Uric acid-induced C-reactive protein expression: implication on cell proliferation and nitric oxide production of human vascular cells

The Fifth Element: Is Vascular Dysfunction an Intrinsic Feature of Gout?

Gout, the most common inflammatory arthritis, affects as many as 5.1% of the adult population. Classically, gout is conceived as four sequential phenotypic states: 1) asymptomatic hyperuricemia 2) acute gout flare 3) inter-critical gout (gout between flares); and 4) tophaceous gout. However, these four states are paralleled by a fifth state, consisting of vascular involvement. The mechanisms and consequences of vascular gout are incompletely elucidated. In vitro and animal models indicate that soluble urate adversely affects vascular endothelium and smooth muscle. The recent discovery that soluble urate can be transported intracellularly to alter cell metabolism and epigenetics (trained innate immunity) suggests additional impacts of urate on leukocytes and endothelium. Once gout has progressed to flares, the vasculature is exposed to inflammatory mediators, both during flares and to a lesser but persistent extent inter-critically, suggesting additional mechanisms of gout's effect. We have reported that patients with gout have diminished endothelial function measured by brachial artery flow-mediated dilation. ACR gout guideline-concordant treatment improves endothelial function but is less effective in patients with cardiometabolic comorbidities. Moreover, treatment of gout patients with the anti-inflammatory colchicine and urate lowering therapy improves endothelial function and reduces the risk of both incident coronary artery disease (CAD), and MACE in patients with established CAD.

JAK2/STAT3/HMGCS2 signaling aggravates mitochondrial dysfunction and oxidative stress in hyperuricemia-induced cardiac dysfunction

BACKGROUND

High uric acid levels play a critical role in cardiovascular disease pathophysiology, being closely linked to their occurrence, progression, and prognosis. To enhance prevention and treatment of hyperuricemia-related cardiovascular diseases, understanding underlying mechanisms and identifying novel therapeutic targets are essential.

METHODS

A hyperuricemic mouse model was established, and transcriptomic analysis of myocardial tissue was conducted using RNA sequencing. The role of HMGCS2 in hyperuricemia-induced cardiomyocytes was investigated through HMGCS2 knockout. The transcriptional regulation of HMGCS2 by STAT3 was explored via STAT3 knockdown, overexpression, and dual-luciferase reporter assays. To further elucidate the role of the JAK2/STAT3/hmgcs2 signaling pathway in hyperuricemia-induced cardiomyocytes, we overexpressed HMGCS2 while intervening in the JAK2/STAT3 pathway in vitro. The therapeutic potential of targeting the JAK2/STAT3/HMGCS2 pathway was evaluated in hyperuricemic mice using STAT3 and JAK inhibitors to assess effects on cardiac dysfunction.

RESULTS

RNA sequencing showed significant upregulation of HMGCS2 mRNA in hyperuricemic mouse cardiac tissue. Increased HMGCS2 protein levels were observed in cardiac tissue and AC16 cardiomyocytes. HMGCS2 knockdown alleviated uric acid-induced mitochondrial dysfunction, oxidative stress, and abnormal energy metabolism in AC16 cardiomyocytes. And high uric acid levels activate the IL-6/JAK2/STAT3 signaling pathway in AC16 cardiomyocytes, which regulates HMGCS2 expression. By modulating JAK2 and STAT3 expression and subsequently overexpressing HMGCS2, we identified the involvement of the JAK2/STAT3/HMGCS2 pathway in uric acid-induced mitochondrial dysfunction, oxidative stress, and energy metabolism abnormalities in AC16 cardiomyocytes. In vitro experiments demonstrated that intervention with the ruxolitinib and S3I-201 could ameliorate mitochondrial dysfunction, oxidative stress, and ATP levels in the heart tissue of hyperuricemic mice. Moreover, these treatments also reversed cardiac function abnormalities.

CONCLUSIONS

The JAK2/STAT3/HMGCS2 pathway may contributes to uric acid-induced cardiac dysfunction by affecting mitochondrial function, oxidative stress, and ATP metabolism, offering a potential therapeutic strategy for mitigating high uric acid-induced cardiac damage.

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.

Efficacy of febuxostat on hyperuricemia and estimated glomerular filtration rate in patients with non-dialysis stage 3/4 chronic kidney disease and assessment of cardiac function: a 12-month interventional study

Objectives

Febuxostat, an oral medication for treating hyperuricemia (HUA), is a non-purine xanthine oxidase inhibitor that regulates serum uric acid (SUA) metabolism in patients with chronic kidney disease (CKD). However, the drug's effectiveness in improving renal function in patients with non-dialysis stage 3/4 CKD remains unclear. Our aim is to investigate the efficacy of febuxostat on kidney function. In addition, the cardiac function will be assessed.

Method

We conducted a single-center, interventional, randomized, controlled, open-label study. A total of 316 patients with non-dialysis stage 3/4 CKD, with SUA ≥6mg/dL in women and ≥7mg/dL in men, were assigned to either the febuxostat group (n=156) or the control group (n=160). The primary endpoint was the evaluation of changes in kidney biomarkers from baseline to 12 months of treatment, and any changes in cardiac biomarkers and echocardiographs were the secondary endpoint.

Results

The primary endpoint was a comparison between the two groups from baseline to 12 months of treatment. SUA was significantly decreased in patients treated with febuxostat 40 mg (6.85 ± 0.41mg/dL at baseline and 5.27 ± 0.70mg/dL at 12 months of treatment, P<0.001) and this was associated with increased eGFR (34.48 ± 8.42ml/min at baseline and 38.46 ± 8.87ml/min at 12 months of treatment, P<0.001). There were significant decreases in high-sensitivity troponin T (19.50 ± 7.24ng/L at baseline and 16.98 ± 7.32ng/L at 12 months of treatment, P<0.001) and N-terminal-pro brain natriuretic peptide (941.35 ± 374.30pg/ml at baseline and 762.22 ± 303.32 pg/ml at 12 months of treatment, P<0.001) in the febuxostat group. These changes were also associated with increased left ventricular ejection fraction in the febuxostat group (50.47 ± 3.95% at baseline and 51.12 ± 3.96% at the end of the study, P<0.001).

Conclusion

In the interventional group, febuxostat was well-tolerated and demonstrated a reduction in SUA associated with an increase in eGFR. This slowed down the progression of renal disease in patients with non-dialysis stage 3/4 CKD and improved cardiac function.

Fructose-Driven glycolysis supports synaptic function in subterranean rodent - Gansu Zokor (Eospalax cansus)

Several studies indicate that fructose can be used as an energy source for subterranean rodents. However, how subterranean rodents utilize fructose metabolism with no apparent physiological drawbacks remains poorly understood. In the present study, we measured field excitatory postsynaptic potentials (fEPSPs) in hippocampal slices from Gansu zokor and SD rats hippocampi before and 60 min after replacement of 10 mM glucose in the artificial cerebrospinal fluid (ACSF) with 10 mM fructose (gassed with 95 % O2 and 5 % CO2). Subsequently, we performed transcriptome analysis on Gansu zokor brains incubated with ACSF containing 10 mM fructose and determined the contents of fructose, lactate, ATP, and UA. Whole brain RNA and proteins were extracted to detect the transcriptional levels of Glut5, Khk, Aldoc, and Cs and the translational levels of GLUT5, CS, NRF2, and c-FOS. The results showed that Gansu zokor brains exhibit higher levels of GLUT5 protein and Khk mRNA levels than SD rats to facilitate fructose uptake and metabolism, resulting in increased fructose, ATP, and lactate content in the brain during fructose incubation. Stable UA levels during fructose metabolism reduce the risk of oxidative stress and neuroinflammation, and activation of the Nrf2 pathway increases downstream antioxidant capacity, thereby reducing brain damage. Persistent fEPSP signaling suggests that fructose supports excitatory synaptic transmission in the CA1 region of the hippocampus of the Gansu zokor but leads to hippocampal dysfunction in SD rats. The unique insights about fructose metabolism in the brain of Gansu zokor obtained in our study will be useful for further studies on the evolution of subterranean rodents.

The association between serum uric acid levels and the cardiometabolic phenotype among healthcare workers of Tabriz University of Medical Sciences

Introduction

It is unclear whether hyperuricemia can be considered as an independent risk factor or just as a marker to represent the correlation between uric acid levels and other risk factors of MetS. In this work, we intend to study the correlation between serum uric acid (SUA) and the cardiometabolic phenotype among Tabriz University of Medical Science healthcare workers.

Methods

In this cross-sectional study, anthropometric measurements, serum fasting blood sugar (FBS), triglyceride (TG), cholesterol, high-density lipoprotein (HDL), liver enzymes, blood urea nitrogen (BUN), SUA, creatinine (Cr), and blood pressures of 1,451 healthcare workers were evaluated. MetS was diagnosed based on ATP III. We classified the participants into four cardiometabolic phenotypes: metabolically-healthy lean (MHL), metabolically-unhealthy lean (MUHL), metabolically-healthy obese (MHO), and metabolically-unhealthy obese (MUHO).

