Elevated serum uric acid is associated with high circulating inflammatory cytokines in the population-based Colaus study. PLoS One. 2011;6:e19901. [PMID: 21625475 PMCID: PMC3098830 DOI: 10.1371/journal.pone.0019901]

High prevalence of hyperuricemia and its risk factors in a Chinese cohort of primary hyperparathyroidism patients

PURPOSE

Primary hyperparathyroidism (PHPT) is characterized by autonomous and excessive parathyroid hormone (PTH) secretion due to parathyroid gland lesions. Patients can be complicated with hyperuricemia (HUA), however, data about HUA in Chinese PHPT patients are lacking. This study aimed to explore the prevalence of HUA, factors influencing serum uric acid (SUA) level and the impacts of parathyroidectomy (PTX).

METHODS

328 inpatients diagnosed with PHPT were included in total. Clinical data were collected and compared between HUA and non-HUA group. Multivariate linear regression was used to explore the factors affecting preoperative SUA and its variation after PTX. The impacts of SUA on bone mineral density (BMD) under different models were also analyzed.

RESULTS

The prevalence of HUA in PHPT patients was nearly 32%. Compared with non-HUA group, HUA group had significantly higher serum calcium (Ca) (2.92 [2.75, 3.26] vs. 2.78 [2.62, 3.03] mmol/L, P < 0.001), while PTH increased without significance. Gender, body mass index, serum Ca, triglycerides and renal function were independently associated with SUA. SUA decreased after PTX (340.00 [291.50, 421.00] vs. 315.00 [270.50, 375.00] μmol/L, P = 0.018), with change of SUA significantly associating with changes in serum Ca and phosphate. Presurgical SUA was positively related with femoral neck, total hip and lumbar spine BMDs after adjusting for confounders.

CONCLUSION

A relatively high proportion of HUA was found in our study. Besides the common risk factors, hypercalcemia may contribute to the increased SUA in PHPT patients, which could be significantly improved by curative PTX. SUA might have a protective effect on bone loss in PHPT patients.

Associations of serum uric acid to eGFR ratio with diabetic retinopathy in individuals with type 2 diabetes

Serum uric acid (SUA) is closely associated with diabetes and its complications. The relationship between SUA and diabetic retinopathy (DR) remains unclear, with conflicting results from current studies on SUA in DR Patients. Since uric acid is primarily excreted by the kidneys, the ratio of SUA to eGFR (SUA/eGFR) serves as a renal function-corrected indicator of SUA levels. We tested whether SUA/eGFR might be involved in the pathogenesis and progression of DR. We collected data from 1,399 patients with type 2 diabetes mellitus (T2DM) who were hospitalized between January 2023 and April 2024. They were divided into diabetes without DR (nondiabetic retinopathy, NDR) group (N = 438), non-proliferative diabetic retinopathy (NPDR) group (N = 902) and proliferative diabetic retinopathy (PDR) group (N = 59). Univariate and multivariate logistic regression analyses were used to analyze the relationship between SUA/eGFR and DR and its severity. The SUA/eGFR levels increased with the severity of DR (P<0.05). In the multinomial logistic regression model using patients without DR as the reference, SUA/eGFR was significantly linked with PDR (OR = 1.07, 95%CI 1.00-1.14; P = 0.036), while NPDR group showed no significant difference (P>0.05). In T2DM patients younger than 60 years, SUA/eGFR was positively associated with an increased risk of DR (OR = 1.20, 95%CI 1.05-1.38, P = 0.01). Among T2DM patients with HbA1c > 7%, higher SUA/eGFR levels were linked to a greater risk of DR(OR = 1.10, 95%CI 1.00-1.20, P = 0.045). Stratified analysis by age showed that in T2DM patients younger than 60 years, SUA/eGFR was positively correlated with the severity of DR (NPDR:OR = 1.20, 95%CI 1.04-1.38, P = 0.01; PDR: OR = 1.20, 95%CI 1.04-1.38, P = 0.012). Additionally, stratified analysis by HbA1c levels indicated that among T2DM patients with HbA1c > 7%, those with higher SUA/eGFR levels had an increased risk of DR severity (NPDR:OR = 1.09, 95%CI 1.00-1.19, P = 0.049; PDR: OR = 1.10, 95%CI 1.01-1.20, P = 0.037). Our study reported a positive association between SUA/eGFR and DR and its severity in younger T2DM patients with poorly controlled blood glucose levels. T2DM patients with higher SUA levels had an increased risk of more severe DR (progressing from NPDR to PDR). However, more prospective and high-quality clinical evidence is needed to confirm these current findings.

Association of Baseline Serum Uric Acid With Venous Thromboembolism and Clinical Outcomes in Patients With Non-Small Cell Lung Cancer

OBJECTIVE

This study aimed to analyze the association between baseline serum uric acid (SUA) level and venous thromboembolism (VTE) and clinical outcomes in patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

We conducted a prospective analysis of 626 patients with newly diagnosed or recurrent/progressive NSCLC between September 2021 and August 2024. Receiver operating characteristic (ROC) curve was used to determine the optimal cutoff values for risk factors related to VTE, and clinical characteristics and treatment outcomes were collected and compared according to these values. Fine-Gray regression analyses were used to identify the risk factors of VTE, and survival was analyzed using log-rank test and Cox regression analysis.

RESULTS

In the study, 72 patients (11.50%) experienced VTE. Patients with VTE had a higher baseline SUA level than those without VTE (p = 0.000). The optimal threshold of baseline SUA to predict VTE was 310 μmol/L. The incidence of VTE was higher in the high SUA group than that of the low SUA group (19.1% vs. 7.9%, p < 0.001). In multivariable analysis, the baseline SUA level was associated with the risk of VTE (sub-distribution hazard ratio (SHR) = 2.830, 95% CI 1.689-4.742, p = 0.000). Additionally, the higher SUA level was associated with a worse disease-free survival (DFS) in newly diagnosed patients with NSCLC staged I-IIIA (adjusted HR = 1.948, 95% CI 1.121-3.384, p = 0.018).

CONCLUSIONS

Among NSCLC patients, a baseline feature of high SUA (≥ 310 μmol/L) was associated with an increased risk of VTE and a worse clinical outcome.

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

INTRODUCTION

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

High serum uric acid/creatinine ratio is a useful predictor of hypertension among Japanese community-dwelling persons

Background

The correlation between serum uric acid/creatinine (SUA/Cr) ratio and hypertension risk has not been well studied. This study aims to examine whether the SUA/Cr ratio is a predictor of hypertension.

Methods

This cohort study comprised 171 men aged 64 ± 11 (mean ± standard deviation) years and 266 women aged 65 ± 10 years recruited for a survey at the community-based annual medical check-up. The main outcome was the presence of hypertension (antihypertensive medication) and having systolic blood pressure (SBP) ≥ 140 mmHg and diastolic blood pressure (DBP) ≥ 90 mmHg.

Results

The baseline SUA/Cr ratio was significantly correlated only with DBP at 3 years in men (r = 0.217, P = 0.004) and women (r = 0.126, P = 0.040), and with both SBP (r = 0.103, P = 0.031) and DBP (r = 0.15, P = 0.001) in the overall participants of men and women. A plausible prognostic cut-off of SUA/Cr ratio (≥ 7.41) was found and was the same in women and in all participants. Multivariable logistic regressions showed that SUA/Cr ratio was significantly linked with hypertension (as a categorical variable, SUA/Cr ratio-2 vs. SUA/Cr ratio-1: odds ratio [OR], 1.68; 95% confidence interval [CI], 0.66-4.30; P = 0.275, SUA/Cr ratio-3 vs. SUA/Cr ratio-1: OR, 2.86; 95% CI, 1.08-7.60; P = 0.035, SUA/Cr ratio-4 vs. SUA/Cr ratio ratio-1: OR, 4.05; 95% CI, 1.32-12.5; P = 0.031, and SUA/Cr ratio ≥ 7.41 vs. SUA/Cr ratio < 7.41: OR, 2.25; 95% CI, 1.32-3.84; P = 0.003). Significant ORs were found for age < 65 years, women, and BMI <25 kg/m2, but no interactions were identified within each group.

Conclusions

These results suggest that the baseline SUA/Cr ratio could be an important predictor for the incidence of hypertension in Japanese community-dwelling persons.

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.

Association between magnesium depletion score and prevalence of hyperuricemia in American adults: a study based on NHANES 2007-2018

Background

The Magnesium Depletion Score (MDS) is a novel indicator that integrates multiple factors to assess systemic magnesium depletion. However, its association with hyperuricemia (HUA) prevalence remains unclear. This study aims to investigate the relationship between MDS and the prevalence of HUA.

Methods

A cross-sectional analysis was conducted using data from the 2007-2018 National Health and Nutrition Examination Survey (NHANES). The MDS was derived by integrating multiple risk factors associated with magnesium depletion: the use of diuretics and proton pump inhibitors (PPI), estimated glomerular filtration rate (eGFR), and alcohol consumption exceeding recommended thresholds. Univariable and multivariable logistic regression models assessed the association between MDS and HUA. Subgroup and sensitivity analyses, including the exclusion of gout patients, further evaluated this association.

Results

Among 18,761 participants, higher MDS were associated with an increased prevalence of HUA. Multivariable logistic regression confirmed a significant positive association between MDS and HUA (OR = 1.73, 95% CI = 1.62-1.84). Restricted cubic splines (RCS) further characterized the non-linear relationship between MDS and HUA prevalence. Subgroup analysis indicated a positive association between MDS and HUA, with significant interactions observed for sex and body mass index. Sensitivity and additional analyses reinforced the robustness of these findings.

