Whole-body Bioimpedance Spectroscopy Research Articles

#2539 Effects of relative blood volume and ultrafiltration volume on pulse wave characteristics during hemodialysis

Abstract Background and Aims Measures of non-invasive pulse wave (PW) analysis can help to assess the status of the central cardiovascular system and to predict clinical outcomes, including morbidity and mortality. During hemodialysis (HD), fluid is extracted from blood. The resulting reduction in relative blood volume (RBV) and collected ultrafiltration volume (UFV) were hypothesized to substantially influence PW characteristics during HD. Volume overload (VO) is common in HD patients and may affect the chance of improving the cardiovascular status of patients during HD. The present study aimed to explore associations between RBV, UFV, VO and a wide range of PW parameters. Method In a single center in Vienna, Austria, 24 patients on maintenance HD underwent four HD sessions each, with whole-body bioimpedance spectroscopy (BIS) before, and automated, cuff-based PW measurements every 15 minutes, RBV- and UFV-monitoring throughout each session. Associations between RBV or UFV as independent variable and 26 different PW characteristics as dependent variables (52 separate models) were tested using confounder-adjusted generalized estimating equations with sandwich estimator and multilevel nested working covariance structure, reporting standardized effect estimates and drop-in-R² to assess variable importance. Sensitivity models including both RBV and UFV as predictors (26 models) were used to assess effects adjusted for confounding and mediation, respectively. The intra-patient correlation between BIS-derived VO and PW parameters at the start of sessions and PW parameter change by end of sessions was assessed using repeated measures correlation analysis. Results Data from 990 PW measurements were available for analysis from an 88% male cohort with median age of 66 years. In half of the PW parameters analyzed, each percent RBV was significantly associated with in summary about 4.3 to 5.7% (95% confidence intervals [CI] 0.9 to 10.46) of the PW parameter's respective standard deviation (SD), negatively so only in heart rate and R-Peak. UFV was negatively associated with a third of PW parameters (effects ranging from −2.5 to −5.47% SD [95% CIs −0.9 to −10.0]), mostly in classical peripheral and central pressures and peripheral resistance. In models including both predictors, RBV overall exhibited greater effect size and variance capture than UFV, except for peripheral resistance. On within-patient level, VO was positively correlated with initial medians of pressure excess (r=0.34, p=0.034), augmentation-index (0.34, p=0.031) and augmentation-pressure (0.32, p=0.042), increase in heart rate (0.32, p=0.04) and decreases in peripheral resistance (0.31, p=0.05), peripheral (systolic: 0.34, p=0.032; diastolic: 0.45, p=0.004; mean: 0.41, p=0.008) and central (diastolic: 0.46, p=0.003) blood pressures during HD. Conclusion The observed PW characteristics were associated with RBV and UFV during HD and may represent modifiable targets for intervention studies. Pressure excess, S-Peak, R-Peak, cardiac and preload parameters were more closely associated with RBV, while classic (especially diastolic) blood pressure parameters, ejection duration and S/D-Ratio were more associated with UFV, in models using both predictors. On average, blood pressure and peripheral resistance tended to decrease less when a patient began HD in a volume-expanded state, which may affect day-to-day feasibility of more classical pressure targets, but perhaps not of other PW parameters. Multiple PW characteristics have previously been shown to be associated with mortality and morbidity and are potential target parameters for future intervention trials. Utilizing RBV modification as an intervention may offer superior precision compared to UFV goals, requiring further studies. PW technology could also be adopted by HD-machine manufacturers at low cost, enabling more precise and individualized treatment options.

