Postdialysis Body Weight Research Articles

Predictors for Unsuccessful Reductions in Hemodialysis Frequency during the Pandemic

Patients receiving in-center hemodialysis are at a high risk of coronavirus disease 2019 (COVID-19) infection. A reduction in hemodialysis frequency is one of the proposed measures for preventing COVID-19 infection. However, the predictors for determining an unsuccessful reduction in hemodialysis frequency are still lacking. This retrospective observational study enrolled patients who were receiving long-term thrice-weekly hemodialysis at the Thammasat University Hospital in 2021 and who decreased their dialysis frequency to twice weekly during the COVID-19 outbreak. The outcomes were to determine the predictors and a prediction model of unsuccessful reduction in dialysis frequency at 4 weeks. Bootstrapping was performed for the purposes of internal validation. Of the 161 patients, 83 patients achieved a dialysis frequency reduction. Further, 33% and 82% of the patients failed to reduce their dialysis frequency at 4 and 8 weeks, respectively. The predictors for unsuccessful reduction were diabetes, congestive heart failure (CHF), pre-dialysis overhydration, set dry weight (DW), DW from bioelectrical impedance analysis, and the mean pre- and post-dialysis body weight. The final model including these predictors demonstrated an AUROC of 0.763 (95% CI 0.654-0.866) for the prediction of an unsuccessful reduction. The prediction score involving diabetes, CHF, pre-dialysis overhydration, DW difference, and net ultrafiltration demonstrated a good performance in predicting an unsuccessful reduction in hemodialysis frequency at 4 weeks.

Factors Associated with Symptom Burden in Adults with Chronic Kidney Disease Undergoing Hemodialysis: A Prospective Study.

People with end stage renal disease and undergoing hemodialysis experience a high symptom burden that impairs quality of life. This study aimed to assess the prevalence, dynamicity and determinants of symptom burden among middle-aged and older adult hemodialysis patients. A descriptive cross-sectional study together with a longitudinal assessment was used. A total of 118 and 102 hemodialysis patients were assessed at baseline and at a 6-month follow-up. Validated questionnaires were used to assess the symptom burden, stress, illness perception and social support. Multiple linear regression analysis was used to determine the factors associated with symptom burden. The median number of symptoms experienced was 21 (Interquartile Range (IQR); 18–23) and 19 (IQR; 13–22) at baseline and 6 months, respectively. Having elevated stress (β = 0.65, p ≤ 0.005) and illness perception (β = 0.21, p = 0.02) were significantly predicted symptom burden at baseline (F (4, 112) = 55.29, p < 0.005, R2 = 0.664). Stress (β = 0.28, p = 0.003), illness perception (β = 0.2, p = 0.03), poor social support (β = −0.22, p = 0.01) and low body weight (β = −0.19, p = 0.03) were the determinants for symptom burden at 6 months (F (5, 93) = 4.85, p ≤ 0.005, R2 = 0.24). Elevated stress, illness perception level, poor social support and low post-dialysis body weight were found to be determinants for symptom burden. Attention should be given to psychosocial factors of hemodialysis patients while conducting assessment and delivering care to patients.

MO656CORRELATION BETWEEN CHANGES IN THE BODY FLUID VOLUME CALCULATED BY THE URIC ACID KINETIC MODEL AND CHANGES IN THE BODY WEIGHT*

Abstract Background and Aims Uric acid (UA) is a solute unable to cross the cell membranes in general tissues by any of simple diffusion, facilitated diffusion or active transport. These facts imply that UA distribution volume (UDiV) equals to the extracellular fluid volume (ECFV). We have developed a method for calculating UDiV from serum uric acid levels before and after hemodialysis based on a uric acid kinetic model (Shinzato T, Int J Artif Organs 2020). Urea is evenly distributed throughout the body fluids. Therefore, the total body fluid volume (TBFV) can be calculated by using the same method as the calculation of UDiV for the serum urea level. The remaining body fluid volume, which is TBFV minus UDiV, is considered to reflect the intracellular fluid volume (ICFV). In this study, we clarified the relationship between the amount of change over time in UDiV and ICFV calculated by the uric acid kinetic model and the amount of change over time in the actual body weight of hemodialysis patients. Method Subjects were 1,101 patients with chronic maintenance hemodialysis. UDiV and ICFV before and after dialysis were calculated for two time points, December 2019 and June 2020. Results The amount of change in UDiV per body during the dialysis session showed a very good correlation with the amount of body weight change during the same dialysis (UDiV change = 0.950 x body weight change - 0.158, R-square 0.90, p &amp;lt; 0.0001). The amount of change in ICFV during the 6 months from December 2019 to June 2020 showed a good correlation with the amount of change in post-dialysis body weight during the same period (ICFV change = 0.270 x post-dialysis body weight change + 0. 240, R-square 0.21, p &amp;lt;0.0001). Conclusion These results suggest that the body fluid volume calculated by the uric acid kinetic model has high accuracy.

