Predialysis Serum Sodium Research Articles

Individualization of the sodium level in the dialysis solution: results of a prospective interventional study and prospects for implementation

BACKGROUND. The achievement and maintenance of euhydration are the key components of dialysis effectiveness, particularly in reducing the risk of cardiovascular events. Sodium loading during the session is one of causes of excessive sodium and water intake. THE AIM: was to evaluate the effectiveness and safety of an individualized approach to the prescription of dialysate sodium based on the serum sodium. PATIENTS AND METHODS. After retrospective analysis of previous serum sodium (1049 patients-months), interdialytic weight gain (IDWG), blood pressure(BP) and dialysate sodium(NaD), we prescribed the NaD at the sodium setpoint (n=45). RESULTS. The stability of predialysis serum sodium was high, and five monthly samples were sufficient to accurately assess the sodium setpoint. After six-month, there was a reduction in IDWG from 2.51±0.86 to 2.26±0.87 kg in the entire group (p=0.003), the result was achieved in both subgroups, with a decrease in NaD (2.63±0.81→2.37±0.82 kg; p=0.021), and with an increase in NaD (2.39±0.90→2.15±0.88 kg; p=0.049). Baseline IDWGs were higher in the first subgroup (p=0.041); but after NaD individualizing they were almost the same. Individualization of NaD was accompanied by a gradual reduction in systolic BP (-0.76±0.14 mmHg/month, p=0.005), but not diastolic BP (-0.13±0.13 mmol/l/month). After bidirectional change in NaD the dynamics of systolic BP didn`t differ between groups with a decrease or increase in NaD: (-0.80±0.13 vs. -0.72±0.11 mmHg/month; p=0.052). CONCLUSION. Individualization of dialysate sodium to set point leads to a decrease in IDWG and BP even while NaD increases, without increasing in the frequency of intradialysis hypotension. The effectiveness and safety of the approach require confirmation in large-scale interventional studies.

Association between home meal preparers and salt intake in haemodialysis patients: a cross-sectional study

ObjectivesThis study aimed to examine the association between home meal preparer and salt intake among haemodialysis patients, including daily dietary status. We hypothesised that salt intake is higher among individuals...

A potential link between AQP3 and SLC14A1 gene expression level and clinical parameters of maintenance hemodialysis patients

BackgroundThe transport of water and urea through the erythrocyte membrane is facilitated by aquaporins such as aquaglyceroporin (AQP3), and type B urea transporters (UT-B). As they may play an important role in osmotic balance of maintenance hemodialysis (HD) patients, the aim of the present study was to determine whether any relationship exists between the expression of their genes and the biochemical / clinical parameters in HD patients.MethodsAQP3 and UT-B (SLC14A1) gene expression was evaluated using RT-qPCR analysis in 76 HD patients and 35 participants with no kidney failure.ResultsThe HD group demonstrated significantly higher median expression of AQP3 and UT-B (Z = 2.16; P = 0.03 and Z = 8.82; p < 0.0001, respectively) than controls. AQP3 negatively correlated with pre-dialysis urea serum concentration (R = -0.22; P = 0.049) and sodium gradient (R = -0.31; P = 0.04); however, no significant UT-B correlations were observed. Regarding the cause of end-stage kidney disease, AQP3 expression positively correlated with erythropoietin dosages in the chronic glomerulonephritis (GN) subgroup (R = 0.6; P = 0.003), but negatively in the diabetic nephropathy subgroup (R = -0.59; P = 0.004). UT-B positively correlated with inter-dialytic weight gain% in the GN subgroup (R = 0.47; P = 0.03).ConclusionMaintenance hemodialysis seems significantly modify AQP3 and UT-B expression but their link to clinical and biochemical parameters needs further large-scale evaluation.

