Sex and the Risk of Atheromatous and Non-Atheromatous Cardiovascular Disease in CKD: Findings From the CKD-REIN Cohort Study

RATIONALE & OBJECTIVE

Sex differences in cardiovascular disease (CVD) are well-established, but whether chronic kidney disease (CKD) modifies these risk differences, and whether they differ between atheromatous (ACVD) and non-atheromatous (N-ACVD) CVD is unknown. Assessing this interaction was the principal goal of this study.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Adults enrolled in the CKD-Renal Epidemiology and Information Network (CKD-REIN) cohort from from 2013 to 2020, a nationally representative sample of 40 nephrology clinics in France.

EXPOSURE

Sex.

OUTCOMES

Fatal and non-fatal composite ACVD events (ischaemic coronary, cerebral, and peripheral artery disease) and composite N-ACVD events (heart failure, haemorrhagic stroke, and arrhythmias).

ANALYTICAL APPROACH

Multivariable cause-specific Cox proportional hazards models.

RESULTS

1,044 women and 1,976 men with moderate to severe CKD (median age, 67 vs. 69; mean estimated glomerular filtration rate [eGFR], 32±12 vs. 33±12 mL/min/1.73m2) were studied. Over a median follow-up of 5.0 (interquartile range, 4.8;5.2) years, the ACVD rate (per 100 patient-years) was significantly lower in women than men: 2.1 (95% confidence interval: 1.6-2.5) vs 3.6 (3.2-4.0) (P<0.01), while the N-ACVD rate was not: 5.7 (5.0-6.5) vs 6.4 (5.8-7.0) (P=0.55). N-ACVD had a steeper relationship with eGFR than did ACVD. There was an interaction (P<0.01) between sex and baseline eGFR and the ACVD hazard: the adjusted hazard ratio for women compared to men was 0.42 (0.25;0.71) at 45 mL/min/1.73m2 and gradually attenuated at lower levels of eGFR, reaching 1.00 (0.62;1.63) at 16 mL/min/1.73m2. In contrast, the N-ACVD hazard did not differ between the sexes across the eGFR range studied.

LIMITATIONS

Cardiovascular biomarkers and sex hormones were not assessed.

CONCLUSION

This study shows how the lower risk of ACVD among women compared to men attenuates fully with kidney disease progression. The equal risk of N-ACVD between sexes across CKD stages and its steeper association with eGFR suggest an important contribution of CKD to the development of this CVD type.

Epidemiology of tobacco use in dialysis patients in France and survey of nephrologists' involvement in counseling on tobacco discontinuation

BACKGROUND

Tobacco smoking is an independent risk factor for chronic kidney disease (CKD) and increases morbidity and mortality in CKD patients. The primary objective of the study was to investigate the epidemiology of smoking in patients undergoing maintenance dialysis in France. A second objective was to assess the involvement of nephrologists in supporting patients for smoking cessation.

METHODS

Data on the smoking history of prevalent patients on maintenance dialysis in France between 2010 and 2020 were obtained from the REIN database (Renal Epidemiology and Information Network), updated by all French nephrology and dialysis centers. As for the support to smoking discontinuation, a questionnaire on smoking cessation assistance was sent to all members of the French Society of Nephrology, Dialysis and Transplantation (SFNDT).

RESULTS

The proportion of current smokers among patients on maintenance dialysis was 10.4% in 2010, 11.2% in 2015 and 11.6% in 2020. A total of 228 nephrologists among the 790 members of the SFNDT participated in the survey (28.9%). Most respondents were women (57.3%), worked at a public hospital (61.1%), were under 40 years of age (51.3%) and had no history of smoking (60.8%). The majority reported asking patients about their smoking status and offering brief advice. Among respondents, 72.8% offered help with smoking cessation, 46.3% referred their smoking patients to a tobacco specialist, 51.8% reported prescribing drugs to quit tobacco, and 81.6% requested further training in how to support patients for smoking cessation.

