A Randomized Trial of Hemodiafiltration and Change in Cardiovascular Parameters

Background and objective

Increased left ventricular mass (LVM), low ventricular ejection fraction (EF), and high pulse-wave velocity (PWV) relate to overall and cardiovascular mortality in patients with ESRD. The aim of this study was to determine the effect of online hemodiafiltration (HDF) versus low-flux hemodialysis (HD) on LVM, EF, and PWV.

Design, setting, participants, & measurements

Echocardiography was used to assess LVM and EF in 342 patients in the CONvective TRAnsport STudy followed for up to 4 years. PWV was measured in 189 patients for up to 3 years. Effect of HDF versus HD on LVM, EF, and PWV was evaluated using linear mixed models.

Results

Patients had a mean age of 63 years, and 61% were male. At baseline, median LVM was 227 g (interquartile range [IQR], 183–279 g), and median EF was 65% (IQR, 55%–72%). Median PWV was 9.8 m/s (IQR, 7.5–12.0 m/s). There was no significant difference between the HDF and HD treatment groups in rate of change in LVM (HDF: change, −0.9 g/yr [95% confidence interval (95% CI), −8.9 to 7.7 g]; HD: change, 12.5 g/yr [95% CI, −3.0 to 27.5 g]; P for difference=0.13), EF (HDF: change, −0.3%/yr [95% CI, −2.3% to 1.8%]; HD: change, −3.4%/yr [95% CI, −5.9% to −0.9%]; P=0.17), or PWV (HDF: change, −0.0 m/s per year [95% CI, −0.4 to 0.4 m/s); HD: change, 0.0 m/s per year [95% CI, −0.3 to 0.2 m/s]; P=0.89). No differences in rate of change between treatment groups were observed for subgroups of age, sex, residual kidney function, dialysis vintage, history of cardiovascular disease, diabetes, or convection volume.

Conclusions

Treatment with online HDF did not affect changes in LVM, EF, or PWV over time compared with HD.     

Comparative Effectiveness of Two Catheter Locking Solutions to Reduce Catheter-Related Bloodstream Infection in Hemodialysis Patients

Background and objectives

Infection is the second leading cause of death in hemodialysis patients. Catheter-related bloodstream infection and infection-related mortality have not improved in this population over the past two decades. This study evaluated the impact of a prophylactic antibiotic lock solution on the incidence of catheter-related bloodstream infection and mortality.

Design, setting, participants, & measurements

This prospective, multicenter, observational cohort study compared the effectiveness of two catheter locking solutions (gentamicin/citrate versus heparin) in 555 hemodialysis patients dialyzing with a tunneled cuffed catheter between 2008 and 2011. The groups were not mutually exclusive. Rates of catheter-related bloodstream infection and mortality hazards were compared between groups.

Results

The study population (n=555 and 1350 catheters) had a median age of 62 years (interquartile range=41–83 years), with 50% men and 71% black. There were 427 patients evaluable in the heparin period (84,326 days) and 322 patients evaluable in the antibiotic lock period (71,192 days). Catheter-related bloodstream infection in the antibiotic lock period (0.45/1000 catheter days) was 73% lower than the heparin period (1.68/1000 catheter days; P=0.001). Antibiotic lock use was associated with a decreased risk of catheter-related bloodstream infection compared with heparin (risk ratio, 0.23; 95% confidence interval, 0.13 to 0.38 after multivariate adjustment). Cox proportional hazards modeling found that antibiotic lock was associated with a reduction in mortality (hazard ratio, 0.36; 95% confidence interval, 0.22 to 0.58 in unadjusted analyses; hazard ratio, 0.32; 95% confidence interval, 0.14 to 0.75 after multivariate adjustment). The rate of gentamicin-resistant organisms decreased (0.40/1000 person-years to 0.22/1000 person-years) in the antibiotic lock period (P=0.01).

Conclusions

The results of this study show that the use of a prophylactic, gentamicin/citrate lock was associated with a substantial reduction in catheter-related bloodstream infection and is the first to report a survival advantage of antibiotic lock in a population at high risk of infection-related morbidity and mortality.     

Quality of Life and Physical Function in Older Patients on Dialysis: A Comparison of Assisted Peritoneal Dialysis with Hemodialysis

Background and objectives

In-center hemodialysis (HD) is often the default dialysis modality for older patients. Few centers use assisted peritoneal dialysis (PD), which enables treatment at home. This observational study compared quality of life (QoL) and physical function between older patients on assisted PD and HD.

Design, setting, participants, & measurements

Patients on assisted PD who were >60 years old and on dialysis for >3 months were recruited and matched to patients on HD (needing hospital transport) by age, sex, diabetes, dialysis vintage, ethnicity, and index of deprivation. Frailty was assessed using the Clinical Frailty Scale. QoL assessments included Hospital Anxiety and Depression Scale (HADS), Short Form-12, Palliative Outcomes Symptom Scale (renal), Illness Intrusiveness Rating Scale, and Renal Treatment Satisfaction Questionnaire (RTSQ). Physical function was evaluated by Barthel Score and timed up and go test.

