment of confounding variables. Body mass index, waist circumference, waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triglycerides, alanine aminotransferase, aspartate aminotransferase, SUA, and the prevalence of hypertension and hyperuricemia were significantly higher in males than in females (P < .001). The females had significantly higher levels of total cholesterol and high-density lipoprotein cholesterol. Besides, after adjustment for confounding variables, hyperuricemia was associated with an increased risk of hypertension in both male and female patients, with odds ratios of 2.152 (95% confidence interval 1.324-3.498) and 2.133(95% confidence interval 1.409-3.229), respectively.Hyperuricemia was significantly associated with the risk of hypertension. Further longitudinal studies and trails are needed to confirm our findings.

The waist circumference-adjusted associations between hyperuricemia and other lifestyle-related diseases

BACKGROUND

Few studies have assessed the associations between hyperuricemia and lifestyle-related diseases after adjusting for waist circumference (WC) and sex.

METHODS

This cross-sectional study included 33,498 Japanese individuals, and was conducted at the Center for Preventive Medicine, NTT Kanto Medical Center, Tokyo, from May 2006 to March 2015. Hyperuricemia was defined as a uric acid level of >7 mg/dl in men; >6 mg/dl in women. Metabolic syndrome (Mets) components were defined using the Japanese criteria for Mets. The subjects were stratified into quartiles according to their WC as follows: males: <78.4, 78.4 to <83.5, 83.5 to <89, and ≥89 cm; females: <71.6, 71.6 to <77, 77 to <83.2, and ≥83.2 cm. The relationships between these quartiles and the presence of ≥2 components of Mets or hyperuricemia were then evaluated using Chi square analysis. The presence of ≥2 components of Mets were then determined using multivariate logistic regression analysis adjusting for age, the presence of hyperuricemia, WC, and lifestyle habits.

RESULTS

Hyperuricemia was found to be an independent predictor of lifestyle-related diseases after adjusting for age, WC, and lifestyle in both sexes. Males: a uric acid level of >7 mg/dl (odds ratio [OR]: 1.70, 95% confidence interval [CI]: 1.57-1.83), Females: a uric acid level of >6 mg/dl (OR: 2.35, 95% CI 1.83-2.99).

CONCLUSION

Hyperuricemia was found to be an independent predictor of several lifestyle-related diseases, even after adjusting for WC which is closely related with insulin resistance. Hyperuricemia might require greater attention during the prevention of lifestyle-related diseases and future cardiovascular disease.

Baseline and Change in Uric Acid Concentration Over Time Are Associated With Incident Hypertension in Large Korean Cohort

BACKGROUND

It is uncertain whether high-baseline uric acid (UA) or change in UA concentration over time is related to development of incident hypertension. To investigate relationships between: (i) baseline serum UA concentration and (ii) change in UA concentration and incident hypertension.

METHODS

About 96,606 Korean individuals (with follow-up UA data available for 56,085 people) participating in a health check program was undertaken. Cox regression models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for incident hypertension according to UA quartiles regarding the lowest UA quartile as the reference, and also according to change in UA concentration comparing individuals with an increase in UA to those with a decrease in UA concentration over time.

RESULTS

Total follow up time was 8 years (median follow-up 3.3 years; interquartile range, 1.9-5.1). About 10,405 cases of incident hypertension occurred. In the fully adjusted regression models, the HRs (95% CI) for incident hypertension comparing the highest vs. the lowest quartiles of UA were 1.29 (1.19-1.38) in men and 1.24 (1.09-1.42) in women, with statistically significant P for trend for both gender. Additionally, stable or increasing UA concentration over time was associated with increased risk of incident hypertension, particularly in participants with baseline UA concentration ≥median (aHRs 1.14; 95% CI (1.03-1.26) and 1.18; 95% CI (0.98-1.40) in men and women, respectively).

CONCLUSIONS

High initial UA concentration and increases in UA concentration over time should be considered independent risk factors for hypertension.

The Role of Uric Acid for Predicting Future Metabolic Syndrome and Type 2 Diabetes in Older People

OBJECTIVE

Although it is known that high uric acid (UA) level is associated with type 2 diabetes (T2DM) and metabolic syndrome (MetS), most of the previous studies were focused on adults. Since aging becomes a major problem for many societies, in this longitudinal study, we investigated the role of UA in future T2DM and MetS in a large cohort of people who were older than 65 years.