CONCLUSION

Smoking cessation training for nephrologists and dedicated programs for patients in nephrology units could improve our practices and decrease the high prevalence of smoking in patients with ESKD.

Discovery of age-related early-stage glycated proteins based on deep quantitative serum glycated proteome analysis

Aging is a pressing global health issue that is linked to various diseases, such as diabetes and Alzheimer's disease. It is well known that glycation plays a pathological role in the aging process and age-related diseases. Thus, it is of great significance to discover protein glycation at an early stage for monitoring and intervention in the aging process. However, the endogenous age-related early-stage glycated proteome remains insufficiently profiled. To address this research gap, our study focuses on assessing glycated proteomics profiles in the serum of mice. We employ a robust and quantitative strategy previously developed by our team, to analyze endogenous glycated proteome in serum samples of 4 age groups of mice (10 weeks, 16 weeks, 48 weeks and 80 weeks). In total, 2959 endogenous glycated peptides corresponding to 296 serum proteins are identified from 48 runs of serum samples from 16 mice across the four age groups. By comparing these glycated peptides between adjacent age groups, we discover 49 glycated peptides from 35 proteins that show significant upregulation between the 48-week and 80-week age groups. Furthermore, we identify 10 glycated proteins (or protein groups) that are significantly upregulated only between the 48-week and 80-week age groups, including lecithin-cholesterol acyltransferase (LCAT) and apolipoprotein A-II (Apo A-II). These novel findings provide unique signatures for understanding the aging process and age-related diseases. By shedding light on the early-stage glycated proteome, our study contributes valuable insights that may have implications for future interventions and therapeutic approaches.

[Clinical significance of uremic toxin indoxyl sulfate and inflammation in the development of vascular calcification and cardiovascular complications in stage C3-C5D chronic kidney disease]

AIM

To clarify the role of the uremic toxin indoxyl sulfate (IS) and inflammation in the development of vascular calcification and cardiovascular complications in chronic kidney disease (CKD).

MATERIALS AND METHODS

One hundred fifteen patients aged 25 to 68 years with CKD stage C3-C5D were examined. Serum concentrations of IS, interleukin 6 (IL-6), tumor necrosis factor (TNF-α), troponin I, parathyroid hormone were determined by enzyme immunoassay using kits from BluGene biotech (Shanghai, China), Cloud-Clone Corp. (USA), ELISA Kit (Biomedica, Austria).

RESULTS

An increase in the serum concentration of IS, IL-6, TNF-α was revealed, which was significantly associated with a deterioration in renal function and changes in the morphological and functional parameters of the heart and aorta.

CONCLUSION

High concentrations of IS, IL-6, TNF-α, which are closely associated with an increase in renal failure and cardiovascular complications, indicate their significant role in vascular calcification, which underlies the damage to the cardiovascular system in CKD.

Yishen-Qingli-Huoxue formula attenuates renal fibrosis by inhibiting indoxyl sulfate via AhR/snai1 signaling

BACKGROUND

Chronic kidney disease (CKD) is challenging to reverse and its treatment options are limited. Yishen-Qingli-Huoxue Formula (YQHF) is an effective treatment Chinese formula for CKD, as verified by clinical randomized controlled trial. However, the correlative YQHF therapeutic mechanisms are still unknown.

PURPOSE

The current study aimed to investigate the potential anti-renal fibrosis effects of YQHF as well as the underlying mechanism.

METHODS

After affirming the curative effects of YQHF on adenine-induced CKD rats, Masson staining, immunohistochemistry, and ELISA were used to assess the effects of YQHF on renal fibrosis. Subsequently, metabolomics and transcriptomics analyses were conducted to clarify the potential mechanisms. Furthermore, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), molecular docking analysis and in vitro experiments were used to verify final mechanism of anti-fibrosis.

