Inflammation in end-stage renal disease: sources, consequences, and therapy

Stop chronic kidney disease progression: Time is approaching

Progression of chronic kidney disease (CKD) is inevitable. However, the last decade has witnessed tremendous achievements in this field. Today we are optimistic; the dream of withholding this progression is about to be realistic. The recent discoveries in the field of CKD management involved most of the individual diseases leading the patients to end-stage renal disease. Most of these advances involved patients suffering diabetic kidney disease, chronic glomerulonephritis, polycystic kidney disease, renal amyloidosis and chronic tubulointerstitial disease. The chronic systemic inflammatory status and increased oxidative stress were also investigated. This inflammatory status influences the anti-senescence Klotho gene expression. The role of Klotho in CKD progression together with its therapeutic value are explored. The role of gut as a major source of inflammation, the pathogenesis of intestinal mucosal barrier damage, the role of intestinal alkaline phosphatase and the dietary and therapeutic implications add a novel therapeutic tool to delay CKD progression.

Impedance ratio: a novel marker and a powerful predictor of mortality in hemodialysis patients

PURPOSE

Impedance ratio (Imp-R) obtained by multifrequency bioimpedance analysis (BIA) has been shown to be associated with volume and nutrition status. In this prospective study, the predictive role of Imp-R for mortality in hemodialysis (HD) patients was investigated.

METHODS

Multifrequency (5-50-100-200 kHz) BIA was applied to 493 prevalent HD patients in March-April 2006. Imp-R was defined as the ratio of 200-5 kHz impedance values. Demographical, clinical and laboratory data at the time of the analysis were recorded. All-cause and cardiovascular (CV) mortality were assessed during 3 years of follow-up.

RESULTS

Mean age was 57.7 ± 13.9 years, HD duration 52.1 ± 42.6 months and prevalence of diabetes 21.7 %. Imp-R was negatively correlated with nutritional markers including albumin, creatinine and hemoglobin levels. In addition, there was a positive correlation between Imp-R and age, ratio of extracellular water to total body water and high-sensitive C-reactive protein. Over a mean follow-up period of 27.9 ± 11.1 months, 93 deaths (52 from CV reasons) were observed. In the multivariate analysis, Imp-R was significantly associated with all-cause and CV mortality after adjustments [HR 1.13, 95 % CI (1.04-1.23); p = 0.004 and HR 1.15, 95 % CI (1.03-1.27); p = 0.01, respectively]. The risk of all-cause mortality was 3.4 times higher in the fourth quartile of Imp-R (>83.5 %) compared to the first Imp-R quartile (<78.8 %) as reference. Cutoff value of Imp-R for all-cause mortality was 82.0 % with a sensitivity of 65.5 % and specificity of 64 %.

CONCLUSION

Impedance ratio measured by multifrequency in standardized conditions BIA is an independent and powerful predictor of both all-cause and CV mortality in hemodialysis patients.

sTREM-1 in patients with chronic kidney disease on hemodialysis

The triggering receptor expressed on myeloid cells-1 (TREM-1) is a member of the immunoglobulin superfamily. TREM-1 has been implicated as an amplifier of inflammation. Soluble TREM-1 (sTREM-1) was investigated in different clinical conditions, but not in hemodialysis (HD) patients. We aimed to investigate sTREM-1 as a marker of inflammation in HD patients. We investigated 40 CKD patients undergoing chronic HD treatment and 15 controls. Routine laboratory investigations in addition to CRP measured by immunoturbidimetry, TNF- α, and sTREM-1 measured by ELISA were assayed in post-hemodialysis patients' blood samples and in controls' blood samples. CRP, TNF-α, and sTREM-1 levels were significantly higher in HD patients than in controls (p < 0.001 for all). sTREM-1 was positively correlated with CRP and TNF-α (r = +0.50, p < 0.001 and r = +0.53, p < 0.001 respectively). It was negatively correlated with hemoglobin concentration (r = -0.69, p < 0.001). Hemoglobin concentration was the significant predictor of sTREM-1 level (p < 0.001). In conclusion, sTREM-1 level is significantly increased in HD patients as are other pro-inflammatory markers.

Repositioning Clofazimine as a Macrophage-Targeting Photoacoustic Contrast Agent

Photoacoustic Tomography (PAT) is a deep-tissue imaging modality, with potential clinical applications in the diagnosis of arthritis, cancer and other disease conditions. Here, we identified Clofazimine (CFZ), a red-pigmented dye and anti-inflammatory FDA-approved drug, as a macrophage-targeting photoacoustic (PA) imaging agent. Spectroscopic experiments revealed that CFZ and its various protonated forms yielded optimal PAT signals at wavelengths −450 to 540 nm. CFZ’s macrophage-targeting chemical and structural forms were detected with PA microscopy at a high contrast-to-noise ratio (CNR > 22 dB) as well as with macroscopic imaging using synthetic gelatin phantoms. In vivo, natural and synthetic CFZ formulations also demonstrated significant anti-inflammatory activity. Finally, the injection of CFZ was monitored via a real-time ultrasound-photoacoustic (US-PA) dual imaging system in a live animal and clinically relevant human hand model. These results demonstrate an anti-inflammatory drug repurposing strategy, while identifying a new PA contrast agent with potential applications in the diagnosis and treatment of arthritis.

Connecting heart failure with preserved ejection fraction and renal dysfunction: the role of endothelial dysfunction and inflammation

Renal dysfunction in heart failure with preserved ejection fraction (HFpEF) is common and is associated with increased mortality. Impaired renal function is also a risk factor for developing HFpEF. A new paradigm for HFpEF, proposing a sequence of events leading to myocardial remodelling and dysfunction in HFpEF, was recently introduced, involving inflammatory, microvascular, and cardiac components. The kidney might play a key role in this systemic process. Renal impairment causes metabolic and systemic derangements in circulating factors, causing an activated systemic inflammatory state and endothelial dysfunction, which may lead to cardiomyocyte stiffening, hypertrophy, and interstitial fibrosis via cross-talk between the endothelium and cardiomyocyte compartments. Here, we review the role of endothelial dysfunction and inflammation to explain the link between renal dysfunction and HFpEF, which allows for identification of new early risk markers, prognostic factors, and unique targets for intervention.

