Cardiovascular risk in chronic kidney disease

Cardiovascular risk due to diabetes mellitus in patients with chronic kidney disease-prospective data from the German Chronic Kidney Disease cohort

Background

Diabetes mellitus (DM) and chronic kidney disease (CKD) are well-known cardiovascular and mortality risk factors. To what extent they act in an additive manner and whether the etiology of CKD modifies the risk is uncertain.

Methods

The multicenter, prospective, observational German Chronic Kidney Disease study comprises 5217 participants (1868 with DM) with a baseline mean estimated glomerular filtration rate of 30-60 mL/min/1.73 m2 and/or proteinuria >0.5 g/day. We categorized patients whose CKD was caused by cardiovascular or metabolic diseases (CKDcvm) with and without DM, as opposed to genuine CKD (CKDgen) with and without DM. Recorded outcomes were first events of non-cardiovascular and cardiovascular death, 4-point major adverse cardiovascular events (4-point MACE) and hospitalization for heart failure (HHF).

Results

During the 6.5-year follow-up 603 (12%) non-cardiovascular and 209 (4%) cardiovascular deaths, 645 (12%) 4-point MACE, and 398 (8%) HHF were observed, most frequently in patients with DM having CKDcvm. DM increased the risk of non-cardiovascular [hazard ratio (HR) 1.92; 95% confidence interval (CI) 1.59-2.32] and cardiovascular (HR 2.25; 95% CI 1.62-3.12) deaths, 4-point MACE (HR 1.93; 95% CI 1.62-2.31) and HHF (HR 1.87; 95% CI 1.48-2.36). Mortality risks were elevated by DM to a similar extent in CKDcvm and CKDgen, but for HHF in CKDcvm only (HR 2.07; 95% CI 1.55-2.77). In patients with DM, CKDcvm (versus CKDgen) only increased the risk for HHF (HR 1.93; 95% CI 1.15-3.22).

Conclusions

DM contributes to cardiovascular and mortality excess risk in patients with moderate to severe CKD in both, CKDcvm and CKDgen. Patients with DM and CKDcvm are particularly susceptible to HHF.

Pericardial Tamponade and Berger's Disease: An Unusual Association

Cardiac tamponade is considered a medical emergency because a patient can deteriorate easily and die of cardiac arrest if the fluid is not drained immediately. The most common etiologies are the same as pericarditis as fluid accumulates due to pericardial inflammation, including infection, malignancy, trauma, iatrogenic, autoimmune, post-myocardial infarction, radiation, and renal failure. Although the treatment is pericardiocentesis or pericardial window, finding the etiology responsible for the development of pericardial effusion is important. Here, we describe the case of a 40-year-old female who presented to the emergency department with a chief complaint of severe epigastric pain of a two-day duration that was associated with multiple episodes of nausea, vomiting, dysphagia, and severe shortness of breath (New York Heart Association III). The patient was eventually diagnosed with cardiac tamponade as a cause of her dyspnea, as a two-dimensional cardiac echocardiogram detected a large pericardial effusion (>2 cm) with echocardiographic indications for cardiac tamponade with severe pulmonary hypertension. The patient underwent a therapeutic pericardial window with drainage of 250 mL of pericardial fluid. Ultrasound of the abdomen focusing on the kidneys showed an atrophic and echogenic right kidney with a bidirectional flow in the hepatic veins, suggestive of right heart failure. Subsequently, she underwent a kidney biopsy that showed diffuse mesangial proliferative glomerulonephritis with segmental sclerosing features consistent with IgA nephropathy, associated with tubular atrophy, interstitial fibrosis, interstitial inflammation, and moderate arteriosclerosis. The patient was diagnosed with stage V chronic kidney disease secondary to IgA nephropathy. IgA nephropathy is usually common in Caucasian or Asian males in their teens and late 30s, with hematuria as a usual presentation. This case is unique as cardiac tamponade with renal failure is rarely the presenting symptom of IgA nephropathy.

Effect of Dialyzer Reuse on the Activity of Paraoxonase 1 in Patients on Hemodialysis

Background

Cardiovascular disease is the major cause of mortality in patients undergoing chronic hemodialysis treatment. The oxidative modification of low-density lipoprotein is a crucial step in the pathogenesis of atherosclerosis. Paraoxonase 1 (PON1) is the protein responsible for most of the antioxidant activity of high-density lipoprotein, and its reduced levels are associated with more cardiovascular events in several populations. In hemodialysis patients, reduced PON1 activity has been shown to be associated with increased cardiovascular mortality. Studies have shown that after the hemodialysis session, the activity of PON1 increases. The influence of dialyzer reuse on the activity of PON1 is unknown. We aimed to evaluate the effect of the reuse of two types of dialyzers (polynephron and polyethersulfone) on the PON1 activity of hemodialysis patients.

Subjects and Methods

A total of 30 patients on hemodialysis were included. Pre- and post-dialysis blood samples were collected to analyze the activity of PON1 in thefirst use of the dialyzer and in the hemodialysis session of its sixth reuse. This process was carried out with polynephron (bisphenol-free) and polyethersulfone dialyzers.

Results

We found that post-dialysis PON1 activity was significantly higher than pre-dialysis activity in both thefirst use and sixth reuse (P < 0.001).

Conclusion

The practice of reusing the dialyzer did not interfere with the improvement of PON1 activity after the hemodialysis session.

Uremic Toxin-Producing Bacteroides Species Prevail in the Gut Microbiota of Taiwanese CKD Patients: An Analysis Using the New Taiwan Microbiome Baseline

Rationale and Objective

Gut microbiota have been targeted by alternative therapies for non-communicable diseases. We examined the gut microbiota of a healthy Taiwanese population, identified various bacterial drivers in different demographics, and compared them with dialysis patients to associate kidney disease progression with changes in gut microbiota.

Study Design

This was a cross-sectional cohort study.

Settings and Participants

Fecal samples were obtained from 119 healthy Taiwanese volunteers, and 16S rRNA sequencing was done on the V3-V4 regions to identify the bacterial enterotypes. Twenty-six samples from the above cohort were compared with fecal samples from 22 peritoneal dialysis and 16 hemodialysis patients to identify species-level bacterial biomarkers in the dysbiotic gut of chronic kidney disease (CKD) patients.

Results

Specific bacterial species were identified pertaining to different demographics such as gender, age, BMI, physical activity, and sleeping habits. Dialysis patients had a significant difference in gut microbiome composition compared to healthy controls. The most abundant genus identified in CKD patients was Bacteroides, and at the species level hemodialysis patients showed significant abundance in B. ovatus, B. caccae, B. uniformis, and peritoneal dialysis patients showed higher abundance in Blautia producta (p ≤ 0.05) than the control group. Pathways pertaining to the production of uremic toxins were enriched in CKD patients. The abundance of the bacterial species depended on the type of dialysis treatment.

