Chronic Kidney Disease Diagnosis and Management: A Review

Binding interactions with sevelamer and polystyrene sulfonate in vitro

This study explored the binding of 28 drugs, which were selected based on frequency of concomitant use and chemical properties, to sevelamer and polystyrene sulfonate in vitro. The relative binding was determined by dissolving the investigated drugs alone (=control), together with 800 mg of sevelamer and 15 g of polystyrene sulfonate at different pH levels (1.5, 5.5, and 7.4), respectively. After incubation at 37℃ and shaking for 60 min, the solutions were diluted and centrifuged, and the drug concentrations were quantified with validated analytical assays. The binding assays were performed in threefold. The mean relative binding (MRB) at each pH level was calculated, with a MRB >20% for at least one pH level to be considered as relevant binding. Fourteen and 23 potentially new binding interactions were identified with sevelamer and polystyrene sulfonate, respectively. These potentially new binding interactions have to be studied in vivo to assess their clinical relevance.

Dimethylamine enhances platelet hyperactivity in chronic kidney disease model

Chronic kidney disease (CKD) remains a major health threat worldwide which is associated with elevated blood level of dimethylamine (DMA) and unbalanced platelet functions. Dimethylamine, a simple aliphatic amine, is abundantly found in human urine as well as other body fluids like plasma. However, the relation between dimethylamine and platelet activation is unclear. This study aims to unravel the mechanism of DMA and platelet function in chronic kidney disease. Through in vitro platelet characterization assay and in vivo CKD mouse model, the level of DMA, platelet activity and renal function were assessed by established methods. PKCδ and its downstream kinase MEK1/2 were examined by immunoblotting analysis of human platelet extract. Rescue experiments with PKCδ inhibitor or choline deficient diet were also conducted. DMA level in plasma of mouse CKD model was elevated along with enhanced platelet activation and comprised renal function. DMA can activate platelet in vitro and in vivo. Inhibition of PKCδ could antagonize the effect of DMA on platelet activation. When choline as the dietary source of DMA was deprived from CKD mouse, the level DMA was reduced and platelet activation was attenuated. Our results demonstrate that dimethylamine could enhance platelet activation in CKD model, potentially through activation of PKCδ.

Periodontal disease as a predictor of chronic kidney disease (CKD) stage in older adults

Objective

The aim of this study was to evaluate periodontal disease as a predictor of chronic kidney disease (CKD) stage in older adults.

Methods

A total of 1159 adults aged 65 to 80 years and diagnosed with periodontal disease and CKD (stages 1, 2, and 3) were randomly selected for a cross-sectional study. Periodontal status was assessed using the Community Periodontal Index of Treatment Needs (CPITN) and CKD was staged using the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) guidelines.

Results

In patients with stage 1 CKD, the odds ratios (ORs) (95% confidence intervals [CIs]) for CPITN-1, CPITN-2, CPITN-3, and CPITN-4 were 1.13 (0.83–1.55), 1.47 (1.13–1.81), 1, and 1, respectively. In patients with stage 2 CKD, the ORs (95% CIs) for CPITN-1, CPITN-2, CPITN-3, and CPITN-4 were 1.49 (1.14–1.93), 1.37 (1.02–1.78), 3.07 (2.81–3.25), and 3.65 (3.49–3.71), respectively. In patients with stage 3 CKD, the ORs (95% CIs) for CPITN-1, CPITN-2, CPITN-3, and CPITN-4 were 1, 1, 4.61 (4.47–5.21), and 5.23 (5.14–5.47), respectively.

Conclusion

The highest CPITN values (CPITN-3 and CPITN-4) were associated with CKD stages 2 and 3. Thus, periodontal disease may be associated with progression of CKD.

Nutritional Approaches for the Management of Metabolic Acidosis in Chronic Kidney Disease

Metabolic acidosis is a severe complication of chronic kidney disease (CKD) which is associated with nefarious impairments such as bone demineralization, muscle wasting, and hormonal alterations, for example, insulin resistance. Whilst it is possible to control this condition with alkali treatment, consisting in the oral administration of sodium citrate or sodium bicarbonate, this type of intervention is not free from side effects. On the contrary, opting for the implementation of a targeted dietetic-nutritional treatment for the control of CKD metabolic acidosis also comes with a range of additional benefits such as lipid profile control, increased vitamins, and antioxidants intake. In our review, we evaluated the main dietary-nutritional regimens useful to counteract metabolic acidosis, such as the Mediterranean diet, the alkaline diet, the low-protein diet, and the vegan low-protein diet, analyzing the potentialities and limits of every dietary-nutritional treatment. Literature data suggest that the Mediterranean and alkaline diets represent a valid nutritional approach in the prevention and correction of metabolic acidosis in CKD early stages, while the low-protein diet and the vegan low-protein diet are more effective in CKD advanced stages. In conclusion, we propose that tailored nutritional approaches should represent a valid therapeutic alternative to counteract metabolic acidosis.

Translation and Validation of the TANGO Nocturia Screening Tool into Greek

Purpose

The present study aimed to translate the Targeting the individual's Aetiology of Nocturia to Guide Outcomes Questionnaire (TANGO) into the Greek language to create TANGO-Gr. A relative reliability study in prospective samples of community dwellers and rehabilitation centre residents was undertaken in order to validate the translation. In terms of nocturia severity, these groups were considered to be representative of patients at both ends of the scale, and therefore suitable validation purposes.

Patients and Methods

The prospective descriptive study took place between 07 and 09/2020. Fifty residents in a rehabilitation centre and thirty-seven community dwellers were included in the study. All participants had more than one episode of nocturia per night. They were asked to complete the newly translated TANGO-Gr Questionnaire twice (test-retest procedure). TANGO-Gr includes three possible answers ("yes", "no", and "DK/NA") to facilitate increased validity. The study group evaluated the socio and demographic characteristics, the level of independence and the comprehensive frailty of all participants.

Results

Both groups satisfactorily completed questionnaire responses. The overall Cronbach's alpha coefficient was 0.753 (community-dwelling people: 0.776; rehabilitation centre residents: 0.531). A test-retest statistical analysis to determine reliability found an overall median Kappa of 0.88 (IQR: 0.79-0.94) in community dwellers and 0.91 (IQR: 0.84-1.00) in rehabilitation centre residents, thereby confirming an almost perfect respective agreement.

Conclusion

The validity of the newly translated TANGO-Gr Questionnaire was proven. It should be considered to be a reliable, self-administered screening tool suitable for clinical practice, and therefore invaluable for Greek-speaking people. The study also determined that certain environment-related variables may contribute to nocturia in rehabilitation centre populations, which is a finding which invites further study.

Prevalence and Risk Factors for Chronic Kidney Disease in Belize: A Population-based Survey

Background

Health resources supporting dialysis and chronic kidney disease (CKD) patients are limited in Central America, and little information about the prevalence and risk factors for CKD in this region is available.

Methods

The Survey of Risk Factors for Chronic Kidney Disease was a population-based cross-sectional study conducted throughout Belize in 2017. The study aimed to assess the prevalence and risk factors for CKD via structured questionnaires and clinical measurements in Belizeans aged 20-55 years. A two-stage stratified sampling technique was applied. CKD was defined as an estimated glomerular filtration rate < 60 mL/min/1·73 m² or the presence of proteinuria.

Findings

A total of 7,506 adults with a mean age of 34·6 years old completed the survey; 53·2% were women. The overall CKD prevalence was 13·7%. Women had a higher CKD prevalence than men (14·8% vs. 12·5%), and the overall awareness of CKD was low (3·7%). The prevalences of stage 1, 2, 3a, 3b, 4, and 5 CKD were 2·85%, 2·93%, 6·59%, 1·10%, 0·18%, and 0·06%, respectively. Older age, female sex, Mestizo/Hispanic ethnicity, diabetes, hypertension, hypercholesterolaemia, and obesity were identified as independent risk factors for CKD.

Interpretation

The prevalence of CKD was 13·7% in Belizeans aged 20-55 years. The study confirms the high burden of CKD in Belize and provides important epidemiological information for Central America. Case management systems and surveillance programmes targeting high-risk populations are crucial for ameliorating the burden of CKD.

Funding

Capacity Building Project for the Prevention and Control of Chronic Renal Failure in Belize.

