Factors that affect albumin concentration in dialysis patients and their relationship to vascular disease

Protein energy wasting in pre-dialysis chronic kidney disease patients in Benin City, Nigeria: A cross-sectional study

INTRODUCTION

Protein energy wasting (PEW) is common among chronic kidney disease (CKD) patients, especially those with advanced stage. It worsens frailty, sarcopenia and debility in CKD patients. Despite the importance of PEW, it is not routinely assessed during management of CKD patients in Nigeria. The prevalence of PEW and its associated factors were determined in pre-dialysis CKD patients.

METHODS

This was a cross-sectional study that involved 250 pre-dialysis CKD patients and 125 age- and sex- matched healthy controls. Body mass index (BMI), subjective global assessment (SGA) scores and serum albumin levels were used in PEW assessment. The factors associated with PEW were identified. P-value of < 0.05 was taken as significant.

RESULTS

The mean age of CKD and control group were 52.3±16.0 years and 50.5±16.0 years, respectively. The prevalence of low BMI, hypoalbuminaemia and malnutrition defined by SGA in pre-dialysis CKD patients were 42.4%, 62.0% and 74.8%, respectively. The overall prevalence of PEW among the pre-dialysis CKD patients was 33.3%. On multiple logistic regression, the factors associated with PEW in CKD were being middle aged (adjusted odds ratio: 12.50; confidence interval: 3.42-45.00; p <0.001), depression (adjusted odds ratio: 2.34; confidence interval: 1.02-5.40; p = 0.046) and CKD stage 5 (adjusted odds ratio: 12.83; confidence interval: 3.53-46.60; p <0.001).

CONCLUSION

PEW is common in pre-dialysis CKD patients and it was associated with middle age, depression and advanced CKD. Early intervention aimed at addressing depression in early stages of CKD may prevent PEW and improve overall outcome in CKD patients.

Development and Validation of a Novel Nomogram to Predict Hypoalbuminemia among Patients with Stroke in the Neurocritical Care Unit

This study aimed to investigate hypoalbuminemia-related factors in patients with stroke in the neurocritical care unit (NCU) and to establish a nomogram model for hypoalbuminemia prediction. Data from 902 patients hospitalized for stroke in the NCU who had normal albumin levels on admission from March 2018 to December 2020 were analyzed. Logistic regression was used to identify the risk factors associated with hypoalbuminemia. A novel nomogram prediction model for hypoalbuminemia was constructed, and it was validated in an independent set (n = 233). The nomogram incorporated seven risk factors, including age, high comorbidity, mechanical ventilation, feeding routes, total protein, high-sensitivity C-reactive protein, and fibrinogen levels, and its area under the curve for predicting hypoalbuminemia in the developmental set and validation set were 0.856 and 0.870, respectively. The novel nomogram facilitates risk prediction of hypoalbuminemia among patients with stroke in the NCU, which might be useful for selecting treatment strategies and management.

Risk Factors for Cardiovascular Disease in Patients Undergoing Peritoneal Dialysis

Patients on peritoneal dialysis (PD) are at high cardiovascular risk. Although some risk factors are unmodifiable (for example, age, sex, genetics), others are exacerbated in the unfriendly uremic milieu (inflammation, oxidative stress, mineral disturbances) or contribute per se to kidney disease and cardiovascular progression (diabetes mellitus, hypertension). Moreover, several factors associated with PD therapy may both increase (by altered lipid profile, hyperinsulinemia, and formation of advanced glycation end-products) and decrease (by better blood pressure control and anemia management) cardiovascular risk. The present review discusses recent findings and therapy trends in cardiovascular research on the PD population, with emphasis on the roles of inflammation, insulin resistance, homocysteinemia, dyslipidemia, vascular calcification, and genetics/epigenetics.

Increased Serum CRP-Albumin Ratio Is Independently Associated With Severity of Carotid Artery Stenosis

Carotid artery stenosis (CAS), mainly caused by carotid atherosclerosis, is related to ischemic stroke. We investigated whether C-reactive protein (CRP) to albumin ratio (CAR) was associated with increased severity of carotid stenosis in patients undergoing carotid angiography. A total of 269 patients who were undergoing carotid angiography were included in this study. The patients were divided into 2 groups with respect to the severe CAS: group 1 (stenosis < 70%, n = 189) or group II (stenosis ≥ 70%, n = 80). C-reactive protein to albumin ratio was higher in group II compared to group I (0.56 ± 0.25 vs 0.14 ± 0.01, P < .001). The CAR (odds ratio [OR]: 1.051, 95%CI: 1.027-1.076, P < .001), neutrophil to lymphocyte ratio (NLR), and total cholesterol levels were independent predictors of severe CAS. The area under the receiver operating characteristic curve (area under the curve) for the CAR to predict severe CAS was 0.798 (95% CI: 0.741-0.854, P < .001). C-reactive to protein albumin ratio was an independent risk factor of severe CAS. Therefore, CAR might be considered a potential index in the severity of carotid artery disease.

Effects of online hemodiafiltration on anemia and nutritional status in chronic hemodialysis patients

Background

Online hemodiafiltration (OL-HDF) offers considerable advantages in clearance of molecules of various sizes. However, evidence of clinical effects of OL-HDF is scarce in Korea. In this study, we investigated changes in laboratory values over more than 12 months after switching to OL-HDF.

Methods

Adult patients with end-stage renal disease undergoing hemodialysis (HD) were prospectively enrolled in a K-cohort (CRIS no. KCT0003281) from 6 tertiary hospitals in South Korea. We recruited 435 patients, 339 of whom were on HD at enrollment. One hundred eighty-two patients were followed for more than 24 months. Among them, 44 were switched to OL-HDF for more than 12 months without conversion to HD. We used a paired t test to compare baseline and 24-month follow-up results.