Results

MHL (26.6%) and MHO (65.8 %) had the highest prevalence rates in the first and second SUA categories, respectively (P≤0.001). Compared to the lowest SUA category, the odds of MHO and MUHO increased by 3.13 (95% CI 2.21-4.44) and 5.50 (95%CI 3.53-8.57) in the highest category, respectively. This trend was not observed regarding the association between MUHL and the SUA classification.

Conclusion

We propose using the easily-measured SUA level as a marker for early diagnosis of at-risk MUHL and MHO individuals to administer proper interventions. Further prospective studies are needed to identify the effects of SUA on the progression of MetS in various body-size subgroups.

Hyperuricemia and the risk of stroke incidence and mortality: A systematic review and meta-analysis

Objectives

The relationship between hyperuricemia (HUA) and stroke remains controversial. In this systematic review, we discuss the association between HUA and stroke.

Materials and methods

The PubMed, Embase, Web of Science, and Cochrane Library were searched from their earliest records to March 13th, 2024, and additional papers were identified through a manual search. Prospective studies that provided a multivariate-adjusted estimate of the association between HUA and risk of stroke incidence and mortality, represented as relative risks (RRs) with 95% confidence intervals (CIs), were eligible.

Results

A total of 22 studies including 770,532 adults were eligible and included. Hyperuricemia was associated with a significantly increasing risk of both stroke incidence (pooled RR, 1.42; 95% CI, 1.31-1.53) and stroke mortality (pooled RR, 1.53; 95% CI, 1.18-1.99) in our meta-analyses. Relative risk of stroke incidence was as follows: females (pooled RR, 1.67; 95% CI, 1.44-1.92) and males (pooled RR, 1.13; 95% CI, 1.02-1.25). Relative risk of mortality was as follows: female (pooled RR, 1.41; 95% CI, 1.31-1.52) and males (pooled RR, 1.27; 95% CI, 1.20-1.34). For the risk of stroke mortality, the association between HUA and ischemic stroke (pooled RR, 1.39; 95% CI, 1.31-1.47) was more significant than that of hemorrhagic stroke (pooled RR, 1.13; 95% CI, 1.02-1.26).

Conclusion

Our study confirms an association between HUA and risk of stroke, which is more pronounced in females.

Association Between Serum Uric Acid to High-Density Lipoprotein Cholesterol Ratio and Pneumonia After Endovascular Treatment of Vertebrobasilar Artery Occlusion

Background

The uric acid to high-density lipoprotein cholesterol ratio (UHR) is a novel marker of inflammation and metabolism. We aimed to explore the association of UHR with pneumonia after endovascular thrombectomy (EVT) in patients with vertebrobasilar artery occlusion (VBAO).

Methods

We retrospectively enrolled participants diagnosed with acute VBAO treated with EVT within 24 hours of estimated occlusion time from the multicenter PERSIST study. The primary outcome was pneumonia within 7 days after EVT according to the Pneumonia in Stroke Consensus Group recommendations. We utilized the restricted cubic spline curve to explore the dose-response relationship between UHR and pneumonia. We used multivariable logistic regression models to assess the association between UHR and the risk of pneumonia after EVT and verified the findings in subgroup analysis.

Results

Three hundred and seventy-eight patients were enrolled in this study, and 236 (62.4%) were diagnosed with pneumonia. In multivariable models, a higher UHR was associated with an increased risk of pneumonia after EVT (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01-1.10; P = 0.020; tertile 3 versus tertile 1: OR, 2.09; 95% CI, 1.15-3.82; P = 0.016). The dose-response relationship indicated that UHR was linearly associated with the risk of pneumonia (P = 0.888). The association between UHR and pneumonia remained significant in different subgroups.

Conclusion

This study demonstrated that a higher UHR was associated with an increased risk of pneumonia in VABO patients treated with EVT. Further studies were warranted to verify the prognostic values of UHR in pneumonia after EVT.

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.

Risk of Sudden Sensorineural Hearing Loss in Patients with Gout: A Population-Level Study in a South Korean National Health Screening Cohort

Background: Gout, characterized by serum uric acid accumulation, prompts inflammation, leading to tissue damage and comorbidities. Prior studies reported a higher risk of hearing loss in gout patients; however, the specific risk of sudden sensorineural hearing loss (SSNHL) remains unclear. Method: This population-based study assessed SSNHL incidence and risk in patients aged ≥ 40 years with or without gout, excluding those with prior SSNHL, within the Korean National Health Insurance Service Health Screening Cohort (2002-2019). A total of 24,508 gout patients were matched 1:4 with 98,032 controls by age, sex, income, and region. SSNHL incidence was compared, and Kaplan-Meier curves with log-rank tests evaluated cumulative incidence over 200 months. Hazard ratios (HRs) were calculated using stratified Cox models adjusted for patient characteristics. Results: SSNHL incidence was slightly higher in the gout cohort vs. controls (1.70% vs. 1.96%, SD = 0.02). Kaplan-Meier analysis revealed significantly higher cumulative SSNHL incidence in gout patients (p = 0.009). Patients with gout had a significantly higher risk of developing SSNHL in both the unadjusted (HR [95% CI]: 1.14 [1.03-1.27]; p = 0.010) and adjusted Cox models (1.13 [1.02-1.26]; p = 0.021). Subgroup analyses indicated higher risk in gout patients aged <60 years, males, non-smokers, non-drinkers, moderately-high income, normal BMI, Charlson Comorbidity Index score of 0, or fasting blood glucose < 100 mg/dL (all p < 0.05). Conclusions: Korean adults with gout, particularly younger, healthier patients, face increased SSNHL risk. Early, effective gout management may help mitigate this risk.

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.

Serum uric acid is independently associated with impaired nitroglycerine-induced vasodilation of the brachial artery in women

Experimental and clinical studies have suggested atherosclerotic effects of uric acid (UA) on vascular smooth muscle cells (VSMCs). Nitroglycerine-induced vasodilation (NID), a control test for flow-mediated vasodilation, can be used as a possible marker of VSMC dysfunction. However, there is little information on the association between UA and NID. Therefore, we investigated the association between serum UA levels and NID according to sex. We measured NID of the brachial artery in 598 women (mean age: 66.2 ± 12.0 years) and 1008 men (mean age: 59.0 ± 18.0 years). In women, the mean serum UA level was 5.06 ± 1.24 mg/dL. Serum UA levels were negatively correlated with NID (p < 0.001), and NID significantly decreased with increasing serum UA levels (≤4.0 mg/dL, 13.4 ± 6.4%; 4.0 to ≤5.0 mg/dL, 11.4 ± 5.3%; 5.0 to ≤6.0 mg/dL, 10.8 ± 5.7%; >6.0 mg/dL, 9.7 ± 5.7%; p < 0.001). The prevalence of VSMC dysfunction, defined as NID < 8.4%, the division points for the lowest and middle tertiles of NID in women, increased with increasing serum UA levels ( ≤ 4.0 mg/dL, 23.3%; 4.0 to ≤5.0 mg/dL, 30.9%; 5.0 to ≤6.0 mg/dL, 36.4%; >6.0 mg/dL, 44.6%; p < 0.001). Multiple logistic regression analysis showed a significant association between serum UA levels and VSMC dysfunction (odds ratio, 1.21; 95% confidence interval, 1.02─1.43; p = 0.03). There was no interaction between age (<50 or ≥50 years) and the effect of serum UA levels on VSMC dysfunction (p interaction = 0.88). In contrast, no association was observed between serum UA levels and NID in men. Serum UA levels were significantly associated with VSMC dysfunction as assessed by NID in women.

Uric Acid and Atherosclerosis in Patients with Chronic Kidney Disease: Recent Progress, Mechanisms, and Prospect

Background

Chronic kidney disease (CKD) is a prevalent global health concern, significantly linked to increased cardiovascular morbidity and mortality. Among various risk factors, uric acid (UA) has emerged as a potentially modifiable contributor to cardiovascular complications in CKD patients.

Summary

Elevated serum uric acid levels frequently occur in individuals with CKD and are associated with the development of atherosclerosis (AS). Uric acid has been demonstrated to exacerbate inflammatory processes, promote oxidative stress, and cause endothelial dysfunction, which are critical factors that drive the formation of atherosclerotic plaques. Furthermore, high uric acid levels can worsen renal function, establishing a detrimental cycle that amplifies cardiovascular risk.

Key Messages

This review investigates the complex interconnection between UA and AS in patients with CKD, highlighting the underlying mechanisms and therapeutic considerations. A more profound comprehension of this relationship is essential for enhancing cardiovascular health and outcomes in this vulnerable population.

