Prevalence of chronic kidney disease and its association with metabolic diseases: a cross-sectional survey in Zhejiang province, Eastern China

The effect of hyperuricemia and its interaction with hypertension towards chronic kidney disease in patients with type 2 diabetes: evidence from a cross- sectional study in Eastern China

Objectives

This study aimed to explore the synergistic interaction effect between hyperuricemia and hypertension towards chronic kidney disease in patients with type 2 diabetes.

Methods

This research originates from a cross-sectional study performed in Zhejiang Province, Eastern China, between March and November 2018. The correlation between serum uric acid levels and the risk of chronic kidney disease was assessed using a restricted cubic spline model. An unconditional multivariable logistic regression model, along with an interaction table, was utilized to explore the potential interaction effect of hyperuricemia and hypertension towards chronic kidney disease.

Results

1,756 patients with type 2 diabetes were included in this study, the prevalence of chronic kidney disease (CKD) was 27.62% in this population. A U-shaped non-linear pattern emerged correlating serum uric acid (SUA) levels and CKD risk, indicating that both low and high SUA levels were linked to an increased CKD risk. This risk achieved its lowest point (nadir) at SUA approximately equals to 285μmol/L (p for trend <0.05). Once adjustments for age, gender, education level, abnormal fasting plasma glucose (FPG), abnormal hemoglobin A1c (HbA1c), abnormal total cholesterol (TC), abnormal high-density lipoprotein cholesterol (HDL-C), alcohol consumption and duration of diabetes were factored in, it was found that patients with both hyperuricemia and hypertension demonstrated a 5.42-fold (95% CI: 3.72-7.90) increased CKD risk compared to the reference group. The additive interaction between hyperuricemia and hypertension was statistically significant, as manifested by the following values: a relative excess risk due to interaction (RERI) of 2.57 (95% CI: 0.71-4.71), an attributable proportion due to interaction (AP) of 0.47 (95% CI: 0.14-0.64), and a synergy index (SI) of 2.39 (95% CI: 1.24-4.58). In contrast, there was no significant interaction effect in multiplicative scale.

Conclusion

Hyperuricemia and hypertension may contribute additively to CKD, beyond their isolated impacts. Evaluating the risk of CKD in type 2 diabetes patients necessitates considering this potential interaction.

Effects of cell-free DNA on kidney disease and intervention strategies

Kidney disease has become a global public health problem. Patients with end-stage kidney disease must rely on dialysis or undergo renal transplantation, placing heavy burdens on their families and society. Therefore, it is important to develop new therapeutic targets and intervention strategies during early stages of chronic kidney disease. The widespread application of liquid biopsy has led to an increasing number of studies concerning the roles of cell-free DNA (cfDNA) in kidney disease. In this review, we summarize relevant studies concerning the roles of cfDNA in kidney disease and describe various strategies for targeted removal of cfDNA, with the goal of establishing novel therapeutic approaches for kidney disease.

Effects of uric acid-lowering therapy (ULT) on renal outcomes in CKD patients with asymptomatic hyperuricemia: a systematic review and meta-analysis

BACKGROUND

It is well known that asymptomatic hyperuricemia and gout play an important role in patients with chronic kidney disease (CKD). However, the effect of uric acid-lowering therapy (ULT) on the prognosis of CKD patients with asymptomatic hyperuricemia remains controversial. Therefore, we aim to investigate the influence of ULT on renal outcomes in these patients.

METHODS

Comprehensive searches were conducted in PubMed, EMBASE, China National Knowledge Internet (CNKI), and the Cochrane Library, up until January 2024. We included randomized controlled trials (RCTs) that evaluated the effects of ULT on renal outcomes in CKD patients with asymptomatic hyperuricemia.

RESULTS

A total of 17 studies were included in the meta-analysis. Compared with placebo or no treatment, ULT preserved the loss of estimated glomerular filtrating rate (eGFR) (Weighted mean difference [WMD] and its 95% confidence intercal(CI): 2.07 [0.15,3.98] mL/min/1.73m2) at long-term subgroup. At the same time, short-term subgroup also proved the preserved loss of eGFR (WMD 5.74[2.09, 9.39] mL/min/1.73m2). Compared with placebo or no treatment, ULT also reduced the increase in serum creatinine (Scr) at short-term (WMD -44.48[-84.03,-4.92]μmol/L) subgroup and long-term (WMD -46.13[-65.64,-26.62]μmol/L) subgroup. ULT was associated with lower incidence of the events of doubling of Scr without dialysis (relative risk (RR) 0.32 [0.21, 0.49], p < 0.001). However, no difference was found for lower incidence of acute kidney injury (AKI) (p = 0.943).

CONCLUSIONS

According to our study, ULT is beneficial for slowing CKD progression both in short to long-term follow-ups. Additionally, in patients younger than 60 years old, the protective effect of ULT on renal outcome is more pronounced. However, it showed no significant difference in the incidence of AKI. These findings underscore the importance of considering ULT in clinical strategies for CKD patients with asymptomatic hyperuricemia.

Prevalence of chronic kidney disease and metabolic related indicators in Mianzhu, Sichuan, China

Background

Chronic kidney disease (CKD) is a major public health problem worldwide. Periodic surveys are essential for monitoring the prevalence of CKD and its risk factors. We assessed the prevalence of CKD and its risk factors in Mianzhu City in 2020.

Method

The Natural Population Cohort Study surveyed 7,770 individuals aged>20 years in Mianzhu City of Sichuan province in 2020. Our investigation encompassed the measurement of CKD prevalence, the evaluation of various renal function indicators, and comparisons based on age, gender, and hukou status. Additionally, some metabolic indices were also measured to identify the underlying causes of CKD.

Results

(1) Overall, the prevalence of reduced renal function (eGFR<60 mL/min/1.73m2), albuminuria, and CKD were 1.3, 10.0, and 10.4%, respectively, (2) the overall prevalence of CKD was higher among men than among women (14.5% vs. 8.6%). Similarly, the prevalence of CKD was higher among men than women in most age groups, (3) among urban residents, the prevalence of CKD was higher among middle-aged individuals and lower among young individuals and older adults, and (4) considering eGFR, the albuminuria and CKD for group definition, Blood pressure, triglyceride, high-density lipoprotein, blood sugar, and BMI were all statistically different among between normal groups and abnormal groups s in the albuminuria and CKD.

Conclusion

The incidence of CKD greatly varied between Mianzhu City and other regions in China and other countries. The differences in risk factors of CKD should be explored in the future. The gender difference in the prevalence of CKD in this study was markedly different from that in previous studies. More high-quality studies are needed to further explore this controversy. Based on the different prevalence of CKD and metabolism-related indices in rural and urban areas in this study, we speculated that the high incidence of CKD in Mianzhu City might be related to diet, lifestyle, and availability of healthcare services.

Drug-related problems in hospitalized patients with chronic kidney diseases and clinical pharmacist interventions

BACKGROUND

Patients with chronic kidney disease (CKD) are at high risk of drug-related problems (DRPs) because of extensive comorbidities and pharmacokinetic changes. This study aimed to identify DRPs and possible contributing factors in hospitalized patients with CKD, and evaluate the efficacy of the clinical pharmacist services in detection and intervention of DRPs in a large general hospital in Zhejiang Province, eastern China.

METHODS

With the approval of the Ethics Committee, patients with CKD admitted to the nephrology ward from January to December 2020 were enrolled in this prospective study. The clinical pharmacist identified and intervened the DRPs during hospitalization. The DRPs were classified using the Pharmaceutical Care Network Europe (PCNE) DRP classification system, and all data were statistically analyzed using Statistical Package for Social Science (SPSS) version 26.0.

RESULTS

A total of 914 patients with CKD were included, with 463 DRPs observed among 420 (45.95%) participants; the average DRP per patient was 0.51 (standard deviation [SD], 0.60) before pharmacist intervention. Treatment safety accounted for the highest proportion of problems (43.84%), followed by treatment efficacy, accounting for 43.20%. Drug selection was the most common cause of DRPs (60.26%), and antibiotics and cardiovascular agents were the most common drugs associated with DRPs (32.84% and 28.66%, respectively). A total of 85.53% of pharmaceutical intervention recommendations were followed, and 84.23% of DRPs were completely resolved after intervention by the clinical pharmacist. The proportion of patients who experienced DRPs decreased to 7.77%, with an average of 0.08 (SD 0.28) DRPs during hospitalization after pharmacist's intervention. Significant contributing factors for DRPs were CKD stage 4, number of comorbid diseases, number of prescribed medications, and hospitalization days in both the univariate and multivariate logistic regression models.

CONCLUSION

DRPs are common among hospitalized patients with CKD in China. CKD stage 4, the number of comorbidities, use of multiple prescription drugs, and extended length of hospital stay are contributing factors for DRPs. Even only one clinical nephrology pharmacist in the nephrology ward, clinical pharmacist can play an important role in facilitating the identification of DRPs in patients with CKD and assisting physicians resolve DRPs in this single center study in China.

Sinomenine improves renal fibrosis by regulating mesenchymal stem cell-derived exosomes and affecting autophagy levels

BACKGROUND

This study attempts to investigate the therapeutic effect of sinomenine on renal fibrosis and its mechanism.