DESIGN

A cross-sectional and longitudinal study.

SETTING/PARTICIPANTS

18,907 elderly (9,732 men, 9,175 women) aged above 65 years, enrolled from health check-up centers, were classified into three subgroups by 10-year intervals (young old 65-74 years, YO; old old 75-84 years, OO; and oldest old 85-94 years, ODO), with the average follow-up period of 4.3 years.

MEASUREMENTS

The optimal cut-off values (CoVs) of baseline UA to predict future MetS and T2DM were determined by receiving operating characteristic (ROC) curve analysis. Using these CoVs of UA, the participants were divided into normal- and high-level groups of UA. Cox proportional hazard analysis was used to calculate hazard ratios (HRs) for the subjects with a high level of UA for the risk of future MetS and T2DM. In addition, Kaplan-Meier plots and log rank test were used to evaluate the time effect on the incidence of developing MetS and T2DM between the two groups.

RESULTS

In ROC curve analysis, the optimal CoVs of baseline UA were 6.0, 6.3 and 6.7 mg/dl in YO, OO, and ODO men, respectively; 5.5 and 4.9 mg/dl in YO and OO women, respectively (all p < 0.05). However, the CoVs of UA in ODO women (6.1 mg/dl) failed to show its discriminant power (p = 0.13). The Cox regression analysis showed the YO subjects with a higher baseline level of UA had a higher risk of developing MetS (HRs 1.56 and 1.58 for men and women, respectively, both p < 0.001); as for T2DM the HRs were 1.39 and 1.57. In OO men, the HRs was 1.89 for developing future MetS. However, no significant findings could be noted in the ODO group. Kaplan-Meier plots and log rank test also showed the same findings.

CONCLUSION

Our study showed that old subjects with high levels of UA will have a higher chance to have MetS and T2DM, particularly in the YO group (6.0 mg/dl for men and 5.5 mg/dl for women, respectively). Using UA as one of the metabolic biomarkers may help clinicians to early detect and prevent MetS and diabetes.

Elevation of serum uric acid and incidence of type 2 diabetes: A systematic review and meta-analysis

Objective

Recently, several cohort studies suggested a positive relationship between serum uric acid (SUA) and type 2 diabetes mellitus (T2DM), which is inconsistent with the results of functional research. Our aim was to further evaluate this correlation by conducting a systematic review.

Methods

Computerized literature searches of the Medline database, EMBASE database, and PubMed were used to evaluate the relationship between SUA and T2DM in cohort studies. Cochran's Q and I² statistics were used to evaluate heterogeneity among studies, and pooled relative risk (RR) and odds ratio (OR) with 95% confidence intervals (CIs) were calculated using random-effects and fixed-effects models. The summary RR and OR of per 1 mg/ml-SUA increase were calculated separately because of their different epidemiological implications and calculation methods. Additionally, sensitivity analysis, stratified analysis, meta-regression, and multiple meta-regression were applied to investigate the heterogeneity among studies.

Results

A total of 970 articles were retrieved from the searches. Sixteen publications of cohort studies containing 61,714 participants were included. The pooled RR was 1.131 (95% CI: 1.084–1.179) with significant heterogeneity among studies (I² = 51.9%, P = 0.018). Adjusted RR to evaluate the stability of the relationship between SUA and T2DM in the sensitivity analysis was similar (RR = 1.140, 95% CI: 1.087–1.197), with statistically significant heterogeneity (I² = 54.5%, P = 0.015). Stratified analysis and meta-regression showed that the positive relationship remained irrespective of age, sex, region, and adjustment for confounding factors including body mass index, fasting blood glucose, systolic blood pressure, diastolic blood pressure, alcohol consumption, smoking, blood cholesterol, waist circumference, fatty liver, and drugs affecting SUA.

Conclusion

Although SUA is independently associated with development of T2DM, insulin resistance increased as the baseline SUA concentration increased; thus, the correlation between SUA and T2DM requires further evaluation and the baseline insulin resistance status should also be considered.

