Cardiovascular complications in children with chronic kidney disease

Prospective Study of Modifiable Risk Factors of Arterial Hypertension and Left Ventricular Hypertrophy in Pediatric Patients on Hemodialysis

Introduction

Fluid and salt overload in patients on dialysis result in high blood pressure (BP), left ventricular hypertrophy (LVH) and hemodynamic instability, resulting in cardiovascular morbidity.

Methods

Analysis of 910 pediatric patients on maintenance hemodialysis/hemodiafiltration (HD/HDF), prospectively followed-up with 2758 observations recorded every 6-months in the International Pediatric Hemodialysis Network (IPHN).

Results

Uncontrolled hypertension was present in 55% of observations, with 27% of patients exhibiting persistently elevated predialysis BP. Systolic and diastolic age- and height-standardized BP (BP-SDS) were independently associated with the number of antihypertensive medications (odds ratio [OR] = 1.47, 95% confidence interval 1.39-1.56, 1.36 [1.23-1.36]) and interdialytic weight gain (IDWG; 1.19 [1.14-1.22], 1.09 [1.06-1.11]; all P < 0.0001). IDWG was related to urine output (OR = 0.27 [0.23-0.32]) and dialysate sodium (dNa; 1.06 [1.01-1.10]; all P < 0.0001). The prevalence of masked hypertension was 24%, and HD versus HDF use was an independent risk factor of elevated age- and height-standardized mean arterial pressure (MAP-SDS) (OR = 2.28 [1.18-4.41], P = 0.01). Of the 1135 echocardiograms, 51% demonstrated LVH. Modifiable risk factors included predialysis systolic BP-SDS (OR = 1.06 [1.04-1.09], P < 0.0001), blood hemoglobin (0.97 [0.95-0.99], P = 0.004), HD versus HDF modality (1.09 [1.02-1.18], P = 0.01), and IDWG (1.02 [1.02-1.03], P = 0.04). In addition, HD modality increased the risk of LVH progression (OR = 1.23 [1.03-1.48], P = 0.02). Intradialytic hypotension (IDH) was prevalent in patients progressing to LVH and independently associated with predialysis BP-SDS below 25th percentile, lower number of antihypertensives, HD versus HDF modality, ultrafiltration (UF) rate, and urine output, but not with dNa.

Conclusion

Uncontrolled hypertension and LVH are common in pediatric HD, despite intense pharmacologic therapy. The outcome may improve with use of HDF, and superior anemia and IDWG control; the latter via lowering dNa, without increasing the risk of IDH.

Physical activity and its impact on cardiovascular health in pediatric kidney transplant recipients

BACKGROUND

Cardiovascular (CV) morbidity after kidney transplantation (KTx) in childhood is of increasing importance. In light of a high prevalence of CV risk factors, protective measures such as physical activity (PA) come into focus. Our aim was to comprehensively assess PA in pediatric KTx recipients and evaluate its impact on CV health.

METHODS

Forty-eight patients were assessed for frequency, duration, intensity, and setting of PA using the "Motorik-Modul" PA questionnaire. Walking-based activity was measured by accelerometer in a subgroup (n = 23). CV risk factors and subclinical CV organ damage were determined. The impact of PA on CV parameters was analyzed using linear regression models.

RESULTS

Fifty-two percent of pediatric KTx recipients did not reach WHO recommended PA level; 54% did not engage in PA with vigorous intensity (VPA). Twenty-nine percent indicated an extremely inactive lifestyle (< 120 min/week of moderate to vigorous intensity PA, MVPA). Compared to the healthy German KiGGS cohort, KTx recipients specifically lacked engagement in sport activities (KTx: 129 min/week; 95%CI, 97-162 vs. KiGGS, 242 min/week; 95%CI, 230-253). VPA was associated with lower systolic blood pressure (p = 0.024) and resting heart rate (p = 0.005), MVPA with fewer components of the post-transplant metabolic syndrome (p = 0.037), and better left ventricular diastolic function (p = 0.006).

CONCLUSIONS

A considerable lack of PA, especially VPA, exists in young KTx recipients. PA was positively associated with important parameters of CV health. While long-term CV protection through PA seems promising in pediatric KTx recipients, specific educational approaches are most likely needed to increase patients' engagement in sport activities.

Role of Nutrients in Pediatric Non-Dialysis Chronic Kidney Disease: From Pathogenesis to Correct Supplementation

Nutrition management is fundamental for children with chronic kidney disease (CKD). Fluid balance and low-protein and low-sodium diets are the more stressed fields from a nutritional point of view. At the same time, the role of micronutrients is often underestimated. Starting from the causes that could lead to potential micronutrient deficiencies in these patients, this review considers all micronutrients that could be administered in CKD to improve the prognosis of this disease.