The impact of chronic pre-dialysis hyponatremia on clinical outcomes in maintenance hemodialysis patients

ObjectiveChronic pre-dialysis hyponatremia is not rare in maintenance hemodialysis (MHD) patients. However, the association between chronic pre-dialysis hyponatremia and mortality is uncertain due to multiple potential confounders such as hyperglycemia, fluid overload, and malnutrition. This study aimed to more comprehensively evaluate the association between chronic pre-dialysis hyponatremia and clinical outcomes in MHD patients.MethodsWe analyzed the data of 194 MHD patients with regular real-time measurements of pre-dialysis serum sodium from July 2015 to March 2021. Hyponatremia was defined as SNa ≤ 135 mmol/L and normonatremia as SNa > 135 mmol/L and < 145 mmol/L. We evaluated the association of baseline pre-dialysis serum sodium (SNa) and time-averaged SNa (TASNa) levels with all-cause mortality or new major adverse cardiovascular events (MACE) in MHD patients. Furthermore, the SNa levels were glucose, serum albumin, and fluid overload adjusted. The associations between SNa levels and all-cause mortality or new MACE were analyzed using time-varying Cox regression models.ResultsAmong the total of 194 patients, 24 patients died and 45 new MACE occurred during a mean 35.2-month follow-up period. The baseline pre-dialysis SNa level was 137.1 ± 2.8 mmol/L (127–144 mmol/L). Kaplan–Meier survival analysis showed that there were no significant differences in all-cause mortality or new MACE between hyponatremia and normonatremia groups according to baseline pre-dialysis SNa or glucose-corrected SNa (gcSNa). The mean values of both TASNa and time-averaged glucose-corrected SNa (TAgcSNa) were 136.9 ± 2.4 mmol/L and 138.3 ± 2.0 mmol/L, respectively. Kaplan–Meier survival analysis showed that patients with pre-dialysis hyponatremia had higher all-cause mortality or new MACE compared with normonatremia patients whether grouped on TASNa or TAgcSNa. Cox models showed an increased risk of all‐cause mortality and new MACE in MHD patients with pre-dialysis hyponatremia based on TASNa or TAgcSNa. Even after full adjustment including time-dependent age and dialysis vintage, gender, diabetes, time-averaged weight gain (TAWG), and serum albumin, patients with pre-dialysis hyponatremia based on TASNa (HR 2.89; 95% CI 1.18–7.04; model 3) or TAgcSNa (HR 5.03; 95% CI 1.87–13.57; model 3) had approximately twofold or fourfold greater risk of all-cause mortality, respectively, compared with those with normonatremia. The risk of new MACE was also significantly elevated in patients with pre-dialysis hyponatremia based on TASNa (HR 3.86; 95% CI 2.13–7.01; model 1) or TAgcSNa (HR 2.43; 95% CI 1.14–5.15; model 1). After adjustment for time-dependent age and dialysis vintage, gender, diabetes, TAWG, and serum albumin, patients with pre-dialysis hyponatremia based on TASNa (HR 2.33; 95% CI 1.16–4.68; model 3) had a higher risk of new MACE compared with those with normonatremia.ConclusionsPre-dialysis time-averaged hyponatremia is independently associated with increased risks of all-cause mortality or new MACE in MHD patients. The baseline SNa level is not a predictor of clinical outcomes due to its variation over time. Hyperglycemia, fluid overload, and malnutrition do not have a significant impact on the risk association between chronic hyponatremia and all-cause mortality or new MACE in MHD patients.

MO903: Associations of Serum Sodium With Mortality in Patients on Maintenance Haemodialysis Treatment

