Hyperuricemia and Progression of CKD in Children and Adolescents: The Chronic Kidney Disease in Children (CKiD) Cohort Study

Clinical characteristics of adolescent-onset gout in Chinese: A hospital-based cross-sectional study

OBJECTIVE

Adolescent-onset gout has a greater impact on the lives and health of patients than adult-onset gout. However, there is a relative lack of clinical information on adolescent-onset gout. Hence, we analyzed a Chinese cohort.

METHODS

We studied clinical features of 9,003 Chinese patients. Gout onset age of 12 - 19 years is defined as adolescent-onset group (AG), 20 - 40 years as early-onset group (EG), and 41 - 64 years as late-onset group (LG). Multivariable regression analysis evaluated factors associated with recurrent flares, serum urate (SU) levels, and underexcretion type in AG.

RESULTS

Compared with EG and LG, the AG had higher SU levels [AG: 9.5 (2.2) mg/dL, EG: 8.6 (2.1) mg/dL, LG: 7.73 (2.0) mg/dL, P < 0.001], higher percentage of positive family history of gout (AG: 41.8 %, EG: 29.6 %, LG: 24.6 %, P < 0.001), underexcretion type (AG: 62.4 %, EG: 62.5 %, LG: 58.8 %, P = 0.04), recurrent flares (AG: 78.1 %, EG: 70.3 %, LG: 68.9 %, P = 0.01). Urate-lowering therapy (ULT) initiated [OR 6.58 (95 % CI 1.35 - 32.00)] and hypercholesterolemia [OR 4.16 (95 % CI 1.28 - 13.53)] were associated with recurrent flares. eGFR was identified to be a significant variable of increasing SU levels [beta -0.24 (95 % CI -0.04 to -0.01)]. Hypertriglyceridemia [OR 0.35 (95 % CI 0.17 - 0.71)] was related to underexcretion type.

CONCLUSION

Adolescent-onset gout patients had clinically distinctive features with higher SU levels, BMI, positive gout family history, underexcretion type and recurrent flares. These specific populations were less likely to achieve ULT target, requiring more clinical attention.

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.

Role of TFEB-autophagy lysosomal pathway in palmitic acid induced renal tubular epithelial cell injury

Lysosomal dysfunction and impaired autophagic flux are involved in the pathogenesis of lipotoxicity in the kidney. Here, we investigated the role of transcription factor EB (TFEB), a master regulator of autophagy-lysosomal pathway, in palmitic acid induced renal tubular epithelial cells injury. We examined lipid accumulation, autophagic flux, expression of Ps211-TFEB, and nuclear translocation of TFEB in HK-2 cells overloaded with palmitic acid (PA). By utilizing immunohistochemistry, we detected TFEB expression in renal biopsy tissues from patients with diabetic nephropathy and normal renal tissue adjacent to surgically removed renal carcinoma (controls), as well as kidney tissues from rat fed with high-fat diet (HFD) and low-fat diet (LFD). We found significant lipid accumulation, increased apoptosis, accompanied with elevated Ps211-TFEB, decreased nuclear TFEB, reduced lysosome biogenesis and insufficient autophagy in HK-2 cells treated with PA. Kidney tissues from patients with diabetic nephropathy had lower nuclear and total levels of TFEB than that in control kidney tissues. Level of renal nuclear TFEB in HFD rats was also lower than that in LFD rats. Exogenous overexpression of TFEB increased the nuclear TFEB level in HK-2 cells treated with PA, promoted lysosomal biogenesis, improved autophagic flux, reduced lipid accumulation and apoptosis. Our results collectively indicate that PA is a strong inducer for TFEB phosphorylation modification at ser211 accompanied with lower nuclear translocation of TFEB. Impairment of TFEB-mediated lysosomal biogenesis and function by palmitic acid may lead to insufficient autophagy and promote HK-2 cells injury.

Kidney damage predictors in children with metabolically healthy and metabolically unhealthy obesity phenotype

BACKGROUND

Obesity and kidney damage have been closely linked in adults, but little is still known in childhood.

OBJECTIVE

To identify predictors of kidney damage in children with metabolically healthy (MHO) and metabolically unhealthy (MUO) obesity phenotypes.

METHODS

We retrospectively examined 396 children with obesity (mean age 10.72 ± 2.71 years, body mass index-standard deviation score, BMI-SDS, 2.23 ± 0.57) stratified according to metabolic phenotypes. Kidney damage was defined as the presence of reduced estimated glomerular filtration rate (eGFR < 90 mL/min/1.73m2) and/or albuminuria (≥ 30 mg/g urinary creatinine).

RESULTS

Kidney damage was found in 20.9% of the study population. Children with kidney damage had higher BMI-SDS, homeostasis model assessment of insulin resistance (HOMA-IR), and inflammation markers levels and increased prevalence of non-alcoholic fatty liver disease (NAFLD) than those without kidney damage (all p < 0.005). MUO and MHO subjects had respectively an odds ratio (OR) to show kidney damage of of 1.92 (95%CI:1.22-3.01; p = 0.005) and 1.05 (95%CI:1.00-1.09; p = 0.028) after adjustments. Moreover, we found that only HOMA-IR was closely associated to kidney damage in MUO group (OR = 2.07;95%CI:1.20-3.57; p = 0.007), while HOMA-IR (OR = 1.15;95%CI:1.02-1.29; p = 0.011) and uric acid (OR = 1.15;95% CI:1.02-1.30; p = 0.010) were the only significant risk factors for kidney damage in MHO group.

CONCLUSION

An increased risk of kidney damage has been observed in children with obesity and in particular in those with MUO phenotype. As their role on kidney function, HOMA-IR should be monitored in MUO children and both HOMA-IR and uric acid in MHO children.

Nutrition in Children With Chronic Kidney Disease: How to Thrive?

The nutritional status and management of children with chronic kidney disease (CKD) are complex and require a combined pediatric nephrology team work approach with physicians, nutritionists, nurses, and physical/occupational therapists. Prospective observational studies such as Children with CKD in the US, the 4C study in Europe and the International Pediatric Peritoneal Dialysis Network have advanced the field. However, most recommendations and guidelines from international task forces such as Kidney Diseases Improving Global Outcomes and Pediatric Renal Nutrition Taskforce are opinion-based rather than evidence-based. There is exciting ongoing research to improve nutrition in children with CKD to help them thrive.

Development of an adaptive clinical web-based prediction tool for kidney replacement therapy in children with chronic kidney disease

Clinicians need improved prediction models to estimate time to kidney replacement therapy (KRT) for children with chronic kidney disease (CKD). Here, we aimed to develop and validate a prediction tool based on common clinical variables for time to KRT in children using statistical learning methods and design a corresponding online calculator for clinical use. Among 890 children with CKD in the Chronic Kidney Disease in Children (CKiD) study, 172 variables related to sociodemographics, kidney/cardiovascular health, and therapy use, including longitudinal changes over one year were evaluated as candidate predictors in a random survival forest for time to KRT. An elementary model was specified with diagnosis, estimated glomerular filtration rate and proteinuria as predictors and then random survival forest identified nine additional candidate predictors for further evaluation. Best subset selection using these nine additional candidate predictors yielded an enriched model additionally based on blood pressure, change in estimated glomerular filtration rate over one year, anemia, albumin, chloride and bicarbonate. Four additional partially enriched models were constructed for clinical situations with incomplete data. Models performed well in cross-validation, and the elementary model was then externally validated using data from a European pediatric CKD cohort. A corresponding user-friendly online tool was developed for clinicians. Thus, our clinical prediction tool for time to KRT in children was developed in a large, representative pediatric CKD cohort with an exhaustive evaluation of potential predictors and supervised statistical learning methods. While our models performed well internally and externally, further external validation of enriched models is needed.

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).

Exploring the Multifaceted Nexus of Uric Acid and Health: A Review of Recent Studies on Diverse Diseases

The prevalence of patients with hyperuricemia or gout is increasing worldwide. Hyperuricemia and gout are primarily attributed to genetic factors, along with lifestyle factors like consuming a purine-rich diet, alcohol and/or fructose intake, and physical activity. While numerous studies have reported various comorbidities linked to hyperuricemia or gout, the range of these associations is extensive. This review article focuses on the relationship between uric acid and thirteen specific domains: transporters, genetic factors, diet, lifestyle, gout, diabetes mellitus, metabolic syndrome, atherosclerosis, hypertension, kidney diseases, cardiovascular diseases, neurological diseases, and malignancies. The present article provides a comprehensive review of recent developments in these areas, compiled by experts from the Young Committee of the Japanese Society of Gout and Uric and Nucleic Acids. The consolidated summary serves to enhance the global comprehension of uric acid-related matters.

