Uric acid and cardiovascular risk

HepG2 cells do not express xanthine oxidoreductase (XOR): Implications for XOR and uric acid-related research

Although the relative extent of xanthine oxidoreductase (XOR) varies considerably in human tissues, the greatest specific activity is reported in the liver and intestines. Unlike murine models, where primary hepatocytes are readily available, human counterparts are not. As such, investigators often utilize the human carcinoma cell line HepG2 for in vitro experimentation as these cells proliferate well in culture medium. Some of the studies using HepG2 cells for proof-of-principal experimentation focus on uric acid (UA) and/or XOR activity. However, it has been reported that hepatocellular carcinoma diminishes XOR expression to nearly unmeasurable levels when compared to normal cell counterparts which posits the question of validity in the context of using HepG2 cells for XOR/UA assessments. As such, we closely examined XOR expression, protein abundance, and enzymatic activity in HepG2 cells and compared these results to an immortalized murine hepatocyte line (AML12) as well as murine liver homogenate. We report the absence of detectable XOR message, protein, and enzymatic activity in HepG2 cells. Since cellular XOR expression has been reported to be stimulated by hypoxia and serum starvation, we then exposed both AML12 and HepG2 cells to hypoxia (1% O2) for 24 h or serum starvation which impacted XOR activity in AML12 cells, but not in HepG2 cells. Knowing that several studies report XOR activity in HepG2 cells, we compared a commonly used non-selective XOR assay kit to our sensitive and selective HPLC/electrochemical assay. The kit assay indicated XOR activity in HepG2 cells; however, XOR inhibition did not diminish this activity. To account for alternative enzymatic oxidization of hypo/xanthine to UA, we investigated HepG2 cells for aldehyde oxidase (AO) abundance and found immunodetectable AO protein as well as AO-inhibitable conversion of hypoxanthine to UA; albeit, at a much slower rate when compared to XOR. In toto, these data confirm that HepG2 cells do not demonstrate XOR activity and thus commonly used kit assays for XOR, in the absence of XOR inhibitor controls, may indicate a positive response induced by an alternative source of peroxide and UA such as AO.

Unraveling the effects of uric acid on endothelial cells: A global proteomic study

This work aims to understand how normouricemic levels of uric acid can induce endothelial dysfunction seeking global proteomic alterations in Human Umbilical Vein cells (HUVEC). It reveals significant alterations in redox-sensitive and antioxidant proteins, chaperones, and proteins associated with cell migration and adhesion in response to uric acid exposure. Monitoring cellular oxidation with the roGFP2-Grx1 probe proved increased oxidation levels induced by uric acid, which can be attenuated by peroxidasin (PXDN) inhibition, suggesting a regulatory role for PXDN in mitigating oxidative stress induced by uric acid. As a consequence of uric acid oxidation and the formation of reactive intermediate, we identified adducts in proteins (+140 kDa) in a novel post-translation modification named uratylation. Increased misfolded protein levels and p62 aggregation were also found, indicating disturbances in cellular proteostasis. Furthermore, uric acid promoted monocyte adhesion and upregulated ICAM and VCAM protein levels, implicating a pro-inflammatory response in endothelial cells. These findings provide critical insights into the molecular mechanisms underlying vascular damage associated with uric acid.

Gut microbiota contribute to cold adaptation in mammals-primates and ungulates

Gut microbiota play an influential role in how animals adapt to extreme environments. Two phylogenetically distant mammals, Yunnan snub-nosed monkey and reindeer both adapted to frigid environments. Metagenomic analyses revealed they developed similar cold adaptation strategies in response to food scarcity (enhanced fiber degradation and nitrogen balance maintenance), energy shortages (increased short-chain fatty acid [SCFA] synthesis), and a constant body temperature sustainment (stimulation of non-shivering thermogenesis [NST]). Moreover, they evolved distinct adaptation strategies to cope with different cold ecosystems. Yunnan snub-nosed monkey adapt to high-altitude hypoxia environment through enhancing ability to synthesize lactate and metabolize purine, while reindeer adapt to extreme cold environment through increasing blood flow, strengthening urea cycling, and enriching fat storage associated bacteria. Notably, reindeer microbiota uniquely enriched cholesterol-degrading bacteria, potentially mitigating cardiovascular risks from lipid storage. Our study expands the knowledge of how gut microbiome promotes cold adaptation through shared and specialized mechanisms shaped by different phylogenetic and ecological contexts.

Urate-lowering effect of delphinidin-3-glucoside in red kidney beans via binding to the FAD site of the XO enzyme

BACKGROUND

The incidence of hyperuricemia (HUA) is increasing globally, posing serious health risks. The discovery of natural urate-lowering agents is urgently needed.

OBJECTIVE

To discover natural urate-lowering agents and investigate their effect and action mechanisms for ameliorating HUA.

METHODS

Our study comprehensively explored the association between the intake of 13 specific legume varieties in the US population. A composition-target-metabolic (C-T-M) pathway network was constructed to identify key agents and their interactions with key proteins, which were verified by molecular dynamics simulations (MD) and surface plasmon resonance (SPR). Biochemical, in vitro, and in vivo metabolomic studies in male ICR mice were conducted to examine the effects of the key agent in red kidney beans on uric acid production and other metabolisms.

RESULTS

We found that consuming red kidney beans was robustly negatively associated with the risk of HUA. Based on the C-T-M network, delphinidin-3-glucoside (Dp-3G) was identified as the key agent in red kidney beans, focusing on its binding to xanthine oxidase (XO) enzyme. This interaction was subsequently verified by MD and SPR, revealing that Dp-3G binds to the FAD site of the XO enzyme, thereby blocking electron transfer during enzyme catalysis involving Moco, [2Fe-2S], and FAD. Dp-3G consistently reduces uric acid production under biochemical, in vitro, and in vivo conditions and reverses metabolic abnormalities related to HUA in mice, including methionine, proline, and folate.

CONCLUSIONS

This study identifies Dp-3G, a novel natural agent enriched in red kidney beans, as capable of occupying the FAD site of the XO enzyme, thereby interfering with uric acid synthesis, and suggesting its potential for preventing and treating HUA.

Correlation between obesity-related indices and hyperuricemia among the elderly population in China: A cross-sectional study

Hyperuricemia (HUA), a key risk factor for gout and cardiometabolic diseases, is underdiagnosed in elderly populations due to limited serum uric acid (SUA) testing in routine blood panels. Identifying noninvasive obesity-related indices for HUA could enhance early risk stratification, particularly in resource-constrained settings. This study evaluates the correlation and predictive performance of 6 obesity indices for HUA in Chinese elderly adults. A cross-sectional analysis of 8362 adults aged ≥ 65 years was conducted using 2021 health examination data from Guangdong, China. Multivariable logistic regression evaluated associations between obesity indices - Body Mass Index (BMI), Waist-to-Height Ratio (WHtR), Body Roundness Index (BRI), Weight-Adjusted-Waist Index (WWI), A Body Shape Index (ABSI), and Cardiometabolic Index (CMI) - and HUA. Receiver Operating Characteristic (ROC) curves with DeLong's test compared differences in Area Under the Curve (AUC). HUA prevalence was 48.62%, higher in females (53.07%) than males (43.20%). Adjusted for confounders, all indices showed significant associations: BMI (OR = 1.106, 95% CI = 1.090-1.121), WHtR (OR = 1.056 per 0.01-unit, 95% CI = 1.047-1.064), BRI (OR = 1.204, 95% CI = 1.173-1.236), WWI (OR = 1.185, 95% CI = 1.120-1.253), ABSI (OR = 1.083 per 0.01-unit, 95% CI = 1.002-1.171), and CMI (OR = 1.606, 95% CI = 1.488-1.735). CMI demonstrated the highest AUC (0.645, 95% CI = 0.633-0.656), significantly outperforming BMI, WHtR, BRI, WWI, and ABSI (DeLong's P < .001). WHtR (AUC = 0.621, 95% CI = 0.609-0.633) and BRI (AUC = 0.619, 95% CI = 0.608-0.631) showed comparable performance (P = .386). While CMI had superior predictive accuracy, its reliance on blood lipids limits practicality for routine screening. WHtR and BRI - requiring only waist circumference and height - offer optimal balance between performance and clinical feasibility, especially in primary care settings lacking laboratory infrastructure. These noninvasive tools could complement SUA testing to improve HUA risk assessment in elderly populations.

The exploration of the relationship between hyperuricemia, gout and vitamin D deficiency

Our study aims to provide evidence concerning the relationship between hyperuricemia, gout and Vitamin D deficiency by analyzing data from Peking Union Medical College Hospital (PUMCH), the National Health and Nutrition Examination Survey (NHANES) database, and through Mendelian randomization (MR) analyses. Sample 1 involved patients from PUMCH (n = 13,532), and sample 2 involved participants from NHANES (Unweighted n = 22,860; weight n = 182,829,142). Logistic regression and restricted cubic spline analyses were applied to assess above relationship. A two-sample MR analysis was performed using the genome-wide association study summary statistics to identify the causal association between gout and 25-hydroxyvitamin D (25(OH)D). The results from both samples confirmed a positive correlation among hyperuricemia, gout and risk of Vitamin D deficiency. The restricted cubic spline showed positive dose-response relationship between uric acid and risk of Vitamin D deficiency and the minimal threshold of uric acid at 307.5 umol/L and 316.1 umol/L, respectively. Mediation analysis in the sample 2 found that about 29.4% of the total effect of gout on Vitamin D deficiency were mediated by serum uric acid, and 37.1% of which were mediated by body mass index.The results of our MR analysis supported a causal association between gout (IVW β(SE), -0.843 (0.337); P = .0123) and 25(OH)D. Sensitivity analysis and genetic risk scores approach confirmed the robustness and reliability of the above findings. Hyperuricemia and gout are both strong indicators of increased risk of Vitamin D deficiency. Findings highlight the causal effects of gout-associated genetic variants on 25(OH)D.

Clinical implications of longitudinally assessed uric acid in heart failure

BACKGROUND AND AIMS

Numerous studies have evaluated the association between baseline uric acid (UA) and heart failure (HF) outcomes. The impact of longitudinal UA on HF survival remains unknown. We aim to investigate the association between different parameterizations of longitudinal UA measurements and survival outcomes in HF patients.