Abstract BACKGROUND AND AIMS Chronic HD-patients have a 50% 5-year survival and unphysiological fluid and sodium shifts are key pathophysiological contributors. Several studies have shown that hyponatremia is associated with worse outcomes in haemodialysis patients. However, the association of all-cause mortality with volume status in hyponatremic patients is uncertain. Body composition monitoring has provided a more precise tool to estimate fluid status in dialysis patients. The primary aim of this international observational study performed in a large patient database (EUCLID5) was to quantify the association between salt exposure, fluid overload (FO) and mortality risk in haemodialysis patients. METHOD We included 71 706 incident haemodialysis patients from 1 January 2010 to 4 December 2020 in an extended Cox regression model for a time to death analysis. Exposure variables were defined as predialysis serum sodium and fluid overload (in liters as determined by the BCM—Body Composition Monitor using bioimpedance spectroscopy) on a monthly time grid. Effect modifiers, mediators, confounders and predictors were defined a priori. Adults were included with at least one valid BCM measurement within 3 months from first haemodialysis treatment and followed up until death or administrative censoring. All patients included in the study cohort were treated in the NephroCare–FMC dialysis centre network operating in 26 countries. Data were retrieved from the central EuCliD5 database. RESULTS In hyponatremic patients (serum sodium &amp;lt; 135 mmol/L), the association to the risk of death doubled [(HR = 1.97 (1.82–2.12)] in overhydrated patients (relative FO defined as 13% in men, and 15% in women &amp;gt;90th percentile of physiological hydration), was increased by 56% [HR = 1.56 (1.27–1.93)] in underhydrated patients (&amp;lt;–7% &amp;lt;10th percentile of normohydration) and was modestly higher in states of isovolemia (–7%–13% in women and 15% in men). The associated risk of death in states of overhydration decreased [HR = 1.50 (1.27–-1.76)] when patients were hypernatremic (serum sodium &amp;gt;142 mmol/L), (Table 1). Generally, the risk increased with rising FO and declining sodium concentration. CONCLUSION The observed associations to the risk of death reflecting the interplay between states of hypo-, iso- and hypernatremia and states of under, normal and over hydration deserve further study to understand the underlying complex mechanisms and identify therapeutic approaches. When assessing the risk level of different sodium concentrations, fluid status should be taken into account.

Echocardiographic left ventricular hypertrophy and geometry in Chinese chronic hemodialysis patients: the prevalence and determinants

BackgroundTo investigate the prevalence of left ventricular hypertrophy (LVH) and explore left ventricular geometry in maintenance hemodialysis (MHD) patients, and to explore the risk factors of LVH which is an important predictor of cardiovascular events.MethodsThe subjects were patients who are on MHD for more than 3 months in Peking University People's Hospital from March 2015 to February 2017. Demographic and clinical data were retrospectively collected. Left ventricular mass was measured by echocardiography. LVH is defined by Left ventricular mass index (LVMI) > 115 g/m2 for men and > 95 g/m2 in women. LVMI and relative wall thickness were used to determine left ventricular geometry. Logistic regression was used to analyze the risk factors of LVH.ResultsAltogether, 131 patients including 77 males were enrolled. The median age was 60 (47, 69) years, with a median dialysis vintage of 48 (18, 104) months. There were 80 patients with LVH, the prevalence rate was 61.1%, and 66.3% of them were moderate to severe LVH. We found that (1) most of the patients were concentric hypertrophy; (2) one-third of the patients were concentric remodeling; (3) only 4 cases with normal geometry. The pre-dialysis serum sodium level and time average pre-dialysis systolic blood pressure (SBP) were independent risk factors of LVH.ConclusionLVH is prevalent in MHD patients. Concentric hypertrophy and concentric remodeling are the most common geometric patterns. Attention should be paid to long-term pre-dialysis SBP management and pre-dialysis sodium control as they might be potentially modifiable risk factors for LVH.

Clinical impact of personalized sodium prescriptions in hemodialysis

Dialysate sodium prescription is often standardized. In some patients, this can be hypernatremic compared to serum sodium, causing a positive sodium balance at the end of treatment that will contribute to increased extracellular volume and interdialytic weight gain. A prospective study was carried out to monitor and compare the clinical implications between different prescriptions of sodium dialysate (isonatremic versus hyponatremic hemodialysis). For that purpose, we included hemodialysis patients in treatment for at least 9 months. The individual sodium setpoint was determined through the median of pre-dialysis sodium measurements, carried out for 6 treatments. The prescribed dialysate sodium was equal to the setpoint (isonatremic period) for 4 weeks and then 2 meq/L inferior to the setpoint (hyponatremic period) for another 4 weeks. The main outcome was interdialytic weight gain. Secondary outcomes were ultrafiltration rate, blood pressure at the beginning of treatment, intradialytic complications, and qualitative assessment of symptoms. Twenty patients were included. Pre-dialysis serum sodium assessments in both periods tended to be patient specific with a stable value. The interdialytic weight gain was lower in the hyponatremic period (1.83±0.50 kg versus 2.04±0.58 kg) but without statistical significance (p value=0.387). The same trend was found in mean ultrafiltration and blood pressure. Dialysis complications were low in both periods. The percentage of cramps and hypotension requiring intervention was higher in the hyponatremic period with no statistically significant differences. Concerning thirst, there was a symptomatic improvement with sodium customization. This improvement was even more significant in the hyponatremic period. This study allowed us to reinforce the existence of a “sodium setpoint” for each patient and the importance of an individualized dialysis prescription. Our results suggest the safety of using isonatremic hemodialysis with improving patients’ symptoms. Regarding hyponatremic hemodialysis, despite being beneficial, it seemed to be associated with a higher number of complications.