METHODS

The 8-week-old C57BL/6 male mice were randomly divided into sham group, UUO model group, UUO sinomenine group (UUO + Sino 50), UUO + sinomenine group (UUO + Sino 100), UUO + exosome group (exo), and UUO + exo-inhibitor. The pathological changes of kidney were observed by H&E staining, the degree of renal interstitial fibrosis was detected by MASSON and Sirius red staining, and the expressions of fibrosis and autophagy markers were detected by real-time fluorescence quantitative PCR and WB. NTA and electron microscopy were used to analyze exo secretion after sinomenine treatment.

RESULTS

Sinomenine could improve the progression of renal fibrosis without causing tissue damage including heart, lungs and liver. Sinomenine could promote autophagosome formation. It could promote the secretion of exosomes from bone marrow mesenchymal stem cells (BMSCs). Sinomine regulates the PI3K-AKT pathway through BMSC-exo carrying miR-204-5p, affecting autophagy level and alleviating the process of renal fibrosis.

CONCLUSION

Our study suggests that sinomine could improve the progression of renal fibrosis by influencing the expression of miR-204-5p in BMSC-exo and regulating the PI3K-AKT pathway.

Probability of chronic kidney disease and associated risk factors in Chinese adults: a cross-sectional study of 9 million Chinese adults in the Meinian Onehealth screening survey

Background

Chronic kidney disease (CKD) is an increasing global health problem, but little is known about the age- and sex-specific prevalence of CKD and the associated risk factors in low- and middle-income populations. We examined the age- and sex-specific prevalence of CKD and the associated risk factors in a population-based study of 9 million Chinese adults.

Methods

The study involved a cross-sectional survey of 9 461 631 adults, >18 years of age, who were recruited in 2017 from 31 provinces in the Meinian Onehealth screening survey. All participants had plasma creatinine measured by standard methods and CKD was defined if the estimated glomerular filtration rate (eGFR) was <60 ml/min/1.73 m².

Results

Overall, among 9.5 million adults [mean age 41 years (standard deviation 13.1)], 88 271 (1.26%) had CKD. The prevalence rate of CKD was 1.20%, 0.04% and 0.02% for stage 3, 4 and 5, respectively. After adjustment for the proportion and prevalence of urban and rural areas, the overall prevalence rate of CKD was 1.07%, indicating that ∼14 million Chinese adults have CKD. The prevalence of CKD increased 3-fold for each 10-year increment in age (1.15%, 3.05% and 13.02% at age 50-59, 60-69 and >70 years, respectively) and was 1.8-fold higher in women than men. The prevalence of CKD was higher in the Southwest region {1.68% [95% confidence interval (CI) 1.12-2.24]} but lower in the Northwest region [0.84% (95% CI 0.61-1.07)] than other regions. If proteinuria is also used as a diagnostic criterion, the prevalence rate increased to 2.16%. Stepwise logistic regression analysis demonstrated that body mass index; history of hypertension, cardiovascular disease or diabetes; and levels of systolic blood pressure, triglycerides, fasting glucose and uric acid were independent risk factors for CKD.

Conclusion

CKD is an important public health problem in Chinese adults and this study highlights the need for public health strategies to detect and reduce modifiable risk factors for prevention of CKD.

The Prevalence, Progress and Risk Factor Control of Chronic Kidney Disease in Chinese Adults With Type 2 Diabetes Mellitus in Primary Care

Objective

This study aimed to evaluate the prevalence of chronic kidney disease (CKD) in Chinese adults with T2DM in primary care, and the association of HbA1c, blood pressure (BP) and triglycerides (TG), i.e. ABC control at follow up (FU) with the progress and regression of CKD.

Methods

A total of 5123 patients with ≥3 measurements of estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (UACR), HbA1c, BP, LDL-C and TG, and FU ≥ 12 months were included into final analysis. The presence of CKD was defined as the presence of albuminuria (UACR ≥ 30 mg/g), impaired eGFR (eGFR < 60 ml/min/1.73 m2) or both, and was categorised as low, moderate and high/very high risk. The change of CKD risk for outcome was categorised as stable (no change), progress (risk increase) and regress (risk decrease) from baseline to the last visits (LV).

Results

The prevalence of CKD, impaired eGFR and albuminuria was 29.6%, 5.8% and 27.1% at baseline, with 70.4%, 20.3%, 7.0% and 2.3% of patients distributed in low, moderate, high and very high risk group. There were 3457 (67.5%), 1120 (21.8%) and 546 (10.7%) patients had CKD outcome risk stable, progressed and regressed respectively. The proportion of patients reaching targets of BP ≤ 130/80 mmHg, HbA1c<7.5%, LDL-C<2.60 mmol/L increased from baseline to FU and LV, together with increased usage of insulin, RAS inhibitors and lipid lowering medications. After multivariable adjustment, the HbA1c<7.5% (OR: 0.66, 95%CI 0.56-0.78), TG< 1.7 mmol/L (OR: 0.81, 95%CI 0.68-0.96) at FU and BP ≤ 130/80 mmHg at LV (OR: 0.82, 95%CI 0.70-0.95) was negatively associated with CKD outcome risk progress.

Conclusion

The prevalence of CKD was high with 21.8% of patients progressing to higher CKD outcome risk at FU, attention should be paid on long term and better ABC control.

Prevalence of chronic kidney disease and associated factors among patients with chronic illness in Ethiopia: A systematic review and meta-analysis

Objective:

The main aim of this systematic review and meta-analysis is to provide summarized evidence on the prevalence of chronic kidney disease and associated factors among patients with chronic illness in Ethiopia.

Method:

Databases of MEDLINE/PubMed, Embase, Google Scholar, CINAHL, Cochrane library, and ScienceDirect were searched. In addition, gray literatures were searched manually from university repositories. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was used to select potential studies. Microsoft Excel 2013 sheet template was used to extract data. The quality of included studies was assessed by utilizing the Newcastle-Ottawa Scale. STATA software version 14.0 is used to compute the estimated pooled prevalence and associated factors of chronic kidney disease.

Result:

Twelve articles that fulfilled the inclusion criteria were included. The pooled estimate of chronic kidney disease among patients with chronic illnesses in Ethiopia is 21.71% (95% confidence interval: 17.67, 25.74). The highest prevalence of chronic kidney disease among patients with chronic illnesses is from Oromia (32.55% (confidence interval: 19.91, 45.19)). Glomerular filtration rate showed a comparable pooled prevalence from Cockroft-Gault and MDRD methods; 22.38% (confidence interval: 15.83, 28.92), 22.18 (confidence interval: 18.01, 26.34), respectively. Hypertensives become more likely to have chronic kidney disease compared with normotensive patients, (odds ratio = 3.01, 95% confidence interval: 1.33, 6.81).

Conclusion:

Prevalence of chronic kidney disease among chronic illness patients was significantly high. Hypertension is significantly associated with chronic kidney disease. Hence, we recommend that continuous screening of possible risk factors and proper follow-up and management strategies should be designed.

Association Between the Surrogate Markers of Insulin Resistance and Chronic Kidney Disease in Chinese Hypertensive Patients

Background

We aim to evaluate the four surrogate markers of insulin resistance (IR), including triglyceride-glucose index (TyG), lipid accumulation product index (LAP), visceral adiposity index (VAI), triglycerides to high-density lipoprotein cholesterol ratio (TG/HDL), on prevalence of chronic kidney disease (CKD) and to examine any possible effect modifiers in Chinese hypertensive patients.

Methods

A total of 13,055 hypertensive participants were included in this cross-sectional study. In addition, average age of the study population was 63.81 ± 9.46 years, and 47.66% of them are men. The primary outcome was CKD, defined as eGFR &lt;60 ml/min/1.73 m2. Multivariate logistic regression analysis and the generalized additive model and a fitted smoothing curve (penalized spline method) were used to examine the association between the surrogate markers of IR and CKD.

Results

Four surrogate markers of IR were independently and positively associated with CKD in a dose-response fashion. The association between four surrogate markers of IR and the prevalence of CKD was examined as a continuous variable per one unit increment and also as a categorical variable using tertiles with the tertiles (T1) as the reference group. In the fully adjusted model, multivariate logistic analyses showed that the per one unit increments of the TyG, LAP, VAI, and TG/HDL ratios were all significantly associated with 42, 31, 67, and 78% higher risk for CKD, respectively. Consistently, the adjusted ORs (95% CI) for CKD were 1.48 (1.21, 1.81), 1.34 (1.06, 1.69), 1.26 (1.03, 1.53), 1.35 (1.12, 1.63) when comparing the highest tertile to the lowest tertile of the TyG, LAP, VAI, and TG/HDL ratios, respectively. The stratification analysis showed that a significant positive correlation between TyG, VAI, and TG/HDL and CKD in patients over 65 years old.

Conclusion

Four surrogate markers of IR were independently and positively correlated with CKD, and LAP was better than the other surrogate markers of IR for predicting CKD. Only among participants aged over 65 years were higher levels of TyG, VAI and TG/HDL found to be closely related to the increased prevalence of CKD.

Development and Validation of a Prediction Model for 5-Year Risk of Kidney Dysfunction in Patients with Hypertension and Glucose Metabolism Disorder

Purpose

Patients with hypertension and glucose metabolism disorder (GMD) are at high risk of developing kidney dysfunction (KD). Therefore, we aimed to develop a nomogram for predicting individuals’ 5-year risk of KD in hypertensives with GMD.

