Groningen, Netherlands
Groningen, Netherlands

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Cranenburg E.C.M.,Maastricht University | Schurgers L.J.,Maastricht University | Uiterwijk H.H.,Dialysis Center Groningen | Beulens J.W.J.,University Utrecht | And 7 more authors.
Kidney International | Year: 2012

Vitamin K is essential for the activity of γ-carboxyglutamate (Gla)-proteins including matrix Gla28 protein and osteocalcin; an inhibitor of vascular calcification and a bone matrix protein, respectively. Insufficient vitamin K intake leads to the production of non-carboxylated, inactive proteins and this could contribute to the high risk of vascular calcification in hemodialysis patients. To help resolve this, we measured vitamin K1 and K2 intake (4-day food record), and the vitamin K status in 40 hemodialysis patients. The intake was low in these patients (median 140 μg/day), especially on days of dialysis and the weekend as compared to intakes reported in a reference population of healthy adults (mean K1 and K2 intake 200 μg/day and 31 μg/day, respectively). Non-carboxylated bone and coagulation proteins were found to be elevated in 33 hemodialysis patients, indicating subclinical hepatic vitamin K deficiency. Additionally, very high non-carboxylated matrix Gla28 protein levels, endemic to all patients, suggest vascular vitamin K deficiency. Thus, compared to healthy individuals, hemodialysis patients have a poor overall vitamin K status due to low intake. A randomized controlled trial is needed to test whether vitamin K supplementation reduces the risk of arterial calcification and mortality in hemodialysis patients. © 2012 International Society of Nephrology.


Assa S.,University of Groningen | Hummel Y.M.,University of Groningen | Voors A.A.,University of Groningen | Kuipers J.,Dialysis Center Groningen | And 5 more authors.
American Journal of Kidney Diseases | Year: 2013

Background: Left ventricular diastolic dysfunction is common in hemodialysis patients and is associated with worse outcome. Previous studies have shown that diastolic function worsens from pre- to post-dialysis session, but this has not been studied during hemodialysis. We studied the evolution of diastolic function parameters early and late during hemodialysis. Study Design: Observational study. Setting & Participants: 109 hemodialysis patients on a thrice-weekly dialysis schedule with a mean age of 62.5 ± 15.6 (SD) years were studied between March 2009 and March 2010. Predictor: Hemodialysis with constant ultrafiltration rate and dialysate conductivity. Outcomes: Changes in diastolic function parameters. Measurements: Mitral early inflow (E) and tissue Doppler early diastolic velocity (mean e′) were evaluated by echocardiography predialysis, at 60 and 180 minutes intradialysis, and postdialysis. Relative blood volume changes were calculated from changes in hematocrit. Results: Predialysis E and mean e′ were 0.93 ± 0.24 m/s and 6.6 ± 2.1 cm/s, respectively. E and mean e′ values decreased significantly during hemodialysis (P < 0.001). The steepest change occurred at 60 minutes intradialysis (E, -21.4% ± 17.6% and -30.5% ± 19.2% at 60 and 180 minutes, respectively; mean e′, -16.0% ± 18.6% and -19.5% ± 21.8% at 60 and 180 minutes, respectively). At 60 minutes intradialysis, changes in relative blood volume and brain natriuretic peptide level were associated significantly with the change in E but not with the change in mean e′. Limitations: Changes in relative blood volume may not fully reflect central blood volume changes and do not capture the effect of blood loss to the extracorporal circuit. Left atrial volume was not measured. Conclusions: Left ventricular diastolic function worsens early during a hemodialysis session. The decrease in mean e′ at 60 minutes intradialysis was unrelated to changes in relative blood volume. Although this finding does not exclude a role of hypovolemia because of the limitations of the measurement of relative blood volume, it raises the possibility that non-volume-related mechanisms are involved in the early decrease in mean e′ during hemodialysis. © 2013 National Kidney Foundation, Inc.


Assa S.,University of Groningen | Hummel Y.M.,University of Groningen | Voors A.A.,University of Groningen | Kuipers J.,Dialysis Center Groningen | And 9 more authors.
American Journal of Kidney Diseases | Year: 2014

