Hyperuricemia, Acute and Chronic Kidney Disease, Hypertension, and Cardiovascular Disease: Report of a Scientific Workshop Organized by the National Kidney Foundation

Management of hypertension addressing hyperuricaemia: introduction of nano-based approaches

Uric acid (UA) levels in blood serum have been associated with hypertension, indicating a potential causal relationship between high serum UA levels and the progression of hypertension. Therefore, the reduction of serum UA level is considered a potential strategy for lowering and mitigating blood pressure. If an individual is at risk of developing or already manifesting elevated blood pressure, this intervention could be an integral part of a comprehensive treatment plan. By addressing hyperuricaemia, practitioners may subsidize the optimization of blood pressure regulation, which illustrates the importance of addressing UA levels as a valuable strategy within the broader context of hypertension management. In this analysis, we outlined the operational principles of effective xanthine oxidase inhibitors for the treatment of hyperuricaemia and hypertension, along with an exploration of the contribution of nanotechnology to this field.

The alleviatory effects of koumine on MSU-induced gouty arthritis via the TLR4/NF-κB/NLRP3 pathway

The aim of this study was to validate the preventive effects of koumine (KM), a monoterpene indole alkaloid, on gouty arthritis (GA) and to explore its possible mechanisms. C57BL/6 mice were intraperitoneally administered KM (0.8, 2.4 or 7.2 mg/kg), colchicine (3.0 mg/kg) or sterile saline. One hour later, a monosodium urate (MSU) suspension was injected into the right hind paws of the mice to establish an acute gout model. Inflammation symptoms were evaluated at 0, 3, 6, 12 and 24 h, and the mechanical withdrawal threshold was evaluated at 0, 6 and 24 h. After 24 h, the mice were euthanized, and the joint tissue, kidney and blood were collected for subsequent experiments. Histological examination and antioxidant enzyme, kidney index and serum uric acid (UA) measurements were taken. The expression levels of the signalling pathway components were determined. KM effectively alleviated the symptoms of redness, swelling and pain; counteracted inflammatory cell infiltration; and increased antioxidant enzyme levels, reduced kidney index and serum UA levels through regulating UA excretion in MSU-induced mice. The expression of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB)/nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing 3 (NLRP3) signalling pathway proteins and mRNA were reduced in the KM group. These results suggest that KM may be effective in alleviating GA through the TLR4/NF-κB/NLRP3 pathway.

Intermittent high altitude hypoxia induced liver and kidney injury leading to hyperuricemia

About 140 million people worldwide live at an altitude above 2500 m. Studies have showed an increase of the incidence of hyperuricemia among plateau populations, but little is known about the possible mechanisms. This study aims to assess the effects of high altitude on hyperuricemia and explore the corresponding mechanisms at the histological, inflammatory and molecular levels. This study finds that intermittent hypobaric hypoxia (IHH) exposure results in an increase of serum uric acid level and a decrease of uric acid clearance rate. Compared with the control group, the IHH group shows significant increases in hemoglobin concentration (HGB) and red blood cell counts (RBC), indicating that high altitude hyperuricemia is associated with polycythemia. This study also shows that IHH exposure induces oxidative stress, which causes the injury of liver and renal structures and functions. Additionally, altered expressions of organic anion transporter 1 (OAT1) and organic cation transporter 1 (OCT1) of kidney have been detected in the IHH exposed rats. The adenosine deaminase (ADA) expression levels and the xanthione oxidase (XOD) and ADA activity of liver of the IHH exposure group have significantly increased compared with those of the control group. Furthermore, the spleen coefficients, IL-2, IL-1β and IL-8, have seen significant increases among the IHH exposure group. TLR/MyD88/NF-κB pathway is activated in the process of IHH induced inflammatory response in joints. Importantly, these results jointly show that IHH exposure causes hyperuricemia. IHH induced oxidative stress along with liver and kidney injury, unusual expression of the uric acid synthesis/excretion regulator and inflammatory response, thus suggesting a potential mechanism underlying IHH-induced hyperuricemia.

Integrated Bioinformatics Analysis Reveals the Aberrantly Methylated Differentially Expressed Genes in Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) causes heart failure and sudden death. Epigenetics is crucial in cardiomyopathy susceptibility and progression; however, the relationship between epigenetics, particularly DNA methylation, and DCM remains unknown. Therefore, this study identified aberrantly methylated differentially expressed genes (DEGs) associated with DCM using bioinformatics analysis and characterized their clinical utility in DCM. DNA methylation expression profiles and transcriptome data from public datasets of human DCM and healthy control cardiac tissues were obtained from the Gene Expression Omnibus public datasets. Then an epigenome-wide association study was performed. DEGs were identified in both DCM and healthy control cardiac tissues. In total, 3,353 cytosine-guanine dinucleotide sites annotated to 2,818 mRNAs were identified, and 479 DCM-related genes were identified. Subsequently, core genes were screened using logistic, least absolute shrinkage and selection operator, random forest, and support vector machine analyses. The overlapping of these genes resulted in DEGs with abnormal methylation patterns. Cross-tabulation analysis identified 8 DEGs with abnormal methylation. Real-time quantitative polymerase chain reaction confirmed the expression of aberrantly methylated DEGs in mice. In DCM murine cardiac tissues, the expressions of SLC16A9, SNCA, PDE5A, FNDC1, and HTRA1 were higher compared to normal murine cardiac tissues. Moreover, logistic regression model associated with aberrantly methylated DEGs was developed to evaluate the diagnostic value, and the area under the receiver operating characteristic curve was 0.949, indicating that the diagnostic model could reliably distinguish DCM from non-DCM samples. In summary, our study identified 5 DEGs through integrated bioinformatic analysis and in vivo experiments, which could serve as potential targets for further comprehensive investigation.

Multimodal Machine Learning-Based Marker Enables Early Detection and Prognosis Prediction for Hyperuricemia

Hyperuricemia (HUA) has emerged as the second most prevalent metabolic disorder characterized by prolonged and asymptomatic period, triggering gout and metabolism-related outcomes. Early detection and prognosis prediction for HUA and gout are crucial for pre-emptive interventions. Integrating genetic and clinical data from 421287 UK Biobank and 8900 Nanfang Hospital participants, a stacked multimodal machine learning model is developed and validated to synthesize its probabilities as an in-silico quantitative marker for hyperuricemia (ISHUA). The model demonstrates satisfactory performance in detecting HUA, exhibiting area under the curves (AUCs) of 0.859, 0.836, and 0.779 within the train, internal, and external test sets, respectively. ISHUA is significantly associated with gout and metabolism-related outcomes, effectively classifying individuals into low- and high-risk groups for gout in the train (AUC, 0.815) and internal test (AUC, 0.814) sets. The high-risk group shows increased susceptibility to metabolism-related outcomes, and participants with intermediate or favorable lifestyle profiles have hazard ratios of 0.75 and 0.53 for gout compared with those with unfavorable lifestyles. Similar trends are observed for other metabolism-related outcomes. The multimodal machine learning-based ISHUA marker enables personalized risk stratification for gout and metabolism-related outcomes, and it is unveiled that lifestyle changes can ameliorate these outcomes within high-risk group, providing guidance for preventive interventions.

Preexisting Hyperuricemia Before High-Altitude Ascent is Associated with a Slower Recovery of Estimated Glomerular Filtration Rate Following Descent

Zhao, Linggong, Yujie Huang, and Xiaoling Tan. Preexisting hyperuricemia before high-altitude ascent is associated with a slower recovery of estimated glomerular filtration rate following descent. High Alt Med Biol. 00:00-00, 2024. Objectives: Hypoxia at high altitudes results in elevated uric acid (UA) and reduced estimated glomerular filtration rate (eGFR). However, the impact of a prolonged high-altitude sojourn on UA levels and renal function in patients with preexisting hyperuricemia warrants further exploration. The study was to investigate the eGFR and related factors in patients with preexisting hyperuricemia following exposure to high altitude. Methods: The study included 345 participants, who worked at a high altitude for 1 year. Anthropometric and laboratory indices were collected before ascent (i.e., baseline), as well as 20 and 80 days after descent. The participants were categorized into individuals with hyperuricemia (HUA) or normal uric acid (NUA) group based on the presence or absence of hyperuricemia at baseline. Results: No difference in baseline eGFR was observed between the two groups before ascend or on day 20 after descent (p > 0.05). However, on day 80, eGFR of the HUA group was lower compared with the NUA group (p < 0.05). Correlations existed between post-descent eGFR levels and variables, including sampling time, UA levels, total and direct bilirubin, and baseline grouping. Conclusions: After high-altitude exposure, the recovery of eGFR was delayed in participants with preexisting hyperuricemia. Preexisting hyperuricemia and high-altitude hypoxia jointly contribute to renal impairment.