Elevated serum uric acid and risk of cardiovascular or all-cause mortality in people with suspected or definite coronary artery disease: A meta-analysis

BACKGROUND AND AIMS

Serum uric acid (SUA) has been recognized as an independent risk factor for mortality in the general population. We performed this meta-analysis to determine whether elevated SUA levels are associated with greater risk of cardiovascular or all-cause mortality in people with suspected or definite coronary artery disease (CAD).

METHODS

The Pubmed and Embase databases were searched up to April 1, 2016 for the longitudinal studies that investigated the association between the elevated SUA and cardiovascular or all-cause mortality risk in people with suspected or definite CAD. Pooled adjusted risk ratio (RR) and corresponding 95% confidence interval (CI) were calculated for the highest vs. the lowest SUA category or each 1 mg/ml SUA rise.

RESULTS

Nine studies enrolling 25,229 participants were included in the analyses. The highest vs. lowest SUA category was associated with greater risk of cardiovascular mortality (RR 2.09; 95% CI: 1.45-3.02) and all-cause mortality (RR 1.80; 95% CI: 1.39-2.34) after adjustment for potential confounders in a random effects model. Moreover, each 1 mg/ml SUA rise significantly increased by 12% cardiovascular mortality and by 20% all-cause mortality.

CONCLUSIONS

Elevated SUA levels are strongly and independently associated with greater risk of cardiovascular and all-cause mortality in people with suspected or definite CAD.

Serum uric acid: A strong and independent predictor of metabolic syndrome after adjusting for body composition

BACKGROUND

Some observational studies have suggested that serum uric acid (SUA) levels are one of the determinants of the metabolic syndrome (MetS). However, previous studies reported combined results for men and women after adjusting for sex and few studies take body composition into consideration. Therefore, we performed this sex-specific longitudinal study to investigate how baseline SUA levels influence incident MetS, including body composition as an adjusting factor in a large number of subjects.

METHODS

A total of 14,442 participants (8715 men and 5727 women) participating in a medical health check-up program without diagnosed MetS at baseline were enrolled. Separate analyses were performed for men and women including body composition as a confounding factor. Cox proportional hazards models were used to quantify independent associations between SUA levels and incident MetS.

RESULTS

During 63,940person-years of follow-up, there were 4215 (2974 men, 1241 women) incident cases of MetS between 2006 and 2012. After adjustments for age, systolic BP, diastolic BP, BMI, eGFR, smoking status, TG, LDL-C, HDL-C, fasting glucose, and proportion of fat-free mass (100-fat mass, %), the hazard ratios (HR) [95% confidence interval (CI)] for incident MetS comparing the second, the third, and the fourth quartiles to the first quartile of SUA levels were 0.862 (0.770-0.965), 1.102 (0.991-1.225), and 1.246 (1.121-1.385) in men (p for trend<0.001), and 1.045 (0.862-1.266), 1.251 (1.050-1.490), and 1.321 (1.109-1.574) in women (p for trend<0.001), respectively. As a continuous variable, in fully-adjusted models, the HRs (95% CI) for incident MetS associated with each increase of 1mg/dl of SUA levels were 1.094 (1.060-1.130) in men (p<0.001) and 1.148 (1.072-1.228) in women (p<0.001), respectively.

CONCLUSION

We demonstrated that SUA levels are strong and independent predictors of MetS. This relationship remained significant after full adjustments for multiple associated confounders including body composition in both men and women.

Cardiometabolic risk in young adults from northern Mexico: Revisiting body mass index and waist-circumference as predictors

BACKGROUND

A body mass index (BMI) ≥30 kg/m(2) and a waist circumference (WC) ≥80 cm in women (WCF) or ≥90 cm in men (WCM) are reference cardiometabolic risk markers (CMM) for Mexicans adults. However, their reliability to predict other CMM (index tests) in young Mexicans has not been studied in depth.

METHODS

A cross-sectional descriptive study evaluating several anthropometric, physiological and biochemical CMM from 295 young Mexicans was performed. Sensitivity (Se), specificity (Sp) and Youden's index (J) of reference BMI/WC cutoffs toward other CMM (n = 14) were obtained and their most reliable cutoffs were further calculated at Jmax.