METHODS AND RESULTS

We retrospectively included patients hospitalized for HF with multiple repeated UA measurements. Joint models were fitted to assess the longitudinal association between UA and outcomes of all-cause and cardiovascular (CV) death. The study included 1596 patients (mean age 54 years, 26.9 % women) with 7875 UA measurements. During a median follow-up of 34.7 months, 330 all-cause deaths occurred, among them 280 of CV causes. After adjusting for clinically relevant covariates, every doubling of UA at any time led to a 5.14-fold increase of all-cause death risk (95 % confidence interval [CI] 3.79-8.29) and a 4.56-fold increase of CV death risk (95 % CI 2.96-8.29) for men; for women, the corresponding hazard ratios were 4.47 for all-cause death (95 % CI 3.02-7.40) and 4.93 for CV death (95 % CI 2.78-8.58). The increase in slope and area under the UA trajectory were additionally associated with a higher risk of all-cause and CV death in both genders. All the associations remained consistent after adjusting for repeatedly measured renal function and across the ejection fraction phenotypes.

CONCLUSION

The longitudinally measured UA and its derived parameterizations are strong prognostic factors in hospitalized HF patients, independent of clinically relevant confounders and repeatedly assessed renal function.

Isorhamnetin ameliorates hyperuricemia by regulating uric acid metabolism and alleviates renal inflammation through the PI3K/AKT/NF-κB signaling pathway

Hyperuricemia is a chronic metabolic disease with high incidence, and it has become a severe health risk in modern times. Isorhamnetin is a natural flavonoid found in a variety of plants, especially fruits such as buckthorn. The in vivo hyperuricemia ameliorating effect of isorhamnetin and the specific molecular mechanism were profoundly investigated using a hyperuricemia mouse model in this study. Results indicated that isorhamnetin showed a significant uric acid-lowering effect in mice. Isorhamnetin was able to reduce uric acid production by inhibiting XOD activity. Furthermore, it reduced the expression of GLUT9 to inhibit uric acid reabsorption and enhanced the expression of ABCG2, OAT1, and OAT3 to promote uric acid excretion. Metabolomics analysis revealed that gavage administration of isorhamnetin restored purine metabolism and riboflavin metabolism disorders and thus significantly alleviated hyperuricemia in mice. Furthermore, the alleviating effect of isorhamnetin on hyperuricemia-induced renal inflammation and its specific mechanism were explored through network pharmacology and molecular validation experiments. Network pharmacology predicted that seven targets were enriched in the PI3K/AKT pathway (CDK6, SYK, KDR, RELA, PIK3CG, IGF1R, and MCL1) and four targets were enriched in the NF-κB pathway (SYK, PARP1, PTGS2, and RELA). Western blot analysis validated that isorhamnetin inhibited the phosphorylation of PI3K and AKT and down-regulated the expression of NF-κB p65. It indicated that isorhamnetin could inhibit the PI3K/AKT/NF-κB signaling pathway to reduce the levels of renal inflammatory factors (TNF-α, IL-β and IL-6) and ultimately ameliorate hyperuricemia-induced renal inflammation in mice. This study provides a comprehensive and strong theoretical basis for the application of isorhamnetin in the field of functional foods or dietary supplements to improve hyperuricemia.

Association between sleep duration, sleep trouble and all-cause mortality in individuals with hyperuricemia in the United States

Objectives

Despite the crucial role of sleep quality in hyperuricemia onset and progression, there is limited evidence on sleep interventions to improve outcomes for hyperuricemic individuals. This study aims to investigate the effects of sleep duration and sleep difficulties on all-cause mortality in this population.

Materials and methods

We conducted a secondary analysis of the National Health and Nutrition Examination Survey (NHANES) data from 2007 to 2018, including 5,837 participants. We employed weighted multivariable Cox proportional hazard models to evaluate the independent predictive value of sleep duration and trouble for all-cause mortality. Restricted cubic splines and segmented Cox proportional hazard models were used to examine threshold effects.

Results

During a mean follow-up of 6.5 years, 906 participants experienced all-cause mortality. After adjusting for confounders, both short (< 7 h; HR = 1.25; 95%CI: 1.04, 1.51; p = 0.018) and long (>9 h; HR = 1.50; 95%CI: 1.10, 2.04; p = 0.011) sleep durations were associated with increased all-cause mortality. The threshold analysis identified an optimal sleep duration of 7.23 h, and when sleep duration was below 7.23 h, it was inversely related to mortality (HR: 0.879; 95% CI: 0.788, 0.981; p = 0.022). Conversely, when sleep duration exceeded 7.23 h, it was positively associated with mortality (HR: 1.187; 95% CI: 1.066, 1.320; p = 0.002).

Conclusion

Sleep duration is U-shapedly associated with all-cause mortality among individuals with hyperuricemia in the United States. However sleep trouble was not associated with all-cause mortality. Maintaining optimal sleep duration helps improve the prognostic survival rates of those with hyperuricemia.

Association of Triglyceride-Glucose-Related Obesity Indices With All-Cause and Cardiovascular Mortality Among Individuals With Hyperuricemia: A Retrospective Cohort Study

OBJECTIVE

This study sought to clarify the relationship between triglyceride-glucose (TyG)-related obesity indices and all-cause and cardiovascular mortality in patients with hyperuricemia (HUA).

METHOD

A total of 4207 patients with HUA from the National Health and Nutrition Examination Survey (NHANES) database were included in this study. Various methods were employed, including weighted multivariate-adjusted Cox regression models, Kaplan-Meier curves, restricted cubic spline, and receiver operating curves.

RESULTS

A nonlinear relationship was identified between TyG-related obesity indices and all-cause mortality, while a linear positive relationship was observed for cardiovascular mortality. Among the indices, TyG-ABSI (a body shape index) demonstrated the strongest predictive ability, with areas under the curve for all-cause mortality at 3, 5, and 10 years being 0.638, 0.632, and 0.650, respectively, and for cardiovascular mortality at 3, 5, and 10 years being 0.699, 0.673, and 0.671, respectively. Threshold analysis revealed the potential inflection point (k) of the nonlinear relationship. Subgroup analyses indicated interactions with age, diabetes, or cardiovascular disease. Additionally, serum uric acid was found to partially mediate the association between TyG-derived indices and follow-up time. The results of the sensitivity analysis were consistent with those of the original analysis.

CONCLUSIONS

TyG-ABSI, which exhibited the best predictive ability, may serve as a valuable biomarker for the long-term follow-up of individuals with HUA.

Associations of body mass index and remnant cholesterol with hyperuricemia in patients with hypertension

BACKGROUND

There is a paucity of prior research on residual cholesterol (RC) and hyperuricemia, and it remains unclear whether body mass index (BMI) functions as a mediating factor between them or intensifies lipid metabolic dysregulation, thereby elevating the risk of hyperuricemia. This study aims to investigate whether BMI mediates the association between RC and hyperuricemia, as well as the interaction or joint effect of BMI and RC on hyperuricemia.

METHODS

This is a cross-sectional study, involving a total of 14,218 hypertensive patients. Exposure factors include RC and BMI. The outcome was Hyperuricemia, defined as serum uric acid (SUA) ≥ 420 µmol/L. Multivariable logistic regression models and causal mediation analysis were used to examine the association between RC and BMI and the prevalence of hyperuricemia.

RESULTS

A total of 14,218 hypertensive patients were enrolled in this cross-sectional study, comprising 6,713 (47.2%) males, with a mean age of 63.8 (9.36) years. The prevalence of diabetes mellitus was found to be 10.4% (1,473), while hyperuricemia accounted for approximately 44.4% (6,319). The results show that there is a linear positive correlation between RC and hyperuricemia (P for trend < 0.01). RC and BMI only had significant additive interaction on hyperuricemia, but there was no multiplicative interaction (Additive: RERI = 0.45, 95%CI: 0.13-0.78; Multiplicative, OR = 1.09, 95% CI 0.92-1.3, P = 0.308). There are direct and indirect effects between RC and hyperuricemia [estimate (95% CI): DE = 0.063 (0.048, 0.070), IE = 0.005 (0.003, 0.001)]. In the aforementioned causal mediation analysis, among the hyperuricemia caused by RC, BMI mediates 7.1%.

CONCLUSION

The intermediary role of BMI and its interaction with RC play a pivotal role in augmenting the prevalence of hyperuricemia.

TRIAL REGISTRATION

Registered prospectively in the Chinese Clinical Trial Registry (ChiCTR1800017274) on July 20, 2018. Access at https://www.chictr.org.cn/showproj.html?proj=28262 .

Relationship between serum uric acid and ventricular diastolic dysfunction in type 2 diabetes mellitus patients

OBJECTIVE

To investigate the correlation of serum uric acid (SUA) levels with ventricular diastolic dysfunction (DD) in the diabetic population.

METHODS

Clinical data from 702 patients with type 2 diabetes mellitus (T2DM), including 394 males and 308 females, were retrospectively analyzed in this study. The data included demographic characteristics, biochemical test results, and echocardiography findings. Univariate and multivariate logistic regression analyses were performed to assess the association between SUA and DD. Additionally, the diagnostic efficacies of SUA and the multivariate logistic regression model (Logit P) for DD were evaluated using receiver operating characteristic (ROC) curves.

RESULTS

Compared to T2DM patients with normal diastolic function, those with DD had a higher prevalence of hypertension, older age, longer diabetes duration, elevated levels of low-density lipoprotein cholesterol (LDL-c), total cholesterol (TC), blood urea nitrogen (BUN), SUA, and hemoglobin A1c (HbA1c), as well as lower levels of 1,5-anhydroglucitol (1,5-AG) and estimated glomerular filtration rate (eGFR) (P<0.05). As indicated by the Logistic regression analysis, gender, age, and SUA were independent risk factors for DD (P<0.05). Women had a 47.8% lower risk of DD compared to men [95% CI (0.318-0.718)]. The risk of DD increased by 6.8% for each one-year rise in age [OR 1.068, 95% CI (1.051-1.085)] and by 0.5% for each 1 mmol/L increase in SUA [OR 1.005, 95% CI (1.003-1.007)]. The regression model incorporating sex, age, and SUA exhibited an area under the curve (AUC) of 0.753 (95% CI 0.712-0.794) for diagnosing DD, with a sensitivity of 65.65% and specificity of 78.65%.