Integrin αM promotes macrophage alternative M2 polarization in hyperuricemia-related chronic kidney disease

Hyperuricemia is an essential risk factor in chronic kidney disease (CKD), while urate-lowering therapy to prevent or delay CKD is controversial. Alternatively activated macrophages in response to local microenvironment play diverse roles in kidney diseases. Here, we aim to investigate whether and how macrophage integrin αM (ITGAM) contributes to hyperuricemia-related CKD. In vivo, we explored dynamic characteristics of renal tissue in hyperuricemia-related CKD mice. By incorporating transcriptomics and phosphoproteomics data, we analyzed gene expression profile, hub genes and potential pathways. In vitro, we validated bioinformatic findings under different conditions with interventions corresponding to core nodes. We found that hyperuricemia-related CKD was characterized by elevated serum uric acid levels, impaired renal function, activation of macrophage alternative (M2) polarization, and kidney fibrosis. Integrated bioinformatic analyses revealed Itgam as the potential core gene, which was associated with focal adhesion signaling. Notably, we confirmed the upregulated expression of macrophage ITGAM, activated pathway, and macrophage M2 polarization in injured kidneys. In vitro, through silencing Itgam, inhibiting p-FAK or p-AKT1 phosphorylation, and concurrent inhibiting of p-FAK while activating p-AKT1 all contributed to the modulation of macrophage M2 polarization. Our results indicated targeting macrophage ITGAM might be a promising therapeutic approach for preventing CKD.

A national study exploring the association between triglyceride-glucose index and risk of hyperuricemia events in adults with hypertension

Background

The triglyceride-glucose (TyG) index has been recommended as a practical surrogate of insulin resistance (IR). However, the association between the TyG index and hyperuricemia among adults with hypertension remains to be elucidated.

Methods

We included and analyzed 3134 HTN patients and 4233 non-HTN participants from the cross-sectional 2013-2018 U.S. National Health and Nutrition Examination Surveys (NHANES). Multivariable logistic regression and restricted cubic splines (RCS) were used to explore the association between the TyG index and hyperuricemia. Stratifed analyses were performed to assess the association in populations with different subgroups of hypertension.

Results

The prevalence of hyperuricemia was higher in HTN patients (28.00 %) than in non-HTN participants (12.47 %). The multivariable logistic regression showed that the TyG index was significantly associated with hyperuricemia. After multivariable adjustment, higher TyG index levels were found to be associated with a higher prevalence of hyperuricemia in HTN patients (OR: 2.39, 95 % CI: 1.37-4.17, Ptrend < 0.001) and non-HTN participants (OR: 2.61, 95 % CI: 1.45-4.69, Ptrend < 0.001). Restricted cubic spline regression showed linearity of the associations between the TyG index and hyperuricemia (p-nonlinear > 0.05). In the subgroup analysis suggested that the positive association seemed to be strong among male, alcohol use, and diabetes group (P for interaction < 0.05).

Conclusions

TyG index, a practical surrogate of IR, was linearly and positively associated with hyperuricemia in HTN and non-HTN participants. Proactive measures are needed to prevent the comorbidity of IR-driven hyperuricemia in the future.

Development of a Predictive Model for Potentially Inappropriate Medications in Older Patients with Cardiovascular Disease

BACKGROUND

Older patients with cardiovascular disease (CVD) are highly susceptible to adverse drug reactions due to age-related physiological changes and the presence of multiple comorbidities, polypharmacy, and potentially inappropriate medications (PIMs).

OBJECTIVE

This study aimed to develop a predictive model to identify the use of PIMs in older patients with CVD.

METHODS

Data from 2012 to 2021 from the Changhua Christian Hospital Clinical Research Database (CCHRD) and the Kaohsiung Medical University Hospital Research Database (KMUHRD) were analyzed. Participants over the age of 65 years with CVD diagnoses were included. The CCHRD data were randomly divided into a training set (80% of the database) and an internal validation set (20% of the database), while the KMUHRD data served as an external validation set. The training set was used to construct the prediction models, and both validation sets were used to validate the proposed models.

RESULTS

A total of 48,569 patients were included. Comprehensive data analysis revealed significant associations between the use of PIMs and clinical factors such as total cholesterol, glycated hemoglobin (HbA1c), creatinine, and uric acid levels, as well as the presence of diabetes, hypertension, and cerebrovascular accidents. The predictive models demonstrated moderate power, indicating the importance of these factors in assessing the risk of PIMs.

CONCLUSIONS

This study developed predictive models that improve understanding of the use of PIMs in older patients with CVD. These models may assist clinicians in making informed decisions regarding medication safety.

Association of uric acid with length of stay and mortality in pediatric hospitalized population

PURPOSE

Elevated uric acid (UA) levels have been associated with acute and chronic diseases, which could affect the prognosis of pediatric hospitalized patients. However, the association of UA levels with length of hospital stay (LOS) and mortality in hospitalized children and adolescents remains unknown. Therefore, the aim of this study was to evaluate the association of serum UA levels with in-hospital mortality and prolonged LOS in hospitalized children and adolescents.

METHODS

A retrospective cohort study was conducted, involving 128 patients under 18 years of age, admitted to a tertiary-care hospital between January 2014 and December 2018. UA levels were assessed with an average of 3 days before the in-hospital outcome (discharge or death). Logistic regression was used to determine the association of UA with prolonged LOS (defined as over 30 days of hospitalization), while Cox regression multivariate analysis was employed to assess UA as a predictor of in-hospital mortality.

RESULTS

UA levels showed an inverse association with prolonged LOS. Specifically, for every 1 mg/dL increase in UA level, the odds of experiencing prolonged LOS decreased by 31% (OR = 0.69; 95% CI: 0.50-0.95). Additionally, individuals with elevated UA levels had lower odds of prolonged LOS (OR = 0.23; 95% CI: 0.08-0.66). However, UA levels were not associated with in-hospital mortality (HR = 1.63; 95% CI: 0.94-2.82).

CONCLUSION

Serum UA was inversely associated with LOS among children and adolescents, but no association was observed with in-hospital mortality.

Impact of health literacy, social support, and socioeconomic position on the serum uric acid level in asymptomatic hyperuricaemia patients in China: a structural equation model

BACKGROUND

Hyperuricaemia (HUA) poses a significant public health challenge on a global scale. It is mostly asymptomatic hyperuricemia (AHU) with unsatisfactory recognition and control rates. The role of health literacy in influencing health outcomes is of utmost importance, and enhancing health literacy is helpful for patients in managing risk factors. Additionally, social support and socioeconomic position (SEP) have been identified as potential factors influencing health. However, the exact relationships between these factors and AHU remain unclear. This study aimed to investigate the status of health literacy among patients with AHU and explore the relationships between health literacy, social support, SEP, and serum uric acid (SUA) levels.

METHODS

A cross-sectional study was conducted among 349 participants with AHU in Luzhou, China. The research instruments included a sociodemographic characteristics questionnaire, the Health Literacy Scale for Chronic Patients (HLSCP), and the Social Support Scale (SSRS). The construction of the SEP index was achieved through the application of principal component analysis. Univariate and hierarchical regression analyses were used to evaluate the associations between SEP, social support, health literacy, and SUA levels. Furthermore, structural equation modelling (SEM) was utilized to examine these associations.

RESULTS

(1) Most patients exhibited low health literacy (90.18 ± 15.11), and only 44.4% possessed basic health literacy. (2) SEP was positively correlated with SUA levels (β = 4.086, P < 0.001), and health literacy was negatively related to SUA levels (β = -0.399, P < 0.001). There was no significant relationship between social support and SUA levels (β = 0.051, t = 1.085). (3) Health literacy mediated the association between SEP and SUA levels (β = -0.490, 95% CI: -0.620 to -0.382). SEP had a direct positive effect on SUA levels (β = 0.723) and health literacy (β = 0.696), and the total effect of SEP on SUA levels was 0.233.

CONCLUSIONS

The findings indicate a low level of health literacy among patients with AHU and suggest that health literacy might play a mediating role in the relationship between SEP and SUA levels. Consequently, future initiatives are recommended to prioritize health literacy and devise appropriate intervention strategies to enhance the self-management capabilities of patients with AHU.

Raffinose Ameliorates DSS-Induced Colitis in Mice by Modulating Gut Microbiota and Targeting the Inflammatory TLR4-MyD88-NF-κB Signaling Pathway

This study aimed to explore the protective effects of raffinose (Raf) against inflammatory bowel disease in mice with colitis. Mice were administered 100, 200, or 400 mg/kg Raf for 21 d, followed by drinking-water containing 3% dextran sulfate sodium salt (DSS) for 3 d. Thereafter, the phenotype, pathological lesions in the colon, cytokines levels, and gut microbiota were evaluated. Treatment with Raf reduced the severity of the pathological changes in the colon, mitigating the reduction in colon length. Following Raf intervention, serum levels of inflammatory cytokines (IL-2, IL-6, IL-1β, and TNF-α) tended to return to normal. These results suggest that the anti-inflammatory effects of Raf are associated with a reduction in TLR4-MyD88-NF-κB pathway expression in mouse colonic tissues. Analysis of gut microbiota abundance and its correlation with colitis parameters revealed that DSS-induced dysbiosis was partially mitigated by Raf. In conclusion, Raf exerts a protective effect in colitis by modulating the gut microbiota and TLR4-MyD88-NF-κB pathway.

