Global Cardiovascular and Renal Outcomes of Reduced GFR

Kidney Disease, Race, and GFR Estimation

Assessment of GFR is central to clinical practice, research, and public health. Current Kidney Disease Improving Global Outcomes guidelines recommend measurement of serum creatinine to estimate GFR as the initial step in GFR evaluation. Serum creatinine is influenced by creatinine metabolism as well as GFR; hence, all equations to estimate GFR from serum creatinine include surrogates for muscle mass, such as age, sex, race, height, or weight. The guideline-recommended equation in adults (the 2009 Chronic Kidney Disease Epidemiology Collaboration creatinine equation) includes a term for race (specified as black versus nonblack), which improves the accuracy of GFR estimation by accounting for differences in non-GFR determinants of serum creatinine by race in the study populations used to develop the equation. In that study, blacks had a 16% higher average measured GFR compared with nonblacks with the same age, sex, and serum creatinine. The reasons for this difference are only partly understood, and the use of race in GFR estimation has limitations. Some have proposed eliminating the race coefficient, but this would induce a systematic underestimation of measured GFR in blacks, with potential unintended consequences at the individual and population levels. We propose a more cautious approach that maintains and improves accuracy of GFR estimates and avoids disadvantaging any racial group. We suggest full disclosure of use of race in GFR estimation, accommodation of those who decline to identify their race, and shared decision making between health care providers and patients. We also suggest mindful use of cystatin C as a confirmatory test as well as clearance measurements. It would be preferable to avoid specification of race in GFR estimation if there was a superior, evidence-based substitute. The goal of future research should be to develop more accurate methods for GFR estimation that do not require use of race or other demographic characteristics.

Impaired fasting glucose and development of chronic kidney disease in non-diabetic population: a Mendelian randomization study

INTRODUCTION

Diabetes mellitus is a risk factor of chronic kidney disease (CKD); however, the relationship between fasting glucose and CKD remains controversial in non-diabetic population. This study aimed to assess causal relationship between genetically predicted fasting glucose and incident CKD.

RESEARCH DESIGN AND METHODS

This study included 5909 participants without diabetes and CKD from the Korean Genome Epidemiology Study. The genetic risk score (GRS₉) was calculated using nine genetic variants associated with fasting glucose in previous genome-wide association studies. Incident CKD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² and/or proteinuria (≥1+). The causal relationship between fasting glucose and CKD was evaluated using the Mendelian randomization (MR) approach.

RESULTS

The GRS₉ was strongly associated with fasting glucose (β, 1.01; p<0.001). During a median follow-up of 11.6 years, 490 (8.3%) CKD events occurred. However, GRS₉ was not significantly different between participants with CKD events and those without. After adjusting for confounding factors, fasting glucose was not associated with incident CKD (OR 0.990; 95% CI 0.977 to 1.002; p=0.098). In the MR analysis, GRS₉ was not associated with CKD development (OR per 1 SD increase, 1.179; 95% CI 0.819 to 1.696; p=0.376). Further evaluation using various other MR methods and strict CKD criteria (decrease in the eGFR of ≥30% to a value of <60 mL/min/1.73 m²) found no significant relationship between GRS₉ and incident CKD.

CONCLUSIONS

Fasting glucose was not causally associated with CKD development in non-diabetic population.

Chronic kidney disease progression and mortality risk profiles in Germany: results from the Chronic Kidney Disease Outcomes and Practice Patterns Study

BACKGROUND

Chronic kidney disease (CKD) progression among German patients in a representative setting has not been described previously. The Verband Deutsche Nierenzentren and Chronic Kidney Disease Outcomes and Practice Patterns Study established a longitudinal observational cohort among German CKD patients to research variations in patient care and outcomes in real-world nephrology practices.

METHODS

A cohort of CKD Stages 3 (25%) and 4 (75%) patients was established from German nephrologist-run CKD clinics in 2013-16. Linear models were used to determine the estimated glomerular filtration rate (eGFR) slope during follow-up and Cox models were used to assess outcomes of end-stage kidney disease (ESKD) and death.

RESULTS

A total of 1834 patients (median age 75 years, 58% male, 42% diabetics, median baseline eGFR 25 mL/min/1.73 m2) were followed for a median of 29 months. More than 50% had slow or no decline and 17% declined ≥5 mL/min/1.73 m2/year. After 4.5 years, the incidence of ESKD was 8% and of deaths without ESKD 16% among patients with eGFR ≥30 mL/min/1.73 m2 and 37% and 19% for eGFR <30 mL/min/1.73 m2. Adjusted models showed higher risks of ESKD or death for patients with worse kidney function at baseline, male sex, diabetes and higher blood pressure; a higher risk of ESKD with higher albuminuria; and a higher risk of death with older age or cardiovascular comorbidity.

CONCLUSIONS

Routine nephrology care of patients in Germany comprises mostly elderly patients, many with slow CKD progression. Identification of risk factors for CKD progression and mortality may help guide resources by closer follow-up of high-risk patients.

Albuminuria Downregulation of the Anti-Aging Factor Klotho: The Missing Link Potentially Explaining the Association of Pathological Albuminuria with Premature Death

Ten percent of the adult population has chronic kidney disease (CKD), which is diagnosed when the glomerular filtration rate (GFR) is below 60 mL/min per 1.73 m² or when albuminuria is above 30 mg/day. The numerical thresholds were chosen because they are associated with an increased risk of CKD progression or premature death within a wider scenario of accelerated aging. Indeed, CKD is one of the fastest growing causes of death worldwide. A decreased GFR is associated with the accumulation of uraemic toxins that may promote tissue and organ damage. However, CKD may be diagnosed when the GFR is completely normal, as long as there is pathological albuminuria. A key unanswered question to stem the rise of CKD-associated deaths is whether the association between isolated albuminuria (when the GFR is normal) and premature death is causal. The recent demonstration that albuminuria per se directly suppresses the production of the anti-aging factor Klotho by kidney tubular cells may be one of the first steps to address the causality of the albuminuria-premature death-accelerated aging association. This hypothesis should be tested in interventional studies that should draw from translational science advances. Thus, the observation that albuminuria decreases Klotho production through epigenetic mechanisms implies that Klotho downregulation may persist after the correction of albuminuria, and innovative therapeutic approaches are needed to restore Klotho production. On the basis of recent literature, these may include manipulation of NF-kappaB regulators such as B cell lymphoma 3 protein (BCL-3), and epigenetic regulators such as histone deacetylases, or the repurposing of drugs such as pentoxifylline.

Primary chemoablation of low-grade upper tract urothelial carcinoma using UGN-101, a mitomycin-containing reverse thermal gel (OLYMPUS): an open-label, single-arm, phase 3 trial

BACKGROUND

Most patients with low-grade upper tract urothelial cancer are treated by radical nephroureterectomy. We aimed to assess the safety and activity of a non-surgical treatment using instillation of UGN-101, a mitomycin-containing reverse thermal gel.

METHODS

In this open-label, single-arm, phase 3 trial, participants were recruited from 24 academic sites in the USA and Israel. Patients (aged ≥18 years) with primary or recurrent biopsy-proven, low-grade upper tract urothelial cancer (measuring 5-15 mm in maximum diameter) and an Eastern Cooperative Oncology Group performance status score of less than 3 (Karnofsky Performance Status score >40) were registered to receive six instillations of once-weekly UGN-101 (mitomycin 4 mg per mL; dosed according to volume of patient's renal pelvis and calyces, maximum 60 mg per instillation) via retrograde catheter to the renal pelvis and calyces. All patients had a planned primary disease evaluation 4-6 weeks after the completion of initial therapy, in which the primary outcome of complete response was assessed, defined as negative 3-month ureteroscopic evaluation, negative cytology, and negative for-cause biopsy. Activity (complete response, expected to occur in >15% of patients) and safety were assessed by the investigator in all patients who received at least one dose of UGN-101. Data presented are from the data cutoff on May 22, 2019. This study is registered with ClinicalTrials.gov, NCT02793128.

FINDINGS

Between April 6, 2017, and Nov 26, 2018, 71 (96%) of 74 enrolled patients received at least one dose of UGN-101. 42 (59%, 95% CI 47-71; p<0·0001) patients had a complete response at the primary disease evaluation visit. The median follow-up for patients with a complete response was 11·0 months (IQR 5·1-12·4). The most frequently reported all-cause adverse events were ureteric stenosis in 31 (44%) of 71 patients, urinary tract infection in 23 (32%), haematuria in 22 (31%), flank pain in 21 (30%), and nausea in 17 (24%). 19 (27%) of 71 patients had study drug-related or procedure-related serious adverse events. No deaths were regarded as related to treatment.

