Hyperuricemia, the heart, and the kidneys - to treat or not to treat?

Pro-inflammatory diets promote the formation of hyperuricemia

Background

Hyperuricemia, as a very prevalent chronic metabolic disease with increasing prevalence year by year, poses a significant burden on individual patients as well as on the global health care and disease burden, and there is growing evidence that it is associated with other underlying diseases such as hypertension and cardiovascular disease. The association between hyperuricemia and dietary inflammatory index (DII) scores was investigated in this study.

Methods

This study enrolled 13, 040 adult subjects (aged ≥ 20 years) from the US National Health and Nutrition Survey from 2003 to 2018. The inflammatory potential of the diet was assessed by the DII score, and logistic regression was performed to evaluate the relationship between the DII score and the development of hyperuricemia; subgroup analyses were used to discuss the influence of other factors on the relationship.

Results

Participants in the other quartiles had an increased risk of hyperuricemia compared to those in the lowest quartile of DII scores. Stratification analyses stratified by body mass index (BMI), sex, hypertension, drinking, diabetes, education level and albumin-creatinine-ratio (ACR) revealed that the DII score was also associated with the risk of hyperuricemia (P<0.05). There was an interaction in subgroup analysis stratified by sex, age, and hypertension (P for interaction <0.05). The results showed a linear-like relationship between DII and hyperuricemia, with a relatively low risk of developing hyperuricemia at lower DII scores and an increased risk of developing hyperuricemia as DII scores increased.

Conclusions

This study showed that the risk of hyperuricemia increased at slightly higher DII scores (i.e., with pro-inflammatory diets), but not significantly at lower levels (i.e., with anti-inflammatory diets). The contribution of the DII score to the development of hyperuricemia increased with higher scores. The relationship between inflammatory diets and hyperuricemia requires more research on inflammation, and this study alerts the public that pro-inflammatory diets may increase the risk of developing hyperuricemia.

Lactococcus cremoris D2022 alleviates hyperuricemia and suppresses renal inflammation via potential gut-kidney axis

Hyperuricemia (HUA) is a widespread metabolic disorder. Probiotics have drawn increasing attention as an adjunctive treatment with fewer side effects. However, thus far the effective strains are limited and the mechanisms for their serum uric acid (SUA)-lowering effect are not well understood. Along this line, we conducted the current study using a hyperuricemia mouse model induced by potassium oxonate and adenine. A novel strain of Lactococcus cremoris named D2022 was identified to have significant SUA-lowering capability. Lactococcus cremoris D2022 significantly reduced SUA levels by inhibiting uric acid synthesis and regulating uric acid transportation. It was also found that Lactococcus cremoris D2022 alleviated HUA-induced renal inflammatory injury involving multiple signaling pathways. By focusing on the expression of NLRP3-related inflammatory genes, we found correlations between the expression levels of these genes and free fatty acid receptors (FFARs). In addition, oral administration of Lactococcus cremoris D2022 increased short-chain fatty acids (SCFAs) in cecal samples, which may be one of the mechanisms by which oral probiotics alleviate renal inflammation. Serum untargeted metabolomics showed changes in a variety of serum metabolites associated with purine metabolism and inflammation after oral administration of Lactococcus cremoris D2022, further confirming its systemic bioactivity. Finally, it was proved that Lactococcus cremoris D2022 improved intestinal barrier function. In conclusion, Lactococcus cremoris D2022 can alleviate HUA and HUA-induced nephropathy by increasing the production of SCFAs in the gut and systemic metabolism.

Colorimetric and fluorometric determination of uric acid by a suspension-based assay using enzyme-immobilized micro-sized particles

Daily monitoring of serum uric acid levels is very important to provide appropriate treatment according to the constitution and lifestyle of individual hyperuricemic patients. We have developed a suspension-based assay to measure uric acid by adding a sample solution to the suspension containing micro-sized particles immobilized on uricase and horseradish peroxidase (HRP). In the proposed method, the mediator reaction of uricase, HRP, and uric acid produces resorufin from Amplex red. This resorufin is adsorbed onto enzyme-immobilized micro-sized particles simultaneously with its production, resulting in the red color of the micro-sized particles. The concentration of resorufin on the small surface area of the microscopic particles achieves a colorimetric analysis of uric acid with superior visibility. In addition, ethanol-induced desorption of resorufin allowed quantitative measurement of uric acid using a 96-well fluorescent microplate reader. The limit of detection (3σ) and RSD (n = 3) were estimated to be 2.2 × 10-2 μg/mL and ≤ 12.1%, respectively. This approach could also be applied to a portable fluorometer.

Correlation analysis of serum TLR4 protein levels and TLR4 gene polymorphisms in gouty arthritis patients

OBJECTIVE

The Toll-like receptor (TLR) 4-mediated nuclear factor kappa B (NF-κB) signaling pathway regulates the production of inflammatory factors and plays a key role in the pathogenesis of gouty arthritis. The aim of the present study was to investigate the link among TLR4 gene polymorphisms at various loci, protein expression, and gouty arthritis susceptibility.

