Clarifying the concept of chronic kidney disease for non-nephrologists

The Relationship of Fetuin-A with Coronary Calcification, Carotid Atherosclerosis, and Mortality Risk in Non-Dialysis Chronic Kidney Disease

Objective

This study investigated the relationship of fetuin-A with coronary calcification, carotid atherosclerosis, and mortality risk in non-dialysis chronic kidney disease (CKD).

Methods

The study included 135 adult patients with CKD at stages 3-5, who were divided into coronary artery calcification (CAC) and non-CAC groups. We excluded current smokers and individuals with diabetes mellitus, inflammatory conditions, liver diseases, acute kidney failure, chronic hemodialysis, and cancer. We conducted kidney function tests, complete blood counts, and measured serum levels of fetuin-A, tumor necrosis factor-alpha (TNF-α), high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), total cholesterol (TC), total triglycerides (TG), high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol. Cardiac spiral computed tomography was used to calculate the CAC score, employing the Agatston method. Carotid ultrasonography was performed to assess carotid intima-media thickness (CIMT) and to detect the presence of plaques.

Results

CAC patients had considerably higher levels of TNF-α (p<0.001), IL-6 (p<0.001), hs-CRP (p=0.006), TC, TG, parathyroid hormone (PTH) (p<0.001) and phosphorus (p<0.001) than non-CAC patients. They also had significantly lower levels of fetuin-A (p<0.001). Fetuin-A was considerably lower in CKD subgroups as CKD progressed. Fetuin-A (p=0.046), age (p=0.009), TNF-α (p=0.027), IL-6 (p=0.005), TG (p=0.002), PTH (p=0.002), and phosphorus (p=0.004) were significant predictors of CAC. CAC and fetuin-A were strong predictors of all-cause mortality and cardiovascular (CV) mortality. Fetuin-A was a significant predictor of CIMT (p=0.045).

Conclusion

Fetuin-A reliably predicted CAC and CIMT. Fetuin-A and CAC emerged as significant risk factors for all-cause and CV mortality in non-dialysis CKD.

Risk Prediction and Management of Chronic Kidney Disease in People Living with Type 2 Diabetes Mellitus

People with type 2 diabetes mellitus have increased risk of chronic kidney disease and atherosclerotic cardiovascular disease. Improved care delivery and implementation of guideline-directed medical therapy have contributed to the declining incidence of atherosclerotic cardiovascular disease in high-income countries. By contrast, the global incidence of chronic kidney disease and associated mortality is either plateaued or increased, leading to escalating direct and indirect medical costs. Given limited resources, better risk stratification approaches to identify people at risk of rapid progression to end-stage kidney disease can reduce therapeutic inertia, facilitate timely interventions and identify the need for early nephrologist referral. Among people with chronic kidney disease G3a and beyond, the kidney failure risk equations (KFRE) have been externally validated and outperformed other risk prediction models. The KFRE can also guide the timing of preparation for kidney replacement therapy with improved healthcare resources planning and may prevent multiple complications and premature mortality among people with chronic kidney disease with and without type 2 diabetes mellitus. The present review summarizes the evidence of KFRE to date and call for future research to validate and evaluate its impact on cardiovascular and mortality outcomes, as well as healthcare resource utilization in multiethnic populations and different healthcare settings.

Hemodialysis-induced chronodisruption and chronotype distribution in patients with chronic kidney disease

Changes in circadian rhythms have been observed in patients with chronic kidney disease (CKD), and evidence suggests that these changes can have a negative impact on health. This study aimed to investigate the existence of hemodialysis-induced chronodisruption, the chronotype distribution, and their association with sleep quality and quality of life (QoL). This was a cross-sectional study that enrolled 165 patients (mean age: 51.1 ± 12.5 y, 60.6% male) undergoing hemodialysis from three local units. The following instruments were used: the Morning-Eveningness Questionnaire (MEQ); a modified version of the Munich Chronotype Questionnaire (MCQT) to estimate hemodialysis-induced chronodisruption (HIC); the Kidney Disease QoL Short Form (KDQOL-SF); the Epworth Sleepiness Scale (ESS); the Pittsburgh Sleep Quality Index (PSQI) and the 10-Cognitive Screener (10-CS). HIC was present in 40.6% of CKD patients. Morning chronotype was prevalent in CKD patients (69%) compared to evening-type (17.1%) and significantly different from a paired sample from the general population (p < 0.001). HIC and chronotype were associated with different domains of QoL but not with sleep quality. This study suggests that there is a HIC and that morning chronotype is associated with CKD patients undergoing hemodialysis, with implications for QoL.

RIPK3 and kidney disease

Receptor interacting protein kinase 3 (RIPK3) is an intracellular kinase at the crossroads of cell death and inflammation. RIPK3 contains a RIP homotypic interaction motif (RHIM) domain which allows interactions with other RHIM-containing proteins and a kinase domain that allows phosphorylation of target proteins. RIPK3 may be activated through interaction with RHIM-containing proteins such as RIPK1, TRIF and DAI (ZBP1, DLM-1) or through RHIM-independent mechanisms in an alkaline intracellular pH. RIPK3 mediates necroptosis and promotes inflammation, independently of necroptosis, through either activation of NFκB or the inflammasome. There is in vivo preclinical evidence of the contribution of RIPK3 to both acute kidney injury (AKI) and chronic kidney disease (CKD) and to the AKI-to-CKD transition derived from RIPK3 deficient mice or the use of small molecule RIPK3 inhibitors. In these studies, RIPK3 targeting decreased inflammation but kidney injury improved only in some contexts. Clinical translation of these findings has been delayed by the potential of some small molecule inhibitors of RIPK3 kinase activity to trigger apoptotic cell death by inducing conformational changes of the protein. A better understanding of the conformational changes in RIPK3 that trigger apoptosis, dual RIPK3/RIPK1 inhibitors or repurposing of multiple kinase inhibitors such as dabrafenib may facilitate clinical development of the RIPK3 inhibition concept for diverse inflammatory diseases, including kidney diseases.

Chronic kidney disease: the missing concept in the 2019 EULAR/ERA-EDTA recommendations for lupus nephritis

Chronic kidney disease (CKD) is diagnosed when glomerular filtration rate (GFR) falls below 60 ml/min/1.73 m2 or urinary albumin:creatinine ratio (UACR) reaches ≥30 mg/g, as these two thresholds indicate a higher risk of adverse health outcomes, including cardiovascular mortality. CKD is classified as mild, moderate or severe, based on GFR and UACR values, and the latter two classifications convey a high or very high cardiovascular risk, respectively. Additionally, CKD can be diagnosed based on abnormalities detected by histology or imaging. Lupus nephritis (LN) is a cause of CKD. Despite the high cardiovascular mortality of patients with LN, neither albuminuria nor CKD are discussed in the 2019 European League Against Rheumatism (EULAR)/European Renal Association-European Dialysis and Transplant Association recommendations for the management of LN or the more recent 2022 EULAR recommendations for cardiovascular risk management in rheumatic and musculoskeletal diseases. Indeed, the proteinuria target values discussed in the recommendations may be present in patients with severe CKD and a very high cardiovascular risk who may benefit from guidance detailed in the 2021 European Society of Cardiology guidelines on cardiovascular disease prevention in clinical practice. We propose that the recommendations should move from a conceptual framework of LN as an entity separate from CKD to a framework in which LN is considered a cause of CKD and evidence generated from large CKD trials applies unless demonstrated otherwise.

