Higher N-terminal pro-brain natriuretic peptide level at onset of peritoneal dialysis-related peritonitis is a risk factor for technique failure

BACKGROUND

Recent studies have suggested that the N-terminal fragment of B-type natriuretic peptide (NT-proBNP) level serve as a significant risk factor for mortality in patients with end-stage renal disease. However, the relationship between NT-proBNP levels and technique failure in peritoneal dialysis-associated peritonitis (PDAP) remains unclear. This study investigated the relationship between NT-proBNP levels at the onset of PDAP and the risk of technique failure in patients with PDAP.

METHODS

A retrospective analysis was conducted on patients with PDAP from December 1, 2009, to December 31, 2021, at our peritoneal dialysis center. We recorded all demographic and baseline clinical data at the time of admission for each PDAP episode. Logistic and Cox regression analyses were performed to assess the association between NT-proBNP levels and technique failure.

RESULTS

Of 485 PDAP episodes included in this study, 130 episodes of technique failure were observed. Multivariate logistic analysis revealed that hospital stay, Na and NT-proBNP levels, and peritoneal dialysate white blood cell counts on days 3 and 5 were independently associated with technique failure. The receiver operating characteristic curve demonstrated that the NT-proBNP level was a better indicator than the other four variables in indicating technique failure. In the multivariate Cox regression analysis, after adjusting for confounding factors, higher NT-proBNP levels (HR of 3.020, 95% CI 1.771, 5.150, P < 0.001) were associated with PDAP technique failure.

CONCLUSIONS

This retrospective study identified the serum NT-proBNP level at the onset of PDAP as an independent risk factor for technique failure in these patients.

Gut permeability, circulating bacterial fragments and measures of congestion in peritoneal dialysis

Background

Limited data exist on the association between gut permeability, circulating bacterial fragment and volume overload in peritoneal dialysis (PD) patients. We measured circulating bacterial fragments, N-terminal pro B-type natriuretic peptide (NT-proBNP), calprotectin and zonulin levels, and evaluate their association with the clinical outcomes in PD patients.

Methods

This was a single-center prospective study on 108 consecutive incident PD patients. Plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels were measured. Primary outcomes were technique and patient survival, secondary outcomes were hospitalization data.

Results

There was no significant correlation between plasma endotoxin and bacterial DNA, and serum NT-proBNP, calprotectin and zonulin levels. The Homeostatic Model Assessment for Insulin Resistance (HOMA)-2β index, which represents insulin resistance, positively correlated with plasma bacterial DNA (r = 0.421, P < .001) and calprotectin levels (r = 0.362, P = .003), while serum NT-proBNP level correlated with the severity of volume overload and residual renal function. Serum NT-proBNP level was associated with technique survival even after adjusting for confounding factors [adjusted hazard ratio (aHR) 1.030, 95% confidence interval 1.009-1.051]. NT-proBNP level was also associated with patient survival by univariate analysis, but the association became insignificant after adjusting for confounding factors (aHR 1.010, P = .073). Similarly, NT-proBNP correlated with the number of hospitalizations and duration of hospitalization by univariate analysis, but the association became insignificant after adjusting for confounding factors.

Conclusion

There was no correlation between markers of gut permeability, circulating bacterial fragments and measures of congestion in PD patients. Bacterial fragments levels and gut permeability are both associated with insulin resistance. Serum NT-proBNP level is associated with the severity of volume overload and technique survival. Further studies are required to delineate the mechanism of high circulating bacterial fragment levels in PD patients.

Multifrequency bioimpedance by spectroscopy vs. routine methods in the management of hydration status in peritoneal dialysis patients: A randomized control trial

Background

Overhydration (OH) is common in peritoneal dialysis (PD) and increases the cardiovascular risk. Multifrequency bioimpedance spectroscopy (BIS) has been proposed to estimate the hydration in dialysis. Our objective was to evaluate if BIS is superior than control based on clinical assessment plus single-frequency bioimpedance (SF-BIA) on the fluid control and intermediate cardiovascular outcomes.

Methods

Randomized controlled study in adult PD patients, with a 9-month follow-up, allocated into two groups: control and BIS. Data were collected from medical records. SF-BIA and BIS, laboratory exams, ambulatory blood pressure monitoring, echocardiography (ECHO), and pulse wave velocity (PWV) were evaluated. The BIS data were available to the medical team only in BIS group.

Results

34 patients completed the study, 17 in each group. At the endpoint the BIS group had a significant (p < 0.05) greater proportion of patients with OH/extracellular water (OH/ECW%) ≤ 15% than the control (94.1% vs. 52.9%), and a lower OH mean (2.1 ± 1.6 vs. 0.9 ± 1.1 L). The control group has a significant increase in the tumor necrosis factor alpha median concentration from baseline to six [11.9 (6.0–24.1) vs. 44.7 (9.4–70.6) pg/ml] and 9 months [11.9 (6.0–24.1) vs. 39.4 (27.9–62.6) pg/ml], and in the N-terminal fragment of pro-B-type natriuretic peptide median [239 (171.5–360.5) vs. 356 (219–1,555) pg/ml]. For cardiovascular parameters, BIS group presented a significant reduction in radial PWV [7.7 (6.9–9.2) vs. 6.5 (5.5–8.4) m/s] at 9 month, while in the control presented a significant increase in mean central systolic blood pressure (BP) (106.8 ± 11.2 vs. 117.6 ± 16.5 mmHg) and in central diastolic BP (90.4 ± 9.8 vs. 103.3 ± 12.5 mmHg) at 9 months. The left ventricular mass (LVM)/body surface presented a significant reduction in the control (109.6 ± 30.8 vs. 101.2 ± 28.9 g/m²) and BIS group (107.7 ± 24.9 vs. 96.1 ± 27.0 g/m²) at 9 months.

Conclusion

The results suggest BIS is superior than the clinical evaluation plus SF-BIA for the fluid control of PD patients.

Clinical trial registration

[https://www.ClinicalTrials.gov], identifier [RBR-10k8j3bx].

Association between phase angle and coronary artery calcium score in patients on peritoneal dialysis

Introduction

The phase angle (PhA) has been used as a nutritional marker and predictor of mortality in patients on peritoneal dialysis (PD). The coronary artery calcium (CAC) score has shown to predict the incidence of acute myocardial infarction and death from cardiovascular disease in these patients. However, the association between PhA and CAC score in patients with PD is not well-established, which is the objective of this study.

Materials and methods

Cross-sectional study with patients on PD, followed up at a University Hospital, between March 2018 and August 2019. PhA was evaluated by unifrequency bioimpedance (BIA). The CAC score was calculated based on cardiovascular computed tomography, considering positive when greater than or equal to 100 Agatston and negative when less than 100 Agatston.

Results

We evaluated 44 patients on dialysis, with a mean age of 56 years and median time on dialysis therapy was 11.7 months. In the statistical analysis, a significant association was only observed between the CAC score and the PhA.

Conclusion

The PhA is associated with a positive CAC score in patients with PD, and despite other factors, may be useful as a risk marker for coronary artery disease in this population.