How to Adjust the Sodium Concentration in Dialysate Individually and Practically?

The optimal dialysate sodium concentration for chronic hemodialysis patients remains controversial. Conflicting data from small observational studies and large cohort study data have not convinced nephrologists to choose either a high or low sodium dialysate. Despite a lack of evidence, I would prescribe individualized dialysate sodium concentrations for patients with a risk of hypertension or volume overload, aligning the dialysate sodium concentration with patients’ predialysis serum sodium level. The concentration of dialysate sodium would usually be 0–2 mEq/L below the patient’s serum sodium concentration. I believe that this strategy would help improve hypertension, intradialytic weight gain, cardiac outcomes, and deliver precision medicine.

Opinion on the (Hemo)dialysate Sodium Prescription: Dialysate Sodium Prescription Should Not Be Considered in Isolation

With advances in hemodialysis technology and the desire to achieve cardiovascular stability during dialysis, prescribed dialysate sodium concentration has gradually increased over the years. Short-term trials suggest low dialysate sodium (&lt;138 mEq/L) is beneficial in reducing interdialytic weight gain, pre- and post-dialysis BP, and predialysis serum sodium; but it increases intradialytic hypotensive episodes. We believe dialysate sodium prescription cannot be considered in isolation. Our approach is to use patient symptoms, meticulous fluid volume management and low temperature dialysate in conjunction with neutral dialysate sodium in managing our dialysis patients. Long-term trials are needed to inform optimum dialysate sodium prescription.

New Estimation Formulas for Daily Sodium Intake in Hemodialysis Patients by a Duplicate Portion Method

Excess sodium intake is associated with volume overload and increased blood pressure. Therefore, to prevent future cardiovascular events, a sodium-restricted diet is strongly recommended for patients on maintenance hemodialysis (HD). However, only one formula for estimating dietary sodium intake in HD patients is available, and its validity has not been adequately evaluated. This study aimed to measure daily sodium intake using the duplicate portion method and provide a new formula for estimating dietary sodium intake. Nineteen Japanese patients undergoing HD were enrolled in this cross-sectional multicenter study. The daily sodium intake of these patients was measured directly using the duplicate portion method. Two formulas for estimating sodium intake were developed by stepwise regression analysis. Their validities were compared with the validity of the previous formula. Furthermore, using these new formulas, we estimated the daily consumption of sodium in a large number of Japanese HD patients. The previous formula underestimated true sodium intake using Bland-Altman diagrams. No significant correlation was noted between the measured sodium intake and the estimated intake (r=0.30, P=.23, Fisher's Z-transformation). The new formulas 1 and 2, which included age, predialysis and postdialysis serum sodium levels, predialysis body weight, and interdialytic body weight gain, accurately estimated sodium consumption. The coefficients of correlation between the estimated values and the true sodium intake were r=0.858 and r=0.805, respectively. The simulation model using data from the Japanese Society for Dialysis Therapy showed that the distribution of the estimated sodium intake using the previous formula shifted left compared with that using the new formulas. The new formulas accurately estimated the daily sodium consumption in HD patients. Further longitudinal studies are required to determine whether the estimated sodium intake level calculated using the new formulas would serve as a potential marker and/or therapeutic target to prevent cardiovascular events in HD patients.

Consequences of Interdialytic Weight Gain Among Hemodialysis Patients.