SCARF Genes in COVID-19 and Kidney Disease: A Path to Comorbidity-Specific Therapies

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which has killed ~7 million persons worldwide. Chronic kidney disease (CKD) is the most common risk factor for severe COVID-19 and one that most increases the risk of COVID-19-related death. Moreover, CKD increases the risk of acute kidney injury (AKI), and COVID-19 patients with AKI are at an increased risk of death. However, the molecular basis underlying this risk has not been well characterized. CKD patients are at increased risk of death from multiple infections, to which immune deficiency in non-specific host defenses may contribute. However, COVID-19-associated AKI has specific molecular features and CKD modulates the local (kidney) and systemic (lung, aorta) expression of host genes encoding coronavirus-associated receptors and factors (SCARFs), which SARS-CoV-2 hijacks to enter cells and replicate. We review the interaction between kidney disease and COVID-19, including the over 200 host genes that may influence the severity of COVID-19, and provide evidence suggesting that kidney disease may modulate the expression of SCARF genes and other key host genes involved in an effective adaptive defense against coronaviruses. Given the poor response of certain CKD populations (e.g., kidney transplant recipients) to SARS-CoV-2 vaccines and their suboptimal outcomes when infected, we propose a research agenda focusing on CKD to develop the concept of comorbidity-specific targeted therapeutic approaches to SARS-CoV-2 infection or to future coronavirus infections.

The prevalence of vascular and metabolic complications after lung transplant in people with cystic fibrosis in a Dutch cohort

BACKGROUND

With improvements in care for people with Cystic Fibrosis (pwCF), total survival after Lung Transplantation (LTx) will be longer. Therefore, this population's up-to-date analysis of late-onset post-transplant metabolic and vascular complications will be more relevant in current clinical practice.

METHODS

We studied 100 pwCF who underwent an LTx between 2001 and 2020 at the University Medical Centre Utrecht, the Netherlands. The median age at transplant was 31 years and 55 percent was male. We assessed survival, the prevalence of metabolic complications (diabetes, renal damage, dyslipidemia, and metabolic syndrome), and vascular complications (hypertension, heart rhythm disease, micro-, and macrovascular disease). In addition, differences in risks for developing complications based on sex and overall survival were analyzed.

RESULTS

The prevalence of macrovascular disease raised to 15.9 percent 15 years post-LTx. The prevalence of diabetes increased from 63 percent at LTx to over 90 percent 15 years post-LTx and the prevalence of dyslipidemia increased from 21 percent to over 80 percent. Survival 1-, 2-, 5-, and 10 years post-transplant were 84, 80, 76, and 58 percent respectively. No significant differences were found based on sex.

CONCLUSION

This study shows that the prevalence of cardiovascular risk factors increases after LTx for CF, potentially leading to major complications. These data emphasize the necessity of regular check-ups for metabolic and vascular complications after LTx with specific attention to renal damage. Early recognition of these complications is crucial and will lead to earlier intervention, which could lead to improved prognosis after lung transplantation.

EMPA-KIDNEY: expanding the range of kidney protection by SGLT2 inhibitors

In the EMPA-KIDNEY (The Study of Heart and Kidney Protection With Empagliflozin) trial, empagliflozin reduced cardiorenal outcomes by 28% (hazard ratio 0.72; 95% confidence interval 0.64-0.82; P < .0001) in a diverse population of over 6000 chronic kidney disease (CKD) patients, of whom >50% were not diabetic. It expanded the spectrum of CKD that may benefit from sodium-glucose cotransporter 2 (SGLT2) inhibition to participants with urinary albumin: creatinine ratio <30 mg/g and estimated glomerular filtration rate (eGFR) >20 mL/min/1.73 m² or even lower (254 participants had an eGFR 15-20 mL/min/1.73 m²). EMPA-KIDNEY was stopped prematurely because of efficacy, thus limiting the ability to confirm benefit on the primary outcome in every pre-specified subgroup, especially in those with more slowly progressive CKD. However, data on chronic eGFR slopes were consistent with benefit at any eGFR or urinary albumin:creatinine ratio level potentially delaying kidney replacement therapy by 2-27 years, depending on baseline eGFR. The representation of diverse causes of CKD (>1600 participants with glomerular disease, >1400 with hypertensive kidney disease, >450 with tubulointerstitial disease and >600 with unknown cause) was higher than in prior SGLT2 inhibitor trials, although polycystic kidney disease was excluded. Around 15% (almost 1000) of participants were not on renin-angiotensin system blockade. The clinical characteristics of the cohort differed from DAPA-CKD (A Study to Evaluate the Effect of Dapagliflozin on Renal Outcomes and Cardiovascular Mortality in Patients With Chronic Kidney Disease), as did the frequency of individual components of the primary outcome in the placebo arm. Thus, rather than compare EMPA-KIDNEY with DAPA-CKD, the results of both trials should be seen as complementary to those of other SGLT2 inhibitor trials. Overall, EMPA-KIDNEY, a recent meta-analysis and post hoc analyses of participants with type 2 diabetes mellitus (T2DM) but no baseline CKD in other trials, indicates that SGLT2 inhibitor treatment will benefit an expanded CKD population with diverse baseline albuminuria or eGFR values, presence of T2DM or cause of CKD, as well as providing primary prevention of CKD in at least the T2DM setting.

Finerenone: towards a holistic therapeutic approach to patients with diabetic kidney disease

Despite current treatments, which include renin angiotensin system blockers and SGLT2 inhibitors, the risk of progression of kidney disease among patients with diabetes and chronic kidney disease (CKD) remains unacceptably high. The pathogenesis of CKD in patients with diabetes is complex and includes hemodynamic and metabolic factors, as well as inflammation and fibrosis. Finerenone is a highly selective nonsteroidal mineralocorticoid antagonist that, in contrast to current therapies, may directly reduce inflammation and fibrosis, thus adding value in the management of these patients. In fact, finerenone decreases albuminuria and slows CKD progression in persons with diabetes. We now review the mechanisms of action of finerenone, the results of recent clinical trials, and the integration of the kidney and cardiovascular protection afforded by finerenone in the routine care of patients with diabetes and CKD.