Longitudinal Trend in Lipid Profile of Incident Peritoneal Dialysis Patients is Not Influenced by the Use of Biocompatible Solutions

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BACKGROUND

The longitudinal trends of lipid parameters and the impact of biocompatible peritoneal dialysis (PD) solutions on these levels remain to be fully defined. The present study aimed to a) evaluate the influence of neutral pH, low glucose degradation product (GDP) PD solutions on serum lipid parameters, and b) explore the capacity of lipid parameters (total cholesterol [TC], triglyceride [TG], high density lipoprotein [HDL], TC/HDL, low density lipoprotein [LDL], very low density lipoprotein [VLDL]) to predict cardiovascular events (CVE) and mortality in PD patients. ♦

METHODS

The study included 175 incident participants from the balANZ trial with at least 1 stored serum sample. A composite CVE score was used as a primary clinical outcome measure. Multilevel linear regression and Poisson regression models were fitted to describe the trend of lipid parameters over time and its ability to predict composite CVE, respectively. ♦

RESULTS

Small but statistically significant increases in serum TG (coefficient 0.006, p < 0.001), TC/HDL (coefficient 0.004, p = 0.001), and VLDL cholesterol (coefficient 0.005, p = 0.001) levels and a decrease in the serum HDL cholesterol levels (coefficient -0.004, p = 0.009) were observed with longer time on PD, whilst the type of PD solution (biocompatible vs standard) received had no significant effect on these levels. Peritoneal dialysis glucose exposure was significantly associated with trends in TG, TC/HDL, HDL and VLDL levels. Baseline lipid parameter levels were not predictive of composite CVEs or all-cause mortality. ♦

CONCLUSION

Serum TG, TC/HDL, and VLDL levels increased and the serum HDL levels decreased with increasing PD duration. None of the lipid parameters were significantly modified by biocompatible PD solution use over the time period studied or predictive of composite CVE or mortality.

Optimizing haemodialysate composition

Survival and quality of life of dialysis patients are strictly dependent on the quality of the haemodialysis (HD) treatment. In this respect, dialysate composition, including water purity, plays a crucial role. A major aim of HD is to normalize predialysis plasma electrolyte and mineral concentrations, while minimizing wide swings in the patient's intradialytic plasma concentrations. Adequate sodium (Na) and water removal is critical for preventing intra- and interdialytic hypotension and pulmonary edema. Avoiding both hyper- and hypokalaemia prevents life-threatening cardiac arrhythmias. Optimal calcium (Ca) and magnesium (Mg) dialysate concentrations may protect the cardiovascular system and the bones, preventing extraskeletal calcifications, severe secondary hyperparathyroidism and adynamic bone disease. Adequate bicarbonate concentration [HCO₃⁻] maintains a stable pH in the body fluids for appropriate protein and membrane functioning and also protects the bones. An adequate dialysate glucose concentration prevents severe hyperglycaemia and life-threating hypoglycaemia, which can lead to severe cardiovascular complications and a worsening of diabetic comorbidities.

Cathasept Line Lock and Microbial Colonization of Tunneled Hemodialysis Catheters: A Multicenter Randomized Controlled Trial

BACKGROUND

Catheter-related bloodstream infections (CRBSIs) cause morbidity and mortality in hemodialysis (HD) patients. Cathasept (tetra-sodium EDTA) solution has antimicrobial and anticoagulant activities.

STUDY DESIGN

Multicenter prospective randomized controlled study.

SETTING & PARTICIPANTS

117 maintenance HD patients with confirmed uncolonized tunneled HD catheters from 4 HD centers.

INTERVENTION

Patients were randomly assigned to receive Cathasept 4% locks (Cathasept group) or stayed with heparin 5,000 U/mL locks (heparin group), filled thrice weekly according to catheter lumen volume until the catheter was removed or for a maximum of 8 months.

OUTCOMES

Primary outcome was clinically significant microbial colonization of the catheter, defined as a through-catheter quantitative blood culture yielding ≥ 1,000 colony-forming units/mL of bacteria or yeast. Secondary outcomes included CRBSI rate, catheter patency, and biomarkers of inflammation and anemia.

MEASUREMENTS

Weekly through-catheter quantitative blood culture, high-sensitivity C-reactive protein fortnightly, and full blood count and ferritin monthly.

RESULTS

Incidence rates of catheter colonization were 0.14/1,000 catheter-days in the Cathasept group and 1.08/1,000 catheter-days in the heparin group (incidence rate ratio [IRR], 0.13; 95% CI, 0.003-0.94; P=0.02). CRBSI rates were 0.28/1,000 catheter-days in the Cathasept group and 0.68/1,000 catheter days in the heparin group (IRR, 0.40; 95% CI, 0.08-2.09; P=0.3). The proportion of dialysis sessions with achieved prescribed blood flow rate was significantly lower in the Cathasept group (66.8% vs 75.3%; P<0.001), with more patients requiring thrombolytic locks or infusions to maintain catheter patency (22 vs 9; P=0.01). Mean high-sensitivity C-reactive protein level was 11.6±5.3 (SE) mg/L lower for patients in the heparin group (P=0.03). Anemia marker levels were similar in both groups.

LIMITATIONS

Study was underpowered to assess effect on CRBSI, terminated early due to slow recruitment, and not double blinded.

CONCLUSIONS

Cathasept significantly reduced tunneled hemodialysis catheter colonization, but the reduction in CRBSIs was not statistically significant, and it was associated with more thrombotic complications. Its safety profile was comparable to heparin lock solution.

Transcriptome analysis in patients with chronic kidney disease on hemodialysis disclosing a key role for CD16+CX3CR1+ monocytes

The risk for cardiovascular morbidity and mortality is increased in chronic kidney disease; in this process micro-inflammation plays an essential role. Responsible mechanisms remain to a large extent unidentified. In this pilot study transcriptome analysis of peripheral blood monocytes was used to identify in an unprejudiced manner which factors could be discriminative for cardiovascular disease in patients with chronic kidney disease on hemodialysis. Forty gender- and age-matched, non-diabetic, non-smoking subjects with CRP < 20 mg/L were recruited: 9 healthy controls, 11 patients with eGFR > 60 mL/min/1.73m² and a history of cardiovascular event (CVE), 10 patients with chronic kidney disease stage 5 on hemodialysis without previous cardiovascular event (CKD5HD) and 10 with a previous cardiovascular event (CKD5HD/CVE). Monocytes were isolated and their mRNA was submitted to focused transcriptome analysis using a macroarray platform containing ca. 700 genes associated with macrophage functional capacity. The macroarray data indicated 9 genes (8 upregulated and 1 downregulated) with a significant differential expression in CKD5HD/CVE vs. CVE alone, after excluding genes differentially expressed in CKD5HD vs. control. For FCGR3A (CD16) and CX3CR1 (chemokine receptor) the upregulation vs. control and vs. CVE could be confirmed by quantitative RT-PCR for all CKD5HD patients. Furthermore, CX3CR1 relative expression on monocytes correlated with CRP. Flow cytometric analysis of purified monocytes confirmed a significant increase in the percentage of CD16 positive monocytes in all CKD5HD patients vs. control and CVE. The present study indicates the importance of a specific pro-inflammatory monocyte subpopulation, positive for CD16 and the co-expressed chemokine receptor, CX3CR1, discriminative for CKD5HD patients.

