Strong association between malnutrition, inflammation, and atherosclerosis in chronic renal failure

Inverse J-shaped relation between coronary arterial calcium density and mortality in advanced chronic kidney disease

BACKGROUND

The coronary artery calcium (CAC) score from cardiac computed tomography (CT) is a composite of CAC volume and CAC density. In the general population, CAC volume is positively and CAC density inversely associated with cardiovascular disease (CVD) events, implying that decreased CAC density reflects atherosclerotic plaque instability. We analysed associations of CAC indices with mortality risk in patients with end-stage renal disease [chronic kidney disease Stage 5 (CKD5)].

METHODS

In 296 CKD5 patients undergoing cardiac CT (median age 55 years, 67% male, 19% diabetes, 133 dialysed), the Framingham risk score (FRS), presence of CVD and protein-energy wasting (PEW; subjective global assessment) and high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) were determined at baseline. During follow-up for a median of 35 months, 51 patients died and 75 patients underwent renal transplantation. All-cause mortality risk was analysed with competing-risk regression models. Vascular calcification was analysed in biopsies of the arteria epigastrica inferior in 111 patients.

RESULTS

Patients in the middle tertile of CAC density had the highest CAC score, CAC volume, age, CVD, PEW, FRS, hsCRP and IL-6. In competing risk analysis, the middle {subhazard ratio [sHR] 10.7 [95% confidence interval (CI) 2.0-57.3]} and high [sHR 8.9 (95% CI 1.5-51.8)] tertiles of CAC density associated with increased mortality, independent of CAC volume. The high tertile of CAC volume, independent of CAC density, associated with increased mortality [sHR 8.9 (95% CI 1.5-51.8)]. Arterial media calcification was prominent and associated with CAC volume and CAC density.

CONCLUSIONS

In CKD5, mortality increased linearly with higher CAC score and CAC volume whereas for CAC density an inverse J-shaped pattern was observed, with the crude mortality rate being highest for the middle tertile of CAC density. CAC volume and CAC density were associated with the extent of arterial media calcification.

Prevalence of malnutrition inflammation complex syndrome among patients on maintenance haemodialysis at Muhimbili National Hospital in Tanzania: a cross-sectional study

Background

Malnutrition, inflammation, and the combination thereof are predictors of poor outcomes in haemodialysis patients. Malnutrition Inflammation Complex Syndrome (MICS) is an accelerator of atherosclerosis and portends high mortality. Early recognition and treatment of MICS may help to improve the clinical outlook of such patients. This study investigated the prevalence of MICS and its associated factors among patients on maintenance haemodialysis at Muhimbili National Hospital (MNH) in Dar es Salaam, Tanzania.

Methods

This was a prospective cross-sectional observational study done among 160 adult patients on maintenance haemodialysis at MNH in 2019. All participants provided written informed consent. Questionnaires were used to collect data and patients’ blood was tested for complete blood count (CBC), C-reactive protein (CRP), ferritin, transferrin, creatinine, urea, total cholesterol, and albumin. The Malnutrition Inflammation Score was used to assess MICS and its severity. Data analysis was done using the SPSS 20 software.

Results

Of the 160 patients included in the study, 111 (69.4%) were male. The mean age (±SD) of patients and mean duration (±SD) on haemodialysis were 52.2(13.3) years and 22(18) months respectively. MICS was prevalent in 46.3% (mild in 24.4% and moderate to severe in 21.9%).

Long-term haemodialysis (> 4 years) was an independent predictor of MICS [Adjusted Odds Ratio, AOR 5.04 (95% CI: 1.33–19.2), p < 0.05]. Hypercholesterolaemia was a negative predictor of MICS [AOR 0.11 (95% CI: 0.01–0.97), p < 0.05]. Patients with MICS had significantly lower mean body mass index, serum albumin, total cholesterol, transferrin, haemoglobin, and creatinine levels. The presence of MICS was higher in underweight patients and those who had inflammation. Haemodialysis adequacy did not correlate with MICS.

Conclusion

Malnutrition Inflammation Complex Syndrome is relatively common among patients on haemodialysis in Dar es Salaam, Tanzania. Our study has shown a longer duration on haemodialysis to be associated with the occurrence of MICS; on the contrary, having hypercholesterolaemia seems to be protective against MICS consistent with the concept of reverse epidemiology. Patients on haemodialysis should be assessed regularly for malnutrition and inflammation and should receive appropriate and timely treatment to reduce the burden of associated morbidity, and mortality to these patients.

Application of homograft for intraoperative severe atherosclerotictic iliac vessel finding in renal transplantation: A case report

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Severe atherosclerosis is a complicated condition in patients with CKD and as the number of waiting list for renal transplantation rose, the rate is increasing.

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Surgeons should not omit artherosclerosis even pre-operative results did not suggest it.

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One-stage approach (renal transplantation and vascular reconstruction altogether) is a feasible and safe method for treating the conditions.

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The role of the surgeon’s skills and experiences, and especially tissue bank should be highlighted.

Introduction

Severe atherosclerosis is a complicated condition in chronic kidney disease (CKD) and could lead to the operation’s failure, when it was not detectable by pre-operative diagnostic imaging. Several methods including two-stage approach, synthetic graft, stent… have been reported, but complications (i.e. infection, graft rejection) are a matter of concern. The aim of this case is to provide the one-stage approach, in which renal transplantation and vascular reconstruction using fresh homografts from one brain-dead donor were used.

Presentation of case

We reported a case of a 33-year-old male, who was diagnosed with CKD caused by chronic glomerulonephritis since the age of 28 and had been on hemodialysis. Not until did the transplantation take place that the operation team spotted the atherosclerotic external iliac artery, and vessel graft from the same donor was used and the renal was transplanted. The patient was discharged 14 days after the surgery without any complications.

Discussion

Kidney transplantation has revolutionized the life of patients with end-stage renal disease (ESRD). Around 6% of patients have severe atherosclerosis and the figure is increasing. Vascular degradation in ESRD might lead to unsuccessful operation. One-stage approach (including renal transplantation and external iliac artery replacement) using homograft from one doner is feasible to handle the situation.

Conclusion

Severe atherosclerosis often accompanies with CKD. The difficulties of doing arterial anastomosis increases, which requires advanced techniques to deal with. Surgeons should be prepared about this circumstance. One-stage approach using one donor’s homografts, is a possible and safe procedure.

Serum C-reactive protein to albumin ratio and mortality associated with peritoneal dialysis

Background: Serum C-reactive protein to albumin ratio (CAR) was recently identified as a poor marker of prognosis among various populations. The current study aimed to examine the association between CAR and all-cause mortality among patients undergoing peritoneal dialysis (PD).Methods: A total of 758 patients with PD were included in this study during the period from 1 November 2005 to 28 February 2017 and followed up until 31 May 2017. The primary outcome was all-cause mortality. We used multivariate Cox proportional hazard models and Kaplan-Meier survival curves to assess the relationship between CAR and all-cause mortality in these patients.Results: Among 758 participants, mean age was 49.1 ± 14.2 years, with 56% males and 18.6% prevalence of diabetes. Median CAR was 0.13 (interquartile range [IQR], 0.07-0.34). After 27 months (IQR, 14-40 months) of follow-up, 157 deaths had been reported. After adjusting for confounding factors, we found a significant association between serum CAR and all-cause mortality among those in the highest CAR group (hazard ratio 1.91, 95% confidence interval 1.05- 3.47, p = 0.034).Conclusions: In patients undergoing PD, an increase in serum CAR is independently associated with increased risk for all-cause mortality.

Immune Dysfunction in Dialysis Patients—Prevention and Treatment Strategies

Immune dysfunction, resulting in infection or inflammation, or both, is closely associated with poor clinical outcome in end-stage renal disease patients. So far, no single measure can effectively address this condition, because many factors, such as uremia per se and dialysis treatment are involved in the pathogenesis. Our review focuses on currently available treatments and prevention options, and identifies future research needs.

Infectious Complications in Chronic Dialysis Patients

Surprisingly little formal research has examined the issue of major bacterial infections in chronic dialysis patients. This is a surprising situation, because uremia is a classic state of immune hyporesponsiveness, and infection rates are believed to be several times higher in dialysis populations than in age-matched segments of the general population. The present paper focuses on the clinical epidemiology of major bacterial infections in dialysis patients, associations between bacterial infections and cardiovascular disease, and interventions aimed at averting these infections.