Background Hemodialysis may acutely induce regional left ventricular (LV) systolic dysfunction, which is associated with increased mortality and progressive heart failure. We tested the hypothesis that hemodialysis-induced regional LV systolic dysfunction is associated with inflammation and endothelial injury. Additionally, we studied whether hemodialysis-induced LV systolic dysfunction is associated with an exaggerated bioincompatibility reaction to hemodialysis. Study Design Cross-sectional study. Setting & Participants 105 hemodialysis patients on a thrice-weekly dialysis schedule were studied between March 2009 and March 2010. Predictors Plasma indexes of inflammation (high-sensitivity C-reactive protein, pentraxin 3 [PTX3], interleukin 6 [IL-6], and IL-6:IL-10 ratio), bioincompatibility (leukocytes, neutrophils, complement C3, and myeloperoxidase), and endothelial function (soluble intercellular adhesion molecule 1 [ICAM-1], von Willebrand factor, proendothelin, and endothelin) were measured just before dialysis and at 60, 180, and 240 minutes intradialysis. Outcomes Hemodialysis-induced regional LV systolic function. Wall motion score was measured by echocardiography at 30 minutes predialysis, 60 and 180 minutes intradialysis, and 30 minutes postdialysis. We defined hemodialysis-induced regional LV systolic dysfunction as an increase in wall motion score in 2 or more segments. Results Patients with hemodialysis-induced regional LV systolic dysfunction (n = 29 [27%]) had significantly higher predialysis high-sensitivity C-reactive protein, PTX3, IL-6, and lL-6:IL-10 ratio values. Predialysis levels of bioincompatibility and endothelial markers did not differ between groups. Intradialysis courses of markers of inflammation, bioincompatibility, and endothelial function did not differ in patients with versus without hemodialysis-induced regional LV systolic dysfunction. Limitations Coronary angiography or computed tomography for quantification of coronary calcifications in our patients was not performed; therefore, we could not relate markers of inflammation to the extent of atherosclerosis. Conclusions Patients with hemodialysis-induced regional LV systolic dysfunction have a proinflammatory cytokine profile. There was no indication of an association with an exaggerated bioincompatibility reaction to hemodialysis. © 2014 by the National Kidney Foundation, Inc.


Kuipers J.,Dialysis Center Groningen | Usvyat L.A.,Renal Research Institute | Oosterhuis J.K.,University of Groningen | Dasselaar J.J.,University of Groningen | And 6 more authors.
American Journal of Kidney Diseases | Year: 2013

Background: Patients with thrice-weekly hemodialysis have higher predialysis weights and ultrafiltration rates at the first compared with subsequent dialysis sessions of the week. We hypothesized that these variations in weight and ultrafiltration rate are associated with a systematic difference in blood pressure. Study Design: Observational study. Setting & Participants: During 3 months, we prospectively collected hemodynamic data for 4,007 hemodialysis sessions involving 124 Dutch patients. A similar analysis was performed with 789 US patients, comprising 6,060 hemodialysis sessions. Factor: First versus subsequent hemodialysis sessions of the week. Outcomes: Blood pressure. Measurements: Blood pressure, weight, and ultrafiltration rate were analyzed separately for the first, second, and third dialysis sessions of the week. Comparisons were made with linear mixed models. Results: In Dutch patients, predialysis weight and ultrafiltration rate were significantly greater at the first compared with subsequent hemodialysis sessions of the week (P < 0.001). Predialysis systolic and diastolic blood pressures were higher at the first than at subsequent sessions of the week (P < 0.001). Predialysis blood pressure differences persisted throughout the session: systolic and diastolic blood pressures were on average 5.0 and 2.5 mm Hg higher during the first compared to the third session of the week. Postdialysis blood pressures followed a similar pattern (P < 0.001). Blood pressure differences between the first and subsequent days of the week persisted after adjustment for possible confounders. Results in the US cohort were materially identical despite differences in patient characteristics and treatment practice between the 2 cohorts. Limitations: Dry weight was not assessed by objective methods. Conclusions: Blood pressure of patients on a thrice-weekly dialysis schedule varies systematically over the week. Predialysis blood pressure is highest at the first hemodialysis session of the week, most likely due to greater interdialytic weight gain. Intra- and postdialytic blood pressures also are highest at the first session of the week despite higher ultrafiltration rates. © 2013 National Kidney Foundation, Inc.


Schulz T.,University of Groningen | Niesing J.,University of Groningen | Homan Van Der Heide J.J.,University of Amsterdam | Westerhuis R.,Dialysis Center Groningen | And 2 more authors.
Transplantation Proceedings | Year: 2013

Although increased longevity of grafts has led to a growing number of long-term kidney transplant recipients, knowledge about the perceived health of these patients remains limited. A cross-sectional sample of 609 patients (60% response) was stratified into a short-term (≤1 year), midterm (>1 and ≤8 years), and long-term cohort (>8 and ≤15 years posttransplantation). Cohorts were compared for perceived health (Visual Analogue Scale of the EQ-5D), number of symptoms, and number of comorbidities by analysis of variance/covariance and multivariate regression analyses. Long-term patients reported more symptoms, (F[2, 606] = 3.09, P =.046) and more comorbidities, (F[2, 588] = 4.75, P =.009) but similar levels of perceived health, (F[2, 550] = 2.37, P >.05). Furthermore, symptoms were less influential for perceived health among long- versus short-term (z = -2.08, P =.038) or midterm cohorts (z = -2.60, P =.009). Previously identified predictors of perceived health accounted for less variance in the long-term as opposed to short-term (z = 4.30, P <.001) and midterm cohort (z = 2.07, P =.039). Despite more symptoms and comorbidities, the perceived health of long-term kidney transplant recipients was comparable to the short- and midterm, possibly due to selective survival or patient adjustment. Because kidney function and symptoms were predominantly associated with short-term perceived health, there is an urgent need to identify variables associated with long-term perceived health. © 2013 Elsevier Inc.