[Key guidelines on the Spanish multi-society consensus on chronic kidney disease]

Chronic kidney disease (CKD) is a global health problem and affects approximately 15.1% of the general population in Spain (IBERICAN and ENRCA studies), although most of the literature agrees that there is an underdiagnosis that would further increase this prevalence. This article from the CKD monograph aims to summarize the main consensus guidelines for the management of CKD, highlighting the most important and novel aspects, as well as recently updated terminology and concepts. Sections addressing specific populations and prevention strategies are also included. As the family doctor (MAP) plays a fundamental role in the detection of CKD, recommendations on the multidisciplinary approach to CKD are collected.

Optimization of potassium management in patients with chronic kidney disease and type 2 diabetes on finerenone

INTRODUCTION

Patients with type 2 diabetes (T2DM) and chronic kidney disease (CKD) are at high risk of CKD progression and cardiovascular events. Despite treatment with renin-angiotensin system inhibitors and SGLT-2 inhibitors, the residual risk is substantial. There is preclinical and clinical evidence supporting a key role of mineralocorticoid receptor in cardiorenal injury in T2DM.

AREAS COVERED

Finerenone is a selective and nonsteroidal mineralocorticoid receptor antagonist that reduces -on preclinical studies- heart and kidney inflammation and fibrosis. Clinical trials have demonstrated that among patients with T2DM and CKD, finerenone reduces CKD progression and the risk of cardiovascular events. The incidence of adverse events is similar than for placebo. Permanent discontinuation of study drug due to hyperkalemia was low (1.7% of finerenone and 0.6% of placebo participants) as was the risk of hyperkalemia-related severe-adverse events (1.1%). We provide an overview of risk factors for hyperkalemia and management of serum potassium in people with CKD and T2DM on finerenone.

EXPERT OPINION

As finerenone increases potassium levels in a predictable way, patients at risk of hyperkalemia can be identified early in clinical practice and monitored for an easy management. This will allow people with T2DM and CKD to safely benefit from improved cardiorenal outcomes.

The Spanish Scientific Societies before the ESC 2021 guidelines on vascular disease prevention: Generalizing the measurement of albuminuria to identify vascular risk and prevent vascular disease

The 2021 guidelines on the prevention of vascular disease (VD) in clinical practice published by the European Society of Cardiology (ESC) and supported by 13 other European scientific societies recognize the key role of screening for chronic kidney disease (CKD) in the prevention of VD. Vascular risk in CKD is categorized based on measurements of estimated glomerular filtration rate (eGFR) and urine albumin to creatinine ratio (ACR). Thus, moderate CKD is associated with a high vascular risk and severe CKD with a very high vascular risk requiring therapeutic action, and there is no need to apply other vascular risk scores when vascular risk is already very high due to CKD. Moreover, the ESC indicates that vascular risk assessment and the subsequent decision algorithm should start with measurement of eGFR and ACR. To optimize the implementation of the ESC 2021 guidelines on the prevention of CVD in Spain, we consider that: 1) Urine testing for albuminuria using ACR should be part of the clinical routine at the same level as blood glucose, cholesterolemia, and GFR estimation when these are used to make decisions on CVD risk. 2) Spanish public and private health services should have the necessary means and resources to optimally implement the ESC 2021 guidelines for the prevention of CVD in Spain, including ACR testing.

Chronic kidney disease as cardiovascular risk factor in routine clinical practice: a position statement by the Council of the European Renal Association

ABSTRACT

The European Society of Cardiology 2021 guideline on cardiovascular (CV) disease (CVD) prevention in clinical practice has major implications for both CV risk screening and kidney health of interest to primary care physicians, cardiologists, nephrologists, and other professionals involved in CVD prevention. The proposed CVD prevention strategies require as first step the categorization of individuals into those with established atherosclerotic CVD, diabetes, familiar hypercholesterolaemia, or chronic kidney disease (CKD), i.e. conditions that are already associated with a moderate to very-high CVD risk. This places CKD, defined as decreased kidney function or increased albuminuria as a starting step for CVD risk assessment. Thus, for adequate CVD risk assessment, patients with diabetes, familiar hypercholesterolaemia, or CKD should be identified by an initial laboratory assessment that requires not only serum to assess glucose, cholesterol, and creatinine to estimate the glomerular filtration rate, but also urine to assess albuminuria. The addition of albuminuria as an entry-level step in CVD risk assessment should change clinical practice as it differs from the current healthcare situation in which albuminuria is only assessed in persons already considered to be at high risk of CVD. A diagnosis of moderate of severe CKD requires a specific set of interventions to prevent CVD. Further research should address the optimal method for CV risk assessment that includes CKD assessment in the general population, i.e. whether this should remain opportunistic screening or whether systematic screening.

Chronic kidney disease as cardiovascular risk factor in routine clinical practice: a position statement by the Council of the European Renal Association

The European Society of Cardiology 2021 guideline on cardiovascular (CV) disease (CVD) prevention in clinical practice has major implications for both CV risk screening and kidney health of interest to primary care physicians, cardiologists, nephrol-ogists, and other professionals involved in CVD prevention. The proposed CVD prevention strategies require as first step the categorization of individuals into those with established atherosclerotic CVD, diabetes, familiar hypercholesterolaemia, or chronic kidney disease (CKD), i.e. conditions that are already associated with a moderate to very-high CVD risk. This places CKD, defined as decreased kidney function or increased albuminuria as a starting step for CVD risk assessment. Thus, for adequate CVD risk assessment, patients with diabetes, familiar hypercholesterolaemia, or CKD should be identified by an initial laboratory assessment that requires not only serum to assess glucose, cholesterol, and creatinine to estimate the glomerular filtration rate, but also urine to assess albuminuria. The addition of albuminuria as an entry-level step in CVD risk assessment should change clinical practice as it differs from the current healthcare situation in which albuminuria is only assessed in persons already considered to be at high risk of CVD. A diagnosis of moderate of severe CKD requires a specific set of interventions to prevent CVD. Further research should address the optimal method for CV risk assessment that includes CKD assessment in the general population, i.e. whether this should remain opportunistic screening or whether systematic screening.

