What are the causes and consequences of the chronic inflammatory state in chronic dialysis patients?

Clinical Features and Risk Factors for Outcome in Hemodialysis Patients with COVID-19 after Complete Liberalization of Epidemic Control in China

INTRODUCTION

Patients undergoing hemodialysis (HD) are highly vulnerable during the COVID-19 pandemic. We aimed to investigate the risk factors associated with the severity of COVID-19 and death after the complete liberalization of epidemic control in China.

METHODS

We followed the outcomes of the HD patients of Central Hospital of Dalian University of Technology, from December 6, 2022, to January 8, 2023. The non-contrast-enhanced chest computed tomography (CT) was performed on all COVID-19-infected hospitalized patients. We recorded the patient's clinical characteristics, demographic features, vaccination history, treatments, and lung lesions. Odds ratios and 95% confidence intervals were calculated using logistic regression models to identify independent risk factors for COVID-19-related severity and mortality.

RESULTS

This study included a total of 858 HD patients, of which 660 were infected with COVID-19. The mean age was (55.61 ± 14.61) years, with a median (interquartile range) dialysis duration of 44.5 (69.5) months. Over half (60%) of the study participants were male, and the majority had hypertension as a comorbidity. Multivariable analysis revealed that age, pre-dialysis diastolic pressure, fever, white blood cell (WBC) count, potassium, β2-microglobulin level, and calcium were independent risk factors for disease severity, while platelets, urea nitrogen, serum chlorine and creatinine were identified as independent protective factors. Furthermore, total iron-binding capacity and vaccination were found to be independent protective factors against mortality, and WBC count was an independent risk factor for in-hospital mortality (p < 0.05). The most frequent CT finding among hospitalized patients with chest symptoms was patchy shadow or pleural effusion, observed in 64.8% of cases. More than half of the patients exhibited bilateral lung lesions, and over 60% involved two or more lobes.

CONCLUSION

The majority of HD patients are susceptible to COVID-19. Demographic, clinical features, and laboratory indicators can be used to predict the severity and mortality associated with COVID-19. Our findings will assist clinicians in identifying markers for the early detection of high mortality risk in HD patients with COVID-19.

Bone marrow-derived exosomes promote inflammation and osteoclast differentiation in high-turnover renal osteodystrophy

Introduction: Renal osteodystrophy (ROD) is a type of bone metabolic disorder in patients with chronic kidney disease (CKD). Inflammation is associated with bone loss in ROD. However, its precise mechanism has not yet been elucidated. The present study was conducted to investigate whether exosomes (Exos) in bone marrow (BM) are involved in the pathogenesis of high-turnover ROD.Methods: Bone mass, osteoclast number, and pro-inflammatory cytokines levels of BM supernatant were detected in adenine-induced ROD rats. The effect of Exos derived from BM (BM-Exos) of ROD (ROD-Exos) on inflammatory genes and osteoclast differentiation of BM-derived macrophages (BMMs) were further examined. Then, exosomal miRNA sequencing was performed and an miRNA-mRNA-pathway network was constructed.Results: we found increased osteoclasts and decreased bone mass in ROD rats, as well as inflammatory activation in the BM niche. Furthermore, BMMs from ROD rats displayed overproduction of proinflammatory cytokines and increased osteoclast differentiation, accompanied by nuclear factor κB (NF-κB) signaling activation. Mechanistically, we found that ROD-Exos activates NF-κB signaling to promote the release of proinflammatory cytokines and increase osteoclast differentiation of BMMs. Meanwhile, a total of 24 differentially expressed miRNAs were identified between BM-Exos from ROD and normal control (NC). The miRNA-mRNA-pathway network suggests that rno-miR-9a-5p, rno-miR-133a-3p, rno-miR-30c-5p, rno-miR-206-3p, and rno-miR-17-5p might play pivotal roles in inflammation and osteoclast differentiation. Additionally, we validated that the expression of miR-9a-5p is upregulated in ROD-Exos.Conclusion: The BM niche of ROD alters the miRNA cargo of BM-Exos to promote inflammation and osteoclast differentiation of BMMs, at least partially contributing to the pathogenesis of high-turnover ROD.

Interventions for fatigue in people with kidney failure requiring dialysis

BACKGROUND

Fatigue is a common and debilitating symptom in people receiving dialysis that is associated with an increased risk of death, cardiovascular disease and depression. Fatigue can also impair quality of life (QoL) and the ability to participate in daily activities. Fatigue has been established by patients, caregivers and health professionals as a core outcome for haemodialysis (HD).

OBJECTIVES

We aimed to evaluate the effects of pharmacological and non-pharmacological interventions on fatigue in people with kidney failure receiving dialysis, including HD and peritoneal dialysis (PD), including any setting and frequency of the dialysis treatment.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 18 October 2022 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Studies evaluating pharmacological and non-pharmacological interventions affecting levels of fatigue or fatigue-related outcomes in people receiving dialysis were included. Studies were eligible if fatigue or fatigue-related outcomes were reported as a primary or secondary outcome. Any mode, frequency, prescription, and duration of therapy were considered.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data and assessed the risk of bias. Treatment estimates were summarised using random effects meta-analysis and expressed as a risk ratio (RR) or mean difference (MD), with a corresponding 95% confidence interval (CI) or standardised MD (SMD) if different scales were used. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Ninety-four studies involving 8191 randomised participants were eligible. Pharmacological and non-pharmacological interventions were compared either to placebo or control, or to another pharmacological or non-pharmacological intervention. In the majority of domains, risks of bias in the included studies were unclear or high. In low certainty evidence, when compared to control, exercise may improve fatigue (4 studies, 217 participants (Iowa Fatigue Scale, Modified Fatigue Impact Scale, Piper Fatigue Scale (PFS), or Haemodialysis-Related Fatigue scale score): SMD -1.18, 95% CI -2.04 to -0.31; I2 = 87%) in HD. In low certainty evidence, when compared to placebo or standard care, aromatherapy may improve fatigue (7 studies, 542 participants (Fatigue Severity Scale (FSS), Rhoten Fatigue Scale (RFS), PFS or Brief Fatigue Inventory score): SMD -1.23, 95% CI -1.96 to -0.50; I2 = 93%) in HD. In low certainty evidence, when compared to no intervention, massage may improve fatigue (7 studies, 657 participants (FSS, RFS, PFS or Visual Analogue Scale (VAS) score): SMD -1.06, 95% CI -1.47, -0.65; I2 = 81%) and increase energy (2 studies, 152 participants (VAS score): MD 4.87, 95% CI 1.69 to 8.06, I2 = 59%) in HD. In low certainty evidence, when compared to placebo or control, acupressure may reduce fatigue (6 studies, 459 participants (PFS score, revised PFS, or Fatigue Index): SMD -0.64, 95% CI -1.03 to -0.25; I2 = 75%) in HD. A wide range of heterogenous interventions and fatigue-related outcomes were reported for exercise, aromatherapy, massage and acupressure, preventing our capability to pool and analyse the data. Due to the paucity of studies, the effects of pharmacological and other non-pharmacological interventions on fatigue or fatigue-related outcomes, including non-physiological neutral amino acid, relaxation with or without music therapy, meditation, exercise with nandrolone, nutritional supplementation, cognitive-behavioural therapy, ESAs, frequent HD sections, home blood pressure monitoring, blood flow rate reduction, serotonin reuptake inhibitor, beta-blockers, anabolic steroids, glucose-enriched dialysate, or light therapy, were very uncertain. The effects of pharmacological and non-pharmacological treatments on death, cardiovascular diseases, vascular access, QoL, depression, anxiety, hypertension or diabetes were sparse. No studies assessed tiredness, exhaustion or asthenia. Adverse events were rarely and inconsistently reported.