A faster decline of residual kidney function and erythropoietin stimulating agent hyporesponsiveness in incident hemodialysis patients.

Erythropoietin stimulating agents (ESA) hyporesposiveness has been associated with increased mortality in hemodialysis (HD) patients. However, the impact of decline of residual kidney function (RKF) on ESA hyporesposiveness has not been adequately elucidated among patients receiving HD. The associations of RKF decline with erythropoietin resistance index (ERI; average weekly ESA dose [units])/post-dialysis body weight [kg]/hemoglobin [g/dL]) were retrospectively examined across four strata of annual change in RKF (residual renal urea clearance [KRU] < -3.0, -3.0 to <-1.5, -1.5 to <0, ≥0 mL/min/1.73 m2 per year; urinary volume < -600, -600 to<-300, -300 to <0, ≥0 mL/day per year) using logistic regression models adjusted for clinical characteristics and laboratory variables in 5239 incident HD patients in a large US dialysis organization between 1 January 2007 and 31 December 2011. The median values of the annual change in KRU and urinary volume were -1.2 (interquartile range [IQR]: -2.8 to 0.1) mL/min/1.73 m2 per year and -250 (IQR: -600 to 100) mL/day per year. A faster KRU decline in the first year of HD was associated with higher odds for ESA hyporesponsiveness: KRU decline of <-3.0, -3.0 to <-1.5, and -1.5 to <0/min/1.73 m2 per year were associated with adjusted odds ratios (OR) of 2.07 (95% confidence interval [CI]: 1.66-2.58), 1.54 (95%CI: 1.28-1.85), and 1.26 (95%CI: 1.07-1.49), respectively (reference: ≥0 mL/min/1.73 m2 per year). These associations were consistent across strata of baseline KRU, age, sex, race, diabetes, congestive heart failure, hemoglobin, and serum albumin. Sensitivity analyses using urinary volume as another index of RKF showed consistent associations. A faster RKF decline during the first year of dialysis was associated with ESA hyporesponsiveness and low hemoglobin levels among incident HD patients.

Effects of dialysate to serum sodium (Na+) alignment in chronic hemodialysis (HD) patients: retrospective cohort study from a quality improvement project

BackgroundEvidence indicates favorable effects of dialysate (DNa+) to serum sodium concentration (SNa+) alignment, however, results from larger sample populations are needed. For this reason, we conducted a retrospective propensity score-matched cohort study from a quality improvement project to investigate the effects of alignment on population of maintenance hemodialysis patients.MethodsAt 4 participating hemodialysis (HD) clinics, patients with SNa+ lower than the standard DNa+ of 137 mEq/L who received HD with DNa+ aligned to the average of the last 4 SNa+ measurements were evaluated (clinicaltrials.gov #NCT01825590). In this retrospective data analysis, an intention-to-treat (primary) and an as-treated “intervention” (secondary) cohort were created. “Aligned” patients from both cohorts (N = 163 for the primary and N = 137 for the secondary) were then propensity-score matched in a 1:1 fashion to “unaligned” patients from the Renal Research Institute database. The propensity score was generated based on age, gender, white race, Hispanic ethnicity, absence or presence of diabetes, hemodialysis vintage, interdialytic weight gain (IDWG; as a percentage of postdialysis body weight), catheter as primary dialysis access, predialysis systolic blood pressure, serum sodium concentration, hospitalization count during baseline. T-Test was employed for group comparisons of changes to the primary (volume-related and hemodynamic parameters) and tertiary outcomes. All-cause and fluid overload-related hospitalization admission rates were compared using Wilcoxon Rank Sum test and Cox regression analysis for repeated events.ResultsIn the primary analysis, aligned and unaligned subjects showed comparable demographics at baseline. Treatment effects were significant for IDWG [−0.12 (95% CI −0.24 to 0) L] and showed decreasing non-significant trends for pre-dialysis hemodynamic parameters. Count comparison and Cox regression analysis showed no clear advantage of alignment in terms of all-cause and fluid overload-related hospitalization.ConclusionsResults from the largest sodium alignment program to date suggest positive treatment effects on volume-related and hemodynamic parameters, but no clear effect on risk of hospitalization. Well-matched control patients minimized confounding effects. Small effects and lack of significant differences may be explained by a low baseline DNa+ limiting the interventional change.