Results

In total, 251 patients (129 PD and 122 HD) were recruited. In unadjusted analysis, patients on assisted PD had a higher prevalence of possible depression (HADS>8; PD=38.8%; HD=23.8%; P=0.05) and higher HADS depression score (median: PD=6; HD=5; P=0.05) but higher RTSQ scores (median: PD=55; HD=51; P<0.01). In a generalized linear regression model adjusting for age, sex, comorbidity, dialysis vintage, and frailty, assisted PD continued to be associated with higher RTSQ scores (P=0.04) but not with other QoL measures.

Conclusions

There are no differences in measures of QoL and physical function between older patients on assisted PD and comparable patients on HD, except for treatment satisfaction, which is higher in patients on PD. Assisted PD should be considered as an alternative to HD for older patients, allowing them to make their preferred choices.     

Dialysis Modality and Mortality in the Elderly: A Meta-Analysis

Background and objectives

Identifying the appropriate choice between hemodialysis (HD) and peritoneal dialysis (PD) is an unresolved issue in elderly patients with ESRD, who are at high risk for death but have a low chance of receiving kidney transplantation.

Design, setting, participants, & measurements

Data on 13,065 incident dialysis Korean patients (age≥65 years) receiving HD (n=10,675) or PD (n=2390) were obtained from the Korean Health Insurance dataset. Multiple statistical approaches, including the multivariate Cox model, were used to compare mortality between Korean patients receiving PD and those receiving HD. Subsequently, meta-analysis of previous comparison studies (published since the year 2000; population-based studies) and the Korean dataset was performed.

Results

During a mean duration of 1.8±1.3 years (maximum of 5 years), the Korean PD group had a higher mortality rate than the Korean HD group (hazard ratio [HR], 1.20 [95% confidence interval (95% CI), 1.13 to 1.28]; P<0.001 by multivariate Cox model). The discrepancy between the two modalities was greater in the presence of certain conditions, such as diabetes mellitus or longer dialysis duration. In the meta-analysis, 15 studies involving >631,421 elderly patients were reviewed. Compared with HD, the pooled HR with PD was 1.10 (95% CI, 1.01 to 1.20). When the meta-analysis was stratified by confounding factors, the survival benefit from HD was particularly strong in subgroups that had diabetes mellitus, had long dialysis duration (>1 year), or contained cohorts starting dialysis in the 1990s.

Conclusions

A meta-analysis that included results in Korean patients suggests a higher risk for death in elderly patients receiving PD than in those receiving HD.     

Association of Corrected QT and QT Dispersion with Echocardiographic and Laboratory Findings in Uremic Patients under Chronic Hemodialysis

Introduction:

Cardiovascular disease is the most common cause of mortality in dialysis patients. Chronic renal failure and hemodialysis (HD) patients may have longer corrected QT (QTc) interval compared with the normal population. Long QTc interval may be a predictor of ventricular arrhythmia and cardiovascular mortality in these patients and hence the aim of this study was the evaluation of the relationship between QTc interval and some echocardiographic findings and laboratory exam results in HD patients.

Materials and Methods:

In a cross-sectional study, 60 HD patients with age >18 years and the dialysis duration >3 months were enrolled. Blood samples were taken, and electrocardiography and echocardiography were done before the dialysis session in the patients.

Results:

Mean age of the patients was 56.15 ± 14.6 years. QTc interval of the patients was 0.441 ± 0.056 s and QT dispersion (QTd) was 64.17 ± 25.93 ms. There was no statistically significant relationship between QTc interval and QTd with duration of dialysis, body mass index, age, and gender (P > 0.05). There was also no significant relationship between QTc interval and QTd with mitral regurgitation, tricuspid regurgitation and aortic insufficiency (P > 0.05). In addition, QTc interval and QTd of the patients had not any correlation with serum parathormon and serum Ca, K, HCO₃ (P > 0.05).

Conclusion:

Based on our results, in HD patients, QTc interval and QTd were not correlated with echocardiographic findings or laboratory exam results. Therefore, it can be concluded that QTc interval prolongation probably has not any correlation with cardiac mortality of the HD patients.     

Nutritional Competence and Resilience among Hemodialysis Patients in the Setting of Dialysis Initiation and Hospitalization

Background and objectives

Dialysis patients have a high risk for inadequate nutrition. Their nutritional status is particularly susceptible to deterioration when faced with intercurrent events such as hospitalization. This study was conducted to improve the understanding of the temporal evolution of nutritional parameters as a foundation for rational and proactive nutritional intervention.

Design, setting, participants, & measurements

A retrospective cohort study was performed to investigate the temporal evolution of nutritional parameters (serum albumin, serum phosphate, serum creatinine, equilibrated normalized protein catabolic rate, and interdialytic weight gain) and a composite nutritional score derived from these parameters, in two populations: (1) incident hemodialysis (HD) patients who started HD between January 2006 and December 2011 and were followed for up to 54 months (median 16.3), and (2) prevalent patients with HD vintage ≥2.5 years who were hospitalized between January 2006 and December 2011 and followed from 6 months before to 6 months after hospitalization.