Growth hormone in pediatric chronic kidney disease: more than just height

Recombinant human growth hormone therapy, which was introduced in the 1980s, is now routine for children with advanced chronic kidney disease (CKD) who are exhibiting growth impairment. Growth hormone usage remains variable across different centers, with some showing low uptake. Much of the focus on growth hormone supplementation has been on increasing height because of social and psychological effects of short stature. There are, however, numerous other changes that occur in CKD that have not received as much attention but are biologically important for pediatric growth and development. This article reviews the current knowledge about the multisystem effects of growth hormone therapy in pediatric patients with CKD and highlights areas where additional clinical research is needed. We also included clinical data on children and adults who had received growth hormone for other indications apart from CKD. Ultimately, having robust clinical studies which examine these effects will allow children and their families to make more informed decisions about this therapy.

Chronic kidney disease mineral bone disorder in childhood and young adulthood: a 'growing' understanding

Chronic kidney disease (CKD) mineral and bone disorder (MBD) comprises a triad of biochemical abnormalities (of calcium, phosphate, parathyroid hormone and vitamin D), bone abnormalities (turnover, mineralization and growth) and extra-skeletal calcification. Mineral dysregulation leads to bone demineralization causing bone pain and an increased fracture risk compared to healthy peers. Vascular calcification, with hydroxyapatite deposition in the vessel wall, is a part of the CKD-MBD spectrum and, in turn, leads to vascular stiffness, left ventricular hypertrophy and a very high cardiovascular mortality risk. While the growing bone requires calcium, excess calcium can deposit in the vessels, such that the intake of calcium, calcium- containing medications and high calcium dialysate need to be carefully regulated. Normal physiological bone mineralization continues into the third decade of life, many years beyond the rapid growth in childhood and adolescence, implying that skeletal calcium requirements are much higher in younger people compared to the elderly. Much of the research into the link between bone (de)mineralization and vascular calcification in CKD has been performed in older adults and these data must not be extrapolated to children or younger adults. In this article, we explore the physiological changes in bone turnover and mineralization in children and young adults, the pathophysiology of mineral bone disease in CKD and a potential link between bone demineralization and vascular calcification.

Decline in Left Ventricular Early Systolic Function with Worsening Kidney Function in Children with Chronic Kidney Disease: Insights from the 4C and HOT-KID Studies

INTRODUCTION

Adults with childhood-onset chronic kidney disease (CKD) have an increased risk of cardiovascular disease. First-phase ejection fraction (EF1), a novel measure of early systolic function, may be a more sensitive marker of left ventricular dysfunction than other markers in children with CKD.

OBJECTIVE

To examine whether EF1 is reduced in children with CKD.

METHODS

Children from the 4C and HOT-KID studies were stratified according to estimated glomerular filtration rate (eGFR). The EF1 was calculated from the fraction of left ventricular (LV) volume ejected up to the time of peak aortic flow velocity.

RESULTS

The EF1 was measured in children ages 10.9 ± 3.7 (mean ± SD) years, 312 with CKD and 63 healthy controls. The EF1 was lower, while overall ejection fraction was similar, in those with CKD compared with controls and decreased across stages of CKD (29.3% ± 3.7%, 23.5% ± 4.5%, 19.8% ± 4.0%, 18.5% ± 5.1%, and 16.7% ± 6.6% in controls, CKD 1, 2, 3, and ≥ 4, respectively, P < .001). The relationship of EF1 to eGFR persisted after adjustment for relevant confounders (P < .001). The effect size for association of measures of LV structure or function with eGFR (SD change per unit change in eGFR) was greater for EF1 (β = 0.365, P < .001) than for other measures: LV mass index (β = -0.311), relative wall thickness (β = -0.223), E/e' (β = -0.147), and e' (β = 0.141) after adjustment for confounders in children with CKD.

CONCLUSIONS

Children with CKD exhibit a marked and progressive decline in EF1 with falling eGFR. This suggests that EF1 is a more sensitive marker of LV dysfunction when compared to other structural or functional measures and that early LV systolic function is a key feature in the pathophysiology of cardiac dysfunction in CKD.

Longitudinal follow-up on vascular morphology and function in children with kidney transplants

AIM

Our aim was to evaluate cardiovascular risk profile in 42 children with kidney transplants (KT) at the Queen Silvia Children's Hospital, Gothenburg Sweden.

METHODS

Forty-two children (7.1-18 years) with KT, time from transplantation 3.5 (0.9-13) years, were examined at inclusion and annually for three consecutive years. Eighteen matched controls were examined once. Cardiovascular phenotyping included ultra-high-frequency ultrasound (UHFUS), pulse wave velocity (PWV), and endothelial function.

RESULTS

Children with KT had higher body mass index (BMI) z-score and blood pressure (BP) z-score than healthy controls (BMI z-score: 0.4 ± 1.0 and - 0.2 ± 0.9, respectively, p = 0.02; SBP z-score: 0.5 ± 0.9 and - 0.8 ± 0.7; DBP z-score: 0.7 ± 0.7 and - 0.3 ± 0.5, respectively, p < 0.001). BP z-score decreased significantly over 3 years; other vascular markers remained unchanged. PWV and carotid intima thickness (IT) were higher in children with KT compared to healthy controls. Children with pre-emptive KT had lower radial IT and dorsal pedal media thickness (MT) compared to children with preceding dialysis.