RESULTS

Prevalence, incidence and magnitude of most CMM increased along the BMI range (p < 0.01). BMI explained 81 % of WC's variance [Se (97 %), Sp (71 %), J (68 %), Jmax (86 %), BMI = 30 kg/m(2)] and 4-50 % of other CMM. The five most prevalent (≥71 %) CMM in obese subjects were high WC, low HDL-C, and three insulin-related CMM [Fasting insulin, HOMA-IR, and QUICKI]. For a BMI = 30 kg/m(2), J ranged from 16 % (HDL-C/LDL-C) to 68 % (WC), being moderately reliable (Jmax = 61-67) to predict high uric acid (UA), metabolic syndrome (MetS) and the hypertriglyceridemic-waist phenotype (HTGW). Corrected WCM/WCF were moderate-highly reliable (Jmax = 66-90) to predict HTGW, MetS, fasting glucose and UA. Most CMM were moderate-highly predicted at 27 ± 3 kg/m(2) (CI 95 %, 25-28), 85 ± 5 cm (CI 95 %, 82-88) and 81 ± 6cm (CI 95 %, 75-87), for BMI, WCM and WCF, respectively.

CONCLUSION

BMI and WC are good predictors of several CMM in the studied population, although at different cutoffs than current reference values.

Comparison of the effect of high fruit and soybean products diet and standard diet interventions on serum uric acid in asymptomatic hyperuricemia adults: an open randomized controlled trial

The aim of this study was to compare the effect of high fruit and soybean products diet and standard diet interventions on serum uric acid (SUA) in asymptomatic hyperuricemia adults. A total of 187 Chinese adults (20-59 years old) with asymptomatic hyperuricemia participated in this randomized trial and were assigned to receive the standard diet recommended by guideline (group 1) and high fruit and soybean products diet (group 2) for 3 months. The outcome of SUA was assessed before and at the end of the intervention period. After 3 months, the SUA in group 1 and group 2 was significant reduced, whereas the SUA was not significantly changed in-between groups. These data suggest that over a 3-month period, although the high fruit and soybean products diet and standard diet interventions yield no different effects on SUA, the high fruit and soybean products dietary intervention could be an effective alternative to a standard diet for achieving clinically important reductions in SUA for asymptomatic hyperuricemia patients.

The Power of Serum Uric Acid in Predicting Metabolic Syndrome Diminishes With Age in an Elderly Chinese Population

OBJECTIVES

Although serum uric acid (sUA) is not a criterion for diagnosing metabolic syndrome (MetS), many studies have identified a positive association between sUA and MetS in patients of various ages and ethnicities. This association has not been fully established in the very elderly.

DESIGN

Cross-sectional and longitudinal study.

SETTING AND PARTICIPANTS

A total of 18,906 Chinese elderly aged 65 and older undergoing routine health checkups in Taiwan were enrolled.

MEASUREMENTS

Modified Adult Treatment Panel III criteria were used to define MetS. All participants were further divided into nine groups with gender specification according to age (the young-old, 65 to 74; old-old, 75 to 84; and oldest-old, 85 and over) and sUA concentration tertile (males: sUAG1, <5.7 mg/dL; sUAG2, 5.7-6.7 mg/dL; and sUAG3, > 6.7 mg/dL; females: sUAG1, <4.9 mg/dL; sUAG2, 4.9-5.9 mg/dL; and sUAG3, > 5.9 mg/dL). A cross-sectional study was first performed to determine the correlation between sUA and MetS and its components. A longitudinal study then excluded subjects with MetS at baseline to explore the risk of MetS according to sUA levels in 3 age groups.

RESULTS

In the cross-sectional study, we observed a graded, positive association between sUA and MetS components that diminished after age 75. Subjects with higher sUA levels had higher odds ratios (OR) for the occurrence of MetS in the young-old and old-old groups of both sexes (P<0.001) except sUAG2 males in the old-old group. However, the association diminished with age and only a higher OR was observed in sUAG2 males in the oldest-old group (OR, 3.38; 95% CI, 1.11-10.30; P = 0.032). In the longitudinal study, the Kaplan-Meier plot showed that higher sUA levels were associated with a higher risk of MetS in the young-old group of both genders (P < 0.001 sUAG3 vs. sUAG1 and sUAG2). Cox regression analysis further confirmed these results (young-old group: sUAG3 HR, 1.90; 95% CI, 1.42-2.54; P < 0.001; old-old group males: HR, 2.20; 95% CI, 1.04-4.65; P = 0.039; young-old females: HR, 1.83; 95% CI, 1.38 - 2.43; P < 0.001).

