Risk factors for hypertension in chronic hemodialysis patients: baseline data from the HEMO study

Effect of medium cut-off and high-flux hemodialysis membranes on blood pressure assessed by ambulatory blood pressure monitoring

BACKGROUND

Hypertension is one of the most critical risk factors for cardiovascular disease, which is the leading cause of death in hemodialysis (HD) patients. Medium cut-off (MCO) membrane increases the clearance of medium molecules, which could improve blood pressure (BP) control. This study aimed to compare the effect of MCO and high-flux hemodialysis membranes on BP assessed by ambulatory blood pressure monitoring (ABPM).

METHODS

This is a pre-established secondary analysis of a 28-week, randomized, open-label crossover clinical trial. Patients were randomized to HD with MCO or high-flux membranes over 12 weeks, followed by a 4-week washout period, and then switched to the alternate membrane treatment for 12 weeks. ABPM was started before the HD session and ended at least 24 h later in weeks 1, 12, 16, and 28.

RESULTS

32 patients, 59% male, with a mean age of 52.7 years, and 40% with unknown CKD etiology, were enrolled. The dialysis vintage was 8 years, and more than 70% of the patients had hypertension. Regarding 24-h BP control, morning diastolic BP showed an increase in the high-flux compared to stability in the MCO group (interaction effect, p = 0.039). The adjusted ANOVA models showed no significant difference in the morning BP levels between the groups. Considering only the period of the HD session, patients in the MCO, compared to those in the high-flux membrane group, showed greater BP stability during dialysis, characterized by smaller variation in the pre-post HD systolic and minimum systolic BP (treatment effect, p = 0.039, and p = 0.023, respectively).

CONCLUSIONS

MCO membrane seems to have a beneficial effect on morning BP and favors better BP stability during HD sessions.

Different time points, different blood pressures: complexity of blood pressure measurement in hemodialysis patients

OBJECTIVE

We used our established database to investigate predialysis blood pressure (BP) measurements at different time points.

METHODS

Our study period spanned from 1 January 2019 to 31 December 2019. The different time points included: the long interdialytic interval versus the short interdialytic interval; different hemodialysis shifts. Multiple linear regression was used to explore the association between BP measurements and different time points.

RESULTS

A total of 37 081 cases of hemodialysis therapies were included. After a long interdialytic interval, predialysis SBP and DBP were significantly elevated. Predialysis BP was 147.72/86.73 mmHg on Monday and 148.26/86.52 mmHg on Tuesday, respectively. Both predialysis SBP and DBP were higher in the a.m. shift. The mean BP in the a.m. and p.m. shifts were 147.56/87 mmHg and 144.83/84.64 mmHg, respectively. In both diabetic nephropathy and non-diabetic nephropathy patients, higher SBP measurements after a long interdialytic interval were observed; however, in diabetic nephropathy patients, we did not find significant differences in DBP among different dates. In diabetic nephropathy and non-diabetic nephropathy patients, we observed that the effect of different shifts on BP was similar. In Monday, Wednesday and Friday subgroups, the long interdialytic interval was also associated with BP; however, in Tuesday, Thursday and Saturday subgroups, different shifts but not the long interdialytic interval was associated with BP.

CONCLUSION

The long interdialytic interval and different hemodialysis shifts have a significant effect on predialysis BP in patients with hemodialysis. When interpreting BP in patients with hemodialysis, different time points is a confounder.

Diagnosis and treatment of hypertension in dialysis patients: a systematic review

In patients with end-stage renal disease (ESRD) undergoing dialysis, hypertension is common but often inadequately controlled. The prevalence of hypertension varies widely among studies because of differences in the definition of hypertension and the methods of used to measure blood pressure (BP), i.e., peri-dialysis or ambulatory BP monitoring (ABPM). Recently, ABPM has become the gold standard for diagnosing hypertension in dialysis patients. Home BP monitoring can also be a good alternative to ABPM, emphasizing BP measurement outside the hemodialysis (HD) unit. One thing for sure is pre- and post-dialysis BP measurements should not be used alone to diagnose and manage hypertension in dialysis patients. The exact target of BP and the relationship between BP and all-cause mortality or cause-specific mortality are unclear in this population. Many observational studies with HD cohorts have almost universally reported a U-shaped or even an L-shaped association between BP and all-cause mortality, but most of these data are based on the BP measured in HD units. Some data with ABPM have shown a linear association between BP and mortality even in HD patients, similar to the general population. Supporting this, the results of meta-analysis have shown a clear benefit of BP reduction in HD patients. Therefore, further research is needed to determine the optimal target BP in the dialysis population, and for now, an individualized approach is appropriate, with particular emphasis on avoiding excessively low BP. Maintaining euvolemia is of paramount importance for BP control in dialysis patients. Patient heterogeneity and the lack of comparative evidence preclude the recommendation of one class of medication over another for all patients. Recently, however, β-blockers could be considered as a first-line therapy in dialysis patients, as they can reduce sympathetic overactivity and left ventricular hypertrophy, which contribute to the high incidence of arrhythmias and sudden cardiac death. Several studies with mineralocorticoid receptor antagonists have also reported promising results in reducing mortality in dialysis patients. However, safety issues such as hyperkalemia or hypotension should be further evaluated before their use.

Resistant hypertension in dialysis

Hypertension is the most common finding in chronic kidney disease patients, with prevalence ranging from 60% to 90% depending on the stage and etiology of the disease. It is also a significant independent risk factor for cardiovascular disease, progression to end-stage kidney disease and mortality. According to the current guidelines, resistant hypertension is defined in the general population as uncontrolled blood pressure on three or more antihypertensive drugs in adequate doses or when patients are on four or more antihypertensive drug categories irrespective of the blood pressure control, providing that antihypertensive treatment included diuretics. The currently established definitions of resistant hypertension are not directly applicable to the end-stage kidney disease setting. The diagnosis of true resistant hypertension requires confirmation of adherence to therapy and confirmation of uncontrolled blood pressure values by ambulatory blood pressure measurement or home blood pressure measurement. In addition, the term "apparent treatment-resistant hypertension," defined as an uncontrolled blood pressure on three or more antihypertensive medication classes, or use of four or more medications regardless of blood pressure level was introduced. In this comprehensive review we focused on the definitions of hypertension, and therapeutic targets in patients on renal replacement therapy, including the limitations and biases. We discussed the issue of pathophysiology and assessment of blood pressure in the dialyzed population, management of resistant hypertension as well as available data on prevalence of apparent treatment-resistant hypertension in end-stage kidney disease. To conclude, larger sample-size and even higher quality studies about drug adherence should be conducted in the population of patients with the end-stage kidney disease who are on dialysis. It also should be determined how and when blood pressure should be measured in the group of dialysis patients. Additionally, it should be stated what the target blood pressure values in this group of patients really are. The definition of resistant hypertension in this group should be revisited, and its relationship to both subclinical and clinical endpoints should be established.

Apparently Resistant Hypertension in Polish Hemodialyzed Population: Prevalence and Risk Factors

BACKGROUND

The aim of this study was to assess the prevalence, characteristics, and determinants of apparent treatment-resistant hypertension (aTRH) in an unselected large population of patients with end-stage kidney disease (ESKD) treated with hemodialysis (HD) throughout the country.

METHODS

A database of 5879 patients (mean age 65.2 ± 14.2 years, 60% of males receiving hemodialysis) was obtained from the biggest provider of hemodialysis in the country. Hypertension and aTRH were defined using pre- or/and post-dialysis BP values. Patients with and without aTRH (non-aTRH) were compared.