AUTHORS' CONCLUSIONS

Exercise, aromatherapy, massage and acupressure may improve fatigue compared to placebo, standard care or no intervention. Pharmacological and other non-pharmacological interventions had uncertain effects on fatigue or fatigue-related outcomes in people receiving dialysis. Future adequately powered, high-quality studies are likely to change the estimated effects of interventions for fatigue and fatigue-related outcomes in people receiving dialysis.

Effect of an aerobic and strength exercise combined program on oxidative stress and inflammatory biomarkers in patients undergoing hemodialysis: a single blind randomized controlled trial

BACKGROUND

Chronic kidney disease patients on hemodialysis treatment are characterized by increased levels of inflammatory markers and oxidative stress, in addition to a significant deterioration in physical function. The benefits of physical exercise on the functional capacity of this patients are well known; however, it can also improve the endogenous antioxidant defense system and the inflammatory state, but still very few studies have been carried out. This is the first study to analyze the effect of a 4-month exercise program with combined aerobic and strength training in patients undergoing hemodialysis, under two modalities.

METHODS

Seventy-one patients undergoing hemodialysis were enrolled and randomized in two groups, one of them performing an intra-dialysis exercise program (n = 36), and the other carrying out a home-based exercise program (n = 35). Serum levels of oxidative stress and inflammation biomarkers were determined before and after the intervention.

RESULTS

IL-6 plasma levels showed a significant decrease in the intra-dialysis group after exercise (42.61 ± 9.21 to 26.40 ± 7.84, p = 0.03), while CRP levels decreased significantly in the home-based group (16.12 ± 24.18 to 8.50 ± 11.28, p = 0.03). MCP-1, TNF-α, ICAM-1 and the oxidative stress markers MDA, GSH and GSSG, did not undergo significant changes after the intervention.

CONCLUSION

Four months of combined strength and aerobic endurance exercise improve the inflammatory status of hemodialysis patients by significantly reducing IL-6 levels in those subjects who perform intra-dialysis exercise and CRP levels in those who do it at home.

Combination of High-Density Lipoprotein Cholesterol and Lipoprotein(a) as a Predictor of Collateral Circulation in Patients With Severe Unilateral Internal Carotid Artery Stenosis or Occlusion

BACKGROUND AND PURPOSE

Collateral circulation is considered an important factor affecting the risk of stroke, but the factors that affect collateral circulation remain unclear. This study was performed to identify the factors associated with collateral circulation, especially blood lipids.

METHODS

The study involved patients who had undergone digital subtraction angiography and were confirmed as having severe unilateral stenosis or occlusion of the internal carotid artery (ICA). We classified the collateral circulation status of each patient as good (Grade 3 or 4) or poor (Grade 0, 1, or 2) according to the grading system of the American Society of Interventional and Therapeutic Neuroradiology/American Society of Interventional Radiology. We collected data on patients' characteristics and identified the factors that affect collateral circulation.

RESULTS

This study included 212 patients. The multivariate logistic regression analysis showed that the high-density lipoprotein cholesterol (HDL-C) concentration and a complete anterior half of the circle of Willis were independent protective factors for good collateral circulation, whereas elevated lipoprotein(a) [Lp(a)] and serum creatinine concentrations were independent risk factors for good collateral circulation. The area under the receiver operating characteristics curve (AUC) was 0.68 (95% confidence interval [CI], 0.61-0.76) for HDL-C and 0.69 (95% CI, 0.62-0.76) for Lp(a). A binary logistic regression model analysis of the joint factor of HDL-C and Lp(a) yielded an AUC of 0.77 (95% CI, 0.71-0.84).

CONCLUSIONS

In patients with severe unilateral ICA stenosis or occlusion, the combination of HDL-C and Lp(a) is a useful predictor of collateral circulation.

Immunogenicity of SARS-CoV-2 Vaccine in Dialysis

BACKGROUND

Patients receiving maintenance dialysis represent a high-risk, immune-compromised population with 15%-25% COVID-19 mortality rate who were unrepresented in clinical trials of mRNA vaccines.

METHODS

All patients receiving maintenance dialysis who received two doses of SARS-CoV-2 mRNA vaccines with antibody test results drawn ≥14 days after the second dose, as documented in the electronic health record through March 18, 2021, were included. Response was on the basis of levels of Ig-G against the receptor binding domain of the S1 subunit of SARS-CoV-2 spike-antigen (seropositive ≥2 U/L) using an FDA-approved semiquantitative chemiluminescent assay (ADVIA Centaur XP/XPT COV2G).

RESULTS

Among 186 patients on dialysis from 30 clinics in eight states tested 23±8 days after receiving two vaccine doses, there were 165 (88.7%) responders with 70% at maximum titer. There was no significant difference between BNT162b2/Pfizer (148 out of 168, 88.1%) and mRNA-1273/Moderna (17 out of 18, 94.4%), P=0.42. All 38 patients with COVID-19 history were responders, with 97% at maximum titer. Among patients without COVID-19, 127 out of 148 (85.8%) were responders, comparable between BNT162b2/Pfizer (113 out of 133) and mRNA-1273/Moderna (14 out of 15) vaccines (85.0% versus 93.3%, P=0.38).

CONCLUSIONS

Most patients receiving maintenance dialysis responded after two doses of BNT162b2/Pfizer or mRNA-1273/Moderna vaccine, suggesting the short-term development of antispike antibody is good, giving hope that most of these patients who are vulnerable, once immunized, will be protected from COVID-19. Longer-term evaluation is needed to determine antibody titer durability and if booster dose(s) are warranted. Further research to evaluate the approach to patients without a serologic response is needed, including benefits of additional dose(s) or administration of alternate options.

Association of serum globulin with all-cause mortality in incident hemodialysis patients

BACKGROUND

Serum globulin is a major component of total protein and can be elevated in inflammatory disease states. While inflammation is common in hemodialysis patients and associated with mortality and morbidity, the association between serum globulin and mortality have never been examined in hemodialysis patients.

METHODS

In a retrospective cohort of 104,164 incident hemodialysis patients treated by a large dialysis organization from 2007 to 2011, we explored the association between baseline serum globulin, A/G ratio and serum protein levels and all-cause, cardiovascular and infection-related mortality with adjustments for demographic variables and laboratory markers of malnutrition and inflammation using Cox proportional hazard models.

RESULTS

Patients with globulin concentration >3.8 g/dL had higher all-cause and infection-related mortality risk (Hazard Ratio [HR] 1.11, 95% Confidence Interval [95%CI]: 1.06, 1.16 and HR 1.28, 95%CI: 1.09, 1.51; respectively) in the fully adjusted model when compared to the reference group of 3.0-<3.2 g/dL. In addition, patients with A/G ratio <0.75 had a 45% higher all-cause mortality hazard (HR 1.45, 95%CI: 1.38, 1.52) and patients with total serum protein <5.5 g/dL had a 34% higher risk of death (HR: 1.34, 95%CI: 1.27, 1.42) when compared to the reference (A/G ratio 1.05-<1.15 and total serum protein 6.5-<7 g/dL, respectively).

CONCLUSIONS

Among incident hemodialysis patients, higher globulin level was associated with higher mortality risk independent of other markers of malnutrition and inflammation, including albumin. Lower A/G ratio and serum protein was also associated with higher mortality hazard. The mechanisms that contribute to elevated serum globulin should be further explored.

A Critical Review of Exercise Training in Hemodialysis Patients: Personalized Activity Prescriptions Are Needed

Exercise training appears to have modest or inconsistent benefits in hemodialysis patients. This may be due to the low volume and intensity of exercise often prescribed. To address this, research is needed to evaluate the efficacy of individualized exercise prescriptions as a component of a comprehensive lifestyle intervention strategy that gives patients more autonomy to choose preferred types of physical activity.