Combination of sST2/LVMI Ratio and Modified MELD Scores Predicts Mortality in End-Stage Heart Failure

Biomarkers are critical for heart failure (HF) management by facilitating risk stratification, therapeutic decision-making, and monitoring treatment response. This prospective, single-center study aimed to assess predictors of death during one-year follow-up in patients with end-stage HF, with particular emphasis on the soluble suppression of tumorigenicity 2/left ventricular mass index (sST2/LVMI) ratio, modified Model for End-stage Liver Disease (modMELD), and Model for End-stage Liver Disease excluding INR (MELD-XI). This study comprised 429 consecutive patients with end-stage HF hospitalized between 2018 and 2023. The median age was 56.0 (50.0-60.0) years; and 89.2% were male. During the follow-up, 134 (31.2%) patients died. The area under the receiver operating characteristics (ROC) curves showed good predictive powers of sST2/LVMI-MELDXI (AUC: 0.90 [CI: 0.87-0.93]; specificity 85% and sensitivity 80%) and sST2/LVMI-modMELD (AUC: 0.92 [95% CI: 0.90-0.95]; specificity 92%, sensitivity 81%) for assessment of one-year mortality. In conclusion: the sST2/LVMI-modMELD and sST2/LVMI-MELD-XI ratios are independently related to one-year mortality in the analyzed group of patients. The prognostic power of these new models is significantly better than their individual components. This single-center study comprised a relatively small group of patients, so the prognostic value of these new models cannot be generalized to the entire HF population. Considering the limitations of this analysis, further randomized trials with a large cohort are necessary to confirm the utility of the new prognostic models in HF patients.

Metabolomics in Atrial Fibrillation: Unlocking Novel Biomarkers and Pathways for Diagnosis, Prognosis, and Personalized Treatment

BACKGROUND/OBJECTIVES

Atrial fibrillation (AF) is the most frequent arrhythmia in the adult population associated with a high rate of severe consequences leading to significant morbidity and mortality worldwide. Therefore, its prompt recognition is of high clinical importance. AF detection often remains challenging due to unspecific symptoms and a lack of reliable biomarkers for its prediction. Herein, novel bioanalytical methodologies, such as metabolomics, offer new opportunities for a better understanding of the underlying pathological mechanisms of cardiovascular diseases, including AF. The metabolome, considered a complete set of small molecules present in the organism, directly reflects the current phenotype of the studied system and is highly sensitive to any changes, including arrhythmia's onset. A growing body of evidence suggests that metabolite profiling has prognostic value in AF prediction, highlighting its potential role not only in early diagnosis but also in guiding therapeutic interventions. By identifying specific metabolites as a disease biomarker or recognising particular metabolomic pathways involved in the AF pathomechanisms, metabolomics could be of great clinical value for further clinical decision-making, risk stratification, and an individual personalised approach. The presented narrative review aims to summarise the current state of knowledge on metabolomics in AF with a special emphasis on its implications for clinical practice and personalised medicine.

Emergencies in Hematology: Why, When and How I Treat?

Hematological emergencies are critical medical conditions that require immediate attention due to their rapid progression and life-threatening nature. As various examples, hypercalcemia, often associated with cancers such as multiple myeloma, can lead to severe neurological and cardiac dysfunction. Hyperleukocytosis, common in acute myeloid leukemias, increases the risk of leukostasis and multiorgan failure. Sickle cell crisis, a common complication in sickle cell disease, results from vaso-occlusion, leading to acute pain and tissue ischemia. Tumor lysis syndrome, reported in cases of rapid destruction of cancer cells, causes electrolyte imbalances and acute kidney injury. Acute transfusion reactions, fundamental in hematological conditions, can range from mild allergic responses to severe hemolysis and shock, requiring prompt management. Disseminated intravascular coagulation, involving excessive coagulation and bleeding, is commonly triggered by hematological malignancies, common in the first phases of acute promyelocytic leukemia. Recently, in the era of bispecific antibodies and chimeric antigen receptor T cells, cytokine release syndrome is a manifestation that must be recognized and promptly treated. Understanding the pathophysiology, recognizing the clinical manifestations, and ensuring adequate diagnostic strategies and management approaches for each condition are central to early intervention in improving patient outcomes and reducing mortality.

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.

Diagnostic value of uric acid to high-density lipoprotein cholesterol ratio in abdominal aortic aneurysms

BACKGROUND

Abdominal aortic aneurysm (AAA) is highly lethal upon onset of acute aortic diseases (AAD) or rupture. Dyslipidaemia and hyperuricaemia are important risk factors for the development of AAA and AAD as well as aortic disease-related death. The aim of this study was to explore whether uric acid (UA) to high-density lipoprotein cholesterol (HDL-C) ratio (UHR) can be used as an independent predictor of the presence of AAA or AAD.

METHODS

Three hundred subjects, including 100 AAA patients (AAA group), 100 AAD patients (AAD group) and 100 controls (CON group), were recruited in this study. UHR and other serum samples were obtained upon the patients' admission before any medical treatment. The optimal cut-off points of UHR were determined using receiver operating characteristic (ROC) curve analysis.

RESULTS

The UHR in AAA group was significantly higher than that in CON group, but there was no significant difference between AAD group and CON group. The optimal cut-off point of UHR for AAA was 7.78 (sensitivity 84.7%, specificity 62.4%, and AUC 0.811; p < 0.001), and UHR (OR: 1.122, 95%CI: 1.064-1.184; p < 0.001) was found to be an independent factor for predicting AAA after adjusting for traditional AAA risk factor.

CONCLUSION

UHR can be widely used in clinical practice as an auxiliary tool for screening AAA. The optimal cut-off point for UHR to AAA was determined for the first time in Chinese subjects.

Fetoplacental unit involvement in uric acid production in women with severe preeclampsia: a prospective case control pilot study

PURPOSE

Preeclampsia (PE) is a common complication of pregnancy that carries significant risks for both the mother and the fetus, and is frequently accompanied by hyperuricemia, yet the exact source of elevated uric acid (UA) levels remains partially elucidated. Several potential origins for increased UA levels include abnormal renal function, increased tissue breakdown, and increased activity of the enzyme Xanthine Oxidase (XO). The aim of the study was to determine serum levels of UA and XO not only in maternal serum, but also in umbilical vein (UV) and umbilical artery (UA) and explore their possible role in PE development.

METHODS

A prospective case-control pilot study was conducted in women who were found positive for PE with severe features, and had elevated UA levels above 6 mg/dL, with normotensive pregnant women serving as controls. Renal function, UA and XO levels were measured in maternal, UV and UA serums immediately after delivery. They were then compared between PE (n = 21) and control (n = 18) groups, as well as across all mediums (maternal, UV and UA) among the total study sample (N = 39). Diastolic blood pressure (DBP) was also measured immediately following delivery.

RESULTS

The mean serum maternal creatinine levels did not differ significantly between groups (0.65 ± 0.03 vs 0.6 ± 0.07, p = 0.13). Both mean maternal serum UA and XO concentrations were higher in PE group than in control (7.3 ± 1.2 vs 4.2 ± 0.9, p < 0.01 and 3.6 ± 3.5 Vs 1.7 ± 0.8, p < 0.01, respectively). The mean UV and UA serum XO concentrations were significantly higher in PE group compared to control (4.2 ± 3.6 vs 2.2 ± 1.4, p < 0.01 and 4.2 ± 3.6 vs 2.1 ± 1.5, p < 0.01, respectively). Polynomial fit correlation test demonstrated a significant association between maternal DBP and UV XO concentration for all the total study participants (p = 0.03).

CONCLUSION

Despite preserved renal functions, UA and XO levels were elevated in women with PE. Importantly, this pattern was found to be applied to the feto-placental unit as well, which may indicate an active involvement of the fetus in the hypoxic process. Further study is needed to clarify the possible role of the feto-placental unit in pregnancies complicated by PE.

Effect of high sensitivity C-reactive protein on uric acid-related cardiometabolic risk in patients with coronary artery disease-a large multicenter prospective study

Although serum uric acid (SUA) is a risk factor for cardiometabolic outcome, but it remains unclear which patients with coronary artery disease (CAD) benefit the most from SUA lowering therapy (ULT). The association of SUA level, systemic inflammation and cardiometabolic risk is still unclear. The current study is aimed to examine whether SUA-associated cardiometabolic risk is modulated by systemic inflammation in CAD patients. A total of 16,598 CAD patients with baseline high-sensitivity C-Reactive Protein (hsCRP) and SUA available were included. Baseline and follow-up data were collected. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), including death, myocardial infarction and stroke. In patients with hsCRP ≥ 2 mg/L, increasing quintiles of SUA were significantly associated with increased rates of 2-year MACCE (adjusted p < 0.001 for trend, p = 0.037 for interaction). Each unit increase in SUA levels was associated with a 11.3% increased risk of MACCE (adjusted p < 0.001, p = 0.002 for interaction). However, in patients with hsCRP < 2 mg/L, increasing quintiles of SUA were not associated with increased MACCE (adjusted p = 0.120). Elevated SUA levels are related to MACCE when hsCRP levels are 2 mg/L or more but not less than 2 mg/L. This finding suggests a potential benefit of combined ULT and anti-inflammation therapy in patients with hyperuricemia and greater systemic inflammation.