INTERPRETATION

Primary chemoablation of low-grade upper tract urothelial cancer with intracavitary UGN-101 results in clinically significant disease eradication and might offer a kidney-sparing treatment alternative for these patients.

FUNDING

UroGen Pharma.

Probiotics, prebiotics, and synbiotics for the improvement of metabolic profiles in patients with chronic kidney disease: A systematic review and meta-analysis of randomized controlled trials

This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to quantify the effects of probiotic, prebiotic, and synbiotic supplementation on biomarkers of inflammation and oxidative stress, as well as lipid profiles among patients with chronic kidney disease (CKD). Electronic databases, including PubMed, the Cochrane Database, and the Web of Science were searched from January 1, 2000, to May 15, 2019. All RCTs that investigated the effect of prebiotics, probiotics, and synbiotics on a circulating (serum and plasma) inflammatory marker (C-reactive protein [CRP]), oxidative stress indicators (malondialdehyde [MDA], glutathione [GSH], and total anti-oxidant capacity [TAC]); and lipid profiles (total cholesterol [TC], triglycerides [TG], low-density lipoprotein cholesterol [LDL-c], and high-density lipoprotein cholesterol [HDL-c]) among patients with CKD were included. Data were pooled and expressed as a standardized mean difference (SMD) with a 95% confidence interval (CI). The protocol for this meta-analysis is registered with PROSPERO; No. CRD42019139090. Thirteen trials that included 671 patients were identified for analysis. The methodological quality varied across studies. Meta-analysis indicated that microbial therapies significantly reduced CRP (SMD, -0.75; 95% CI, -1.03 to -0.47; p = 0.000), MDA (SMD, -1.06; 95% CI, -1.59 to -0.52; p = 0.000), TC (SMD, -0.33; 95% CI, -0.52 to -0.13; p = 0.000), and LDL-c (SMD, -0.44; 95% CI, -0.86 to -0.02; p = 0.000) levels; they also increased the GSH (SMD, 0.44; 95% CI, 0.25 to 0.65; p = 0.000), TAC (SMD, 0.61; 95% CI, 0.07 to 1.15; p = 0.000), and HDL-c (SMD, 0.45; 95% CI, 0.03 to 0.87; p = 0.000) levels in CKD patients, as compared to the placebo groups; however, there was no statistically significant TG concentration among patients with CKD. Subgroup analyses showed that other key factors, such as the duration of intervention, participants' baseline body mass index (BMI), type of intervention, and age, had an effect of microbial therapies on outcomes. This meta-analysis supports the potential use of probiotic, prebiotic, and synbiotic supplements in the improvement of established biomarkers of inflammation and oxidative stress, as well as lipid profiles among patients with CKD, which are well-known cardiovascular risk factors. Further research into these interventions should consider the limitations of our study to explore the effect of long-term administration of these supplements in the CKD population.

Clinical Potential of Targeting Fibroblast Growth Factor-23 and αKlotho in the Treatment of Uremic Cardiomyopathy

Chronic kidney disease is highly prevalent, affecting 10% to 15% of the adult population worldwide and is associated with increased cardiovascular morbidity and mortality. As chronic kidney disease worsens, a unique cardiovascular phenotype develops characterized by heart muscle disease, increased arterial stiffness, atherosclerosis, and hypertension. Cardiovascular risk is multifaceted, but most cardiovascular deaths in patients with advanced chronic kidney disease are caused by heart failure and sudden cardiac death. While the exact drivers of these deaths are unknown, they are believed to be caused by uremic cardiomyopathy: a specific pattern of myocardial hypertrophy, fibrosis, with both diastolic and systolic dysfunction. Although the pathogenesis of uremic cardiomyopathy is likely to be multifactorial, accumulating evidence suggests increased production of fibroblast growth factor-23 and αKlotho deficiency as potential major drivers of cardiac remodeling in patients with uremic cardiomyopathy. In this article we review the increasing understanding of the physiology and clinical aspects of uremic cardiomyopathy and the rapidly increasing knowledge of the biology of both fibroblast growth factor-23 and αKlotho. Finally, we discuss how dissection of these pathological processes is aiding the development of therapeutic options, including small molecules and antibodies, directly aimed at improving the cardiovascular outcomes of patients with chronic kidney disease and end-stage renal disease.

Inflammation and Premature Ageing in Chronic Kidney Disease

Persistent low-grade inflammation and premature ageing are hallmarks of the uremic phenotype and contribute to impaired health status, reduced quality of life, and premature mortality in chronic kidney disease (CKD). Because there is a huge global burden of disease due to CKD, treatment strategies targeting inflammation and premature ageing in CKD are of particular interest. Several distinct features of the uremic phenotype may represent potential treatment options to attenuate the risk of progression and poor outcome in CKD. The nuclear factor erythroid 2-related factor 2 (NRF2)-kelch-like erythroid cell-derived protein with CNC homology [ECH]-associated protein 1 (KEAP1) signaling pathway, the endocrine phosphate-fibroblast growth factor-23-klotho axis, increased cellular senescence, and impaired mitochondrial biogenesis are currently the most promising candidates, and different pharmaceutical compounds are already under evaluation. If studies in humans show beneficial effects, carefully phenotyped patients with CKD can benefit from them.

The global and national burden of chronic kidney disease attributable to ambient fine particulate matter air pollution: a modelling study

Introduction

We aimed to integrate all available epidemiological evidence to characterise an exposure-response model of ambient fine particulate matter (PM2.5) and the risk of chronic kidney disease (CKD) across the spectrum of PM2.5 concentrations experienced by humans. We then estimated the global and national burden of CKD attributable to PM2.5.

Methods

We collected data from prior studies on the association of PM2.5 with CKD and used an integrative meta-regression approach to build non-linear exposure-response models of the risk of CKD associated with PM2.5 exposure. We then estimated the 2017 global and national incidence, prevalence, disability-adjusted life-years (DALYs) and deaths due to CKD attributable to PM2.5 in 194 countries and territories. Burden estimates were generated by linkage of risk estimates to Global Burden of Disease study datasets.

Results

The exposure-response function exhibited evidence of an increase in risk with increasing PM2.5 concentrations, where the rate of risk increase gradually attenuated at higher PM2.5 concentrations. Globally, in 2017, there were 3 284 358.2 (95% UI 2 800 710.5 to 3 747 046.1) incident and 122 409 460.2 (108 142 312.2 to 136 424 137.9) prevalent cases of CKD attributable to PM2.5, and 6 593 134.6 (5 705 180.4 to 7 479 818.4) DALYs and 211 019.2 (184 292.5 to 236 520.4) deaths due to CKD attributable to PM2.5. The burden was disproportionately borne by low income and lower middle income countries and exhibited substantial geographic variability, even among countries with similar levels of sociodemographic development. Globally, 72.8% of prevalent cases of CKD attributable to PM2.5 and 74.2% of DALYs due to CKD attributable to PM2.5 were due to concentrations above 10 µg/m3, the WHO air quality guidelines.

Conclusion

The global burden of CKD attributable to PM2.5 is substantial, varies by geography and is disproportionally borne by disadvantaged countries. Most of the burden is associated with PM2.5 levels above the WHO guidelines, suggesting that achieving those targets may yield reduction in CKD burden.

Children of a lesser god: exclusion of chronic kidney disease patients from clinical trials

The exclusion of chronic kidney disease (CKD) patients from clinical trials-particularly cardiovascular trials-remains a long-standing, unsolved problem, which prevents the optimization of clinical care in these patients. The situation recalls the insufficient recruitment of women in cardiovascular trials until the 1980s, a problem that was only resolved following regulatory interventions. Regulatory agencies are in a unique position to promote recruitment of CKD patients in clinical trials. The main stakeholders, namely patients' associations and scientific societies, should make major lobbying efforts to persuade these agencies that the issue is an absolute public health priority.

Comparison of Renal Effects of Ezetimibe-Statin Combination versus Statin Monotherapy: A Propensity-Score-Matched Analysis

Neither lowering of blood lipid levels nor treatment with statins definitively improves renal outcomes. Ezetimibe, a non-statin antilipidemic agent, is known to not only decrease blood lipid levels but also reduce inflammatory response and activate autophagy. We evaluated the effect of adding ezetimibe to a statin on renal outcome compared with statin monotherapy by analyzing longitudinal data of 4537 patients treated with simvastatin 20 mg plus ezetimibe 10 mg (S + E) or simvastatin 20 mg alone (S) for more than 180 days. A propensity-score-based process was used to match baseline characteristics, medical history, and estimated glomerular filtration rate (eGFR) between S + E and S groups. Changes in serum creatinine and incidence of renal events, defined as doubling of serum creatinine to ≥1.5 mg/dL or occurrence of end-stage renal disease after the first day of treatment initiation, were compared between the groups. Among 3104 well-matched patients with a median follow-up of 4.2 years, the S + E group showed a significantly lower risk of renal events than the S group (hazard ratio 0.58; 95% CI 0.35-0.95, P = 0.032). In addition, the S + E group tended to preserve renal function compared with the S group throughout follow-up, as assessed by serum creatinine changes (P-values for time-group interactions <0.001). These data support the beneficial effects on renal function when combining ezetimibe with a statin.