Skeletal Muscle Mitochondrial Dysfunction Is Present in Patients with CKD before Initiation of Maintenance Hemodialysis

BACKGROUND AND OBJECTIVES

Patients with CKD suffer from frailty and sarcopenia, which is associated with higher morbidity and mortality. Skeletal muscle mitochondria are important for physical function and could be a target to prevent frailty and sarcopenia. In this study, we tested the hypothesis that mitochondrial dysfunction is associated with the severity of CKD. We also evaluated the interaction between mitochondrial function and coexisting comorbidities, such as impaired physical performance, intermuscular adipose tissue infiltration, inflammation, and oxidative stress.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Sixty-three participants were studied, including controls (n=21), patients with CKD not on maintenance hemodialysis (CKD 3-5; n=20), and patients on maintenance hemodialysis (n=22). We evaluated in vivo knee extensors mitochondrial function using ³¹P magnetic resonance spectroscopy to obtain the phosphocreatine recovery time constant, a measure of mitochondrial function. We measured physical performance using the 6-minute walk test, intermuscular adipose tissue infiltration with magnetic resonance imaging, and markers of inflammation and oxidative stress in plasma. In skeletal muscle biopsies from a select number of patients on maintenance hemodialysis, we also measured markers of mitochondrial dynamics (fusion and fission).

RESULTS

We found a prolonged phosphocreatine recovery constant in patients on maintenance hemodialysis (53.3 [43.4-70.1] seconds, median [interquartile range]) and patients with CKD not on maintenance hemodialysis (41.5 [35.4-49.1] seconds) compared with controls (38.9 [32.5-46.0] seconds; P=0.001 among groups). Mitochondrial dysfunction was associated with poor physical performance (r=0.62; P=0.001), greater intermuscular adipose tissue (r=0.44; P=0.001), and increased markers of inflammation and oxidative stress (r=0.60; P=0.001). We found mitochondrial fragmentation and increased content of dynamin-related protein 1, a marker of mitochondrial fission, in skeletal muscles from patients on maintenance hemodialysis (0.86 [0.48-1.35] arbitrary units (A.U.), median [interquartile range]) compared with controls (0.60 [0.24-0.75] A.U.).

CONCLUSIONS

Mitochondrial dysfunction is due to multifactorial etiologies and presents prior to the initiation of maintenance hemodialysis, including in patients with CKD stages 3-5.

Anemia Is Correlated with Malnutrition and Inflammation in Croatian Peritoneal Dialysis Patients: A Multicenter Nationwide Study

Malnutrition, inflammation, and anemia are common in peritoneal dialysis (PD) patients. In this study, correlations between Malnutrition Inflammation Score (MIS), laboratory and anthropometric parameters, and anemia indices in Croatian PD patients were analyzed. One hundred and one PD patients (males/females 54/47, age 58.71 ± 14.68 years, mean PD duration 21.82 ± 21.71 months) were included. Clinical, laboratory, and anthropometric parameters were measured. Statistically significant correlations between MIS and erythropoietin weekly dose per kg of body weight (ESA weekly dose), hemoglobin (Hb), and erythrocytes were found (r = 0.439, p < 0.001; r = -0.032, p < 0.001; r = -0.435, p < 0.001), respectively. Also, statistically significant correlations were found between MIS and mean corpuscular volume (r = 0.344, p < 0.001), iron (r = -0.229, p = 0.021), and total iron binding capacity (TIBC) (r = -0.362, p < 0.001), respectively. Furthermore, statistically significant correlations between ESA weekly dose and serum albumin level and body mass index (BMI) were found (r = -0.272, p = 0.006; r = -0.269, p = 0.006), respectively. When we divided PD patients into 2 groups according Hb level (Hb ≥ 110 [N = 60, 59.41 %]) and Hb < 110 [N = 41, 40.59%]), statistically significant differences were found in MIS score (3.02 ± 2.54 vs 4.54 ± 3.54, p = 0.014), C-reactive protein (CRP) (3.52 ± 6.36 vs 7.85 ± 7.96, p = 0.005), and serum albumin level (44.22 ± 8.54 vs 39.94 ± 8.56, p = 0.003), respectively. Our findings suggest that anemia is correlated with malnutrition and inflammation in Croatian PD patients. Further studies are needed to assess whether modulating inflammatory or nutritional processes can improve anemia management in PD patients.

Changes of serum and peritoneal inflammatory mediators in laparoscopic radical resection for right colon carcinoma

Objective:

The objective of this study is to investigate the effects of laparoscopic and open operation on serum and peritoneal inflammatory mediators in patients with right colon carcinoma.

Patients and Methods:

A total of 100 patients were randomly divided into laparoscopic group (n = 50) and open group (n = 50). The age, sex, operation time, operation blood loss, post-operative Dukes stage, time to first passage of flatus and post-operative hospital stay were recorded. The levels of hypersensitive C reactive protein (hsCRP) and tumour necrosis factor-α (TNF-α) in serum and abdominal exudate were measured by ELISA at the time of pre-operative 2 h and post-operative 6 h and 24 h.

Results:

There was no significant difference in age, sex, Dukes stage and pre-operative inflammatory mediators between the two groups (P > 0.05). The operation time, intraoperative blood loss, time to first passage of flatus and post-operative hospital stay were significantly better in laparoscopic group than those in open operation group. At 6 h and 24 h after operation, the levels of hsCRP and TNF-α in serum and abdominal exudate in laparoscopic group were significantly lower than those in open operation group.

Conclusions:

Laparoscopic surgery for the treatment of right colon carcinoma has the advantages of fewer traumas, less systemic and local inflammatory response, rapider post-operative recovery and shorter hospital stay. It is worthy of clinical application.

Systemic inflammation is associated with exaggerated skeletal muscle protein catabolism in maintenance hemodialysis patients

BACKGROUND

Systemic inflammation and muscle wasting are highly prevalent and coexist in patients on maintenance hemodialysis (MHD). We aimed to determine the effects of systemic inflammation on skeletal muscle protein metabolism in MHD patients.

METHODS

Whole body and skeletal muscle protein turnover were assessed by stable isotope kinetic studies. We incorporated expressions of E1, E214K, E3αI, E3αII, MuRF-1, and atrogin-1 in skeletal muscle tissue from integrin β1 gene KO CKD mice models.

RESULTS

Among 129 patients with mean (± SD) age 47 ± 12 years, 74% were African American, 73% were male, and 22% had diabetes mellitus. Median high-sensitivity C-reactive protein (hs-CRP) concentration was 13 (interquartile range 0.8, 33) mg/l. There were statistically significant associations between hs-CRP and forearm skeletal muscle protein synthesis, degradation, and net forearm skeletal muscle protein balance (P < 0.001 for all). The associations remained statistically significant after adjustment for clinical and demographic confounders, as well as in sensitivity analysis, excluding patients with diabetes mellitus. In attempting to identify potential mechanisms involved in this correlation, we show increased expressions of E1, E214K, E3αI, E3αII, MuRF-1, and atrogin-1 in skeletal muscle tissue obtained from an animal model of chronic kidney disease.

CONCLUSION

These data suggest that systemic inflammation is a strong and independent determinant of skeletal muscle protein homeostasis in MHD patients, providing rationale for further studies using anticytokine therapies in patients with underlying systemic inflammation.

FUNDING

This study was in part supported by NIH grants R01 DK45604 and 1K24 DK62849, the Clinical Translational Science Award UL1-TR000445 from the National Center for Advancing Translational Sciences, the Veterans Administration Merit Award I01 CX000414, the SatelliteHealth Normon Coplon Extramural Grant Program, and the FDA grant 000943.

Different effect of hypercholesterolemia on mortality in hemodialysis patients based on coronary artery disease or myocardial infarction

Background

Studies on the association of total cholesterol (TC) levels and mortality in hemodialysis (HD) patients demonstrated conflicting results. The differenct effect of Hypercholesterolemia on HD patients based on the presence of myocardial infarction (MI) or coronary artery disease (CAD) is unknown.