MIF associated with pulmonary hypertension susceptibility and severity in non-dialysis Chronic kidney disease patients

Pulmonary hypertension (PAH) is one of the more serious complications of Chronic kidney disease (CKD), and its exact pathogenesis has not been clarified. As an upstream proinflammatory factor, macrophage migration inhibitor (MIF) is involved in the occurrence and development of many diseases. This study aimed to detect the relationship between serum MIF and PAH in non-dialysis CKD patients. A total of 382 non-dialysis CKD patients were enrolled in this study. Bio-Plex cytokine assay was used to detect MIF. CKD patients were divided into the PAH group and non-PAH group according to echocardiographic results. Relative risk was determined by logistic regression analysis. The pulmonary artery pressure in the CKD group was higher than that in the control group ( p < 0.01). Pulmonary arterial pressure was higher in stage 4 to 5 CKD patients than in Stage 1 to 3 CKD patients ( p < 0. 01), and the incidence of PAH was also increased ( p < 0. 01). MIF in the CKD group were higher than in the control group ( p < 0.05). MIF in CKD patients with PAH were higher than those without PAH ( p < 0.05). Multivariate logistic regression analysis showed that MIF is correlated with PAH (OR = 10.745; 95% CI 2.288–89.447, p < 0.05). PAH is common in non-dialysis CKD patients, and with the deterioration of kidney disease, the incidence of PAH is gradually increased, indicating that MIF plays an important role in the development of PAH in CKD patients.

Importance of Dietary Phosphorus for Bone Metabolism and Healthy Aging

Inorganic phosphate (Pi) plays a critical function in many tissues of the body: for example, as part of the hydroxyapatite in the skeleton and as a substrate for ATP synthesis. Pi is the main source of dietary phosphorus. Reduced bioavailability of Pi or excessive losses in the urine causes rickets and osteomalacia. While critical for health in normal amounts, dietary phosphorus is plentiful in the Western diet and is often added to foods as a preservative. This abundance of phosphorus may reduce longevity due to metabolic changes and tissue calcifications. In this review, we examine how dietary phosphorus is absorbed in the gut, current knowledge about Pi sensing, and endocrine regulation of Pi levels. Moreover, we also examine the roles of Pi in different tissues, the consequences of low and high dietary phosphorus in these tissues, and the implications for healthy aging.

Change in Oxidative Stress Biomarkers During 30 Days in Saturation Dive: A Pilot Study

Saturation diving allows divers to reduce the risk of decompression sickness while working at depth for prolonged periods but may increase reactive oxygen species (ROS) production. Such modifications can affect endothelial function by exacerbating oxidative stress. This study investigated the effects of saturation diving on oxidative stress damage. Redox status was evaluated through: ROS production; total antioxidant capacity (TAC); nitric oxide metabolites (NOx); nitrotyrosine (3-NT); and lipid peroxidation (8-iso-PGF2α) assessment. Creatinine and neopterin were analyzed as markers of renal function and damage. Measurements were performed on saliva and urine samples obtained at four time points: pre; deep; post; and 24 h post. Four divers were included in the study. After the saturation dive (post), significant (p < 0.05) increases in ROS (0.12 ± 0.03 vs. 0.36 ± 0.06 µmol.min^-1), TAC (1.88 ± 0.03 vs. 2.01 ± 0.08 mM), NOx (207.0 ± 103.3 vs. 441.8 ± 97.3 µM), 3-NT (43.32 ± 18.03 vs. 18.64 ± 7.45 nM·L^-1), and 8-iso-PGF2α (249.7 ± 45.1 vs. 371.9 ± 54.9 pg·mg^-1 creatinine) were detected. Markers of renal damage were increased as well after the end of the saturation dive (creatinine 0.54 ± 0.22 vs. 2.72 ± 1.12 g-L^-1; neopterin 73.3 ± 27.9 vs. 174.3 ± 20.53 μmol·mol^-1 creatinine). These results could ameliorate commercial or military diving protocols or improve the understanding of symptoms caused by oxygen level elevation.

Impacts of geriatric nutritional risk index on prognosis of patients with non-ST-segment elevation acute coronary syndrome: Results from an observational cohort study in China

BACKGROUND AND AIMS

It is recognized that malnutrition increases risk of worse prognosis in patients with various diseases. The present study investigated if poor nutritional status predicts adverse outcomes in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) undergoing percutaneous coronary intervention (PCI).

METHODS AND RESULTS

The study enrolled 2299 patients (mean age: 60.01 ± 8.95 years; 71.8% male) with NSTE-ACS who underwent PCI at Beijing Anzhen Hospital from January to December 2015. The entire cohort was divided into training set (n = 1519) and testing set (n = 780) at a ratio of approximate 2 : 1. Nutritional status was assessed by geriatric nutritional risk index (GNRI). The primary endpoint was a composite of adverse events as follows: all-cause death, non-fatal myocardial infarction (MI) and any revascularization. Multivariate Cox analysis showed that GNRI significantly associated with primary endpoint, independent of other risk factors [hazard ratio (HR) 1.159 per 1-point decrease of GNRI, 95% confidence interval (CI) 1.130-1.189, p < 0.001]. The addition of GNRI to a baseline model had an incremental effect on the predictive value for adverse prognosis in training set [AUC: from 0.821 to 0.873, p < 0.001; category-free net reclassification improvement (NRI): 0.313, p < 0.001; integrated discrimination improvement (IDI): 0.108, p < 0.001]. The incremental effect of GNRI was further validated and confirmed in testing set.

CONCLUSION

Lower GNRI is a significant predictor of adverse prognosis in patients with NSTE-ACS undergoing PCI. Further studies need to be performed to determine whether nutritional interventions have a positive impact on improving clinical prognosis.

Protein Energy Wasting in Children With Chronic Kidney Disease and End-Stage Kidney Disease: An Observational Study

OBJECTIVES

Protein energy wasting (PEW), a specific nutritional comorbidity associated with increased mortality, is underrecognized in children with chronic kidney disease (CKD). The aim of this study was to determine the burden and factors associated with PEW and assess the utility of parameters used to diagnose PEW in children with CKD and End stage kidney disease (ESKD).

METHODS

Children between 2 and 18 years of age with CKD stages 2-5 were recruited over 30 months. Parameters of PEW assessed included body mass index for height, mid-upper arm circumference, height for age, appetite, serum albumin, cholesterol, transferrin, and C-reactive protein. Based on number of criteria fulfilled in each subject, PEW was further stratified as mild, standard, and modified PEW.

RESULTS

One hundred twenty-three children (male:female 3:1, 73 in CKD stages 2-4, 50 with ESKD) were recruited. PEW was observed in 58% (47% in CKD stages 2-4 vs. 73% ESKD, P = .035). Longer duration and severity of disease was associated PEW. Reduced appetite (P = .001, P = .04), low mid-upper arm circumference (P = .000, P = .006), and low body mass index for height (P = .000, P = .007) were useful criteria to diagnose PEW in CKD stages 2-4 and ESKD, while most children did not meet biochemical criteria. Inflammation observed in 47% was higher in those with ESKD [CKD stages 2-4: 72 (39%) vs. ESKD: 29 (59%), P = .02] but was associated with PEW only in CKD stages 2-4.

CONCLUSION

PEW was highly prevalent in children with CKD and ESKD. Appetite and anthropometry measures were more useful than biochemical criteria for diagnosis of PEW. Whereas inflammation was common, it was associated with PEW only in CKD stages 2-4. Pediatric CKD and ESKD may need exclusive diagnostic criteria for PEW based on anthropometry, appetite, and inflammation.

Oxidative stress accelerates the carotid atherosclerosis process in patients with chronic kidney disease

INTRODUCTION

The atherosclerosis process is highly accelerated in patients with chronic kidney disease (CKD). Oxidative stress is considered as one of the pro-atherogenic factors involved in accelerating the atherosclerosis process of the carotid artery. The aim of the present study was to determine the relationship between oxidative stress markers and the progression of carotid atherosclerosis in CKD patients.

MATERIAL AND METHODS

The study was conducted on 162 patients with CKD and 40 controls, and the disease stage was scored between 2 and 5D. Blood samples were taken and advanced oxidative protein product, myeloperoxidases, malondialdehyde, nitric oxide, glutathione, and oxidised low-density lipoprotein were measured. Furthermore, we studied the correlations between these biomarkers and clinical and para-clinical cardiovascular complications.