Xanthoceras sorbifolium leaves alleviate hyperuricemic nephropathy by inhibiting the PI3K/AKT signaling pathway to regulate uric acid transport

ETHNOPHARMACOLOGICAL RELEVANCE

In China, Xanthoceras sorbifolium Bunge was first documented as "Wen Guan Hua" in the "Jiu Huang Ben Cao" in 1406 A.D. According to the "National Compilation of Chinese Herbal Medicine," X. sorbifolium leaves are sweet and flat in nature and can dispel wind and dampness, suggesting that their extract can be used to treat rheumatoid arthritis. X. sorbifolium Bunge has also been used to treat arteriosclerosis, hyperlipidemia, hypertension, chronic hepatitis, and rheumatism, complications associated with hyperuricemic nephropathy (HN), a condition characterized by kidney damage resulting from high levels of uric acid (UA) in the blood.

AIM OF THE STUDY

The purpose of this study was to investigate the effects and underlying mechanisms of a 70% ethanol extract from X. sorbifolium leaves (EX) in alleviating HN.

MATERIALS AND METHODS

A mouse model of hyperuricemia was established to initially evaluate the hypouricemic effects and determine the effective dose of EX. Phytochemical analyses were conducted using ultra high-performance liquid chromatography and liquid chromatography-mass spectroscopy. The potential key pathways of EX in the alleviation of HN were inferred using network pharmacology and bioinformatics. An HN rat model was then established, and experiments including biomarker detection, western blotting, reverse transcription quantitative polymerase chain reaction, immunohistochemical and Masson's trichrome staining, and transmission electron microscopy were conducted to evaluate the effect of EX on UA transporter expression in vitro.

RESULTS

Network pharmacology and bioinformatics analyses revealed that the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway was the key pathway for the alleviation of HN progression by EX. EX treatment reduced serum biomarkers in HN rats, downregulated the expression of p-PI3K, p-AKT, glucose transporter 9 (GLUT9), urate transporter 1 (URAT1), Collagen I, matrix metalloproteinase (MMP)-2, and MMP-9, and upregulated the expression of ATP binding cassette subfamily G member 2 (ABCG2) to improve renal interstitial fibrosis in HN rats. A high content of both quercitrin and cynaroside were identified in EX; their administration inhibited the increased expression of GLUT9 and URAT1 in damaged HK-2 cells.

CONCLUSION

Our study provides evidence that EX alleviates HN. The potential mechanism underlying this effect may be the regulation of UA transporters, such as GLUT9 and URAT1, by limiting the activation of the PI3K/AKT signaling pathway to improve renal injury.

Association of urinary excretion rates of uric acid with biomarkers of kidney injury in patients with advanced chronic kidney disease

BACKGROUND

The potential influence of hyperuricemia on the genesis and progression of chronic kidney disease (CKD) remains controversial. In general, the correlation between blood levels of uric acid (UA) and the rate of progression of CKD is considered to be modest, if any, and the results of relevant trials oriented to disclose the effect of urate-lowering therapies on this outcome have been disappointing. Urinary excretion rates of UA could reflect more accurately the potential consequences of urate-related kidney injury.

METHOD

Using a cross-sectional design, we investigated the correlation between different estimators of the rates of urinary excretion of UA (total 24-hour excretion, mean urinary concentration, renal clearance and fractional excretion)(main study variables), on one side, and urinary levels of selected biomarkers of kidney injury and CKD progression (DKK3, KIM1, NGAL, interleukin 1b and MCP)(main outcome variables), in 120 patients with advanced CKD (mean glomerular filtration rate 21.5 mL/minute). We took into consideration essential demographic, clinical and analytic variables with a potential confounding effect on the explored correlations (control variables). Spearman's rho correlation and nonlinear generalized additive regression models (GAM) with p-splines smoothers were used for statistical analysis.

MAIN RESULTS

Multivariate analysis disclosed independent correlations between urinary UA concentrations, clearances and fractional excretion rates (but not plasma UA or total 24-hour excretion rates of UA), on one side, and the scrutinized markers. These correlations were more consistent for DKK3 and NGAL than for the other biomarkers. Glomerular filtration rate, proteinuria and treatment with statins or RAA axis antagonists were other independent correlates of the main outcome variables.

CONCLUSIONS

Our results support the hypothesis that urinary excretion rates of UA may represent a more accurate marker of UA-related kidney injury than plasma levels of this metabolite, in patients with advanced stages of CKD. Further, longitudinal studies will be necessary, to disclose the clinical significance of these findings.

Mechanisms of epigallocatechin gallate (EGCG) in ameliorating hyperuricemia: insights into gut microbiota and intestinal function in a mouse model

Epigallocatechin gallate (EGCG), a prominent bioactive compound found in tea, offers numerous health benefits. Previous studies have highlighted its potential in mitigating hyperuricemia. In this study, hyperuricemic mice induced by potassium oxonate (PO) were treated with EGCG or the anti-hyperuricemia medication allopurinol (AP) to investigate the mechanisms underlying their anti-hyperuricemic effects. The results demonstrated that both EGCG and AP significantly reduced serum uric acid (UA) levels. Further analysis revealed that EGCG promoted the expression of UA secretion transporter genes (Oat1 and Oct1) while inhibiting the expression of UA reabsorption transporter genes (Urat1 and Glut9) in the kidney. By 16S rDNA sequencing, EGCG, but not AP, was found to alter the composition of the gut microbiota. Notably, EGCG induced significant changes in the relative abundance of specific bacteria such as Lactobacillus, Faecalibaculum, and Bifidobacterium, which displayed high correlations with serum UA levels and UA-related gene expression. Metabolomic analysis suggested that EGCG-induced modifications in bacterial metabolites might contribute to the alleviation of hyperuricemia. Transcriptomic analysis of the intestinal epithelium identifies 191 differentially expressed genes (DEGs) in EGCG-treated mice, including 8 purine-related genes. This study elucidates the anti-hyperuricemic mechanisms of EGCG, particularly its influence on the gut microbiota and gene expression in the intestinal epithelium.

Uric Acid Mitigates Cognitive Deficits via TFEB-Mediated Microglial Autophagy in Mice Models of Alzheimer's Disease

Clinical trials have demonstrated the potential neuroprotective effects of uric acid (UA) in Alzheimer's disease (AD). However, the specific mechanism underlying the neuroprotective effect of UA remains unclear. In the present study, we investigated the neuroprotective effect and underlying mechanism of UA in AD mouse models. Various behavioral tests including an elevated plus maze, Barnes maze, and Morris water maze were conducted to evaluate the impact of UA on cognitive function in β-amyloid (Aβ) microinjection and APP23/PS45 double transgenic mice models of AD. Immunohistochemical staining was employed to visualize pathological changes in the brains of AD model mice. Western blotting and immunofluorescence techniques were used to assess levels of autophagy-related proteins and transcription factor EB (TFEB)-related signaling pathways. BV2 cells were used to investigate the association between UA and microglial autophagy. We reported that UA treatment significantly alleviated memory decline in Aβ-induced AD model mice and APP23/PS45 double transgenic AD model mice. Furthermore, UA activated microglia and upregulated the autophagy-related proteins such as LC3II/I ratio, Beclin-1, and LAMP1 in the hippocampus of AD model mice. Similarly, UA protected BV2 cells from Aβ toxicity by upregulating the expressions of Beclin-1, LAMP1, and the LC3II/I ratio, whereas genetic inhibition of TFEB completely abolished these protective effects. Our results indicate that UA may serve as a novel activator of TFEB to induce microglia autophagy and facilitate Aβ degradation, thereby improving cognitive function in AD model mice. Therefore, these findings suggest that UA may be a novel therapeutic agent for AD treatment.

Large-Sample Genome-Wide Association Study of Resistance to Retained Placenta in U.S. Holstein Cows

A genome-wide association study of resistance to retained placenta (RETP) using 632,212 Holstein cows and 74,747 SNPs identified 200 additive effects with p-values < 10-8 on thirteen chromosomes but no dominance effect was statistically significant. The regions of 87.61-88.74 Mb of Chr09 about 1.13 Mb in size had the most significant effect in LOC112448080 and other highly significant effects in CCDC170 and ESR1, and in or near RMND1 and AKAP12. Four non-ESR1 genes in this region were reported to be involved in ESR1 fusions in humans. Chr23 had the largest number of significant effects that peaked in SLC17A1, which was involved in urate metabolism and transport that could contribute to kidney disease. The PKHD1 gene contained seven significant effects and was downstream of another six significant effects. The ACOT13 gene also had a highly significant effect. Both PKHD1 and ACOT13 were associated with kidney disease. Another highly significant effect was upstream of BOLA-DQA2. The KITLG gene of Chr05 that acts in utero in germ cell and neural cell development, and hematopoiesis was upstream of a highly significant effect, contained a significant effect, and was between another two significant effects. The results of this study provided a new understanding of genetic factors underlying RETP in U.S. Holstein cows.