Results

In incident patients (n=126,964), each of the nutritional parameters improved after HD initiation, with a mean composite nutritional score at the 24th percentile at the start of HD and reaching a plateau at the 57th percentile toward the end of the second year on dialysis. Nutritional parameters increased more rapidly and reached higher values among patients who survived longer. In hospitalized patients (n=14,193), the nutritional parameters and the composite score began to decline 1–2 months before hospitalization, reached their lowest level in the month after hospitalization, and then partially recovered in the subsequent 5 months. The degree of recovery of the nutritional score was inversely related to the number of rehospitalizations.

Conclusions

This study increases the understanding of nutritional resilience and its determinants in HD patients. Application of the nutritional score, pending further validation, may facilitate targeted and timely interventions to avert the negative consequences of inadequate nutrition in chronic HD patients.     

Frailty and Cognitive Function in Incident Hemodialysis Patients

Background and objectives

Patients of all ages undergoing hemodialysis (HD) have a high prevalence of cognitive impairment and worse cognitive function than healthy controls, and those with dementia are at high risk of death. Frailty has been associated with poor cognitive function in older adults without kidney disease. We hypothesized that frailty might also be associated with poor cognitive function in adults of all ages undergoing HD.

Design, setting, participants, & measurements

At HD initiation, 324 adults enrolled (November 2008 to July 2012) in a longitudinal cohort study (Predictors of Arrhythmic and Cardiovascular Risk in ESRD) were classified into three groups (frail, intermediately frail, and nonfrail) based on the Fried frailty phenotype. Global cognitive function (3MS) and speed/attention (Trail Making Tests A and B [TMTA and TMTB, respectively]) were assessed at cohort entry and 1-year follow-up. Associations between frailty and cognitive function (at cohort entry and 1-year follow-up) were evaluated in adjusted (for sex, age, race, body mass index, education, depression and comorbidity at baseline) linear (3MS, TMTA) and Tobit (TMTB) regression models.

Results

At cohort entry, the mean age was 54.8 years (SD 13.3), 56.5% were men, and 72.8% were black. The prevalence of frailty and intermediate frailty were 34.0% and 37.7%, respectively. The mean 3MS was 89.8 (SD 7.6), TMTA was 55.4 (SD 29), and TMTB was 161 (SD 83). Frailty was independently associated with lower cognitive function at cohort entry for all three measures (3MS: −2.4 points; 95% confidence interval [95% CI], −4.2 to −0.5; P=0.01; TMTA: 12.1 seconds; 95% CI, 4.7 to 19.4; P<0.001; and TMTB: 33.2 seconds; 95% CI, 9.9 to 56.4; P=0.01; all tests for trend, P<0.001) and with worse 3MS at 1-year follow-up (−2.8 points; 95% CI, −5.4 to −0.2; P=0.03).

Conclusions

In adult incident HD patients, frailty is associated with worse cognitive function, particularly global cognitive function (3MS).     

Obstructive Sleep Apnea Severity and Overnight Body Fluid Shift before and after Hemodialysis

Background and objectives

Obstructive sleep apnea is associated with significantly increased cardiovascular morbidity and mortality. Fluid overload may promote obstructive sleep apnea in patients with ESRD through an overnight fluid shift from the legs to the neck soft tissues. Body fluid shift and severity of obstructive sleep apnea before and after hemodialysis were compared in patients with ESRD.

Design, setting, participants, & measurements

Seventeen patients with hemodialysis and moderate to severe obstructive sleep apnea were included. Polysomnographies were performed the night before and after hemodialysis to assess obstructive sleep apnea, and bioimpedance was used to measure fluid overload and leg fluid volume.

Results

The mean overnight rostral fluid shift was 1.27±0.41 L prehemodialysis; it correlated positively with fluid overload volume (r=0.39; P=0.02) and was significantly lower posthemodialysis (0.78±0.38 L; P<0.001). There was no significant difference in the mean obstructive apnea-hypopnea index before and after hemodialysis (46.8±22.0 versus 42.1±18.6 per hour; P=0.21), but obstructive apnea-hypopnea index was significantly lower posthemodialysis (−10.1±10.8 per hour) in the group of 12 patients, with a concomitant reduction of fluid overload compared with participants without change in fluid overload (obstructive apnea-hypopnea index +8.2±16.1 per hour; P<0.01). A lower fluid overload after hemodialysis was significantly correlated (r=0.49; P=0.04) with a lower obstructive apnea-hypopnea index. Fluid overload—assessed by bioimpedance—was the best predictor of the change in obstructive apnea-hypopnea index observed after hemodialysis (standardized r=−0.68; P=0.01) in multivariate regression analysis.

