Uric Acid and the Risks of Kidney Failure and Death in Individuals With CKD

Impact of Ramadan fasting on lipid profile, uric acid, and HbA1c in CKD: A systematic review and meta-analysis

Studies have shown that fasting during Ramadan has different effects on circulating levels of several biochemical markers. This study aims to conduct a comprehensive evaluation of studies related to the effect of fasting in the holy month of Ramadan on lipid profile, uric acid, and HbA1c in CKD patients. Studies were systematically searched and collected from three databases (PubMed, Scopus, and Web of Science). After screening, the quality and risk of bias assessment of the selected articles were evaluated. Study heterogeneity was assessed using the Cochrane test and I² statistic. In case of any heterogeneity random effects model with the inverse-variance method was applied. All analyses were performed using STATA software version 16. Four observational studies were included in this study. The results of this meta-analysis were that cholesterol (Weighted mean differences (WMD):0.21 with 95% CI:-0.09-0.51 (P-value=:0.18)), LDL (WMD:0.06 with 95% CI -0.24-0.36 (P-value:0.69)), triglyceride (WMD:0.05 with 95% CI:-0.25-0.35 (P-value:0.73)) had not-significant increase. Uric acid (WMD: -0.11 with 95% CI: -0.42-0.21 (P-value:0.51)) and HbA1c (WMD: -0.22 with 95% CI: -0.79-0.36 (P-value: 0.46)) show a non-significant decrease. The results of the analyses did not report significant changes in the lipid profile, uric acid, and HbA1c in CKD patients after Ramadan fasting.

Impacts of Febuxostat on Cerebral and Cardiovascular Events in Elderly Patients with Hyperuricemia: Post Hoc Analysis of a Randomized Controlled Trial

A recent meta-analysis found no benefit of uric acid-lowering therapy including febuxostat on death, cardiovascular events, or renal impairment. However, there may be populations that benefit from febuxostat in reducing mortality and cerebral and cardiovascular events. The aim of the present study was to examine the clinical benefit of febuxostat in elderly patients stratified by age using Febuxostat for Cerebral and CaRdiorenovascular Events PrEvEntion StuDy (FREED) data. FREED was a randomized study involving patients aged 65 years or older with hyperuricemia and risk factors for cerebral, cardiovascular, or renal diseases. A total of 1,070 patients were included in this post hoc analysis, divided into 2 age groups: 65-74 years and ≥ 75 years. Patients were randomized into febuxostat and non-febuxostat groups, with uric acid levels monitored for 36 months. The primary composite end point included cerebral, cardiovascular, and renal events. In patients aged between 65 and 74 years, febuxostat significantly reduced the risk of future cerebral and cardiorenovascular events. However, no effects of febuxostat were found in the older population aged ≥ 75 years. Heterogeneity in potential interactions between the age and febuxostat treatment was particularly observed in non-fatal cerebral and cardiovascular events and all-cause death. Patients aged ≥ 75 years exhibited more pre-existing factors associated with cerebral and cardiorenovascular events than those aged 65-74 years. The effectiveness of febuxostat varies by age group, with potential benefits for patients aged 65-74 years. The effects of febuxostat are complex and it is important to consider patient characteristics in its clinical use.

Association of serum uric acid with all-cause and cardiovascular mortality in chronic kidney disease stages 3-5

BACKGROUND AND AIMS

The role of serum uric acid (SUA) in the prognosis of chronic kidney disease (CKD) is inconclusive. To explore the association of SUA level with all-cause and cardiovascular disease (CVD) mortality in patients with CKD.

METHODS AND RESULTS

Leveraging data from the National Health and Nutritional Examination Survey (NHANES) and linked national death records up to December 31 2019, we explored the association of SUA with all-cause and CVD mortality using weighted cox proportional hazards regression models and restricted cubic spline (RCS) models in patients with CKD stages 3-5. The study finally included 2644 patients with CKD stages 3-5, with a median SUA level of 6.5 mg/dL. After a median follow-up of 55 months, a total of 763 deaths were recorded, with 279 of them attributed to CVD. In the fully adjusted model, per 1 mg/dL increment in SUA concentration was found to be associated with increased HRs (95% CIs) of 1.07 (1.00, 1.14) for all-cause mortality and 1.11 (1.00, 1.24) for CVD mortality. Compared to Q2 (reference), those in Q4 had adjusted HRs of 1.72 (1.36, 2.17) for all-cause mortality and 2.17 (1.38, 3.41) for CVD mortality, while those in Q1 had adjusted HRs of 1.49 (1.19, 1.85) for all-cause mortality and 1.93 (1.26, 2.98) for CVD mortality.

CONCLUSIONS

Both higher and lower SUA levels were associated with increased risks of all-cause and CVD mortality in patients with CKD stages 3-5.

Association between hyperuricemia and the risk of mortality in patients with osteoarthritis: A study based on the National Health and Nutrition Examination Survey database

BACKGROUND

The purpose of this study was to evaluate the relationship between hyperuricemia and the risks of all-cause mortality and cardiovascular disease (CVD) mortality in patients with osteoarthritis (OA).

METHODS

A retrospective cohort study was performed on 3,971 patients using data from the National Health and Nutrition Examination Survey database between 1999 and 2018. OA was diagnosed through specific questions and responses. The weighted COX regression models were used to explore the factors associated with all-cause mortality/CVD mortality in OA patients. Subgroup analyses were conducted based on age, gender, hypertension, dyslipidemia, CVD, and chronic kidney disease (CKD). Hazard ratio (HR) and 95% confidence interval (95% CI) were measured as the evaluation indexes.

RESULTS

During the duration of follow-up time (116.38 ± 2.19 months), 33.69% (1,338 patients) experienced all-cause mortality, and 11.36% (451 patients) died from CVD. Hyperuricemia was associated with higher risks of all-cause mortality (HR: 1.22, 95% CI: 1.06-1.41, P = 0.008) and CVD mortality (HR: 1.32, 95% CI: 1.02-1.72, P = 0.036) in OA patients. Subgroup analyses showed that hyperuricemia was related to the risk of all-cause mortality in OA patients aged >65 years (HR: 1.17, 95% CI: 1.01-1.36, P = 0.042), in all male patients (HR: 1.41, 95% CI: 1.10-1.80, P = 0.006), those diagnosed with hypertension (HR: 1.17, 95% CI: 1.01-1.37, P = 0.049), dyslipidemia (HR: 1.18, 95% CI: 1.01-1.39, P = 0.041), CVD (HR: 1.30, 95% CI: 1.09-1.55, P = 0.004), and CKD (HR: 1.31, 95% CI: 1.01-1.70, P = 0.046). The association between hyperuricemia and a higher risk of CVD mortality was found in OA patients aged ≤ 65 years (HR: 1.90, 95% CI: 1.06-3.41, P = 0.032), who did not suffer from diabetes (HR: 1.36, 95% CI: 1.01-1.86, P = 0.048), who did not suffer from hypertension (HR: 2.56, 95% CI: 1.12-5.86, P = 0.026), and who did not suffer from dyslipidemia (HR: 2.39, 95% CI: 1.15-4.97, P = 0.020).

CONCLUSION

These findings emphasize the importance of monitoring serum uric acid levels in OA patients for potentially reducing mortality associated with the disease.

Hyperuricemia and gout enhanced the risk of long-term mortality in hypertension: insights from the National Health and Nutrition Examination Survey 2007-2018

BACKGROUND

Asymptomatic hyperuricemia (HUA) and normouricemic gout are common in clinic but recommendations for them in hypertension management are absent. The present study aims to simultaneously evaluate the effect of HUA and gout on long-term mortality in hypertension.

METHODS

Individuals from 2007-2018 National Health and Nutrition Examination Survey were enrolled. Hazard ratios and 95% confidence intervals (CIs) were calculated with the aid of the Cox proportional-hazards model. The restricted cubic spline (RCS) analysis was made to show the dose-response relationship between uric acid and mortality. All-cause mortality and cardiovascular mortality were compared using the Kaplan-Meier curve with a log-rank test.

RESULTS

Thirty thousand eight hundred and nineteen eligible individuals were included, of which 5841 suffered from HUA and 1476 suffered from gout. During a median follow-up of 7.25 (95% CI 7.18-7.32) years, 2924 (6.8%) patients died, including 722 (1.6%) cases of cardiovascular death. Hypertensive patients with HUA and gout showed 1.34 and 1.29 times higher all-cause mortality compared with those without HUA or gout. For hypertensive patients without gout, HUA was significantly associated with higher risk of all-cause [1.27 (1.13, 1.43)] and cardiovascular [1.80 (1.44, 2.24)] mortality compared with normouricemia. However, for hypertensive patients without HUA, gout was associated with a higher mortality but not statistically significant. A J-shaped relationship was found between serum uric acid and mortality.

CONCLUSION

HUA and gout are additive risk factors for all-cause and cardiovascular mortality in hypertension. Furthermore, asymptomatic HUA is significantly associated with poor long-term prognosis but normouricemic gout is not.

Additional renoprotective effect of the SGLT2 inhibitor dapagliflozin in a patient with ADPKD receiving tolvaptan treatment

Autosomal dominant polycystic kidney disease (ADPKD) is a major cause of end-stage kidney disease (ESKD). Vasopressin plays a pivotal role in ADPKD progression; therefore, the selective vasopressin V2 receptor antagonist tolvaptan is used as a key drug in the management of ADPKD. On the other hand, sodium-glucose cotransporter-2 inhibitors (SGLT2i), which may possibly stimulate vasopressin secretion due to the diuretic effect of the drug, have been shown to have both renal and cardioprotective effects in various populations, including those with non-diabetic chronic kidney disease. However, the effect of SGLT2i in patients with ADPKD have not been fully elucidated. Herein, we report the case of a patient with ADPKD on tolvaptan who was administered the SGLT2i dapagliflozin. The patient was a Japanese woman diagnosed with ADPKD at age 30. Despite the treatment with tolvaptan, eGFR was gradually declined from 79.8 to 50 ml/min/1.73 m2 in almost 5 years and 10 mg of dapagliflozin was initiated in the hope of renoprotective effects. Although a small increase in vasopressin levels was observed, eGFR decline rate was moderated after dapagliflozin initiation. This case suggested an additional renoprotective effect of dapagliflozin in patient with ADPKD receiving tolvaptan. Although there is no evidence about the renal protective effect of SGLT2i in patients with ADPKD, we hereby report a case successfully treated with dapagliflozin for approximately 2 years. Further research, including clinical trials, is needed to evaluate whether SGLT2i are effective in patients with ADPKD.