Nonlinear relationship between oxidative balance score and hyperuricemia: analyses of NHANES 2007-2018

BACKGROUND

Limited data regarding the correlation between oxidative balance score (OBS) and hyperuricemia highlights the necessity for thorough investigations. This study aims to examine the link between OBS, which incorporates dietary and lifestyle factors, and the occurrence of hyperuricemia.

METHODS

We conducted a cross-sectional study involving 13,636 participants from the 2007-2018 National Health and Nutrition Examination Survey (NHANES). The oxidative balance score (OBS) was determined based on four lifestyle factors and sixteen dietary nutrients. We assessed the levels of serum uric acid (SUA) and the occurrence of hyperuricemia as outcomes. Weighted logistic regression and linear models were used for statistical analysis, using Restricted Cubic Splines (RCS) to examine potential nonlinear associations. Subgroup analysis and sensitivity assessments were performed to identify any variations and ensure the robustness of the findings.

RESULTS

Higher OBS was consistently correlated with decreased SUA levels and a reduced prevalence of hyperuricemia. RCS highlighted a significant negative nonlinear association, particularly in females. Subgroup analysis revealed gender-based differences and interactive correlation, providing additional insights regarding OBS and hyperuricemia relationship.

CONCLUSION

This study underscores a robust negative correlation between OBS and SUA levels as well as the incidence of hyperuricemia, emphasizing the importance of dietary and lifestyle factors. Incorporating RCS, subgroup analysis, and sensitivity assessments enhances the depth of our findings, providing valuable insights for further research.

Does Serum Uric Acid to Creatinine Ratio Predict Mortality Risk in Patients With Heart Failure?

BACKGROUND

Previous studies have established a positive correlation between serum uric acid to creatinine (SUA/Cr) ratio and cardiovascular disease, but the relationship between SUA/Cr ratio and the prognosis of heart failure (HF) remains unknown. This study investigated the potential of SUA/Cr ratio as a prognostic predictor for patients with HF.

METHODS

This single-center prospective cohort study enrolled 2,122 patients with HF between March 2013 and June 2017. All patients were divided into 3 groups according to SUA/Cr ratio tertiles and were followed up with until December 31, 2022. The association between SUA/Cr ratio and the prognosis of HF was assessed using the Cox proportional hazards model.

RESULTS

The mean (SD) age and mean (SD) SUA/Cr ratio of the study cohort (66% male) were 59.3 (14.7) years and 4.71 (2.09), respectively. During a median follow-up period of 15 months (range, 11-26 months), 390 end-point events were observed. Prognosis analysis revealed that a high SUA/Cr ratio was associated with an increased mortality risk of HF (hazard ratio, 1.62 [95% CI, 1.26-2.09]; P < .001) compared with the SUA/Cr ratio in the lowest tertile. After adjusting for covariates, the hazard ratio for mortality risk of HF was 1.71 (95% CI, 1.23-2.37; P = .001). Subgroup analysis showed that mortality risk increased in direct proportion with the SUA/Cr ratio in female patients, patients with a history of hypertension and β-blocker use, and patients with UA levels below 428 μmol/L and creatinine levels less than 97 mg/dL. Stratification by age; by history of diabetes, hyperlipidemia, and smoking; and by level of fasting plasma glucose, however, had no obvious effect on the association between SUA/Cr ratio and HF prognosis. Patients with higher SUA/Cr ratios had reduced left ventricular ejection fraction and increased left ventricular end-diastolic diameter.

CONCLUSION

A high SUA/Cr ratio was an independent risk factor for the mortality risk of HF.

Dietary anthocyanin is associated with a lower prevalence of hyperuricemia independently of metabolic syndrome among females: Results from NHANES 2007-2010 and 2017-2018

OBJECTIVE

Known for anti-inflammatory and antioxidant properties, flavonoid has phytoestrogenic effects, but it is unclear whether its role in hyperuricemia and metabolic syndrome (MetS) differs by gender. Moreover, given the strong association between hyperuricemia and MetS, we aimed to explore whether flavonoid is a protective factor for hyperuricemia, independently of MetS, in different genders.

METHODS

Data for 2007-2010 and 2017-2018 were obtained from the National Health and Nutrition Examination Survey (NHANES) and the Food and Nutrient Database for Dietary Studies (FNDDS). To assess the association among flavonoid, hyperuricemia, and MetS, multivariate logistic regression and subgroup analyses were conducted. Besides, to investigate whether the association between flavonoid and hyperuricemia was independent of MetS, multivariate logistic regression models were further conducted to explore the association between flavonoid and MetS among females with hyperuricemia and to investigate the association between flavonoid and hyperuricemia among females after excluding MetS.

RESULT

Among 5356 females, anthocyanin intake was inversely associated with the prevalence of hyperuricemia (Q4 vs. Q1: OR 0.49, 95% CI 0.31 to 0.76), and MetS (Q4 vs. Q1: OR 0.68, 95% CI 0.50 to 0.93). Furthermore, subgroup analyses showed the beneficial association between anthocyanin and hyperuricemia among females aged 40 to 59 years and menopausal. However, among 5104 males, no significant association was observed after adjustment for covariates (Q4 vs. Q1: OR 0.81, 95% CI 0.56 to 1.18). While in 372 females with hyperuricemia, no significant association was found between MetS and anthocyanin (Q4 vs. Q1: OR 0.88, 95% CI 0.31 to 2.49). Meanwhile, among 3335 females after excluding MetS, there was still a significant association between anthocyanin and a lower prevalence of hyperuricemia (Q4 vs. Q1: OR 0.38, 95% CI 0.17 to 0.85).

CONCLUSION

Dietary anthocyanin is associated with a lower prevalence of hyperuricemia independently of MetS among females. Foods rich in anthocyanin should be emphasized for females, especially those aged 40 to 59 years and menopausal, which may be of potential significance in the prevention of hyperuricemia.

Correlation of uric acid with microalbuminuria in Type-2 diabetic patients with normal creatinine

Objective

To find the correlation of serum uric acid with microalbuminuria in Type-2 diabetic patients with normal creatinine.

Methods

This cross-sectional study was conducted in the Department of Diabetes, Endocrinology and Metabolic diseases, Hayatabad Medical Complex, Peshawar, Pakistan from 1st April, 2022 to 30th September, 2022. Total 160 diabetic patients between the age of 30 and 65 years were enrolled in the study. Type-2 diabetic patients with microalbuminuria between 2.5 and 30 mg/mmol were included. The demographic details of patients were recorded in the questionnaire after taking consent. Fasting Uric acid, lipid profile and glucose along with creatinine and HbA1C were estimated from patient's venous blood samples. Ratio of albumin to creatinine (ACR) in the random spot urine sample was used to detect microalbuminuria.

Results

Out of 160 participants enrolled in the study there were 86 (54%) males and 74 (46%) females with the mean age of 50.15 ± 11.1 years and BMI of 20.93 kg/m2. Ninety six (60%) of the patients had Type-2 DM for less than five years, while remaining 64 (40%) were more than five years diabetic. Mean serum uric acid calculated was 6.85±2.06(mg/dl), while microalbuminuria was calculated as 8.02±0.78 (mg/mmol). The Pearson correlation of serum uric acid and microalbuminuria based on sex and age was statistically significant(p<0.05).

Conclusion

We found that uric acid level was significantly associated with microalbuminuria in people with Type-2 diabetes with normal serum creatinine. Uric acid level can be a potential screening tool for early detection of DKD.

Priestia megaterium ASC-1 Isolated from Pickled Cabbage Ameliorates Hyperuricemia by Degrading Uric Acid in Rats

Pickled cabbage, a traditional fermented food rich in functional microorganisms, can effectively control hyperuricemia and gout. In this study, a Priestia megaterium ASC-1 strain with strong uric acid (UA) degradation ability was isolated from pickled cabbage. After oral administration for 15 days, ASC-1 was stably colonized in the rats in this study. ASC-1 significantly reduced UA levels (67.24%) in hyperuricemic rats. Additionally, ASC-1 alleviated hyperuricemia-related inflammatory response, oxidative stress, and blood urea nitrogen. Intestinal microbial diversity results showed that ASC-1 restored intestinal injury and gut flora dysbiosis caused by hyperuricemia. These findings suggest that P. megaterium ASC-1 may be used as a therapeutic adjuvant for the treatment of hyperuricemia.

Resveratrol Improves Hyperuricemia and Ameliorates Renal Injury by Modulating the Gut Microbiota

Resveratrol (RES) has been reported to prevent hyperuricemia (HUA); however, its effect on intestinal uric acid metabolism remains unclear. This study evaluated the impact of RES on intestinal uric acid metabolism in mice with HUA induced by a high-fat diet (HFD). Moreover, we revealed the underlying mechanism through metagenomics, fecal microbiota transplantation (FMT), and 16S ribosomal RNA analysis. We demonstrated that RES reduced the serum uric acid, creatinine, urea nitrogen, and urinary protein levels, and improved the glomerular atrophy, unclear renal tubule structure, fibrosis, and renal inflammation. The results also showed that RES increased intestinal uric acid degradation. RES significantly changed the intestinal flora composition of HFD-fed mice by enriching the beneficial bacteria that degrade uric acid, reducing harmful bacteria that promote inflammation, and improving microbial function via the upregulation of purine metabolism. The FMT results further showed that the intestinal microbiota is essential for the effect of RES on HUA, and that Lactobacillus may play a key role in this process. The present study demonstrated that RES alleviates HFD-induced HUA and renal injury by regulating the gut microbiota composition and the metabolism of uric acid.