Effects of Oral Nutritional Supplements on Mortality, Missed Dialysis Treatments, and Nutritional Markers in Hemodialysis Patients

Protein-energy wasting is common in end-stage renal disease patients undergoing dialysis and is strongly associated with mortality and adverse outcomes. Intradialytic oral nutritional supplements (ONS) reduce risk of mortality in these patients. Large studies characterizing the impact of ONS on other outcomes are lacking. We assessed the associations between administration of ONS and clinical and nutritional outcomes. Retrospective evaluation of a pilot program providing ONS to patients at a large dialysis organization in the United States. The pilot program provided ONS to in-center hemodialysis patients with serum albumin ≤3.5g/dL at 408 facilities. ONS patients were compared to matched controls with serum albumin ≤3.5g/dL, identified from facilities not participating in the ONS program (n=3,374 per group). Receipt of ONS. Death, missed dialysis treatments, hospitalizations, serum albumin, normalized protein catabolic rate, and postdialysis body weight were abstracted from large dialysis organization electronic medical records. There was a 69% reduction in deaths (hazard ratio=0.31; 95% confidence interval=0.25-0.39), and 33% fewer missed dialysis treatments (incidence rate ratio=0.77; 95% confidence interval=0.73-0.82) among ONS patients compared to controls (P<.001 for both). The effects of ONS on nutritional indices were mixed: serum albumin was lower, whereas normalized protein catabolic rate values, a surrogate for dietary protein intake, and postdialysis body weights were higher for ONS patients compared to controls during follow-up. Our evaluation confirmed the beneficial effects of ONS in reducing mortality and improving some indices of nutritional status for hypoalbuminemic hemodialysis patients. We also report the novel finding that ONS can reduce the number of missed dialysis treatments. These results support the use of intradialytic ONS as an effective intervention to improve the outcomes in hemodialysis patients with low serum albumin.

Interplay of volume, blood pressure, organ ischemia, residual renal function, and diet: certainties and uncertainties with dialytic management.

Extracellular fluid volume overload and its inevitable consequence, hypertension, increases cardiovascular mortality in the long term by leading to left ventricular hypertrophy, heart failure, and ischemic heart disease in dialysis patients. Unlike antihypertensive medications, a strict volume control strategy provides optimal blood pressure control without need for antihypertensive drugs. However, utilization of this strategy has remained limited because of several factors, including the absence of a gold standard method to assess volume status, difficulties in reducing extracellular fluid volume, and safety concerns associated with reduction of extracellular volume. These include intradialytic hypotension; ischemia of heart, brain, and gut; loss of residual renal function; and vascular access thrombosis. Comprehensibly, physicians are hesitant to follow strict volume control policy because of these safety concerns. Current data, however, suggest that a high ultrafiltration rate rather than the reduction in excess volume is related to these complications. Restriction of dietary salt intake, increased frequency, and/or duration of hemodialysis sessions or addition of temporary extra sessions during the process of gradually reducing postdialysis body weight in conventional hemodialysis and discontinuation of antihypertensive medications may prevent these complications. We believe that even if an unwanted effect occurs while gradually reaching euvolemia, this is likely to be counterbalanced by favorable cardiovascular outcomes such as regression of left ventricular hypertrophy, prevention of heart failure, and, ultimately, cardiovascular mortality as a result of the eventual achievement of normal extracellular fluid volume and blood pressure over the long term.