Caspase-11/GSDMD contributes to the progression of hyperuricemic nephropathy by promoting NETs formation

Hyperuricemia is an independent risk factor for chronic kidney disease (CKD) and promotes renal fibrosis, but the underlying mechanism remains largely unknown. Unresolved inflammation is strongly associated with renal fibrosis and is a well-known significant contributor to the progression of CKD, including hyperuricemia nephropathy. In the current study, we elucidated the impact of Caspase-11/Gasdermin D (GSDMD)-dependent neutrophil extracellular traps (NETs) on progressive hyperuricemic nephropathy. We found that the Caspase-11/GSDMD signaling were markedly activated in the kidneys of hyperuricemic nephropathy. Deletion of Gsdmd or Caspase-11 protects against the progression of hyperuricemic nephropathy by reducing kidney inflammation, proinflammatory and profibrogenic factors expression, NETs generation, α-smooth muscle actin expression, and fibrosis. Furthermore, specific deletion of Gsdmd or Caspase-11 in hematopoietic cells showed a protective effect on renal fibrosis in hyperuricemic nephropathy. Additionally, in vitro studies unveiled the capability of uric acid in inducing Caspase-11/GSDMD-dependent NETs formation, consequently enhancing α-smooth muscle actin production in macrophages. In summary, this study demonstrated the contributory role of Caspase-11/GSDMD in the progression of hyperuricemic nephropathy by promoting NETs formation, which may shed new light on the therapeutic approach to treating and reversing hyperuricemic nephropathy.

Febuxostat dose requirement according to renal function in patients who achieve target serum urate levels: A retrospective cohort study

OBJECTIVES

To determine the febuxostat dose requirement according to renal function in patients who achieve target serum urate (SU) levels.

METHODS

Of 3153 gout patients who underwent febuxostat treatment, 873 patients with an initial SU level>6mg/dL were included and categorized by the estimated glomerular filtration rate: normal, chronic kidney disease (CKD) stage 3, and stages 4-5. Ninety-five patients with insufficient follow-up were further excluded. The dose of febuxostat in patients who achieved the SU target (< 6mg/dL) was defined as the average daily dosage at the time of SU target achievement.

RESULTS

The cohort of 778 gout patients had a median age of 52.0 years (IQR, 41.0-63.0) and comprised 711 (91.4%) men. The mean SU at febuxostat initiation was higher in the CKD 4-5 (9.6 [± 3.1] mg/dL) than in the other groups (CKD 3, 8.7 [± 1.7]; normal, 8.4 [± 1.7]; P<0.001). Patients achieved target SU at a median of 4.0 (1.9-9.6) months and in those who achieved target SU, the dose of febuxostat at the time of SU target achievement was significantly lower in the CKD 4-5 group (50.0 [± 16.5] mg) than in the other groups (vs. CKD stage 3, 60.0 [± 19.5] mg; P<0.01, vs. normal, 60.0 [± 19.8] mg; P<0.01). Furthermore, CKD stage 4-5 had a negative correlation with the febuxostat dose requirement (Beta: -2.334, P<0.05).

CONCLUSION

Among patients who achieved SU target, those with severely decreased renal function (CKD 4-5) required a lower febuxostat dose to achieve the target SU level compared to patients with normal or mild renal impairment.

Serum uric acid levels and health outcomes in CKD: a prospective cohort study

BACKGROUND

Hyperuricemia is prevalent in individuals with chronic kidney disease (CKD). Elevated serum uric acid (SUA) concentrations have been considered an independent risk factor for the onset of CKD. However, the relationship between SUA concentrations and long-term health outcomes among patients with CKD remains unclear.

METHODS

We performed a prospective cohort study with nationally representative sample to investigate the relationship between SUA concentrations and mortality risk including all-cause, cardiovascular disease (CVD) and cancer mortality, among patients with CKD. The weighted restricted cubic spline analyses combined with the multivariate-adjusted Cox proportional hazard models were used to test the nonlinearity of relationship.

RESULTS

The 6642 patients participating in National Health and Nutrition Examination Survey 1999-2018 were enrolled. During 656 885 person-months of follow-up time, 2619 all-cause deaths were recorded, including 1030 CVD deaths and 458 cancer deaths. Our study presented J-shaped non-linear relationships between SUA concentrations and all-cause and CVD mortality with inflection points at 311.65 μmol/L and 392.34 μmol/L, respectively. When SUA concentration was higher than those inflection points, every increase of 50 μmol/L SUA was associated with 11.7% and 17.0% greater multivariable-adjusted hazard ratio of all-cause and CVD mortality, respectively. In addition, a negative linear correlation with cancer mortality was detected.

CONCLUSION

These findings suggested that maintaining appropriate SUA concentrations may improve long-term health outcomes among CKD patients. The corresponding inflection points of J-shaped non-linear relationships were 311.65 and 392.34 μmol/L for all-cause and CVD mortality. Further clinical trials are required to investigate uric acid-lowering targets.

Associations between metabolic profiles and incident CKD in the Chinese population aged 45-85 years

PURPOSE

The roles of metabolic indices in predicting chronic kidney disease (CKD) were lacking. This study aimed to examine the concomitant impact of metabolic and novel anthropometric indices on incident CKD in the Chinese populations.

METHODS

This prospective cohort study included 1825 males and 2218 females aged between 45 and 85 years, derived from the ongoing prospectively cohort of China Health and Retirement Longitudinal Study (CHARLS), from 2011 to 2015. The outcome was defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2.

RESULTS

During the 5-years follow-up period, 3.0% (55/1825) of males and 4.1% (90/2218) of the females developed CKD. After multivariable adjustment, elevated triglyceride (TG), low high-density lipoprotein cholesterol (HDL-C), serum uric acid (sUA), elevated visceral fat index (VFI), elevated body shape index (BSI) and elevated body roundness index (BRI) in males, and sUA, and BRI in females were the independent predictors for CKD. Composite scores, composed of sUA, history of cardiovascular disease (CVD), waist circumstance (WC), HDL-C, and BRI in males and sUA, hypertension, and BRI in females were constructed that could accurately predict CKD.

CONCLUSION

Our study found that elevated levels of TG, sUA, BSI, BRI, and diminished HDL in males and elevated levels of sUA, and BRI in females, are indicative of the incident CKD. The composite score, integrating a history of disease, metabolic indices, and noval anthropometric indices, could accurately differentiate individuals with and without incident CKD, proving useful for CKD care and management.

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.

Relationship of Serum Uric Acid with Kidney Function Decline Mediated by Systemic Arterial Stiffness: A Retrospective Cohort Study in Japan

Hyperuricemia is associated with kidney function decline (KFD), although whether hyperuricemia directly causes nephrotoxicity or is indirectly mediated by systemic arterial stiffening remains unclear. We examined the detailed relationship of serum uric acid (SUA) with KFD and potential mediation by arterial stiffness. Study population was 27,648 urban residents with an estimated glomerular filtration rate (eGFR) of ≥60 mL/min/1.73 m2 at baseline, and they participated in a median of three consecutive annual health examinations. Arterial stiffness was assessed using cardio-ankle vascular index (CAVI). KFD was defined as a decrease in eGFR to below 60. Multivariate analysis showed an association between baseline SUA and CAVI independent of eGFR. During the study period, 6.6% of participants developed KFD. Stratified analysis revealed a linear relationship between the contribution of CAVI or SUA and KFD. ROC analysis determined a cutoff CAVI of 8.0 (males) or 7.9 (females) and a cutoff SUA of 6.3 (males) or 4.5 mg/dL (females) for predicting KFD. The linkage between SUA and CAVI was associated with a greater increase in the hazard ratio for KFD with an increase in SUA. CAVI showed the mediating effect on the relationship of SUA with KFD after an adjustment for confounders. SUA was associated positively with CAVI-mediated KFD. Further studies should verify whether intensive SUA-lowering treatment prevents KFD via improving vascular function.

Nonlinearity association between hyperuricemia and all-cause mortality in patients with chronic kidney disease

Controversy surrounds the role of serum uric acid and whether treatment intervention is favorable in retarding the progression of chronic kidney disease (CKD). The association of serum uric acid levels and CKD patient mortality risk needs to be further determined by large sample cohort studies. The National Health and Nutrition Examination Survey participants with CKD from 1998 to 2017 were enrolled in the study. Multivariable Cox regression models were used to reveal the association of serum uric acid concentrations and CKD mortality risks. A total of 9891 CKD patients were enrolled in the study, and 3698 individuals died during the follow-up. Increasing serum uric acid levels are independently relevant to higher mortality risks of CKD patients (HR per SD increase). A restricted cubic spline curve showed a nonlinear association between serum uric acid and CKD mortality risks (p for nonlinearity = 0.046). CKD patients with higher levels of serum uric acid (≥ 5.900 mg/dL) show a significant increase in mortality risks (HR = 1.102, 95% CI 1.043-1.165). Sensitivity analysis demonstrated that the results were stable and robust. High serum uric acid levels (≥ 5.900 mg/dL) may be associated with increased mortality risks in CKD patients.

