Hypertension In Hemodialysis Patients Research Articles

Extracellular Volume Changes and Blood Pressure Levels in Hemodialysis Patients

Despite the use of highly efficient antihypertensive drugs (AHD), blood pressure (BP) is poorly controlled in the vast majority of hemodialysis (HD) patients. Many of them show no reduction in nocturnal BP, a finding that is associated with left ventricular hypertrophy. The aim of the study was to investigate the effect of the removal of a fluid overload on BP by monitoring the ambulatory BP during 48 hours in 16 hypertensive HD patients treated with AHD. Our aim was to obtain a gradual reduction in post-HD body weight (BW) over a period of 3 to 4 months. During a period of 3-4 months, the postdialysis BW was reduced as the minimal tolerable BW was gradually achieved by slightly increasing the ultrafiltration volume. The Na concentration in the dialysate was reduced from 143-141 mmol/L to 139-138 mmol/L. Extracellular volume (ECV) was measured with a multiple-frequency bioimpedance analyzer (Xitron 4000B, Xitron Technologies Inc., San Diego, CA, USA). Based on the change in ECV, the patients were subdivided into two groups: group 1 with a reduction in ECV (n = 10), and group 2 with no reduction (n = 6). At the start of the study, BW, BP, and AHD in group 1 and group 2 were virtually identical. Group 1 showed a significant reduction during the entire 48-hour period in systolic (156 +/- 16 mmHg vs. 140 +/- 14 mmHg, P = 0.030) and diastolic BP (97 +/- 12 mmHg vs. 87 +/- 9 mmHg, P = 0.026) as well as in mean arterial pressure (MAP, 117 +/- 13 vs. 105 +/- 10 mmHg, P = 0.027). This reduction was more marked during the night (systolic BP 156 +/- 15 mmHg vs. 138 +/- 14 mmHg, P = 0.007; diastolic BP 97 +/- 12 mmHg vs. 85 +/- 9 mmHg, P = 0.009) than during the day (157 +/- 18 mmHg vs. 142 +/- 15 mmHg, P = 0.067; diastolic BP 97 +/- 13 mmHg vs. 90 +/- 9 mmHg, P = 0.126). A significant reduction in systolic load also occurred during the entire 48-hour period (76 +/- 24% vs. 46 +/- 28%, P = 0.043) as well as in night systolic load (75 +/- 21% vs. 41 +/- 30%, P = 0.015) and night diastolic load (67 +/- 32% vs. 39 +/- 31%, P = 0.030). AHD were stopped in eight and reduced in two patients. There were no significant reductions in BP and AHD in group 2. The removal of excess fluid is necessary for adequate BP control and especially for the reduction in elevated BP during the night.

Increased Endothelin: Nitric Oxide Ratio Is Associated with Erythropoietin-Induced Hypertension in Hemodialysis Patients

Regular administration of recombinant human erythropoietin (rHuEPO) is frequently associated with a rise in arterial blood pressure in hemodialysis (HD) patients. The aim of this study was to examine the effects of rHuEPO on plasma endothelin (ET)-1 and nitric oxide products (NOx) concentration in HD patients. Fifteen patients on maintenance HD with hematocrit of less than 25% were included in the present study. All patients received 3,000 units of rHuEPO intravenously three times a week at the end of each HD session. Plasma levels of ET-1, NOx, thromboxane B2 (TXB2), prostacyclin (6-keto-PGF1α), and cyclic guanosine 3′,5′-monophosphate (cGMP) were measured before, 2, and 4 weeks after rHuEPO treatment. Plasma concentrations of ET-1, TXB2, and 6-keto-PGF1α were measured by radioimmunoassay. Plasma NOx was measured by highperformance liquid chromatography. An rHuEPO-induced increase in mean arterial blood pressure of over 6 mmHg occurred in 7 patients (hypertensive group), whereas the elevation of mean arterial blood pressure was less than 5 mmHg in 8 patients (nonhypertensive group). Plasma ET-1 levels were elevated in all HD patients. Elevated plasma ET-1 levels remained unchanged after rHuEPO treatment in the hypertensive group, whereas the increase in plasma ET-1 levels was attenuated in the nonhypertensive group. Plasma NOx concentrations were also increased in all HD patients. This increase in plasma NOx levels was lessened in the hypertensive group after rHuEPO administration; however, plasma NOx levels remained increased in the nonhypertensive group. Changes in mean arterial blood pressure were significantly correlated with changes in plasma ET-1/NOx ratio. Plasma levels of TXB2, 6-keto-PGF1α, and cGMP were unchanged after rHuEPO administration in the hypertensive and nonhypertensive groups. These results suggest that an increase in ET-1/NOx ratio in blood, probably occurring in vascular endothelial cells, may be associated with rHuEPO-induced hypertension in HD patients.