CONCLUSIONS

Gender, age, and SUA were independent factors influencing the development of DD in T2DM patients. Among them, SUA is the only modifiable factor. Early and long-term control of SUA levels is essential to reduce the risk of DD in T2DM patients.

Risk acceleration by gout on major adverse cardiovascular events and all-cause death in patients with diabetes and chronic kidney disease

AIMS

We aimed to examine the impact of gout on cardiovascular disease (CVD) and mortality risk in patients with type 2 diabetes and explore whether chronic kidney disease (CKD) modifies this association.

MATERIALS AND METHODS

Using the Korean National Health Insurance Service database, 757 378 individuals with type 2 diabetes were classified into the CKD-Gout-, CKD-Gout+, CKD+Gout-, and CKD+Gout+ groups. Cox proportional hazard models were used to assess the risk of myocardial infarction (MI), ischemic stroke, and mortality, after adjusting for cardiometabolic factors.

RESULTS

Over a median follow-up of 9.3 years, 25 618, 38 691, and 78 628 individuals experienced MI, stroke, and mortality, respectively. The risk of MI or stroke progressively increased across the groups, with the highest adjusted hazard ratio (HR) in the CKD+Gout+ group (HR: 1.57, 95% confidence interval [CI]: 1.46-1.69), followed by the CKD+Gout- group (HR: 1.23, 95% CI 1.20-1.26). The CKD+Gout+ group showed the greatest risks for MI (HR: 1.71), stroke (HR: 1.46), and mortality (HR: 1.78). Individuals with gout alone did not exhibit a significant increase in risk compared with those without gout or CKD. Interaction analyses indicated that the effect of gout on the outcomes was more pronounced in patients with CKD. Subgroup analyses yielded consistent findings across diverse demographic and clinical characteristics.

CONCLUSIONS

CKD with or without gout increased the risk of CVD and mortality, with the highest risk observed in the CKD+Gout+ group. The interaction between CKD and gout significantly influenced these outcomes.

Clinical outcomes in patients with cardiorenal multimorbidity: the role of serum uric acid/serum creatinine ratio

INTRODUCTION

Serum uric acid (SUA), the final product of purine metabolism, is an independent risk factor for cardiovascular (CV) disease. Since SUA levels depend on renal function, SUA to serum creatinine ratio (SUA/sCr) is emerging as a more specific biomarker of CV risk.

AIM

To evaluate in hospitalized patients with cardiorenal multimorbidity (CRM) if the SUA/sCr ≥ 5.35 is associated with clinical outcomes. The primary outcome was in-hospital mortality. The secondary outcome was the composite of all-cause of mortality and adverse clinical events.

METHODS

We conducted a retrospective review of medical records from consecutive CRM inpatients admitted to the medical ward. The composite endpoint was calculated as all-cause mortality and adverse clinical events such as acute coronary syndrome, stroke, infections, and renal replacement therapy.

RESULTS

In our cohort, 141 patients (mean age of 75.6 ± 10.2 years) were identified with CRM. In-hospital mortality occurred in 17 patients (16%), and 64 patients (60.4%) experienced adverse clinical outcomes. Among the 106 patients, 20 (18.9%) had an SUA/sCr ≥ 5.35, while 86 (81.1%) had an SUA/sCr < 5.35. Male gender was significantly associated with SUA/sCr ≥ 5.35 (p = 0.007). In-hospital mortality was significantly higher in patients with SUA/sCr ≥ 5.35 (p = 0.010), and a positive correlation with adverse clinical outcomes was documented in this subgroup (p = 0.012).

CONCLUSION

in patients with CRM, SUA/sCr ≥ 5.35 is associated with increased in-hospital mortality and worse clinical outcomes. The ratio and related cut-off value of SUA/sCr could represent a useful biomarker to assess in-hospital complications in CRM patients.

Hyperuricemia, A new cardiovascular risk

BACKGROUND AND AIMS

Hyperuricemia is strongly linked to increased cardiovascular risk, including hypertension, coronary artery disease, arrythmia, and heart failure. Uric acid, as the end-product of purine metabolism, plays a critical role in cellular processes, but elevated levels can drive inflammation and oxidative stress. This review aims to emphasize the robust association between hyperuricemia and cardiovascular diseases, exploring whether uric acid-lowering therapies can mitigate cardiovascular events and improve patient outcomes.

METHODS AND RESULTS

A comprehensive review of PubMed sources was conducted, underscoring the significant link between high uric acid levels and cardiovascular events, particularly in patients with gout. Gender differences were observed, where premenopausal women have lower uric acid levels, likely due to hormonal effects, suggesting the potential need for gender-specific definitions in assessing cardiovascular risk. Epidemiological studies demonstrate a consistent correlation between hyperuricemia and adverse cardiovascular outcomes. However, interventional trials using xanthine oxidase inhibitors, such as allopurinol and febuxostat, have shown mixed results regarding their impact on reducing cardiovascular events. Additionally, emerging evidence suggests a "xanthine oxidase withdrawal syndrome" upon discontinuation of these therapies, highlighting the need for cautious management.

CONCLUSION

The strong association between elevated uric acid levels and cardiovascular diseases is well-documented. While lowering uric acid shows potential for reducing cardiovascular risk, current evidence from interventional trials remains inconclusive. Future research should focus on patient-specific therapeutic strategies, particularly for those at high cardiovascular risk with hyperuricemia and/or gout, to better define the benefits of targeted treatments.

Elevated Soluble Suppressor of Tumorigenicity 2 Levels in Gout Patients and Its Association with Cardiovascular Disease Risk Indicators

PURPOSE

To investigate the association between soluble suppressor of tumorigenicity 2 (sST2) levels and cardiovascular disease predictors in patients with gout.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of patients with gout who were tested for sST2 but did not receive uric acid-lowering therapy. These patients were classified into elevated and normal sST2 groups using a cut-off of >49.6 ng/mL and >35.4 ng/mL in males and females, respectively. Correlations between clinical and laboratory variables, sST2 levels, and elevated sST2 level predictors were assessed using linear and logistic regression analyses.

RESULTS

Notably, 27 (11.3%) and 211 (88.7%) of the 238 identified patients had elevated and normal sST2 levels, respectively. Linear regression analysis revealed that male sex (β=-0.190, p=0.002), body mass index (BMI) (β=-0.184, p=0.002), white blood cell count (β=0.231, p<0.001), C-reactive protein (β=0.135, p=0.031), and fasting blood glucose (β=0.210, p<0.001) were independently associated with sST2 levels. In multivariate logistic regression analysis, male sex [odds ratio (OR) 0.112, p=0.001], BMI (OR 0.836, p=0.008), creatinine (OR 5.730, p=0.024), and fasting blood glucose (OR 1.042, p=0.002) predicted elevated sST2 levels. Patients with increased sST2 levels had a significantly higher atherosclerotic cardiovascular disease risk score and a greater proportion of high-risk Framingham Risk Score compared to the normal sST2 group (p=0.002 and p<0.001).

CONCLUSION

Patients with gout and elevated sST2 levels have a higher risk of future cardiovascular disorders, which may provide insights into risk stratification and the implementation of intervention strategies.

Associations of Serum Urate and Cardiovascular Events in a Clinical Trial of Interleukin-1β Blockade

BACKGROUND

Serum urate (SU) associates with cardiovascular (CV) events, mortality, and gout.

OBJECTIVES

The purpose of this study was to assess whether SU predicts CV risk in a trial of interleukin (IL)-1β inhibition with canakinumab, and whether IL-1β blockade, kidney function, or gout alter these associations.

METHODS

This study is a subanalysis of the Canakinumab Antiinflammatory Thrombosis Outcome Study (CANTOS), which randomized 10,061 patients with prior myocardial infarction and elevated high-sensitivity C-reactive protein to 3 doses of canakinumab or placebo. SU was measured at baseline. Cox proportional hazards models compared major adverse cardiovascular events (MACE), CV death, and all-cause mortality among those with SU ≤6.8 mg/dL (normal), 6.8 to 9.0 mg/dL (elevated), and ≥9.0 mg/dL (markedly elevated). Cox regressions were repeated within subgroups, including canakinumab vs placebo, estimated glomerular filtration rate ≥60 vs <60 mL/min, and gout vs no gout.

RESULTS

Markedly elevated SU associated with MACE (HR: 1.66 [95% CI: 1.38-1.99]; P < 0.0001), CV death (HR: 2.52 [95% CI: 1.98-3.21]; P < 0.0001), and all-cause mortality (HR: 2.43 [95% CI: 2.01-2.94]; P < 0.0001) compared to normal SU. After multivariable adjustment for a minimal set of potential confounders, SU independently predicted all 3 endpoints. Associations were unchanged after IL-1β blockade with canakinumab. For normal estimated glomerular filtration rate, SU associated with CV and all-cause mortality, but not MACE. Participants with gout had higher event rates independent of SU.

CONCLUSIONS

In over 10,000 patients with coronary artery disease, individuals with markedly elevated SU have elevated CV risk despite aggressive treatment. IL-1β blockade did not modify these associations. Baseline kidney function and monosodium urate deposition may function as effect modifiers.

Potential association between magnesium depletion score and hyperuricemia in American adults, a cross-sectional study based on NHANES 2003-2018

Objective

The pathophysiological mechanisms underlying hyperuricemia necessitate the identification of contributing factors to better understand disease progression and develop effective therapies. This study aimed to investigate the association between Magnesium Depletion Score (MDS) and hyperuricemia.

Methods

A cross-sectional study was sourced from the National Health and Nutrition Examination Survey 2003-2018. Hyperuricemia was defined by serum uric acid levels. MDS was calculated by incorporating factors affecting renal magnesium reabsorption.Weighted multivariable logistic regression was employed to assess the association between MDS and hyperuricemia, with sensitivity analyses to confirm robustness. Additionally, Restricted Cubic Spline (RCS) and Receiver Operating Characteristic (ROC) curve analyses were used to further elucidate the relationship.