Label-Free Creatinine Optical Sensing Using Molecularly Imprinted Titanium Dioxide-Polycarboxylic Acid Hybrid Thin Films: A Preliminary Study for Urine Sample Analysis

Creatinine (CR) is a representative metabolic byproduct of muscles, and its sensitive and selective detection has become critical in the diagnosis of kidney diseases. In this study, poly(acrylic acid) (PAA)-assisted molecularly imprinted (MI) TiO2 nanothin films fabricated via liquid phase deposition (LPD) were employed for CR detection. The molecular recognition properties of the fabricated films were evaluated using fiber optic long period grating (LPG) and quartz crystal microbalance sensors. Imprinting effects were examined compared with nonimprinted (NI) pure TiO2 and PAA-assisted TiO2 films fabricated similarly without a template. In addition, the surface modification of the optical fiber section containing the LPG with a mesoporous base coating of silica nanoparticles, which was conducted before LPD-based TiO2 film deposition, contributed to the improvement of the sensitivity of the MI LPG sensor. The sensitivity and selectivity of LPGs coated with MI films were tested using CR solutions dissolved in different pH waters and artificial urine (near pH 7). The CR binding constants of the MI and NI films, which were calculated from the Benesi–Hildebrand plots of the wavelength shifts of the second LPG band recorded in water at pH 4.6, were estimated to be 67 and 7.8 M–1, respectively, showing an almost ninefold higher sensitivity in the MI film. The mechanism of the interaction between the template and the TiO2 matrix and the film composition was investigated via ultraviolet–visible and attenuated total reflectance Fourier-transform infrared spectroscopy along with X-ray photoelectron spectroscopy analysis. In addition, morphological studies using a scanning electron microscope and atomic force microscope were conducted. The proposed system has the potential for practical use to determine CR levels in urine samples. This LPG-based label-free CR biosensor is innovative and expected to be a new tool to identify complex biomolecules in terms of its easy fabrication and simplicity in methodology.

Associations between elevated growth differentiation factor-15 and sarcopenia among community-dwelling older adults

BACKGROUND

Growth differentiation factor 15 (GDF-15) is associated with disease progression, mitochondrial dysfunction, and mortality. Elevated GDF-15 level was recently reported to be associated with poorer physical performance in healthy adults. However, the association between serum GDF-15 level and sarcopenia in community-dwelling older adults has not been well characterized.

METHODS

We conducted cross-sectional (n = 929) and two-year prospective analyses (n = 788) among participants aged 70-84 years enrolled in the Korean Frailty and Aging Cohort Study. Participants with an estimated glomerular filtration rate of <60 mL/min/1.73 m 2 were excluded. Appendicular lean mass was measured using dual-energy X-ray absorptiometry. Sarcopenia status was determined according to the Asian Working Group for Sarcopenia-2019 algorithm.

RESULTS

At baseline, 16.6% of the participants had sarcopenia. Median GDF-15 concentration was higher in the sarcopenic group than in the non-sarcopenic group (1221 pg/mL vs. 1019 pg/mL, p<0.001). In the multivariate analysis adjusted for cardiometabolic risk and biological factors, the highest GDF-15 tertile (≥1245 pg/mL) had an increased likelihood of sarcopenia (odds ratio, 1.96; 95% confidence interval, 1.16-3.33) than the lowest tertile (<885 pg/mL). During the two-year follow-up period, 67 (10.1%) individuals without sarcopenia at baseline developed sarcopenia. There were no significant associations between baseline serum GDF-15 levels and incident sarcopenia or its components (all p>0.05).

CONCLUSIONS

Elevated GDF-15 was associated with prevalent sarcopenia but not able to predict incident sarcopenia in the 2-year follow-up. Further studies are needed to explore the pathophysiological roles of GDF-15 in the development of sarcopenia.

Management of the major complications of cirrhosis: Beyond guidelines

Along with a growing understanding of the pathophysiology of cirrhosis and its complications, new therapies and management strategies have emerged in recent years. Many of these advances have helped inform the current EASL clinical practice guidelines¹ on the management of some of the key complications of cirrhosis, such as ascites, variceal bleeding and infection. However, there are still some aspects of management where the evidence base is less clear, and/or where opinions amongst practitioners remain divided. Some of these more controversial areas are explored in this section, wherein we present evidence culminating in a suggested management approach based on expert opinion and extending beyond the current guidelines.

Overcoming Barriers to Implementing New Therapies for Diabetic Kidney Disease: Lessons Learned

As a result of the growing number of patients with type 2 diabetes mellitus, the prevalence of diabetic kidney disease (DKD) has proven to be one of the fastest growing health care challenges globally. Early detection and initiation of appropriate interventions to slow the progression of DKD are impeded by low awareness of the health consequences of DKD, high complexity of care that includes the need for lifestyle modifications, difficulties with adhering to increasingly complicated medication regimens, and low acceptance and application of guideline-directed management. After 2 decades of status quo in the care of patients with DKD, recently approved glucose-lowering agents are promising to transform care by demonstrating slowed DKD disease progression and improved survival. As has been learned over the last 2 decades, multiple barriers exist to the optimal integration and utilization of new therapies to improve kidney outcomes. The health care community, professional societies, and regulatory agencies must join efforts to develop implementation strategies for increasing DKD awareness, detection, and treatment.

Uric acid albumin ratio as a predictive marker of short-term mortality in patients with acute kidney injury

OBJECTIVE

We aimed to investigate uric acid and albumin ratio (UA/A) as a marker of short-term mortality in acute kidney injury (AKI). Both uric acid and albumin are strongly correlated with the development and mortality of AKI.

METHODS

The patients hospitalized from May 2019 to September 2019 for AKI were included in this study. The diagnostic odds ratio (DOR), Youden index (J), and the area under a receiver operating characteristic curve (AUROC) determined a cut-off UA/A ratio for mortality. Cox-regression analysis was performed to identify UA/A as a prognostic marker of the 30-day mortality rate.

RESULTS

A total of 171 patients with an average age of 69.20±13.0 (45.6% women) were included in the study. The average UA/A ratio was 3.3±1.5 mg/g and 2.5±1.0 mg/g in the non-survivor and survivor groups, respectively (P=0.001). The best cut-off UA/A ratio associated with mortality was determined as 2.4 mg/g with a specificity of 52% and a sensitivity of 77% (DOR, 3.6; J, 28.8; AUROC, 0.644). Thirty-day cumulative survival rates of the low and high UA/A ratio groups were 85.9±4.0% and 63.7±5.0%, respectively. The estimated survival times of the low and high UA/A ratio groups were 27.7 days (95% confidence interval [CI], 26.2-29.3) and 23.9 days (95% Cl, 22.0-25.9), respectively.

CONCLUSION

We found a direct correlation between 30-day mortality and UA/A ratio at initial presentation in AKI patients regardless of age, comorbidities, and clinical and laboratory findings, including albuminuria.

The association between Hba1c and arterial stiffness among non-diabetic patients with chronic kidney disease

Background

Cardiovascular events are seen more frequently after the age of 60 and they are a significant cause of morbidity and mortality. Arterial stiffness is a property that can be expressed by pulse wave velocity and this value is assumed to be a predictor of cardiovascular events. Patients with chronic kidney disease and dysregulated blood sugar have increased atherosclerosis and arterial stiffness, but the relationship between physiological levels of Hba1c and arterial stiffness is less clear in chronic kidney disease patients without diabetes mellitus.

Objectives

Here, we aimed to investigate the degree of arterial stiffness among non-diabetic, non-dialysis dependent chronic kidney disease patients with physiological HbA1c levels.

Methods

We enrolled 51 patients who were followed up at Ege University Hospital Nephrology Department between February and June 2015. Non-diabetic, non-dialysis dependent chronic kidney disease patients were included in the study. Blood pressure and pulse wave velocity were measured with an applanation tonometry device (Sphygmocor Vx Software Atcor Medical, Australia). Correlations between pulse wave velocity and the aforementioned parameters were investigated (see below).

Results

We detected a significant correlation between pulse wave velocity and systolic blood pressure (p=0.0001) and Hba1c (p=0.044) separately. There was an inverse correlation with creatinine clearance (p=0.04). We also detected a significant correlation with serum phosphorus level (p=0.0077) and furosemide use (p=0.014). No correlations were found among the other parameters.

Conclusions

Arterial stiffness is an important predictor of cardiovascular events and measuring it is an inexpensive method for estimating morbidity and mortality. Our study supports the importance of measuring arterial stiffness and of controlling blood glucose levels, even at physiological Hba1c values, especially for chronic kidney disease patients.