Osteoprotegerin Is a Better Predictor for Cardiovascular and All-Cause Mortality than Vascular Calcifications in a Multicenter Cohort of Patients on Peritoneal Dialysis

The purpose of this study was to compare vascular calcification (VC), serum osteoprotegerin (OPG) levels, and other biochemical markers to determine their value as available predictors of all-cause and cardiovascular (CV) mortality in patients on peritoneal dialysis (PD). A total of 197 patients were recruited from seven dialysis centers in Mexico City. VC was assessed with multi-slice computed tomography, measured using the calcification score (CaSc). OPG, albumin, calcium, hsC-reactive protein, phosphorous, osteocalcin, total alkaline phosphatase, and intact parathormone were also analyzed. Follow-up and mortality analyses were assessed using the Cox regression model. The mean age was 43.9 ± 12.9 years, 64% were males, and 53% were diabetics. The median OPG was 11.28 (IQR: 7.6−17.4 pmol/L), and 42% of cases had cardiovascular calcifications. The median VC was 424 (IQR:101−886). During follow-up (23 ± 7 months), there were 34 deaths, and 44% were cardiovascular in origin. In multivariable analysis, OPG was a significant predictor for all-cause (HR 1.08; p < 0.002) and CV mortality (HR 1.09; p < 0.013), and performed better than VC (HR 1.00; p < 0.62 for all-cause mortality and HR 1.00; p < 0.16 for CV mortality). For each mg/dL of albumin-corrected calcium, there was an increased risk for CV mortality, and each g/dL of albumin decreased the risk factor for all-cause mortality. OPG levels above 14.37 and 13.57 pmol/L showed the highest predictive value for all-cause and CV mortality in incident PD patients and performed better than VC.

Association of Phase Angle, but Not Inflammation and Overhydration, With Physical Function in Peritoneal Dialysis Patients

Introduction: Muscle mass depletion, overhydration, and inflammatory state have been related to impaired physical function in chronic kidney disease patients. The relationship between bioelectrical impedance analysis (BIA) parameters, such as hydration status and phase angle (PhA), with physical function in peritoneal dialysis (PD), is still not well-established. Therefore, the objective was to evaluate the association of BIA parameters (overhydration index and PhA) and inflammatory markers with physical function in patients on PD.

Methods: The present cross-sectional study enrolled PD patients. Multifrequency BIA was performed to obtain overhydration index and PhA. The Short Physical Performance Battery (SPPB) test battery was applied to assess physical function. The time to complete the 4-m gait test and sit-to-stand test was also considered for physical function assessment. The inflammatory markers tumor necrosis factor-alpha and C-reactive protein levels were determined. Multiple linear regression models were performed, with the physical function variables as dependent variables, adjusted for age, diabetes, and sex.

Results: Forty-nine PD patients were enrolled, 53.1% (n = 26) women; mean age, 55.5 ± 16.3 years. There were significant correlations between PhA and SPPB (r = 0.550, p < 0.001), time of 4-m gait test (r = −0.613, p < 0.001) and sit-to-stand test and (r = −0.547, p < 0.001). Overhydration index was significantly correlated with SPPB, 4-m gait test (r = 0.339, p = 0.017), and sit-to-stand test (r = 0.335, p = 0.019). Inflammatory markers were not significantly correlated with physical function parameters. In the multiple linear regression analysis, PhA was associated with physical function parameters, even after adjustments. Overhydration index was associated with all physical function tests only in the models with no adjustments.

Conclusion: PhA was independently associated with physical function in PD patients. Inflammatory markers and overhydration index were not associated with physical function.

Increased extracellular water measured by bioimpedance analysis and increased serum levels of atrial natriuretic peptide in polymyalgia rheumatica patients : Signs of volume overload

BACKGROUND

Water retention is a typical feature of acute inflammatory episodes, chiefly implemented by the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis. This is an important compensatory mechanism counteracting expected water loss, e.g., due to sweating. Both the SNS and HPA axis are activated in polymyalgia rheumatica (PMR). As retention mechanisms may similarly apply in this disease, we hypothesized increased water retention in PMR.

METHODS

Using bioimpedance analysis body composition was investigated in 64 healthy controls and 32 treatment-naive PMR patients. All PMR patients satisfied the 2012 EULAR/ACR classification criteria for PMR. 32 PMR patients were tested before and after 7 days of glucocorticoid-based therapy. Serum levels of pro-atrial natriuretic peptide (proANP) were investigated in all PMR patients and 15 healthy controls.

RESULTS

Extracellular water (ECW) was markedly higher in PMR patients than in controls (mean ± SD: 49.1 ± 6.0% versus 36.3 ± 2.5% of total body water, p < 0.001). Patients with PMR demonstrated significantly higher serum levels of proANP compared to controls. Even before glucocorticoid treatment was initiated, systolic and diastolic blood pressure were higher in PMR patients compared to controls. Extracellular water levels did not change in PMR patients upon 7 days of intensified treatment.

CONCLUSION

This study demonstrated increased extracellular water and elevated serum levels of proANP as signs of fluid overload in patients with PMR. Volume changes are imprinted as long-lasting mechanisms as water distribution is not affected by short-term anti-inflammatory therapy.

Immune Dysfunction in Dialysis Patients—Prevention and Treatment Strategies

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

Subjective global assessment of nutrition, dialysis quality, and the theory of the scientific method in Nephrology practice

In an era of evidence-based medicine and dialysis performance measures, there is strong motivation to find specific, objective, quantifiable, and reproducible parameters to characterize the clinical condition of chronic kidney disease patients and to present population-wide statistics that may describe quality of care in dialysis centers. Yet, in the last three decades, several studies demonstrated that while parameters including Kt/V urea, serum phosphorus, parathyroid hormone, serum cholesterol fulfill all these criteria, efforts to optimize these lab parameters failed to improve survival on dialysis. However, subjective assessments of nutrition including subjective global assessment and malnutrition-inflammation score, while not ideally suited for statistical analysis and not optimal from the point of view of scientific methodology due to their general, semi-quantifiable, subjective nature have, nevertheless, proved themselves as some of the strongest predictors of clinical outcomes in the dialysis population. Where does this paradox leave us? We propose that a deeper understanding of relevance of these variables in the dialysis population may improve appreciation of the clinical situation of individual patients and may result in a paradigm shift from dialysis adequacy to quality dialysis.

Inflammation in Peritoneal Dialysis: A Latin-American Perspective

Peritoneal dialysis (PD) patients present an extremely high mortality rate, but the mechanisms mediating the increased risk of mortality observed in this group of patients are still largely unknown, which limits the perspective of effective therapeutic strategies. The leading hypothesis that tries to explain this high mortality risk is that PD patients are exposed to a number of traditional risk factors for cardiovascular disease (CVD) already at the onset of their chronic kidney disease (CKD), since many of these risk factors are common to both CVD and CKD. Of particular importance, chronic inflammation recently emerged as an important novel risk factor related to multiple complications of CKD. There are many stimuli of the inflammatory response in CKD patients, such as fluid overload, decreased cytokine clearance, presence of uremia-modified proteins, presence of chronic infections, metabolic disturbances (including hyperglycemia), obesity. Many of these factors are related to PD. Latin America has made some progress in economic issues; however, a large portion of the population is still living in poverty, in poor sanitary conditions, and with many health-related issues, such as an increasing elderly population, low birth weights, and increasingly high energy intake in the adult population, which, in combination with changes in lifestyle, has provoked an increase in the prevalence of obesity, diabetes, and CVD. Therefore, in Latin America, there seems to be a peculiar situation combining high prevalence of low education level, poor sanitary conditions, and poverty with increases in obesity, diabetes, and sedentary lifestyle. Since inflammation and mortality risk are intimately related to both sides of those health issues, in this review we aim to analyze the peculiarities of inflammation and mortality risk in the Latin-American PD population.