Patients and Methods

In total, 1961 hypertensives with GMD were consecutively included. Baseline data were extracted from medical electronic system, and follow-up data were obtained using annual health check-ups or hospital readmission. KD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m². Subjects were randomly divided into training and validation sets with a ratio of 7 to 3. Least absolute shrinkage and selection operator method was used to identify potential predictors. Cox proportional hazard model was applied to build a nomogram for predicting KD risk. The discriminative ability, calibration and usefulness of the model were evaluated. The prediction model was verified by internal validation.

Results

During the follow-up of 5351 person-years with a median follow-up of 32 (range: 3–91) months, 130 patients developed KD. Age, sex, ethnicity, hemoglobin A1c, uric acid, and baseline eGFR were identified as significant predictors for incident KD and used for establishing nomogram. The prediction model displayed good discrimination with C-index of 0.770 (95% CI: 0.712–0.828) and 0.763 (95% CI: 0.704–0.823) in training and validation sets, respectively. Calibration curve indicated good agreement between the predicted and actual probabilities. The decision curve analysis demonstrated that the model was clinically useful.

Conclusion

The prediction nomogram, including six common easy-to-obtain factors, shows good performance for predicting 5-year risk of KD in hypertensives with GMD. This quantitative tool could help clinicians, and even primary care providers, recognize potential KD patients early and make strategy for prevention and management.

Interaction of sex and HIV infection on renal impairment: baseline evidence from the CHART cohort

OBJECTIVE

Females are more vulnerable to renal impairment (RI) in people living with HIV (PLWH), but few studies have examined sex disparity in the association of HIV serostatus with RI.

METHODS

In total, 2,101 PLWH on antiretroviral treatment (ART) and 4,202 HIV-negative people were selected and frequency matched in 1:2 ratio by sex and age categories. RI was defined as estimated glomerular filtration rate (eGFR) <90 mL/min/1.73 m². The interaction effect of sex with HIV serostatus and correlates of RI were assessed by logistic regression models.

RESULTS

In total, 78.2% of participants were males with median age 43.7 (IQR: 32.5-54.4) years. The prevalence of RI was comparable for PLWH and HIV-negative people overall (30.4% vs 30.1%) but significantly higher for HIV-positive females (37.1%) than HIV-negative females (30.1%). Multiple logistic regression identified an interaction between sex and HIV serostatus on RI (adjusted odds ratio [aOR] of the interaction term: 1.66, 95% CI: 1.23-2.26). HIV infection was significantly associated with RI in females (aOR: 1.55, 95% CI: 1.17-2.06) but not in males. Central obesity and nadir CD4 count were significantly associated with RI in HIV-infected females but not in HIV-infected males.

CONCLUSIONS

Sex seems to modify the association between HIV infection and RI, suggesting a sex-specific mechanistic pathogenesis of RI in PLWH, which warrants further investigation and intervention.

Role of asymptomatic hyperuricemia in the progression of chronic kidney disease and cardiovascular disease

Previous research has investigated whether hyperuricemia serves as an independent risk factor for cardiovascular and renal diseases. Hyperuricemia is defined as an abnormally high level of uric acid (UA; i.e., serum urate level > 6.8 mg/dL). Hyperuricemia has been considered a complication of chronic kidney disease (CKD). However, it seems to play a pathogenic role in the progression of renal diseases. There has been increasing focus on the link between hyperuricemia and CKD. The results of randomized controlled trials have implied independent associations between hyperuricemia and the progression of cardiovascular and renal morbidities. These associations may be mediated by renin-angiotensin system activation, nitric oxide synthase inhibition, and macrovascular/microvascular disease development. There remains controversy regarding the use of serum UA level as an indirect index of renal vascular disease. This literature review focuses on the role of asymptomatic hyperuricemia in the progression of CKD, as well as the association between hyperuricemia and cardiovascular disease. It also provides a general overview of the physiological metabolism of UA.

Curcumin modulates gut microbiota and improves renal function in rats with uric acid nephropathy

It is well known that the progression of hyperuricemia disease often contributes to renal dysfunction. However, there have been few studies on uric acid nephropathy (UAN), especially its relationship with gut microbiota. UAN is usually accompanied by disordered intestinal flora, and damaged gut barrier, which are closely related to tubulointerstitial fibrosis, and systemic inflammation. In previous studies, it has been confirmed that curcumin could alleviate tubulointerstitial fibrosis, and improve renal function through its antioxidant, anti-apoptotic, and anti-inflammatory efficacies. However, the effects curcumin exerts on intestinal flora in uric acid nephropathy are still unknown. Therefore, we used next-generation sequencing technology to investigate the effects of curcumin on gut microbiota in a rat model of UAN induced by adenine and potassium oxonate, and rats were randomly divided into control, model or curcumin treatment groups. The results demonstrated that, compared to the model group, the treatment group showed decreased serum uric acid (156.80 ± 11.90 μmol/L vs. 325.60 ± 18.65 μmol/L, p < 0.001), serum creatinine (66.20 ± 11.88 μmol/L vs. 182.20 ± 8.87 μmol/L, p < 0.001) and BUN level (13.33 ± 3.16 mmol/L vs. 36.04 ± 6.60 mmol/L, p < 0.001). The treatment group also displayed attenuated renal pathological lesions and metabolic endotoxemia (25.60 ± 5.90 ng/mL vs. 38.40 ± 4.98 ng/mL, p < 0.01), and improved tightly linked proteins expression. Besides, curcumin altered the gut microbiota structure in UAN rats. More specifically, curcumin treatment protected against the overgrowth of opportunistic pathogens in UAN, including Escherichia-Shigella and Bacteroides, and increased the relative abundance of bacteria producing short‐chain fatty acids (SCFAs), such as Lactobacillus and Ruminococcaceae. These results suggest that curcumin could modulate gut microbiota, fortify the intestinal barrier, attenuate metabolic endotoxemia, and consequently protect the renal function in UAN rats.

Histone Methyltransferase EZH2: A Potential Therapeutic Target for Kidney Diseases

Enhancer of zeste homolog 2 (EZH2) is a histone-lysine N-methyltransferase enzyme that catalyzes the addition of methyl groups to histone H3 at lysine 27, leading to gene silencing. Mutation or over-expression of EZH2 has been linked to many cancers including renal carcinoma. Recent studies have shown that EZH2 expression and activity are also increased in several animal models of kidney injury, such as acute kidney injury (AKI), renal fibrosis, diabetic nephropathy, lupus nephritis (LN), and renal transplantation rejection. The pharmacological and/or genetic inhibition of EZH2 can alleviate AKI, renal fibrosis, and LN, but potentiate podocyte injury in animal models, suggesting that the functional role of EZH2 varies with renal cell type and disease model. In this article, we summarize the role of EZH2 in the pathology of renal injury and relevant mechanisms and highlight EZH2 as a potential therapeutic target for kidney diseases.

Burden of Chronic Kidney Disease by KDIGO Categories of Glomerular Filtration Rate and Albuminuria: A Systematic Review

Introduction

The Kidney Disease: Improving Global Outcomes (KDIGO) 2012 guidelines recommend classifying patients by glomerular filtration rate (GFR) and albuminuria to predict chronic kidney disease (CKD) prognosis. The aim of this systematic review was to explore the epidemiological burden of CKD stratified by the KDIGO 2012 categories.

Methods

MEDLINE® and Embase were searched for observational studies of patients with CKD with results stratified according to the KDIGO 2012 classification. Investigated outcomes were prevalence, incidence, and risk factors and complications of CKD, including mortality.

Results

The review included ten observational studies with 3033 to 46,949 participants, conducted in the USA, China, France, Italy and Spain. The most frequently reported outcome was the prevalence of CKD (GFR categories G3–5), ranging from 2% to 17%. Most participants were normoalbuminuric, with 0.4–3.2% macroalbuminuric, and most fell within the KDIGO 2012 low-risk or moderate-risk groups, with 0.9–5.6% in the high-risk and 0.3–4.8% in the very high-risk groups. Although scarce, data on the prevalence of comorbidities in CKD according to the KDIGO classification suggest that they increase with albuminuria severity.

Conclusions

Patients with CKD frequently have complications, but only a small proportion have severely increased albuminuria or fall within the KDIGO high-risk or very high-risk groups. These groups, however, are associated with the highest burden of disease, as comorbidities are more prevalent with increasing albuminuria severity. New studies framed by the KDIGO 2012 classification are needed to address key gaps in the understanding of CKD burden and outcomes.

Electronic supplementary material

The online version of this article (10.1007/s12325-020-01568-8) contains supplementary material, which is available to authorized users.

Ethanol extract of Liriodendron chinense (Hemsl.) Sarg barks attenuates hyperuricemic nephropathy by inhibiting renal fibrosis and inflammation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Liriodendron chinense (Hemsl.) Sarg, known as the Chinese tulip tree, has a long history of cultivation and utilization in many Asia countries, especially in China to use in traditional Chinese medicine for expelling "wind and dampness", a term corresponding to rheumatic fever and rheumatoid arthritis. Interestingly, the barks of Liriodendron chinense (Hemsl.) Sarg was also found in folk to treat gout. However, further experimental studies remained to confirm its uric acid-lowering effects.

