Hyperuricemia and endothelial function: From molecular background to clinical perspectives

Uric acid and cardiovascular diseases: a reappraisal

Serum uric acid (SUA) has garnered an increased interest in recent years as an important determinant of cardiovascular disease. Uric acid, a degradation product of purine metabolism, is affected by several inheritable and acquired factors, such as genetic mutation, metabolic syndrome, chronic kidney disease, and medication interactions. Even though elevated SUA have been commonly associated with the development of gout, it has significant impact in the development of hypertension, metabolic syndrome, and cardiovascular disease. Uric acid, in both crystalline and soluble forms, plays a key role in the induction of inflammatory cascade and development of atherosclerotic diseases. This concise reappraisal emphasizes key features about the complex and challenging role of uric acid in the development and progression of atherosclerosis and cardiovascular disease. It explores the pathogenesis and historical significance of uric acid, highlights the complex interplay between uric acid and components of metabolic syndrome, focuses on the pro-inflammatory and pro-atherogenic effects of uric acid, as well as discusses the role of urate lowering therapies in mitigating the risk of cardiovascular disease while providing the latest evidence to the healthcare professionals focusing on the clinical importance of SUA levels with regards to cardiovascular disease.

Association of platelet to high-density lipoprotein cholesterol ratio with hyperuricemia

The platelet/high-density lipoprotein ratio (PHR) has been identified as a significant indicator of inflammation and a hypercoagulable state, demonstrating a strong link with the severity of nonalcoholic fatty liver disease (NAFLD) and metabolic syndrome (MetS). However, its correlation with hyperuricemia has not yet been documented. This study utilized a cross-sectional design, analyzing data collected from the National Health and Nutrition Examination Survey (NHANES) between 2007 and 2016 in the United States. The platelet/high-density lipoprotein ratio (PHR) was determined by dividing the number of platelets (PLT) by the level of high-density lipoprotein cholesterol (HDL-C). We employed multivariable logistic regression analyses, generalized additive models, and subgroup analyses to investigate the correlation between PHR and hyperuricemia. The study revealed a hyperuricemia prevalence of 18.56%. Analysis indicated a significant positive correlation between PHR and the risk of hyperuricemia (OR 1.11, 95% CI 1.08, 1.14). This correlation remained consistent across different subgroups including age, ethnicity, gender, and body mass index (BMI). Smooth curve fitting demonstrated a saturation effect between PHR and the risk of hyperuricemia. PHR is positively correlated with hyperuricemia and may serve as a novel biomarker for predicting the onset of this condition. Additionally, targeted interventions to improve PHR might help reduce the incidence of hyperuricemia.

Co-delivery of indomethacin and uricase as a new strategy for inflammatory diseases associated with high uric acid

Uric acid is the final metabolite in humans. High level of uric acid chronically induces urate deposition, aggravates kidney damage, and concomitantly causes an increase in inflammatory factors. Alleviating acute inflammation and decreasing uric acid levels are the key points in the treatment of inflammatory diseases associated with high uric acid. However, a drug delivery system that combines anti-inflammatory and uric acid reduction functions at the same time remains a challenge to be settled. Here, we designed a nanocrystal-based co-delivery platform, IND Nplex, characterized by loading of indomethacin (IND) and uricase. Compared with free IND or uricase, IND Nplex possessed a better anti-inflammatory effect by restraining the release of inflammation-related factors in vitro. In addition, pharmacokinetic and biodistribution studies revealed that IND Nplex significantly prolonged the retention time in vivo and was more concentrated in the kidney. In acute gouty arthritis model rats, IND Nplex markedly relieved ankle joint swelling and mitigated synovial inflammation. In acute kidney injury model rats, IND Nplex indicated better biocompatibility and significant amelioration of renal fibrosis. Moreover, IND Nplex showed the effect of anti-inflammatory and improved renal function via determination of inflammatory factors and biochemical markers in the serum and kidney. In conclusion, these results indicate that IND Nplex exerts anti-inflammatory activity and uric acid-lowering effect and could become a promising candidate for the treatment of uric acid-related diseases.

Frequently Encountered Artifacts in the Application of Dual-Energy Computed Tomography to Cardiovascular Imaging for Urate Crystals in Gout: A Matched-Control Study

OBJECTIVE

There is surging interest in using dual-energy computed tomography (DECT) to identify cardiovascular monosodium urate (MSU) deposits in patients with gout. We sought to examine the prevalence and characterization of cardiovascular DECT artifacts using non-electrocardiogram (EKG)-gated DECT pulmonary angiograms.

METHODS

We retrospectively reviewed non-EKG-gated DECT pulmonary angiograms performed on patients with and without gout at a single academic center. We noted the presence and locations of vascular green colorization using the default postprocessing two-material decomposition algorithm for MSU. The high- and low-energy grayscale images and advanced DECT measurements were used to determine whether they were true findings or artifacts. We classified artifacts into five categories: streak, contrast medium mixing, misregistration due to motion, foreign body, and noise.

RESULTS

Our study included CT scans from 48 patients with gout and 48 age- and sex-matched controls. The majority of patients were male with a mean age of 67 years. Two independent observers attributed all areas of vascular green colorization to artifacts. The most common types of artifacts were streak (56% vs 57% between patients and controls, respectively) and contrast medium mixing (51% vs 65%, respectively). Whereas some of the default DECT measurements of cardiovascular green colorization were consistent with values reported for subcutaneous tophi, advanced DECT measurements were not consistent with that of tophi.

CONCLUSION

Artifacts that could be misconstrued as cardiovascular MSU deposits were commonly identified in patients with and without gout on non-EKG-gated DECT pulmonary angiograms. These artifacts can inform future vascular DECT studies on patients with gout to minimize false-positive findings.

The Combination of Hyperuricemia and Elevated High-Sensitivity C-Reactive Protein Increased the Risk of Cardiac Conduction Block

Objective

This study aimed to explore the impact of a combination of hyperuricemia (HUA) and excessive high-sensitivity C-reactive protein (hs-CRP) levels on the likelihood of developing cardiac conduction block (CCB). Additionally, it sought to assess whether the influence of uric acid (UA) on CCB is mediated by hs-CRP.

Methods

A prospective study was executed utilizing data from the Kailuan cohort, including 81,896 individuals initially free from CCB. The participants were categorized into four groups depending on the existence of HUA and low-grade inflammation (hs-CRP>3 mg/L). Cox regression analysis was employed to ascertain hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of incident CCB. A mediation analysis was performed to determine if hs-CRP functioned as a mediator in the connection between UA levels and the incidence of CCB.

Results

During a median observation period of 11.8 years, we identified 3160 cases of newly occurring CCB. Compared with the low UA/low CRP group, the combination of HUA and low-grade inflammation elevated the CCB risks (HR:1.56, 95% CI:1.22-1.99), atrioventricular block (AVB) (HR:1.88, 95% CI:1.27-2.77), and right bundle branch block (HR:1.47, 95% CI:1.02-2.12), respectively. Mediation analysis revealed that in the HUA group, compared with the non-HUA group, the risk of CCB elevated by 14.0%, with 10.3% of the increase mediated through hs-CRP.

Conclusion

HUA combined with elevated hs-CRP increased the risk of CCB, especially AVB. The connection between UA and the CCB risk was partly mediated by hs-CRP.

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.

Association of serum uric acid level with intracranial aneurysms: A Mendelian randomization study

Objective

Numerous studies have posited the involvement of serum uric acid (SUA) in the pathogenesis and progression of various cardiovascular diseases, particularly aortic aneurysms. However, the casual effect of SUA level on intracranial aneurysms (IAs) was rarely studied. Consequently, we aimed to explore the causal association between SUA and IAs using Mendelian randomization (MR) analysis.

Methods

We conducted a two-sample MR analysis with SUA as the exposure variable and IAs as the outcome variable. Genome-wide association study (GWAS) datasets for SUA were acquired from the Open GWAS catalog, including 389,404 European and 129,405 East Asian individuals. The dataset for IAs was sourced from a meta-analysis of GWASs comprising 317,636 individuals across different ancestral populations (European: 7495 cases and 71,934 controls; East Asian: 3259 cases and 234,948 controls). The MR analyses were performed according to populations (European and East Asian) and IAs status [unruptured IAs (uIAs) or aneurysmal subarachnoid hemorrhage (aSAH)], respectively. The inverse variance weighted (IVW) method was employed as primary analysis to discern causal estimates.

Results

Our findings revealed that an elevated genetically predicted SUA level (mg/dL) correlated with an increased risk of IAs among the European population (OR = 1.29 [95%CI:1.05-1.57], P = 0.013) and East Asian population (OR = 1.56 [95%CI: 1.27-1.92], P < 0.001). Among European individuals, subgroup analysis indicated a persistent causal association of SUA with uIAs (OR = 1.50 [95%CI: 1.08-2.08], P = 0.015) and aSAH (OR = 1.26 [95%CI: 1.00-1.60], P = 0.049). However, subgroup analysis in East Asian populations was not conducted due to the lack of separate data on uIAs and aSAH.

Conclusions

Our MR analysis demonstrated a causal relationship between elevated SUA levels and an amplified risk of IAs. Further rigorous investigations are imperative to provide evidence and elucidate the underlying mechanisms.