Preventing CKD in Developed Countries

Chronic kidney disease (CKD) is an important public health concern in developed countries because of both the number of people affected and the high cost of care when prevention strategies are not effectively implemented. Prevention should start at the governance level with the institution of multisectoral polices supporting sustainable development goals and ensuring safe and healthy environments. Primordial prevention of CKD can be achieved through implementation of measures to ensure healthy fetal (kidney) development. Public health strategies to prevent diabetes, hypertension, and obesity as risk factors for CKD are important. These approaches are cost-effective and reduce the overall noncommunicable disease burden. Strategies to prevent nontraditional CKD risk factors, including nephrotoxin exposure, kidney stones, infections, environmental exposures, and acute kidney injury (AKI), need to be tailored to local needs and epidemiology. Early diagnosis and treatment of CKD risk factors such as diabetes, obesity, and hypertension are key for primary prevention of CKD. CKD tends to occur more frequently and to progress more rapidly among indigenous, minority, and socioeconomically disadvantaged populations. Special attention is required to meet the CKD prevention needs of these populations. Effective secondary prevention of CKD relies on screening of individuals at risk to detect and treat CKD early, using established and emerging strategies. Within high-income countries, barriers to accessing effective CKD therapies must be recognized, and public health strategies must be developed to overcome these obstacles, including training and support at the primary care level to identify individuals at risk of CKD, and appropriately implement clinical practice guidelines.

Cardiovascular risk in mild to moderately decreased glomerular filtration rate, diabetes and coronary heart disease in a southern European region

INTRODUCTION AND OBJECTIVES

Individuals with mild to moderately decreased estimated glomerular filtration rate (eGFR=30-59 mL/min/1.73 m²) are considered at high risk of cardiovascular disease (CVD). No studies have compared this risk in eGFR=30-59, diabetes mellitus (DM), and coronary heart disease (CHD) in regions with a low incidence of CHD.

METHODS

We performed a retrospective cohort study of 122 443 individuals aged 60-84 years from a region with a low CHD incidence with creatinine measured between January 1, 2010 and December 31, 2011. We identified hospital admissions due to CHD (myocardial infarction, angina) or CVD (CHD, stroke, or transient ischemic attack) from electronic medical records up to December 31, 2013. We estimated incidence rates and Cox regression adjusted subdistribution hazard ratio (sHR) including competing risks in patients with eGFR=30-59, DM and CHD, or combinations, compared with individuals without these diseases.

RESULTS

The median follow-up was 38.3 [IQR, 33.8-42.7] months. Adjusted sHR for CHD in individuals with eGFR=30-59, DM, eGFR=30-59 plus DM, previous CHD, CHD plus DM, and CHD plus eGFR=30-59 plus DM, were 1.34 (95%CI, 1.04-1.74), 1.61 (95%CI, 1.36-1.90), 1.96 (95%CI, 1.42-2.70), 4.33 (95%CI, 3.58-5.25), 7.05 (5.80-8.58) and 7.72 (5.72-10.41), respectively. The corresponding sHR for CVD were 1.25 (95%CI, 1.06-1.46), 1.56 (95%CI, 1.41-1.74), 1.83 (95%CI, 1.50-2.23), 2.86 (95%CI, 2.48-3.29), 4.54 (95%CI, 3.93-5.24), and 5.33 (95%CI, 4.31-6.60).

CONCLUSIONS

In 60- to 84-year-olds with eGFR=30-59, similarly to DM, the likelihood of being admitted to hospital for CHD and CVD was about half that of individuals with established CHD. Thus, eGFR=30-59 does not appear to be a coronary-risk equivalent. Individuals with CHD and DM, or eGFR=30-59 plus DM, should be prioritized for more intensive risk management.

Global, regional, and national burden of chronic kidney disease, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout.

METHODS

The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function.

FINDINGS

Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, -1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, -1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function.

INTERPRETATION

Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI.

FUNDING

Bill & Melinda Gates Foundation.

Risk profile, quality of life and care of patients with moderate and advanced CKD: The French CKD-REIN Cohort Study

Background

The French Chronic Kidney Disease-Renal Epidemiology and Information Network (CKD-REIN) cohort study was designed to investigate the determinants of prognosis and care of patients referred to nephrologists with moderate and advanced chronic kidney disease (CKD). We examined their baseline risk profile and experience.

Methods

We collected bioclinical and patient-reported information from 3033 outpatients with CKD and estimated glomerular filtration rates (eGFRs) of 15-60 mL/min/1.73 m2 treated at 40 nationally representative public and private facilities.

Results

The patients' median age was 69 (60-76) years, 65% were men, their mean eGFR was 33 mL/min/1.73 m2, 43% had diabetes, 24% had a history of acute kidney injury (AKI) and 57% had uncontrolled blood pressure (BP; >140/90 mmHg). Men had worse risk profiles than women and were more likely to be past or current smokers (73% versus 34%) and have cardiovascular disease (59% versus 42%), albuminuria >30 mg/mmol (or proteinuria > 50) (40% versus 30%) (all P < 0.001) and a higher median risk of end-stage renal disease within 5 years, predicted by the kidney failure risk equation {12% [interquartile range (IQR) 3-37%] versus 9% [3-31%], P = 0.008}. During the previous year, 60% of patients reported one-to-two nephrologist visits and four or more general practitioner visits; only 25% saw a dietician and 75% were prescribed five or more medications daily. Physical and mental quality of life (QoL) were poor, with scores <50/100.

Conclusions

The CKD-REIN study highlights high-risk profiles of cohort members and identifies several priorities, including improving BP control and dietary counselling and increasing doctors' awareness of AKI, polypharmacy and QoL.

Trial registration

ClinicalTrials.gov identifier: NCT03381950.

Targeting the progression of chronic kidney disease

Chronic kidney disease (CKD) is a devastating condition that is reaching epidemic levels owing to the increasing prevalence of diabetes mellitus, hypertension and obesity, as well as ageing of the population. Regardless of the underlying aetiology, CKD is slowly progressive and leads to irreversible nephron loss, end-stage renal disease and/or premature death. Factors that contribute to CKD progression include parenchymal cell loss, chronic inflammation, fibrosis and reduced regenerative capacity of the kidney. Current therapies have limited effectiveness and only delay disease progression, underscoring the need to develop novel therapeutic approaches to either stop or reverse progression. Preclinical studies have identified several approaches that reduce fibrosis in experimental models, including targeting cytokines, transcription factors, developmental and signalling pathways and epigenetic modulators, particularly microRNAs. Some of these nephroprotective strategies are now being tested in clinical trials. Lessons learned from the failure of clinical studies of transforming growth factor β1 (TGFβ1) blockade underscore the need for alternative approaches to CKD therapy, as strategies that target a single pathogenic process may result in unexpected negative effects on simultaneously occurring processes. Additional promising avenues include preventing tubular cell injury and anti-fibrotic therapies that target activated myofibroblasts, the main collagen-producing cells.

Association Between Income Disparities and Risk of Chronic Kidney Disease: A Nationwide Cohort Study of Seven Million Adults in Korea

OBJECTIVE

To examine the association between income level and incident chronic kidney disease (CKD) in adults with normal baseline kidney function.

PATIENT AND METHODS

We studied the association between income level categorized into deciles and incident CKD in a national cohort comprised of 7,405,715 adults who underwent National Health Insurance Service health examinations during January 1, 2009, to December 31, 2015, with baseline estimated glomerular filtration rates (eGFRs) ≥60 mL/min/1.73 m². Incident CKD was defined as de novo development of eGFR <60 mL/min/1.73 m² (model 1) or ≥25% decline in eGFR from baseline values accompanied by eGFR <60 mL/min/1.73 m² (model 2).

RESULTS

During a median follow-up of 4.8 years, there were 122,032 of 7,405,715 (1.65%) and 55,779 of 7,405,715 (0.75%) incident CKD events based on model 1 and 2 definitions, respectively. Compared with income levels in the sixth decile, there was an inverse association between lower income level and higher risk for CKD up to the fourth decile, above which no additional reduction (model 1) or slightly higher risk for CKD (model 2) was observed at higher income levels. The multivariable-adjusted hazard ratios from the lowest to fourth deciles were 1.30 (95% CI, 1.26-1.33), 1.16 (95% CI, 1.13-1.19), 1.07 (95% CI, 1.05-1.10), and 1.06 (95% CI, 1.03-1.09) in model 1 and 1.32 (95% CI, 1.27-1.37), 1.18 (95% CI, 1.14-1.22), 1.08 (95% CI, 1.04-1.13), and 1.05 (95% CI, 1.01-1.09) in model 2, respectively. These associations persisted across various subgroups of age, sex, and comorbidity status.