RESULTS

The average age of patients was 56.5 years. The oxidative stress markers average ± SD levels in CKD groups compared to the control were as follows: advanced oxidation protein product (61.89 ±1.4 vs. 26.65 ±1.05 µmol/l), myeloperoxidase (59.89 ±1.98 vs. 38.45 ±1.98 UI/ml), malondialdehyde (6.1 ±0.12 vs. 3.26 ±0.03 µmol/l), nitric oxide (65.82 ±1.06 vs. 52.19 ±2.1 µmol/l), glutathione (52.21 ±1.3 vs. 89.4 ±2.6 IU/ml), and oxLDL (15.57 ±1.07 vs. 1.72 ±0.82 µmol/l). While the glutathione level decreased significantly in advanced CKD stage (p < 0.05), the concentrations of all the other biomarkers increased significantly in accordance with CKD score (p < 0.05).

CONCLUSIONS

Cardiovascular diseases, mainly atherosclerosis, can be diagnosed indirectly by measuring oxidative stress markers. Furthermore, theses markers can be used to predict the progression of CKD, for better management of the disease.

Markers of protein-energy wasting and physical performance in haemodialysis patients: A cross-sectional study

Background

Physical impairments are common in uraemia, as reflected by the high risk of falls of haemodialysis (HD) patients. Furthermore, these patients often suffer from malnutrition.

Objective

Up to now, it is unknown which aspects of physical performance are predominantly driven by malnutrition in HD patients. As this answer could steer different interventions, the aim of this study was to evaluate the cross-sectional relationship between nutritional status, muscle strength, exercise capacity and the risk of falls.

Methods

This study recruited HD patients between December 2016 and March 2018 from two hospital-based and five satellite dialysis units (registration number on clinicaltrial.gov: NCT03910426). The mini-nutritional assessment scale as well as objective measures of protein-energy wasting were obtained (total iron-binding capacity, total protein levels, and CRP). Physical assessment included muscle strength (quadriceps, handgrip force, and sit-to-stand test), exercise capacity (six-minute walking test) and the risk of falls (Tinetti, FICSIT, and dialysis fall index). Their interrelationship was analysed by ridge regression models.

Results

Out of 113 HD patients (mean age 67 years ± 16.1, 57.5% male) 36.3% were malnourished according to the mini-nutritional assessment scale and a majority had impaired quadriceps force (86.7%), six-minute walking test (92%), and an increased risk of falls (73.5%). Total protein and CRP levels were identified as relevant nutritional factors in the association with physical performance. Nutritional parameters explained 9.2% of the variance in the risk of falls and 7.6% of the variance in exercise capacity. No conclusive association was found between nutritional status and muscle strength.

Conclusion

Protein-energy wasting is a determinant of the risk of falls and exercise capacity in patients on HD. The association between malnutrition and muscle weakness remains inconclusive.

Endocan: A novel biomarker for risk stratification, prognosis and therapeutic monitoring in human cardiovascular and renal diseases

The vascular endothelium is localized at the interface between the blood and surrounding tissues, playing a pivotal role in the maintenance of tissue-fluid homeostasis and in the regulation of host defense, inflammation, vascular tone and remodeling, angiogenesis and haemostasis. The dysfunctional endothelium was shown to be implicated in the pathophysiology of several endothelial-dependent disorders, such as arterial hypertension, coronary artery disease, heart failure and chronic kidney disease, in which it is an early predictor of cardiovascular events. Endocan is a soluble dermatan sulphate proteoglycan mainly secreted by the activated endothelium. It is upregulated by several proinflammatory cytokines and proangiogenic factors and may itself contribute to the inflammatory status. In addition of being a surrogate marker of inflammation and endothelial dysfunction, it seems to be involved in the regulation of several proliferative and neovascularization processes. Therefore, its utility as a biomarker in a wide spectrum of diseases has been increasingly explored. Here, we review the current evidence concerning the role of endocan in several human cardiovascular and renal diseases, where it seems to be a promising biomarker for risk stratification, prognosis and therapeutic monitoring.

Serum levels of protein carbonyl, a marker of oxidative stress, are associated with overhydration, sarcopenia and mortality in hemodialysis patients

Background

Increased oxidative stress in end-stage renal disease is regarded as one of the important mechanisms in the atherosclerosis and muscle wasting. However, studies examining the clinical significance of oxidative stress by direct measurement of these markers and its association with volume status and sarcopenia are limited.

Methods

A follow-up cross-sectional study was performed in stable hemodialysis (HD) patients and serum protein carbonyl levels were measured as a biomarker of oxidative stress. Additionally, multi-frequency body composition analysis, handgrip strength (HGS) and nutritional assessments were performed at baseline.

Results

Eighty-eight patients undergoing HD were included and 30 (34.1%) patients died during a mean follow-up of 5.2 years. The mean patient age was 60.6 ± 13.5 years, and the mean HD duration was 50.8 ± 41.3 months. In total, 16 patients (18.2%) were overhydrated, 49 (55.7%) had low HGS and 36 (40.9%) had low muscle mass. Serum protein carbonyl levels were associated with serum levels of albumin, prealbumin and transferrin, hydration status and low HGS. Overhydration (odds ratio [OR] 7.01, 95% CI 1.77–27.79, p = 0.006), prealbumin (OR 0.91, 95% CI 0.83–0.99, p = 0.030), subjective global assessment (OR 3.52, 95% CI 1.08–11.46, p = 0.037) and sarcopenia (OR 3.41, 95% CI 1.02–11.32, p = 0.046) were significantly related to increased serum protein carbonyl levels. Multivariate analysis showed that the serum levels of protein carbonyl (Hazard ratio [HR] 2.37, 95% CI 1.02–5.55, p = 0.036), albumin (HR 0.17, 95% CI 0.06–0.46, p = 0.003), prealbumin (HR 0.86, 95% CI 0.80–0.92, p = 0.001), overhydration (HR 2.31, 95% CI 1.26–8.71, p = 0.015) and sarcopenia (HR 2.72, 95% CI 1.11–6.63, p = 0.028) were independent determinants of all-cause mortality.

Conclusions

Serum protein carbonyl was significantly associated with overhydration, nutritional status and sarcopenia, and could be a new predictor of mortality in patients undergoing HD.

A Pilot Study of a Natural Food Supplement as New Possible Therapeutic Approach in Chronic Kidney Disease Patients

The identification of natural bioactive compounds, able to counteract the abnormal increase of oxidative stress and inflammatory status in chronic degenerative non-communicable diseases is useful for the clinical management of these conditions. We tested an oral food supplement (OFS), chemically characterized and evaluated for in vitro and in vivo activity. Vitamin C, analyzed by High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD), was 0.19 mg/g in rosehip dry extract and 15.74 mg/capsule in the OFS. The identification of polyphenols was performed by HPLC-DAD; the total antioxidant capacity was assessed by Folin-Ciocalteu test. Total polyphenols were 14.73 mg/g gallic acid equivalents (GAE) for rosehip extract and 1.93 mg/g GAE for OFS. A total of 21 chronic kidney disease (CKD) patients and 10 healthy volunteers were recruited. The evaluation of routine laboratory and inflammatory parameters, erythrocyte glutathione transferase (e-GST), human oxidized serum albumin (HSAox), and assessment of body composition were performed at two different times, at baseline and after 5 weeks of OFS assumption. In the study, we highlighted a significant decrease of traditional inflammatory biomarkers (such as C-reactive protein, erythrocyte sedimentation rate, platelet to lymphocyte ratio) and other laboratory parameters like e-GST, azotaemia, and albuminuria after OFS treatment in CKD patients. Moreover, we demonstrated a lipid profile improvement in CKD patients after OFS supplementation.