BackgroundInterdialytic weight gain (IDWG) is a marker of higher pre-dialysis blood pressure, nutrition, and survival in hemodialysis (HD) patients. However, this relationship is incompletely characterized. In this study, we seek to define the association of IDWG/dry weight x100 (IDWG%) on blood pressure (BP), and the nutritional status of an HD population.Material and MethodsThis study was performed on 300 HD patients. The data was collected over four weeks, including total IDWG, IDWG%, and blood pressure. Normalized protein nitrogen appearance (nPNA), and serum albumin were used as markers of nutritional status. Participants were divided into three groups according to the mean of the IDWG% between two sessions of HD (group A < 3%, group B = 3% - 3.9%, and group C ≥ 4%); they were then compared on various aspects. Student t-test, analysis of variance (ANOVA), and linear regression analysis were used as statistical tools.ResultsThe mean (± standard deviation (SD)) age was 61.7 ± 14.2 years with 57.7% of the patients being male and 42.3% being female. The mean IDWG% for the whole studied population was 3.72% ± 1.73%. Between these three groups, a higher IDWG% was associated with younger males (p = 0.032), lower dry weight (p = 0.009), and longer duration on HD therapy (p = 0.009). IDWG% was directly associated with lower pre-dialysis serum sodium (p = 0.04), higher pre-dialysis serum creatinine (P = 0.002), and lower body mass index (BMI) (p= 0.003). Between these three groups, interdialytic variations in weight gain were not associated with increased BP. There was no significant difference between the three groups in terms of nPNA and serum albumin. ConclusionsThe most important associations of IDWG% are age, weight, pre-dialysis sodium, serum creatinine, and duration of dialysis (months). There was no association between IDWG% and increased systolic BP. IDWG% had no association with nutritional status.

CONTRIBUTING FACTORS OF INTRADIALYTIC HYPERTENSION IN MAINTENANCE HAEMODIALYSIS PATIENTS

Objective: The objective of this study was to determine the proportion of IDH and to evaluate its association with fluid overload using Bioimpedance Analysis (BIA). Design and method: A cross-sectional study involving 130 chronic haemodialysis patients in Cipto Mangunkusumo hospital Jakarta. This study is conducted between September to November 2019. IDH was defined as an increase in Mean Arterial Pressure (MAP) of at least 15 mmHg within or after dialysis or an increase of systolic blood pressure more than 10 mmHg after dialysis. Results: The prevalence of IDH was 17,7% (n = 23). There was a trend towards predialysis excess fluid in the IDH group with 10 (45,5%) samples when compared with NIDH with 35 (32,7%) samples respectively; as measured by BCM (p = 0.184). A trend towards use of more than 3 antihypertensives was noted in the IDH group [12 (52,1%) samples versus &lt;3 types was 11 (47.8%) samples; p &gt; 0.000]. On bivariate analysis, post dialysis blood pressure and post dialysis MAP are significantly greater in IDH group, as expected. None of the predialysis blood pressure, BMI, ultrafiltration, and serum sodium were associated with incident of IDH Conclusions: The prevalence of IDH in our treatment centres is 17,7%. Subclinical fluid overload was found higher in IDH patients, although statistically non significant. The use of BIA identifies patients who may benefit from additional UF.

The Association Between Handgrip Strength and Predialysis Serum Sodium Level in Patients With Chronic Kidney Disease Stage 5D.