CONCLUSIONS

Higher sUA levels in the young-old group of Chinese elderly were associated with a higher risk of developing MetS. sUA levels are thus regarded as a potential tool for early diagnosis of MetS. However, this association diminished in those over 75 years of age.

High serum uric acid levels increase the risk of metabolic syndrome in elderly women: The PRO.V.A study

BACKGROUND AND AIMS

Serum uric acid (SUA) is the end-product of purine metabolism in humans, and its levels often increase in subjects with metabolic syndrome (MetS). Despite several studies demonstrating a relationship between increased SUA levels and the prevalence of MetS, prospective data on SUA as a predictor of the incidence of MetS in the elderly are limited. Our aim was to conduct a prospective study on the association between SUA concentrations and the onset of MetS in an elderly Italian cohort.

METHODS AND RESULTS

This is a cohort study (Progetto Veneto Anziani; Pro.V.A.) involving community-dwelling subjects aged ≥65 years and followed up for a mean 4.4 years. We included 1128 participants (aged 74.7 ± 7.1 years) without MetS at the baseline. Gender-specific SUA groups according to the standard deviation (SD) from the mean were considered, taking the incidence of MetS as the main outcome. The mean SUA level was significantly higher in men than in women (5.4 ± 1.2 vs. 4.5 ± 1.2 mg/dl; p < 0.0001). Over the 4.4-year follow-up, 496 individuals developed MetS. After adjusting for potential confounders, Cox's regression analysis revealed no relationship between higher baseline SUA concentrations and the incidence of MetS in men or in the sample as whole, while women with SUA levels more than 1 SD above the mean (≥5.7 mg/dl) carried a 58% higher risk (95%CI: 1.03-2.40; p = 0.03) of being newly diagnosed with MetS during the follow-up.

CONCLUSION

High SUA levels significantly and independently predicted MetS in older women, but not in men, over a 4.4-year follow-up.

Hemoglobin concentration and incident metabolic syndrome: a population-based large-scale cohort study

Previous cross-sectional studies revealed an association between hemoglobin concentration and a prevalence of metabolic syndrome (MetS). However, the association between hemoglobin concentration and incident MetS remains to be elucidated. Thus, the aim of this study was to investigate the association between hemoglobin concentration and incident MetS. We enrolled 2695 subjects (1454 men and 1241 women) and performed 8-year follow-up cohort study. MetS was diagnosed, according to the joint interim statement, when a subject had three or more of the following components: hypertension; hyperglycemia; hypertriglyceridemia; low high-density lipoprotein cholesterol; and abdominal obesity. Logistic regression analyses were performed to assess the impact of hemoglobin concentration on incident MetS by adjusting for age, body mass index, lifestyle factors, including smoking status, habit of alcohol and habit of exercise, systolic blood pressure, fasting plasma glucose, triglycerides, high-density lipoprotein cholesterol, creatinine, and uric acid. The highest (≥157 g/L) and third (151-156 g/L) hemoglobin concentration quartiles were associated with the increased risk of incident MetS compared to the lowest (<145 g/L) hemoglobin concentration quartile after adjusting for covariates in men (multivariate odds ratio (OR) 2.24, 95% CI 1.34-3.85, P = 0.0021 and multivariate OR 2.03, 95% CI 1.21-3.45, P = 0.0070). On the other hand, there was no association between hemoglobin concentration and incident MetS in women. Hemoglobin concentration was a novel risk marker for incident MetS in men.