Myeloid cell-derived coagulation tissue factor is associated with renal tubular damage in mice fed an adenine diet

Patients with chronic kidney disease (CKD) commonly exhibit hypercoagulability. Increased levels of uremic toxins cause thrombogenicity by increasing tissue factor (TF) expression and activating the extrinsic coagulation cascade. TF is induced in monocytes and macrophages under pathological conditions, such as inflammatory diseases. However, the role of monocyte myeloid cell TF in CKD progression remains unclear. We aimed to clarify this issue, and the present study found that patients with CKD had elevated levels of D-dimer, a marker of fibrin degradation, which was associated with decreased estimated glomerular filtration rate and increased serum levels of uremic toxins, such as indoxyl sulfate. In vitro studies showed that several uremic toxins increased cellular TF levels in monocytic THP-1 cells. Mice with TF specifically deleted in myeloid cells were fed an adenine diet to cause uremic kidney injury. Myeloid TF deletion reduced tubular injury and pro-inflammatory gene expression in the kidneys of adenine-induced CKD but did not improve renal function as measured by plasma creatinine or blood urea nitrogen. Collectively, our findings suggest a novel concept of pathogenesis of coagulation-mediated kidney injury, in which elevated TF levels in monocytes under uremic conditions is partly involved in the development of CKD.

Association of Depressive Symptoms with Rapid Kidney Function Decline in Adults with Normal Kidney Function

BACKGROUND AND OBJECTIVES

The relationship of depressive symptoms with kidney function remains poorly investigated. We aimed to evaluate the prospective association between depressive symptoms and rapid decline in kidney function in Chinese adults with normal kidney function.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 4763 participants with eGFR≥60 ml/min per 1.73 m² at baseline were enrolled from the China Health and Retirement Longitudinal Study. Baseline depressive symptoms were determined using a ten-item Center for Epidemiologic Studies Depression scale with a cutoff score of greater than or equal to ten to define high depressive symptoms. The GFR was estimated by a combination of serum creatinine and cystatin C. The primary outcome was rapid decline in kidney function, defined as an annualized decline in eGFR of ≥5 ml/min per 1.73 m². Secondary outcome was defined as an annualized decline in eGFR of ≥5 ml/min per 1.73 m² and to a level of <60 ml/min per 1.73 m² at the exit visit.

RESULTS

During a median follow-up of 4 years (interquartile range, 3.92-4.00), 260 (6%) participants developed rapid decline in kidney function. Overall, there was a significant positive association between baseline depressive symptoms and rapid decline in kidney function (per five-scores increment; adjusted odds ratio, 1.15; 95% confidence interval, 1.03 to 1.28) after adjustments for major demographic, clinical, or psychosocial covariates. Consistently, compared with participants with low depressive symptoms (total Center for Epidemiologic Studies Depression scale score less than ten), a significantly higher risk of rapid decline in kidney function was found among those with high depressive symptoms (total Center for Epidemiologic Studies Depression scale score greater than or equal to ten; adjusted odds ratio, 1.39; 95% confidence interval, 1.03 to 1.88). Similar results were found for the secondary outcome (per five-scores increment; adjusted odds ratio, 1.26; 95% confidence interval, 1.06 to 1.51).

CONCLUSIONS

High depressive symptoms were significantly associated with a higher risk of rapid kidney function decline among Chinese adults with normal kidney function.

Hospitalization Trajectories and Risks of ESKD and Death in Individuals With CKD

INTRODUCTION

Management of chronic kidney disease (CKD) entails high medical complexity and often results in high hospitalization burden. There are limited data on the associations of longitudinal hospital utilization patterns with adverse clinical outcomes in individuals with CKD.

METHODS

We derived cumulative all-cause hospitalization trajectory groups using latent class trajectory analysis in 3012 participants of the Chronic Renal Insufficiency Cohort (CRIC) Study who were alive and did not reach end-stage kidney disease (ESKD) within 4 years of study entry. Cox proportional hazards models tested the associations between hospitalization trajectory groups and risks of ESKD and death prior to the onset of ESKD (ESKD-censored death).

RESULTS

Within 4 years of study entry, there were 5658 hospitalizations among 3012 participants. We identified 3 distinct subgroups of individuals with CKD based on cumulative all-cause hospitalization trajectories over 4 years: low-utilizer (n = 1066), intermediate-utilizer (n = 1802), and high-utilizer (n = 144). High-utilizers represented a patient population of lower socioeconomic status who had a greater prevalence of comorbid conditions and lower kidney function compared with intermediate- and low-utilizers. After the 4-year ascertainment period to form the trajectory subgroups, there were 544 ESKD events and 437 ESKD-censored deaths during a median follow-up time of 5.1 years. Compared with low-utilizers, intermediate-utilizers and high-utilizers were at 1.49-fold (95% confidence interval [CI] 1.22-1.84) and 1.75-fold (95% CI 1.20-2.56) higher risk of ESKD in adjusted analyses, respectively. Compared with low-utilizers, intermediate-utilizers and high-utilizers were at 1.48-fold (95% CI 1.17-1.87) and 2.58-fold (95% CI 1.74-3.83) higher risk of ESKD-censored death in adjusted analyses, respectively.

CONCLUSIONS

Trajectories of cumulative all-cause hospitalization identify subgroups of individuals with CKD who are at high risk of ESKD and death.

Depression and Associated Factors in Chinese Patients With Chronic Kidney Disease Without Dialysis: A Cross-Sectional Study

Background: Chronic kidney disease (CKD) has been a globally public health problem over the past decades. The maintenance of physical and mental health is of importance for patients nowadays. Notably, depression is prevalent and associated with various adverse events in CKD patients without dialysis. Prior studies have reported that pain, negative illness perception, pain, and low self-esteem are potential risk factors of depression, while few studies have comprehensively investigated the mechanisms among these factors and depression among this population.

Purpose: This study aims to investigate the prevalence of depression and further explore the factors associated with depression among CKD patients without dialysis in China.

Design and Methods: We conducted a cross-sectional study in patients with diagnosed CKD to investigate the prevalence of depression was by the Beck Depression Inventory-II (BDI-II). The data on pain interference, illness perception, and self-esteem were also collected via self-administered questionnaires. A structural equation model (SEM) was used to examine the factors associated with depression.

Main Findings: From June to October 2019, we successfully interviewed 334 CKD patients at the outpatient clinics. Their mean age was 45.6 years (ranging from 19 to 74 years), and 48.5% were male. Most respondents were at early CKD stages (77.5% stage 1–3) and the prevalence of depression was 22.2%. We found a moderate association between illness perception and depression, which was modified by self-esteem. Similar but weaker association was found between pain interference and depression.

Conclusion and Recommendations: Negative illness perception, low self-esteem and severe pain interference were associated with depression among Chinese CKD patients without dialysis. Future studies are warranted to investigate the underlying mechanism and formulate the intervention strategies for this high-risk population.

The Correlation between Estimated Glomerular Filtration Rate and Parathyroid Hormone Levels in Predialysis-chronic Kidney Disease Adult Patients at Sanglah General Hospital, Bali, Indonesia

BACKGROUND: Chronic kidney disease (CKD) is a structural or functional kidney disease for more than 3 months. In predialysis CKD patients, the serum parathyroid hormone levels increase progressively since the early stages of the disease to maintain phosphate homeostasis. Glomerular filtration rate (GFR) has been widely accepted to assess renal function. The GFR assessment is used to determine the CKD stadium. AIM: This study aims to analyze the correlation between GFR and parathyroid hormone levels in predialysis CKD patients undergoing treatment at Sanglah General Hospital Denpasar. METHODS: A cross-sectional observational study was conducted among predialysis CKD patients undergoing treatment at Sanglah General Hospital Denpasar who met the inclusion and exclusion criteria. The inclusion criteria were adult patients (≥18 years) who were accepting to participate in the study. Exclusion criteria were patients with predialysis CKD after thyroidectomy and/or parathyroidectomy and liver disease. The parathyroid hormone levels, blood urea nitrogen, creatinine, and GFR were examined and analyzed by SPSS version 17 for Windows. RESULTS: A total of 77 patients with predialysis CKD in this study obtained a median of e-GFR of 21.09 (4.72–75.80) mL/min/1.73 m2. The median level of parathyroid hormone was 82.07 pg/mL (15.83–716.60 pg/mL). Spearman’s correlation analysis results obtained a strong and significant negative correlation between the e-GFR value and parathyroid hormone levels (r = −0.540; p = 0.000). CONCLUSION: The parathyroid hormone levels assessment could be used as a recommendation in evaluating the CKD progressivity among predialysis adult patients at Sanglah General Hospital, Bali, Indonesia, due to the strong significant correlation.