RESULTS

Using pre- and post-dialysis criteria, hypertension was diagnosed in 90.7% and 89.1% of subjects, respectively. According to pre- and post-dialysis blood pressure criteria, aTRH incidences were 40.9% and 38.4%, respectively. The hypertensive patients with aTRH versus non-aTRH were younger, had a higher rate of cardiovascular disease, lower dialysis vintage, shorter time on dialysis, higher eKt/V, higher ultrafiltration, higher pre- and post-dialysis BP and HR, and higher use of antihypertensive drugs. Factors that increase the risk of aTRH according to both pre- and post-dialysis BP criteria were age-OR 0.99 [0.98-0.99] and 0.99 [0.98-0.99], the history of CVD 1.26 [1.08-1.46] and 1.30 [1.12-1.51], and diabetes 1.26 [1.08-1.47] and 1.28 [1.09-1.49], adjusted OR with 95% CI.

CONCLUSIONS

In the real-life world, as much as 40% of HD patients may have aTRH. In ESKD HD patients, aTRH seems to be multifactorial, influenced by patient-related rather than dialysis-related factors. Various definitions of aTRH preclude easy comparisons between studies.

Role of Antihypertensives in End-Stage Renal Disease: A Systematic Review

The primary goal of this research is to identify the factors of intradialytic hypertension in hemodialysis patients and stabilize blood pressure (BP) even without antihypertensive medicines. There are various treatment alternatives for lowering BP in these patients, many of which do not require extra pharmacological therapy (e.g. long, slow hemodialysis; short, daily hemodialysis; nocturnal hemodialysis; or, most effectively, dietary salt and fluid restriction in addition to the reduction of dialysate sodium concentration). These parameters provide good monitoring of BP, even with previously diagnosed hypertension. The adjustment of the extracellular volume with a low incidence of intradialytic hypotensive episodes is the most plausible explanation for this outcome.

We did a systematic evaluation of all published articles since 1994 to evaluate antihypertensive drug outcomes in hemodialysis patients. All articles were searched in the English language using PubMed and Google Scholar databases. The screening techniques, study selection, data extraction procedures, and risk evaluation of bias were done using specified criteria and overseen by one of the senior writers with the application of quality assessment tools to the final articles. Data were searched using regular and MeSH (Medical Subject Headings) keywords. Although substantial developments have emerged in the medical field, there is still a significant knowledge gap in the sector, particularly when it comes to BP guidelines and therapy choices for hypertensive hemodialysis patients. Until additional data are available, we should treat hypertension in hemodialysis with the use of active pursuit of euvolemia using dry weight probing and reduction of salt excess.

Prevalence and control of hypertension among patients on haemodialysis

BACKGROUND

Earlier studies provided considerably variable estimates on the prevalence and control rates of hypertension in haemodialysis because of their heterogeneity in definitions and blood pressure (BP) measurement techniques applied to detect hypertension.

MATERIALS AND METHODS

In this cross-sectional study, 116 clinically stable haemodialysis patients from 3 dialysis centres of Northern Greece underwent home BP monitoring for 1 week with the validated automatic device HEM-705 (Omron, Healthcare). Routine BP recordings taken before and after dialysis over 6 consecutive sessions were also prospectively collected and averaged. Hypertension was defined as: (a) 1-week averaged home BP ≥ 135/85 mm Hg; (b) 2-week averaged predialysis BP ≥ 140/90 mm Hg; and (c) 2-week averaged postdialysis BP ≥ 130/80 mm Hg. Participants on treatment with ≥1 antihypertensives were also classified as hypertensives.

RESULTS

The prevalence of hypertension was 88.8% by home, 86.2% by predialysis and 91.4% by postdialysis BP recordings. In all, 96 participants (82.7%) were being treated with an average of 2.0 ± 1.1 antihypertensive medications. Among drug-treated participants, 32.6% were controlled by home, 50.5% by predialysis and 45.3% by postdialysis BP recordings. In multivariate logistic regression analysis, greater use of antihypertensive medications and postdialysis overhydration, assessed with bioimpedance spectroscopy, were both independently associated with higher odds of inadequate home BP control.

CONCLUSIONS

This study shows that the prevalence, but mainly the control rates of hypertension in patients on haemodialysis, differs between peridialytic and interdialytic BP recordings. Therefore, the wider use of home BP monitoring may improve the determination of BP control status in this high-risk population.

Should we abandon GFR in the decision to initiate chronic dialysis?

The best time to start chronic dialysis during the course of CKD stage 5 is controversial. The first randomised control trial of dialysis initiation either in early or late CKD stage 5 in adults (IDEAL study), and 3 studies from the two largest paediatric registries, the U.S. Renal Data System (USRDS) and the European Society of Paediatric Nephrology (ESPN) Registry, have now provided us with evidence to guide us in this important decision-making process. The message 'no benefit from early start of dialysis' is the conclusion from all four studies. However, what are the limitations of these studies? Can GFR be assessed at CKD stages 4 and 5? What are the factors used to assess the benefit of early or late start? These issues are discussed in this review.

Sodium Removal in Patients Undergoing CAPD and Automated Peritoneal Dialysis

Objectives

To compare sodium removal in continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD) patients, and to identify the main factors that modify Na removal in clinical practice in these patients.

Design

Study in three steps. Cross-sectional observational (Study A), and longitudinal interventional (Studies B and C).

Patients and Methods

First (Study A) we carried out a cross-sectional survey of Na removal in 63 patients on CAPD and 78 patients on APD. Second (Study B), we studied Na removal in 32 patients before and after changing from CAPD to APD therapy. Finally (Study C), we analyzed the impact on Na removal of introducing icodextrin for the long dwell in 16 patients undergoing CAPD or APD.

Results

In Study A, total Na removal averaged 210 mmol/day for CAPD patients and 91 mmol/day for APD patients ( p < 0.001); Na removal was < 100 mmol/day in 7.1% of CAPD patients and 56.4% of APD patients. Multivariate analysis identified ultrafiltration [B = 125 mmol/day, 95% confidence interval (CI) 110, 140], CAPD therapy (B = 60 mmol/day, 95%CI 37, 83), and residual diuresis (B = 51 mmol/L, 95%CI 34, 69) as independent predictors of Na removal (adjusted r2 = 0.76). For APD patients, longer nocturnal dwell times and performing a supplementary diurnal exchange were also independently associated with higher Na removal rates. In Study B, Na removal decreased from 192 to 92 mmol/day (median) after the change to APD ( p = 0.02). In Study C, peritoneal Na removal increased from 98 to 148 mmol/day (median) ( p = 0.04) after introducing icodextrin.

Conclusions

Standard APD schedules are frequently associated with poor Na removal rates. For any degree of ultrafiltration, Na removal is better in CAPD than in APD. Icodextrin, supplementary diurnal exchanges, and longer nocturnal dwell times improve Na removal in APD. Sodium removal can be estimated from ultrafiltration in patients on CAPD, but must be specifically monitored in patients on APD.

Prevalence of Hypertension in Renal Diseases in Iran: Systematic Review and Meta-Analysis

BACKGROUND

Hypertension is a risk factor for renal disease. Therefore, this study was aimed at estimating the prevalence of hypertension in renal patients in Iran through meta-analysis.

METHODS

The search was carried out using authentic Persian and English keywords in national and international databases including IranMedex, SID, Magiran, IranDoc, Medlib, ScienceDirect, Pubmed, Scopus, Cochrane, Embase, Web of Science, Medline, and Google Scholar search engine without any time limitation until 2017. Heterogeneity of studies was assessed using the I 2 index. Data were analyzed using STATA ver 11.

RESULTS

In 35 reviewed studies with a sample of 39,621 subjects, the prevalence of hypertension in renal patients was 35% (95% CI: 29%-41%) (25% in women and 18% in men). The prevalence of systolic hypertension in renal patients was 5%, diastolic hypertension 26%, and diabetes 23%. The prevalence of hypertension in hemodialysis patients was 34%, 27% in peritoneal dialysis, 43% in kidney transplantation, and 26% in chronic renal failure. In addition, meta-regression showed that the prevalence of hypertension in renal patients did not significantly decrease during the years 1988-2017.