Conclusions

Fluid overload influences overnight rostral fluid shift and obstructive sleep apnea severity in patients with ESRD undergoing intermittent hemodialysis. Although no benefit of hemodialysis on obstructive sleep apnea severity was observed in the whole group, the change in obstructive apnea-hypopnea index was significantly correlated with the change in fluid overload after hemodialysis. Moreover, the subgroup with lower fluid overload posthemodialysis showed a significantly lower obstructive sleep apnea severity, which provides a strong incentive to further study whether optimizing fluid status in patients with obstructive sleep apnea and ESRD will improve the obstructive apnea-hypopnea index.     

Comparison of Subdural Hematoma Risk between Hemodialysis and Peritoneal Dialysis Patients with ESRD

Background and objectives

This study compared the risk of subdural hematoma (SDH) and subsequent mortality in hemodialysis (HD) and peritoneal dialysis (PD) patients with ESRD.

Design, setting, participants, & measurements

Claims data were obtained from the National Health Insurance Administration Research Database in Taiwan. This retrospective cohort study comprised 10,136 PD patients and 10,136 HD patients with newly diagnosed ESRD from 1998 to 2010. Patients were matched by propensity score and year of dialysis initiation. Incidence rates and hazard ratios of SDH as well as odds ratios of subsequent 30-day deaths from SDH were evaluated from the date of the first dialysis session to the date when SDH was diagnosed, or the date of renal transplantation, death, withdraw from insurance, or the end of the follow-up period (December 31, 2011).

Results

Median (25th percentile, 75th percentile) follow-up times for SDH events were 3.61 years (1.91, 6.33) and 3.33 years (1.83, 5.66) in the HD and PD cohorts, respectively. The overall SDH incidence rate (95% confidence interval [95% CI]) was 61.4% higher in the HD cohort than in the PD cohort (34.7 [95% CI, 31.4 to 35.4] versus 21.5 [95% CI, 20.2 to 22.9] per 10,000 person-years, with an adjusted hazard ratio of 1.62 [95% CI, 1.17 to 2.33]). Approximately 152 of 253 (60%) of SDH events were associated with trauma. Subsequent 30-day SDH-related mortality was not statistically higher in HD patients than in PD patients (29.1% versus 25.3%; adjusted odds ratio, 1.30; 95% CI, 0.70 to 2.41).

Conclusions

HD patients have a higher risk of developing SDH than PD patients. Both patient groups have a high risk of mortality. Routine education on fall prevention is needed for dialysis patients.     

IL-6 Levels,Nutritional Status,and Mortality in Prevalent Hemodialysis Patients

Summary

Background and objectives

The influence of serum IL-6 levels on nutritional status in chronic hemodialysis (HD) patients remains to be elucidated. The present report describes a prospective longitudinal study of IL-6 levels and nutritional parameters to determine whether high IL-6 levels are independently associated with nutritional status over time in a cohort of prevalent hemodialysis patients.

Design, setting, participants, & measurements

85 clinically stable hemodialysis patients (37.6% women), with a mean age of 66.5 ± 10.6 years, were studied after exclusion of patients with BMI < 20 kg/m² and/or serum albumin <35 g/L. IL-6, dietary energy and protein intake, and biochemical markers of nutrition and body composition (anthropometry and bioimpedance analysis) were measured at baseline and at 6, 12, 18, and 24 months following enrollment. Observation of this cohort was continued over 2 additional years.

Results

IL-6 levels increased with time in both unadjusted (linear estimate: 2.57 ± 0.44 pg/ml per 2 yrs; P = 0.001) and adjusted models (linear estimate: 2.35 ± 0.57 pg/ml per 2 yrs; P = 0.049). Significant reductions of daily energy intake, laboratory markers (albumin, transferrin, cholesterol, creatinine), and body composition (fat mass) with higher IL-6 levels were observed over the duration of the longitudinal observation period. However, none of the studied parameters were associated with changes in IL-6 levels over time (IL-6-by-time interactions were NS). Furthermore, cumulative incidences of survival were correlated with the baseline serum IL-6 levels (P = 0.004 by log-rank test). Finally, for each pg/ml increase in IL-6 level, the hazard ratio for death from all causes was 1.06 (95% CI 1.01 to 1.10) after adjustment for demographic and clinical parameters.

Conclusions

Our results suggest that higher serum IL-6 levels are associated with all-cause mortality without additional changes in clinical and laboratory markers of nutritional status in clinically stable HD patients.     

Vasculoprotective Effects of Dietary Cocoa Flavanols in Patients on Hemodialysis: A Double–Blind,Randomized, Placebo–Controlled Trial

Background and objectives

Hemodialysis (HD) per se entails vascular dysfunction in patients with ESRD. Endothelial dysfunction is a key step in atherosclerosis and is characterized by impaired flow–mediated dilation (FMD). Interventional studies have shown that cocoa flavanol (CF)–rich supplements improve vascular function. Aim of this study was to investigate the effect of flavanol–rich bioactive food ingredients on acute and chronic HD–induced vascular dysfunction in ESRD.