#5367 CLINICAL SIGNIFICANCE OF NORMO-HYDRATION STATE IN PERITONEAL DIALYSIS PATIENTS

Abstract Background and Aims The assessment of fluid status in dialysis patients is of paramount importance. Managing persistent volume overload and instability during dialysis is a significant challenge, with concomitant symptomatic and asymptomatic intradialytic hypotension (IDH) that results in dialysis-induced myocardial ischemia (cardiac stunning) and long patient recovery times.Our aim was to estimate the status of hydration in our peritoneal dialysis population by body composition monitoring (BCM) device to modify our pharmacological and dialysis policy and to evaluate echocardiographic parameters of the RV functions in patients with end-stage renal disease (ESRD) undergoing PD. Method We used a Fresenius Body Composition Monitor (BCM), a whole-body bioimpedance spectroscopy (50 frequencies, 5–1,000 kHz), to assess the body composition of 35 patients on peritoneal dialysis in our centre..We measured body weight, 24 h diuresis and performed a BCM session. Analysed results of echocardiography focused on RV (tricuspid annular plane systolic excursion (TAPSE). As per statistics, comparisons between 2 groups done by students t test, Mann Whitney U test or Wilcoxon test. Correlation between data was done by Pearson or spearman correlation. And lastly categorical variables were assessed by fisher's exact, and Chi squared test. Results Average age was 47 years old (SD 9,45 t-test p = 0,1154:). Gender distribution was 54,3% of our patients were female. 8,6% of our patients were anuric, 91,4% had residual urine (more than 1 litre). TAPSE value were average 23,17 mm (±4,5).We measured over-hydration in 8 cases by BCM that followed dialysis policy modification. In 8 PD patients we measured more than 2 L volume overload (VO) with BCM followed by dialysis policy modification (fluid intake restriction, diuretic dose increasing, frequent solution exchange). Conclusion Our data raised the importance of regular echocardiography to identify it. More attention should be focused on improving BP and volume control and identifying treatment strategies that effectively lower further deterioration in PD patients. One way of doing this is monitoring with BCM. With this clinician can manage persistent overload in CAPD patients, to better modify the dialysis regime, restrict fluid intake and use diuretics, to all in all preserve LV and RV function, and to prevent deterioration of the peritoneal membrane, and most importantly improve their survival.

Effect of predialysis fluid overload on sleep quality in hemodialysis patients

Background Sleep disorders are common among end-stage renal disease patients undergoing hemodialysis (HD). The etiology of sleep disorders in these patients is known to be multifactorial. However, the role of hydration status in sleep disorders in HD patients is not well studied. Therefore, our aim was to study the effect of predialysis fluid overload on sleep quality in HD patients. Patients and methods This cross-sectional study included 100 prevalent HD patients from the HD unit of El Sahel Teaching Hospital. Fluid status and fluid compartments [total body water), extracellular water (ECW),and overhydration (OH) index] were analyzed by a portable whole-body bioimpedance spectroscopy (body composition monitor) before a mid-week dialysis session. OH was defined as OH/ECW% more than or equal to 15%. HD patients were then classified into two groups: group 1 (normohydrated) and group 2 (overhydrated) according to the relative OH index (OH/ECW%). Sleep quality was assessed in all patients by the Pittsburgh Sleep Quality Index (PSQI) questionnaire. Patients with concurrent diagnosis of either obstructive sleep apnea or psychiatric disorder and patients on any medications that affect the sleep pattern were excluded. Results Our study included 100 HD patients (49 male, 51 female; mean age, 49.3 ± 11); 42 (42%) patients had OH (i.e. group 2). Poor sleep quality (defined as PSQI score ≥5) was reported in 57% (n=57) of HD patients included in our study. Poor sleep quality was significantly higher in the HD patients with OH (group 2). Total PSQI scores were significantly higher in overhydrated patients (group 2) compared with normohydrated patients (group 1) (7.92 ± 3.32 vs. 4.83 ± 2.27, P≤0.001). The component scores 1, 2, 3, 4, 6, and 7 of the PSQI showed significant higher values (i.e. poor sleep quality) in overhydrated patients (group 2). Moreover, there was significant positive correlation between total PSQI score both of OH (r=0.259, P=0.009) and OH index (OH/ECW%) (r=0.283, P=0.004) in all HD patients included in the study. Conclusion We may conclude from our study that sleep disorders are prevalent in HD patients. Predialysis fluid overload in HD patients may be associated significantly with poor sleep quality.

MO935: A Propensity-Matched Study of The Effect of Short Daily Home Haemodialysis With Low Flow Dialysate on Nutritional Status and Body Composition