Results

The mean age of the subjects was 61.2 ± 12.2 years, and 62.6% were male. The baseline hemoglobin level was not significantly different between HD and OL-HDF group (10.61 ± 1.15 vs. 10.46 ± 1.03 g/dL, P = 0.437). However, the baseline serum protein and albumin levels were significantly lower in the OL-HDF group (6.82 ± 0.49 vs. 6.59 ± 0.48 g/dL, P = 0.006; 3.93 ± 0.28 vs. 3.73 ± 0.29 g/dL, P < 0.001). In patients switched to OL-HDF, levels of hemoglobin and serum albumin significantly increased (10.46 ± 1.03 vs. 11.08 ± 0.82 g/dL, P = 0.001; 3.73 ± 0.29 vs. 3.87 ± 0.30 g/dL, P = 0.001). The normalized protein catabolic rate decreased after 24 months, but the change was not significant (1.07 ± 0.25 vs. 1.03 ± 0.21 g/kg/day, P = 0.433). Although the dose of erythropoiesis-stimulating agent was lower in patients who converted to HDF, it was not significantly different (-115.7 ± 189.7 vs. -170.5 ± 257.1 P = 0.206).

Conclusion

OL-HDF treatment over more than 12 months was associated with no harmful effects on anemia and nutritional status.

Clinical Epidemiology of Major Nontraditional Risk Factors in Peritoneal Dialysis Patients

♦ Background

End-stage renal disease (ESRD) is a situation with a cardiovascular (CV) risk profile of almost unique severity. While traditional risk factors dominate the scene in the general population, in chronic kidney disease (CKD), nontraditional risk factors play an increasingly important role, being perhaps dominant in ESRD patients.

♦ Objective

We review the role inflammation [C-reactive protein (CRP)], hyperhomocysteinemia, high plasma norepinephrine, and accumulation of the endogenous inhibitor of the nitric oxide synthase asymmetric dimethylarginine (ADMA) in the high all-cause and CV mortality of patients on continuous ambulatory peritoneal dialysis (CAPD).

♦ Results

The association between CRP and clinical outcomes in patients on peritoneal dialysis (PD) was examined in six studies totaling 692 subjects. The largest of these studies in Caucasians indicates that the independent risk of CV events in patients in the top CRP quartile is about five times higher than in the bottom quartile. Seven prospective studies, including over 1000 hemodialysis and 176 CAPD patients, reported both positive and negative associations between homocysteine and mortality and/or CV events. Because homocysteine circulates bound to albumin, negative associations — rather than negating the vasculotoxicity of homocysteine — most likely reflect the very deleterious effects of malnutrition. Plasma norepinephrine is higher in CAPD than in hemodialysis patients, and multivariate analyses suggest the difference quantitatively entails a 16% higher risk of incident CV events. Likewise, ADMA is more elevated in CAPD patients and such an elevation corresponds to a 15% increase in risk.

♦ Conclusion

Nontraditional risk factors are far more prevalent in ESRD patients than in the general population. ADMA and norepinephrine may play a greater role in CV risk in CAPD than in hemodialysis patients.

Changes in serum albumin and other nutritional markers when using sucroferric oxyhydroxide as phosphate binder among hemodialysis patients: a historical cohort study

Background

Elevated serum phosphorus concentrations are common among maintenance hemodialysis patients. Protein is a major source of dietary phosphate, but restriction of protein intake can result in hypoalbuminemia and protein-energy wasting. We hypothesized that sucroferric oxyhydroxide (SO), a potent phosphate binder with a low pill burden, may reduce serum phosphorus levels in hemodialysis patients with hypoalbuminemia without adversely impacting albumin levels or dietary intake of protein.

Methods

We retrospectively examined de-identified data from 79 adult, in-center hemodialysis patients with baseline hypoalbuminemia (≤ 3.5 g/dL) switched to SO as part of routine clinical care for at least 1 year. Temporal changes (3-month intervals from baseline through Q4) in phosphate binder pill burden, serum phosphorous levels, nutritional markers, and equilibrated Kt/V were analyzed. Data from a matched reference group of non-hypoalbuminemic patients (N = 79) switched to SO were also examined.

Results

SO therapy was associated with a mean reduction of 45.7 and 45.1% in daily phosphate binder pill burden, and a mean reduction of 0.4 mg/dL and 0.51 mg/dL in serum phosphorus levels for the hypoalbuminemic and non-hypoalbuminemic patients, respectively. Hypoalbuminemic patients demonstrated significant increases in mean serum albumin levels from 3.50 mg/dL at baseline to 3.69, 3.74, 3.70, and 3.69 mg/dL during Q1 through Q4, respectively (P < 0.0001), whereas serum albumin levels remained unchanged in the non-hypoalbuminemic group.

Conclusions

Both hypoalbuminemic and non-hypoalbuminemic patients switching to SO exhibited significant reductions in serum phosphorus concentrations and daily phosphate binder pill burden. Among hypoalbuminemic patients, the initiation of SO therapy was also associated with increases in serum albumin, suggesting therapy may have allowed patients to increase their dietary intake of protein.

Pro-inflammatory and pro-resolving mechanisms in the immunopathology of arteriovenous fistula maturation

Introduction: With high rates of arteriovenous fistula (AVF) failure, there is a continued need to predict other factors and mechanisms associated with maturation deficits. Given the central association of inflammation with AVF failure, with neointimal hyperplasia (NIH) as one such mechanism, inflammation must be considered in two endogenous ways, either pro-inflammatory or pro-resolving, resulting in inward or outward vascular remodeling. Areas covered: This review summarizes and critically evaluates the preclinical and interventional data underlying AVF failure in attempts to elucidate the necessary balance between inflammation and its resolution. Expert opinion: Understanding the pro-inflammatory and pro-resolving mechanisms underlying inward and outward vascular remodeling and NIH prevention with AVF maturation is a necessary effort to develop key diagnostic and therapeutic interventions towards the ongoing issue of long-term AVF patency. The ability for clinical application has progressed but is limited to the identification of key targets and pathways with little understanding of how they are related synergistically or antagonistically. Likewise, the balance between acute inflammation and pro-resolution requires pertinent temporal considerations necessary for timely therapeutic application and predictive measurement.