Design, setting, participants, & measurements

We conducted a randomized, double–blind, placebo–controlled trial from 2012 to 2013. Fifty-seven participants were enrolled, ingested CF-rich beverages (900 mg CF per study day), and were compared with those ingesting CF-free placebo. This included (1) a baseline cross–over acute study to determine safety and efficacy of CF and (2) a subsequent chronic parallel group study with a 30-day follow-up period to study effects of CF on HD–mediated vascular dysfunction entailing (3) an acute substudy during HD in flavanol-naive patients and (4) an acute on chronic study during HD. Primary and secondary outcome measures included changes in FMD and hemodynamics.

Results

CF ingestion was well tolerated. Acute ingestion improved FMD by 53% (3.2±0.6% to 4.8±0.9% versus placebo, 3.2±0.7% to 3.3±0.8%; P<0.001), with no effects on BP or heart rate. A 30-day ingestion of CF led to an increase in baseline FMD by 18% (3.4±0.9% to 3.9±0.8% versus placebo, 3.5±0.7% to 3.5±0.7%; P<0.001), with reduced diastolic BP (73±12 to 69±11 mmHg versus placebo, 70±11 to 73±13 mmHg; P=0.03) and increased heart rate (70±12 to 74±13 bpm versus placebo, 75±15 to 74±13 bpm; P=0.01). No effects were observed for placebo. Acute ingestion of CF during HD alleviated HD–induced vascular dysfunction (3.4±0.9% to 2.7±0.6% versus placebo, 3.5±0.7% to 2.0±0.6%; P<0.001). This effect was sustained throughout the study (acute on chronic, 3.9±0.9% to 3.0±0.7% versus placebo, 3.5±0.7% to 2.2±0.6; P=0.01).

Conclusions

Dietary CF ingestion mitigates acute HD–induced and chronic endothelial dysfunction in patients with ESRD and thus, improves vascular function in this high-risk population. Larger clinical trials are warranted to test whether this translates into an improved cardiovascular prognosis in patients with ESRD.     

Intradialytic Hypotension and Risk of Cardiovascular Disease

Background and objectives

Patients undergoing hemodialysis have an elevated risk of cardiovascular disease–related morbidity and mortality compared with the general population. Intradialytic hypotension (IDH) is estimated to occur during 20%–30% of hemodialysis sessions. To date, no large studies have examined whether IDH is associated with cardiovascular outcomes. This study determined the prevalence of IDH according to interdialytic weight gain (IDWG) and studied the association between IDH and outcomes for cardiovascular events and mortality to better understand its role.

Design, setting, participants, & measurements

This study retrospectively examined records of 39,497 hemodialysis patients during 2007 and 2008. US Renal Data System claims and dialysis provider data were used to determine outcomes. IDH was defined by current Kidney Disease Outcomes Quality Initiative guidelines (≥20 mmHg fall in systolic BP from predialysis to nadir intradialytic levels plus ≥2 responsive measures [dialysis stopped, saline administered, etc.]). IDWG was measured absolutely (in kilograms) and relatively (in percentages).

Results

IDH occurred in 31.1% of patients during the 90-day exposure assessment period. At baseline, the higher the IDWG (relative or absolute), the greater the frequency of IDH (P<0.001). For all-cause mortality, the median follow-up was 398 days (interquartile range, 231–602 days). Compared with patients without IDH, IDH was associated with all-cause mortality (7646 events; adjusted hazard ratio, 1.07 [95% confidence interval, 1.01 to 1.14]), myocardial infarction (2396 events; 1.20 [1.10 to 1.31]), hospitalization for heart failure/volume overload (8896 events; 1.13 [1.08 to 1.18]), composite hospitalization for heart failure/volume overload or cardiovascular mortality (10,805 events; 1.12 [1.08 to 1.17]), major adverse cardiac events (MACEs; myocardial infarction, stroke, cardiovascular mortality) (4994 events, 1.10 [1.03 to 1.17]), and MACEs+ (MACEs plus arrhythmia or hospitalization for heart failure/volume overload) (12,221 events; 1.14 [1.09 to 1.19]).

Conclusions

IDH was potently associated with cardiovascular morbidity and mortality. Clinical trials to ascertain causality are needed and should consider reduction in IDWG as a potential means to reduce IDH.     

Influenza A/H1N1 Vaccine in Patients Treated by Kidney Transplant or Dialysis: A Cohort Study

Summary

Background and objectives

In 2009, the pandemic influenza A/H1N1 accounted for worldwide recommendations about vaccination. There are few data concerning the immunogenicity or the security of the adjuvanted-A/H1N1 vaccine in transplanted and hemodialyzed patients.

Design, setting, participants, & measurements

Sera from 21 controls, 53 hemodialyzed (HD) patients, and 111 renal transplant recipients (RT) were sampled before (T0) and 1 month after (T1) a single dose of Pandemrix® vaccine (GSK Biologicals, AS03-adjuvanted). We measured the neutralizing antibodies against A/H1N1/2009, the geometric mean (GM) titers, the GM titer ratios (T1/T0) with 95% confidence intervals, and the seroconversion rate (responders: ≥4-fold increase in titer). The HLA and MICA immunization was determined by Luminex technology.