Renal interstitial fibrotic assessment using non-Gaussian diffusion kurtosis imaging in a rat model of hyperuricemia

BACKGROUND

To investigate the feasibility of Diffusion Kurtosis Imaging (DKI) in assessing renal interstitial fibrosis induced by hyperuricemia.

METHODS

A hyperuricemia rat model was established, and the rats were randomly split into the hyperuricemia (HUA), allopurinol (AP), and AP + empagliflozin (AP + EM) groups (n = 19 per group). Also, the normal rats were selected as controls (CON, n = 19). DKI was performed before treatment (baseline) and on days 1, 3, 5, 7, and 9 days after treatment. The DKI indicators, including mean kurtosis (MK), fractional anisotropy (FA), and mean diffusivity (MD) of the cortex (CO), outer stripe of the outer medulla (OS), and inner stripe of the outer medulla (IS) were acquired. Additionally, hematoxylin and eosin (H&E) staining, Masson trichrome staining, and nuclear factor kappa B (NF-κB) immunostaining were used to reveal renal histopathological changes at baseline, 1, 5, and 9 days after treatment.

RESULTS

The HUA, AP, and AP + EM group MKOS and MKIS values gradually increased during this study. The HUA group exhibited the highest MK value in outer medulla. Except for the CON group, all the groups showed a decreasing trend in the FA and MD values of outer medulla. The HUA group exhibited the lowest FA and MD values. The MKOS and MKIS values were positively correlated with Masson's trichrome staining results (r = 0.687, P < 0.001 and r = 0.604, P = 0.001, respectively). The MDOS and FAIS were negatively correlated with Masson's trichrome staining (r = -626, P < 0.0014 and r = -0.468, P = 0.01, respectively).

CONCLUSION

DKI may be a non-invasive method for monitoring renal interstitial fibrosis induced by hyperuricemia.

Urate-lowering therapy is associated with a reduced risk of arrhythmias: a systematic review and meta-analysis

Objective

While urate-lowering therapy (ULT) is linked to increased cardioprotective benefits on primary prevention of cardiovascular events such myocardial infarction or heart failure, little is known regarding their effects on arrhythmia risk. The purpose of this study was to investigate the relationship between incident arrhythmias and ULT.

Methods

We searched MEDLINE and Embase from inception to May 2023. Included studies were randomized controlled trials and cohort studies that compared the risk of cardiac arrhythmias among ULT users with non-ULT users.

Results

A total of 12,420 patients from five studies were analyzed, comprising 7,359 subjects in the ULT group and 5,061 subjects in the non-ULT group. Our results showed that ULT users had significant reductions in the risk of arrhythmias (pooled relative risk [RR] 0.82, 95% confidence interval [CI] 0.74~0.92, p<0.001, I2=0.0%) compared to non-ULT users. Subgroup analysis did not show that ULT users had a significant reduced risk of atrial fibrillation (pooled RR 0.76, 95% CI 0.54~1.05, p=0.096 with I2=15.4%) compared to non-ULT users.

Conclusion

ULT is associated with lower risk of overall arrhythmias. Further studies are warranted to confirm our findings.

Hyperuricemia as an independent risk factor for achilles tendon rupture in male: a case-control study

OBJECTIVE

To study the correlation between achilles tendon rupture (ATR) and hyperuricemia, also verify the known risk factors for ATR.

METHODS

A retrospective review of 488 subjects was performed (182 with Achilles tendon rupture, 306 controls with ankle sprains). Demographic variables and risk factors for rupture were tabulated and compared. The baseline data and related indicators were compared, and the risk factors of ATR were analyzed by constructing a binary logistic regression model.

RESULTS

Univariate logistic analysis showed that BMI, smoking, and hyperuricemia were risk factors for the development of ATR (OR = 1.65, 95%CI 1.13-2.42, P = 0.01; OR = 1.47, 95%CI 1.00-2.24, P < 0.05; OR = 2.85, 95%CI 1.84-4.42, P < 0.01). Multifactorial analysis showed that BMI ≥ 25 kg/m2, smoking, and hyperuricemia were independent risk factors for the development of ATR (OR = 1.66, 95%CI 1.11-2.49, P = 0.01; OR = 2.15, 95%CI 1.28-3.60, P < 0.01; OR = 3.06, 95%CI 1.92-4.89, P < 0.01). Among the blood biochemical indicators, total cholesterol (TC) and uric acid (UA) were independent risk factors for the occurrence of ATR (OR = 1.54, 95% CI 1.12-2.12, P = 0.01; OR = 1.01, 95% CI 1.01-1.01, P < 0.01).

CONCLUSION

Our study confirmed that, as in previous results, higher BMI, smoking, and total cholesterol are risk factors for ATR, Hyperuricemia may contribute to the development of ATR, and adjunctive tests for TC and UA in the blood biochemistry may be helpful in predicting the risk of ATR.

Interaction between anemia and hyperuricemia in the risk of all-cause mortality in patients with chronic kidney disease

Aim

Both hyperuricemia and anemia are not only the manifestation of chronic kidney disease (CKD) but also related to its occurrence and development. A recent study has found that there was a synergetic effect between hyperuricemia and anemia on new-onset CKD. Herein we aimed to explore the roles of hyperuricemia and anemia in the all-cause mortality in patients with CKD.

Methods

Data of adult patients with CKD were extracted from the National Health and Nutrition Examination Surveys (NHANES) database in 2009-2018 in this retrospective cohort study. Weighted univariate and multivariate COX regression analyses were used to investigate the associations of hyperuricemia and anemia with all-cause mortality, and the evaluation indexes were hazard ratios (HRs) and 95% confidence intervals (CIs). The interaction effect between hyperuricemia and anemia on the risk of all-cause mortality was assessed via relative excess risk due to interaction (RERI) and attributable proportion of interaction (AP). Subgroup analyses of age, gender, CVD, hypertension, DM, and cancer were also performed to assess this interaction effect.

Results

Among 3,678 eligible patients, 819 died from all causes. After adjusting for covariables, we found that CKD patients with anemia (HR = 1.72, 95%CI: 1.42-2.09) or hyperuricemia (HR = 1.21, 95%CI: 1.01-11.45) had a higher risk of all-cause mortality. There was a potential synergetic effect between anemia and hyperuricemia on all-cause mortality, with RERI of 0.630 and AP of 0.291. Moreover, this synergetic effect was also observed in ≥65 years old (AP = 0.330), male (AP = 0.355), hypertension (AP = 0.736), non-hypertension (AP = 0.281), DM (AP = 0.371), and cancer (AP = 0.391) subgroups.

Conclusion

A potential synergetic effect between anemia and hyperuricemia on all-cause mortality was found in patients with CKD. However, further studies are needed to clarify the causal relationship between them.

Clinical and histopathological characteristics of primary focal segmental glomerulosclerosis in Turkish adults

The data regarding primary FSGS (pFSGS) from different parts of the world differ. While the prevalence of pFSGS has been increasing in Western countries like the USA, it follows an inconsistent trend in Europe and Asia and a decreasing trend in Far Eastern countries such as China in the last two decades. There are undetermined factors to explain those national and geographic discrepancies. Herein, we aimed to reveal the current prevalence with clinical and histopathological characteristics of pFSGS in Turkish adults. This study includes the biopsy-proven pFSGS patients data recorded between 2009 and 2019, obtained from the national multicenter primary glomerulonephritis registry system of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) database. 850 of the 3875 primer glomerulonephritis patients(21.9%) have pFSGS. The mean age is 40.5 ± 14.2 and 435 (51.2%) of patients are male. Nephrotic syndrome is the most common biopsy indication (59.2%). 32.6% of patients have hematuria, 15.2% have leukocyturia and 7.8% have both. Serum creatinine, albumin, and proteinuria are 1.0 mg/dL (IQR = 0.7-1.4) mg/dl, 3.4 ± 0.9 g/dl, 3400 mg/day(IQR, 1774-5740), respectively. Females have lower mean arterial pressure (- 2.2 mmHg), higher eGFR (+ 10.0 mL/min/1.73 m2), and BMI (+ 1.6 kg/m2) than males. Thickened basal membrane(76.6%) and mesangial proliferation (53.5%) on light microscopy are the major findings after segmental sclerosis. IgM (32.7%) and C3 (32.9%) depositions are the most common findings on immunofluorescence microscopy. IgM positivity is related to lower eGFR, serum albumin, and higher proteinuria. The prevalence of pFSGS is stable although slightly increasing in Turkish adults. The characteristics of the patients are similar to those seen in Western countries.