Association between primary angle closure glaucoma and uric acid levels in serum and aqueous humor

Purpose

To evaluate abnormalities in serum and aqueous humor uric acid (UA) levels in primary angle closure glaucoma (PACG).

Methods

Patients with PACG and age-similar and gender-similar controls (patients scheduled for cataract extraction) were enrolled prospectively. Serum UA levels were determined by enzymatic colorimetry; aqueous humor UA levels by Enzyme-Linked ImmunoSorbent Assay. A t-test was used to compare UA levels between PACG patients and controls, with one-way ANOVA used to compare levels across PACG subgroups with differing disease severity. Comparisons between PACG patients and controls were adjusted for systemic and ocular confounding factors using binary logistic regression.

Results

In all, 131 PACG patients and 112 controls were included. The serum UA level was 266 ± 69 μmol/L in the PACG group and 269 ± 73 μmol/L in the control group (p = 0.71). The aqueous humor UA level was 35.4 ± 8.2 μmol/L in the PACG group and 53.9 ± 18.6 μmol/L in the control group (p < 0.001). This difference remained significant after adjusting for age, gender, systolic blood pressure, diastolic blood pressure, body mass index, axial length, central corneal thickness, anterior chamber depth, lens thickness, white-to-white distance, corneal endothelial cell density, and serum UA level (odds ratio: 0.88, 95 % confidence interval: 0.83-0.93, p < 0.001).

Conclusion

Aqueous humor UA levels differ between PACG patients and controls, but serum UA levels do not. This indicates that local UA plays a role in the pathogenesis of PACG, but systemic UA does not.

Tophi and carotid atherosclerosis in gout patients: Role of insulin resistance

BACKGROUND AND AIM

Gout and cardiovascular disease are closely related, but the mechanism linking them is still unknown. Gout may affect the insulin signaling pathway inducing insulin resistance (IR). The study aims to evaluate the association between tophi and carotid atherosclerosis, considering the potential role of IR.

METHODS AND RESULTS

A total of 595 patients with gout aged 18 to 80 were enrolled in this study. Carotid intima-media thickness, plaques and tophi were evaluated by B-mode ultrasonography. IR was assessed by the HOMA index (hepatic IR) and Gutt index (peripheral IR). Multivariable logistic regression and interaction analysis were used to examine the association between tophi and IR and its impact on carotid atherosclerosis. Among these participants, the average age was 55.4 (±12.54) years, and 94.6 % were male. Tophi were associated with increased odds of carotid atherosclerosis and burden after adjustment for confounders (P < 0.05). Tophi and IR synergically interacted for inducing carotid atherosclerosis. The interaction between peripheral IR with tophi was more pronounced than hepatic IR with tophi.

CONCLUSIONS

Tophi were independently associated with carotid atherosclerosis risk. IR mediated a significant amount of the effect of tophi on the development of carotid atherosclerosis. Peripheral IR probably plays a more important role than hepatic IR does.

Prediction of Acute Kidney Injury After Coronary Artery Bypass Graft From Preoperative Serum Uric Acid

OBJECTIVE

To examine the association of an elevated level of uric acid (UA) in the bloodstream with an increased likelihood of acute kidney injury (AKI) following coronary artery bypass grafting (CABG) surgery.

DESIGN

Retrospective cohort study using a multivariate logistic regression model.

SETTING

Single institution.

PARTICIPANTS

Recipients of CABG surgery.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

A total of 761 individuals who underwent CABG were included in the study. The participants were categorized into 4 groups based on their UA level: Q1 group (UA <292.5 μmol/L), Q2 group (292.5 ≤ UA <353 μmol/L), Q3 group (353 ≤ UA < 423 μmol/L), and Q4 group (UA ≥423 μmol/L). A total of 167 patients, accounting for 21.9% of the sample, experienced postoperative AKI. The study found a significantly higher risk of AKI in the Q4 group compared to the Q1 group (40.4% v 8.9%; p < 0.001). After adjustment for confounding variables, an independent association between serum UA concentration and an elevated risk of AKI post-CABG was identified (odds ratio, 6.41; 95% confidence interval, 3.49-12.32; p < 0.001; p for trend < 0.001).

CONCLUSIONS

There is a relationship between preoperative blood UA level and the occurrence of AKI following CABG surgery.

Timing of Initiation of Xanthine Oxidase Inhibitors Based on Serum Uric Acid Level Does Not Predict Renoprognosis in Patients with Preserved Kidney Function

Background: Despite recent evidence of remaining possibility that early initiation of xanthine oxidase inhibitors (XOIs) is beneficial in renoprognosis for patients with stage 2 or less chronic kidney disease (CKD), no evidence is available regarding the difference in renoprognosis based on serum uric acid (sUA) levels at the initiation of XOIs among patients with preserved kidney function. Methods: New XOI initiators were divided into quartiles based on baseline sUA. Primary outcome was the composite incidence of a significant estimated glomerular filtration rate (eGFR) decline (≥40% decline in eGFR from baseline or development of eGFR <30 mL/1.73 m2/min) or all-cause death within 5 years. Results: After excluding inapplicable patients, 1170 XOI initiators were analyzed (mean ± standard deviation age: 68 ± 14.3 years; sUA: 10.6 ± 1.15 mg/dL). On overall median [interquartile range (IQR)] follow-up of 824 (342, 1576) days, incidence rate of the primary outcome was 287 per 1000 person-years for 5 years. Although the nonadjusted model showed a dose-response association between baseline sUA level and the outcome, the adjusted model showed no significant association. Adjusted hazard ratios (95% confidence interval) of the second, third, and fourth quartiles of baseline sUA with the composite outcome within 5 years compared to the first quartile were 1.00 (0.78, 1.29), 1.00 (0.80, 1.30), and 1.02 (0.80, 1.32), respectively. Conclusions: Early initiation of XOIs did not predict a significant benefit on renoprognosis even among the population with preserved kidney function. The validity of initiating XOIs with the aim of improving renoprognosis based on sUA is questionable.

Association between serum uric acid and deep venous thrombosis in European populations: A two-sample Mendelian randomization study

BACKGROUND AND AIM

Previous experimental and observational studies showed that serum uric acid (SUA) was associated with deep venous thrombosis (DVT), but the causal relationship is unclear. This study aimed to explore the potential causal association between SUA and DVT.

METHODS AND RESULTS

We designed a two-sample Mendelian randomization (MR) analysis by using summary-level data from large genome-wide association studies performed in European individuals. A total of 14 SUA-related single-nucleotide polymorphisms (SNPs) (P value < 5 × 10-8) were identified as instrumental variables. The inverse variance weighted method was used as the primary method to compute the odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for per standard deviation increase in SUA. MR Egger, weighted median, weighted mode, and simple mode were also applied to test the robustness of the results. We found no significant causal effects of serum uric acid on deep venous thrombosis (odds ratio [OR]: 1.000, 95 % confidence interval [CI]: 0.998-1.002, p = 0.78) by using inverse variance weighted. MR analyses based on other methods showed similar results.

CONCLUSIONS

There was no potential causal associations between higher genetically predicted SUA levels and increased risk of deep venous thrombosis. Further, MR studies with more valid SNPs and more DVT cases are needed. Validation of the findings is also recommended.

Serum uric acid level is associated with glomerular ischemic lesions in patients with primary membranous nephropathy: an analytical, cross-sectional study

To investigate the relationship between serum uric acid level and glomerular ischemic lesions (GIL) in patients with primary membranous nephropathy (PMN) and identify relevant risk factors. A total of 201 patients with PMN but normal renal function confirmed by renal biopsy executed in the Liaocheng People's Hospital, China, during January 2020-January 2023 were analyzed retrospectively. The enrolled patients were divided into a hyperuricemia group and a normal serum uric acid group (control group) according to their serum uric acid levels. Then, the participants were further divided into a non-GIL group or a GIL group based on the patient's renal biopsy results. The two groups' clinical and pathological data and meaningful indicators for differences were analyzed by binary logistic regression analysis. Additionally, the serum uric acid level prediction value on GIL was investigated using receiver operating characteristic (ROC) curves. Compared with the control group, the hyperuricemia group exhibited high serum uric acid, the prevalence of GIL, serum albumin, the prevalence of hypertension, and low-density lipoprotein cholesterol (LDL) levels (P < 0.05). Compared with the non-GIL group, the GIL group exhibited were older, had enhanced serum uric acid, serum albumin, and an increased prevalence of tubular atrophy/interstitial fibrosis (TA/IF), arteriolosclerosis, and low eGFR levels (P < 0.05). The binary logistic regression analysis revealed that the serum uric acid and the TA/IF are independent risk factors of GIL (P < 0.05). The AUC of ROC of GIL of PMN patients, predicted based on the serum uric acid concentration, was 0.736 (P < 0.05), wherein the threshold = 426.5 μmol/L and the Youden's index = 0.41. Serum uric acid concentration and the TA/IF are independent risk factors of GIL in patients with PMN, and the former exhibits prediction value on GIL in patients with PMN.