CONCLUSION

In this large nationwide cohort, lower income levels were associated with higher risk for incident CKD.

Investigating associated factors with glomerular filtration rate: structural equation modeling

Background

Glomerular filtration rate (GFR) is a valid indicator of kidney function. Different factors can affect GFR. The purpose of this study is to assess the direct and indirect effects of GFR-related factors using structural equation modeling.

Patients and methods

We analyzed data from the baseline phase of the Ravansar Non-Communicable Disease cohort study. Data on socio-behavioral, nutritional, cardiovascular, and metabolic risk factors were analyzed using a conceptual model in order to test direct and indirect effects of factors related to GFR, separately in male and female, using the structural equation modeling.

Results

Of 8927 individuals who participated in this study, 4212 subjects were male (47.20%). The mean and standard deviation of GFR was 76.05 (±14.31) per 1.73 m². GFR for 0.2, 11.3, 73.0 and 15.5% of people were < 30, 30 − 59, 60 − 90 and >90, respectively. Hypertension and aging in both sexes and atherogenic factor in males directly, and in females, directly and indirectly, had decreasing effects on GFR. Blood urea nitrogen and smoking in male and female, directly or indirectly through other variables, were associated with a lower GFR. In females, diabetes had a direct and indirect decreasing effect on GFR. Obesity in females was directly associated with upper and indirectly associated with lower GFR.

Conclusion

According to our results, aging, hypertension, diabetes, obesity, high lipid profile, and BUN had a decreasing direct and indirect effect on GFR. Although low GFR might have different reasons, our findings, are in line with other reports and provide more detailed information about important risk factors of low GFR. Public awareness of such factors can improve practice of positive health behaviors.

Serum lipoprotein(a) and risk of mortality in patients on peritoneal dialysis

BACKGROUND

Elevated serum lipoprotein(a) [Lp(a)] level is an independent risk factor for atherosclerotic diseases in the general population and hemodialysis patients. However, the association between Lp(a) levels and mortality has received little attention in peritoneal dialysis (PD) patients.

OBJECTIVE

The objective of the study was to evaluate the association of Lp(a) levels with all-cause and cardiovascular (CV) mortality in PD patients.

METHODS

This retrospective cohort study was conducted in PD patients enrolled from January 1, 2006 to December 31, 2015, and followed until December 31, 2018. Cox regression models were performed to assess the association of serum Lp(a) levels with all-cause and CV mortality in PD patients.

RESULTS

In total, 1492 incident PD patients were eligible for the study. During a median follow-up period of 45.1 months, 402 all-cause and 210 CV deaths occurred. Multivariate Cox regression analysis revealed that the first and third tertiles of Lp(a) levels were significantly associated with increased risk for all-cause mortality [hazard ratio (HR) = 1.33, 95% confidence interval (95% CI) = 1.01-1.75, P = .041; HR = 1.53, 95% CI = 1.18-1.98, P = .001, respectively] when compared with the second tertile, and the third tertile of Lp(a) level was independently associated with an 80% increased risk of CV mortality (HR = 1.80, 95% CI = 1.26-2.56, P = .001). Moreover, our results showed that the HRs per log unit higher Lp(a) level for all-cause and CV mortality were 1.53 (95% CI = 1.05-2.22, P = .027) and 2.41 (95% CI = 1.44-4.03, P < .001), respectively.

CONCLUSIONS

Our results suggest that both low and high serum Lp(a) levels are risk markers for all-cause death, but only a higher baseline serum Lp(a) level is an independent risk factor for CV mortality in PD patients.

Decreased eGFR Is Associated With Ischemic Stroke in Patients With Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is increasingly indicated as a cause of cardioembolic syndrome, in particular, cardioembolic ischemia stroke. However, the potential risk factors for stroke among DCM patients remain under investigated. DCM patients hospitalized from June 2011 to June 2016 were included. The cases were defined as the group of DCM patients with stroke compared with those without stroke. Clinical characteristic data were collected and compared between the two groups including demographic data, complicated diseases, echocardiography index, and laboratory parameters and estimated glomerular filtration rate (eGFR). A multivariate logistic regression analysis model adjusted by sex and age was used to explore the related risk factors for stroke in DCM patients. A total of 779 hospitalized patients with DCM were included. Of these, 55 (7.1%) had experienced a stroke. Significantly lower eGFR levels (68.03 ± 26.22 vs 79.88 ± 24.25 mL/min/1.73 m², P = .001) and larger left atrial diameters (45.32 ± 7.79 vs 43.25 ± 7.11 mm, P = .04) were found in the group of patients having DCM with stroke compared to those without stroke. When the eGFR was categorized as eGFR >60, 30<eGFR≤ 60 and eGFR ≤ 30, there were more patients with 30<eGFR≤ 60 (30.9% vs 17.7%) and eGFR≤ 30 (9.1% vs 3.3%) in the ischemic stroke group (P = 0.003). A multivariate logistic regression analysis model adjusted by sex and age showed that 30 <eGFR≤60 (odds ratio [OR]: 2.07, 95% confidence interval [CI]: [1.05-4.07], P = .035) and eGFR≤30 (OR: 4.04, 95% CI: [1.41-11.62], P = .009) were statistically associated with ischemic stroke in patients with DCM. It is concluded that decreased eGFR is significantly associated with an increased risk of ischemic stroke in patients with DCM.

Un nuevo paradigma en el fracaso renal agudo

El fracaso renal agudo es una de las patologías con las que más ha avanzado el conocimiento médico y, sin embargo, menos se ha modificado el tratamiento o el pronóstico. Con un crecimiento anual de un 25%, el fracaso renal afecta a más de trece millones de personas en el mundo cada año. Cuando aparece en un paciente hospitalizado por otro motivo, aumenta la duración de la estancia media en casi cuatro días. La mortalidad por fracaso renal agudo es mayor que la mortalidad combinada por cáncer de mama, cáncer de próstata, insuficiencia cardíaca y diabetes. Varios factores pueden estar contribuyendo a esta epidemia mundial que afecta por igual, aunque por distintas causas, a los países del primer mundo tanto como a los subdesarrollados. - El envejecimiento de la población. - La aparición de gérmenes más agresivos y resistentes que requieren tratamientos más nefrotóxicos. - El aumento de la fragilidad en los pacientes seleccionados para tratamientos quirúrgicos, oncológicos y antibióticos cada vez más exigentes. - El aumento de prevalencia de enfermedades crónicas con un riesgo cardiovascular progresivamente mayor y proporcional al nivel de inflamación.

Unraveling Cardiovascular Risk in Renal Patients: A New Take on Old Tale

Chronic kidney disease (CKD), defined by an estimated glomerular filtration rate <60 ml/min/1.73 m² and/or an increase in urine protein excretion (i.e., albuminuria), is an important public health problem. Prevalence and incidence of CKD have risen by 87 and 89%, worldwide, over the last three decades. The onset of either albuminuria and eGFR reduction has found to predict higher cardiovascular (CV) risk, being this association strong, independent from traditional CV risk factors and reproducible across different setting of patients. Indeed, this relationship is present not only in high risk cohorts of CKD patients under regular nephrology care and in those with hypertension or type 2 diabetes, but also in general, otherwise healthy population. As underlying mechanisms of damage, it has hypothesized and partially proved that eGFR reduction and albuminuria can directly promote endothelial dysfunction, accelerate atherosclerosis and the deleterious effects of hypertension. Moreover, the predictive accuracy of risk prediction models was consistently improved when eGFR and albuminuria have been added to the traditional CV risk factors (i.e., Framingham risk score). These important findings led to consider CKD as an equivalent CV risk. Although it is hard to accept this definition in absence of additional reports from scientific Literature, a great effort has been done to reduce the CV risk in CKD patients. A large number of clinical trials have tested the effect of drugs on CV risk reduction. The targets used in these trials were different, including blood pressure, lipids, albuminuria, inflammation, and glucose. All these trials have determined an overall better control of CV risk, performed by clinicians. However, a non-negligible residual risk is still present and has been attributed to: (1) missed response to study treatment in a consistent portion of patients, (2) role of many CV risk factors in CKD patients not yet completely investigated. These combined observations provide a strong argument that kidney measures should be regularly included in individual prediction models for improving CV risk stratification. Further studies are needed to identify high risk patients and novel therapeutic targets to improve CV protection in CKD patients.