Brain Natriuretic Peptide Is a Marker of Fluid Overload in Incident Hemodialysis Patients

Background/Aims: Brain natriuretic peptide (BNP) is secreted by cardiomyocytes under stretch condition. High blood levels are associated with decreased patient survival in heart failure patients and in hemodialysis (HD) patients. We report the monthly BNP change in the first months of HD therapy in incident patients and its relationship with fluid removal and cardiac history (CH). Methods: All patients starting HD therapy in our unit from May 2008 to December 2012 were retrospectively analyzed. Every month (M1 to M6), BNP was assessed before a midweek dialysis session. CH, monthly pre- and postdialysis blood pressure, and postdialysis body weight were collected. Results: A total of 236 patients were included in the analysis. The median BNP at HD start was 593 (175-1,433) pg/mL, with a significant difference between CH- and CH+ patients (291 vs. 731 pg/mL, p < 0.0001). Mortality was significantly higher in patients in the higher BNP tertile. BNP decreased significantly between M1 and M2 and then plateaued. The BNP change between M1 and M2 and between M1 and M6 was significantly correlated with the initial fluid removal. Applying stepwise multiple regression, the BNP change between M1 and M2 was significantly and independently related to fluid removal. The BNP level at M6 was also related to patient survival. Conclusions: We confirm that in incident HD patients, BNP level is related to fluid excess and cardiac status. The BNP decrease in the first months of HD therapy is related to fluid excess correction. BNP appears as an important tool to evaluate hydration status correction after HD onset.

Efficacy of hemocontrol biofeedback system in intradialytic hypotension-prone hemodialysis patients.

We conducted a study to determine whether the hemocontrol biofeedback system (HBS) can improve intradialytic hypotension (IDH) in hypotension-prone hemodialysis (HD) patients compared with conventional HD. In this multicenter prospective crossover study, 60 hypotension-prone patients were serially treated by conventional HD for 8 weeks (period A), by HD with hemoscan blood volume monitoring for 2 weeks (period B0), and by HBS HD for 8 weeks (period B1). The number of sessions complicated by symptomatic IDH during 24 HD sessions (14.9 ± 5.8 sessions, 62.1% in period A vs 9.2 ± 7.2 sessions, 38.4% in period B1, P<0.001) and the number of IDH-related nursing interventions in a session (0.96 ± 0.66 in period A vs 0.56 ± 0.54 in period B1, P<0.001) significantly decreased in period B1 than in period A. Recovery time from fatigue after dialysis was significantly shorter in period B1 than in period A. The patients with higher post-dialysis blood pressure, lower difference between pre- and post-dialysis blood pressure, less frequent IDH, and higher pre- and post-dialysis body weight in period A responded better to HBS in period B1 in regard to the reduction of IDH. In conclusion, HBS may improve the patient tolerability to HD by reducing the IDH frequency and promoting faster recovery from fatigue after dialysis.

Determinants of phosphorus mobilization during hemodialysis

Our recent work proposed a pseudo one-compartment model for describing intradialysis and postdialysis rebound kinetics of phosphorus. In this model, phosphorus is removed directly from a central distribution volume with the rate of phosphorus mobilization from a second, very large compartment proportional to the phosphorus mobilization clearance. Here, we evaluated factors of phosphorus mobilization clearance and postdialysis central distribution volume from 774 patients in the HEMO Study. Phosphorus mobilization clearance and postdialysis central distribution volume were 87 (65, 116) ml/min, median (interquartile range), and 9.4 (7.2, 12.0) liter, respectively. The phosphorus mobilization clearance was significantly higher for male patients than for female patients. Both the phosphorus mobilization clearance and the postdialysis central distribution volume were significantly associated with postdialysis body weight but negatively with the predialysis serum phosphorus concentration. The postdialysis central distribution volume was also significantly associated with age. Overall, the postdialysis central distribution volume was 13.6% of the postdialysis body weight. Thus, the phosphorus mobilization clearance during hemodialysis is higher when predialysis serum phosphorus concentration is low and higher in male patients than in female patients. The central distribution volume of phosphorus is a space approximating the extracellular fluid volume.