Conclusion

This study characterizes the healthy gut microbiome of a Taiwanese population in terms of various demographics. In a case-control examination, the results showed the alteration in gut microbiota in CKD patients corresponding to different dialysis treatments. Also, this study identified the bacterial species abundant in CKD patients and their possible role in complicating the patients’ condition.

The risk of major bleeding event in patients with chronic kidney disease on pentoxifylline treatment

Patients with chronic kidney diseases (CKD) are often treated with antiplatelets due to aberrant haemostasis. This study aimed to evaluate the bleeding risk with CKD patients undergoing pentoxifylline (PTX) treatment with/without aspirin. In this retrospective study, we used Taiwan’s National Health Insurance Research Database to identify PTX treated CKD patients. Patients undergoing PTX treatment after CKD diagnosis were PTX group. A 1:4 age, sex and aspirin used condition matched CKD patients non-using PTX were identified as controls. The outcome was major bleeding event (MBE: intracranial haemorrhage (ICH) and gastrointestinal tract bleeding) during 2-year follow-up period. Risk factors were estimated using Cox regression for overall and stratified analysis. The PTX group had higher MBE risk than controls (hazard ratio (HR) 1.19; 95% confidence interval (CI) 0.94–1.50). In stratified analysis, hyperlipidaemia was a significant risk factor (HR: 1.42; 95% CI 1.01–2.01) of MBE. A daily PTX dose larger than 800 mg, females, non-regular aspirin usage, and ischaemic stroke were risk factors for MBE in PTX group. When prescribing PTX in CKD patients, bleeding should be closely monitored, especially in those with daily dose more than 800 mg, aspirin users, and with a history of ischaemic stroke.

Circulating Renalase as Predictor of Renal and Cardiovascular Outcomes in Pre-Dialysis CKD Patients: A 5-Year Prospective Cohort Study

Chronic kidney disease (CKD) is an independent risk factor for adverse cardiovascular and cerebrovascular events (MACCEs), and mortality since the earlier stages. Therefore, it is critical to identify the link between CKD and cardiovascular risk (CVR) through early and reliable biomarkers. Acknowledging that CKD and CKD progression are associated with increased sympathetic tone, which is implicated in CVR, and that renalase metabolizes catecholamines, we aimed to evaluate the relationship between renalase serum levels (RNLS) and cardiovascular and renal outcomes. The study included 40 pre-dialysis CKD patients (19F:21M) with median age of 61 (IQ 45–66) years. At baseline, we measured RNLS as well as routine biomarkers of renal and cardiovascular risk. A prospective analysis was performed to determine whether RNLS are associated with CKD progression, MACCEs, hospitalizations and all-cause mortality. At baseline, the median level of RNLS and median estimated glomerular filtration rate (eGFR) were 63.5 (IQ 48.4–82.7) µg/mL and 47 (IQ 13–119) mL/min/1.73 m², respectively. In univariate analysis, RNLS were strongly associated with eGFR, age and Charlson Index. Over the course of a mean follow-up of 65 (47 to 70) months, 3 (7.5%) deaths, 2 (5%) fatal MACCEs, 17 (42.5%) hospital admissions occurred, and 16 (40%) patients experienced CKD progression. In univariate analysis, RNLS were associated with CKD progression (p = 0.001), hospitalizations (p = 0.001) and all-cause mortality (p = 0.022) but not with MACCEs (p = 0.094). In adjusted analysis, RNLS predicted CKD progression and hospitalizations regardless of age, Charlson comorbidity index, cardiovascular disease, hypertension, diabetes and dyslipidemia. Our results suggest that RNLS, closely related with renal function, might have a potential role as predictor of renal outcomes, hospitalizations, and mortality in pre-dialysis CKD patients.

Cholesterol Disturbances and the Role of Proper Nutrition in CKD Patients

Chronic kidney disease (CKD) is a widespread disease with increasing prevalence in the modern society. Lipid disturbances are common in this group of patients. In most patients with CKD atherogenic dyslipidemia is observed. Dyslipidemia in patients with renal diseases increases the risk of cardiovascular diseases and it accelerates the progression of chronic kidney disease to its end stage. The amelioration of dyslipidemia and the lowering of oxidative stress, inflammatory processes, insulin sensitivity and remnant lipoproteins levels may lead to the reduction in cardiovascular burden. Nutritional interventions can strengthen the beneficial effect of treatment and they play an important role in the preservation of overall well-being of the patients with CKD since the aim of appropriate diet is to reduce the risk of cardiovascular events, prevent malnutrition, and hamper the progression of kidney disease. The management of dyslipidemia, regardless of the presence of chronic kidney disease, should be initiated by the introduction of therapeutic lifestyle changes. The introduction of diet change was shown to exert beneficial effect on the lipid level lowering that reaches beyond pharmacological therapy. Currently available evidence give the impression that data on dietary interventions in CKD patients is not sufficient to make any clinical practice guidelines and is of low quality.

Emerging Factors Implicated in Fibrotic Organ-Associated Thrombosis: The Case of Two Organs

Thrombosis is at the heart of cardiovascular complications observed in specific diseases. A heightened thrombosis risk above that in general population in diseases such as myelofibrosis and chronic kidney disease implicates disease-specific mediators of thrombosis. This relative lack of information regarding the mechanisms of thrombosis in specific organ pathologies hitherto has remained limited. Evolving literature implicates some soluble factors in the blood of patients with discrete disorders, inflicting fundamental changes in the components of thrombosis. In this era of precision medicine, integrating these disease-specific factors in a comprehensive thrombotic risk assessment of patients is imperative in guiding therapeutic decisions. A complex network of mechanisms regulates each organ pathology and resultant thrombotic phenotypes. This review surveys different effectors of thrombogenicity associated with two pathologically fibrotic organs used as model systems, the bone marrow and kidney, as well as focuses attention to a common inducer of fibrosis and thrombosis, lysyl oxidase.

Renal function and isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS): Isomers of C8 Health Project in China

Perfluoroalkyl substances (PFASs) are widely-utilized synthetic chemicals commonly found in industrial and consumer products. Previous studies have examined associations between PFASs and renal function, yet the results are mixed. Moreover, evidence on the associations of isomers of PFASs with renal function in population from high polluted areas is scant. To help to address this data gap, we used high performance liquid chromatography-mass spectrometry to measure serum isomers of perfluorooctanoate (PFOA), perfluorooctanesulfonate (PFOS), and other PFASs from 1612 adults residing in Shenyang, China, and characterized their associations with estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD). Results showed that after adjusted for multiple confounding factors, most of the higher fluorinated PFASs, except for PFOA and PFDA, were negatively associated with eGFR and positively associated with CKD. Compared with linear PFOS (n-PFOS), branched PFOS isomers (Br-PFOS) were more strongly associated with eGFR (Br-PFOS; β = -1.22, 95%CI: 2.02, -0.42; p = 0.003 vs. n-PFOS; β = -0.16, 95%CI: 0.98, 0.65; p = 0.691) and CKD (Br-PFOS; OR = 1.27; 95% CI: 1.02, 1.58; p = 0.037 vs. n-PFOS; OR = 0.98; 95% CI: 0.80, 1.20; p = 0.834). In conclusion, branched PFOS isomers were negatively associated with renal function whereas their linear counterparts were not. Given widespread exposure to PFASs, potential nephrotoxic effects are of great public health concern, Furthermore, longitudinal research on the potential nephrotoxic effects of PFASs isomers will be necessary to more definitively assess the risk.