METTL14-dependent m6A regulates vascular calcification induced by indoxyl sulfate

AIMS

Although the functional importance of N6-methyladenosine (m6A) in various fundamental bioprocesses are well known, its effect on vascular calcification is not well studied. We investigated the role of methyltransferase-like 14 (METTL14), an m6A methylase, in vascular calcification.

MAIN METHODS

We used clinical human samples as well as rat models and primary human artery smooth muscle cell (HASMC) cultures to study the functional role of m6A and METTL14 in vascular calcification and in HASMCs. We modulated the expression of METTL14 using siRNAs (in vitro) to study its function in regulating HASMCs m6A, osteoblasts induced by indoxyl sulfate. We performed the MeRIP-qPCR assays to map and validate m6A in individual transcripts, controls, and calcific HASMCs.

KEY FINDINGS

We discovered that the METTL14 expression increases in calcific arteries and in HASMCs induced by indoxyl sulfate, thereby increasing the m6A level in RNA and decreasing the vascular repair function. Decreasing the expression of METTL14 in calcified arteries attenuated the indoxyl sulfate-induced increase in m6A and decrease in HASMCs calcification. We performed the methylation activity of METTL14, which selectively methylates vascular osteogenic transcripts, thereby promoting their degradation and improving their protein expression induced by indoxyl sulfate. Moreover, we demonstrated that the METTL14 de-expression in HASMCs models of calcification decreased the calcification and enhanced the vascular repair function.

SIGNIFICANCE

Collectively, our results demonstrated the functional importance of METTL14-dependent vascular m6A methylome in vascular functions during calcification and provided a novel mechanistic insight to the therapeutic mechanisms of METTL14.

Status of care for end stage kidney disease in countries and regions worldwide: international cross sectional survey

OBJECTIVE

To determine the global capacity (availability, accessibility, quality, and affordability) to deliver kidney replacement therapy (dialysis and transplantation) and conservative kidney management.

DESIGN

International cross sectional survey.

SETTING

International Society of Nephrology (ISN) survey of 182 countries from July to September 2018.

PARTICIPANTS

Key stakeholders identified by ISN's national and regional leaders.

MAIN OUTCOME MEASURES

Markers of national capacity to deliver core components of kidney replacement therapy and conservative kidney management.

RESULTS

Responses were received from 160 (87.9%) of 182 countries, comprising 97.8% (7338.5 million of 7501.3 million) of the world's population. A wide variation was found in capacity and structures for kidney replacement therapy and conservative kidney management-namely, funding mechanisms, health workforce, service delivery, and available technologies. Information on the prevalence of treated end stage kidney disease was available in 91 (42%) of 218 countries worldwide. Estimates varied more than 800-fold from 4 to 3392 per million population. Rwanda was the only low income country to report data on the prevalence of treated disease; 5 (<10%) of 53 African countries reported these data. Of 159 countries, 102 (64%) provided public funding for kidney replacement therapy. Sixty eight (43%) of 159 countries charged no fees at the point of care delivery and 34 (21%) made some charge. Haemodialysis was reported as available in 156 (100%) of 156 countries, peritoneal dialysis in 119 (76%) of 156 countries, and kidney transplantation in 114 (74%) of 155 countries. Dialysis and kidney transplantation were available to more than 50% of patients in only 108 (70%) and 45 (29%) of 154 countries that offered these services, respectively. Conservative kidney management was available in 124 (81%) of 154 countries. Worldwide, the median number of nephrologists was 9.96 per million population, which varied with income level.

CONCLUSIONS

These comprehensive data show the capacity of countries (including low income countries) to provide optimal care for patients with end stage kidney disease. They demonstrate substantial variability in the burden of such disease and capacity for kidney replacement therapy and conservative kidney management, which have implications for policy.

CKD: A Call for an Age-Adapted Definition

Current criteria for the diagnosis of CKD in adults include persistent signs of kidney damage, such as increased urine albumin-to-creatinine ratio or a GFR below the threshold of 60 ml/min per 1.73 m2 This threshold has important caveats because it does not separate kidney disease from kidney aging, and therefore does not hold for all ages. In an extensive review of the literature, we found that GFR declines with healthy aging without any overt signs of compensation (such as elevated single-nephron GFR) or kidney damage. Older living kidney donors, who are carefully selected based on good health, have a lower predonation GFR compared with younger donors. Furthermore, the results from the large meta-analyses conducted by the CKD Prognosis Consortium and from numerous other studies indicate that the GFR threshold above which the risk of mortality is increased is not consistent across all ages. Among younger persons, mortality is increased at GFR <75 ml/min per 1.73 m2, whereas in elderly people it is increased at levels <45 ml/min per 1.73 m2 Therefore, we suggest that amending the CKD definition to include age-specific thresholds for GFR. The implications of an updated definition are far reaching. Having fewer healthy elderly individuals diagnosed with CKD could help reduce inappropriate care and its associated adverse effects. Global prevalence estimates for CKD would be substantially reduced. Also, using an age-specific threshold for younger persons might lead to earlier identification of CKD onset for such individuals, at a point when progressive kidney damage may still be preventable.

A collaborative, individual-level analysis compared longitudinal outcomes across the International Network of Chronic Kidney Disease (iNETCKD) cohorts

Rates of chronic kidney disease (CKD) progression, end stage kidney disease (ESKD), all-cause mortality, and cardiovascular (CVD) events among individuals with CKD vary widely across countries. Well-characterized demographic, comorbidity, and laboratory markers captured for prospective cohorts may explain, in part, such differences. To investigate whether core characteristics of individuals with CKD explain differences in rates of outcomes, we conducted an individual-level analysis of eight studies that are part of iNET-CKD, an international network of CKD cohort studies. Overall, the rate of CKD progression was 40 events/1000 person-year (95% confidence interval 39 - 41), 28 (27 - 29) for ESKD, 41 (40 - 42) for death, and 29 (28 - 30) for CVD events. However, standardized rates were highly heterogeneous across studies (over 92.5%). Interactions by study group on the association between baseline characteristics and outcomes were then identified. For example, the adjusted hazard ratio for CKD progression was 0.44 (95% confidence interval 0.35 - 0.56) for women vs. men among the Japanese (CKD-JAC), while it was 0.66 (0.59 - 0.75) among the Uruguayan (NRHP). The adjusted hazard ratio for ESKD was 2.02 (95% CI 1.88 - 2.17) per 10 units lower baseline eGFR among Americans (CRIC), while it was 3.01 (2.57 - 3.53) among Canadians (CanPREDDICT) (significant interaction for comparisons across all studies). The risks of CKD progression, ESKD, death, and CVD vary across countries even after accounting for the distributions of age, sex, comorbidities, and laboratory markers. Thus, our findings support the need for a better understanding of specific factors in different populations that explain this variation.

Bardoxolone methyl analog attenuates proteinuria-induced tubular damage by modulating mitochondrial function

Multiple clinical studies have shown that bardoxolone methyl, a potent activator of nuclear factor erythroid 2–related factor 2 (Nrf2), is effective in increasing glomerular filtration rate in patients with chronic kidney disease. However, whether an Nrf2 activator can protect tubules from proteinuria-induced tubular damage via anti-inflammatory and antioxidative stress mechanisms is unknown. Using an Institute of Cancer Research–derived glomerulonephritis (ICGN) mouse model of nephrosis, we examined the effects of dihydro-CDDO-trifluoroethyl amide (dh404), a rodent-tolerable bardoxolone methyl analog, in protecting the tubulointerstitium; dh404 markedly suppressed tubular epithelial cell damage in the renal interstitium of ICGN mice. The tubular epithelial cells of ICGN mice showed a decrease in the size and number of mitochondria, as well as the breakdown of the crista structure, whereas the number and ultrastructure of mitochondria were maintained by the dh404 treatment. To further determine the effect of dh404 on mitochondrial function, we used human proximal tubular cells in vitro. Stimulation with albumin and free fatty acid increased mitochondrial reactive oxygen species (ROS). However, dh404 administration diminished mitochondrial ROS. Our data show that dh404 significantly reduced proteinuria-induced tubular cell mitochondrial damage, suggesting that improved redox balance and mitochondrial function and suppression of inflammation underlie the cytoprotective mechanism of Nrf2 activators, including bardoxolone methyl, in diabetic kidney disease.—Nagasu, H., Sogawa, Y., Kidokoro, K., Itano, S., Yamamoto, T., Satoh, M., Sasaki, T., Suzuki, T., Yamamoto, M., Wigley, W. C., Proksch, J. W., Meyer, C. J., Kashihara, N. Bardoxolone methyl analog attenuates proteinuria-induced tubular damage by modulating mitochondrial function.