METHODS

Between 2016 and 2021, a case-control study was used to collect a total of 1207 study subjects, including 317 male patients with gouty arthritis (gout group) and 890 healthy males (control group). The association between gout susceptibility and different genetic models was analyzed by typing three loci of the TLR4 gene (rs2149356, rs2737191, and rs10759932) using a multiplex point mutation rapid assay, and the association between protein expression and gout was confirmed by measuring TLR4 protein concentrations using enzyme-linked immunosorbent assays (ELISAs).

RESULTS

In a codominant models AA and AG, the rs2737191 polymorphism in the gout group increased the risk of gout compared to the AA genotype (OR = 2.249, 95%CI 1.010~5.008), and the risk of gout was higher for those carrying the G allele compared to the A allele (OR = 2.227, 95%CI 1.006~4.932). TLR4 protein expression was different between the two groups with different locus genotypes. The differences in TLR4 protein expression between the gout group and control group were statistically significant between the following genotypes: the GG and GT genotypes of the rs2149356 polymorphism; the AA and AG genotypes of the rs2737191 polymorphism; and the TT and TC genotypes of the rs10759932 polymorphism(P<0.05). The TLR4 protein level in the gout group (19.19±3.09 ng/ml) was significantly higher than that in the control group (15.85±4.75 ng/ml).

CONCLUSION

The AG genotype of the TLR4 gene rs2737191 polymorphism may be correlated with the development of gouty arthritis. The level of TLR4 protein expression is significantly higher in patients with gouty arthritis than in controls, and there is a correlation between high TLR4 protein expression and the development of gouty arthritis.

Preventive effect of Lactobacillus johnsonii YH1136 against uric acid accumulation and renal damages

Background

Hyperuricemia (HUA) is a prevalent metabolic disorder whose development is associated with intestinal microbiota. Therefore, probiotics have emerged as a potential and safe approach for lowering uric acid (UA) levels. However, the underlying mechanisms of many effective probiotic strains remain unknown.

Methods and results

C57BL/6 mice were randomly divided into two groups: control and model groups. The model group received 12 weeks of potassium oxonate. Through 16s sequencing we found that HUA resulted in a significant decrease in the total diversity of all intestinal segments. When each intestinal segment was analyzed individually, the reduction in diversity was only significant in the cecum and colon sections. RDA analysis showed that lactobacilli in the rat colon exhibited a strong correlation with model group, suggesting that Lactobacillus may play an important role in HUA. Consequently, the preventive effects of Lactobacillus johnsonii YH1136 against HUA were investigated. C57BL/6 mice were randomly divided into three groups: control, model and YH1136 groups. The results showed that administering Lactobacillus johnsonii YH1136 effectively reduced serum UA levels in vivo by inhibiting hepatic xanthine oxidase (XOD) activity and promoting renal ABCG2 transporter expression. Moreover, supplementation with Lactobacillus johnsonii YH1136 significantly ameliorated pathological damage in the kidney and liver, thereby reducing UA accumulation.

Conclusion

Hyperuricemia is accompanied by an altered composition of multiple gut bacteria, of which Lactobacillus is a key genus. Lactobacillus johnsonii YH1136 may ameliorate renal involvement in HUA via the gut-kidney axis.

Si Miao San relieves hyperuricemia by regulating intestinal flora

This study seeks to investigate the therapeutic effects of Si Miao San (SMS) on hyperuricemia and its underlying mechanisms, particularly focusing on the role of intestinal flora. The key components of SMS were identified using high-performance liquid chromatography (HPLC). To establish a rat model of hyperuricemia, an intraperitoneal injection of potassium oxonate was performed, followed by oral administration of various concentrations of SMS. The study evaluated the status of hyperuricemia, renal pathology, xanthine oxidase (XO) activity, and intestinal flora. Utilizing HPLC, we identified five active components of SMS. Following SMS intervention, there was a significant reduction in serum levels of uric acid (UA), blood urea nitrogen, and creatinine, accompanied by an increase in urine UA levels in rats with hyperuricemia. Distinct pathological injuries were evident in the renal tissues of hyperuricemic rats, and these were partially alleviated following SMS intervention. Moreover, SMS exhibited a dose-dependent reduction in XO activity both in the serum and hepatic tissues. Notably, SMS contributed to an enhancement in the diversity of intestinal flora in hyperuricemic rats. The intervention of SMS resulted in a reduction in the abundance of certain bacterial species, including Parabacteroides johnsonii, Corynebacterium urealyticum, and Burkholderiales bacterium. This suggests that SMS may exert anti-hyperuricemia effects, potentially by modulating the composition of intestinal flora.

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.

[Analysis of Influencing Factors of Hyperuricemia in Tibetan Population in Nagqu City, Tibet]

Objective

To analyze the prevalence of hyperuricemia (HUA) among the Tibetan population in Nagqu City, Tibet and to uncover the relevant influencing factors.

Methods

From July 2020 to August 2021, 763 Tibetan natives from Bangor County (specifically Xinji Township and Jiaqiong Township) and Seni District (specificially Sexiong Township), Nagqu City were investigated by multi-stage cluster random sampling method and the prevalence of HUA was studied by retrospective analysis. Chi-square test and multiple logistic regression were used to analyze the influencing factors of HUA prevalence.