Relationship between hyperuricemia and the risk of cardiovascular events and chronic kidney disease in both the general population and hypertensive patients: A systematic review and meta-analysis

BACKGROUND

To explore the relationships between hyperuricemia and the risk of cardiovascular diseases (CVD) and chronic kidney disease (CKD) in both the general population and hypertensive patients through meta-analysis.

METHODS AND RESULTS

We systematically searched PubMed, Embase, and Cochrane Library databases from January 2012. The eligibility criteria were predefined, and quality was assessed using the Newcastle-Ottawa Scale (NOS). Stata 15.1 was used for meta-analysis, heterogeneity and sensitivity analysis. Subgroup analysis was used to explore heterogeneity, funnel plots and Egger tests were used to assesse publication bias and applicability. A total of 10,662 studies were retrieved, 45 of which were included in this meta-analysis utilizing a random effects model. Hyperuricemia was significantly associated with an increased risk of new-onset hypertension (RR = 1.36, 95% CI 1.16-1.59; I2 = 98.8%), total CVD (RR = 1.53, 95% CI 1.23-1.89; I2 = 93.7%), stroke (RR = 1.97, 95% CI 1.71-2.26, I2 = 0.0%), coronary heart disease (CHD) (RR = 1.56, 95% CI 1.06-2.30, I2 = 93.3%), and CKD (RR = 1.71, 95% CI 1.56-1.87; I2 = 87.3%). However, subgroup analysis showed no significant associations between hyperuricemia and hypertension in non-Asian populations (RR = 0.88, 95% CI 0.59-1.33), or between hyperuricemia and CVD with a follow-up duration <5 years (RR = 1.26, 95% CI 0.97-1.63). Among hypertensive patients, hyperuricemia was significantly associated with total CVD (RR = 2.32, 95% CI 1.31-4.12, I2 = 90.2%), but not with stroke (RR = 1.48, 95% CI 0.86-2.55; I2 = 90.7%) or CHD (RR = 1.51, 95% CI 0.98-2.33; I2 = 71.7%).

CONCLUSION

Hyperuricemia was significantly associated with an increased risk of new-onset hypertension, total CVD, stroke, CHD, and CKD in the general population. Among hypertensive patients, hyperuricemia was associated with an increased risk of CVD but not stroke or CHD alone.

REGISTRATION NUMBER

CRD42022370692.

Relationship of single and co-exposure of per-and polyfluoroalkyl substances and their alternatives with uric acid: A community-based study in China

Numerous studies have suggested per-and polyfluoroalkyl substances (PFASs) are related to uric acid levels, but evidence related to PFAS alternatives is limited. Moreover, the effect of the combined exposure to PFASs and their alternatives on uric acid has not been reported. Hence, we conducted a cross-sectional study involving 1312 adults in Guangzhou, China. Generalized linear regression model was adopted to explore the effect of single PFAS exposure on serum uric acid levels. Further, multi-pollutant models such as Bayesian kernel machine regression, weighted quantile sum, and quantile G-computation were employed to investigate the combined association of PFASs and alternatives with serum uric acid levels. We performed molecular docking to understand the potential interaction of PFAS with Organic Anion Transporters (OATs), involved in the secretion of uric acid. Per log serum 6:2 Cl-PFESA and PFOA increases were accompanied with an increase of serum uric acid with statistical significance (for 6:2 Cl-PFESA: beta: 0.19 ng/mL, 95% CI 0.11-0.26 and for PFOA: beta: 0.43 ng/mL, 95% CI 0.34-0.52). The associations were strongest among overweight and elderly. Multi-pollutant models also revealed a positive association. These positive associations may be PFASs can competitively combine with OAT1 and OAT3, leading to the increase of serum uric acid.

Alistipes indistinctus-derived hippuric acid promotes intestinal urate excretion to alleviate hyperuricemia

Hyperuricemia induces inflammatory arthritis and accelerates the progression of renal and cardiovascular diseases. Gut microbiota has been linked to the development of hyperuricemia through unclear mechanisms. Here, we show that the abundance and centrality of Alistipes indistinctus are depleted in subjects with hyperuricemia. Integrative metagenomic and metabolomic analysis identified hippuric acid as the key microbial effector that mediates the uric-acid-lowering effect of A. indistinctus. Mechanistically, A. indistinctus-derived hippuric acid enhances the binding of peroxisome-proliferator-activated receptor γ (PPARγ) to the promoter of ATP-binding cassette subfamily G member 2 (ABCG2), which in turn boosts intestinal urate excretion. To facilitate this enhanced excretion, hippuric acid also promotes ABCG2 localization to the brush border membranes in a PDZ-domain-containing 1 (PDZK1)-dependent manner. These findings indicate that A. indistinctus and hippuric acid promote intestinal urate excretion and offer insights into microbiota-host crosstalk in the maintenance of uric acid homeostasis.

Association between anthropometric indices and hyperuricemia: a nationwide study in China

This article explored the relationship between anthropometric indices and hyperuricemia in Chinese adults. The ability of each anthropometric index to predict hyperuricemia was also compared in this article. This is a cross-sectional study containing 69,842 samples from 31 provinces and cities in China. Anthropometric indices included body mass index (BMI), waist circumference (WC), a body shape index (ABSI), body roundness index (BRI), waist-to-height ratio (WHtR), lipid accumulation product (LAP), visceral adiposity index (VAI), triglyceride-glucose index (TyG), waist circumference-triglyceride index (WTI), and weight-adjusted waist index (WWI). The survey data obtained were disaggregated and analyzed according to sex and age. BMI, WC, BRI, WHtR, LAP, VAI, TyG, WTI, and WWI were all significantly associated with hyperuricemia (P < 0.001). In the total population, WTI (AUC 0.7015, P < 0.001) had the highest predictive power, and WWI (AUC 0.5417, P < 0.001) had the lowest. In addition, after dividing the male and female populations, LAP (AUC 0.6571, P < 0.001 for men; AUC 0.7326, P < 0.001 for women) had the highest predictive power among both men and women. The ABSI (AUC 0.5189, P < 0.001 for men; AUC 0.5788, P < 0.001 for women) had the lowest predictive power among both men and women. BMI, WC, BRI, WHtR, LAP, VAI, TyG, and WTI were positively correlated with the risk of hyperuricemia and serum uric acid concentrations in both sexes. Among the general population, WTI had the highest predictive power. After dividing the population by sex, LAP had the highest predictive power in both men and women. Key Points • Anthropometric indices are highly correlated with hyperuricemia. Waist circumference-triglyceride index (WTI) is first found to be associated with hyperuricemia, and it has high predictive power. • The predictive power of anthropometric indices for hyperuricemia is more useful in women. • The restricted cubic splines visually shows the ratio of anthropometric indices to hyperuricemia ratio and the patient's serum uric acid concentration.

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

Introduction

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

Methods

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

Results

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

Conclusion

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

Inhibition mechanism of cordycepin and ergosterol from Cordyceps militaris Link. against xanthine oxidase and cyclooxygenase-2

Cordyceps militaris Link. (C. militaris) is an entomopathogenic fungus that parasitizes the pupa or cocoon of lepidopteran insect larvae, with various bioactive compounds. Cordycepin and ergosterol are the two active components in C. militaris. This study aimed to evaluate the inhibitory activity of cordycepin and ergosterol against xanthine oxidase (XO) and cyclooxygenase-2 (COX-2), as well as investigate the inhibition mechanism. Cordycepin could better inhibit XO (IC50 = 0.014 mg/mL) and COX-2 (IC50 = 0.055 mg/mL) than ergosterol. Additionally, surface hydrophobicity and circular dichroism (CD) spectra results confirmed the conformational changes in enzymes induced by cordycepin and ergosterol. Finally, cordycepin and ergosterol significantly decreased uric acid (UA) and inflammatory factors to normal level in mice with gouty nephropathy (GN). This study could provide theoretical evidence for utilization of C. militaris in hyperuricemia-management functional foods.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Core-shell structured microneedles with programmed drug release functions for prolonged hyperuricemia management

An appropriate non-oral platform via transdermal delivery of drugs is highly recommended for the treatment of hyperuricemia. Herein, a core-shell structured microneedle patch with programmed drug release functions was designed to regulate serum uric acid (SUA) levels for prolonged hyperuricemia management. The patch was fabricated using a three-step casting method. Allopurinol (AP), an anti-hyperuricemic drug, was encapsulated within the carboxymethyl cellulose (CMC) layer, forming the "shell" of the MNs. The MN's inner core was composed of polyvinylpyrrolidone (PVP) loaded with urate oxidase-calcium peroxide nanoparticles (UOx-CaO2 NPs). When the as-fabricated core-shell structured microneedles were inserted into the skin, the loaded AP was first released immediately to effectively inhibit the production of SUA due to the water solubility of CMC. Subsequently, the internal SUA was further metabolized by UOx, leading to exposure of CaO2 NPs. The sustained release of UOx accompanied by the decomposition of CaO2 NPs contributed to maintaining a state of normal uric acid levels over an extended period. More attractively, uric acid could be oxidized due to the strong oxidant of CaO2, which was beneficial to the continuous consumption of uric acid. In vivo results showed that the as-fabricated MNs exhibited an excellent anti-hyperuricemia effect to reduce SUA levels to the normal state within 3 h and maintain the normouricemia state for 12 h. In addition, the levels of creatinine (Cr) and blood urea nitrogen (BUN) in the serum remained within the normal range, and the activities of adenosine deaminase (ADA) and xanthine oxidase (XOD) in the liver were effectively inhabited, mitigating the risk of liver and kidney damage for clinical anti-hyperuricemia management.