Primary care physicians' perceptions of barriers and facilitators to management of chronic kidney disease: A mixed methods study

BACKGROUND

Given the high prevalence of chronic kidney disease (CKD), primary care physicians (PCPs) frequently manage early stage CKD. Nonetheless, there are challenges in providing optimal CKD care in the primary care setting. This study sought to understand PCPs' perceptions of barriers and facilitators to the optimal management of CKD.

STUDY DESIGN

Mixed methods study.

SETTINGS AND PARTICIPANTS

Community-based PCPs in four US cities: Baltimore, MD; St. Louis, MO; Raleigh, NC and San Francisco, CA.

METHODOLOGY

We used a self-administered questionnaire and conducted 4 focus groups of PCPs (n = 8 PCPs/focus group) in each city to identify key barriers and facilitators to management of patients with CKD in primary care.

ANALYTIC APPROACH

We conducted descriptive analyses of the survey data. Major themes were identified from audio-recorded interviews that were transcribed and coded by the research team.

RESULTS

Of 32 participating PCPs, 31 (97%) had been in practice for >10 years, and 29 (91%) practiced in a non-academic setting. PCPs identified multiple barriers to managing CKD in primary care including at the level of the patient (e.g., low awareness of CKD, poor adherence to treatment recommendations), the provider (e.g., staying current with CKD guidelines), and the health care system (e.g., inflexible electronic medical record, limited time and resources). PCPs desired electronic prompts and lab decision support, concise guidelines, and healthcare financing reform to improve CKD care.

CONCLUSIONS

PCPs face substantial but modifiable barriers in providing care to patients with CKD. Interventions that address these barriers and promote facilitative tools may improve PCPs' effectiveness and capacity to care for patients with CKD.

Ghrelin-mediated pathway in Apolipoprotein-E deficient mice: a survival system

Renal diseases interfere with the regulation of several metabolic pathways including dyslipidemia. The latter includes increased triglycerides, very low-density lipoprotein levels and decreased high-density lipoproteins. These lipoproteins change during renal injury. Apolipoprotein-E deficient mice (ApoE-/-) are considered a very well accepted model of hypercholesterolemia with marked renal pathological alterations. Ghrelin hormone is mainly secreted from the stomach when the stomach is empty, but it is also found in the kidney. In this organ it has autocrine and/or paracrine roles determining glomerular filtration rate, tubular phosphate and sodium reabsorption. Interestingly, it has been demonstrated that ghrelin levels increase after fasting. This mechanism induces an interaction with sirtuin 1 (SIRT1)/p53 pathway suggesting a link between ghrelin and SIRT1 in the regulation of salt and water metabolism. The mechanisms of ghrelin-induced SIRT1 expression are not yet fully understood. Recent studies indicate that SIRT1 exerts renoprotective properties against kidney diseases. This could be a very interesting point for underlining the important role of the ghrelin-SIRT1 system. Water movement across biological cell membranes is enhanced or facilitated by tetrameric membrane-bound channels, named aquaporin (AQP) family, and in particular, AQP1 and AQP2 proteins. In this study, we evaluated the possible pathway existing among the ghrelin/SIRT1/AQP1/AQP2 system in APOE-/- mice in order to clarify or stress the role played by said system in renal diseases associated to aging with or without comorbities. The results could provide a basis for considering ghrelin as a new target for therapeutic strategies of renal injury.

Development of a mortality score to assess risk of adverse drug reactions among hospitalized patients with moderate to severe chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a significant health burden that increases the risk of adverse events. Currently, there is no validated models to predict risk of mortality among CKD patients experienced adverse drug reactions (ADRs) during hospitalization. This study aimed to develop a mortality risk prediction model among hospitalized CKD patients whom experienced ADRs.

METHODS

Patients data with CKD stages 3-5 admitted at various wards were included in the model development. The data collected included demographic characteristics, comorbid conditions, laboratory tests and types of medicines taken. Sequential series of logistic regression models using mortality as the dependent variable were developed. Bootstrapping method was used to evaluate the model's internal validation. Variables odd ratio (OR) of the best model were used to calculate the predictive capacity of the risk scores using the area under the curve (AUC).

RESULTS

The best prediction model included comorbidities heart disease, dyslipidaemia and electrolyte imbalance; psychotic agents; creatinine kinase; number of total medication use; and conservative management (Hosmer and Lemeshow test =0.643). Model performance was relatively modest (R square = 0.399) and AUC which determines the risk score's ability to predict mortality associated with ADRs was 0.789 (95% CI, 0.700-0.878). Creatinine kinase, followed by psychotic agents and electrolyte disorder, was most strongly associated with mortality after ADRs during hospitalization. This model correctly predicts 71.4% of all mortality pertaining to ADRs (sensitivity) and with specificity of 77.3%.

CONCLUSION

Mortality prediction model among hospitalized stages 3 to 5 CKD patients experienced ADR was developed in this study. This prediction model adds new knowledge to the healthcare system despite its modest performance coupled with its high sensitivity and specificity. This tool is clinically useful and effective in identifying potential CKD patients at high risk of ADR-related mortality during hospitalization using routinely performed clinical data.

Nephrologists' perspectives on ambulatory care of patients with non-dialysis chronic kidney disease - A qualitative study

Little is known on the perspectives of nephrologists on managing non-dialysis patients with chronic kidney disease (CKD). The purpose of this qualitative study was to explore the experiences and perspectives of nephrologists regarding the interface with general practitioners (GP) and GPs' management of patients with non-dialysis CKD, so that barriers to cooperation and need for improved management can be identified. Twenty semi-structured interviews were conducted for this qualitative study. The interviews were audio-recorded and coded to be analysed. The concept of knowledge systems served as a sensitising concept. Optimising underlying diseases, medication adaptation and patient awareness of CKD were regarded as the most important treatment measures in CKD management. Differing views exist on who should be responsible for lifestyle interventions, patient education and timing of referral. Nephrologists generally preferred the referral of patients with high progression risk and co-treatment models in which daily care was performed by GP, but some preferred referral of all patients with early CKD and some nephrologists stated that patient care should be in the hands of nephrologists entirely in case of CKD. Doctor-patient communication predominantly remained within the medical-scientific knowledge system whereas patients' everyday knowledge systems were rarely considered. While stressing optimisation of laboratory values, diabetes and hypertension, patients' perspectives and shared decision-making to identify and prioritise patients' individual health goals were rarely considered by nephrologists. Instead, most nephrologists regarded educating patients and GPs as an important part of their professional role. Defining the interface between GPs and nephrologists, with specific recommendations on when to refer and which tasks each professional group should perform can lead to standardisation and improved interdisciplinary management of CKD patients. Addressing patients' everyday knowledge systems can be valuable in formulating and prioritising health goals with patients.

Association of systolic blood pressure and pulse pressure with microalbuminuria in treatment-naïve hypertensive patients

INTRODUCTION

To investigate the association between blood pressure components and microalbuminuria (MAU) in newly diagnosed and treatment-naïve hypertensive patients.

MATERIAL AND METHODS

A total of 1858 newly diagnosed and treatment-naïve hypertensive patients were enrolled. Based on 24 h urine albumin concentration, all patients were divided into MAU and normo-albuminuria groups. The associations between blood pressure (BP) components, namely systolic/diastolic BP (SBP/DBP) and pulse pressure (PP) and MAU, as well as the sensitivity and specificity of each BP component in predicting MAU, were evaluated.

RESULTS

Compared to the normo-albuminuria group, patients in the MAU group were older and had significantly higher SBP and PP (p < 0.05). Serum levels of fasting blood glucose, total protein and creatinine were significantly higher in the MAU group (p < 0.05). 24-hour urine albumin excretion was significantly higher in the MAU group than the normo-albuminuria group (182.5 ±156.5 mg vs. 17.6 ±7.1 mg, p < 0.001). Logistic regression analyses revealed that SBP and PP were significantly associated with MAU, with an odds ratio (OR) of 1.010 (95% confidence interval (CI): 1.005-1.016, p < 0.001) in SBP and OR of 1.009 (95% CI: 1.003-1.015, p = 0.003) in PP. The receiver operating characteristic curve showed that the area under the curve for SBP to predict MAU was 0.541 ±0.013, and PP was 0.536 ±0.013. The difference in predicting MAU by SBP or PP was non-significant.

CONCLUSIONS

In newly diagnosed and treatment-naïve hypertensive patients, increased SBP and PP were independently associated with MAU.