Results

The GM titer ratio was 38 (19 to 78), 9 (5 to 16), and 5 (3 to 6) for controls, HD patients, and RT patients, respectively (P < 0.001). The proportion of responders was 90%, 57%, and 44%, respectively (P < 0.001). In RT patients, the prevalence of histocompatibility leukocyte antigen (HLA) class I, histocompatibility leukocyte antigen class II, and MHC class I-related chain A immunization, was, respectively, 15%, 14%, and 14% before and 14%, 14%, and 11% after vaccination (P = 1, 1, and 0.39).

Conclusions

The influenza A/H1N1-adjuvanted vaccine is of limited efficacy but is safe in renal disease populations. The humoral response is lower in transplanted versus hemodialyzed patients. Further studies are needed to improve the efficacy of vaccination in those populations.     

Casual Blood Pressure and Neurocognitive Function in Children with Chronic Kidney Disease: A Report of the Children with Chronic Kidney Disease Cohort Study

Summary

Background and objectives

Children with chronic kidney disease (CKD) are at risk for cognitive dysfunction, and over half have hypertension. Data on the potential contribution of hypertension to CKD-associated neurocognitive deficits in children are limited. Our objective was to determine whether children with CKD and elevated BP (EBP) had decreased performance on neurocognitive testing compared with children with CKD and normal BP.

Design, setting, participants, & measurements

This was a cross-sectional analysis of the relation between auscultatory BP and neurocognitive test performance in children 6 to 17 years enrolled in the Chronic Kidney Disease in Children (CKiD) project.

Results

Of 383 subjects, 132 (34%) had EBP (systolic BP and/or diastolic BP ≥90^th percentile). Subjects with EBP had lower mean (SD) scores on Wechsler Abbreviated Scales of Intelligence (WASI) Performance IQ than those with normal BP (normal BP versus EBP, 96.1 (16.7) versus 92.4 (14.9), P = 0.03) and WASI Full Scale IQ (97.0 (16.2) versus 93.4 (16.5), P = 0.04). BP index (subject''s BP/95^th percentile BP) correlated inversely with Performance IQ score (systolic, r = −0.13, P = 0.01; diastolic, r = −0.19, P < 0.001). On multivariate analysis, the association between lower Performance IQ score and increased BP remained significant after controlling for demographic and disease-related variables (EBP, β = −3.7, 95% confidence interval [CI]: −7.3 to −0.06; systolic BP index, β = −1.16 to 95% CI: −2.1, −0.21; diastolic BP index, β = −1.17, 95% CI: −1.8 to −0.55).

Conclusions

Higher BP was independently associated with decreased WASI Performance IQ scores in children with mild-to-moderate CKD.     

Ambulatory Recording of Wave Reflections and Arterial Stiffness during Intra- and Interdialytic Periods in Patients Treated with Dialysis

Background and objectives

Wave reflections and arterial stiffness are independent cardiovascular risk factors in ESRD. Previous studies in this population included only static recordings before and after dialysis. This study investigated the variation of these indices during intra- and interdialytic intervals and examined demographic, clinical, and hemodynamic variables related to arterial function in patients undergoing hemodialysis.

Design, setting, participants, & measurements

Between February 2013 and May 2014, a total of 153 patients receiving maintenance hemodialysis in five dialysis centers of northern Greece underwent ambulatory BP monitoring with the newly introduced Mobil-O-Graph device (IEM, Stolberg, Germany) over a midweek dialysis session and the subsequent interdialytic period. Mobil-O-Graph is an oscillometric device that records brachial BP and pulse waves and estimates, via generalized transfer function, aortic BP, augmentation index (AIx) as a measure of wave reflections, and pulse wave velocity (PWV) as an index of arterial stiffness.

Results

AIx was lower during dialysis than in the interdialytic period of dialysis-on day (Day 1) (mean±SD, 24.7%±9.7% versus 26.8%±9.4%; P<0.001). In contrast, PWV remained unchanged between these intervals (9.31±2.2 versus 9.29±2.3 m/sec; P=0.60). Both AIx and PWV increased during dialysis-off day (Day 2) versus the out-of-dialysis period of Day 1 (28.8%±9.8% versus 26.8%±9.4% [P<0.001] and 9.39±2.3 versus 9.29±2.3 m/sec [P<0.001]). Older age (odds ratio [OR], 1.09; 95% confidence interval [95% CI], 1.02 to 1.15), female sex (OR, 7.56; 95% CI, 1.64 to 34.81), diabetic status (OR, 8.84; 95% CI, 1.76 to 17.48), and higher mean BP (OR, 1.17; 95% CI, 1.09 to 1.27) were associated with higher odds of high AIx; higher heart rate was associated with lower odds (OR, 0.71; 95% CI, 0.63 to 0.80) of high AIx. Older age (OR, 2.04; 95% CI, 1.61 to 2.58) and higher mean BP (OR, 1.15; 95% CI, 1.05 to 1.27) were independent correlates of high PWV.

Conclusions

This study showed a gradual interdialytic increase in AIx, whereas PWV was only slightly elevated during Day 2. Future studies are needed to elucidate the value of these ambulatory measures for cardiovascular risk prediction in ESRD.     