Assa S.,University of Groningen | Hummel Y.M.,University of Groningen | Voors A.A.,University of Groningen | Kuipers J.,Dialysis Center Groningen | And 4 more authors.
Clinical Journal of the American Society of Nephrology | Year: 2012

Background and objectives The hemodialysis procedure may acutely induce regional left ventricular systolic dysfunction. This study evaluated the prevalence, time course, and associated patient- and dialysis-related factors of this entity and its association with outcome. Design, setting, participants, & measurements Hemodialysis patients (105) on a three times per week dialysis schedule were studied between March of 2009 and March of 2010. Echocardiography was performed before dialysis, at 60 and 180 minutes intradialysis, and at 30 minutes postdialysis. Hemodialysis-induced regional left ventricular systolic dysfunction was defined as an increase in wall motion score in more than or equal to two segments. Results Hemodialysis-induced regional left ventricular systolic dysfunction occurred in 29 (27%) patients; 17 patients developed regional left ventricular systolic dysfunction 60 minutes after onset of dialysis. Patients with hemodialysis-induced left ventricular systolic dysfunction were more often male, had higher left ventricular mass index, and had worse predialysis left ventricular systolic function (left ventricular ejection fraction). The course of blood volume, BP, heart rate, electrolytes, and acid-base parameters during dialysis did not differ significantly between the two groups. Patients with hemodialysis-induced regional left ventricular systolic dysfunction had a significantly higher mortality after correction for age, sex, dialysis vintage, diabetes, cardiovascular history, ultrafiltration volume, left ventricular mass index, and predialysis wall motion score index. Conclusions Hemodialysis induces regional wall motion abnormalities in a significant proportion of patients, and these changes are independently associated with increased mortality. Hemodialysis-induced regional left ventricular systolic dysfunction occurs early during hemodialysis and is not related to changes in blood volume, electrolytes, and acid-base parameters. © 2012 by the American Society of Nephrology.


PubMed | Dialysis Center Groningen and University of Groningen
Type: Journal Article | Journal: PloS one | Year: 2016

Hemodialysis patients experience an elevated risk of malnutrition associated with increased morbidity and mortality. Nocturnal hemodialysis (NHD) results in more effective removal of waste products and fluids. Therefore, diet and fluid restrictions are less restricted in NHD patients. However, it is ambiguous whether transition from conventional hemodialysis (CHD) to NHD leads to improved intake and nutritional status. We studied the effect of NHD on protein intake, laboratory indices of nutritional status, and body composition.Systematic review with meta-analysis.NHD patients.Systematic literature search from databases, Medline, Cinahl, EMBASE and The Cochrane Library, to identify studies reporting on nutritional status post-transition from CHD to NHD.Transition from CHD to NHD.Albumin, normalized protein catabolic rate (nPCR), dry body weight (DBW), body mass index (BMI), phase angle, protein intake, and energy intake.Systematic literature search revealed 13 studies comprising 282 patients that made the transition from CHD to NHD. Meta-analysis included nine studies in 229 patients. In control group controlled studies (n = 4), serum albumin increased significantly from baseline to 4-6 months in NHD patients compared with patients that remained on CHD (mean difference 1.3 g/l, 95% CI 0.02; 2.58, p = 0.05). In baseline controlled studies, from baseline to 4-6 months of NHD treatment, significant increases were ascertained in serum albumin (mean difference (MD) 1.63 g/l, 95% CI 0.73-2.53, p<0.001); nPCR (MD 0.16 g/kg/day; 95% CI 0.04-0.29, p = 0.01); protein intake (MD 18.9 g, 95% CI 9.7-28.2, p<0.001); and energy intake (MD 183.2 kcal, 95% CI 16.8-349.7, p = 0.03). Homogeneity was rejected only for nPCR (baseline versus 4-6 months). DBW, BMI, and phase angle did not significantly change. Similar results were obtained for comparison between baseline and 8-12 months of NHD treatment.Most studies had moderate sample sizes; some had incomplete dietary records and relatively brief follow-up period. Studies markedly differed with regard to study design.NHD is associated with significantly higher protein and energy intake as well as increases in serum albumin and nPCR. However, the data on body composition are inconclusive.