AIM OF THE STUDY

The aim of the study was to evaluate the protective effect of ethanol extract of the barks of Liriodendron chinense (Hemsl.) Sarg (EELC) in a mouse model of hyperuricemic nephropathy (HN) and the involved mechanisms.

MATERIALS AND METHODS

EELC at a respective dose of 250 mg/kg/d or 500 mg/kg/d were orally administered to HN mice induced by a mixture of adenine (160 mg/kg/d)/potassium oxonate (2.4 g/kg/d) for 21 days. At the end of the treatment, serum uric acid, kidney functions (serum creatinine, blood urea nitrogen and urine microalbumin), 24-h urine uric acid excretion, as well as kidney pathological changes were investigated by biochemical assay, histopathological score, immunofluorescence and histochemistry, RT-qPCR, and western blotting analysis.

RESULTS AND DISCUSSION

Oral administration of EELC significantly lowered serum uric acid level at 500 mg/kg (185.75 ± 15.49 μmol/L of EELC vs. 238.28 ± 20.97 μmol/L of HN model, p < 0.01) in HN mice. EELC at 500 mg/kg also remarkably reduced the levels of serum creatinine (82.92 ± 7.86 μmol/L of EELC vs. 92.08 ± 6.13 μmol/L of HN model, p < 0.0001), blood urea nitrogen (21.50 ± 1.87 mmol/L of EELC vs. 29.40 ± 3.95 mmol/L of HN model, p < 0.001) and urine microalbumin (4.25 ± 0.40 mg/L of EELC vs. 5.95 ± 0.33 mg/L of HN model, p < 0.001) to improve renal function. It also attenuated renal fibrosis, especially the high-dose of EELC. Furthermore, EELC could inhibit the activation of NF-κB, ASK1/JNK/c-Jun, JAK2/STAT3 signaling pathways and reduce the release of pro-inflammatory cytokine TNF-α in the kidneys of HN mice. Additionally, EELC remarkably increased urine uric acid excretion of HN mice, which may be achieved by the upregulation of organic anion transporter 1 (OAT1), OAT3 and ATP-binding cassette subfamily G member 2 (ABCG2) proteins.

CONCLUSIONS

EELC alleviated the progression of HN by suppressing the activation of NF-κB, ASK1/JNK/c-Jun and JAK2/STAT3 signaling pathway, reducing the infiltration of inflammatory factors and uric acid accumulation in the kidney.

Diffusional kurtosis imaging of kidneys in patients with hyperuricemia: initial study

BACKGROUND

At present, there remains a lack of a reliable indicator for monitoring renal function in patients with hyperuricemia.

PURPOSE

This study aimed to evaluate the feasibility of diffusion kurtosis imaging in the assessment of renal function in patients with hyperuricemia.

MATERIAL AND METHODS

A total of 75 male participants, including 25 with asymptomatic hyperuricemia, 25 with gouty arthritis, and 25 age-matched male healthy controls, were enrolled in this study. Diffusion kurtosis imaging data were acquired to derive axial (Ka), radial (Kr), and mean kurtosis (MK), fractional anisotropy, axial (Da), radial (Dr), and mean diffusivity (MD) for comparisons among the three groups. They were also correlated with estimated glomerular filtration rate (eGFR).

RESULTS

The MK values of the renal cortex and medulla and Kr value of the renal medulla in patients with asymptomatic hyperuricemia and gouty arthritis significantly increased compared with those in the controls (P < 0.05). Patients with gouty arthritis showed significant higher cortical and medullary Ka values compared with the other two groups (P < 0.05). The cortical Kr values of the asymptomatic hyperuricemia and gouty arthritis patients were significantly higher than that of the controls (P < 0.05). The medullary fractional anisotropy value showed a significant difference between the control and gouty arthritis groups (P < 0.05). No correlation was found between any diffusion kurtosis imaging parameters and eGFR value.

CONCLUSION

Diffusion kurtosis imaging is feasible in the assessment of the early changes of renal cortex and medulla in patients with hyperuricemia.

Metabolic syndrome and concomitant diabetes mellitus are associated with higher risk of cardiovascular comorbidity in patients with primary glomerular diseases: A retrospective observational study

BACKGROUND

Metabolic syndrome (MS) and diabetes mellitus (DM) are risk factors for cardiovascular diseases in general population. However, there was a paucity of studies investigating their impact in primary glomerular diseases (PGD).

HYPOTHESIS

MS and concomitant DM are associated with higher risk of cardiovascular comorbidity in PGD.

METHODS

In a retrospective observational design, we analyzed 3622 hospitalized adult PGD patients and compared the prevalence of cardiovascular comorbidity in non-MS, MS with and without DM. Risk factors for cardiovascular comorbidity were identified using univariate and multivariate logistic regression.

RESULTS

Among 3622 PGD patients, 308 (8.5%) cases accompanied with MS, including 180 (5.0%) patients with DM and 128 (3.5%) without DM. One hundred and sixty four (4.5%) cases coexisted with cardiovascular comorbidity. Patients with MS and concomitant DM exhibited a higher prevalence of cardiovascular comorbidity than those without MS stratified by estimated glomerular filtration rate and pathological types. Logistic regression showed that MS and concomitant DM (OR: 2.496, 95% CI: 1.600-3.894, P < .001), older age (OR: 1.060, 95% CI: 1.047-1.074, P < .001), male (OR: 1.536, 95% CI: 1.072-2.200, P = .019), higher level of serum ti (OR: 1.002, 95% CI: 1.001-1.003, P < .001), hyperuricemia (OR: 1.901, 95% CI: 1.327-2.725, P < .001), idiopathic membranous nephropathy (OR: 2.874, 95% CI: 1.244-6.640, P < .001) and focal segmental glomerulosclerosis (OR: 2.906, 95% CI: 1.147-7.358, P < .001) were independently associated with a higher risk for cardiovascular comorbidity.

CONCLUSIONS

In PGD patients, MS and concomitant DM are associated with an increased risk for cardiovascular comorbidity. More evidence for the causal link between MS/DM and cardiovascular outcomes is needed to be clarified.

The relationship between hemodialysis mortality and the Chinese medical insurance type

Objectives: In China, there are two major medical insurance models: the Urban Basic Medical Insurance (UBMI) and the New Cooperative Medical Scheme (NCMS). The aim of the present study was to evaluate the association of the medical insurance type of patients undergoing hemodialysis (HD) with their survival.

Methods: We retrospectively analyzed the end-stage renal disease adult patients initiating HD between January 2010 and December 2014 in Zhejiang province, followed up through 31 December 2015. Patients who had received HD for over 3 months were separated into two groups, based on different medical insurance type. Demographic, clinical data, and clinical outcomes were analyzed. The survival rates were calculated by using the Kaplan–Meier method.

Results: A total of 6779 patients (59 ± 16 years old, 4331 males (63.9%)) with UBMI and 7177 (59 ± 16 years old, 3778 males (52.8%)) with NCMS enrolled from 226 hemodialysis units. Compared with UBMI group, patients with NCMS had a smaller percentage of hypertensive nephropathy, diabetes mellitus and arteriovenous fistula, faced with more problems in anemia, hypoalbuminemia and metabolism of calcium and phosphorous. The 1-, 3- and 5-year survival rates were 95.4, 84.4, and 74.1% in UBMI group, 93.1, 79.7, and 67.7% in NCMS group, respectively. Patients with NCMS showed higher all-cause mortality compared with UBMI (p < 0.001). In multivariate Cox proportional hazards model, NCMS was independently associated with higher mortality (AHR = 1.53; 95% CI 1.38 ∼ 1.68).

Conclusions: The medical insurance model was independently associated with HD patient survival, NCMS was associated with increased mortality among patients undergoing maintenance hemodialysis in China.

Risk scores for predicting incident chronic kidney disease among rural Chinese people: a village-based cohort study

Background

Few chronic kidney disease (CKD) risk prediction models have been investigated in low- and middle-income areas worldwide. We developed new risk scores for predicting incident CKD in low- and middle-income rural Chinese populations.

Methods

Data from the Handan Eye Study, which was a village-based cohort study and conducted from 2006 to 2013, were utilized as part of this analysis. The present study utilized data generated from 3266 participants who were ≥ 30 years of age. Two risk models for predicting incident CKD were derived using two-thirds of the sample cohort (selected randomly) using stepwise logistic regression, and were subsequently validated using data from the final third of the sample cohort. In addition, two simple point systems for incident CKD were generated according to the procedures described in the Framingham Study. CKD was defined as reduced renal function (estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m²) or the presence of albuminuria (urinary albumin-to-creatinine ratio (UACR) ≥30 mg/g).

Results

The Simple Risk Score included waist circumference, systolic blood pressure (SBP), diabetes, sex, and education. The Best-fit Risk Score included urinary albumin-to-creatinine ratio, SBP, C-reactive protein, triglyceride, sex, education, and diabetes. In the validation sample, the areas under the receiver operating curve of the Simple Risk Score and Best-fit Risk Score were 0.717 (95% CI, 0.689–0.744) and 0.721 (95% CI, 0.693–0.748), respectively; the discrimination difference between the score systems was not significant (P = 0.455). The Simple Risk Score had a higher Youden index, sensitivity, and negative predictive value, with an optimal cutoff value of 14.