Ultrafiltration Volume Is Associated with Changes in Blood Pressure in Chronically Hemodialyzed Patients

Introduction. Volume overload is a main factor in development of hypertension in hemodialysis patients. In order to demonstrate impact of ultrafiltration volume on blood pressure during 15-months period in a group of patients undergoing chronic hemodialysis therapy, we conducted this study. We hypothesized that ultrafiltration volume different affects the pre/postdialysis systolic pressure, diastolic pressure, mean arterial pressure (MAP), and pulse pressure (PP) values. Subjects and Methods. Study subjects were 23 anuric chronically hemodialyzed patients. The overall study time was 15 months, and 136 single hemodialysis treatments were analyzed. Results. Ultrafiltration was negatively correlated with predialysis systolic blood pressure (r = −0.169, p = 0.025), postdialysis systolic blood pressure (r = −0.292, p<0.001), postdialysis MAP (r = −0.186, p = 0.015), predialysis PP (r = −0.290, p<0.001), and postdialysis PP (r = −0.370, p<0.001). Ultrafiltration/dry body mass (UF/W) ratio was negatively correlated with predialysis PP (r = −0.222, p = 0.005), postdialysis PP (r = −0.340, p<0.001), and postdialysis systolic blood pressure (r = −0.243, p = 0.002). We found significant difference in postdialysis PP between dialyses with UF/W ratio ≤0.05 and dialyses with UF/W ratio >0.05 (63.49 ± 20.76 vs. 56.27 ± 16.33 mmHg, p = 0.033). Conclusion. The ultrafiltration volume strongly affects postdialysis PP values. Evaluation of elevated blood pressure treatment in patients undergoing chronic hemodialysis therapy must be considered in respect of postdialysis PP values, not just depending on pre/postdialysis systolic and diastolic pressure or MAP values.

Ultrafiltration Volume is Associated with Changes in Blood Pressure in Chronically Hemodialyzed Patients

Introduction: Volume overload is a main factor in development of hypertension in hemodialysis patients. In order to demonstrate impact of ultrafiltration volume on blood pressure during 15-month period in a group of patients undergoing chronic hemodialysis therapy, we conducted this study. We hypothezed that ultrafiltration volume different affects the pre/postdialysis systolic pressure, diastolic pressure, mean arterial pressure (MAP) and pulse pressure (PP) values. Subjects and Methods: Study subjects were 23 anuric chronically hemodialyzed patients. The overall study time was 15 months, and 136 single hemodialysis treatments were analyzed. Results: Ultrafiltration was negatively correlated with predialysis systolic blood pressure (r=-0.169, p=0.025), postdialysis systolic blood pressure (r=-0.292, p0.05 (63.49±20.76 vs. 56.27±16.33 mmHg, p=0.033). Conclusion: The ultrafiltration volume strongly affects postdialysis PP values. Evaluation of elevated blood pressure treatment in patients undergoing chronic hemodialysis therapy must be consider in respect of postdialysis PP values, not just depending on pre/postdialysis systolic and diastolic pressure or MAP values.