Chronic Kidney Disease and Dialysis in Mexico

The increasing rates in incidence and prevalence of chronic kidney disease (CKD) are important challenges for health systems around the world, and are even more significant for undeveloped countries. In Mexico the prevalence of CKD seems to be similar to that in highly developed nations, with diabetes as the leading cause of CKD; however, human and economic resources seem to be insufficient for treatment needs. This is reflected in the unacceptably high mortality rates and in noncompliance with established standards and guidelines. Several measures need to be taken to improve this picture, such as more efficient programs for the prevention of obesity, diabetes, and hypertension. Organizing a national registry of patients with CKD is now a pressing need, as is a continuous search for additional funding and budgets to increase the number of qualified nephrologists and specialized nurses and to continue the much-needed research on CKD.

Phase Angle Predicts Arterial Stiffness and Vascular Calcification in Peritoneal Dialysis Patients

Objectives

Fluid overload (FO) is frequently present in peritoneal dialysis (PD) patients and is associated with markers of malnutrition, inflammation, and atherosclerosis/calcification (MIAC) syndrome. We examined the relationships in stable PD patients between phase angle (PhA) and the spectrum of uremic vasculopathy including vascular calcification and arterial stiffness and between PhA and changes in serum fetuin-A levels.

Methods

Sixty-one stable adult PD patients were evaluated in a cross-sectional study (ST1). Phase angle was measured by multifrequency bioimpedance analysis (InbodyS10, Biospace, Korea) at 50 kHz. Augmentation index (AI), a surrogate marker of arterial stiffness, was assessed by digital pulse amplitude tonometry (Endo PAT, Itamar Medical, Caesarea, Israel). Vascular calcification was assessed by simplified calcification score (SCS). Serum fetuin-A levels were measured by ELISA (Thermo scientific; Waltham, MA, USA). Serum albumin was used as a nutritional marker, and serum C-reactive protein (CRP) was used as an inflammatory marker. The same assessments were carried out longitudinally (ST2) in the first 33 patients who completed 1 year of evaluation in ST1.

Results

In ST1, patients with PhA < 6° had higher CRP levels, AI, and SCS and lower serum albumin and fetuin-A levels, in comparison with patients with PhA ≥ 6°. In addition, PhA was a predictor of both AI ((3 = -0.351, p = 0.023) and SCS > 3 (EXP (B) = 0.243, p = 0.005). In ST2, the increase of PhA over time was associated with decreases in both AI ( r = -0.378, p = 0.042) and CRP levels ( r = -0.426, p = 0.021), as well as with the increase in serum fetuin-A levels ( r = 0.411, p = 0.030).

Conclusions

Phase angle predicts both arterial stiffness and vascular calcification in stable PD patients.

The association of overhydration with chronic inflammation in chronic maintenance hemodiafiltration patients

INTRODUCTION

Achieving euvolemia is one of the major challenges when treating end-stage renal disease (ESRD) patients receiving maintenance renal replacement therapy. Fluid overload is recognized as an independent predictor of mortality in ESRD, but its association with chronic inflammation is less well explored especially in chronic maintenance hemodiafiltration.

METHODS

We performed a cross-sectional study of 87 prevalent ESRD patients receiving chronic maintenance hemodiafiltration (vintage 66.5 ± 57.1 months) with bioimpedance analysis to characterize the degree of percent overhydration (OH%). We also compared the levels of inflammatory markers, including C-reactive protein (CRP), serum albumin, neutrophil/lymphocyte ratio (NLR), and hemoglobin red cell distribution width (RDW) for the overhydrated (OH% ≥ 15%) versus euvolemic (OH% < 15%) groups. Linear regression analysis was performed to explore relationships between the degree of OH and inflammatory indicators.

FINDINGS

The cohort represented an all-European population with a mean age of 60.9 ± 14.7 years and prevalence of diabetes mellitus of 27%. The entire cohort's OH% was 14.9% ± 5.1% (range -11.1% to 39.0%); further, the <15% group of patients' OH% was 8.0% ± 8.5% versus 20.9% ± 5.1% in the OH% ≥ 15% group (P < 0.0001). Forty-seven patients (53%) were overhydrated by traditional criteria (OH% ≥15%) and 20 patients (23%) were severely overhydrated (OH% > 20%). The euvolemic (OH% <15%) versus severely overhydrated (OH% > 20%) groups had significant differences in markers of inflammation: CRP (9.8 ± 10.6 vs. 21.5 ± 21.6 mg/L, P < 0.006), serum albumin (37.6 ± 02.9 vs. 34.5 ± 5.3 g/L, P < 0.004), and NLR (3.06 ± 1.25 vs. 3.92 ± 2.04; P < 0.004). On linear regression, significant correlations were found between OH% and CRP (r = 0.2899, P < 0.006), serum albumin (r = -0.3670; P < 0.0005), RDW (r = 0.2992; P < 0.005), and NLR (r = 0.2900; P < 0.006).

DISCUSSION

In a prevalent hemodiafiltration cohort, OH was common and correlated with several inflammatory markers.

Fluid restriction reduces pulmonary edema in a model of acute lung injury in mechanically ventilated rats

Experimental acute lung injury models are often used to increase our knowledge on the acute respiratory distress syndrome (ARDS), however, existing animal models often do not take into account the impact of specific fluid strategies on the development of lung injury. In contrast, the current literature strongly suggests that fluid management strategies have a significant impact on clinical outcome of patients with ARDS. Thus, it is important to characterize the role of fluid management strategies in experimental models of lung injury. In this study we investigated the effect of two different fluid strategies on commonly used outcome variables in a short-term model of acute lung injury, in relation to age. Infant (2–3 weeks) and adult (3–4 months) Wistar rats received intratracheal instillations of lipopolysaccharide and 24 hours later were mechanically ventilated for 6 hours. During mechanical ventilation, rats from both age groups were randomized to either a standard or conservative intravenous fluid strategy. We found that the hemodynamic response in infant and adult rats was similar in both fluid strategies. Lung wet-to-dry ratios were lower in adult, but not in infant rats receiving the conservative fluid strategy as compared to the standard fluid strategy. There were age-related differences in markers of alveolar capillary barrier disruption and alveolar fluid clearance, yet these were unaffected by fluid strategy. Finally, we found significantly higher IL-1β and TNF-α concentrations in the adult rats treated with the conservative as compared to the standard fluid regimen. In conclusion, the choice of fluid strategy in mechanically ventilated rats with experimental LPS-induced acute lung injury has a significant effect on pulmonary extravascular water, an important and well-recognized lung injury marker, and on the local pro-inflammatory cytokine profiles. We advocate the use of a more uniform, conservative, fluid strategy regimen in experimental models of acute lung injury.

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.