Methods

We analyzed data from the Taiwan Renal Registry Data System (TWRDS) between 2005 and 2012. Patients were divided into MI/CAD or non-MI/CAD group. The primary outcome was three-year mortality. The association between primary outcome and first year average TC and effect of change in cholesterol level between the first and third year of dialysis were explored.

Results

Of 90,795 HD patients, 77,762 (85.6%) patients were assigned to non-MI/CAD group and 13,033 (14.4%) to the MI/CAD group. In the non-MI/CAD subjects, both TC > 250 mg/dL and < 150 mg/dL were associated with increased risk of mortality (adjusted hazard ratio [HR]; 95% confidence interval [CI]: 1.27; 1.17–1.37 and 1.14; 1.11–1.18) compared to the reference (TC: 150–200 mg/dL). In the MI/CAD patients, only TC < 150 mg/dL had increased risk (HR; 95% CI: 1.15; 1.08–1.24). In addition, patients of the non-MI/CAD group with highest level of TC (>250 mg/dL) in both first and third year of dialysis had a 64% increased risk for mortality (HR: 1.64, 95% CI: 1.51–1.80).

Conclusion

In this nationwide hemodialysis cohort, hypercholesterolemia was associated with increased mortality in HD patients without MI/CAD. Further investigation on primary prevention of CAD with statin is warranted.

Acupuncture and related interventions for symptoms of chronic kidney disease

BACKGROUND

People living with chronic kidney disease (CKD) experience a range of symptoms and often have complex comorbidities. Many pharmacological interventions for people with CKD have known risks of adverse events. Acupuncture is widely used for symptom management in patients with chronic diseases and in other palliative care settings. However, the safety and efficacy of acupuncture for people with CKD remains largely unknown.

OBJECTIVES

We aimed to evaluate the benefits and harms of acupuncture, electro-acupuncture, acupressure, moxibustion and other acupuncture-related interventions (alone or combined with other acupuncture-related interventions) for symptoms of CKD. In particular, we planned to compare acupuncture and related interventions with conventional medicine, active non-pharmacological interventions, and routine care for symptoms of CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register up to 28 January 2016 through contact with the Information Specialist using search terms relevant to this review. We also searched Korean medical databases (including Korean Studies Information, DBPIA, Korea Institute of Science and Technology Information, Research Information Centre for Health Database, KoreaMed, the National Assembly Library) and Chinese databases (including the China Academic Journal).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that investigated the effects of acupuncture and related point-stimulation interventions with or without needle penetration that involved six sessions or more in adults with CKD stage 3 to 5, regardless of the language and type of publication. We excluded studies that used herbal medicine or co-interventions administered unequally among the study groups.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and assessed risk of bias. We calculated the mean difference (MD) or standardised mean difference (SMD) with 95% confidence intervals (CI) for continuous outcomes and risk ratio (RR) for dichotomous outcomes. Primary outcomes were changes in pain and depression, and occurrence of serious of adverse events.

MAIN RESULTS

We included 24 studies that involved a total of 1787 participants. Studies reported on various types of acupuncture and related interventions including manual acupuncture and acupressure, ear acupressure, transcutaneous electrical acupuncture point stimulation, far-infrared radiation on acupuncture points and indirect moxibustion. CKD stages included pre-dialysis stage 3 or 4 and end-stage kidney disease on either haemodialysis or peritoneal dialysis.None of the included studies assessed pain outcomes, nor formally addressed occurrence of serious adverse events, although three studies reported three participant deaths and three hospitalisations as reasons for attrition. Three studies reported minor acupuncture-related harms; the remainder did not report if those events occurred.All studies were assessed at high or unclear risk of bias in terms of allocation concealment. Seventeen studies reported outcomes measured for only two months.There was very low quality of evidence that compared with routine care, manual acupressure reduced scores of the Beck Depression Inventory score (scale from 0 to 63) (3 studies, 128 participants: MD -4.29, 95% CI -7.48 to -1.11, I(2) = 0%), the revised Piper Fatigue Scale (scale from 0 to 10) (3 studies, 128 participants: MD -1.19, 95% CI -1.77 to -0.60, I(2) = 0%), and the Pittsburgh Sleep Quality Index (scale from 0 to 21) (4 studies, 180 participants: MD -2.46, 95% CI -4.23 to -0.69, I(2) = 50%).We were unable to perform further meta-analyses because of the paucity of data and problems with clinical heterogeneity, such as different interventions, comparisons and timing of outcome measurements.

AUTHORS' CONCLUSIONS

There was very low quality of evidence of the short-term effects of manual acupressure as an adjuvant intervention for fatigue, depression, sleep disturbance and uraemic pruritus in patients undergoing regular haemodialysis. The paucity of evidence indicates that there is little evidence of the effects of other types of acupuncture for other outcomes, including pain, in patients with other stages of CKD. Overall high or unclear risk of bias distorts the validity of the reported benefit of acupuncture and makes the estimated effects uncertain. The incomplete reporting of acupuncture-related harm does not permit us to assess the safety of acupuncture and related interventions. Future studies should investigate the effects and safety of acupuncture for pain and other common symptoms in patients with CKD and those undergoing dialysis.

Effects of Pomegranate Extract Supplementation on Cardiovascular Risk Factors and Physical Function in Hemodialysis Patients

The purpose of this study was to evaluate the effects of oral supplementation with pomegranate extract on cardiovascular risk, physical function, oxidative stress, and inflammation in hemodialysis (HD) patients. Thirty-three HD subjects were randomized to the pomegranate (POM) or placebo (CON) group. Patients in POM ingested a 1000 mg capsule of a purified pomegranate polyphenol extract 7 days/week for 6 months. Individuals in CON ingested a noncaloric placebo capsule using the same protocol. Measurements were conducted at baseline and repeated 6 months following the start of the intervention. Brachial blood pressure (BP) was obtained using an automatic digital BP monitor. Cardiovascular risk was assessed using ultrasound and arterial tonometry. Blood samples were collected for the measurements of circulating markers of inflammation, oxidative stress, and antioxidant capacity. Muscle strength and physical function were assessed by isokinetic dynamometry, a validated shuttle walk test, and a battery of tests to assess functional fitness. Systolic blood pressure and diastolic blood pressure were reduced by 24 ± 13.7 and 10 ± 5.3 mmHg, respectively, in POM (P < .05). However, the BP differences in POM were no longer significant after controlling for baseline BP. The paraoxonase-1 activity increased by 26.6% (P < .05) in POM, compared to no significant change in CON. However, pomegranate supplementation had no effect on other markers of cardiovascular disease risk, inflammation and oxidative stress, or measures of physical function and muscle strength. While pomegranate extract supplementation may reduce BP and increase the antioxidant activity in HD patients, it does not improve other markers of cardiovascular risk, physical function, or muscle strength.

Intradialytic protein supplementation reduces inflammation and improves physical function in maintenance hemodialysis patients

OBJECTIVE

Protein malnutrition is both a cause and consequence of inflammation and related comorbidities for maintenance hemodialysis (MHD) patients. This study sought to determine if oral supplementation with soy or whey protein during dialysis treatment reduces inflammation and improves physical function and body composition in MHD patients.

DESIGN

The design used in the study was randomized controlled trial, and the setting used was hemodialysis clinics in Champaign and Chicago, Illinois.

SUBJECTS

Patients who received treatment ≥3 days/week, were ages ≥30 years did not have congestive heart failure or chronic obstructive pulmonary disease, and were receiving dialysis treatment for ≥3 months were eligible for inclusion.

INTERVENTION

Patients were randomized to oral supplementation with a whey protein, soy protein, or placebo beverage. Patients (WHEY, n = 11; SOY, n = 12; CON, n = 15) consumed their assigned beverage before every dialysis session for 6 months.

MAIN OUTCOME MEASURES

Body composition was measured by dual-energy x-ray absorptiometry, physical function by gait speed and shuttle walk test, and markers of inflammation (C-reactive protein and interleukin 6) using commercially available enzyme-linked immunosorbent assay kits before and after the 6-month intervention. Dietary intake was assessed by 24-hour dietary recalls.