Obstructive sleep apnea and ambulatory blood pressure abnormalities in children with chronic kidney disease

BACKGROUND

Obstructive sleep apnea (OSA) and hypertension are common complications in children with chronic kidney disease (CKD). Progression of CKD can aggravate OSA and hypertension whereas worsening sleep apnea can make hypertension difficult to treat in CKD patients. We, therefore, conducted a prospective study to evaluate the association between OSA and hypertension in pediatric patients with CKD.

METHOD

In this prospective observational study consecutive children with CKD stage 3-5 (nondialysis dependent) underwent overnight polysomnography and 24-h ambulatory blood pressure monitoring (ABPM). The detailed clinical features and investigations were recorded in a prestructured performa.

RESULTS

Twenty-two children completed overnight polysomnography and 24-h ABPM was performed within 48 h of performing polysomnography. The median (IQR) age of the study population was 11 (8.5-15.5) years, with an age range of 5-18 years. Moderate-severe OSA defined as apnea-hypopnea index (AHI ≥5) was seen in 14 (63.6%) children, periodic limb movement syndrome in 20 (91%) and poor sleep efficacy in 9 (40.9%) children. Ambulatory blood pressure was abnormal in 15 (68.2%) children with CKD. Of them, 4 (18.2%) had ambulatory hypertension, 9 (40.9%) had severe ambulatory hypertension and 2 (9.1%) had masked hypertension. A statistically significant correlation of sleep efficiency with nighttime DBP SD score/Z score (SDS/Z) (r = -0.47; P = 0.02); estimated glomerular filtration rate with SBP loads (r = -0.61; P < 0.012); DBP loads (r = -0.63; P < ) and BMI with SBP load (r = 0.46; P = 0.012) was found.

CONCLUSION

Our preliminary findings suggest that ambulatory blood pressure abnormalities, OSA, periodic limb movement syndrome and poor sleep efficiency are highly prevalent in children with CKD stages 3-5.

Association of uric acid with the decline in estimated glomerular filtration rate in middle-aged and elderly populations: evidence based on the China Health and Retirement Longitudinal Study

OBJECTIVE

Whether uric acid (UA) has an effect on renal function remains controversial. We aimed to investigate the association between serum UA with the decline in estimated glomerular filtration rate (eGFR) in middle-aged and elderly populations in the China Health and Retirement Longitudinal Study (CHARLS).

DESIGN

Longitudinal cohort study.

SETTING

This was a second analysis of a public dataset (CHARLS).

PARTICIPANTS

In this study, 4538 middle-aged and elderly individuals were screened after removing individuals younger than 45 years old, with kidney disease, malignant tumour and missing values.

OUTCOME MEASURES

Blood tests were performed both in 2011 and 2015. Decline in eGFR was defined as an eGFR decrease of more than 25% or deterioration of the eGFR stage during the 4-year follow-up period. Logistic models corrected for multiple covariables were used to analyse the association of UA with the decline in eGFR.

RESULTS

The median (IQR) concentrations of serum UA grouped by quartiles were 3.1 (0.6), 3.9 (0.3), 4.6 (0.4) and 5.7 (1.0) mg/dL, respectively. After multivariable adjustment, the OR of the decline in eGFR was higher for quartile 2 (3.5-<4.2 mg/dL: OR 1.44; 95% CI 1.07 to 1.64; p<0.01), quartile 3 (4.2-<5.0 mg/dL: OR 1.72; 95% CI 1.36 to 2.18; p<0.001) and quartile 4 (≥5.0 mg/dL: OR 2.04; 95% CI 1.58 to 2.63; p<0.001) when compared with quartile 1 (<3.5 mg/dL), and the p value for the trend was <0.001.

CONCLUSIONS

Over a 4-year follow-up period, we found that elevated UA was associated with a decline in eGFR in the middle-aged and elderly individuals with normal renal function.

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.

Does uric acid-lowering treatment slow the progression of chronic kidney disease? A meta-analysis of randomized controlled trials

INTRODUCTION

Hyperuricemia has been proposed as an independent factor in the development and progression of chronic kidney disease (CKD). However, the effect of uric acid-lowering therapies on delaying CKD progression is still uncertain. Therefore, this systemic review aims to assess the effect of uric acid-lowering therapies on renal outcomes in pre-dialysis CKD patients.

METHODS

PubMed, Cochrane Library, and Lilacs databases were searched until April 24, 2021, for randomized clinical trials of CKD patients on uric acid-lowering treatment with xanthine-oxidase (XO) inhibitors. The weighted mean difference (WMD) or standard mean difference (SMD) with confidence interval (CI) were pooled using a random-effects model.

RESULTS

Among 567 studies found, eighteen met the inclusion criteria (n=2463 participants). Compared to the patient's control group, the WMD for the glomerular filtration ratio (GFR) and serum creatinine changes of the treated group was 2.02ml/min/1.73m² (95%CI 0.41 to 3.63, P=0.014) and -0.19mg/dl (95%CI -0.34 to -0.04, I²=86.2%, P=0.011), respectively. Subgroup analyses showed that the difference in follow-up time and CKD population type in the studies may explain the controversy about the role of uric acid-lowering therapies in CKD progression. The GFR and creatinine outcomes analysis by types of XO inhibitors showed no difference between the control and treated groups. Uric acid-lowering therapies were strongly associated with decreased serum uric acid and urinary protein-creatinine ratio and urinary albumin-creatinine ratio.

CONCLUSIONS

These findings suggest that uric acid-lowering treatment may slow CKD progress and reduce protein and albumin excretion. However, larger and properly powered randomized clinical trials with specific CKD populations are needed to confirm these findings.

The elevated visceral adiposity index increases the risk of hyperuricemia in Chinese hypertensive patients: A cross-sectional study

Background

Uncertainty still remained about the relationship between visceral adiposity index (VAI) and hyperuricemia. The aim of this study was to investigate whether VAI was an independent risk factor for hyperuricemia in hypertensive Chinese patients.

Methods

A cross-sectional study including 13176 hypertensive participants (6478 males) recruited from Wuyuan County, Jiangxi province, was conducted. All patients received anthropometric measurements, completed questionnaires and provided blood samples for biochemical testing. VAI was calculated by waist circumference, BMI, triglyceride and high-density lipoprotein cholesterol. Hyperuricemia was defined as serum uric acid ≥ 7 mg/dL in men and ≥ 6 mg/dL in women.

Results

Overall, the average level of uric acid was 7.8 ± 2.0 mg/dL in males and 6.34 ± 1.78 in females and prevalence of hyperuricemia was 61.4% and 51.30%, respectively. In multivariate logistic regression analysis, the risk of hyperuricemia increased 1.77 times and 1.88 times with the increase of ln VAI in males (OR:1.77, 95% CI: 1.62, 1.94) and females (OR:1.88, 95% CI: 1.73, 2.04). For males, compared to quartile 1, the risk of hyperuricemia in the second, third and the forth quartile of visceral adiposity index were 1.34 (95% CI: 1.14, 1.57),1.82(95% CI: 1.54, 2.14) and 2.97 (95% CI: 2.48, 3.57). For females, compared to quartile 1, the risk of hyperuricemia in the second, third and the forth quartile of visceral adiposity index were 1.48 (95% CI: 1.28, 1.72), 1.99 (95% CI: 1.71, 2.32) and 2.92 (95% CI: 2.50, 3.42).

Conclusions

This study found that VAI was an independent risk factor for hyperuricemia among hypertensive patients, which may provide some strategies for reducing the level of uric acid.