Results

Compared to the low MDS group (0-1), the odds ratios (OR) and 95 % confidence intervals (CI) for the middle MDS group (2) and high MDS group (3-5) were 1.76 (1.52-2.04), and 3.14(2.54-3.88), respectively. The RCS analysis illustrated a linear dose-response relationship between MDS and hyperuricemia. The ROC analysis demonstrated that MDS had an area under the curve of 0.720 (95 % CI, 0.717-0.721).

Conclusions

This study highlights a strong association between MDS and hyperuricemia risk, emphasizing the importance of addressing magnesium deficiency in hyperuricemic patients.

A New Perspective on the Prediction and Treatment of Stroke: The Role of Uric Acid

Stroke, a major cerebrovascular disease, has high morbidity and mortality. Effective methods to reduce the risk and improve the prognosis are lacking. Currently, uric acid (UA) is associated with the pathological mechanism, prognosis, and therapy of stroke. UA plays pro/anti-oxidative and pro-inflammatory roles in vivo. The specific role of UA in stroke, which may have both neuroprotective and damaging effects, remains unclear. There is a U-shaped association between serum uric acid (SUA) levels and ischemic stroke (IS). UA therapy provides neuroprotection during reperfusion therapy for acute ischemic stroke (AIS). Urate-lowering therapy (ULT) plays a protective role in IS with hyperuricemia or gout. SUA levels are associated with the cerebrovascular injury mechanism, risk, and outcomes of hemorrhagic stroke. In this review, we summarize the current research on the role of UA in stroke, providing potential targets for its prediction and treatment.

The role of hyperuricemia in the progression of end-stage kidney disease and its molecular prospective in inflammation and cardiovascular diseases: A general review

With the ongoing development of the Chinese economy, the occurrence of chronic kidney disease (CKD) has experienced a remarkable upsurge recently, and due to uremia caused by CKD, the number of patients undergoing dialysis has shown a dramatic increase. China has been ranked first in the world for patients undergoing hemodialysis (HD) and peritoneal dialysis (PD) with approximately one million patients across the country. Due to the loss of kidney function caused by CKD, the kidneys tend to lose their ability to excrete uric acid (UA) out of the body; therefore, most patients undergoing dialysis are complicated with hyperuricemia (HUA). HUA is an abnormal disease of purine metabolism, and it's considered a chronic disease. More than 90% of patients suffering from HUA will not show any symptoms on physical examination. According to statistics, if high serum UA is left untreated, 55% of patients will develop severe problems due to the purine crystallization in the body, and the kidneys are the most affected organs by HUA causing renal insufficiency that can promote end-stage kidney disease (ESKD) by activating the renin-angiotensin system (RAS), which will lead to inflammation, arteriosclerosis, cardiovascular diseases (CVD), and other diseases. Lifestyle modifications and pharmacological interventions are the first primary choice for lowering UA, although dialysis will tend to reduce the high UA levels in the blood, drugs are also necessary. This review will summarize the mechanisms and metabolism of UA, the relationship between HUA and ESKD progression, HUA and inflammation, HUA and CVD, and pharmacological treatment of HUA.

Association between Hp infection and serum uric acid to high-density lipoprotein cholesterol ratio in adults

Background

Helicobacter pylori (Hp) infection is one of the major global health problems resulting in multiple system disorders. The serum uric acid to high density lipoprotein cholesterol ratio (UHR) is a novel index of inflammation and metabolism, but its association with the development of Hp infection is still unclear.

Materials and methods

This is a cross-sectional study involving 2,666 participants, using data from the National Health and Nutrition Examination Survey (NHANES) conducted in the United States. The relationship between UHR and Hp infection was evaluated by multivariate logistic regression and sensitivity analysis to enhance the stability of the results.

Results

Among all individuals, 1,165 were Hp positive (43.7%) and 1,501 were Hp negative (56.3%). After adjustment, there was a positive correlation between UHR and Hp infection (OR = 1.15; 95% CI 1.02-1.30; P = 0.020). This association is relatively stable in the subgroup analysis (P > 0.05).

Conclusion

There is a positive correlation between the UHR and the development of Hp infection in our study. This non-invasive indicator can improve the ability to monitor Hp infection and may find alternative therapeutic intervention targets.

Fast Detection of Uric Acid in Urine for Early Diagnosis Using THz Polarized Waves

Towards new and improved techniques in liquid biopsy for the diagnosis of diseases, this study reports experimental evidence of a rapid and reliable method based on terahertz (THz) time-domain spectroscopic ellipsometry (TDSE) for the early diagnosis of kidney-related diseases, using the detection of uric acid (UA) content in urine. Employing a custom-built THz-TDSE system, we analyzed the absorption and dispersion response of synthetic urine samples with varying concentrations of UA. The technique provides a prompt indication of UA presence and concentration, thanks to the sensitivity of THz waves to intermolecular interactions such as hydrogen bonding. The results clearly show a linear correlation between the UA concentration and changes in the absorption spectra of urine in the frequency window 0.2-1.2 THz, with the minimum detectable UA concentration being approximately close to the upper limit of normal UA levels in urine. The increase in the absorption coefficient as a function of the UA concentration provides a means for a quantifiable measure of the UA biomarker in urine for assessing disease stage. This study proves that THz-TDSE is capable of detecting UA at concentrations relevant for early-stage diagnosis of renal diseases, with an estimated sensitivity of 0.2 g/L in the region where the material response is linear.

The link between hyperuricemia and diabetes: insights from a quantitative analysis of scientific literature

Background

Hyperuricemia (HUA) is a significant public health issue, ranking second only to diabetes in prevalence. While existing research demonstrates a robust correlation between these two conditions, the precise etiological mechanisms remain inadequately elucidated. This study utilized scientometric analysis to investigate the global association between HUA and diabetes.

Methods

Data on HUA and diabetes were retrieved from the Web of Science Core Collection database, encompassing the period from its inception until September 30, 2024. Collaboration networks were examined using VOSviewer, cluster analysis was executed with CiteSpace, and systematic mapping was conducted using Bibliometrix.

Results

By September 30, 2024, 1,464 studies indicated a consistent yearly increase in publications connecting HUA and diabetes despite some fluctuations. The lead authors were Richard J. Johnson, Miguel A. Lanaspa, and Masanari Kuwabara, with most contributors from China, the United States, and Japan. Key institutions include China Medical University, Shanghai Jiao Tong University, and Capital Medical University. The most published journal was Nutrition, Metabolism and Cardiovascular Diseases (CVDs), whereas the most cited journal was Diabetes Care. The reference network from 1987 to September 30, 2024, identified 19 clusters highlighting key research areas in HUA and diabetes, such as metabolic syndrome, uropathology, chronic kidney disease (CKD), and CVD. Exploring pathological mechanisms and pharmacological interventions linked to diabetes concomitant with HUA has emerged as a focal point of research and a burgeoning trend within the field.

Conclusion

This study is the first scientometric analysis to synthesize research trends on HUA and diabetes, revealing molecular mechanisms and treatment strategies and providing theoretical insights for future clinical use.

Mendelian randomization study of serum uric acid levels and urate-lowering drugs on pulmonary arterial hypertension outcomes

This study aims to explore the causal relationships between serum uric acid level and pulmonary arterial hypertension (PAH) using the Mendelian randomization (MR) approach, and to assess the therapeutic impacts of urate-lowering drugs on PAH. Utilizing published genome-wide association study (GWAS) data, we applied MR and colocalization analysis to assess the link between serum uric acid levesl and PAH across four GWAS datasets from two distinct European populations. The validity and reliability of these findings were confirmed through multiple statistical methods, along with an MR analysis of urate-lowering drug targets to investigate their potential effects on PAH treatment. MR analysis revealed a significant positive correlation between serum uric acid levels and PAH (odds ratio (OR) 1.106, 95% confidence intervals (CI) 1.021-1.200, P = 0.014), corroborated by a replication MR analysis (OR 1.859, 95% CI 1.130-3.057, P = 0.015). No significant heterogeneity or horizontal pleiotropy was found in the sensitivity analyses. However, urate-lowering drugs did not demonstrate a significant direct therapeutic effect on PAH. This study establishes a genetic basis for a causal link between serum uric acid levels and PAH. However, urate-lowering drugs do not appear to have a direct causal effect on improving PAH. These findings provide a novel reference point for developing future therapeutic strategies for PAH.

The impact of uric acid on musculoskeletal diseases: clinical associations and underlying mechanisms

Serum urate (SU) levels are significantly elevated in conditions such as gout, type 2 diabetes (T2D), obesity, and other metabolic syndromes. Recently, due to the high prevalence of hyperuricemia (HUA), numerous clinical connections between SU and musculoskeletal disorders like sarcopenia, osteoarthritis (OA), rheumatoid arthritis (RA), intervertebral disc degeneration (IDD), and osteoporosis (OP) have been identified. This review discusses the mechanisms linking SU to musculoskeletal disorders, as well as the clinical associations of SU with conditions such as sarcopenia, T2D with sarcopenia, McArdle disease, heart failure, gout, OA, IDD, OP and exercise-induced acute kidney injury (EIAKI), offering valuable insights for improved prevention and treatment strategies. Mechanisms linking SU to musculoskeletal disorders include oxidative stress, MSU (monosodium urate) crystal deposition, inflammation, and other factors. In adults, both age and SU levels should be considered for preventing sarcopenia, while gender and SU may directly impact muscle mass in children and adolescents. HUA and gout may be risk factors for OA progression, although some reports suggest otherwise. A U-shaped relationship between SU and IDD has been reported, particularly in Chinese men, indicating lower or higher SU level may be risk factors for IDD. Maintaining SU levels within a certain range may help prevent OP and fractures. Future research, including epidemiological studies and new pathogenesis findings, will further clarify the relationship between musculoskeletal diseases and SU.