Sodium-glucose co-transporter-2 inhibitors increase Klotho in patients with diabetic kidney disease: A clinical and experimental study

Sodium-glucose co-transporter-2 inhibitors (SGLT2i) provide cardiorenal protection. However, the molecular mechanisms remain poorly understood. We explored the impact of SGLT2i on Klotho, a kidney-derived protein with antiaging, renal-protective and heart-protective properties. A real world prospective observational study addressed the impact of initiating SGLT2i (canagliflozin, dapagliflozin, empagliflozin) or dipeptidyl peptidase-4 inhibitors (DPP4i) in patients with early diabetic kidney disease (DKD). Serum and urinary soluble Klotho, albuminuria and serum and urinary tumor necrosis factor-alpha (TNFa) were measured. The effect of SGLT2i on Klotho mRNA and protein was explored in vitro in kidney proximal tubular cells stressed with high glucose concentrations to simulate the diabetic milieu, albumin to simulate albuminuria, and the inflammatory cytokine TWEAK to simulate the inflammatory environment in DKD. Baseline urinary Klotho was negatively associated with albuminuria (r - 0.45, P < 0.001) and urinary TNFa (r - 0.40, P < 0.01). Both DPP4i and SGLT2i reduced HbA1c similarly, but only SGLT2i decreased eGFR, albuminuria and urinary TNFa and increased (P < 0.001) serum (5.2 %) and urinary Klotho (38.9 %). Changes in urinary TNFa (β - 0.53, P = 0.001) and albuminuria (β - 0.31, P < 0.05) were independently associated with changes in urinary Klotho (adjusted R² = 0.54, P < 0.001). Studies in renal tubular cells demonstrated that high glucose, albumin and TWEAK decreased Klotho mRNA expression and protein levels, an effect similarly prevented by SGLT2i. SGLT2i increase Klotho availability in type 2 diabetic patients with poorly controlled diabetes and early DKD, as well as in stressed tubular cells. This effect on Klotho may contribute to the kidney and heart protection afforded by SGLT2i.

The Influence of the Severity of Early Chronic Kidney Disease on Oxidative Stress in Patients with and without Type 2 Diabetes Mellitus

Early Chronic Kidney Disease (CKD) is a condition that tends to progress to End-Stage Kidney Disease (ESKD). Early diagnosis of kidney disease in the early stages can reduce complications. Alterations in renal function represent a complication of diabetes mellitus (DM). The mechanisms underlying the progression of CKD in diabetes could be associated with oxidative and inflammatory processes. This study aimed to evaluate the state of inflammation and oxidative stress (OS) on the progression of CKD in the early stages in patients with and without type 2 diabetes mellitus (T2DM). An analytical cross-sectional study was carried out in patients with CKD in early stages (1, 2, 3) with and without T2DM. The ELISA method determined the expression of pro-inflammatory cytokines IL-6 and TNF-α as well as lipoperoxides (LPO), nitric oxide (NO), and superoxide dismutase activity (SOD). Colorimetric methods determined glutathione peroxidase (GPx) and total antioxidant capacity (TAC). Patients with CKD and T2DM had significantly decreased antioxidant defenses for SOD (p < 0.01), GPx (p < 0.01), and TAC (p < 0.01) compared to patients without T2DM. Consequently, patients with T2DM had higher concentrations of oxidant markers, NO (p < 0.01), inflammation markers, IL-6 (p < 0.01), and TNF-α than patients without T2DM. CKD stages were not related to oxidative, antioxidant, and inflammatory marker outcomes in T2DM patients. Patients without T2DM presented an increase in SOD (p = 0.04) and a decrease in NO (p < 0.01) when the stage of CKD increased. In conclusion, patients with T2DM present higher levels of oxidative and inflammatory markers accompanied by a decrease in antioxidant defense. However, these oxidative status markers were associated with CKD stage progression in patients without T2DM. Thus, NO and SOD markers could help detect the early stages of CKD in patients who have not yet developed metabolic comorbidities such as T2DM.

Novel strategies in nephrology: what to expect from the future?

Chronic kidney disease (CKD) will become the fifth global case of death by 2040. Its largest impact is on premature mortality but the number of persons with kidney failure requiring renal replacement therapy (RRT) is also increasing dramatically. Current RRT is suboptimal due to the shortage of kidney donors and dismal outcomes associated with both hemodialysis and peritoneal dialysis. Kidney care needs a revolution. In this review, we provide an update on emerging knowledge and technologies that will allow an earlier diagnosis of CKD, addressing the current so-called blind spot (e.g. imaging and biomarkers), and improve renal replacement therapies (wearable artificial kidneys, xenotransplantation, stem cell-derived therapies, bioengineered and bio-artificial kidneys).

Postbiotics and Kidney Disease

Chronic kidney disease (CKD) is projected to become the fifth global cause of death by 2040 as a result of key shortcomings in the current methods available to diagnose and treat kidney diseases. In this regard, the novel holobiont concept, used to describe an individual host and its microbial community, may pave the way towards a better understanding of kidney disease pathogenesis and progression. Microbiota-modulating or -derived interventions include probiotics, prebiotics, synbiotics and postbiotics. As of 2019, the concept of postbiotics was updated by the International Scientific Association of Probiotics and Prebiotics (ISAPP) to refer to preparations of inanimate microorganisms and/or their components that confer a health benefit to the host. By explicitly excluding purified metabolites without a cellular biomass, any literature making use of such term is potentially rendered obsolete. We now review the revised concept of postbiotics concerning their potential clinical applications and research in kidney disease, by discussing in detail several formulations that are undergoing preclinical development such as GABA-salt for diet-induced hypertension and kidney injury, sonicated Lactobacillus paracasei in high fat diet-induced kidney injury, GABA-salt, lacto-GABA-salt and postbiotic-GABA-salt in acute kidney injury, and O. formigenes lysates for hyperoxaluria. Furthermore, we provide a roadmap for postbiotics research in kidney disease to expedite clinical translation.

Ageing meets kidney disease

Chronic kidney disease (CKD) is defined as abnormalities of kidney structure or function, present for >3 months, with implications for health. The most used diagnostic criteria are a urinary albumin: creatinine ratio ≥30 mg/g or an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Either of these diagnostic thresholds is associated with adverse health outcomes. GFR decreases with age and the prevalence of CKD is highest in older adults; moreover, the presence of CKD is associated with an increased risk of all-cause and cardiovascular death related to accelerated ageing in all age ranges, and the absolute increase in risk is highest for those aged >75 years. Indeed, premature death is a more common outcome than CKD progression to kidney failure requiring kidney replacement therapy. The progressive ageing of the world population contributes to the projection that CKD will become the second most common cause of death before the end of the century in countries with long life expectancy. The current collection of selected studies on kidney disease and ageing published in Age&Ageing, NDT and CKJ provides an overview of key topics, including cognitive decline, sarcopaenia, wasting and cardiovascular and non-cardiovascular morbidity and mortality, the management of kidney failure and gender differences in CKD progression.

Ageing meets kidney disease

Chronic kidney disease (CKD) is defined as abnormalities of kidney structure or function, present for ˃3 months, with implications for health. The most used diagnostic criteria are a urinary albumin: creatinine ratio ≥30 mg/g or an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Either of these diagnostic thresholds is associated with adverse health outcomes. GFR decreases with age and the prevalence of CKD is highest in older adults; moreover, the presence of CKD is associated with an increased risk of all-cause and cardiovascular death related to accelerated ageing in all age ranges, and the absolute increase in risk is highest for those aged ˃75 years. Indeed, premature death is a more common outcome than CKD progression to kidney failure requiring kidney replacement therapy. The progressive ageing of the world population contributes to the projection that CKD will become the second most common cause of death before the end of the century in countries with long life expectancy. The current collection of selected studies on kidney disease and ageing published in Age&Ageing, NDT and CKJ provides an overview of key topics, including cognitive decline, sarcopaenia, wasting and cardiovascular and non-cardiovascular morbidity and mortality, the management of kidney failure and gender differences in CKD progression.