Conclusion

Among U.S. adults, higher MDS were significantly associated with an increased prevalence of HUA, suggesting that interventions targeting magnesium deficiency could be beneficial in reducing HUA prevalence within this population. However, prospective studies are needed to further confirm these findings.

Uric acid in diabetic microvascular complications: Mechanisms and therapy

Uric acid (UA) is mainly synthesized in the liver, intestine, and vascular endothelium and excreted by the kidney (70 %) and intestine (30 %). Hyperuricemia (HUA) occurs when UA production exceeds excretion. Many studies have found that elevated UA is associated with diabetic microvascular complications (DMC), including diabetic retinopathy (DR), diabetic nephropathy (DN), and diabetic peripheral neuropathy (DPN). In addition, too high or too low UA levels will promote the occurrence and development of chronic diseases, but the relationship between UA and diabetic microvascular complications (DMC) is not clear. Therefore, the rational treatment of UA in patients with diabetes is essential. In this review, we summarize and discuss the mechanism and treatment of UA and DMC and may provide potential advice for rational drug selection.

Evaluation of Xanthine Oxidase Inhibitors Febuxostat and Allopurinol on Kidney Dysfunction and Histological Damage in Two-Kidney, One-Clip (2K1C) Rats

In chronic kidney disease (CKD), hyperuricemia is a common phenomenon, presumably due to reduced renal clearance of uric acid. This study investigated the effect of xanthine oxidase (XO) inhibitors allopurinol and febuxostat to prevent oxidative stress in the kidney of two-kidney, one-clip (2K1C) rats. In this investigation, 2K1C rats were used as an experimental animal model for kidney dysfunction. 2K1C rats were provided with food and drinking water and received febuxostat at a dose of 10 mg/kg or allopurinol at 100 mg/kg, respectively. After the treatment completion, all rats were sacrificed, and tissue samples were collected. 2K1C rats exhibited increased plasma creatinine, uric acid level, and glomerular injury assessed based on microscopic findings. Both allopurinol and febuxostat significantly normalized creatinine and uric acid levels. Furthermore, 2K1C rats showed increased lipid peroxidation (LPO), nitric oxide (NO), and advanced oxidation protein products (AOPP) alongside decreased superoxide dismutase (SOD) and catalase activity. Again, both drug treatments ameliorated these elevated oxidative stress parameters in 2K1C rats. The antioxidant genes such as Nrf-2, HO-1, and SOD were also restored in the kidneys of 2K1C rats by allopurinol and febuxostat treatment. 2K1C rats also showed increased IL-1β, IL-6, TNF-α, and NF-кB mRNA expression in the kidneys which were normalized by allopurinol and febuxostat treatment. Thus, the data suggest that XO inhibition protects kidney function potentially by restoring antioxidant enzyme function and suppressing inflammation.

Roles of serum uric acid on the association between arsenic exposure and incident metabolic syndrome in an older Chinese population

Growing evidences showed that heavy metals exposure may be associated with metabolic diseases. Nevertheless, the mechanism underlying arsenic (As) exposure and metabolic syndrome (MetS) risk has not been fully elucidated. So we aimed to prospectively investigate the role of serum uric acid (SUA) on the association between blood As exposure and incident MetS. A sample of 1045 older participants in a community in China was analyzed. We determined As at baseline and SUA concentration at follow-up in the Yiwu Elderly Cohort. MetS events were defined according to the criteria of the International Diabetes Federation (IDF). Generalized linear model with log-binominal regression model was applied to estimate the association of As with incident MetS. To investigate the role of SUA in the association between As and MetS, a mediation analysis was conducted. In the fully adjusted log-binominal model, per interquartile range increment of As, the risk of MetS increased 1.25-fold. Compared with the lowest quartile of As, the adjusted relative risk (RR) of MetS in the highest quartile was 1.42 (95% confidence interval, CI: 1.03, 2.00). Additionally, blood As was positively associated with SUA, while SUA had significant association with MetS risk. Further mediation analysis demonstrated that the association of As and MetS risk was mediated by SUA, with the proportion of 15.7%. Our study found higher As was remarkably associated with the elevated risk of MetS in the Chinese older adults population. Mediation analysis indicated that SUA might be a mediator in the association between As exposure and MetS.

Relationship between serum uric acid levels and pulmonary embolism: an age-based stratified analysis

BACKGROUND

The association between uric acid and pulmonary embolism(PE) remains controversial, and there has been limited investigation into how uric acid influences pulmonary embolism across different age groups. Our study aimed to elucidate the relationship between uric acid levels and pulmonary embolism, considering variations across age groups.

METHODS

A total of 368 patients who underwent computed tomography pulmonary angiography from July 2018 to May 2022 were included in the analysis. Subsequently, the cohort was stratified by age, with separate univariate and multivariate logistic regression analyses conducted for the elderly (aged ≥ 60 years) and non-elderly (aged < 60 years), respectively.

RESULTS

The study revealed that patients with PE exhibited higher uric acid levels compared to those without (325.11 ± 137.02 vs. 298.26 ± 110.54 (umol/l), p = 0.039). This disparity persisted even after adjusting for multiple confounders (OR = 1.002, 95% CI 1.000-1.005, p = 0.042). Additionally, a notable age difference was observed between PE and non-PE patients (65.7 ± 16.12 vs. 61.42 ± 15.03 (umol/l), p = 0.009). Subsequently, upon age stratification, significant differences (p < 0.05) in serum uric acid were noted between PE and non-PE patients in both elderly and non-elderly populations. However, elevated uric acid levels were independently associated with PE only in the elderly following adjustment for multiple confounders (OR = 1.003, 95% CI 1.001-1.005, p = 0.008).

CONCLUSION

High uric acid levels are an independent risk factor for pulmonary embolism in the elderly (≥ 60 years).

Association of uric acid with body adiposity and biochemical parameters in kidney transplant patients

BACKGROUND

Obesity and various biochemical parameters, including triglycerides, cholesterol, glucose, C-reactive protein, and estimated glomerular filtration rate, have been linked to elevated uric acid (UA) levels in populations with normal kidney function due to decreased UA excretion and/or increased UA synthesis. However, it remains unclear whether all these factors exhibit similar associations with UA levels in clinical populations characterized by compromised renal function, such as kidney transplant patients (KTPs).

OBJECTIVE

To evaluate whether serum UA levels are associated with body adiposity and biochemical parameters in KTPs.

METHODS

A cross-sectional study involving 113 KTPs was conducted. Body fat was estimated using bioelectrical impedance, and waist circumference was measured using an inelastic tape. Serum levels of UA, creatinine, glucose, triglycerides, total cholesterol, and its fractions were measured using the colorimetric method. C-reactive protein levels were assessed using the immunoturbidimetric method, and urea levels were determined via enzymatic kinetics. Glomerular filtration rate was estimated using the chronic kidney disease epidemiology collaboration equation. Linear regression analyses were employed to assess the association between serum UA levels and body adiposity as well as biochemical parameters, while adjusting for confounders.

RESULTS

Serum UA levels exhibited a positive association with creatinine (β = 0.402; p = 0.013) and urea (β = 0.024; p = 0.001), while demonstrating an inverse association with estimated glomerular filtration rate (β = -0.030; p < 0.001). However, serum UA levels were not significantly associated with fat mass (both in kilograms and as a percentage), waist circumference, triglycerides, C-reactive protein, glucose, HDL cholesterol, LDL cholesterol, VLDL cholesterol, or total cholesterol.

CONCLUSION

Serum UA levels are only associated with biochemical parameters linked to renal function in KTPs. Consequently, in individuals with suboptimal renal function, such as KTPs, UA does not exhibit associations with other biochemical parameters and body adiposity, as commonly observed in non-renal disease populations.

The relationship between uric acid levels, cognition and inflammation in a cohort of elderly subjects

BACKGROUND

Uric acid (UA) is the most powerful antioxidant found among human body fluids. With this effect, UA protects neurons from oxidant effects and ensures the continuation of the structure and functions of neuronal tissue. However, UA has effects on the immune system. This study aims to explain the relationship between UA, cognitive level and inflammation in cases with a wide spectrum of cognitive function.

METHODS

A total of 67 women and 62 men who applied to the psychiatry outpatient clinic to obtain a health report were evaluated. The cognitive states of the individuals were determined with the mini-mental state examination test (MMSE). Additionally, serum uric acid levels and simple inflammatory parameters such as CRP, sedimentation, neutrophil-lymphocyte ratio (NLR), and monocyte-lymphocyte ratio (MLR) were measured. According to the MMSE results, two groups were created. Those with an MMSE score of 24 or above formed the first group, and those with an MMSE score below 24 formed the second group.

RESULTS

While a statistically significant positive strong correlation was found between UA and MMSE in all individuals, negative correlations were found between UA and NLR and MLR in men. UA was found to be significantly lower in the group with MMSE scores below 24 and NLR values were higher in the same group.

CONCLUSION

According to these results, UA seems to have a protective effect on cognitive functions. This situation manifests itself more clearly in men. At physiological concentrations, UA may have an anti-inflammatory effect. It appears that there are complex interactions between UA, cognition, and inflammation. Particularly, men appear to be more susceptible to UA effects.