Dapagliflozin and metformin in combination ameliorates diabetic nephropathy by suppressing oxidative stress, inflammation, and apoptosis and activating autophagy in diabetic rats

Considering the effects of sodium-glucose cotransporter inhibitors and metformin on the kidneys, a combination of both agents is postulated to provide protection against diabetic nephropathy (DN). We examined the potential protective effects of dapagliflozin, metformin, and their combination on kidney injury in rats with type 2 diabetes. Diabetic (DM) rats were administered dapagliflozin (1.0 mg/kg/day), metformin (100 mg/kg/day), or a combination (dapagliflozin 0.5 mg/kg/day plus metformin 50 mg/kg/day) by oral gavage for 4 weeks. Dapagliflozin monotherapy or in combination with metformin was more effective than metformin monotherapy in attenuating renal dysfunction, improving renal organic anion transporter 3 expression, and activating renal autophagy by modulating the AMPK/mTOR/SIRT1 axis in DM rats. Interestingly, dapagliflozin monotherapy exhibited greater efficacy in suppressing renal oxidative stress in DM rats than metformin or the combination treatment. Renal and pancreatic injury scores decreased in all treatment groups. Apoptotic markers were predominantly reduced in dapagliflozin monotherapy and combination treatment groups. The low-dose combination treatment, through synergistic coordination, appeared to modulate oxidative, autophagic, and apoptotic signaling and confer significant renoprotective effects against DM-induced complications. In addition, a low dose of the combination might be beneficial to patients by avoiding the risk of side effects of the medication. Future clinical trials are necessary to study the nephroprotective effects of the combined treatment at a low dosage in patients with diabetes.

Chemical Comparison and Identification of Xanthine Oxidase Inhibitors of Dioscoreae Hypoglaucae Rhizoma and Dioscoreae Spongiosae Rhizoma by Chemometric Analysis and Spectrum-Effect Relationship

Dioscoreae hypoglaucae Rhizoma (DH) and Dioscoreae spongiosae Rhizoma (DS) are two similar Chinese herbal medicines derived from the Dioscorea family. DH and DS have been used as medicines in China and other Asian countries for a long time, but study on their phytochemicals and bioactive composition is limited. This present study aimed to compare the chemical compositions of DH and DS, and explore the anti-xanthine oxidase components based on chemometric analysis and spectrum-effect relationship. Firstly, an HPLC method was used to establish the chemical fingerprints of DH and DS samples, and nine common peaks were selected. Then, hierarchical clustering analysis, principal component analysis and orthogonal partial least squares discriminant analysis were employed to compare and discriminate DH and DS samples based on the fingerprints data, and four steroidal saponins compounds (protodioscin, protogracillin, dioscin, gracillin) could be chemical markers responsible for the differences between DH and DS. Meanwhile, the anti-xanthine oxidase activities of these two herbal medicines were evaluated by xanthine oxidase inhibitory assay in vitro. Pearson correlation analysis and partial least squares regression analysis were subsequently used to investigate the spectrum-effect relationship between chemical fingerprints and xanthine oxidase inhibitory activities. The results showed that four steroidal saponins, including protodioscin, protogracillin, methyl protodioscin and pseudoprogracillin could be potential anti-xanthine oxidase compounds in DH and DS. Furthermore, the xanthine oxidase inhibitory activities of the four selected inhibitors were validated by anti-xanthine oxidase inhibitory assessment and molecular docking experiments. The present work provided evidence for understanding of the chemical differences and the discovery of the anti-xanthine oxidase constituent of DH and DS, which could be useful for quality evaluation and bioactive components screening of these two herbal medicines.

Association between cumulative uric acid to high-density lipoprotein cholesterol ratio and the incidence and progression of chronic kidney disease

Objective

The ratio of uric acid to high-density lipoprotein cholesterol (UHR) was related to the risk of chronic kidney disease (CKD), we aimed to investigate the association of cumulative UHR (cumUHR) with incidence and progression of CKD.

Methods

Our study included a total of 49,913 participants (mean age 52.57 years, 77% males) from the Kailuan Study conducted between 2006 and 2018. Participants who completed three consecutive physical examinations were included. Cumulative UHR (cumUHR) was computed as the summed average UHR between two consecutive physical examinations, multiplied by the time between the two examinations. Participants were then categorized into four groups based on cumUHR quartiles. Subsequently, participants were further divided into a CKD group and a non-CKD group. The associations between cumUHR and CKD and it's progression were assessed by Cox proportional hazards regression models. The cumulative incidence of endpoint events was compared between the cumUHR groups using the log-rank test. The C-index, net reclassification improvement (NRI) and integrated discrimination improvement (IDI) were calculated to assess the predictive performance of cumUHR.

Results

After a mean follow-up of 8.0 ± 1.7 years, there were 4843 cases of new-onset CKD, 2504 of low eGFR, and 2617 of proteinuria in the non-CKD group. Within the CKD group, there were 1952 cases of decline in eGFR category, 1465 of >30% decline in eGFR, and 2100 of increased proteinuria. In the non-CKD group, the adjusted hazard ratios (HRs) and confidence intervals (CIs) in the fourth quartile were 1.484 (1.362-1.617), 1.643 (1.457-1.852), and 1.324 (1.179-1.486) for new-onset CKD, low eGFR, and proteinuria, respectively. In the CKD group, the adjusted HRs in the fourth quartile were 1.337 (1.164-1.534), 1.428 (1.216-1.677), and 1.446 (1.267-1.651) for decline in eGFR category, >30% decline in eGFR, and increase in proteinuria, respectively. In addition, we separately added a single UHR measurement and cumUHR to the CKD base prediction model and the CKD progression base prediction model, and found that the models added cumUHR had the highest predictive value.

Conclusion

High cumUHR exposure was an independent risk factor for the incidence and progression of CKD, and it was a better predictor than a single UHR measurement.

Cross-sectional analysis of the correlation between serum uric acid and trabecular bone score: NHANES 2005-2008

Serum uric acid (SUA) has been discovered to be associated with bone mineral density (BMD), but its relationship with trabecular bone score (TBS) remains unclear. Thus, the aim of our study was to investigate the association between SUA levels and TBS. Our study included 5895 individuals over 20 years old (3061 men and 2834 women) from NHANES 2005-2008. To analyze the association between SUA and TBS, multivariate linear regression models with covariate adjustments were applied. Furthermore, population description, stratified analysis, single factor analysis, smooth curve fitting, interaction analysis, and threshold effect and saturation effect analysis were also conducted. After adjusting for covariates, SUA showed a strong negative relationship with total TBS (β = 0.319; 95% CI 0.145-0.494; P < 0.001). The relationship between SUA levels and total TBS was found to be nonlinear, with inflection points at 4.8 mg/dL for the overall population, 4.2 mg/dL for women, and 5.7 mg/dL for non-Hispanic whites, indicating a saturation effect. Additionally, no interactions were found in any of the subgroups. Our study found a negative association between SUA and total TBS in adults. Maintaining SUA at a saturated level can benefit in preventing osteoporosis and fractures.

[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.

Leukocyte-endothelial interaction in CKD

Chronic kidney disease (CKD) represents an independent risk factor for cardiovascular diseases (CVD). Accordingly, CKD patients show a substantial increased risk of cardiovascular mortality. Inflammation represents an important link between CKD and CVD. The interaction between endothelial cells and effector cells of the innate immune system plays a central role in the development and progression of inflammation. Vascular injury causes endothelial dysfunction, leading to augmented oxidative stress, increased expression of leukocyte adhesion molecules and chronic inflammation. CKD induces numerous metabolic changes, creating a uremic milieu resulting in the accumulation of various uremic toxins. These toxins lead to vascular injury, endothelial dysfunction and activation of the innate immune system. Recent studies describe CKD-dependent changes in monocytes that promote endothelial dysfunction and thus CKD progression and CKD-associated CVD. The NLR family pyrin domain containing 3-interleukin-1β-interleukin-6 (NLRP3-IL-1β-IL-6) signaling pathway plays a pivotal role in the development and progression of CVD and CKD alike. Several clinical trials are investigating targeted inhibition of this pathway indicating that anti-inflammatory therapeutic strategies may emerge as novel approaches in patients at high cardiovascular risk and nonresolving inflammation. CKD patients in particular would benefit from targeted anti-inflammatory therapy, since conventional therapeutic regimens have limited efficacy in this population.

Associations between dietary patterns and serum uric acid concentrations in children and adolescents: a cross-sectional study

The serum uric acid (SUA) concentrations in children and adolescents in southeast coastal China are generally high. The relationship between diet and SUA in children and adolescents remains unclear. The objective of the study was to assess the associations between data-driven dietary patterns with SUA concentrations and hyperuricemia in Chinese children and adolescents and to explore the role of food components. This study involved 3383 participants aged 9 to 17 years from a representative nutrition and growth survey conducted in Shenzhen, a southeast coastal city in China. The dietary intake data, obtained from a validated food frequency questionnaire, were categorized into 19 food groups for factor analysis to derive dietary patterns. Weighted least squares regression was performed to examine the associations between dietary patterns and SUA concentrations, logistic regression was used to analyze the relationship between dietary patterns and hyperuricemia, and the relationship between food groups and food components with SUA concentrations was further analyzed. The potential dietary factors contributing to the associations between dietary patterns and SUA concentrations were explored by adjusting various food components. Six dietary patterns were identified by factor analysis, including an ultra-processed diet, plant-based nutritious diet, meat-based diet, soup/seafood/egg diet, vegetarian diet, and mushroom/animal organ diet. After adjusting for confounders, the meat-based diet exhibited a positive correlation with SUA concentrations (β = 4.89; 95% confidence interval (CI): 0.60-9.18; P = 0.03), while the vegetarian diet could reduce the risk of hyperuricemia (odds ratio = 0.88; 95% CI: 0.80-0.98; P = 0.02). In addition, dietary intake of poultry (g per d) (β = 0.09, 95% CI: 0.02, 0.16, P = 0.02), animal organs, blood (g per d) (β = 0.32, 95% CI: 0.12, 0.51, P = 0.002) and hypoxanthine (mg per d) (β = 0.03, 95% CI: 0.01, 0.06, P = 0.02) showed a significantly positive correlation with SUA concentrations, while that of vegetables (g per d) (β = -0.02, 95% CI: -0.03, -0.01, P = 0.03) showed a significantly negative correlation. In summary, for children and adolescents, it is recommended to increase vegetable intake and reduce animal-based food intake in order to control SUA concentration and prevent hyperuricemia. This study was registered at the China Clinical Trials Registry (ChiCTR2100051722).

An integrated machine learning predictive scheme for longitudinal laboratory data to evaluate the factors determining renal function changes in patients with different chronic kidney disease stages

Background and objectives

Chronic kidney disease (CKD) is a global health concern. This study aims to identify key factors associated with renal function changes using the proposed machine learning and important variable selection (ML&IVS) scheme on longitudinal laboratory data. The goal is to predict changes in the estimated glomerular filtration rate (eGFR) in a cohort of patients with CKD stages 3-5.