A novel combination of OHVIRA syndrome and likely causal variant in UMOD gene

OHVIRA syndrome (or Herlyn-Werner-Wunderlich syndrome) is a rare condition, consisting classically of obstructed hemi-vagina with ipsilateral renal agenesis. It may be associated with complex uterine malformations and more rarely with lower urinary tract anomalies. The contralateral kidney usually has normal function. A genetic etiology of this syndrome has not yet been confirmed. We report a patient who was diagnosed to have unilateral renal agenesis in early childhood, and then presented after menarche with features of OHVIRA syndrome. The contralateral kidney was relatively small and echogenic, and serum creatinine and uric acid were raised. A likely causal variant of the UMOD gene was detected on whole exome sequencing. Genetic studies in more patients with OHVIRA syndrome may elucidate further, whether the association with UMOD gene is causal in nature.

Hyperuricemia: an unrecognized risk factor for kidney-related sequelae in children with hemolytic uremic syndrome

BACKGROUND

Chronic kidney-related sequelae after STEC-HUS occur in 20-40% of patients. Hyperuricemia (HU) may cause acute and chronic toxicity involving the kidneys. We retrospectively assessed if there was an association between the presence of HU during the acute illness and that of kidney-related sequelae in children with STEC-HUS.

METHODS

Children with STEC-HUS who had clinical and laboratory data at 2 years of follow-up were included in this case-control study. Univariate and multivariate analyses were performed between patients with (cases) or without (controls) kidney-related sequelae to identify factors associated with outcomes, including different measures of serum uric acid (sUA) (baseline level, peak, and duration of HU). HU was defined as sUA > 8 mg/dL.

RESULTS

Of 86 patients included, 77.9% had HU. Patients with sequelae (n = 41) had a higher prevalence of HU (41/41 vs. 26/45, p < 0.01), higher baseline leukocyte count, serum creatinine (sCr), and sUA levels as well as lower sodium than controls. During hospitalization, cases also had higher sCr peak, sUA peak and duration of HU, requirement and duration of dialysis, extrarenal complications, and hypertension. By multivariate analysis, after adjusting for length of dialysis, only duration of HU (p = 0.0005; OR 1.7, 95% CI 1.27-2.36) remained as an independent predictor of sequelae, with a best cutoff of 5.5 days (AUC 0.95, specificity 80%, sensitivity 100%).

CONCLUSIONS

The presence of HU is a common finding in children with STEC-HUS and its duration during the acute stage was associated with kidney-related sequelae, regardless of the duration of dialysis. A higher resolution version of the Graphical abstract is available as Supplementary Information.

Dietary Fructose and Fructose-Induced Pathologies

The consumption of fructose as sugar and high-fructose corn syrup has markedly increased during the past several decades. This trend coincides with the exponential rise of metabolic diseases, including obesity, nonalcoholic fatty liver disease, cardiovascular disease, and diabetes. While the biochemical pathways of fructose metabolism were elucidated in the early 1990s, organismal-level fructose metabolism and its whole-body pathophysiological impacts have been only recently investigated. In this review, we discuss the history of fructose consumption, biochemical and molecular pathways involved in fructose metabolism in different organs and gut microbiota, the role of fructose in the pathogenesis of metabolic diseases, and the remaining questions to treat such diseases.

Non-Immunologic Causes of Late Death-Censored Kidney Graft Failure: A Personalized Approach

Despite continuous advances in surgical and immunosuppressive protocols, the long-term survival of transplanted kidneys is still far from being satisfactory. Antibody-mediated rejection, recurrent autoimmune diseases, and death with functioning graft are the most frequent causes of late-kidney allograft failure. However, in addition to these complications, a number of other non-immunologic events may impair the function of transplanted kidneys and directly or indirectly lead to their failure. In this narrative review, we will list and discuss the most important nonimmune causes of late death-censored kidney graft failure, including quality of the donated kidney, adherence to prescriptions, drug toxicities, arterial hypertension, dyslipidemia, new onset diabetes mellitus, hyperuricemia, and lifestyle of the renal transplant recipient. For each of these risk factors, we will report the etiopathogenesis and the potential consequences on graft function, keeping in mind that in many cases, two or more risk factors may negatively interact together.

Febuxostat Improves Uric Acid Levels and Renal Function in Patients with Chronic Kidney Disease and Hyperuricemia: A Meta-Analysis

Background. Uric acid nephropathy, also known as hyperuricemia nephropathy or gouty nephropathy, is characterized by uric acid crystal deposition and inflammatory cell infiltration. Herein, we aimed to demonstrate the role of febuxostat on uric acid levels and renal function in patients with chronic kidney disease and hyperuricemia. Methods. Eight databases included were searched for clinical randomized controlled trials. Meanwhile, the confidence interval (CI) of either relative risk or mean difference was set to 95%. Besides, the heterogeneity of the research results is tested by $I^2$ . Results. Ten studies were ultimately included in this meta-analysis. All of them were considered to be random controlled trials. 10 studies reported the serum uric acid of the test group and the control group, which was significantly lower (SMD: -146.44, 95% Cl: -195.96, -86.93, and $P<0.01$ ) than the control group, EGFR (SMD: 3.21, 95% Cl: 1.17, 5.25, and $P<0.01$ ), serum creatinine (SMD: -15.27, 95% Cl: -20.75, -9.79, and $P<0.01$ ), serum urea nitrogen (SMD: -2.37, 95% Cl: -3.31, -1.61, and $P<0.01$ ), and adverse reactions (OR: 0.74, 95% Cl: 0.32, 1.68, and $P=0.47$ ). Conclusion. The results of this study suggest that febuxostat may be effective in patients with CKD with HUA, as evidenced by serum uric acid, creatinine, urea nitrogen, and EGFR. However, large sample, multicenter, low risk of bias clinical studies, as well as basic medical research, are needed.

Prevalence and potential relevance of hyperuricemia in pediatric kidney transplant recipients-a CERTAIN registry analysis

BACKGROUND

Asymptomatic hyperuricemia is frequently observed in pediatric kidney transplant recipients; symptomatic hyperuricemia, however, is a rare complication. Only few data are available in this patient population. We, therefore, investigated the prevalence of hyperuricemia and its association with kidney transplant function and blood pressure in a multicenter cohort of pediatric kidney transplant recipients.

METHODS

This is a retrospective, observational multicenter registry study. All pediatric kidney transplant recipients in the CERTAIN database with at least one documented serum uric acid level and a follow-up of 5 years posttransplant were eligible. We identified 151 patients with 395 measurements of serum uric acid. We calculated the prevalence of hyperuricemia, analyzed potential risk factors and clinical consequences such as elevated blood pressure and reduced estimated glomerular filtration rate (eGFR). Statistical analysis was performed using IBM SPSS Statistics 26.

RESULTS

One hundred and ten of 395 (27.8%) serum uric acid levels were above 416 µmol/L (7.0 mg/dL), defined as the upper limit of normal. Univariate analysis showed a significant (p = .026) inverse association of serum uric acid with eGFR overtime. There was no significant association of serum uric acid concentrations with body mass index (z-score), blood pressure (z-score), or sex. No episodes of gout were documented.

CONCLUSION

This study shows that hyperuricemia is present in a considerable number of patients sometime after pediatric kidney transplantation and is associated with lower eGFR. Whether hyperuricemia contributes to faster decline of graft function or to the overall cardiovascular risk of these patients remains to be elucidated.

Clinicopathological Patterns and Outcomes in Patients with Lupus Nephritis and Hyperuricemia

A limited number of large cohort studies have reported the clinicopathological characteristics and prognosis of patients with lupus nephritis (LN) and hyperuricemia (HUA). In this retrospective cohort study, 1297 LN patients were enrolled from January 1996 to December 2011 in the First Affiliated Hospital of Sun Yat-Sen University, and HUA occurred in 649 (50.04%) of these 1297 LN patients. Compared to patients without HUA, those with HUA presented with higher blood pressure and triglyceride levels, lower hemoglobin and serum albumin levels, worse renal function, more severe hematuria and proteinuria, higher lupus activity, and more positive antiphospholipid antibody. Pathologically, HUA cases presented more crescents, a higher degree of mesangial matrix, endothelial cell proliferation, and inflammatory cell infiltration. During the 52-month follow-up, the 5-year and 10-year incidence rates of renal endpoint events were 11.1% and 19.5% in the HUA group, and 8.3% and 13.8% in the non-HUA group, respectively (p = 0.073). In addition, the 5-year and 10-year mortality rates did not differ significantly between the HUA (12.0% and 18.2%) and non-HUA (12.2% and 17.5%) groups, respectively. This study verified that HUA was not an independent risk for poor clinical outcomes, and steroids that delay the deterioration of renal function did not affect the survival of these patients.