Conclusions

Our Simple Risk Score for predicting incident CKD in a low- and middle-income rural Chinese population will help identify individuals at risk for developing incident CKD.

Decreased glomerular filtration rate in patients with at least 5 years of type 2 diabetes in Ho Chi Minh City, Vietnam: Prevalence and associated factors

AIMS

This study determined the prevalence and associated factors of decreased estimated glomerular filtration rate (eGFR) in patients who had type 2 diabetes for at least 5 years.

METHODS

A cohort study was conducted in 467 outpatients in a community-based hospital in Ho Chi Minh City, Vietnam. Serum creatinine were tested twice, at two occasions at least 3 months apart. The confirmatory eGFR was the average of the two eGFR of which the difference was ≤20%. The mean urine albumin-to-creatinine ratio was calculated from two consecutive early morning specimens.

RESULTS

Most patients were female with a mean age of 61.7 (8.0) years. Albuminuria was found in 40% of participants, and the prevalence of decreased eGFR was 7.5% (n=35). Individuals with declined eGFR were older (p<0.001), had duration of diabetes longer (p=0.025), higher systolic blood pressure (p=0.010) and higher acid uric level (p<0.001), increased albumin excretion (p=0.009), and more proliferative retinopathy (p=0.011) than those with non-declined eGFR.

CONCLUSIONS

Although decreased eGFR in type 2 diabetes patients was not prevalent, the strategies to prevent the progressive decline of GFR should be done to prevent patients from progressing to advanced renal disease.

Pathological spectrum of glomerular disease in patients with renal insufficiency: a single-center study in Northeastern China

Background: To investigate the pathological spectrum of glomerular disease in patients with renal insufficiency (RI) from 2008 to 2017. Methods and results: We calculated the estimated glomerular filtration rate (eGFR) with the Chronic Kidney Disease Epidemiology Collaboration creatinine (CKD-EPI) equation and defined RI as an eGFR <60 ml/min/1.73 m². A total of 969 RI patients were included in our study. IgA nephropathy (IgAN) was the most common subtype of primary glomerulonephritis (37.2%). The frequencies of IgAN and non-IgA mesangioproliferative glomerulonephritis decreased from 27.3% and 9.5% during 2008-2012 to 20.7% and 2.6% during 2013-2017, respectively. However, the frequency of membranous nephropathy increased from 6.8% to 16.2%. Lupus nephritis was the most common subtype of secondary glomerulonephritis (32.1%). The frequencies of both ANCA-associated systemic vasculitis and diabetic nephropathy increased from 3.8% to 7.6% and from 4.3% to 7.6%, respectively. The number of elderly patients (≥60 years) in our study increased sharply, from 15.6% in 2008 to 35.0% in 2017. Membranous nephropathy, minimal change disease, membranoproliferative glomerulonephritis, lupus nephritis and renal amyloidosis are more frequently observed in the elderly patients than in nonelderly patients (<60 years) (p < .05). Excluding those with acute kidney injury, IgAN was the leading cause of RI (24.9%), followed by membranous nephropathy (13.3%) and lupus nephritis (12.0%). Conclusions: IgAN and lupus nephritis were the most prevalent primary glomerulonephritis and secondary glomerulonephritis in patients with RI, respectively. The frequencies of membranous nephropathy, ANCA-associated systemic vasculitis and diabetic nephropathy increased significantly. The number of elderly patients with RI increased sharply.

Visceral Adiposity Index and Chronic Kidney Disease in a Non-Diabetic Population: A Cross-Sectional Study

PURPOSE

To investigate the correlation between visceral obesity and pathogenesis of chronic kidney disease (CKD) among non-diabetic individuals, and to evaluate the potential of visceral adiposity index (VAI) as a predictor of CKD.

PATIENTS AND METHODS

From December 2017 to March 2018, 1877 non-diabetic participants (male n=699, female n=1208) in southern China were recruited for a cross-sectional survey. Males and females were divided into four groups according to gender-specific quartiles of VAI scores. A logistic regression model was established to analyze the correlation between visceral adiposity index and CKD.

RESULTS

Visceral adiposity index was positively correlated with CKD and was negatively associated with estimated glomerular filtration rate (eGFR). Using group one as the control, odds ratios (ORs) were calculated to determine the risk of developing CKD as VAI increased (male: group four 2.73 [P<0.005]; female: Group three 1.76 [P<0.05], Group four 2.88 [P<0.005]). When related factors such as history of hypertension, smoking, alcohol use, and physical inactivity were normalized in the logistic model before calculation, ORs became 2.73 (male: P<0.05), and 2.18 (female: P<0.05), respectively. The results differed after normalizing further for systolic blood pressure (SBP), diastolic blood pressure (DBP), hypersensitive c-reactive protein (hsCRP), interleukin-6 (IL-6), homocysteine (Hcy), superoxide dismutase (SOD), and retinol-binding protein (RBP). There were no significant differences in ORs among the female groups.

CONCLUSION

Visceral adiposity index was significantly associated with CKD in non-diabetic individuals. It may be a good predictor of the pathogenesis of CKD and was dependent on hsCRP, IL-6, Hcy, SOD, RBP, and blood pressure levels in females and males with VAI scores of 1.41 and higher. Visceral adiposity index may be used to predict CKD in males with VAI less than 0.983.

Investigation of the Causes and Risk Factors of Previous End-Stage Renal Disease in Kidney Transplant Recipients

BACKGROUND

Chronic kidney disease (CKD) is a pathophysiological process with many etiologic causes, often leading to end-stage renal disease (ESRD). The distribution of the causes that lead to ESRD varies by country, race, and sex. Renal failure may be prevented by determining these differences and reducing the risk factors.

OBJECTIVE

The purpose of the study was to determine the causes and risk factors of previous ESRD in kidney transplant (KT) recipients.

METHODS

In this descriptive, cross-sectional study, 393 KT recipients fitting the study criteria gave written consent to participate. Data were collected in face-to-face interviews at the Transplant Center using survey forms prepared by the researchers.

RESULTS

According to a multivariate logistic regression analysis of the dependent variable of ESRD diagnosis age of KT recipients, the factors affecting ESRD diagnosis age were found to be job (Odds ratio (OD) = 5.76; 95% CI [2.291-14.481]), diabetes mellitus (DM) (OD = 2.94; 95% CI [1.143-7.571]), polycystic kidney disease (PKD) (OD = 4.55; 95% CI [1.737-11.919]), hypertension (HT) (OD = 3.53; 95% CI [2.132-5.854]), family history of ESRD (OD = 0.57; 95% CI [0.341-0.963]), surgical procedure history (OD = 1.93; 95% CI [1.150-3.230]), and stress level (OD = 5.86, 95% CI [2.212-15.528]).

CONCLUSION

It is important that we determine the changeable risk factors related to ESRD development in order to prepare strategies aimed at preventing ESRD, the frequency and prevalence of which is gradually increasing. Modifiable risk factors should be identified, particularly in KT recipients, to preserve the functions of the transplanted kidney.

The relationship between hemodialysis mortality and the Chinese medical insurance type

Objective: In China, there are two major medical insurance models: the Urban Basic Medical Insurance (UBMI) and the New Cooperative Medical Scheme (NCMS). The aim of the present study was to evaluate the association of the medical insurance type of patients undergoing hemodialysis (HD) with their survival. Methods: We retrospectively analyzed the end-stage renal disease adult patients initiating HD between January 2010 and December 2014 in Zhejiang province, followed up through 31 December 2015. Patients who had received HD for over 3 months were separated into two groups, based on different medical insurance type. Demographic, clinical data, and clinical outcomes were analyzed. The survival rates were calculated by using the Kaplan-Meier method. Results: A total of 6779 patients (59 ± 16 years old, 4331 males (63.9%)) with UBMI and 7177 (59 ± 16 years old, 3778 males (52.8%)) with NCMS enrolled from 226 hemodialysis units. Compared with UBMI group, patients with NCMS had a smaller percentage of hypertensive nephropathy, diabetes mellitus and arteriovenous fistula, faced with more problems in anemia, hypoalbuminemia and metabolism of calcium and phosphorous. The 1-, 3- and 5-year survival rates were 95.4%, 84.4%, and 74.1% in UBMI group, 93.1%, 79.7%, and 67.7% in NCMS group, respectively. Patients with NCMS showed higher all-cause mortality compared with UBMI (p < .001). In multivariate Cox proportional hazards model, NCMS was independently associated with higher mortality (AHR = 1.53; 95% CI 1.38 ∼ 1.68). Conclusions: The medical insurance model was independently associated with HD patient survival, NCMS was associated with increased mortality among patients undergoing maintenance hemodialysis in China.

Prevalence of kidney damage in Chinese elderly: a large-scale population-based study

BACKGROUND

In China, both population aging and kidney damage has become emerging public health challenges. Despite the number of elders is huge, data on kidney damage in this population are scarce. The present study aimed to describe the prevalence of kidney damage among older adults in Wuhan, China.

METHODS

To describe the prevalence of kidney damage among Chinese elderly, the health screening data of 350,881 adults older than 65 years in Wuhan, China were collected and analyzed. Kidney damage was defined as eGFR less than 60 mL/min per 1·73 m2 or the presence of proteinuria. Decreased renal function was defined as an eGFR < 60 mL/min/1.73 m2. Proteinuria was defined as urine protein ≥1+ and without urine WBC or nitrite positive. The associated risk factors of eGFR decline and kidney damage were analyzed by multivariate logistic regression.