Interleukine 6 and C-reactive protein predict growth impairment and acute malnutrition in children and adolescents with chronic kidney disease

Introduction

Objective: secondary malnutrition and systemic inflammation may impair growth and body composition in children and adolescents with chronic kidney disease (CKD). This association has been scantily studied, particularly in pre-dialytic stages. Our aim was to correlate growth and nutritional status indicators with the serum concentration of interleukine 6 (IL-6) and ultrasensitive C-reactive protein (CRP) in children with CKD. Methods: this was a prospective cross-sectional study in 29 children and adolescents aged 3-16 years with CKD, stages 3 or 4, in two third-level general hospitals. The outcome variables were height for age, body mass index, arm anthropometric indicators, plus lean mass/fat percentage by bioelectrical impedance. The independent variables were IL-6 and CRP. This study was reviewed and approved by the Health Research and Ethics Committees of both hospitals. Results: height for age, body mass index, subscapular skinfold, arm fat area, and lean mass had a significant negative correlation with IL-6. The height-for-age z-score had a negative correlation with CRP. IL-6 explained 15% to 35% of the variance in height for age and nutritional status indicators. CRP predicted 22% of height for age. One fifth of the patients had acute malnutrition, and one third were stunted. Muscle was the most affected compartment. Conclusion: IL-6 and CRP in children and adolescents with CKD in the pre-dialytic stage predicted one fifth and one third of the variance in acute and chronic malnutrition indicators. The frequency of acute malnutrition and impaired growth was clinically significant. Muscular mass deficit was a central component of malnutrition.

Association of protein-energy wasting and inflammation status with mortality after coronary revascularisation in patients on haemodialysis

OBJECTIVE

Protein-energy wasting is associated with chronic inflammation and advanced atherosclerosis in haemodialysis (HD) patients. We investigated association of geriatric nutritional risk index (GNRI), C reactive protein (CRP) with prediction of mortality after coronary revascularisation in chronic HD patients.

METHODS

We enrolled 721 HD patients electively undergoing coronary revascularisation. They were divided into tertiles according to preprocedural GNRI levels (tertile 1 (T1):<91.5, T2: 91.5-98.1 and T3:>98.1) and CRP levels (T1:≤1.4 mg/L, T2: 1.5-7.0 mg/L and T3:≥7.1 mg/L).

RESULTS

Kaplan-Meier 10 years survival rates were 32.3%, 44.8% and 72.5% in T1, T2 and T3 of GNRI and 60.9%, 49.2% and 23.5% in T1, T2 and T3 of CRP, respectively (p<0.0001 in both). Declined GNRI (HR 2.40, 95% CI 1.58 to 3.74, p<0.0001 for T1 vs T3) and elevated CRP (HR 2.31, 95% CI 1.58 to 3.43, p<0.0001 for T3 vs T1) were identified as independent predictors of mortality. In combined setting of both variables, risk of mortality was 5.55 times higher (95% CI 2.64 to 13.6, p<0.0001) in T1 of GNRI with T3 of CRP than in T3 of GNRI with T1 of CRP. Addition of GNRI and CRP in a model with established risk factors improved C-statistics (0.648 to 0.724, p<0.0001) greater than that of each alone.

CONCLUSION

Preprocedural declined GNRI and elevated CRP were closely associated with mortality after coronary revascularisation in chronic HD patients. Furthermore, combination of both variables not only stratified risk of mortality but also improved the predictability.

Impact of Dietary Potassium Restrictions in CKD on Clinical Outcomes: Benefits of a Plant-Based Diet

In patients with advanced-stage chronic kidney disease (CKD), progressive kidney function decline leads to increased risk for hyperkalemia (serum potassium > 5.0 or >5.5 mEq/L). Medications such as renin-angiotensin-aldosterone system inhibitors pose an additional hyperkalemia risk, especially in patients with CKD. When hyperkalemia develops, clinicians often recommend a diet that is lower in potassium content. This review discusses the barriers to adherence to a low-potassium diet and the impact of dietary restrictions on adverse clinical outcomes. Accumulating evidence indicates that a diet that incorporates potassium-rich foods has multiple health benefits, which may also be attributable to the other vitamin, mineral, and fiber content of potassium-rich foods. These benefits include blood pressure reductions and reduced risks for cardiovascular disease and stroke. High-potassium foods may also prevent CKD progression and reduce mortality risk in patients with CKD. Adjunctive treatment with the newer potassium-binding agents, patiromer and sodium zirconium cyclosilicate, may allow for optimal renin-angiotensin-aldosterone system inhibitor therapy in patients with CKD and hyperkalemia, potentially making it possible for patients with CKD and hyperkalemia to liberalize their diet. This may allow them the health benefits of a high-potassium diet without the increased risk for hyperkalemia, although further studies are needed.

Molecular targeting of renal inflammation using drug delivery technology to inhibit NF-κB improves renal recovery in chronic kidney disease

Inflammation is a major determinant for the progression of chronic kidney disease (CKD). NF-κB is a master transcription factor upregulated in CKD that promotes inflammation and regulates apoptosis and vascular remodeling. We aimed to modulate this pathway for CKD therapy in a swine model of CKD using a peptide inhibitor of the NF-κB p50 subunit (p50i) fused to a protein carrier [elastin-like polypeptide (ELP)] and equipped with a cell-penetrating peptide (SynB1). We hypothesized that intrarenal SynB1-ELP-p50i therapy would inhibit NF-κB-driven inflammation and induce renal recovery. CKD was induced in 14 pigs. After 6 wk, pigs received single intrarenal SynB1-ELP-p50i therapy (10 mg/kg) or placebo (n = 7 each). Renal hemodynamics were quantified in vivo using multidetector computed tomography before and 8 wk after treatment. Pigs were then euthanized. Ex vivo experiments were performed to quantify renal activation of NF-κB, expression of downstream mediators of NF-κB signaling, renal microvascular density, inflammation, and fibrosis. Fourteen weeks of CKD stimulated NF-κB signaling and downstream mediators (e.g., TNF-α, monocyte chemoattractant protein-1, and IL-6) accompanying loss of renal function, inflammation, fibrosis, and microvascular rarefaction versus controls. All of these were improved after SynB1-ELP-p50i therapy, accompanied by reduced circulating inflammatory cytokines as well, which were evident up to 8 wk after treatment. Current treatments for CKD are largely ineffective. Our study shows the feasibility of a new treatment to induce renal recovery by offsetting inflammation at a molecular level. It also supports the therapeutic potential of targeted inhibition of the NF-κB pathway using novel drug delivery technology in a translational model of CKD.

Cardiovascular Protection of Nephropathic Male Patients by Oral Food Supplements

Nephropathic patients show elevated cardiovascular morbidity and mortality compared to the general population. In order to delve deeper into the understanding of this phenomenon, it is necessary to recognize risk factors that are distinctive to the uremic state, such as oxidative stress and chronic low-grade inflammation. Moreover, gender differences have been reported in nephrology, as it has been observed that chronic kidney disease has higher prevalence in males than in females. The use of an oral food supplement (OFS) containing natural active compounds from Capsicum annuum L., Garcinia cambogia, Centella asiatica L., artichoke, and Aesculus hippocastanum L. which are virtually devoid from side effects, but rich in antioxidant and antiradical properties, could represent a valid therapeutic adjunct in the clinical management of nephropathic patients. Moreover, quantitative analysis performed in vitro on such compounds showed that they expressed good total antioxidant (7.28 gallic acid equivalents) and antiradical activity (above 80%). In this study, 23 male nephropathic patients and 10 age and body composition parameter matched healthy males (control group) were enrolled and took 3 cps/day of OFS for 5 weeks. At the end of the study, the nephropathic patient group showed a statistically significant reduction in the following laboratory parameters: total cholesterol (TC) (p = 0.044), atherogenic index TC/high-density lipoprotein cholesterol (p = 0.010), inflammatory parameters (C-reactive protein, p = 0.048, and erythrocyte sedimentation rate, p = 0.019), systolic (p = 0.044), and diastolic arterial blood pressure (p = 0.003). Regarding body composition, there was an increase in total body water % (p = 0.035) with redistribution of extracellular water % (p = 0.030) and intracellular water % (p = 0.049). In the control group, there was a reduction in fat mass % (p = 0.017) and extracellular water % (p = 0.047). Therefore, this OFS may represent a valid adjunct therapy to counteract comorbidities related to uremia.

Fibrinogen/Albumin ratio: A more powerful prognostic index for patients with end-stage renal disease

BACKGROUND

Microinflammation is linked to an increased risk of death due to cardiovascular disease (CVD) in patients with end-stage renal disease (ESRD). Although the fibrinogen/albumin ratio (FAR), a novel inflammatory marker, has been shown to predict mortality in various diseases, limited evidence is available for its role in ESRD. The purpose of this study is to explore the prognostic value of the FAR in ESRD patients on peritoneal dialysis (PD).

METHODS

In this retrospective observational study, we enrolled patients with ESRD who underwent PD therapy in our hospital between 1 January 2011 and 31 December 2017. The Kaplan-Meier method and Cox proportional hazards models were used to determine the contact between the FAR level and mortality.