Factors precipitating erythropoiesis-stimulating agent responsiveness in a European haemodialysis cohort: case-crossover study

Purpose

Hyporesponsiveness to erythropoiesis‐stimulating agents (ESAs) is clinically and economically important in the treatment of anaemia in chronic kidney disease (CKD) patients. Previous studies focused on baseline predictors of ESA hyporesponsiveness, rather than factors associated with the transition to this state. Reversibility of ESA hyporesponsiveness has also not been studied previously.

Methods

Case‐crossover methodology was applied to a cohort of 6645 European CKD patients undergoing haemodialysis and prescribed ESAs. Ninety‐day ESA exposure periods were defined, haemoglobin (Hb) response was calculated using the last 30 days of one period and the first 30 days of the next, and periods were classified based on a median ESA dose (80.8 IU/kg/week) and a 10 g/dL Hb threshold. Clinical, dialysis and laboratory data from patients' first hyporesponsive ‘case’ period was compared with the preceding responsive ‘control’ period using conditional logistic regression. A similar approach was applied to hyporesponsiveness reversal.

Results

Of the patients, 672 experienced hyporesponsiveness periods with preceding responsive periods; 711 reversed to normality from hyporesponsiveness periods. Transition to hyporesponsiveness was associated with hospitalization, vascular access changes or worsening inflammation, with these factors accounting for over two‐thirds of transitions. Findings were largely insensitive to alternative ESA doses and Hb thresholds. Continued hospitalization, catheter insertion and uncontrolled secondary hyperparathyroidism were associated with a lack of regain of responsiveness.

Conclusions

Transition to hyporesponsiveness is linked to the development of conditions such as hospitalization events, vascular access issues or episodes of systemic inflammation. However, a third of hyporesponsive episodes remain unexplained. © 2015 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.

Inflammatory markers as mortality predictors in continuous ambulatory peritoneal dialysis patients

BACKGROUND/AIM

Besides peritonitis, the most common complication, indicators of chronic inflammation are also present in patients treated by peritoneal dialysis. The aim of this study was to analyze the predictive value of inflammatory parameters on mortality of continuous ambulatory peritoneal dialysis (CAPD) patients.

METHODS

Eighty-seven patients (57 males), aged from 30 to 85 [62.92 (10.61)] years who had been treated by a chronic program of CAPD for 3-113 months were analyzed. The basal period lasted 3 months with a follow-up of 30 months. Clinical parameters, dialysis adequacy and laboratory parameters including some inflammatory markers: serum amyloid-A (SAA), high sensitive C-reactive protein (hs-CRP), fibrinogen, erythrocyte sedimentation rate (ESR) and leukocytes were determined for each patient. Cox regression analysis selected the parameters of univariate and multivariate survival analysis.

RESULTS

During the follow-up period, 37 patients (42.5%) died. Univariate analysis selected the following potential mortality predictors (p<0.10): age, months on CAPD, residual urine output, presence of cerebrovascular insult (CVI), KT/V, serum urea and albumin concentrations, SAA, hs-CRP, fibrinogen and ESR. In the multivariate survival analysis four models were created, each with a single inflammatory parameter. In all of these models, besides the age and CVI, inflammatory parameters were the most significant mortality predictors. When the inflammatory markers were analyzed altogether, multivariate analysis established that independent mortality predictors in this group of patients were: SAA, age and CVI.

CONCLUSION

It may be concluded that in this studied group treated by CAPD, SAA was the most significant independent mortality predictor among the analyzed inflammatory markers.

Gut microbiota-dependent trimethylamine N-oxide (TMAO) pathway contributes to both development of renal insufficiency and mortality risk in chronic kidney disease

RATIONALE

Trimethylamine-N-oxide (TMAO), a gut microbial-dependent metabolite of dietary choline, phosphatidylcholine (lecithin), and l-carnitine, is elevated in chronic kidney diseases (CKD) and associated with coronary artery disease pathogenesis.

OBJECTIVE

To both investigate the clinical prognostic value of TMAO in subjects with versus without CKD, and test the hypothesis that TMAO plays a direct contributory role in the development and progression of renal dysfunction.

METHODS AND RESULTS

We first examined the relationship between fasting plasma TMAO and all-cause mortality over 5-year follow-up in 521 stable subjects with CKD (estimated glomerular filtration rate, <60 mL/min per 1.73 m(2)). Median TMAO level among CKD subjects was 7.9 μmol/L (interquartile range, 5.2-12.4 μmol/L), which was markedly higher (P<0.001) than in non-CKD subjects (n=3166). Within CKD subjects, higher (fourth versus first quartile) plasma TMAO level was associated with a 2.8-fold increased mortality risk. After adjustments for traditional risk factors, high-sensitivity C-reactive protein, estimated glomerular filtration rate, elevated TMAO levels remained predictive of 5-year mortality risk (hazard ratio, 1.93; 95% confidence interval, 1.13-3.29; P<0.05). TMAO provided significant incremental prognostic value (net reclassification index, 17.26%; P<0.001 and differences in area under receiver operator characteristic curve, 63.26% versus 65.95%; P=0.036). Among non-CKD subjects, elevated TMAO levels portend poorer prognosis within cohorts of high and low cystatin C. In animal models, elevated dietary choline or TMAO directly led to progressive renal tubulointerstitial fibrosis and dysfunction.

CONCLUSIONS

Plasma TMAO levels are both elevated in patients with CKD and portend poorer long-term survival. Chronic dietary exposures that increase TMAO directly contributes to progressive renal fibrosis and dysfunction in animal models.

Therapeutic C3 inhibitor Cp40 abrogates complement activation induced by modern hemodialysis filters

Approximately 350,000 individuals in the United States rely on maintenance hemodialysis treatment because of end-stage renal disease. Despite improvements in dialysis technology, the mortality rate for patients treated with maintenance dialysis is still exceptionally high, with a 5-year survival rate of only 35%. Many patients succumb to conditions resulting at least in part from the chronic induction of inflammation. Among the triggers of inflammation, the complement system is of particular importance, being a well-appreciated mediator of inflammatory processes that is involved in many pathologic states. Here we used a refined pre-clinical model of hemodialysis in cynomolgus monkeys to confirm that even modern, polymer-based hemodialysis filters activate complement and to evaluate the potential of Cp40, a peptidic C3 inhibitor, to attenuate hemodialysis-induced complement activation. Our data show marked induction of complement activation even after only a single session of hemodialysis. Importantly, complete inhibition of complement activation was achieved in response to two distinct Cp40 treatment regimens. Further, we show that application of Cp40 during hemodialysis resulted in increased levels of the anti-inflammatory cytokine IL-10, indicating that Cp40 may be a potent and cost-effective treatment option for attenuating chronic inflammatory conditions in dialysis-dependent patients.