RESULTS

Our results demonstrated that YQHF could improve renal morphology, decrease blood urea nitrogen (BUN), serum creatinine (Scr), and increase body weight gain of model rats. Masson staining, immunohistochemistry of collagen I, fibronectin (FN), α-smooth muscle actin (α-SMA), vimentin and E-cadherin showed that YQHF delayed CKD progression by alleviating renal fibrosis, and the expression of fibrotic factors smoc2 and cdh11 were obviously suppressed by YQHF. Metabolomic and transcriptomic measures discovered that indoxyl sulfate might be a crucial factor inducing renal fibrosis, and the antagonistic effect of YQHF on renal fibrosis may be exerted via AhR/snai1 signaling. Subsequently, western blot and immunohistochemical experiments revealed YQHF indeed inhibited AhR/snai1 signaling in adenine-induced renal fibrosis of CKD rat, which confirmed previous results. In addition, molecular docking and in vitro experiments further supported this conclusion, in which astilbin, the main compound identified YQHF, was certified to exert a significant effect on AhR.

CONCLUSION

Our findings showed that YQHF can effectively treat CKD by antagonizing renal fibrosis, the potential mechanisms were relating with the regulation on AhR/snai1 signaling.

Rheopheresis Performed in Hemodialysis Patients Targets Endothelium and Has an Acute Anti-Inflammatory Effect

Background: Rheopheresis is a double-filtration plasmapheresis that removes a defined spectrum of high-molecular-weight proteins to lower plasma viscosity and improves microcirculation disorders. This technique can be performed in hemodialysis (HD) patients with severe microischemia. Interestingly, some studies showed that rheopheresis sessions improve endothelial function. Methods: Our study evaluated the inflammatory and endothelial biomarker evolution in 23 HD patients treated or not with rheopheresis. A p value ≤ 0.001 was considered statistically significant. Results: Thirteen HD patients treated by rheopheresis either for a severe peripheral arterial disease (N = 8) or calciphylaxis (N = 5) were analyzed. Ten control HD patients were also included in order to avoid any misinterpretation of the rheopheresis effects in regard to the HD circuit. In the HD group without rheopheresis, the circulating endothelial adhesion molecules, cytokines, angiogenic factor concentrations, and circulating levels were not modified. In the HD group with rheopheresis, the circulating endothelial adhesion molecules (sVCAM-1, sP-selectin, and sE-selectin) experienced a significant reduction, except sICAM-1. Among the pro-inflammatory cytokines, TNF-α was significantly reduced by 32.6% [(−42.2)−(−22.5)] (p < 0.0001), while the anti-inflammatory cytokine IL-10 increased by 674% (306−1299) (p < 0.0001). Among the angiogenic factors, only sEndoglin experienced a significant reduction. The CEC level trended to increase from 13 (3−33) cells/mL to 43 (8−140) cells/mL (p = 0.002). We did not observe any difference on the pre-session values of the molecules of interest between the first rheopheresis session and the last rheopheresis session. Conclusion: Rheopheresis immediately modified the inflammation balance and the endothelial injury biomarkers. Further studies are needed to understand the mechanisms underlying these biological observations.

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.

Uremic Toxins and Cardiovascular Risk in Chronic Kidney Disease: What Have We Learned Recently beyond the Past Findings?

Patients with chronic kidney disease (CKD) have an elevated prevalence of atheromatous (ATH) and/or non-atheromatous (non-ATH) cardiovascular disease (CVD) due to an array of CKD-related risk factors, such as uremic toxins (UTs). Indeed, UTs have a major role in the emergence of a spectrum of CVDs, which constitute the leading cause of death in patients with end-stage renal disease. The European Uremic Toxin Work Group has identified over 100 UTs, more than 25 of which are dietary or gut-derived. Even though relationships between UTs and CVDs have been described in the literature, there are few reviews on the involvement of the most toxic compounds and the corresponding physiopathologic mechanisms. Here, we review the scientific literature on the dietary and gut-derived UTs with the greatest toxicity in vitro and in vivo. A better understanding of these toxins’ roles in the elevated prevalence of CVDs among CKD patients might facilitate the development of targeted treatments. Hence, we review (i) ATH and non-ATH CVDs and the respective levels of risk in patients with CKD and (ii) the mechanisms that underlie the influence of dietary and gut-derived UTs on CVDs.