Results

The overall prevalence of HUA among the Tibetan population in the three townships of Nagqu City was 19.66% (150/763). In particular, the prevalence in men was 35.00%, while that in women was 8.58%, showing significant difference (P<0.05). According to the results of univariate analysis, there were significant differences in the distribution of sex, abnormal liver function, abnormal hemoglobin, hyperlipidemia, high level of low-density lipoprotein, hypertriglyceridemia, hypercholesterolemia, abnormal creatinine, hyperhomocysteinemia, obesity, and hypertension between HUA and non-HUA patients (P<0.05). Multiple logistic regression showed that female sex (odds ratio [OR]=0.195, 95% confidence interval [CI]: 0.120-0.315) was a protective factor for HUA, while abnormal liver function (OR=2.812, 95% CI: 1.685-4.692), abnormal creatinine (OR=7.374, 95% CI: 1.446-37.620), high level of low-density lipoprotein (OR=2.357, 95% CI: 1.011-5.492), and hyperlipidemia (OR=3.056, 95% CI: 1.886-4.951) were independent risk factors.

Conclusion

The prevalence of HUA is relatively high in Nagqu city and the prevalence of HUA is much higher in men than that in women. Male sex, abnormal liver function, abnormal creatinine, elevated low-density lipoprotein, and hyperlipidemia may be the risk factors for HUA in the local Tibetan population.

Prediction of hyperuricemia in people taking low-dose aspirin using a machine learning algorithm: a cross-sectional study of the National Health and Nutrition Examination Survey

Background: Hyperuricemia is a serious health problem related to not only gout but also cardiovascular diseases (CVDs). Low-dose aspirin was reported to inhibit uric acid excretion, which leads to hyperuricemia. To decrease hyperuricemia-related CVD, this study aimed to identify the risk of hyperuricemia in people taking aspirin. Method: The original data of this cross-sectional study were obtained from the National Health and Nutrition Examination Survey between 2011 and 2018. Participants who filled in the "Preventive Aspirin Use" questionnaire with a positive answer were included in the analysis. Six machine learning algorithms were screened, and eXtreme Gradient Boosting (XGBoost) was employed to establish a model to predict the risk of hyperuricemia. Results: A total of 805 participants were enrolled in the final analysis, of which 190 participants had hyperuricemia. The participants were divided into a training set and testing set at a ratio of 8:2. The area under the curve for the training set was 0.864 and for the testing set was 0.811. The SHapley Additive exPlanations (SHAP) method was used to evaluate the performances of the modeling. Based on the SHAP results, the feature ranking interpretation showed that the estimated glomerular filtration rate, body mass index, and waist circumference were the three most important features for hyperuricemia in individuals taking aspirin. In addition, triglyceride, hypertension, total cholesterol, high-density lipoprotein, low-density lipoprotein, age, race, and smoking were also correlated with the development of hyperuricemia. Conclusion: A predictive model established by XGBoost algorithms can potentially help clinicians make an early detection of hyperuricemia risk in people taking low-dose aspirin.

Renal Metabolomics Study and Critical Pathway Validation of Shenkang Injection in the Treatment of Chronic Renal Failure

To reveal the mechanism of Shenkang injection (SKI) in the treatment of chronic renal failure, and verify the key pathway. In this work, an untargeted metabolomics approach was performed by LC-MS coupled with multivariate statistical analysis to provide new insights into therapeutic mechanism of SKI. Hematoxylin-eosin (H&E) Staining and Immunohistochemistry were used to evaluate the effects of drug treatment, Western blot was used to verify the critical pathway. Then, a total of 44 potential biomarkers of chronic renal failure (CRF) were identified and reversed regulation, including 2,8-dihydroxypurine, 5-methoxytryptophan, uric acid, acetylcarnitine, taurine, etc. Mainly concerned with arginine and proline metabolism, purine metabolism, histidine metabolism, etc. Pathological examination showed that the renal interstitium of SKI group was significantly improved, with fewer inflammatory cells and thinner vascular walls compared with the model group. Immunohistochemical results showed that the expression of α-smooth muscle actin (α-SMA) was decreased, and the expression of E-cadherin was increased in CRF model group, and the two indicators were reversed regulation in SKI injection, indicating that the degree of fibrosis was relieved. Critical signaling pathway phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) and nuclear factor-kappaB (NF-κB) protein expressions were significantly inhibited. This study was the first to employ metabolomics to elucidate the underlying mechanisms of SKI in chronic renal failure. The results would provide some support for clinical application of traditional Chinese medicines in clinic.

Hyperuricemia is associated with metabolic syndrome: A cross-sectional analysis of the National Health and Nutrition Examination Survey (NHANES)

This study aimed to understand the prevalence of hyperuricemia and MetS in the United States and evaluate the potential effect of gender and ethnicity on hyperuricemia and MetS. Data was obtained from National Health and Nutrition Examination Survey (NHANES) between 2011 and 2018. Logistic regression analysis was utilized to investigate the association between hyperuricemia and MetS. A total of 7273 participants with an average age of 47.59 ± 16.92 years old were enrolled in our analysis. Of all the people, 1833 were diagnosed with MetS, with which 547 (29.8 %) were found with hyperuricemia. As for gender, 261 (28.3 %) females were with both Mets and hyperuricemia and this number came to 286 (31.4 %) for males.For population distribution, Non-Hispanic American white, and Hispanic American making up 61.2 % of the cohort. The logistic regression analysis showed that there was a significant association between MetS and hyperuricemia (OR = 2.608, 95 %CI: 2.281-2.982). And the relationship still existed between both males (OR = 2.172, 95 %CI: 1.829-2.579) and females (OR = 3.464, 95 %CI: 2.868-4.185); in addition, participant's ethnicity was also found to play an important role. And the association was found either in Hispanic Americans Non-Hispanic Americans White and black or from other races. In conclusion, our study found a significant association between hyperuricemia and MetS. The higher the uric acid level, the greater risk of people getting MetS and this risk was not influenced by people's gender and ethnicity.