Adiponectin receptor and adiponectin signaling in human tissue among patients with end-stage renal disease

BACKGROUND

Adiponectin plasma levels in chronic kidney disease (CKD) are two to three times higher than in individuals with normal kidney function. Despite adiponectin's anti-diabetic, anti-inflammatory and anti-atherogenic properties, patients with CKD have insulin resistance, systemic inflammation and accelerated atherogenesis. Hence, although adiponectin production is increased by adipose tissue in end-stage renal disease (ESRD), it is unclear if its effects on metabolism remain intact.

METHODS

To determine if there is adiponectin resistance in ESRD, we measured tissue levels of adiponectin receptor-1 (AdipoR1) and adiponectin downstream effectors in ESRD patients compared with normal kidney function controls. Blood and tissue samples were obtained from participants at the time of kidney transplantation or kidney donation. A follow-up blood sample was obtained 3-6 months after transplantation.

RESULTS

AdipoR1 was higher in muscle and peripheral blood mononuclear cells collected from ESRD patients. There was also a nonsignificant increase in AdipoR1 in visceral fat of ESRD compared with controls. Compared with controls, phosphorylation of the adiponectin downstream effector adenosine monophosphate-activated protein kinase (AMPK) was higher in ESRD while acetyl-CoA carboxylase phosphorylation (ACC-P) and carnitine palmitoyl transferase-1 (CPT-1) levels were lower. In vitro, exposure of C2C12 cells to uremic serum resulted in upregulation of AdipoR1 and increased phosphorylation of AMPK but decreased ACC-P and CPT-1 expression.

CONCLUSION

Both our in vivo and in vitro observations indicate that uremia results in upregulation of AdipoR1 but adiponectin resistance at the post-receptor level.

Association between depression and inflammatory/anti-inflammatory cytokines in chronic kidney disease and end-stage renal disease patients: a review of literature

Depression is a common psychiatric disorder in patients with advanced chronic kidney diseases (CKDs). Strong correlation has been reported between depression and patients' morbidity and mortality among dialysis patients. On the contrary, chronic inflammation may be a major contributor to morbidity and mortality in these patients. Elevated plasma levels of proinflammatory cytokines, especially C-reactive protein and interleukin (IL)-6, have been correlated with cardiovascular events, hospitalization, and all-cause and cardiovascular-associated mortality in dialysis patients. Studies suggested that inflammation-mediated atherosclerotic cardiovascular diseases are the possible reasons for depression-induced mortality among patients without renal diseases. Several studies found significant elevations in circulating levels of proinflammatory cytokines, particularly IL-6 and tumor necrosis factor-α, in patients with major depression. Furthermore, depressive mood and behaviors, including sadness and suicidal ideation, were observed in patients who received repeated injections of recombinant cytokines. A thorough literature review indicates that while depressive symptoms and elevated inflammatory cytokine levels coexist in CKD and dialysis patients, their association is uncertain. Depression seems to be more associated with elevated serum levels of IL-6 than other cytokines in these patients. Further studies are needed to clarify the possibility of a causal relationship between inflammation and depressive symptoms in CKD and dialysis patients.

Depression and chronic kidney disease: A review for clinicians

OBJECTIVE

To review the recent academic literature surrounding the prevalence, aetiopathology, associations and management of depression in chronic kidney disease (CKD), in order to provide a practical and up-to-date resource for clinicians.

METHODS

We conducted electronic searches of the following databases: MEDLINE, EMBASE and PsycINFO. The main search terms were: depression, mood disorders, depressive disorder, mental illness, in combination with kidney disease, renal insufficiency, dialysis, kidney failure. Separate searches were conducted regarding antidepressant use in CKD.

RESULTS

A number of recent, large and well-conducted studies have confirmed markedly raised rates of depression amongst those with CKD, with meta-analysis suggesting the prevalence of interview-defined depression to be approximately 20%. The interactions between depression and CKD are complex, bidirectional and multifactorial. Depression in CKD has been shown to be associated with multiple poor outcomes, including increased mortality and hospitalisation rates, as well as poorer treatment compliance and quality of life. Clinical evaluation of depression in patients with CKD can be challenging; however, once a diagnosis is made, a range of treatment modalities can be considered.

CONCLUSIONS

Depression is common in CKD and is associated with a significant risk of adverse outcomes. Given the importance of this issue, there is now an urgent need for well-conducted randomised trials of interventions for depression in CKD in order to provide information on the safety and efficacy of treatments.

Nonregenerative anemia: mechanisms of decreased or ineffective erythropoiesis

In veterinary medicine, anemia without an appropriate compensatory hematopoietic response is termed nonregenerative. Nonregenerative anemia is a common clinical entity, occurring as a result of diminished or ineffective erythropoiesis in association with many types of pathology. This article reviews nonregenerative anemia in domestic animals, emphasizing mechanisms of disease, and also covers other conditions associated with nonregenerative anemia in people. Many aspects of nonregenerative anemia in animals are worthy of further investigation, from molecular mechanisms of disease to epidemiologic impacts.

Effects of alpha lipoic acid supplementation on serum levels of IL-8 and TNF-α in patient with ESRD undergoing hemodialysis

BACKGROUND

Chronic renal failure is a progressive and irreversible loss of kidney function, and the hemodialysis (HD) is one of the most common modalities in this regard. Oxidative stresses [like interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α)] and inflammation are the main risk factors associated with cardiovascular diseases and other complications in many organs in hemodialysis patients; meanwhile, antioxidants like alpha lipoic acid (ALA) may reduce the oxidative stress markers and the levels of inflammatory cytokines, so can improve of the patient's quality of life.

METHODS

In this randomized clinical trial study, 60 HD patients were randomly categorized in two case and control groups. Case group received a daily capsule of 600 mg of ALA supplementation for 8 weeks, and the control group received placebo capsules daily. The serum level of IL-8 and TNF-α was measured in both groups before and after the intervention.

RESULTS

There were no significant differences in age, gender, duration of dialysis, and causative factor for dialysis between both groups (P > 0.05). The mean of IL-8 and TNF-α after the intervention in case group was 26.20 ± 15.34 and 21.25 ± 9.61, respectively; the difference between both groups was not statistically significant (P > 0.05).