Zebrafish Model-Based Assessment of Indoxyl Sulfate-Induced Oxidative Stress and Its Impact on Renal and Cardiac Development

Kidney disease patients may have concurrent chronic kidney disease-associated mineral bone disorder and hypertension. Cardiovascular disease (CVD) and neuropathy occur due to kidney failure-induced accumulation of uremic toxins in the body. Indoxyl sulfate (IS), a product of indole metabolism in the liver, is produced from tryptophan by the intestinal flora and is ultimately excreted through the kidneys. Hemodialysis helps renal failure patients eliminate many nephrotoxins, except for IS, which leads to a poor prognosis. Although the impacts of IS on cardiac and renal development have been well documented using mouse and rat models, other model organisms, such as zebrafish, have rarely been studied. The zebrafish genome shares at least 70% similarity with the human genome; therefore, zebrafish are ideal model organisms for studying vertebrate development, including renal development. In this study, we aimed to investigate the impact of IS on the development of zebrafish embryos, especially cardiac and renal development. At 24 h postfertilization (hpf), zebrafish were exposed to IS at concentrations ranging from 2.5 to 10 mM. IS reduced survival and the hatching rate, caused cardiac edema, increased mortality, and shortened the body length of zebrafish embryos. In addition, IS decreased heart rates and renal function. IS affected zebrafish development via the ROS and MAPK pathways, which subsequently led to inflammation in the embryos. The results suggest that IS interferes with cardiac and renal development in zebrafish embryos, providing new evidence about the toxicity of IS to aquatic organisms and new insights for the assessment of human health risks. Accordingly, we suggest that zebrafish studies can ideally complement mouse model studies to allow the simultaneous and comprehensive investigation of the physiological impacts of uremic endotheliotoxins, such as IS, on cardiac and renal development.

Valvular Heart Disease in Patients with Chronic Kidney Disease

Valvular heart disease (VHD) is highly prevalent in patients with chronic kidney disease (CKD) from the early stages to end-stage renal disease (ESRD). Aortic and mitral valves are the most frequently affected, leading to aortic valve and/or mitral annular calcification, which, in turn, causes either valve stenosis or regurgitation at an accelerated rate compared with the general population. Tricuspid regurgitation is also prevalent in CKD and ESRD, and haemodialysis patients are at an increasingly high risk of infective endocarditis. As for pathophysiology, several mechanisms causing VHD in CKD have been proposed, highlighting the complexity of the process. Echocardiography constitutes the gold standard for the assessment of VHD in CKD/ESRD patients, despite the progress of other imaging modalities. With regard to treatment, the existing 2017 European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines on the management of VHD addressing patients with normal kidney function are also applied to patients with CKD/ESRD.

Is a treat-to-target approach to lipid-lowering therapy appropriate in patients with chronic kidney disease? A prospective French cohort study

BACKGROUND

Whereas European guidelines recommend adjusting lipid-lowering therapy (LLT) to meet prespecified targets ('treat-to-target') for low-density lipoprotein cholesterol (LDL-C), other guidelines do not ('fire and forget'). In a large observational prospective cohort, we sought to evaluate which strategy could be associated with better cardiovascular outcomes in chronic kidney disease (CKD).

METHODS

In CKD-REIN, patients (CKD stages 3 and 4) on LLT were categorized according to achievement of LDL-C targets for high and very high cardiovascular risk (< 2.6 and < 1.8 mmol/L, respectively) at baseline. Primary outcome was fatal/non-fatal atheromatous cardiovascular disease (CVD). Secondary outcomes were non-atheromatous CVD, atheromatous or non-atheromatous CVD, and major adverse cardiovascular events.