Hippocampal mitogen-activated protein kinase phosphatase-1 regulates behavioral and systemic effects of chronic corticosterone administration

Clinical reports indicate a bidirectional relationship between mental illness and chronic systemic diseases. However, brain mechanisms linking chronic stress and development of mood disorders to accompanying peripheral organ dysfunction are still not well characterized in animal models. In the current study, we investigated whether activation of hippocampal mitogen-activated protein kinase phosphatase-1 (MKP-1), a key factor in depression pathophysiology, also acts as a mediator of systemic effects of stress. First, we demonstrated that treatment with the glucocorticoid receptor (GR) agonist dexamethasone or acute restraint stress (ARS) significantly increased Mkp-1 mRNA levels within the rat hippocampus. Conversely, administration of the GR antagonist mifepristone 30 min before ARS produced a partial blockade of Mkp-1 upregulation, suggesting that stress activates MKP-1, at least in part, through upstream GR signaling. Chronic corticosterone (CORT) administration evoked comparable increases in hippocampal MKP-1 protein levels and produced a robust increase in behavioral emotionality. In addition to behavioral deficits, chronic CORT treatment also produced systemic pathophysiological effects. Elevated levels of renal inflammation protein markers (NGAL and IL18) were observed suggesting tissue damage and early kidney impairment. In a rescue experiment, the effects of CORT on development of depressive-like behaviors and increased NGAL and IL18 protein levels in the kidney were blocked by CRISPR-mediated knockdown of hippocampal Mkp-1 prior to CORT exposure. In sum, these findings further demonstrate that MKP-1 is necessary for development of enhanced behavioral emotionality, while also suggesting a role in stress mechanisms linking brain dysfunction and systemic illness such as kidney disease.

A qualitative study documenting unmet needs in the management of diabetic kidney disease (DKD) in the primary care setting

BACKGROUND

A majority of diabetic kidney disease (DKD) patients receive medical care in the primary care setting, making it an important opportunity to improve patient management. There is limited evidence evaluating whether primary care physicians (PCPs) are equipped to effectively manage these patients in routine clinical practice. The present study was undertaken to identify gaps in primary care and unmet needs in the diagnosis and monitoring of DKD in type 2 diabetes (T2D) patients among PCPs.

METHODS

This was a qualitative analysis based on 30-45-min interviews with PCPs treating T2D patients. PCPs were recruited via email and were board-certified, in practice for more than 3 years, spent most of their time in direct clinical care, and provided care for more than three T2D patients in a week. Descriptive data analysis was conducted to identify and examine themes that were generated by interviews. Two reviewers evaluated interview data to identify themes and developed consensus on the priority themes identified.

RESULTS

A total of 16 PCPs satisfying the inclusion criteria were recruited for qualitative interviews. Although the PCPs recognized kidney disease as an important comorbidity in T2D patients, testing for kidney disease was not consistently top of mind, with 56% reportedly performing kidney function testing in their T2D patients. PCPs most frequently reported using estimated glomerular filtration rate (eGFR) alone to monitor and stage DKD; only 25% PCPs reported testing for albuminuria. Most PCPs incorrectly believed that a majority of DKD patients are diagnosed in early stages. Also, early stages of DKD emerged as ambiguous areas of decision-making, wherein treatments prescribed greatly varied among PCPs. Lastly, early and accurate risk stratification of DKD patients emerged as the most important unmet need; which, if it could be overcome, was consistently identified by PCPs as a key to monitoring, appropriate nephrologist referrals, and intervening to improve outcomes in patients with DKD.

CONCLUSIONS

Our study highlights important unmet needs in T2D DKD testing, staging, and stratification in the PCP setting that limit effective patient care. Health systems and insurers in the U.S. should prioritize the review and approval of new strategies that can improve DKD staging and risk stratification.

Impact of Kidney Failure on the Severity of COVID-19

Background: Patients with kidney failure are at an increased risk of progression to a severe form of coronavirus disease 2019 (COVID-19) with high mortality. The current analysis was aimed to assess the impact of renal failure on the severity of COVID-19 and identify the risk factors of the fatal outcome in this population. Methods: The analysis included patients from the SARSTer database, a national real-world study evaluating treatment for COVID-19 in 30 Polish centers. Data were completed retrospectively and submitted online. Results: A total of 2322 patients were included in the analysis. Kidney failure was diagnosed in 455 individuals (19.65%), of whom 373 presented moderate stage and 82 patients, including 14 dialysis individuals, presented severe renal failure. Patients with kidney failure were significantly older and demonstrated a more severe course of COVID-19. The age, baseline SpO₂, the ordinal scale of 4 and 5, neutrophil and platelet count, estimated glomerular filtration rate, and C-reactive protein concentration as well as malignancy and arterial hypertension were the independent predictors of 28-day mortality in logistic regression analysis. Conclusions: Underlying kidney disease in patients with COVID-19 is among the leading factors associated with a higher risk of severe clinical presentation and increased mortality rate.

Imaging the Renal Microcirculation in Cell Therapy

Renal microvascular rarefaction plays a pivotal role in progressive kidney disease. Therefore, modalities to visualize the microcirculation of the kidney will increase our understanding of disease mechanisms and consequently may provide new approaches for evaluating cell-based therapy. At the moment, however, clinical practice is lacking non-invasive, safe, and efficient imaging modalities to monitor renal microvascular changes over time in patients suffering from renal disease. To emphasize the importance, we summarize current knowledge of the renal microcirculation and discussed the involvement in progressive kidney disease. Moreover, an overview of available imaging techniques to uncover renal microvascular morphology, function, and behavior is presented with the associated benefits and limitations. Ultimately, the necessity to assess and investigate renal disease based on in vivo readouts with a resolution up to capillary level may provide a paradigm shift for diagnosis and therapy in the field of nephrology.

Deletion of Alox15 improves kidney dysfunction and inhibits fibrosis by increased PGD2 in the kidney

BACKGROUND

Lipid-metabolizing enzymes and their metabolites affect inflammation and fibrosis, but their roles in chronic kidney disease (CKD) have not been completely understood.

METHODS

To clarify their role in CKD, we measured the mRNA levels of major lipid-metabolizing enzymes in 5/6 nephrectomized (Nx) kidneys of C57BL/6 J mice. Mediator lipidomics was performed to reveal lipid profiles of CKD kidneys.

RESULTS

In 5/6 Nx kidneys, both mRNA and protein levels of Alox15 were higher when compared with those in sham kidneys. With respect to in situ hybridization, the mRNA level of Alox15 was higher in renal tubules of 5/6 Nx kidneys. To examine the role of Alox15 in CKD pathogenesis, we performed 5/6 Nx on Alox15-/- mice. Alox15-/- CKD mice exhibited better renal functions than wild-type mice. Interstitial fibrosis was also inhibited in Alox15-/- CKD mice. Mediator lipidomics revealed that Alox15-/- CKD mouse kidneys had significantly higher levels of PGD2 than the control. To investigate the effects of PGD2 on renal fibrosis, we administered PGD2 to TGF-β1-stimulated NRK-52E cells and HK-2 cells, which lead to a dose-dependent suppression of type I collagen and αSMA in both cell lines.

CONCLUSION

Increased PGD2 in Alox15-/- CKD mouse kidneys could inhibit fibrosis, thereby resulting in CKD improvement. Thus, Alox15 inhibition and PGD2 administration may be novel therapeutic targets for CKD.

Intestinal flora alterations in patients with early chronic kidney disease: a case-control study among the Han population in southwestern China

Objective

In this case–control study, we retrospectively analyzed the intestinal flora compositions of patients with early-stage chronic kidney disease (CKD).

Methods

Forty-seven patients with early CKD who were treated at the Traditional Chinese Medicine Hospital between March and October 2018 were enrolled, and 150 healthy volunteers were enrolled in the healthy control group. Fresh stool samples were collected. The V3–V4 region of the bacterial 16S rRNA was amplified via PCR. Biterminal sequencing was performed using the Illumina MiSeq platform. The flora compositions were compared between the two groups.

Results

The Chao1 and Shannon indices showed significantly lower intestinal flora diversity and abundances in the CKD group than in the healthy controls. Beta diversity analysis revealed notable differences in the intestinal flora compositions between the groups. At the phylum level, Actinobacteria and Proteobacteria abundances were significantly higher in the CKD group. Thirty-one species differed significantly between both groups, among which, differences in Ruminococcus and Roseburia displayed the highest diagnostic values for distinguishing CKD patients from healthy controls.

Conclusions

Intestinal flora compositions are altered in early-stage CKD patients among the Han population in southwestern China.

Methods and rationale of the DISCOVER CKD global observational study

Background

Real-world data for patients with chronic kidney disease (CKD), specifically pertaining to clinical management, metabolic control, treatment patterns, quality of life (QoL) and dietary patterns, are limited. Understanding these gaps using real-world, routine care data will improve our understanding of the challenges and consequences faced by patients with CKD, and will facilitate the long-term goal of improving their management and prognosis.

Methods

DISCOVER CKD follows an enriched hybrid study design, with both retrospective and prospective patient cohorts, integrating primary and secondary data from patients with CKD from China, Italy, Japan, Sweden, the UK and the USA. Data will be prospectively captured over a 3-year period from >1000 patients with CKD who will be followed up for at least 1 year via electronic case report form entry during routine clinical visits and also via a mobile/tablet-based application, enabling the capture of patient-reported outcomes (PROs). In-depth interviews will be conducted in a subset of ∼100 patients. Separately, secondary data will be retrospectively captured from >2 000 000 patients with CKD, extracted from existing datasets and registries.