CONCLUSION

Based on the better feeling and other beneficial effects of ALA were found in our study; we can conclude that it is a beneficial and recommended supplement, especially, for diabetic and dialysis patients.

Cross-over study of influence of oral vitamin C supplementation on inflammatory status in maintenance hemodialysis patients

BACKGROUND

Both vitamin C deficiency and inflammation are prevalent in maintenance hemodialysis (MHD) patients. In this study, we aimed to elucidate the effect of oral vitamin C supplementation on inflammatory status in MHD patients with low vitamin C level and high hypersensitive C-reactive protein (hs-CRP) level.

METHODS

A total of 128 patients were recruited in our present study. Patients were divided into two groups. In group 1 (n = 67), patients were orally administered with 200 mg/day vitamin C in the first 3 months, and then the vitamin C supplementation was withdrawn in the next 3 months. In group 2 (n = 61), patients were not given vitamin C in the first 3 months, and then they were orally administered with 200 mg/day in the next 3 months. Levels of hs-CRP, prealbumin, albumin and hemoglobin as well as the EPO resistance index (ERI) were determined at the baseline and every 3 months throughout the study. Plasma vitamin C level was determined by high-performance liquid chromatography with UV detection.

RESULTS

Among the 128 patients, 28 of them dropped out of the study before completion. Consequently, a total of 100 patients (group 1: n = 48; group 2: n = 52) were included in the final analysis. At the baseline, the plasma vitamin C level of all patients was less than 4 μg/mL. However, this proportion was decreased to 20% after the vitamin C supplementation for 3 months. Compared with patients without the vitamin C supplementation, a decreased level of hs-CRP and an increased level of prealbumin were induced by the vitamin C supplementation for 3 months in both groups. However, levels of these biomarkers returned to their original state after the supplementation was withdrawn. Same beneficial effects on plasma albumin, hemoglobin and ERI response to vitamin C supplementation were observed in the two groups without statistical significance.

CONCLUSIONS

The inflammatory status in MHD patients with plasma vitamin C deficiency and high levels of inflammatory markers could be partially improved by long-term oral administration of small doses of vitamin C.

TRIAL REGISTRATION

The clinical trial number: NCT01356433.

Description and predictive factors of infection in patients with chronic kidney disease admitted to the critical care unit

OBJECTIVES

To describe the spectrum of infection and multidrug-resistant bacterial colonization, and to identify early predictors of infection in patients with chronic kidney disease (CKD) admitted to the critical care unit (CCU).

METHODS

A 7-month observational prospective single-centre study in a French university hospital.

RESULTS

791 patients were admitted to the CCU, 135 of whom (17%) had severe CKD. Among these, 41 (30%) were infected on admission. Infection was microbiologically documented in 32 patients (78%), of which 7 (22%) were related to Pseudomonas aeruginosa. There was no infection related to extended-spectrum β-lactamase-producing enterobacteriaceae despite a 12% carriage rate on admission. A temperature ≥37.6 °C and a leukocyte count >12.000/mm³ were specific but poorly sensitive of infection (91% and 80%, and 45% and 39%, respectively). Using the threshold of 0.85 ng/ml, procalcitonin was a strong independent predictor of infection on admission (OR 12.8, 95% CI 4.4-37.3). Age (≥60 years) and the cause of CKD were two other predictors.

CONCLUSIONS

Infection accounts for one-third of CCU admissions in CKD patients, with a high prevalence of P. aeruginosa. The usual diagnostic criteria are inaccurate for diagnosing infection in this population. A procalcitonin ≥0.85 ng/ml might be helpful for early identifying CKD patients with infection.

Hemodialysis and water quality

Over 383,900 individuals in the U.S. undergo maintenance hemodialysis that exposes them to water, primarily in the form of dialysate. The quality of water and associated dialysis solutions have been implicated in adverse patient outcomes and is therefore critical. The Association for the Advancement of Medical Instrumentation has published both standards and recommended practices that address both water and the dialyzing solutions. Some of these recommendations have been adopted into Federal Regulations by the Centers for Medicare and Medicaid Services as part of the Conditions for Coverage, which includes limits on specific contaminants within water used for dialysis, dialysate, and substitution fluids. Chemical, bacterial, and endotoxin contaminants are health threats to dialysis patients, as shown by the continued episodic nature of outbreaks since the 1960s causing at least 592 cases and 16 deaths in the U.S. The importance of the dialysis water distribution system, current standards and recommendations, acceptable monitoring methods, a review of chemical, bacterial, and endotoxin outbreaks, and infection control programs are discussed.

Post-transcriptional nature of uremia-induced downregulation of hepatic apolipoprotein A-I production

Chronic kidney disease is associated with premature death from cardiovascular disease, which is, in part, driven by high density lipoprotein deficiency and dysfunction. One of the main causes of high density lipoprotein deficiency in chronic kidney disease is diminished plasma apolipoprotein (Apo)A-I level. Plasma ApoA-I is reduced in dialysis patients and hepatic ApoA-I messenger RNA (mRNA) is decreased in the uremic rats. This study explored the mechanism of uremia-induced downregulation of ApoA-I. Human hepatoma derived cells were incubated in media containing whole plasma or plasma subfractionation from normal subjects and patients with end stage renal disease pre- and posthemodialysis. Cells and culture media were isolated to measure ApoA-I protein and mRNA. ApoA-I promoter activity was measured using transfection with a luciferase promoter construct containing the -2096 to +293 segment of ApoA-I gene. Finally, effect of uremic and control plasma was assessed on ApoA-I RNA stability. Exposure to uremic plasma significantly reduced ApoA-I mRNA expression and ApoA-I protein production. These effects were reversed by replacing uremic plasma with normal plasma. Although no difference in ApoA-I promoter activity was found between cells exposed to uremic and normal plasma, uremic plasma significantly reduced ApoA-I RNA stability. Experiments using plasma subfractions revealed that the inhibitory effect of uremic plasma on ApoA-I mRNA expression resides in fractions containing molecules larger but not smaller than 30 kd. The pre- and postdialysis plasma exerted an equally potent inhibitory effect on ApoA-I mRNA abundance. Uremia lowers ApoA-I production by reducing its RNA stability. The inhibitory effect of uremic milieu on ApoA-I mRNA expression is mediated by non-dialyzable molecule(s) larger than 30 kd.