Linoleyl acetate and mandenol alleviate HUA-induced ED via NLRP3 inflammasome and JAK2/STAT3 signalling conduction in rats

Hyperuricemia (HUA) is characterized by elevated blood uric acid levels, which can increase the risk of erectile dysfunction (ED). Clinical studies have demonstrated satisfactory efficacy of a traditional Chinese medicine formula QYHT decoction in improving ED. Furthermore, the main monomeric components of this formula, linoleyl acetate and mandenol, demonstrate promise in the treatment of ED. This study established an ED rat model induced by HUA and the animals were administered with linoleyl acetate and mandenol. HE and TUNEL were performed to detect tissue changes, ELISA to measure the levels of serum testosterone (T), MDA, NO, CRP, and TNF-α and qPCR and WB to assess the expression levels of NLRP3, ASC, Caspase-1, JAK2, and STAT3 in whole blood. The findings showed that linoleyl acetate and mandenol improved kidney tissue morphology, reduced cell apoptosis in penile tissue, significantly increased T and NO levels, while substantially decreasing levels of MDA, CRP, and TNF-α. Meanwhile, the expression of NLRP3, ASC, and Caspase-1 mRNAs and proteins was markedly reduced, and the phosphorylation of JAK2 and STAT3 was inhibited. These findings were further validated through faecal microbiota transplantation results. Taken together, linoleyl acetate and mandenol could inhibit NLRP3 inflammasome activation, reduce inflammatory and oxidative stress responses, suppress the activity of JAK-STAT signalling pathway, ultimately providing a potential treatment for HUA-induced ED.

Potential use of sodium glucose co-transporter 2 inhibitors during acute illness: a systematic review based on COVID-19

OBJECTIVE

SGLT-2i are increasingly recognized for their benefits in patients with cardiometabolic risk factors. Additionally, emerging evidence suggests potential applications in acute illnesses, including COVID-19. This systematic review aims to evaluate the effects of SGLT-2i in patients facing acute illness, particularly focusing on SARS-CoV-2 infection.

METHODS

Following PRISMA guidelines, a systematic search of PubMed, Scopus, medRxiv, Research Square, and Google Scholar identified 22 studies meeting inclusion criteria, including randomized controlled trials and observational studies. Data extraction and quality assessment were conducted independently.

RESULTS

Out of the 22 studies included in the review, six reported reduced mortality in DM-2 patients taking SGLT-2i, while two found a decreased risk of hospitalization. Moreover, one study demonstrated a lower in-hospital mortality rate in DM-2 patients under combined therapy of metformin plus SGLT-2i. However, three studies showed a neutral effect on the risk of hospitalization. No increased risk of developing COVID-19 was associated with SGLT-2i use in DM-2 patients. Prior use of SGLT-2i was not associated with ICU admission and need for MV. The risk of acute kidney injury showed variability, with inconsistent evidence regarding diabetic ketoacidosis.

CONCLUSION

Our systematic review reveals mixed findings on the efficacy of SGLT-2i use in COVID-19 patients with cardiometabolic risk factors. While some studies suggest potential benefits in reducing mortality and hospitalizations, others report inconclusive results. Further research is needed to clarify optimal usage and mitigate associated risks, emphasizing caution in clinical interpretation.

N-acetyl Cysteine Overdose Induced Acute Toxicity and Hepatic Microvesicular Steatosis by Disrupting GSH and Interfering Lipid Metabolisms in Normal Mice

N-acetyl cysteine (NAC) is a versatile drug used in various conditions, but the limitations and toxicities are not clear. The acute toxicity and toxicological mechanisms of an intraperitoneal injection of NAC in normal mice were deciphered. The LD50 for male and female BALB/cByJNarl mice were 800 mg/kg and 933 mg/kg. The toxicological mechanisms of 800 mg/kg NAC (N800) were investigated. The serum biomarkers of hepatic and renal indices dramatically increased, followed by hepatic microvesicular steatosis, renal tubular injury and necrosis, and splenic red pulp atrophy and loss. Thus, N800 resulted in mouse mortality mainly due to acute liver, kidney, and spleen damages. The safe dose (275 mg/kg) of NAC (N275) increased hepatic antioxidant capacity by increasing glutathione levels and catalase activity. N275 elevated the hepatic gene expressions of lipid transporter, lipid synthesis, β-oxidation, and ketogenesis, suggesting a balance between lipid production and consumption, and finally, increased ATP production. In contrast, N800 increased hepatic oxidative stress by decreasing glutathione levels through suppressing Gclc, and reducing catalase activity. N800 decreased the hepatic gene expressions of lipid transporter, lipid synthesis, and interferred β-oxidation, leading to lipid accumulation and increasing Cyp2E1 expression, and finally, decreased ATP production. Therefore, NAC doses are limited for normal individuals, especially via intraperitoneal injection or similar means.

J-shaped association of serum uric acid concentrations with all-cause mortality in individuals with osteoarthritis: A prospective cohort study

OBJECTIVE

The purpose of this study was to explore the relationship between serum uric acid (SUA) concentrations and all-cause mortality in individuals with osteoarthritis (OA).

METHODS

All participant data were retrieved from the National Health and Nutrition Examination Survey database. A total of 4671 participants (age range: 20 to 85 years old), including 2988 females and 1683 males, were included in this study. The determination of death outcome was based on the National Death Index (up to December 31, 2019). We explored the nonlinear relationship between SUA concentrations and all-cause mortality in OA patients by establishing a Cox proportional risk model and a two-segment Cox proportional risk model and ran an interaction test to identify the high-risk population for all-cause mortality.

RESULTS

During 30,645 person-years of follow-up, the number of all-cause deaths for females and males was 736 and 516, respectively. After multivariate adjustment, we found a nonlinear relationship between SUA concentrations and all-cause mortality in both females and males with OA. In addition, we found a J-shaped relationship between SUA concentrations and all-cause mortality. The SUA concentration thresholds for all-cause mortality of females and males were stable at 5.6mg/dl and 6.2mg/dl, respectively. Compared with SUA concentrations below the inflection point, the all-cause mortality risk at higher SUA concentrations in females and males with OA increased by 20% (hazard ratio [HR]: 1.2, 95% confidence interval [CI]: 1.1 to 1.2) and 25% (HR: 1.2, 95% CI: 1.12 to 1.39), respectively.

CONCLUSIONS

There is a nonlinear relationship between SUA concentrations and all-cause mortality in the American OA population (J-shaped association). The all-cause mortality thresholds for SUA concentrations in females and males are 5.6mg/dl and 6.2mg/dl, respectively.

Association of Serum Uric Acid with Non-Valvular Atrial Fibrillation: A Retrospective Study in China

Purpose

The association between serum uric acid (SUA) and atrial fibrillation (AF) has been widely focused on and studied in recent years. However, the exact association between SUA and AF is unclear, and the effect of gender on the association between SUA levels and AF has been controversial. This study aimed to investigate the association between SUA levels and non-valvular AF (NVAF) and the potential effect of gender on it.

Patients and Methods

A total of 866 NVAF patients (463 males, age 69.44 ± 8.07 years) and 646 sex-matched control patients in sinus rhythm, with no history of arrhythmia were included in this study. t-test, ANOVA, and chi-square test were used for baseline data analysis. The receiver operating characteristic curve, logistic regression and Pearson correlation analysis were used for correlation analysis.

Results

Compared to controls, NVAF patients exhibited higher SUA (P<0.001). After adjusting for confounders of NVAF, SUA remained significantly associated with NVAF, regardless of gender (OR= 1.31, 95% CI 1.18-1.43, P<0.001). SUA demonstrated higher predictability and sensitivity in predicting the occurrence of female NVAF compared to male (area under the curve was 0.68 (95% CI 0.64-0.72, P<0.001), sensitivity 87.3%), with the optimal cut-off point identified as 5.72 mg/dL. Furthermore, SUA levels correlated with APOA1, Scr and NT-proBNP in NVAF patients. SUA levels varied significantly among NVAF subtypes.

Conclusion

High SUA levels were independently associated with NVAF, regardless of gender. SUA exhibited higher predictability and sensitivity in predicting the occurrence of NVAF in females compared to males. High SUA levels may affect other NVAF-related factors and participate in the pathophysiological process of NVAF.

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.

Prognostic Significance of Uric Acid Levels in Intracerebral Hemorrhage Patients

Background and Purpose

The role of serum uric acid (UA) level in patients suffering from stroke remains controversial. Our aim was to investigate the effect of UA level on clinical outcomes in patients with intracerebral hemorrhage (ICH).

Methods

In the retrospective cohort study, we analyzed data from 250 patients with intracerebral hemorrhage (85 women and 165 men) to investigate the difference in UA levels between patients with a good prognosis and those with a poor prognosis. Additionally, we analyzed the impact of UA levels on the risk of short-time prognosis of ICH patients.

Results

Patients with a good prognosis presented with significantly lower levels of UA (348.71 ± 84.97 μmol/L) than those with poor prognosis (393.06 ± 148.46 μmol/L). Furthermore, multivariate logistic regression model demonstrated that a high UA level was a likely risk factor for worse prognosis among patients suffering in ICH (odds ratio [95% confidence interval], 1.006 [1.0012, 1.0108]; P = 0.015). Additionally, UA has a threshold effect value of 363.9 μmol/L and was presented in levels that were in a nonlinear relationship with incidence rate of short-time prognosis outcome of ICH patients.

Conclusion

Our findings indicate that higher UA levels can increase the risk of poor clinical prognosis in patients with ICH and high UA levels are not conductive to the clinical prognosis of patients with ICH. These findings provide a new perspective on the treatment and prevention of ICH.

Serum uric acid and prognosis of ischemic stroke: Cohort study, meta-analysis and Mendelian randomization study

INTRODUCTION

The role of serum uric acid (UA) levels in the functional recovery of ischemic stroke remains uncertain. To evaluate whether UA could predict clinical outcomes in patients with ischemic stroke.