Impact of Hyperuricemia and Urate-Lowering Agents on Cardiovascular Diseases

The association between hyperuricemia and cardiovascular diseases has been studied for many years. Research has shown a link between high uric acid levels and increased risk of including coronary artery disease hypertension and other cardiovascular conditions. Urate-lowering therapy, particularly with xanthine oxidase inhibitors like allopurinol, has shown promising results in reducing blood pressure in individuals with hyperuricemia and hypertension. Clinical trials and studies have demonstrated significant reductions in both systolic and diastolic blood pressure with urate-lowering treatment. Urate-lowering treatment has shown a favorable effect on reducing systolic blood pressure and major adverse cardiovascular events in patients with previous cardiovascular disease. In terms of cardiovascular safety, clinical trials have indicated that xanthine oxidase inhibitors such as febuxostat are non-inferior to allopurinol and do not increase the risk of death or serious adverse events. Overall, these findings highlight the importance of managing hyperuricemia and utilizing urate-lowering therapy to mitigate the adverse cardiovascular effects associated with elevated uric acid levels.

Uncovering the Potential Mechanisms and Effects of Hyperuricemia and its Associated Diseases on Male Reproduction

Male fertility and metabolic disorders, including obesity and diabetes, are closely connected. Since hyperuricemia and metabolic syndrome are strongly related, male fertility and hyperuricemia may, to some degree, be associated. According to recent studies, hyperuricemia imposes various effects on sex hormones, semen quality, and male erectile dysfunction. Some researchers claim that uric acid worsens male semen and raises the risk of erectile dysfunction (ED), while others state that it safeguards both penile erection and male semen. Additionally, it has been shown that gout and metabolic syndrome also raise the risk of ED. To clarify this controversy, the influence and potential mechanisms of hyperuricemia on ED, semen quality, sex hormone levels, and the effects of hyperuricemia-related disorders on ED will be comprehensively summarized.

Identification of hub genes and transcription factors in patients with primary gout complicated with atherosclerosis

Evidence shows that primary gout is prone to develop to atherosclerosis, but the mechanism of its occurrence is still not fully clarified. The aim of this study was to explore the molecular mechanism of the occurrence of this complication in gout. The gene expression profiles of primary gout and atherosclerosis were downloaded from the gene expression omnibus database. Overlapping differentially expressed genes (DEGs) between gout and atherosclerosis were identified. The biological roles of common DEGs were explored through enrichment analyses. Hub genes were identified using protein-protein interaction networks. The immune infiltrations of 28 types of immune cells in gout and control samples from GSE160170 were evaluated by the ssGSEA method. Transcription factors (TFs) were predicted using Transcriptional Regulatory Relationships Unraveled by Sentence Based Text Mining (TRRUST) database. A total of 168 overlapping DEGs were identified. Functional enrichment analyses indicated that DEGs were mostly enriched in chemokine signaling pathway, regulation of actin cytoskeleton, and TNF signaling pathway. CytoScape demonstrated 11 hub genes and two gene cluster modules. The immune infiltration analysis showed that the expression of DEGs in gout was significantly upregulated in activated CD4 T cells, gamma delta T cells, T follicular helper cell, CD56dim natural killer cells, and eosinophil. TRRUST predicted one TF, RUNX family transcription factor 1. Our study explored the pathogenesis of gout with atherosclerosis and discovered the immune infiltration of gout. These results may guide future experimental research and clinical transformation.

Analysis of the Model of Atherosclerosis Formation in Pig Hearts as a Result of Impaired Activity of DNA Repair Enzymes

Excessive consumption of food rich in saturated fatty acids and carbohydrates can lead to metabolic disturbances and cardiovascular disease. Hyperlipidemia is a significant risk factor for acute cardiac events due to its association with oxidative stress. This leads to arterial wall remodeling, including an increase in the thickness of the intima media complex (IMT), and endothelial dysfunction leading to plaque formation. The decreased nitric oxide synthesis and accumulation of lipids in the wall result in a reduction in the vasodilating potential of the vessel. This study aimed to establish a clear relationship between markers of endothelial dysfunction and the activity of repair enzymes in cardiac tissue from a pig model of early atherosclerosis. The study was conducted on 28 female Polish Landrace pigs, weighing 40 kg (approximately 3.5 months old), which were divided into three groups. The control group (n = 11) was fed a standard, commercial, balanced diet (BDG) for 12 months. The second group (n = 9) was fed an unbalanced, high-calorie Western-type diet (UDG). The third group (n = 8) was fed a Western-type diet for nine months and then switched to a standard, balanced diet (regression group, RG). Control examinations, including blood and urine sampling, were conducted every three months under identical conditions with food restriction for 12 h and water restriction for four hours before general anesthesia. The study analyzed markers of oxidative stress formed during lipid peroxidation processes, including etheno DNA adducts, ADMA, and NEFA. These markers play a crucial role in reactive oxygen species analysis in ischemia-reperfusion and atherosclerosis in mammalian tissue. Essential genes involved in oxidative-stress-induced DNA demethylation like OGG1 (8-oxoguanine DNA glycosylase), MPG (N-Methylpurine DNA Glycosylase), TDG (Thymine-DNA glycosylase), APEX (apurinic/apirymidinic endodeoxyribonuclease 1), PTGS2 (prostaglandin-endoperoxide synthase 2), and ALOX (Arachidonate Lipoxygenase) were measured using the Real-Time RT-PCR method. The data suggest that high oxidative stress, as indicated by TBARS levels, is associated with high levels of DNA repair enzymes and depends on the expression of genes involved in the repair pathway. In all analyzed groups of heart tissue homogenates, the highest enzyme activity and gene expression values were observed for the OGG1 protein recognizing the modified 8oxoG. Conclusion: With the long-term use of an unbalanced diet, the levels of all DNA repair genes are increased, especially (significantly) Apex, Alox, and Ptgs, which strongly supports the hypothesis that an unbalanced diet induces oxidative stress that deregulates DNA repair mechanisms and may contribute to genome instability and tissue damage.

Association of serum uric acid levels with blood pressure and the incidence of hypertension in the middle-aged and elderly populations

OBJECTIVE

This study aimed to investigate the relationship between serum uric acid (SUA) levels and hypertension in the middle-aged and elderly populations.

METHODS

The cross-sectional analysis included 13 349 middle-aged and elderly general health checkup examinees without cardiovascular disease. The retrospective cohort analysis included 6659 normotensive participants (mean age: 64.6 years). Participants were divided into three groups based on their SBP/DBP levels: normal (<120/<80 mmHg), high normal (120-129/<80 mmHg), and elevated (130-139/80-89 mmHg), and were classified into three groups based on the results of 75 g oral glucose tolerance test: normoglycemia, prediabetes, and diabetes.

RESULTS

SUA levels were significantly associated with SBP and DBP in this cross-sectional study. Over a mean 6.5-year follow-up period, 2038 participants developed hypertension. According to the SUA quartiles, the incidence of hypertension increased [26.1% in quartile (Q1) (≤4.1 mg/dl), 28.6% in Q2 (4.2-4.9 mg/dl), 32.6% in Q3 (5.0-5.8 mg/dl), 34.9% in Q4 (≥5.9 mg/dl); P for trend <0.001]. In multivariable analyses, SUA levels were positively associated with hypertension incidence only in the normal BP group [Q4 vs. Q1 odds ratio (OR): 1.64, 95% confidence intervals (CIs): 1.11-2.44; Q3 vs. Q1 OR: 1.69, 95% CI: 1.19-2.42] and in the normoglycemic group (Q4 vs. Q1 OR: 1.34, 95% CI: 1.02-1.76; Q3 vs. Q1 OR: 1.36, 95% CI: 1.07-1.74).

CONCLUSION

In the middle-aged and elderly populations, normotensive or normoglycemic individuals with SUA levels at least 5 mg/dl may be potential targets for SUA management to prevent hypertension.

Risk factors for peripheral artery disease and diabetic peripheral neuropathy among patients with type 2 diabetes

AIMS

To investigate the prevalence of peripheral artery disease (PAD) and diabetic peripheral neuropathy (DPN) and the associated risk factors among Chinese patients with type 2 diabetes mellitus.

METHODS

A cross-sectional study was conducted using data between November 1, 2018, and December 31, 2022. PAD was defined as ABI ≤ 0.9. DPN diagnosis involved specialized physician assessments using questionnaires and vibration perception threshold tests. Logistic regression analysis was used to identify related factors. We also evaluated the association between the clustering of risk factors and disease incidence.

RESULTS

The study population comprised 13,315 patients (mean age: 63.3 years). 4.9 % of the patients had PAD and 43.9 % had DPN. Multivariate regression analysis revealed advanced age, smoking, hypertension, coronary heart disease, dyslipidemia, elevated HbA1c, and uric acid levels as independent risk factors for PAD. For DPN, independent risk factors included advanced age, female gender, hypertension, coronary heart disease, elevated total cholesterol, triglycerides, lipoprotein(a), fasting plasma glucose, HbA1c, alkaline phosphatase, cystatin C, albumin-to-creatinine ratio, and elevated homocysteine levels, whereas apolipoprotein A was a protective factor. The clustering of risk factors was prevalent and associated with higher disease risk.

CONCLUSIONS

Our study contributed to identifying high-risk individuals and improving lower limb health among diabetic individuals.

All-cause and specific mortality in patients with gout: A systematic review and meta-analysis

OBJECTIVES

This meta-analysis aims to examine the general mortality risk and specific mortality risk of gout, as the incidence of the condition is on the rise but information on mortality rates remains uncertain.