Analysis of clinical efficacy of comprehensive nursing intervention on elderly patients with hypertension combined with hyperuricemia

Objective

To evaluate the clinical efficacy of the comprehensive nursing intervention on elderly patients with hypertension combined with hyperuricemia.

Methods

This was a retrospective study. One hundred elderly patients with hypertension combined with hyperuricemia admitted to the Baoding No.1 Central Hospital from May 2019 to May 2020 were included and randomly divided into two groups. Patients in the control group were treated with conventional nursing intervention, while those in the experimental group were treated with comprehensive nursing intervention based on the therapy in the control group. The improvement of compliance behavior, clinical efficacy, quality of life and satisfaction with hypertension combined with hyperuricemia before and after treatment were compared and analyzed between the two groups. The proportion of patients in both groups who developed gout or renal insufficiency was recorded, and their long-term treatment outcomes were compared and analyzed.

Results

After the comprehensive nursing intervention, the number of cases of compliance behaviors in the experimental group was significantly higher than that in the control group(p<0.05). The systolic and diastolic blood pressure and uric acid levels were significantly lower in the experimental group compared to the control group after the intervention(p=0.00). The scores of physical function, psychological function, social function and material life status improved significantly in the experimental group compared to the control group after the intervention(p=0.00). The satisfaction rate of the experimental group was significantly higher than the control group(p=0.02). The proportion of patients in the experimental group who developed gout was significantly lower than that in the control group(p=0.03).

Conclusion

Comprehensive nursing intervention plays a vital role in the treatment and prognosis of hypertension combined with hyperuricemia.

Biodegradation of Inosine and Guanosine by Bacillus paranthracis YD01

Both inosine and guanosine are precursors of uric acid that may cause the diseases of hyperuricemia and gout in humans. Here, a promising bacterial strain for efficiently biodegrading both inosine and guanosine was successfully isolated from a healthy human intestine and identified as Bacillus paranthracis YD01 with 16S rRNA analysis. An initial amount of 49.6 mg·L-1 of inosine or 49.9 mg·L-1 of guanosine was completely removed by YD01 within 12 h, which showed that YD01 had a strong ability to biodegrade inosine and guanosine. Furthermore, the initial amount of 49.2 mg·L-1 of inosine or 49.5 mg·L-1 of guanosine was totally catalyzed by the intracellular crude enzymes of YD01 within 6 h, and the initial inosine amount of 49.6 mg·L-1 or guanosine of 49.7 mg·L-1 was biodegraded by the extracellular crude enzymes of YD01 within 9 h. Illumina Hiseq sequencing and database gene annotation were used to elucidate the genomic characteristics of B. paranthracis YD01. Purine nucleoside phosphorylase, encoded by gene 1785, gene 3933, and gene 4403, was found in the KEEG database, which played a crucial role in the biodegradation of inosine and guanosine. The results of this study provide valuable insights into the mechanisms for biodegrading inosine and guanosine using B. paranthracis YD01.

Spatial distribution of gut microbiota in mice during the occurrence and remission of hyperuricemia

BACKGROUND

Previous studies have shown that anserine can alleviate hyperuricemia by changing the fecal microbiota of hyperuricemic mice.

TOPIC

However, the fecal microbiota could not fully represent the distribution of the whole gut microbiota. Knowing the spatial distribution of the gastrointestinal tract microbiota is therefore important for understanding its action in the occurrence and remission of hyperuricemia.

METHODS

This study provides a comprehensive map of the most common bacterial communities that colonize different parts of the mouse gastrointestinal tract (stomach, duodenum, ileum, cecum, and colon) using a modern methodological approach.

RESULTS

The stomach, colon, and cecum showed the greatest richness and diversity in bacterial species. Three clusters of bacterial populations were observed along the digestive system: (1) in the stomach, (2) in the duodenum and ileum, and (3) in the colon and cecum. A high purine solution changed the composition and abundance of the digestive tract microbiota, and anserine relieved hyperuricemia by restoring the homeostasis of the digestive tract microbiota, especially improving the abundance of probiotics in the digestive tract.

IMPLICATION

This could be the starting point for further research on the regulation of hyperuricemia by gut microbiota with the ultimate goal of promoting health and welfare. © 2022 Society of Chemical Industry.

Hyperuricaemia: prevalence and association with mortality in an elderly Finnish population

OBJECTIVE

To establish the prevalence of hyperuricaemia in an elderly Finnish cohort and to assess its association with comorbidities and mortality.

DESIGN

Prospective cohort study.