Asymmetric Dimethylarginine,Race, and Mortality in Hemodialysis Patients

Background and objectives

Levels of asymmetric dimethylarginine, an inhibitor of nitric oxide synthase, are elevated in kidney disease and associated with mortality in white European hemodialysis populations. Nitric oxide production and degradation are partially genetically determined and differ by racial background. No studies have measured asymmetric dimethylarginine in African Americans on dialysis and assessed whether differences exist in its association with mortality by race.

Design, setting, participants, & measurements

Asymmetric dimethylarginine was measured in 259 patients on maintenance hemodialysis assembled from 2004 to 2012 in Boston area outpatient centers. Cox proportional hazards models were used to determine the association between asymmetric dimethylarginine and all-cause mortality, and an interaction with race was tested.

Results

Mean (SD) age was 63 (17) years, 46% were women, and 22% were African American. Mean asymmetric dimethylarginine in non–African Americans was 0.79 µmol/L (0.16) versus 0.70 µmol/L (0.11) in African Americans (P<0.001); 130 patients died over a median follow-up of 2.3 years. African Americans had lower mortality risk than non–African Americans (hazard ratio, 0.27; 95% confidence interval, 0.15 to 0.50) that was robust to adjustment for age, comorbidity, and asymmetric dimethylarginine (hazard ratio, 0.35; 95% confidence interval, 0.17 to 0.69). An interaction was noted between race and asymmetric dimethylarginine (P=0.03), such that asymmetric dimethylarginine was associated with higher mortality in non–African Americans (adjusted hazard ratio, 1.29; 95% confidence interval, 1.06 to 1.57 per 1 SD higher asymmetric dimethylarginine) but not in African Americans (adjusted hazard ratio, 0.57; 95% confidence interval, 0.28 to 1.18). Additional adjustment for fibroblast growth factor 23 partially attenuated the association for non–African Americans (adjusted hazard ratio, 1.22; 95% confidence interval, 0.98 to 1.50).

Conclusions

African Americans have lower asymmetric dimethylarginine levels and lower hazard for mortality compared with non–African Americans. Levels of asymmetric dimethylarginine did not explain lower hazard for mortality in non–African American patients. High asymmetric dimethylarginine was a risk factor for mortality exclusively in non–African Americans. Mechanisms explaining these relationships need to be evaluated.     

Effects of Frequent Hemodialysis on Perceived Caregiver Burden in the Frequent Hemodialysis Network Trials

Background and objectives

Patients receiving hemodialysis often perceive their caregivers are overburdened. We hypothesize that increasing hemodialysis frequency would result in higher patient perceptions of burden on their unpaid caregivers.

Design, setting, participants, & measurements

In two separate trials, 245 patients were randomized to receive in-center daily hemodialysis (6 days/week) or conventional hemodialysis (3 days/week) while 87 patients were randomized to receive home nocturnal hemodialysis (6 nights/week) or home conventional hemodialysis for 12 months. Changes in overall mean scores over time in the 10-question Cousineau perceived burden scale were compared.

Results

In total, 173 of 245 (70%) and 80 of 87 (92%) randomized patients in the Daily and Nocturnal Trials, respectively, reported having an unpaid caregiver at baseline or during follow-up. Relative to in-center conventional dialysis, the 12-month change in mean perceived burden score with in-center daily hemodialysis was −2.1 (95% confidence interval, −9.4 to +5.3; P=0.58). Relative to home conventional dialysis, the 12-month change in mean perceived burden score with home nocturnal dialysis was +6.1 (95% confidence interval, −0.8 to +13.1; P=0.08). After multiple imputation for missing data in the Nocturnal Trial, the relative difference between home nocturnal and home conventional hemodialysis was +9.4 (95% confidence interval, +0.55 to +18.3; P=0.04). In the Nocturnal Trial, changes in perceived burden were inversely correlated with adherence to dialysis treatments (Pearson r=−0.35; P=0.02).

Conclusion

Relative to conventional hemodialysis, in-center daily hemodialysis did not result in higher perceptions of caregiver burden. There was a trend to higher perceived caregiver burden among patients randomized to home nocturnal hemodialysis. These findings may have implications for the adoption of and adherence to frequent nocturnal hemodialysis.     

Effect of Phosphate Binders on Serum Inflammatory Profile,Soluble CD14, and Endotoxin Levels in Hemodialysis Patients

Summary

Background and objectives

Hyperphosphatemia and subclinical endotoxemia are important sources of inflammation in HD. Proinflammatory cytokines are strong correlates of soluble CD14 (sCD14) concentrations, an independent predictor of mortality in this population. We evaluated the effects of calcium acetate and sevelamer hydrochloride on serum inflammatory profile, endotoxin concentrations, and sCD14 levels in HD patients.