METHOD

The researchers conducted a search of published cohort studies on gout and mortality using Medical subject headings and keywords in PubMed, EMBASE, and Cochrane Library databases from inception to September 2022. The quality of study was evaluated using the NOS scale. Statistical analysis was performed using STATA software (version 16.0). Publication bias was assessed using funnel plots and Egger's test.

RESULT

This meta-analysis included 11 cohort studies (2010-2022), covering 14,854,490 people with a follow-up time of 1.66-16 years. The pooled analysis shows increased risk of overall mortality [HR=1.23, 95 % CI (1.13-1.35), I2=96.4 %, P<0.001], cardiovascular mortality [HR=1.29, 95 % CI (1.13-1.48), I2=98.5 %, P<0.001], infection mortality [HR=1.24, 95 % CI (1.04-1.47), I2=88.5 %, P = 0.019], and digestive system disease mortality [HR=1.42, 95 % CI (1.13-1.80), I2=91.7 %, P = 0.003] in gout. Sensitivity and subgroup analysis support the findings, and publication bias was not evident.

CONCLUSION

The findings from our meta-analysis indicate that gout is associated with an increased risk of all-cause mortality, as well as mortality related to cardiovascular disease, infections, and digestive system diseases. This has important implications for clinical practice, nursing care of patients with gout, and guidance on lifestyle modifications to prevent adverse outcomes such as cardiovascular events, infections, and digestive disorders.

The Correlation of Serum Uric Acid Levels With the Severity of Coronary Artery Disease in Diabetic Patients: A Cross-Sectional Study

Background and aim  Coronary artery disease (CAD) is a severe and life-threatening complication in patients with diabetes, resulting in significant morbidity and death burden globally. Although serum uric acid levels have been linked to the aetiology of both CAD and diabetes, the association between uric acid and CAD severity in diabetic patients remains unknown. This study aimed to investigate the relationship between serum uric acid levels and the severity of CAD in patients with diabetes undergoing coronary angiography. This study also compared patient parameters and comorbidities linked with high uric acid levels. Material and methods This cross-sectional study was conducted at the Lady Reading Hospital in Peshawar, Pakistan, from October 20, 2022, to September 20, 2023. A total of 290 patients with diabetes were enrolled. These participants were divided into groups depending on their serum uric acid levels: Group A (n = 145) and Group B (n = 145). On average, patients in Group A had high serum uric acid levels, whereas those in Group B had normal serum uric acid levels. Coronary angiograms were analysed using well-established assessment methods to determine the severity of CAD using the Syntax score as the mean score was greater for Group A with higher serum uric acid levels than Group B.  Results The mean age of patients in Group A was 59.2±7.1 years, whereas in Group B, it was 60.5±6.8 years. The percentage of male patients in Group A was 62% and 58.6% in Group B. The mean BMI for group A was 28.4±2.3 kg/m2, while the mean BMI for group B was 27.9±2.1 kg/m2. In both groups, the prevalence of hypertension, dyslipidemia and family history of CAD did not differ significantly. Group A's mean serum uric acid levels were 8.17 ± 1.64, while in Group B, 5.03 ± 1.09. Similarly, the mean Syntax score, which is a visual estimate of CAD burden and complexity, was higher in Group A (37.59 ± 3.41) compared to Group B (26.44 ± 2.97), and the difference was statistically significant (p = 0.001). The severity of CAD based on syntax score was found to be significantly different in both groups (p=0.04). Conclusion This study illustrates that patients with high uric acid levels are more likely to have CAD as indicated by a higher mean Syntax score in Group A compared to Group B. However, serum uric acid levels alone cannot accurately predict the severity of CAD on coronary angiography in diabetic patients. These findings add to the evidence already available, emphasizing the significance of serum uric acid as a potential biomarker for risk stratification in this vulnerable population.

Uric acid and evaluate the coronary vascular stenosis gensini score correlation research and in gender differences

BACKGROUND AND AIMS

Recent studies have shown that the negative effect of uric acid (UA) on coronary arteries determines the severity of atherosclerotic disease. This study aims to explore the relationship between serum UA level and Gensini score, which reflects the severity of coronary artery disease.

METHODS

A total of 860 patients with suspected coronary heart disease who were admitted to hospital due to angina pectoris or myocardial ischemia related symptoms and received coronary angiography were selected. Based on the findings of the angiography, they were categorized into two groups: the coronary heart disease (CHD) group (n = 625) and the control group (n = 235). The uric acid levels and other clinical data were compared between these groups. Additionally, the prevalence of coronary heart disease and Gensini score were compared between the groups, considering gender-specific quartiles of uric acid levels. The clinical baseline data were analyzed using appropriate statistical methods, and multivariate logistic regression analysis was conducted to identify independent risk factors for coronary heart disease.

RESULTS

Of 860 patients (mean age, 63.97 ± 11.87 years), 528 were men (mean age, 62.06 ± 11.5 years) and 332 were women (mean age, 66.99 ± 10.11 years). The proportion of smoking, diabetes, hypertension, and hyperlipidemia in the coronary heart disease group was higher than that in the control group (P < 0.05). HbA1C, Gensini score, BMI, TG and hsCRP in the coronary heart disease group were higher than those in the control group (P < 0.05), and HDL-C was lower than that in the control group (P < 0.05). There were no significant differences in age, heart rate, Cr, TC and LDL-C between the two groups (P > 0.05).Multivariate logistic regression analysis showed that age, hypertension, hsCRP and SUA levels increased the risk of coronary heart disease, and the difference was statistically significant(OR = 1.034,95%CI 1.016-1.052, P = 0.001; OR = 1.469,95%CI 1.007-2.142, P = 0.046;OR = 1.064,95%CI 1.026-1.105, P = 0.001; OR = 1.011,95%CI 1.008-1.014, P < 0.001).

CONCLUSION

Serum uric acid is positively correlated with Gensini score in patients with coronary heart disease, which is an independent factor for evaluating the degree of coronary artery stenosis and has a predictive effect.

Efficacy of Allopurinol in Improving Endothelial Dysfunction: A Systematic Review and Meta-Analysis

INTRODUCTION

Endothelial dysfunction has been implicated in various cardiovascular disorders as the initial pathology. Allopurinol has been shown to improve endothelial dysfunction in patients with gout, but its effect on cardiovascular patients is unclear.

AIMS

We aim to assess allopurinol efficacy in improving endothelial dysfunction overall and in different disease states including but not limited to heart failure, chronic kidney disease, ischemic heart disease METHODS: We conducted a literature search of PubMed, Cochrane's Central Library, and Scopus until December 2022, including randomized controlled trials and double-arm observational studies. The primary outcome measure was endothelial function assessed by change in flow mediated dilation (FMD) RESULTS: Our meta-analysis included 22 studies with a total of 1472 patients. Our pooled analysis shows that allopurinol significantly improved FMD (WMD = 1.46%, 95% CI [0.70, 2.22], p < 0.01) compared to control. However, there was no significant difference between allopurinol and control for endothelial-independent vasodilation measured by forearm blood flow (WMD = 0.10%, 95% CI [- 0.89, 0.69], p = 0.80). Subgroup analysis indicated that the effect of allopurinol on FMD was more significant in diabetic and congestive heart failure patients.

CONCLUSION

While allopurinol may improve endothelial function in various patient populations, further high-quality randomized controlled trials are needed to determine its efficacy in preventing cardiovascular disease exacerbation.

Exploring the Multifaceted Nexus of Uric Acid and Health: A Review of Recent Studies on Diverse Diseases

The prevalence of patients with hyperuricemia or gout is increasing worldwide. Hyperuricemia and gout are primarily attributed to genetic factors, along with lifestyle factors like consuming a purine-rich diet, alcohol and/or fructose intake, and physical activity. While numerous studies have reported various comorbidities linked to hyperuricemia or gout, the range of these associations is extensive. This review article focuses on the relationship between uric acid and thirteen specific domains: transporters, genetic factors, diet, lifestyle, gout, diabetes mellitus, metabolic syndrome, atherosclerosis, hypertension, kidney diseases, cardiovascular diseases, neurological diseases, and malignancies. The present article provides a comprehensive review of recent developments in these areas, compiled by experts from the Young Committee of the Japanese Society of Gout and Uric and Nucleic Acids. The consolidated summary serves to enhance the global comprehension of uric acid-related matters.

Uric acid index is a risk for mild cognitive impairment in type 2 diabetes

BACKGROUND

A new uric acid (UA) index has recently been proposed, while serum uric acid (SUA), fasting triglyceride, and fasting blood glucose levels in the index are shown to affect cognitive function. This study aims to investigate the clinical value of the UA index for assessing mild cognitive impairment (MCI) in type 2 diabetes (T2D) patients.

METHODS

This was an observational cross-sectional study with 616 participants. A generalized additive model was used to determine a linear or curvilinear relationship between cognitive performance and the UA index. Logistic regression and random forest models were both developed. A receiver operating characteristic curve (ROC) was delineated and the area under the curve (AUC) was calculated.