SETTING

Good Ageing in Lahti Region study, Finland 2002-2012 (mortality data analysed until 2018).

PARTICIPANTS

2673 participants (mean age 64 years; 47% men).

PRIMARY AND SECONDARY OUTCOME MEASURES

Prevalence of hyperuricaemia in the study population was detected. Associations between hyperuricaemia and mortality were assessed using multivariable adjusted Cox proportional hazards models.

METHODS

Data from a prospective, population-based study of elderly people (52-76 years) in the Lahti region, Finland, were used. Information on serum uric acid (SUA) levels as well as several other laboratory variables, comorbidities, lifestyle habits and socioeconomic factors was collected, and the association between SUA level and mortality in a 15-year follow-up period was analysed.

RESULTS

Of 2673 elderly Finnish persons included in the study 1197 (48%) were hyperuricaemic. Hyperuricaemia was extremely prevalent in men (60%). There was an association between elevated SUA and mortality which remained after adjustment for potential confounding factors (age, gender, education, smoking status, body mass index, hypertension and dyslipidaemia). The adjusted HR for all-cause mortality among clearly hyperuricaemic individuals with SUA≥420 µmol/L compared with normouricaemic individuals (SUA<360 µmol/L) was 1.32 (95% CI 1.05 to 1.60) in women and 1.29 (95% CI 1.05 to 1.60) in men. In slightly hyperuricaemic individuals (SUA 360-420 µmol/L) the corresponding HRs were 1.03 (95% CI 0.78 to 1.35) and 1.11 (95% CI 0.89 to 1.39).

CONCLUSIONS

Hyperuricaemia is very prevalent in the elderly Finnish population and is independently associated with increased mortality.

Lactiplantibacillus pentosus P2020 protects the hyperuricemia and renal inflammation in mice

Introduction

Hyperuricemia (HUA) is a common metabolic disease, and its prevalence has been increasing worldwide. Pharmaceutical drugs have been used for controlling HUA but they all have certain side effects, which thus calls for discovering alternative options including using treatment of probiotics to prevent the development of HUA.

Methods

We established HUA mice model induced by potassium oxonate and adenine and performed in vivo experiments to verify the ability to lower serum uric acid of Lactiplantibacillus pentosus P2020 (LPP), a probiotics stain extracted from Chinese pickle. We also tried to discussed the underlying mechanisms.

Results

Oral administration with LPP significantly decreased serum uric acid and reduced renal inflammatory response by downregulating multiple inflammation pathways including NK-kB, MAPK, and TNFα. We also found that LPP administration significantly promoted uric acid excretion by regulating expression of transporters in the kidney and ileum. In addition, LPP intake improved intestinal barrier function and modulated the composition of gut microbiota.

Discussion

These results suggest that probiotics LPP may have a promising potential to protect against development of HUA and HUA-related renal damage, and its working mechanisms involve regulation of inflammation pathways and expression of transporters in the kidney and ileum.

Association of hyperuricemia with cardiovascular diseases: current evidence

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

Associated Clinical Factors for Coagulation Dysfunction due to Trimeresurus stejnegeri: A Retrospective Observational Study

Background

Trimeresurus stejnegeri (T.s) accounts for most snakebites in southern China, which always leads to coagulation dysfunction. Coagulopathy due to venom is widely considered to be a characteristic phenomenon of the DIC-like syndrome. It is vitally important for first-line clinicians to improve this condition as soon as possible. However, clinical factors associated with coagulation function in Trimeresurus stejnegeri has not been well characterized yet.

Materials

Patients bitten by vipers were admitted to the Emergency Department of a hospital in Shenzhen, southern China, from 2021 to 2022 and were retrospectively reviewed. Patient clinical characteristics and laboratory data were compared in the eligible patients bitten by T.s by their prothrombin time (PT), fibrinogen level (FIB), and platelet count on 2-3 days after bitten.

Results

105 patients were included in this study. The mean values of PT, FIB, and PLT are as follows: 12.8 ± 0.79 s, 2.25 ± 0.47 g/L, and 196.2 ± 57.1 × 10⁹/L. Uric acid (UA) (367.9 ± 103.85), blood glucose (6.53 + 1.64) show negative trend of correlation, while CRP (2.12 + 4.17) shows positive trend of association with coagulation function. The smoke and systolic blood pressure may exert negative effects on PT and PLT, respectively. Logistic regression analysis indicated that uric acid (UA) shows significant connection with PT (OR = 1.15 and P value <0.0001), FIB (OR = 0.89 and P value = 0.026), and PLT (OR = 0.79 and P value = 0.007). CRP is also shown to be associated with FIB (OR = 1.33 and P value = 0.043).

Conclusion

: Uric acid (UA) shows a significant association with PT, FIB, and PLT. CRP is related to FIB. Blood glucose shows a negative trend of correlation with PT. We do recommend physician should low the level of UA in some degree on the basis of injection of an antivenom serum.