Fluid management and bioimpedance study in peritoneal dialysis

PURPOSE OF REVIEW

Maintaining euvolaemia is an essential yet challenging objective in management of patients on peritoneal dialysis. Optimal method to assess volume status remains to be determined. In this review, we will discuss the risk factors and clinical outcomes of fluid overload in PD patients, and examine the role of bioimpedance study in fluid management.

RECENT FINDINGS

Applying bioimpedance study to measure body composition has attracted increasing attention because it is noninvasive and provides point-of-care assessment of fluid status. Observational studies suggested that presence of residual renal function did not necessarily protect peritoneal dialysis patients from developing fluid overload. This reinforces the importance of fluid restriction in peritoneal dialysis patients, in whom the thirst sensation could be exacerbated by hyperglycaemia. Notably, fluid overload is present in significant portion of asymptomatic patients. Moreover, bioimpedance-defined fluid overload is associated with increase in all-cause mortality, technique failure and possibly excess peritonitis rate.

SUMMARY

Although future studies should investigate the clinical benefit of bioimpedance-guided fluid management in high-risk subgroup, raising awareness among clinicians, together with structured clinical assessment and dietary counselling are the cornerstone to maintain stable fluid status.

Status of hydration assessed by bioelectrical impedance analysis: a valuable predictive factor for radiation-induced oral mucositis in head and neck cancer patients

BACKGROUND

Apart from surgery, the methods of treatment of HNC are radiotherapy (RTH) and/or chemotherapy (CRTH/CHT). One of the most frequent and serious complications of RTH is oral mucositis (OM). There is a strict correlation between the inflammation and the status of hydration. The aim of the study was to evaluate the changes in hydration, occurring in the course of RTH, measured by means of bioelectrical impedance analysis (BIA) and to analyze them in correlation with the intensification of OM in HNC patients.

PATIENTS AND METHODS

Data from 49 HNC patients (stages I-IV) were analyzed. All of them were irradiated using IMRT technique with the doses of 50-70 Gy. Oral mucositis (OM) was evaluated according to RTOG/EORTC guidelines. BIA was performed using ImpediMed bioimpedance analysis SFB7 BioImp v1.55.

RESULTS

In the fourth week of RTH, 4-5 days before the occurrence of severe OM, it was found that patients with OM grade 3 or higher compared to OM grade 2 or lower had significantly: lower ICW% values (respectively, 53.02% vs 50.72%; p = 0.0047), higher: ECW%: (47.95% vs 46.92%; p = 0.0020), TBW% (respectively, 56.34% vs 51.06%; p = 0.0455), ECW/ICW (respectively, 0.96 vs 0.86; p = 0.0007) and ECW/TBW (respectively, 0.49 vs 0.46, p = 0.0033).

CONCLUSION

Our study indicates that HNC patients undergo changes in hydration in the course of RTH. We have also confirmed that the intensification of OM leads to ICW decrease and the increase of ECW, TBW as well as ECW/ICW and ECW/TBW values.

Inflammation and Peritoneal Dialysis

Inflammation is one of the well-recognized nontraditional risk factors that contributes to the excessive cardiovascular mortality in peritoneal dialysis (PD) patients. Serum C-reactive protein and interleukin-6 levels are common surrogate markers used to measure inflammatory burden and predict adverse clinical outcomes in PD patients. Causes of inflammation are complex and can be categorized into factors related to a decrease in renal function and factors related to dialysis. They interact with each other and finally result in systemic and intraperitoneal inflammation. This review discusses the various causes and clinical implications of inflammation in PD patients. More importantly, potential therapeutic options that target the underlying pathogenic mechanisms are explored.

The importance of residual renal function in peritoneal dialysis

BACKGROUND

Peritoneal dialysis (PD) patients with preserved residual diuresis have a lower risk of death and complications. Here we analyzed associations between residual diuresis and presence of fluid overload and biomarkers of cardiac strain and nutrition in PD patients.

METHODS

Among 44 PD patients placed into three subgroups, depending on volume of residual diuresis (group A ≤ 500; group B 600-1900; and group C ≥ 2000 mL/day), we examined: overhydration (OH) assessed by bioimpedance analysis (BIA; yielding OH index OHBIA) and by clinical criteria (edema and hypertension); nutritional status (by subjective global assessment, SGA); metabolic status (electrolytes, serum lipid profile, CRP, and albumin); biomarkers of fluid overload and cardiac strain (N-terminal probrain natriuretic peptide, NT-proBNP, and troponin T, TnT); and, echocardiography and chest X-ray.

RESULTS

With increasing residual diuresis in group A, B and C, fewer patients had signs of overhydration defined as OHBIA > 1.1 L (75.0, 42.9 and 33.3 %) or peripheral edema (25.0, 21.4 and 0 %) and NT-proBNP (15199 ± 16150 vs. 5930 ± 9256 vs. 2600 ± 3907 pg/mL; p < 0.05) and TnT (0.15 ± 0.17 vs. 0.07 ± 0.09 vs. 0.04 ± 0.03 ng/mL; p < 0.05) were significantly lower. Significant differences were found also in ejection fraction, SGA, and total cholesterol, albumin and hemoglobin levels whereas blood pressures and serum CRP did not differ significantly.

CONCLUSION

Signs of OH and cardiac strain are common in PD patients, even in those with diuresis of 1000-2000 mL/day and with no clinical signs or symptoms, suggesting that even moderate decrease in residual renal function in PD patients associate with OH and other complications.

Increased extracellular water measured by bioimpedance and by increased serum levels of atrial natriuretic peptide in RA patients-signs of volume overload

The aim of the study is to investigate water compartments in patients with rheumatoid arthritis (RA). Acute inflammatory episodes such as infection stimulate water retention, chiefly implemented by the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axis. This is an important compensatory mechanism due to expected water loss (sweating etc.). Since SNS and HPA axis are activated in RA, inflammation might be accompanied by water retention. Using bioimpedance analysis, body composition was investigated in 429 controls and 156 treatment-naïve RA patients between January 2008 and December 2014. A group of 34 RA patients was tested before and after 10 days of intensified therapy. Levels of pro-atrial natriuretic peptide (proANP) and expression of atrial natriuretic peptide in synovial tissue were investigated in 15 controls and 14 RA patients. Extracellular water was higher in RA patients than controls (mean ± SEM: 49.5 ± 0.3 vs. 36.7 ± 0.1, % of total body water, p < 0.0001). Plasma levels of proANP were higher in RA than controls. RA patients expressed ANP in synovial tissue, but synovial fluid levels and synovial tissue superfusate levels were much lower than plasma levels indicating systemic origin. Systolic/diastolic blood pressure was higher in RA patients than controls. Extracellular water levels did not change in RA patients despite 10 days of intensified treatment. This study demonstrates signs of intravascular overload in RA patients. Short-term intensification of anti-inflammatory therapy induced no change of a longer-lasting imprinting of water retention indicating the requirement of additional treatment. The study can direct attention to the area of volume overload.

The Impact of Fluid Overload and Variation on Residual Renal Function in Peritoneal Dialysis Patient

BACKGROUND

The effect of fluid overload and variation on residual renal function (RRF) in peritoneal dialysis (PD) patients is controversial.