RESULTS

A total of 562 patients were enrolled in our research. The median FAR was 0.12, and patients were divided into two groups (low FAR group: FAR < 0.12, n = 250, and high FAR group: FAR ≥ 0.12, n = 312) according to the median FAR. Kaplan-Meier curves showed that the cumulative incidences of both all-cause mortality and CVD mortality were significantly higher in patients with FAR ≥ 0.12 (both P < .001). In multivariable analysis, the high FAR group had an important increased risk of all-cause and CVD mortality (HR: 1.80; 95% CI: 1.03-3.14, P = .038 and HR: 2.31; 95% CI: 1.17-4.59, P = .016, respectively).

CONCLUSIONS

Our results suggest that a high baseline FAR value is an independent prognostic factor in ESRD patients on PD.

The predictive role of serum calprotectin on mortality in hemodialysis patients with high phosphoremia

Background

The inflammatory mediator calprotectin (CPT, myeloid-related protein 8/14) is known as an endogenous ligand contributing to pathophysiology in inflammatory diseases. Serum CPT reportedly became a potential biomarker in these conditions, though there is no report predicting the prognosis in hemodialysis patients. The aim of this study is to investigate the predictive role of serum CPT on mortality in hemodialysis patients.

Methods

We conducted a multicenter, observational cohort study of 388 Japanese subjects undergoing hemodialysis. Serum CPT were measured using an ELISA. The potential associations between serum CPT and clinical variables were cross-sectionally examined. Multivariate Cox regression was used to estimate the association between serum CPT, high-sensitivity C reactive protein (hs-CRP), white blood cell (WBC) count and mortality. Median follow-up was 6.6 years.

Results

The median CPT level was 6108 ng/ml (median in healthy subjects, 2800) at baseline. Serum CPT positively correlated with WBC count (ρ = 0.54, P < 0.001) and hs-CRP values (ρ = 0.35, P < 0.001). In multivariate analysis, hs-CRP was an independent predictor of all-cause mortality after adjusting confounding factors (middle vs. low: hazard ratio [HR] 2.09, 95% confidence interval [CI] 1.23–3.66; high vs. low: 2.47, 1.40–4.47). In the analysis by stratum of phosphate levels, elevated CPT levels were significantly associated with all-cause mortality in the highest tertile (18.1; 3.15–345.9) among the high-phosphate group, but not among the low-phosphate group.

Conclusions

Serum CPT would become a potential predictive marker on mortality in hemodialysis patients with high-phosphate levels.

Ameliorating Chronic Kidney Disease Using a Whole Food Plant-Based Diet

Novel approaches to ameliorating chronic kidney disease (CKD) are warranted as most patients are undiagnosed until they begin displaying symptoms of kidney failure. There is increasing evidence that a whole food plant-based (WFPB) diet may offer benefits that slow the progression of CKD, decrease the incidence cardiovascular disease, decrease rates of diabetes and obesity, and reduce inflammation and cholesterol, which in turn can delay kidney failure and the initiation of dialysis. While animal-based protein ingestion promotes an acidic environment, inflammation and renal hyperfiltration, study authors report plant-based protein can be alkaline-producing and anti-inflammatory and can contain renoprotective properties. Although there may be benefits to adopting a WFPB diet, macronutrient and micronutrient content should be carefully considered and adjusted to avoid malnutrition in CKD patients. Further research needs to be done in order to establish the biological plausibility and feasibility of a WFPB in individuals with diagnosed CKD.

Geriatric Nutritional Risk Index (GNRI) and Creatinine Index Equally Predict the Risk of Mortality in Hemodialysis Patients: J-DOPPS

The geriatric nutritional risk index (GNRI) and creatinine (Cr) index are indexes often used as nutritional surrogates in patients receiving hemodialysis. However, few studies have directly compared the clinical characteristics of these two indexes. We investigated 3,536 hemodialysis patients enrolled in the Japan DOPPS phases 4 and 5. The primary outcome was all-cause mortality and the main exposures were the GNRI and Cr index. We confirmed and compared the association between these indexes and mortality risk as estimated by a multivariable-adjusted Cox proportional hazards model. During the median 2.2-year follow-up period, 414 patients died of any cause. In the multivariable-adjusted model, lower GNRI and Cr index were both associated with increased risk of all-cause mortality, and these associations were further confirmed by restricted cubic spline curves. The predictability of all-cause mortality, as represented by the c-statistic, was comparable between the two indexes. Furthermore, baseline nutritional surrogates that corresponded with lower GNRI or Cr index values were comparable between the two indexes. Given that calculating the GNRI is simpler than calculating the Cr index, our data suggest that the GNRI may be preferable to the Cr index for predicting clinical outcomes in patients undergoing maintenance hemodialysis.

Central obesity and incident atherosclerotic cardiovascular disease events in hemodialysis patients

BACKGROUND AND AIMS

Waist circumference and waist-hip ratio have been shown to predict atherosclerotic cardiovascular disease (ASCVD) in the general population, but the association is less clear in patients with CKD. Both anthropometric measures of central obesity are surrogates for underlying fat and are prone to measurement error. The aim of this study was to investigate the association between central obesity determined by dual-energy X-ray -absorptiometry (DXA) and ASCVD among patients undergoing maintenance hemodialysis.

METHODS AND RESULTS

We prospectively analyzed a cohort of 166 prevalent hemodialysis patients (60 ± 12 years of age). Total adiposity (total fat mass) and central adiposity (android and gynoid fat mass) were assessed by using DXA. Central obesity was defined as a sex-specific android to gynoid fat mass ratio (A/G ratio) above the median. The main outcome measure was incident ASCVD events. Patients with central obesity had significantly higher BMI, total fat mass, high-sensitivity C-reactive protein, and triglycerides but significantly lower high-density lipoprotein cholesterol than patients without central obesity. During a median follow-up of 4.3 years, 40 patients had an incident ASCVD event. Patients with central obesity did not display a significantly higher risk of ASCVD in multivariate Cox regression analysis (hazard ratio 1.03, 95% confidence interval 0.54-1.97). A/G ratio, when examined as a continuous variable, was not an independent predictor of ASCVD in either sex.

CONCLUSIONS

Hemodialysis patients with central obesity, as measured by the A/G ratio, had less favorable plasma lipid profiles and higher levels of inflammation but not an increased risk of ASCVD.

Propionate supplementation promotes the expansion of peripheral regulatory T-Cells in patients with end-stage renal disease

Patients with end-stage renal disease (ESRD) suffer from a progressively increasing low-grade systemic inflammation, which is associated with higher morbidity and mortality. Regulatory T cells (Tregs) play an important role in regulation of the inflammatory process. Previously, it has been demonstrated that short-chain fatty acids reduce inflammation in the central nervous system in a murine model of multiple sclerosis through an increase in tissue infiltrating Tregs. Here, we evaluated the effect of the short-chain fatty acid propionate on the chronic inflammatory state and T-cell composition in ESRD patients. Analyzing ESRD patients and healthy blood donors before, during, and 60 days after the propionate supplementation by multiparametric flow cytometry we observed a gradual and significant expansion in the frequencies of CD25^highCD127^- Tregs in both groups. Phenotypic characterization suggests that polarization of naïve T cells towards Tregs is responsible for the observed expansion. In line with this, we observed a significant reduction of inflammatory marker CRP under propionate supplementation. Of interest, the observed anti-inflammatory surroundings did not affect the protective pathogen-specific immunity as demonstrated by the stable frequencies of effector/memory T cells specific for tetanus/diphtheria recall antigens. Collectively, our data suggest that dietary supplements with propionate have a beneficial effect on the elevated systemic inflammation of ESRD patients. The effect can be achieved through an expansion of circulating Tregs without affecting the protective pathogen-reactive immunity.

The Ratio of Extracellular Fluid to Total Body Water and Technique Survival in Peritoneal Dialysis Patients

Background

Patients receiving peritoneal dialysis experience a high technique failure rate and are often overhydrated. We examined whether an increased extracellular fluid volume (VECF) as a proportion of the total body water (VTBW) predicted technique survival (TS) in a prevalent patient cohort.