Abstract BACKGROUND AND AIMS The present study tested the hypothesis that short daily home haemodilaysis (HDD) with low flow dialysate using the NxStage monitor (Fresenius Medical Care) could preserve muscle mass and prevent protein-energy wasting in HD patients, despite using low-flux, lactate-buffered dialysate. METHOD This 12-month, prospective, controlled study examined 25 consecutive, non-selected CKD stage 5 patients who initiated short daily HHD with low-flow dialysate (HHD group) in our centre, and were compared with data from 50 patients on high-flux HD (HF-HD group) and 50 patients on on-line haemodiafiltration (OL-HDF group) obtained from the Fresenius Medical Care clinical database EuCliD after matching for clinical characteristics and propensity scores. Changes in body composition were assessed by whole-body bioimpedance spectroscopy (BIS; Fresenius Medical Care) at baseline, months 3, 6 and 12, by experienced research staff blinded to all clinical and biochemical data of the patients. In order to control for potential variability and the effect of overhydration, all BIS analyses were performed before a mid-week dialysis session. Linear mixed-effects models were used for the analysis of the repeated measures data. RESULTS Compared with in centre HF-HD, patients assigned to HHD experienced a gradual improvement in LTM. These differences reached statistical significance at Month 6 and Month 12, with a relative difference of 2.76 kg [95% confidence interval (95% CI): 0.53–4.99; P = 0.01] and 3.08 kg (95% CI: 0.68–5.45; P = 0.01), respectively. Changes in fat inversely mirrored those of LTM, with a relative difference between groups of –3.29 kg (95% CI: –6.66–0.07; P = 0.05) at Month 12. No differences in hydration status or dry weight were noted between groups (Table 1). No significant changes in body composition were observed between the HDD and the OL-HDF groups (data not shown). CONCLUSION Short daily HHD with the NxStage system for 1 year compared with HF-HD increased muscle mass, supporting the hypothesis that short daily HHD with low-flow dialysate could benefit nutritional status and prevent protein-energy wasting in HD patients.

Fluid balance assessment in pediatric hemodialysis patients by using whole-body bioimpedance spectroscopy (WB-BIS).

Fluid overload is a major factor in morbidity and mortality in dialysis patients. Whole-body bioimpedance spectroscopy (WB-BIS) is a noninvasive method for assessing fluid status. We hypothesized that fluid status measurement of changes in total body water (TBW), extracellular fluid (ECF), and intracellular fluid (ICF) by WB-BIS would correlate with the weight (Wt) changes before and after hemodialysis (HD) and the amount of ultrafiltration (UF) in pediatric HD patients. We also examined the relationship between the ECF percent of total body water (ECF%) and ECF/ICF ratio with the pre-HD systolic blood pressure percentile (SBP%ile). WB-BIS measurements were made both before and after HD on three separate occasions in each patient. Pre- and post-HD Wt, BP, and UF volumes were collected on the day of BIS measurement. At total of 96 measurements were obtained from 16 HD patients. There were 6 females (mean age: 13.2 ± 4.5 yrs). UF correlated with changes in weight, TBW and ECF (p < 0.001) but not with ICF changes (p = 0.345). Pre-HD SBP%ile correlated with ECF%. Our findings suggest that WB-BIS can be used to monitor the fluid status in pediatric HD patients. The fluid that is removed from the patient during the HD treatment primarily comes from the ECF and not the ICF. Mobilization of fluid from the ICF appears to be delayed. Patients with significantly higher pre-HD ECF% and ECF/ICF ratio had higher pre-HD systolic BP. A higher resolution version of the Graphical abstract is available as Supplementary information.

Longitudinal Assessment of Body Composition and Its Association With Survival Among Participants of the ACTIVE/ADIPOSE Study

The importance of muscle wasting as a predictor of mortality in the hemodialysis population is not clear. Lack of association of muscle mass with survival in some studies could be related to reliance on single measures or to incorporation of excess extracellular water (ECW) into estimates of muscle mass. We examined changes in body composition over a 2-year period and the association of body composition with survival. We analyzed data from 325 adults receiving hemodialysis in the Bay Area. We estimated ECW, intracellular water (ICW), and fat mass by whole-body bioimpedance spectroscopy (BIS) at 0, 12, and 24months from enrollment. We used linear mixed modeling to examine changes in body mass index and BIS-derived estimates of body composition and Cox modeling with BIS-derived estimates as time-varying independent variables to examine associations between body composition and survival in multivariable analyses. Body mass index declined over time. Considering individual components of body composition, ICW declined (-0.09kg/m2 per year, 95% confidence interval -0.14 to -0.04), but fat mass and ECW did not change significantly. There were 120 deaths over a median of 5.2years. The relationship between ICW and mortality was not linear such that the association was steeper at low values of ICW, whereas higher ICW was associated with better survival that was relatively stable above 9kg/m2. Higher ECW was associated with higher mortality, and fat mass was not associated with survival. These associations were independent of markers of inflammation and nutritional status. ICW declined over 2years in this cohort, whereas fat mass and ECW remained relatively stable. Higher ICW was associated with better survival, but higher fat mass was not. Higher ECW was associated with worse survival. These results suggest that muscle mass may predict survival among patients on hemodialysis.

Overhydration as a modifiable cardiovascular risk factor in patients undergoing hemodialysis.