Taurine alleviates dysfunction of cholesterol metabolism under hyperuricemia by inhibiting A2AR-SREBP-2/CREB/HMGCR axis

Dysfunctional cholesterol metabolism is highly prevalent in patients with hyperuricemia. Both uric acid and cholesterol are independent risk factors for atherosclerosis, contributing to an increased incidence of cardiovascular disease in hyperuricemia. Investigating the pathological mechanisms underlying cholesterol metabolism dysfunction in hyperuricemia is essential. This study identified adenosine and inosine, two major purine metabolites, as key regulators of cholesterol biosynthesis. These metabolites upregulate 3-hydroxy-3-methylglutaryl-CoA. Further mechanistic studies revealed that adenosine/inosine up-regulated the expression of 3-hydroxy-3-methylglutaryl-CoA by activating adenosine A2A receptor via the Srebp-2/Creb axis in hyperuricemia. Additionally, we found that taurine deficiency contributes to cholesterol metabolism dysfunction in hyperuricemia. Taurine administration in hyperuricemia mice significantly reduced cholesterol elevation by inhibiting adenosine A2A receptor. This study provides a promising strategy for treating comorbid hypercholesterolemia and hyperuricemia.

Serum uric acid trajectories and the risk of cardiovascular disease: a longitudinal association and pathway analysis

BACKGROUND

Age-specifically longitudinal associations and potential pathways between serum uric acid (SUA) and cardiovascular disease (CVD) remained unclear. This study aimed to explore SUA trajectories in different age populations and to determine their associations and potential pathways with incident CVD.

METHODS

This prospective cohort included 41,367 participants from the Kailuan study, including 30,938 participants aged <55 years and 10,419 participants aged ≥55. The SUA trajectories during year 2006-2012 were identified by latent class growth models.

RESULTS

Three SUA trajectories were identified in the overall, aged <55 and aged ≥55 years participants, as "low-stable" (51.9%, 54.4%, and 43.3%), "moderate-stable" (39.0%, 36.9%, and 45.6%), and "high-stable" (9.1%, 9.7%, and 11.1%), respectively. During a median follow-up of 6.75 years, incident CVD occurred in 2302 participants (5.56%). Overall, a high-stable trajectory was independently associated with a higher risk of CVD (hazard ratio [HR], 1.23; 95% [confidence interval], 1.06-1.42). Notably, the associations differed by age, a significant association was only observed in participants aged ≥55 years (HR, 1.29; 95% CI, 1.05-1.58), rather than those aged <55 years (HR, 1.08; 95% CI, 0.89-1.33). The addition of SUA trajectories to a baseline risk model for CVD improved the integrated discrimination improvement value (P < 0.05) and category-free net reclassification improvement value (P < 0.05). Bayesian network showed the conditional probability of high CVD risk associated with aging, elevated SUA trajectories, blood pressure, glucose, and inflammation was 15.5%.

CONCLUSIONS

High-stable SUA trajectories were independently associated with an elevated risk of CVD, which is mainly induced by hypertension, diabetes, and inflammation, especially in participants aged ≥55 years.

Current updates and future perspectives in uric acid research, 2024

Uric acid, the final product of purine metabolism, plays a significant role in hypertension Research on uric acid has advanced significantly, particularly regarding its links to hypertension and cardiovascular disease (CVD). Our 2023 review covered the relationship between uric acid, hypertension; and CVD, however, numerous new studies have emerged since then. This paper provides an update, summarizing recent findings over the past two years on hyperuricemia and its association with hypertension, preeclampsia, arteriosclerosis, kidney disease, sleep-disordered breathing, CVD, and so on. Hyperuricemia, often driven by reduced uric acid excretion or increased production, is influenced by genetic factors and lifestyle habits, including high-purine foods, alcohol, and fructose intake. While hyperuricemia has been proposed to contribute to hypertension and CVD through mechanisms like inflammasome activation and oxidative stress, its causal role remains debated. Further clinical and basic science studies on hyperuricemia and purine metabolism are necessary to clarify its impact on CVD and guide therapeutic approaches.

Predictive value of TG/HDL-C and GFR-adjusted uric acid levels on cardiovascular mortality: the URRAH study

BACKGROUND

Insulin resistance (IR) and serum uric acid (SUA) are closely interconnected: SUA contributes to adversely affects the insulin signaling pathway and contributes to IR, while IR is a known predictor for the development of hyperuricemia. The triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) ratio has been proposed as an easily obtainable marker for IR. This research aimed to investigate the interaction between IR and glomerular filtration rate (GFR)-adjusted uricemia (SUA/GFR ratio) in determining CV risk in a large population cohort study.

METHODS

Data from 18,694 subjects were analyzed from Uric acid Right foR heArt Healt (URRAH) database. The study evaluated the association between TG/HDL-C ratio and SUA/GFR ratio, as well as their impact on the development of outcomes during the follow-up study period. The primary endpoint was CV mortality.

RESULTS

After a mean follow-up of 124 ± 64 months, 2,665 (14.2%) CV deaths occurred. The incidence of fatal and non-fatal CV events increased in parallel with the increase of TG/HDL-C quintiles. TG/HDL-C ratio showed a positive association with increasing of SUA/GFR ratio, even in non-diabetic patients. Multivariate analysis showed that the TG/HDL-C ratio increases the mortality risk even after adjustment for potential confounding factors. Finally, IR and GFR-adjusted hyperuricemia showed an additive effect on CV mortality.

CONCLUSIONS

Both IR and SUA/GFR ratio independently predict CV mortality, regardless of age, gender, BMI, diabetes, hypertension and statin use. The joint effect of the TG/HDL-C ratio and the elevated SUA/GFR ratio was greater than the presence of each single risk factor on CV mortality. This highlights the importance of monitoring these markers to better assess cardiovascular risk.

Gender differences in the prognostic impact of uric acid in patients with heart failure and preserved ejection fraction

BACKGROUND

Uric acid has been identified as an independent predictor of poor outcomes in patients with heart failure with preserved ejection fraction (HFpEF). However, the impact of gender differences on this association is not fully explored.

METHODS

This retrospective cohort study included hospitalized patients with HFpEF from June 2018 to October 2022. The primary outcome was a composite endpoint, defined as the occurrence of all-cause mortality and heart failure readmission. Kaplan-Meier survival analysis and stratified Cox regression examined the combined effect of gender and uric acid on the composite endpoint, and restricted cubic spline curves were applied to visualize the relationship.

RESULTS

The study included 547 patients, with 267 females and 280 males. In the entire cohort, each mg/dL increase in uric acid was associated with a 4% increase in the risk of the composite endpoint (HR: 1.04, 95%CI:1.01-1.09). This association was more pronounced in females, with a 9% increase in the risk of the composite endpoint per mg/dL increase in uric acid (95%CI: 1.02-1.17). Restrict cubic spline curves analysis demonstrated a significant linear correlation between increasing uric acid levels and higher risk of the composite endpoint in female patients (P = 0.028). Kaplan-Meier analysis revealed higher survival probabilities for females compared to males (P = 0.002). However, survival rates for females with high uric acid levels were similar to those for males with high uric acid levels.

CONCLUSIONS

Baseline serum uric acid levels are significantly associated with the composite endpoint in patients with HFpEF, particularly among females.

Association between serum uric acid, hyperuricemia and low muscle mass in middle-aged and elderly adults: A national health and nutrition examination study

BACKGROUNDS

Recent research suggests that uric acid, as a metabolite with antioxidant properties, may affect muscle function and health. However, the association between serum uric acid (SUA) and low muscle mass remains relatively obscure. This study focuses on the association between SUA and low muscle mass in a middle-aged and elderly population in the United States.

METHODS

Utilizing data from the National Health and Nutrition Examination Survey (NHANES), a total of 12,106 patients aged ≥45 years, possessing complete analytical data, were incorporated. Low muscle mass in our study is defined as indices below 0.789 for males and 0.512 for females, according to the FNIH Biomarkers Consortium. Gender stratified analyses were conducted employing a multivariate weighted logistic regression model. When examining serum uric acid (SUA) levels, the SUA dataset was stratified into deciles, and odds ratios (ORs) were calculated across distinct subgroups of males and females. A restricted cubic spline (RCS) method was employed to investigate the potential nonlinear association between SUA levels and low muscle mass. A series of subgroup analyses stratified by demographic variables and clinical experience were conducted.

RESULTS

A total of 2,185 participants (18.05%) were identified with low muscle mass, comprising 1,121 males and 1,064 females. Females with low muscle mass had higher SUA levels and an increased incidence of hyperuricemia compared to those without low muscle mass. In females, a fully adjusted multivariable weighted regression model revealed a positive association between hyperuricemia and low muscle mass (OR, 1.43; 95% CI, 1.06 to 1.92; P = 0.021). No significant association was observed in males. Additionally, RCS curves indicated a J-shaped relationship between increasing SUA levels and the risk of low muscle mass in females, and an inverse J-shaped relationship in males.

CONCLUSIONS

This study reveals a significant positive correlation between hyperuricemia and the risk of low muscle mass in middle-aged and older women in the United States, whereas the relationship between SUA levels and low muscle mass did not attain statistical significance. In the male cohort, neither SUA levels nor hyperuricemia demonstrated a significant association with low muscle mass.

Serum Uric Acid and Bone Health in Middle-Aged and Elderly Hypertensive Patients: A Potential U-Shaped Association and Implications for Future Fracture Risk

BACKGROUND

The influence of serum uric acid (SUA) on bone metabolism, as suggested by previous studies, remains a contentious issue. SUA plays a complex role in bone health and hypertension, making it challenging to discern its impact on the skeletal status of middle-aged and elderly hypertensive patients. This study aims to elucidate the effects of SUA on bone health, with a particular focus on its association with osteoporosis and the risk of fractures.

METHODS

Multiple linear regression analyzed SUA levels against bone mineral density (BMD) and future fracture risk. Additionally, multivariate logistic regression was used to examine the association between SUA and osteoporosis. Dose-response relationship analysis was conducted using generalized smooth curve fitting (GSCF) and restricted cubic spline (RCS) methods.

RESULTS

With the exception of the total femur region, SUA and BMD showed a positive connection. GSCF analysis revealed an inverted U-shaped relationship between SUA and BMD, alongside a U-shaped trend with FRAX scores. Moreover, RCS analysis indicated a U-shaped relationship between osteoporosis risk and SUA levels, with higher risks identified in the first and third tertiles compared to the second tertile.

CONCLUSIONS

In individuals with middle-aged and older hypertension, SUA is substantially linked to bone health. The identification of an inverted U-shaped relationship with BMD and U-shaped relationships with FRAX scores and osteoporosis risk highlights the nuanced influence of SUA. These findings suggest that both low and high SUA levels may adversely affect bone health, emphasizing the need for further research.