RESULTS

The population comprised 1521 patients (68 ± 12 years, 31% women, mean estimated glomerular filtration rate [eGFR] 35 mL/min/1.73 m²). Overall, 523 (34%) met their LDL-C targets at baseline. Median follow-up was 2.9 years (interquartile range 2.2-3.0). Incidence rates per 100 patient-years were 6.2% (95% confidence interval [CI] 5.5-7.0) for atheromatous CVD, 9.2% (8.3-10.1) for non-atheromatous CVD, 15.2% (14.0-16.4) for atheromatous/non-atheromatous CVD, and 6.3% (5.5-7.1) for major adverse cardiovascular events. Corresponding rates in patients who achieved targets were 6.6%, 9.8%, 16.1%, and 6.3%, respectively. Target achievement was not associated with risk of fatal/non-fatal atheromatous CVD (adjusted hazard ratio 1.04, 95% CI 0.76-1.44, p = 0.77) or fatal/non-fatal atheromatous or non-atheromatous CVD (0.98, 0.78-1.23, p = 0.91).

CONCLUSIONS

These findings do not appear to support a treat-to-target approach in CKD patients on LLT, and may favor the hypothesis of an advantage of fire-and-forget. Randomized trials are needed to confirm this theory.

Consequences of oral antithrombotic use in patients with chronic kidney disease

We assessed the risks of bleeding, acute kidney injury (AKI), and kidney failure associated with the prescription of antithrombotic agents (oral anticoagulants and/or antiplatelet agents) in patients with moderate‐to‐advanced chronic kidney disease (CKD). CKD‐REIN is a prospective cohort of 3022 nephrology outpatients with CKD stages 2–5 at baseline. We used cause‐specific Cox proportional hazard models to estimate hazard ratios (HRs) for bleeding (identified through hospitalizations), AKI, and kidney failure. Prescriptions of oral antithrombotics were treated as time‐dependent variables. At baseline, 339 (11%) patients (65% men; 69 [60–76] years) were prescribed oral anticoagulants only, 1095 (36%) antiplatelets only, and 101 (3%) both type of oral antithrombotics. Over a median (interquartile range [IQR]) follow‐up period of 3.0 (IQR, 2.8–3.1) years, 152 patients experienced a bleeding event, 414 patients experienced an episode of AKI, and 270 experienced kidney failure. The adjusted HRs (95% confidence interval [95% CI]) for bleeding associated with prescriptions of antiplatelets only, oral anticoagulants only, and antiplatelet + oral anticoagulant were, respectively, 0.74 (95% CI, 0.46–1.19), 2.38 (95% CI, 1.45–3.89), and 3.96 (95% CI, 2.20–7.12). An increased risk of AKI risk was associated with the prescription of oral anticoagulants (adjusted HR, 1.90, 95% CI, 1.47–2.45) but not the prescription of antiplatelets (HR, 1.24, 95% CI, 0.98–1.56). Kidney failure was not associated with the prescription of oral antithrombotics of any type. This study confirms the high risk of AKI associated with oral anticoagulants prescription in patients with CKD and also highlights the potential aggravating effect of combining vitamin K antagonist (VKA) and antiplatelets on the risk of bleeding.