Results

The DISCOVER CKD program captures and will report on patient demographics, biomarker and laboratory measurements, medical histories, clinical outcomes, healthcare resource utilization, medications, dietary patterns, physical activity and PROs (including QoL and qualitative interviews).

Conclusions

The DISCOVER CKD program will provide contemporary real-world insight to inform clinical practice and improve our understanding of the epidemiology and clinical and economic burden of CKD, as well as determinants of clinical outcomes and PROs from a range of geographical regions in a real-world CKD setting.

Targeting immune cell metabolism in kidney diseases

Insights into the relationship between immunometabolism and inflammation have enabled the targeting of several immunity-mediated inflammatory processes that underlie infectious diseases and cancer or drive transplant rejection, but this field remains largely unexplored in kidney diseases. The kidneys comprise heterogeneous cell populations, contain distinct microenvironments such as areas of hypoxia and hypersalinity, and are responsible for a functional triad of filtration, reabsorption and secretion. These distinctive features create myriad potential metabolic therapeutic targets in the kidney. Immune cells have crucial roles in the maintenance of kidney homeostasis and in the response to kidney injury, and their function is intricately connected to their metabolic properties. Changes in nutrient availability and biomolecules, such as cytokines, growth factors and hormones, initiate cellular signalling events that involve energy-sensing molecules and other metabolism-related proteins to coordinate immune cell differentiation, activation and function. Disruption of homeostasis promptly triggers the metabolic reorganization of kidney immune and non-immune cells, which can promote inflammation and tissue damage. The metabolic differences between kidney and immune cells offer an opportunity to specifically target immunometabolism in the kidney.

Relationship between mortality and use of sodium bicarbonate at the time of dialysis initiation: a prospective observational study

Background

Patients with chronic kidney disease often experience metabolic acidosis. Whether oral sodium bicarbonate can reduce mortality in patients with metabolic acidosis has been debated for years. Hence, this study was conducted to evaluate the utility of sodium bicarbonate in patients who will undergo dialysis therapy. In this study, we investigated the effect of oral sodium bicarbonate therapy on mortality in patients with end-stage kidney disease (ESKD) initiated on dialysis therapy.

Methods

We conducted an observational study of patients when they started dialysis therapy. There were 17 centres participating in the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis. Data were available on patients’ sex, age, use of sodium bicarbonate, drug history, medical history, vital data, and laboratory data. We investigated whether patients on oral sodium bicarbonate for more than three months before dialysis initiation had a better prognosis than those without sodium bicarbonate therapy. The primary outcome was defined as all-cause mortality.

Results

The study included 1524 patients with chronic kidney disease who initiated dialysis between October 2011 and September 2013. Among them, 1030 were men and 492 women, with a mean age of 67.5 ± 13.1 years. Of these, 677 used sodium bicarbonate and 845 did not; 13.6% of the patients in the former group and 21.2% of those in the latter group died by March 2015 (p <  0.001). Even after adjusting for various factors, the use of sodium bicarbonate independently reduced mortality (p <  0.001).

Conclusions

The use of oral sodium bicarbonate at the time of dialysis initiation significantly reduced all-cause mortality in patients undergoing dialysis therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02330-0.

Temporary impairment of renal function in patients with rectal cancer treated with diverting ileostomy

Background

Fluid and electrolyte disturbance, which impairs renal function, has been reported in patients with temporary ileostomy. However, the dynamic changes in serum electrolytes and renal function in rectal cancer patients with ileostomy have not been well described. In the present study, we aimed to evaluate alterations in serum electrolytes and renal function in rectal cancer patients undergoing ileostomy creation and closure.

Methods

The levels of serum potassium, serum sodium, serum blood urea nitrogen, serum creatinine and estimated glomerular filtration rate (eGFR) were analyzed in 320 patients with rectal cancer including 156 patients with an ileostomy (the ileostomy group) and 164 patients without an ileostomy (the control group).

Results

After index surgery, the levels of serum potassium and serum creatinine in the ileostomy group were significantly higher than those in the control group (P<0.05). In contrast, the levels of serum sodium and the eGFR showed decreases in the ileostomy group compared to the control group after index surgery (P<0.05). At 3 months after ileostomy creation, the ileostomy group had a significantly increased rate of eGFR <60 mL/min/1.73 m² compared to the control group (5.8% vs. 1.2%, P=0.032). In line with the results of univariate analysis, multivariable analysis identified ileostomy and diabetes as independent risk factors for a decreased eGFR (P=0.005 and P=0.022, respectively). Furthermore, a significantly rebound of eGFR was observed in patients after ileostomy closure (P=0.013).

Conclusions

Ileostomy can cause temporary electrolyte disturbance and renal function impairment in patients with rectal cancer. Diabetes is an independent risk factor for renal function damage in patients with rectal cancer who receive a temporary ileostomy.

Nationwide Glaucoma incidence in end stage renal disease patients and kidney transplant recipients

Glaucoma shares common risk factors with chronic kidney disease (CKD) but previous cross-sectional studies have demonstrated discrepancies in the risk of glaucoma in CKD patients. This study enrolled kidney transplantation recipients (KTRs) (n = 10,955), end stage renal disease (ESRD) patients (n = 10,955) and healthy controls (n = 10,955) from National Health Insurance Service database of the Republic of Korea. A Cox proportional hazard regression model was used to calculate the hazard ratios (HR) for primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) incidences. The incidence of POAG was higher in ESRD patients (3.36/1,000 person-years, P < 0.0001) and KTRs (3.22 /1,000 person-years, P < 0.0001), than in healthy controls (1.20/1,000 person-years). However, POAG risk showed no significant increase in either ESRD patients (P = 0.07) or KTRs (P = 0.08) when adjusted for the confounding factors. The incidence of PACG was significantly higher in ESRD patients (0.41/1,000 person-years) than in healthy controls (0.14/1,000 person-years, P = 0.008). The PACG incidence was significantly lower in KTRs than in ESRD patients (HR = 0.35, P = 0.015). In conclusion, this nationwide cohort study demonstrated that kidney transplantation can reduce the risk of PACG but not POAG in ESRD patients.

Transplantation of Apoptosis-Resistant Endothelial Progenitor Cells Improves Renal Function in Diabetic Kidney Disease

Background

Diabetic kidney disease is associated with glomerulosclerosis and poor renal perfusion. Increased capillary formation and improved perfusion may help to halt or reverse the injury. Transplanting apoptosis‐resistant p53‐silenced endothelial progenitor cells (p53sh‐EPCs) may help improve vascularization and renal perfusion and could be more beneficial than another stem cell such as the mouse mesenchymal stromal cell (mMSC).

Methods and Results

Hyperglycemia and proteinuria were confirmed at 8 to 10 weeks in streptozotocin‐induced type1 diabetic C57Bl/6 mice, followed by transplantation of 0.3 million p53sh‐EPCs, Null‐EPCs (control), or mMSC under each kidney capsule. Urine was collected weekly for creatinine and protein levels. Blood pressure was measured by direct arterial cannulation and renal perfusion was measured by renal ultrasound. The kidneys were harvested for histology and mRNA expression. Reduction of protein/creatinine (AUC) was observed in p53sh‐EPC‐transplanted mice more than null‐EPC (1.8‐fold, P=0.03) or null‐mMSC (1.6‐fold, P=0.04, n=4) transplanted mice. Markers for angiogenesis, such as endothelial nitric oxide synthase (1.7‐fold, P=0.06), were upregulated post p53sh‐EPC transplantation compared with null EPC. However, vascular endothelial growth factor‐A expression was reduced (7‐fold, P=0.0004) in mMSC‐transplanted mice, compared with p53sh‐EPC‐transplanted mice. Isolectin‐B4 staining of kidney section showed improvement of glomerular sclerosis when p53sh‐EPC was transplanted, compared with null‐EPC or mMSC. In addition, mean and peak renal blood velocity (1.3‐fold, P=0.01, 1.4‐fold, P=0.001, respectively) were increased in p53sh‐EPC‐transplanted mice, relative to null‐EPC transplanted mice.

Conclusions

Apoptosis‐resistant p53sh EPC transplantation could be beneficial in the treatment of diabetic kidney disease by decreasing proteinuria, and improving renal perfusion and glomerular architecture.