Introduction: Cardiovascular mortality in patients with end-stage renal disease (ESRD) remains high despite advances in dialysis techniques. This can be attributed to several traditional and nontraditional risk factors. Overhydration seems to be one of the promising cardiovascular risk factors that could be targeted to improve survival. Objectives: We aimed to assess the effect of chronic overhydration as well as changes in the degree of overhydration over time on cardiovascular and all-cause morbidity and mortality in patients undergoing hemodialysis. Patients and methods: We enrolled 511 patients with ESRD undergoing hemodialysis. The hydration status was assessed with whole-body bioimpedance spectroscopy. Patients were divided into 4 subgroups according to baseline hydration status. Additionally, patients with at least 2 follow-up visits (n = 277) were classified into 4 subgroups according to changes in the hydration status over time. Results: Statistical analysis showed that male sex (P <⁠0.001), diabetes (P <⁠0.001), cardiac insufficiency (P <⁠0.001), smoking (P = 0.049), and cerebrovascular events (P = 0.007) were significant risk factors for overhydration. Cardiovascular toxicity of overhydration was reflected by elevated levels of N-terminal pro-B-type natriuretic peptide (P <⁠0.001) and cardiac troponin T (P <⁠0.001). Albumin and total cholesterol levels were the lowest in patients with severe overhydration (P <⁠0.001). Mortality was lower in patients with normal hydration status and mild overhydration (P <⁠0.001) as well as in those with stable low or descending overhydration pattern (P = 0.002). Conclusions: We showed that the degree of overhydration is significantly associated with the incidence of cardiovascular complications and prognosis in patients with ESRD undergoing hemodialysis.

Differential assessment of fluid compartments by bioimpedance in pediatric patients with kidney diseases

BackgroundThe kidney is central for maintaining water balance. As a corollary, patients with impaired kidney function are prone to pathological fluid volumes. Total body water (TBW) is distributed between the extracellular (ECW) and intracellular fluid compartments (ICW). In clinical practice, the judgment of hydration status does not allow to distinguish between ECW and ICW. Here, we evaluate the hydration status in children with chronic kidney disease by analyzing TBW, ECW, and ICW.MethodsHydration was quantified using whole-body bioimpedance spectroscopy (BCM) in 128 outpatients (1–25 years, 52 girls). Forty-two were transplanted (TPL), 43 suffered from chronic kidney disease without kidney replacement therapy (CKD), 21 were on peritoneal dialysis (PD), and 22 on hemodialysis (HD). HD patients were investigated before, after, and sequentially during dialysis.ResultsThe ECW and ICW values obtained by BCM were of the same magnitude as those from the literature using isotope dilution. When compared with a healthy control group, TBW was increased in 9 TPL, 9 CKD, 1 PD, and 11 HD patients before but in none after dialysis. The decline of overhydration during dialysis (p < 0.001, n = 22) correlated with the change in body weight (R2 = 0.62). The kinetics of fluid compartment changes assessed twice in six HD patients revealed a reproducible linear decay of the ECW/ICW ratio due to an increase of ICW and a decrease of ECW.ConclusionBCM quantifies TBW and acute changes of ECW and ICW in children with chronic kidney failure. The clinical utility of measuring TBW, ECW, and ICW should be defined in the future.

Characteristics of bioimpedance-determined fluid shifts according to intradialytic blood pressure difference

This study was designed to identify the fluid spaces that are most changed during ultrafiltration (UF) according to intradialytic blood pressure (BP) difference. BP data were collected five times (before hemodialysis [HD] and 1–4 h of HD). Intradialytic BP difference was calculated as the highest minus lowest of these BP measurements. Intradialytic systolic BP (SBP) difference over 20 mm Hg and diastolic BP (DBP) difference over 10 mm Hg were defined as wide intradialytic SBP difference (SYS-W) and DBP difference (DIA-W), respectively. We measured the various fluid spaces before HD and 1–4 h of HD, and 30 min after HD using a portable, whole-body bioimpedance spectroscopy (BIS). In this study, 85 prevalent patients aged over 18 years with a fixed dry weight (65.38 ± 12.45 years, 54.18% men, 52.50% patients with diabetes), undergoing HD had participated. 1) Mean relative reduction of extracellular water (ECW) was significantly higher in SYS-W than in narrow intradialytic SBP difference (SYS-N) patients from 1 h to 30 min after HD. 2) Mean relative reduction of intracellular water (ICW) was significantly lower in DIA-W than in narrow intradialytic DBP difference (DIA-N) patients from 1 h to 30 min after HD. 3) ECW of patients with SYS-W was significantly lower than that of patients with SYS-N. Patients with SYS-W have the characteristics of fluid shifts in which reduction of ECW was steeper than patients with SYS-N whereas fluid shifts of ICW were lower in patients with DIA-W than patients with DIA-N.