Folic Acid Protects against Hyperuricemia in C57BL/6J Mice via Ameliorating Gut-Kidney Axis Dysfunction

Emerging lines of research evidence point to a vital role of gut-kidney axis in the development of hyperuricemia (HUA), which has been identified as an increasing burden worldwide due to the high prevalence. The involved crosstalk which links the metabolic and immune-related pathways is mainly responsible for maintaining the axial homeostasis of uric acid (UA) metabolism. Nowadays, the urate-lowering drugs only aim to treat acute gouty arthritis as a result of their controversial clinical application in HUA. In this study, we established the HUA model of C57BL/6J mice to evaluate the effectiveness of folic acid on UA metabolism and further explored the underlying mechanisms. Folic acid attenuated the kidney tissue injury and excretion dysfunction, as well as the typical fibrosis in HUA mice. Molecular docking results also revealed the structure-activity relationship of the folic acid metabolic unit and the UA transporters GLUT9 and URAT1, implying the potential interaction. Also, folic acid alleviated HUA-induced Th17/Treg imbalance and intestinal tissue damage and inhibited the active state of the TLR4/NF-κB signaling pathway, which is closely associated with the circulating LPS level caused by the impaired intestinal permeability. Furthermore, the changes of intestinal microecology induced by HUA were restored by folic acid, including the alteration in the structure and species composition of the gut microbiome community, and metabolite short-chain fatty acids. Collectively, this study revealed that folic acid intervention exerted improving effects on HUA by ameliorating gut-kidney axis dysfunction.

Gene Dose-Dependent and Additive Effects of ABCG2 rs2231142 and SLC2A9 rs3733591 Genetic Polymorphisms on Serum Uric Acid Levels

This study aimed to evaluate whether the single nucleotide polymorphisms of ATP-binding cassette subfamily G member 2 (ABCG2) and solute carrier family 2 member 9 (SLC2A9) affect individual blood uric acid levels using pyrosequencing. ABCG2 (rs2231142, rs72552713, rs2231137), SLC2A9 (rs3734553, rs3733591, rs16890979), and individual uric acid levels were prospectively analyzed in 250 healthy young Korean male participants. Prominent differences in uric acid levels of the alleles were observed in the SLC2A9 rs3733591 polymorphism: wild-type (AA) vs. heterozygote (AG), 0.7 mg/dL (p < 0.0001); AA vs. mutant type (GG), 1.32 mg/dL (p < 0.0001); and AG vs. GG, 0.62 mg/dL (p < 0.01). In ABCG2 single nucleotide polymorphisms (SNPs), the statistically significant differences in uric acid levels were only found in rs2231142 between CC vs. AA (1.06 mg/dL; p < 0.001), and CC vs. CA (0.59 mg/dL; p < 0.01). Serum uric acid levels based on the ABCG2 and SLC2A9 diplotype groups were also compared. The uric acid levels were the lowest in the CC/AA diplotype and highest in the AA/AG diplotype. In addition, the SNP SLC2A9 rs3733591 tended to increase the uric acid levels when the ABCG2 rs2231142 haplotypes were fixed. In conclusion, both the ABCG2 rs2231142 and SLC2A9 rs3733591 polymorphisms may additively elevate blood uric acid levels.

Plasma S-Klotho level affects the risk of hyperuricemia in the middle-aged and elderly people

BACKGROUND

Soluble Klotho (S-Klotho) is an anti-aging protein mainly secreted by the kidneys. Hyperuricemia is prevalent among middle-aged and elderly individuals, which affects the development of various chronic diseases. However, there are relatively few studies investigating the association between plasma S-Klotho levels and hyperuricemia in middle-aged and elderly individuals. This study sought to clarify the relationship between S-Klotho and the risk of hyperuricemia in middle-aged and elderly people.

METHODS

During 2007-2016, a total of 50,588 people participated in the National Health and Nutrition Examination Survey. Finally, 12,441 middle-aged and elderly people (aged 40-79) completed the soluble Klotho tests and had obtained complete data. S-Klotho was detected by ELISA kit, and the relationship between S-Klotho and hyperuricemia was assessed by multiple logistic regression. Hyperuricemia is defined as serum uric acid levels higher than or equal to 420 mmol/l in men and 360 mmol/l in women.

RESULTS

In the middle-aged and elderly, plasma S-Klotho levels were negatively correlated with hyperuricemia, and there was a saturation effect. The inflection point of S-Klotho was 927.8 pg/ml (logarithmic likelihood ratio test = 0.002). When plasma S-Klotho < 927.8 pg/ml, the prevalence of hyperuricemia in middle-aged and elderly individuals with higher levels of S-Klotho decreased by 25.6% compared with those with low levels of S-Klotho [Q4 vs Q1, OR: 0.744, 95%CI: (0.634, 0.874), P < 0.001]; In different age groups, S-Klotho had a significantly greater effect on hyperuricemia in middle-aged people [age: 40-65 years, Q4 vs Q1, OR (95%CI): 0.69 (0.58, 0.82), P < 0.001; Age > 65 years: Q4 vs Q1, OR (95%CI): 0.72 (0.56, 0.92), P = 0.008)].When the level of S-Klotho was higher, the risk of hyperuricemia in men was lower than that in women [male: Q4 vs Q1, OR (95%CI): 0.67 (0.56, 0.81), P < 0.001; female: Q4 vs Q1 (95%CI):0.72 (0.58, 0.88), P < 0.001].