Potential Opportunities for Pharmacogenetic-Based Therapeutic Exploitation of Xanthine Dehydrogenase in Cardiovascular Disease

The majority of naturally occurring mutations of the human gene XDH, are associated with reduced or completely absent xanthine oxidoreductase (XOR) activity, leading to a disease known as classical xanthinuria, which is due to the accumulation and excretion of xanthine in urine. Three types of classical xanthinuria have been identified: type I, characterised by XOR deficiency, type II, caused by XOR and aldehyde oxidase (AO) deficiency, and type III due to XOR, AO, and sulphite oxidase (SO) deficiency. Type I and II are considered rare autosomal recessive disorders, a condition where two copies of the mutated gene must be present to develop the disease or trait. In most cases, xanthinuria type I and II result to be asymptomatic, and only occasionally lead to renal failure due to urolithiasis caused by xanthine deposition. However, in the last 10-15 years, new observations have been made about the link between naturally occurring mutations and pathological phenotypes particularly pertinent to cardiovascular diseases (CVD). These links have been attributed to a genetically driven increase of XOR expression and activity that is responsible for what is thought to be damaging uric acid (UA) and reactive oxygen species (ROS) accumulation, nitric oxide (·NO) depletion and endothelial dysfunction. In this review, we discuss the importance of genetics for interindividual variability of XOR expression and activity while focusing mainly on those variants thought to be relevant for CVD. In addition, we discuss the potential exploitation of the genetically driven increase of XOR activity to deliver more beneficial bioavailable ·NO. Finally, we examine the effect that non-synonymous mutations have on the tertiary structure of the protein and consequently on its capacity to interact with glycosaminoglycans (GAGs) localised on the outer surface of endothelial cells.

Extrarenal Benefits of SGLT2 Inhibitors in the Treatment of Cardiomyopathies

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have emerged as pivotal medications for heart failure, demonstrating remarkable cardiovascular benefits extending beyond their glucose-lowering effects. The unexpected cardiovascular advantages have intrigued and prompted the scientific community to delve into the mechanistic underpinnings of these novel actions. Preclinical studies have generated many mechanistic theories, ranging from their renal and extrarenal effects to potential direct actions on cardiac muscle cells, to elucidate the mechanisms linking these drugs to clinical cardiovascular outcomes. Despite the strengths and limitations of each theory, many await validation in human studies. Furthermore, whether SGLT2 inhibitors confer therapeutic benefits in specific subsets of cardiomyopathies akin to their efficacy in other heart failure populations remains unclear. By examining the shared pathological features between heart failure resulting from vascular diseases and other causes of cardiomyopathy, certain specific molecular actions of SGLT2 inhibitors (particularly those targeting cardiomyocytes) would support the concept that these medications will yield therapeutic benefits across a broad range of cardiomyopathies. This article aims to discuss the important mechanisms of SGLT2 inhibitors and their implications in hypertrophic and dilated cardiomyopathies. Furthermore, we offer insights into future research directions for SGLT2 inhibitor studies, which hold the potential to further elucidate the proposed biological mechanisms in greater detail.

Factors Associated with the Onset of Acute Kidney Injury Following Subarachnoid Hemorrhage

BACKGROUND

Acute kidney injury (AKI) is a complication often observed in critically ill patients, indicating a worsening prognosis. However, factors predicting AKI in subarachnoid hemorrhage (SAH) patients are unclear. This study aims to elucidate the predictors of AKI occurrence.

METHODS

All patients with SAH admitted to the intensive care unit between 2013 and 2019 were included. Patients with very severe SAH who are unsuitable to receive aggressive treatment, those who previously received a contrast medium at another medical institution within 24 hours before admission, and those on maintenance dialysis were excluded. We retrospectively examined blood tests conducted upon admission, oral medications administered, and the total amount of contrast medium used after initiating treatment to investigate their association with AKI occurrence.

RESULTS

Of the 254 SAH patients treated during the relevant period, 195 (median age 64 years, 72 males) met the inclusion/exclusion criteria, and 32 patients (16.3%) developed AKI. When multivariate analysis was performed using sex, uric acid level, and hemoglobin, which obtained P < 0.01 in the univariate analysis, as variables, only uric acid level was found as an independent predictor of AKI (odds ratio, 1.501; 95% confidence interval, 1.109-2.033, P value of 0.009). There was no difference in the occurrence of AKI between survivors and nonsurvivors (12/163 vs. 2/32, P = 0.824).

CONCLUSIONS

AKI occurred in 16.3% of the patients with SAH. Patients who developed AKI had significantly higher uric acid levels. SAH with high uric acid levels warrants attention for AKI.

Salivary uric acid dynamics are associated with stress response hormones among African Americans in an urban sample

Acute physiological responses to psychosocial stressors are a potential pathway underlying racial disparities in stress-related illnesses. Uric acid (UA) is a potent antioxidant that has been linked to disparities in stress-related illnesses, and recent research has shown that UA is responsive to acute social stress. However, an examination of the relationships between the purinergic system and other commonly measured stress systems is lacking. Here, we measure and characterize associations of salivary uric acid (sUA) with markers of hypothalamic-pituitary-adrenal (HPA) axis activation, sympathetic-adreno-medullar (SAM) axis activation, and acute inflammation. A community sample of 103 African Americans (33 male, 70 female) completed the Trier Social Stress Test to induce social-evaluative threat. Passive drool collected before, during, and after the stressor task provided salivary reactivity measures of UA (sUA), cortisol, dehydroepiandrosterone sulfate (DHEAS), salivary alpha amylase (sAA - a surrogate marker of SAM activity) and C-reactive protein (sCRP). Multiple regressions revealed that total activation of cortisol, DHEAS, and sCRP were each positively associated with higher total activation of sUA. Additionally, DHEAS reactivity was positively associated with sUA reactivity. Relationships between HPA-axis markers and sUA were especially observed among younger and male participants. Overall, findings suggest potential coordination of stress systems with sUA in response to acute stress, which may further the contributions of biological stress processes to racial health disparities.

Association of serum uric acid to all-cause and cardiovascular mortality in patients with cardiovascular disease

Serum uric acid (SUA) has been linked to mortality in heart failure, hypertension, diabetes, hyperlipidemia, obstructive sleep apnea, and metabolic dysfunction-associated fatty liver disease. However, data are lacking on how it affects the mortality risk of patients with cardiovascluar disease (CVD). This study evaluated the data of 4 308 individuals from the National Health and Nutrition Examination Survey 1999-2008 using multivariate Cox proportional hazards regression, trend, restricted cubic splines (RCS), subgroup and inflection point analyses. All-cause and cardiovascular mortality accounted for 42.8% and 17.6% of cases, respectively, over a median 80- month follow-up. Upon control for confounding variables, no linear trend was seen in the Cox proportional hazards regression analysis between SUA and all-cause (P = 0.001) or cardiovascular death (P = 0.007) mortality. On the RCS analysis, SUA showed an L-shaped connection with all-cause (non-linear P < 0.001) and cardiovascular mortality (non-linear P = 0.003) mortality. On the inflection point analysis, patients with CVD and an SUA ≥ 6.127 mg/dL had an all-cause mortality hazard ratio of 1.146 (95% confidence interval, 1.078-1.217; P < 0.001), while those with CVD and an SUA ≥ 5.938 mg/dL had a cardiovascular mortality hazard ratio of 1.123 (95% confidence interval, 1.03-1.225; P = 0.007). In patients with CVD, higher SUA was non-linearly correlated with all-cause and cardiovascular mortality.