Risk of acute myocardial infarction in upper tract urothelial carcinoma patients receiving radical nephroureterectomy: a population-based cohort study

Background

The outcomes of upper tract urothelial carcinoma (UTUC) receiving radical nephroureterectomy were usually limited to small sample size, case-control studies, and often focused on cancer progression. Risk of acute myocardial infarction (AMI) in these patients was never investigated.

Results

The overall incidences of AMI were 3.39, 1.44, and 1.70 per 10,000 person-years in the radical nephroureterectomy, nonnephroureterectomy, and non-UTUC cohorts, respectively. Multivariable Cox proportional hazard regression analysis revealed a significantly higher AMI risk in the radical nephroureterectomy cohort [adjusted HR (aHR) = 1.83, 95% confidence interval (CI) = 1.08–3.11], compared with non-UTUC cohorts. The risk of mortality were the highest in patients with UTUC who had undergone radical nephroureterectomy [adjusted HR (aHR) = 5.37, 95% confidence interval (CI) = 4.80–6.02].

Materials and Methods

From the Taiwan National Health Insurance claims data, 1,359 patients with UTUC who had undergone radical nephroureterectomy and 3,154 patients with UTUC who had undergone nephron sparing surgery and were newly diagnosed between 2000 and 2010 were identified. For each patient, 4 individuals without UTUC were randomly selected and frequency matched by age, sex, and diagnosis year.

Conclusions

Patients with UTUC who have undergone radical nephroureterectomy are at a higher risk of developing AMI, compared with those receiving nephron sparing surgery.

Uremic pericarditis, pericardial effusion, and constrictive pericarditis in end-stage renal disease: Insights and pathophysiology

A rising prevalence of end-stage renal disease (ESRD) has led to a rise in ESRD-related pericardial syndromes, calling for a better understanding of its pathophysiology, diagnoses, and management. Uremic pericarditis, the most common manifestation of uremic pericardial disease, is a contemporary problem that calls for intensive hemodialysis, anti-inflammatories, and often, drainage of large inflammatory pericardial effusions. Likewise, asymptomatic pericardial effusions can become large and impact the hemodynamics of patients on chronic hemodialysis. Constrictive pericarditis is also well documented in this population, ultimately resulting in pericardiectomy for definitive treatment. The management of pericardial diseases in ESRD patients involves internists, cardiologists, and nephrologists. Current guidelines lack clarity with respect to the management of pericardial processes in the ESRD population. Our review aims to describe the etiology, classification, clinical manifestations, diagnostic imaging tools, and treatment options of pericardial diseases in this population.

Cardiovascular disease in patients with chronic kidney disease: a neglected subgroup

The burden of non-communicable diseases has increased exponentially over the past decade and they account for majority of the health-related morbidity and mortality worldwide. In line with this, the prevalence of chronic kidney disease (CKD) has been increasing over the years. CKD progresses through stages and it is well known that patients are more likely to die than to progress to end-stage renal disease. The presence of multiple classical and novel risk factors predisposes this group of patients to premature cardiovascular mortality. Though being a common entity, prevention, diagnosis and treatment of cardiovascular diseases in CKD are mired with controversies. This is due to the fact that many of the well-established diagnostic modalities and treatment strategies have not been studied in detail in patients with CKD. Moreover, most of the studies have excluded patients with renal dysfunction though they are at a higher risk for adverse outcomes and require specific dose modifications. This has limited the evidence base for optimal decision making. In this review, we aim to cover the risk factors, diagnosis and effectiveness of interventional strategies in patients with CKD.

Pure red cell aplasia due to antibody against erythropoietin in hemodialysis patients

Background

Anemia is a common complication of chronic renal failure due to reduce erythropoietin production by kidneys. Anemia treated with recombinant human erythropoietin (rHu-EPO). Pure red cell aplasia (PRCA) due to antibody productionagainst rHu-EPO is a rare but major complication of this drug.

Objectives

The aim of this study was to determine the prevalence of PRCA due to antibodies in dialysis patients with resistant anemia who received erythropoietin.

Patients and Methods

We studied 128 under maintenance hemodialysis patients more than 3 month in Kashan. In patients with anemia who received erythropoietin with dose requirements based on weight and anemia and without any another cause for anemia, evaluate for PRCA and anti-rHu-EPO antibody level were measured by ELISA.

Results

In this research, 75 patients (58.6%) were male and 53 patients (41.4%) were female. The mean age of the patients was 59.05 ± 16.66 years. The result of analysis showed that 55 (43%) patients had anemia with hemoglobin level less than 10 mg/dL. Only 3 patients had PRCA and antibodies against erythropoietin in serum. There were no correlation between age, gender, cause of renal failure, hemodialysis duration, hemoglobin level, rHu-EPO dose and levels of anti-rHu-EPO antibody serum value.

Conclusions

The result of this study indicated that administration of rHu-EPO in dialysis patients afflicted to kidney failure may cause PRCA especially through intravenous injection. However, this change is not statistically significant.

Brain natriuretic peptide as a potential novel marker of salt-sensitivity in chronic kidney disease patients without cardiac dysfunction

Although the renin-angiotensin system (RAS) is counter-balanced by a salt-sensitive mechanism in the hypertensive state, both are reported to be up-regulated in chronic kidney disease (CKD) patients. We conducted this study to evaluate the associations among the RAS, renal function, hypertension, and atherosclerosis, as well as to identify markers for salt-sensitivity. A total of 213 pre-dialysis CKD patients with preserved cardiac function (EF >50 %) were enrolled. Their renal and cardiac biochemical markers and plasma renin activity (PRA) were measured, and echocardiography and carotid artery ultrasound were performed. Their salt intake was estimated by the NaCl excretion from a 24-h collected urine sample. The PRA was higher in patients with hypertension (p = 0.018), and had a significant negative correlation with the eGFR (r = -0.23, p = 0.0067). Importantly, the PRA had a strong negative correlation with the brain natriuretic peptide (BNP) level (r = -0.28, p = 0.017) regardless of whether the patients were being treated with RAS inhibitors. The BNP level was related to the renal functions (eGFR: p = 0.001, ACR: p = 0.009). There was a significant positive correlation between the BNP level and carotid intima-media thickness (p < 0.001). A multivariate analysis revealed that older age and an excess of NaCl excretion were independent predictors of BNP elevation (p = 0.02 and 0.003, respectively). Our analysis revealed details of the counterbalance between BNP and PRA, as well as identifying that excess salt intake is a predictor of BNP elevation. These results indicate that the BNP could be a possible valuable marker for salt sensitivity, and that high salt sensitivity could facilitate atherosclerosis in CKD patients.