Advanced glycation end-products, a pathophysiological pathway in the cardiorenal syndrome

The prevalence of heart failure (HF) is increasing. A distinction is made between diastolic HF (preserved left ventricular ejection fraction (LVEF)) and systolic HF (reduced LVEF). Advanced glycation end-products (AGEs) are crystallized proteins that accumulate during ageing, but are particularly increased in patients with diabetes mellitus and in patients with renal failure. Through the formation of collagen crosslinks, and by interaction with the AGE-receptor, which impairs calcium handling and increases fibrosis, AGE-accumulation has pathophysiologically been associated with the development of diastolic and renal dysfunction. Interestingly, diastolic dysfunction is a frequent finding in elderly patients, diabetic patients and in patients with renal failure. Taken together, this suggests that AGEs are related to the development and progression of diastolic HF and renal failure. In this review, the role of AGEs as a possible pathophysiological factor that link the development and progression of heart and renal failure, is discussed. Finally, the role of AGE intervention as a possible treatment in HF patients will be discussed.

Targeted complement inhibition as a promising strategy for preventing inflammatory complications in hemodialysis

Hemodialysis is the most common method used to remove waste and hazardous products of metabolism in patients suffering from renal failure. Hundreds of thousands of people with end-stage renal disease undergo hemodialysis treatment in the United States each year. Strikingly, the 5-year survival rate for all dialysis patients is only 35%. Most of the patients succumb to cardiovascular disease that is exacerbated by the chronic induction of inflammation caused by contact of the blood with the dialysis membrane. The complement system, a strong mediator of pro-inflammatory networks, is a key contributor to such biomaterial-induced inflammation. Though only evaluated in experimental ex vivo settings, specific targeting of complement activation during hemodialysis has uncovered valuable information that points toward the therapeutic use of complement inhibitors as a means to control the unwelcomed inflammatory responses and consequent pathologies in hemodialysis patients.

High-density lipoprotein in uremic patients: metabolism, impairment, and therapy

Several studies have shown that HDL has altered antioxidant and anti-inflammatory effects in chronic uremia, either by the reduction in its antioxidant enzymes or by the impairment of their activity. Systemic oxidative stress, which is highly prevalent in chronic kidney disease (CKD) patients, has been shown to decrease antioxidant and anti-inflammatory effects of HDL and even transform it into a pro-oxidant and pro-inflammatory agent. For this reason, we believe that the propensity for accelerated cardiovascular disease in CKD is facilitated by a few key features of this disease, namely, oxidative stress, inflammation, hypertension, and disorders of lipid metabolism. In a nutshell, oxidative stress and inflammation enhance atherosclerosis leading to increased cardiovascular mortality and morbidity in this population. In this detailed review, we highlight the current knowledge on HDL dysfunction and impairment in chronic kidney disease as well as the available therapy.

Management of cardiovascular disease in patients with kidney disease

The burden of cardiovascular disease is high in patients with chronic kidney disease or end-stage renal disease. The presence of kidney dysfunction affects the cardiovascular system in multiple ways, including accelerated progression of atherosclerosis and valvular disease, the exacerbation of congestive heart failure, and the development of pericardial disease. This comorbidity results not only from the concordance of shared risk factors, but also from other issues specific to this population, such as systemic inflammation and vascular calcification. Furthermore, both the sensitivity and specificity of noninvasive testing modalities, and the efficacy of several pharmacotherapeutic strategies, are diminished in this population. The exclusion of patients with severe kidney disease from many clinical trials of cardiac interventions raises various therapeutic uncertainties, and kidney disease itself is likely to alter the underlying cardiovascular physiology. In this Review, we discuss aspects of the epidemiology, pathophysiology, and diagnosis of cardiovascular disease in patients with kidney disease, and propose specific, evidence-based recommendations for pharmacological and surgical treatment.

Reasons for the lack of salutary effects of cholesterol-lowering interventions in end-stage renal disease populations

Cardiovascular disease (CVD) is the main cause of premature death in patients with chronic kidney disease (CKD). The underlying mechanisms of CVD in patients with mild to moderate CKD are different from those with end-stage renal disease (ESRD). While serum cholesterol is frequently elevated and contributes to atherosclerosis in many CKD patients, particularly those with nephrotic proteinuria, it is usually normal, even subnormal, in most ESRD patients receiving hemodialysis. CVD in the ESRD population is primarily driven by oxidative stress, inflammation, accumulation of the oxidation-prone intermediate-density lipoproteins, chylomicron remnants and small dense low-density lipoprotein particles as well as high-density lipoprotein deficiency and dysfunction, hypertension, vascular calcification, and arrhythmias. Only a minority of hemodialysis patients have hypercholesterolemia which is most likely due to genetic or unrelated factors. In addition, due to peritoneal losses of proteins which simulate nephrotic syndrome, peritoneal dialysis patients often exhibit hypercholesterolemia. Clearly when present, hypercholesterolemia contributes to CVD in the CKD and ESRD population and justifies cholesterol-lowering therapy. However, the majority of ESRD patients and a subpopulation of CKD patients with minimal proteinuria have normal or subnormal serum cholesterol levels and do not benefit from and can be potentially harmed by statin therapy. In fact the lack of efficacy of statins in hemodialysis patients has been demonstrated in several randomized clinical trials. This review is intended to provide an overview of the mechanisms responsible for the failure of statins to reduce cardiovascular morbidity and mortality in most ESRD patients and to advocate the adoption of individualized care principles in the management of dyslipidemia in this population.

Endotoxin binding by sevelamer: potential impact on nutritional status

Patients on hemodialysis (HD) have a high burden of chronic inflammation induced associated with multiple comorbidities including poor nutritional status. Endotoxin (ET) is a Gram-negative bacterial cell wall component and a potent stimulus for innate immune system activation leading to the transcription of proinflammatory cytokines (e.g., IL-1, IL-6, and TNFα) that adversely affect protein metabolism and nutrition. Several cross-sectional observational studies have found that elevated serum ET concentrations in hemodialysis patients are associated with lower serum albumin, higher proinflammatory cytokine, and C-reactive protein concentrations. Possible sources of ET in the systemic circulation are bacterial translocation from the gastrointestinal tract and iron supplementation, potentially leading to intestinal bacterial overgrowth. Sevelamer is a nonabsorbable hydrogel approved for use as a phosphate binder in HD patients. Reductions in serum ET concentrations in hemodialysis patients have been observed with sevelamer therapy in observational studies and the few published interventional studies. Reduction of ET concentrations was associated with concomitant reductions in TNFα, IL-6, and CRP and improvement in serum albumin in the majority of these small studies. Additional studies are needed to evaluate the potential effects of sevelamer treatment on nutritional status in chronic kidney disease (CKD) patients with elevated ET.