P1487EFFECT OF PREDIALYSIS FLUID OVERLOAD ON SLEEP QUALITY IN HEMODIALYSIS PATIENTS

Abstract Background and Aims Sleep disorders are common among end stage renal disease (ESRD)patients undergoing hemodialysis (HD). The etiology of sleep disorders in these patients is known to be multifactorial. However, the role of hydration status in sleep disorders in HD patients is not well studied. Therefore, our aim was to study the effect of predialysis fluid overload on sleep quality in HD patients. Methods This cross-sectional study included 100 prevalent HD patients from HD unit of El Sahel teaching hospital. fluid status and fluid compartments [total body water (TBW)], extracellular water (ECW)] and overhydration index (OH) were analyzed by a portable whole-body bio-impedance spectroscopy (Body Composition Monitor ‘BCM’) before mid-week dialysis session. Overhydration was defined as OH/ECW ≥15%. HD patients were then classified into 2 groups: Group 1 (non- overhydrated) and Group 2 (Overhydrated) according to OH/ECW. Sleep quality were assessed in all patients by Pittsburgh Sleep Quality Index (PSQI) questionnaire. Patients with Concurrent diagnosis of either obstructive sleep Apnea or psychiatric disorder and patients on any medications which affect the sleep pattern were excluded. Results our study included 100 HD patients (49 male, 51 female - mean age 49.3 ±11). 42 patients (42%) had overhydration (i.e. Group 2). Poor sleep quality (defined as PSQI score ≥5) was reported in 57% (n=57) of HD patients included in our study. Poor sleep quality was significantly higher in the HD patients with overhydrated (Group 2). Total PSQI scores were significantly higher in overhydrated patients (Group2) compared to non-overhydrated patients (Group1) (7.92±3.32 vs 4.83±2.27, P= &amp;lt;0.001). The component scores 1, 2, 3, 4, 6 and 7 of the PSQI showed significant differences between the overhydration and non-overhydration groups with higher values (i.e poor sleep quality) in overhydrated patients (Group2). Moreover, there was significant positive correlation between total PSQI score and overhydration index (OH/ECW %) in all HD patients included in the study (r=0.283, P= 0.004). Conclusion We may conclude from our study that sleep disorders are prevalent in HD patients. Predialysis fluid overload in HD patients may be associated significantly with poor sleep quality.

Association of the malnutrition-inflammation score with anthropometry and body composition measurements in patients with chronic kidney disease.

The malnutrition-inflammation score (MIS) is a nutritional scoring system that has been validated in chronic kidney disease (CKD) stages III-V, especially in dialysis patients. We aimed to test whether the MIS changed in the early stages of CKD and whether it was associated with anthropometry and body composition measurements (BCMs) in patients with CKD. This was a cross-sectional study conducted in the Nephrology Department. A total of 144 patients with CKD were included in the study between May 2017 and December 2017. The MIS was calculated without computing the dialysis vintage in the scoring. Body composition was measured using a portable whole-body bioimpedance spectroscopy device. Anthropometric, laboratory, and other body composition parameters were recorded. The MIS was increased in patients with CKD. It was negatively correlated with body mass index (BMI), mid-arm muscle circumference (MAMC), handgrip strength, lean tissue index (LTI), fat tissue index (FTI), phase angle (PA), and hemoglobin and albumin concentrations, and it was positively correlated with sex, overhydration, urinary protein excretion and IL-6. A high MIS was significantly correlated with a low LTI (r=-0.274; P=0.001), low FTI (r=-0.179; P=0.032), overhydration (r=0.457; P<0.001) and low PA (r=-0.475; P<0.001). A rather strong correlation was observed between the PA and the MIS. In the multivariate regressions, after adjusting for age, sex, presence of diabetes, handgrip strength, BMI, overhydration, glomerular filtration rate, albumin and IL-6 concentrations, these relationships did not diminish. The MIS was strongly linked with indicators of nutrition. As a simple and practical tool for assessing nutritional status, the MIS should be calculated in the early stages of CKD.