RESULTS

MCI was diagnosed in 313 participants (50.81%). Compared with the T2D-normal cognitive function group, MCI subjects had higher UA indexes, lower cognitive scores, and lower education levels (p < 0.001). Generalized additive models showed the UA index and the Montreal Cognitive Assessment (MoCA) score to be decreased linearly (p < 0.001). The UA index AUC was 0.751 (95% CI = 0.713-0.789, p < 0.001). The optimal cut-off point for the identification of MCI based on the UA index was 11.26 (sensitivity: 62.3%, specificity: 75.9%). Results for females in the cohort yielded an AUC change of + 2.5%, the less-educated population (AUC change of + 4.7%), and the hypertensive population (AUC change of + 1.1%). The AUCs were 0.791 (95% CI = 0.720-0.863) for the random forest model and 0.804 (95% CI = 0.770-0.837) for the logistic regression model, and no statistical significance was found (p = 0.758).

CONCLUSION

This study showed that the increased UA index was independently associated with MCI in patients with T2D, especially among female, less-educated, and hypertensive patients. It could be a potential indicator of MCI in T2D patients.

Non-Conventional Risk Factors: "Fact" or "Fake" in Cardiovascular Disease Prevention?

Cardiovascular diseases (CVDs), such as arterial hypertension, myocardial infarction, stroke, heart failure, atrial fibrillation, etc., still represent the main cause of morbidity and mortality worldwide. They significantly modify the patients' quality of life with a tremendous economic impact. It is well established that cardiovascular risk factors increase the probability of fatal and non-fatal cardiac events. These risk factors are classified into modifiable (smoking, arterial hypertension, hypercholesterolemia, low HDL cholesterol, diabetes, excessive alcohol consumption, high-fat and high-calorie diet, reduced physical activity) and non-modifiable (sex, age, family history, of previous cardiovascular disease). Hence, CVD prevention is based on early identification and management of modifiable risk factors whose impact on the CV outcome is now performed by the use of CV risk assessment models, such as the Framingham Risk Score, Pooled Cohort Equations, or the SCORE2. However, in recent years, emerging, non-traditional factors (metabolic and non-metabolic) seem to significantly affect this assessment. In this article, we aim at defining these emerging factors and describe the potential mechanisms by which they might contribute to the development of CVD.

Asymptomatic hyperuricemia associated with increased risk of nephrolithiasis: a cross-sectional study

BACKGROUND

Existing evidence shows that there is an independent correlation between nephrolithiasis and gout, and hyperuricemia is the most important risk factor for gout. However, hyperuricemia was often used as an accompanying symptom of gout to explore its association with nephrolithiasis, there were few studies to explore whether hyperuricemia itself or serum uric acid (SUA) is related to the risk of nephrolithiasis. Evidence on the relationship between hyperuricemia and nephrolithiasis is still insufficient.

METHODS

A total of 22,303 participants aged 30 to 79 years who participated in the China Multi-Ethnic Cohort (CMEC) study in Yunnan Province from May 2018 to September 2019 were included in the study. All participants received standardized face-to-face interviews, medical examinations, and biochemical examinations. Logistic regression was used to estimate the association between hyperuricemia and nephrolithiasis, and a restricted cubic spline (RCS) model was used to explore the dose-response relationship between SUA and the risk of nephrolithiasis.

RESULTS

14.5% of all participants were diagnosed with hyperuricemia, and 12.1% were diagnosed with nephrolithiasis. After adjusting for all potential confounders, the OR (95%CI) for nephrolithiasis in participants with hyperuricemia compared with participants without hyperuricemia was 1.464 (1.312,1.633), p < 0.001. Restricted cubic spline regression analysis showed that the risk of nephrolithiasis increased with the increase of SUA, and when the level of SUA is higher than 356 μmol/L in males and higher than 265 μmol/L in females, there is a dose-response relationship between the increase of SUA and the risk of nephrolithiasis in both males and females (p for nonlinearity = 0.1668, p for nonlinearity = 0.0667).

CONCLUSION

Asymptomatic hyperuricemia is associated with an increased risk of developing nephrolithiasis. Before reaching the diagnostic criteria for hyperuricemia, the risk of nephrolithiasis rises with the increase in SUA. This suggests that controlling SUA levels may be significant for the prevention of nephrolithiasis.

Hyperuricemia promotes the progression of atherosclerosis by activating endothelial cell pyroptosis via the ROS/NLRP3 pathway

Hyperuricemia closely correlates with the development of atherosclerosis, but little is known of the mechanism by which atherosclerosis progression occurs in hyperuricemia. Atherosclerosis appears to involve pyroptosis, an emerging mechanism of proinflammatory regulated cell death. This study tested the hypothesis that pyroptosis underlies the relationship between hyperuricemia and atherosclerosis, using ApoE-/- mice (a model of atherosclerosis), human umbilical vein endothelial cells (HUVECs), and human atherosclerotic arterial samples. We found that hyperuricemia can aggravate the aortic atherosclerotic plaque-load in ApoE-/- mice and promote endothelial cell pyroptosis. Additionally, hyperuricemia can increase the levels of serum inflammatory factors (including IL-1β and IL-18). Exposure to lipopolysaccharide plus a high concentration of soluble uric acid (≥12 mg/dL) induced cell pyroptosis in HUVECs, as evidenced by increased expression of pyroptosis-related proteins and elevated release of lactate dehydrogenase (a marker of tissue damage). Further, MCC950, a selective nucleotide-binding oligomerization domain (NOD)-like receptor 3 (NLRP3) inflammasome inhibitor, and N-acetyl- l-cysteine, an antioxidant, attenuated HUVEC pyroptosis by inhibiting activation of the NLRP3 inflammasome and production of intracellular reactive oxygen species (ROS). Finally, we detected significantly higher expression of pyroptosis-associated proteins in carotid specimens from patients with hyperuricemia. Collectively, our findings suggest that hyperuricemia can aggravate endothelial cell pyroptosis in aortic atherosclerotic plaques, promoting the development of atherosclerosis. Additionally, a high concentration of soluble uric acid can trigger the activation stage of the NLRP3 inflammasome, mediating endothelial cell pyroptosis, and this process is regulated by the cellular ROS level.

Does the Micronutrient Molybdenum Have a Role in Gestational Complications and Placental Health?

Molybdenum is an essential trace element for human health and survival, with molybdenum-containing enzymes catalysing multiple reactions in the metabolism of purines, aldehydes, and sulfur-containing amino acids. Recommended daily intakes vary globally, with molybdenum primarily sourced through the diet, and supplementation is not common. Although the benefits of molybdenum as an anti-diabetic and antioxidant inducer have been reported in the literature, there are conflicting data on the benefits of molybdenum for chronic diseases. Overexposure and deficiency can result in adverse health outcomes and mortality, although physiological doses remain largely unexplored in relation to human health. The lack of knowledge surrounding molybdenum intake and the role it plays in physiology is compounded during pregnancy. As pregnancy progresses, micronutrient demand increases, and diet is an established factor in programming gestational outcomes and maternal health. This review summarises the current literature concerning varied recommendations on molybdenum intake, the role of molybdenum and molybdoenzymes in physiology, and the contribution these play in gestational outcomes.

Comparison of benzbromarone and allopurinol on the risk of chronic kidney disease in people with asymptomatic hyperuricemia

OBJECTIVE

The objective of the study was to compare the relative effects of benzbromarone and allopurinol on the risk of developing chronic kidney disease in persons with asymptomatic hyperuricemia.

METHODS

A retrospective cohort study was conducted to analyze a 2003-2015 national database including all claims data of 2 million beneficiaries in Taiwan. Asymptomatic hyperuricemia was defined as follows: persons using urate-lowering drugs who never developed gout flares. The benzbromarone group included persons ages 20-84 that had asymptomatic hyperuricemia and received benzbromarone alone. The allopurinol group included persons ages 20-84 that had asymptomatic hyperuricemia and received allopurinol alone. The maximum follow-up time was set as 5 years in this study. The main outcome was defined as follows: persons were newly diagnosed with chronic kidney disease. A Cox proportional hazards regression analysis was performed to test the association between variables and the risk of chronic kidney disease.

RESULTS

After propensity score matching, 9107 persons in the benzbromarone group and 4554 persons in the allopurinol group were eligible for the study. Approximately 71% of the study subjects were males. The mean age was 56 years old. The incidence rate of chronic kidney disease was lower in the benzbromarone group than in the allopurinol group (1.18 versus 1.99/per 100 person-years, incidence ratio = 0.60, and 95% confidence interval = 0.52-0.68).The Cox proportional hazards regression analysis disclosed that after adjusting for co-variables, there was a decreased risk of developing chronic kidney disease in the benzbromarone group as compared with the allopurinol group (hazard ratio = 0.59, 95% confidence interval = 0.52-0.67 and P<0.001).

CONCLUSIONS

The use of benzbromarone is associated with a lower hazard of developing chronic kidney disease as compared to allopurinol use among persons ages 20-84 with asymptomatic hyperuricemia. More studies are needed to confirm our findings.

Association between serum uric acid levels and cardiovascular risk factors among adults in India

BACKGROUND AND AIM

The objective of this study was to explore the association between serum uric acid (SUA) levels and cardiovascular risk factors in the Indian population.