Impact of hyperuricemia on CKD risk beyond genetic predisposition in a population-based cohort study

The bidirectional effect of hyperuricemia on chronic kidney disease (CKD) underscores the importance of hyperuricemia as a risk factor for CKD. We evaluated the effect of hyperuricemia on the presence and development of CKD after considering genetic background by calculating polygenic risk scores (PRSs). We employed genome-wide association study summary statistics-excluding the United Kingdom Biobank (UKB) datasets among published CKD Gen Consortium papers-to calculate the PRSs for CKD in white background subjects. To validate PRS performance, we divided the UKB into two datasets to validate and test the data. We used logistic regression analysis to evaluate the association between hyperuricemia and CKD, and performed Kaplan-Meier survival analysis exclusively for subjects with available follow-up data. In total, 438,253 clinical data and 4,307,940 single nucleotide polymorphisms from 459,155 samples were included. We observed a significant positive association between PRS and CKD and the presence and development of CKD. Hyperuricemia significantly increased CKD risk (adjusted odds ratio 1.55, 95% confidence interval 1.48-1.61). The impact of hyperuricemia on CKD was maintained irrespective of PRS range. In addition, negative interaction between hyperuricemia and PRS for CKD was found. Survival analysis indicates that the presence of hyperuricemia significantly increased the risk of CKD development. The PRS for CKD thoroughly reflects the risk of CKD development. Hyperuricemia is a significant indicator of CKD risk, even after incorporating the genetic risk score for CKD. Irrespective of genetic risk, patients with a prospective risk of developing CKD require uric acid monitoring and management.

Connecting the Dots: FGF21 as a Potential Link between Obesity and Cardiovascular Health in Acute Coronary Syndrome Patients

Fibroblast growth factor 21 (FGF21) is a hormone involved in regulating the metabolism, energy balance, and glucose homeostasis, with new studies demonstrating its beneficial effects on the heart. This study investigated the relationship between FGF21 levels and clinical, biochemical, and echocardiographic parameters in patients with acute coronary syndromes (ACSs). This study included 80 patients diagnosed with ACS between May and July 2023, categorized into four groups based on body mass index (BMI): Group 1 (BMI 18.5-24.9 kg/m2), Group 2 (BMI 25-29.9 kg/m2), Group 3 (BMI 30-34.9 kg/m2), and Group 4 (BMI ≥ 35 kg/m2). Serum FGF21 levels were measured by ELISA (Abclonal Catalog NO.: RK00084). Serum FGF21 levels were quantifiable in 55 samples (mean ± SD: 342.42 ± 430.17 pg/mL). Group-specific mean FGF21 levels were 238.98 pg/mL ± SD in Group 1 (n = 14), 296.78 pg/mL ± SD in Group 2 (n = 13), 373.77 pg/mL ± SD in Group 3 (n = 12), and 449.94 pg/mL ± SD in Group 4 (n = 16), with no statistically significant differences between groups (p = 0.47). Based on ACS diagnoses, mean FGF21 levels were 245.72 pg/mL for STEMI (n = 21), 257.89 pg/mL for NSTEMI (n = 9), and 456.28 pg/mL for unstable angina (n = 25), with no significant differences observed between these diagnostic categories. Significant correlations were identified between FGF21 levels and BMI, diastolic blood pressure, and serum chloride. Regression analyses revealed correlations with uric acid, chloride, and creatinine kinase MB. This study highlights the complex interplay between FGF21, BMI, and acute coronary syndromes. While no significant differences were found in FGF21 levels between the different BMI and ACS diagnostic groups, correlations with clinical and biochemical parameters suggest a multifaceted role of FGF21 in cardiovascular health. Further research with a larger sample size is warranted to elucidate these relationships.

Uric acid and acute kidney injury in high-risk patients for developing acute kidney injury undergoing cardiac surgery: A prospective multicenter study

PURPOSE

It is unclear whether preoperative serum uric acid (SUA) elevation may play a role in the development of acute kidney injury (AKI) associated with cardiac surgery (CSA-AKI). We conducted a cohort study to evaluate the influence of preoperative hyperuricemia on AKI in patients at high risk for developing SC-AKI.

DESIGN

Multicenter prospective international cohort study.

SETTING

Fourteen university hospitals in Spain and the United Kingdom.

PARTICIPANTS

We studied 261 consecutive patients at high risk of developing CSA-AKI, according to a Cleveland score ≥ 4 points, from July to December 2017.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

AKIN criteria were used for the definition of AKI. Multivariable logistic regression models and propensity score-matched pairwise analysis were used to determine the adjusted association between preoperative hyperuricemia (≥7 mg/dL) and AKI. Elevated preoperative AUS (≥7 mg/dL) was present in 190 patients (72.8%), whereas CSA-AKI occurred in 145 patients (55.5%). In multivariable logistic regression models, hyperuricemia was not associated with a significantly increased risk of AKI (adjusted Odds Ratio [OR]: 1.58; 95% confidence interval [CI]: 0.81-3; P = .17). In propensity score-matched analysis of 140 patients, the hyperuricemia group experienced similar adjusted odds of AKI (OR 1.05, 95%CI 0.93-1.19, P = .37).

CONCLUSIONS

Hyperuricemia was not associated with an increased risk of AKI in this cohort of patients undergoing cardiac surgery at high risk of developing CSA-AKI.

John Yudkin's hypothesis: sugar is a major dietary culprit in the development of cardiovascular disease

To date, the risk of developing atherosclerosis has extended beyond Western countries and now affecting individuals from various ethnic backgrounds and age groups. Traditional risk factors of atherosclerosis, such as hypercholesterolemia, has been better controlled than before due to highly effective and inexpensive therapies at lowering plasma cholesterol levels. However, the role of reducing dietary cholesterol intake, as a public healthy strategy, in preventing the occurrence of cardiovascular mortalities has been recently challenged. Indeed, despite our continuous decline of dietary cholesterol intake within the last 50 years, the incidence of cardiovascular mortalities has continued to rise, thus raising the possibility that other dietary factors, such as fructose-containing sugars, are the major culprit. In the 1970s, John Yudkin first proposed that sugar was the predominant dietary factor that underlies the majority of cardiovascular mortalities, yet his hypothesis was dismissed. However, over the last 25 years substantial scientific evidence has been accumulated to support Yudkin's hypothesis. The objectives of this review are to highlight Yudkin's significant contribution to nutritional science by reviewing his hypothesis and summarizing the recent advances in our understanding of fructose metabolism. The metabolic consequences of fructose metabolism, such as fructose-induced uricemia, insulin resistance, lipoprotein hyperproduction and chronic inflammation, and how they are linked to atherosclerosis as risk factors will be discussed. Finally, the review will explore areas that warrant future research and raise important considerations that we need to evaluate when designing future studies.

Predictors of autosomal dominant polycystic kidney disease progression: a Brazilian single-center cohort

INTRODUCTION

Identifying risk factors for autosomal dominant polycystic kidney disease (ADPKD) progression is important. However, studies that have evaluated this subject using a Brazilian sample is sparce. Therefore, the aim of this study was to identify risk factors for renal outcomes and death in a Brazilian cohort of ADPKD patients.

METHODS

Patients had the first medical appointment between January 2002 and December 2014, and were followed up until December 2019. Associations between clinical and laboratory variables with the primary outcome (sustained decrease of at least 57% in the eGFR from baseline, need for dialysis or renal transplantation) and the secondary outcome (death from any cause) were analyzed using a multiple Cox regression model. Among 80 ADPKD patients, those under 18 years, with glomerular filtration rate <30 mL/min/1.73 m2, and/or those with missing data were excluded. There were 70 patients followed.

RESULTS

The factors independently associated with the renal outcomes were total kidney length - adjusted Hazard Ratio (HR) with a 95% confidence interval (95% CI): 1.137 (1.057-1.224), glomerular filtration rate - HR (95% CI): 0.970 (0.949-0.992), and serum uric acid level - HR (95% CI): 1.643 (1.118-2.415). Diabetes mellitus - HR (95% CI): 8.115 (1.985-33.180) and glomerular filtration rate - HR (95% CI): 0.957 (0.919-0.997) were associated with the secondary outcome.

CONCLUSIONS

These findings corroborate the hypothesis that total kidney length, glomerular filtration rate and serum uric acid level may be important prognostic predictors of ADPKD in a Brazilian cohort, which could help to select patients who require closer follow up.

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.

Effect of the Xanthine Oxidase Inhibitor, Febuxostat, on WBC Count in Asymptomatic Hyperuricemia: Subanalysis of the Randomized PRIZE Study

AIMS

The anti-inflammatory effects of the xanthine oxidase inhibitor, febuxostat, a urate-lowering agent, have been reported in animal studies. However, the anti-inflammatory effects of urate-lowering therapy and its associated cardiovascular protective effects have not been fully determined in actual clinical practice. This study aimed to investigate the effect of febuxostat on white blood cell (WBC) count in patients with asymptomatic hyperuricemia and to assess for potential correlations between changes in WBC count and inflammatory biomarkers and atherosclerosis in this patient population.

METHODS

This was a post hoc subanalysis of the PRIZE study, a multicenter, prospective, randomized, open-label clinical trial. In the PRIZE study, asymptomatic hyperuricemia patients were randomized to febuxostat group or control group with non-pharmacological therapy and evaluated the effect on vascular. The primary endpoints of this study were the assessment of the time course of WBC count over 24 months and its changes from baseline. Correlations of WBC count with high-sensitivity C-reactive protein (hs-CRP) and mean common carotid artery (CCA)-IMT were also exploratorily examined in the febuxostat group.