Elevated Monocyte to Lymphocyte Ratio and Increased Mortality among Patients with Chronic Kidney Disease Hospitalized for COVID-19

Chronic kidney disease (CKD) constitutes a major health problem and one of the leading causes of death worldwide. Patients with CKD have impaired immune functions that predispose them to an increased risk of infections, as well as virus-associated cancers and a diminished vaccine response. In this study, we aimed to identify clinical and laboratory parameters associated with in-hospital mortality in patients evaluated in the department of emergency (ER) and admitted with the diagnosis of severe acute respiratory syndrome (SARS) caused by coronavirus disease 2019 (COVID-19) at the Baptist Hospital of Nicaragua (BHN). There were 37 patients with CKD, mean age 58.3 ± 14.1 years, admitted to BHN due to COVID-19, and among them, 24 (65.7%) were males (p = 0.016). During hospitalization, 23 patients with CKD (62.1%) died of complications associated with COVID-19 disease, which was a higher proportion (odds ratio (OR) 5.6, confidence interval (CI) 2.1-15.7, p = 0.001) compared to a group of 70 patients (64.8% males, mean age 57.5 ± 13.7 years) without CKD admitted during the same period in whom 28.5% died of COVID-19. In the entire cohort, the majority of patients presented with bilateral pneumonia, and the most common symptoms at admission were dyspnea, cough, and fever. Serum levels of D-dimer, ferritin and procalcitonin were significantly higher in patients with CKD compared with those without CKD. Multivariate analysis revealed that CKD, age (>60 years), and hypoxia measured in the ER were factors associated with increased in-hospital mortality. Among patients with CKD but not in those without CKD (OR 36.8, CI 1.5-88.3, p = 0.026), an increased monocytes-to-lymphocyte ratio (MLR) was associated with higher mortality and remained statistically significant after adjusting for confounders. The MLR measured in the ER may be useful for predicting in-hospital mortality in patients with CKD and COVID-19 and could contribute to early risk stratification in this group.

A Contrast Examination of Proinflammatory Effects on Kidney Function for γ-Fe2O3 NP and Gadolinium Dimeglumine

BACKGROUND

Contrast-enhanced magnetic resonance imaging (MRI) is a powerful diagnostic tool for many diseases. In many situations, the contrasts are repeatedly administrated in order to monitor and assess the disease progression.

OBJECTIVE

To investigate and compare the biological effects of γ-Fe2O3 nanoparticle (NP) and gadolinium dimeglumine (Gd-DTPA) with high and multiple doses on the kidney of healthy mice.

METHODS

Polydextrose sorbitol carboxymethyl ether coated γ-Fe2O3 NP with hydrodynamic size of 68.2 nm and clinically applied Gd-DTPA were employed on healthy mice with the repeatedly intravenous administration of high doses. The cell viability of human umbilical vein endothelial cells (HUVEC) in high doses of these two contrast agents were measured using the xCELLigence Real-Time Cell Analysis (RTCA) S16 Instrument. The biological effects of γ-Fe2O3 NP and Gd-DTPA on the kidney were obtained using a biochemical automatic analyzer and multiple proinflammatory factor kit on the serum. Histopathological and immunohistochemistry analysis were taken on kidney tissues.

RESULTS

It showed that the proinflammatory responses elicited by the γ-Fe2O3 NPs were weaker than that by Gd-DTPA, evidenced by the relatively much lower level of IL-1β, IL-6, IL-18, TNF-α, C-reactive protein (CRP) and Ferritin. At the same time, the γ-Fe2O3 NPs did not have the biochemical index elevated, while the Gd-DTPA did.

CONCLUSION

The γ-Fe2O3 NPs induced weaker proinflammatory effects in reference to the Gd-DTPA, indicating better renal safety. Therefore, it is suggested that γ-Fe2O3 NPs should be safer and optional choice when repeated contrast-enhanced MRI is necessary.

Lowest nocturnal systolic blood pressure is related to heavy proteinuria and outcomes in elderly patients with chronic kidney disease

Ambulatory blood pressure monitoring (ABPM) can produce many variables, of which the lowest nocturnal systolic blood pressure (LNSBP) currently used in calculating morning surge is occasionally overlooked in recent kidney studies compared with other ABPM parameters. We explored the clinical effects of LNSBP in elderly patients with chronic kidney disease (CKD) in a multicenter, observational cohort study. A total of 356 elderly patients with CKD from 19 clinics were included in this analysis. We used multiple logistic regression and survival analyses to assess the associations between the lowest nocturnal systolic blood pressure and heavy proteinuria and kidney disease outcomes, respectively. The median age was 66 years, and 66.6% were men. The median eGFR was 49.2 ml/min/1.73 m². Multivariate logistic regression analysis demonstrated that LNSBP (OR 1.24; 95% CI 1.10–1.39; P < 0.001; per 10 mmHg) was associated with heavy proteinuria. During the median follow-up of 23 months, 70 patients (19.7%) had a composite outcome; of these, 25 initiated dialysis, 25 had 40% eGFR loss, and 20 died. Cox analysis showed that the renal risk of LNSBP for CKD outcomes remained significant even after adjusting for background factors, including age, sex, medical history of hypertension and diabetes, smoking status, eGFR, 24-h proteinuria, and etiology of CKD (HR 1.18; 95% CI 1.06–1.32; P = 0.002; per 10 mmHg). Concentrating on LNSBP could be valuable in guiding antihypertensive treatment to control heavy proteinuria and improve renal prognosis in elderly CKD patients.

The need for a cardionephrology subspecialty

Chronic kidney disease (CKD) has structural and functional repercussions for the cardiovascular system that facilitate the development of cardiovascular disease (CVD). In fact, cardiovascular complications are frequent in the CKD population and thus cause a great clinical, public health and economic burden. Despite this challenge, the prevention and management of cardiovascular complications is one among several aspects of CKD that meets the criteria of an unmet medical need. This probably has to do with the misperception by the nephrologist of the global relevance of CVD in the CKD patient which, in turn, may be due to insufficient cardiovascular training during nephrology specialization. Therefore a change in approach is necessary to understand CKD as a disease in which the manifestations and complications related to CVD become so frequent and important that they require dedicated multidisciplinary clinical management. From this perspective, it makes sense to consider training in the subspecialty of cardionephrology to provide adequate cardiovascular care for CKD patients by the nephrologist. In addition, the cardionephrology subspecialist would be better able to interact with other specialists in multidisciplinary care settings created to achieve a deeper understanding and more effective clinical handling of the interactions between CKD and CVD.

Stress Related Disorders and the Risk of Kidney Disease

INTRODUCTION

Stress related disorders (SRDs, i.e., psychiatric disorders induced by significant life stressors) increase vulnerability to health problems. Whether SRDs associate with risk of acute kidney injury (AKI) and chronic kidney disease (CKD) is unknown.

METHODS

A population-matched cohort study in Sweden included 30,998 patients receiving a SRDs diagnosis and 116,677 unexposed patients matched by age, sex and estimated glomerular filtration rates (eGFR). The primary outcome was CKD progression, defined as a sustained relative decline in eGFR of more than 40% or commencement of kidney replacement therapy. The secondary outcome was AKI, defined by death or hospitalization attributed to AKI or rapid creatinine changes (increase ≥ 0.3 mg/d over 48 hours or 1.5x over 7 days). Cox models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

During a medium follow-up of 3.2 years, compared to the unexposed, patients with SRDs (median age 45 years, 71% women), were at increased risk of CKD progression (HR 1.23, 95% CI 1.10-1.37) and AKI (HR 1.22, 95% CI 1.04-1.42). While the HR of CKD progression remained similarly elevated during the entire follow-up period, the association with AKI was only observed during the first year after SRDs diagnosis. Results were consistent in stratified analyses, when only considering AKI-hospitalizations/death, and when disregarding eGFR measurements close to index date.

CONCLUSIONS

A diagnosis of SRDs is associated with subsequent risk of AKI and CKD progression. While studies should confirm this observation and characterize underlying mechanisms, close monitoring of kidney function following SRDs diagnosis may be indicated.

Controversies: Stroke Prevention in Chronic Kidney Disease

Risk of both ischemic and hemorrhagic stroke is increased in the chronic kidney disease (CKD) population, particularly in end-stage kidney disease patients. Uremic factors that contribute to stroke risk include blood pressure variability, vascular calcification, build-up of vascular toxins, chronic inflammation, platelet dysfunction and increased brain microbleeds. This paper discusses the controversial evidence for stroke prevention strategies including blood pressure control, statins, antiplatelet agents, and anticoagulation in the CKD population. Only a few randomized clinical trials included patients with advanced CKD, thus evidence is derived mostly from observational cohorts and real-world data. Overall, targeting a lower systolic blood pressure below 120 mmHg and statin prescription do not appear to decrease stroke risk in CKD. Antiplatelet agents have not shown a clear benefit for secondary stroke prevention, but aspirin may reduce incident stroke in hypertensive CKD stage 3B-5 patients. Observational data suggests that the factor Xa inhibitor apixaban has a favorable profile over warfarin in dialysis patients with atrial fibrillation; apixaban being associated with lower stroke risk and fewer major bleeding events.