METHODS

Retrospective cohort study was designed. One-hundred and ninety PD patients with measured glomerular filtration rate (mGFR) ≧ 3 ml/min/1.73 m2 were recruit. Fluid status of every participant was assessed by bioelectrical impedance analysis (BIA) every 3 months for 1 year. The cohort was divided into three hydration groups, namely persistent overhydration (PO) group, intermittent overhydration (IO) group and normal hydration (NH) group. Additionally, participants were also divided into high or low fluid variation groups. The decline rate of RRF and the event of anuria were followed up for 1 year. The association of fluid overload with RRF loss was evaluated by Cox proportional hazard models adjusted for confounders.

RESULTS

Thirty-six (18.9%) patients developed anuria. The decline rate of mGFR in both PO and IO groups were significantly faster than that of NH group (PO vs NH: -0.2 vs -0.1 ml/min/1.73 m2/month, p < 0.01; IO vs NH: -0.2 vs -0.1 ml/min/1.73 m2/month, p < 0.01). Kaplan-Meier analysis showed poorer RRF outcome in both PO and IO groups compared with that of NH group (PO vs NH: p < 0.001; IO vs NH: p = 0.006). Patients with high fluid variation had worse RRF survival than those with low fluid variation (p = 0.04). Adjusted Cox regression models indicated the hazard ratio of RRF loss in PO group was 8.90-folds higher (95% confidence interval 3.07-31.89) than that in NH group.

CONCLUSIONS

These findings suggested fluid overload was independently associated with the decline of RRF in PD patients.

Pediatric Acute Respiratory Distress Syndrome: Fluid Management in the PICU

The administration of an appropriate volume of intravenous fluids, while avoiding fluid overload, is a major challenge in the pediatric intensive care unit. Despite our efforts, fluid overload is a very common clinical observation in critically ill children, in particular in those with pediatric acute respiratory distress syndrome (PARDS). Patients with ARDS have widespread damage of the alveolar-capillary barrier, potentially making them vulnerable to fluid overload with the development of pulmonary edema leading to prolonged course of disease. Indeed, studies in adults with ARDS have shown that an increased cumulative fluid balance is associated with adverse outcome. However, age-related differences in the development and consequences of fluid overload in ARDS may exist due to disparities in immunologic response and body water distribution. This systematic review summarizes the current literature on fluid imbalance and management in PARDS, with special emphasis on potential differences with adult patients. It discusses the adverse effects associated with fluid overload and the corresponding possible pathophysiological mechanisms of its development. Our intent is to provide an incentive to develop age-specific fluid management protocols to improve PARDS outcomes.

Evaluation of Protein-Energy Wasting and Inflammation on Patients Undergoing Continuous Ambulatory Peritoneal Dialysis and its Correlations

BACKGROUND

Protein-energy wasting (PEW) and heightened inflammation are prevalent in patients undergoing continuous ambulatory peritoneal dialysis (CAPD) and is a strong risk factor for morbidity and mortality in these patients. Evaluation of PEW, prevalence of inflammation as well as interrelationship between various nutritional indices and inflammation has not been studied in much detail in patients undergoing CAPD.

OBJECTIVES

This study was conducted to evaluate the interrelationship between PEW and inflammation in patients undergoing CAPD.

PATIENTS AND METHODS

Sixty-three patients undergoing CAPD (M = 28, F = 35) were assessed with regard to their nutritional status and inflammation after a minimum of 3 months CAPD initiation. Nutritional status was assessed by dietary diary, anthropometry, subjective global assessment, and multifrequency bioelectrical impedance analysis (BIA). In addition, their serum albumin, prealbumin, transferrin, and cholesterol level were measured. Also, inflammation in these patients was assessed by High-Sensitivity C-Reactive Protein (hs-CRP > 3 mg/L) and Interleukin-6 (IL-6 > 2 µg/mL). Later on, diagnosis of malnutrition was made based on different methods. Correlation between inflammation and various nutritional assessment indices were analyzed statistically.

RESULTS

Mean (SD) age of the patients was 57.6 (11.6) years. The average (SD) calorie and protein intake per day were 25.5 (4.6) kcal and 0.81 (0.2) mg, respectively. The mean and standard deviation of anthropometry variables of body mass index (BMI), mid-arm circumference (MAC), tricipital skin-fold thickness (TST), mid-arm muscle circumference (MAMC), and corrected mid-arm muscle area (cMAMA) were 23.7 ± 5 kg/m(2), 26.3 ± 4.5 cm, 1.624 ± 0.4 cm, 25.6 ± 4.5 cm, and 45.7 ± 19.7 cm(2), respectively. The mean values of serum protein, albumin, prealbumin, transferrin, cholesterol, triglyceride, hs-CRP, and IL-6 were 5.9 g/dL, 3.0 g/dL, 21.11 mg/dL, 130.6 mg/dL, 155.9 mg/dL, 136.1 mg/dL, 8.8 ± 7.6 mg/L, and 8.4 ± 12.2 µg/dL, respectively. Based on subjective global assessment (SGA); 11.63 (17.4%), 34.63 (54%), and 18.65 (28.6%) patients undergoing CAPD had normal, moderate, and severe malnutrition status, respectively. According to serum albumin level; 13.63 (21%), 39.63 (62%), and 11.63 (17%) patients undergoing CAPD had normal, moderate, and severe malnutrition status, respectively. Finally, based on BMI; 33.63 (52%), 23.63 (37%), and 7.63 (11%) patients undergoing CAPD had normal, moderate, and severe malnutrition status, respectively. About 76.1% and 9.5% of patients undergoing CAPD were malnourished based on lean tissue index (LTI) and fat tissue index (FTI), respectively. Based on hs-CRP and IL-6 findings, 70% (44/63) and 71.8% (45/63) of patients undergoing CAPD had high inflammation, respectively. High sensitive C-reactive protein correlated negatively (significantly) with serum albumin, prealbumin, and transferrin. Interleukin -6 correlated negatively (significantly) with MAC; MAMA; serum albumin, cholesterol, and transferrin. There was significant positive correlation between hs-CRP and IL-6. There is statistically significant difference in total protein intake (g/d), protein intake (g/kg/d), serum protein (g/dL), albumin (g/dL), transferrin (mg/dL), and cholesterol (mg/dL) between patients with and without inflammation.

CONCLUSIONS

Protein-energy wasting (80% - 85%) by various methods and inflammation (70%) was very prevalent among patients undergoing CAPD. Inflammatory markers show significant negative correlation with anthropometry and serological markers. Inflammatory markers are suggested to be included in the regular assessment of patients undergoing CAPD, for the better management of protein-energy wasting.

Inflammation is associated to volume status in peritoneal dialysis patients

AIM

The aim of this study is to investigate whether there is a relationship between inflammation and volume status in patients underwent peritoneal dialysis (PD).

PATIENTS AND METHOD

This cross-sectional study included 159 PD patients. The median duration of PD was 17 (range, 1-151) months. All patients were examined using bioelectrical impedance analysis to estimate the ratio of extracellular water to total body water (ECW/TBW), which was used to assess their volume status. The patients were categorized as having one of the following three volume statuses: hypervolemic (above +2 SD from the mean, which was obtained from healthy controls), normovolemic (between +2 SD and -2 SD), or hypovolemic (below -2 SD from the mean). Five patients with hypovolemia were excluded from the study. Fifty-six patients were hypervolemic whereas 98 patients were euvolemic. High-sensitive C-reactive protein (hs-CRP) levels were measured to evaluate inflammation in all patients.