Asymptomatic Hyperuricemia and the Kidney: Lessons from the URRAH Study

Chronic kidney disease (CKD) is a prevalent global health concern affecting approximately 850 million people worldwide, with a significant and rising mortality rate. CKD often coexists with hyperuricemia (HSUA), which is also increasingly common due to its association with hypertension, obesity, and diabetes. The interplay between hyperuricemia and CKD is complex; while in vitro studies and animal models support a role for uric acid mediating glomerular and tubule-interstitial damage, and HSUA has been shown to predict the onset and progression of CKD, the expectations of renal protection by the use of urate lowering treatment (ULT) are inconsistent. A significant challenge in managing asymptomatic HSUA in CKD patients lies in determining the appropriate SUA threshold values. Recent research, including the URRAH project, has sought to identify SUA cut-offs predictive of cardiovascular mortality, but these thresholds may vary depending on the severity of CKD. This variability complicates the establishment of universal guidelines for treating asymptomatic HSUA, leading to a lack of specific recommendations in clinical practice. In conclusion, while hyperuricemia is recognized as a prognostic factor for CKD and cardiovascular risk, more research is needed to refine the threshold values for SUA and to identify which patients may benefit from ULT. Stratification based on glomerular filtration rate may be necessary to tailor the treatments and improve outcomes in this population.

Predictors of Inflammation-Mediated Preterm Birth

Preterm birth remains a worldwide health concern because of ongoing challenges in prediction and prevention. Current predictors are limited by poor performance, need for invasive sampling, and an inability to identify patients in a timely fashion to allow for effective intervention. The multiple etiologies of preterm birth often have an inflammatory component. Thus, a deeper understanding of the inflammatory mechanisms involved in preterm birth may provide opportunities to identify new predictors of preterm birth. This review discusses the multiple etiologies of preterm birth, their links to inflammation, current predictors available, and new directions for the field.

Associations of aldehyde exposure with serum uric acid and hyperuricemia among U.S. adults from NHANES 2013-2014

Background

Aldehyde is a kind of important environmental pollutant, which has been demonstrated to be associated with increased risks of various chronic diseases with the economic and social development. However, the effects of aldehydes on serum uric acid (SUA) and hyperuricemia remained inexplicit, and the potential mediating pathways for this relationship needed to be addressed.

Methods

This study investigated the associations of individual and mixed aldehydes with SUA and hyperuricemia among 1588 U S. adults from the National Health and Nutrition Examination Survey 2013-2014. The generalized linear regression model was applied to assess the effects of individual aldehydes and the Bayesian kernel machine regression were incorporated to examine the impacts of mixed aldehydes. Mediation analyses were performed to explore the roles of inflammation and oxidative stress indices in aldehyde-induced SUA and hyperuricemia. Moreover, we conducted subgroup analyses for demographic and physical factors to detect disparity between groups.

Results

Propanaldehyde, butyraldehyde, and hexanaldehyde were associated with higher SUA level and butyraldehyde was correlated with increased hyperuricemia prevalence after multiple correction. Positive relationships between aldehyde mixtures and SUA level were also observed and hexanaldehyde contributed most. In addition, lymphocyte count and gamma glutamyl transferase partially mediated the associations between propanaldehyde, butyraldehyde, hexanaldehyde and SUA level, with mediation proportions ranging from 19.105 % to 27.316 %. Subgroup analyses showed that SUA level of participants with obesity, hypercholesterolemia, and hypertension tended to be more sensitive to aldehyde exposure.

Conclusions

Our results highlighted that multiple aldehydes mixtures exposure might increase SUA level, and revealed underlying mediating role of inflammation and oxidative stress. These findings provided crucial evidence for the impacts of environmental pollutants on human health and further prospective studies are still required to verify the findings.

Nonlinear association between the serum uric acid-to-creatinine ratio and all cause mortality in patients with hypertension: a ten-year cohort study using the NHANES database

The serum uric acid-to-creatinine ratio (UCR) may be a simple method for assessing xanthine oxidase overactivation, which may contribute to an increase in serum uric acid production and oxidative stress. In this study, we investigated the nonlinear association between the UCR and long-term mortality in patients with hypertension. Data were acquired from the National Health and Nutrition Examination Survey database, and a total of 11,346 patients with hypertension were included. We explored the nonlinear link between the UCR and all-cause mortality via spline smoothing, threshold saturation, and log-likelihood ratio tests. The results were validated through a competing risk model. A nonlinear pattern emerged between the UCR and all-cause mortality in hypertensive patients, with an inflection point at 4.3. Below this point, an increased UCR was associated with a decreased mortality risk (OR = 0.80, 95% CI: 0.68-0.94, P = 0.008), whereas above this point, the risk increased (OR = 1.21, 95% CI: 1.07-1.36, P = 0.004). The competing risk model yielded similar findings for cardiovascular and chronic kidney disease-related deaths. In patients with hypertension, the UCR nonlinearly predicted all-cause mortality, with a notable inflection at 4.3. These findings suggest that the UCR is a valuable prognostic indicator for assessing long-term outcomes in patients with hypertension.

Association between serum uric acid and all-cause and cardiovascular-related mortality in hemodialysis patients

Background

The association between serum uric acid (UA) and all-cause and cardiovascular-related mortality in hemodialysis (HD) patients is conflicting. We investigated this association and explored the effect modification of underlying nutritional status, as reflected in the lean tissue index (LTI) and the Geriatric Nutritional Risk Index (GNRI), which serve as markers of muscle mass and nutritional risk in HD patients.

Methods

A retrospective cohort study was conducted from January 2019 to December 2023. We investigated the association between serum UA and the outcomes using the Cox proportional hazards regression and restricted cubic splines. Subgroup analyses based on the LTI and GNRI were conducted to explore possible effect modification.

Results

During a mean follow-up of 32.9 months, 876 patients who underwent HD were included in the analysis. The association between serum UA and all-cause mortality showed a non-linear U-shaped pattern (p = 0.007), with a survival benefit observed for the patients with serum UA levels between 3.4 and 6.8 mg/dL. In the multivariable-adjusted model, the low and high UA groups were associated with a greater risk of all-cause mortality compared to the reference UA group (hazard ratio (HR) =1.24, confidence interval (CI) 1.03-2.12, p = 0.027; HR = 1.09; CI 1.05-2.08. p = 0.012). In the low UA group, a greater risk of mortality was observed in patients with low LTI (<12.3; HR 1.56, 95% CI 1.22-1.82) and GNRI values (<102.1; HR 1.43, 95% CI 1.12-1.76), but not in those with high LTI and GNRI values. There was no significant association between serum UA and cardiovascular disease-related mortality.

Conclusion

Our study showed that lower and higher serum UA levels increase the risk of all-cause mortality in HD patients. Among the patients with lower UA levels, low LTI and GNRI values showed a greater risk of mortality. This finding suggested that better nutritional status, rather than elevated UA levels, is likely to improve long-term survival in HD patients.

Association Between Remnant Cholesterol and Risk of Hyperuricemia: A Cross-Sectional Study

Remnant cholesterol (RC) is closely related to metabolic diseases. Our study aims to explore the relationship between RC and hyperuricemia. This cross-sectional study included 14 568 adults aged 20 years or older from the National Health and Nutrition Examination Survey (NHANES) conducted between 2007 and 2018 in the United States. RC is calculated by subtracting high-density lipoprotein cholesterol (HDL-c) and low-density lipoprotein cholesterol (LDL-c) from total cholesterol (TC). Hyperuricemia is defined by serum uric acid (SUA) levels≥7 mg/dl in men and≥6 mg/dl in women. The independent association between RC and hyperuricemia was evaluated. As the quartile range of RC levels increases, the prevalence of hyperuricemia also rises (7.84% vs. 13.71% vs. 18.61% vs. 26.24%, p<0.001). After adjusting for confounding factors, the fourth quartile of RC was associated with an increased risk of hyperuricemia compared with the first quartile (OR=2.942, 95% CI 2.473-3.502, p<0.001). Receiver Operating Characteristic (ROC) analysis shows that RC outperforms other single lipid indices in hyperuricemia. Further Restricted Cubic Splines (RCS) analysis suggests a nonlinear relationship between RC levels and hyperuricemia. Elevated RC levels were found to be linked to hyperuricemia. Further studies on RC hold promise for both preventing and addressing hyperuricemia.

Effects of uric acid on oxidative stress in vascular smooth muscle cells

Hyperuricemia during hypertension is associated with aberrant vascular functions and increased oxidative stress, which affects endothelial dysfunction. Nevertheless, the molecular mechanisms underlying the effects of uric acid on vascular smooth muscle cells (VSMCs) through oxidative stress remain unclear. The aim of the present study was to investigate the dose- and time-dependent effects of uric acid on oxidative stress and p53 protein expression in VSMCs. VSMCs were incubated with various concentrations of uric acid (0-50 mg/dl) for different time periods (1-24 h). Thiobarbituric acid reactive substances (TBARs), protein carbonylation and nitric oxide (NO) levels were determined using appropriate assay kits. Superoxide anion release was detected using the Görlach method. Western blotting was performed to determine the protein expression levels of p53. The findings demonstrated that the application of uric acid led to an increase in protein carbonylation and superoxide anion levels while causing a decrease in NO levels. Conversely, no significant effect was observed on TBARS levels. Additionally, it was observed that high concentrations of uric acid suppressed p53 expression at 6, 12 and 24 h. The present study provided evidence that the influence of uric acid on oxidative stress was more closely associated with time than dose; however, not all effects observed were strictly time-dependent.