PATIENTS AND METHODS

A three-stage study design was employed, combining a large-scale prospective cohort study, a meta-analysis and a Mendelian randomization (MR) analysis. Firstly, we conducted a cohort study using data from the Nanjing Stroke Registry Program (NSRP) to assess the association between UA levels and 3-month functional outcomes in ischemic stroke patients. Secondly, the meta-analysis was conducted to integrate currently available cohort evidence. Lastly, MR analysis was utilized to explore whether genetically determined UA had a causal link to the functional outcomes of ischemic stroke using summary data from the CKDGen and GISCOME datasets.

RESULTS

In the first stage, the cohort study included 5631 patients and found no significant association between UA levels and functional outcomes at 3 months after ischemic stroke. In the second stage, the meta-analysis, including 10 studies with 14,657 patients, also showed no significant association between UA levels and stroke prognosis. Finally, in the third stage, MR analysis using data from 6165 patients in the GISCOME study revealed no evidence of a causal relationship between genetically determined UA and stroke functional outcomes.

DISCUSSION AND CONCLUSION

Our comprehensive triangulation approach found no significant association between UA levels and functional outcomes at 3 months after ischemic stroke.

Crosstalk between inflammasomes, inflammation, and Nrf2: Implications for gestational diabetes mellitus pathogenesis and therapeutics

The role of inflammasomes in gestational diabetes mellitus (GDM) has emerged as a critical area of research in recent years. Inflammasomes, key components of the innate immune system, are now recognized for their involvement in the pathogenesis of GDM. Activation of inflammasomes in response to various triggers during pregnancy can produce pro-inflammatory cytokines, such as interleukin-1β (IL-1β) and interleukin-18 (IL-18), contributing to systemic inflammation and insulin resistance. This dysregulation not only impacts maternal health but also poses significant risks to fetal development and long-term health outcomes. Understanding the intricate interplay between inflammasomes and GDM holds promise for developing novel therapeutic strategies and interventions to mitigate the adverse effects of this condition on both mothers and their offspring. Researchers have elucidated that targeting inflammasomes using anti-inflammatory drugs and compounds can effectively reduce inflammation in GDM. Furthermore, the addition of nuclear factor erythroid 2-related factor 2 (Nrf2) to this complex mechanism opens novel avenues for therapeutics. The antioxidant properties of Nrf2 may potentially suppress inflammasome activation in GDM. This comprehensive review investigates the intricate relationship between inflammasomes and GDM, emphasizing the pivotal role of inflammation in its pathogenesis. It also sheds light on potential therapeutic strategies targeting inflammasome activation and explores the role of Nrf2 in mitigating inflammation in GDM.

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.

Association between uric acid and risk of venous thromboembolism in East Asian populations: a cohort and Mendelian randomization study

Background

Serum uric acid (SUA) levels have been associated with an increased risk and recurrence of venous thromboembolism (VTE) in European populations, but the potential causal relationship remains unclear. Large-scale studies on the association between SUA and VTE in East Asian populations are lacking, despite the high prevalence of hyperuricemia in this region. To address this, we conducted a cohort analysis and a two-sample Mendelian randomization (MR) study in East Asian populations.

Methods

We collected data on VTE patients from the China Pulmonary Thromboembolism Registry Study (CURES) and compared them to controls obtained from the China Health and Retirement Longitudinal Survey (CHARLS). Propensity score matching (PSM) and cubic-spline models were applied to assess the effect of SUA on VTE risk while adjusting for multiple covariates. We also performed two-sample MR analyses to infer potential causality based on summary statistics from Genome-wide Association Studies (GWAS) of SUA and VTE in the East Asian population.

Findings

We found that the SUA levels were higher in VTE patients (317.95 mmol/L) compared to the general population (295.75 mmol/L), and SUA ≥ 325 mmol/L was associated with an increased risk of VTE recurrence (P-value = 0.0001). The univariable MR suggested a causal relationship between elevated SUA and higher VTE risk (Pinverse variance weighted < 0.05), and multivariable MR showed that elevated SUA levels continued to promote the development of VTE after adjusting for multiple covariates (Pmultivariable residual < 0.05). Sensitivity analyses produced similar results for these estimations.

Interpretation

Our study provides evidence supporting a robust positive association between SUA and VTE in the East Asian population, and MR analyses suggest that this association is likely to be causal. Our findings underscore the importance of monitoring SUA levels in VTE prevention and call for urgent action to address the growing burden of hyperuricemia in the Asia-Pacific region.

Funding

This research was funded by Beijing Nova Program (No. Z211100002121057), National Natural Science Foundation of China (No. 82100065 and No. 62350004), CAMS Innovation Fund for Medical Sciences (No. 2021-I2M-1-061 and No. 2021-1-I2M-001), Elite Medical Professionals project of China-Japan Friendship Hospital (No. ZRJY2021-QM12), National Key Research and Development Project (No. 2021YFF1201200 and No. 2022YFC3341004).

Comparative polar and lipid plasma metabolomics differentiate KSHV infection and disease states

BACKGROUND

Kaposi sarcoma (KS) is a neoplastic disease etiologically associated with infection by the Kaposi sarcoma-associated herpesvirus (KSHV). KS manifests primarily as cutaneous lesions in individuals due to either age (classical KS), HIV infection (epidemic KS), or tissue rejection preventatives in transplantation (iatrogenic KS) but can also occur in individuals, predominantly in sub-Saharan Africa (SSA), lacking any obvious immune suppression (endemic KS). The high endemicity of KSHV and human immunodeficiency virus-1 (HIV) co-infection in Africa results in KS being one of the top 5 cancers there. As with most viral cancers, infection with KSHV alone is insufficient to induce tumorigenesis. Indeed, KSHV infection of primary human endothelial cell cultures, even at high levels, is rarely associated with long-term culture, transformation, or growth deregulation, yet infection in vivo is sustained for life. Investigations of immune mediators that distinguish KSHV infection, KSHV/HIV co-infection, and symptomatic KS disease have yet to reveal consistent correlates of protection against or progression to KS. In addition to viral infection, it is plausible that pathogenesis also requires an immunological and metabolic environment permissive to the abnormal endothelial cell growth evident in KS tumors. In this study, we explored whether plasma metabolomes could differentiate asymptomatic KSHV-infected individuals with or without HIV co-infection and symptomatic KS from each other.

METHODS

To investigate how metabolic changes may correlate with co-infections and tumorigenesis, plasma samples derived from KSHV seropositive sub-Saharan African subjects in three groups, (A) asymptomatic (lacking neoplastic disease) with KSHV infection only, (B) asymptomatic co-infected with KSHV and HIV, and (C) symptomatic with clinically diagnosed KS, were subjected to analysis of lipid and polar metabolite profiles RESULTS: Polar and nonpolar plasma metabolic differentials were evident in both comparisons. Integration of the metabolic findings with our previously reported KS transcriptomics data suggests dysregulation of amino acid/urea cycle and purine metabolic pathways, in concert with viral infection in KS disease progression.

CONCLUSIONS

This study is, to our knowledge, the first to report human plasma metabolic differentials between in vivo KSHV infection and co-infection with HIV, as well as differentials between co-infection and epidemic KS.

Oral microbial communities in children, caregivers, and associations with salivary biomeasures and environmental tobacco smoke exposure

Human oral microbial communities are diverse, with implications for oral and systemic health. Oral microbial communities change over time; thus, it is important to understand how healthy versus dysbiotic oral microbiomes differ, especially within and between families. There is also a need to understand how the oral microbiome composition is changed within an individual including by factors such as environmental tobacco smoke (ETS) exposure, metabolic regulation, inflammation, and antioxidant potential. Using archived saliva samples collected from caregivers and children during a 90-month follow-up assessment in a longitudinal study of child development in the context of rural poverty, we used 16S rRNA gene sequencing to determine the salivary microbiome. A total of 724 saliva samples were available, 448 of which were from caregiver/child dyads, an additional 70 from children and 206 from adults. We compared children's and caregivers' oral microbiomes, performed "stomatotype" analyses, and examined microbial relations with concentrations of salivary markers associated with ETS exposure, metabolic regulation, inflammation, and antioxidant potential (i.e., salivary cotinine, adiponectin, C-reactive protein, and uric acid) assayed from the same biospecimens. Our results indicate that children and caregivers share much of their oral microbiome diversity, but there are distinct differences. Microbiomes from intrafamily individuals are more similar than microbiomes from nonfamily individuals, with child/caregiver dyad explaining 52% of overall microbial variation. Notably, children harbor fewer potential pathogens than caregivers, and participants' microbiomes clustered into two groups, with major differences being driven by Streptococcus spp. Differences in salivary microbiome composition associated with ETS exposure, and taxa associated with salivary analytes representing potential associations between antioxidant potential, metabolic regulation, and the oral microbiome. IMPORTANCE The human oral cavity is a multi-environment habitat that harbors a diversity of microorganisms. This oral microbiome is often transmitted between cohabitating individuals, which may associate oral and systemic health within family members. Furthermore, family social ecology plays a significant role in childhood development, which may be associated with lifelong health outcomes. In this study, we collected saliva from children and their caregivers and used 16S rRNA gene sequencing to characterize their oral microbiomes. We also analyzed salivary biomeasures of environmental tobacco smoke exposure, metabolic regulation, inflammation, and antioxidant potential. We show there are differences in individuals' oral microbiomes mainly due to Streptococcus spp. that family members share much of their microbes, and several bacterial taxa associate with the selected salivary biomeasures. Our results suggest there are large-scale oral microbiome patterns, and there are likely relationships between oral microbiomes and the social ecology of families.