CONCLUSIONS

More than a third of kidney patients in Iran suffer from high blood pressure. The diastolic blood pressure of these patients is about five times higher than their systolic blood pressure. Moreover, the age group under 30 is a high-risk group. The prevalence of hypertension in women with kidney disease is higher than in men. In addition, patients who have kidney transplants are more likely to have high blood pressure than other kidney patients.

Comparison of Chronic Hemodialysis Patients under Strict Volume Control with respect to Cardiovascular Disease

BACKGROUND

The objective of this study was to determine the effects of strict volume control and nondipper situation on cardiovascular disease in chronic hemodialysis patients.

METHODS

This study is an observational and cross-sectional study including 62 patients with normotensive chronic hemodialysis using no antihypertensive drugs. A series of measurements including ambulatory blood pressure monitoring, left ventricular mass index by echocardiography, common carotid artery intima-media thickness by ultrasound, and body fluids by bioimpedance analysis were conducted for all subjects.

RESULTS

The patients were divided into two groups as dippers and nondippers according to their ambulatory blood pressure monitoring results. Average 48 h systolic, diastolic, and mean arterial blood pressure and nocturnal systolic, diastolic, and mean arterial blood pressure were significantly different between the dipper and nondipper groups (p<0.05). Before and after dialysis, extracellular fluid/intracellular fluid and extracellular fluid/dry body weight ratios were significantly higher in the nondipper group. Left ventricle mass index and interventricular septum thickness were significantly higher in the nondipper group (p<0.05). Left ventricle ejection fraction was significantly lower and common carotid artery intima-media thickness was higher in the nondipper group with a statistical significance (p<0.05). A two-predictor logistic model was fitted to the data to predict the comparability of dippers and nondippers.

CONCLUSION

According to logistic regression analysis, the odds ratio for daytime diastolic blood pressure indicates that nondippers are 0.45 times more likely to have high blood pressure than dippers in daytime. But in night time, nondippers are about 2.55 times more likely to have high blood pressure comparing to dippers. An important finding of this study is that nondipping pattern is associated with cardiac hypertrophy and lower left ventricle ejection fraction in dialysis of patients with no hypertension. The results also suggest that applying strict volume control to achieve a normal blood pressure alone is not sufficient to reduce the risk of cardiovascular morbidity and mortality if the patients do not have a dipper status of nocturnal blood pressure.

A need for a paradigm shift in focus: From Kt/Vurea to appropriate removal of sodium (the ignored uremic toxin)

Hemodialysis for chronic renal failure was introduced and developed in Seattle, WA, in the 1960s. Using Kiil dialyzers, weekly dialysis time and frequency were established to be about 30 hours on 3 time weekly dialysis. This dialysis time and frequency was associated with 10% yearly mortality in the United States in 1970s. Later in 1970s, newer and more efficient dialyzers were developed and it was felt that dialysis time could be shortened. An additional incentive to shorten dialysis was felt to be lower cost and higher convenience. Additional support for shortening dialysis time was provided by a randomized prospective trial performed by National Cooperative Dialysis Study (NCDS). This study committed a Type II statistical error rejecting the time of dialysis as an important factor in determining the quality of dialysis. This study also provided the basis for the establishment of the Kt/V_urea index as a measure of dialysis adequacy. This index having been established in a sacrosanct randomized controlled trial (RCT), was readily accepted by the HD community, and led to shorter dialysis, and higher mortality in the United States. Kt/V_urea is a poor measure of dialysis quality because it combines three unrelated variables into a single formula. These variables influence the clinical status of the patient independent of each other. It is impossible to compensate short dialysis duration (t) with the increased clearance of urea (K), because the tolerance of ultrafiltration depends on the plasma-refilling rate, which has nothing in common with urea clearance. Later, another RCT (the HEMO study) committed a Type III statistical error by asking the wrong research question, thus not yielding any valuable results. Fortunately, it did not lead to deterioration of dialysis outcomes in the United States. The third RCT in this field ("in-center hemodialysis 6 times per week versus 3 times per week") did not bring forth any valuable results, but at least confirmed what was already known. The fourth such trial ("The effects of frequent nocturnal home hemodialysis") too did not show any positive results primarily due to significant subject recruitment issues leading to inappropriate selection of patients. Comparison of the value of peritoneal dialysis and HD in RCTs could not be completed because of recruitment problems. Randomized controlled trials have therefore failed to yield any meaningful information in the area of dose and or frequency of hemodialysis.

Association of Ultrafiltration Rate with Mortality in Incident Hemodialysis Patients

BACKGROUND/AIMS

Ultrafiltration rate (UFR) appears to be associated with mortality in prevalent hemodialysis (HD) patients. However, the association of UFR with mortality in incident HD patients remains unknown.

METHODS

We examined a US cohort of 110,880 patients who initiated HD from 2007 to 2011. Baseline UFR was divided into 5 groups (<4, 4 to <6, 6 to <8, 8 to <10, and ≥10 mL/h/kg body weight [BW]). We examined predictors of higher baseline UFR using logistic regression and the association of baseline UFR and all-cause and cardiovascular (CV) mortality using Cox proportional hazard models with adjustments for demographics, comorbidities, and markers of malnutrition-inflammation-cachexia syndrome.

RESULTS

Patients were 63 ± 15 years, with 43% women, 32% African Americans, and had a mean baseline UFR of 7.5 ± 3.1 mL/h/kg BW. In the fully adjusted logistic regression models, factors associated with higher UFR (≥7.5 mL/h/kg BW) included Hispanic ethnicity, diabetes, and higher dietary protein intake. There was a linear association between UFR and all-cause and CV mortality, where UFR ≥10 mL/h/kg BW (reference UFR 6-<8 mL/h/kg BW) conferred the highest risk in both unadjusted (HR 1.15 [95% CI 1.10-1.19]) and adjusted models (HR 1.23 [95% CI 1.16-1.31]). The linear association with all-cause mortality remained consistent across strata of age, urine volume, and treatment time.

CONCLUSIONS

Higher UFR is independently associated with higher all-cause and CV mortality in incident HD patients. Clinical trials are warranted to examine the effects of lowering UFR on outcomes.

N-Terminal Prohormone of Brain Natriuretic Peptide but not C-Terminal Pre-Pro Vasopressin (Copeptin) Level is Associated with the Response to Antihypertensive Therapy in Haemodialysis Patients

BACKGROUND/AIMS

Volume overload, frequently clinically asymptomatic is considered as a causative factor limiting the effectiveness of antihypertensive therapy in haemodialysis (HD) patients. Therefore, the aim of this study was to assess plasma levels of N-terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP) and a C-terminal portion of the precursor of vasopressin (CT-proAVP, copeptin), surrogate markers of volume overload in HD patients in relation to the number of antihypertensive drugs used in the hypertension treatment.

METHODS

One hundred and fifty adult HD patients (92 males) were enrolled into this study. Clinical data concerning blood pressure (BP) measurements prior haemodialysis session and pharmacotherapy were collected from all patients. In addition to routine laboratory parameters, plasma levels of NT-proBNP and CT-proAVP were measured, and daily sodium and water consumption were estimated with a portion-size food frequency questionnaire.

RESULTS

Among 145 (96.7%) hypertensive HD patients, 131 were receiving antihypertensive medication. Despite antihypertensive therapy, 31.0% had inadequate BP control. Plasma concentration of NT-proBNP was associated with systolic (R=0.19; p=0.02) but not diastolic BP values and with the number of received antihypertensive drugs (R=0.21; p=0.01). The highest NT-proBNP values were observed in patients receiving 3 or more antihypertensive drugs. In contrast, no significant correlation was found between plasma CT-proAVP concentrations and BP values as well as and the number of antihypertensive drugs. Receiver operator curve analysis showed that NT-proBNP values over 13,184 pg/mL predicted the use of at least 3 antihypertensive drugs in maximal doses in the therapy of hypertension, similar analyses performed for CT-proAVP showed much less specificity.