Ageing meets kidney disease

Chronic kidney disease (CKD) is defined as abnormalities of kidney structure or function, present for ˃3 months, with implications for health. The most used diagnostic criteria are a urinary albumin: creatinine ratio ≥30 mg/g or an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m². Either of these diagnostic thresholds is associated with adverse health outcomes. GFR decreases with age and the prevalence of CKD is highest in older adults; moreover, the presence of CKD is associated with an increased risk of all-cause and cardiovascular death related to accelerated ageing in all age ranges, and the absolute increase in risk is highest for those aged ˃75 years. Indeed, premature death is a more common outcome than CKD progression to kidney failure requiring kidney replacement therapy. The progressive ageing of the world population contributes to the projection that CKD will become the second most common cause of death before the end of the century in countries with long life expectancy. The current collection of selected studies on kidney disease and ageing published in Age&Ageing, NDT and CKJ provides an overview of key topics, including cognitive decline, sarcopaenia, wasting and cardiovascular and non-cardiovascular morbidity and mortality, the management of kidney failure and gender differences in CKD progression.

Alteration of Skin Microbiome in CKD Patients Is Associated With Pruritus and Renal Function

Dysbiotic gut microbiome in chronic kidney disease (CKD) patients has been extensively explored in recent years. Skin microbiome plays a crucial role in patients with skin diseases or even systemic disorders. Pruritus is caused by the retention of uremic solutes in the skin. Until now, no studies have investigated the role of skin microbiome in CKD and its association with pruritus. Here, we aim to examine the bacterial profile of skin microbiome in CKD and whether it is correlated to pruritus. A total of 105 CKD patients and 38 healthy controls (HC) were recruited. Skin swab was used to collect skin samples at the antecubital fossa of participants. Bacterial 16S rRNA genes V3–V4 region was sequenced on NovaSeq platform. On the day of skin sample collection, renal function was assessed, and numeric rating scale was used to measure pruritus severity. Principal coordinate analysis (PCoA) revealed a significant difference in bacterial composition between the groups of CKD and HC. A depletion of bacterial diversity was observed in CKD patients. Akkermansia, Albimonas, Escherichia–Shigella, etc. showed significant higher abundance in CKD patients, whereas Flavobacterium, Blastomonas, Lautropia, etc. significantly declined in patients. Escherichia–Shigella achieved an acceptable diagnostic biomarker with area under the curve (AUC) value of 0.784 in the receiver operating characteristics (ROC) curve. In addition, CKD patients with pruritus (P-CKD) had a different bacterial community comparing to those without pruritus (non-P-CKD) and HC group. Several bacterial genera showing significant difference between P-CKD and non-P-CKD/HC, such as Oribacterium, significantly declined in P-CKD patients than that in the HC group, and Methylophaga significantly increased in P-CKD patients compared to that in HC subjects. Escherichia–Shigella was positively associated with the levels of pruritus severity, blood urea nitrogen (BUN), uric acid, and urine protein; Oribacterium was negatively associated with pruritus severity, whereas it was positively associated with estimated glomerular filtration rate (eGFR) and 24-h urine volume. The dysbiotic of skin microbiome in CKD patients and its association with pruritus and renal function shed a light on skin probiotics.

Gut Mycobiome in Patients With Chronic Kidney Disease Was Altered and Associated With Immunological Profiles

Objectives

Mounting evidence suggests that bacterial dysbiosis and immunity disorder are associated with patients with chronic kidney disease (CKD), but the mycobiome is beginning to gain recognition as a fundamental part of our microbiome. We aim to characterize the profile of the mycobiome in the gut of CKD patients and its correlation to serum immunological profiles.

Methods and materials

Ninety-two CKD patients and sex-age-body mass index (BMI)-matched healthy controls (HCs) were recruited. Fresh samples were collected using sterile containers. ITS transcribed spacer ribosomal RNA gene sequencing was performed on the samples. An immunoturbidimetric test was used to assess the serum levels of immunological features.

Results

The CKD cohort displayed a different microbial community from that in the HC cohort according to principal coordinate analysis (PCoA). (P=0.001). The comparison of the two cohorts showed that the CKD cohort had significantly higher gut microbial richness and diversity (P<0.05). The CKD cohort had lower abundances of Candida, Bjerkandera, Rhodotorula, and Ganoderma compared to the HC cohort, while it had higher Saccharomyces (P<0.05). However, the microbial community alteration was inconsistent with the severity of kidney damage in patients, as only patients in CKD stage 1~3 had differed microbial community concerning for HCs based on PCoA (P<0.05). The serum concentration of the kappa light chain in CKD patients was positively associated with Saccharomyces, whereas the it was negatively associated with Ganoderma (P<0.05).

Conclusions

Not only was gut mycobiome dysbiosis observed in CKD patients, but the dysbiosis was also associated with the immunological disorder. These findings suggest that therapeutic strategies targeting gut mycobiome might be effective.

Information and consensus document for the detection and management of chronic kidney disease

Chronic kidney disease (CKD) is a major public health problem worldwide that affects more than 10% of the Spanish population. CKD is associated with high comorbidity rates, poor prognosis and major consumption of health system resources. Since the publication of the last consensus document on CKD seven years ago, little evidence has emerged and few clinical trials on new diagnostic and treatment strategies in CKD have been conducted, apart from new trials in diabetic kidney disease. Therefore, CKD international guidelines have not been recently updated. The rigidity and conservative attitude of the guidelines should not prevent the publication of updates in knowledge about certain matters that may be key in detecting CKD and managing patients with this disease. This document, also prepared by 10 scientific associations, provides an update on concepts, clarifications, diagnostic criteria, remission strategies and new treatment options. The evidence and the main studies published on these aspects of CKD have been reviewed. This should be considered more as an information document on CKD. It includes an update on CKD detection, risk factors and screening; a definition of renal progression; an update of remission criteria with new suggestions in the older population; CKD monitoring and prevention strategies; management of associated comorbidities, particularly in diabetes mellitus; roles of the Primary Care physician in CKD management; and what not to do in Nephrology. The aim of the document is to serve as an aid in the multidisciplinary management of the patient with CKD based on current recommendations and knowledge.