Screening for Nephropathy in Diabetes Mellitus: Is Micral-Test Valid among All Diabetics?

Background. Using Micral-test (MT) for screening microalbuminuria (MA) among type 2 diabetics (T2D) is helpful. We aimed at determining prevalence of MA and at describing the MT validity. Methods. We studied 182 T2D followed up in family medicine. Two 24-hour urinary quantitative assays of MA had been used as a gold standard. Results. Prevalence of MA was 23%, CI 95%: 16.9–29.1. MT validity was 77% for sensitivity, 88% for negative predictive value, and 0.2 for Kappa coefficient (p = 0.001). Among subjects having a blood pressure ≥130/80 mmHg, having a CHT/HDL ratio ≥ 3, being a T2D for more than 5 years, and being women, negative predictive values were, respectively, 91%, 89%, 95%, and 91%. The area under the ROC curve was 0.81 in men (p = 0.008) and 0.80 when diabetes duration exceeds 5 years (p = 0.001). The MA value at 100% Sp for MT was 35 mg/L. Conclusion. The use of MT in primary healthcare for yearly screening for MA in T2D must be accentuated especially when diabetes duration exceeds 5 years or when associated with other cardiovascular risks.

Chronic kidney disease in children

Chronic kidney disease (CKD) is a major health problem worldwide. Although relatively uncommon in children, it can be a devastating illness with many long-term consequences. CKD presents unique features in childhood and may be considered, at least in part, as a stand-alone nosologic entity. Moreover, some typical features of paediatric CKD, such as the disease aetiology or cardiovascular complications, will not only influence the child's health, but also have long-term impact on the life of the adult that they will become. In this review we will focus on the unique issues of paediatric CKD, in terms of aetiology, clinical features and treatment. In addition, we will discuss factors related to CKD that start during childhood and require appropriate treatments in order to optimize health outcomes and transition to nephrologist management in adult life.

High-Sensitivity Cardiac Troponin Concentrations in Patients with Chest Discomfort: Is It the Heart or the Kidneys As Well?

BACKGROUND

High-sensitivity cardiac troponins (hs-cTn) are the preferred biomarkers to detect myocardial injury, making them promising risk-stratifying tools for patients with symptoms of chest pain. However, circulating hs-cTn are also elevated in other conditions like renal dysfunction, complicating appropriate interpretation of low-level hs-cTn concentrations.

METHODS

A cross-sectional analysis was performed in 1864 patients with symptoms of chest discomfort from the cardiology outpatient department who underwent cardiac computed tomographic angiography (CCTA). Serum samples were analyzed using hs-cTnT and hs-cTnI assays. Renal function was measured by the estimated glomerular filtration rate (eGFR), established from serum creatinine and cystatin C. On follow-up, the incidence of adverse events was assessed.

RESULTS

Median hs-cTnT and hs-cTnI concentrations were 7.2(5.8-9.2) ng/L and 2.6(1.8-4.1) ng/L, respectively. Multivariable regression analysis revealed that both assay results were more strongly associated with eGFR (hs-cTnT:stβ:-0.290;hs-cTnI:stβ:-0.222) than with cardiac imaging parameters, such as coronary calcium score, CCTA plaque severity score and left ventricular mass (all p<0.01). Furthermore, survival analysis indicated lower relative risks in patients with normal compared to reduced renal function for hs-cTnT [HR(95%CI), 1.02(1.00-1.03) compared to 1.07(1.05-1.09)] and hs-cTnI [1.01(1.00-1.01) compared to 1.02(1.01-1.02)] (all p<0.001).

CONCLUSION

In patients with chest discomfort, we identified an independent influence of renal function on hs-cTn concentrations besides CAD, that affected the association of hs-cTn concentrations with adverse events. Estimating renal function is therefore warranted when interpreting baseline hs-cTn concentrations.

Perfluorooctanoic acid and chronic kidney disease: Longitudinal analysis of a Mid-Ohio Valley community

INTRODUCTION

Perfluorooctanoic acid (PFOA) is an environmentally persistent chemical found at low-levels in the serum of almost all U.S. residents. Chronic kidney disease (CKD) has been positively associated with serum PFOA in prior cross-sectional studies and in one occupational mortality study, while other investigations have found no association between kidney function and PFOA.

METHODS

We conducted a longitudinal analysis of chronic kidney disease among adults, aged ≥20 years, (N=32,254) in a Mid-Ohio Valley community cohort, exposed to high PFOA levels from contaminated drinking water. Estimated retrospective yearly serum PFOA concentrations (1951-2011) were previously modeled in this population. Information about lifetime history of CKD diagnosis was collected during surveys in 2008-2011; self-reported CKD diagnoses were validated through medical record review. Using a Cox proportional hazards model, we retrospectively examined the association between validated adult onset CKD, and modeled PFOA exposure, from time of first exposure. We also analyzed data for the cohort prospectively, among people with no CKD diagnosis prior to enrollment in a baseline survey in 2005-2006. Both the full cohort and a non-diabetic subset were analyzed, retrospectively and prospectively.

RESULTS

Neither in retrospective nor in prospective analyses did we find a significant (α=0.05) trend between PFOA exposure and CKD. In the full cohort, estimated hazard ratios by quintile of cumulative serum PFOA in the retrospective analysis were 1.00 (referent), 1.26, 1.12, 1.12 and 1.24 (trend test for log cumulative exposure: p=0.80).

CONCLUSION

Our analyses suggest that CKD is not associated with exposure to PFOA.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Baroreflex dysfunction in chronic kidney disease

Chronic kidney disease (CKD) patients have high cardiovascular mortality and morbidity. The presence of traditional and CKD related risk factors results in exaggerated vascular calcification in these patients. Vascular calcification is associated with reduced large arterial compliance and thus impaired baroreflex sensitivity (BRS) resulting in augmented blood pressure (BP) variability and hampered BP regulation. Baroreflex plays a vital role in short term regulation of BP. This review discusses the normal baroreflex physiology, methods to assess baroreflex function, its determinants along with the prognostic significance of assessing BRS in CKD patients, available literature on BRS in CKD patients and the probable patho-physiology of baroreflex dysfunction in CKD.

Plasma Nitration of High-Density and Low-Density Lipoproteins in Chronic Kidney Disease Patients Receiving Kidney Transplants

BACKGROUND

Functional abnormalities of high-density lipoprotein (HDL) could contribute to cardiovascular disease in chronic kidney disease patients. We measured a validated marker of HDL dysfunction, nitrated apolipoprotein A-I, in kidney transplant recipients to test the hypothesis that a functioning kidney transplant reduces serum nitrated apoA-I concentrations.