Design

A retrospective cohort study.

Setting and participants

A total of 710 outpatients who presented with stable nondialysis-dependent CKD stages 3-5 at the Shin-Kong Wu Ho-Su Memorial Hospital Medical Center from 2016 to 2021.

Methods

This study analyzed trimonthly laboratory data including 47 indicators. The proposed scheme used stochastic gradient boosting, multivariate adaptive regression splines, random forest, eXtreme gradient boosting, and light gradient boosting machine algorithms to evaluate the important factors for predicting the results of the fourth eGFR examination, especially in patients with CKD stage 3 and those with CKD stages 4-5, with or without diabetes mellitus (DM).

Main outcome measurement

Subsequent eGFR level after three consecutive laboratory data assessments.

Results

Our ML&IVS scheme demonstrated superior predictive capabilities and identified significant factors contributing to renal function changes in various CKD groups. The latest levels of eGFR, blood urea nitrogen (BUN), proteinuria, sodium, and systolic blood pressure as well as mean levels of eGFR, BUN, proteinuria, and triglyceride were the top 10 significantly important factors for predicting the subsequent eGFR level in patients with CKD stages 3-5. In individuals with DM, the latest levels of BUN and proteinuria, mean levels of phosphate and proteinuria, and variations in diastolic blood pressure levels emerged as important factors for predicting the decline of renal function. In individuals without DM, all phosphate patterns and latest albumin levels were found to be key factors in the advanced CKD group. Moreover, proteinuria was identified as an important factor in the CKD stage 3 group without DM and CKD stages 4-5 group with DM.

Conclusion

The proposed scheme highlighted factors associated with renal function changes in different CKD conditions, offering valuable insights to physicians for raising awareness about renal function changes.

Associations of circulating multiple metals with the risk of incident hyperuricemia and the average annual change in uric acid levels

BACKGROUND

Hyperuricemia has been linked to exposure to certain metals in cross-sectional studies. However, prospective studies evaluating the associations of multiple metal exposures with incident hyperuricemia are scarce.

OBJECTIVES

To prospectively investigate the associations of multiple metal/metalloid concentrations with incident hyperuricemia as well as average annual change in uric acid levels in a longitudinal cohort.

METHODS

A longitudinal cohort study included 3957 subjects who were free of cardiovascular disease with certain risk factors for cardiovascular disease at baseline. Incident hyperuricemia was ascertained if serum uric acid level was ≥ 420 μmol/L for men and ≥ 360 μmol/L for women during the follow-up visit in 2013. The relationships between 17 single plasma metals/metalloids and incident hyperuricemia were assessed using unconditional logistic regression models. For metals/metalloids significantly related to incident hyperuricemia, we further utilized generalized linear regression models to evaluate their associations with the average annual change in uric acid levels. Finally, we applied the weighted quantile sum (WQS) regression to investigate the joint effects of metals/metalloids on hyperuricemia risk and uric acid changes, and to identify the most significant metals.

RESULTS

After adjusting for potential confounders, plasma aluminum, arsenic, barium, lead, strontium, vanadium, and zinc concentrations were positively associated with incident hyperuricemia in both main analyses and sensitivity analyzes. Compared to the lowest quartiles, participants in the highest quartiles had 63 %-125 % higher risks of incident hyperuricemia (all FDR < 0.05). Furthermore, the positive associations of these seven metals with an average annual uric acid increase reinforced the findings. Finally, the WQS analyses showed that plasma metals mixtures were positively associated with the risk of incident hyperuricemia (OR: 1.47; 95 % CI: 1.23, 1.76) and the average annual change in uric acid levels (β: 3.17; 95 % CI: 2.42, 3.93), and strontium and vanadium were the most heavily weighted metals, respectively.

CONCLUSION

Our findings identify aluminum, arsenic, barium, lead, strontium, vanadium, and zinc exposures as independent risk factors for hyperuricemia and provide new insights into the prevention of hyperuricemia.

Relationship between serum uric acid and estimated glomerular filtration rate in adolescents aged 12-19 years with different body mass indices: a cross-sectional study

Background

Globally, chronic kidney disease (CKD) is a growing public health concern. Serum uric acid (SUA) is an easily detectable and readily available biochemical indicator that has long been recognized as an independent risk factor for CKD. In addition, studies have indicated a potential relationship between SUA and body mass index (BMI). However, studies on the effect of SUA levels on the estimated glomerular filtration rate (eGFR) in adolescents with different BMIs are very rare.

Methods

Weighted multiple regression analysis was used to estimate the independent relationship between SUA and log-transformed eGFR. Additionally, we used a weighted generalized additive model and smooth curve fitting to describe the nonlinear relationships in the subgroup analysis.

Results

First, SUA was negatively associated with log-transformed eGFR even after adjusting for all covariates (β=-0.0177, 95% CI: -0.0203-0.0151, P<0.0001). Second, the results of the stratified analysis found that after adjusting for all covariates, the decrease in log-transformed eGFR due to changes in per SUA levels (Per 1, mg/dL increase) was elevated in female adolescents (β=-0.0177, 95% CI: -0.0216, -0.0138, P<0.0001), adolescents aged 12-15 years (β=-0.0163, 95% CI: -0.0200, -0.0125, P<0.0001) and black (β=-0.0199, 95% CI: -0.0251, -0.0148, P<0.0001) adolescents. Furthermore, we found that adolescents with a higher BMI had higher SUA levels, and the effect of SUA on eGFR was significantly higher in underweight adolescents (β=-0.0386, 95% CI: (-0.0550, -0.0223), P<0.0001).

Conclusion

SUA was negatively associated with the eGFR in adolescents aged 12-19 years. Furthermore, we found for the first time that SUA affects the eGFR differently in adolescents with different BMIs. This effect was particularly significant in underweight adolescents.

Hyperuricemia and gout increased the risk of long-term mortality in patients with heart failure: insights from the National Health and Nutrition Examination Survey

BACKGROUND

The prevalence of hyperuricemia, gout, and heart failure (HF) is on the rise, and these conditions often share similar risk factors. The present study aimed to evaluate the relationship among hyperuricemia, gout, HF, and all-cause mortality.

METHODS

The data on nonpregnant participants aged ≥ 20 years with or without hyperuricemia, gout, and HF from the National Health and Nutrition Examination Survey 2001-2018 and 2007-2018 were included in this study. The binary logistic regression, Kaplan-Meier curve, Cox proportional-hazards model, and restricted cubic spline analysis were employed to evaluate the relationship among hyperuricemia, gout, HF, and all-cause mortality.

RESULTS

Of 204,179,060 and 223,702,171 weighted eligible participants, 40,044,228 (19.6%) and 9,158,600 (4.1%) had hyperuricemia and gout, respectively. Older age, diabetes, stroke, and coronary artery disease were the risk factors for HF among patients with hyperuricemia and gout. The median survival time was 7.00 years and 6.25 years and the 5-year survival rate was 59.9% and 55.9% for patients with HF and hyperuricemia and those with HF and gout, respectively. Patients with hyperuricemia or gout were 2.46 and 2.35 times more likely to have HF and 1.37 and 1.45 times more likely to experience all-cause mortality compared with those who did not exhibit these conditions. The restricted cubic spline showed a nonlinear correlation between uric acid levels and HF and a J-shaped correlation between uric acid levels and all-cause mortality.

CONCLUSIONS

Ambulatory patients with hyperuricemia or gout were more likely to have HF compared with those without hyperuricemia or gout. Patients with HF with hyperuricemia or gout were more likely to experience all-cause mortality in the long-term follow-up.

Serum uric acid levels in kidney transplant recipients: A cause for concern? A review of recent literature

The impact of elevated serum uric acid levels i.e., hyperuricemia, on native and transplant chronic kidney disease progression has been debated. This literature review presents an analysis of multiple studies exploring the relationship between serum uric acid levels and kidney transplant outcomes. The review includes a summary of the pathophysiology of hyperuricemia and gout, a review of urate-lowering therapies, and an appraisal of multiple studies examining the association or lack thereof between serum uric acid level and kidney transplant outcomes. Based on these studies, elevated serum uric acid levels may contribute to CKD progression in kidney transplant recipients. In this review, we also summarize current literature to highlight risk factors associated with hyperuricemia as well as the need for further investigation to monitor and manage hyperuricemia in kidney transplant recipients.

Salivary Markers in Patients with Chronic Kidney Disease

Aim of the study: To determine the possibility of using saliva as a diagnostic and prognostic tool for screening and monitoring kidney function. Methods: This study included 32 patients with different stages of chronic kidney disease (CKD) and 20 healthy examinees for the control group. Saliva was collected using the spitting method, and on the same day blood was also drawn from the examinees to determine serum concentrations of urea and creatinine. The salivary values of uric acid, urea, creatinine and albumin were determined with a spectrophotometer, as well as the serum concentrations of urea and creatinine. Results: Our results showed a statistically significant positive correlation between salivary and serum levels of urea and creatinine in patients with CKD (Pearson's correlation coefficient for urea was r =0.6527, p = 0.000, while for creatinine it was r = 0.5486, p = 0.001). We detected a statistically significant positive correlation between the salivary levels of urea and the clinical stage of CKD (r = 0.4667, p = 0.007). We did not register a significant correlation between the salivary levels of creatinine and the clinical stage of CKD (r = 0.1643, p = 0.369). Conclusion : Salivary urea is a valid marker for determining kidney function and a potential salivary marker for screening and monitoring kidney function. Salivary creatinine can be used as a qualitative marker, only indicating the existence of a disease.

Association between the Triglyceride Glucose Index and Hyperuricemia in Patients with Primary Hypertension: A Cross-Sectional Study

Objective

The aim of this study was to investigate the association between the triglyceride glucose (TyG) index and hyperuricemia (HUA) in patients with grades 1-3 hypertension. Study Design. This is a cross-sectional study. A total of 1,707 patients from the cardiovascular department of Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine were studied. In this study, 899 patients with grades 1-2 hypertension were included, of which 151 had HUA; additionally, 808 patients with grade 3 hypertension were included, of which 162 patients had HUA. This study obtained all patient data from the electronic medical record system of the Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine. The TyG index was calculated as Ln (triglycerides × fasting glucose/2). Hyperuricemia was defined as uric acid ≥420 μmol/L (7 mg/dL). Multivariate logistic regression, penalized spline regression, and generalized additive models were used to evaluate the association between the TyG index and HUA. Stratified analyses were performed to assess the association in populations with different grades of hypertension.