OUP accepted manuscript

The year 2021 was the last full year of Alberto Ortiz’s editorship at Clinical Kidney Journal (CKJ). On May 2022, Maria José Soler will start her term as the Editor-in-Chief. Over these years, CKJ obtained its first journal impact factor and has consolidated its position among the top journals in the field, consistently ranking among the top 25% (first quartile) journals in Urology and Nephrology. The 2020 journal impact factor rose to 4.45, becoming the top open access journal in Nephrology and the ninth ranked Nephrology journal overall. We now review the recent history of the journal and the most highly cited topics which include the epidemiology of kidney disease, chronic kidney disease topics, such as the assessment and treatment of chronic kidney disease, onconephrology, cardionephrology, glomerular disease, transplantation and coronavirus disease 2019 (COVID-19).

Targeted Training for Subspecialist Care in Children With Medical Complexity

BACKGROUND

Children with medical complexity (CMC) are prone to medical errors and longer hospital stays, while residents do not feel prepared to provide adequate medical care for this vulnerable population. No educational guidance for the training of future pediatric tertiary care specialists outside their field of expertise involving the multidisciplinary care of CMC exists. We investigated pediatric residents past educational needs and challenges to identify key learning content for future training involving care for CMC.

METHODS

This was a prospective mixed-methods study at a single pediatric tertiary care center. Qualitative semi-structured interviews with residents were conducted, submitted to thematic content analysis, linked to the American Board of Pediatrics (ABP) general pediatrics content outline, and analyzed with importance performance analysis (IPA). Quantitative validation was focused on key themes of pediatric nephrology within the scope of an online survey among pediatric residents and specialists.

RESULTS

A total of 16 interviews, median duration 69 min [interquartile range IQR 35], were conducted. The 280 listed themes of the ABP general pediatrics content outline were reduced to 165 themes, with 86% (theoretical) knowledge, 12% practical skills, and 2% soft skills. IPA identified 23 knowledge themes to be of high importance where improvement is necessary and deemed fruitful. Quantitative validation among 84 residents and specialists (response rate 55%) of key themes in nephrology yielded high agreement among specialists in pediatric nephrology but low interrater agreement among trainees and "trained" non-nephrologists. The occurrence of themes in the qualitative interviews and their calculated importance in the quantitative survey were highly correlated (tau = 0.57, p = 0.001). Two clusters of high importance for other pediatric specialties emerged together with a contextual cluster of frequent encounters in both in- and outpatient care.

CONCLUSION

Regarding patient safety, this study revealed the heterogeneous aspects and the importance of training future pediatric tertiary care specialists outside their field of expertise involving the multidisciplinary care of CMC. Our results may lay the groundwork for future detailed analysis and development of training boot camps that might be able to aid the improvement of patient safety by decreasing preventable harm by medical errors, especially for vulnerable patient groups, such as CMC in tertiary care pediatrics.

CKD: The burden of disease invisible to research funders

The uptake of the current concept of chronic kidney disease (CKD) by the public, physicians and health authorities is low. Physicians still mix up CKD with chronic kidney insufficiency or failure. In a recent manuscript, only 23% of participants in a cohort of persons with CKD had been diagnosed by their physicians as having CKD while 29% has a diagnosis of cancer and 82% had a diagnosis of hypertension. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. A prevalent view is that for those in whom kidneys fail, the problem is "solved" by dialysis or kidney transplantation. However, the main burden of CKD is accelerated aging and all-cause and cardiovascular premature death. CKD is the most prevalent risk factor for lethal COVID-19 and the factor that most increases the risk of death in COVID-19, after old age. Moreover, men and women undergoing KRT still have an annual mortality which is 10-100-fold higher than similar age peers, and life expectancy is shortened by around 40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth global cause of death by 2040 and the second cause of death in Spain before the end of the century, a time when 1 in 4 Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded CIBER network research structure in Spain. Leading Spanish kidney researchers grouped in the kidney collaborative research network REDINREN have now applied for the RICORS call of collaborative research in Spain with the support of the Spanish Society of Nephrology, ALCER and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true. However, only the highest level of research funding through the CIBER will allow to adequately address the issue before it is too late.

More on the invisibility of chronic kidney disease… and counting

Lack of awareness of a diagnosis of chronic kidney disease (CKD) in patients and physicians is a major contributor to fueling the CKD pandemic by also making it invisible to researchers and health authorities. This is an urgent matter to tackle if dire predictions of future CKD burden are to be addressed. CKD is set to become the fifth-leading global cause of death by 2040 and the second-leading cause of death before the end of the century in some countries with long life expectancy. Coronavirus disease 2019 (COVID-19) illustrated this invisibility: only after the summer of 2020 did it become clear that CKD was a major driver of COVID-19 mortality, both in terms of prevalence as a risk factor and of the risk conferred for lethal COVID-19. However, by that time the damage was done: news outlets and scientific publications continued to list diabetes and hypertension, but not CKD, as major risk factors for severe COVID-19. In a shocking recent example from Sweden, CKD was found to be diagnosed in just 23% of 57 880 persons who fulfilled diagnostic criteria for CKD. In the very same large cohort, diabetes or cancer were diagnosed in 29% of persons, hypertension in 82%, cardiovascular disease in 39% and heart failure in 28%. Thus, from the point of view of physicians, patients and health authorities, CKD was the least common comorbidity in persons with CKD, ranking sixth, after other better-known conditions. One of the consequences of this lack of awareness was that nephrotoxic medications were more commonly prescribed in patients with CKD who did not have a diagnosis of CKD. Low awareness of CKD may also fuel concepts such as the high prevalence of hypertensive nephropathy when CKD is diagnosed after the better-known condition of hypertension.

CKD: The burden of disease invisible to research funders

The uptake of the current concept of chronic kidney disease (CKD) by the public, physicians and health authorities is low. Physicians still mix up CKD with chronic kidney insufficiency or failure. In a recent manuscript, only 23% of participants in a cohort of persons with CKD had been diagnosed by their physicians as having CKD while 29% has a diagnosis of cancer and 82% had a diagnosis of hypertension. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. A prevalent view is that for those in whom kidneys fail, the problem is “solved” by dialysis or kidney transplantation. However, the main burden of CKD is accelerated aging and all-cause and cardiovascular premature death. CKD is the most prevalent risk factor for lethal COVID-19 and the factor that most increases the risk of death in COVID-19, after old age. Moreover, men and women undergoing KRT still have an annual mortality which is 10–100-fold higher than similar age peers, and life expectancy is shortened by around 40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth global cause of death by 2040 and the second cause of death in Spain before the end of the century, a time when 1 in 4 Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded CIBER network research structure in Spain. Leading Spanish kidney researchers grouped in the kidney collaborative research network REDINREN have now applied for the RICORS call of collaborative research in Spain with the support of the Spanish Society of Nephrology, ALCER and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true. However, only the highest level of research funding through the CIBER will allow to adequately address the issue before it is too late.