RESULTS

The age-standardized prevalence of kidney damage, decreased renal function and proteinuria was 17.2, 13.5 and 5.3%. Among the patients, up to 74.4% was stage 3. The prevalence of kidney damage and eGFR decline were higher in suburbs than in urban (18.3% vs 16.0 and 14.6% vs 12.4%). Factors independently associated with kidney damage were age, female, BMI, abdominal circumference, hypertension, diabetes, stroke and coronary heart disease.

CONCLUSIONS

Kidney damage has become an important public health problem in Chinese elderly. More attention should be paid to elderly lived in suburbs or rural area in our further work.

Glycogen Synthase Kinase-3β Inhibitor Attenuates Renal Damage Through Regulating Antioxidant and Anti-inflammation in Rat Kidney Transplant With Cold Ischemia Reperfusion

BACKGROUD

The glycogen synthase kinase-3β inhibitor thiadiazolidinone derivative 8 (TDZD-8) has been reported to reduce renal ischemia reperfusion (I/R) injury through inhibiting cell damage. However, it is not known whether TDZD-8 could also play a role in protecting the kidney in rat kidney transplantation with renal cold I/R. The aim of the present study was to explore the possible role of TDZD-8 in protecting renal damage in a cold I/R model of rat kidney transplantation.

METHODS

The rat model of kidney transplantation with renal cold I/R was established. The renal tissue pathomorphologic changes, renal function, oxidative stress, and inflammatory response were evaluated by detection of a series of indices by hematoxylin and eosin staining, commercial kits, enzyme-linked immunosorbent assay, and spectrophotofluorometry, respectively.

RESULTS

Compared with I/R and Graft groups, renal function was significantly improved in TDZD and TDZD-G groups, which were accompanied by the reduction of renal injury, oxidative stress, and inflammation.

CONCLUSIONS

These results suggest that preconditioning with glycogen synthase kinase-3β inhibitor can attenuate kidney transplantation with renal cold I/R through regulating endogenous antioxidant activity and inflammation.

The association between socioeconomic status and prevalence of chronic kidney disease: A cross-sectional study among rural residents in eastern China

To investigate the prevalence of chronic kidney disease (CKD) among eastern Chinese rural residents and analyze the relationship between socioeconomic conditions and CKD.A cross-sectional survey of 1713 adults, enrolled from 4 villages in the north-central part of Zhejiang province in eastern China was conducted by collecting data on socioeconomic status, physical examination, and laboratory investigations. CKD was defined as estimated glomerular filtration rate < 60 mL/min per 1.73 m or urinary albumin/creatinine ratio more than 30 mg/g. The crude and adjusted prevalence of CKD was estimated and the association of socioeconomic status was analyzed by logistic regression.A total of 1654 adults (96.53%) completed the screening, and 1627 (98.37%) of them had complete questionnaire and test information. The standardized prevalence of CKD adjusted by age and sex was 9.21% (95% confidence interval, 7.8-10.63). People with hypertension, hyperglycemia, hyperuricemia, high fasting blood glucose, and high body mass index had higher risk for CKD. Socioeconomic status was found to be partly related to CKD, especially educational level and occupational nature.A high prevalence of CKD was observed among rural residents in north-central Zhejiang province in eastern China. Socioeconomic statuses were partly related to the prevalence of CKD.

Effects of Chicory on Serum Uric Acid, Renal Function, and GLUT9 Expression in Hyperuricaemic Rats with Renal Injury and In Vitro Verification with Cells

Hyperuricaemia (HUA) is an independent risk factor for chronic kidney disease. Urate crystals are deposited in the kidney and can cause renal tubular interstitial fibrosis, leading to renal dysfunction. Chicory extract (hereafter referred to as chicory) clearly reduced serum uric acid levels in rats with HUA induced by 10% fructose. This is the first study to observe the effect of chicory on serum uric acid levels and renal function in rats with HUA and renal injury. In vivo studies using hyperuricaemic rats with renal injury induced by yeast and adenine demonstrated that chicory decreased serum uric acid level, and its effect of delaying the progression of kidney injury was better than that of benzbromarone. In vitro cell experiments showed that this effect is related to the inhibition of GLUT9 protein expression in renal tubules and that lowering blood uric acid concentrations is one of the factors that alleviates renal damage. The results of this study indicate that chicory can be used as an alternative for alleviating renal dysfunction in hyperuricaemia.

Economic Burden and Medical Insurance Impact of the Different Dialysis for End-stage Renal Diseases

BACKGROUND

Dialysis costs was a heavy burden in End Stage Renal Disease (ESRD) patients. In China, the two major medical insurance systems are the New Cooperative Medical Scheme (NCMS) for rural residents and the Urban Employees' Medical Insurance (UEMI) for urban patients. This study compared the economic burden of ESRD patients under different dialysis methods and the impact of the medical insurance system on it.

METHODS

Overall, 156 ESRD patients were enrolled at the Department of Nephrology in the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China between Jan 2013 and Jan 2014. They were divided into hemodialysis group (HD group, n=84) and peritoneal dialysis group (PD group, n=72). The data, such as the patient's basic information, total expenses and self-paid expenses in the early stage of dialysis and 1-year treatment, and medical insurance type, were separately collected.

RESULTS

The early-stage average total expenses and self-paid expenses in the PD group were higher than those in the HD group (P<0.01). The average total expenses and self-paid expenses in the PD group were lower than those in the HD group (P<0.01). Whichever dialysis method was used, the self-paid expense percentage for the NCMS patients and was higher than UEMI patients.

CONCLUSION

In terms of the long-term dialysis treatment for ESRD patients, the better choice was PD judging by the treatment expenses. Meanwhile, different medical insurance types had significant economic burden impacts on dialysis patients.

Chronic kidney disease of unknown etiology and the effect of multiple-ion interactions

High incidence of chronic kidney disease of unknown etiology (CKDU) prevalent in many countries (e.g., Sri Lanka, equatorial America) is reviewed in the context of recent experimental work and using our understanding of the hydration of ions and proteins. Qualitative considerations based on Hofmeister-type action of these ions, as well as quantitative electrochemical models for the Gibbs free energy change for ionpair formation, are used to explain why (1) fluoride and water hardness due to magnesium ions (but not due to calcium ions) and similarly (2) cadmium ions in the presence of suitable pairing ions can be expected to be more nephrotoxic, while arsenite in the presence of fluoride and hardness may be expected to be less nephrotoxic. No synergy of arsenic with calcium hardness is found. The analysis is applied to a variety of ionic species that may be found in typical water sources to predict their likely combined electrochemical action. These results clarify the origins of chronic kidney disease that has reached epidemic proportions in the North Central Province of Sri Lanka as being most likely due to the joint presence of fluoride and magnesium ions in drinking water. The conclusion is further strengthened by a study of the dietary load of Cd and other toxins in the affected regions and in the healthy regions where the dietary toxin loads and lifestyles are similar, and found to be safe especially when the mitigating effects of micronutrient ionic forms of Zn, Se, as well as corrections for bioavailability are taken into account. The resulting etiological picture is consistent with the views of most workers in the field who have suspected that fluoride and other ions found in the hard water stagnant in shallow household wells were the major causative factors of the disease. Similar incidence of CKDu found in other hot tropical climates is likely to have similar origins.

Comparison of visceral, body fat indices and anthropometric measures in relation to chronic kidney disease among Chinese adults from a large scale cross-sectional study

Background

The aim of the study was to assess the association between chronic kidney disease (CKD) and obesity in predicting CKD among Chinese adults, distinguishing between 5 different adiposity indices: visceral fat index (VFI), percentage body fat (PBF), body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR).

Methods

A total of 29,516 participants aged 35 years or above were selected using a stratified multistage random sampling method across China during 2012–2015. CKD was defined as an estimated glomerular filtration (eGFR) < 60 ml/min/1.72m².

Results

The overall weighted prevalence of CKD was 3.94% (3.62% in males and 4.25% in females). All five adiposity indices had significant negative correlations to eGFR (P < 0.05). The area under the ROC (receiver operating characteristic) curves (AUC) for PBF was almost significantly larger than the other adiposity indices (P < 0.001). In addition, PBF yielded the highest Youden index in identifying CKD (male: 0.15; female: 0.20). In the logistic analysis, PBF had the highest crude odds ratios (ORs) in both males (OR: 1.819, 95% CI 1.559–2.123) and females (OR: 2.268, 95% CI 1.980–2.597). After adjusted for age, smoking status, alcohol use, education level, marital status, rural vs. urban area, geographic regions, and diagnosis of hypertension, diabetes mellitus, myocardial infarction and stroke, the ORs on PBF remained significant for both genders (P < 0.05).

Conclusions

Obesity is associated with an increased risk of CKD. Furthermore, PBF was a better predictor for identifying CKD than other adiposity indices (BMI, WC, WHtR, and VFI).

Electronic supplementary material

The online version of this article (10.1186/s12882-018-0837-1) contains supplementary material, which is available to authorized users.

Prevalence and burden of chronic kidney disease among the general population and high-risk groups in Africa: a systematic review

OBJECTIVES

While increasing attention is paid to the rising prevalence of chronic diseases in Africa, there is little focus on chronic kidney disease (CKD). This systematic review assesses CKD burden among the general population and high-risk groups on the entire African continent.