Anticoagulation With Fondaparinux for Hemodiafiltration in Patients With Heparin‐Induced Thrombocytopenia: Dose‐Finding Study and Safety Evaluation

The optimal anticoagulation regimen for hemodialysis (HD) in patients with heparin-induced thrombocytopenia (HIT) has not been defined. Hemodiafiltration (HDF) adds a large convective component to HD, thereby changing the pharmacokinetics of most anticoagulants. Data on coagulation regimens for HDF are scant. We therefore aimed to study the feasibility, effectiveness, tolerability, and pharmacokinetics of fondaparinux anticoagulation in HDF. This was a prospective observational dose-finding study. Patients were started on fondaparinux at a dose of 0.05 mg/kg postdialysis body weight. Per protocol dose escalation was performed when significant clotting was observed and reduced when the anti-Xa activity postdialysis exceeded 0.4 IU/mL. Dose adjustments were made by steps of 0.01 mg/kg postdialysis weight. Anti-Xa activity was measured using a chromogenic method calibrated with low-molecular-weight heparin and validated against fondaparinux-calibrated anti-Xa activity. Four patients with HIT were followed for 160 sessions in total. At the end of the dose titration study, three patients ended at a maintenance dose of 0.03 mg/kg and one patient at 0.04 mg/kg of fondaparinux. Significant bleeding attributable to fondaparinux did not occur. The occurrence of clotting increased parallel to the reduction of fondaparinux dose, from 0/53 and 0/15 sessions at the higher doses (0.04 and 0.05 mg/kg) to 3/75 (4%) at 0.03 mg/kg and 1/17 (6%) at 0.02 mg/kg. Fondaparinux may be safely used and provides adequate anticoagulation for HDF in patients with HIT. We recommend to adjust dosage of fondaparinux to body weight and to initiate therapy at a dose of 0.03 mg/kg to prevent accumulation. Dose titration can be achieved by targeting postdialysis anti-Xa activity.

The effect of frequent hemodialysis on nutrition and body composition: Frequent Hemodialysis Network Trial

We investigated the effects of frequency of hemodialysis on nutritional status by analyzing the data in the Frequent Hemodialysis Network Trial. We compared changes in albumin, body weight and composition among 245 patients randomized to 6- or 3-times per week in-center hemodialysis (Daily Trial) and 87 patients randomized to 6-times per week nocturnal or 3-times per week conventional hemodialysis, performed largely at home (Nocturnal Trial). In the Daily Trial, there were no significant differences between groups in changes in serum albumin or the equilibrated protein catabolic rate by 12 months. There was a significant relative decrease in pre-dialysis body weight of 1.5 ± 0.2 kg in the 6 times per week group at one month, but this significantly rebounded by 1.3 ± 0.5 kg over the remaining 11 months. Extracellular water decreased in the 6 times per week compared to the 3 per week hemodialysis group. There were no significant between-group differences in phase angle, intracellular water or body cell mass. In the Nocturnal Trial, there were no significant between-group differences in any study parameter. Any gain in “dry” body weight corresponded to increased adiposity rather than muscle mass but was not statistically significant. Thus, frequent in-center hemodialysis reduced extracellular water but did not increase serum albumin or body cell mass while frequent nocturnal hemodialysis yielded no net effect on parameters of nutritional status or body composition.

PROTEIN CATABOLIC RATE SHOULD BE NORMALIZED BY IDEAL BODY WEIGHT NOT BY POST-DIALYSIS BODY WEIGHT.