Left ventricular mass and hemodynamic overload in normotensive hemodialysis patients

It remains uncertain whether the hemodynamic parameters are important determinants of left ventricular mass (LVM) in normotensive chronic hemodialysis (NTHD) patients, as has been found in their hypertensive counterparts. Forty NTHD patients (mean age, 53.7 +/- 14.4 years; male/female, 18/22) without the requirement of antihypertensive drugs for at least six months were studied. Controls were 41 hypertensive hemodialysis patients (HTHD) and 46 normotensive subjects with normal renal function (NTNR). The influence of anthropometrics, cardiovascular structure and function, and volume status on LVM (by two-dimensional echocardiography) was analyzed by steps of multiple linear regression. As compared with the NTNR and NTHD group, the HTHD group had obvious pressure and volume/flow overload, and greater LV wall thickness, chamber size and mass. In contrast, NTHD subjects had similar blood pressure, large artery function, LV chamber size and stroke volume as the NTNR subjects. However, the NTHD patients still had greater wall thickness and LVM, along with greater cardiac output, lower total peripheral resistance and lower end-systolic meridional stress to volume ratio (ESSV) than the NTNR group. LVM in the NTHD group was significantly positively related to averaged systolic blood pressure (SBPavg), body surface area, extracellular fluid (ECF), carotid intima-media thickness (IMT), aortic pulse wave velocity (PWV), and negatively related to ESSV and Kt/V. The independent significant noncardiac structural determinants of LVM in NTHD subjects were ESSV, SBPavg, PWV and SV (model r2 = 0.617, P < 0.001). The NTHD patients, without significant pressure and volume overload, still had increased LVM that was partially explained by the persistent flow overload and subclinical LV dysfunction.

Central, peripheral, and other blood volume changes during hemodialysis.

Volume overload is a factor in development of hypertension in hemodialysis patients. Fluid removal by hemodialysis (HD), however, may cause intradialytic hypotension and associated symptoms. A better understanding of the relationships between blood pressure volume status and the pathophysiology of fluid removal during HD are, therefore, necessary to control blood pressure and to eliminate intradialytic hypotension. The objectives of the study were to determine the amount and direction of change of body fluid compartments after ultrafiltration (UF) and to determine whether any correlations exist between mean arterial pressure (MAP), change in circulating blood volume (deltaBV), total body water (TBW), central blood volume (which constitutes the volume of blood in the lungs, heart, and great vessels [CBV]), and intracellular and extracellular fluid volumes (ICF, ECF). The study population included 20 patients on regular HD. Each individual had their CBV, cardiac output, and peripheral vascular resistance (PVR) measured by means of saline dilution technique and deltaBV monitored by an online hematocrit sensor (Crit Line). MAP was calculated from measured blood pressure and ICF and ECF were measured using bioelectric impedance analysis techniques. Measurements were obtained before and after maximum UF measured by deltaBV (reduction of 6-10% by Crit Line). Ten healthy controls also had ECF and ICF values measured by bioelectric impedance analysis. Before HD, MAP correlated with TBW (r = 0.473, p = 0.035) and CBV (r = 0.419, p = 0.066), suggesting that hypertension here may be due to volume overload. Patients were ECF expanded before HD with an ECF:ICF ratio of 0.96, which was significantly higher than the control ratio of 0.74 (p < 0.0001). During UF, fluid was removed from both ECF and ICF, but more from the ECF volume ratio 0.92 post UF, a significant reduction (p < 0.0001). After UF, MAP no longer correlated with TBW or CBV but correlated with peripheral vascular resistance (r = 0.4575, p = 0.043). After UF, deltaBV correlated inversely with PVR (r = -0.50, p = 0.024). Despite the fall in deltaBV (7.11+/-2.49%) with UF, CBV was maintained. CBV were 0.899 L and 0.967 L pre and post UF, respectively. These data suggest that in hemodialysis patients, predialysis volume status influences predialysis blood pressure. UF causes BV to fall, but CBV is preferentially conserved by increasing PVR, which also maintains blood pressure. Failure of a PVR response likely leads to intradialytic hypotension.