Purpose: Handgrip strength (HGS) is a useful tool for the systematic assessment of muscle function related to nutritional status. Reduced HGS has been associated with adverse clinical outcomes in chronic kidney disease (CKD) stage 5D patients. In the same patients, predialysis low serum sodium (sNa) has been associated with malnutrition and mortality. Here, we investigated the role of predialysis sNa on muscle function in CKD-5D patients.Methods: We evaluated 45 patients on hemodialysis (HD) and 28 patients on peritoneal dialysis (PD) with HGS measurement, bioimpedance analysis, anthropometric measures, and malnutrition inflammation score (MIS). According to established diagnostic criteria, reduced HGS was defined as strength below 30 and 20 Kg in men and women, respectively. Predialysis sNa values were defined as the mean of all predialysis measurements during the preceding 6 months. Data analysis was performed separately for each of the HD and PD groups.Results: The proportions of reduced HGS did not differ between the HD (66%) and PD (54%) groups, respectively. Patients in the HD group as compared to those in the PD group had higher serum albumin and potassium and mid-arm muscle circumference and lower residual renal function (RRF) and residual urine volume. Multivariate logistic analysis, after controlling for muscle mass, nutritional biomarkers, MIS, fluid overload and RRF, showed that for every 1 mmol/l increase of sNa the odds of reduced HGS was decreased by 60% (OR = 0.40, 95% CI: 0.16–0.99) and 42% (OR = 0.58, 95% CI: 0.36–0.93) in HD and PD patients, respectively. However, stratified analysis indicated that lower sNa levels predicted reduced HGS in individuals with a background of malnutrition, inflammation, overhydration and less preserved RRF, representing unfavorable conditions strongly related to muscle wasting in the dialysis setting.Conclusions: Predialysis sNa is a strong and independent determinant of HGS, a reliable nutritional marker in CKD-5D stage patients. However, according to our findings, lower sNa levels appear to be a marker of underlying unfavorable conditions that are heavily associated with reduced HGS, rather than a causal determinant of reduced HGS. Whether optimizing sNa levels improves patient muscle performance requires further investigations.

The Predialysis Serum Sodium Level Modifies the Effect of Hemodialysis Frequency on Left-Ventricular Mass: The Frequent Hemodialysis Network Trials

Introduction: The Frequent Hemodialysis Network (FHN) Daily and Nocturnal trials aimed to compare the effects of hemodialysis (HD) given 6 versus 3 times per week. More frequent in-center HD significantly reduced left-ventricular mass (LVM), with more pronounced effects in patients with low urine volumes. In this study, we aimed to explore another potential effect modifier: the predialysis serum sodium (SNa) and related proxies of plasma tonicity. Methods: Using data from the FHN Daily and Nocturnal Trials, we compared the effects of frequent HD on LVM among patients stratified by SNa, dialysate-to-predialysis serum-sodium gradient (GNa), systolic and diastolic blood pressure, time-integrated sodium-adjusted fluid load (TIFL), and extracellular fluid volume estimated by bioelectrical impedance analysis. Results: In 197 enrolled subjects in the FHN Daily Trial, the treatment effect of frequent HD on ∆LVM was modified by SNa. When the FHN Daily Trial participants are divided into lower and higher predialysis SNa groups (less and greater than 138 mEq/L), the LVM reduction in the lower group was substantially higher (−28.0 [95% CI −40.5 to −15.4] g) than in the higher predialysis SNa group (−2.0 [95% CI −15.5 to 11.5] g). Accounting for GNa, TIFL also showed more pronounced effects among patients with higher GNa or higher TIFL. Results in the Nocturnal Trial were similar in direction and magnitude but did not reach statistical significance. Discussion/Conclusion: In the FHN Daily Trial, the favorable effects of frequent HD on left-ventricular hypertrophy were more pronounced among patients with lower predialysis SNa and higher GNa and TIFL. Whether these metrics can be used to identify patients most likely to benefit from frequent HD or other dialytic or nondialytic interventions remains to be determined. Prospective, adequately powered studies studying the effect of GNa reduction on mortality and hospitalization are needed.

Low Sodium Dialysate for Hemodialysis Is Associated with Lower Blood Pressure and Interdialytic Weight Gain, but Not a Lower Pre-Dialysis Serum Sodium

Low Sodium Dialysate for Hemodialysis Is Associated with Lower Blood Pressure and Interdialytic Weight Gain, but Not a Lower Pre-Dialysis Serum Sodium

Practice Patterns and Outcomes of Online Hemodiafiltration: A Real-World Evidence Study in a Russian Dialysis Network