METHODS AND RESULTS

This was a cross-sectional, population-based study. The study enrolled adults aged 20 years and above residing in rural, sub-urban, and urban. All participants completed a detailed questionnaire, underwent anthropometric measurements, and had blood samples collected. Participants were divided into three tertiles based on their SUA concentrations. A total of 2976 participants were included in this study, with 865 from rural, 1030 from sub-urban, and 1081 from urban populations. The mean values of cardiovascular risk factors were significantly higher in tertile 3 (p < 0.001) as compared to the other tertiles. However, we observed a negative trend between the increase of SUA and SUA/Scr ratio and HbA1c levels (Pearson correlation r = -0.068; p < 0.001 and r = -0.140; p < 0.001, respectively). The healthy and prediabetic groups did not show any significant change in HbA1c with increasing SUA levels, while an inverse trend was observed in diabetics. In the diabetic population, both men and women showed an inverse trend between increasing SUA levels and HbA1c in both known and newly diagnosed diabetes (p < 0.001).

CONCLUSIONS

The study found a positive association between SUA levels and cardiovascular risk factors. However, HbA1c was inversely correlated with increasing SUA tertiles in both known and newly diagnosed diabetes, as compared to the general population. Additionally, both men and women with diabetes consistently showed an inverse relationship between increasing SUA/SCr ratio and HbA1c levels.

Influence of Serum Uric Acid on Macular Choroidal Thickness and Ganglion Cell Inner Plexiform Layer Thickness

Purpose

The purpose of this study was to determine the influence of serum uric acid (UA) on macular choroidal and ganglion cell inner plexiform layer (GC-IPL) thickness.

Methods

This cross-sectional study enrolled adult individuals in communities in Guangzhou, China. All participants underwent a comprehensive ophthalmologic examination. They were divided into four groups according to UA quartiles. The choroidal and GC-IPL thickness was measured by swept-source optical coherence tomography (SS-OCT).

Results

A total of 719 subjects (1389 eyes) were included in the study. The average UA was 348.50 ± 86.16 mmol/L. The average choroidal and GC-IPL thickness decreased with UA quartiles (P < 0.001). Multivariate linear regression analyses showed that UA was negatively associated with average choroidal (β = -0.073, 95% confidence interval [CI] = -0.117 to -0.028, P = 0.001) and GC-IPL thickness (β = -0.006, 95% CI = -0.009 to -0.002, P = 0.001). After adjusting for confounding factors, the average choroidal thickness was decreased in quartile 4 as compared with quartile 1 by -14.737 µm (95% CI = -24.460 to -5.015, P = 0.003). The average GC-IPL thickness was decreased in quartile 4 versus quartile 1 by -1.028 (95% CI = -1.873 to -0.290, P = 0.007).

Conclusions

Higher UA levels were independently associated with macular choroid and GC-IPL thinning. These contribute to a better understanding of ocular pathological mechanisms.

Translational Relevance

The associated UA with choroidal and GC-IPL thickness helps to understand the ocular pathological and retinal neurodegenerative mechanism.

Mechanistic insights of soluble uric acid-induced insulin resistance: Insulin signaling and beyond

Hyperuricemia is a metabolic disease caused by purine nucleotide metabolism disorder. The prevalence of hyperuricemia is increasing worldwide, with a growing trend in the younger populations. Although numerous studies have indicated that hyperuricemia may be an independent risk factor for insulin resistance, the causal relationship between the two is controversial. There are few reviews, however, focusing on the relationship between uric acid (UA) and insulin resistance from experimental studies. In this review, we summarized the experimental models related to soluble UA-induced insulin resistance in pancreas and peripheral tissues, including skeletal muscles, adipose tissue, liver, heart/cardiomyocytes, vascular endothelial cells and macrophages. In addition, we summarized the research advances about the key mechanism of UA-induced insulin resistance. Moreover, we attempt to identify novel targets for the treatment of hyperuricemia-related insulin resistance. Lastly, we hope that the present review will encourage further researches to solve the chicken-and-egg dilemma between UA and insulin resistance, and provide strategies for the pathogenesis and treatment of hyperuricemia related metabolic diseases.

Correlation of elevated serum uric acid with coronary artery disease in Xinjiang, China: A retrospective case-control study

Elevated serum uric acid (SUA) levels are associated with coronary artery disease (CAD). However, whether this association is independent of traditional cardiovascular risk factors remains controversial. Our study aimed to determine the concentration of SUA in the presence and severity of CAD in multi-ethnic patients in Xinjiang, China. For this study, 412 consecutive patients with percutaneous coronary intervention (PCI) and 845 individuals with normal coronary angiograms were included in the study. CAD severity was evaluated using the Gensini score index. The SUA concentrations and the levels of various cardiometabolic risk factors were investigated. We assessed the relationship between SUA levels and other cardiometabolic risk factors. Logistic regression was used to evaluate risk factors for PCI patients. SUA levels were significantly elevated in PCI patients compared to those in control subjects (P < .01). With increased UA levels, we found that the risk factors for CAD increased. SUA concentration had a significant positive relationship with total cholesterol (P < .01), triglycerides (P < .01), low-density lipoprotein cholesterol (P < .01), and creatinine (P < .01) in both sexes. In the PCI group, there was no significant correlation between UA levels. SUA levels are not an independent risk factor for CAD. It can be concluded that in Xinjiang, China, SUA is related to multiple risk factors for CAD, but not related to the severity of CAD.

Responses to Hypoxia: How Fructose Metabolism and Hypoxia-Inducible Factor-1a Pathways Converge in Health and Disease

PURPOSE OF REVIEW

Oxygen is critical for the high output of energy (adenosine triphosphate) generated by oxidative phosphorylation in the mitochondria, and when oxygen delivery is impaired due to systemic hypoxia, impaired or reduced delivery of red blood cells, or from local ischemia, survival processes are activated.

RECENT FINDINGS

One major mechanism is the activation of hypoxia-inducible factors (HIFs) that act to reduce oxygen needs by blocking mitochondrial function and stimulating glucose uptake and glycolysis while also stimulating red blood cell production and local angiogenesis. Recently, endogenous fructose production with uric acid generation has also been shown to occur in hypoxic and ischemic tissues where it also appears to drive the same functions, and indeed, there is evidence that many of hypoxia-inducible factors effects may be mediated by the stimulation of fructose production and metabolism. Unfortunately, while being acutely protective, these same systems in overdrive lead to chronic inflammation and disease and may also be involved in the development of metabolic syndrome and related disease. The benefit of SGLT2 inhibitors may act in part by reducing the delivery of glucose with the stimulation of fructose formation, thereby allowing a conversion from the glycolytic metabolism to one involving mitochondrial metabolism. The use of hypoxia-inducible factor stabilizers is expected to aid the treatment of anemia but, in the long-term, could potentially lead to worsening cardiovascular and metabolic outcomes. We suggest more studies are needed on the use of these agents.

The Singapore Experience With Uncontrolled Gout: Unmet Needs in the Management of Patients

Gout is the most common type of inflammatory arthritis, and its impact on cardiovascular health and quality of life is often underestimated. The prevalence and incidence of gout are increasing globally. Further, ischemic heart disease (IHD) and chronic kidney disease (CKD) are prevalent in gout patients. Some unmet needs for gout management include physicians' low initiation rate of urate-lowering therapy (ULT) and poor treatment adherence in patients with gout. There is also a lack of randomized controlled trials that establish safe doses of acute and long-term treatment for gout, particularly in patients with IHD and stage 4 CKD and above (including end-stage renal failure). Furthermore, there is also a lack of studies showing optimal serum uric acid (SUA) target and validated clinical outcome measures, including disease activity and remission criteria for gout tailored to treat-to-target approaches and the high cost of newer gout medications. The causal relationship between asymptomatic hyperuricemia or gout with comorbidities such as IHD and CKD has yet to be fully elucidated. There is a pressing need for collaborative international efforts to address the overall suboptimal management of gout.

Endothelial function measured by peripheral arterial tonometry in patients with chronic myeloid leukemia on tyrosine kinase inhibitor therapy: a pilot study

BACKGROUND

Arterial occlusive events are an emerging problem in patients with chronic myeloid leukemia (CML) receiving tyrosine kinase inhibitor (TKI) therapy. Endothelial cell damage is thought to play an important role in the development of vascular events. Measurement of the peripheral vasodilator response by peripheral arterial tonometry (PAT) has reportedly been useful in the non-invasive assessment of endothelial dysfunction. To date, no studies have assessed endothelial function using PAT in patients with CML receiving TKIs.

METHOD

We measured the reactive hyperemia index (RHI) using PAT in young patients with CML (men aged ≤ 55 years and women aged ≤ 65 years) receiving TKIs.

RESULTS

Thirty patients with CML were examined (mean age, 43.5 ± 9.8 years; men, 57%). The median RHI was 1.81. Among these patients, 16.7% and 83.3% were taking imatinib and second- or third-generation TKIs, respectively. There were no differences in the baseline characteristics between the low RHI (< 1.67, n = 10), borderline RHI (≥ 1.67 and < 2.10, n = 14), and normal RHI (≥ 2.10, n = 6) groups. Serum uric acid (UA) levels and the RHI were significantly negatively correlated (r = -0.40, p = 0.029).

CONCLUSION

One-third of young patients with CML receiving TKI therapy were classified as having a low RHI. The RHI was negatively correlated with serum UA level. Larger prospective studies are necessary to examine whether the RHI predicts cardiovascular events in such patients.

Association between serum uric acid levels of patients with gout and their complications and examination fees: A cross-sectional analysis

OBJECTIVE

Correlation influence factor analysis of gout patients' serum uric acid (SUA) levels, their examination fees, and various complications were explored.