Long-term consequences of acute kidney injury: a narrative review

The incidence of acute kidney injury (AKI) has increased in the past decades. AKI complicates up to 15% of hospitalizations and can reach up to 50-60% in critically ill patients. Besides the short-term impact of AKI in patient outcomes, several studies report the association between AKI and adverse long-term outcomes, such as recurrent AKI episodes in 25-30% of cases, hospital re-admissions in up to 40% of patients, an increased risk of cardiovascular events, an increased risk of progression of chronic kidney disease (CKD) after AKI and a significantly increased long-term mortality. Despite the long-term impact of AKI, there are neither established guidelines on the follow-up care of AKI patients, nor treatment strategies to reduce the incidence of sequelae after AKI. Only a minority of patients have been referred to nephrology post-discharge care, despite the evidence of improved outcomes associated with nephrology referral by addressing cardiovascular risk and risk of progression to CKD. Indeed, AKI survivors should have specialized nephrology follow-up to assess kidney function after AKI, perform medication reconciliation, educate patients on nephrotoxic avoidance and implement strategies to prevent CKD progression. The authors provide a comprehensive review of the transition from AKI to CKD, analyse the current evidence on the long-term outcomes of AKI and describe predisposing risk factors, highlight the importance of follow-up care in these patients and describe the current therapeutic strategies which are being investigated on their impact in improving patient outcomes.

Ten things to know about ten cardiovascular disease risk factors

Given rapid advancements in medical science, it is often challenging for the busy clinician to remain up-to-date on the fundamental and multifaceted aspects of preventive cardiology and maintain awareness of the latest guidelines applicable to cardiovascular disease (CVD) risk factors. The "American Society for Preventive Cardiology (ASPC) Top Ten CVD Risk Factors 2021 Update" is a summary document (updated yearly) regarding CVD risk factors. This "ASPC Top Ten CVD Risk Factors 2021 Update" summary document reflects the perspective of the section authors regarding ten things to know about ten sentinel CVD risk factors. It also includes quick access to sentinel references (applicable guidelines and select reviews) for each CVD risk factor section. The ten CVD risk factors include unhealthful nutrition, physical inactivity, dyslipidemia, hyperglycemia, high blood pressure, obesity, considerations of select populations (older age, race/ethnicity, and sex differences), thrombosis/smoking, kidney dysfunction and genetics/familial hypercholesterolemia. For the individual patient, other CVD risk factors may be relevant, beyond the CVD risk factors discussed here. However, it is the intent of the "ASPC Top Ten CVD Risk Factors 2021 Update" to provide a succinct overview of things to know about ten common CVD risk factors applicable to preventive cardiology.

MicroRNA-363-3p Inhibits the Expression of Renal Fibrosis Markers in TGF-β1-Treated HK-2 Cells by Targeting TGF-β2

This study aimed to explore the role of miR-363-3p in renal fibrosis (RF) in vitro. HK-2 cells were treated with transforming growth factor (TGF)-β1 for 72 h to establish an in vitro model of RF. Subsequently, western blot analysis and reverse transcription-quantitative PCR were used to detect the protein and mRNA expression levels of RF markers in TGF-β1-treated HK-2 cells, respectively. The results showed that the protein and mRNA expression levels of TGF-β2, α-smooth muscle actin (SMA), fibronectin, vimentin, collagen II and N-cadherin were increased, while the protein and mRNA expression levels of E-cadherin were decreased in TGF-β1-treated HK-2 cells. The level of miR-363-3p was significantly decreased in TGF-β1-treated HK-2 cells. TargetScan indicated that TGF-β2 was a direct target gene for miR-363-3p, which was further verified using dual luciferase reporter gene assays. Further analyses revealed that the increased protein and mRNA expression levels of TGF-β2, α-SMA, fibronectin, vimentin, collagen II, N-cadherin, increased phosphorylated-Smad3 protein level, and decreased E-cadherin protein and mRNA expression in TGF-β1-treated HK-2 cells were significantly reversed by miR-363-3p mimics. However, all the effects were suppressed by a TGF-β2-plasmid. The results suggested that miR-363-3p plays a protective role in RF by regulating the TGF-β2/Smad3 signaling pathway.

Child-to-adult body mass index trajectories and the risk of subclinical renal damage in middle age

BACKGROUND

Although it is well established that obesity is a risk factor for chronic kidney disease, the impact of distinct long-term body mass index (BMI) developmental patterns on renal function in later life is poorly understood.

METHODS

This study utilized data derived from the Hanzhong Adolescent Hypertension Cohort, a prospective cohort followed over 30 years. We used latent class growth mixture modeling method to identify the BMI trajectories of participants who had received BMI measurements at least three times from childhood (age: 6-15 years) to adulthood (age: 36-45 years). The modified Poisson regression model was used to identify potential associations between BMI trajectories and subclinical renal damage (SRD) in midlife.

RESULTS

Within a total of 2162 individuals, we identified four distinct long-term BMI trajectories: stable normal (54.72%), moderately increasing overweight (32.42%), resolving (10.27%), and progressively increasing obese (2.59%). By the latest follow-up in 2017, a total of 257 (13.1%) individuals were diagnosed with SRD. Compared with the stable normal group, the moderately increasing overweight group and the progressively increasing obese group exhibited significantly a higher urinary albumin-to-creatinine ratio and a higher odd of existing SRD in 2017 (risk ratio [RR], 1.70 [95% confidence interval (CI), 1.33-2.19] and 4.35 [95% CI, 3.00-6.30], respectively). However, individuals who resolved their elevated BMI in early life had a similar risk for SRD as those who had never been obese or overweight (RR, 1.17 [95% CI, 0.77-1.79]).

CONCLUSIONS

Child-to-adult BMI trajectories that worsen or persist at high levels were associated with an increased risk for SRD in midlife. Maintaining a normal BMI or reversing an elevated BMI in early life may be beneficial to renal function over the long term.

Uremic Toxins in the Progression of Chronic Kidney Disease and Cardiovascular Disease: Mechanisms and Therapeutic Targets

Chronic kidney disease (CKD) is a progressive loss of renal function. The gradual decline in kidney function leads to an accumulation of toxins normally cleared by the kidneys, resulting in uremia. Uremic toxins are classified into three categories: free water-soluble low-molecular-weight solutes, protein-bound solutes, and middle molecules. CKD patients have increased risk of developing cardiovascular disease (CVD), due to an assortment of CKD-specific risk factors. The accumulation of uremic toxins in the circulation and in tissues is associated with the progression of CKD and its co-morbidities, including CVD. Although numerous uremic toxins have been identified to date and many of them are believed to play a role in the progression of CKD and CVD, very few toxins have been extensively studied. The pathophysiological mechanisms of uremic toxins must be investigated further for a better understanding of their roles in disease progression and to develop therapeutic interventions against uremic toxicity. This review discusses the renal and cardiovascular toxicity of uremic toxins indoxyl sulfate, p-cresyl sulfate, hippuric acid, TMAO, ADMA, TNF-α, and IL-6. A focus is also placed on potential therapeutic targets against uremic toxicity.

Screening for chronic kidney disease: moving toward more sustainable health care

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is a pervasive and growing health concern that has a significant impact on mortality and morbidity, putting stress on global healthcare systems. CKD affects ∼14% of general populations and ∼36% of high-risk populations and is projected to rise in the coming decade due to increasing rates of diabetes and hypertension.

RECENT FINDINGS

Screen, triage, and treat programs aim to detect early stage disease with the intention of promoting medical and lifestyle interventions in line with a patient's level of risk that may slow disease progression and reduce morbidity and mortality. Early detection facilitates appropriate risk stratification and coordination of care among patients, primary care and nephrology ensuring resources are utilized appropriately.

SUMMARY

By using readily available laboratory measures, screening for CKD in high-risk populations is cost effective and beneficial to both individuals and healthcare systems. Program models such as Kidney Early Evaluation Program and First Nations Community Based Screening to Improve Kidney Health and Prevent Dialysis have proven the efficacy of screening initiatives in these groups, but improvements are required to maximize the benefits of early CKD detection.