RESULTS

A total of 444 patients (febuxostat group, n=223; control group, n=221) with WBC measurements available at baseline and at least one of the follow-up time points of 12 or 24 months, were enrolled. Febuxostat modestly, but significantly, reduced WBC counts at 12 and 24 months compared with the baseline levels (P=0.002 and P=0.026, respectively). Notably, the WBC count in the febuxostat group at 12 and 24 months was significantly lower than that in the control group (P=0.007 and P=0.023, respectively). The changes in WBC count were associated with those of hs-CRP (P=0.038), but not with CCA-IMT (P=0.727).

CONCLUSIONS

Febuxostat therapy for 24 months modestly, but significantly, decreased WBC count in patients with asymptomatic hyperuricemia. This might potentially reflect a modest anti-inflammatory action of febuxostat in clinical settings.

Glutamine-mediated Modulation of XO/uric acid/NF-kB Signaling Pathway Ameliorates Intestinal I/R-induced Bacterial Translocation and Cardiorenal Inflammatory Injury

This study explored the effect of intestinal ischaemia/reperfusion (I/R) on cardiorenal tissues. The involvement of xanthine oxidase/uric acid/NF-kB signaling in intestinal I/R was also investigated. In addition, the possible protective effect of glutamine was also evaluated. Twenty-four male Wistar rats were acclimatized and then randomly assigned to four groups (n = 6); sham-operated, glutamine-treated rats (GLUT), I/R, and I/R + GLUT. The sham-operated rats were sham-operated and received 0.5 mL of distilled water, GLUT rats were sham-operated and had 1 g/kg b.w. of glutamine, I/R animals had an intestinal I/R procedure and received 0.5 mL of distilled water, and the I/R + GLUT rats had an intestinal I/R procedure and also received 1 g/kg b.w. of glutamine. Treatments were daily and per os. Glutamine attenuated intestinal I/R-induced rise in intestinal and cardiorenal activities of creatinine kinase and lactate dehydrogenase and lactate level. More so, glutamine alleviated I/R-induced rise in malondialdehyde, xanthine oxidase, uric acid, myeloperoxidase, NF-kB, TNF-α, IL-1β, caspase 3 activity, and DNA fragmentation. Furthermore, glutamine suppressed I/R-induced decline in GSH levels and SOD and catalase activities. Moreover, glutamine improved intestinal, cardiac, and renal histology in animals subjected to intestinal I/R.

The combination of high uric acid and high C-reactive protein increased the risk of cardiovascular disease: A 15-year prospective cohort study

BACKGROUND AND AIMS

Uric acid (UA) and C-reactive protein (CRP) may interact synergistically to accelerate the initiation and progression of cardiovascular disease (CVD). This study investigated the effects of a combination of high UA and high CRP on the risks of CVD.

METHODS AND RESULTS

A total of 90,270 participants recruited from the Kailuan study were included, who were divided into four groups according to the presence/absence of hyperuricemia and inflammation. Cox regression was applied to evaluate the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of CVD. C-statistics, net classification index (NRI), and integrated discrimination improvement (IDI) were used to compare the incremental predictive of UA, CRP, and their combined effects on CVD. Mediation analysis was to explore the impact of CRP on the association between UA and CVD. Over a median follow-up of 14.95 years, we identified 11398 incident CVD cases. Compared to the low UA/low CRP group, the high UA/low CRP, low UA/high CRP and high UA/high CRP groups showed progressively higher risks of CVD, HR (95% CI): 1.18(1.10-1.27), 1.27(1.21-1.33) and 1.50 (1.33-1.69), respectively. The incorporation of UA and CRP into the traditional China-PAR model led to improvement in the C-statistic, NRI, and IDI, and was better than incorporation of either UA or CRP alone. Mediation analysis showed that CRP mediated the association between UA and CVD, accounting for 11.57% of the total effects.

CONCLUSIONS

High UA/high CRP is associated with increased risks of CVD. Incorporation of both UA and CRP provided additional value for risk stratification.

Hyperuricemia: An Intriguing Connection to Metabolic Syndrome, Diabetes, Kidney Disease, and Hypertension

PURPOSE OF THE REVIEW

Our review explores the epidemiology, physiology, and clinical data surrounding the connection between hyperuricemia and metabolic syndrome, chronic kidney disease, and hypertension.

RECENT FINDINGS

Compelling physiologic mechanisms have been proposed to explain a causal relationship between hyperuricemia and metabolic syndrome, chronic kidney disease, and hypertension but clinical studies have given mixed results in terms of whether intervening with hyperuricemia using urate-lowering therapy has any beneficial effects for patients with these conditions. Despite the large amount of research already put into this topic, more randomized placebo-controlled trials are needed to more firmly establish whether a cause-effect relationship exists and whether lowering uric acid levels in patients with these conditions is beneficial.

Uric acid in health and disease: From physiological functions to pathogenic mechanisms

Owing to renal reabsorption and the loss of uricase activity, uric acid (UA) is strictly maintained at a higher physiological level in humans than in other mammals, which provides a survival advantage during evolution but increases susceptibility to certain diseases such as gout. Although monosodium urate (MSU) crystal precipitation has been detected in different tissues of patients as a trigger for disease, the pathological role of soluble UA remains controversial due to the lack of causality in the clinical setting. Abnormal elevation or reduction of UA levels has been linked to some of pathological status, also known as U-shaped association, implying that the physiological levels of UA regulated by multiple enzymes and transporters are crucial for the maintenance of health. In addition, the protective potential of UA has also been proposed in aging and some diseases. Therefore, the role of UA as a double-edged sword in humans is determined by its physiological or non-physiological levels. In this review, we summarize biosynthesis, membrane transport, and physiological functions of UA. Then, we discuss the pathological involvement of hyperuricemia and hypouricemia as well as the underlying mechanisms by which UA at abnormal levels regulates the onset and progression of diseases. Finally, pharmacological strategies for urate-lowering therapy (ULT) are introduced, and current challenges in UA study and future perspectives are also described.

Robust positive association between serum urate and the risk of chronic obstructive pulmonary disease: hospital-based cohort and Mendelian randomisation study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and hyperuricaemia are both characterised by systemic inflammation. Preventing chronic diseases among the population with common metabolic abnormality is an effective strategy. However, the association of hyperuricaemia with the higher incidence and risk of COPD remains controversial. Therefore, replicated researches in populations with distinct characteristics or demographics are compellingly warranted.

METHODS

This cohort study adopted a design of ambispective hospital-based cohort. We used propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) to minimise the effects of potential confounding factors. A Cox regression model and restricted cubic spline (RCS) model were applied further to assess the effect of serum urate on the risk of developing COPD. Finally, we conducted a two-sample Mendelian randomisation (MR) analysis to explore evidence of causal association.

RESULTS

There is a higher incidence in the population with hyperuricaemia compared with the population with normal serum urate (22.29/1000 person-years vs 8.89/1000 person-years, p=0.009). This result is robust after performing PSM (p=0.013) and IPTW (p<0.001). The Cox model confirms that hyperuricaemia is associated with higher risk of developing COPD (adjusted HR=3.35 and 95% CI=1.61 to 6.96). Moreover, RCS shows that the risk of developing COPD rapidly increases with the concentration of serum urate when it is higher than the reference (420 µmol/L). Finally, in MR analysis, the inverse variance weighted method evidences that a significant causal effect of serum urate on COPD (OR=1.153, 95% CI=1.034 to 1.289) is likely to be true. The finding of MR is robust in the repeated analysis using different methods and sensitivity analysis.

CONCLUSIONS

Our study provides convincing evidence suggesting a robust positive association between serum urate and the risk of developing COPD, and indicates that the population with hyperuricaemia is at high risk of COPD in the Chinese population who seek medical advice or treatment in the hospital.

A Possible Therapeutic Application of the Selective Inhibitor of Urate Transporter 1, Dotinurad, for Metabolic Syndrome, Chronic Kidney Disease, and Cardiovascular Disease

The reabsorption of uric acid (UA) is mainly mediated by urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) in the kidneys. Dotinurad inhibits URAT1 but does not inhibit other UA transporters, such as GLUT9, ATP-binding cassette transporter G2 (ABCG2), and organic anion transporter 1/3 (OAT1/3). We found that dotinurad ameliorated the metabolic parameters and renal function in hyperuricemic patients. We consider the significance of the highly selective inhibition of URAT1 by dotinurad for metabolic syndrome, chronic kidney disease (CKD), and cardiovascular disease (CVD). The selective inhibition of URAT1 by dotinurad increases urinary UA in the proximal tubules, and this un-reabsorbed UA may compete with urinary glucose for GLUT9, reducing glucose reabsorption. The inhibition by dotinurad of UA entry via URAT1 into the liver and adipose tissues increased energy expenditure and decreased lipid synthesis and inflammation in rats. Such effects may improve metabolic parameters. CKD patients accumulate uremic toxins, including indoxyl sulfate (IS), in the body. ABCG2 regulates the renal and intestinal excretion of IS, which strongly affects CKD. OAT1/3 inhibitors suppress IS uptake into the kidneys, thereby increasing plasma IS, which produces oxidative stress and induces vascular endothelial dysfunction in CKD patients. The highly selective inhibition of URAT1 by dotinurad may be beneficial for metabolic syndrome, CKD, and CVD.