DESIGN, SETTING AND PARTICIPANTS

We searched Medline and PubMed databases for articles published between 1 January 1995 and 7 April 2017 by sensitive search strategies focusing on CKD surveys at the community level and high-risk groups. In total, 7918 references were evaluated, of which 7766 articles were excluded because they did not meet the inclusion criteria. Thus, 152 studies were included in the final analysis.

OUTCOME MEASUREMENT

The prevalence of CKD in each study group was expressed as a range and pooled prevalence rate of CKD was calculated as a point estimate and 95% CI. No meta-analysis was done. Data were presented for different populations.

RESULTS

In the community-level studies, based on available medium-quality and high-quality studies, the prevalence of CKD ranged from 2% to 41% (pooled prevalence: 10.1%; 95% CI 9.8% to 10.5%). The prevalence of CKD in the high-risk groups ranged from 1% to 46% (pooled prevalence: 5.6%; 95% CI 5.4% to 5.8%) in patients with HIV (based on available medium-quality and high-quality studies), 11%-90% (pooled prevalence: 24.7%; 95% CI 23.6% to 25.7%) in patients with diabetes (based on all available studies which are of low quality except four of medium quality) and 13%-51% (pooled prevalence: 34.5%; 95 % CI 34.04% to 36%) in patients with hypertension (based on all available studies which are of low quality except two of medium quality).

CONCLUSION

In Africa, CKD is a public health problem, mainly attributed to high-risk conditions as hypertension and diabetes. The poor data quality restricts the validity of the findings and draws the attention to the importance of designing future robust studies.

Febuxostat attenuates ER stress mediated kidney injury in a rat model of hyperuricemic nephropathy

Hyperuricemia contributes to kidney tubular injury and kidney fibrosis. However, the underlying mechanism remains unclear. Here we examined the role of RTN1A, a novel endoplasmic reticulum (ER)-associated protein and ER stress in hyperuricemic nephropathy. We first found the expression of RTN1A and ER stress markers was significantly increased in kidney biopsies of hyperuricemia patients with kidney injury. In a rat model of hyperuricemic nephropathy (HN) established by oral administration of a mixture of adenine and potassium oxonate, increased expression of RTN1A and ER stress was shown in tubular and interstitial compartment of rat kidneys. Treatment of Febuxostat, a new selective inhibitor of xanthine oxidase (XO), not only attenuated renal tubular injury and tubulointerstitial fibrosis, but also reduced uric acid crystals deposition in HN rat kidneys. In vitro, Febuxostat also reduced ER stress and apoptosis in uric acid treated tubular epithelial cells. Our data suggest that RTN1A and ER stress mediate tubular cell injury and kidney fibrosis in HN. Urate-lowering therapy (ULT) with Febuxostat attenuates uric-acid induced ER stress in renal tubular cells and the progression of HN.

Characteristics and comparison between diabetes mellitus and non-diabetes mellitus among chronic kidney disease patients: A cross-sectional study of the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE)

Although the prevalence of chronic kidney disease (CKD) and diabetes mellitus (DM) is increasing globally, information on Chinese CKD patients with DM is lacking. A total of 3499 pre-dialysis CKD patients from across China were enrolled in the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE) between November 2011 and April 2016. We divided the C-STRIDE patients into CKD with DM and CKD without DM groups and compared their clinical, demographic, and laboratory data in this cross-sectional study. CKD patients with DM were older, had a higher male-to-female ratio, and had more complications than CKD patients without DM. Age, smoking, and 24-h urinary protein levels were associated with co-occurrence of CKD and DM. Less than 50% of patients in either group took antilipemic, cardiovascular, cerebrovascular, or anti-anemic drugs. In addition, only 18.38% of CKD patients with DM had undergone a renal biopsy, and diabetic nephropathy was confirmed in 35.4% of them. Our findings suggest that several types of medication and renal biopsies should be used more frequently in the treatment of Chinese CKD patients with DM.

Metabolic syndrome is independently associated with a mildly reduced estimated glomerular filtration rate: a cross-sectional study

Background

Association between metabolic syndrome (MS) and mildly reduced estimated glomerular filtration rates (eGFRs) remains unclear. Therefore, we aimed to evaluate the association between MS and a mildly reduced eGFR in Chinese adults.

Methods

Anthropometric and biochemical examinations were performed in 2992 individuals. The eGFR was calculated from the creatinine level. MS was defined according to the Adult Treatment Panel III criteria as the presence of three or more risk factors. Mildly reduced eGFR was defined as a value between 60 and 90 mL/min/1.73 m². Multiple linear regression and multiple logistic regression analysis were used to evaluate association between metabolic syndrome and estimate glomerular filtration rate.

Results

After adjusting for several potential confounders, the participants with MS showed a 1.29-fold increased odds ratio for a mildly reduced eGFR compared with those without MS. Additionally, the odds ratios (and 95% confidence intervals (CIs)) for mildly reduced eGFR in participants with elevated triglycerides (TG), decreased high-density lipoprotein (HDL), obesity and elevated fasting blood glucose (FPG) after multivariable adjustment were 1.25 (1.05–1.49), 1.23 (1.03–1.48), 1.22 (1.03–1.45) and 0.64 (0.52–0.78), respectively. The odds ratios (95% CIs) for hyperfiltration in participants with elevated FPG and HbA1c levels after multivariable adjustment were 1.53 (1.30–1.81) and 2.86 (2.00–4.09), respectively.

Conclusions

MS is associated with an increased risk of a mildly reduced eGFR in the Chinese population, and several individual components of MS have different impacts on eGFR levels. MS had dual roles on renal damage.

Trial registration

ChiCTR-TRC-14005029. Registered 28 July 2014.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0597-3) contains supplementary material, which is available to authorized users.

[Effect of Astragali and Angelica particle on proteinuria in Chinese patients with primary glomerulonephritis]

OBJECTIVE

To investigate the effect of the traditional Chinese herbs Astragali and Angelicae Sinensis (A & As) particle [contains Huangqi (Radix Astragali Mongolica), Danggui (Radix Angelicae Sinensis), Huzhanggeng (Rhizoma Polygoni Cuspidati) and Danshen (Radix Salviae Miltiorrhizae)] on proteinuria in glomerulonephritis patients with stage 2 chronic kidney disease.

METHODS

A prospective, multi-center, and randomized controlled clinical trial was performed for 24 weeks. From March 2011 to April 2012, 158 patients from nine hospitals in China participated. They were randomized into the A & As group (79 cases, A & As particle 15.2 g/day) and losartan group (79 cases, losartan 50 mg/day). At each follow-up visit, clinical data including blood pressure, urinalysis, 24-h-urinary protein excretion, serum albumin and serum creatinine were collected.

RESULTS

All 158 patients completed the follow-up. Proteinuria in the losartan group exhibited a biphasic time-dependent decline with a significant steady reduction from baseline to week 12 (P = 0.0014), and a platform level during the remaining 12-week follow-up (P > 0.05). In contrast, there was a continual significant decrease of proteinuria in the A & As group (P < 0.001). When compared with the losartan results, proteinuria in the A & As group from week 16 to week 24 was significantly reduced (P < 0.001). Stable eGFRs and blood pressure were also observed in both groups. Medication side effects were minimal and non-fatal.

CONCLUSION

For Chinese glomerulonephritis patients with stage 2 chronic kidney disease, therapy with A & As particles may provide effective anti-proteinuria treatment.

Global Prevalence of Chronic Kidney Disease - A Systematic Review and Meta-Analysis

Chronic kidney disease (CKD) is a global health burden with a high economic cost to health systems and is an independent risk factor for cardiovascular disease (CVD). All stages of CKD are associated with increased risks of cardiovascular morbidity, premature mortality, and/or decreased quality of life. CKD is usually asymptomatic until later stages and accurate prevalence data are lacking. Thus we sought to determine the prevalence of CKD globally, by stage, geographical location, gender and age. A systematic review and meta-analysis of observational studies estimating CKD prevalence in general populations was conducted through literature searches in 8 databases. We assessed pooled data using a random effects model. Of 5,842 potential articles, 100 studies of diverse quality were included, comprising 6,908,440 patients. Global mean(95%CI) CKD prevalence of 5 stages 13·4%(11·7-15·1%), and stages 3-5 was 10·6%(9·2-12·2%). Weighting by study quality did not affect prevalence estimates. CKD prevalence by stage was Stage-1 (eGFR>90+ACR>30): 3·5% (2·8-4·2%); Stage-2 (eGFR 60-89+ACR>30): 3·9% (2·7-5·3%); Stage-3 (eGFR 30-59): 7·6% (6·4-8·9%); Stage-4 = (eGFR 29-15): 0·4% (0·3-0·5%); and Stage-5 (eGFR<15): 0·1% (0·1-0·1%). CKD has a high global prevalence with a consistent estimated global CKD prevalence of between 11 to 13% with the majority stage 3. Future research should evaluate intervention strategies deliverable at scale to delay the progression of CKD and improve CVD outcomes.

Effects of 1,25(OH)2D3 on proliferation and apoptosis of human glomerular mesangial cells

OBJECTIVE

To investigate the effect of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on cell proliferation and apoptosis of human glomerular mesangial cells.