RESULTS

Six months of whey or soy supplementation significantly reduced predialysis interleukin 6 levels (P < .05 for both), whereas there was a trend for a reduction in C-reactive protein when both protein groups were combined (P = .062). Gait speed and shuttle walk test performance also significantly improved in the protein groups (P < .05 for both). No changes in body composition were observed. However, alkaline phosphatase, a marker of bone turnover, was significantly reduced in the protein groups.

CONCLUSIONS

Intradialytic protein supplementation during a 6-month intervention reduced inflammation and improved physical function and represents an affordable intervention to improve the health of MHD patients.

Depressive affect and hospitalization risk in incident hemodialysis patients

BACKGROUND AND OBJECTIVES

Recent studies demonstrated an association between depressive affect and higher mortality risk in incident hemodialysis patients. This study sought to determine whether an association also exists with hospitalization risk.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

All 8776 adult incident hemodialysis patients with Medical Outcomes Study Short Form 36 survey results treated in Fresenius Medical Care North America facilities in 2006 were followed for 1 year from the date of survey, and all hospitalization events lasting >24 hours were tracked. A depressive affect score was derived from responses to two Medical Outcomes Study Short Form 36 questions ("down in the dumps" and "downhearted and blue"). A high depressive affect score corresponded with an average response of "some of the time" or more frequent occurrence. Cox and Poisson models were constructed to determine associations of depressive affect scores with risk for time to first hospitalization and risk for hospitalization events, as well as total days spent in the hospital, respectively.

RESULTS

Incident patients with high depressive affect score made up 41% of the cohort and had a median (interquartile range) hospitalization event rate of one (0, 3) and 4 (0, 15) total hospital days; the values for patients with low depressive affect scores were one (0, 2) event and 2 (0, 11) days, respectively. For high-scoring patients, the adjusted hazard ratio for first hospitalization was 1.12 (1.04, 1.20). When multiple hospital events were considered, the adjusted risk ratio was 1.13 (1.02, 1.25) and the corresponding risk ratio for total hospital days was 1.20 (1.07, 1.35). High depressive affect score was generally associated with lower physical and mental component scores, but these covariates were adjusted for in the models.

CONCLUSIONS

Depressive affect in incident hemodialysis patients was associated with higher risk of hospitalization and more hospital days. Future studies are needed to investigate the effect of therapeutic interventions to address depressive affect in this high-risk population.

Delta-He: a novel marker of inflammation predicting mortality and ESA response in peritoneal dialysis patients

BACKGROUND

Inflammation impairs erythropoiesis, iron availability and is associated with a higher mortality risk in patients with end-stage renal disease. We studied the associations between Delta-He [the difference between the reticulocyte haemoglobin content (Ret-He) and erythrocyte haemoglobin content], a suggested marker of iron availability, and markers of inflammation, iron status, response to erythropoiesis-stimulating agents (ESAs) and mortality in prevalent peritoneal dialysis (PD) patients.

METHODS

Eighty-two PD patients were followed weekly for 12 weeks with an additional follow-up of 36 months. Delta-He, Ret-He and high-sensitivity C-reactive protein (hs-CRP) were measured weekly and interleukin-6 (IL-6) and iron markers every fourth week. Mortality risk was assessed by Cox proportional hazards model adjusting for potential confounding factors. The relationships between ESA response, inflammatory markers, iron markers and Delta-He were evaluated in the PD patients. The relationship between Delta-He and iron markers was analysed in 87 healthy subjects.

RESULTS

Delta-He correlated with IL-6 (rho = 0.48, P < 0.001), hs-CRP (rho = 0.36, P < 0.001) and ESA hyporesponsivess index (EHRI; rho = -0.44, P < 0.001) in the PD patients. Delta-He did not correlate with iron markers in PD patients nor in healthy subjects. The mean Delta-He levels were significantly different between the tertiles of EHRI (P < 0.01). Delta-He was associated with all-cause mortality risk in PD patients after adjusting for age, gender, hs-CRP, comorbidity and nutritional status [OR 0.70 (0.51-0.96), P < 0.05].

CONCLUSIONS

Delta-He independently predicts all-cause mortality in PD patients after adjusting for potential confounders and is a predictor of ESA response in PD patients.

Interleukin-6 and vitamin D status during high-intensity resistance training in patients with chronic kidney disease

Background. The aim of this study was to investigate IL-6 and 25-hydroxyvitamin D (25-OH D) associations with muscle size and muscle function in dialysis patients. Methods. Patients were included in a 16-week control period followed by 16 weeks of high-intensity resistance training thrice weekly. IL-6 and 25-OH D were analysed after an over-night fast. Muscle fibre size was analysed in biopsies from m. vastus lateralis. Muscle power was tested using a Leg Extensor Power Rig. Results. Patients (n = 36) with IL-6 ≥ 6.49 pg/ml (median) were older and had decreased muscle power and a reduced protein intake (P < 0.05) compared with patients with IL-6 < 6.49 pg/ml. IL-6 was not associated with muscle fibre size. Vitamin D deficiency (25-OH D < 50 nmol/l) was present in 51% of the patients and not associated with muscle power. IL-6 remained unchanged during the training period, whilst muscle power increased by 20-23% (P < 0.001). Conclusion. Elevated IL-6 values were associated with decreased muscle power but not with decreased muscle fibre size. Half of the patients were suffering from vitamin D deficiency, which was not associated with muscle power. IL-6 was unchanged by high-intensity resistance training in dialysis patients in this study.

Cyclooxygenase-2 and vascular endothelial growth factor expressions are involved in ultrafiltration failure

BACKGROUND

Long-term peritoneal dialysis (PD) is associated with ultrafiltration failure (UFF). The aim of the study was to investigate changes in cyclooxygenase-2 (COX-2), vascular endothelial growth factor A (VEGF-A), and vascular endothelial growth factor C (VEGF-C) expressions in a rat model of UFF induced by PD solution.

METHODS

Sprague-Dawley rats were divided into six groups (n = 8/group): normal untreated control group, sham operation group, uremic group (nephrectomy without PD), uremic 2-wk PD group (PD solution for 2 wk), uremic 4-wk PD group (PD solution for 4 wk), and uremic 4-wk PD + celecoxib group (PD solution plus COX-2 inhibitor celecoxib 20 mg/kg for 4 wk). Peritoneal function was determined by peritoneal equilibration test. Peritoneal morphology was determined by hematoxylin and eosin and Masson staining. Microvessel and lymphatic microvessel formation was determined by immunohistochemistry. COX-2, VEGF-A, and VEGF-C expressions were determined by real-time polymerase chain reaction and immunohistochemistry.

RESULTS

Uremic rat model was successfully established. PD-induced peritoneal morphologic changes associated with UFF, characterized by inflammation, edema, and collagen accumulation. PD solution increased the density of microvessels marked by CD31 (microvessel density) and lymphatic microvessels marked by LYVE-1 (lymphatic vessel density) in peritoneum. COX-2, VEGF-A, and VEGF-C expression levels in the uremic 4-wk PD group were higher than those in the uremic group (all P < 0.05). All these changes were partially reversed by celecoxib. VEGF-A and VEGF-C protein expressions were positively correlated with microvessel density and lymphatic vessel density formation.

CONCLUSIONS

COX-2 could increase VEGF-A and VEGF-C expressions in peritoneal tissue, resulting in increased formation of peritoneal microvessels and lymphatic microvessels, playing pivotal roles in the development of UFF.

Association of frailty with body composition among patients on hemodialysis

Although sarcopenia is thought to underlie the manifestations of frailty, association of frailty with measures of body composition is underinvestigated.