Association between serum uric acid and prostate cancer mortality in androgen deprivation therapy: A population-based cohort study

OBJECTIVE

This population-based study examined the association between baseline uric acid (UA) and prostate cancer (PCa)-related mortality amongst PCa patients receiving androgen deprivation therapy (ADT).

METHODS

Adults with PCa who received ADT in Hong Kong between December 1999 and March 2021 were identified. Patients with missing baseline UA were excluded. Patients were followed up until September 2021. The outcome was PCa-related mortality.

RESULTS

Altogether, 4126 patients (median follow-up 3.1[interquartile range 1.4-6.0] years) were included. A J-shaped association was observed between baseline UA level and PCa-related mortality risk, with a direct association in those with mean(0.401 mmol/L) or above-mean baseline UA levels (hazard ratio (HR) per standard deviation-increase 1.35 [95% confidence interval 1.21,1.51], p < 0.001), and an inverse association in those with below-mean baseline UA levels (HR 0.78[0.67,0.92], p = 0.003). The former remained significant on competing risk regression, but not the latter.

CONCLUSIONS

A J-shaped relationship between baseline UA level and PCa-related mortality risk was identified. This study was mainly limited by potential unmeasured and residual confounders. Further validation studies are warranted.

Association between Hyperuricemia and Hearing Impairment: Results from the Korean National Health and Nutrition Examination Survey

Background and Objectives: Hyperuricemia is associated with a variety of comorbidities. The objective of this study was to investigate the association between hyperuricemia and hearing impairment in Korean adults. Materials and Methods: Audiometric and laboratory test data from the 2019 to 2020 Korean National Health and Nutrition Examination Survey (KNHANES) were used for analysis. Hearing impairment was defined as a pure-tone average (0.5, 1, 2, 4 kHz) threshold level ≥ 41 decibels. The definition of hyperuricemia was different for males and females: >7 mg/dL for males vs. >6 mg/dL for females. Results: A total of 4857 (weight n = 17,990,725) subjects were analyzed. The mean age was 56.8 years old. The weighted prevalence was 12.1% for hyperuricemia and 2.5% for gout. The prevalence of hearing impairment was 13.4%. In the univariable analysis, hyperuricemia was significantly associated with hearing impairment. However, the diagnosis of gout was not associated with hearing impairment. In the multivariable analysis, hyperuricemia (odds ratios (OR): 1.41, 95% confidence interval [CI]: 1.03-1.92, p = 0.030) was associated with hearing impairment along with age (OR: 1.12, 95% CI: 1.10-1.14, p < 0.001), female sex (OR: 0.43, 95% CI: 0.34-0.64, p < 0.001), education (OR: 0.43, 95% CI: 0.30-0.63, p = 0.001), and occupational noise exposure (OR: 1.67, 95% CI: 1.25-2.22, p = 0.001). In the subgroup analysis, hyperuricemia was associated with hearing impairment in females (OR: 1.59, 95% CI: 1.02-2.48, p = 0.041) and the elderly aged 60 years or more (OR: 1.45, 95% CI: 1.05-1.99, p = 0.023). Conclusions: Hyperuricemia was independently associated with hearing impairment, especially in females and the elderly aged 60 years or more.

Exposure to Cadmium, Lead, Mercury, and Arsenic and Uric Acid Levels: Results from NHANES 2007-2016

Mechanisms underlying abnormal uric acid (UA) levels from exposure to toxic metals/metalloids have not been not fully elucidated, especially in the context of mixtures. The aim was to identify major toxic metals/metalloids that affected UA levels with a mixture exposure concept in the association model. From 2007-2016 National Health and Nutrition Examination Survey (NHANES), 4794 adults were involved. Serum UA (SUA) and SUA to serum creatinine ratio (SUA/SCr) were used to estimate the UA levels, and cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) in the blood and/or urine were evaluated in the study. We assessed the associations between toxic metals and UA levels using linear regression and Bayesian kernel machine regression (BKMR). The median [P₂₅, P₇₅] SUA/SCr and SUA level were 6.22 [5.27, 7.32] and 0.83 [0.72, 0.98], respectively. There was no difference for SUA/SCr by gender (men, 6.25 [5.39, 7.29]; women, 6.17 [5.17, 7.36], P = 0.162), but men had higher SUA than women (men, 0.95 [0.85, 1.05]; women, 0.72 [0.64, 0.82], P < 0.001). Blood Pb (β_men = 0.651 and β_women = 1.014) and urinary Cd (β_men = 0.252 and β_women = 0.613) were positively associated with SUA/SCr, and urinary Pb (β_men =  - 0.462 and β_women =  - 0.838) was inversely associated with SUA/SCr in multivariate linear regression analysis. However, urinary As (β_men = 0.351) was positively associated with SUA/SCr only in men. BKMR showed that higher concentrations of exposure to a mixture of toxic metals were positively associated with higher UA levels, where Cd, Pb, and urinary As contributed most to the overall mixture effect in men, while Pb and urinary Cd in women. Our study provided the first evidence that mixtures of metals are associated with the UA levels. Increased concentrations of metals, mainly blood Pb, urinary Cd, and As (only in men) may increase the level of UA.

Serum uric acid to creatinine ratio is a useful predictor of all-cause mortality among hypertensive patients

BACKGROUND

Many of the existing research studies have shown that serum uric acid (SUA) is a predictor of renal disease progression. More recently, studies have suggested an association between renal function-normalized SUA and all-cause mortality in adults. This study aims to examine the association between the ratio of SUA to creatinine (SUA/Cr) and all-cause mortality with a focus on hypertensive patients.

METHODS

This study is based on 2,017 participants, of whom 916 were male (mean age, 67 ± 11 years) and 1,101 were female (mean age, 69 ± 9 years). All participants were part of the Nomura Cohort Study in 2002 (cohort 1) and 2014 (cohort 2), as well as the follow-up period (2002 follow-up rate, 94.8%; 2014 follow-up rate, 98.0%). We obtained adjusted relative risk estimates for all-cause mortality from a basic resident register. In addition, we employed a Cox proportional hazards model and adjusted it for possible confounders to determine the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Of the total participants, 639 (31.7%) were deceased; of these, 327 (35.7%) were male and 312 (28.3%) were female. We found an independent association between a higher ratio of SUA/Cr and a higher risk of all-cause mortality in female participants only (HR, 1.10; 95% CI, 1.02-1.18). The multivariable-adjusted HRs (95% CI) for all-cause mortality across quintiles of baseline SUA/Cr were 1.28 (0.91-1.80), 1.00, 1.38 (0.95-1.98), 1.37 (0.94-2.00), and 1.57 (1.03-2.40) for male participants, and 0.92 (0.64-1.33), 1.00, 1.04 (0.72-1.50), 1.56 (1.06-2.30), and 1.59 (1.06-2.38) for female participants. When the data were further stratified on the basis of age (< 65 or ≥ 65 years), body mass index (< 22.0 or ≥ 22.0 kg/m²), estimated glomerular filtration rate (< 60 or ≥ 60 mL/min/1.73 m²), and presence of SUA-lowering medication, trends similar to those of the full population were found in all groups.

CONCLUSION

Baseline SUA/Cr is independently and significantly associated with future all-cause mortality among hypertensive patients.

Machine learning in the prediction of cardiac surgery associated acute kidney injury with early postoperative biomarkers

Purpose

To establish novel prediction models for predicting acute kidney injury (AKI) after cardiac surgery based on early postoperative biomarkers.

Patients and methods

This study enrolled patients who underwent cardiac surgery in a Chinese tertiary cardiac center and consisted of a discovery cohort (n = 452, from November 2018 to June 2019) and a validation cohort (n = 326, from December 2019 to May 2020). 43 biomarkers were screened using the least absolute shrinkage and selection operator and logistic regression to construct a nomogram model. Three tree-based machine learning models were also established: eXtreme Gradient Boosting (XGBoost), random forest (RF) and deep forest (DF). Model performance was accessed using area under the receiver operating characteristic curve (AUC). AKI was defined according to the Kidney Disease Improving Global Outcomes criteria.

Results

Five biomarkers were identified as independent predictors of AKI and were included in the nomogram: soluble ST2 (sST2), N terminal pro-brain natriuretic peptide (NT-proBNP), heart-type fatty acid binding protein (H-FABP), lactic dehydrogenase (LDH), and uric acid (UA). In the validation cohort, the nomogram achieved good discrimination, with AUC of 0.834. The machine learning models also exhibited adequate discrimination, with AUC of 0.856, 0.850, and 0.836 for DF, RF, and XGBoost, respectively. Both nomogram and machine learning models had well calibrated. The AUC of sST2, NT-proBNP, H-FABP, LDH, and UA to discriminate AKI were 0.670, 0.713, 0.725, 0.704, and 0.749, respectively. In addition, all of these biomarkers were significantly correlated with AKI after adjusting clinical confounders (odds ratio and 95% confidence interval of the third vs. the first tertile: sST2, 3.55 [2.34-5.49], NT-proBNP, 5.50 [3.54-8.71], H-FABP, 6.64 [4.11-11.06], LDH, 7.47 [4.54-12.64], and UA, 8.93 [5.46-15.06]).

Conclusion

Our study provides a series of novel predictive models and five biomarkers for enhancing the risk stratification of AKI after cardiac surgery.