METHODS

Concentrations of nitrated apoA-I and apoB were measured using indirect sandwich ELISA assays on sera collected from each transplant subject before transplantation and at 1, 3, and 12 months after transplantation. Patients were excluded if they have history of diabetes, treatment with lipid-lowering medications or HIV protease inhibitors, prednisone dose > 15 mg/day, nephrotic range proteinuria, serum creatinine > 1.5 mg/dL, or active inflammatory disease. Sera from 18 transplanted patients were analyzed. Four subjects were excluded due to insufficient data. Twelve and eight patients had creatinine < 1.5 mg/dL at 3 and 12 months after transplantation, respectively. RESULTS. Nitrated apoA-I was significantly reduced at 12 months after transplantation (p = 0.039). The decrease in apoA-I nitration was associated with significant reduction in myeloperoxidase (MPO) activity (p = 0.047). In contrast to apoA-I, nitrated apoB was not affected after kidney transplantation.

CONCLUSIONS

Patients with well-functioning grafts had significant reduction in nitrated apoA-I 12 months after kidney transplantation. Further studies are needed in a large cohort to determine if nitrated apoA-I can be used as a valuable marker for cardiovascular risk stratification in chronic kidney disease.

Clinical outcomes of treatment by percutaneous coronary intervention versus coronary artery bypass graft surgery in patients with chronic kidney disease undergoing index revascularization in Ontario

BACKGROUND

There is a paucity of data on the comparative effectiveness of percutaneous coronary intervention using contemporary drug-eluting stent (DES) compared with coronary artery bypass graft (CABG) surgery in patients with chronic kidney disease.

METHODS AND RESULTS

A population-based study was performed using the Cardiac Care Network, a provincial registry of all patients undergoing cardiac catheterization in Ontario, to evaluate patients treated with either percutaneous coronary intervention using DES or CABG between October 1, 2008, and September 30, 2011. Chronic kidney disease was defined as creatinine clearance <60 mL/min. A total of 1786 propensity-matched patients from 4006 patients with chronic kidney disease undergoing index revascularization for multivessel disease with either DES or isolated CABG (n=893 each group) were analyzed. Baseline and procedural characteristics between percutaneous coronary intervention and CABG groups were well-balanced, including urgent revascularization priority, diabetes mellitus, left ventricular function, and 3-vessel disease. The 1-, 2-, and 3-year Kaplan-Meier survival analyses in propensity-matched patients favored CABG (93.2% versus 89.3%; 86.6% versus 80.3%; 80.8% versus 71.5%, respectively; P<0.001). The CABG cohort had greater 1-, 2-, and 3-year freedom from major adverse cardiac and cerebrovascular events (89.4% versus 71.2%; 81.9% versus 60.5%; 75.2% versus 51.8%, respectively; P<0.001). Cox regression analysis identified DES use to be associated with greater hazard for late mortality (hazard ratio, 1.58; 95% confidence interval, 1.32-1.90) and major adverse cardiac and cerebrovascular events (2.62; 2.28-3.01; all P<0.001).

CONCLUSIONS

In this large provincial registry, CABG was associated with improved early and late clinical outcomes when compared with percutaneous coronary intervention using DES in patients with chronic kidney disease undergoing index revascularization.

Randomly and Non-Randomly Missing Renal Function Data in the Strong Heart Study: A Comparison of Imputation Methods

Kidney and cardiovascular disease are widespread among populations with high prevalence of diabetes, such as American Indians participating in the Strong Heart Study (SHS). Studying these conditions simultaneously in longitudinal studies is challenging, because the morbidity and mortality associated with these diseases result in missing data, and these data are likely not missing at random. When such data are merely excluded, study findings may be compromised. In this article, a subset of 2264 participants with complete renal function data from Strong Heart Exams 1 (1989-1991), 2 (1993-1995), and 3 (1998-1999) was used to examine the performance of five methods used to impute missing data: listwise deletion, mean of serial measures, adjacent value, multiple imputation, and pattern-mixture. Three missing at random models and one non-missing at random model were used to compare the performance of the imputation techniques on randomly and non-randomly missing data. The pattern-mixture method was found to perform best for imputing renal function data that were not missing at random. Determining whether data are missing at random or not can help in choosing the imputation method that will provide the most accurate results.

p-Cresyl sulfate aggravates cardiac dysfunction associated with chronic kidney disease by enhancing apoptosis of cardiomyocytes

Background

Cardiovascular disease is the leading cause of death in patients with chronic kidney disease. A body of evidence suggests that p-cresyl sulfate (PCS), a uremic toxin, is associated with the cardiovascular mortality rate of patients with chronic kidney disease; however, the molecular mechanisms underlying this feature have not yet been fully elucidated.

Methods and Results

We aimed to determine whether PCS accumulation could adversely affect cardiac dysfunction via direct cytotoxicity to cardiomyocytes. In mice that underwent 5/6 nephrectomy, PCS promoted cardiac apoptosis and affected the ratio of left ventricular transmitral early peak flow velocity to left ventricular transmitral late peak flow velocity (the E/A ratio) observed by echocardiography (n=8 in each group). Apocynin, an inhibitor of NADPH oxidase activity, attenuates this alteration of the E/A ratio (n=6 in each group). PCS also exhibited proapoptotic properties in H9c2 cells by upregulating the expression of p22^phox and p47^phox, NADPH oxidase subunits, and the production of reactive oxygen species. Apocynin and N-acetylcysteine were both able to suppress the effect of PCS, underscoring the importance of NADPH oxidase activation for the mechanism of action.

Conclusions

This study demonstrated that the cardiac toxicity of PCS is at least partially attributed to induced NADPH oxidase activity and reactive oxygen species production facilitating cardiac apoptosis and resulting in diastolic dysfunction.

Prevalence of nephropathy in the German diabetes population-Is early referral to nephrological care a realistic demand today?

In Germany, diabetes mellitus in the general population has increased to ∼8 million people. The implication of this trend for future nephrological care is not well known, as data on this issue are rather limited. Results from different population-based studies suggest that microalbuminuria in diabetic patients is present in 20–30% of the cases. Findings from the diabetes disease management programme in the North-Rhine area revealed the prevalence of chronic kidney disease (CKD) stage II in half of the participants (CKD stage III was present in ∼20%). Only a small proportion of this cohort (∼1–2%) will reach end-stage renal failure, probably due to the excess mortality risks attributed to advanced kidney disease. Results from the QUASI-Niere registry, which reports on renal replacement therapy in Germany, indicate almost constant incidence and prevalence rates of diabetes in the last 5 years (30.6–34.2% and 23.6–27.1%, respectively). The high percentages of early stages of CKD in the diabetes population indicate a potentially high burden of future nephrological care, especially if patients are referred to nephrologists at an early stage. In reality, in nephrological care, bearing this burden is impossible without expanding the resources for this patient group.

p-Cresyl sulfate, a uremic toxin, causes vascular endothelial and smooth muscle cell damages by inducing oxidative stress