Blunted Nocturnal Blood Pressure Decrease and Left-Ventricular Mass in Hypertensive Hemodialysis Patients

Left-ventricular hypertrophy (LVH) represents a frequent complication in hemodialysis (HD) patients. Hypertension is a well-known risk factor of cardiac morbidity which is present in 2 of 3 patients: among them about 60% have a blunted nocturnal decrease of blood pressure (BP). Although some large studies on essential hypertensives have documented that non-dipper patients have a higher number of cardiac events and a higher left ventricle (LV) mass than dipper ones, conflicting results have been reported for dialysis patients. Therefore, the aim of our study was to assess differences in LV mass between dipper and non-dipper hypertensive HD patients. We studied 66 patients with 24-hour ambulatory BP monitoring performed on HD and on inter-HD day. They were classified as dipper when a decrease of at least 10% of nocturnal systolic blood pressure on the inter-HD day was present. Echocardiography and bioimpedance were performed. 29% of the patients were classified as dippers and 71% as non-dippers. The 48-hour systolic and diastolic BP were not significantly different between the two groups (SBP: dipper = 144 ± 12.9 mm Hg, non-dipper = 149 ± 17.8 mm Hg; DBP: dipper = 80 ± 9.9 mm Hg, non-dipper = 81 ± 10.6 mm Hg). LV mass index (LVMi) did not differ between the two groups (dipper = 143.1 ± 40.7 g/m²; non-dipper = 159.4 ± 46.3 g/m²). No differences were reported between dipper and non-dipper patients regarding extracellular water distribution (ECW: 48.1 ± 7.7 vs. 49.8 ± 10.8%). SBP night/day ratio and 48-hour SBP were not correlated to LVMi. A strong correlation was reported between ECW% and LVMi (r = 0.53, p < 0.001). In conclusion, 2 of 3 hypertensive HD patients are non-dipper, and this condition does not seem to be associated with significant differences in 48-hour blood pressure and LV mass. Volume overload appears to be the main independent determinant of LVH in these patients.

Hypertension in hemodialysis patients.

Hypertension is very common and often poorly controlled in patients undergoing chronic hemodialysis. While high blood pressure has been documented to adversely impact several intermediate outcomes of cardiovascular disease, whether hypertension is an independent risk factor for mortality in this population is not clear. Expansion of extracellular fluid volume is the major pathophysiologic mechanism for the development of hypertension in these patients; however, alterations in other humoral mechanisms also play a significant role. Optimization of volume status is, therefore, the cornerstone of therapy with additional use of antihypertensive medications as needed. Good quality prospective studies are urgently needed to define the measurement techniques and blood pressure goals, and to develop therapeutic strategies for more effective management of hypertension in this high-risk population.

Left ventricular diastolic function in patients on maintenance haemodialysis

SUMMARY: The aim of this study was to elucidate the differences in left ventricular (LV) diastolic function between patients on maintenance haemodialysis (HD) with LV hypertrophy (LVH) and those with LVH from other causes. Twenty HD patients (HD group), 11 patients with hypertensive heart disease (HHD group), 11 with hypertrophic cardiomyopathy (HCM group) and 11 age‐matched healthy individuals (N group) were examined using echocardiography. Compared with the HCM group, the HD and HHD groups had smaller total LV wall thickness and left atrial dimension, a higher ratio of LV end‐diastolic dimension to LV posterior wall thickness, a shorter isovolumic relaxation time and a higher ratio of peak flow velocity of early to late LV fillings (E/A). There was a correlation between LV mass index or E/A and systolic blood pressure. These results indicate that HD patients have an LV diastolic dysfunction similar to that observed in HHD patients but which is less severe than that found in HCM patients. It seems reasonable to control hypertension in HD patients in order to favourably influence LV diastolic function.

Short daily hemodialysis: Blood pressure control and left ventricular mass reduction in hypertensive hemodialysis patients