METHODS

From January 2017 to December 2021, 17 666 patients with gout were obtained. Conduct quartile grouping according to gout patients' SUA levels was used to compare the differences between groups in terms of examination fees and complications. Kernel density estimation method was adopted to analyze the data distribution, Spearman and Mantel-Haenszel χ² tests were used to analyze the correlation between SUA levels and examination fees and complications. Binary logistic regression analysis was used to analyze the correlation influence factor between SUA levels and complications.

RESULTS

Of the 17 666 gout cases, 85.46% were male. Among them, 7637 (43.23%) were inpatients and 10 029 (56.77%) were outpatients. Compared with outpatients, age, SUA levels, and examination fees were significantly higher, and there were more complications among inpatients (P < 0.05). Correlation analysis revealed that outpatients and SUA levels of patients with gout were positively correlated with examination fees, cardiovascular diseases, pulmonary diseases, liver diseases, and kidney diseases (P < 0.01). Binary logistic regression analysis showed that SUA level is an independent influence factor for cardiovascular diseases, pulmonary diseases, liver diseases, and kidney diseases (odds ratio [95% confidence interval]: 1.002 [1.002-1.002], 1.001 [1.000-1.001], 1.003 [1.002-1.003], and 1.001 [1.001-1.002], respectively).

CONCLUSIONS

As SUA levels increased, examination fees, cardiovascular disease, pulmonary disease, liver disease, and kidney disease complications increased. SUA level is an independent influence factor for the combination of gout with cardiovascular diseases, pulmonary diseases, liver diseases, and kidney diseases.

Association of hyperuricemia with cardiovascular diseases: current evidence

The aim of the present study is to present a historical and unified perspective on the association of serum uric acid (SUA) in the cause of cardiovascular diseases (CVDs). The association of hyperuricemia (HUC) with CVD begun to be appreciated in the middle 1950s and early 1990s when clinical evidence was shown on the association of HUC with CVD. However, this association was disputed by several investigators including the Framingham group and by professional societies, like the American Heart Association and the American Society of Hypertension. This dispute was weakened or reversed by later studies, which showed a positive association of HUC with CVD, CHD, HF, CKD, and stroke, mediated by several risk factors, both molecular such as, oxidative stress, inflammatory stress, insulin resistance, and endothelial dysfunction, as well as clinical factors such as, atherosclerosis, hypertension, metabolic syndrome, and type 2 diabetes mellitus. The great majority of recent studies show a positive association of HUC with CVDs, and CKD. However, the cutoff of the damaging levels of SUA have not been established as yet. The European Society of Hypertension (ESH) Treatment Guidelines have proposed a cutoff level of SUA for CVD > 7 mg/dl for men and > 6 mg/dl for women. In contrast, the URRAH study has shown a SUA level of 4.7 mg/dl for all-cause mortality and 5.6 mg/dl for CV mortality. These levels are lower than the SUA levels proposed by the ESH, which are consistent with HUC. For a better understanding of this association, a Medline search of the English literature was conducted between 2015 and 2022 and 44 pertinent papers were selected. These papers together with collateral literature will be discussed in this review.

The risk of ischemic cerebrovascular disease associated with benzbromarone use in gout people: A retrospective cohort study in Taiwan

Epidemiological studies have shown that people having hyperuricemia are at increased risk of ischemic cerebrovascular disease. This research aimed to study the relation of ischemic cerebrovascular disease with benzbromarone use among persons with gout-related disorders. This was a retrospective cohort design utilizing a 2003 to 2015 national health insurance database in Taiwan. Subjects aged 20 to 99 years who already had suffered from gout-related disorders were included as eligible subjects. Eligible persons who had the benzbromarone prescription alone were selected into the benzbromarone group. Sex-matched and age-matched eligible persons who never used any urate-lowering agents were selected into the control group. An index date was set as a date of benzbromarone being prescribed. The end-point was defined as ischemic cerebrovascular disease being newly diagnosed. A hazard ratio was applied to measure the association strength between benzbromarone use and ischemic cerebrovascular disease. Totally, there were 13,398 persons in the benzbromarone group and 13,398 persons in the control group. The incidence rate of ischemic cerebrovascular disease seemed to be modestly higher in the benzbromarone group than the control group, but it did not achieve statistical significance (0.78 vs 0.75 every 100 person-years, incidence rate ratio = 1.05, 95% confidence interval = 0.94-1.16). A crude hazard ratio of ischemic cerebrovascular disease showed 1.05 in the benzbromarone group (95% confidence interval = 0.94-1.17, P = .373) comparing with the control group. No significant association can be detected between benzbromarone use and the probability of ischemic cerebrovascular disease among persons with gout-related disorders. We think that reduction of the serum uric acid by use of benzbromarone could not be related to the probability of ischemic cerebrovascular disease. Further research is suggested to clarify this issue.

The Association between Water Consumption and Hyperuricemia and Its Relation with Early Arterial Aging in Middle-Aged Lithuanian Metabolic Patients

BACKGROUND

Hyperuricemia is well-known as an independent risk factor for the development of hypertension, metabolic syndrome, and cardiovascular disease. Water is essential to most bodily functions, and its consumption rates appear to decline with age. The aim was to evaluate the influence of water intake on early vascular aging in metabolic middle-aged patients with hyperuricemia.

MATERIALS AND METHODS

The study included 241 men aged 40-55 years and 420 women aged 50-65 years from the Lithuanian High Cardiovascular Risk (LitHiR) primary prevention program. Anthropometric characteristics, blood pressure, laboratory testing, and the specialized nutrition profile questionnaire were evaluated. Carotid-femoral pulse wave velocity (cfPWV), assessed using applanation tonometry, was evaluated as an early vascular aging parameter in patients with hyperuricemia and with normal serum uric acid (sUA) levels.

RESULTS

72.6% of men and 83.1% of women drink insufficient amounts of water (less than 1.5 L per day). However, our results showed statistically significant relationships only among a group of women. The women in the hyperuricemic group had a higher cfPWV than women with normal sUA levels. In hyperuricemic women, drinking less than 0.5 L per day in combination with other risk factors, such as age, increasing fasting glucose, and systolic blood pressure, was statistically significantly associated with an increased cfPWV (R² = 0.45, Adj. R² = 0.42, p < 0.001).

CONCLUSION

Drinking an insufficient amount of water daily is associated with increased arterial stiffness and has a negative effect on vascular health in metabolic women with hyperuricemia.

Cancer antigen 125 and C-reactive protein inflammatory mediators and uric acid in association with preeclampsia in North Kordofan State, Western Sudan

Pathophysiology of pre-eclampsia depends on a defective trophoblastic invasion of uteroplacental blood vessels that leads to placental ischemia and induction of an inflammatory process within the placenta. This process may trigger the expression of Cancer antigen 125 (CA 125), C-reactive protein (CRP) and uric acid (UA). This research aimed to evaluate the association of serum CA 125, CRP and uric acid with Preeclampsia. The study recruited 200 singleton Sudanese pregnant women, who were divided into three groups: controls (n = 100), mild preeclampsia (n = 46) and severe preeclampsia (n = 54). The study subjects were matched for maternal age, gestational age and body mass index. Blood samples were taken for measurement of the different variables using immune- assay and enzymatic automated chemical analysis. The levels of CA 125 in mild and severe preeclampsia were (21.94±0.749 IU/ml) and (40.78±1.336 IU/ml) respectively, which was significantly different (P<0.001) from the control mean (16.48±0.584 IU/ml). There was also a significant difference between the mean levels of CRP in mild and severe preeclampsia (15.17±0.788 mg/L), (31.50±1.709 mg/L) compared with controls (4.79±0.178 mg/L), (P<0.01). There was also a significant difference in the mean levels of UA in mild and severe cases (6.44±0.293 and7.37±0.272) in comparison with the controls (4.00±0.061); (P<0.001). There were significant differences between severe and mild groups (P<0.05). Cancer antigen 125, CRP and UA levels‎ correlated positively with mean arterial blood pressure (MAP) where (r >0.7; P < 0.001). ROC curve validates the utility of these biomarkers for monitoring preeclampsia (AUC >0.8; P < 0.001). In conclusion CA 125, CRP and UA were significantly higher in preeclampsia compared with the controls. The rise of the analytes was directly associated with the severity of the disease.

Endothelial dysfunction: developmental mechanisms and therapeutic strategies

Introduction: Every year the importance of the normal functioning of the endothelial layer of the vascular wall in maintaining the health of the body becomes more and more obvious.

The physiological role of the endothelium: The endothelium is a metabolically active organ actively involved in the regulation of hemostasis, modulation of inflammation, maintenance of hemovascular homeostasis, regulation of angiogenesis, vascular tone, and permeability.

Risk factors for the development of endothelial dysfunction: Currently, insufficient bioavailability of nitric oxide is considered the most significant risk factor for endothelial dysfunction.

Mechanisms of development of endothelial dysfunction: The genesis of endothelial dysfunction is a multifactorial process. Among various complex mechanisms, this review examines oxidative stress, inflammation, hyperglycemia, vitamin D deficiency, dyslipidemia, excess visceral fat, hyperhomocysteinemia, hyperuricemia, as well as primary genetic defect of endotheliocytes, as the most common causes in the population underlying the development of endothelial dysfunction.