Gout and risk of venous thromboembolism: A systematic review and meta-analysis of cohort studies

BACKGROUND

The association between gout and venous thromboembolism (VTE) remains ambiguous, and the results of current studies are inconsistent. A systematic review and meta-analysis of cohort studies were conducted to comprehensively assess the associations between gout and VTE and its subtypes, deep venous thrombosis (DVT) and pulmonary embolism (PE).

METHODS

PubMed, Web of Science, Embase, Scopus, and the Cochrane Library databases were searched up to June 2021, to identify eligible cohort studies, reporting the association of gout with VTE and its subtypes. We pooled hazard ratios (HRs) with 95% confidence intervals (CIs). Subgroup analysis, sensitivity analysis, and publication bias tests were also conducted.

RESULTS

Five studies involving 642 632 individuals were included. Patients with gout had a statistically significantly higher risk of VTE (HR: 1.33; 95% CI: 1.21, 1.46; P < .001) compared with non-gout controls, and significant associations were also found between gout and DVT (HR: 1.40; 95% CI: 1.22, 1.62; P < .001) and PE (HR: 1.18; 95% CI: 1.07, 1.30; P = .001). Subgroup analysis showed this association in men (HR: 1.37; 95% CI: 1.14, 1.65; P = .001) and women (HR: 1.36; 95% CI: 1.21, 1.53; P < .001) were consistent (P = .980). Meta-regression analysis revealed publication year (P = .005) and quality of study (P = .006) contributed to heterogeneity.

CONCLUSIONS

In conclusion, our study provided evidence that gout was associated with the risk of VTE and its subtypes DVT and PE. However, more prospective and high-quality clinical evidence is required to confirm our findings.

Association between serum uric acid and relative hand grip strength in comparison with metabolic syndrome components

Objectives

To investigate the association between serum uric acid (UA) and relative hand grip strength (HGS) in comparison with metabolic syndrome components.

Methods

We analyzed the data of 5247 Korean adults aged ≥ 20 years (2422 men and 2825 women) who participated in the KNHNES VII (2018).

Results

Among women, relative HGS was significantly lower in participants with hyperuricemia (1.65 ± 0.04) than in those without (1.95 ± 0.01) and was significantly decreased in the highest quartile (4Q: 1.77 ± 0.02) of serum UA compared with that in the lowest quartile (1Q: 1.98 ± 0.02). Among men, relative HGS was lower in participants with hyperuricemia (3.09 ± 0.04 vs. 3.16 ± 0.02) and decreased in 4Q (3.08 ± 0.03) of serum UA compared with that in 1Q (3.15 ± 0.03); however, these results were not statistically significant. In age- and multivariate-adjusted analyses in men, relative HGS was significantly lower in 4Q compared with that in 1Q in model 1 (adjusted for age), but there were no significant differences in model 2 (adjusted for age, BMI, and waist circumference) and model 3 (adjusted for age, BMI, waist circumference, systolic and diastolic blood pressure, fasting blood glucose, triglycerides, and high-density lipoprotein cholesterol). Meanwhile, in women, relative HGS was significantly decreased in 4Q compared with that in 1Q in all models.

Conclusions

A significant inverse correlation was observed between serum UA levels and relative HGS in women, and their significance was maintained even after adjusting for age and metabolic syndrome components.

The Prevalence of Asymptomatic Hyperuricemia in Patients with or Without Psoriatic Arthritis is Associated with a Similar Cardiovascular Risk

Aim: To investigate the association between cardiovascular burden and monosodium urate (MSU) deposits in the joints of patients with asymptomatic hyperuricemia and no evidence of arthritis and subjects with psoriatic arthritis and hyperuricemia.

Patients and methods: A single-center, cross-sectional study including 52 individuals: 39 with asymptomatic hyperuricemia and 13 with psoriatic arthritis and hyperuricemia. All patients underwent ultrasound of the joints by which the presence or absence of MSU crystal deposits was assessed. Subjects underwent transthoracic echocardiography by which left ventricular mass index (LVMI) was estimated. Intima-media thickness (IMT) of the common carotid arteries was measured and the presence of atherosclerotic plaques was registered.

Results: We found no difference in the distribution of cardiovascular risk factors between the two groups. Further, no difference in their distribution was found between those who were not treated and those who were treated with urate-lowering medications. The frequency of articular MSU deposits was similar between non-allopurinol-treated and allopurinol-treated individuals (p = 0.554). There was no difference in the frequency of articular deposits between benzbromarone recipients and non-recipients (p = 0.396). We observed no connection between articular MSU deposits and LVMI (p = 0.625), IMT (p = 0.117) and atherosclerotic plaques (p = 0.102). Among untreated and treated with urate-lowering drugs there was no difference in LVMI (p = 0.063), IMT (p = 0.975) and plaque distribution (p = 1.000).

Conclusion: We can assume that in patients with asymptomatic hyperuricemia and no evidence of arthritis and in subjects with psoriatic arthritis and asymptomatic hyperuricemia, only the prescription of urate-lowering medications for reduction of urate load and cardiovascular risk is not sufficient.

Research Progress on the Relationship between Dietary Patterns and Hyperuricemia

As the final metabolite of purine metabolism, uric acid is critically associated with human health. The serum uric acid level is regulated by diet and the metabolic capacity of the human body. The impaired control of uric acid metabolism and excretion is associated with the increased level of serum uric acid, which ultimately results in hyperuricemia. Hyperuricemia is the "fourth-highest" after hypertension, hyperglycemia, and hyperlipidemia. With progress made in the relationship between diet and hyperuricemia, different dietary patterns and lifestyles have been discussed, such as exercise, the amount intake of meat, seafood, supplements with omega-3 fatty acids, sugar-sweetened soft drinks and energy drinks, and lower-fat-containing foods as well as drinking beer, wine, and spirits in the present article. This study demonstrated that a lower risk of hyperuricemia is substantially correlated with higher baseline adherence to MeDiet, and plant polyphenols can combat hyperuricemia by blocking xanthine oxidase.

J-Shaped Relationship of Serum Uric Acid with Unfavorable Short-Term Outcomes among Patients with Acute Ischemic Stroke

(1) Background: The role of uric acid in stroke outcomes remains inconclusive. (2) Methods: We retrospectively enrolled 3370 patients with acute ischemic stroke. (3) Results: Uric acid level was higher in men than in women. Univariate analyses revealed that the rates of hyperuricemia were higher in all patients and in women for unfavorable outcomes. For death, the hyperuricemia rates were higher in all patients including men and women, and the uric acid levels were also higher in all patients and in women. A J-shaped curve was observed between uric acid and the discharge-modified Rankin Scale score. Patients within Quartiles 1 (<4.1 mg/dL) and 4 (>6.5 mg/dL) of uric acid had higher rates of unfavorable outcomes and death than patients within Quartiles 2 (4.1−5.1 mg/dL) and 3 (5.1−6.2 mg/dL). Multivariable analyses for unfavorable outcomes revealed that Quartile 1 of uric acid was a significant factor in all patients and in men. In men, a significant factor for death was being in Quartile 1 of uric acid. In women, higher levels of uric acid or hyperuricemia (>6.6 mg/dL) were significant factors for death. (4) Conclusions: Lower uric acid levels are a predictor for unfavorable outcomes and death in men, and higher uric acid levels are a predictor for death in women.

Raised total methylated arginine load in patients with gout

Aim: The aim of this study was to measure serum levels of methylarginine derivatives and related metabolites in patients with gout. Materials & methods: This study enrolled 100 patients with gout and 80 patients in the control group. Serum asymmetric dimethylarginine, symmetric dimethylarginine, L-N-monomethylarginine, arginine, homoarginine, citrulline and ornithine levels were measured with tandem mass spectrometry. Results: Serum ornithine, citrulline and total methylated arginine load levels were statistically significantly higher in patients with gout compared with the control group, while serum arginine and homoarginine levels and global arginine bioavailability ratio were statistically significantly lower. Conclusion: There may be an association between gout, methylarginine levels and hyperuricemia and increased risk of cardiovascular disease.

Traditional Chinese herbs and natural products in hyperuricemia-induced chronic kidney disease

Hyperuricemia is a common biochemical disorder, which resulted from both excessive uric acid (UA) production and/or absolute or relative impairment of urinary UA excretion. Growing evidence has indicated that hyperuricemia is an independent risk factor for the development and progression of chronic kidney disease (CKD), causing hyperuricemia-induced CKD (hyperuricemic nephropathy, HN). The therapeutic strategy of HN is managing hyperuricemia and protecting kidney function. Adverse effects of commercial drugs make persistent treatment of HN challenging. Traditional Chinese medicine (TCM) has exact efficacy in lowering serum UA without serious adverse effects. In addition, TCM is widely applied for the treatment of CKD. This review aimed to provide an overview of efficacy and mechanisms of traditional Chinese herbs and natural products in hyperuricemia-induced CKD.

Sex-specific cardiometabolic risk markers of left ventricular mass in physically active young adults: the CHIEF heart study

Greater physical fitness may lead to greater left ventricular mass (LVM) and reduce the effect of cardiometabolic risk factors on LVM. However, the cardiometabolic biomarkers associations for LVM have not been clarified in physically active young adults. This study included 2019 men and 253 women, aged 18-43 years, from the military in Taiwan. All participants underwent anthropometric and blood metabolic markers measurements, and completed a 3000-m run test for assessing fitness. LVM was calculated on the basis of an echocardiography. Multiple linear regression was used to determine the sex-specific associations between cardiometabolic risk markers and LVM indexed for the body height (g/m2.7). In men, age, systolic blood pressure (SBP), 3000-m running time, serum triglycerides, serum uric acid and waist circumference (WC) were correlated with LVM index (β = 0.07, 0.10, - 0.01, 0.01, 0.24 and 0.24, respectively; all p-values < 0.05). The correlations were not significant for fasting plasma glucose, total cholesterol and high-density lipoprotein cholesterol (HDL-C). In women, SBP, HDL-C and WC were correlated with LVM index in the univariate analysis (β = 0.07, - 0.05 and 0.32, respectively; all p-values < 0.05), whereas the correlation was only significant for WC in the multiple linear regression analysis (β = 0.20; p-value < 0.001). In physically active adults, the associations of cardiometabolic risk markers with LVM might vary by sex. Better endurance exercise performance associated with greater LVM was noted only in men, while greater WC was the only metabolic risk marker for greater LVM in both men and women.