Methods

The VECFand VTBWwere estimated by multiple-frequency bioelectric impedance in 59 prevalent peritoneal dialysis patients (median time on dialysis 14 months). Demographic, biochemical (albumin, C-reactive protein, and ferritin), and anthropometric data, forearm muscle strength, nutritional score by three-point Subjective Global Assessment, residual renal function, dialysate-to-plasma (D/P) creatinine ratio, total weekly Kt/V urea, total creatinine clearance, normalized protein equivalent of nitrogen appearance, and midarm muscle circumference were also assessed. Technique survival was determined at 3 years, and significant predictors of TS were sought.

Results

In patient groups defined by falling above or below the median value for each parameter, only residual renal function ( p = 0.002), 24-hour ultrafiltrate volume ( p = 0.02), and VECF/ VTBWratio ( p = 0.05) were significant predictors of TS. Subjects with a higher than median VECF/ VTBWratio had a 3-year TS of 46%, compared to 78% in subjects with a lower than median value. In multivariate analysis, systolic blood pressure and VECF/ VTBWratio (both p < 0.05) were significant predictors of TS. C-reactive protein approached significance.

Conclusion

Increased ratio of extracellular fluid volume to total body water is associated with decreased TS in peritoneal dialysis.

Late Renal Transplant Failure: An Adverse Prognostic Factor at Initiation of Peritoneal Dialysis

Background

Early renal transplant failure necessitating a return to dialysis has been shown to be a poor prognostic factor for survival. Little is known about the outcome of patients with late transplant failure returning to dialysis. It was our clinical impression that late transplant failure (>2 months) carries an increased morbidity and mortality risk in patients returning to dialysis.

Objective

To determine whether patients with a failed renal transplant have an outcome different to those on dialysis who have never received a kidney transplant.

Setting

Peritoneal dialysis (PD) unit in a teaching hospital.

Patients and Design

All failed renal transplant patients (fTx) in the Toronto Hospital Peritoneal Dialysis program between 1989 and 1996 were identified. This cohort of 42 fTx patients was compared with a cohort of randomly selected never-transplanted PD patients (non-Tx). The PD program was selected because of the availability of well-documented patient archival material. The non-Tx group was matched for age and presence of diabetes. Data were collected until retransplantation, change of dialysis modality or center, death, or until June 1998.

Results

There was no difference at initiation of PD between groups in serum albumin, residual renal function, or mean serum parathyroid hormone level. The mean low-density lipoprotein level was significantly higher in the fTx cohort. The duration of dialysis before Tx in fTx patients accounted for the increased total length of dialysis in fTx (mean 15 months). However, post-Tx the duration of PD was similar for both groups (30.7 months for fTx vs 31.6 months for non-Tx). The fTx group had a considerably worse outcome than the non-Tx group. The time to first peritonitis, subsequent episodes of peritonitis, catheter change, or transfer to hemodialysis occurred at a much faster rate in fTx patients. The most dramatic difference was in survival. There were 3 deaths in the non-Tx group and 12 in the fTx group ( p < 0.01). The mean age at time of death in the fTx group was 47.5 years. Deaths were due mainly to gram-negative peritonitis and cardiovascular disease.

Conclusions

W e conclude that late failed renal transplant patients starting dialysis are at increased risk of complications and have strikingly higher mortality rates than non-Tx patients. A previously failed kidney transplant can be considered an adverse prognostic factor for patients commencing PD; these patients need to be closely monitored. Although this study was limited to PD patients, the same principles likely apply to fTx patients returning to any form of renal replacement therapy.

Biocompatibility of New Peritoneal Dialysis Solutions: What Can We Hope to Achieve?

Despite the bioincompatibility of the “old”, standard, high glucose, lactate-buffered peritoneal dialysis (PD) solutions, PD is itself a highly successful dialysis modality with patient survival equivalent to that of hemodialysis (HD) during the initial 3 – 5 years of dialysis therapy. Nevertheless, PD technique survival is often limited by infectious complications and alterations in the structure and function of the peritoneal membrane. These local changes also have a negative impact on patient survival owing to systemic effects such as those often seen in patients with high peritoneal transport rate and loss of ultrafiltration (UF) capacity.

Patient mortality remains unacceptably high in both HD and PD patients, with most premature deaths being associated with signs of malnutrition, inflammation, and atherosclerotic cardiovascular disease (MIA syndrome). These systemic signs are likely to be influenced by PD solutions both directly and indirectly (via changes in the peritoneal membrane). New, biocompatible PD solutions may have favorable local effects (viability and function of the peritoneal membrane) and systemic effects (for example, on MIA syndrome). Amino acid–based solution [Nutrineal (N): Baxter Healthcare Corporation, Deerfield, IL, U.S.A.] may improve nutritional status as well as peritoneal membrane viability. Bicarbonate/lactate–buffered solution [Physioneal (P): Baxter Healthcare Corporation] may ameliorate local and systemic effects of low pH, high lactate, and high glucose degradation products. Icodextrin-based solution [Extraneal (E): Baxter Healthcare SA, Castlebar, Ireland] may improve hypertension and cardiovascular problems associated with fluid overload and may extend time on therapy in patients with loss of UF capacity.

The positive effects of each of these new, biocompatible solutions have been demonstrated in several studies. It is likely that the combined use of N, P, and E solutions will produce favorable synergies in regard to both local effects (peritoneal viability) and systemic effects (less malnutrition, inflammation, and fluid overload). Solution combination is an exciting area for clinical study in the coming years. Furthermore, dialysis fluid additives such as hyaluronan, which protects and improves the function of the peritoneal membrane, may further improve PD solutions. The new, biocompatible PD solutions represent an entirely new era in the evolution of the PD therapy; they are likely to have markedly positive effects on both PD technique and PD patient survival in coming years.

Peritoneal Transport Characteristics, Comorbid Diseases and Survival in CAPD Patients

Objective

To evaluate the influence of initial peritoneal transport rate, serum albumin concentration, and comorbid diseases on continuous ambulatory peritoneal dialysis (CAPD) patient survival.

Design

A prospective single-center study with a long-term follow-up.

Patients

A total of 213 consecutive CAPD patients, who underwent a peritoneal equilibration test (PET) at a mean of 7 days (range 3 – 30 days) after beginning CAPD, were included in this study. One hundred twenty patients were male, 116 patients had comorbid diseases, and mean age was 49.5 years (range 18 – 76 years).

Methods

A modified PET was performed using 4.25% glucose dialysis solution. Based on the dialysate-to-plasma creatinine concentration ratio at 4 hours’ dwell (D4/P4Cr, 0.62 ± 0.14), patients were divided into high (H), high-average (HA), low-average (LA), or low (L) transporters.

Results

Of 213 patients, 16.9% were classified as H transporters, 30.5% as HA, 36.6% as LA, and 16.0% as L transporters. The H transporter group had a higher proportion of men, higher proportion of patients with comorbid diseases, lower initial serum albumin concentration, lower D4/D0glucose, and lower drained volume. The initial D4/P4Cr correlated with initial serum albumin ( r = –0.35, p < 0.001). The patients with comorbid diseases had lower initial serum albumin and higher initial D4/P4Cr. On Kaplan–Meier analysis, 2-year patient survival of group H was significantly lower compared to the other groups combined (57.1% vs 79.5%, p = 0.009). On Cox proportional hazards analysis, age, comorbid diseases, initial serum albumin concentration, and initial D4/P4Cr were found to be independent risk factors for mortality. However, in the patients without comorbid diseases, patient survival was not different between group H and the other transport groups combined ( p > 0.05), and only age was found to be an independent risk factor for mortality.

Conclusion

These data suggest that a high peritoneal transport rate at initial PET is associated with high mortality, and that this is in part due to an increased prevalence of comorbid disease in H transporters. These H transporters with comorbid diseases represent a subset of patients with an especially poor prognosis. In patients without comorbid diseases, high transport status or low serum albumin concentration was not an independent risk factor for mortality.

Influence of Peritoneal Transport Rate, Inflammation, and Fluid Removal on Nutritional Status and Clinical Outcome in Prevalent Peritoneal Dialysis Patients

Objective

To evaluate the possible associations between peritoneal transport rate (PTR), fluid removal, inflammation, and nutritional status in patients treated with peritoneal dialysis (PD) for more than 6 months, and the impact of these factors on subsequent patient survival.

Design and Patients

A prospective study of 82 PD patients (48 males) that had been treated with PD more than 6 months. Based on the dialysate-to-plasma creatinine ratio at 4 hours of dwell (D/PCr; mean ± 1 SD), the patients were classified as having a high (H), high-average (HA), low-average (LA), or low (L) PTR.