The major cause of death in patients with chronic kidney disease (CKD) is cardiovascular disease. Here, p-Cresyl sulfate (PCS), a uremic toxin, is considered to be a risk factor for cardiovascular disease in CKD. However, our understanding of the vascular toxicity induced by PCS and its mechanism is incomplete. The purpose of this study was to determine whether PCS enhances the production of reactive oxygen species (ROS) in vascular endothelial and smooth muscle cells, resulting in cytotoxicity. PCS exhibited pro-oxidant properties in human umbilical vein endothelial cells (HUVEC) and aortic smooth muscle cells (HASMC) by enhancing NADPH oxidase expression. PCS also up-regulates the mRNA levels and the protein secretion of monocyte chemotactic protein-1 (MCP-1) in HUVEC. In HASMC, PCS increased the mRNA levels of alkaline phosphatase (ALP), osteopontin (OPN), core-binding factor alpha 1, and ALP activity. The knockdown of Nox4, a subunit of NADPH oxidase, suppressed the cell toxicity induced by PCS. The vascular damage induced by PCS was largely suppressed in the presence of probenecid, an inhibitor of organic anion transporters (OAT). In PCS-overloaded 5/6-nephrectomized rats, plasma MCP-1 levels, OPN expression, and ALP activity of the aortic arch were increased, accompanied by the induction of Nox4 expression. Collectively, the vascular toxicity of PCS can be attributed to its intracellular accumulation via OAT, which results in an enhanced NADPH oxidase expression and increased ROS production. In conclusion, we found for the first time that PCS could play an important role in the development of cardiovascular disease by inducing vascular toxicity in the CKD condition.

Plasma metabolomic profiles in different stages of CKD

BACKGROUND AND OBJECTIVES

CKD is a common public health problem. Identifying biomarkers adds prognostic/diagnostic value by contributing to an understanding of CKD at the molecular level and possibly defining new drug targets. Metabolomics provides a snapshot of biochemical events at a particular time in the progression of CKD. This cross-sectional metabolomics study ascertained whether plasma metabolite profiles are significantly different in CKD stages 2, 3, and 4.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

An analysis of plasma metabolites, using gas and liquid chromatography coupled to mass spectrometry, was conducted on 30 nondiabetic men ages 40-52 years, with 10 participants each in CKD stages 2, 3, and 4 based on their estimated GFR (calculated by the Modified Diet in Renal Disease formula). Participants were recruited in late 2008, and plasma samples were tested at Metabolon Inc and analyzed in 2012.

RESULTS

Comparison of stage 3/stage 2 identified 62 metabolites that differed (P ≤ 0.05), with 39 higher and 23 lower in stage 3 compared with stage 2; comparisons of stage 4/stage 2 identified 111 metabolites, with 66 higher and 45 lower; and comparisons of stage 4/stage 3 identified 11 metabolites, with 7 higher and 4 lower. Major differences in metabolite profiles with increasing stage of CKD were observed, including altered arginine metabolism, elevated coagulation/inflammation, impaired carboxylate anion transport, and decreased adrenal steroid hormone production.

CONCLUSIONS

Global metabolite profiling of plasma uncovered potential biomarkers of stages of CKD. Moreover, these biomarkers provide insight into possible pathophysiologic processes that may contribute to progression of CKD.

Cardio-renal syndrome: new perspective in diagnostics

Chronic heart failure and chronic renal failure are at epidemic proportions. These patients have significantly altered cardiac, renal, and all-cause outcomes. Much of the current research has focused on treating these individual organs in isolation. Although there are positive data on outcomes with neurohormonal modulation, they, however, remain underused. At present, data lacks for novel treatment options, while evidence continues to point at significantly worsened prognosis. Current diagnostic tools that detect acute changes in renal function or renal injury appear retrospective, which often hinder meaningful diagnostic and therapeutic decisions. This review is aimed at exploring the importance of accurate assessment of renal function for the heart failure patient by providing a synopsis on cardio-renal physiology and establishing the possibility of novel approaches in bridging the divide.

Comparison of different glomerular filtration methods in the elderly: which formula provides better estimates?

OBJECTIVES

Technetium-99m diethylenetriaminepentaacetic acid ((99m)Tc-DTPA) is an ideal radioisotopic method having a high correlation with inulin clearance for the determination of glomerular filtration rate (GFR). Different formulas like creatinine clearance (CrCl) in 24 h urine samples, Cockroft-Gault formula (CGF), and modification of diet in renal disease (MDRD) are being used to come up with an estimate. In this study, we compared (99m)Tc-DTPA with the formulas mentioned above in an attempt to best identify the method that would yield the nearly ideal GFR estimates in the elderly.

MATERIALS AND METHODS

In 76 patients who were admitted to our clinic, we measured 24 h urine volume (V), urine creatinine (Ucr), and serum creatinine (Scr) levels together with CrCl, Scr, serum urea (Su), and albumin (Alb) levels. By using coefficients identified for age, gender, and race, we calculated modification of diet in renal disease 1 (MDRD1). Different from MDRD1, we calculated modification of diet in renal disease 2 (MDRD2) that does not include Su and Alb parameters and formulas like CGF that include Scr, age, gender, and weight parameters to come up with GFR levels. All patients underwent (99m)Tc-DTPA procedure.

RESULTS

The mean of the GFR values measured by (99m)Tc-DTPA was 54.3 ± 19.9. The means of GFR values calculated by CrCl, MDRD1, MDRD2, and CGF were 58.0 ± 30.5, 60.9 ± 22.1, 54.4 ± 20.1, and 57.9 ± 22.4, respectively. GFR as measured by (99m)Tc-DTPA showed statistically significant correlations with the results of other methods (p < 0.001 for all methods). The most significant correlation was with MDRD1.

CONCLUSION

MDRD1 can be used for next to ideal and accurate predictions of GFR in the elderly in the daily practice.

Proteinuria: an ignored marker of inflammation and cardiovascular disease in chronic hemodialysis

BACKGROUND

Cardiovascular disease is the leading cause of morbidity and mortality in hemodialysis (HD) patients, the main etiologies being diabetes and hypertension. Cardiac and inflammatory biomarkers are usually employed to assess risk or damage, or during follow-up. Proteinuria is considered a strong predictor of morbidity, a cause of inflammation, oxidative stress, hemodynamic alteration, and progression of chronic kidney disease. However, proteinuria is rarely considered in the clinical assessment of HD patients.

METHODS

This was a concurrent, cohort-observational, cross-sectional study in which 52 chronic HD subjects were divided into three groups according to the degree of proteinuria: Group (G) A: <1 g/day, n = 25; GB: 1-3 g/day, n = 13; GC: >3 g/day, n = 14. Baseline hemoglobin, albuminemia, cholesterol, body mass index, Malnutrition-Inflammatory Score, pro-B-type natriuretic peptide, troponin T, C-reactive protein (CRP), and ultrafiltration rates were analyzed.