Spontaneous tumour lysis secondary to gastric adenocarcinoma

We present a case of a man in his 70s who presented with worsening rectal and back pain associated with weight loss, dyspnoea and brownish discolouration of urine. Physical examination noted abdominal distention and epigastric tenderness. Laboratory investigations revealed acute kidney injury, hyperkalaemia, hyperphosphataemia and hyperuricaemia. Contrast CT of the abdomen/pelvis showed multiple, low-density masses throughout the liver, suspicious for metastatic disease. Oesophagogastroduodenoscopy demonstrated a large, fungating, infiltrative and ulcerated mass in the gastric body and lesser curvature of the stomach. Surgical pathology confirmed invasive moderately differentiated gastric adenocarcinoma. He met both the laboratory and clinical criteria for spontaneous tumour lysis syndrome (STLS) as per the Cairo-Bishop criteria. He was managed with aggressive fluid hydration, rasburicase and allopurinol, resulting in improvement in his renal function and laboratory findings. STLS of solid organ tumours, especially gastric adenocarcinoma, is rare and requires early detection with timely management to ensure favourable outcomes.

Association between systemic immune-inflammation index and serum uric acid in U.S. adolescents: A population-based study

BACKGROUND AND AIMS

Serum uric acid (SUA) has been reported to be associated with inflammation, and elevated SUA is increasingly prevalent in adolescents. The systemic immune-inflammation index (SII) is an innovative and integrated inflammatory indicator that has not yet been studied with SUA in adolescents. We therefore aimed to investigate the potential relationship between SII and SUA in U.S. adolescents.

METHODS AND RESULTS

A total of 5,568 adolescents aged 12-19 years from NHANES 2009-2018 were analyzed. SII was calculated as platelet count × neutrophil count/lymphocyte count. Elevated SUA was defined as ≥ 5.5 mg/dL. SII was Ln-transformed for analysis for the skewed distribution. Multivariate linear and multiple logistic regression analyses were conducted to explore the association of SII with SUA and elevated SUA. A generalized additive model and a fitted smoothing curve were also performed. The prevalence of elevated SUA was 35.4 %. Multivariate linear regression analyses indicated that LnSII was positively associated with SUA level (β = 0.15, 95 % CI: 0.09-0.20). Multiple logistic analyses indicated that LnSII was associated with a 38 % increased risk of elevated SUA (OR = 1.38, 95 % CI: 1.11-1.70). The smooth curve fitting showed that the associations of LnSII with SUA and elevated SUA were linear. Besides, subgroup analyses showed a stronger association between LnSII and SUA in adolescents aged ≥17 years (P for interaction <0.05).

CONCLUSIONS

SII was positively associated with SUA level and elevated SUA in U.S. adolescents, particularly in populations aged ≥17 years.

Association Between Serum Uric Acid Levels and Neoatherosclerosis

Neoatherosclerosis is a major cause of stent failure after percutaneous coronary intervention. Metabolism such as hyperuricemia is associated with in-stent restenosis (ISR). However, the association between serum uric acid (sUA) levels and in-stent neoatherosclerosis (ISNA) has never been validated.A total of 216 patients with 220 ISR lesions who had undergone optical coherence tomography (OCT) of culprit stents were included in this study. According to their sUA levels, eligible patients were divided into two groups [normal-sUA group: sUA < 7 mg/dL, n = 126, and high-sUA group: sUA ≥ 7 mg/dL, n = 90]. OCT findings were analyzed and compared between the normal- and high-sUA groups.The incidence of ISNA (63.0% versus 43.0%, P = 0.004) was significantly higher in the high-sUA group than in the normal-sUA group. Lipid plaques (66.3% versus 43.0%, P < 0.001) and thin-cap fibroatheroma (38.0% versus 18.0%, P = 0.001) were observed more frequently in the restenotic tissue structure in patients in the high-sUA group than in those in the normal-sUA group. Meanwhile, univariate (OR: 1.208, 95% CI: 1.037-1.407; P = 0.015) and multivariate (OR: 1.254, 95% CI: 1.048-1.501; P = 0.013) logistic regression analyses indicated that sUA levels were an independent risk factor for ISNA after adjusting for relevant risk factors.The high-sUA levels were an independent risk factor for the occurrence of neoatherosclerosis in patients with ISR via OCT.

Relationship between uric acid to albumin ratio and in-stent restenosis in patients with coronary artery disease undergoing drug-eluting stenting

BACKGROUND

In-stent restenosis (ISR) in patients undergoing percutaneous coronary intervention (PCI) to treat coronary artery disease (CAD) is an urgent issue in clinical practice. Recent studies have highlighted uric acid-albumin ratio (UAR) as a new marker for evaluating inflammation and oxidative stress, capable of predicting cardiovascular ailments. We aimed to examine the correlation between UAR levels and ISR in patients who underwent drug-eluting stent (DES) implantation.

METHODS

We included 503 patients with CAD who underwent initial DES implantation and angiography during the follow-up period. Based on coronary angiographic findings, the patients were categorized into ISR (n = 73) and non-ISR groups (n = 430). Before angiography, laboratory parameters were measured for all enrolled patients. To ascertain the influential factors linked to ISR, multivariate logistic regression analysis was performed. The predictive capability of UAR in determining ISR was assessed using receiver operating characteristic (ROC) curve analysis. Statistical significance was set at P  < 0.05.

RESULTS

Multivariate logistic regression analysis revealed that diabetes mellitus, stent length, UAR, albumin levels, and C-reactive protein levels independently predicted ISR. ROC curve analysis revealed that UAR had an area under the curve of 0.767 (95% CI: 0.709 - 0.826) for predicting ISR and demonstrated that UAR outperformed the individual predictive abilities of uric acid and albumin for ISR.

CONCLUSION

UAR was associated with ISR in patients with CAD undergoing PCI with DES implantation. Moreover, ROC curve analysis demonstrated that UAR exhibited superior predictive accuracy for ISR compared with evaluating uric acid and albumin levels separately.

Serum uric acid is independently associated with hypertension in patients with polymyositis and dermatomyositis

Serum uric acid (UA), as an antioxidant, has been associated with hypertension in the general population. Hypertension is highly prevalent in patients with polymyositis and dermatomyositis (PM/DM). Owning elevated levels of reactive oxygen species, patients with PM/DM have lower concentrations of UA in comparison with healthy people. We explored a potential association between UA levels and hypertension in PM/DM and evaluated whether this association is independent of hypertension risk factors, PM/DM characteristics and relevant drugs. A total of 472 PM/DM patients were assessed. UA and related laboratory data were measured. Demographic, hypertension-related factors, PM/DM characteristics and drug use were assessed as potential covariates. Results were analyzed using logistic models to test the independence of the association between UA and hypertension. UA levels were higher in hypertension subjects compared to non-hypertensive PM/DM patients [284.70 (239.93-357.38) vs 264.00(222.50-322.75), p = .017]. When adjusted for hypertension risk factors, PM/DM characteristics and drugs, the odds of being a hypertensive PM/DM patient per 1 μmol/L UA increase were significantly increased: odds ratio = 1.473 (95% confidence interval:1.063-2.042, p = .020). This cross-sectional study suggests that UA levels are independently associated with hypertension in PM/DM patients.

Elevated serum uric acid is associated with cognitive impairment in acute minor ischemic stroke patients

Background

Acute minor ischemic stroke (AMIS) has been proven to be strongly associated with post-stroke cognitive impairment (PSCI). Few studies have reported that uric acid (UA) levels are linked to PSCI in patients with AMIS, and those results are debatable. We investigated the relationship between serum UA levels and cognitive impairment in patients with AMIS.

Methods

A total of 318 patients who were diagnosed with AMIS were recruited from Suining Central Hospital. Fasting serum samples were collected the day after admission for UA measurement. Cognitive function was evaluated at admission and 3 months after stroke using the Montreal Cognitive Assessment (MoCA). The relationship between UA and PSCI was examined using a multivariate binary logistic regression model. The optimal cut-off point for UA levels to predict PSCI was determined using the receiver operating characteristic (ROC) curve.