Using intravoxel incoherent motion imaging to evaluate uric acid-induced renal injury and efficacy after treatment

OBJECTIVES

To validate the feasibility of intravoxel incoherent motion imaging (IVIM) for monitoring renal injury and uric acid-lowering efficacy in a rat model of hyperuricaemia.

METHODS

A total of 92 rats were analysed and categorized into 4 groups: control (CON), hyperuricaemia (HUA), allopurinol intervention (ALL), and combined intervention (COM). Eight rats were randomly selected from each group and underwent IVIM scanning on days 0, 1, 3, 5, 7, and 9. Quantitative magnetic resonance values (D, D*, and f values) measured from the different renal anatomical regions. Quantitative histopathological analysis was performed to assess renal tubular injury using neutrophil gelatinase-associated lipocalin (NGAL), and renal fibrosis using alpha-smooth-muscle-actin (α-SMA). Pearson's correlation analysis was used to determine the correlation between IVIM-derived parameters and the expression of NGAL and α-SMA.

RESULTS

The D values of the HUA, ALL, and COM groups generally showed a downward trend over time, and this fluctuation was most significant in the HUA group. The D values showed significant intergroup differences at each point, whereas only a few discrepancies were found in the D* and f values. In addition, the renal D value was negatively correlated with the positive staining rates for NGAL and α-SMA (P < .05), except for the lack of correlation between Dos and α-SMA (P > .05).

CONCLUSION

IVIM could be a noninvasive and potential assessment modality for the evaluation of renal injury induced by hyperuricaemia and its prognostic efficacy.

ADVANCES IN KNOWLEDGE

IVIM could be a surrogate manner in monitoring renal damage induced by hyperuricaemia and its treatment evaluation.

Consistency between self-reported disease diagnosis and clinical assessment and under-reporting for chronic conditions: data from a community-based study in Xi'an, China

Aims

The current study aims to investigate the consistency between the surveyees' self-reported disease diagnosis and clinical assessment of eight major chronic conditions using community-based survey data collected in Xi'an, China in 2017. With a focus on under-reporting patients, we aim to explore its magnitude and associated factors, to provide an important basis for disease surveillance, health assessment and resource allocation, and public health decision-making and services.

Methods

Questionnaires were administered to collect self-reported chronic condition prevalence among the study participants, while physical examinations and laboratory tests were conducted for clinical assessment. For each of the eight chronic conditions, the sensitivity, specificity, under-reporting, over-reporting, and agreement were calculated. Log-binomial regression analysis was employed to identify potential factors that may influence the consistency of chronic condition reporting.

Results

A total of 2,272 participants were included in the analysis. Four out of the eight chronic conditions displayed under-reporting exceeding 50%. The highest under-reporting was observed for goiter [85.93, 95% confidence interval (CI): 85.25-86.62%], hyperuricemia (83.94, 95% CI: 83.22-84.66%), and thyroid nodules (72.89, 95% CI: 72.02-73.76%). Log-binomial regression analysis indicated that senior age and high BMI were potential factors associated with the under-reporting of chronic condition status in the study population.

Conclusion

The self-reported disease diagnosis by respondents and clinical assessment data exhibit significant inconsistency for all eight chronic conditions. Large proportions of patients with multiple chronic conditions were under-reported in Xi'an, China. Combining relevant potential factors, targeted health screenings for high-risk populations might be an effective method for identifying under-reporting patients.

Establishment and evaluation of a nomogram prediction model for the risk of vascular calcification in stage 5 chronic kidney disease patients

Vascular calcification (VC) is a common complication of chronic kidney disease (CKD) that has a detrimental effect on patients' survival and prognosis. The aim of this study was to develop and validate a practical and reliable prediction model for VC in CKD5 patients. The medical records of 544 CKD5 patients were reviewed retrospectively. Multivariate logistic regression analysis was used to identify the independent risk factors for vascular calcification in patients with CKD5 and then created a nomogram prediction model. The area under the receiver operating characteristic curve (AUC), Hosmer-Lemeshow test, and decision curve analysis (DCA) were used to assess model performance. The patients were split into groups with normal and high serum uric acid levels, and the factors influencing these levels were investigated. Age, BUN, SUA, P and TG were independent risk factors for vascular calcification in CKD5 patients in the modeling group (P < 0.05). In the internal validation, the results of model showed that the AUC was 0.917. No significant divergence between the predicted probability of the nomogram and the actual incidence rate (x2 = 5.406, P = 0.753) was revealed by the calibration plot and HL test, thus confirming that the calibration was satisfactory. The external validation also showed good discrimination (AUC = 0.973). The calibration chart and HL test also demonstrated good consistency. Besides, the correlation analysis of serum uric acid levels in all CKD5 patients revealed that elevated uric acid levels may be related to gender, BUN, P, and TG.

Longitudinal changes in high sensitivity C-reactive protein associated with serum uric acid in the Korean Genome and Epidemiology Study

Cross-sectional studies support the role of serum uric acid (SUA) in inflammation, but evidence from cohort studies is scarce. Longitudinal associations between SUA and high-sensitivity C-reactive protein (hs-CRP) were examined in the general population. Data for participants from the Health Examinees-Gem cohort (n = 50,028; 40-69 years; 67% women) who were examined between 2004 and 2013 and followed up until 2016 were analyzed. SUA and hs-CRP were measured at baseline and during follow-up. SUA was evaluated as a continuous variable and was also divided into sex-specific quartiles. Mean hs-CRP levels at follow-up were evaluated using multivariable proportional odds regression, with non-linear smoothed baseline hs-CRP levels serving as a covariate. Selected pathological markers were also examined in relation to hs-CRP. Increased levels of SUA at baseline were related to increased levels of hs-CRP at follow-up [regression coefficient per mg/dL increase in baseline SUA (β) = 0.08, 95% confidence interval (CI), 0.040-0.128]. A dose-response relationship was observed, (P for linear trend = 0.0015). The mean values of hs-CRP were highest among participants with the highest follow-up but lowest baseline SUA levels. Elevated hs-CRP levels at follow up (> 3 mg/L) were positively related to fasting blood glucose levels, triglycerides levels, liver enzymes, and blood pressure, but negatively related to high density lipoprotein cholesterol levels per unit increase in baseline hs-CRP. High SUA levels were associated with high hs-CRP levels, suggesting a potential role of SUA in inflammation. However, additional research is needed to confirm these findings.

Use of rasburicase to improve kidney function in children with hyperuricemia and acute kidney injury

BACKGROUND

Hyperuricemia contributes to decrease in kidney function and induces additional renal damage in children with acute kidney injury (AKI). Rasburicase oxidizes uric acid (UA), decreasing its serum quantities in less than 24 h.

METHODS

This is a retrospective study involving hospitalized patients under 18 years of age with underlying pathology diagnosed with AKI and severe hyperuricemia treated with rasburicase over a 4-year period.

RESULTS

We describe 15 patients from 4 days of life to 18 years (median: 4.4 years). Seventy-three percent had known underlying pathologies. All presented worsening of basal renal function or AKI data. All received the usual medical treatment for AKI without response. Twenty percent received an extrarenal depuration technique. All had hyperuricemia with a mean (± SD) of 13.1 (± 2.19) mg/dl. After rasburicase administration UA levels fell to a mean (± SD) of 0.76 (± 0.62) mg/dl (p < 0.001) in less than 24 h. In parallel, a decrease in the mean plasma creatinine was observed (2.92 mg/dl to 1.93 mg/dl (p = 0.057)) together with a significant improvement of the mean glomerular filtration rate (16.3 ml/min/1.73 m2 to 78.6 ml/min/1.73 m2) (p = 0.001)). No side effects were recorded. Kidney function normalized in all cases or returned to baseline levels.

CONCLUSIONS

Although the use of rasburicase is not routinely approved in pediatric patients with severe hyperuricemia and AKI, it has been used successfully without complications, and helped prevent progressive kidney damage. This study could serve as a basis for suggesting the off-label use of rasburicase for the management of complex pediatric patients in whom UA plays an important role in the development of AKI.