No effect of HMB or α-HICA supplementation on training-induced changes in body composition

β-hydroxy-β-methylbutyrate (calcium: HMB-Ca and free acid: HMB-FA) and α-hydroxyisocaproic acid (α-HICA) are leucine metabolites that have been proposed to improve body composition and strength when combined with resistance exercise training (RET). In this double-blind randomized controlled pragmatic trial, we evaluated the effects of off-the-shelf supplements: α-HICA, HMB-FA and HMB-Ca, on RET-induced changes in body composition and performance. Forty men were blocked randomized to receive α-HICA (n = 10, fat-free mass [FFM] = 62.0 ± 7.1 kg), HMB-FA (n = 11, FFM = 62.7 ± 10.5 kg), HMB-Ca (n = 9, FFM = 65.6 ± 10.1 kg) or placebo (PLA; n = 10, FFM = 64.2 ± 5.7 kg). The training protocol consisted of a whole-body resistance training routine, thrice weekly for 8 weeks. Body composition was assessed by dual-energy x-ray absorptiometry (DXA) and total body water (TBW) by whole-body bioimpedance spectroscopy (BIS), both at baseline and at the end of weeks 4 and 8. Time-dependent changes were observed for increase in trunk FFM (p < 0.05). No statistically significant between-group or group-by-time interactions were observed. Supplementation with HMB (FA and Ca) or α-HICA failed to enhance body composition to a greater extent than placebo. We do not recommend these leucine metabolites for improving body composition changes with RET in young adult resistance trained men.

The relationship between hydration status, male sexual dysfunction and depression in hemodialysis patients.

BackgroundDisturbances in sexual function are common among dialysis patients. Normal erections require a complex balance of physiological, psychological, emotional, hormonal, neurological and vascular factors. This study examined a possible association of overhydration (OH) with male sexual dysfunction and depression in hemodialysis (HD) patients.Patients and methodsThis cross-sectional study assessed hydration status by whole-body bioimpedance spectroscopy in patients on maintenance HD for more than 12 months. Patients were categorized according to OH to extracellular water (ECW) ratio: OH/ECW ratio >0.15 and OH/ECW ratio ≤0.15. Sexual function was assessed using the International Index of Erectile Function (IIEF) score. Psychological status was evaluated using the Beck Depression Inventory (BDI) score. Serum sex hormones were determined.ResultsOf 39 stable participants on HD, 53.8% were overhydrated (OH/ECW ratio >0.15) and 46.2% not overhydrated (OH/ECW ratio ≤0.15). Of participants with OH/ECW ratio >0.15, 85.7% had mild to severe ED, and 71.4% had abnormal BDI scores, ranging from mild mood disturbance to severe depression. Compared to patients with OH/ECW ratio ≤0.15, BDI scores, serum estradiol and plasma hsCRP were higher (18.48±8.34 vs 10.61±5.46, p<0.001; 140.10±44.51 vs 126.10±32.26, p=0.034; and, 17.70±12.14 vs 9.76±8.79, p=0.013; respectively) in those with OH/ECW ratio >0.15, while their IIEF score, serum total testosterone and dehydroepiandrosterone (DHEA) were lower (12.81±7.31 vs 41.44±23.79, p<0.001; 8.97±5.43 vs 14.10±8.30, p=0.013; and 85.31±55.14 vs 133.3±95.48, p=0.029; respectively). The OH/ECW ratio correlated inversely with the IIEF score (r=−0.69, p<0.001) and positively with BDI scores (r=0.64, p<0.001). IIEF scores were inversely correlated with BDI scores (r=−0.54, p<0.001).ConclusionOH in HD patients was found to be associated with a higher prevalence of sexual dysfunction and depression, lower serum levels of total testosterone and DHEA, and higher levels of serum estradiol.

Chronic Fluid Overload and Mortality in ESRD.