CONCLUSIONS

In middle-aged and elderly individuals, plasma S-Klotho levels were inversely correlated with hyperuricemia, with a saturation effect. Given the limitations of the research results, the underlying mechanism between S-Klotho and hyperuricemia should be further explored.

Hyperuricemia and gout: effects on bone and articular cartilage (literature review)

Gout is a disease characterized by deposition of sodium monourate crystals in tissues which is the reason of inflammation among persons with hyperuricemia (HU). The prevalence of HU, which can be considered the first stage of gout formation, varies in different countries. Despite this, only a small number of persons with HU have been shown to develop symptoms of gout. Recent data suggest that HU is an independent risk factor for cartilage and bone damage. UA, both in the form of crystals and in a dissolved form, activates damage and potentiates cell death by releasing reactive oxygen species, activating the necroptosis pathway, neutrophil traps, synthesis of pro-inflammatory cytokines, and other pathogenetic mechanisms that cause the negative effects of HU and gout on articular cartilage and subchondral bone. The association of HU and osteoarthritis (OA) is well known and based on the common pathogenesis, but the direction of this relationship is still a debatable issue. The accumulated data suggest the need for a deeper study of the relationship of gout and asymptomatic HU with pathological processes leading to the development and progression of OA and disorders of bone metabolism.

Lifestyle-Related Risk Factors for the Incidence and Progression of Chronic Kidney Disease in the Healthy Young and Middle-Aged Population

The prevalence of chronic kidney disease (CKD) increased by 88% from 1990 to 2016. Age of onset of lifestyle-related diseases (such as hypertension, diabetes mellitus, obesity, dyslipidemia, and hyperuricemia), which are risk factors for incident CKD, is lower now compared with the past. Thus, we aimed to evaluate the risk factors for the incidence and progression of CKD in the young and middle-aged population. There are differences in the risk for CKD among the young, middle-aged, and elderly populations. We aimed to assess obesity (which is basic component of metabolic syndrome), waist circumference, and abdominal adiposity, which are predictive factors of CKD in the younger population. Furthermore, we described the management and clinical evidence of hypertension, diabetes mellitus, dyslipidemia, and hyperuricemia for young and middle-aged patients, along with diet management and nutrients associated with kidney function. Kidney function in the young and middle-aged population is mostly normal, and they are considered a low-risk group for incident CKD. Thus, we expect this review to be useful in reducing the prevalence of CKD.

Beyond the Cardiorenal Syndrome: Pathophysiological Approaches and Biomarkers for Renal and Cardiac Crosstalk

Cardiorenal syndrome encompasses complex multifactorial facets and carries significant morbidity and mortality worldwide. The bi-directional relationship between the heart and kidneys, where dysfunction in one organ worsens the function of the other, has been the leading motor for research in the last few years. In the pathophysiological process, small noncoding RNAs, epigenetics, vascular growth factors, oxidative stress, hemodynamic factors, and biomarkers play a pivotal role in the development of cardiorenal syndrome. It is therefore important to elucidate all the mechanisms in order to provide diagnostic and treatments tools. This review summarizes the hemodynamic and non-hemodynamic pathways along with biomarkers that could be the next target for diagnosis, treatment, and prognosis in cardiorenal syndrome.

Uric Acid and Oxidative Stress-Relationship with Cardiovascular, Metabolic, and Renal Impairment

Background: The connection between uric acid (UA) and renal impairment is well known due to the urate capacity to precipitate within the tubules or extra-renal system. Emerging studies allege a new hypothesis concerning UA and renal impairment involving a pro-inflammatory status, endothelial dysfunction, and excessive activation of renin–angiotensin–aldosterone system (RAAS). Additionally, hyperuricemia associated with oxidative stress is incriminated in DNA damage, oxidations, inflammatory cytokine production, and even cell apoptosis. There is also increasing evidence regarding the association of hyperuricemia with chronic kidney disease (CKD), cardiovascular disease, and metabolic syndrome or diabetes mellitus. Conclusions: Important aspects need to be clarified regarding hyperuricemia predisposition to oxidative stress and its effects in order to initiate the proper treatment to determine the optimal maintenance of UA level, improving patients’ long-term prognosis and their quality of life.

Sex Disparities in the Association of Serum Uric Acid With Kidney Stone: A Cross-Sectional Study in China

Background and Aims

Urolithiasis is characterized by high rates of prevalence and recurrence. Hyperuricemia is related to various diseases. We hope to determine the association between serum uric acid (UA) level and kidney stone (KS).

Methods

In this population-based cross-sectional study, a total of 82,017 Chinese individuals who underwent a comprehensive examination in 2017 were included. The KS was diagnosed based on ultrasonography examination outcomes. Fully adjusted odds ratio (OR) for KS, and mean difference between the two groups were applied to determine the association of UA level with KS.