Design, setting, participants, & measurements

Prospective, randomized, open-label, parallel design trial. Fifty-nine stable HD patients, 30 receiving sevelamer, and 29 receiving calcium acetate were evaluated. Serum levels of inflammatory parameters (high-sensitivity C-reactive protein [hs-CRP], TNF-α, interleukin (IL)-1, -6, -10, and -18), as well as endotoxin and sCD14 concentrations, were measured at baseline and after 3 months of therapy.

Results

Serum IL-6 increased in patients receiving calcium acetate, whereas hs-CRP and IL-6 significantly decreased in subjects treated with sevelamer, with IL-10 experiencing a trend to increase (P = 0.052). Serum endotoxin and sCD14 levels did not change after treatment with calcium acetate. However, these parameters decreased by 22.6% and 15.2%, respectively (P < 0.01), in patients receiving sevelamer. Multiple regression analysis showed that variation in serum endotoxin concentrations was the strongest factor associated with IL-6 change, whereas the only variables independently associated with changes in sCD14 levels were the variations in serum IL-6 and endotoxin concentrations.

Conclusions

Administration of the noncalcium phosphate binder sevelamer to maintenance HD patients is associated with a significant decrease in hs-CRP, IL-6, serum endotoxin levels and sCD14 concentrations.     

Effect of Lisinopril and Atenolol on Aortic Stiffness in Patients on Hemodialysis

Background and objectives

Whether improvements in arterial compliance with BP lowering are because of BP reduction alone or if pleiotropic effects of antihypertensive agents contribute remains unclear. It was hypothesized that, among patients on hemodialysis, compared with a β-blocker (atenolol), a lisinopril-based therapy will better reduce arterial stiffness.

Design, setting, participants, & measurements

Among 200 participants of the Hypertension in Hemodialysis Patients Treated with Atenolol or Lisinopril Trial, 179 patients with valid assessment of aortic pulse wave velocity at baseline (89 patients randomly assigned to open-label lisinopril and 90 patients randomly assigned to atenolol three times a week after dialysis) were included in the secondary analysis. Among them, 109 patients had a valid pulse wave velocity measurement at 6 months. Monthly measured home BP was targeted to <140/90 mmHg by addition of antihypertensive drugs and dry weight adjustment. The difference between drugs in percentage change of aortic pulse wave velocity from baseline to 6 months was analyzed.

Results

Contrary to the hypothesis, atenolol-based treatment induced greater reduction in aortic pulse wave velocity relative to lisinopril (between drug difference, 14.8%; 95% confidence interval, 1.5% to 28.5%; P=0.03). Reduction in 44-hour ambulatory systolic and diastolic BP was no different between groups (median [25th, 75th percentile]; atenolol: −21.5 [−37.7, −7.6] versus lisinopril: −15.8 [−28.8, −1.5] mmHg; P=0.27 for systolic BP; −14.1 [−22.6, −5.3] versus −10.9 [−18.4, −0.9] mmHg, respectively; P=0.30 for diastolic BP). Between-drug difference in change of aortic pulse wave velocity persisted after adjustments for age, sex, race, other cardiovascular risk factors, and baseline ambulatory systolic BP but disappeared after adjustment for change in ambulatory systolic BP (11.8%; 95% confidence interval, −2.3% to 25.9%; P=0.10).

Conclusions

Among patients on dialysis, atenolol was superior in improving arterial stiffness. However, differences between atenolol and lisinopril in improving aortic stiffness among patients on hemodialysis may be explained by BP-lowering effects of drugs.     

The family partners for health study: a cluster randomized controlled trial for child and parent weight management

Objective:

The purpose of this study was to test a two-phased nutrition and exercise education, coping skills training, and exercise intervention program for overweight or obese low-income ethnic minority 2nd to 4th grade children and their parents in rural North Carolina, USA.

Methods:

A cluster randomized controlled trial was carried out with 358 children (7–10 years) and a parent for each child (n=358). General linear mixed models were used to determine the effects of the intervention on weight, adiposity, health behaviors, and eating and exercise self-efficacy by examining changes in children and parents from baseline to completion of the study (18 months).

Results:

At 18 months, children in the experimental group did not have a significantly decreased body mass index (BMI) percentile (P=0.470); however, they showed a reduction in the growth rate of their triceps (P=0.001) and subscapular skinfolds (P<0.001) and an improvement in dietary knowledge (P=0.018) and drank less than one glass of soda per day (P=0.052) compared with the control group. Parents in the experimental group had decreased BMI (P=0.001), triceps (P<0.001) and subscapular skinfolds (P<0.001) and increased nutrition (P=0.003) and exercise (P<0.001) knowledge and more often drank water or unsweetened drinks (P=0.029). At 18 months, children in the experimental group did not show significant improvement in eating (P=0.956) or exercise self-efficacy (P=0.976). Experimental parents demonstrated improved socially acceptable eating self-efficacy (P=0.013); however, they did not show significant improvement in self-efficacy pertaining to emotional eating (P=0.155) and exercise (P=0.680).

Conclusion:

The results suggest that inclusion of children and parents in the same intervention program is an effective way to decrease adiposity and improve nutrition behaviors in both children and parents and improve weight and eating self-efficacy in parents.