The Prognostic Significance of Puncture Timing to Survival of Arteriovenous Fistulas in Hemodialysis Patients: A Multicenter Retrospective Cohort Study

(1) Background: A functional shunt is critical to hemodialysis, but the ideal timing of shunt cannulation is still not established. In this study, we assessed the association between ideal puncture timing and shunt survival. (2) Methods: This retrospective cohort study using data from the Taiwan Health and Welfare database, which included 26885 hemodialysis patients with arteriovenous fistulas from 1 July 2008 to 30 June 2012. Fistulas were categorized by functional maturation time, defined as the time from the date of shunt construction to the first successful cannulation. Functional cumulative survival, measured as the duration from the first puncture to shunt abandonment, was mainly regarded. (3) Results: The fistulas created between 91 and 180 days prior to the first cannulation had significantly greater cumulative functional survival (HR 0.883; 95% CI 0.792–0.984), and there was no more benefit on their survival from waiting more than 180 days (HR 0.957; 95% CI 0.853–1.073) for shunt maturity. (4) Conclusions: Our results showed that to achieve better long-term shunt survivals, fistulas should be constructed at least 90 days before starting hemodialysis. Notably, there was no additional benefit on waiting more than 180 days prior to cannulation.

Association of Pre-End-Stage Renal Disease Serum Albumin With Post-End-Stage Renal Disease Outcomes Among Patients Transitioning to Dialysis

OBJECTIVE

Serum albumin is a marker of malnutrition and inflammation and has been demonstrated as a strong predictor of mortality in chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients. Yet, whether serum albumin levels in late-stage CKD are associated with adverse outcomes after the transition to ESRD is unknown. We hypothesize that lower levels and a decline in serum albumin in late-stage CKD are associated with higher risk of mortality and hospitalization rates 1 year after transition to ESRD.

DESIGN AND METHODS

This retrospective cohort study included 29,124 US veterans with advanced CKD transitioning to ESRD between 2007 and 2015. We evaluated the association of pre-ESRD (91 days before transition) serum albumin with 12-month post-ESRD all-cause, cardiovascular, and infection-related mortalities and hospitalization rates as well as the association of 1-year pre-ESRD albumin slope and 12-month post-ESRD mortality using hierarchical multivariable adjustments.

RESULTS

There was a negative linear association between serum albumin and all-cause mortality, such that risk doubled (hazard ratio [HR]: 2.07, 95% confidence interval [CI]: 1.87, 2.28) for patients with the lowest serum albumin <2.8 g/dL (ref: ≥4.0 g/dL) after full adjustment. A consistent relationship was observed between serum albumin and cardiovascular and infection-related mortality, and hospitalization outcomes. An increase in serum albumin of >0.25 g/dL/year was associated with reduced mortality risk (HR: 0.76, 95% CI: 0.63, 0.91) compared with a slight decline in albumin (ref: >-0.25 to 0 g/dL/year), whereas a decline more than 0.5 g/dL/year was associated with a 55% higher risk in mortality (HR: 1.55, 95% CI: 1.43, 1.68) in fully adjusted models.

CONCLUSIONS

Lower pre-ESRD serum albumin was associated with higher post-ESRD all-cause, cardiovascular, and infection-related mortalities and hospitalization rates. Declining serum albumin levels in the pre-ESRD period were also associated with worse 12-month post-ESRD mortality.

Peritoneal protein clearance predicts mortality in peritoneal dialysis patients

BACKGROUND

Peritoneal protein clearance has been suggested to be a marker of peritoneal inflammation and systemic endothelial dysfunction.

METHODS

We enrolled 711 consecutive incident PD patients. Baseline peritoneal protein clearance and other clinical information were reviewed. All patients were followed for at least 1 year for all-cause and cardiovascular mortality.

RESULTS

The average PD effluent protein loss was 6.41 ± 2.16 g/day; peritoneal protein clearance was 97.15 ± 41.55 mL/day. The average duration of follow-up was 50.8 ± 36.2 months. Multivariate linear regression analysis showed that serum albumin, C-reactive protein, and mass transfer area coefficients of creatinine were independently associated with peritoneal protein clearance. By multivariate Cox regression analysis, age, Charlson comorbidity score, volume of overhydration and peritoneal protein clearance were independent predictors of all-cause mortality. Every 10 mL/day increase in peritoneal protein clearance confers 10.4% increase in risk of all-cause mortality (95% confidence interval 2.6-18.7%, p = 0.008). Peritoneal protein clearance was also associated with cardiovascular mortality by univariate analysis, but the association became insignificant after adjusting for confounding factors Cox regression analysis.

CONCLUSIONS

Baseline peritoneal protein clearance is an independent predictor of all-cause mortality in incident PD patients. Routine measurement of peritoneal protein clearance may facilitate patient risk stratification.

Maturation of arteriovenous fistula: Analysis of key factors

The growing proportion of individuals suffering from chronic kidney disease has considerable repercussions for both kidney specialists and primary care. Progressive and permanent renal failure is most frequently treated with hemodialysis. The efficiency of hemodialysis treatment relies on the functional status of vascular access. Determining the type of vascular access has prime significance for maximizing successful maturation of a fistula and avoiding surgical revision. Despite the frequency of arteriovenous fistula procedures, there are no consistent criteria applied before creation of arteriovenous fistulae. Increased prevalence and use of arteriovenous fistulae would result if there were reliable criteria to assess which arteriovenous fistulae are more likely to reach maturity without additional procedures. Published studies assessing the predictive markers of fistula maturation vary to a great extent with regard to definitions, design, study size, patient sample, and clinical factors. As a result, surgeons and specialists must decide which possible risk factors are most likely to occur, as well as which parameters to employ when evaluating the success rate of fistula development in patients awaiting the creation of permanent access. The purpose of this literature review is to discuss the role of patient factors and blood markers in the development of arteriovenous fistulae.