Dose-response Relationship of Serum Uric Acid with Metabolic Syndrome and Non-alcoholic Fatty Liver Disease Incidence: A Meta-analysis of Prospective Studies

Emerging evidence has shown that serum uric acid (SUA) elevation might cause metabolic derangements, including metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD); however, magnitude of the risk has not been quantified. We searched PubMed, EMBASE, and ISI databases for relevant studies through 10 May 2015. Prospective studies reporting the risk of SUA elevation on the incidence of MetS/NAFLD were enrolled. Pooled HR of MetS was 1.55 (95%CI: 1.40-1.70) for the highest versus lowest SUA categories, and 1.05 (95%CI: 1.04-1.07) per incremental increased in SUA of 1 mg/dl. The pooled HR of MetS in younger women was higher than age-matched men and older women (1.17 vs. 1.05 and 1.04, respectively, P < 0.05). Individuals in the highest SUA category had a 40% greater risk of disease NAFLD occurrence. Dose-response increment of NAFLD events was 1.03 (95%CI: 1.02-1.05). A positive relationship with a linear trend for SUA elevation with MetS and NAFLD in different genders was examined by a dose-response meta-analysis (P < 0.001).SUA assay is useful in screening metabolic disorders for linear trend between its elevation and MetS/NAFLD incidence. SUA-lowering therapy is a potential strategy for preventing systemic/hepatic metabolic abnormalities.

Clopidogrel resistance response in patients with coronary artery disease and metabolic syndrome: the role of hyperglycemia and obesity

BACKGROUND

Despite the proven benefits of clopidogrel combined aspirin therapy for coronary artery disease (CAD), CAD patients with metabolic syndrome (MS) still tend to have coronary thrombotic events. We aimed to investigate the influence of metabolic risk factors on the efficacy of clopidogrel treatment in patients with CAD undergoing percutaneous coronary intervention (PCI).

METHODS

Cohorts of 168 MS and 168 non-MS subjects with CAD identified by coronary angiography (CAG) were enrolled in our study. MS was defined by modified Adult Treatment Panel III criteria. All subjects had taken 100 mg aspirin and 75 mg clopidogrel daily for more than 1 month, and administered loading doses of 600 mg clopidogrel and 300 mg aspirin before PCI. Blood samples were taken 24 h after the loading doses of clopidogrel and aspirin. Platelet aggregation was measured using light transmittance aggregometry (LTA) and thrombelastography (TEG). Clopidogrel resistance was defined as more than 50% adenosine diphosphate (ADP) induced platelet aggregation as measured by TEG.

RESULTS

Platelet aggregation inhibition rate by ADP was significantly lower in patients with MS as measured both by TEG (55% ± 31% vs. 68% ± 32%; P < 0.001) and LTA (29% ± 23% vs. 42% ± 29%; P < 0.001). In the multivariate analysis, elderly [OR (95% CI): 1.483 (1.047-6.248); P = 0.002], obesity [OR (95% CI): 3.608 (1.241-10.488); P = 0.018], high fasting plasma glucose level [OR (95% CI): 2.717 (1.176-6.277); P = 0.019] and hyperuricemia [OR (95% CI): 2.583 (1.095-6.094); P = 0.030] were all statistically risk factors for clopidogrel resistance. CAD patients with diabetes and obesity were more likely to have clopidogrel resistance than the CAD patients without diabetes and obesity [75% (61/81) vs. 43% (67/156); P < 0.001].

CONCLUSIONS

CAD patients with MS appeared to have poorer antiplatelet response to clopidogrel compared to those without MS. Obesity, diabetes and hyperuricemia were all significantly associated with clopidogrel resistance.

Nonpharmacological Management of Gout and Hyperuricemia: Hints for Better Lifestyle

We reviewed lifestyle factors that influence serum uric acid levels and risk of gout flare, and how to improve their deleterious effects. Since obesity increases uric acid and weight gain increases gout risk, weight reduction by daily exercise and limiting intake of excess calories is recommended. However, strenuous exercise, which causes adenine nucleotide degradation; starvation, which decreases uric acid excretion; and dehydration may raise the level of uric acid in serum and trigger gout. Increased intake of purine-rich foods, such as meat and seafood, raise the level of uric acid in serum and is associated with increased risk of gout, whereas dairy products, especially low-fat types, are associated with a lower risk of gout. Also, heavy alcohol drinking raises the uric acid level and increases the risk of gout through adenine nucleotide degradation and lactate production. Sweet fruits and soft drinks containing fructose should be moderated, since fructose may raise uric acid and increase gout risk through uric acid production and/or decreased excretion. On the other hand, the Mediterranean diet is recommended for gout patients, since it may also help prevent hyperuricemia. Furthermore, coffee and vitamin C supplementation could be considered as preventive measures, as those can lower serum uric acid levels as well as the risk of gout.