Several retrospective and uncontrolled prospective studies reported blood pressure (BP) normalization and left ventricular mass (LVM) reduction during daily hemodialysis (DHD). Conversely, the burden of these major independent risk factors is only marginally reduced by the initiation of standard thrice-weekly dialysis (SHD), and cardiovascular events still represent the most common cause of death in hemodialysis patients. Therefore, we performed a randomized two-period crossover study to compare the effect of short DHD versus SHD on BP and LVM in hypertensive patients with end-stage renal disease. We studied 12 hypertensive patients who had been stable on SHD treatment for more than 6 months. At the end of 6 months of SHD and 6 months of DHD in a sequence of randomly assigned 24-hour ambulatory BP monitoring, echocardiography and bioimpedance were performed. Throughout the study, patients maintained the same Kt/V. A significant reduction in 24-hour BP during DHD was reported (systolic BP [lsqb ]SBP[rsqb ]: DHD, 128 [plusmn] 11.6 mm Hg; SHD, 148 [plusmn] 19.2 mm Hg; P [lt ] 0.01; diastolic BP: DHD, 67 [plusmn] 8.3mm Hg; SHD, 73 [plusmn] 5.4 mm Hg; P [equals] 0.01). The decrease in BP was accompanied by the withdrawal of antihypertensive therapy in 7 of 8 patients during DHD (P [lt ] 0.01). LVM index (LVMI) decreased significantly during DHD (DHD, 120.1 [plusmn] 60.4 g/m2; SHD, 148.7 [plusmn] 59.7 g/m2; P [equals] 0.01). Extracellular water (ECW) content decreased from 52.7% [plusmn] 11.4% to 47.6% [plusmn] 7.5% (P [equals] 0.02) and correlated with 24-hour SBP (r [equals] 0.63; P [lt ] 0.01) and LVMI (r [equals] 0.66; P [lt ] 0.01). In conclusion, this prospective crossover study confirms that DHD allows optimal control of BP, reduction in LVMI, and withdrawal of antihypertensive treatment. These effects seem to be related to reduction in ECW content. [copy ] 2001 by the National Kidney Foundation, Inc.

CENTRAL AND PERIPHERAL BLOOD VOLUME CHANGES DURING HEMODIALYSIS

Volume overload is a factor in development of hypertension in hemodialysis patients. Fluid removal by hemodialysis (HD), however, may cause intradialytic hypotension (IDH) and associated symptoms. Better understanding of the relationships between blood pressure (BP), volume status and the pathophysiology of fluid removal during HD are necessary to control BP and to eliminate IDH. Objectives of the study were to determine amount and direction of change of body fluid compartments following ultrafiltration (UF) and determine whether crrelations exist between mean arterial pressure (MAP), change in circulating blood volume (ΔBV), total body water (TBW), central blood volume which constitutes the volume of blood in the lungs, heart and great vessels (CBV), intracellular and extracellular fluid volumes (ICF, ECF). The study population included 20 patients on regular HD. Each had their CBV, cardiac output and peripheral vascular resistance (PVR) measured via saline dilution technique, ΔBV monitored by hematocrit sensor (Crit-Line), MAP was calculated from measured BP and ICF and ECF were measured using bioimpedance techniques. Measurements were obtained prior to and following maximum UF measured by ΔBV (reduction of 6–10% by Crit Line). Ten healthy controls also had ECF and ICF values measured by bioimpedance. Prior to HD MAP correlates with TBW (r=0.473, p=0.035) and CBV (r=0.419, p=0.066) confirming that hypertension here may be due to volume overload. Patients are ECF expanded prior to HD with an ECF/ICF ratio of 0.96, which was significantly higher than the control ratio of 0.74 (p<0.0001). During UF fluid is being removed from both ECF and ICF but more from the ECF volume; ratio 0.92 post UF, a significant reduction (p<0.0001). After UF, MAP no longer correlates with TBW or CBV but correlates with peripheral vascular resistance (r=0.4575, p=0.043). After UF, ΔBV correlates inversely with PVR (r=-0.50, p=0.024). In spite of the fall in ΔBV (mean 7.11 ± 2.49 SD) by UF, CBV is maintained. CBV were 0.89L pre and 0.967 L post UF. Thus, predialysis volume status influences preanalysis BP. UF reduces ΔBV but CBV is preferentially conserved by increasing PVR, which also maintains BP. Failure of a PVR response likely leads to IDH.