Sustained fluid overload (FO) is considered a major cause of hypertension, heart failure, and mortality in patients with ESRD on maintenance hemodialysis. However, there has not been a cohort study investigating the relationship between chronic exposure to FO and mortality in this population. We studied the relationship of baseline and cumulative FO exposure over 1 year with mortality in 39,566 patients with incident ESRD in a large dialysis network in 26 countries using whole-body bioimpedance spectroscopy to assess fluid status. Analyses were applied across three discrete systolic BP (syst-BP) categories (<130, 130-160, and >160 mmHg), with nonoverhydrated patients with syst-BP=130-160 mmHg as the reference category; >200,000 FO measurements were performed over follow-up. Baseline FO value predicted excess risk of mortality across syst-BP categories (<130 mmHg: hazard ratio [HR], 1.51; 95% confidence interval [95% CI], 1.38 to 1.65; 130-160 mmHg: HR, 1.25; 95% CI, 1.16 to 1.36; >160 mmHg: HR, 1.30; 95% CI, 1.19 to 1.42; all P<0.001). However, cumulative 1-year FO exposure predicted a higher death risk (P<0.001) across all syst-BP categories (<130 mmHg: HR, 1.94; 95% CI, 1.68 to 2.23; 130-160 mmHg: HR, 1.51; 95% CI, 1.35 to 1.69; >160 mmHg: HR, 1.62; 95% CI, 1.39 to 1.90). In conclusion, chronic exposure to FO in ESRD is a strong risk factor for death across discrete BP categories. Whether treatment policies that account for fluid status monitoring are preferable to policies that account solely for predialysis BP measurements remains to be tested in a clinical trial.

The impact of oxidized serum albumin on the oncotic pressure and hydration status of peritoneal dialysis patients.

ObjectiveHypoalbuminemia, fluid overload (FO), and oxidative stress (OS) may be related to cardiovascular morbidity and mortality in peritoneal dialysis (PD) patients. OS produces molecular modifications of serum albumin that interfere with its quantification by the commonly used bromocresol green assay. This study evaluated the impact of oxidized serum albumin (OSA) on oncotic pressure (OP) and hydration status.Patients and methodsTwenty-four stable hypoalbuminemic PD patients were enrolled in the study. After performing physical examination, assessment of the hydration status using a whole-body bioimpedance spectroscopy technique was performed, and blood samples were drawn for determination of OP, serum albumin levels, and OSA.ResultsExtracellular to total body water (E/TBW) ratio was higher in patients with FO ≥1.5 L with or without edema than in patients with FO <1.5 L (P≤0.043). E/TBW ratio was higher in patients with FO ≥1.5 L and edema compared to those with FO ≥1.5 L but without edema (P=0.004). OP was significantly higher in patients with FO ≥1.5 L and without edema compared to those with FO ≥1.5 L and with edema (P<0.001). Albumin-detection index (ADI) in patients with FO ≥1.5 L and without edema was similar to ADI in patients with FO <1.5 L (P=0.520). ADI was significantly lower in patients with FO ≥1.5 L and without edema compared to those with FO ≥1.5 L and edema (P=0.034). E/TBW ratio correlated positively with the ADI (r=0.60, P=0.001) and inversely with the OP (r=−0.54, P=0.002).ConclusionOverhydration may be clinically undetectable in PD patients. Assessing the hydration status and measuring the total serum albumin levels, including the oxidized fraction, should be considered in evaluating hydration status in PD patients.

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

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

Bioimpedance spectroscopy for assessment of volume status in patients before and after general anaesthesia.

BackgroundTechnically assisted assessment of volume status before surgery may be useful to direct intraoperative fluid administration. We therefore tested a recently developed whole-body bioimpedance spectroscopy device to determine pre- to postoperative fluid distribution.MethodsUsing a three-compartment physiologic tissue model, the body composition monitor (BCM, Fresenius Medical Care, Germany) measures total body fluid volume, extracellular volume, intracellular volume and fluid overload as surplus or deficit of ‘normal’ extracellular volume. BCM-measurements were performed before and after standardized general anaesthesia for gynaecological procedures (laparotomies, laparoscopies and vaginal surgeries). BCM results were blinded to the attending anaesthesiologist and data analysed using the 2-sided, paired Student’s t-test and multiple linear regression.ResultsIn 71 females aged 45±15 years with body weight 67±13 kg and duration of anaesthesia 154±68 min, pre- to postoperative fluid overload increased from −0.7±1.1 L to 0.1±1.0 L, corresponding to −5.1±7.5% and 0.8±6.7% of normal extracellular volume, respectively (both p<0.001), after patients had received 1.9±0.9 L intravenous crystalloid fluid. Perioperative urinary excretion was 0.4±0.3 L. The increase in extracellular volume was paralleled by an increase in total body fluid volume, while intracellular volume increased only slightly and without reaching statistical significance (p = 0.15). Net perioperative fluid balance (administered fluid volume minus urinary excretion) was significantly associated with change in extracellular volume (r2 = 0.65), but was not associated with change in intracellular volume (r2 = 0.01).ConclusionsRoutine intraoperative fluid administration results in a significant, and clinically meaningful increase in the extracellular compartment. BCM-measurements yielded plausible results and may become useful to guide intraoperative fluid therapy in future studies.