An evaluation of the roles of hematuria and uric acid in defining the prognosis of patients with IgA nephropathy

In recent years, many significant advances have been made in determining which clinical manifestations and pathologic lesions can provide prognostic information for patients with IgA nephropathy (IgAN). However, some important questions remain, including the long-term consequences of hematuria, both macroscopic (MH) and microscopic (mH), in patients with IgAN. The importance of distinguishing patients who have a single episode of MH of long duration from those with recurrent episodes of short duration and the prognostic importance of the episodes of acute kidney injury (AKI) that sometimes accompany episodic MH will be discussed. Studies that have evaluated the mechanisms that may be responsible for recurrent MH and the toxic effects of red blood cells (RBCs), or their constituents, on kidney tubules will also be addressed. In the last section, I will review the evidence that hyperuricemia (HU) may be a significant independent risk factor for progressive kidney disease in patients with IgAN.

Hyperuricemia and Associated Factors in Children with Chronic Kidney Disease: A Cross-Sectional Study

Background: Hyperuricemia is increasingly recognized as a risk factor for chronic kidney disease (CKD) just in adults. The purpose of this study was to investigate the clinical characteristics of hyperuricemia and its associated factors in Chinese children with CKD at a single center. Methods: A cross-sectional study of 170 CKD children collected from the Department of Nephrology, The Zhejiang University Children’s Hospital was conducted. The clinical data, including anthropometric data, blood pressure measurements, and biochemical parameters, were recorded and analyzed retrospectively. The factors associated with hyperuricemia in CKD children were evaluated by Pearson and Spearman correlation analysis and multiple logistic regression analysis. Results: The mean age was 9.79 ± 4.10 years, and 72 (42.35%) were girls. Higher blood urea nitrogen (BUN), serum creatinine, cystatin C, D-dimer, lower hemoglobin, albumin, and estimated glomerular filtration rate (eGFR) were significantly associated with higher serum uric acid (SUA). In multiple logistic regression analysis, anemia and higher BUN were both positively associated factors, whereas eGFR ≥ 90 mL/min/1.73 m² was a negatively associated factor for subjects with SUA ≥ 390 µmol/L (6.5 mg/dL). Conclusions: SUA was significantly associated with kidney risk factors in CKD children. Monitoring and controlling SUA, Hb, BUN, and Scr levels in CKD children may help to prevent the progression of CKD.

Kidney Disease Progression in Children and Young Adults With Pediatric CKD: Epidemiologic Perspectives and Clinical Applications

Chronic kidney disease (CKD) progression is typically characterized as either time to a clinically meaningful event (such as dialysis or transplant), or longitudinal changes in kidney function. This review describes pediatric kidney disease progression using these two distinct frameworks by reviewing and discussing data from the Chronic Kidney Disease in Children study. We first describe new equations to estimate glomerular filtration rate (GFR) for patients younger than age 25 years, and how the average of serum creatinine-based and cystatin C-based GFR equations yield valid estimates than either alone. Next, we present a life course description of CKD onset to kidney replacement therapy, prediction models based on clinical measurements, and show the importance of diagnosis (broadly classified as nonglomerular and glomerular in origin), GFR level, and proteinuria on progression. Literature on longitudinal GFR in children and young adults are reviewed and new data are presented to characterize nonlinear changes in estimated GFR in patients younger than age 25 years. These models showed accelerated progression associated with glomerular diagnosis, lower GFR level, and higher proteinuria, which was congruent with time-to-event analyses. Descriptions of online tools for GFR estimation and risk stratification for clinical applications are presented and we offer key epidemiologic considerations for the analysis of longitudinal pediatric CKD studies.

Urate-lowering therapy for gout and asymptomatic hyperuricemia in the pediatric population: a cross-sectional study of a Japanese health insurance database

BACKGROUND

Our previous research showed that uric acid lowering therapy (ULT) for gout and hyperuricemia is being prescribed for pediatric patients even though these drugs have not been approved for use in children. However, the actual clinical situation has not been clearly elucidated. In this paper, we provide an in-depth look at the details of actual clinical practice.

METHODS

This retrospective cross-sectional study accessed health insurance data for 696,277 children from April 2016 through March 2017 to identify pediatric patients with gout or asymptomatic hyperuricemia, calculate the proportion of patients prescribed ULTs, and analyze population characteristics. Adherence and mean dose for febuxostat and allopurinol, the most commonly prescribed drugs, were also analyzed.

RESULTS

Among children with gout or asymptomatic hyperuricemia, we found that 35.1% (97/276) were prescribed ULT. This proportion increased with age, especially among males. By comorbidity, ULT was prescribed to 47.9% (46/96) of patients with kidney disease, 41.3% (26/63) for cardiovascular disease, 40.0% (6/15) for Down syndrome, and 27.1% (32/118) for metabolic syndrome. In patients with kidney disease, febuxostat was prescribed more than twice as frequently as allopurinol (28 vs. 12). Median values for the medication possession ratio (MPR) of febuxostat and allopurinol were 70.1 and 76.7%, respectively, and prescriptions were continued for a relatively long period for both drugs. Both drugs were prescribed at about half the adult dose for patients 6-11 years old and about the same as the adult dose for patients 12-18 years old.

CONCLUSIONS

This study showed that the continuous management of serum uric acid is being explored using off-label use of ULT in pediatric patients with gout or asymptomatic hyperuricemia in Japan. Drug selection is based on patient characteristics such as sex, age, and comorbidities, and pediatric dosage is based on usage experience in adults. To develop appropriate pediatric ULT, clinical trials are needed on the efficacy and safety of ULT in the pediatric population.

TRIAL REGISTRATION

UMIN000036029 .

Hyperuricaemia as a predictor of hospital outcome in patients with sepsis: results of a prospective study

Background

Early management of sepsis in the emergency department improves patient outcomes. The identification of at-risk patients for aggressive management by an easily available biomarker could go a long way in the triage of patients in the emergency department. It is postulated that during sepsis, the majority of patients undergo ischaemic reperfusion injury or inflammation, and uric acid with its oxidant and antioxidant properties may be playing some role and, hence, the measurement of uric acid could possibly predict the hospital course in patients with sepsis. We were prompted to undertake this study as serum uric acid estimation is readily available and economical compared to newly evolving biomarkers in sepsis. Estimation of serum uric acid levels on arrival to the emergency department may prove a useful predictor of hospital outcome in patients with sepsis especially in regions with limited resources.

Results

Of 102 patients, 55 (53.9%) were males. The mean age of the study cohort was 63.2 ± 10.48. Patients with higher qSOFA scores had higher uric acid levels on admission. While 12 (11.8%) patients had a septicaemic shock, acute kidney injury was recorded in 48 (47.1%) patients and 11 (10.8%) patients required dialysis. Thirty-four (33.3%) patients had respiratory failure, and of these, 21 (20.6%) patients required mechanical ventilation. The overall median stay in the medical intensive care (MICU) was 3days (range 2–7 days). The patients with higher uric acid levels had higher rates of respiratory failure but did not reach significant levels. In 15 (14.7%) patients, 7 males expired (mortality rate of 14.7%). There was a significant association between SOFA score and mortality. Patients who succumbed to sepsis had higher serum uric acid levels on arrival.

Conclusions

Patients with higher qSOFA scores had higher uric acid levels on admission. Hyperuricaemia predicted acute kidney injury, a requirement of mechanical ventilation and mean hospital stay in patients with sepsis. Further studies may be required to confirm the association.

Calcitriol Treatment Attenuates Uric Acid-Induced Kidney Injury via Super Oxide Dismutase-1 (SOD-1) Upregulation and Fibrosis Reduction

Background

Hyperuricemia induces nephropathy through the mediation of oxidative stress, tubular injury, inflammation, and fibrosis. The high uric acid level is associated with the reduction of vitamin D levels. However, the reno-protective effects of this vitamin in hyperuricemia condition remain unknown. This study aimed to elucidate calcitriol treatment in a uric acid-induced hyperuricemia mice model.