Lipid abnormalities in patients with chronic kidney disease: implications for the pathophysiology of atherosclerosis

Cardiovascular disease is increased in patients with chronic kidney disease (CKD) and is the principle cause of morbidity and mortality in these patients. In patients with stage 5 CKD, structural changes in the myocardium have been implicated as the principle cardiovascular processes leading to this increase in morbidity and mortality, while atherosclerotic events including acute myocardial infarction and strokes are responsible for approximately 10-15% of cardiovascular deaths. Dyslipidemia is common in CKD patients and is usually not characterized by elevated cholesterol levels, except in patients with marked proteinuria. Increased triglyceride levels in conjunction with decreased high-density lipoprotein levels are the commonest qualitative abnormality. Characteristically, abnormalities in the metabolism of apolipoprotein (apo) B-containing lipoproteins have been described, including both gut derived (apoB-48) as well as those produced by hepatic synthesis (apoB-100). A decrease in enzymatic delipidation as well as reduced receptor removal of these lipoproteins both contribute to the increased levels of these apo-B-containing particles and their remnants (which are believed to be highly atherogenic). Abnormalities in the metabolism of apoA-containing lipoproteins are also present and these changes contribute to the lower levels of HDL seen. Qualitative abnormalities of these HDL particles may be associated with cellular oxidative injury and contribute to a pro-inflammatory, pro-thrombotic milieu that is frequently present in CKD patients.

Statins for renal patients: a fiddler on the roof?

Atherosclerotic cardiovascular disease is the main cause of morbidity and mortality in chronic kidney disease patients. There is a raft of evidence showing that in the general population dyslipidaemia is associated with an increased risk of cardiovascular events, as well as with a greater prevalence of chronic kidney disease. Consequently, the use of statins in the general population with dyslipidaemia is not controversial. Nevertheless, the benefits of statins in patients with chronic kidney disease are more elusive. The authors review the possible effects of statins on the progression of renal disease and cardiovascular events in chronic kidney disease patients.

Pathophysiological and clinical aspects of malnutrition in chronic renal failure

Kidney diseases are the ninth leading cause of death in the USA. In these patients cardiovascular mortality is greater than in the general population. This observation, not completely explained by the so-called 'traditional' cardiovascular risk factors, lead the authors to postulate other 'emerging' ones found in chronic renal failure patients. Among these new findings, nutritional status, considered as the balance existing between nutrient requirements and intakes, plays an important role for the development of cardiovascular diseases. In fact several nutritional parameters are widely known as pathophysiological determinants of cardiovascular disturbances, which are based on accelerated atherosclerosis, due especially to enhanced oxidative stress and endothelial dysfunction. Chronic renal failure is a clinical condition that from many points of view seems to be a chronic inflammatory state, and many studies confirm this observation. This influences nutritional status especially in dialysis patients. Malnutrition is related in turn to accelerated atherosclerosis thus leading to a postulated 'malnutrition, inflammation, atherosclerosis' (MIA) syndrome in which malnutrition, inflammation and atherosclerosis contribute to an elevated cardiovascular mortality rate. The present review explores this issue, first by describing epidemiological aspects of malnutrition in chronic renal failure patients and then by analysing the specific biochemical and metabolic features of these patients.

Is inflammation a new risk factor of depression in haemodialysis patients?

Purpose

Prevalence of depression is high in patients with chronic kidney disease. Depression is associated with increased mortality and the higher rate of suicides in these patients. The aim of the study was to estimate the prevalence of depressive symptoms in haemodialyzed patients in Upper Silesia region of Poland and the possible role of inflammation in depression development.

Methods

Six hundred and ninety-seven haemodialyzed patients from 22 dialysis centres in Upper Silesia region of Poland were enrolled into the study. Mean age was 59.1 ± 0.5 years, and mean time of dialysis treatment was 3.6 ± 0.2 years. Each patient received 21-item Beck Depression Inventory (BDI) questionnaire for depression screening. Additional questions considering length of dialysis treatment, concomitant diseases and number of days spent in hospitals during the last year were also asked.

Results

Depressive symptoms were found in 268 (38.6 %) patients. Patients with depressive symptoms when compared with the patients without them tended to have higher C-reactive protein plasma concentration (14.3 ± 1.3 vs. 11.1 ± 0.9 mg/l; p = 0.067) and were more often dialyzed with central catheter (27.6 vs. 18.2 %; p = 0.0042). During the last year, patients with depressive symptoms spent in hospitals more days than patients without depressive symptoms (24.3 vs. 15.3 days, respectively; p < 0.0001). Significant positive correlation between BDI score and C-reactive protein level (r = 0.1625; p = 0.001) was found both in univariate and multivariate analysis.

Conclusions

(1) Depressive symptoms are frequently found (38.6 %) in haemodialyzed patients in Upper Silesia part of Poland. (2) Catheter placement and inflammation seem to play an important role in the pathogenesis of depression in haemodialysis patients.

Plasma BNP, a useful marker of fluid overload in hospitalized hemodialysis patients

Hospitalization for intercurrent illness frequently disrupts the nutritional status of hemodialysis (HD) patients and jeopardizes the dry weight prescription. We report in this study the evolution of brain natriuretic peptide (BNP), blood pressure and body weight in hospitalized patients and the relationship between BNP plasma level and nutritional and inflammation parameters. We have studied 42 patients requiring hospitalization (F/M: 18/24; 72.5 ± 12.5 years old; 19/42 with diabetes). The plasma BNP levels at baseline, during hospitalization (BNP-Hosp), and in the recovery phase were compared. Predialysis and postdialysis blood pressure and postdialysis body weight were recorded and compared. BNP-Hosp increased significantly when compared with BNP levels at baseline, from 421 ± 647.2 pg/mL to 1584 ± 1584.4 pg/mL (P < 0.0001). Brain natriuretic peptide decreased from 1223 ± 1342.1 pg/mL during hospitalization to 616 ± 892.1 pg/mL after discharge (P = 0.005). The BNP-Hosp was positively correlated with C-reactive protein (P = 0.003) and negatively correlated with serum prealbumin (P = 0.0001) and albumin (P = 0.0001). The postdialysis body weight prescription decreased from 71.0 ± 15.7 kg at baseline to 70.5 ± 15.4 kg during hospitalization and to 67.8 ± 14.4 kg 4 months after discharge (P = 0.0032). Our study displays clearly the significant changes of plasma BNP levels occurring during intercurrent events. Fluid overload triggered by inflammation-associated catabolism and the lag time for dry weight adjustment is the cause of this finding. Hence, plasma BNP level may be used as a marker of fluid overload in patients with intercurrent events and may allow efficient dry weight adjustment. We cannot rule out an effect of inflammation on BNP synthesis.