Results

The average TyG index was 8.71 ± 0.58. After adjusting for correlated variables, the logistic regression analysis revealed a positive correlation between the TyG index and HUA (OR = 1.83; 95% CI: 1.40-2.39). Smooth curve fitting showed that this correlation was linear in the whole range of the TyG index. In the subgroup analysis, the TyG index more strongly associated with HUA in the grades 1-2 hypertension group (OR = 2.22; 95% CI: 1.44-3.42) compared to that in the grade 3 hypertension group (OR = 1.58; 95% CI: 1.11-2.24; P for interaction = 0.03). In addition, this association was consistent in all models.

Conclusion

The TyG index was positively associated with HUA in patients with hypertension, and the association was more strongly confirmed in those with grades 1-2 hypertension rather than in those with grade 3 hypertension.

Predialysis trajectories of estimated GFR and concurrent trends of Chronic Kidney Disease-relevant biomarkers

Background

The glomerular filtration rate (GFR) decline varies in patients with advanced chronic kidney disease (CKD), and the concurrent changes in CKD-related biomarkers are unclear.

Objectives

This study aimed to examine the changes in CKD-related biomarkers along with the kidney function decline in various GFR trajectory groups.

Design

This study was a longitudinal cohort study originated from the pre-end-stage renal disease (pre-ESRD) care program in a single tertiary center between 2006 and 2019.

Methods

We adopted a group-based trajectory model to categorize CKD patients into three trajectories according to estimated glomerular filtration rate (eGFR) changes. A repeated-measures linear mixed model was used to estimate the concurrent biomarker trends in a 2-year period before dialysis and to examine the differences among trajectory groups. A total of 15 biomarkers were analyzed, including urine protein, serum uric acid, albumin, lipid, electrolytes, and hematologic markers.

Results

Using longitudinal data from 2 years before dialysis initiation, 1758 CKD patients were included. We identified three distinct eGFR trajectories: persistently low eGFR levels, progressive loss of eGFR, and accelerated loss of eGFR. Eight of the 15 biomarkers showed distinct patterns among the trajectory groups. Compared with the group with persistently low eGFR values, the other two groups were associated with a more rapid increase in the blood urea nitrogen (BUN) level and urine protein-creatinine ratio (UPCR), especially in the year before dialysis initiation, and a more rapid decline in hemoglobin and platelet counts. A rapid eGFR decline was associated with lower levels of albumin and potassium, and higher levels of mean corpuscular hemoglobin concentration (MCHC) and white blood cell (WBC). The albumin level in the group with an accelerated loss of eGFR was below the normal range.

Conclusion

Using longitudinal data, we delineated the changes in CKD biomarkers with disease progression. The results provide information to clinicians and clues to elucidate the mechanism of CKD progression.

U-shaped association of serum uric acid with all-cause mortality in patients with hyperlipidemia in the United States: a cohort study

Background

Serum uric acid (SUA) interferes with lipid metabolism and is considered an independent risk factor for atherosclerosis, a major complication in patients with hyperlipidemia. However, the effects of uric acid levels on mortality in hyperlipidemic patients has yet to be sufficiently determined. In this study, we aimed to assess the association between all-cause mortality and SUA in a hyperlipidemic population.

Methods

To determine mortality rates, we obtained data for 20,038 hyperlipidemia patients from the U.S. National Health and Nutrition Examination Surveys (NHANES) 2001-2018 and National Death Index. To examine the all-cause mortality effect of SUA, multivariable Cox regression models, restricted cubic spline models, and two pairwise Cox regression models were used.

Results

Over a median follow-up of 9.4 years, a total of 2079 deaths occurred. Mortality was examined according to SUA level quintiles: <4.2, 4.3-4.9, 5.0-5.7, 5.8-6.5, and >6.6 mg/dl. In multivariable analysis using 5.8-6.5 mg/dl SUA as a reference, the hazard ratios (95% confidence interval) of all-cause mortality across the five groups were 1.24 (1.06-1.45), 1.19 (1.03-1.38), 1.07 (0.94-1.23), 1.00 (reference), and 1.29 (1.13-1.48), respectively. According to a restricted cubic spline, we noted a U-shaped relationship between SUA and all-cause mortality. The inflection point was approximately 6.30 mg/dl, with hazard ratios of 0.91 (0.85-0.97) and 1.22 (1.10-1.35) to the left and right of the inflection point, respectively. In both sexes, SUA was characterized by a U-shaped association, with inflection points at 6.5 and 6.0 mg/dl for males and females, respectively.

Conclusion

Using nationally representative NHANES data, we identified a U-shaped association between SUA and all-cause mortality in participants with hyperlipidemia.

Joint association of hyperuricemia and chronic kidney disease with mortality in patients with chronic heart failure

Background

The joint association of hyperuricemia and chronic kidney disease (CKD) with mortality in patients with chronic heart failure (CHF) is not conclusive.

Methods

This retrospective cohort study was conducted in Chinese People's Liberation Army General Hospital, Beijing, China. We included 9,367 patients with CHF, who were hospitalized between January 2011 and June 2019. The definitions of hyperuricemia and CKD were based on laboratory test, medication use, and medical record. We categorized patients with CHF into 4 groups according to the absence (-) or presence (+) of hyperuricemia and CKD. The primary outcomes included in-hospital mortality and long-term mortality. We used multivariate logistic regression and Cox proportional hazards regression to estimate the mortality risk according to the hyperuricemia/CKD groups.

Results

We identified 275 cases of in-hospital mortality and 2,883 cases of long-term mortality in a mean follow-up of 4.81 years. After adjusting for potential confounders, we found that compared with the hyperuricemia-/CKD- group, the risks of in-hospital mortality were higher in the hyperuricemia+/CKD- group (odds ratio [OR], 95% confidence interval [CI]: 1.58 [1.01-2.46]), hyperuricemia-/CKD+ group (OR, 95% CI: 1.67 [1.10-2.55]), and hyperuricemia+/CKD+ group (OR, 95% CI: 2.12 [1.46-3.08]). Similar results were also found in long-term mortality analysis. Compared with the hyperuricemia-/CKD- group, the adjusted hazard ratios and 95% CI for long-term mortality were 1.25 (1.11-1.41) for hyperuricemia+/CKD- group, 1.37 (1.22-1.53) for hyperuricemia-/CKD+ group, and 1.59 (1.43-1.76) for hyperuricemia+/CKD+ group. The results remained robust in the sensitivity analysis.

Conclusions

Hyperuricemia and CKD, both individually and cumulatively, are associated with increased mortality risk in patients with CHF. These results highlighted the importance of the combined control of hyperuricemia and CKD in the management of heart failure.