THE EFFECT OF LOSARTAN ON INSULIN RESISTANCE AND BETA CELL FUNCTION IN CHRONIC HEMODIALYSIS PATIENTS

Insulin resistance (IR) is prevalent in hemodialysis patients. IR and hyperinsulinemia have an important role in the development of atherosclerosis, which is the most common cause of morbidity and mortality in hemodialysis patients. Thus, antihypertensive drugs that lower IR, may have an additional beneficial effect in the treatment of cardiovascular diseases in these patients. In this preliminary study we examined the effect of Losartan (an angiotensin II receptor antagonist) treatment on IR and beta cell function in five hypertensive non-diabetic chronic hemodialysis patients. All other known causes of IR in end stage renal failure were excluded. After a washout period of two weeks, Losartan 50 mg, was administered for 6 weeks. Fasting blood glucose (FBG) and insulin levels were measured before and after the treatment IR and beta cell function were calculated using the “homeostasis model assessment”-HOMA. Systolic and diastolic blood pressure (BP) have not changed significantly throughout the study. FBG increased significantly from 76 mg/dL ± 1 to 89 mg/dL ±4 (p < 0.01), however, insulin levels have not changed significantly. Calculated IR values did not show a difference, but calculated beta cell function decreased significantly after Losartan treatment from 291% ± 50 to 146% ± 10, (p < 0.016). These preliminary results suggest that in chronic hemodialysis hypertensive non-diabetic patients short treatment with Losartan has deleterious effect on glucose homeostasis mediated via a decrease in beta cell function

Hypertension in chronic renal failure and end-stage renal disease patients treated with haemodialysis or peritoneal dialysis.

Guidelines should be used for clinical decisions about although it remains debatable whether ‘dry weight’ individual patients. However, most of the available was really achieved in all of these patients [4,5]. guidelines are based on randomized clinical trials which only provide a statistical prediction of the likely effect of an intervention, usually based on the ‘average’ Effect of hypertension on survival outcome, aggregated across all the heterogeneous patients participating in the trial. Heterogeneity due to The well established concept that hypertension is a the stage of the disease, its severity, organ complica- risk factor for death both in the general population tion, comorbid conditions etc., together with exclusion and in dialysis patients has recently been questioned of the patients with major complications from the trial, by independent studies [4–9] showing that low prelimit the information generated by such trials for a dialysis systolic BP is associated with increased precise prediction of outcome for an individual patient. adjusted mortality risk. No association with elevated Although these limitations may be partially circum- mortality risk has been observed for pre-dialysis sysvented by the clinical experience and pathophysiolog- tolic hypertension. A number of explanations may be ical knowledge of clinicians or experts (in the case of offered for this rather unexpected finding: (i) it may a guideline), personal bias is almost inevitable. A be an iatrogenic effect due to overmedication; (ii) all comprehensive approach to the issue of hypertension the studies were carried out in the USA on patients has recently been published [1]. The present review with an overall poor prognosis. The influence of summarizes the most important aspects discussed in expected survival is indeed crucial. The beneficial effect that review and, in particular, addresses some specific of BP reduction may need several years to become topics whcih, in the opinion of the Medical Expert visible, and this may not be detectable if life expectancy Group, are rather relevant. is only 2–3 years; (iii) older malnourished patients have lower BP and shorter survival; and (iv) the presence of overt or not fully developed heart failure Prevalence or disease may lower BP and survival. The Cox proportional hazard used in some of these studies may be The prevalence of hypertension varies according to the inadequate to correct for all these confounding factors. degree and the cause of renal failure in chronic renal insufficiency (CRI ) or according to the type of dialytic treatment, haemodialysis ( HD) or peritoneal dialysis Pathophysiological basis for management (PD). However, the prevalence of hypertension is much greater in the CRI population (60–100%) than in the In these clinical conditions, it is still not known if general population. With the remarkable exception of hypertension is caused by inappropriate secretion of Tassin, France, where >90% of patients achieve norm- renin for the status of body sodium and water, or if otension without anti-hypertensive medication [2], the other renal or extra-renal factors are involved. A control of hypertension in HD patients is rather poor correct answer to this question is crucial not only for despite administration of anti-hypertensive drugs. This the understanding of the pathogenesis of hypertension poor control has also been documented with 24 h but also for a correct therapeutical approach. ambulatory blood pressure (BP) monitoring where a There are close interrelationships among the various feedback loops regulating BP (renal, hormonal, haemo

Increased plasma adrenomedullin levels in hemodialysis patients with sustained hypotension