Setting

Single PD unit in a university hospital.

Main Outcome Measures

The PTR, evaluation of adequacy of dialysis and nutritional status, and biochemical analyses were assessed at 10.8 ± 2.8 months after the start of PD.

Results

Compared to L and LA (L/LA) transporters, H and HA (H/HA) transporters had increased dialysate protein loss, glucose absorption from dialysate, and peritoneal creatinine clearance (CCr), and decreased night ultrafiltration volume and total Kt/V urea. However, nutritional variables, 24-hour total fluid removal (TFR), total CCr, and residual renal function were not significantly different between the two groups. The 24-hour TFR correlated significantly with D/PCr (rho = –0.25), mean arterial pressure (rho = –0.23), serum albumin (rho = 0.25), normalized protein equivalent of total nitrogen appearance (rho = 0.34), lean body mass (LBM) calculated from creatinine kinetics (rho = 0.41), total Kt/V urea (rho = 0.42), and total CCr (rho = 0.30). The group with serum C-reactive protein (sCRP) ⊕ 10 mg/L had a higher proportion of patients with reduced (< 1000 mL) TFR compared to the group with sCRP < 10 mg/(38% vs 16%, p = 0.04). Two-year patient survival rates from the time of the assessment were not different between the different transport groups (78% vs 73% for H/HA and L/LA, p = 0.99). Upon Cox proportional hazards multivariate analysis, age and high sCRP were independent predictors of mortality.

Conclusions

This study shows that, in a selected group of prevalent PD patients assessed after more than 6 months of PD therapy, ( 1 ) inflammation was an independent predictor for mortality; ( 2 ) reduced TFR was associated with impaired nutritional status, decreased small solute clearance, and inflammation; and ( 3 ) peritoneal transport status was not significantly associated with nutritional status and was not associated with subsequent patient survival. These results indicate that a high peritoneal solute transport rate, as such, should not be regarded as a relative contraindication for PD. Instead, the results suggest that more attention should be given to inflammation and inadequate fluid removal as predictors of mortality in PD patients.

Comparison between DOQI and Canadian Guidelines for Peritoneal Dialysis

The recently published Canadian Society of Nephrology (CSN) Guidelines for Peritoneal Dialysis Adequacy differ in a number of ways from the United States National Kidney Foundation Dialysis Outcomes Quality Initiative (DOQI) guidelines on the same topic. The three main differences are ( 1 ) the CSN targets are the same for continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD), whereas the DOQI targets are higher for APD; ( 2 ) the CSN guidelines have a lower creatinine clearance (CCr) target of 50 L/wk for low and low-average transporters compared to 60 L/wk for high and high-average transporters, but no such distinction is made by DOQI; and ( 3 ) the CSN has set lower limit targets as well as preferred targets for Kt/V and CCr.

Other differences are that the CSN recommendations do not give Kt/V the same primacy over CCr that DOQI does. Also, the CSN recommendations give greater emphasis to the risks associated with high transport status.

This review looks at the reasons for these differences and demonstrates that some are due to information that has become available since the publication of the DOQI guidelines. However, it is emphasized that, when recommendations are predominantly opinion- rather than evidence-based, geographic and economic factors may also account for differences.

Chronic Inflammation in Peritoneal Dialysis: The Search for the Holy Grail?

Mortality and morbidity in chronic kidney disease (CKD) patients are unacceptably high. The annual mortality rate due to cardiovascular disease (CVD) is approximately 9%, which, for the middle-aged person, is at least 10- to 20-fold higher than for the general population. Classic risk factors for CVD are highly prevalent in CKD patients, but they cannot fully account for the excessive rate of CVD in this population. Instead, it has become increasingly clear that nontraditional risk factors, such as systemic inflammation, may play a key role in the development of atherosclerosis. It is well established that inflammatory markers are very powerful predictors of high CVD morbidity and mortality not only in the general population, but particularly in CKD patients. Signs of a sustained low-grade inflammation, such as increased levels of C-reactive protein (CRP), are present in the majority of stage 5 CKD patients, even in patients in clinically stable condition, and they are also commonly observed after the initiation of dialysis therapy. Dialysis therapy — hemodialysis as well as peritoneal dialysis (PD) — may itself contribute to systemic inflammation. Local intraperitoneal inflammation can also occur in patients treated with PD. These local effects may result in a low-grade inflammation, caused by the bioincompatibility of conventional glucose-based dialysis fluids, to intense inflammation associated with peritonitis. Given these circumstances, it is reasonable to hypothesize that strategies aiming to reduce inflammation are potentially important and novel, and could serve to reduce CVD, thereby lowering morbidity and mortality in patients with CKD. In this review we provide information supporting the hypothesis that systemic inflammation is tightly linked to the most common complications of CKD patients, in particular those on PD, and that local inflammation in PD may contribute to various related complications. The aims of this review are to discuss the reasons that make inflammation an attractive target for intervention in CKD, the particular aspects of the inflammation–CVD axis during PD treatment that are likely involved, and possible means for the detection and management of chronic inflammation in PD patients.

Peritoneal Albumin Excretion is a Strong Predictor of Cardiovascular Events in Peritoneal Dialysis Patients: A Prospective Cohort Study

Background

Microalbuminuria is a marker of systemic endothelial dysfunction. We hypothesize that peritoneal albumin excretion in peritoneal dialysis (PD) patients, which is conceptually analogous to microalbuminuria in nonuremic patients, can predict cardiovascular disease in new PD patients.

Method

We studied peritoneal albumin excretion in 43 new PD patients. They were then followed prospectively for the development of cardiovascular events. All-cause mortality and duration of hospitalization for cardiovascular diseases were also recorded.

Result

The average duration of follow-up was 26.5 ± 17.6 months. During the follow-up period, 15 patients developed cardiovascular events. Event-free survival at 36 months was 81.4% and 53.6% for low (<300 mg/L) and high (≥300 mg/L) peritoneal albumin excretion groups respectively (log rank test, p = 0.042). By Cox regression analysis, the only independent factors for event-free survival were diabetic status and peritoneal albumin excretion rate. For every 100 mg/L increase in peritoneal albumin excretion, the adjusted hazard ratio of developing a cardiovascular event was 1.83 [95% confidence interval (CI) 1.11 – 3.02, p = 0.018]. Actuarial patient survival at 36 months was 85.7% and 59.1% for low and high peritoneal albumin excretion groups respectively (log rank test, p = 0.10). After adjusting for the duration of follow-up for individual patients, the average duration of hospitalization was 9.1 ± 16.2 and 21.7 ± 25.7 days per year of follow-up for low and high peritoneal albumin excretion groups respectively (Mann–Whitney U test, p = 0.012).

Conclusion

Although the sample size of our present study is small and does not have adequate statistical power, we conclude that peritoneal albumin excretion may be an important predictor of cardiovascular disease. Further studies are needed to examine the role of dialysate albumin excretion as a means of cardiovascular risk stratification in PD patients.

The Time Course of Serum C-Reactive Protein is More Predictive of Mortality than its Baseline Level in Peritoneal Dialysis Patients

Background

Several recent studies reported that a high baseline serum C-reactive protein (CRP) is a powerful predictor of mortality in dialysis patients. However, the acute-phase response is intermittent and not a continuous feature in an individual patient. The aim of this prospective study was to determine whether serial analysis of serum CRP during follow-up allows better prediction of mortality and echocardiographic cardiac disease than a single baseline measurement in peritoneal dialysis (PD) patients.

Methods

97 PD patients were monitored for 3 years from the beginning of the treatment. We evaluated the effect of demographic features, comorbidity, blood pressure, blood biochemistry, including CRP, residual renal function, and indices of dialysis adequacy, on mortality and left ventricular hypertrophy (LVH). Cox regression analysis using both the baseline and the averaged values of the study parameters was carried out to determine factors predicting mortality. Logistic regression analysis was performed to determine which factors were independently predictive for LVH and the type of time course of serum CRP.

Results

Baseline serum CRP was elevated in 29 patients (29.9%). While serum CRP exhibited a stable course (normal or high) in 55 patients (56.7%), it varied considerably over time in 42 patients (43.2%). In the Cox models, both the averaged serum CRP and the type of variability of CRP were predictors of mortality. On the contrary, baseline CRP did not affect adjusted survival. The averaged CRP was also an independent factor affecting LVH, but baseline CRP was not. Age, comorbidity index, instilled dialysate glucose concentration, and Kt/V urea were independently associated with the type of time course of serum CRP.