Assessing the prevalence of protein-energy wasting in haemodialysis patients: A cross-sectional monocentric study

INTRODUCTION

Protein-energy wasting (PEW) is a strong predictive factor for morbidity and mortality in haemodialysis (HD) patients. However, there is no consensus for its assessment. The present study aimed to assess the nutritional status of patients on chronic HD by use of different nutritional assessment parameters, and at verifying which can identify the greatest number of HD patients with PEW. Also, to investigate predictors of nutritional status in a haemodialysis center in Morocco.

PATIENTS AND METHODS

This is a cross-sectional analysis performed on 126 patients aged 44.82±14.01 years, undergoing maintenance HD in the Department of nephrology of the university hospital centre of Casablanca, Morocco. Energy and nutrients intake assessment was obtained by a three-day period food recall. Biochemical parameters, bioelectric impedance analysis, and subjective global assessment (SGA), have been performed to assess nutritional status.

RESULTS

According to SGA the prevalence of PEW was 74.62%. However, when using the ISRMN malnutrition criteria only 36.50% of the patients were diagnosed with PEW. Pearson correlation showed a negative association between the degree of malnutrition evaluated by SGA and serum prealbumin (r=-0.54; P=0.0001), serum albumin (r=-0.50; P=0.001), energy (r=-0.34; P=0.002), protein intake (r=-0.41; P=0.0001), and a significant positive correlation with CRP (r=0.65; P=0.0001) was determined, but not with anthropometric measurements nor lipids profile. The areas under the receiver operating characteristic curve were 0.841 (95% CI: 0.751-0.932) for serum prealbumin, and 0.737 (95% CI: 0.634-0.840) for serum albumin.

CONCLUSION

Our results showed a high prevalence of PEW among Haemodialysis patients. Also, our findings suggest that SGA, serum albumin and prealbumin may be relative appropriate and practical markers for assessing nutritional status in HD patients.

Is handgrip strength and key pinch measurement related with biochemical parameters of nutrition in peritoneal dialysis patients?

BACKGROUNDS & OBJECTIVE

End-stage renal disease (ESRD) frequently causes Protein Energy Wasting (PEW), which is an important morbidity and mortality factor. Although it is difficult to assess PEW with a reliable method, there are various methods such as Handgrip strength test (HST), serum albumin, cholesterol, etc. HST is a simple and reliable antropometric method which is used for nutritional status and body muscle strength. This study aims to assess the relationship between HST and biochemical markers in evolution of nutritional status of ESRD patients.

METHODS

This cross-sectional study included 36 consecutive patients, who are on peritoneal dialysis and 36 healthy -control subjects. Jamar-hand dynamometer was used for handgrip strength test; a pinch gauge was used for key pinch. Other antropometric tests included skin fold thicknesses at biceps, triceps, umbilical, suprailiac and subscapular regions; circumferences at waist hip, neck and midarm. Biochemical tests were performed only in Peritoneal Dialysis (PD) group. SPSS for Windows ver. 15.0 was used for statistics.

RESULTS

The mean age of patients was 49.3±14.4, and mean age of control group was 43.8±10.6 (p=0.075). In PD group dominant hand dynamometer test 1,2 and 3 results were 19.3±9.3 kg, 25.3±10.8 kg, 25.5± 10.6 kg and; 34.2±10.3 kg, 34.4±9.8 kg, 34.6±10.0 kg for control group (p< 0,001). Right key pinch results were 6.7±1.9 kg for patients; 13.5±4.5 kg for control group (p<0.001). Left key pinch results were 6.8±1.9 kg for patients; 13.2±4.4 kg for control group (p<0.001). There was not any significant relationship concerning handgrip or key pinch tests with biochemical parameters.

CONCLUSION

Handgrip Strength Test and key pinch may be reliable, cheap and easily performed tests for the diagnosis of Protein Energy Wasting in patients on Peritoneal Dialysis.

Pilot validation of objective malnutrition-inflammation scores in pediatric and adolescent cohort on chronic maintenance dialysis

Background:

In recognition of the challenges inherent with the use of single-item indices for the diagnosis of malnutrition–inflammation morbidity in pediatric dialysis patients, to enhance accuracy, we validated a composite scoring system in a pilot study. The objective malnutrition—inflammation score seeks to validate the use of a composite scoring system as a tool for assessing malnutrition—inflammation burden in a pediatric dialysis population.

Methods:

We enrolled 20 patients on hemodialysis (n = 14) and peritoneal dialysis (n = 6) over a period of 12 months. We derived composite scores from selected indices of renal pathology, nutrition, dialysis adequacy, protein catabolism, and dialysis modality. We assessed reliability by a test–retest method and measured validity by defining the relationship of the indices with serum C-reactive protein in a multiple regression analysis. We calculated sensitivity, specificity, accuracy, and precision for the malnutrition—inflammation score.

Results:

The mean age was 12.8 years (standard deviation = 6.1), and male–female ratio was 12:8. Patients (n = 8) with elevated serum C-reactive protein (>0.3 mg/dL) had higher composite score for malnutrition—inflammation morbidity. Similarly, the pediatric cohort on hemodialysis had higher score than those on peritoneal dialysis. Upon reliability testing, a low value of typical error (0.07) and high correlation coefficient (r = 0.95) supported validity of the instrument. Moreover, multiple regression analysis showed a strong predictive relationship (R² = 0.9, p = 0.03) between the indices and serum C-reactive protein. Sensitivity of malnutrition—inflammation score was 62.5%, specificity was 83%, accuracy was 75%, and precision was 71%.