RESULTS

There was no difference between groups in terms of baseline age, gender, hypertension, cause of renal failure, hemoglobin, cholesterol, albumin, CRP levels, cardiac biomarkers, adiponectin, body mass index, or Malnutrition-Inflammatory Score. Time on HD: GA, 34.56 ± 23.3 (range [r]: 6-88); GB, 25.15 ± 19.40 (r: 6-58); GC, 18.21 ± 9.58 (r: 6-74) months; P = 0.048. Proteinuria: GA, 0.33 ± 0.30 (r: 0.0-0.88); GB, 1.66 ± 0.54 (r: 1.03-2.75); GC, 7.18 ± 2.80 (r: 3.04-21.5) g/day; P < 0.001. Mean ultrafiltration rates were significantly different: GA, 2.80 ± 0.73; GB: 1.85 ± 0.96 liters/session; P = 0.003. Fourteen diabetic patients were identified (27%): GA, 3 (12%); GB, 3 (23%); GC, 8 (57%); P = 0.009. A positive and significant correlation was observed between diabetes and proteinuria >3 g/day: rho 0.438, P = 0.027. Although troponin T, pro-B-type natriuretic peptide, adiponectin, and CRP were not different among groups, the positive correlation between troponin T and CRP elevated significantly as proteinuria increased: GA, rho 377, P = 0.063; GB, rho 663, P = 0.013; GC, rho 687, P = 0.007.

CONCLUSION

In chronic HD, nephrotic-range proteinuria was significantly higher in diabetic nephropathy patients versus other causes. This was associated with inflammation and cardiac stress and was independent of fluid removal. Proteinuria >3 g/day was associated with shorter time on HD. Whether severe proteinuria is associated with shorter survival in HD, independent of diabetes, is to be determined. Proteinuria should be considered in the assessment of cardiovascular and inflammatory states in HD patients.

Impact of preoperative renal dysfunction on outcomes of off-pump coronary artery bypass grafting

BACKGROUND

This study assessed whether preoperative renal insufficiency predisposes patients undergoing off-pump coronary artery revascularization to postoperative dialysis.

METHODS

From August 2004 through June 2009, 2,275 patients undergoing off-pump coronary artery bypass were categorized into five groups (stages) by glomerular filtration rate (GFR). Of these, 1,855 patients had renal insufficiency: stage 2: 1,406; stage 3: 428; stage 4: 21, and 414 had normal renal function, stage 1. Excluded were 6 patients with end-stage renal disease (stage 5). Preoperative variables and postoperative outcomes were compared among groups.

RESULTS

Preoperative patient characteristics were similar; however, patients with normal renal function were younger (p = 0.001). Serum creatinine rose significantly above baseline on the first postoperative day in the renal insufficiency groups (p = 0.001). The GFR groups had similar inotrope use, reexploration rate, duration of postoperative mechanical ventilation, postoperative stroke, wound infection, and mortality rate. Stage 4 patients had a higher incidence of postoperative myocardial infarction (p = 0.002). Stage 3 and 4 patients had an increased need for postoperative dialysis vs stage 1 patients (p = 0.002).

CONCLUSIONS

Nonparametric contingency analysis showed patients with low preoperative GFR (stage 3 and 4, p < 0.0001) and a history of smoking (p = 0.04) were at increased risk for postoperative dialysis. Patients who required postoperative inotropic support tended toward requiring postoperative dialysis (p = 0.06). Low preoperative ejection fraction (p = 0.83), class III or IV angina (p = 0.069), and postoperative blood transfusions were not associated with the need for postoperative dialysis in patients undergoing off-pump revascularization.

Rate of kidney function decline associates with mortality

The effect of rate of decline of kidney function on risk for death is not well understood. Using the Department of Veterans Affairs national databases, we retrospectively studied a cohort of 4171 patients who had rheumatoid arthritis and early stage 3 chronic kidney disease (CKD; estimated GFR 45 to 60 ml/min) and followed them longitudinally to characterize predictors of disease progression and the effect of rate of kidney function decline on mortality. After a median of 2.6 years, 1604 (38%) maintained stable kidney function; 426 (10%), 1147 (28%), and 994 (24%) experienced mild, moderate, and severe progression of CKD, respectively (defined as estimated GFR decline of 0 to 1, 1 to 4, and >4 ml/min per yr). Peripheral artery disease predicted moderate progression of CKD progression. Black race, hypertension, diabetes, cardiovascular disease, and peripheral artery disease predicted severe progression of CKD. After a median of 5.7 years, patients with severe progression had a significantly increased risk for mortality (hazard ratio 1.54; 95% confidence interval 1.30 to 1.82) compared with those with mild progression; patients with moderate progression exhibited a similar trend (hazard ratio 1.10; 95% confidence interval 0.98 to 1.30). Our results demonstrate an independent and graded association between the rate of kidney function decline and mortality. Incorporating the rate of decline into the definition of CKD may transform a static definition into a dynamic one that more accurately describes the potential consequences of the disease for an individual.

Effects of renal dysfunction on cardiovascular events in diabetic patients with hypertension: challenge-DM Study subgroup analysis

BACKGROUND

This study investigated the relation between renal dysfunction and cardiovascular events in patients from the Challenge-DM Study (a large-scale investigation of Japanese diabetic patients with hypertension on candesartan therapy).

METHODS

The subjects were 4706 patients in whom renal function could be assessed at the time of registration among 16860 patients analyzed in the Challenge-DM Study. The definition of renal dysfunction (low GFR) was an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2) calculated by the formula for Japanese.

RESULTS

The low GFR group was older, and had a high proportion of females and a high prevalence of cerebrovascular or cardiovascular disease (CVD) compared to the normal GFR group (eGFR ≥ 60 ml/min/1.73 m(2)). Univariate Cox regression analysis of cardiovascular events showed a significant increase in the incidence of primary events and total events in the low GFR group. Among patients <65 years old, the same results were obtained, but no differences were found between the low GFR and normal GFR groups aged over 65 years. Multivariate Cox regression analysis was done with patient characteristics at registration and the presence/absence of achieving the target blood pressure and HbA(1c) before the event as explanatory variables. As a result, low GFR was not the main cause of cardiovascular events, but it had a significant influence on primary events and total events among patients <65 years old.

CONCLUSIONS

Low GFR may be an independent risk factor for cerebrovascular and CVD among young and middle-aged Japanese diabetic patients with hypertension on candesartan therapy.

[Cardiorenal syndrome]

With increasing age of a population, the rate and severity of comorbidities are also growing, resulting in a rising number of people with a condition described as "cardiorenal syndrome". Initially, cardiorenal syndrome defined the decline in cardiac and renal function due to diminished renal perfusion in the context of heart failure. However, in order to give consideration to the numerous comorbidities, nowadays the definition has been widened. Following a new classification, five types of cardiorenal syndrome are distinguished. Such a differentiation is helpful to find the appropriate therapeutic approach, according to the underlying disease. Therefore, the new classification and modern therapeutic concepts shall be presented here.