CONCLUSIONS

1. Increased levels of NT-proBNP seems to be a better biomarker of multidrug antihypertensive therapy requirement than CT-proAVP. 2. Whether estimation of NT-proBNP in these patients will be also better biomarker than copeptin in the prediction of cardiovascular complications related to hypertension needs further investigations.

Hypertension in dialysis patients: a consensus document by the European Renal and Cardiovascular Medicine (EURECA-m) working group of the European Renal Association - European Dialysis and Transplant Association (ERA-EDTA) and the Hypertension and the Kidney working group of the European Society of Hypertension (ESH)

In patients with end-stage renal disease treated with hemodialysis or peritoneal dialysis, hypertension is very common and often poorly controlled. Blood pressure (BP) recordings obtained before or after hemodialysis display a J-shaped or U-shaped association with cardiovascular events and survival, but this most likely reflects the low accuracy of these measurements and the peculiar hemodynamic setting related with dialysis treatment. Elevated BP by home or ambulatory BP monitoring is clearly associated with shorter survival. Sodium and volume excess is the prominent mechanism of hypertension in dialysis patients, but other pathways, such as arterial stiffness, activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, endothelial dysfunction, sleep apnea and the use of erythropoietin-stimulating agents may also be involved. Nonpharmacologic interventions targeting sodium and volume excess are fundamental for hypertension control in this population. If BP remains elevated after appropriate treatment of sodium-volume excess, the use of antihypertensive agents is necessary. Drug treatment in the dialysis population should take into consideration the patient's comorbidities and specific characteristics of each agent, such as dialysability. This document is an overview of the diagnosis, epidemiology, pathogenesis and treatment of hypertension in patients on dialysis, aiming to offer the renal physician practical recommendations based on current knowledge and expert opinion and to highlight areas for future research.

The Combination of Beta Blockers and Renin-Angiotensin System Blockers Improves Survival in Incident Hemodialysis Patients: A Propensity-Matched Study

INTRODUCTION

Although several studies suggest that the prognosis of hypertensive dialysis patients can be improved by using antihypertensive drug therapy, it is unknown whether the prescription of a particular class or combination of antihypertensive drugs is beneficial during hemodialysis.

METHODS

We performed a propensity score matching study to compare the effectiveness of various classes of antihypertensive drugs on cardiovascular (CV) mortality in 2518 incident hemodialysis patients in Spain. The patients had initially received antihypertensive therapy with a renin-angiotensin system (RAS) blocker (728 patients), a ß-blocker (679 patients), antihypertensive drugs other than a RAS blocker or a ß-blocker (787 patients), or the combination of a ß-blocker and a RAS inhibitor (324 patients). These patients were followed for a maximum of 5 years (median: 2.21 yr; range: 1.04-3.34 yr).

RESULTS

After adjustment for baseline CV risk covariates, no significant differences were observed in the risk of CV mortality between patients taking a RAS blocker and patients treated with ß-blocker-based antihypertensive therapy. The combination of a RAS blocker with a ß-blocker was associated with better CV survival than either agent alone (RAS blocker: hazard ratio [HR]: 1.68; 95% confidence interval [CI] 1.05-2.69; ß-blocker: HR: 1.59; 95% CI: 1.01-2.50; antihypertensive medication other than a RAS blocker or ß-blocker: HR: 1.67; 95% CI: 1.08-2.58).

DISCUSSION

Our data suggested that the combination of a RAS blocker and a ß-blocker could improve survival in hemodialysis patients. Further prospective randomized controlled trials are necessary to confirm the beneficial effects of this combination of antihypertensive drugs in patients undergoing hemodialysis.

Hypertension in dialysis patients: a consensus document by the European Renal and Cardiovascular Medicine (EURECA-m) working group of the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) and the Hypertension and the Kidney working group of the European Society of Hypertension (ESH)

In patients with end-stage renal disease (ESRD) treated with haemodialysis or peritoneal dialysis, hypertension is common and often poorly controlled. Blood pressure (BP) recordings obtained before or after haemodialysis display a J- or U-shaped association with cardiovascular events and survival, but this most likely reflects the low accuracy of these measurements and the peculiar haemodynamic setting related to dialysis treatment. Elevated BP detected by home or ambulatory BP monitoring is clearly associated with shorter survival. Sodium and volume excess is the prominent mechanism of hypertension in dialysis patients, but other pathways, such as arterial stiffness, activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, endothelial dysfunction, sleep apnoea and the use of erythropoietin-stimulating agents may also be involved. Non-pharmacologic interventions targeting sodium and volume excess are fundamental for hypertension control in this population. If BP remains elevated after appropriate treatment of sodium and volume excess, the use of antihypertensive agents is necessary. Drug treatment in the dialysis population should take into consideration the patient's comorbidities and specific characteristics of each agent, such as dialysability. This document is an overview of the diagnosis, epidemiology, pathogenesis and treatment of hypertension in patients on dialysis, aiming to offer the renal physician practical recommendations based on current knowledge and expert opinion and to highlight areas for future research.

Blood Pressure of Maintenance Hemodialysis Patients in the Dalmatian Region of Croatia: Differences between Hospital and Out-of-Hospital Dialysis Centers

AIMS

This study was aimed at comparing the incidence of arterial hypertension and blood pressure (BP) variance in hospital and out-of-hospital hemodialysis (HD) patients during HD sessions.

METHODS

A cross-sectional study was conducted for 1 week at all the HD centers in Dalmatia, Croatia. The pre-, intra-, and post-dialysis BP values were collected for 3 consecutive HD sessions per patient.

RESULTS

Of the 399 subjects, 73.9% were hypertensives, who showed higher interdialytic weight gain compared to the normotensives (2.58 vs. 2.40). Hospital and out-of-hospital HD patients received identical antihypertensive therapies, except that beta blockers were more frequently administered to out-of-hospital HD patients. Higher pre-, intra-, and post-dialysis BP values were recorded in patients at out-of-hospital HD centers.

CONCLUSION

The differences in BP variability and antihypertensive therapies administered to hospital HD patients as compared to out-of-hospital HD patients may reflect differing approaches by the nephrologists at these centers.

Nutritional counseling regulates interdialytic weight gain and blood pressure in outpatients receiving maintenance hemodialysis

Maintenance hemodialysis outpatients must limit salt and water intake to maintain electrolyte balance and blood pressure. In Kawashima Hospital, nationally registered dietitians provide hemodialysis patients with monthly nutritional counseling. We investigated whether nutritional counseling affects interdialytic weight gain (IDWG) and blood pressure. We investigated 48 hemodialysis patients whose monthly average IDWG ratio to dry weight exceeded 5.1% and who had not had a long-term hospital admittance of > 1 month. After the 48-month nutritional counseling period, the IDWG ratio had improved in 37 of the patients (77.1%), significantly decreasing from 6.0±0.7 to 5.3±0.9%. Estimated salt and water intake decreased significantly from 13.3±2.7 to 11.8±2.4 g/day and 2528±455 to 2332±410 ml/day, respectively. During the intervention period, normalized protein catabolic rate and body mass index did not change substantially. Pre-hemodialysis systolic and diastolic blood pressures had significantly decreased from 149±19 to 134±18 mmHg, and 82±13 to 75±10 mmHg for 48 months after study initiation, respectively. The dosage of antihypertensive drugs had significantly decreased in the group that experienced improvement in the IDWG ratio. Long-term nutritional counseling by nationally registered dietitians may improve the IDWG ratio and blood pressure of hemodialysis patients by decreasing their salt and water intake. J. Med. Invest. 64: 129-135, February, 2017.