RICORS2040: the need for collaborative research in chronic kidney disease

Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is ‘solved’ by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020–2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true.

Dyslipidemia in Patients with Kidney Disease

Cardiovascular (CV) disease (CVD) is the leading cause of morbidity and mortality in patients with chronic kidney disease (CKD) and with end-stage renal disease. CKD has a strong association with dyslipidemia. Dyslipidemias can affect kidney function and increase the risk for CVD development, so it is an important risk factor. Statin therapy can decrease CV events in patients with pre-end-stage CKD and in renal transplant patients, but not in those already on dialysis. This article focuses on epidemiology of CKD, how dyslipidemias confer a higher risk for CVD, the approach to management and treatment of dyslipidemias, and recent guidelines.

[Self-reported sleep and wake disorders in patients with ostheoarthrosis and end-stage renal disease]

OBJECTIVE

This study aimed to assess subjective sleep and wake disorders (SWD) in patients with osteoarthritis and comorbid end-stage renal disease (ESRD) receiving hemodialysis (ESRD-HD) compared to patients with osteoarthritis and without chronic kidney disease (CKD) as well as to clarify of the association of subjective sleep characteristics with the levels of anxiety and depression and pain, general health score and laboratory parameters in these cohorts.

MATERIAL AND METHODS

This pilot case-control study included the patients with stage III hip osteoarthritis with ESRD-HD (n=19) and without CKD (n=19) aged 18-85 years. The patients received the consultations of orthopedic surgeon and internal medicine specialist with anthropometry and clinical and biochemical blood tests. Subjective SWD were assessed with Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), Insomnia Severity Index (ISI), diagnostic criteria for restless legs syndrome (RLS) and Berlin questionnaire. Anxiety and depression were assessed with Hospital Anxiety and Depression Scale (HADS) and Beck Depression Inventory (BDI). Subjective general health and osteoarthritis-related pain were assessed with visual analog scales (VAS).

RESULTS

Compared to the patients with osteoarthritis and without CKD, the patients with osteoarthritis and ESRD-HD had a lower VAS score for general health (50.00 (40.00-75.00) points and 80.00 (70.00-80.00) points, p=0.014), a higher PSQI (12.0 (8.5-14.5) points and 8.0 (6.0-11.0) points, p=0.046), a higher incidence of RLS (59% and 16.8%, p=0.017) and a lower level of anxiety according to HADS (0.0 (0.0-3.0) points and 3.0 (2.0-5.5) points, p=0.025). The correlation and regression analysis showed the association of PSQI score with VAS score for general health (b= -1.7 points, p=0.002 with adjustment for age, sex and ESRD-HD), as well as the association of SWD with laboratory markers (PSQI score with creatinine level, FSS with eosinophil count, RLS with creatinine, urea and potassium levels).

CONCLUSION

The results of our study demonstrated the high incidence of SWD in patients with osteoarthritis. These SWD have complex pathogenesis and require specific approach in patients with osteoarthritis and ESRD-HD.

Phosphate, Microbiota and CKD

Phosphate is a key uremic toxin associated with adverse outcomes. As chronic kidney disease (CKD) progresses, the kidney capacity to excrete excess dietary phosphate decreases, triggering compensatory endocrine responses that drive CKD-mineral and bone disorder (CKD-MBD). Eventually, hyperphosphatemia develops, and low phosphate diet and phosphate binders are prescribed. Recent data have identified a potential role of the gut microbiota in mineral bone disorders. Thus, parathyroid hormone (PTH) only caused bone loss in mice whose microbiota was enriched in the Th17 cell-inducing taxa segmented filamentous bacteria. Furthermore, the microbiota was required for PTH to stimulate bone formation and increase bone mass, and this was dependent on bacterial production of the short-chain fatty acid butyrate. We review current knowledge on the relationship between phosphate, microbiota and CKD-MBD. Topics include microbial bioactive compounds of special interest in CKD, the impact of dietary phosphate and phosphate binders on the gut microbiota, the modulation of CKD-MBD by the microbiota and the potential therapeutic use of microbiota to treat CKD-MBD through the clinical translation of concepts from other fields of science such as the optimization of phosphorus utilization and the use of phosphate-accumulating organisms.

Alteration of the Gut Microbiome in Chronic Kidney Disease Patients and Its Association With Serum Free Immunoglobulin Light Chains

Objectives

Gut dysbiosis is associated with chronic kidney disease (CKD), and serum free immunoglobulin light chains (FLCs) are biomarkers for CKD. This study aims to assess the CKD gut microbiome and to determine its impact on serum FLC levels.

Methods

To control for confounders, 100 patients and sex- and age-matched healthy controls (HCs) were recruited. The gut microbiome was assessed by sequencing 16S rRNA gene V3-V4 hypervariable regions. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States was applied to infer functional metabolic pathways. When observing group differences in the microbiome and predicted metabolic pathways, demographic confounders were adjusted using binary logistic regression; when examining impacts of the gut microbiome and metabolic pathways on serum FLCs, factors influencing FLC levels were adjusted using multiple regression.

Results

Principal coordinate analysis revealed a significantly different bacterial community between the CKD and HC groups (P < 0.05). After adjusting for confounders, lower Chao 1, observed species and Shannon indices based on binary logistic regression predicted CKD prevalence. Actinobacteria, Alistipes, Bifidobacterium and Bifidobacterium longum enrichment, upregulation of metabolic pathways of bacterial toxin, chloroalkane and chloroalkene degradation, and Staphylococcus aureus infection also predicted CKD prevalence (P < 0.05). Furthermore, depletion of Actinobacteria and Bifidobacterium and reduced chloroalkane and chloroalkene degradation predicted high levels of FLC λ (P < 0.05).

Conclusions

Gut dysbiosis in CKD patients was confirmed by controlling for confounders in the present study. Additionally, the association between gut dysbiosis and FLC λ levels demonstrates the existence of crosstalk between the microbiome and immune response in CKD.

Serum and urinary soluble α-Klotho levels in patients with chronic kidney disease

Background: Chronic kidney disease is an epidemic global health problem that leads to death. To prevent any disease progression and treatment, the diagnosis must be made in the early stage by studying renal damage. Klotho is a protein found in many organs of the human body, but it is mainly abundant in the kidney. Objectives: This study is aimed to evaluate klotho’s clinical significance as an additional biomarker for diagnosing chronic kidney disease in its early stages. Methods: One hundred subjects were included in this study to measure their serum and urinary klotho. Forty patients with chronic kidney disease (pre-dialysis) and sixty normal subjects were enrolled in this study. Serum and urinary klotho were determined using the ELISA technique in addition to other renal function tests. Results: Serum and urinary alpha klotho were decreased in CKD patients when compared with control subjects. A positive correlation was found between serum creatinine and urinary alpha klotho in the patients’ group. Conclusion: Serum and urinary alpha klotho levels were decreased significantly in patients with chronic kidney disease compared with healthy controls.