Conclusion:

Using criterion-validation method, we established the potential use of multi-diagnostic approach to quantify malnutrition—inflammation morbidity in a pediatric dialysis cohort. Given the small sample size, large-scale population-specific studies are needed to ratify these findings and to demonstrate its clinical effectiveness.

Value of the pretreatment albumin to globulin ratio in predicting long-term mortality in breast cancer patients

BACKGROUND

Prior studies have demonstrated the prognostic value of pretreatment serum albumin in different types of cancer. The aim of this study was to assess the predictive value of the albumin to globulin ratio (AGR) on survival in breast cancer patients.

METHODS

This retrospective study used an unselected cohort of 354 breast cancer patients who had documented total protein and albumin levels prior to chemotherapy. Survival status was obtained from our cancer registry. Survival analysis, stratified by AGR tertiles, was used to evaluate the prognostic value of AGR.

RESULTS

Patients in the highest AGR tertiles (AGR > 1.45) had a lower 5-year mortality rate compared with those in the middle (AGR 1.21 to 1.45) and the lowest (AGR < 1.21) tertiles (6% vs. 18% and 32%, P < .001). After adjusting for confounding variables, AGR remained a significant predictor of mortality (P < .002). Moreover, after excluding the patients with albumin levels less than 3.6, the AGR remained a significant predictor of survival (P .0018).

CONCLUSIONS

Pretreatment AGR is an independent, significant predictor of long-term mortality in breast cancer patients, even in patients with normal albumin levels.

Proteomics reveals acute pro-inflammatory and protective responses in rat Kupffer cells and hepatocytes after chemical initiation of liver cancer and after LPS and IL-6

Inflammation is a key event in the development of liver cancer. We studied early inflammatory responses of Kupffer cells (KCs) and hepatocyte (HC) after cancer initiation. The chemical carcinogen N-nitrosomorpholine (NNM) was used in a rat model. We applied a comprehensive analytical strategy including metabolic labeling, 2-D PAGE, LC-MS/MS-based spot identification and shotgun proteomics and thus determined the rates of synthesis of individual proteins, compared whole tissue with isolated constituent cells and performed in vivo to in vitro comparisons of NNM effects. NNM increased synthesis of overall and 138 individual proteins identified in HC and/or KC, indicating reprogramming of metabolism favoring protection, repair and replacement of cell constituents in HC and KC. Secretome analysis by 2-D PAGE and shotgun proteomics of HC revealed the induction of acute phase proteins, in case of KC of proteases, cytokines and chemokines, indicating inflammatory effects. All responses were induced rapidly, independently of signals from other cells, and closely mimicked the pro-inflammatory and protective effects of inflammation modulators LPS in KC and IL-6 in HC. In conclusion, the carcinogen NNM exerts pro-inflammatory effects in the liver, partially by direct activation of KC. The acute inflammation and its protective component will enhance formation, survival and proliferation of initiated cells and may therefore act synergistically with the genotoxic action of the carcinogen.

The effects of angiotensin-converting enzyme inhibitors on peritoneal protein loss and solute transport in peritoneal dialysis patients

OBJECTIVE

The objective of this study was to examine the effects of angiotensin-converting enzyme inhibitors on peritoneal membrane transport, peritoneal protein loss, and proteinuria in peritoneal dialysis patients.

METHODS

Fifty-four peritoneal dialysis patients were included in the study. The patients were divided into two groups. Group 1 (n = 34) was treated with angiotensin-converting enzyme inhibitors. Group 2 (n = 20) did not receive any antihypertensive drugs during the entire follow-up. Eleven patients were excluded from the study thereafter. Thus, a total of 30 patients in Group 1 and 13 patients in Group 2 completed the study. We observed the patients for six months. Group 1 patients received maximal doses of angiotensin-converting enzyme inhibitors for six months. Parameters at the beginning of study and at the end of six months were evaluated.

RESULTS

At the end of six months, total peritoneal protein loss in 24-hour dialysate effluent was significantly decreased in Group 1, whereas it was increased in Group 2. Compared to the baseline level, peritoneal albumin loss in 24-hour dialysate effluent and 4-hour D/P creatinine were significantly increased in Group 2 but were not significantly changed in Group 1. A covariance analysis between the groups revealed a significant difference only in the decreased amount of total protein loss in 24-hour dialysate. Proteinuria was decreased significantly in Group 1.

CONCLUSION

This study suggests that angiotensin-converting enzyme inhibitors reduce peritoneal protein loss and small-solute transport and effectively protect peritoneal membrane transport in peritoneal dialysis patients.

Longitudinal measures of serum albumin and prealbumin concentrations in incident dialysis patients: the comprehensive dialysis study

OBJECTIVE

Serum albumin and prealbumin concentrations are strongly associated with the risk of death in dialysis patients. Our study examined the association among demographic characteristics, body composition, comorbidities, dialysis modality and access, inflammation, and longitudinal measures of albumin and prealbumin concentrations in incident dialysis patients. DESIGN, SETTING, SUBJECTS, AND OUTCOME MEASURES: The Comprehensive Dialysis Study is a prospective cohort study of incident dialysis patients; in this report, we examined the data from 266 Nutrition substudy participants who donated serum. The independent variables of interest were baseline age, sex, race, Quetélet's (body mass) index, dialysis modality and access, diabetes, heart failure, atherosclerotic vascular disease, serum creatinine level, and longitudinal measures of C-reactive protein. The outcomes of interest (dependent variables) were longitudinal measures of albumin and prealbumin concentrations, recorded at study entry and thereafter every 3 months for 1 year.

RESULTS

In multivariable mixed linear models, female sex, peritoneal dialysis, hemodialysis with a catheter, and higher C-reactive protein concentrations were associated with lower serum albumin concentrations, and serum albumin concentrations increased slightly over the year. In comparison, prealbumin concentrations did not significantly change over time; female sex, lower body mass index, diabetes, atherosclerotic vascular disease, and higher C-reactive protein concentrations were associated with lower prealbumin concentrations. Serum creatinine had a curvilinear relation with serum albumin and prealbumin.