Relationship between Hemoglobin Levels Corrected by Interdialytic Weight Gain and Mortality in Japanese Hemodialysis Patients: Miyazaki Dialysis Cohort Study

BACKGROUND

Although hemoglobin (Hb) levels are affected by a change in the body fluid status, the relationship between Hb levels and mortality while taking interdialytic weight gain (IDWG) at blood sampling into account has not yet been examined in hemodialysis patients.

STUDY DESIGN

Cohort study.

SETTING, PARTICIPANTS

Data from the Miyazaki Dialysis cohort study, including 1375 prevalent hemodialysis patients (median age (interquartile range), 69 (60-77) years, 42.3% female).

PREDICTOR

Patients were divided into 5 categories according to baseline Hb levels and two groups based on the median value of IDWG rates at blood sampling at pre-HD on the first dialysis session of the week.

OUTCOMES

All-cause and cardiovascular mortalities during a 3-year follow-up.

MEASUREMENTS

Hazard ratios were estimated using a Cox model for the relationship between Hb categories and mortality, and adjusted for potential confounders such as age, sex, dialysis duration, erythropoiesis-stimulating agent dosage, Kt/V, comorbid conditions, anti-hypertensive drug use, serum albumin, serum C-reactive protein, serum ferritin, and serum intact parathyroid hormone. Patients with Hb levels of 9-9.9 g/dL were set as our reference category.

RESULTS

A total of 246 patients (18%) died of all-cause mortality, including 112 cardiovascular deaths. Lower Hb levels (<9.0g/dL) were associated with all-cause mortality (adjusted HRs 2.043 [95% CI, 1.347-3.009]), while Hb levels were not associated with cardiovascular mortality. When patients were divided into two groups using the median value of IDWG rates (high IDWG, ≥5.4% and low IDWG, <5.4%), the correlation between lower Hb levels and all-cause mortality disappeared in high IDWG patients, but was maintained in low IDWG patients (adjusted HRs 3.058 [95% CI,1.575-5.934]). On the other hand, higher Hb levels (≥12g/dL) were associated with cardiovascular mortality in high IDWG patients (adjusted HRs 2.724 [95% CI, 1.010-7.349]), but not in low IDWG patients.

CONCLUSION

In hemodialysis patients, target Hb levels may need to be selected in consideration of IDWG at blood sampling.

Association Between Hypertension and Residual Renal Function in Hemodialysis Patients

Introduction. Cardiovascular diseases are the leading cause of death in hemodialysis patients. The decline of residual renal function increases the prevalence and severity of risk factors of cardiovascular morbidity and mortality in these patients. Hypertension is common in dialysis patients and represents an important independent factor of survival in these patients.

Methods. The study included 77 patients who are on chronic HD for longer than 3 months. Depending on the measured residual diuresis patients were divided into two groups. The study group consisted of patients with residual diuresis >250 ml/day, while patients from control group had residual diuresis <250 ml/day. All patients had their blood pressure measured before 10 consecutive hemodialysis treatments. Collected data were statistically analyzed using SPSS 16.0.

Results. The study included 77 hemodialysis patients, mean age of 56.56±14.6 years and mean duration of hemodialysis treatment of 24.0 months. Of the total number of patients, 39(50.6%) had preserved residual renal function. Hypertension was more common in the group of patients who did not have preserved residual renal function (68.4% vs 25.6%). There was statistically significant negative linear correlation between the volume of residual urine output and the residual clearance of urea and values of systolic blood pressure [(rho=−0.388; p<0.0001); (rho=−0.392; p<0.0005)], values of mean arterial pressure [(rho =−0.272; p<0.05); (rho=−0.261; p=0.023; p<0.05)] and values of pulse pressure in hemodialysis patients [(rho =−0.387; p<0.001); (rho=−0.400; p<0.0005)].

Conclusions. Residual renal function plays an important role in controlling blood pressure in patients on hemodialysis. More attention should be directed to preserve residual renal function, and after the start of hemodialysis by avoiding intensive ultrafiltration with optimal antihypertensive therapy.

Epidemiology, diagnosis and management of hypertension among patients on chronic dialysis

The diagnosis and management of hypertension among patients on chronic dialysis is challenging. Routine peridialytic blood pressure recordings are unable to accurately diagnose hypertension and stratify cardiovascular risk. By contrast, blood pressure recordings taken outside the dialysis setting exhibit clear prognostic associations with survival and might facilitate the diagnosis and long-term management of hypertension. Once accurately diagnosed, management of hypertension in individuals on chronic dialysis should initially involve non-pharmacological strategies to control volume overload. Accordingly, first-line strategies should focus on achieving dry weight, individualizing dialysate sodium concentrations and ensuring dialysis sessions are at least 4 h in duration. If blood pressure remains unresponsive to volume management strategies, pharmacological treatment is required. The choice of appropriate antihypertensive regimen should be individualized taking into account the efficacy, safety, and pharmacokinetic properties of the antihypertensive medications as well as any comorbid conditions and the overall risk profile of the patient. In contrast to their effects in the general hypertensive population, emerging evidence suggests that β-blockers might offer the greatest cardioprotection in hypertensive patients on dialysis. In this Review, we discuss estimates of the epidemiology of hypertension in the dialysis population as well as the challenges in diagnosing and managing hypertension among these patients.

Antidepressants for treating depression in adults with end-stage kidney disease treated with dialysis

BACKGROUND

Depression affects approximately one-quarter of people treated with dialysis and is considered an important research uncertainty by patients and health professionals. Treatment for depression in dialysis patients may have different benefits and harms compared to the general population due to different clearances of antidepressant medication and the severity of somatic symptoms associated with end-stage kidney disease (ESKD). Guidelines suggest treatment of depression in dialysis patients with pharmacological therapy, preferably a selective serotonin reuptake inhibitor. This is an update of a review first published in 2005.

OBJECTIVES

To evaluate the benefit and harms of antidepressants for treating depression in adults with ESKD treated with dialysis.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register to 20 January 2016 through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing antidepressant treatment with placebo or no treatment, or compared to another antidepressant medication or psychological intervention in adults with ESKD (estimated glomerular filtration rate < 15 mL/min/1.73 m(2)).

DATA COLLECTION AND ANALYSIS

Data were abstracted by two authors independently onto a standard form and subsequently entered into Review Manager. Risk ratios (RR) for dichotomous data and mean differences (MD) for continuous data were calculated with 95% confidence intervals (95% CI).

MAIN RESULTS

Four studies in 170 participants compared antidepressant therapy (fluoxetine, sertraline, citalopram or escitalopram) versus placebo or psychological training for 8 to 12 weeks. In generally very low or ungradeable evidence, compared to placebo, antidepressant therapy had no evidence of benefit on quality of life, had uncertain effects on increasing the risk of hypotension (3 studies, 144 participants: RR 1.72, 95% CI 0.75 to 3.92), headache (2 studies 56 participants: RR 2.91, 95% CI 0.73 to 11.57), and sexual dysfunction (2 studies, 101 participants: RR 3.83, 95% CI 0.63 to 23.34), and increased nausea (3 studies, 114 participants: RR 2.67, 95% CI 1.26 to 5.68). There were few or no data for hospitalisation, suicide or all-cause mortality resulting in inconclusive evidence. Antidepressant therapy may reduce depression scores during treatment compared to placebo (1 study, 43 participants: MD -7.50, 95% CI -11.94 to -3.06). Antidepressant therapy was not statistically different from group psychological therapy for effects on depression scores or withdrawal from treatment and a range of other outcomes were not measured.

AUTHORS' CONCLUSIONS

Despite the high prevalence of depression in dialysis patients and the relative priority that patients place on effective treatments, evidence for antidepressant medication in the dialysis setting is sparse and data are generally inconclusive. The relative benefits and harms of antidepressant therapy in dialysis patients are poorly known and large randomised studies of antidepressants versus placebo are required.