RESULTS

hs-CRP value levels were significantly higher in hypervolemic patients compared with euvolemic patients [7.1 (3.1-44.0) mg/L vs. 4.3 (3.1-39.6), p: 0.015, respectively]. Left ventricular hypertrophy was more frequent in hypervolemic patients compared with euvolemic patients (53.6% vs. 30.6%, p: 0.004, respectively). ECW/TBW ratio positively correlated with hs-CRP (r: 0.166, p: 0.039). Gender, hs-CRP, and residual Kt/V urea were found to be independent risk factors for hypervolemia in multivariate analysis.

CONCLUSION

Inflammation is associated with hypervolemia in PD patients. Residual renal functions play an important role to maintain euvolemia in PD patients.

Effect of icodextrin on heart rate variability in diabetic patients on peritoneal dialysis

INTRODUCTION

Spectral analysis of heart rate variability is a noninvasive method for evaluating autonomic cardiovascular dysfunction under various clinical conditions, such as in dialysis patients, in whom an imbalance between the sympathetic and parasympathetic nervous system appears to be an important risk factor for sudden cardiovascular death and arrhythmia. ♢

OBJECTIVE

We compared the effect of icodextrin-based dialysis solution, an option that allows for better metabolic and fluid overload control, with that of glucose-based dialysis fluid on sympathetic and parasympathetic activity in the heart, as assessed by heart rate variability, in diabetic patients on peritoneal dialysis (PD). ♢

METHODS

This secondary analysis uses data from a randomized controlled trial in diabetic PD patients with high or high-average peritoneal transport using icodextrin-based (ICO group, n = 30) or glucose-based (GLU group, n = 29) solutions for the long dwell. All patients underwent 24-hour electrocardiographic Holter monitoring at baseline, and at 6 and 12 months of follow-up. ♢

RESULTS

We observed no significant differences between the groups in most of the variables analyzed, although values were, in general, below reference values. In the ICO group, total power and both low- and high-frequency power in normalized units increased, but the percentage of RR intervals with variation of more than 50 ms declined over time; in the GLU group, all those values declined. Plasma catecholamine levels were higher at baseline and declined over time. ♢

CONCLUSIONS

These results indicate a partial recovery of sympathetic activity in the ICO group, probably because of better extracellular fluid control and lower exposure to glucose with the use of icodextrin-based dialysis solutions.

The impact of the peritoneal glucose load index on hydration status and inflammation in peritoneal dialysis patients

Objective

To evaluate the impact of the peritoneal glucose load (PGL) on hydration status and inflammation in peritoneal dialysis (PD) patients.

Methods

This cross-sectional study evaluated stable PD patients using a novel PGL index (PGLI), which was calculated as the net glucose content (g) in the PD solutions administered in the daily PD prescription divided by the dry body weight (kg) assessed by whole-body bioimpedance spectroscopy. The relationship between PGLI and glycosylated haemoglobin (HbA1c), fluid overload (FO), and inflammatory markers was investigated.

Results

A total of 43 stable PD patients participated in the study. Significant positive correlations were found between PGLI and HbA1c, FO, plasma high sensitivity C-reactive protein (hsCRP), and plasma interleukin-6 (IL-6) levels. HbA1c, FO, plasma hsCRP and plasma IL-6 levels were significantly higher in patients with PGLI >3 g/kg/day compared with those with PGLI ≤3 g/kg/day.

Conclusions

PGLI values >3 g/kg/day may be associated with poor glycaemic control, over hydration and augmented inflammation. PGLI might be a useful tool for the quantitative assessment of the PGL and could be applied when managing PD patients.

Association of fluid overload with kidney disease progression in advanced CKD: a prospective cohort study

BACKGROUND

Fluid overload is a common phenomenon in patients in a late stage of chronic kidney disease (CKD). However, little is known about whether fluid overload is related to kidney disease progression in patients with CKD. Accordingly, the aim of the study was to assess the association of the severity of fluid status and kidney disease progression in an advanced CKD cohort.

STUDY DESIGN

Prospective observational cohort study.

SETTING & PARTICIPANTS

This cohort study enrolled 472 non-dialysis-dependent patients with CKD stages 4-5 who were in an integrated CKD care program from January 2011 to December 2011 and followed up until December 2012 or initiation of renal replacement therapy (RRT).

PREDICTORS

Tertile of fluid overload, with cutoff values at 0.6 and 1.6 L.

OUTCOMES

RRT, rapid estimated glomerular filtration rate (eGFR) decline (faster than 3 mL/min/1.73 m(2) per year), and change in eGFR.

MEASUREMENTS

The severity of fluid overload was measured by a bioimpedance spectroscopy method. eGFR was computed using the 4-variable MDRD (Modification of Diet in Renal Disease) Study equation.

RESULTS

During a median 17.3-month follow-up, 71 (15.0%) patients initiated RRT and 187 (39.6%) experienced rapid eGFR decline. The severity of fluid overload was associated with increased risk of RRT (tertile 3 vs tertile 1: adjusted HR, 3.16 [95% CI, 1.33-7.50]). Fluid overload value was associated with increased risk of rapid eGFR decline (tertile 3 vs tertile 1: adjusted OR, 4.68 [95% CI, 2.30-9.52]). Furthermore, the linear mixed-effects model showed that the reduction in eGFR over time was faster in tertile 3 than in tertile 1 (P=0.02).

LIMITATIONS

The effect of fluid volume variation over time must be considered.

CONCLUSIONS

Fluid overload is an independent risk factor associated with initiation of RRT and rapid eGFR decline in patients with advanced CKD.

Effect of dialysate sodium reduction on body water volume, blood pressure, and inflammatory markers in hemodialysis patients--a prospective randomized controlled study

Accumulating evidence suggests an association between body volume overload and inflammation in chronic kidney diseases. The purpose of this study was to evaluate the effect of dialysate sodium concentration reduction on extracellular water volume, blood pressure (BP), and inflammatory state in hemodialysis (HD) patients. In this prospective controlled study, adult patients on HD for at least 90 days and those with C-reactive protein (CRP) levels ≥ 0.7 mg/dL were randomly allocated into two groups: group A, which included 29 patients treated with reduction of dialysate sodium concentration from 138 to 135 mEq/L; and group B, which included 23 HD patients not receiving dialysate sodium reduction (controls). Of these, 20 patients in group A and 18 in group B completed the protocol study. Inflammatory, biochemical, hematological, and nutritional markers were assessed at baseline and after 8 and 16 weeks. Baseline characteristics were not significantly different between the two groups. Group A showed a significant reduction in serum concentrations of tumor necrosis factor-α, and interleukin-6 over the study period, while the BP and extracellular water (ECW) did not change. In Group B, there were no changes in serum concentrations of inflammatory markers, BP, and ECW. Dialysate sodium reduction is associated with attenuation of the inflammatory state, without changes in the BP and ECW, suggesting inhibition of a salt-induced inflammatory response.