METHODS

Eighty hemodialysis patients were included in the study. Performance-based frailty (PbF) used gait speed over 20 feet and 5 sit-to-stand (1 point each for lowest quintile) for the physical components of the frailty phenotype plus exhaustion (Short Form-36 [SF-36] vitality score <55) and physical activity (lowest quintile of weekly kcal energy expenditure on leisure activity on the Physical Activity Scale for the Elderly questionnaire; 1 point). Function-based frailty (FbF) defined by questionnaire measures of physical functioning (SF-36 Physical Function score <75; 1 point), exhaustion, and physical activity as for PbF. A score of 2 or greater was defined as frail. Outcomes related to muscle size included muscle area of the contractile tissue of the anterior tibialis and quadriceps muscles using magnetic resonance imaging, phase angle using bioimpedance analysis, lean body mass using dual energy X-ray absorptiometry, and body mass index (BMI). Linear regression was used to analyze associations between frailty and muscle size, with and without sex and age covariates.

RESULTS

Fifty-nine percent of individuals met PbF criteria, 63% met FbF criteria, and 55% met both. In univariate analysis, PbF and FbF were associated with smaller muscle area of the quadriceps, smaller phase angle, and higher BMI. Associations remained significant for the quadriceps after adjustment for age and sex. The magnitude of association of PbF with quadriceps muscle area was greater than 10 years of age (-30.3 cm(2)P = .02 vs. -6.6 cm(2)P < .0001) in multivariate analysis. There was no significant association between either measure of frailty and other measures of body composition after adjustment for age and sex.

CONCLUSION

Frailty was associated with measurements related to muscle size in a population of individuals with chronic kidney disease, a known contributor to muscle wasting.

Association of left ventricular hypertrophy with high-sensitive C-reactive protein in hemodialysis patients

BACKGROUND

Micro inflammation and cardiovascular disease such as left ventricular hypertrophy (LVH) are common in hemodialysis (HD) patients. Hence, we have evaluated the relationship between high-sensitive C-reactive protein (hs-CRP), as an inflammation marker, and left ventricular mass index (LVMi) and left ventricular mass (LVM) in HD patients.

METHODS

An analytical cross-sectional study was performed in 104 HD patients. Serum hs-CRP, LVMi, LVM, and blood pressure were evaluated; demographic data and duration of HD were also recorded. Finally, results were analyzed by using Student's t test, Pearson's correlation coefficient, one-way ANOVA and multiple regression to determine the relationship between LVMi and other variables.

RESULTS

A total of 66 male patients (63.46 %) and 38 female patients, with a mean age of 51.75 ± 15.98 years-old, participated in this study. Hypertension was the most common underlying disease (65.4 %). The mean LVMi was 366.98 ± 120.89 g/m(2) and the mean hs-CRP was 8.55 mg/l. Eighty-nine percent of patients had LVH. The hs-CRP level was significantly associated with age and with LVM (P = 0.0001, P = 0.039, respectively). On multivariate analysis, hs-CRP and systolic blood pressure were found to be independent predictors of LVM and LVMi.

CONCLUSIONS

This study shows that hs-CRP and systolic BP are independent predictors of LVH in HD patients.

Accuracy and limitations of the diagnosis of malnutrition in dialysis patients

Uremic malnutrition, also known as protein-energy wasting (PEW), is a common phenomenon in maintenance dialysis patients and a risk factor for poor clinical outcomes including worse quality of life and increased hospitalization and mortality. The paradoxical association between traditional cardiovascular risk factors and better outcomes in dialysis patients also referred to as "reverse epidemiology," is a good example of the powerful effect-modifying impact of the nutritional status in this population. Measures of food intake, body composition tools, nutritional scoring systems, and laboratory values such as serum albumin are used to diagnose PEW and to assess the degree of severity of PEW without clearly validated diagnostic criteria. Some observational studies suggest that inflammation is a missing link between the PEW and poor clinical outcomes in dialysis patients, although PEW per se may also predispose to illness and inflammation. Ongoing debate as to whether such surrogates as serum albumin or prealbumin concentrations are markers of nutritional status, inflammation, comorbidity, or other conditions has led to confusion and diagnostic and therapeutic nihilism. Irrespective of the cause of hypoalbuminemia in dialysis patients, evidence suggests that nutritional interventions can increase serum albumin in dialysis patients. Hence, we should continue assessing serum albumin and other surrogates of nutritional status to risk-stratify patients and to allocate nutritional therapy, while well-designed, large-scale, randomized, controlled trials of the effects of nutritional intake on clinical outcomes are awaited.

Resistance to erythropoietin-stimulating agents: etiology, evaluation, and therapeutic considerations

Routine clinical and laboratory assessments facilitate diagnosis of erythropoietin (EPO) resistant anemia by allowing early identification of patients with non-adherence. Any new event that impairs response to EPO (e.g., catheter sepsis) must be promptly controlled. Because of the confounding interaction of its risk factors, initial evaluation should include nutrition, dialysis adequacy, hemorrhage, bone mineral metabolism, and inflammation. Prevention of EPO resistance is more cost effective and should include adequate dialysis and nutritional supplements. Blood loss during hemodialysis (HD) procedures should be minimized. If there is laboratory proof of iron deficit intravenous repletion is most effective. Oxidative stress may be attenuated by vitamins E and C, while optimal control of hyperparathyroidism will enhance EPO stimulation. Contaminated dialysates should be suspected if there is EPO-stimulating agents (ESA) resistance at the same time among most members of a dialysis program. Heavy metal toxicity should be suspected in high-risk patients. The impact of co-morbidities such as hemoglobinopathy, glucose 6 phosphate dehydrogenase (G6PD) deficiency and connective tissue diseases must be excluded in an appropriate setting. In conclusion, given the multiple risk factors of EPO resistance promotion of the overall health status will most likely yield an enduring benefit. Finally, there are experimental trials of gene-based (therapy) to stimulate endogenous EPO synthesis with the goal of avoiding the off-target effect of excessive dosing.

Renal anemia of inflammation: the name is self-explanatory

BACKGROUND

Anemia is inevitable as chronic kidney disease (CKD) advances. With the advent of erythropoietin-stimulating agents (ESAs), considerable improvement has been achieved in the management of anemia. However, some patients show a reduced response to ESAs.

METHODS

Many factors affect the response to ESA treatment. CKD is now considered as an inflammatory disorder and this understanding led to the recognition of the central role of inflammation in ESA resistance. Inflammation is related to untoward outcomes, including atherosclerosis and anemia, in the CKD population. Furthermore, recognition of deleterious effects of proinflammatory markers at different levels of erythropoiesis led to a change in the name of 'anemia of chronic disease' to anemia of inflammation.

RESULTS

The discovery of hepcidin as the major controller of iron metabolism in anemia of inflammation answered many questions regarding the interaction of erythropoietin, iron and bone marrow. Hepcidin production in the liver is driven by three major factors: inflammation, iron overload and anemia/hypoxia. Hepcidin levels are increased in patients with CKD due to the interaction of many factors; a comprehensive understanding of these pathways is thus critical in the effort to alleviate anemia of inflammation and ESA resistance.

CONCLUSION

In this review, we discussed the epidemiology, determinants and consequences of anemia of inflammation in CKD patients with special emphasis on the central role of hepcidin along with molecular pathways driving its production.

Acupuncture for symptom management in hemodialysis patients: a prospective, observational pilot study

OBJECTIVES

Patients undergoing hemodialysis suffer from a variety of complications related to end-stage renal disease. This prospective, observational pilot study aims to determine the feasibility, safety, and possible benefits of acupuncture for symptom management in patients undergoing hemodialysis.

METHODS

Twenty-four (24) patients undergoing hemodialysis received acupuncture treatment for their symptoms. Manually stimulated, individualized acupuncture treatments were provided twice a week for 6 consecutive weeks on a nondialysis day or on the day of hemodialysis prior to initiating treatment. Symptoms were evaluated using the Measure Your Medical Outcome Profiles 2 questionnaire, and quality of life was measured by Kidney Disease Quality of Life-Short Form (KDQOL-SF(™)) Version 1.3 at baseline, 7 weeks and 11 weeks from baseline. Statistical analysis was conducted on the basis of the intention-to-treat principle.