44-h ambulatory blood pressure monitoring: revealing the true burden of hypertension in pediatric hemodialysis patients

BACKGROUND

The blood pressure (BP) burden is high in pediatric hemodialysis (HD) patients and adversely affects prognosis. The aim of this study was to examine whether 44-h ambulatory BP monitoring (ABPM) provides additional relevant BP data compared with 24-h ABPM.

METHODS

ABPM was initiated at the end of the mid-week dialysis run in 13 stable pediatric HD patients and continued until the next run for 44 h. Day 1 was defined as the initial 24-h ABPM and Day 2 as the time period after that until the next dialysis run. All patients had an echocardiogram to calculate the left ventricular mass index (LVMI).

RESULTS

A higher percentage of patients were diagnosed with hypertension from the 44-h ABPM than from the 24-h ABPM. All BP indexes and loads (except nighttime diastolic load) were significantly higher on Day 2 than on Day 1. Patients with BP loads of ≥ 25 % on 44-h ABPM had significantly higher LVMI than those patients with normal BP loads. No such association was found with 24-h ABPM and LVMI. Higher interdialytic weight gain was associated with higher Day-2 nighttime systolic BP load.

CONCLUSIONS

The 44-h ABPM provides more information than the 24-h ABPM in terms of diagnosing and assessing the true burden of hypertension in pediatric HD patients. Elevated BP loads from 44-h ABPM correlate with a higher LVMI on the echocardiogram.

Effect of diet education on blood pressure changes and interdialytic weight in hemodialysis patients admitted in hajar hospital in shahrekord

Background and aim:

Nutrition is a key factor in the treatment of patients with chronic kidney disease because kidney burden decrease causes uremic reduction and its side effects. The aim of this research is to examine the effect of diet education on blood pressure changes and interdialytic weight in Hemodialysis patients admitted to Hemodialysis ward of Hajar hospital in Shahrekord.

Methods:

This quasi-experimental and interventional study of 100 dialysis patients referred to Hemodialysis ward of Hajar hospital was performed in a pre-test and post-test in 2011. Diet education, including face to face training with instruction booklets, were conducted in the two sessions. Having carried out the educational program, blood pressure and interdialytic weight gain were measured and recorded one month before and during three stages and after the educational program by researcher-designed checklists. The data were analyzed through Spss16 software by Paired t-test and ANOVA.

Results:

The results showed that mean of primary weight of the patients increase from 66.15±15.10 to 64.43±14.67. Mean of Systolic and diastolic blood pressure in patients in three stages were reduced to 6.65±1.51 mmg 2.24±1.82 mmg respectively. There was a significant difference between the creatinine amount in patients before and after of training (p≤0.01) but no meaningful difference was observed between the BUN amount before and after of training (p≤0.031).

Conclusion:

Training to patients underwent hemodialysis in order to observe diet and its effects on improvement in treatment are of significant importance.

Effect of diet education on blood pressure changes and interdialytic weight in hemodialysis patients admitted in hajar hospital in shahrekord

BACKGROUND AND AIM

Nutrition is a key factor in the treatment of patients with chronic kidney disease because kidney burden decrease causes uremic reduction and its side effects. The aim of this research is to examine the effect of diet education on blood pressure changes and interdialytic weight in Hemodialysis patients admitted to Hemodialysis ward of Hajar hospital in Shahrekord.

METHODS

This quasi-experimental and interventional study of 100 dialysis patients referred to Hemodialysis ward of Hajar hospital was performed in a pre-test and post-test in 2011. Diet education, including face to face training with instruction booklets, were conducted in the two sessions. Having carried out the educational program, blood pressure and interdialytic weight gain were measured and recorded one month before and during three stages and after the educational program by researcher-designed checklists. The data were analyzed through SPSS 16 software by Paired t-test and ANOVA.

RESULTS

The results showed that mean of primary weight of the patients increase from 66.15±15.10 to 64.43±14.67. Mean of Systolic and diastolic blood pressure in patients in three stages were reduced to 6.65±1.51 mmg 2.24±1.82 mmg respectively. There was a significant difference between the creatinine amount in patients before and after of training (p≤0.01) but no meaningful difference was observed between the BUN amount before and after of training (p≤0.031).

CONCLUSION

training to patients underwent hemodialysis in order to observe diet and its effects on improvement in treatment are of significant importance.

Assessment and management of hypertension in patients on dialysis

Hypertension is common, difficult to diagnose, and poorly controlled among patients with ESRD. However, controversy surrounds the diagnosis and treatment of hypertension. Here, we describe the diagnosis, epidemiology, and management of hypertension in dialysis patients, and examine the data sparking debate over appropriate methods for diagnosing and treating hypertension. Furthermore, we consider the issues uniquely related to hypertension in pediatric dialysis patients. Future clinical trials designed to clarify the controversial results discussed here should lead to the implementation of diagnostic and therapeutic techniques that improve long-term cardiovascular outcomes in patients with ESRD.

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

BACKGROUND

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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.

Identification of impeding factors for dry weight achievement in end-stage renal disease after appropriate kidney graft function

The aim of this study was to evaluate the factors that prevent dry weight achievement in patients with end-stage renal disease (ESRD) in renal replacement therapy through the change in their body weight after kidney transplant (KT) compared with 1 week before KT. The study included 188 ESRD patients of diverse etiology who received living kidney transplantation with normal immediate graft function, 62.2% were male, age 29 ± 11 years old. All patients were on renal replacement therapy for at least 1 month before KT with either hemodiafiltration (N = 106), hemodialysis (N = 25), or peritoneal dialysis (N = 57). Based on body weight difference (after transplant-before transplant), patients with body weight difference ≤2 kg were considered as being close to their dry weight (Group 1, N = 112), whereas patients with body weight difference >2 kg were considered as being overhydrated (Group 2, N = 76). Clinical and biochemical characteristics were obtained from the medical records at three periods of time: time of ESRD initiation (baseline), 1 week before undergoing KT, and 1 week after KT. The mean time (± standard deviation) from renal replacement therapy initiation to the week before KT was 9.2 ± 5 months. Group 2 had a higher proportion of men, antihypertensive use, peritoneal dialysis, and higher urine output during all periods. Before KT, Group 2 had higher systolic and diastolic blood pressures than Group 1. After KT, both systolic and diastolic blood pressures decreased in Group 2, whereas no change occurred in Group 1. Before KT, Group 2 had higher levels of blood urea nitrogen, creatinine, uric acid, and phosphorous compared with Group 1. Compared with baseline, Group 1 had more optimal blood urea nitrogen, creatinine, and uric acid parameters before KT than Group 2. After KT, all parameters improved with respect to baseline in both groups. Hemoglobin, albumin, and sodium were similar between groups, except for higher hemoglobin in Group 2 than Group 1 after KT. Multivariate regression analysis showed that male sex, peritoneal dialysis, and systolic blood pressure before KT were independent risk factors for overhydration. In conclusion, high systolic blood pressure and peritoneal dialysis were two independent modifiable variables associated with overhydration before KT. Assessment of the body weight change after KT is a useful tool to evaluate dry weight, in addition to identifying variables associated with poor volume control. This could allow adjustment of clinical and dialysis parameters in future patients.

Clinical audit improves hypertension control in hemodialysis patients

BACKGROUND

In patients on hemodialysis (HD), hypertension is a risk factor for cardiovascular disease. In this study we tested the effectiveness of a clinical audit in improving blood pressure (BP) control in HD patients. 