Sustained hypotension in end-stage renal disease patients is characterized, despite an overactivation of the sympathetic and renin-angiotensin systems, by decreased vascular resistance and a blunted vascular response to pressor stimuli. An increased production of one or more vasodilator substances might play a role in the reduced vascular resistance and response to pressor stimuli in these patients. We evaluated the possible role of an increased production of nitric oxide and/or adrenomedullin (ADM) in the pathophysiology of chronic hypotension in hemodialysis (HD) patients. Three groups of hypotensive (N = 9), normotensive (N = 10), and hypertensive (N = 9) HD patients were included in the study. Plasma renin activity (PRA) and plasma levels of catecholamines, ADM, nitrite/nitrate (an estimator of nitric oxide production), tumor necrosis factor (TNF), and interleukin-1beta (IL-1beta) were measured. Plasma volume and left ventricular ejection fraction (LVEF) were also evaluated. Plasma levels of nitrite/nitrate and ADM were elevated in HD patients with respect to the reference values in normal subjects. Plasma ADM levels, but not nitrite/nitrate levels, were higher in hypotensive (368.1 +/- 25.4 pg/mL) than normotensive (225 +/- 9.9 pg/mL) and hypertensive HD patients (278.2 +/- 15.5 pg/mL, P < 0.01). When considering hypotensive and normotensive patients together, the mean blood pressure inversely correlated with time on HD (r = -0. 53, P < 0.05) and plasma ADM levels (r = -0.78, P < 0.01). Plasma ADM and nitrite/nitrate levels are increased in HD patients, but only ADM levels were higher in hypotensive than in normotensive and hypertensive HD patients. The higher plasma levels of this peptide in hypotensive patients and its inverse correlation with mean arterial pressure suggest that ADM may be involved in the pathophysiology of chronic hypotension in HD patients.

Treatment of hypertension in the hemodialysis patient: beneficial or not?

Hypertension is common in the hemodialysis population. Although hypertension in the general population has been shown to reduce survival and to accelerate atherosclerosis, leading to serious cardiac and cerebrovascular morbidity, its effects are less clear in those undergoing dialysis. This review focuses on recent studies showing a favorable outcome in hypertensive hemodialysis patients when compared with those with lower blood pressure. The possible explanations for this paradoxic relationship are examined, and practical suggestions are given for the management of hypertension in the patient undergoing hemodialysis. We also present information on the morbiditiy associated with hypertension in the hemodialysis population.

Nocturnal blood pressure and 24-hour pulse pressure are potent indicators of mortality in hemodialysis patients

Cardiovascular (CV) complications are the leading cause of mortality in hemodialysis patients. The role of arterial hypertension on the prognosis of CV in hemodialysis patients is not as clear as in the general population. The purpose of this study was to investigate the prognostic role of ambulatory blood pressure (BP) on CV mortality in treated hypertensive hemodialysis patients. Fifty-seven treated hypertensive hemodialysis patients (56.87 +/- 16.22 years, 30 men) were prospectively studied. All patients initially underwent an ambulatory BP monitoring between two dialysis sessions. The outcome event studied was CV death; kidney transplantation and deaths not related to CV disease were censored. The duration of follow-up was 34.4 +/- 20.39 months, during which 10 CV and 8 non-CV fatal events occurred. In the 10 patients who died from CV complications, age, previous CV events, ambulatory systolic BP, ambulatory pulse pressure (PP), and life-long smoking level were significantly higher, and the office diastolic BP was lower at the time of inclusion than in those who did not die from CV complications (N = 47). Based on Cox analysis and after adjustment for age, sex, and previous CV events, a low office diastolic BP [relative risk (RR) 0.49, 95% CI, 0.25 to 0.93, P = 0.03], an elevated 24-hour PP (RR 1.85, 95% CI, 1.28 to 2.65, P = 0.009), and an elevated nocturnal systolic BP (RR 1.41, 95% CI, 1.08 to 1.84, P = 0.01) were predictors of CV mortality (RR associated with a 10 mm Hg increase in BP and in PP). This study demonstrates that nocturnal BP and 24-hour PP are independent predictors of CV mortality in treated hypertensive hemodialysis patients. Randomized trials are needed to investigate whether nocturnal BP and 24-hour PP are superior to office BP as targets for antihypertensive therapy in this high-risk group.

Is Hypertension Beneficial to the Conventional Hemodialysis Patient?