Markers of endothelial dysfunction in various diseases: This article discusses the main biomarkers of endothelial dysfunction currently used, as well as promising biomarkers in the future for laboratory diagnosis of this pathology.

Therapeutic strategies: Therapeutic approaches to the endothelium in order to prevent or reduce a degree of damage to the vascular wall are briefly described.

Conclusion: Endothelial dysfunction is a typical pathological process involved in the pathogenesis of many diseases. Thus, pharmacological agents with endothelioprotective properties can provide more therapeutic benefits than a drug without such an effect.

Association of Elevated Serum Uric Acid with Nerve Conduction Function and Peripheral Neuropathy Stratified by Gender and Age in Type 2 Diabetes Patients

Background: The relationship between serum uric acid (SUA) level and diabetic peripheral neuropathy (DPN) remains controversial. We aimed to investigate the association between SUA level and DPN and evaluate the effects of SUA level on nerve conduction function via electromyography in patients with type 2 diabetes (T2DM), stratified by gender and age. Methods: This cross-sectional study included 647 inpatients with T2DM from the First Affiliated Hospital of Wenzhou Medical University between February 2017 and October 2020. The diagnosis of DPN was confirmed according to the Toronto Expert Consensus. Clinical data, SUA level, and nerve conduction parameters were obtained from electronic medical records. Results: A total of 647 patients with T2DM were included, and 471 patients were diagnosed with DPN. The level of SUA was higher in the DPN group than in the Non-DPN group (330.58 ± 99.67 vs. 309.16 ± 87.04, p < 0.05). After adjustment, a higher SUA level was associated with the presence of DPN [odds ratio (OR) 1.003, 95% confidence interval (CI), 1.001−1.005; p = 0.017]. The area under the curve for the prediction of DPN was 0.558 (95% CI, 0.509−0.608; p = 0.022), and the optimized cut-off of SUA level was 297.5 µmol/L. The SUA > 297.5 µmol/L level was independently associated with DPN in the male subgroup (OR 2.507, 95% CI, 1.405−4.473; p = 0.002) rather than in the female subgroup. Besides, SUA > 297.5 µmol/L was independently associated with DPN in the younger subgroup (age < 65 years) (OR 2.070, 95% CI, 1.278−3.352; p = 0.003) rather than in the older subgroup. In multiple linear regression analysis, SUA was significantly correlated with certain nerve conduction study parameters in the all patients group, and was also observed in the male and younger subgroups. Conclusions: Elevated SUA was independently associated with poorer nerve conduction functions, and hyperuricemia was also significantly associated with a higher risk of developing DPN in T2DM patients, especially in male and younger patients.

There is urgent need to treat atherosclerotic cardiovascular disease risk earlier, more intensively, and with greater precision: A review of current practice and recommendations for improved effectiveness

Atherosclerotic cardiovascular disease (ASCVD) is epidemic throughout the world and is etiologic for such acute cardiovascular events as myocardial infarction, ischemic stroke, unstable angina, and death. ASCVD also impacts risk for dementia, chronic kidney disease peripheral arterial disease and mobility, impaired sexual response, and a host of other visceral impairments that adversely impact the quality and rate of progression of aging. The relationship between low-density lipoprotein cholesterol (LDL-C) and risk for ASCVD is one of the most highly established and investigated issues in the entirety of modern medicine. Elevated LDL-C is a necessary condition for atherogenesis induction. Basic scientific investigation, prospective longitudinal cohorts, and randomized clinical trials have all validated this association. Yet despite the enormous number of clinical trials which support the need for reducing the burden of atherogenic lipoprotein in blood, the percentage of high and very high-risk patients who achieve risk stratified LDL-C target reductions is low and has remained low for the last thirty years. Atherosclerosis is a preventable disease. As clinicians, the time has come for us to take primordial and primary prevention more serously. Despite a plethora of therapeutic approaches, the large majority of patients at risk for ASCVD are poorly or inadequately treated, leaving them vulnerable to disease progression, acute cardiovascular events, and poor aging due to loss of function in multiple visceral organs. Herein we discuss the need to greatly intensify efforts to reduce risk, decrease disease burden, and provide more comprehensive and earlier risk assessment to optimally prevent ASCVD and its complications. Evidence is presented to support that treatment should aim for far lower goals in cholesterol management, should take into account many more factors than commonly employed today and should begin significantly earlier in life.

Risk of Erectile Dysfunction in Male Patients with Gout Treated with Febuxostat or Allopurinol: A Propensity Score-Matched Cohort Study

OBJECTIVE

To evaluate and compare the risk of erectile dysfunction (ED) associated with the use of allopurinol and febuxostat in adult male gout patients.

METHODS

We conducted a cohort study using TriNetX (Cambridge, MA, USA), a global federated health research network that provides real-time electronic medical record datasets. We analyzed and compared the associated risk of ED in gout patients who started taking allopurinol or febuxostat within 12 months. Propensity score matching was performed to adjust for demographic variables, comorbidities, and medication use. Kaplan-Meier analysis was used to estimate the probability of the outcome of interest. The hazard ratio (HR) and associated confidence intervals were calculated along with the proportionality test using R's Survival Package v3.2-3.

RESULTS

We identified 679,862 patients with gout among 107,517,445 patients in the database. Of these patients, 24,000 were treated with febuxostat and 299,726 with allopurinol. After propensity matching, 9075 patients receiving febuxostat without allopurinol (febuxostat group) and 9075 corresponding patients receiving allopurinol without febuxostat (allopurinol group) were analyzed for comparison. Among all male patients over 19 years of age, febuxostat was associated with a significantly higher risk of ED versus allopurinol (HR 1.354; 95% confidence interval (CI) 1.003-1.829; log rank test, p = 0.047). After subgroup analysis, in gout patients aged 19-64 years, a significantly higher incidence of ED was observed in the febuxostat group than in the allopurinol group (HR 2.002, 95% CI 1.282-3.126). The risk of ED did not differ significantly between the allopurinol and febuxostat groups in gout patients older than 65 years.

CONCLUSIONS

Febuxostat may be associated with a higher risk of ED than allopurinol in adult male patients with gout. Future large-scale prospective studies are warranted to confirm our results.

Hyperuricemia and Endothelial Function: Is It a Simple Association or Do Gender Differences Play a Role in This Binomial?

The endothelium plays a fundamental role in the biological processes that ensure physiological vessel integrity, synthesizing numerous substances that are capable of modulating the tone of vessels, inflammation and the immune system, and platelet function. Endothelial dysfunction refers to an anomaly that develops at the level of the tunica that lines the internal surface of arterial and venous vessels, or, more precisely, an alteration to normal endothelial function, which involves the loss of some structural and/or functional characteristics. Studies on sex differences in endothelial function are conflicting, with some showing an earlier decline in endothelial function in men compared to women, while others show a similar age of onset between the sexes. Since increased cardiovascular risk coincides with menopause, female hormones, particularly estrogen, are generally believed to be cardioprotective. Furthermore, it is often proposed that androgens are harmful. In truth, these relationships are more complex than one might think and are not just dependent on fluctuations in circulating hormones. An increase in serum uric acid is widely regarded as a possible risk factor for cardiovascular disease; however, its role in the occurrence of endothelial dysfunction has not yet been elucidated. Several studies in the literature have evaluated sex-related differences in the association between elevated uric acid levels and cardiovascular events, with conflicting results. The association between uric acid and cardiovascular disease is still controversial, and it is not yet clear how gender differences affect the serum concentration of these substances. This review was primarily aimed at clarifying the effects of uric acid at the level of the vascular endothelium and describing how it could theoretically cause damage to endothelial integrity. The second aim was to determine if there are gender differences in uric acid metabolism and how these differences interact with the vascular endothelium.

Allopurinol blocks aortic aneurysm in a mouse model of Marfan syndrome via reducing aortic oxidative stress

BACKGROUND

Increasing evidence indicates that redox stress participates in MFS aortopathy, though its mechanistic contribution is little known. We reported elevated reactive oxygen species (ROS) formation and NADPH oxidase NOX4 upregulation in MFS patients and mouse aortae. Here we address the contribution of xanthine oxidoreductase (XOR), which catabolizes purines into uric acid and ROS in MFS aortopathy.

METHODS AND RESULTS

In aortic samples from MFS patients, XOR protein expression, revealed by immunohistochemistry, increased in both the tunicae intima and media of the dilated zone. In MFS mice (Fbn1^C1041G/+), aortic XOR mRNA transcripts and enzymatic activity of the oxidase form (XO) were augmented in the aorta of 3-month-old mice but not in older animals. The administration of the XOR inhibitor allopurinol (ALO) halted the progression of aortic root aneurysm in MFS mice. ALO administrated before the onset of the aneurysm prevented its subsequent development. ALO also inhibited MFS-associated endothelial dysfunction as well as elastic fiber fragmentation, nuclear translocation of pNRF2 and increased 3'-nitrotyrosine levels, and collagen maturation remodeling, all occurring in the tunica media. ALO reduced the MFS-associated large aortic production of H₂O₂, and NOX4 and MMP2 transcriptional overexpression.

CONCLUSIONS

Allopurinol interferes in aortic aneurysm progression acting as a potent antioxidant. This study strengthens the concept that redox stress is an important determinant of aortic aneurysm formation and progression in MFS and warrants the evaluation of ALO therapy in MFS patients.