Identification of dicarbonyl and L-xylulose reductase as a therapeutic target in human chronic kidney disease

An imbalance of nephroprotective factors and renal damaging molecules contributes to development and progression of chronic kidney disease (CKD). We investigated associations of renoprotective factor gene expression patterns with CKD severity and outcome. Gene expression profiles of 197 previously reported renoprotective factors were analyzed in a discovery cohort in renal biopsies of 63 CKD patients. Downregulation of dicarbonyl and L-xylulose reductase (DCXR) showed the strongest association with disease progression. This significant association was validated in an independent set of 225 patients with nephrotic syndrome from the multicenter NEPTUNE cohort. Reduced expression of DCXR was significantly associated with degree of histological damage as well as with lower estimated glomerular filtration rate and increased urinary protein levels. DCXR downregulation in CKD was confirmed in 3 publicly available transcriptomics data sets in the context of CKD. Expression of DCXR showed positive correlations to enzymes that are involved in dicarbonyl stress detoxification based on transcriptomics profiles. The sodium glucose cotransporter-2 (SGLT2) inhibitors canagliflozin and empagliflozin showed a beneficial effect on renal proximal tubular cells under diabetic stimuli-enhanced DCXR gene expression. In summary, lower expression of the renoprotective factor DCXR in renal tissue is associated with more severe disease and worse outcome in human CKD.

MAP3K kinases and kidney injury

Mitogen-activated protein kinases (MAP kinases) are functionally connected kinases that regulate key cellular process involved in kidney disease such as all survival, death, differentiation and proliferation. The typical MAP kinase module is composed by a cascade of three kinases: a MAP kinase kinase kinase (MAP3K) that phosphorylates and activates a MAP kinase kinase (MAP2K) which phosphorylates a MAP kinase (MAPK). While the role of MAPKs such as ERK, p38 and JNK has been well characterized in experimental kidney injury, much less is known about the apical kinases in the cascade, the MAP3Ks. There are 24 characterized MAP3K (MAP3K1 to MAP3K21 plus RAF1, BRAF and ARAF). We now review current knowledge on the involvement of MAP3K in non-malignant kidney disease and the therapeutic tools available. There is in vivo interventional evidence clearly supporting a role for MAP3K5 (ASK1) and MAP3K14 (NIK) in the pathogenesis of experimental kidney disease. Indeed, the ASK1 inhibitor Selonsertib has undergone clinical trials for diabetic kidney disease. Additionally, although MAP3K7 (MEKK7, TAK1) is required for kidney development, acutely targeting MAP3K7 protected from acute and chronic kidney injury; and targeting MAP3K8 (TPL2/Cot) protected from acute kidney injury. By contrast MAP3K15 (ASK3) may protect from hypertension and BRAF inhibitors in clinical use may induced acute kidney injury and nephrotic syndrome. Given their role as upstream regulators of intracellular signaling, MAP3K are potential therapeutic targets in kidney injury, as demonstrated for some of them. However, the role of most MAP3K in kidney disease remains unexplored.

A Systematic Review and Meta-analysis of Nonpharmacologic-based Interventions for Aortic Stiffness in End-Stage Renal Disease

Introduction

Increased carotid-femoral pulse wave velocity (cf-PWV) in end-stage renal disease (ESRD) indicates enhanced aortic stiffness and mortality risk. We conducted a systematic review and meta-analysis of nonpharmacologic interventions in adults with ESRD to determine their effects on cf-PWV, systolic blood pressure (SBP), and intervention-associated adverse events.

Methods

MEDLINE, EMBASE, and EBM databases were searched. Study screening, selection, data collection, and methodological quality assessments were performed by 2 independent reviewers. Pooled-effect estimates from mean differences and 95% confidence intervals (CIs) were calculated using random effect models.

Results

A total of 2166 subjects with ESRD from 33 studies (17 randomized; 16 nonrandomized) were included. Four intervention-comparator pairs were meta-analyzed. Quality of evidence ranged from very low to moderate. Kidney transplantation decreased cf-PWV (−0.70 m/s; CI: –1.3 to −0.11; P = 0.02) and SBP (−8.3 mm Hg; CI: −13.2 to −3.3; P < 0.001) over pretransplantation. In randomized trials, control of fluid overload by bio-impedance reduced cf-PWV (−1.90 m/s; CI: −3.3 to −0.5); P = 0.02) and SBP (−4.3 mm Hg; CI: −7.7 to −0.93); P = 0.01) compared with clinical assessment alone. Cross-sectional studies also demonstrated significantly lower cf-PWV and SBP in normovolemia compared with hypervolemia (P ≤ 0.01). Low calcium dialysate decreased cf-PWV (−1.70 m/s; CI: −2.4 to −1.0; P < 0.00001) without affecting SBP (−1.6 mm Hg; CI: −8.9 to 5.8; P = 0.61). Intradialytic exercise compared with no exercise reduced cf-PWV (−1.13 m/s; CI: −2.2 to −0.03; P = 0.04), but not SBP (+0.5 mm Hg; CI: −9.5 to 10.4); P = 0.93).

Conclusions

Several nonpharmacologic interventions effectively decrease aortic stiffness in ESRD. The impact of these interventions on cardiovascular outcomes and mortality risk reduction in ESRD requires further study.

Estimates of the 2016 global burden of kidney disease attributable to ambient fine particulate matter air pollution

OBJECTIVE

To quantitate the 2016 global and national burden of chronic kidney disease (CKD) attributable to ambient fine particulate matter air pollution ≤ 2.5 μm in aerodynamic diameter (PM_2.5).

DESIGN

We used the Global Burden of Disease (GBD) study data and methodologies to estimate the 2016 burden of CKD attributable to PM_2.5 in 194 countries and territories. Population-weighted PM_2.5 levels and incident rates of CKD for each country were curated from the GBD study publicly available data sources.

SETTING

GBD global and national data on PM_2.5 and CKD.

PARTICIPANTS

194 countries and territories.

MAIN OUTCOME MEASURES

We estimated the attributable burden of disease (ABD), years living with disability (YLD), years of life lost (YLL) and disability-adjusted life-years (DALYs).

RESULTS

The 2016 global burden of incident CKD attributable to PM_2.5 was 6 950 514 (95% uncertainty interval: 5 061 533-8 914 745). Global YLD, YLL and DALYs of CKD attributable to PM_2.5 were 2 849 311 (1 875 219-3 983 941), 8 587 735 (6 355 784-10 772 239) and 11 445 397 (8 380 246-14 554 091), respectively. Age-standardised ABD, YLL, YLD and DALY rates varied substantially among geographies. Populations in Mesoamerica, Northern Africa, several countries in the Eastern Mediterranean region, Afghanistan, Pakistan, India and several countries in Southeast Asia were among those with highest age-standardised DALY rates. For example, age-standardised DALYs per 100 000 were 543.35 (391.16-707.96) in El Salvador, 455.29 (332.51-577.97) in Mexico, 408.41 (283.82-551.84) in Guatemala, 238.25 (173.90-303.98) in India and 178.26 (125.31-238.47) in Sri Lanka, compared with 5.52 (0.82-11.48) in Sweden, 6.46 (0.00-14.49) in Australia and 12.13 (4.95-21.82) in Canada. Frontier analyses showed that Mesoamerican countries had significantly higher CKD DALY rates relative to other countries with comparable sociodemographic development.

CONCLUSIONS

Our results demonstrate that the global toll of CKD attributable to ambient air pollution is significant and identify several endemic geographies where air pollution may be a significant driver of CKD burden. Air pollution may need to be considered in the discussion of the global epidemiology of CKD.

Periodontitis May Be Associated With Chronic Kidney Disease, but Evidence on Causal Association Is Limited

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

The directional and nondirectional associations of periodontitis with chronic kidney disease: A systematic review and meta-analysis of observational studies. Zhao D, Khawaja AT, Jin L, Li K-Y, Tonetti M, Pelekos G. J Perio Res 2018; 53(5):682-704.

SOURCE OF FUNDING

The authors' own institution, University of Hong Kong.

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis of data.

A Novel Metabolic Signature To Predict the Requirement of Dialysis or Renal Transplantation in Patients with Chronic Kidney Disease

Identification of chronic kidney disease patients at risk of progressing to end-stage renal disease (ESRD) is essential for treatment decision-making and clinical trial design. Here, we explored whether proton nuclear magnetic resonance (NMR) spectroscopy of blood plasma improves the currently best performing kidney failure risk equation, the so-called Tangri score. Our study cohort comprised 4640 participants from the German Chronic Kidney Disease (GCKD) study, of whom 185 (3.99%) progressed over a mean observation time of 3.70 ± 0.88 years to ESRD requiring either dialysis or transplantation. The original four-variable Tangri risk equation yielded a C statistic of 0.863 (95% CI, 0.831-0.900). Upon inclusion of NMR features by state-of-the-art machine learning methods, the C statistic improved to 0.875 (95% CI, 0.850-0.911), thereby outperforming the Tangri score in 94 out of 100 subsampling rounds. Of the 24 NMR features included in the model, creatinine, high-density lipoprotein, valine, acetyl groups of glycoproteins, and Ca²⁺-EDTA carried the highest weights. In conclusion, proton NMR-based plasma fingerprinting improved markedly the detection of patients at risk of developing ESRD, thus enabling enhanced patient treatment.