Quality of care and outcomes among patients with acute myocardial infarction by level of kidney function at admission: report from the get with the guidelines coronary artery disease program

BACKGROUND

Many patients admitted for acute myocardial infarction (AMI) have chronic renal insufficiency. We studied the impact of chronic renal insufficiency on mortality and quality of inpatient care for AMI from the American Heart Association's Get With The Guidelines-Coronary Artery Disease Program.

HYPOTHESIS

We hypothesized that mortality and quality of inpatient care would not vary with renal function.

METHODS

We examined in-hospital AMI performance measures by renal function based on glomerular filtration rate (GFR). Severity of renal insufficiency was categorized as normal (GFR ≥ 90 mL/min/1.73 m(2)), mild (GFR 60-90 mL/min/1.73 m(2)), moderate (GFR 30-60 mL/min/1.73 m(2)), severe (GFR 15-30 mL/min/1.73 m(2)), and kidney failure (GFR ≤ 15 mL/min/1.73 m(2) or dialysis). A total of 21721 patients from 291 sites were studied, with most data collected in 2008 to 2009. Multivariable regression analysis after adjusting for patient characteristics was performed and generalized estimating equations were used to account for within-hospital clustering. In-hospital mortality and quality of inpatient care were assessed.

RESULTS

Renal insufficiency was present in 82.0 percent of AMI patients. The adjusted odds ratio vs normal renal function for mortality increased with worsening renal function: 1.45 for mild renal insufficiency (95% confidence interval [CI]: 1.03-2.05, P = 0.03); 3.36 for moderate renal insufficiency (95% CI: 2.31-4.89, P < 0.0001); 5.43 for severe renal insufficiency (95% CI: 3.70-7.95, P < 0.0001); and 6.35 for kidney failure (95% CI: 4.48-9.01, P < 0.0001). Patients with renal insufficiency received less inpatient and discharge guideline-recommended therapy for AMI.

CONCLUSIONS

Among AMI patients, mortality and guideline-recommended inpatient therapy correlated inversely with renal function. Adjusted mortality was equally poor among patients with severe renal dysfunction and on dialysis.

HDL proteome in hemodialysis patients: a quantitative nanoflow liquid chromatography-tandem mass spectrometry approach

Aside from a decrease in the high-density lipoprotein (HDL) cholesterol levels, qualitative abnormalities of HDL can contribute to an increase in cardiovascular (CV) risk in end-stage renal disease (ESRD) patients undergoing chronic hemodialysis (HD). Dysfunctional HDL leads to an alteration of reverse cholesterol transport and the antioxidant and anti-inflammatory properties of HDL. In this study, a quantitative proteomics approach, based on iTRAQ labeling and nanoflow liquid chromatography mass spectrometry analysis, was used to generate detailed data on HDL-associated proteins. The HDL composition was compared between seven chronic HD patients and a pool of seven healthy controls. To confirm the proteomics results, specific biochemical assays were then performed in triplicate in the 14 samples as well as 46 sex-matched independent chronic HD patients and healthy volunteers. Of the 122 proteins identified in the HDL fraction, 40 were differentially expressed between the healthy volunteers and the HD patients. These proteins are involved in many HDL functions, including lipid metabolism, the acute inflammatory response, complement activation, the regulation of lipoprotein oxidation, and metal cation homeostasis. Among the identified proteins, apolipoprotein C-II and apolipoprotein C-III were significantly increased in the HDL fraction of HD patients whereas serotransferrin was decreased. In this study, we identified new markers of potential relevance to the pathways linked to HDL dysfunction in HD. Proteomic analysis of the HDL fraction provides an efficient method to identify new and uncharacterized candidate biomarkers of CV risk in HD patients.

Chronic Inflammation and Coronary Atherosclerosis in Patients with End-Stage Renal Disease

The key role of chronic inflammation in the pathogenesis of atherosclerosis has become increasingly apparent in recent years based on the results of experimental, epidemiologic and clinical studies. Coronary artery disease and its complications occur with disproportionately high frequency in patients with end-stage renal disease (ESRD) and contribute substantially to cardiovascular morbidity and mortality in this population. Traditional cardiovascular risk factors occur commonly in patients with ESRD. In addition, a variety of patient-related and dialysis-related factors unique to ESRD predispose to chronic inflammation and by doing so are thought to contribute to coronary atherosclerosis and its complications. These risk factors may serve as therapeutic targets and as such may offer the potential for altering the natural history of coronary atherosclerosis in ESRD.

Relationship between fat mass and serum high-sensitivity C-reactive protein levels in prevalent hemodialysis patients

BACKGROUND/AIMS

Little is known about the relationship between fat mass distribution and chronic inflammation in dialysis patients, in whom chronic inflammation is related to morbidity and mortality.

METHODS

The fat and lean masses (truncal and nontruncal) of 452 hemodialysis patients (age: 64 ± 11 years; hemodialysis duration: 89 ± 77 months; 37% diabetics) were measured by dual X-ray absorptiometry and their association with high-sensitivity C-reactive protein (hsCRP) was examined.

RESULTS

The fat mass of the high hsCRP group (n = 106) was significantly higher than that of the normal hsCRP group (n = 346; p < 0.05); there were no significant differences in lean mass between the two groups. Truncal fat mass of the former group was significantly greater than that of the latter (p < 0.05), but there was no significant difference in nontruncal fat mass between the two groups. In multiple regression analysis, truncal fat mass (β = 0.227, p < 0.01) was significantly and independently associated with serum hsCRP levels after adjustment for age, gender and serum albumin (R(2) = 0.137, p < 0.01), whereas nontruncal fat mass was not.

CONCLUSION

Fat mass, particularly truncal fat mass, but not lean body mass, was significantly associated with serum hsCRP levels. The results suggest that truncal fat mass exhibits a distinct effect on chronic inflammation in hemodialysis patients.

Statins in the management of dyslipidemia associated with chronic kidney disease

The cause of death in the majority of patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) is accelerated cardiovascular disease and not renal failure per se, suggesting a role for statin therapy in this setting. During the past 6 years three large, randomized, placebo-controlled studies of three different statins have been conducted in the dialysis population-but two of these studies did not demonstrate any benefits of statin therapy, and the third study showed only marginally positive results. To understand why statins have failed to reduce cardiovascular events in patients with ESRD, the basic mechanisms underlying the pathogenesis of dyslipidemia in CKD must be critically examined. The observed negative results in the clinical trials of statin therapy might also reflect the biomarkers and targets that were chosen to be evaluated. The characteristics of dyslipidemia in patients with CKD not yet requiring dialysis treatment differ markedly from those of individuals with established ESRD and form the basis for therapeutic recommendations. The potential adverse effects associated with statin therapy are important to consider in the management of dyslipidemia in patients with CKD.