Genetic and Epigenetic Regulation of the Innate Immune Response to Gout

Gout is a disease caused by uric acid (UA) accumulation in the joints, causing inflammation. Two UA forms - monosodium urate (MSU) and soluble uric acid (sUA) have been shown to interact physically with inflammasomes, especially with the nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3), albeit the role of the immune response to UA is poorly understood, given that asymptomatic hyperuricemia does also exist. Macrophage phagocytosis of UA activate NLRP3, lead to cytokines release, and ultimately, lead to chemoattract neutrophils and lymphocytes to the gout flare joint spot. Genetic variants of inflammasome genes and of genes encoding their molecular partners may influence hyperuricemia and gout susceptibility, while also influencing other comorbidities such as metabolic syndrome and cardiovascular diseases. In this review, we summarize the inflammatory responses in acute and chronic gout, specifically focusing on innate immune cell mechanisms and genetic and epigenetic characteristics of participating molecules. Unprecedently, a novel UA binding protein - the neuronal apoptosis inhibitor protein (NAIP) - is suggested as responsible for the asymptomatic hyperuricemia paradox.Abbreviation: β2-integrins: leukocyte-specific adhesion molecules; ABCG2: ATP-binding cassete family/breast cancer-resistant protein; ACR: American college of rheumatology; AIM2: absent in melanoma 2, type of pattern recognition receptor; ALPK1: alpha-protein kinase 1; ANGPTL2: angiopoietin-like protein 2; ASC: apoptosis-associated speck-like protein; BIR: baculovirus inhibitor of apoptosis protein repeat; BIRC1: baculovirus IAP repeat-containing protein 1; BIRC2: baculoviral IAP repeat-containing protein 2; C5a: complement anaphylatoxin; cAMP: cyclic adenosine monophosphate; CARD: caspase activation and recruitment domains; CARD8: caspase recruitment domain-containing protein 8; CASP1: caspase 1; CCL3: chemokine (C-C motif) ligand 3; CD14: cluster of differentiation 14; CD44: cluster of differentiation 44; Cg05102552: DNA-methylation site, usually cytosine followed by guanine nucleotides; contains arbitrary identification code; CIDEC: cell death-inducing DNA fragmentation factor-like effector family; CKD: chronic kidney disease; CNV: copy number variation; CPT1A: carnitine palmitoyl transferase - type 1a; CXCL1: chemokine (CXC motif) ligand 1; DAMPs: damage associated molecular patterns; DC: dendritic cells; DNMT(1): maintenance DNA methyltransferase; eQTL: expression quantitative trait loci; ERK1: extracellular signal-regulated kinase 1; ERK2: extracellular signal-regulated kinase 2; EULAR: European league against rheumatism; GMCSF: granulocyte-macrophage colony-stimulating factor; GWAS: global wide association studies; H3K27me3: tri-methylation at the 27th lysine residue of the histone h3 protein; H3K4me1: mono-methylation at the 4th lysine residue of the histone h3 protein; H3K4me3: tri-methylation at the 4th lysine residue of the histone h3 protein; HOTAIR: human gene located between hoxc11 and hoxc12 on chromosome 12; IκBα: cytoplasmatic protein/Nf-κb transcription inhibitor; IAP: inhibitory apoptosis protein; IFNγ: interferon gamma; IL-1β: interleukin 1 beta; IL-12: interleukin 12; IL-17: interleukin 17; IL18: interleukin 18; IL1R1: interleukin-1 receptor; IL-1Ra: interleukin-1 receptor antagonist; IL-22: interleukin 22; IL-23: interleukin 23; IL23R: interleukin 23 receptor; IL-33: interleukin 33; IL-6: interleukin 6; IMP: inosine monophosphate; INSIG1: insulin-induced gene 1; JNK1: c-jun n-terminal kinase 1; lncRNA: long non-coding ribonucleic acid; LRR: leucine-rich repeats; miR: mature non-coding microRNAs measuring from 20 to 24 nucleotides, animal origin; miR-1: miR followed by arbitrary identification code; miR-145: miR followed by arbitrary identification code; miR-146a: miR followed by arbitrary identification code, "a" stands for mir family; "a" family presents similar mir sequence to "b" family, but different precursors; miR-20b: miR followed by arbitrary identification code; "b" stands for mir family; "b" family presents similar mir sequence to "a" family, but different precursors; miR-221: miR - followed by arbitrary identification code; miR-221-5p: miR followed by arbitrary identification code; "5p" indicates different mature miRNAs generated from the 5' arm of the pre-miRNA hairpin; miR-223: miR followed by arbitrary identification code; miR-223-3p: mir followed by arbitrary identification code; "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; miR-22-3p: miR followed by arbitrary identification code, "3p" indicates different mature miRNAs generated from the 3' arm of the pre-miRNA hairpin; MLKL: mixed lineage kinase domain-like pseudo kinase; MM2P: inductor of m2-macrophage polarization; MSU: monosodium urate; mTOR: mammalian target of rapamycin; MyD88: myeloid differentiation primary response 88; n-3-PUFAs: n-3-polyunsaturated fatty-acids; NACHT: acronym for NAIP (neuronal apoptosis inhibitor protein), C2TA (MHC class 2 transcription activator), HET-E (incompatibility locus protein from podospora anserina) and TP1 (telomerase-associated protein); NAIP: neuronal apoptosis inhibitory protein (human); Naip1: neuronal apoptosis inhibitory protein type 1 (murine); Naip5: neuronal apoptosis inhibitory protein type 5 (murine); Naip6: neuronal apoptosis inhibitory protein type 6 (murine); NBD: nucleotide-binding domain; Nek7: smallest NIMA-related kinase; NET: neutrophil extracellular traps; Nf-κB: nuclear factor kappa-light-chain-enhancer of activated b cells; NFIL3: nuclear-factor, interleukin 3 regulated protein; NIIMA: network of immunity in infection, malignancy, and autoimmunity; NLR: nod-like receptor; NLRA: nod-like receptor NLRA containing acidic domain; NLRB: nod-like receptor NLRA containing BIR domain; NLRC: nod-like receptor NLRA containing CARD domain; NLRC4: nod-like receptor family CARD domain containing 4; NLRP: nod-like receptor NLRA containing PYD domain; NLRP1: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 1; NLRP12: nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 12; NLRP3: nod-like receptor family pyrin domain containing 3; NOD2: nucleotide-binding oligomerization domain; NRBP1: nuclear receptor-binding protein; Nrf2: nuclear factor erythroid 2-related factor 2; OR: odds ratio; P2X: group of membrane ion channels activated by the binding of extracellular; P2X7: p2x purinoceptor 7 gene; p38: member of the mitogen-activated protein kinase family; PAMPs: pathogen associated molecular patters; PBMC: peripheral blood mononuclear cells; PGGT1B: geranylgeranyl transferase type-1 subunit beta; PHGDH: phosphoglycerate dehydrogenase; PI3-K: phospho-inositol; PPARγ: peroxisome proliferator-activated receptor gamma; PPARGC1B: peroxisome proliferative activated receptor, gamma, coactivator 1 beta; PR3: proteinase 3 antigen; Pro-CASP1: inactive precursor of caspase 1; Pro-IL1β: inactive precursor of interleukin 1 beta; PRR: pattern recognition receptors; PYD: pyrin domain; RAPTOR: regulatory associated protein of mTOR complex 1; RAS: renin-angiotensin system; REDD1: regulated in DNA damage and development 1; ROS: reactive oxygen species; rs000*G: single nuclear polymorphism, "*G" is related to snp where replaced nucleotide is guanine, usually preceded by an id number; SLC2A9: solute carrier family 2, member 9; SLC7A11: solute carrier family 7, member 11; SMA: smooth muscular atrophy; Smac: second mitochondrial-derived activator of caspases; SNP: single nuclear polymorphism; Sp3: specificity protein 3; ST2: serum stimulation-2; STK11: serine/threonine kinase 11; sUA: soluble uric acid; Syk: spleen tyrosine kinase; TAK1: transforming growth factor beta activated kinase; Th1: type 1 helper T cells; Th17: type 17 helper T cells; Th2: type 2 helper T cells; Th22: type 22 helper T cells; TLR: tool-like receptor; TLR2: toll-like receptor 2; TLR4: toll-like receptor 4; TNFα: tumor necrosis factor alpha; TNFR1: tumor necrosis factor receptor 1; TNFR2: tumor necrosis factor receptor 2; UA: uric acid; UBAP1: ubiquitin associated protein; ULT: urate-lowering therapy; URAT1: urate transporter 1; VDAC1: voltage-dependent anion-selective channel 1.

Association between serum uric acid and phase angle in patients with type 2 diabetes mellitus: A cross-sectional study

Background

The purpose of this analysis was to investigate the associations between serum uric acid and phase angle in patients with type 2 diabetes mellitus.

Methods

In this retrospective cross-sectional study, we included 200 type 2 diabetes mellitus (T2DM) patients treated during 2018-2019 at Zhongda Hospital Southeast University. Phase angle (PhA) and other body composition indicators were measured by bioelectrical impedance analysis (BIA). All patients underwent routine clinical examinations on the day of hospitalization, and the basic information and clinical symptoms of these patients were recorded.

Results

Serum uric acid (UA) was significantly associated with PhA (p <0.001). Overall, in the crude model and minor, all adjusted models (crude model, Models I-II), the phase angle increased as the tertiles of serum uric acid increased. In the minor adjusted model (Model I, adjustment for age and duration) fully adjusted model (Model II, adjustment for age, duration, Lpa, BMI, and WHR), the adjusted β for participants in tertiles of serum uric acid were 0.26 (95% CI: 0.05-0.46) and 0.32 (95% CI: 0.11-0.54), respectively, compared with those in the lowest tertile 1.

Conclusion

There was a nonlinear relationship between serum uric acid and PhA in T2DM patients, and the phase angle increased as uric acid increased within a certain range, and this effect disappeared when uric acid exceeded a certain value.

Longitudinal uric acid has nonlinear association with kidney failure and mortality in chronic kidney disease

We investigated the shape of the relationship between longitudinal uric acid (UA) and the hazard of kidney failure and death in chronic kidney disease (CKD) patients, and attempted to identify thresholds associated with increased hazards. We included CKD stage 3-5 patients from the CKD-REIN cohort with one serum UA measurement at cohort entry. We used cause-specific multivariate Cox models including a spline function of current values of UA (cUA), estimated from a separate linear mixed model. We followed 2781 patients (66% men, median age, 69 years) for a median of 3.2 years with a median of five longitudinal UA measures per patient. The hazard of kidney failure increased with increasing cUA, with a plateau between 6 and 10 mg/dl and a sharp increase above 11 mg/dl. The hazard of death had a U-shape relationship with cUA, with a hazard twice higher for 3 or 11 mg/dl, compared to 5 mg/dl. In CKD patients, our results indicate that UA above 10 mg/dl is a strong risk marker for kidney failure and death and that low UA levels below 5 mg/dl are associated with death before kidney failure.

Concentration of serum uric acid in patients with Renal Artery Stenosis and Hypertension prEdict Future nephropathy and death: C-RASHEF study

Since both serum uric acid (SUA) and renal artery stenosis (RAS) are associated with atherosclerotic events and renal events, it is interesting to investigate whether SUA could predict long-term outcome in patients with RAS. Patients were enrolled from inpatients from 2010 to 2014, must be ≥40-year-old. There were 3269 hypertensive patients enrolled, including 325 RAS patients. Endpoints included all-cause death and new or worsening nephropathy (NNP). In analysis for all-cause mortality, associations between SUA and risk of all-cause mortality were an arising curve in total population, a U-shape curve in non-RAS population, and an arising curve in RAS population. When RAS was involved in multivariate analysis, association between SUA and risk of all-cause mortality was still an arising curve in total population. In analysis for NNP, associations between SUA and risk of NNP were a declining curve in total population, not significant in non-RAS population, and a U-shape curve in RAS population. When RAS was involved in multivariate analysis, association between SUA and risk of NNP in total population was no longer significant. Not only association curve of SUA with mortality in non-RAS patients is different from association curve in RAS patients, but also association curve of SUA with NNP in non-RAS patients is different from association curve in RAS patients. The authors conclude that mechanisms of uric acid for mortality and NNP in RAS patients are different from non-RAS patients. In addition to renal vascular obstruction, uric acid is another significant factor for NNP and death in RAS patients.

Longitudinal changes in uric acid concentration and their relationship with chronic kidney disease progression in children and adolescents

BACKGROUND

Elevated serum uric acid concentration is a risk factor for CKD progression. Its change over time and association with CKD etiology and concomitant changes in estimated glomerular filtration rate (eGFR) in children and adolescents are unknown.

METHODS

Longitudinal study of 153 children/adolescents with glomerular (G) and 540 with non-glomerular (NG) etiology from the CKD in Children (CKiD) study. Baseline serum uric acid, change in uric acid and eGFR over time, CKD etiology, and comorbidities were monitored. Adjusted linear mixed-effects regression models quantified the relationship between within-person changes in uric acid and concurrent within-person changes in eGFR.