Results

A total of 197 (61.9 %) of the 318 participants in this study exhibited cognitive impairment at 3 months. Serum UA was strongly linked with PSCI after adjusting for confounding factors (OR = 1.82, 95 % CI: 1.56 to 2.11, P < 0.0001). The ROC curve revealed a cut-off of 363.58 μmol/L serum UA, and the predicted sensitivity and specificity for PSCI were 67.5 % and 83.5 %, respectively. Subgroup analysis showed that confounding factors had no impact on the association between serum UA and PSCI risk.

Conclusions

Higher baseline serum UA levels might be an independent risk factor for cognitive impairment in AMIS patients. Serum UA levels above 363.58 μmol/L may have clinical implications in predicting PSCI.

C-reactive Protein Levels and Cardiovascular Outcomes After Febuxostat Treatment in Patients with Asymptomatic Hyperuricemia: Post-hoc Analysis of a Randomized Controlled Study

PURPOSE

Inflammation plays an important role in the initiation and progression of atherosclerosis, leading to poor clinical outcomes. Hyperuricemia is associated with the activation of the Nod-like receptor protein 3 inflammasome. Here, we investigated whether inhibition of inflammation using febuxostat lowered the risk of cardiovascular events.

METHODS

This is a post-hoc analysis of the randomized trial, Febuxostat for Cerebral and CaRdiorenovascular Events PrEvEntion StuDy (FREED). In total, 1067 patients (736 men and 331 women) were included in the analysis. We compared the serial changes in high-sensitivity C-reactive protein (hs-CRP) levels between febuxostat and non-febuxostat groups and assessed the correlation between the changes in uric acid (UA) and hs-CRP levels after febuxostat treatment. We also determined whether febuxostat could reduce a hard endpoint, defined as a composite of cardiovascular events and all-cause mortality.

RESULTS

Serum UA levels in the febuxostat group were significantly lower than those in the non-febuxostat group after randomization (p < 0.05). However, hs-CRP levels were comparable between the two groups during the study. No significant correlation was observed between the changes in UA and hs-CRP levels after febuxostat treatment. The hard endpoints did not differ significantly between the two groups. In patients with baseline hs-CRP levels > 0.2 mg/dL or those administered 40 mg of febuxostat, the drug did not reduce hs-CRP levels or decrease the hard endpoint.

CONCLUSION

Febuxostat reduced the UA levels but did not affect the CRP levels, and therefore may fail to improve cardiovascular outcomes after treatment.

TRIAL REGISTRATION

ClinicalTrial.gov (NCT01984749). https://clinicaltrials.gov/ct2/show/NCT01984749.

C-Reactive Protein: Pathophysiology, Diagnosis, False Test Results and a Novel Diagnostic Algorithm for Clinicians

The current literature provides a body of evidence on C-Reactive Protein (CRP) and its potential role in inflammation. However, most pieces of evidence are sparse and controversial. This critical state-of-the-art monography provides all the crucial data on the potential biochemical properties of the protein, along with further evidence on its potential pathobiology, both for its pentameric and monomeric forms, including information for its ligands as well as the possible function of autoantibodies against the protein. Furthermore, the current evidence on its potential utility as a biomarker of various diseases is presented, of all cardiovascular, respiratory, hepatobiliary, gastrointestinal, pancreatic, renal, gynecological, andrological, dental, oral, otorhinolaryngological, ophthalmological, dermatological, musculoskeletal, neurological, mental, splenic, thyroid conditions, as well as infections, autoimmune-supposed conditions and neoplasms, including other possible factors that have been linked with elevated concentrations of that protein. Moreover, data on molecular diagnostics on CRP are discussed, and possible etiologies of false test results are highlighted. Additionally, this review evaluates all current pieces of evidence on CRP and systemic inflammation, and highlights future goals. Finally, a novel diagnostic algorithm to carefully assess the CRP level for a precise diagnosis of a medical condition is illustrated.

A biofunctional review of C-reactive protein (CRP) as a mediator of inflammatory and immune responses: differentiating pentameric and modified CRP isoform effects

C-reactive protein (CRP) is an acute phase, predominantly hepatically synthesized protein, secreted in response to cytokine signaling at sites of tissue injury or infection with the physiological function of acute pro-inflammatory response. Historically, CRP has been classified as a mediator of the innate immune system, acting as a pattern recognition receptor for phosphocholine-containing ligands. For decades, CRP was envisioned as a single, non-glycosylated, multi-subunit protein arranged non-covalently in cyclic symmetry around a central void. Over the past few years, however, CRP has been shown to exist in at least three distinct isoforms: 1.) a pentamer of five identical globular subunits (pCRP), 2.) a modified monomer (mCRP) resulting from a conformational change when subunits are dissociated from the pentamer, and 3.) a transitional isoform where the pentamer remains intact but is partially changed to express mCRP structural characteristics (referred to as pCRP* or mCRPm). The conversion of pCRP into mCRP can occur spontaneously and is observed under commonly used experimental conditions. In careful consideration of experimental design used in published reports of in vitro pro- and anti-inflammatory CRP bioactivities, we herein provide an interpretation of how distinctive CRP isoforms may have affected reported results. We argue that pro-inflammatory amplification mechanisms are consistent with the biofunction of mCRP, while weak anti-inflammatory mechanisms are consistent with pCRP. The interplay of each CRP isoform with specific immune cells (platelets, neutrophils, monocytes, endothelial cells, natural killer cells) and mechanisms of the innate immune system (complement), as well as differences in mCRP and pCRP ligand recognition and effector functions are discussed. This review will serve as a revised understanding of the structure-function relationship between CRP isoforms as related to inflammation and innate immunity mechanisms.

The fructose survival hypothesis for obesity

The fructose survival hypothesis proposes that obesity and metabolic disorders may have developed from over-stimulation of an evolutionary-based biologic response (survival switch) that aims to protect animals in advance of crisis. The response is characterized by hunger, thirst, foraging, weight gain, fat accumulation, insulin resistance, systemic inflammation and increased blood pressure. The process is initiated by the ingestion of fructose or by stimulating endogenous fructose production via the polyol pathway. Unlike other nutrients, fructose reduces the active energy (adenosine triphosphate) in the cell, while blocking its regeneration from fat stores. This is mediated by intracellular uric acid, mitochondrial oxidative stress, the inhibition of AMP kinase and stimulation of vasopressin. Mitochondrial oxidative phosphorylation is suppressed, and glycolysis stimulated. While this response is aimed to be modest and short-lived, the response in humans is exaggerated due to gain of 'thrifty genes' coupled with a western diet rich in foods that contain or generate fructose. We propose excessive fructose metabolism not only explains obesity but the epidemics of diabetes, hypertension, non-alcoholic fatty liver disease, obesity-associated cancers, vascular and Alzheimer's dementia, and even ageing. Moreover, the hypothesis unites current hypotheses on obesity. Reducing activation and/or blocking this pathway and stimulating mitochondrial regeneration may benefit health-span. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part I)'.

Uric acid plasma levels are associated with C-reactive protein concentrations and the extent of coronary artery lesions in patients with acute coronary syndromes

Many studies have pointed out that inflammation plays a pivotal role in pathophysiology of acute coronary syndromes (ACS) because several inflammatory molecules impair the endothelial functions in the coronary circulation and promote atherothrombotic events. Recently, many clinical/experimental evidences indicate that elevated plasma levels of uric acid (UA) might be considered a risk factor for developing ACS. It has been reported that elevated UA doses impair physiologic functions of endothelial cells, shifting them toward a pro atherothrombotic phenotype. In the present manuscript, we investigated the relationship between UA plasma levels, inflammatory burden, and extension of coronary atherosclerotic disease in patients with ACS. Patients with a clinical presentation of ACS (ST-elevated and non-ST-elevated myocardial infarction) admitted to the Vanvitelli Catheterization Laboratory at Monaldi Hospital in 2019, before the COVID-19 pandemia, were retrospectively analyzed. Biochemical profile, type of ACS presentation, as well as extension of coronary atherosclerosis were assessed. A total of 132 ACS patients were included in the analysis, and grouped into 3 tertiles according to the UA values (UA < 4.72 mg/dl, UA between 4.72 and 6.15 mg/dl, and UA > 6.15 mg/dl). Patients with UA plasma levels ≥ 6.15 mg/dL showed higher levels of C-reactive protein (mean of 5.1 mg/dL) as compared to patients with lower UA plasma levels. Moreover, the former group of patients showed higher levels of cardiac troponin and CPK, and presented more often with multivessel disease and complex coronary stenosis (type C of Ellis classification). Even though monocentric and with limited sample size, the present study shows that plasma levels of UA and hs-CRP are elevated in ACS patients and are associated with a more severe coronary disease, suggesting a potential role of UA in the pathophysiology of acute coronary events.