Sodium removal and peritoneal dialysis modalities: no differences with optimal prescription of icodextrin

Continuous ambulatory peritoneal dialysis (CAPD) has been considered as a more efficient modality for sodium removal than automated peritoneal dialysis (APD), due to the longer dwell times and the sodium sieving phenomenon. However, because studies regarding sodium removal in peritoneal dialysis (PD) report rather controversial results and carry various methodological flaws, it remains uncertain whether they offer enough significant information regarding PD prescription and therapy. The aim of the present observational cross-sectional study was to evaluate the impact of the optimal prescription of CAPD and APD, regarding solute clearances and daily ultrafiltrate, on daily sodium removal. Forty-six (46) patients aged 52.3 ± 14 years were studied. Twenty-six (26) patients were subjected to CAPD, and 20 patients were subjected to APD. Ten (10) patients per group were prescribed icodextrin for the long dwell to achieve optimal adequacy and ultrafiltration (UF) targets. CAPD patients removed a higher, albeit not statistically significant, daily amount of sodium (131.7 ± 98.2 mmol) compared with APD patients (79.4 ± 129.2 mmol). Their Kt/V urea was lower (1.48 ± 0.3 vs. 2.17 ± 0.33, P < 0.05), and there were no differences on daily UF (1119 ± 533 vs. 1005 ± 517 mL). In both groups, icodextrin use for the long dwell resulted in equal sodium removal with that of patients not prescribed icodextrin. Our results, derived from an unselected PD population, indicate that although classic CAPD may be more efficient for sodium removal than APD, the use of icodextrin as an adjuvant for higher daily UF not only increases solute clearance but also removes more sodium for both modalities. In addition, calculations of sodium removal in PD do not seem to benefit the everyday clinical practice, provided that PD patients can achieve the adequacy targets and present optimal daily UF without signs of volume overload.

Differential association of proinflammatory cytokines with left ventricular diastolic dysfunction in subjects with and without continuous ambulatory peritoneal dialysis

BACKGROUND AND AIMS

The association between inflammation and left ventricular (LV) diastolic dysfunction in continuous ambulatory peritoneal dialysis (CAPD) and non-CAPD patients is not established. The objective of this study was to test the above association and whether inflammation interacts with CAPD to increase LV diastolic dysfunction risks.

METHODS AND RESULTS

120 subjects with normal creatinine levels and 101 CAPD patients were recruited. Echocardiographic parameters were assessed in all patients. The participants were classified as having LV diastolic dysfunction by echocardiographic findings including mitral inflow E/A ratio < 1, deceleration time > 220 cm/s, or decreased peak annular early diastolic velocity in tissue Doppler imaging. Blood was sampled at the baseline for measurement of inflammation markers, including tissue necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Subjects with LV diastolic dysfunction had higher proinflammation cytokines levels in both groups. Inflamed markers correlated significantly with echocardiography parameters for LV diastolic dysfunction in patients receiving CAPD. In a multivariate regression analysis adjusting for all the factors associated with LV diastolic dysfunction, inflammation is still significantly associated with left ventricular diastolic dysfunction (TNF-alpha, OR: 2.6, 95% CI: 2.0-3.35, p < 0.001; IL-6, OR: 1.26, 95% CI: 1.25-1.26, p = 0.01). In addition, the interaction of CAPD and inflammation significantly contributed to the development of LV diastolic dysfunction (CAPD∗ TNF-α: OR: 1.45, 95% CI: 1.13-1.79, P = 0.004).

CONCLUSION

We found inflammation plays a vital role for LV diastolic dysfunction especially in CAPD patients. A synergistic effect between CAPD and inflammation, especially TNF-α, would further aggravate LV diastolic dysfunction.

Volume status in peritoneal dialysis

Fluid homeostasis is one of the fundamental roles of the kidney and a crucial aspect in clinical management of patients on peritoneal dialysis (PD). Volume status has an important impact on the outcome of PD patients. Fluid excess leads to accelerated development of cardiovascular disease. Volume status may also impact on disorders and assessment of nutritional state. While ultrafiltration and residual urine volume have featured prominently in PD research, the importance of fluid intake and thirst in PD patients has received relatively little attention. Despite older studies suggesting that fluid overload is common in PD, current PD techniques can produce sufficient fluid removal to achieve good control of fluid, with associated cardiac benefits in PD patients. One of the major challenges is to apply these techniques to obtain ideal volume status in patients. Bioelectrical impedance analysis appears to be the most promising technique currently available to guide fluid management.

Time-dependent associations between total sodium removal and mortality in patients on peritoneal dialysis

PURPOSE

To determine if the time-dependent association between total sodium removal and mortality in patients on continuous ambulatory peritoneal dialysis (CAPD) is confounded by markers of diet and nutrition.

METHODS

The study enrolled 305 incident patients who started CAPD between July 2002 and February 2007. All patients were followed until death or censoring in February 2008. Demographics, blood pressure, and markers of volume and inflammation were collected at baseline. Biochemistry, fluid and solute removal, and diet and nutrition parameters were collected quarterly and thus calculated as time-averaged values.

RESULTS

Mean age of the study patients was 59.4 years, 42.3% were men, and 40.3% had diabetes. During the 31.4-month follow-up, 74 patients died. The time-averaged daily total sodium removal (TSR) in the overall cohort was 2.67 g (range: 2.02 g-3.47 g). Participants with a high time-averaged TSR tended to experience higher fluid, sodium, urea, and creatinine removal, mainly as a result of better residual renal function (RRF). They also had a higher nutrient intake and a higher lean body mass. Time-dependent TSR was an independent predictor of death, including when adjusted for age, Charlson index, time-dependent hemoglobin, RRF, and peritoneal transport rate (hazard ratio: 0.84; 95% confidence interval: 0.70 to 1.00; p=0.05), but the predictive effect disappeared in multivariate models after further individual adjustment for time-dependent total energy intake, total protein intake, serum albumin, and lean body mass. By contrast, the predictive effect did not disappear if the only adjustment was for time-dependent RRF.

CONCLUSIONS

The time-dependent association between TSR and mortality in patients on peritoneal dialysis can be largely explained by diet and nutrition parameters.

Relevância do estado de hidratação na interpretação de parâmetros nutricionais em diálise peritoneal

OBJETIVO: Identificar determinantes do estado de hidratação de pacientes em diálise peritoneal crônica, bem como investigar os efeitos da sobrecarga líquida sobre o estado nutricional. MÉTODOS: Foi feito estudo transversal, realizado em 2006, avaliando 27 pacientes em diálise peritoneal crônica, acompanhados no Hospital das Clínicas da Faculdade de Medicina de Botucatu (SP), quanto a parâmetros clínicos, dialíticos, laboratoriais, antropométricos e de bioimpedância elétrica. Para avaliar a influência de parâmetros sobre o estado de hidratação empregou-se modelo de regressão linear múltipla. A amostra foi estratificada quanto ao estado de hidratação pela relação entre água extracelular e água corporal total (0,47 para homens e 0,52 para mulheres), parâmetros obtidos por meio de bioimpedância elétrica. Comparações foram realizadas por análise de covariância, Mann-Whitney, Qui-quadrado ou teste exato de Fisher. Considerou-se significância estatística quando p≤0,05. RESULTADOS: Pacientes com maior volume urinário e em modalidade dialítica automatizada apresentaram melhor estado de hidratação. Pacientes com maior sobrecarga líquida, comparados àqueles com menor sobrecarga, apresentaram menor ângulo de fase (M=4,2, DP=0,9 vs M=5,7, DP=0,7º; p=0,006), menor albumina (M=3,06, DP=0,46 vs M=3,55, DP=0,52g/dL; p=0,05) e maior % prega cutânea tricipital (M=75,3, DP=36,9 vs M=92,1, DP=56,9%; p=0,058), sem outras evidências antropométricas. CONCLUSÃO: Pode-se sugerir que os níveis reduzidos de albumina e ângulo de fase nos pacientes com maior sobrecarga líquida não estiveram relacionados a pior estado nutricional. Para o diagnóstico nutricional em vigência de sobrecarga líquida, deve-se considerar o conjunto de variáveis obtidas por diversos métodos, buscando relacioná-las e interpretá-las de maneira abrangente, possibilitando um diagnóstico nutricional fidedigno.