Conclusion

The averaged value of serum CRP is more predictive of prognosis compared to the baseline value in PD patients. Determining serum CRP on a regular basis may be helpful to detect early signs of tissue damage or asymptomatic inflammation.

Peritoneal Membrane Transport and Hypoalbuminemia: Cause or Effect?

Objective

Peritoneal membrane transport has been associated with serum albumin and clinical outcome. We examined the relationship between serum albumin and peritoneal membrane transport status before and after the initiation of peritoneal dialysis.

Setting

Patients were followed at a tertiary-care regional nephrology program at St. Joseph's Hospital, McMaster University, Hamilton, Ontario, Canada.

Methods

Incident peritoneal dialysis patients between 1 January 1995 and 31 May 1998 were eligible if there was a peritoneal equilibration test within 180 days of starting dialysis, and a serum albumin value measured within 90 days prior to, and 20 to 70 days after initiating dialysis.

Main Outcome Measures

Serum albumin, before and after the initiation of dialysis, and the presence of proteinuric renal disease were compared with the peritoneal equilibration test results.

Results

Among 67 identified patients, there were 7 high, 27 high-average, 26 low-average, and 7 low transporters and the mean serum albumin values before dialysis were 35.1, 37.4, 37.8, and 40.4 g/L, respectively ( p < 0.001). Serum albumin values prior to the initiation of dialysis correlated significantly with the 4-hour D/P creatinine ratio ( r = –0.251, p = 0.040). After initiation of dialysis, the correlation was stronger ( r = –0.447, p < 0.001). Serum albumin prior to initiation of dialysis was lower for those with proteinuric than nonproteinuric renal disease (36.4 g/L vs 38.8 g/L, p = 0.04). The trend to lower serum albumin in high transporters was seen in patients with both proteinuric and nonproteinuric renal disease.

Conclusion

The association between higher peritoneal membrane transport and lower serum albumin is present before initiation of dialysis in both proteinuric and nonproteinuric renal disease. The poor outcomes associated with low serum albumin and higher peritoneal membrane transport might be explained by other underlying factors. The contribution of inflammation, malnutrition, and fluid overload requires further study.

Aortic Valve Calcium Associates with All-Cause Mortality Independent of Coronary Artery Calcium and Inflammation in Patients with End-Stage Renal Disease

BACKGROUND

Aortic valve calcium (AVC) and coronary artery calcium (CAC) are common complications in end-stage renal disease (ESRD). We investigated the prognostic significance of overlapping presence of AVC and CAC, and whether AVC was associated with all-cause mortality independent of the presence of CAC in ESRD.

METHODS

259 ESRD patients (median age 55 years, 67% males) undergoing cardiac computed tomography were included. Framingham risk score (FRS), presence of cardiovascular disease (CVD), statin use, nutritional status and other relevant laboratory data were determined at baseline. During follow-up for median 36 months, 44 patients died, and 68 patients underwent renal transplantation.

RESULTS

The baseline overlap presence of AVC and CAC was 37%. Multivariate regression analysis showed that FRS (odds ratio (OR) 2.25; 95% confidence interval (95% CI), 1.43-3.55) and CAC score (OR (95% CI), 2.18 (1.34-3.59)) were independent determinants of AVC. In competing-risk regression models adjusted for presence of CAC, inflammation, nutritional status, CVD, FRS and statin use, AVC remained independently associated with all-cause mortality (sub-hazard ratio (95% CI), 2.57 (1.20-5.51)).

CONCLUSIONS

The overlap of AVC and CAC was 37% in this ESRD cohort. AVC was associated with increased all-cause mortality independent of presence of CAC, traditional risk factors and inflammation.

What is the Link between Poor Ultrafiltration and Increased Mortality in Anuric Patients on Automated Peritoneal Dialysis? Analysis of Data from Eapos

Background

Primary analysis of the European Automated Peritoneal Dialysis Outcomes Study (EAPOS) found that patients with daily ultrafiltration (UF) below a predefined target of 750 mL at baseline experienced increased mortality and continuing low UF over 2 years.

Setting

Multicenter, prospective observational study of prevalent, functionally anuric patients on automated peritoneal dialysis (APD) treated to predefined standards.

Methods

Secondary data analysis to determine clinical covariates that might support a link between poor UF and outcome, including pattern of comorbidity, prescription, nutrition as determined by Subjective Global Assessment (SGA), membrane function, and blood pressure (BP). Ultrafiltration was treated as a categorical (comparing patients above and below target at baseline) and continuous dependent variable in univariate and multivariate regression. The relationship between BP and survival was also explored.

Results

Of 177 patients recruited from 28 centers across Europe, 43 were below the UF target at baseline. Compared to those above target, there were no differences in the spread of comorbidity, type of APD prescription, SGA, BP, hemoglobin, HCO3, or parathyroid hormone, at baseline or at any later time. At baseline, plasma calcium and, at 12 months, plasma phosphate were lower in the low UF group. There was a weak positive correlation between baseline systolic or diastolic BP and UF, which remained on multivariate analysis but accounted for just 9% of the variability in BP. There was no clear relationship between baseline BP and survival, although, if anything, low BP was associated with earlier death. Poor UF was associated with lower mean dialysate glucose concentration during the first 4 months and with consistently worse membrane function.

Conclusions

The increased mortality associated with poor UF is likely multifactorial and not easily explained by clear differences in comorbidity, nutritional state, or other indices of treatment at baseline. The lower plasma phosphate suggests a subsequent fall in appetite. Poor BP control is unlikely to be the explanation, and a link between lower BP, reduced UF, and earlier death is suggested. Failure to achieve adequate UF due to worse membrane function remains an important and potentially reversible or preventable cause.

Determinants of Peritoneal Solute Transport Rates in Newly Started Nondiabetic Peritoneal Dialysis Patients

Objective

An overrepresentation of a fast peritoneal transport status in new peritoneal dialysis (PD) patients with extensive comorbidity has been reported in some studies. High mass transfer area coefficients (MTACs) of low MW solutes suggest the presence of a large effective peritoneal surface area. The mechanism is unknown. It might include comorbidity, chronic inflammation, or an effect of mesothelial cell mass on peritoneal transport by the production of vasoactive substances. To investigate their relative importance in early PD, peritoneal permeability characteristics in incident PD patients were analyzed for relationships with comorbidity, serum concentrations of inflammatory markers, and products of the mesothelial cells that can be detected in dialysate.

Design

A cross-sectional study.

Setting

A university hospital.

Methods

46 patients who fulfilled the following inclusion criteria were analyzed: a standard peritoneal permeability analysis (SPA) within 6 months after the start of PD, no peritonitis prior to the SPA, older than 18 years, and without diabetes mellitus as a primary renal disease. The patients were divided into tertiles based on the MTAC creatinine: slow, medium, and fast transport groups. The Davies comorbidity score was used to assess comorbidity. Serum and dialysate samples obtained during the SPA were used to determine hyaluronan, interleukin (IL)-6, vascular endothelial growth factor (VEGF), and cancer antigen 125 (CA125). The dialysate concentrations of these substances were expressed as their dialysate appearance rates.

Results

No significant differences were present in the three transport groups for comorbidity, serum concentrations of inflammatory markers, or serum VEGF. Interleukin-6 and VEGF concentration attributed to local VEGF production were not different between the tertiles. Levels of VEGF were higher in the medium transport group compared to the slow transport group ( p = 0.02); CA125 was higher in the fast transport group compared to the medium transport group ( p = 0.01). When analyzed as continuous variables, MTAC creatinine was related to VEGF ( r = 0.33, p < 0.05) and CA125 ( r = 0.41, p = 0.03). In linear regression analysis, VEGF influenced the association between CA125 and MTAC creatinine; IL-6 weakened this association only marginally.

Conclusion

A fast peritoneal transport status in incident nondiabetic PD patients was not related to comorbidity. The relationships found between VEGF, CA125, and MTAC creatinine may suggest a role of VEGF in the regulation of the vascular peritoneal surface area, possibly already before structural abnormalities have developed. Our analyses are consistent with the hypothesis that mesothelial cell mass is an important determinant of the peritoneal transport status in incident nondiabetic PD patients without previous peritonitis. Of the many potential mediators produced by mesothelial cells, VEGF was more important than the inflammation marker IL-6.