The role of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) as a prognostic marker in older people: the impact of reduced renal function

The N-terminal pro-brain natriuretic peptide (NT-pro-BNP) is released in response to volume expansion and/or increased tension on left ventricular myocytes. NT-pro-BNP is a useful diagnostic and prognostic biomarker both in patients with dyspnoea of unknown aetiology, and for risk assessment of patients with established heart failure. However, impaired kidney function – a common condition in older people as well as a strong risk factor for cardiovascular disease is associated with elevated circulating levels of NT-pro-BNP. Therefore, it is important to know the kidney function when interpreting an elevated NT-pro-BNP measurement obtained in older people in order to diagnose or stage congestive heart failure.

ROS and PDFG-β receptors are critically involved in indoxyl sulfate actions that promote vascular smooth muscle cell proliferation and migration

Patients with chronic renal failure are at greater risk of developing atherosclerosis than healthy individuals, and recent data suggest that the putative uremic toxin indoxyl sulfate (IS) promotes the pathogenesis of atherosclerosis. The present study examined the effects of IS on vascular smooth muscle cells (VSMCs) with respect to reactive oxygen species (ROS), platelet-derived growth factor (PDGF) receptors, and mitogen-activated protein kinases (MAPKs). IS induced the migration and proliferation of VSMCs and synergistically enhanced their PDGF-induced migration as well as proliferation. The effects of PDGF were promoted after a 24-h incubation with IS despite the absence of IS during PDGF stimulation. Intracellular ROS levels were increased in the presence of IS, and PDGF-dependent ROS production was augmented by a prior 24-h incubation with IS even in the absence of IS during PDGF stimulation. These data suggest that IS increases the sensitivity of VSMCs to PDGF. IS also phosphorylated PDGF-β-receptors and upregulated PDGF-β receptor but not α-receptor protein expression in the absence of exogenous PDGF. The NADPH oxidase inhibitor diphenylene iodonium blocked IS-dependent increase in receptor expression. Administration of IS to nephrectomized rats also elevated receptor protein expression in arterial VSMCs. Inhibitors of NADPH oxidase, PDGF-β receptors, extracellular-regulated protein kinase (ERK), and p38 MAPK all inhibited IS-induced VSMCs migration and proliferation. Taken together, these findings indicate that IS induces the migration as well as proliferation of VSMCs through PDGF-β receptors and that ROS generation is critically involved in this process, which promotes the development of atherosclerosis.

Cardiovascular risk and management in chronic kidney disease

Chronic kidney disease (CKD) is associated with accelerated progression of cardiovascular disease, perhaps because patients with CKD have a high burden of traditional cardiovascular risk factors in addition to a range of nontraditional risk factors such as inflammation and abnormal metabolism of calcium and phosphate. Although the cardiovascular burden of CKD is well documented, potentially beneficial therapies are sometimes underused in patients with stage 3-4 CKD and are rarely studied in patients on dialysis. In this Review, we describe the epidemiology of cardiovascular disease in patients with stage 3-5 CKD (excluding kidney transplant recipients) and outline cardiovascular risk factors that are relevant in this population; we then discuss the implications of this knowledge for the optimal management of cardiovascular risk in this setting. Finally, we highlight opportunities for further research.

Risk Factors and Prevention of End Stage Renal Disease in Uruguay

Uruguay is a developing country with a privileged established program for renal replacement therapy (RRT) for all patients with end stage renal disease (ESRD) since 1981. In December 2004, the RRT prevalence reached 916 patients per million population. The ESRD incidence has not changed significantly in the last eight years, differing with what is observed in other countries. In contrast, the ESRD incidence secondary to diabetic nephropathy has shown a permanent increase. The prevention of chronic kidney disease (CKD) began in 1989 with the Program of Prevention and Treatment of Glomerulonephritis (PPTG), being extended in 2002 to all CKD and canalized through the National Program of Renal Healthcare (NPRH) since 2004. The registry of glomerulonephritis has been demonstrated in recent years: patients are referral to nephrologists earlier, there is an increase of the frequency of patients with "clinical remission," and thus there is a decrease of the frequency of ESRD in the first three months after referral. The NPRH has been developed in a progressive way with the involvement of government authorities and the active participation of the nephrologists. A global prevention program, integrating the prevention of CKD, cardiovascular diseases, hypertension, and diabetes was developed. The first steps of the program have had important achievements: a rational reorientation of nephrologic care in the first level of attention, patient access to renoprotective medications without cost; a registration system of patients, the creation of a formal multidisciplinary team, and the instauration of a continuous medical education program.

Association between atherosclerosis and newly classified chronic kidney disease stage for Japanese patients with type 2 diabetes

Using a new estimated glomerular filtration rate (eGFR) equation, we undertook a retrospective chart review to investigate the clinical significance of chronic kidney disease (CKD) stage for atherosclerosis in 653 Japanese patients with type 2 diabetes that were followed from January 2004 to December 2006 at Juntendo University Hospital. Diabetic patients with CKD stage 2 or 3 detected in 2004 or before had more history of cardiovascular disease (CVD) compared with those patients without CKD [ischemic heart disease (IHD): 25% vs. 9.3%, P<0.01 and stroke: 17.6% vs. 10.5%, P<0.05]. In Addition, the incidence of CVD through the observation period tended to increase with progression of CKD stage (0.9% in stage 0, 3.2% in stage 1 or 2, and 3.4% in stage > or =3, P=0.056), and patients with eGFR<75 had a higher incidence of IHD (2.5% vs. 0.3%) and IHD or Stroke (3.3% vs. 0.7%) compared with those who had eGFR > or =75. Patients with urinary albumin excretion rate (UACR) > or =20mg/g Cr also had a higher incidence of IHD or stroke compared to patients with UACR<20 (3.5% vs. 0.6%). In conclusion, diabetic patients with eGFR<75 and/or UACR > or =20 might be a high-risk population for CVD.

Cardiovascular disease in chronic kidney disease

The presence of kidney disease, manifested by low glomerular filtration rates (GFR) and/or large amounts of protein in the urine, is independently associated with increased rates of cardiovascular disease (CVD). The severity of kidney disease is associated with graded increases in risk for CVD and death. Chronic kidney disease (CKD) should be recognized and treatment initiated early to maximize the chances for slowing nephropathy progression and reducing proteinuria. We recommend screening for CKD in all patients with CVD, including computing an estimated GFR and evaluating for proteinuria using a spot urine albumin:creatinine ratio. Aggressive management of traditional cardiovascular risk factors should be employed in this high-risk population, specifically rigorous hypertension control (including the use of angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor blocking agents (ARB)), management of hyperglycemia, hyperlipidemia and smoking cessation. Further studies are needed to identify the unique renal failure-related (non-traditional) risk factors that contribute to accelerated atherosclerosis in this population and performance of randomized trials to assess the effects of cardiovascular interventions in individuals with CKD.