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

Introduction

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

Methods

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

Results

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

Conclusions

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

Electronic supplementary material

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

Assessment of Thrombotic and Bleeding Tendency in Two Mouse Models of Chronic Kidney Disease: Adenine-Diet and 5/6th Nephrectomy

The coexistence of bleeding and thrombosis in patients with chronic kidney disease (CKD) is frequent and poorly understood. Mouse models are essential to understand complications of CKD and to develop new therapeutic approaches improving the health of patients. We evaluated the hemostasis in two models of renal insufficiency: adenine-diet and 5/6th nephrectomy (5/6Nx). Compared with 5/6Nx mice, mice fed with 0.25% adenine had more severe renal insufficiency and so higher levels of prothrombotic uremic toxins like indoxyl sulfate. More severe renal inflammation and fibrosis were observed in the adenine group, as demonstrated by histological and reverse transcription quantitative polymerase chain reaction experiments. Liver fibrinogen γ chain expression and level of plasma fibrinogen were increased only in adenine mice. In both CKD mouse models, tissue factor (TF) expression was increased in kidney and aorta extracts. Immunochemistry analysis of kidney sections showed that TF is localized in the vascular walls. Thrombin–antithrombin complexes were significantly increased in plasma from both adenine and 5/6Nx mice. Tail bleeding time increased significantly only in adenine mice, whereas platelet count was not significant altered. Finally, results obtained by intravital microscopy after laser-induced endothelial injury showed impaired platelet function in adenine mice and an increase in fibrin generation in 5/6Nx mice. To summarize, adenine diet causes a more severe renal insufficiency compared with 5/6Nx. The TF upregulation and the hypercoagulable state were observed in both CKD models. Bleeding tendency was observed only in the adenine model of CKD that recapitulates the whole spectrum of hemostasis abnormalities observed in advanced human CKD.

Indoxyl Sulfate, a Uremic Endotheliotoxin

Chronic kidney disease (CKD) is associated with a high prevalence of cardiovascular diseases. During CKD, the uremic toxin indoxyl sulfate (IS)—derived from tryptophan metabolism—accumulates. IS is involved in the pathophysiology of cardiovascular complications. IS can be described as an endotheliotoxin: IS induces endothelial dysfunction implicated in cardiovascular morbidity and mortality during CKD. In this review, we describe clinical and experimental evidence for IS endothelial toxicity and focus on the various molecular pathways implicated. In patients with CKD, plasma concentrations of IS correlate with cardiovascular events and mortality, with vascular calcification and atherosclerotic markers. Moreover, IS induces a prothrombotic state and impaired neovascularization. IS reduction by AST-120 reverse these abnormalities. In vitro, IS induces endothelial aryl hydrocarbon receptor (AhR) activation and proinflammatory transcription factors as NF-κB or AP-1. IS has a prooxidant effect with reduction of nitric oxide (NO) bioavailability. Finally, IS alters endothelial cell and endothelial progenitor cell migration, regeneration and control vascular smooth muscle cells proliferation. Reducing IS endothelial toxicity appears to be necessary to improve cardiovascular health in CKD patients.

Female AhR Knockout Mice Develop a Minor Renal Insufficiency in an Adenine-Diet Model of Chronic Kidney Disease

Cardiovascular complications observed in chronic kidney disease (CKD) are associated with aryl hydrocarbon receptor (AhR) activation by tryptophan-derived uremic toxins-mainly indoxyl sulfate (IS). AhR is a ligand-activated transcription factor originally characterized as a receptor of xenobiotics involved in detoxification. The aim of this study was to determine the role of AhR in a CKD mouse model based on an adenine diet. Wild-type (WT) and AhR^-/- mice were fed by alternating an adenine-enriched diet and a regular diet for 6 weeks. Our results showed an increased mortality rate of AhR^-/- males. AhR^-/- females survived and developed a less severe renal insufficiency that WT mice, reflected by urea, creatinine, and IS measurement in serum. The protective effect was related to a decrease of pro-inflammatory and pro-fibrotic gene expression, an attenuation of tubular injury, and a decrease of 2,8-dihydroxyadenine crystal deposition in the kidneys of AhR^-/- mice. These mice expressed low levels of xanthine dehydrogenase, which oxidizes adenine into 2,8-dihydroxyadenine, and low levels of the IS metabolism enzymes. In conclusion, the CKD model of adenine diet is not suitable for AhR knockout mice when studying the role of this transcription factor in cardiovascular complications, as observed in human CKD.