Role of Klotho in the Development of Essential Hypertension

Klotho has antiaging properties, and serum levels decrease with physiological aging and aging-related diseases, such as hypertension, cardiovascular, and chronic kidney disease. Klotho deficiency in mice results in accelerated aging and cardiovascular injury, whereas Klotho supplementation slows down the progression of aging-related diseases. The pleiotropic functions of Klotho include, but are not limited to, inhibition of insulin/IGF-1 (insulin-like growth factor 1) and WNT (wingless-related integration site) signaling pathways, suppression of oxidative stress and aldosterone secretion, regulation of calcium-phosphate homeostasis, and modulation of autophagy with inhibition of apoptosis, fibrosis, and cell senescence. Accumulating evidence shows an interconnection between Klotho deficiency and hypertension, and Klotho gene polymorphisms are associated with hypertension in humans. In this review, we critically review the current understanding of the role of Klotho in the development of essential hypertension and the most important underlying pathways involved, such as the FGF23 (fibroblast growth factor 23)/Klotho axis, aldosterone, Wnt5a/RhoA, and SIRT1 (Sirtuin1). Based on this critical review, we suggest avenues for further research.

Undiagnosed cardiovascular risk factors in overweight and obese individuals: a low income country experience

Background

Overweight and obesity are associated with diabetes, hypertension and chronic kidney disease (CKD). However, there is scarce information from lower income countries about undiagnosed obesity-associated conditions. This information is necessary for healthcare planning and for assessment of Global Burden of Disease.

Methods

We assessed the prevalence of obesity-associated conditions in 656 overweight (n = 360) and obese (n = 296) adults from inner-city Portoviejo (Ecuador), in descriptive field research, based on an opportunistic and selective sampling strategy.

Results

Of 316 men and 340 women, 73% met criteria for prehypertension (27%) or hypertension (46%), 50% met criteria for prediabetes (30%) or diabetes (20%), 11% had an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² consistent with chronic kidney disease (CKD) and 5.5% had pathological albuminuria for a total CKD prevalence of 16%. Age-related prevalence data were generated. In all participants, serum total cholesterol and triglycerides were >200 and >150 mg/dl, respectively. Hyperuricemia and microhematuria (<2%) were uncommon. Women were more likely to have low eGFR (18 vs 5%, p 0.000). Diabetes and pathological albuminuria prevalence were higher in obese than in overweight participants (15 vs 12%, p 0.018; and 8 vs 4%, p 0.0199, respectively).

Discussion

In conclusion, undiagnosed hypertension, diabetes and CKD were more common than expected in overweight and obese persons from Ecuador. Detection rates exceeded official estimates of prevalene of these conditions. Screening the overweight/obese for these conditions, especially at the age ranges at higher risk, may be cost-effective to identify a high number of persons who may benefit from early inexpensive intervention.

Chronic kidney disease is a key risk factor for severe COVID-19: a call to action by the ERA-EDTA

Diabetes, hypertension and cardiovascular disease have been listed as risk factors for severe coronavirus disease 2019 (COVID-19) since the first report of the disease in January 2020. However, this report did not mention chronic kidney disease (CKD) nor did it provide information on the relevance of estimated glomerular filtration rate (eGFR) or albuminuria. As the disease spread across the globe, information on larger populations with greater granularity on risk factors emerged. The recently published OpenSAFELY project analysed factors associated with COVID-19 death in 17 million patients. The picture that arose differs significantly from initial reports. For example, hypertension is not an independent risk factor for COVID-19 death [adjusted hazard ratio (aHR) 0.89], but renal disease very much is. Dialysis (aHR 3.69), organ transplantation (aHR 3.53) and CKD (aHR 2.52 for patients with eGFR <30 mL/min/1.73 m2) represent three of the four comorbidities associated with the highest mortality risk from COVID-19. The risk associated with CKD Stages 4 and 5 is higher than the risk associated with diabetes mellitus (aHR range 1.31-1.95, depending upon glycaemic control) or chronic heart disease (aHR 1.17). In another recent publication, the Global Burden of Disease collaboration identified that worldwide, CKD is the most prevalent risk factor for severe COVID-19. Moreover, the distribution of risk factors for COVID-19 mortality appears to be different in patients with CKD when compared with the general population. The high prevalence of CKD in combination with the elevated risk of mortality from COVID-19 in CKD necessitates urgent action for this group of patients. This article defines essential action points (summarized in Box 1), among which is advocating the inclusion of CKD patients in clinical trials testing the efficacy of drugs and vaccines to prevent severe COVID-19.

European East-West divide in kidney disease: the need to understand the drivers of chronic kidney disease outcomes

In this issue of ckj, Sever et al. (A roadmap for optimizing chronic kidney disease patient care and patient-oriented research in the Eastern European nephrology community. Clin Kidney J, this issue) present a roadmap for optimizing chronic kidney disease (CKD) patient care and patient-oriented research in Eastern Europe. The document clearly identifies current unmet needs and proposes corrective actions. Focusing on CKD epidemiology and outcomes, it collects evidence pointing to an East-West gradient for some key risk factors for CKD development. Thus, the prevalence of diabetes, raised blood pressure, obesity and tobacco use is higher in Eastern than in Western Europe. These risk factors may contribute to the higher CKD prevalence in Eastern Europe, which for the Eastern-most countries may be more than 2-fold higher than in Western Europe. The problem is compounded by the lower prevalence of dialysis and transplantation in Eastern Europe, especially in lower income countries. The combination of higher prevalence of CKD with lower prevalence of renal replacement therapy would be expected to result in higher CKD-associated mortality, but this is not the case. CKD-associated mortality may even be lower in the Eastern-most European countries than in Western Europe. The reasons for this discrepancy should be studied, since it may reveal serious additional healthcare issues, potentially related to high mortality from other non-communicable diseases (NCDs). If this is the case and the high mortality from other NCD is successfully addressed, pressure will further mount on renal replacement capacity needs in Eastern Europe.

Protective Role of Nrf2 in Renal Disease

Chronic kidney disease (CKD) is one of the fastest-growing causes of death and is predicted to become by 2040 the fifth global cause of death. CKD is characterized by increased oxidative stress and chronic inflammation. However, therapies to slow or prevent CKD progression remain an unmet need. Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor that plays a key role in protection against oxidative stress and regulation of the inflammatory response. Consequently, the use of compounds targeting Nrf2 has generated growing interest for nephrologists. Pre-clinical and clinical studies have demonstrated that Nrf2-inducing strategies prevent CKD progression and protect from acute kidney injury (AKI). In this article, we review current knowledge on the protective mechanisms mediated by Nrf2 against kidney injury, novel therapeutic strategies to induce Nrf2 activation, and the status of ongoing clinical trials targeting Nrf2 in renal diseases.