Methods

: Uric acid (125 mg/kg body weight [BW]) was administered intraperitoneally for 7 (UA7) and 14 (UA14) days. Calcitriol (0.5 g/kg BW) was intraperitoneally injected for the following seven days, after 14 days of uric acid induction (UA14VD7 group). The control group received NaCl 0.9%, by the same route. Serum creatinine was measured using calorimetric method, and uric acid levels were assessed using enzymatic calorimetric assay. Tubular injury and fibrosis were assessed using PAS and Sirius red staining. RT-PCR and real-time reverse transcription PCR were carried out for the analyses of SOD-1, Collagen-1, and TGF-1 mRNA expression in the kidney. Immunostaining of super oxide dismutase type 1 (SOD-1) was performed to detect its expression in the kidney.

Results

Uric acid and creatinine levels markedly increased in UA14 groups, followed by an exacerbation of tubular injury. RT-PCR revealed the upregulation of Collagen-1 and TGF-1, along with the downregulation of SOD-1. Calcitriol treatment attenuated the injury with reducing uric acid and creatinine levels, as well as tubular injury. This was associated with lower Collagen-1 and TGF-1 mRNA expression compared to the UA7 and UA14 groups. SOD-1 was upregulated in epithelial cells in the UA14VD7 group.

Conclusion

Calcitriol treatment after uric acid induction may attenuate kidney injury through upregulation of SOD-1 and downregulation of Collagen-1 and TGF-1 gene expression.

Organophosphate pesticides and progression of chronic kidney disease among children: A prospective cohort study

BACKGROUND

Growing evidence suggests that exposure to environmental chemicals, such as pesticides, impacts renal function and chronic kidney disease (CKD). However, it is not clear if pesticides may affect CKD progression and no studies exist in children.

OBJECTIVES

The objective of this study was to examine associations between serially measured urinary OP pesticide metabolites and clinical and laboratory measures of kidney function over time among children with CKD.

METHODS

This study used data on 618 participants enrolled in the CKD in Children study (CKiD), a cohort study of pediatric CKD patients from the US and Canada. Children were followed over an average of 3.0 years (standard deviation (SD) = 1.6) between 2005 and 2015. In serially collected urine samples over time, six nonspecific dialkyl phosphate (DAP) metabolites of OP pesticides were measured. Biomarkers of tubular injury (kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL)) and oxidant stress (8-hydroxy-2'-deoxyguanosine (8-OHdG) and F2-isoprostane) were determined in the same specimens. Estimated glomerular filtration rate (eGFR), proteinuria, and blood pressure were assessed annually.

RESULTS

DAPs were associated with increased KIM-1 and 8-OHdG throughout follow-up. A standard deviation increase in ∑diethyl metabolites was associated with increases of 11.9% (95% Confidence Interval (CI): 4.8%, 19.4%) and 13.2% (95% CI: 9.3%, 17.2%) in KIM-1 and 8-OHdG over time, respectively. DAPs were associated with lower eGFR at baseline and higher eGFR over subsequent years.

CONCLUSIONS

These findings provide preliminary evidence suggesting that urinary DAP metabolites are associated with subclinical kidney injury among children with CKD, which may signal the potential for clinical events to manifest in the future. The results from this study are significant from both a clinical and public health perspective, given that OP pesticide exposure is a modifiable risk factor.

Prevalence and related factors of hyperuricaemia in Shanghai adult women of different ages: a multicentre and cross-sectional study

OBJECTIVE

Women in different age phases have different metabolism and hormone levels that influence the production and excretion of uric acid. We aimed to investigate the prevalence and related factors of hyperuricaemia among women in various age phases.

STUDY DESIGN

Observational, cross-sectional study.

SETTING

Data were obtained from women at three health check-up centres in Shanghai.

PARTICIPANTS

Adult women from three health check-up centres were recruited. Exclusion criteria were individuals with pregnancy, cancer, incomplete information. Finally, 11 601 participants were enrolled.

RESULTS

The prevalence rates of hyperuricaemia of total subjects were 11.15% (95% CIs 10.57% to 11.72%). The prevalence of hyperuricaemia in 18-29, 30-39, 40-49, 50-59, 60-69 and ≥70 years old was 6.41% (95% CI 4.97% to 7.86%), 5.63% (4.71% to 6.55%), 6.02% (5.01%% to 7.03%), 11.51% (10.19% to 12.82%), 16.49% (15.03% to 17.95%) and 23.98% (21.56% to 26.40%), respectively. Compared with 18-29 years old, the ORs for hyperuricaemia in other age phases were 0.870 (95% CI 0.647 to 1.170, p=0.357), 0.935 (0.693 to 1.261, p=0.659), 1.898 (1.444 to 2.493, p<0.001), 2.882 (2.216 to 3.748, p<0.001) and 4.602 (3.497 to 6.056, p<0.001), respectively. During the 18-29 years old, the related factors for hyperuricaemia were obesity and dyslipidaemia. During the 30-59 years old, the related factors were obesity, dyslipidaemia, hypertension and chronic kidney disease (CKD). Over the 60 years old, the occurrence of hyperuricaemia was mainly affected by obesity, dyslipidaemia and CKD, while hypertension cannot be an impact factor for hyperuricaemia independently of obesity and dyslipidaemia.

CONCLUSION

After 50 years old, the prevalence of hyperuricaemia in Shanghai women has increased significantly and reaches the peak after 70. Obesity and dyslipidaemia are two main related factors for hyperuricaemia during all ages, while diabetes mellitus and nephrolithiasis have no relationship with hyperuricaemia throughout. CKD is an independent impact factor for hyperuricaemia after 30 years old.

[Epidemiology of pediatric chronic kidney disease]

Major advances have been made in the management of children with chronic kidney disease over the past 30 years. However, existing epidemiology data are primarily from kidney replacement therapy registries, and information available at earlier stages of chronic kidney disease is limited. The incidence and prevalence of chronic kidney disease stages 2 to 5 remain poorly understood. However, rare population-based studies suggest that the prevalence of all-stage chronic kidney disease may be as high as 1% of the pediatric population. Congenital disorders including congenital abnormalities of the kidney and urinary tract and hereditary nephropathies account for one-half to two-thirds of pediatric chronic kidney disease cases in middle and high-income countries, whereas acquired nephropathies seem to predominate in low-income countries. The progression of chronic kidney disease is slower in children with congenital disorders than in those with acquired nephropathy, particularly glomerular disease, resulting in a lower proportion of congenital abnormalities of the kidney and urinary tract as a cause of end-stage kidney disease compared to less advanced stages of chronic kidney disease. The incidence of kidney replacement therapy in the pediatric population ranged by country from 1 to 14 per million children of the same age in 2018 (approximately 8 per million children in France) in patients younger than 20 years. The prevalence of kidney replacement therapy in children under 20 years of age in 2018 ranged from 15-30 per million children in some Eastern European and Latin American countries to 100 per million children in Finland and the United States (56 per million children in France). Most children with end-stage kidney disease initiate kidney replacement therapy with dialysis (more frequently hemodialysis than peritoneal dialysis). In about 20% of cases, the initial kidney replacement therapy modality is a pre-emptive kidney transplantation. In high-income countries, 60-80% of prevalent children with end-stage kidney disease live with a functioning transplant (75% in France). While the survival of children with chronic kidney disease has continuously improved over time, mortality remains about 30 times higher than in the general pediatric population.

Serum and pulmonary uric acid in pulmonary arterial hypertension

Previous studies have suggested an association between uric acid (UA) and the severity of pulmonary arterial hypertension (PAH), but it is unknown whether UA contributes to disease pathogenesis.The aim of this study was to determine the prognostic value of circulating UA in the era of current management of PAH and to investigate the role of UA in pulmonary vascular remodelling.Serum UA levels were determined in idiopathic, heritable or anorexigen PAH at baseline and first re-evaluation in the French Pulmonary Hypertension Network. We studied protein levels of xanthine oxidase (XO) and the voltage-driven urate transporter 1 (URATv1) in lungs of control and PAH patients and of monocrotaline (MCT) and Sugen/hypoxia (SuHx) rats. Functional studies were performed using human pulmonary artery smooth muscle cells (PA-SMCs) and two animal models of pulmonary hypertension (PH).High serum UA levels at first follow-up, but not at baseline, were associated with a poor prognosis. Both the generating enzyme XO and URATv1 were upregulated in the wall of remodelled pulmonary arteries in idiopathic PAH patients and MCT and SuHx rats. High UA concentrations promoted a mild increase in cell growth in idiopathic PAH PA-SMCs, but not in control PA-SMCs. Consistent with these observations, oxonic acid-induced hyperuricaemia did not aggravate MCT-induced PH in rats. Finally, chronic treatment of MCT and SuHx rats with benzbromarone mildly attenuated pulmonary vascular remodelling.UA levels in idiopathic PAH patients were associated with an impaired clinical and haemodynamic profile and might be used as a non-invasive indicator of clinical prognosis during follow-up. Our findings also indicate that UA metabolism is disturbed in remodelled pulmonary vascular walls in both experimental and human PAH.