METHODS

Human glomerular mesangial cells were cultured for 48 h and randomly divided into four groups, normal control group (N group), proliferation group (EGF group ), vitamin D3 intervention group (VD3 group), proliferation intervention group (EGF+VD3 group ). Flow cytometry was used to detect the cell cycle and apoptosis rate, and Western blot was used to detect the PCNA and Caspases-3 expression. The effect of 1,25(OH)2D3 on human mesangial cell proliferation was detected by CCK-8.

RESULTS

Compared with the control group, G1 phase cells in EGF group were significantly reduced, S, G2/M phase cells were increased, and the higher PI and PCNA expression levels were increased; G1 phase cells in VD3 group were increased, S, G2/M phase cells were decreased, and the lower PI and PCNA expression levels were reduced. Compared with EGF group, G1 phase cells in EGF+VD3 group were increased, S, G2/M phase cells were decreased, and the lower PI and PCNA expression levels were significantly reduced. Compared with normal control group, the apoptosis rate in EGF group was significantly lower, and the Caspase-3 expression level was reduced; the apoptosis rate in VD3 group was significantly higher, and Caspase-3 expression was significantly increased. Compared with EGF group, the apoptotic rate of mesangial cells in EGF+VD3 group was significantly increased, and the Caspase-3 expression level was increased, with significant difference.

CONCLUSION

1,25(OH)2D3 inhibited the proliferation of mesangial cells and induced their apoptosis by blocking the cell cycle, inhibiting expression of PCNA, and upregulating Caspase-3 expression.

Determination of Environmental Exposure to Microcystin and Aflatoxin as a Risk for Renal Function Based on 5493 Rural People in Southwest China

Although the nephrotoxicity of microcystin and aflatoxin has been observed in animal and clinical cases, few population data are available. We conducted a cross-sectional study in Southwest China to investigate the association of renal function indicators (RFIs, including BUN, SCr, and eGFR) with exposure to microcystin and aflatoxin in 5493 members of the general population. Microcystin-LR levels in water and aquatic products and aflatoxin B1 levels in daily foods were measured by ELISA, and individual estimated daily intake (EDI) was assessed on the basis of the measurement and questionnaire. We found that participants with abnormal RFIs had a much higher mean level of microcystin-LR EDI than those with normal RFIs and that there was a significant increasing trend for abnormal rates and odds ratios of RFIs with increasing microcystin-LR EDI quartiles (p for trend = 0.000). Compared with the lowest quartile of microcystin-LR exposure, those in the highest quartile had significantly higher risks of abnormal BUN (OR = 1.80, 95% CI = 1.34-2.42), SCr (OR = 4.58, 95% CI = 2.92-7.21), and eGFR (OR = 4.41, 95% CI = 2.55-7.63), respectively, but no higher risk was found in subjects with higher AFB1 exposure. After adjustment for confounding factors, risk associations with microcystin-LR persisted. Consequently, our results suggest that microcystin, rather than aflatoxin, might be one important risk of renal-function impairment.

Smoking and Adverse Outcomes in Patients With CKD: The Study of Heart and Renal Protection (SHARP)

Background

The absolute and relative importance of smoking to vascular and nonvascular outcomes in people with chronic kidney disease (CKD), as well its relevance to kidney disease progression, is uncertain.

Study Design

Observational study.

Setting & Participants

9,270 participants with CKD enrolled in SHARP.

Predictor

Baseline smoking status (current, former, and never).

Outcomes

Vascular events, site-specific cancer, ESRD, rate of change in estimated glomerular filtration rate (eGFR), and cause-specific mortality.

Results

At baseline, 1,243 (13%) participants were current smokers (median consumption, 10 cigarettes/day); 3,272 (35%), former smokers; and 4,755 (51%), never smokers. Median follow-up was 4.9 years. Vascular event rates were 36% higher for current than never smokers (2,317 events; relative risk [RR], 1.36; 95% CI, 1.19-1.55), reflecting increases in both atherosclerotic (RR, 1.49; 95% CI, 1.26-1.76) and nonatherosclerotic (RR, 1.25; 95% CI, 1.05-1.50) events. Cancer was 37% higher among current smokers (632 events; RR, 1.37; 95% CI, 1.07-1.76), with the biggest RRs for lung (RR, 9.31; 95% CI, 4.37-19.83) and upper aerodigestive tract (RR, 4.87; 95% CI, 2.10-11.32) cancers. For 6,245 patients not receiving dialysis at baseline, ESRD incidence did not differ significantly between current and never smokers (2,141 events; RR, 1.02; 95% CI, 0.89-1.17), nor did estimated rate of change in eGFR (current smokers, −1.77 ± 0.14 [SE]; never smokers, −1.70 ± 0.07 mL/min/1.73 m² per year). All-cause mortality was 48% higher among current smokers (2,257 events; RR, 1.48; 95% CI, 1.30-1.70), with significant increases in vascular (RR, 1.35; 95% CI, 1.07-1.69) and nonvascular (RR, 1.60; 95% CI, 1.34-1.91) causes of death, especially cancer (RR, 2.32; 95% CI, 1.58-3.40) and respiratory (RR, 2.25; 95% CI, 1.51-3.35) mortality.

Limitations

Smoking status not assessed during follow-up.

Conclusions

In this study of patients with CKD, smoking significantly increased the risks for vascular and nonvascular morbidity and mortality, but was not associated with kidney disease progression. The associations with vascular and neoplastic disease are in keeping with those observed in the general population and are likely modifiable by cessation.

Metabolic syndrome does not always play a critical role in decreased GFR

BACKGROUND

There is a paucity of literature available as to the relationship between different levels of each metabolic syndrome (MetS) component and decreased GFR. In the present study, we aimed to demonstrate whether MetS always plays a critical role in decreased GFR.

METHODS

A cross-sectional study was conducted between February 2010 and September 2012, with 75,468 adults enrolled undergoing measurements of blood pressure as well as tests of blood and urine samples. Univariate and multivariable logistic regression analyses were performed to estimate the odds ratio (OR) with 95% confidence intervals (CI), and the chi-square test was used for categorical variables and described as a percentage.

RESULTS

Of the 75,468 participants, 350 (0.5%) subjects met criteria for the decreased GFR, with a mean age of 48.79 ± 13.76 years. After adjustment for age, diastolic blood pressure and high-density lipoprotein were inversely related to decreased estimated glomerular filtration rate (eGFR) in multivariable analyses, with an OR (95% CI) of 0.57 (0.39-0.84) and 0.41 (0.24-0.72), respectively. The prevalence rate of CKD in critical group was 0.73% (154 of 21,127) and 0% (0 of 370) in noncritical group. In analysis stratified by the type of MetS components, the differences in noncritical group and the reference group were not statistically significant (χ(2 )=( )1.349, p > 0.05).

CONCLUSIONS

MetS does not always play a critical role in decreased GFR, with different levels of individual components of MetS exerting idiosyncratic effects in decreased eGFR. In fact, patients with abnormal body mass index, high triglycerides, and elevated fasting plasma glucose would not have impact on decreased GFR.

Prehypertension and Chronic Kidney Disease in Chinese Population: Four-Year Follow-Up Study

Hypertension is a well established cause of chronic kidney disease (CKD). However, the effect of prehypertension on risk of CKD is controversial. The aim of this study is to determine whether prehypertension increases the risk of CKD events in the Chinese population. We enrolled 20,034 with prehypertension and 12,351 with ideal blood pressure in this prospective study. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min 1.73 m2. The new occurrences of CKD events were collected during follow-up. Cumulative survival and freedom for the occurrence of new CKD events was analyzed using the Kaplan-Meier approach. Multivariate Cox Regression was used to analyze the effect of prehypertension on CKD. The median follow-up time was 47 (interquartile range 44-51) months. 601 new onset CKD events occurred during the follow-up period. The cumulative incidence of new CKD events was higher in the prehypertensive population than that in the ideal blood pressure population (2.10% vs 1.46%, P = 0.0001). Multivariate Cox Regression showed that relative risks (RRs) for the new onset CKD events in the prehypertensive population were 1.69 (95% confidence intervals (CI): 1.41~2.04, P = 0.001) higher than those in the ideal blood pressure population. Similarly, the risks were 1.68 (95% CI: 1.33~2.13 P = 0.001) times higher in females and 2.14 (95% CI: 1.58~2.91 P = 0.001) times higher in males by adjustment for traditional CV risk factors. Our findings demonstrated prehypertension is an independent risk factor for the occurrence of new CKD events in the Chinese population.

Chronic kidney disease of unknown aetiology and ground-water ionicity: study based on Sri Lanka

High incidence of chronic kidney disease of unknown aetiology (CKDU) in Sri Lanka is shown to correlate with the presence of irrigation works and rivers that bring-in 'nonpoint source' fertilizer runoff from intensely agricultural regions. We review previous attempts to link CKDU with As, Cd and other standard toxins. Those studies (e.g. the WHO-sponsored study), while providing a wealth of data, are inconclusive in regard to aetiology. Here, we present new proposals based on increased ionicity of drinking water due to fertilizer runoff into the river system, redox processes in the soil and features of 'tank'-cascades and aquifers. The consequent chronic exposure to high ionicity in drinking water is proposed to debilitate the kidney via a Hofmeister-type (i.e. protein-denaturing) mechanism.