CONCLUSIONS

Serum albumin level increases early in the course of dialysis, whereas prealbumin level does not, and the predictors of serum concentrations differ at any given time. Further understanding of the mechanisms underlying differences between albumin and prealbumin kinetics in dialysis patients may lead to an improved approach to the management of protein-energy wasting.

Different independent susceptibility markers for first-ever cerebral infarction and myocardial infarction in young patients

Cerebral infarction (CI) and myocardial infarction (MI) share some common features, but there are other differences in risk factors. The aim of our study is to determine whether there are some significantly independent susceptibility markers for them. All consecutive patients between the ages of 18 and 45 years with first-ever CI and MI during 2001-2010 were recruited to participate in the study. Using multivariate logistic regression modeling, we explore many different data, such as age at onset, sex ratio, numbers of patients with history of hypertension, smoking, drinking, and serum lipid, uric acid, prealbumin (PA), and white blood cell (WBC) count levels. Logistic regression analysis adjusted for confounders confirmed the following independent susceptibility markers for young CI patients: hypertension, admission serum PA levels, daily alcohol [odds ratio (OR), 0.251; 95% confidence interval (CI), 0.097-0.648, p = 0.004; OR, 0.994; 95% CI, 0.988-0.999, p = 0.031; OR, 0.150; 95% CI, 0.047-0.473, p = 0.001], and for MI patients: age at onset, current smoking, serum WBC, and glucose levels (OR, 1.293; 95% CI, 1.146-1.457, p = 0.000; OR, 8.914; 95% CI, 3.575-22.231, p = 0.000; OR, 1.344; 95% CI, 1.169-1.544, p = 0.000; OR, 1.149; 95% CI, 1.022-1.291, p = 0.020). We conclude that there are some significantly different independent susceptibility markers for young CI and MI patients.

Veterans more likely to start hemodialysis with an arteriovenous fistula

Hemodialysis via arteriovenous fistulas (AVFs) is associated with reduced morbidity and mortality when compared to alternative vascular accesses, yet few patients in the United States start dialysis with AVFs. Recent studies have demonstrated higher quality of care for many conditions in Veterans Affairs' Medical Centers (VAMC); however, differences in quality of vascular access care are unknown. We used patient-level data (6/05-5/06) from Medicare claims (n = 25,912) to compare the proportions of AVF among incident patients at VAMC-affiliated (n = 20) and unaffiliated dialysis (n = 1631) facilities. Multivariate logistic regression was used to determine whether associations of access type with facility type were independent. Compared to non-VAMC patients, a larger proportion of VAMC patients started dialysis with AVFs (20.9% versus 11.6% in non-VAMC patients; OR 1.99, [95% CI 1.55-2.56]). Although attenuated, this finding persisted in models adjusted for demographics (OR 1.65 [95% CI 1.28-2.13]) and demographics with comorbidities (OR 1.70 [95% CI 1.31-2.20]). However, after accounting for pre end-stage renal disease (ESRD) care, similar proportions of VAMC and non-VAMC patients started hemodialysis with an AVF (OR 1.28 [95% CI 0.98-1.66]). In conclusion, patients receiving care at VAMC-associated facilities were more likely to start hemodialysis with AVFs, perhaps because of better pre-ESRD care. Nonetheless, AVF rates remain suboptimal, indicating a need for ongoing vascular access evaluation and improvement.

Treatment time, chronic inflammation, and hemodynamic stability: the overlooked parameters in hemodialysis quantification

Decades after the introduction of chronic maintenance hemodialysis, the optimal means of quantifying dialysis dose remains controversial. Differences of opinion in the international dialysis community lead to substantial diversity in everyday clinical practice. Several studies suggest that the well-recognized international mortality differences in hemodialysis populations may result from these divergent approaches to dialysis care. One of the main areas of divergence is the different degree of reliance on dialysis clearance when prescribing dialysis. The "clearance approach" implies that treatment quality is primarily dependent on efficient removal of uremic toxins as estimated by dialytic urea clearance. Urea can be rapidly removed by high efficiency dialysis in a relatively short time. The main alternative to this strategy is the "time approach" based on the recognition that longer or more frequent dialysis provides benefits beyond increasing urea removal. Some of the putative benefits are more effective volume and blood pressure control, better maintenance of hemodynamic stability because of slower ultrafiltration and removal of uremic toxins that do not behave like urea. Recently, chronic inflammation has been proposed to be an important predictor of outcome in dialysis patients. Inflammatory markers are commonly elevated in chronic renal failure and levels of these seem to correlate with malnutrition, maintenance of residual renal function, and volume control. The relationships between dialysis clearance, treatment time, chronic inflammation, volume control, and hemodynamic stability are explored in this review. We propose that a better understanding of these complex relationships may provide opportunities for improving outcomes of maintenance hemodialysis patients.

Hypoalbuminemia is Also a Marker of Fluid Excess Determined by Bioelectrical Impedance Parameters in Dialysis Patients