RESULTS

Twenty-one (21) patients (87%) completed the whole treatment course and follow-up evaluation. Three (3) patients dropped out due to increased fatigue (n = 1), pancreatic and renal transplantation (n = 1), and infections of the arteriovenous fistula used for hemodialysis access (n = 1). Patients experienced a significant improvement of symptoms considered the most bothersome, reporting a decrease of 1.87 and 2.08 points on a 0-6 symptom scale at 7 weeks and 11 weeks, respectively (both p < 0.0001). Some subscales of KDQOL-SF(™) showed significant improvement at 7 weeks (effects of kidney disease, burden of kidney disease, role-limitations physical, emotional well-being, and energy/fatigue) and 11 weeks (physical functioning and energy/fatigue). No serious adverse events related to acupuncture occurred.

CONCLUSIONS

Acupuncture seems feasible and safe for symptom management in patients undergoing hemodialysis. Future controlled trials are needed to confirm the benefits of acupuncture.

Association of self-reported physical activity with laboratory markers of nutrition and inflammation: the Comprehensive Dialysis Study

OBJECTIVE

Patients on dialysis maintain extremely low levels of physical activity. Prior studies have demonstrated a direct correlation between nutrition and physical activity but provide conflicting data on the link between inflammation and physical activity. Using a cohort of patients new to dialysis from the Comprehensive Dialysis Study (CDS), we examined associations of self-reported physical activity with laboratory markers of nutrition and inflammation.

DESIGN, SETTING, AND PATIENTS

Between June 2005 and June 2007, CDS collected data on self-reported physical activity, nutrition, and health-related quality of life from patients starting dialysis in 296 facilities located throughout the United States. Baseline serum samples were collected from participants in a nutrition sub-study of CDS.

MEASURES

Serum albumin and prealbumin were measured as markers of nutrition, and C-reactive protein (CRP) and α-1-acid glycoprotein as markers of inflammation. Self-reported physical activity was characterized by the maximum activity score (MAS) and adjusted activity score (AAS) of the Human Activity Profile.

RESULTS

The mean age of participants in the analytic cohort (n = 201) was 61 years. The MAS and AAS were below the 10th and first percentile, respectively, in comparison with healthy 60 year-old norms. Both activity scores were directly correlated with albumin (r(2) = 0.3, P < .0001) and prealbumin (r(2) = 0.3, P < .0001), and inversely correlated with CRP (AAS: r(2) = -0.2, P = .01; MAS: r(2) = -0.1, P = .08). In multivariate analyses adjusting for age, gender, race/ethnicity, diabetes status, and center, both activity scores were directly correlated with prealbumin and inversely correlated with CRP.

CONCLUSIONS

Patients new to dialysis with laboratory-based evidence of malnutrition and/or inflammation are likely to report lower levels of physical activity.

Hormonal regulation of energy-protein homeostasis in hemodialysis patients: an anorexigenic profile that may predispose to adverse cardiovascular outcomes

To assess whether endocrine dysfunction may cause derangement in energy homeostasis in patients undergoing hemodialysis (HD), we profiled hormones, during a 3-day period, from the adipose tissue and the gut and the nervous system around the circadian clock in 10 otherwise healthy HD patients and 8 normal controls. The protocol included a 40-h fast. We also measured energy-protein intake and output and assessed appetite and body composition. We found many hormonal abnormalities in HD patients: 1) leptin levels were elevated, due, in part, to increased production, and nocturnal surge in response to daytime feeding, exaggerated. 2) Peptide YY (PYY), an anorexigenic gut hormone, was markedly elevated and displayed an augmented response to feeding. 3) Acylated ghrelin, an orexigenic gut hormone, was lower and did not exhibit the premeal spike as observed in the controls. 4) neuropeptide Y (NPY), a potent orexigenic peptide, was markedly elevated and did not display any circadian variation. 5) Norepinephrine, marginally elevated, did not exhibit the normal nocturnal dip. By contrast, α-melanocyte-stimulating hormone and glucagon-like peptide-1 were not different between the two groups. Despite these hormonal abnormalities, HD patients maintained a good appetite and had normal body lean and fat mass, and there was no evidence of increased energy expenditure or protein catabolism. We explain the hormonal abnormalities as well as the absence of anorexia on suppression of parasympathetic activity (vagus nerve dysfunction), a phenomenon well documented in dialysis patients. Unexpectedly, we noted that the combination of high leptin, PYY, and NPY with suppressed ghrelin may increase arterial blood pressure, impair vasodilatation, and induce cardiac hypertrophy, and thus could predispose to adverse cardiovascular events that are the major causes of morbidity and mortality in the HD population. This is the first report attempting to link hormonal abnormalities associated with energy homeostasis to adverse cardiovascular outcome in the HD patients.

Insulin resistance and protein energy metabolism in patients with advanced chronic kidney disease

Insulin resistance (IR), the reciprocal of insulin sensitivity is a known complication of advanced chronic kidney disease (CKD) and is associated with a number of metabolic derangements. The complex metabolic abnormalities observed in CKD such as vitamin D deficiency, obesity, metabolic acidosis, inflammation, and accumulation of "uremic toxins" are believed to contribute to the etiology of IR and acquired defects in the insulin-receptor signaling pathway in this patient population. Only a few investigations have explored the validity of commonly used assessment methods in comparison to gold standard hyperinsulinemic hyperglycemic clamp technique in CKD patients. An important consequence of insulin resistance is its role in the pathogenesis of protein energy wasting, a state of metabolic derangement characterized by loss of somatic and visceral protein stores not entirely accounted for by inadequate nutrient intake. In the general population, insulin resistance has been associated with accelerated protein catabolism. Among end-stage renal disease (ESRD) patients, enhanced muscle protein breakdown has been observed in patients with Type II diabetes compared to ESRD patients without diabetes. In the absence of diabetes mellitus (DM) or severe obesity, insulin resistance is detectable in dialysis patients and strongly associated with increased muscle protein breakdown, primarily mediated by the ubiquitin-proteasome pathway. Recent epidemiological data indicate a survival advantage and better nutritional status in insulin-free Type II DM patients treated with insulin sensitizer thiazolidinediones. Given the high prevalence of protein energy wasting in ESRD and its unequivocal association with adverse clinical outcomes, insulin resistance may represent an important modifiable target for intervention in the ESRD population.

Investigation of skeletal muscle quantity and quality in end-stage renal disease

AIM

A more precise understanding of the aetiology and sequelae of muscle wasting in end-stage renal disease (ESRD) is required for the development of effective interventions to target this pathology.

METHODS

We investigated 49 patients with ESRD (62.6 +/- 14.2 years, 0.3-16.7 years on haemodialysis). Thigh muscle cross-sectional area (CSA), intramuscular lipid and intermuscular adipose tissue (IMAT) were measured via computed tomography as indices of muscle quantity (i.e. CSA) and quality (i.e. intramuscular lipid and IMAT). Additional health and clinical measures were investigated to determine associations with these variables.

RESULTS

Age, energy intake, disease burden, pro-inflammatory cytokines, nutritional status, strength and functioning were related to muscle quantity and quality. Potential aetiological factors entered into forward stepwise regression models indicated that hypoalbuminaemia and lower body mass index accounted significantly and independently for 32% of the variance in muscle CSA (r = 0.56, P < 0.001), while older age and interleukin-8 accounted for 41% of the variance in intramuscular lipid (r = 0.64, P < 0.001) and body mass index accounted for 45% of the variance in IMAT (r = 0.67, P < 0.001). Stepwise regression models revealed that intramuscular lipid was independently predictive of habitual gait velocity and 6 min walk distance, while CSA was independently predictive of maximal isometric strength (P < 0.05).