Chronic Kidney Disease-Associated Itch (CKD-aI) in Children-A Narrative Review

Chronic kidney disease (CKD) is a condition of widespread epidemiology and serious consequences affecting all organs of the organism and associated with significant mortality. The knowledge on CKD is rapidly evolving, especially concerning adults. Recently, more data is also appearing regarding CKD in children. Chronic itch (CI) is a common symptom appearing due to various underlying dermatological and systemic conditions. CI may also appear in association with CKD and is termed chronic kidney disease-associated itch (CKD-aI). CKD-aI is relatively well-described in the literature concerning adults, yet it also affects children. Unfortunately, the data on paediatric CKD-aI is particularly scarce. This narrative review aims to describe various aspects of CKD-aI with an emphasis on children, based on the available data in this population and the data extrapolated from adults. Its pathogenesis is described in details, focusing on the growing role of uraemic toxins (UTs), as well as immune dysfunction, altered opioid transmission, infectious agents, xerosis, neuropathy and dialysis-associated aspects. Moreover, epidemiological and clinical aspects are reviewed based on the few data on CKD-aI in children, whereas treatment recommendations are proposed as well, based on the literature on CKD-aI in adults and own experience in managing CI in children.

Designing a Strategy Trial for the Management of Gout: The Use of a Modified Delphi Panel

OBJECTIVE

Disagreement exists between rheumatology and primary care societies regarding gout management. This paper describes a formal process for gathering input from stakeholders in the planning of a trial to compare gout management strategies.

METHODS

We recruited patients, nurses, physician assistants, primary care clinicians, and rheumatologists to participate in a modified Delphi panel (mDP) to provide input on design of a trial focused on optimal management for primary care patients with gout. The 16 panelists received a plain-language briefing document that discussed the rationale for the trial, key clinical issues in gout, and aspects of trial design. The panelists also received information and considerations on nine voting questions (VQs), judged to be the key design questions. Cognitive interviews with panelists ensured that the VQs were understood by the range of panelists involved in the mDP. Panelists were asked to score all VQs from 1 (definitely no) to 9 (definitely yes). Two voting rounds were conducted-round 1 by email and round 2 by video conference.

RESULTS

The VQs were modified through the cognitive interviews. The round 1 voting resulted in consensus on eight items, with consensus defined as median voting score in the same tercile (1-3, 4-6 or 7-9). Re-voting at the meeting (round 2) reached consensus on the remaining item.

CONCLUSION

An mDP with various stakeholders facilitated consensus on the design of a trial of different management strategies for chronic gout. This method may be useful for designing trials of clinical questions with substantial disagreement across stakeholders.

Anti-Hyperuricemic and Nephroprotective Effects of Dihydroberberine in Potassium Oxonate- and Hypoxanthine-Induced Hyperuricemic Mice

Phellodendri Chinese Cortex has long been used to treat hyperuricemia and gout. Berberine (BBR), its characteristic ingredient, has also been shown to be effective in alleviating monosodium urate crystals-triggered gout inflammation in vitro and in vivo. Dihydroberberine (DHB) is a hydrogenated derivative of BBR that showed improved in vivo efficacy on many metabolic disorders. However, its anti-hyperuricemia effect remains underexplored. In the present work, the hypouricemic and renoprotective effects of DHB on hyperuricemic mice were investigated. The hyperuricemic mice model was induced by intraperitoneal injection of potassium oxonate (PO, 300 mg/kg) combined with intragastric administration of hypoxanthine (HX, 300 mg/kg) for 7 days. Different dosages of DHB (25, 50 mg/kg), BBR (50 mg/kg) or febuxostat (Feb, 5 mg/kg) were orally given to mice 1 h after modeling. The molecular docking results showed that DHB effectively inhibited xanthine oxidase (XOD) by binding with its active site. In vitro, DHB exhibited significant XOD inhibitory activity (IC₅₀ value, 34.37 μM). The in vivo results showed that DHB had obvious hypouricemic and renoprotective effects in hyperuricemic mice. It could not only lower the uric acid and XOD levels in serum, but also suppress the activities of XOD and adenosine deaminase (ADA) in the liver. Furthermore, DHB noticeably down-regulated the renal mRNA and protein expression of XOD. Besides, DHB remarkably and dose-dependently ameliorated renal damage, as evidenced by considerably reducing serum creatinine and blood urea nitrogen (BUN) levels, inflammatory cytokine (TNF-α, IL-1β, IL-6 and IL-18) levels and restoring kidney histological deteriorations. Further mechanistic investigation showed that DHB distinctly down-regulated renal mRNA and protein levels of URAT1, GLUT9, NOD-like receptor 3 (NLRP3), apoptosis-associated speck-like (ASC), caspase-1 and IL-1β. Our study revealed that DHB had outstanding hypouricemic and renoprotective effects via suppressing XOD, URAT1, GLUT9 and NLRP3 inflammasome activation in the kidney.

Cardiovascular disease in childhood and adolescence: Lessons from children with chronic kidney disease

Children suffering from chronic kidney disease (CKD) have the apparent highest risk for the development of cardiovascular disease (CVD) at a young age. While symptoms of CVD are characteristically absent in childhood and adolescence, remodelling of the myocardium, medium and large-sized arteries and of the microcirculation is clinically significant and can be assessed with non-invasive technology. Kidney disease and its progression are the driver of CVD, mediated by an unparalleled accumulation of risk factors converging on several comorbid conditions including hypertension, anaemia, dyslipidaemia, disturbed mineral metabolism and chronic persistent inflammation. Large prospective paediatric cohorts studies have provided valuable insights into the pathogenesis and the progression of CKD-induced cardiovascular comorbidity and have characterised the cardiovascular phenotype in young patients. They have also provided the rationale for close monitoring of risk factors and have defined therapeutic targets. Recently discovered new biomarkers could help identify the individual risk for CVD. Prevention of CVD by aggressive therapy of modifiable risk factors is essential to enable long-term survival of young patients with CKD.

Unnoticed Adverse Effect of Isoniazid during Childhood Tuberculosis Preventive Treatment: Hyperuricemia

Objective Isoniazid for 6 to 9 months is the most widely used form of tuberculosis (TB) preventive treatment. We aimed to assess the adverse effects of isoniazid by using the serum levels of aspartate transaminase (AST), alanine transaminase (ALT), and uric acid (SUA) in children and adolescents receiving long-term isoniazid for latent TB infection.

Methods The study included children ≤18 years of age who underwent TB preventive treatment with isoniazid (IPT) between 2015 and 2019 at a university hospital. Serum transaminase, SUA, urea, and creatinine levels of patients were measured before the initiation of IPT, 15th day, and once a month during treatment. Patients with ALT, AST, or SUA results above cut-off levels during treatment were evaluated. The final values in follow-up were included in the data analysis.

Results A total of 141 children who underwent IPT were included. In total, 70 children had family members with confirmed TB disease, and 71 children had a positive tuberculin skin test. SUA increased above cut-off values in 16 children (11.3%), and half of them had uric acid levels over 7 mg/dL. The median duration of the development of hyperuricemia was 4.0 months. ALT or AST increased above cut-off values in 23 children (16.3%). ALT was above cut-off values in seven patients, AST was high in 20 patients. The median duration to the development of AST and/or ALT levels above cut-off was 4.0 months. Two patients had hepatotoxic transaminase levels. Three patients had both elevated transaminases and SUA levels.