Protein catabolic rate (PCR) is calculated by urea kinetic model thorough the dialysis session and it is recognized as expressing the protein intake in the steady state of dialysis patients. PCR is generally normalized by post-dialysis body weight (BW), expressed as nPCR, however, most dietary guidelines for protein intake are documented as PCR normalized by ideal BW (iPCR). We evaluated which is better nPCR or iPCR to estimate the impact on the patient survival and to use it for dietary education for dialysis patients. 119 chronic dialysis patients whose dialysis vintages were longer than 3 years were selected into this study. The mean age of them was 62.4years old and the mean dialysis vintage was 115.4 months. The patients were divided into 4 groups by each PCR value as less than 0.7, 0.7– 0.9, 0.9–1.1, greater than 1.1 g/Kg/day. Kaplan-Meier analysis was conducted to evaluate the 5–year patient survival in each PCR method. The difference in the patient survival between 4 groups in each PCR method was evaluated by Log-rank test. Among 119 patients 30 patients died and 9 patients were censored out, and the overall 5-year survival rate was 74.4%. There were no significant differences between 4 groups in nPCR. However, a significant risk in the group less than 0.7 g/Kg/day and a significant benefit in the group greater than 1.1 g/Kg/day were observed in iPCR. Both nPCR and iPCR were not independent significant risk factor on the patient survival. Only age and the serum level of CRP were significant risk factor. We concluded the PCR should be normalized by ideal BW not by post-dialysis BW.

Pioglitazone improves insulin sensitivity, reduces visceral fat and stimulates lipolysis in non diabetic dialyzed patients

Insulin resistance is common in dialyzed patients and is associated with increased mortality and protein-energy wasting. The aim of this study was to investigate the effect of pioglitazone (PIO), a powerful insulin sensitizer, on insulin sensitivity, body composition and adipose tissue metabolism, in dialyzed patients. A double blind randomized cross-over study was performed in non diabetic dialysis patients. Each patient followed 2 treatment phases of 16 weeks, starting either with oral PIO 45 mg/d or placebo (PL), and then switched to the other phase. At the end of each phase, patients underwent hyperinsulinemic euglycemic clamps, dual energy X-ray absorptiometry, an abdominal CT, and extensive plasma biochemical analysis. Twelve patients including 8 HD (59.6±4.4 y) and 4 PD patients (43.5±3.6 y) were recruited. Nine patients completed both phases and 3 patients dropped out (renal transplantation/2 HD and peritonitis/1 PD). PIO was safe and well tolerated. Under PIO, insulin sensitivity improved, as assessed by increased total glucose disposal rate (1.98±0.24 for PIO versus 1.58±0.12 umol/kg/min for PL, p<0.05), and reduced glucose endogenous hepatic production. PIO did not affect post-dialysis body weight, total fat and lean body mass, but significantly reduced visceral adipose tissue (VAT) area and the VAT/SAT (subcutaneous adipose tissue) ratio. HDL-cholesterol significantly increased. PIO decreased CRP (3.96±1.44 mg/l vs 7.88±2.56, p<0.05), plasma leptin, and dramatically reduced leptin/adiponectin ratio. Glycerol turnover, circulating glycerol and non esterified fatty acids were paradoxically increased. In conclusion, the improvement in insulin sensitivity by PIO, in non diabetic dialyzed patients, was associated with favorable metabolic effects, reduction in inflammation and body fat redistribution. The stimulation of systemic lipolysis was a surprising finding which may reflect adipose tissue remodeling and/or a paradoxical lypolitic effect of PIO in this population.

Predialysis Systolic Blood Pressure Evolution in Incident Hemodialysis Patients: Effects of the Dry Weight Method and Prognostic Value

Background: The relationship between predialysis blood pressure (BP) and hemodialysis (HD) patient outcomes is controversial. We report the evolution of predialysis BP in incident patients treated with the dry weight method and its relationship with patients’ outcomes. Methods: Between January 2000 and 2009, 308 patients started HD treatment. Fluid was progressively removed. The patients were encouraged to accept long-hour dialysis session and to follow a salt-restricted diet. BP and body weight (BW) were recorded and analyzed at start (week 1, W1) and weeks 8, 12, 26 and 52. Results: The predialysis systolic BP decreased from 142.1 at W1 to 130.7 mm Hg at W52. Postdialysis BW decreased from W1 to W8 (–5.0 ± 4.5%). It was correlated with the decrease of the predialysis systolic BP at W26 and W52. Whereas the patient survival was significantly lower in the lower predialysis systolic BP tertile at W1 like in previous reports calling this phenomenon ‘reverse epidemiology’, no relationship between predialysis BP levels and outcomes was found at W12, W26 and W52. The patients in the tertile of the greater predialysis systolic BP decrease at W12 had significantly better survival in the whole group and in hypertensive patients. This relationship remained significant in the Cox proportional-hazards analysis. Conclusions: Hence the dry weight method is efficient in decreasing the predialysis BP in incident HD patients. The initial BW decrease was correlated with BP decrease at W26 and W52. Early correction of BP by fluid removal erases the reverse epidemiology for BP and influences positively the patient survival.