PubMed | Dialysis Center Groningen
Type: Journal Article | Journal: Kidney & blood pressure research | Year: 2016

Higher interdialytic weight gain (IDWG) is associated with higher predialysis blood pressure and increased mortality. IDWG is also increasingly being recognized as an indicator of nutritional status. We studied in detail the associations of various patient factors and nutritional parameters with IDWG.We collected data during one week for IDWG and hemodynamic parameters in 138 prevalent adult haemodialysis patients on a thrice-weekly haemodialysis schedule. A multivariate linear regression analysis was employed to identify factors that are associated with IDWG.The mean (SD) age was 62.5 (18.2) years, 36% were female, 36% had diuresis, and 23% had diabetes. Patients in the highest IDWG tertile were significantly younger, more frequently male, and had a significantly higher subjective global assessment score (SGA). A higher IDWG as a percentage of body weight (%IDWG) was associated with a younger age, greater height and weight, absence of diuresis, and lower postdialysis plasma sodium levels. The model with these five parameters explained 37% of the variance of %IDWG. Predialysis, intradialysis, and postdialysis diastolic blood pressure was significantly higher in the highest tertile of IDWG.The most important associations of %IDWG are age, height, weight, diuresis, and postdialysis sodium. Patients with the highest IDWG have significantly higher diastolic blood pressures.


PubMed | Dialysis Center Groningen and University of Groningen
Type: | Journal: BMC nephrology | Year: 2016

Intradialytic hypotension (IDH) is considered one of the most frequent complications of haemodialysis with an estimated prevalence of 20-50%, but studies investigating its exact prevalence are scarce. A complicating factor is that several definitions of IDH are used. The goal of this study was, to assess the prevalence of IDH, primarily in reference to the European Best Practice Guideline (EBPG) on haemodynamic instability: A decrease in systolic blood pressure (SBP) 20mmHg or in mean arterial pressure (MAP) 10mmHg associated with a clinical event and the need for nursing intervention.During 3months we prospectively collected haemodynamic data, clinical events, and nursing interventions of 3818 haemodialysis sessions from 124 prevalent patients who dialyzed with constant ultrafiltration rate and dialysate conductivity. Patients were considered as having frequent IDH if it occurred in >20% of dialysis sessions.Decreases in SBP 20mmHg or MAP 10mmHg occurred in 77.7%, clinical symptoms occurred in 21.4%, and nursing interventions were performed in 8.5% of dialysis sessions. Dialysis hypotension according to the full EBPG definition occurred in only 6.7% of dialysis sessions. Eight percent of patients had frequent IDH.The prevalence of IDH according to the EBPG definition is low. The dominant determinant of the EBPG definition was nursing intervention since this was the component with the lowest prevalence. IDH seems to be less common than indicated in the literature but a proper comparison with previous studies is complicated by the lack of a uniform definition.


PubMed | University of Groningen and Dialysis Center Groningen
Type: Journal Article | Journal: Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association | Year: 2016

Recent data suggest a role for fibroblast growth factor 23 (FGF-23) in volume regulation. In haemodialysis patients, a large ultrafiltration volume (UFV) reflects poor volume control, and both FGF-23 and a large UFV are risk factors for mortality in this population. We studied the association between FGF-23 and markers of volume status including UFV, as well as the intradialytic course of FGF-23, in a cohort of haemodialysis patients.We carried out observational, post hoc analysis of 109 prevalent haemodialysis patients who underwent a standardized, low-flux, haemodialysis session with constant ultrafiltration rate. We measured UFV, plasma copeptinand echocardiographic parameters including cardiac output, end-diastolic volumeand left ventricular mass index at the onset of the haemodialysis session. We measured the intradialytic course of plasma C-terminal FGF-23 (corrected for haemoconcentration) and serum phosphate levels at 0, 1, 3and 4 h after onset of haemodialysis and analysed changes with linear mixed effect model.Median age was 66 (interquartile range: 51-75) years, 65% were male with a weekly Kt/V 4.3 0.7 and dialysis vintage of 25.4 (8.5-52.5) months. In univariable analysis, pre-dialysis plasma FGF-23 was associated with UFV, end-diastolic volume, cardiac output, early diastolic velocity e and plasma copeptin. In multivariable regression analysis, UFV correlated with FGF-23 (standardized : 0.373, P < 0.001, model R(2): 57%), independent of serum calcium and phosphate. The association between FGF-23 and echocardiographic volume markers was lost for all but cardiac output upon adjustment for UFV. Overall, FGF-23 levels did not change during dialysis [7627 (3300-13 514) to 7503 (3109-14 433) RU/mL; P = 0.98], whereas phosphate decreased (1.71 0.50 to 0.88 0.26 mmol/L; P < 0.001).FGF-23 was associated with volume status in haemodialysis patients. The strong association with UFV suggests that optimization of volume status, for example by more intensive haemodialysis regimens, may also benefit mineral homeostasis. A single dialysis session did not lower FGF-23 levels.

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