Hypertension is common in the conventional hemodialysis population. While hypertension in the general population has been shown to reduce survival, the issue is less clear in the dialysis population. This review focuses on recent studies showing a favorable outcome in hypertensive hemodialysis patients compared to those with lower blood pressure. Possible explanations for this paradoxical relationship are examined and practical suggestions given for the management of hypertension in the hemodialysis patient.

The impact of withdrawing ACE inhibitors on erythropoietin responsiveness and left ventricular hypertrophy in haemodialysis patients.

Angiotensin-converting enzyme (ACE) inhibitors have the capability of decreasing left ventricular mass index (LVMI) in chronic haemodialysis (HD) patients. On the other hand, recent reports provide conflicting information regarding the impact of ACE inhibitors on responsiveness to recombinant human erythropoietin (rHuEpo), and there are no data about the effect of withdrawing ACE inhibitors both on rHuEpo response and LVMI in HD patients. ACE inhibitors were switched to another antihypertensive medication in 23 out of 68 patients in our HD unit who were receiving both rHuEpo and an ACE inhibitor for more than 1 year. Blood pressure at the pre- and post-dialysis phases, haematocrit levels and rHuEpo doses were determined at the end of the first and of the third years, and the LVMI was determined at the end of the third year. Statistical analyses were done in 15 patients in whom the study could be completed. The mean (+/-SD) haematocrit level was increased from 26.3+6.4% to 29.8+/-6.3% at the first year (P<0.05), and to 29.4+/-6.5% at the third year (P<0.05 vs before), while the mean dose of rHuEpo was decreased from 208.3+/-99.0 UI/kg/week to 141.0+/-91.8 at the first year (P=0.01), and to 141.4+/-81.0 at the third year (P=0.01 vs before). Administration of rHuEpo had been stopped in two patients at the end of the first year. The mean blood pressure level and the mean LVMI were not changed (P>0.05 vs before). There were no significant changes in dialysis parameters, iron status, plasma renin activities, and levels of aldosterone, intact parathyroid hormone, aluminum and erythropoietin. The findings of this small uncontrolled study indicate that withdrawal of ACE inhibitors in hypertensive chronic HD patients receiving rHuEpo may result in an increase in haematocrit level, and a decrease in dose of rHuEpo without any significant changes in the blood pressure level and LVMI. Controlled prospective studies are needed to clarify this issue.

Hypertension in haemodialysis patients

Ang, Kim Seng1; Benarbia, Seddik1; Boulahrouz, Rehouni1; Stanescu, Corinna1; Charasse, Christophe1; Cacheux, Philippe Le1; Simon, Pierre1 Author Information

Ambulatory blood pressure monitoring and interdialytic weight gain in children receiving chronic hemodialysis.

Volume overload appears to induce hypertension in hemodialysis patients, yet studies of the effect of hydration status on interdialytic blood pressure (BP) have yielded contradictory results. We measured interdialytic BP by ambulatory BP monitoring (ABPM) during inpatient fluid restriction in 12 children receiving chronic hemodialysis to describe the overall BP pattern and to determine the effect of weight gain on BP change. Weight was measured on admission and four times each day. For each weight, casual BP was measured and compared with the mean of 3 hours of ABPM surrounding the weight measurement. Sleep BP decreased from daytime BP by 6% for systolic BP (SBP) and 11% for diastolic BP (DBP). Sleep loads were greater than daytime loads (P < 0.01) for SBP (53% v 28%) and DBP (57% v 27%). Overall, 58% (7 of 12) of the patients had sleep SBP load greater than 50%, and 67% (8 of 12) of the patients had sleep DBP load greater than 50%. Casual and ABPM measurements of BP showed moderate correlations for SBP (r = 0.51) and DBP (r = 0.46) and mean differences between methods of 6.3 +/- 13.2 mm Hg and -1.4 +/- 12.6 mm Hg, respectively. Increases in interdialytic weight were positively associated with increases in SBP (r = 0.41; P < 0.001), and interdialytic BP changes varied closely with corresponding weight changes. We conclude that in children receiving chronic hemodialysis: (1) sleep BP decreases are attenuated and sleep BP loads are elevated, (2) casual BP correlates poorly with ABPM, and (3) interdialytic weight and BP are related.