CRISPR/Cas9 Mediated Deletion of the Uox Gene Generates a Mouse Model of Hyperuricemia with Multiple Complications

Hyperuricemia is a common metabolic disorder with severe complications. We aimed to develop a mouse model for spontaneous hyperuricemia. Uox-/- mouse model was generated on C57BL/6J background by deleting exon 2-4 of Uox using the CRISPR/Cas9 system. The prototypic Uox -/-mice had 5.5-fold increased serum uric acid (1351.04±276.58μmol/L) as compared to the wild type mice (P<0.0001), but died by 4 weeks. After allopurinol (3ug/g) intervention, they all survived > 8 weeks. The serum uric acid was 612.55±146.98μmol/L in the 8-week-old allopurinol-rescued Uox -/-mice, which manifested multiple complications including severe renal insufficiency, hypertension, left ventricular remodeling and systolic dysfunction, aortic endothelial dysfunction, hepatic steatosis and elevated liver enzymes, as well as hyperglycemia and hypercholesteremia. The present Uox-/- mice developed spontaneous hyperuricemia complicated with urate nephropathy, cardiovascular disease and cardiometabolic disorders, and may provide a novel tool to study hyperuricemia associated early-onset cardiovascular disorders in human.

Post-hoc analysis of two gout remission definitions in a two-year randomized controlled trial of nurse-led versus usual gout care

OBJECTIVE

To compare the performance of the 2016 preliminary gout remission definition and a simplified gout remission definition in a clinical trial of nurse-led gout care.

METHODS

Data from a 2-year parallel arm, non-blinded, randomised controlled trial of 517 community-derived people with gout were analyzed. Participants were assigned 1:1 to receive nurse-led care or general practitioner usual care. Remission was defined using the 2016 preliminary gout remission definition and a simplified gout remission definition without patient reported outcomes. Binary logistic regression was used to compare intervention groups. General linear models were used to compare Gout Impact Scale (GIS) scores between those in remission and those not in remission using either definition.

RESULTS

Participants in the nurse-led care group were more likely to achieve remission using either definition; at Year 2 the odds ratio was 7.92 [95 % CI 4.86-12.92] using the 2016 preliminary definition and 11.88 [95 % CI 7.49-18.84] using the simplified definition. For all participants, the 2016 preliminary definition was fulfilled by 9.9 % at Year 1 and 28.4 % at Year 2, p < 0.001 and the simplified definition was fulfilled by 17.6 % at Year 1 and 42.7 % at Year 2, p < 0.001. People in remission using either definition had better gout outcomes assessed using the GIS, including greater control over their gout.

CONCLUSION

Both definitions discriminated between the intervention groups and showed high construct validity. The simplified definition identified more people as being in gout remission at Year 1 and Year 2. The simplified definition is a feasible and valid option for defining gout remission.

Decoding the fatty liver-hyperuricemia link in the obese and nonobese hypertensive patients: insights from a cohort study

Metabolic-dysfunction-associated fatty liver disease (MAFLD) and serum uric acid are closely related to cardiovascular and cerebrovascular diseases. However, the causal association between MAFLD and serum uric acid remains unclear. A total of 3417 patients without hyperuricemia were included in the final analysis. MAFLD was defined as fatty liver index (FLI) ≥ 30. Multivariate Cox regression analysis was used to explore the association between FLI and new-onset hyperuricemia. Restricted cubic splines and threshold saturation effect analysis were used to detect nonlinear associations. The mean age was 62.8 ± 8.3 year, and 68.5% were women. A total of 738 (21.6%) hypertensive patients developed new-onset hyperuricemia, 388 (11.4%) new-onset hyperuricemia10 and 190 (5.6%) new-onset hyperuricemia20 during the 4-year midday follow-up period. In the fully adjusted model, compared with the Q1 (FLI ≤ 8.5) group, the risk of hyperuricemia increased by 56% (HR: 1.56; 95% CI: 1.02, 2.38) in the Q4 (FLI > 39.4) group, new-onset hyperuricemia10 increased by 108% (HR: 2.08; 95% CI: 1.15, 3.78), and new-onset hyperuricemia20 increased by 156% (HR: 2.56; 95% CI: 1.11, 5.94), respectively. Saturation effects showed a nonlinear association between FLI and new-onset hyperuricemia (p for log likelihood ratio test < 0.05). Subgroup analysis and stratified analysis showed that there had a significantly higher risk of new-onset hyperuricemia in the patients with normal body mass index (< 24 kg/m2) (p for interaction: 0.018) and non-central obesity (p for interaction: 0.024). MAFLD is an independent risk factor for hyperuricemia in hypertensive patients, especially in patients with normal body mass index and non-central obesity.

Gender-specific relationships between hyperuricemia and idiopathic deep venous thrombosis in the Chinese population: a case‒control study

BACKGROUND

Many studies have indicated that hyperuricemia is positively correlated with secondary deep venous thrombosis (DVT); however, the risk factors for idiopathic DVT based on gender differences, such as serum uric acid (SUA) and hyperuricemia, have not been fully examined.

OBJECTIVES

To investigate the association between hyperuricemia and the occurrence of idiopathic lower extremity DVT based on gender differences.

METHODS

This was a retrospective analysis of 4299 patients who were hospitalized at the Affiliated Hospital of Qingdao University from January 2012 to October 2021 and who underwent ultrasound of the lower limbs. A total of 930 patients were diagnosed in the DVT group, and 3369 patients were diagnosed in the control group without DVT. The baseline SUA and other important baseline data were compared between the two groups, and sex was stratified. Multivariate logistic regression analysis models adjusted for potential confounders were used to investigate the associations between hyperuricemia and idiopathic lower extremity DVT.

RESULTS

The SUA level in patients with idiopathic DVT was significantly greater than that in patients without DVT (total: 6.00 ± 1.75 vs. 5.40 ± 1.56 mg/dL, respectively; male: 6.42 ± 1.60 vs. 5.87 ± 1.57 mg/dL, respectively; female: 5.58 ± 1.79 vs. 4.72 ± 1.27 mg/dL, respectively; all P < 0.001). The proportion of patients with hyperuricemia in the idiopathic DVT group was significantly greater than that in the control group (total: 29.03% vs. 16.10%, respectively; male: 35.26% vs. 23.19%, respectively; female: 22.73% vs. 5.74%, respectively; all P < 0.001). The incidence of DVT in patients with hyperuricemia was significantly greater than patients with normouricemia (33.29% vs. 18.92%, respectively), and this difference was particularly prominent among women (58.01%). According to the univariate model, hyperuricemia was significantly associated with a grester risk of idiopathic DVT. After adjustment for potential confounders, this association remained significant. The risk of idiopathic lower extremity DVT in patients with hyperuricemia was 2.643-fold greater than that in patients with normouricemia (Model 3: OR: 2.643, 95% CI: 2.165-3.228). After stratification by sex, the risk of idiopathic lower extremity DVT in female patients with hyperuricemia was 7.482-fold greater than that in patients with normouricemia (Model 3, OR: 7.482, 95% CI: 4.999-11.199).

CONCLUSION

In the Chinese population, hyperuricemia is closely related to an increased risk of idiopathic lower extremity DVT, especially in female patients.

One-Year Risk Prediction of Elevated Serum Uric Acid Levels in Older Adults: A Longitudinal Cohort Study

Objective

To develop and externally validate a nomogram to predict elevated serum uric acid (SUA) levels in older adults.

Study Design

This is a longitudinal Chinese cohort study.

Methods

A cohort of 2788 older adults was established at Huadong Hospital, followed-up for at least one year, and screened for risk factors for elevated SUA levels. A logistic regression model was built to predict elevated SUA, and its performance was validated.

Results

The risk prediction model showed good discrimination ability in both the development cohort (area under the curve (AUC) = 0.82; 95% confidence interval (CI) =0.79~0.86) and the external validation cohort (AUC=0.76; 95% CI=0.70~0.82). The model was adequately calibrated, and the predictions correlated with the observed outcome (χ 2 = 6.36, P = 0.607). Men were more prone to elevated SUA levels than women were, and a baseline SUA level ≥360 μmol/L was a common risk factor for both males and females. Proteinuria status was an additional risk factor for males, whereas a baseline estimated glomerular filtration rate (eGFR)<60 mL/min·1.73 m2 and diabetes status were additional risk factors for females.

Conclusion

The externally validated nomogram, which is predictive of elevated SUA in older adults, might aid in the detection of individual diseases, the development of preventive interventions and clinical decision-making.

Association Between Serum Uric Acid and Pregnancy Outcomes: A Study in Chinese Women

OBJECTIVE

The study aims to explore the relationship between serum uric acid (UA) levels in the first trimester and pregnancy outcomes.

METHODS

The clinical data of 1381 pregnant women who delivered in the Department of Obstetrics and Gynecology of Beijing Chao-Yang Hospital from June 2021 to July 2022 were collected. All patients were categorized into four groups (Q1-Q4) according to quartiles of UA, using the first quartile of UA as the reference group. Logistic regression analysis was used to observe the correlation between UA and pregnancy outcomes. Restricted cubic spline (RCS) was drawn to observe the dose-response relationship between UA and pregnancy outcomes.

RESULTS

The numbers of GDM patients in Q1-Q4 were 40 (11.70%), 46 (13.49%), 60 (17.29%) and 83 (23.65%), respectively (p < 0.001). Logistic regression analysis showed that higher quartiles of UA were significantly associated with an increased prevalence of gestational diabetes mellitus (GDM). After adjusting for confounding factors (maternal age, prepregnancy BMI, gestational weight gain, and gestational age), compared with the lowest quartile of UA, the highest quartile of UA had 2.06 times odds of GDM (OR, 2.06; 95% CI, 1.34, 3.18; p = 0.001) in Q4. RCS suggested that the risk of GDM increased slowly until UA levels reached 219.43 µmol/L and then began to increase rapidly afterward (overall p = 0.0037).

CONCLUSIONS

Increased uric acid concentrations in the first trimester are associated with an increased risk of GDM and gestational hypertension.