Conclusion Isoniazid may also cause hyperuricemia besides elevation in transaminases in children.

The CKiD study: overview and summary of findings related to kidney disease progression

The Chronic Kidney Disease in Children (CKiD) cohort study is a North American (USA and Canada) multicenter, prospective study of children with chronic kidney disease (CKD). The original aims of the study were (1) to identify novel risk factors for CKD progression; (2) to measure the impact of kidney function decline on growth, cognition, and behavior; and (3) to characterize the evolution of cardiovascular disease risk factors. CKiD has developed into a national and international resource for the investigation of a variety of factors related to CKD in children. This review highlights notable findings in the area of CKD progression and outlines ongoing opportunities to enhance understanding of CKD progression in children. CKiD's contributions to the clinical care of children with CKD include updated and more accurate glomerular filtration rate estimating equations for children and young adults, and resources designed to help estimate the CKD progression timeline. In addition, results from CKiD have strengthened the evidence that treatment of hypertension and proteinuria should continue as a primary strategy for slowing the rate of disease progression in children.

Effects of losartan and enalapril on serum uric acid and GFR in children with proteinuria

BACKGROUND

Studies have shown that losartan reduces serum uric acid in adults, unlike angiotensin-converting enzyme inhibitors. A previous study demonstrated that losartan and enalapril had comparable effects on proteinuria in children.

METHODS

We conducted a post hoc analysis of results from a prospective trial in which the proteinuria-reducing effects of losartan and enalapril were compared. We have now evaluated (a) the effects of these medications on SUA in 248 children with proteinuria and (b) the correlation between changes in SUA and eGFR.

RESULTS

SUA levels after 36 months were found to be increased when compared to baseline in both losartan and enalapril groups. The mean change in SUA from baseline was significantly different at 12 months between 23 hypertensive patients randomised to losartan (3.69% decrease [95% CI 11.31%, 3.93%]) and 24 randomised to enalapril (12.57% increase [95% CI 3.72%, 21.41%]), p = 0.007. This significant difference remained after 24, 30 and 36 months but was observed in the entire group of 248 patients only at 12 months. There was a statistically significant negative correlation between changes in SUA and changes in eGFR at each time point over 36 months.

CONCLUSIONS

Losartan may have long-term beneficial effects on SUA and eGFR in children with proteinuria.

Renal effects of uric acid: hyperuricemia and hypouricemia

The prevalence of chronic kidney disease (CKD) is increasing worldwide. Although hyperuricemia has been associated with CKD in many studies, it remains controversial whether this is the cause or the result of decreased renal function. Recent observational studies of healthy populations and patients with CKD have reported that uric acid (UA) has an independent role in the development or progression of CKD. Experimental studies have shown several potential mechanisms by which hyperuricemia may cause or promote CKD. However, other reports have indicated an association between hypouricemia and CKD. This opposing effect is hypothesized to occur because UA is a major antioxidant in human plasma and is associated with oxidative stress. In this article, we discuss the potential association between UA imbalance and CKD and how they can be treated.

Association of Oral Status and Early Primary Hypertension Biomarkers among Children and Adolescents

The aim of this case-control study was the evaluation of the association between biomarkers of early primary arterial hypertension (HA) and oral diseases among children and adolescents. Material and methods. Subjects suspected of primary HA (n = 180) underwent a complex evaluation of their vascular status: blood pressure, heart rate, vascular stiffness, sympathetic activity in a 24 h ambulatory examination, followed by measurement of serum uric acid (UA), cystatin C, and creatinine. This procedure allowed the identification of children with primary (n = 58) and secondary HA (n = 74), as well as of children with normal arterial blood pressure, who served as a control group (n = 48). All subjects with secondary HA were excluded from further investigation. Oral examination included the measurement of caries intensity (using the decayed, missing, filled index for permanent teeth DMFT /primary teeth dmft), bacterial plaque (by the plaque control record index, PCR%), and gingivitis (by the bleeding on probing index, BOP%). For statistical analysis, a linear regression model and Spearman rank correlation were used. Results. UA, cystatin C, and creatinine were not altered in the HA group. However, the number of decayed permanent teeth (DT) and the DMFT, PCR%, and BOP% indexes were significantly higher in the primary HA group compared to the control group (p = 0.0006; p = 0.02; p = 0.0009; p = 0.003). Our results are not sufficient to prove the important role of caries and gingival inflammation in the modulation of HA symptoms, although they prove the association of oral diseases with primary HA symptoms. This may indicate future strategies for preventive measures for hypertensive children and adolescents.

Ambulatory blood pressure in relation to interaction between dietary sodium intake and serum uric acid in the young

PURPOSE

We hypothesise that dietary sodium intake interacts with serum uric acid to influence blood pressure (BP) in children and adolescents. In the present study, we investigated ambulatory BP in relation to hyperuricaemia, dietary sodium intake and their interaction in children and adolescents with hypertension.

MATERIALS AND METHODS

A total of 616 study participants were 10-24 years old and had primary hypertension diagnosed after admission in a specialised inpatient ward. Ambulatory BP monitoring was performed during hospitalisation. 24-h urine was collected for measurements of electrolytes. Hyperuricaemia was defined as a serum uric acid of ≥327.25 μmol/L in patients <18 years old and of ≥420 and ≥360 μmol/L, respectively, in male and female patients ≥18 years old.

RESULTS

In adjusted analyses, patients with hyperuricaemia (n = 283), compared with those with normal serum uric acid, had similar 24-h systolic BP (131.7 mmHg, p = 0.54) and a significantly (p ≤ 0.005) lower 24-h diastolic BP (77.5 vs. 80.9 mmHg) and higher 24-h pulse pressure (54.2 vs. 51.7 mmHg). In similar adjusted analyses, 24-h ambulatory pulse pressure, but not systolic/diastolic BP (p ≥ 0.12), significantly differed across the quartile distributions of urinary sodium excretion (p for trend ≤ 0.04). Further adjusted analyses showed significant (p ≤ 0.04) interaction between serum uric acid and urinary sodium excretion in relation to 24-h systolic BP. In patients with hyperuricaemia (p = 0.04), but not those with normal serum uric acid (p = 0.13), 24-h systolic BP was significantly associated with urinary sodium excretion, with a 6.5 ± 2.1 mmHg difference between quartiles 4 and 1. Similar results were observed for daytime and night-time BP and pulse pressure.

CONCLUSIONS

Both hyperuricaemia and higher dietary sodium intake were associated with higher pulse pressure, and their interaction further heightened systolic BP.

Identifying risk factors for chronic kidney disease stage 3 in adults with acquired solitary kidney from unilateral nephrectomy: a retrospective cohort study

Background

We aimed to examine the risk factors for chronic kidney disease (CKD) stage 3 among adults with ASK from unilateral nephrectomy.

Methods

We retrospectively collected data from adult patients with ASK between January, 2009 and January, 2019, identified from a tertiary hospital in China. The clinical data were compared between patients who developed CKD stage 3 and those who did not develop CKD stage 3 during follow-up.

Results

In total, 172 patients with ASK (110 men; median 58.0 years) were enrolled, with a median follow-up duration of 5.0 years. During follow-up, 91 (52.9%) and 24 (14.0%) patients developed CKD stage 3 and end-stage renal disease, respectively. Multiple regression analyses showed that age (odds ratio [OR] 1.076, 95% confidence interval [CI] 1.039–1.115, p < 0.001), diabetes (OR 4.401, 95% CI 1.693–11.44, p = 0.002), hyperuricemia (OR 2.733, 95% CI 1.104–6.764, p = 0.03), a history of cardiovascular disease (CVD) (OR 5.583, 95% CI 1.884–18.068, p = 0.002), and ASK due to renal tuberculosis (OR 8.816, 95% CI 2.92–26.62, p < 0.001) were independent risk factors for developing CKD stage 3 among patients with ASK.

Conclusions

Regular follow-up of renal function is needed among adult patients with ASK. Optimal management of diabetes, hyperuricemia, and CVD may reduce their risk of CKD stage 3, especially among those that undergo unilateral nephrectomy for renal tuberculosis.