Statut d’hydratation extracellulaire et natriurèse résiduelle en hémodialyse chronique : une étude transversale multicentrique

BackgroundIn dialysis patients, a misevaluation of dry weight may lead to an increased morbidity and mortality. The aim of this cross-sectional multicenter study was to evaluate the association between residual urinary sodium excretion and extracellular volume status in chronically treated hemodialysis patients. Patients and methodsDry weight was determined clinically and by whole-body bioimpedance spectroscopy (Body Composition Monitor, Fresenius Medical Care) prior to a mid-week session in 40 chronic hemodialysis patients with significant residual diuresis (more than 250 mL per day) and receiving treatment in four dialysis centers. Regarding their hydration status assessed by the Body Composition Monitor and in comparison to a healthy reference population, patients were assigned to 1 of the 3 categories: overhydrated, normohydrated and dehydrated. Urine output, urinary sodium excretion and residual renal function were measured for all patients within 30 days before dry weight assessment. ResultsThe median post-HD session FO was of−0.40 L (IQR: from−1.95 to+0.90) and the median residual urinary sodium excretion was of 64 mmol/L (IQR: 46–79). Among these patients, 16 were normohydated, 16 were dehydrated and 8 were overhydrated. There was a linear relationship between the hydration status after HD session and the urinary sodium excretion (estimate: 5.6±1.5; p<0.001). Compared with normohydrated patients, overhydrated patients had a higher residual urinary sodium excretion (estimate: 26±10; p<0.01). ConclusionIn this study, urinary sodium excretion is associated with the hydration status evaluated by whole-body bioimpedance spectroscopy.

Hydration measurement by bioimpedance spectroscopy and blood pressure management in children on hemodialysis

Hypertension is frequent in chronic hemodialyzed patients and usually treated by reducing extracellular fluid. Probing dry weight only based on a clinical evaluation may be hazardous, especially in case of volume independent hypertension. We performed a 1-year retrospective study in three pediatric centers to define the relation between blood pressure (BP) and hydration status, assessed by whole-body bioimpedance spectroscopy (BIS). We analyzed 463 concomitant measurements of BP, relative overhydration (rel.OH), and plasma sodium (Napl) in 23 children (mean age 13.9 ± 5.1 years). Pre-dialytic under-hydration (rel.OH < -7%) was present in 5.4% of the sessions, out of which 24% showed hypertension. Normohydration (rel.OH -7 - +7%) was observed in 62.4% of the sessions, 45.3% of them revealed hypertension. Moderate OH (rel.OH +7 - +15%) was present in 21% of the sessions, 47.4% of them showed normal BP. In 11.2% of the sessions, severe overhydration (rel.OH > +15%) was assessed, however, the majority (73%) showed normal BP. Patient-specific Napl setpoint could not be described. Mean dialysate sodium concentration was higher than mean Napl. Hypertension is not always related to overhydration. Therefore, BIS should restrict the practice of "probing dry weight" in hypertensive children. Moreover, sodium dialytic balance needs to be considered to improve BP management.

Importance of normohydration for the long-term survival of haemodialysis patients

Fluid overload and hypertension are among the most important risk factors for haemodialysis (HD) patients. The aim of this study was to analyse the impact of fluid overload for the survival of HD patients by using a selected reference population from Tassin. A positively selected HD population (n = 50) from Tassin (Lyon-France) was used as a reference for fluid status and all-cause mortality. This population was compared to one dialysis centre from Giessen (Germany) which was separated into a non-hyperhydrated (n = 123) and a hyperhydrated (n = 35) patient group. The hydration status (ΔHS) of all patients was objectively measured with whole-body bioimpedance spectroscopy in 2003. All-cause mortality was analysed after a 6.5-year follow-up. Most of the reference patients from Tassin were normohydrated (ΔHS = 0.25 ± 1.15 L) at the start of the HD session. The hydration status of the Tassin patients was not different to the non-hyperhydrated Giessen patients (ΔHS = 0.8 ± 1.1 L) but significantly lower than in the hyperhydrated Giessen group (ΔHS = 3.5 ± 1.2 L). Multivariate adjusted all-cause mortality was significantly increased in the hyperhydrated patient group (hazard ratio = 3.41)- no difference in mortality could be observed between the Tassin and the non-hyperhydrated group from Giessen-even considering the fact that Tassin patients presented a significantly lower blood pressure. Fluid overload has a very high predictive value for all-cause mortality and seems to be one of the major killers in the HD population. Patients might strongly benefit from active management of fluid overload.