METHODS

177 adult, prevalent patients undergoing dialysis in NephroCare centers in Italy were audited. At the conclusion of the audit, individual strategies were developed in order to improve BP control. Patient data was collected and examined at months -1 (Pre), 0 (the date of the audit- Audit), and +1 and +6 after the audit (Post-1 and Post-6, respectively).
We recorded BP, information on factors affecting BP, and anti-hypertensive drug regimen. The primary outcome of the study was to decrease prevalence of hypertension (BP ≥ 140/90 mmHg). Secondary outcomes were a reduction in average BP in hypertensive patients and/or a decrease in drug delivery associated with lower or unchanged BP.


RESULTS

104 patients out of 177 (58.7%) were hypertensive at Audit. BP levels were directly related to comorbidity and male sex, and inversely related to dialysate sodium concentration. The announcement of the audit alone was associated with a decreased prevalence of hypertension (Pre 64.4% to Audit 58.7%); a further decrease followed the audit (Post-1 51.1%, Post-6 47.6%, p<0.05 vs. Audit). Systolic BP in hypertensive patients also decreased (mean decrease was -8.5 and -14.1; p = 0.007 and p<0.001 at Post-1 and Post-6). Number of drugs assumed was significantly lower at Post-1 and Post-6 vs. Audit (p = 0.005 and p<0.001, respectively).


CONCLUSIONS

A clinical audit is an effective tool to improve BP control in HD patients.

Reliability of blood pressure parameters for dry weight estimation in hemodialysis patients

Chronic volume overload resulting from interdialytic weight gain and inadequate fluid removal plays a significant role in poorly controlled high blood pressure. Although bioimpedance has been introduced as an accurate method for assessing hydration status, the instrument is not available in general hemodialysis (HEMO) centers. This study was conducted to explore the correlation between hydration status measured by bioimpedance and blood pressure parameters in chronic HEMO patients. Multifrequency bioimpedance analysis was used to determine pre- and post-dialysis hydration status in 32 stable HEMO patients. Extracellular water/total body water (ECW/TBW) determined by sum of segments from bioimpedance analysis was used as an index of hydration status. The mean age was 57.9 ± 16.4 years. The mean dry weight and body mass index were 57.7 ± 14.5 kg and 22.3 ± 4.7 kg/m(2), respectively. Pre-dialysis ECW/TBW was significantly correlated with only pulse pressure (r = 0.5, P = 0.003) whereas post-dialysis ECW/TBW had significant correlations with pulse pressure, systolic blood pressure, and diastolic blood pressure (r = 0.6, P = 0.001, r = 0.4, P = 0.04, r = -0.4, and P = 0.02, respectively). After dialysis, the mean values of ECW/TBW, systolic blood pressure, mean arterial pressure, and pulse pressure were significantly decreased. ECW/TBW was used to classify the patients into normohydration (≤ 0.4) and overhydration (>0.4) groups. Systolic blood pressure, mean arterial pressure, and pulse pressure significantly reduced after dialysis in the normohydration group but did not significantly change in the overhydration group. Pre-dialysis pulse pressure, post-dialysis pulse pressure, and post-dialysis systolic blood pressure in the overhydration group were significantly higher than normohydration group. Due to the simplicity and cost, blood pressure parameters, especially pulse pressure, might be a simple reference for clinicians to determine hydration status in HEMO patients.

Complications observed in older new haemodialysis patients in Taiwan

AIM

We aimed to evaluate the impacts of heomodialysis (HD) in older patients, and potential consequences of adverse events for health insurance costs.

METHODS

Two hundred and fifty-five new patients (130 were younger than 65 years and 125 were older than 65 years) who had received conventional HD for at least 1 year were reviewed.

RESULTS

Older patients had significantly more arteriovenous (AV) shunt failures (0.7 ± 0.1 vs 0.4 ± 0.07, P = 0.006) and hospitalisations (0.8 ± 0.1 vs 0.4 ± 0.09, P = 0.03) than younger ones. Stepwise multivariate linear regression analysis showed that AV shunt failure was an independent risk factor for hospitalisation.

CONCLUSIONS

The relatively high risk of AV shunt failures and hospitalisation in older patients highlights the additional expenditure on HD required in terms of health insurance.

Dialysis adequacy today: a European perspective

The need to improve haemodialysis (HD) therapies and to reduce cardiovascular and all-cause mortality frequently encountered by dialysis patients has been recognized and addressed for many years. A number of approaches, including increasing the frequency versus duration of treatment, have been proposed and debated in terms of their clinical efficacy and economic feasibility. Future prescription of dialysis to an expanding end-stage chronic kidney disease (CKD-5D) population needs a re-evaluation of existing practices while maintaining the emphasis on patient well-being both in the short and in the long term. Efficient cleansing of the blood of all relevant uraemic toxins, including fluid and salt overload, remains the fundamental objective of all dialysis therapies. Simultaneously, metabolic disorders (e.g. anaemia, mineral bone disease, oxidative stress) that accompany renal failure need to be corrected also as part of the delivery of dialysis therapy itself. Usage of high-flux membranes that enable small and large uraemic toxins to be eliminated from the blood is the first prerequisite towards the aforementioned goals. Application of convective therapies [(online-haemodiafiltration (OL-HDF)] further enhances the detoxification effects of high-flux haemodialysis (HF-HD). However, despite an extended clinical experience with both HF-HD and OL-HDF spanning more than two decades, a more widespread prescription of convective treatment modalities awaits more conclusive evidence from large-scale prospective randomized controlled trials. In this review, we present a European perspective on the need to implement optimal dialysis and to improve it by adopting high convective therapies and to discuss whether inertia to implement these practice patterns may deprive patients of significantly improved well-being and survival.

Association of base excision repair gene polymorphisms with ESRD risk in a Chinese population

The base excision repair (BER) pathway, containing OGG1, MTH1 and MUTYH, is a major protector from oxidative DNA damage in humans, while 8-oxoguanine (8-OHdG), an index of DNA oxidation, is increased in maintenance hemodialysis (HD) patients. Four polymorphisms of BER genes, OGG1 c.977C > G (rs1052133), MTH1 c.247G > A (rs4866), MUTYH c.972G > C (rs3219489), and AluYb8MUTYH (rs10527342), were examined in 337 HD patients and 404 healthy controls. And the 8-OHdG levels in leukocyte DNA were examined in 116 HD patients. The distribution of MUTYH c.972 GG or AluYb8MUTYH differed between the two groups and was associated with a moderately increased risk for end-stage renal disease (ESRD) (P = 0.013 and 0.034, resp.). The average 8-OHdG/10⁶ dG value was significantly higher in patients with the OGG1 c.977G, MUTYH c.972G or AluYb8MUTYH alleles (P < 0.001 via ANOVA). Further analysis showed that combination of MUTYH c.972GG with OGG1 c.977GG or AluYb8MUTYH increased both the risk for ESRD and leukocyte DNA 8-OHdG levels in HD patients. Our study showed that MUTYH c.972GG, AluYb8MUTYH, and combination of OGG1 c.977GG increased the risk for ESRD development in China and suggested that DNA oxidative damage might be involved in such process.

Blood pressure stability in hemodialysis patients confers a survival advantage: results from a large retrospective cohort study

The association between changes in systolic and diastolic blood pressure, and the use of cardioprotective drugs on survival of incident hemodialysis patients, was examined in this retrospective cohort study. Pre-hemodialysis systolic and diastolic blood pressures were averaged over the first month of hemodialysis. Slopes, reflecting temporal changes, were computed by linear regression of systolic blood pressures and Cox regression was used for survival analyses. Patients were initially stratified into four cohorts (below 120, 120 to 150, 151 to 180, and above 180 mm Hg) and further subdivided into groups with stable (no more than a 1-mm Hg change per month), increasing (over 1-mm Hg per month), and decreasing (less than 1-mm Hg per month) slopes during the first year. Analyses were repeated for patients who were treated with cardioprotective drugs for 1 month or more in the second year. In 10,245 patients (59% prescribed cardioprotective drugs), both increases and decreases in all ranges of blood pressure were associated with worse outcomes, whereas stable blood pressure had a survival advantage at all levels of systolic and diastolic pressures. Use of cardioprotective drugs attenuated changes and improved survival. Validation and sensitivity analyses confirmed the primary findings. Therefore, previous temporal trends need to be considered in patient care, and the use of cardioprotective agents is associated with enhanced survival at all blood pressure levels.