Background: Evidence suggests that online hemodiafiltration (OL-HDF) is associated with improved survival. Whether the dose-response relationship between convective volume and mortality may be confounded by selection bias or descends from practice patterns is not clear. We sought to evaluate the role of patients’ characteristics and practice patterns on OL-HDF dose and mortality in a large private dialysis network in the Republic of Russia. Methods: In this multicenter, historical cohort study, we included adult incident patients on OL-HDF with at least 90 days of survival on renal replacement therapy in centers belonging to the Russian Federation Fresenius Medical Care network (January 1, 2011, to December 31, 2016). We evaluated predictors and outcomes (survival) of substitution volume target achievement (Q_sub > 21 L/session). Results: Among 1,081 enrolled patients, the average Q_sub was 22.9 (±3.2) L/session; the mean ultrafiltration volume was 1.6 (±0.8) L/session. The mean age was 55.8 ± 13.2; 42% were woman. Most common comorbidities were congestive heart failure (39.7%) and peripheral vascular disease (21.7%). The average hemoglobin was 9.3 ± 1.3. The case-mix adjusted center effect accounted for 20% of variance in Q_sub. The top 10 most important variables associated with higher Q_sub were effective Q_b, serum protein, Charlson’s comorbidity index, hemoglobin, year of dialysis initiation (proxy of high Q_sub treatment policy in the clinic network), predialysis heart rate, serum bicarbonate, serum phosphate, age, serum sodium, and dry body weight. In addition, we found that the association of Q_b with Q_sub is moderated by year of enrollment, intradialytic weight gain, and coronary artery disease, whereas higher hemoglobin concentration moderated the relationship between treatment time and Q_sub. Finally, Q_sub between 21 and 25 L/session was associated with longer 5-year survival. Conclusions: Both center-dependent clinical practice standards and patient clinical conditions substantially contributed to the risk of low Q_sub. We confirmed previous evidence indicating better survival among patients with Q_sub ≥ 21 L/session.

Association of predialysis serum sodium level with fluid status in patients on maintenance hemodialysis.

The ability to maintain sodium and water homeostasis is impaired in patients with end-stage renal disease (ESRD), leading to hyponatremia and fluid overload. The aim of this study was to evaluate the association between serum sodium level and body fluid status in patients on maintenance hemodialysis (HD). This was a prospective observational study on patients with ESRD and who were on maintenance HD between June and November 2018. Assessment of body fluid status using bioimpedance spectroscopy and measurement of serum sodium level were conducted simultaneously predialysis. The association of fluid status with predialysis sodium level was analyzed. Sixty-two patients were enrolled in the study group. Compared with patients with predialysis normonatremia, those with predialysis hyponatremia had higher levels of blood urea nitrogen, serum potassium, phosphate, normalized protein catabolic rate, and interdialytic weight gain (IDWG) (p < 0.05). The correlations of predialysis sodium level with chronic fluid status, such as fluid overload, were not significant. Logistic regression analysis found significant association of IDWG with predialysis hyponatremia. Predialysis hyponatremia was associated with increased IDWG. The substantial variation in serum sodium levels, regardless of fluid status, indicated the complex relationship between sodium and water balance in patients on maintenance HD.

Impact of Dialysate Sodium Concentration Lowering on Home Blood Pressure Variability in Hemodialysis Patients.

Blood pressure variability is an independent risk factor for mortality and cardiovascular events in hemodialysis patients. Dialysate sodium concentration may not only have effects on blood pressure but also on blood pressure variability. We investigated whether dialysate sodium concentration lowering could decrease home blood pressure variability in hemodialysis patients. Forty-three hemodialysis patients at their dry weight assessed by bioimpedance methods with pre-dialysis serum sodium >136 mmol/L were recruited. Firstly, patients underwent a 1-month standard dialysis with dialysate sodium concentration of 138 mmol/L, and then the dialysate sodium concentration was decreased to 136 mmol/L for 8 weeks. Home blood pressure was assessed on waking up and at bedtime for 1 week. Coefficient of variation was used to define home blood pressure variability. After the intervention, whole-day systolic blood pressure variability decreased from 5.7 ± 2.6% to 4.3 ± 1.7% and evening systolic blood pressure variability decreased from 7.9 ± 4.1% to 6.2 ± 3.1%. Morning systolic blood pressure variability had a reduction from 7.8 ± 2.4% to 5.9 ± 3.3% but did not achieve statistical significance (P = 0.077). Whole-day, morning and evening systolic blood pressure were decreased significantly. Less changes were observed in diastolic blood pressure parameters. Interdialytic weight gain mildly but significantly decreased. Volume parameters, dietary sodium intake and incidence of adverse events were similar throughout the study period. Lowering dialysate sodium concentration could improve home blood pressure variability among hemodialysis patients who had achieved their dry weight.