Concurrent presence of high serum uric acid and inflammation is associated with increased incidence of type 2 diabetes mellitus in Korean adult population

Although serum uric acid level and systemic inflammation have been highlighted as risk factors for type 2 diabetes mellitus (T2DM), little is known about these associations in the Korean population. Thus, we examined the individual and combined associations of serum uric acid and systemic inflammation (evaluated using high-sensitivity C-reactive protein [hs-CRP] measurement) with the future risk of T2DM. A total of 4152 Korean adults aged 45–76 years without T2DM, cancer, or gout at baseline in 2007–2008 from the Korean Genome and Epidemiology Study were followed up until 2016. Cox proportional hazard models were used to estimate the multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of T2DM according to sex-specific tertiles of serum uric acid and hs-CRP levels after adjustment for confounders. During the mean follow-up of 7.3 years, 548 participants developed T2DM. High serum uric acid and hs-CRP levels were independently associated with an increased incidence of T2DM. The multivariable-adjusted HRs (95% CIs) for the incidence of T2DM in the highest tertiles of serum uric acid and hs-CRP were 1.54 (1.24–1.93) and 1.90 (1.48–2.43), respectively. High levels of serum uric acid and hs-CRP in combination were associated with an increased incidence of T2DM (HR: 4.69; 95% CI: 2.81–7.84) compared to low levels of serum uric acid and hs-CRP. These findings suggest that the combination of high serum uric acid and hs-CRP levels was significantly associated with an elevated incidence of T2DM; however, their synergistic effects were not observed in middle-aged and elderly Korean adults.

Osteosarcopenic obesity and its components-osteoporosis, sarcopenia, and obesity-are associated with blood cell count-derived inflammation indices in older Chinese people

Background

The aim of this study was to investigate the associations of osteosarcopenic obesity (OSO) and its components with complete blood cell count-derived inflammation indices.

Methods

In this cross-sectional study, data of 648 participants aged ≥60 years (men/women: 232/416, mean age: 67.21 ± 6.40 years) were collected from January 2018 to December 2020. Areal bone mineral density and body fat percentage were used to define osteopenia/osteoporosis and obesity, respectively. The criteria of the 2019 Asian Working Group for Sarcopenia were used to diagnose sarcopenia. Based on the number of these conditions, participants were divided into four groups: OSO/0, OSO/1, OSO/2, and OSO/3. Logistic regression analysis was conducted to identify associations between blood cell count-derived inflammation indices and the number of disorders with abnormal body composition.

Results

Systemic inflammation response index (SIRI), white blood cells, neutrophil-to-lymphocyte ratio (NLR), aggregate inflammation systemic index (AISI), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) showed statistically significant differences among the four groups (P < 0.05). Unlike in the OSO/0 group, in all other groups, AISI, SIRI, PLR, and NLR were significantly associated with increased likelihood of having multiple disorders with abnormal body composition after adjustment for confounders (P < 0.0001 for all). However, LMR showed an inverse correlation with the number of these conditions (P < 0.05).

Conclusion

Higher SIRI, AISI, NLR, and PLR values and lower LMR values are closely associated with OSO and its individual components—osteoporosis, sarcopenia, and obesity—in older adults, suggesting that the value of these indices in the evaluation of OSO warrants further investigation.

Uric Acid and Diabetic Retinopathy: A Systematic Review and Meta-Analysis

Background

The relationship between uric acid (UA) and diabetic retinopathy (DR) remains ambiguous, and the results of current studies on the UA levels in patients with DR are conflicting. A meta-analysis was performed to provide a better understanding of the relationship between UA levels and DR.

Methods

PubMed, Web of Science, Embase, and the Cochrane Library databases were searched until December 11, 2021 to identify eligible studies, that compared the UA levels of the case group (patients with DR) and control group (controls with diabetes and healthy participants). The weighted mean difference (WMD) with a 95% confidence interval (CI) was used to evaluate the difference in UA levels between the case and control groups.

Results

Twenty-one studies involving 4,340 patients with DR and 8,595 controls (8,029 controls with diabetes and 566 healthy participants) were included in this meta-analysis. We found that patients with DR had significantly higher UA levels than those in the controls with diabetes (WMD = 36.28; 95% CI: 15.68, 56.89; P < 0.001) and healthy participants (WMD = 70.80; 95% CI: 19.85, 121.75; P = 0.006). There was an obvious heterogeneity among the 21 studies (I² = 97%, P < 0.001). Subgroup analyses of different phases of DR showed that UA levels were significantly increased in participants with proliferative diabetic retinopathy (PDR) (WMD = 46.57; 95% CI: 28.51, 64.63; P < 0.001) than in controls with diabetes; however, the difference is not statistically significant when comparing UA levels in patients with non-proliferative diabetic retinopathy (NPDR) and controls with diabetes (WMD = 22.50; 95% CI: −6.07, 51.08; P = 0.120). In addition, UA levels were higher in participants with a body mass index (BMI) ≥25.0 kg/m² and over 15 years of diabetes. Univariate meta-regression analysis revealed that BMI (P = 0.007, Adj R² = 40.12%) and fasting blood glucose (FBG) (P = 0.040, Adj R² = 29.72%) contributed to between-study heterogeneity.

Conclusions

In conclusion, our study provides evidence that UA levels are higher in patients with DR than those in the controls, but this difference is not statistically significant in the early phases. UA might be a potential biomarker for identifying disease severity in patients with DR, rather than predicting the onset of DR among patients with diabetes. However, more prospective and high-quality clinical evidence is required to confirm these present findings.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=297708.

Interleukin-6 Predicts Carotid Plaque Severity, Vulnerability, and Progression

BACKGROUND

IL-6 (interleukin-6) has important roles in atherosclerosis pathophysiology. To determine if anti-IL-6 therapy warrants evaluation as an adjuvant stroke prevention strategy in patients with carotid atherosclerosis, we tested whether circulating IL-6 levels predict carotid plaque severity, vulnerability, and progression in the prospective population-based CHS (Cardiovascular Health Study).

METHODS

Duplex carotid ultrasound was performed at baseline and 5 years. Baseline plaque severity was scored 0 to 5 based on North American Symptomatic Carotid Endarterectomy Trial grade of stenosis. Plaque vulnerability at baseline was the presence of markedly irregular, ulcerated, or echolucent plaques. Plaque progression at 5 years was a ≥1 point increase in stenosis severity. The relationship of baseline plasma IL-6 levels with plaque characteristics was modeled using multivariable linear (severity) or logistic (vulnerability and progression) regression. Risk factors of atherosclerosis were included as independent variables. Stepwise backward elimination was used with P>0.05 for variable removal. To assess model stability, we computed the E-value or minimum strength of association (odds ratio scale) that unmeasured confounders must have with log IL-6 and the outcome to suppress the association. We performed internal validation with 100 bootstrap samples.

RESULTS

There were 4334 participants with complete data (58.9% women, mean age: 72.7±5.1 years), including 1267 (29.2%) with vulnerable plaque and 1474 (34.0%) with plaque progression. Log IL-6 predicted plaque severity (β=0.09, P=1.3×10^-3), vulnerability (OR, 1.21 [95% CI, 1.05-1.40]; P=7.4×10^-3, E-value=1.71), and progression (OR, 1.44 [95% CI, 1.23-1.69], P=9.1×10^-6, E-value 2.24). In participants with >50% predicted probability of progression, mean log IL-6 was 0.54 corresponding to 2.0 pg/mL. Dichotomizing IL-6 levels did not affect the performance of prediction models.

CONCLUSIONS

Circulating IL-6 predicts carotid plaque severity, vulnerability, and progression. The 2.0 pg/mL cutoff could facilitate the selection of individuals that would benefit from anti-IL-6 drugs for stroke prevention.

Hyperuricemia is associated with all-cause mortality among males and females: Findings from a study on Japanese community-dwelling individuals

Background

Serum uric acid (SUA) is a key determinant of cardiovascular diseases (CVDs). Studies have also shown that SUA independently impacts age-related health outcomes, although their findings differ between males and females. Furthermore, predictive data on all-cause mortality remain limited, particularly for the Japanese population. Thus, this study examined the association between SUA and survival prognosis among males and females based on a follow-up period of 7 or 19 years.

Methods

The study was based on 1,573 male (63 ± 14 years) and 1,980 female (65 ± 12 years) participants who participated in a Nomura Cohort Study in 2002 (Cohort 1) and 2014 (Cohort 2), and continued throughout the follow-up period. A basic resident register was referenced to derive the adjusted relative risk estimates for all-cause mortality. Finally, a Cox proportional hazards model analysis was conducted and was adjusted for possible confounders to estimate hazard ratios (HRs). 95% confidence intervals (CIs) were computed separately for male and female participants.