Hypoalbuminemia may be secondary to volume expansion conditions and an independent risk factor for cardiovascular disease. Bioelectrical impedance analysis (BIA) is an accurate, non-invasive method to measure body composition, especially the water compartments in humans. The aim of this cross-sectional study is to evaluate the relationship between serum albumin concentration (SA) and hydration state measured by whole BIA. The study investigated 108 non-selected patients (73 on hemodialysis, 35 on peritoneal dialysis) with a mean age of 61.4 +/- 15.6 years, 42.7% of whom were female. The patients were allotted to groups according to their SA: Group 1, < or = 3.5 g/dL; Group 2, 3.6-4.0 g/dL; and Group 3, >4.0 g/dL. The BIA parameters used included: total body water, intracellular water (ICW), extracellular water (ECW), phase angle (PA), body cell mass (BCM), ICW/ECW ratio and ICW/ECW ratio patients/controls (fluid index). Seventy-five healthy volunteers formed the control group. A strong positive correlation was found between the PA and fluid index (r (2) = 0.993, P < 0.001), as well as between the PA and SA (r = 0.386, P < 0.001), and the ICW/ECW ratio and SA (r = 0.227, P < 0.001). The ECW was negatively correlated with SA (r = -0.330, P < 0.001). Every 0.1 g/dL decrease in SA was associated with a 0.33 L increase in ECW. Group 1 patients had lower reactance (P = 0.006), PA (P < 0.001), BCM (P = 0.012), fluid index (P < 0.001) and ICW/ECW ratio (P = 0.015), and an increased ECW (NS) than groups 2 and 3. We conclude that hypoalbuminemia is also a marker of fluid excess. The SA is associated to the fluid index and the PA allows assessment of the dry weight and its variations in an individualized manner in dialysis patients.

Can we predict the development of ischemic colitis among patients with lower abdominal pain?

PURPOSE

This study was performed to find clinical risk factors for developing ischemic colitis in patients experiencing lower abdominal discomfort with or without bloody diarrhea.

METHODS

A total of 467 patients who underwent sigmoidoscopy or colonoscopy because of lower abdominal discomforts with or without blood in stool were consecutively enrolled; 147 patients were diagnosed endoscopically and histologically as having ischemic colitis. The control group was composed of the remaining 320 patients with nonspecific endoscopic/histologic findings. Clinical variables were compared between the ischemic colitis group and the control group.

RESULTS

After excluding 67 patients in the ischemic colitis group, we compared the remaining 80 patients to the control group, using various clinical parameters. According to the logistic regression analysis, six factors were significantly related to ischemic colitis: older than aged 60 years (adjusted odds ratio, 5.7; 95 percent confidence interval: 2.6-11.7), hemodialysis (5; 1.2-21.6), hypertension (4.9; 2.3-10.5), hypoalbuminemia (3.5; 1.8-6.7), diabetes mellitus (3.4; 1.3-8.8), and constipation-inducing medications (2.8; 1.1-7.1). Through our analysis, we were able to predict the development of ischemic colitis for the patients with 0, 1, 2, 3, or 4+ risk factors: 8, 21, 55, 79, and 100 percent, respectively.

CONCLUSIONS

Old age, hemodialysis, hypertension, diabetes mellitus, hypoalbuminemia, and constipation-inducing medications are clinically important risk factors for ischemic colitis in patients experiencing lower abdominal discomfort with or without bloody stool. By considering these factors, we were able to predict with high accuracy the development of ischemic colitis.

Traditional and emerging cardiovascular and renal risk factors: An epidemiologic perspective

Patients with chronic kidney disease (CKD) represent an important segment of the population (7-10%) and, mostly because of the high risk of cardiovascular complications associated with renal insufficiency, detection and treatment of CKD is now a public health priority. Traditional risk factors can incite renal dysfunction and cardiovascular damage as well. As renal function deteriorates, non-traditional risk factors play an increasing role both in glomerular filtration rate (GFR) loss and cardiovascular damage. Secondary analyses of controlled clinical trials suggest that inflammation may be a modifiable risk factor both for cardiac ischemia and renal disease progression in patients with or at risk of coronary heart disease. Homocysteine predicts renal function loss in the general population and cardiovascular events in end-stage renal disease (ESRD), but evidence that this sulfur amino acid is directly implicated in the progression of renal disease and in the high cardiovascular mortality of uremic patients is still lacking. High sympathetic activity and raised plasma concentration of asymmetric dimethylarginine (ADMA) have been associated to reduced GFR in patients with CKD and to cardiovascular complications in those with ESRD but again we still lack clinical trials targeting these risk factors. Presently, the clinical management of CKD patients remains largely unsatisfactory because only a minority of these attain the treatment goals recommended by current guidelines. Thus, in addition to research into new and established risk factors, it is important that nephrologists make the best use of knowledge already available to optimize the follow-up of these patients.

Thrombosed arteriovenous fistula for hemodialysis access is characterized by a marked inflammatory activity

BACKGROUND

Thrombosis is the dominant cause of failure of arteriovenous fistulas for hemodialysis access. Vascular inflammation, an important pathologic change in various human vascular diseases, may be involved in the thrombotic process of arteriovenous fistulas.

METHODS

The inflammatory activities of 23 thrombosed and 13 non-thrombosed stenotic arteriovenous fistulas were compared by investigating the contents of macrophages and lymphocytes, and the expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6) using immunohistochemistry method. The expression of matrix metalloproteinase (MMP)-2 and MMP-9, which play important roles in thrombosis of human coronary artery, was also investigated. The immunoreaction results were characterized using a semiquantitative scoring system.

RESULTS

The macrophage and lymphocyte contents of the thrombosed group were abundant, and markedly greater than those of the non-thrombosed group (P < 0.001 and P = 0.001, respectively). The infiltration of macrophages and neovasculature were spatially closely correlated. The expressions of VCAM-1, IL-6, and TNF-alpha, but not ICAM-1, were significantly higher in the thrombosed group (P = 0.031, P = 0.010, P < 0.001, and P= 1.000, respectively). The expression of MMP-2 was not different in either groups (P = 0. 344). Differential expression of MMP-9 by macrophages near the vascular lumen, but not those distant from the lumen, was observed in most thrombosed specimens.

CONCLUSION

This study demonstrated that the thrombosed arteriovenous fistula was characterized by marked inflammation. We hypothesize that the preferential expression of MMP-9 at luminal edge may cause disruption of the anticoagulant endothelial barrier and contribute to luminal thrombosis of arteriovenous fistulas.