Results

Among the 82,017 participants included in this study (aged 18~99 years), 9,435 participants (11.5%) are diagnosed with KS. A proportion of 56.3% of individuals is male. The mean UA level of overall participants is 341.77 μmol/L. The participants with KS report higher UA level than the participants without KS [mean UA level 369.91 vs. 338.11 μmol/L; mean difference (MD), 31.96 (95% CI, 29.61~34.28) μmol/L]. In men, the OR for KS significantly increases from 330 μmol/L UA level. Every 50 μmol/L elevation of UA level increases the risk of KS formation by about 10.7% above the UA level of 330 μmol/L in men. The subgroup analysis for male is consistent with the overall result except for the participants presenting underweight [adjusted OR, 1.035 (0.875~1.217); MD, −5.57 (−16.45~11.37)], low cholesterol [adjusted OR, 1.088 (0.938~1.261); MD, 8.18 (−7.93~24.68)] or high estimated glomerular filtration rate (eGFR) [adjusted OR, 1.044 (0.983~1.108); MD, 5.61 (−1.84~13.36)]. However, no significant association is observed in women between UA and KS either in all female participants or in female subgroups.

Conclusion

Among Chinese adults, UA level is associated with KS in a dose-response manner in men but not in women. However, the association becomes considerably weak in male participants with malnutrition status.

Eurycomanol alleviates hyperuricemia by promoting uric acid excretion and reducing purine synthesis

BACKGROUND

An elevated level of blood uric acid (UA) leads to serious damages to human health. In clinic, xanthine oxidase inhibitor is commonly used to reduce uric acid production. However, UA excretion promotion drug is rare. Our previous study demonstrated that the 70% ethanolic extract of stem of Eurycoma longifolia could effectively increase UA excretion and decrease blood level of UA in hyperuricemia animal model. In this paper, we tried to find active substance on UA regulation from E. longifolia.

METHODS

The constituents of stem from E. longifolia were isolated and analyzed by chemical and spectral methods. Ultra Performance Liquid Chromatography was applied to measure the concentrations of UA in serum and urine. H&E staining was used to characterize renal histopathological changes. The protein and mRNA expressions of UA transporters were measured by western blot and quantitative real-time PCR analysis.

RESULTS

Ten kinds of quassinoids were isolated from stem of E. longifolia, and the structures were identified. Pharmacological research revealed the major component, eurycomanol (5-20 mg/kg, p.o.) significantly decreased serum UA level and increased 24 h clearance of uric acid in potassium oxonate and adenine induced hyperuricemic mice. Eurycomanol ameliorated UA induced kidney histological injury, inhibited hepatic purine synthesis through decreasing phosphoribosyl pyrophosphate synthetase, promoted UA excretion by modulation of renal and intestinal urate transporters, such as GLUT9, ABCG2, OAT1, and NPT1.

CONCLUSION

The results showed eurycomanol from E. longifolia can promote UA excretion through kidney and intestine, decrease hepatic purine synthesis and further keep UA homeostasis, suggesting that eurycomanol has the potential to be developed into a novel drug for the treatment of under-excretion type hyperuricemia.

Alteration of normal level of serum urate may contribute to decrease in estimated glomerular filtration rate decline in healthy Japanese men

INTRODUCTION

Serum uric acid (SUA) levels have a linear relationship with the estimated glomerular filtration rate (eGFR). It is unclear whether further changes, subsequent to normal level of SUA can attenuate eGFR decline in a healthy population, so we aimed to determine the normal level of SUA that can contribute to preventing kidney dysfunction.

METHODS

In this retrospective cohort study from Japan, annual health checkup data from 2009 to 2014 was collected. After propensity score matching (1:1), data from 2,634 individuals with basal SUA ≤7.0 mg/dL (normal; mean age, 39 y; mean eGFR, 80.8 mL/min/1.73 m²) and 1,642 individuals with basal SUA >7.0 mg/dL (elevated; mean age, 42 y; mean eGFR, 75.0 mL/min/1.73 m²) were collected to determine the relationship between followed-up SUA level and the rate of change in eGFR.

RESULTS

In individuals with normal level SUA at baseline, the elevation of SUA (>7.0 mg/dL) accelerated eGFR decline compared to those with normal SUA levels at 5-year follow-up (-4.1 ± 9.6% vs -9.9 ± 9.0%, p < .0001). Digression of SUA level (≤7.0 mg/dL) reduced eGFR decline compared with persistent SUA level over 7.0 mg/dL (-1.5 ± 11.5% vs -7.0 ± 10.1, p < .0001). In multiple linear regression analysis, there was strong association between the rate of change in SUA and eGFR in individuals with basal SUA ≤7.0 and >7.0 mg/dL (standardized coefficient; -0.3348, p < .001 and -.2523, p < .001, respectively).

CONCLUSION

Subsequent to normal level of SUA (under 7.0 mg/dL) may contribute to a decrease in eGFR decline in apparently healthy men.

Tophaceous gout of the atlantoaxial joint: a case report

Background

To report the occurrence of tophaceous gout in the cervical spine and to review the literature on spinal gout.

Case presentation

This report details the occurrence of a large and clinically significant finding of tophaceous gout in the atlantoaxial joint of the cervical spine in an 82-year-old Caucasian man with a 40-year history of crystal-proven gout and a 3-month history of new-onset progressive myelopathy. The patient's American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria score was 15.0.

Conclusion

Spinal gout is more common than previously thought, and it should be considered in patients who present with symptoms of myelopathy. Diagnosis can be made without a tissue sample of the affected joint(s) with tools like the ACR/EULAR criteria and the use of the “diagnostic clinical rule” for determining the likelihood of gout. Early conservative management with neck immobilization and medical management can avoid the need for surgical intervention.