Uricase-Expressing Engineered Macrophages Alleviate Murine Hyperuricemia

Background: Uricase, or urate oxidase (Uox) is a key enzyme in uric acid (UA) metabolism and has been applied in clinical treatment of human hyperuricemia (HUA). However, the current clinically applied uricases, despite their potent urate-lowering capacity, tend to form anti-drug antibodies because of their immunogenicity, leading to increased risk of anaphylaxis, faster drug clearance and reduced or even complete loss of therapeutic effect, limiting their clinical application. In this study, we constructed engineered macrophages that stably expressed uricase, which might serve as a promising alternative to the direct injection of uricases. Materials and Methods: Engineered macrophages RAW264.7 cells were injected intravenously to treat hyperuricemic KM mice. Serum uric acid and bio-indicators for renal and hepatic functions were detected by an automatic biochemical analyzer; inflammatory cytokines were determined by ELISA; the livers and kidneys of the mice were sectioned for histological examination. Results: The uricase-expressing macrophages reduced UA levels from 300 ± 1.5 μmol/L to 101 ± 8.3 μmol/L in vitro. And in an HUA mouse model established by gavage with yeast extract, intravenous injection of the engineered macrophages could reduce the serum uric acid (sUA) of mice to normal level on the 14th day of modeling, with a decrease of 48.6%, and the urate-lowering effect was comparable to that of the first-line clinical drug allopurinol. In terms of safety, engineered macrophages did not cause liver or kidney dysfunction in mice, nor did they induce systemic immune response. Conclusions: Using macrophages as a chassis to deliver uricase might be a new, safe and effective strategy for the treatment and control of hyperuricemia.

Prevalence of and trends in hyperuricemia by race and ethnicity among US adolescents, 1999-2018

PURPOSE

Our objective was to ascertain the most recent prevalence and trends of hyperuricemia among adolescents, stratified by sex and race/ethnicity subgroups, as well as to investigate potential risk factors associated with hyperuricemia in US adolescents.

METHODS

Data were obtained from adolescents aged 12-17 years in the 1999-2018 NHANES cycles. Hyperuricemia for adolescents was defined as ≥ 5.5 mg/dL. The prevalence of hyperuricemia, along with 95% confidence intervals (CIs), was calculated for each four-year survey cycle, stratified by sex, race/ethnicity, body mass index (BMI), poverty income ratio (PIR), and parental education levels. Linear regression and logistic regression analyses were conducted independently to evaluate the linear trends in mean serum urate levels and the prevalence of hyperuricemia across the four-year cycles. Utilizing NHANES data from 2011 to 2018, we identified factors associated with mean serum urate levels and hyperuricemia through the application of linear regression and Poisson regression analyses.

RESULTS

A total of 11 264 participants were included in the analysis. In 2015-2018, the overall hyperuricemia prevalence was 32.78%, 50.7% in males, and 13.51% in females. No significant trends were identified in the prevalence of hyperuricemia from 1999 to 2002 to 2015-2018. Between 2011 and 2018, hyperuricemia was significantly more prevalent among males compared to females (prevalence ratio [PR], 3.50 [95% CI, 2.83-4.33]), non-Hispanic Asians compared to non-Hispanic Whites (PR, 1.26 [95% CI, 1.04-1.53]), and individuals with overweight (PR, 1.63 [95% CI, 1.32-2.01]) or obesity (PR, 2.45 [95% CI, 2.08-2.88]) compared to those of normal weight. There was a stronger correlation between obesity and hyperuricemia among females (PR, 4.77 [95% CI, 3.08-7.39]) than in males (PR, 2.06 [95% CI, 1.82-2.34]). Furthermore, non-Hispanic Black adolescents with obesity exhibited higher PRs (PR, 3.40 [95% CI, 2.54-4.55]) for hyperuricemia in comparison to other ethnic groups.

CONCLUSIONS

This study has updated recent trends in hyperuricemia by sex and race/ethnicity among US adolescents. Our results suggest that hyperuricemia has a significant association with greater obesity in US adolescents, and the degree of correlation varies by sex and race/ethnicity.

Association between life's essential 8 and hyperuricemia among adults in the United States: insights from NHANES 2005-2018

Background

Hyperuricemia is a significant risk factor for various metabolic and cardiovascular conditions. Life's Essential 8 (LE8), a comprehensive measure of cardiovascular health promoted by the American Heart Association, may have a protective role against hyperuricemia. This study aims to evaluate the association between LE8 scores and hyperuricemia in a representative sample of US adults.

Methods

We conducted a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) 2005-2018, encompassing 26,885 adults. LE8 scores were calculated based on diet, physical activity, nicotine exposure, sleep health, body mass index, blood lipids, blood glucose, and blood pressure. Hyperuricemia was defined as serum uric acid levels ≥7.0 mg/dL in men and ≥ 6.0 mg/dL in women. Logistic regression and generalized additive models (GAMs) were used to analyze the relationship between LE8 scores and hyperuricemia, adjusting for potential confounders.

Results

Higher LE8 scores were significantly associated with lower odds of hyperuricemia (OR per 10-point increase: 0.73, 95% CI: 0.72-0.75, p < 0.001). Stratified analyses revealed consistent protective effects across subgroups defined by sex, age, race/ethnicity, PIR (poverty income ratio), education level, drinking status, eGFR, and CVD status. Logistic regression and GAM analyses both confirmed a linear relationship between increasing LE8 scores and reduced hyperuricemia risk. For example, in males, the OR was 0.81 (95% CI: 0.78-0.84), and in females, it was 0.66 (95% CI: 0.64-0.68).

Conclusion

The findings suggest that higher LE8 scores are robustly associated with lower odds of hyperuricemia in US adults. These results support the promotion of comprehensive cardiovascular health behaviors encapsulated by LE8 to mitigate hyperuricemia risk. Further studies are needed to explore the causal pathways and potential interventions.

Association between dietary iron intake and hyperuricemia in U.S. adults: a cross-sectional study

BACKGROUND

Elevating blood iron levels may increase the risk of hyperuricemia. However, the association between dietary iron intake and hyperuricemia remains unclear. This study examines the association between dietary iron and hyperuricemia.

METHODS

The data for this cross-sectional study came from the 2011-2020 National Health and Nutrition Examination Survey (NHANES), which included adults aged 20 and above in the United States. Detailed information on their demographics, dietary iron intake, serum uric acid, and other variables were gathered. This study employs a multifactorial logistic regression method to assess the relationship between dietary iron intake and hyperuricemia. Additionally, it utilizes Restricted Cubic Spline analysis to determine whether there is a non-linear relationship between dietary iron and hyperuricemia. Furthermore, sub-group analyses are conducted to further validate the robustness of this correlation.

RESULTS

This study included 11,441 patients, with a prevalence of hyperuricemia at 14.96%. Regardless of whether confounding factors were adjusted for, there was a positive correlation between dietary iron intake and hyperuricemia. In Model III, after adjusting for age, gender, race, educational background, body mass index, hypertension, carbohydrate intake, dietary fiber intake, total saturated fatty acid intake, vitamin K intake, vitamin C intake, marital status, poverty income ratio, smoking status, drinking status, work activity, diabetes, sodium intake, energy intake, protein intake, zinc intake, copper intake, selenium intake and total sugars intake, we found that compared to the lowest quintile of dietary iron intake (Q1, ≤ 8.03 mg/day), the odds ratios (ORs) for hyperuricemia in the second (Q2, 8.04-11.07 mg/day), third (Q3, 11.08-14.27 mg/day), fourth (Q4, 14.28-19.33 mg/day), and fifth quintiles (Q5, ≥ 19.34 mg/day) were 1.05 (95% confidence interval: 0.79-1.40), 1.30 (95% confidence interval: 0.99-1.73), 1.39 (95% confidence interval: 1.02-1.89), and 1.36 (95% confidence interval: 0.95-1.97), respectively. The study results indicate that a higher dietary iron intake is significantly positively associated with the likelihood of hyperuricemia.

CONCLUSION

In the adult population of the United States, there is a positive correlation between dietary iron intake and hyperuricemia, with higher dietary iron intake associated with an increased likelihood of hyperuricemia.

The impact of chrysanthemi indici flos-enriched flavonoid part on the model of hyperuricemia based on inhibiting synthesis and promoting excretion of uric acid

ETHNOPHARMACOLOGICAL RELEVANCE

In recent years, in addition to hypertension, hyperglycemia, and hyperlipidemia, the prevalence of hyperuricemia (HUA) has increased considerably. Being the fourth major health risk factor, HUA can affect the kidneys and cardiovascular system. Chrysanthemi Indici Flos is a flavonoid-containing traditional Chinese patent medicine that exhibits a uric acid (UA)-lowering effect. However, the mechanisms underlying Chrysanthemi Indici Flos-enriched flavonoid part (CYM.E) mediated alleviation of HUA remain unelucidated.

AIM OF THE STUDY

This study aimed to elucidate the efficacy of CYM.E in preventing and treating HUA and its specific effects on UA-related transport proteins, to explore possible mechanism.

METHODS

The buddleoside content in CYM.E was determined through high-performance liquid chromatography. HUA was induced in mice models using adenine and potassium oxonate. Subsequently, mice were administered 10 mg/kg allopurinol, and 30, 60, and 90 mg/kg CYM.E to evaluate the effects of CYM.E on the of HUA mice model. Herein, plasma uric acid (UA), creatinine (CR), blood urea nitrogen (BUN), total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c) contents, along with serum alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities were measured. Additionally, xanthine oxidase (XOD) and adenosine deaminase (ADA) activities in the liver were determined. The histomorphologies of the liver and kidney tissues were examined through hematoxylin and eosin staining. The messenger RNA (mRNA) expression of facilitated glucose transporter 9 (GLUT9), organic anion transporter (OAT)1, OAT3, and adenosine triphosphate binding cassette subfamily G2 (ABCG2) in the kidney was assessed by real-time quantitative polymerase chain reaction. Furthermore, the expression of urate transporter 1 (URAT1), GLUT9, OAT1, and OAT3 in the kidney, OAT4, and ABCG2 proteins was determined by immunohistochemistry and western blotting.

RESULTS

The buddleoside content in CYM.E was approximately 32.77%. CYM.E improved body weight and autonomous activity in HUA mice. Additionally, it reduced plasma UA, BUN, and CR levels and serum ALT and AST activities, thus improving hepatic and renal functions, which further reduced the plasma UA content. CYM.E reduced histopathological damage to the kidneys. Furthermore, it lowered plasma TC, TG, and LDL-c levels, thereby improving lipid metabolism disorder. CYM.E administration inhibited hepatic XOD and ADA activities and reduced the mRNA expression of renal GLUT9. CYM.E inhibited the protein expression of renal URAT1, GLUT9, and OAT4, and increased the mRNA and protein expression of renal OAT1, OAT3, and ABCG2. Altogether, these results show that CYM.E could inhibit the production and promote reabsorption of UA and its excretion.