Plasma volume, albumin, and fluid status in peritoneal dialysis patients

BACKGROUND AND OBJECTIVES

Peritoneal dialysis (PD) patients may be overhydrated especially when inflammation is present. We hypothesized that patients with a plasma albumin below the median value would have measurable overhydration without a proportional increase in plasma volume (PV).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We investigated a cross-sectional sample of 46 prevalent PD patients powered to detect a proportional increase in PV associated with whole body overhydration and hypoalbuminemia. PV was determined from (125)I-labeled albumin dilution, absolute total body water from D dilution (TBW(D)), and relative hydration from multifrequency bioimpedance analysis (BIA; Xitron 4200) expressed as the extracellular water (ECW):TBW(BIA) ratio.

RESULTS

Whereas patients with plasma albumin below the median (31.4 g/dl) were overhydrated as determined both by BIA alone (ECW:TBW(BIA) 0.49 versus 0.47, P < 0.036) and the difference between estimated TBW(BIA) and measured TBW(D) (3.55 versus 0.94 L, P = 0.012), corrected PV was not different (1463 versus 1482 ml/m(2), NS). Mean PV was not different from predicted, and its variance did not correlate with any other clinical measures. Multivariate analysis showed that the only independent predictor of whole body overhydration was reduced plasma albumin.

CONCLUSIONS

Hypoalbuminemia is an important determinant of tissue overhydration in PD patients. This overhydration is not associated with an increased plasma volume. Attempts to normalize the ECW:TBW ratio in hypoalbuminemic, inflamed PD patients may lead to hypovolemia and loss of residual renal function.

Comparison of fluid status in patients treated by different modalities of peritoneal dialysis using multi-frequency bioimpedance

BACKGROUND AND AIMS

Patients treated by peritoneal dialysis, especially those using automatic cyclers, are frequently found to be hypervolemic. To determine whether there are significant differences between the currently available modalities of peritoneal dialysis, we analyzed whether differences in transporter status and treatment modality had a discernible effect on extracellular fluid volumes as measured by multi-frequency bioimpedance.

METHODS

Two hundred prevalent peritoneal dialysis patients, 48% male, mean age 54.9 yr (SD+/-15.6), were studied using multi-frequency bioimpedance following a standard peritoneal equilibration test; 63 patients were treated by CAPD, 29 by APD, 96 by CCPD and 12 by OCCPD.

RESULTS

There were no differences in extracellular volumes, or extracellular volume adjusted for height, or as a ratio to total body water between the groups. As expected, extracellular volume adjusted for height depended upon bodyweight (r=0.412, p<0.001), sex (r=0.457, p<0.001) and systolic blood pressure (r=0.162, p=0.023), and extracellular volume to total body water related to the reciprocal of total daily peritoneal ultrafiltration losses (r=-0.0254, p=0.003) and urine output (-0.254, p=0.003). More importantly, on logistical regression analysis the ratio of extracellular fluid to total body fluid increased with falling albumin, F=21.5 p<0.001, increasing age, F=18.5 p<0.001, urine output F=6.46, p=0.014, total daily ultrafiltration, F=3.52 and protein intake p=0.003. Extracellular fluid adjusted for total body fluid was associated with CRP (males F=6.03, p=0.03, females F=4.438, p=0.04).

CONCLUSION

Patients were more likely to have an expanded extracellular fluid volume if they had reduced daily fluid losses, but also with biomarkers typically associated with poor nutrition and inflammation.

Low dietary sodium intake increases the death risk in peritoneal dialysis

BACKGROUND AND OBJECTIVES

To explore the correlation between dietary sodium intake and cardiovascular and overall mortality, and then determine whether this correlation can be explained by protein and energy intake paralleled with sodium intake in dialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This single-center retrospective cohort study enrolled 305 incident patients who started peritoneal dialysis in our unit from July 2002 to February 2007. All patients were followed until death or until being censored in February 2008. Demographic data were collected at baseline. Biochemical, dietary, and nutrition data were examined at baseline and thereafter at regular intervals to calculate the average values throughout the study.

RESULTS

Participants with the highest average sodium intake were more likely to be younger, male, and overweight. Patients in the high tertile of average sodium intake had higher albumin, prealbumin, and lean body mass levels, and more nutrient intakes paralleling with sodium intake. Low average sodium intake independently predicted the increased risk for overall and cardiovascular death after adjusting for recognized confounders. Further adjustment for dietary protein, energy, and other nutrient intakes individually had minimal impact on the association between average sodium intake and overall death, with hazard ratios varying between 0.35 and 0.44, and cardiovascular death, with hazard ratios varying between 0.06 and 0.11.

CONCLUSIONS

This study revealed that low dietary sodium intake independently predicts the high overall and cardiovascular mortality in dialysis patients. This correlation could not be entirely explained by deficient protein and energy intake.

Comparison of volume overload with cycler-assisted versus continuous ambulatory peritoneal dialysis

BACKGROUND AND OBJECTIVES

Cycler-assisted peritoneal dialysis (CCPD) has been associated with decreased sodium removal compared with continuous ambulatory peritoneal dialysis (CAPD) as a result of peritoneal sodium sieving during the short dwells that are associated with CCPD. This may have adverse consequences for management of extracellular fluid volume (ECFV). This study compared ECFV in patients who received CAPD or CCPD; CCPD dwell times were maximized by limiting the number of exchanges, and the use of icodextrin for the long daytime dwells was widespread.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was an observational, cross-sectional study of 158 prevalent patients (90 CAPD, 68 CCPD). Demographic data, blood work, and 24-h dialysate and urine samples were collected from all participants between January 2004 and July 2006. They subsequently underwent assessment of ECFV by multifrequency bioimpedance spectroscopy analysis. Multivariate analysis was used to determine the relationship between peritoneal dialysis modality and ECFV. Potential cofounders including age, comorbidity, time on dialysis, residual renal function, and icodextrin use were identified a priori.

RESULTS

There were no differences in BP, use of antihypertensive medications, or the presence of peripheral edema between CAPD and CCPD patients. Similarly, there was no difference in the ratio of ECFV to total body water between CAPD (51.8%) and CCPD (51.9%) patients (P = 0.929).

CONCLUSIONS

There is no difference in BP, sodium removal, or volume control in patients who use a contemporary approach to CCPD that uses fewer night cycles and liberalizes the use of icodextrin when compared with CAPD.

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.