Xanthine Oxidoreductase in the Pathogenesis of Endothelial Dysfunction: An Update

Xanthine oxidoreductase (XOR) is a rate-limiting enzyme in the formation of uric acid (UA) and is involved in the generation of reactive oxygen species (ROS). Overproduction of ROS has been linked to the pathogenesis of hypertension, atherosclerosis, and cardiovascular disease, with multiple studies over the last 30 years demonstrating that XOR inhibition is beneficial. The involvement of XOR and its constituents in the advancement of chronic inflammation and ROS, which are responsible for endothelial dysfunction, is the focus of this evidence-based review. An overabundance of XOR products and ROS appears to drive the inflammatory response, resulting in significant endothelium damage. It has also been demonstrated that XOR activity and ED are connected. Diabetes, hypertension, and cardiovascular disease are all associated with endothelial dysfunction. ROS mainly modifies the activity of vascular cells and can be important in normal vascular physiology as well as the development of vascular disease. Suppressing XOR activity appears to decrease endothelial dysfunction, probably because it lessens the generation of reactive oxygen species and the oxidative stress brought on by XOR. Although there has long been a link between higher vascular XOR activity and worse clinical outcomes, new research suggests a different picture in which positive results are mediated by XOR enzymatic activity. Here in this study, we aimed to review the association between XOR and vascular endothelial dysfunction. The prevention and treatment approaches against vascular endothelial dysfunction in atherosclerotic disease.

In vivo comprehensive metabolite profiling of esculetin and esculin derived from chicory in hyperuricemia rats using ultra-high-performance liquid chromatography coupled with quadrupole-orbitrap high-resolution mass spectrometry

Chicory, renowned for its multifaceted benefits, houses two vital coumarins, esculetin and esculin, both instrumental in reducing uric acid. This study emphasizes the metabolic pathways of esculetin and esculin under both standard and hyperuricemia conditions. Hyperuricemia was induced in Sprague-Dawley rats using oxonic acid potassium salt (300 mg·kg-1 ) and a 10% fructose water regimen over 21 days. Leveraging the ultra-high-performance liquid chromatography-Q Exactive hybrid quadrupole-orbitrap high resolution mass spectrometry, we analyzed the fragmentation behaviors of esculetin and esculin in rat bio-samples. Post oral-intake of esculetin or esculin, a notable dip in serum uric acid levels was observed in hyperuricemia rats. The investigation unveiled 24 esculetin metabolites and 14 for esculin. The metabolic pathways of both compounds were hydrolysis, hydroxylation, hydrogenation, dehydroxylation, glucuronidation, sulfation, and methylation. Interestingly, certain metabolites presented variations between standard and hyperuricemia rats, indicating that elevated levels of uric acid may affect enzyme activity linked to these metabolic reactions. This is the first systematic study on comparison of metabolic profiles of esculetin and esculin in both normal and hyperuricemia states, which was helpful to enrich our understanding of the complicated structure-activity relationships between esculin and esculetin and shed light to their action mechanism.

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

OBJECTIVES

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

METHOD

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

RESULT

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

CONCLUSION

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

Target Screen of Anti-Hyperuricemia Compounds from Cortex Fraxini In Vivo Based on ABCG2 and Bioaffinity Ultrafiltration Mass Spectrometry

The ATP-binding cassette (ABC) transporter ABCG2 is a significant urate transporter with a high capacity, and it plays a crucial role in the development of hyperuricemia and gout. Therefore, it has the potential to be targeted for therapeutic interventions. Cortex Fraxini, a traditional Chinese medicine (TCM), has been found to possess anti-hyperuricemia properties. However, the specific constituents of Cortex Fraxini responsible for this effect are still unknown, particularly the compound that is responsible for reducing uric acid levels in vivo. In this study, we propose a target screening protocol utilizing bio-affinity ultrafiltration mass spectrometry (BA-UF-MS) to expediently ascertain ABCG2 ligands from the plasma of rats administered with Cortex Fraxini. Our screening protocol successfully identified fraxin as a potential ligand that interacts with ABCG2 when it functions as the target protein. Subsequent investigations substantiated fraxin as an activated ligand of ABCG2. These findings imply that fraxin exhibits promise as a drug candidate for the treatment of hyperuricemia. Furthermore, the utilization of BA-UF-MS demonstrates its efficacy as a valuable methodology for identifying hit compounds that exhibit binding affinity towards ABCG2 within TCMs.

[Retrospective Analysis of the Effect of Uric Acid on the Prognosis of Immunoglobulin A Nephropathy With Stage 3-4 Chronic Kidney Disease]

Objective

To investigate the effect of uric acid on the clinicopathological characteristics and prognosis of immunoglobulin A nephropathy (IgAN) in patients with stage 3-4 chronic kidney disease (CKD).

Methods

The clinical and pathological data of 263 IgAN patients who had stage 3-4 CKD and who had confrimed diagosis through renal biopsy at the First Affiliated Hospital of Air Force Medical University between December 2008 and January 2020 were retrospectively collected. According to the levels of uric acid, the patients were divided into a hyperuricemia group (n=102) and a normal uric acid group (n=161), and the clinicopathological characteristics of the two groups were compared accordingly. With progression to end-stage renal disease or death as the endpoint event, the renal survival rate of the two groups was compared by the Kaplan-Meier method and the relationship between uric acid and the prognosis was analyzed by Cox regression and LASSO regression.

Results

Compared with the normal uric acid group, the hyperuricemia group had a significantly higher proportion of male patients and patients with a history of hypertension, a significantly higher level of blood urea nitrogen, and lower levels of estimated glomerular filtration rate and high-density lipoprotein. In terms of pathology, patients in the hyperuricemia group had significantly higher proportion of glomerulosclerosis, higher mesangial hypercellularity, and higher tubular atrophy/interstitial fibrosis (P<0.05). Kaplan-Meier curve showed that there was a significant difference in renal survival rate between the two groups (P<0.0001). LASSO regression showed that high uric acid was a risk factor for the prognosis of IgAN patients with stage 3-4 CKD. Further multivariate Cox analysis showed that, compared with the normal uric acid group, the hyperuricemia group had a higher risk of incurring composite outcomes (hazard ratio [HR]=1.61, 95% confidence interval [CI]: 1.10-2.34). When uric acid was used as a continuous variable, the increase of 1 mg/dL in uric acid concentration was associated with an increased HR of 1.18 (95% CI: 1.08-1.29) for the composite outcome.

Conclusion

High uric acid is a risk factor for poor renal prognosis in IgAN patients with stage 3-4 CKD and reducing uric acid levels may effectively improve the prognosis of high-risk IgAN patients.

Agents for the Treatment of Gout: Current Advances and Future Perspectives

Gout is characterized by hyperuricemia and the deposition of monosodium urate (MSU) crystals around joints. Despite the availability of several drugs on the market, its treatment remains challenging owing to the notable side effects, such as hepatorenal toxicity and cardiovascular complications, that are associated with most existing agents. This perspective aims to summarize the current research progress in the development of antigout agents, particularly focusing on xanthine oxidase (XO) and urate anion transporter 1 (URAT1) inhibitors from a medicinal chemistry viewpoint and their preliminary structure-activity relationships (SARs). This perspective provides valuable insights and theoretical guidance to medicinal chemists for the discovery of antigout agents with novel chemical structures, better efficiency, and lower toxicity.

Coinfection with Schistosoma mansoni Enhances Disease Severity in Human African Trypanosomiasis

Introduction

Human African trypanosomiasis (HAT) and schistosomiasis are neglected parasitic diseases found in the African continent. This study was conducted to determine how primary infection with Schistosoma mansoni affects HAT disease progression with a secondary infection with Trypanosoma brucei rhodesiense (T.b.r) in a mouse model.

Methods

Female BALB-c mice (6-8 weeks old) were randomly divided into four groups of 12 mice each. The different groups were infected with Schistosoma mansoni (100 cercariae) and Trypanosoma brucei rhodesiense (5.0 × 104) separately or together. Twenty-one days after infection with T.b.r, mice were sacrificed and samples were collected for analysis.

Results

The primary infection with S. mansoni significantly enhanced successive infection by the T.b.r; consequently, promoting HAT disease severity and curtailing host survival time. T.b.r-induced impairment of the neurological integrity and breach of the blood-brain barrier were markedly pronounced on coinfection with S. mansoni. Coinfection with S. mansoni and T.b.r resulted in microcytic hypochromic anemia characterized by the suppression of RBCs, hematocrit, hemoglobin, and red cell indices. Moreover, coinfection of the mice with the two parasites resulted in leukocytosis which was accompanied by the elevation of basophils, neutrophils, lymphocytes, monocytes, and eosinophils. More importantly, coinfection resulted in a significant elevation of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin, creatinine, urea, and uric acid, which are the markers of liver and kidney damage. Meanwhile, S. mansoni-driven dyslipidemia was significantly enhanced by the coinfection of mice with T.b.r. Moreover, coinfection with S. mansoni and T.b.r led to a strong immune response characterized by a significant increase in serum TNF-α and IFN-γ. T.b.r infection enhanced S. mansoni-induced depletion of cellular-reduced glutathione (GSH) in the brain and liver tissues, indicative of lethal oxidative damage. Similarly, coinfection resulted in a significant rise in nitric oxide (NO) and malondialdehyde (MDA) levels.

Conclusion

Primary infection with S. mansoni exacerbates disease severity of secondary infection with T.b.r in a mouse model that is associated with harmful inflammatory response, oxidative stress, and organ injury.