Home systolic blood pressure on the morning of dialysis days has prognostic impact for hypertensive hemodialysis patients

Background

Hypertension is a leading cause of cardiovascular (CV) disease in the general population. Although hypertension is very common in maintenance hemodialysis (HD) patients, adequate blood pressure (BP) values and measurement timing have not been defined.

Methods

A total of 49 hypertensive HD patients were recruited. Average age was 63 ± 11 years, and duration of dialysis therapy was 6.2 ± 4.2 years. Dialysis unit BPs and various types of home BPs were separately measured, and which BPs were the most critical markers in evaluating the effect of hypertension on left ventricular hypertrophy and CV events was investigated.

Results

Predialysis systolic BPs were not correlated with any home BPs. Left ventricular mass index (LVMI) had a significant positive correlation with home BPs, especially morning systolic BPs on HD days (P < 0.01) and non-HD days (P < 0.05), on univariate and multivariate analysis. In contrast, predialysis BPs did not correlate with LVMI. During the follow-up period (47 ± 18 months), it was demonstrated that diabetes and home BPs, especially systolic BPs on the morning of HD days, were significant predictors of CV events on multivariate Cox regression analysis. A 10 mmHg increase in BP had a significantly elevated relative risk for CV events.

Conclusions

Home BP, especially systolic BPs in the morning on HD days, can provide pivotal information for management of HD patients.

Epidemiology of interdialytic ambulatory hypertension and the role of volume excess

BACKGROUND

The epidemiology of hypertension among hemodialysis (HD) patients is difficult to describe accurately because of difficulties in the assessment of blood pressure (BP).

METHODS

Using 44-hour interdialytic ambulatory BP measurements, we describe the epidemiology of hypertension in a cohort of 369 patients. To seek correlates of hypertension control, antihypertensive agents were withdrawn among patients with controlled hypertension and ambulatory BP monitoring was repeated.

RESULTS

Hypertension (defined as an average ambulatory systolic BP ≥135 mm Hg or diastolic BP ≥85 mm Hg, or the use of antihypertensive medications) was prevalent in 82% of the patients and independently associated with epoetin use, lower body mass index and fewer years on dialysis. Although 89% of the patients were being treated, hypertension was controlled adequately in only 38%. Poor control was independently associated with greater antihypertensive drug use. Inferior vena cava (IVC) diameter in expiration was associated with increased risk of poorly controlled hypertension both in cross-sectional analysis and after withdrawal of antihypertensive drugs.

CONCLUSIONS

Interdialytic hypertension is highly prevalent and difficult to control among HD patients. End-expiration IVC diameter is associated with poor control of hypertension in cross-sectional analyses as well as after washout of antihypertensive drugs. Among HD patients, an attractive target for improving hypertension control appears to be the reduction of extracellular fluid volume.

Nutritional Intake in Adult Hemodialysis Patients

BACKGROUND

Research pertaining to the nutritional intake of hemodialysis patients is limited.

PURPOSE

Describe the nutritional quality of foods consumed by hemodialysis patients and variation by day of the week.

METHODS

Dietary recalls were obtained from 22 hemodialysis patients and analyzed using the Nutrition Data System for Research.

RESULTS

Few statistically significant differences were found by day of the week, but several dietary deficits were noted.

CONCLUSION

The data suggest poor intake of calories, protein, and several vitamins and minerals, as well as excess sodium consumption, but little variation by day of the week. Additional research is needed.

Effect of intradialytic change in plasma volume on blood pressure in patients undergoing maintenance hemodialysis

BACKGROUND

Hypervolemia is a common complication in patients on hemodialysis (HD). To determine the effect of volume change on blood pressure in HD population, this cohort was conducted.

MATERIALS AND METHODS

The study population was composed of 60 non-diabetic patients on maintenance HD, with mean age of 59.95±15.28 years. They were divided into hypertensive group A (n=26) and normotensive group B (n=34). Data were collected by a questionnaire. Pre and post-dialysis blood levels of urea, sodium, total protein, and hemoglobin were measured and intradialytic change of plasma volume were calculated. Data analyses were performed by the SPSS v.16.

RESULTS

Out of 60 patients, 58.3% were male and 41.7% female. Post-dialysis systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly lower than pre-dialysis values in both groups (P=0.001, each). No correlation was found between intradialytic change in plasma volume or body weight and alterations of SBP or DBP during HD in the study groups (P>0.05, each). Intradialytic changes of body weight did not correlate to intradialytic changes of plasma volume (P=0.15).

CONCLUSION

HD effectively reduces blood pressure and volume expansion, however, intradialytic changes of plasma volume and body weight do not influence on SBP and DBP.

Pharmacotherapy of end-stage renal disease

IMPORTANCE OF THE FIELD

The incidence and prevalence of end-stage renal disease (ESRD) requiring renal replacement therapy (RRT) continues to grow worldwide. ESRD causes significant morbidity and mortality and has enormous financial and personal costs.

AREAS COVERED IN THIS REVIEW

Major electronic databases (including the Cochrane Library, MEDLINE and EMBASE) were searched from 1989 to September 2009 to summarize current pharmacotherapy of ESRD-associated complications in adults receiving maintenance dialysis (hemodialysis or continuous ambulatory peritoneal dialysis). Current guidelines for the treatment of ESRD (e.g., NKF-K/DOQI, KDIGO, and the ERA-EDTA's European Renal Best Practice Guidelines) were included.

WHAT THE READER WILL GAIN

Commonly used pharmacological treatment strategies for chronic arterial hypertension, anemia, iron management, dyslipidemia, hyperglycemia, and for disturbances of bone and mineral metabolism, including hyperphosphatemia and secondary hyperparathyroidism in ESRD, are presented. In addition, the reader will learn that nonadherence to oral medication in ESRD can contribute significantly to excess morbidity and mortality of the dialysis population.

TAKE HOME MESSAGE

Improvements in pharmacotherapy of ESRD may be at least in part counteracted by continuously increasing age and comorbid disease of the dialysis population. Individualized and tailor-made pharmacological management of the ESRD patient remains a challenge for the future.

Association of calcium-phosphorus product with blood pressure in dialysis

Hypertension is very common in dialysis patients. Disorders of mineral metabolism have been linked to vascular calcification and hypertension in dialysis. Fifty-four hemodialysis patients were included in a cross-sectional study in a dialysis unit during a 6-month period. Linear regression analysis was done between averages of calcium and phosphorus (ca x ph) product and blood pressures (BPs). Ca x ph was significantly associated with systolic BP predialysis (P=.03, R=0.28), diastolic BP predialysis (P=.001, R=0.44), predialysis mean arterial pressure (MAP) (P=.002, R=0.4), and diastolic BP postdialysis (P=.03, R=0.26). No relationship was found with pulse pressures. Multilinear regression analysis was then done between ca x ph product and BPs adjusting for age, sex, hemoglobin, diabetes, albumin, parathyroid hormone, ultrafiltration volume, and average BP medications per patient. There was a strong positive association with predialysis systolic BP (P=.003, R(2)=0.49), predialysis MAP (P=.001, R(2)=0.51), and postdialysis MAP (P=.02, R(2)=0.65). No associations with pulse pressures were detected. The study findings suggest that ca x ph product is significantly associated with dialysis MAP and not pulse pressure. This is likely secondary to the stronger relationship with diastolic BP than with systolic BP. Prospective studies looking into the associated hemodynamic parameters related to arterial stiffness and endothelial dysfunction along with measures for calcifications would be very beneficial.