Relation between serum estradiol levels and mortality in postmenopausal female hemodialysis patients

Recently, low serum estradiol levels have been associated with increased cardiovascular risk and mortality in non-uremic patient populations. We investigated the predictive value of serum estradiol levels for mortality in female hemodialysis patients. One hundred and forty-seven prevalent female hemodialysis patients were included in March 2005 and followed up for 32 ± 16 months. Serum estradiol levels were determined by ELISA at baseline and studied in relation to cardiovascular and overall mortality. Mean serum estradiol level was 28.6 ± 15.4 pg/ml (5.7-81.3). Patients in the higher estradiol tertile were likely to be more often diabetic and to have more cardiovascular diseases and higher body mass index (BMI). Serum estradiol was inversely correlated with age and urea reduction rate and positively correlated with postdialysis body weight, BMI and hs-CRP levels. During the follow-up period, 52 (35.6 %) patients died. Patients who died were older, had shorter dialysis vintage, were more likely to have a history of diabetes and cardiovascular disease, and lower serum creatinine, albumin, hemoglobin, and higher hs-CRP levels than those who survived. In Cox regression analysis, estradiol levels, in a bimodal (U-shaped) distribution, along with diabetes, low serum albumin and high hs-CRP levels, were predictors for overall mortality. A U-shaped association between serum estradiol levels and cardiovascular and overall mortality was found in postmenopausal hemodialysis patients.

PlasmaBNP, a useful marker of fluid overload in hospitalized hemodialysis patients

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

Fluid overload correction and cardiac history influence brain natriuretic peptide evolution in incident haemodialysis patients

Brain natriuretic peptide (BNP) is a cardiac peptide secreted by ventricle myocardial cells under stretch constraint. Increased BNP has been shown associated with increased mortality in end-stage renal disease patients. In patients starting haemodialysis (HD), both fluid overload and cardiac history are frequently present and may be responsible for a high BNP plasma level. We report in this study the evolution of BNP levels in incident HD patients, its relationship with fluid removal and cardiac history as well as its prognostic value. Forty-six patients (female/male: 21/25; 68.6 ± 14.5 years old) surviving at least 6 months after HD treatment onset were retrospectively analysed. Plasma BNP (Chemoluminescent Microparticule ImmunoAssay on i8200 Architect Abbott, Paris, France; normal value < 100 pg/mL) was assessed at HD start and during the second quarter of HD treatment (Q2). At dialysis start, the plasma BNP level was 1041 ± 1178 pg/mL (range: 14-4181 pg/mL). It was correlated with age (P = 0.0017) and was significantly higher in males (P = 0.0017) and in patients with cardiac disease history (P = 0.001). The plasma BNP level at baseline was not related to the mortality risk. At Q2, predialysis systolic blood pressure (BP) decreased from 140.5 ± 24.5 to 129.4 ± 20.6 mmHg (P = 0.0001) and the postdialysis body weight by 7.6 ± 8.4% (P < 0.0001). The BNP level decreased to 631 ± 707 pg/mL (P = 0.01) at Q2. Its variation was significantly correlated with systolic BP decrease (P = 0.006). A high BNP level was found associated with an increased risk of mortality. Hence, plasma BNP levels decreased during the first months of HD treatment during the dry weight quest. Whereas initial BNP values were not associated with increased mortality risk, the BNP level at Q2 was independently predictive of mortality. Hence, BNP is a useful tool to follow patient dehydration after dialysis start. Initial fluid overload may act as a confounding factor for its value as a prognostic marker because of cardiac disease.