Increased Mortality Associated with Higher Pre-Dialysis Serum Sodium Variability: Results of the International MONitoring Dialysis Outcome Initiative

Background: Low serum sodium (SNa) is associated with an increased mortality in chronic hemodialysis (HD) patients. Dialysis patients are thought to have an individual pre-dialysis SNa set-point, yet there is evidence for variability of pre-dialysis SNa in individual patient. In this study, we explored the association of several SNa variability metrics with all-cause mortality in a large patient population from the international MONitoring Dialysis Outcomes (MONDO) Initiative. Methods: All adult incident patients from the MONDO database with more than 5 SNa measurements during the first year on HD were included. All patients were required to survive the first year on HD (defined as the baseline). During the subsequent 2 years of follow-up, all-cause mortality was recorded. The following variability indicators were calculated during baseline: mean SNa and its SD; average real variability (ARV, average the absolute distance of the 2 consecutive SNa measurements), and average directional range (DR, the difference between minimum and maximum values). We used Cox Proportional hazard model with bivariate spline terms to analyze the joint association of SNa and SD, ARV and DR, respectively, with all-cause mortality. While conducting the multivariate Cox regression analyses, patients were stratified into 3 groups of DR (Negative DR: –20≤ DR ≤ –6, Null DR: –6< DR < 6 and Positive DR: 6≤ DR ≤20) with the Null DR as the reference group. Results: We included 20,216 patients in the study. A SNa ≤135 mEq/L was observed to be the strongest predictor of evaluated mortality risk. Higher SNa variability (quantified as SD, ARV, and DR) was also associated with an increased mortality irrespective of SNa levels. When compared with higher SD or ARV, greater DR showed a stronger association with an elevated risk of death. Controlling the Cox Proportional hazard models for additional parameters showed consistent results. Conclusion: Higher SNa variability associated with increased all-cause mortality at all levels of SNa. DR of SNa showed the strongest association with mortality and may constitute a Simple and novel prognostic indicator, easily applicable at the bedside.

Primary outcomes of the Monitoring in Dialysis Study indicate that clinically significant arrhythmias are common in hemodialysis patients and related to dialytic cycle

Sudden death is one of the more frequent causes of death for hemodialysis patients, but the underlying mechanisms, contribution of arrhythmia, and associations with serum chemistries or the dialysis procedure are incompletely understood. To study this, implantable loop recorders were utilized for continuous cardiac rhythm monitoring to detect clinically significant arrhythmias including sustained ventricular tachycardia, bradycardia, asystole, or symptomatic arrhythmias in hemodialysis patients over six months. Serum chemistries were tested pre- and post-dialysis at least weekly. Dialysis procedure data were collected at every session. Associations with clinically significant arrhythmias were assessed using negative binomial regression modeling. Sixty-six patients were implanted and 1678 events were recorded in 44 patients. The majority were bradycardias (1461), with 14 episodes of asystole and only one of sustained ventricular tachycardia. Atrial fibrillation, although not defined as clinically significant arrhythmias, was detected in 41% of patients. With thrice-weekly dialysis, the rate was highest during the first dialysis session of the week and was increased during the last 12 hours of each inter-dialytic interval, particularly the long interval. Among serum and dialytic parameters, only higher pre-dialysis serum sodium and dialysate calcium over 2.5 mEq/L were independently associated with clinically significant arrhythmias. Thus, clinically significant arrhythmias are common in hemodialysis patients, and bradycardia and asystole rather than ventricular tachycardia may be key causes of sudden death in hemodialysis patients. Associations with the temporal pattern of dialysis suggest that modification of current dialysis practices could reduce the incidence of sudden death.