Chronic kidney disease and kidney health care status: the healthy life in Suriname (HeliSur) study

The high cardiovascular risk burden in low- and middle-income countries is expected to lead to an explosive increase in chronic kidney disease (CKD). However, population data on CKD from these countries are scarce. Therefore, we assessed kidney health in Suriname. In the Healthy Life in Suriname (HeliSur) study, a random sample of the adult population, we collected data with standardized questionnaires, physical examination, and blood and urine samples analysed in a central laboratory. Prevalent CKD was graded with KDIGO guidelines. In addition, we assessed national data on prevalent renal replacement therapy (RRT), estimated the future need for RRT, and evaluated national kidney health work force and policies. We include 1117 participants (2.0‰ of the population), 63% women, 40% of African ancestry and 43% of Asian ancestry, with a mean age of 42.2 (SE 0.4) years. Blood pressure is elevated in 72% of the participants, 26% have diabetes or prediabetes, and 78% are obese or overweight. The prevalence of CKD is 5.4%, and around 0.3% have kidney failure, translating to approximately 1500 patients nationally (2690 per million population, pmp), with currently 516 patients (920 pmp) on dialysis. Based on the participants from the random population sample in CKD stage G3 or G4, we estimate that 6750-10,750 pmp may develop kidney failure within the next 10 years. However, specialized kidney health workforce is currently very limited, and specific national or local policies for CKD management are lacking. Since the large majority of the general population has one or more risk factors for CKD including elevated blood pressure, urgent action is needed to strengthen kidney health care and prevent a catastrophic rise in need for RRT in the coming years.

Causes of death across categories of estimated glomerular filtration rate: The Stockholm CREAtinine Measurements (SCREAM) project

Introduction

Reduced kidney function increases the risk of death, but there is limited information on causes of death across stages of chronic kidney disease (CKD). We aimed to identify leading causes of death in community-dwelling individuals with differing kidney function.

Methods

Observational analysis from SCREAM, a healthcare utilization cohort of Stockholm, Sweden. We included all individuals who died during 2006–2012 and had one serum creatinine measured in the year prior to death. Using the CKD-EPI formula, we calculated eGFR and stratified individuals according to CKD stages. Causes of death were classified as cardiovascular (CVD), cancer, infection and other, using ICD-10 codes. We compared age- and sex-adjusted differences in the proportions of deaths from each cause.

Results

Out of 89,117 registered deaths, 70,547 (79%) had a recent eGFR estimation and were included in this study. Individuals had a median age of 82 (IRE 62–93) years and 52% were women. The proportions of deaths from CVD increased with lower eGFR, along with the proportion of deaths from infections. Deaths due to diabetes and genito-urinary diseases increased. Deaths due to cancer decreased, but other death causes did not vary. Within CVD causes of death, the proportion of arrhythmias and heart failure increased, but ischemic heart disease and cerebrovascular disease remained stable.

Conclusion

In a region-representative Swedish healthcare extraction, we observe differences regarding specific causes of death across different CKD stages. Increasing patient and provider awareness of this differential pattern of risk may have benefits for patient management, prevention strategies, and health service planning.

Home-Based Kidney Care, Patient Activation, and Risk Factors for CKD Progression in Zuni Indians: A Randomized, Controlled Clinical Trial

BACKGROUND AND OBJECTIVES

The burden of CKD is greater in ethnic and racial minorities and persons living in rural communities, where access to care is limited.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A 12-month clinical trial was performed in 98 rural adult Zuni Indians with CKD to examine the efficacy of a home-based kidney care program. Participants were randomized by household to receive usual care or home-based care. After initial lifestyle coaching, the intervention group received frequent additional reinforcement by community health representatives about adherence to medicines, diet and exercise, self-monitoring, and coping strategies for living with stress. The primary outcome was change in patient activation score, which assesses a participant's knowledge, skill, and confidence in managing his/her own health and health care.

RESULTS

Of 125 randomized individuals (63 intervention and 62 usual care), 98 (78%; 50 intervention and 48 usual care) completed the 12-month study. The average patient activation score after 12 months was 8.7 (95% confidence interval, 1.9 to 15.5) points higher in the intervention group than in the usual care group after adjusting for baseline score using linear models with generalized estimating equations. Participants randomized to the intervention had 4.8 (95% confidence interval, 1.4 to 16.7) times the odds of having a final activation level of at least three ("taking action") than those in the usual care group. Body mass index declined by 1.1 kg/m2 (P=0.01), hemoglobin A1c declined by 0.7% (P=0.01), high-sensitivity C-reactive protein declined by 3.3-fold (P<0.001), and the Short-Form 12 Health Survey mental score increased by five points (P=0.002) in the intervention group relative to usual care.

CONCLUSIONS

A home-based intervention improves participants' activation in their own health and health care, and it may reduce risk factors for CKD in a rural disadvantaged population.

Chronic Kidney Disease Severity Is Associated With Selective Expansion of a Distinctive Intermediate Monocyte Subpopulation

Chronic kidney disease (CKD) affects 11–13% of the world's population and greatly increases risk of atherosclerotic cardiovascular disease (ASCVD) and death. It is characterized by systemic inflammation and disturbances in the blood leukocytes that remain incompletely understood. In particular, abnormalities in the numbers and relative proportions of the three major monocyte subsets—classical, intermediate, and non-classical—are described in CKD and end-stage renal disease. In this study, we characterized absolute numbers of blood leukocyte subtypes in adults with renal function varying from normal to advanced CKD. The primary aim was to identify monocyte subpopulations that associated most closely with current estimated glomerular filtration rate (eGFR) and subsequent rate of eGFR decline. Leucocyte and monocyte populations were enumerated by multi-color flow cytometry of whole blood and peripheral blood mononuclear cell (PBMC) samples from adults with CKD stage 1–5 (n = 154) and healthy adults (n = 33). Multiple-linear regression analyses were performed to identify associations between numbers of leucocyte and monocyte populations and clinical characteristics including eGFR and rate of eGFR decline with adjustment for age and gender. In whole blood, total monocyte and neutrophil, but not lymphocyte, numbers were higher in adults with CKD 1-5 compared to no CKD and were significantly associated with current eGFR even following correction for age. In PBMC, classical and intermediate monocyte numbers were higher in CKD 1-5 but only intermediate monocyte numbers were significantly associated with current eGFR in an age-corrected analysis. When intermediate monocytes were further sub-divided into those with mid- and high-level expression of class II MHC (HLA-DR^mid and HLA-DR^hi intermediate monocytes) it was found that only DR^hi intermediate monocytes were increased in number in CKD 1-5 compared to no CKD and were significantly associated with eGFR independently of age among the total (No CKD + CKD 1-5) study cohort as well as those with established CKD (CKD 1-5 only). Furthermore, blood number of DR^hi intermediate monocytes alone proved to be significantly associated with subsequent rate of renal functional decline. Together, our data confirm neutrophil and monocyte subset dysregulation in CKD and identify a distinct subpopulation of intermediate monocytes that is associated with higher rate of loss of kidney function.

Effects of Cardiovascular Risk Factors on Cardiac STAT3

Nuclear, mitochondrial and cytoplasmic signal transducer and activator of transcription 3 (STAT3) regulates many cellular processes, e.g., the transcription or opening of mitochondrial permeability transition pore, and its activity depends on the phosphorylation of Tyr705 and/or Ser727 sites. In the heterogeneous network of cardiac cells, STAT3 promotes cardiac muscle differentiation, vascular element formation and extracellular matrix homeostasis. Overwhelming evidence suggests that STAT3 is beneficial for the heart, plays a role in the prevention of age-related and postpartum heart failure, protects the heart against cardiotoxic doxorubicin or ischaemia/reperfusion injury, and is involved in many cardioprotective strategies (e.g., ischaemic preconditioning, perconditioning, postconditioning, remote or pharmacological conditioning). Ischaemic heart disease is still the leading cause of death worldwide, and many cardiovascular risk factors contribute to the development of the disease. This review focuses on the effects of various cardiovascular risk factors (diabetes, aging, obesity, smoking, alcohol, depression, gender, comedications) on cardiac STAT3 under non-ischaemic baseline conditions, and in settings of ischaemia/reperfusion injury with or without cardioprotective strategies.