Glycyrrhetinic Acid Protects Renal Tubular Cells against Oxidative Injury via Reciprocal Regulation of JNK-Connexin 43-Thioredoxin 1 Signaling

Background and Objective: The incidence of chronic kidney disease (CKD) is steadily increasing. Although renal tubular epithelium injury is closely correlated with the prognosis of CKD, the underlying mechanism is not fully understood and therapeutic strategies are limited. The main bioactive component of the Chinese medicine herb, glycyrrhiza, is 18α-glycyrrhetinic acid (Ga), which is also a pharmacological inhibitor of gap junctions. Our previous studies indicated that Ga is able to ameliorate renal cell injury. The present study explored the regulatory role of Ga in redox signaling in renal tubular epithelial cells with oxidative injury. Methods: Rat renal tubular epithelial cells, NRK-52E, were incubated with Px-12, a thioredoxin inhibitor, to mimic thioredoxin deficiency and induce oxidative injury in vitro. A Cell Counting Kit-8 was used to analyze cell viability while a reactive oxygen species (ROS)/superoxide (O₂ ^-) fluorescence probe was employed to determine oxidative stress. Apoptosis was evaluated using DT-mediated dUTP nick end labeling/4,6-diamidino-2-phenylindole staining and cleaved caspase 3 protein analysis. Western blot analysis was used to analyze the expression of specific proteins while siRNA transfection was performed to downregulate targeted proteins. Results: Inhibition of thioredoxin 1 by Px-12 triggered renal tubular cell oxidative injury as evidenced by morphological change, loss of cellular viability, over production of ROS and O₂ ^-, and appearance of cleaved caspase-3. Ga significantly attenuated cell oxidative injury, as indicated by the parameters mentioned above. Px-12 induced phosphorylation of c-Jun N-terminal kinase (JNK) and subsequently the expression of connexin 43 (Cx43) in NRK-52E cells. Ga and the JNK inhibitor, sp600125, markedly suppressed Px-12-induced generation of intracellular ROS and O₂ ^-. Inhibition of JNK improved Px-12-elicited NRK-52E cell injury. Moreover, sp600125 inhibited Cx43 expression. After downregulation of Cx43 via Cx43 siRNA transfection, the phosphorylation of JNK was markedly reduced. Furthermore, Ga restored the expression of thioredoxin 1 inhibited by Px-12. Conclusion: ROS-JNK-Cx43-thioredoxin 1 signaling plays a crucial role in renal tubular cell injury. JNK is involved in the regulation of thioredoxin 1 and Cx43, and Cx43 reciprocally regulates thioredoxin 1. Inhibition of gap junctions by Ga alleviated renal tubular oxidative injury via improvement of thioredoxin 1-mediated redox signaling.

Alpha-Klotho is a novel predictor of treatment responsiveness in patients with heart failure

Heart failure is a major cause of death with an increasing population of elderly individuals. Several studies have demonstrated the involvement of soluble alpha-Klotho (sαKl) in various diseases. However, the correlation between sαKl and heart failure remains to be understood. The aim of this study is to investigate the levels and role of sαKl in patients with heart failure. Twenty-eight consecutive patients with acute heart failure (19 male, 9 female), admitted to the Osaka University Hospital from 2010 to 2018, were enrolled in this study. Mean NYHA score, left ventricular ejection fraction and BNP were 3.3, 17.0% and 588 pg/mL, respectively. SαKl significantly increased in heart failure patients. SαKl on admission were significantly higher in patients with heart failure who showed improvement after intensive treatment than that in patients who did not show improvement after the treatment. SαKl levels decreased significantly in patients who showed improvement. Interestingly, sαKl levels increased in male patients with heart failure, but not in female patients. Our data suggest that soluble αKl may be a novel biomarker for the responsiveness against treatment in patients with heart failure with reduced ejection fraction. Our findings may help developing a personalized therapy for different patients with heart failure.

Efficacy and Safety of Daprodustat for Anemia Therapy in Chronic Kidney Disease Patients: A Systematic Review and Meta-Analysis

Objective: Daprodustat is a novel oral agent in treating anemia of chronic kidney disease (CKD), and several clinical trials have been conducted to compare daprodustat with recombinant human erythropoietin (rhEPO) or placebo. Our systematic review aimed to investigate the efficacy and safety of daprodustat for anemia treatment in both dialysis-dependent (DD) and non-dialysis-dependent (NDD) patients.

Methods: Six databases were searched for randomized controlled trials (RCTs) reporting daprodustat vs. rhEPO or placebo for anemia patients in CKD. The outcome indicators were focused on hemoglobin (Hb), ferritin, transferrin saturation (TSAT), total iron-binding capacity (TIBC), vascular endothelial growth factor (VEGF), and serious adverse events (SAEs).

Results: Eight eligible studies with 1,516 participants were included. For both NDD and DD patients, changes in Hb levels from baseline were significantly higher in daprodustat group than that in the placebo (mean difference (MD) = 1.73, [95% confidence interval (CI), 0.34 to 3.12], p = 0.01; MD = 1.88, [95% CI, 0.68 to 3.09], p = 0.002; respectively), and there was no significant difference between daprodustat and rhEPO group (MD = 0.05, [95% CI, −0.49 to 0.59], p = 0.86; MD = 0.12, [95% CI, −0.28 to 0.52], p = 0.55; respectively). The indexes of iron metabolism were improved significantly in the daprodustat group compared to placebo- or rhEPO-treated patients, while there was no similar change in terms of TSAT for DD patients. Furthermore, no trend of increasing plasma VEGF was observed in daprodustat-treated subjects. As for safety, there was no significant difference in the incidence of SAEs between daprodustat and placebo treatment, while the incidence of SAEs in the daprodustat group was significantly lower than that in the rhEPO group.

Conclusion: Daprodustat was efficacious and well tolerated for anemia in both NDD and DD patients in the short term based on current RCTs. And daprodustat may become an effective alternative for treatment of anemia with CKD. Since the application of daprodustat is still under exploration, future researches should consider the limitations of our study to evaluate the value of daprodustat.

Mechanisms and Effects of Health Coaching in Patients With Early-Stage Chronic Kidney Disease: A Randomized Controlled Trial

PURPOSE

To examine the effects of health coaching on self-management and quality of life (QOL) in patients with chronic kidney disease (CKD) and to evaluate whether self-efficacy and patient activation mediate the effect of health coaching on self-management and QOL.

DESIGN AND METHODS

A single-center, parallel-group, randomized controlled trial. A total of 108 patients with stages 1 to 3a CKD participated in the study. Participants were randomly assigned to a health-coaching intervention group or a usual care control group. Participants' QOL (World Health Organization Quality of Life Scale), self-management (CKD Self-Management instrument), patient activation (Patient Activation Measure), and self-efficacy (CKD Self-Efficacy instrument) were measured at baseline, immediately after, and 6 weeks after the intervention.

FINDINGS

Health coaching improved QOL, self-management, patient activation, and self-efficacy at postintervention and at 12 weeks' follow-up. Health coaching had a significant indirect effect on QOL through improvements in patient activation. Health coaching exerted a significant indirect effect on self-management through improvements in self-efficacy and patient activation.

CONCLUSIONS

The findings demonstrated that health coaching can effectively improve QOL and self-management. A health-coaching intervention can raise self-efficacy and activation levels through which self-management and QOL further improve.

CLINICAL RELEVANCE

Health-coaching strategies can be used to assist patients with early-stage CKD in reaching their health goals and becoming activated in self-management of their diseases.

The association between platelet indices and cardiovascular events in chronic kidney disease patients without dialysis

PURPOSE

Previous studies have indicated that platelet indices are related to the pathogenesis of cardiovascular diseases (CVD). However, it is unclear which platelet-related indicators are associated with CVD events in patients with chronic kidney disease (CKD) without dialysis.

METHODS

We performed a single-center prospective cohort study involved 1391 CKD patients to explore the relationship between platelet indices and CVD events in CKD patients. A nomogram was generated to predict CVD-free survival after 3 and 5 years of follow-up in terms of the fitted Cox regression model. And the time-dependent receiver-operating characteristic (ROC) curves were applied to evaluate the prediction accuracy of platelet indices on CVD events.

RESULTS

During a median follow-up of 3.41 years, 211 (15.2%) patients experienced CVD events. Results showed that platelet counts (PLT), plateletcrit (PCT), platelet-large cell ratio (P-LCR), and platelet distribution width (PDW) among 5 platelet indices were significantly lower in advanced CKD stages. Cox regression model showed that PLT, PDW, and PCT were associated with CVD events. However, after multivariable-adjusted, low level of PLT, hazard ratio (HR) 0.994 and 95% confidence interval (95% CI 0.989-1.000, p = 0.04), and PDW, HR 0.936 (95% CI 0.878-0.998, p = 0.044) predicted CVD events. The area under the ROC curve (AUC) of platelet indices assessed by time-dependent ROC curve analysis showed that only PLT and PDW were significant for predicting CVD events for 5 years.

CONCLUSIONS

We demonstrated that PLT and PDW among 5 platelet indices were independently associated with CVD events in patients with CKD.