Gender medicine: Lessons from COVID-19 and other medical conditions for designing health policy

Gender-specific differences in the prevalence, incidence, comorbidities, prognosis, severity, risk factors, drug-related aspects and outcomes of various medical conditions are well documented. We present a literature review on the extent to which research in this field has developed over the years, and reveal gaps in gender-sensitive awareness between the clinical portrayal and the translation into gender-specific treatment regimens, guidelines and into gender-oriented preventive strategies and health policies. Subsequently, through the lens of gender, we describe these domains in detail for four selected medical conditions: Asthma, obesity and overweight, chronic kidney disease and coronavirus disease 2019. As some of the key gender differences become more apparent during adolescence, we focus on this developmental stage. Finally, we propose a model which is based on three influential issues: (1) Investigating gender-specific medical profiles of related health conditions, rather than a single disease; (2) The dynamics of gender disparities across developmental stages; and (3) An integrative approach which takes into account additional risk factors (ethnicity, socio-demographic variables, minorities, lifestyle habits etc.). Increasing the awareness of gender-specific medicine in daily practice and in tailored guidelines, already among adolescents, may reduce inequities, facilitate the prediction of future trends and properly address the characteristics and needs of certain subpopulations within each gender.

A longitudinal analysis of the effect of anemia on health-related quality of life in children with mild-to-moderate chronic kidney disease

BACKGROUND

To evaluate impact of anemia on health-related quality of life (HRQOL) over time in a large pediatric cohort with mild-to-moderate chronic kidney disease (CKD).

METHODS

Participants were enrolled in the Chronic Kidney Disease in Children Study (CKiD), a multicenter, longitudinal cohort. HRQOL was measured using the Pediatric Quality of Life Inventory (PedsQL). Anemia was defined as hemoglobin < 5th percentile for age, sex, and race. Two longitudinal analyses were conducted on consecutive visit pairs. Models examined effects of anemia status on both HRQOL score over time and change in HRQOL score between consecutive visits. The sample included 733 children with a median estimated GFR 54 ml/min/1.73 m². Thirty percent of children had anemia at index visit.

RESULTS

Analysis of HRQOL scores revealed the presence of anemia was associated with significantly lower overall HRQOL (β = - 2.90 (95% CI = - 7.74, - 0.21), p = 0.04) and physical functioning (β = - 5.72 (- 9.49, - 2.25), p = 0.001) according to children. On parent ratings, the development of anemia was associated with lower emotional functioning scores (β = - 4.87 (- 8.72, - 0.11), p = 0.045). In the second model, children who developed anemia were rated by caregivers as having more decreased physical functioning than children who remained anemia-free (β = - 3.30 per year (- 5.83, - 0.76), p = 0.01). Caregivers did not observe declines in their children's other PedsQL subscales in the presence of developed anemia. Children with resolved or persistence did not show improvement or decline in any aspect of HRQOL functioning relative to non-anemic subjects.

CONCLUSIONS

In children with CKD, anemia has an adverse effect on HRQOL which persists over time but does not appear to be progressive.

Fructose and Uric Acid: Major Mediators of Cardiovascular Disease Risk Starting at Pediatric Age

Recently, there has been a growing interest in epidemiological and clinical studies supporting a pathogenetic role of fructose in cardio-metabolic diseases, especially in children and adolescents. In the present review, we summarize experimental data on the potential biological mechanisms linking fructose and uric acid in the development of insulin resistance, metabolic syndrome, obesity, diabetes, hypertension, non-alcoholic fatty liver disease and chronic renal disease, thereby contributing to an increase in cardiovascular risk at pediatric age.

Eating Habits and Their Association with Weight Status in Chinese School-Age Children: A Cross-Sectional Study

BACKGROUND

Poor eating habits increase children's risk of chronic diseases such as overweight and obesity, adult diabetes, and cardiovascular and cerebrovascular diseases. Therefore, this study aimed to examine the eating habits of school-age children and their impact on children's body mass index.

METHODS

Multistage cluster sampling was used to sample 2224 students in grades 4 to 6 from 16 primary schools in Changsha. A self-designed questionnaire was used to collect general demographic, eating habit, and snack consumption data from school-age children. Height and weight were measured so that the body mass index Z-score could be calculated and evaluated according to the 2007 World Health Organization's Body Mass Index (BMI) reference standard.

RESULTS

The prevalence rates of overweight and obesity in school-age children were 17.0% and 8.3%, respectively. Boys had higher rates of overweight and obesity than girls (19.9% vs. 13.6%, 12.9% vs. 3.0%, respectively, p < 0.05). Among the total population of children, 71.6% reported picky eating habits, and 55.1% had late-night snacks. Children who skipped breakfast (OR 1.507 and 95% CI 1.116~2.035) and ate puffed food (OR 1.571 and 95% CI 1.170~2.110) were more likely to be overweight/obese.

CONCLUSIONS

The eating habits of school-age children are closely related to their weight status. Poor eating habits can be risk factors for overweight and obesity. The dietary management of children should be strengthened so that they develop good eating habits and the incidence of overweight and obesity in school-age children decreases.

Hyperuricemia is associated with a lower glomerular filtration rate in pediatric sickle cell disease patients

BACKGROUND

Sickle cell nephropathy (SCN) is a progressive disease that contributes significant morbidity and mortality in sickle cell disease (SCD), yet it remains poorly understood. Hyperuricemia negatively impacts renal function in the non-sickle cell population but is understudied in SCD.

METHODS

We performed a cross-sectional analysis of the first 78 pediatric SCD patients enrolled in a cohort study. The mechanism of development of hyperuricemia (defined, serum uric acid (UA) ≥ 5.5 mg/dL) was characterized as a result of either UA overproduction or inefficient renal excretion by the Simkin index and fractional clearance of urate (FCU) equations. Associations between hyperuricemia and albuminuria or estimated glomerular filtration rate (eGFR) were determined by linear regression.

RESULTS

The prevalence of hyperuricemia in this young population (mean age 11.6 ± 3.77 years) was 34.2%. Only 1 hyperuricemic participant overproduced UA by Simkin index, while 62.5% were inefficient renal excretors of UA (FCU < 4%). Hyperuricemia was associated with a significant decrease in average eGFR, -27 ml/min/1.73m² below normouricemia (mean eGFR 151.6 ± 40.32), p = 0.0122. Notably, the previously accepted association between decline of eGFR with age is significantly modified by hyperuricemia stratification, where hyperuricemia explains 44% of the variance in eGFR by age (R² = 0.44, p = 0.0004) and is nonsignificant in normouricemia (R² = 0.07, p = 0.0775).

CONCLUSION

These findings indicate that hyperuricemia may be associated with early eGFR decline in SCN. This association must be further characterized in prospective cohort studies in SCN, and hyperuricemia must be investigated as a potential therapeutic target for SCN.

Sex and Glomerular Filtration Rate Trajectories in Children

BACKGROUND AND OBJECTIVES

Differences in CKD progression by sex have been hypothesized to explain disparities in access to kidney transplantation in children. This study aims to identify distinct trajectories of eGFR decline and to investigate the association of sex with eGFR decline.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used data from the CKD in Children study. Latent class mixed models were used to identify eGFR trajectories and patient characteristics were compared between trajectories. Progression was studied to two outcomes: ESKD (dialysis or transplantation) and a combined outcome of ESKD or 50% eGFR decline from baseline, using multivariable parametric failure time models.

RESULTS

Among 888 patients, 613 with nonglomerular and 275 with glomerular diseases, we observed four and two distinct GFR trajectories, respectively. Among patients with nonglomerular diseases, there was a higher proportion of males in the group with a low baseline GFR. This group had an increased risk of ESKD or 50% GFR decline, despite a similar absolute decline in GFR. Eight patients with nonglomerular diseases, mostly males with obstructive uropathies, had a more rapid absolute GFR decline. However, the association between male sex and rapid absolute GFR decline was NS after adjustment for age, baseline GFR, and proteinuria. Among patients with glomerular diseases, a subgroup including mostly females with systemic immunologic diseases or crescentic GN had a rapid absolute GFR decline.

CONCLUSIONS

This study identifies different trajectories of CKD progression in children and found a faster progression of CKD in females in patients with glomerular diseases, but no significant sex difference in patients with nonglomerular diseases. The differences in progression seem likely explained by sex differences in the underlying primary kidney disease and in baseline GFR rather than by a direct effect of sex on progression.