Association between novel indices of malnutrition-inflammation complex syndrome and cardiovascular disease in hemodialysis patients

BACKGROUND

Inflammation and malnutrition are recognized as important risk factors for cardiovascular disease (CVD) in hemodialysis (HD) patients. Owing to substantial short-term variability of serum C-reactive protein (CRP), more reliable markers of malnutrition-inflammation complex syndrome should be sought with stronger associations with the risk of CVD in HD patients. We therefore explored the clinical relevance of a composite inflammatory index (prognostic inflammatory and nutritional index [PINI]) and of muscle protein mass indicators, derived from creatinine kinetics.

METHODS

This cross-sectional study included 177 HD patients (89 women and 88 men; median age, 67.73 years). CVD and risk factors were assessed using medical charts, clinical examination, and biochemical measurements performed at inclusion. Lean body mass (LBM) was derived from creatinine kinetic modeling, whereas PINI was calculated as the ratio (CRP xalpha1-acid-glycoprotein)/(albumin x transthyretin). Patients were divided according to the presence or absence of established CVD.

RESULTS

The traditional risk factors diabetes (odds ratio [OR], 5.83; p = 0.0045) and smoking (OR, 3.50; p < 0.02) were associated with an increase in prevalent CVD. Low transthyretin (OR, 3.79; p < 0.02) and high levels of CRP (OR, 2.70; p < 0.05), PINI (OR, 3.44; p < 0.02), observed LBM (OR, 3.01; p < 0.05), and the ratio of observed/expected LBM (OR, 4.24; p < 0.01) were associated with CVD after adjustment for age, sex, dialysis center, and dialysis vintage. After additional adjustment for diabetes and smoking, only PINI (OR, 2.85; p = 0.0446) and observed/expected LBM (OR, 2.96; p = 0.0361) were still significant.

CONCLUSION

PINI and LBM are associated with increased relative risk for having CVD and could be used routinely to examine the degree of severity of malnutrition inflammation complex syndrome.

Evaluation of handgrip strength as a nutritional marker and prognostic indicator in peritoneal dialysis patients

BACKGROUND

Serum albumin has limitations as a nutritional marker in patients undergoing peritoneal dialysis (PD) in that it is affected by inflammation, systemic disease, overhydration, and urinary and dialysate protein loss. Handgrip strength is a simple, easily performed bedside test that has been shown to correlate with lean body mass in patients close to inception of dialysis.

OBJECTIVE

We evaluated the associations of handgrip strength with other clinical factors and examined its relations with mortality and cardiovascular death in PD patients.

DESIGN

We prospectively enrolled 233 chronic PD patients and assessed handgrip strength and other variables at baseline and then followed the patients for a mean (+/-SD) of 30 +/- 14 mo.

RESULTS

Baseline handgrip strength was significantly associated with age, sex, height, diabetes, residual glomerular filtration rate (GFR), and hemoglobin but not with C-reactive protein (CRP). After adjustment for age, sex, and height, handgrip strength was most strongly correlated with lean body mass on the basis of creatinine kinetics (r = 0.334, P < 0.001), followed by serum albumin and subjective global assessment. Both men and women who died had lower handgrip strengths than did those who remained alive (P < 0.001). After control for age, sex, diabetes, atherosclerotic vascular disease, GFR, hemoglobin, CRP, and serum albumin, greater handgrip strength was predictive of lower all-cause [hazards ratio (HR): 0.95 (95% CI: 0.92, 0.99); P = 0.005] and cardiovascular [HR: 0.94 (0.90, 0.98); P = 0.004] mortality.

CONCLUSIONS

Handgrip strength not only is a marker of body lean muscle mass but also provides important prognostic information independent of other covariates, including CRP and serum albumin. Our data suggest that handgrip strength may be used in conjunction with serum albumin as a nutrition-monitoring tool in patients undergoing PD.

Albumin turnover: experimental approach and its application in health and renal diseases

Plasma albumin is an important protein in the human body and is responsible for transport and binding of many molecules. Furthermore, it is involved in mediating blood volume and colloid osmotic pressure (COP). As hypoalbuminemia occurs, as is the case in a number of clinical disorders, adaptation mechanisms may be involved. Serum albumin concentration is the net result of physiological processes like synthesis and catabolism. Measurement of one of these processes can provide therefore a more dynamic insight into the adaptation mechanism of albumin metabolism in relation to an underlying disease than would be obtained by changes in albumin concentration alone. This review highlights several studies over the past years that have contributed to knowledge of albumin metabolism. A short introduction is given for synthesis, formation and catabolism of albumin, after which an overview is given on how to measure albumin turnover including a general approach. Finally, albumin metabolism focused on patients with renal diseases will be discussed.

POOR NUTRITIONAL STATUS AND INFLAMMATION: Serum Albumin: Relationship to Inflammation and Nutrition

Hypoalbuminemia is the result of the combined effects of inflammation and inadequate protein and caloric intake in patients with chronic disease such as chronic renal failure. Inflammation and malnutrition both reduce albumin concentration by decreasing its rate of synthesis, while inflammation alone is associated with a greater fractional catabolic rate (FCR) and, when extreme, increased transfer of albumin out of the vascular compartment. A vicious cascade of events ensues in which inflammation induces anorexia and reduces the effective use of dietary protein and energy intake and augments catabolism of the key somatic protein, albumin. Hypoalbuminemia is a powerful predictor of mortality in patients with chronic renal failure, and the major cause of death in this population is due to cardiovascular events. Inflammation is associated with vascular disease and likely causes injury to the vascular endothelium, and hypoalbuminemia as two separate expressions of the inflammatory process. Albumin has a myriad of important physiologic effects that are essential for normal health. However, simply administering albumin to critically ill patients with hypoalbuminemia has not been shown to improve survival or reduce morbidity. Thus the inference from these clinical studies suggests that the cause of hypoalbuminemia, rather than low albumin levels specifically, is responsible for morbidity and mortality.