RESULTS

Participants with stable uric acid over follow-up had CKD progression which became worse for increased baseline uric acid (average annual percentage changes in eGFR were - 1.4%, - 7.7%, and - 14.7% in those with G CKD with baseline uric acid < 5.5 mg/dL, 5.5 - 7.5 mg/dL, and > 7.5 mg/dL, respectively; these changes were - 1.4%, - 4.1%, and - 8.6% in NG CKD). Each 1 mg/dL increase in uric acid over follow-up was independently associated with significant concomitant eGFR decreases of - 5.7% (95%CI - 8.4 to - 3.0%) (G) and - 5.1% (95%CI - 6.3 to - 4.0%) (NG) for those with baseline uric acid < 5.5 mg/dL and - 4.3% (95%CI - 6.8 to - 1.6%) (G) and - 3.3% (95%CI - 4.1 to - 2.6%) (NG) with baseline uric acid between 5.5 and 7.5 mg/dL.

CONCLUSIONS

Higher uric acid levels and increases in uric acid over time are risk factors for more severe progression of CKD in children and adolescents. A higher resolution version of the Graphical abstract is available as Supplementary information.

Therapeutic effects of traditional Chinese medicine on gouty nephropathy: Based on NF-κB signalingpathways

As the final product of purine metabolism, excess serum uric acid (SUA) aggravates the process of some metabolic diseases. SUA causes renal tubule damage, interstitial fibrosis, and glomerular hardening, leading to gouty nephropathy (GN). A growing number of investigations have shown that NF-κB mediated inflammation and oxidative stress have been directly involved in the pathogenesis of GN. Traditional Chinese medicine's treatment methods of GN have amassed a wealth of treatment experience. In this review, we first describe the mechanism of NF-κB signaling pathways in GN. Subsequently, we highlight traditional Chinese medicine that can treat GN through NF-κB pathways. Finally, commenting on promising candidate targets of herbal medicine for GN treatment via suppressing NF-κB signaling pathways was summarized.

Metabolic Dysfunction-Associated Fatty Liver Disease in Newly Diagnosed, Treatment-Naive Hypertensive Patients and Its Association with Cardiorenal Risk Markers

INTRODUCTION

Patients with arterial hypertension frequently present with comorbidities that are associated with increased cardiorenal risk, such as metabolic dysfunction-associated fatty liver disease (MAFLD).

AIMS

Our study aimed to assess the prevalence and the association of MAFLD with cardiorenal risk markers in newly diagnosed, treatment-naïve hypertensive patients.

METHODS

We recruited 281 individuals with new-onset hypertension who were not prescribed any medication. Medical history, clinical examination findings, and laboratory test results were recorded. Liver steatosis was assessed through fatty liver index (FLI) calculation. Patients with FLI ≥ 60 together with one main metabolic abnormality (type 2 diabetes mellitus or overweight/obesity) or at least two metabolic risk abnormalities (increased waist circumference, blood pressure, plasma triglycerides, presence of prediabetes or insulin resistance, decreased plasma high-density lipoprotein) fulfilled the diagnostic criteria for MAFLD.

RESULTS

The prevalence of MAFLD in our study population was 28.7%. Individuals with MAFLD were more frequently male and had increased body mass index. Systolic, diastolic, and pulse pressure values were significantly higher in this group of patients. Moreover, lipid, renal, glucose, and inflammatory markers were considerably deranged in patients with MAFLD. After multivariate regression analysis, uric acid, ferritin, and apoE emerged as independent predictors of MAFLD. Area under receiver operating characteristics curve revealed that uric acid had the greatest diagnostic accuracy, with the ideal cutoff being ≥ 5.2 mg/dl (sensitivity: 77.6%, specificity: 76.3%).

CONCLUSION

MAFLD represents a common comorbidity in hypertensive patients and is associated with markers of cardiorenal risk. Uric acid may be indicative of MAFLD in particular.

Paper-based colorimetric glucose sensor using Prussian blue nanoparticles as mimic peroxidase

A novel paper-based colorimetric glucose sensor was proposed employing Prussian blue nanoparticles (PB NPs) as mimic peroxidase. The sensor was manufactured by spraying solution containing PB NPs, glucose oxidase and chromogenic agents into a paper, then coating the filter layer and spreading layer on the top. The layer-by-layer structure enabled the sensor detect glucose in whole blood, as well as elimination of the coffee-ring effect which ensure the performance. As a powerful alternative to natural peroxidase, PB NPs showed the mimic enzymatic activity well preserved in dry environment. The manufacture process of the sensor is easy to be industrialized. Under optimal conditions, the sensor exhibited a linear range from 2.5 mM to 25 mM for glucose in blood with satisfactory reproducibility (the coefficient of variant <4%), great storage stability (1 month at 45 °C) and excellent linearity compared with those commercial kits (R > 0.99). Coupled with a handhold device, the PB NPs-based test strip realized the goal of personal operation, user-friendly control, automatic readouts, and data storage, and able to link the Cloud, showing unique potential in clinical application, especially in community-level medical scenarios.

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.

Association of caffeine intake with all-cause and cardiovascular mortality in elderly patients with hypertension

Background

Caffeine is widely consumed not only in coffee but also in soft drinks and tea. However, the long-term health effects of caffeine are still controversial, especially in people with high cardiovascular risk such as elderly patients with hypertension.

Methods

This study analyzed data from the National Health and Nutrition Examination Survey 2003-2018. Caffeine intake was calculated by two 24-h dietary recall interviews. Complex sampling-weighted multivariable Cox proportional hazards models were used to compare the hazard ratios (HRs) of all-cause and cardiovascular mortality in elderly hypertensive patients with different caffeine intake (<10, 10 to <100, 100 to <200, 200 to <300, and ≥300 mg/day).

Results

This study included 6,076 elderly hypertensive patients. The mean ± standard error follow-up duration was 6.86 ± 0.12 years. During this period, a total of 2,200 all-cause deaths occurred, of which 765 were cardiovascular deaths. Taking patients with caffeine intake < 10 mg/day as a reference, patients with moderate caffeine intake (200 to <300 mg/day) had a lower risk of all-cause (HR, 0.70 [95% CI, 0.56-0.87]) and cardiovascular (HR, 0.55 [95% CI, 0.39-0.77]) mortality. The benefit of reducing all-cause mortality risk was significant in female patients (HR, 0.65 [95% CI, 0.50-0.85]) or patients with well-controlled blood pressure (HR, 0.63 [95% CI, 0.46-0.87]), but not in male patients or patients with poorly controlled blood pressure. In addition, non-linear relationship analysis also showed that moderate caffeine intake had the lowest HRs of all-cause (Non-linear p = 0.022) and cardiovascular mortality (Non-linear p = 0.032) in the present study.

Conclusion

Moderate caffeine intake is associated with reduced risk of all-cause and cardiovascular mortality in elderly hypertensive patients.

Whole transcriptome expression profiles in kidney samples from rats with hyperuricaemic nephropathy

Hyperuricaemic nephropathy (HN) is a common clinical complication of hyperuricaemia (HUA) and poses a huge threat to human health. Hence, we aimed to prospectively investigate the dysregulated genes, pathways and networks involved in HN by performing whole transcriptome sequencing using RNA sequencing. Six kidney samples from HN group (n = 3) and a control group (n = 3) were obtained to conduct RNA sequencing. To disclose the relevant signalling pathways, we conducted the analysis of differentially expressed genes (DEGs), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. A competitive endogenous RNA (ceRNA) network was established to reveal the interactions between lncRNAs, circRNAs, mRNAs and miRNAs and investigate the potential mechanisms of HN. Ultimately, 2250 mRNAs, 306 lncRNAs, 5 circRNAs, and 70 miRNAs were determined to be significantly differentially expressed in the HN group relative to the control group. We further authenticated 8 differentially expressed (DE)-ncRNAs by quantitative real-time polymerase chain reaction, and these findings were in accordance with the sequencing results. The analysis results evidently showed that these DE-ncRNAs were significantly enriched in pathways related to inflammatory reaction. In conclusion, HUA may generate abnormal gene expression changes and regulate signalling pathways in kidney samples. Potentially related genes and pathways involved in HN were identified.

Prevalence and related factors of hyperuricaemia in Chinese children and adolescents: a pooled analysis of 11 population-based studies

BACKGROUND AND AIMS

Hyperuricaemia can lead to gout and is associated with an increased risk of cardiometabolic disease. We aimed to investigate the prevalence of hyperuricaemia and its related factors in Chinese children and adolescents.

METHODS

We pooled data from 11 population-based studies comprising 54,580 participants aged 3-19 years. The sex- and age-standardized prevalence of hyperuricaemia was estimated overall and by sex, age, weight status, geographic region and survey year.

RESULTS

Serum uric acid (SUA) increased gradually from 3 to 11 years with no significant sex difference, and then increased dramatically during 11-15 years. The estimated overall prevalence of hyperuricaemia was 23.3% (26.6% in boys and 19.8% in girls, p < .001). The prevalence increased with growing age (3.7, 9.8, 15.8, 35.5 and 31.7% among children aged 3-5, 6-8, 9-11, 12-15 and 16-19 years, respectively, p for trend < .001) and with increasing weight status (18.2, 37.6, 50.6 and 64.5% among children with non-overweight, overweight, obesity and extreme obesity, respectively, p for trend < .001). The prevalence was higher in North than in South (24.2 vs. 19.7%, p < .001), and increased markedly from 16.7% during 2009-2015 to 24.8% during 2016-2019. In multivariable regression analyses, sex, age, obesity, region and survey year were independently associated with odds of hyperuricaemia.

CONCLUSIONS

The prevalence of hyperuricaemia in Chinese children and adolescents is unexpectedly high. The findings suggest an urgent need to implement effective interventions to reduce risk of hyperuricaemia in Chinese youths.KEY MESSAGESQuestion: What is the prevalence of hyperuricaemia in Chinese children and adolescents?Findings: In this large pooled cross-sectional study comprising >50,000 children and adolescents aged 3-19 years, we found that the prevalence of hyperuricaemia was high in overall population and subgroups of sex, age, obesity, region and survey year.Meaning: Our findings indicate that hyperuricaemia is an important health problem in Chinese children and adolescents, and effective intervention strategies are needed to reduce its burden.