Sodium Setpoint and Sodium Gradient: Influence on Plasma Sodium Change and Weight Gain

Background/Aims: In hemodialysis and hemodiafiltration patients, the plasma sodium (PNa) measured before dialysis can be regarded as the sodium setpoint. By the end of dialysis, the PNa typically approximates the prescribed dialysate sodium (DNa), the difference between DNa and PNa being considered the sodium gradient. We determined the relationship between setpoint, gradient and pre- to postdialysis PNa change (delta PNa), and studied associations with dialysis-related variables. Methods: Cohort study. Measurements from 132 patients during 12 consecutive treatments included PNa and DNa concentrations, pre- to postdialysis body weight and predialysis systolic blood pressure. Results: Sodium setpoints were normally distributed (137.9 ± 2.4 mmol/l), DNa prescriptions were non-normally distributed (138.9 ± 1.8 mmol/l). The sodium gradient correlated strongly with delta PNa (r = 0.76, p < 0.001). Both sodium gradient and delta PNa correlated with relative interdialytic weight gain (IDWG; r = 0.25, p = 0.004, and r = 0.44, p < 0.001, respectively), but not with predialysis systolic blood pressure. These correlations were consistent after exclusion of patients with urine volume >500 ml/day and patients undergoing sodium profiling, and increased after exclusion of patients with hemodiafiltration protocols. Predictors for having higher relative IDWG (≧2.8%) were delta PNa concentrations ≧0 mmol/l and younger age. Predictors for having a delta PNa concentration ≧0 mmol/l were lower sodium setpoints, higher DNa prescriptions, use of Nikkiso machines, sodium profiling and younger age. Patients with positive delta PNa despite negative gradients were significantly younger, used more Nikkiso machines and presented with higher IDWG. Conclusion: IDWG correlated with the sodium gradient and more strongly with delta PNa, suggesting the need for studying other outcomes, such as morbidity and mortality.

Hypertension in Hemodialysis. An Overview on Physiopathology and Therapeutic Approach in Adults and Children

Chronic Kidney disease (CKD) patients, particularly those with end stage renal disease (ESRD), are at much higher risk of cardiovascular disease than the general population. Cardiovascular disease is by far the leading cause of morbidity and mortality in dyalisis patients, accounting for almost 40% of hospitalizations and almost 50% of deaths. Hypertension is the single most important factor for the development of cardio and cerebrovascular complications. The etio-pathogenesis of hypertension in dialysis patients is multifactorial, sodium excess and extracellular volume expansion is the major factor in the development of hypertension, however there are other pathogenetic factors that should be con- sidered, such as renin-angiotensin system hyperactivity, increased sympatic activity, altered endothelial cell function, hy- perparathiroidism, and oxidative stress. The most important risk factors are anemia, hypoalbuminemia, chronic inflamma- tion, prothrombotic factors, hyperomocisteinemia, vascular calcification and the traditional factors for cardiovascular risk (age, male gender, diabetes mellitus, dyslipidemia, smoke, physical inactivity, alcohol abuse). Elevated blood pressure is frequent also in children on long term dialysis therapy. Data suggest that uremic factors or fac- tors related to renal replacement therapy may be implicated in the pathogenesis of heart disease in adults and pediatric pa- tients, because cardiovascular survival improves after transplantation. The management of hypertension requires lifestyle modifications and control of volume status, with dietary salt and fluid restriction in combination with reduction of dialysate sodium concentration or with programmed variable-sodium dialy- sis. The relationship between interdialytic weight and blood pressure is incompletely characterized; the dry weight (DW) method relies on the progressive reduction of the postdialysis body weight until blood pressure is normalized. There are several non clinical methods for evaluation DW such as measure the inferior vena cava diameter whit ultrasound, measure blood volume (BV) whit radiolabeled albumin and calculating post-hemodialysis BV from the change in hematocrit. It may exist a lag time of several weeks between the normalization of the extracellular volume and blood pressure. It is re- lated to the correction of the hemodinamic consequences of the extracellular volume overload. The other problems to limit the possibility of correcting adequately volume expansion with dialysis are the use of anti- hypertensive drugs and the aggressive ultrafiltration required by short dialysis times. A possible treatment option for these patients may be increase time hemodialysis with slow, long hemodialysis; short, daily hemodialysis or nocturnal hemo- dialysis. All classes of antihypertensive drugs can be used in dialysis patients, except the diuretics because inefficacy. Angiotensin- converting enzyme (ACE) and Angiotensin T1 receptor antagonist (AT1RA) appear to have the greatest ability to reduce left ventricular mass.