Achievement of Low-Density Lipoprotein Cholesterol Targets in CKD

Introduction

We describe the characteristics of patients with moderate/advanced chronic kidney disease (CKD) according to receipt of lipid-lowering therapy (LLT), and whether they achieved low-density lipoprotein cholesterol (LDL-C) targets for high- and very high-risk patients.

Methods

CKD-REIN (NCT03381950), a prospective cohort study conducted in 40 nephrology clinics in France, enrolled 3033 patients with moderate (stage G3) or advanced (stage G4/G5) CKD (2013-2016) who had not been on chronic dialysis or undergone kidney transplantation. Data were collected from patients' interviews and medical records. Patients were followed up at 1 year.

Results

Among 2542 patients (mean [SD] age 67 [13] years, 34% women) with LDL-C measurements at baseline (mean [SD] LDL-C 2.7 [1.1] mmol/l; cholesterol 4.8 [1.3] mmol/l), 63% were on LLT; 24% were at high (CKD stage G3, no cardiovascular disease [CVD] or diabetes) and 74% at very high (CKD stage G3 with diabetes or CVD, or CKD stage G4/5) cardiovascular risk. Among high-risk patients, 45% of those on statin and/or ezetimibe achieved the LDL-C treatment target (<2.6 mmol/l). Among very high-risk patients, the percentage at goal (<1.8 mmol/l) was 38% for CKD stage G3 and 29% for stage G4/5. There was a trend toward higher achievement of LDL-C targets with increasing LLT intensity (adjusted odds ratios for moderate vs. low intensity 1.20; 95% confidence interval 0.92-1.56; high vs. low intensity 1.46; 1.02-2.09; P _trend = 0.036).

Conclusion

Many patients with CKD stage G3-G5 who are eligible for LLT are not treated, and those on LLT rarely achieve LDL-C targets.

Impact of age on cardiovascular drug use in patients with chronic kidney disease

Background

Elderly patients with chronic kidney disease (CKD) are often excluded from clinical trials; this may affect their use of essential drugs for cardiovascular complications. We sought to assess the impact of age on cardiovascular drug use in elderly patients with CKD.

Methods

We used baseline data from the Chronic Kidney Disease-Renal Epidemiology and Information Network (CKD-REIN) cohort including 3033 adult patients with CKD Stages 3 and 4. We studied the use of recommended drugs for coronary artery disease (CAD), stroke and atrial fibrillation by age, after adjusting for socio-demographic and clinical conditions.

Results

The patients’ mean age was 66.8 years (mean estimated glomerular filtration rate 32.9 mL/min/1.73 m²). The prevalence of CAD was 24.5% [81.3% receiving antiplatelet agents, 75.6% renin–angiotensin system (RAS) blockers, 65.4% β-blockers and 81.3% lipid-lowering therapy], that of stroke 10.0% (88.8% receiving antithrombotic drugs) and that of atrial fibrillation 11.1% (69.5% receiving oral anticoagulants). Compared with patients aged <65 years, older age (≥65 years) was associated with greater use of antithrombotic drugs in stroke [adjusted odds ratio (aOR) (95% confidence interval) = 2.83 (1.04–7.73) for patients aged (75–84 years)] and less use of RAS blockers [aOR = 0.39 (0.16–0.89) for patients aged ≥85 years], β-blockers [aOR = 0.31 (0.19–0.53) for patients aged 75–84 years] and lipid-lowering therapy [aOR = 0.39 (0.15–1.02) for patients aged ≥85 years, P for trend = 0.01] in CAD. Older age was not associated with less use of antiplatelet agents in CAD or oral anticoagulants in atrial fibrillation.

Conclusions

In patients with CKD, older age per se was not associated with the underuse of antithrombotic drugs but was for other major drugs, with a potential impact on cardiovascular outcomes.