CONCLUSION

Ageing, poor nutritional status and elevated interleukin-8 are factors potentially contributing to the loss of muscle quality and quantity in ESRD. These deficits can predict functional impairments, with intramuscular lipid accumulation most closely related to decline of submaximal musculoskeletal performance (walking), and low muscle CSA most closely related to decline of maximal performance (peak isometric strength).

Review article: Tackling the survival issue in end-stage renal disease: time to get physical on haemodialysis

Life expectancy in haemodialysis patients is reduced fourfold on average versus healthy age-matched individuals. The purpose of this review is to present empirical evidence that intradialytic exercise can mitigate primary independent risk factors for early mortality in end-stage renal disease. These risk factors include measures of skeletal muscle wasting, systemic inflammation, cardiovascular functioning and dialysis adequacy. Overall, the available literature provides support for the integration of exercise within the conventional outpatient haemodialysis unit. The amelioration of various physiological risk factors through an appropriate exercise prescription may enhance survival in this vulnerable cohort. Investigations are required to determine the effects of various doses of intradialytic exercise on a broad range of clinical outcomes, and more thoroughly elucidate the relationship between exercise-induced adaptations and survival advantage in end-stage renal disease.

Why is protein-energy wasting associated with mortality in chronic kidney disease?

Observational studies in chronic kidney disease (CKD) populations consistently have shown the strong mortality-predictability of such markers of protein-energy wasting (PEW) as hypoalbuminemia, low serum cholesterol levels, low body mass index, and reduced dietary protein intake. Even though the PEW-mortality association data traditionally are reported mostly in maintenance dialysis patients, emerging studies extend the existence of these associations to predialysis stages of CKD. Paradoxic risk factor patterns (reverse epidemiology) for both obesity and cholesterol recently have been reported in predialysis CKD, underscoring the overwhelming impact of PEW, a short-term killer, on reversing the long-term effect of conventional cardiovascular risk factors. Multiple pathophysiologic mechanisms have been suggested to explain the link between PEW and mortality in CKD, including derangements in muscle, adipose tissue, and the gastrointestinal, hematopoietic, and immune systems; complications related to deficiencies of multiple micronutrients; and the maladaptive activation of the inflammatory cascade. In addition to well-described pathophysiologic mechanisms involved in the higher mortality seen with PEW, we also discuss the potential role of novel factors such as circulating actin, gelsolin, and proinflammatory high-density lipoprotein. Whether PEW is causally related to adverse outcomes in CKD needs to be verified in randomized controlled trials of nutritional interventions. The initiation of major clinical trials targeting nutritional interventions with the goal of improving survival in CKD offer the promise of extending the survival of this vulnerable patient population.

Fatigue in patients receiving maintenance dialysis: a review of definitions, measures, and contributing factors

Fatigue is a debilitating symptom or side effect experienced by many patients on long-term dialysis therapy. Fatigue has a considerable effect on patient health-related quality of life and is viewed as being more important than survival by some patients. Renal providers face many challenges when attempting to reduce fatigue in dialysis patients. The lack of a reliable, valid, and sensitive fatigue scale complicates the accurate identification of this symptom. Symptoms of daytime sleepiness and depression overlap with fatigue, making it difficult to target specific therapies. Moreover, many chronic health conditions common in the long-term dialysis population may lead to the development of fatigue and contribute to the day-to-day and diurnal variation in fatigue in patients. Key to improving the assessment and treatment of fatigue is improving our understanding of potential mediators, as well as potential therapies. Cytokines have emerged as an important mediator of fatigue and have been studied extensively in patients with cancer-related fatigue. In addition, although erythropoietin-stimulating agents have been shown to mitigate fatigue, the recent controversy regarding erythropoietin-stimulating agent dosing in patients with chronic kidney disease suggests that erythropoietin-stimulating agent therapy may not serve as the sole therapy to improve fatigue in this population. In conclusion, fatigue is an important and often underrecognized symptom in the dialysis population. Possible interventions for minimizing fatigue in patients on long-term dialysis therapy should aim at improving health care provider awareness, developing improved methods of measurement, understanding the pathogenesis better, and managing known contributing factors.

Nutrition, inflammation and chronic kidney disease

PURPOSE OF REVIEW

Protein-energy wasting and chronic inflammation are important comorbid conditions that predict poor clinical outcome in patients with advanced chronic kidney disease. The current article aims to provide a brief overview of the etiology and nutritional consequences of chronic inflammation with an outline of potential treatment options.

RECENT FINDINGS

The exact mechanisms leading to these unfavorable conditions are not fully elucidated and are most likely multifactorial. Irrespective of the specific etiologic mechanisms, it appears that the common pathway for all the metabolic derangements is related to exaggerated protein degradation relative to protein synthesis. Several studies suggest that chronic inflammation can predispose advanced chronic kidney disease patients to a catabolic state leading to worsening of protein-energy wasting by both increasing protein breakdown and decreasing protein synthesis. Chronic administration of nutritional supplementation, both parenterally and orally, improves nutritional status even in inflamed hemodialysis patients. Several pilot studies indicate that antiinflammatory intervention can also improve the metabolic and nutritional profiles.

SUMMARY

While a single common etiology has not been identified in this complex process, nutritional and antiinflammatory interventions can provide potential treatment options to improve the high mortality and morbidity in patients with advanced chronic kidney disease.

Serum Concentrations of F2-Isoprostanes and 4-Hydroxynonenal in Hemodialysis Patients in Relation to Inflammation and Renal Anemia

Background

Patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) are apparently exposed to enhanced oxidative stress and to inflammation. It was the aim of this study to characterize the state of systemic oxidative stress of ESRD patients before and following HD using highly specific biomarkers, F₂-isoprostanes and 4-hydroxynonenal (HNE). Furthermore the question should be answered, if there are associations between inflammation and systemic oxidative stress and/or between systemic oxidative stress and renal anemia, which is more or less typical for HD patients.

Patients and methods

Concentrations of F₂-isoprostanes, HNE, C-reactive protein (CRP) as marker of inflammation, and hemoglobin were measured in serum samples of patients with ESRD before and after HD and of healthy control persons for comparison. Total (esterified plus free) F₂-isoprostanes were quantified by highly sensitive gas chromatography/mass spectrometry technique, HNE by thin layer chromatography and HPLC/UV detection, CRP by immunoturbidimetry and hemoglobin by clinico-chemical routine assay.

Results

1. HD patients showed significantly higher serum concentrations of F₂-isoprostanes and HNE than healthy human control subjects. 2. Total (esterified plus free) F₂-isoprostane levels before HD were not significantly different from those after HD, whereas HNE levels were significantly decreased in patients after HD. 3. F₂-isoprostane concentrations in HD patients correlated with the levels of CRP, whereas HNE concentrations inversely correlated with the content of hemoglobin.

Conclusion

Both, F₂-isoprostanes and HNE serum concentrations are useful oxidative stress parameters in ESRD patients undergoing HD. Whereas HNE strongly correlates with the severity of renal anemia, leading to left heart insufficiency, F₂-isoprostanes (sum of free plus esterified) highly correlate with the degree of inflammation.

Remission of aseptic inflammatory ascites after nephrectomy of a failed allograft

There are multiple possible causes of ascites in patients with end-stage renal disease on hemodialysis therapy. In this report, we describe a patient with chronic hepatitis C infection who presented with refractory inflammatory ascites, along with cachexia, hypoalbuminemia, and erythropoietin resistance associated with the chronic inflammatory state induced by a failed kidney transplant. Evaluation showed only mild hepatic fibrosis, absence of portal hypertension, and no other identifiable cause of the ascites. Furthermore, the inflammatory ascites did not respond to antibiotic therapy, but promptly resolved, along with the other manifestations of the chronic inflammatory state, after transplant nephrectomy. This report describes a novel cause for refractory inflammatory ascites in a patient with a failed kidney transplant and emphasizes the importance of transplant nephrectomy.