Alpha-mangostin counteracts hyperuricemia and renal dysfunction by inhibiting URAT1 renal transporter in insulin resistance rat model

Background

Alpha-mangostin (AM) has been shown to have hypoglycemic activity. This study aimed to analyze the effects of AM at a dose of 100 mg/kg and 200 mg/kg to alleviate hyperuricemia and renal dysfunction on high-fat/high-glucose diet and low dose streptozotocin (HF/HG/STZ) injection-induced IR rat model. IR was induced in male Wistar rats by giving a HF/HG diet for 11 weeks and single injection of STZ (35 mg/kg, i.p.), then divided randomly into IR rats, IR rats treated with AM 100 and 200 mg/kgBW given by gavage for 8 weeks. At the end of the 11th week, all rats were killed, and the kidneys were taken to be analyzed for urate transporters 1 (URAT1) and glucose transporters 9 (GLUT9). We also assessed serum uric acid, proteinuria, BUN, creatinine clearance, HOMA-IR, and fasting blood glucose (FBG).

Results

We have found the significant increase in HOMA-IR and FBG levels of the IR rats, in comparison with its control groups, which were decreased significantly after AM administration at both doses. URAT1 and GLUT9 mRNA and protein expressions in kidney in the IR + AM at both doses groups also decreased compared those in the IR without treatment group, though the decrease in GLUT9 did not appear to be statistically significant. Consequently, hyperuricemia and renal dysfunction were attenuated by AM treatment at both doses.

Conclusion

After considering all findings, AM might be a potential candidate to ameliorate IR-induced hyperuricemia and renal dysfunction at least in part by modulating the renal URAT1.

Effects of allopurinol on renal function in patients with diabetes: a systematic review and meta-analysis

BACKGROUND/OBJECTIVE

Diabetes mellitus is a common "non-gout" disease with high incidence. Several studies have shown that serum uric acid level in patients with diabetes is higher than that in healthy individuals, and is accompanied by severe albuminuria and high serum creatinine (Scr). Recent clinical studies have found that uric acid-lowering therapy (such as allopurinol) could reduce urinary albumin excretion rates (UAER) and Scr, increase eGFR, and thus reduce kidney damage in patients with diabetes. Therefore, this meta-analysis [PROSPERO CRD42021274465] intended to evaluate the efficacy and safety of allopurinol in patients with diabetes mellitus.

METHODS

We thoroughly searched five electronic resource databases for randomized controlled trials (RCTs) that compared the efficacy and safety of allopurinol versus conventional treatment or placebo for the treatment of patients with diabetes mellitus. Predetermined outcomes were considered continuous variables, mean difference (MD) was used for the determination of effect size (standardized mean difference [SMD] was used to determine the effect size when there were different evaluation criteria in different articles), and the corresponding 95% confidence interval (CI) was calculated. All outcome measures were analyzed using a random-effects model for data analysis.

RESULTS

Ten eligible trials with a total of 866 participants were included in the meta-analysis. Allopurinol was more effective in decreasing serum uric acid (SUA) levels compared with conventional treatment (p = 0.0001) or placebo (p < 0.00001). Moreover, the levels of 24-hour urine protein were significantly lower in the allopurinol group (p < 0.00001). The subgroup analysis of Scr showed that the Scr of patients with an allopurinol treatment duration of fewer than six months was significantly lower than that of the control group (p = 0.03). No significant difference in adverse events (AEs) was identified between the treatment and control groups.

CONCLUSIONS

Our meta-analysis of RCTs showed that oral administration of allopurinol effectively reduced SUA levels in patients with diabetes, and patients' renal function was protected. More RCTs with larger sample sizes and higher quality are needed to clarify the role of allopurinol use in decreasing blood pressure, maintaining blood glucose levels, and improving renal function in patients with diabetes.

Triglyceride-glucose index is significantly associated with the risk of hyperuricemia in patients with diabetic kidney disease

Triglyceride-glucose (TyG) index has been proposed to be a simple, economical, and reliable marker of insulin resistance. We aimed to investigate whether TyG is an independent predictor of hyperuricemia in diabetic kidney disease (DKD) populations by conducting a cross-sectional and longitudinal study. A total of 6,471 patients were enrolled in cross-sectional analysis, and 3,634 patients without hyperuricemia at the baseline were included in longitudinal analysis and were followed up for a median of 23.0 months. Hyperuricemia was categorized as a serum uric acid level ≥ 420 umol/L (7 mg/dL). In this study, 19.58% of participants had hyperuricemia. In the cross-sectional analysis, multivariate logistics regression analysis showed that the ORs (95% CI) for hyperuricemia in the second, third, and fourth TyG quartiles were 1.40 (95% CI 0.73-2.65), 1.69 (95% CI 0.90-3.18), and 4.53 (95% CI 2.39-8.57), respectively, compared with the first quartile. Longitudinally, the Kaplan-Meier survival analysis showed that higher TyG levels predicted higher incidence of hyperuricemia. Multivariate Cox regression model revealed that the hazard ratios for hyperuricemia in the upper quartiles of the TyG index were 1.69 (95% CI 0.97-2.93), 2.23 (95% CI 1.33-3.75), and 2.50 (95% CI 1.46-4.27), respectively, compared with the first quartile. Moreover, the subgroup analyses revealed that the relationship between TyG levels and hyperuricemia was robust in DKD patients. Our findings indicate a significant independent correlation between the TyG index and the risk of hyperuricemia in DKD patients.

Predictive markers in chronic kidney disease

Chronic kidney disease (CKD) is defined by gradual deterioration of the renal parenchyma and decline of functioning nephrons. CKD is now recognized as a distinct risk factor for cardiovascular disease (CVD). This risk rises in tandem with the decline in kidney function and peaks at the end-stage. It is important to identify individuals with CKD who are at a higher risk of advancing to end-stage renal disease (ESRD) and the beginning of CVD. This will enhance the clinical benefits and so that evidence-based therapy may be started at the initial stages for those individuals. A promising biomarker must represent tissue damage, and be easy to detect using non-invasive methods. Current CKD progression indicators have difficulties in reaching this aim. Hence this review presents an update on markers studied in the last decade, which help in the prediction of CKD progression such as neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, urinary liver-type fatty acid-binding protein, cystatin-C, asymmetric dimethylarginine, symmetric dimethylarginine, endotrophin, methylglyoxal, sclerostin, uric acid, and miRNA-196a. Additional research is needed to determine the predictive usefulness of these indicators in clinical samples for disease development. Their utility as surrogate markers need to be explored further for the early identification of CKD progression.

Fibroblast Growth Factor 21 Attenuates the Progression of Hyperuricemic Nephropathy through Inhibiting Inflammation, Fibrosis and Oxidative stress

Elevated levels of circulating fibroblast growth factor 21 (FGF21) have been reported in patients with hyperuricemia. However, the effect of FGF21 in hyperuricemic nephropathy (HN) remains unexplored. Here, we investigated the effect and mechanism of action of FGF21 on HN. HN model was induced with adenine and potassium oxysalt in wild-type C57BL/6 mice and FGF21^-/- mice. For in vitro studies, human renal tubular epithelial (HK-2) cells were exposed to uric acid with/without FGF21 or β-Klotho-siRNA. Here, we reported aggravated renal dysfunction and structural damage in the FGF21^-/- mice compared to the wild-type mice. These were evident in the upsurge of inflammatory factors IL-1β, TNF-α, IL-6 and IL-18, fibrotic markers Collagen I and α-SMA, and oxidation products ROS and MDA. However, exogenous administration of FGF21 to wild-type HN mice significantly reversed these negative effects. In terms of mechanism, FGF21 significantly inhibited NF-κB/NLRP3 and TGF-β1/Smad3 pathways and promoted nuclear translocation of Nrf2 both in vivo and in vitro. Furthermore, the silencing of β-Klotho was marked by the attenuation of the improved effect of FGF21 on cell damage. In conclusion, our studies revealed that exogenous FGF21 treatment significantly improved HN, which was achieved by the inhibition of inflammation, fibrosis and oxidative stress.

Research progress of risk factors and early diagnostic biomarkers of gout-induced renal injury

Gout renal injury has an insidious onset, no obvious symptoms, and laboratory abnormalities in the early stages of the disease. The injury is not easily detected, and in many cases, the patients have entered the renal failure stage at the time of diagnosis. Therefore, the detection of gout renal injury–related risk factors and early diagnostic biomarkers of gout renal injury is essential for the prevention and early diagnosis of the disease. This article reviews the research progress in risk factors and early diagnostic biomarkers of gout renal injury.

Autophagy-dependent Na+-K+-ATPase signalling and abnormal urate reabsorption in hyperuricaemia-induced renal tubular injury

Increasing evidence indicates that hyperuricaemia (HUA) is not only a result of decreased renal urate excretion but also a contributor to kidney disease. Na⁺-K⁺-ATPase (NKA), which establishes the sodium gradient for urate transport in proximal tubular epithelial cells (PTECs), its impairment leads to HUA-induced nephropathy. However, the specific mechanism underlying NKA impairment-mediated renal tubular injury and increased urate reabsorption in HUA is not well understood. In this study, we investigated whether autophagy plays a key role in the NKA impairment signalling and increased urate reabsorption in HUA-induced renal tubular injury. Protein spectrum analysis of exosomes from the urine of HUA patients revealed the activation of lysosomal processes, and exosomal expression of lysosome membrane protein 2 was associated with increased serum levels and decreased renal urate excretion in patients. We demonstrated that high uric acid (UA) induced lysosome dysfunction, autophagy and inflammation in a time- and dose-dependent manner and that high UA and/or NKA α1 siRNA significantly increased mitochondrial abnormalities, such as reductions in mitochondrial respiratory complexes and cellular ATP levels, accompanied by increased apoptosis in cultured PTECs. The autophagy inhibitor hydroxychloroquine (HCQ) ameliorated NKA impairment-mediated mitochondrial dysfunction, Nod-like receptor pyrin domain-containing protein 3 (NLRP3)-interleukin-1β (IL-1β) production, and abnormal urate reabsorption in PTECs stimulated with high UA and in rats with oxonic acid (OA)-induced HUA. Our findings suggest that autophagy plays a pivotal role in NKA impairment-mediated signalling and abnormal urate reabsorption in HUA-induced renal tubular injury and that inhibition of autophagy by HCQ could be a promising treatment for HUA.