Results

Of the total 3,553 participants, 905 (25.5%) were deceased. Of these, 473 were male (30.1% of all males) and 432 were female (21.8% of all females). Hyperuricemia was defined in males with SUA levels of 8.5 mg/dL or higher, and in females with SUA levels of 7.5 mg/dL or higher, and was associated with a significantly increased HR for all-cause mortality (males: 1.67; 95% CI: 1.06-2.63; females: 2.17; 95% CI: 1.20-3.94). The data were further stratified based on age (< 65 years or ≥ 65 years), body mass index (BMI) (< 25.0 kg/m2 or ≥ 25.0 kg/m2), History of cardiovascular disease, estimated glomerular filtration rate (< 60 mL/min/1.73 m2 or ≥ 60 mL/min/1.73 m2), and presence of SUA-lowering medication. All stratified groups demonstrated a similar trend. The hyperuricemia group in particular reported a significant increase in HR. On the other hand, a U-shaped increase in HR was observed in those with BMI greater than 25 kg/m2 and SUA-lowering medication, but interaction effect was not significant.

Conclusions

Hyperuricemia is a key risk indicator for all-cause mortality in male and female community-dwelling individuals in Japan.

Early hearing loss detection in gout using extended high frequency audiometry

OBJECTIVE

The study aimed to analyse the hearing levels of patients with gout using extended high frequencies (EHFs) audiometry. Thus, we aimed to reveal the early detectability of potential hearing losses.

DESIGN

Comparative cross-sectional study.

SETTINGS

A single centre patient was diagnosed with gout disease.

PARTICIPANTS

Two groups consisted of 32 patients with gout and 32 healthy volunteers.

MAIN OUTCOME MEASURES

The primary outcome was hearing thresholds in pure tone (PT) audiometry and EHFs audiometry. Also, the association between audiometric results and haematological and biochemical parameters were evaluated.

RESULTS

There was no significant difference between groups in terms of mean hearing thresholds in PT audiometry. But, at all frequencies above 4000 Hz (4000-18 000 Hz), the hearing thresholds were significantly higher in patients with gout. Also, the hearing thresholds above 8000 Hz were positively correlated with serum uric acid levels. Hearing thresholds at higher frequencies were positively correlated with haemoglobin levels and negatively correlated with high-density lipoprotein levels.

CONCLUSION

To our knowledge, this is the first study in the literature demonstrating the high frequency of hearing loss in patients with gout using EHFs audiometry. We consider that using EHFs audiometry should have an important place in the early detection of potential hearing losses in gout patients.

Anti-inflammatory effect of SGLT-2 inhibitors via uric acid and insulin

Sodium-glucose cotransporter 2 (SGLT-2) inhibitors (i) reduce cardiovascular and renal events in patients with and without type 2 diabetes (T2D). However, the underlying mechanisms are debated. Low-grade inflammation (LGI) is a key driver of vascular complications, suggested to be attenuated by SGLT-2i in animal models. Based on a specific working hypothesis, here we investigated the net effect of SGLT-2i on LGI in patients with T2D and the possible underlying mechanism. We enrolled patients with T2D treated either with a stable therapy with SGLT-2i or with other glucose-lowering drugs (GLD) (n = 43 per group after matching for a range of pro-inflammatory variables), and tested hs-CRP and interleukin (IL)-6 as primary variables of interest. Patients treated with SGLT-2i had lower circulating levels of IL-6, a prototypical marker of LGI, but also of uric acid and fasting insulin, compared with patients treated with other GLD. Then, to explore whether uric acid and insulin might mediate the effect of SGLT-2i on IL-6, we tested physiologically pertinent doses of these two molecules (i.e. 0.5 mM uric acid and 1 nM insulin) in two in vitro models of LGI, i.e. monocytes (THP-1) treated with LPS and endothelial cells (HUVEC) exposed to hyperglycaemia. Results from in vitro models supported a pro-inflammatory role for uric acid and its combination with insulin in monocytes and for uric acid alone in hyperglycaemia-stimulated endothelial cells. On the contrary, we observed no drug-intrinsic, anti-inflammatory effect for dapagliflozin, empagliflozin, and canagliflozin in the same models. Overall, these results suggest that SGLT-2i possess a tangible activity against LGI, an effect possibly mediated by their ability to lower uric acid and insulin concentrations and that juxtaposes other proposed mechanisms in explaining the observed benefit of this class on cardiovascular and renal endpoints.

Association Between Serum Uric Acid and Lung Function in People with and without Chronic Obstructive Pulmonary Disease

Background

The effect of serum uric acid (SUA) levels on lung function in chronic obstructive pulmonary disease (COPD) people remained unclear. We aimed to investigate the association between SUA and lung function.

Methods

A cross-sectional study was performed to measure the SUA levels and lung function in 2797 consecutive eligible individuals. Of these, individuals in our study were divided into two groups, the COPD group (n=1387) and the non-COPD group (n=1410). The diagnosis of COPD is defined as post-bronchodilator first second of forced expiratory volume (FEV₁)/forced vital capacity (FVC) ratio of less than 0.70. Multivariable adjustment linear models were applied to estimate the effect of SUA levels on FEV₁% predicted, FVC% predicted, and FEV₁/FVC stratified by COPD status.

Results

After multivariable adjustment, each 1 mg/dL increase of SUA was significantly associated with a decrease in FEV₁% predicted (−1.63%, 95% confidence interval [CI] −2.37 to −0.90), FVC % predicted (−0.89%, 95% CI −1.55 to −0.24), and FEV₁/FVC (−0.70%, 95% CI −1.10 to −0.30). In the COPD group, each 1 mg/dL increase of SUA was significantly associated with decreases in FEV₁% predicted (−1.87%, 95% CI −2.91 to −0.84), FVC% predicted (−1.35%, 95% CI −2.35 to −0.34), and FEV₁/FVC (−0.63%, 95% CI −1.18 to −0.08). However, no significant association between lung function and SUA was found among people without COPD.

Conclusion

High SUA levels were associated with lower lung function, especially in COPD patients. However, no statistically significant effect of SUA on lung function was found in people without COPD.

Anti-Hyperuricemic Effect of Ethyl Acetate Sub-Fractions from Chrysanthemum morifolium Ramat. Dried Flowers on Potassium Oxonate-Induced Hyperuricemic Rats

Xanthine oxidase (XO) plays an important role in purine degradation in humans. The study aimed to determine the XO inhibitory potential of Chrysanthemum morifolium dried flower ethyl acetate sub-fractions and its anti-hyperuricemic effect in rat models. Bioassay-guided fractionation based on XO inhibitory assay was employed to obtain bioactive fractions and sub-fractions. In vitro cytotoxicity and cellular antioxidant capacity of the sub-fraction and its mode of XO inhibition were also investigated. The anti-hyperuricemic effect of the bioactive sub-fraction was investigated using rat models via oral consumption, and followed by an XO mRNA gene expression study. The compounds in the bioactive sub-fractions were identified putatively using HPLC-Q-TOF-MS/MS. Ethyl acetate (EtOAc) fraction exhibited the highest XO inhibition among the fractions. It was further fractionated into 15 sub-fractions. F10 exhibited high XO inhibitory activity, cellular pro-proliferative effect, and intracellular antioxidant activity among the sub-fractions tested. This sub-fraction was non-cytotoxic at 0.1–10 µg/mL, and very effective in lowering serum and urine uric acid level in rat models upon oral consumption. A total of 26 known compounds were identified and seven unknown compounds were detected via HPLC-Q-TOF–MS/MS analysis. The possible mechanisms contributing to the anti-hyperuricemic effect were suggested to be the non-competitive inhibition of XO enzyme, XO gene expression down-regulation, and the enhancement of uric acid excretion.

Serum Uric Acid as a Diagnostic Biomarker for Rheumatoid Arthritis-Associated Interstitial Lung Disease

Previous studies have suggested a correlation between uric acid (UA) and lung lesion in some diseases. However, it remains unknown whether UA contributes to the lung injury in rheumatoid arthritis (RA). Our study aimed to investigate the clinical value of the UA level in the severity of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). We measured UA in serum and bronchoalveolar lavage fluid (BALF), and UA levels of subjects were compared. As for the role of UA on ILD, we incubated A549 cells with UA and the expression of EMT markers was measured by immunofluorescence staining. The concentrations and messenger RNA expression of IL-1, IL-6, and transforming growth factor-β (TGF-β) were measured by ELISA and RT-PCR, respectively. We observed that serum UA levels in RA were significantly higher than those in controls. And, higher UA was measured in both serum and BALF of patients with RA-ILD, particularly those with interstitial pneumonia (UIP) pattern. Additionally, the correlation of the serum and BALF UA levels with serum KL-6, a biomarker of ILDs, in RA was significant (r = 0.44, p < 0.01; r = 0.43, p < 0.01). And, the negative correlations of UA, in both serum and BALF, with forced vital capacity (r =  -0.61, p < 0.01; r =  -0.34, p < 0.01) and diffusing capacity for carbon monoxide (r =  -0.43, p < 0.01; r =  -0.30, p < 0.01) were measured in patients. In the ROC curve analysis, the AUC value of UA for RA-ILD was 0.744 (95% CI: 0.69-0.80; p < 0.01), and the AUC of serum UA for predicting UIP pattern of patients with RA-ILD was 0.845 (95% CI: 0.78-0.91; p < 0.01), which showed the significance of the UA in clinical settings. Also, the in vitro experiment showed that UA induced epithelial-to-mesenchymal transition (EMT) and production of IL-1, IL-6, and TGF-β in A549 cells. Therefore, the elevated UA levels may be a diagnostic marker in RA-ILD, particularly RA-UIP.