CONCLUSION

Children with KT show increased cardiovascular risk parameters, not increasing over time. Children on dialysis before KT have more pronounced vascular changes than those with pre-emptive KT, suggesting pre-emptive transplantation more beneficial for cardiovascular health.

Effects of pediatric chronic kidney disease and its etiology on tissue sodium concentration: a pilot study

BACKGROUND

Sodium-23 magnetic resonance imaging (²³Na MRI) allows non-invasive assessment of tissue sodium concentration ([Na⁺]). Age and chronic kidney disease (CKD) are associated with increased tissue [Na⁺] in adults, but limited information is available pertaining to children and adolescents. We hypothesized that pediatric CKD is associated with altered tissue [Na⁺] compared to healthy controls.

METHODS

This was a case-control exploratory study on healthy children and adults and pediatric CKD patients. Study participants underwent an investigational visit, blood/urine biochemistry, and leg ²³Na MRI for tissue [Na⁺] quantification (whole leg, skin, soleus muscle). CKD was stratified by etiology and patients' tissue [Na⁺] was compared against healthy controls by computing individual Z-scores. An absolute Z-score > 1.96 was deemed to deviate significantly from the mean of healthy controls. Pearson correlation was used to compute the associations between tissue [Na⁺] and kidney function.

RESULTS

A total of 36 pediatric participants (17 healthy, 19 CKD) and 19 healthy adults completed the study. Healthy adults had significantly higher tissue [Na⁺] compared with pediatric groups; conversely, no significant differences were found between healthy children/adolescents and CKD patients. Four patients with glomerular disease and one kidney transplant recipient due to atypical hemolytic-uremic syndrome had elevated whole-leg [Na⁺] Z-scores. Reduced whole-leg [Na⁺] Z-scores were found in two patients with tubular disorders (Fanconi syndrome, proximal-distal renal tubular acidosis). All tissue [Na⁺] measures were significantly associated with proteinuria and hypoalbuminemia.

CONCLUSIONS

Depending on etiology, pediatric CKD was associated with either increased (glomerular disease) or reduced (tubular disorders) tissue [Na⁺] compared with healthy controls. A higher resolution version of the Graphical abstract is available as Supplementary information.

Adipokines as predictive factor of cardiac function in pediatric patients with chronic kidney disease

BACKGROUND

Adipokines are associated with cardiovascular disease; in chronic kidney disease (CKD) patients adipokines could be useful prognostic factors.

OBJECTIVES

To explore whether leptin and adiponectin in kidney replacement therapy (KRT) children could have a role on their cardiac function, in the long-term.

DESIGN

Prospective cohort study was performed with pediatric KRT patients, aged 8 to 17 years who were undergoing hemodialysis or peritoneal dialysis. At enrollment, lipid profile, adipokines (leptin, leptin receptor, free leptin, and adiponectin), anthropometric measurements and cardiological evaluation were determined. At two-year follow-up, a new cardiological evaluation was performed. Statistical analysis: Quantitative data are presented as median and interquartile range (IQR). Mann-Whitney U test and Chi-squared were used for the between-group comparison. Multivariate analyzes were performed to determine the association of adipokines levels with ventricular ejection fraction (LEVF).

RESULTS

We included 56 patients, with a median age of 12.5 years. In the first cardiological evaluation, median LVEF was 70.0% (IQR 61%, 76%), 20 patients (35.7%) had some cardiovascular condition, and 10 (17.8%) altered LVEF. At 24-month follow-up, the median LVEF was 70.5% (IQR 65.1%, 77%), while the delta-LVEF values was 3% (IQR -6.5%, 7%). Delta-LVEF were correlated with baseline adipokines serum levels, and the only positive correlation found was with free leptin (r=0.303, p=0.025). In multivariate analysis, levels of free leptin (Coef. 0.12, p<0.036) and leptin (coef. 1.72, p=0.049), as well as baseline LVEF (Coef. -0.65, p<0.001) were associated with delta-LVEF.

CONCLUSIONS

Free leptin, leptin and LVEF at the beginning of follow-up were associated with the LVEF decrease at the 24-month follow-up in KRT children.

Low-density lipoprotein and blood pressure are important risk factors for vasculopathy in children on dialysis: a single center study

INTRODUCTION

We searched for risk factors of cardiovascular assessment among children on dialysis.

METHODS

This is a cross-sectional study of cardiovascular assessment of all patients on dialysis at xxx University Children's Hospital. Pediatric patients between the ages of 6 and 21 who were on hemodialysis and peritoneal dialysis treatment were included in the study. Cardiovascular evaluation included left ventricular mass index (LVMI), pulse wave velocity (PWV), and carotid intima-media thickness (cIMT) measurements.

RESULTS

Nineteen patients were included in this study. The LDL had a correlation with the cIMT z-score, but not to PWVz-score. Binary Logistic regression analysis found that only LDL was significantly associated to increased cIMT.

CONCLUSION

This study reports an association between high LDL and high blood pressure increased cIMT on dialyzed children. Strategies to reduce LDL and blood pressure in dialysis patients may prevent vasculopathy and long-term cardiovascular complications.

Steroid avoidance/withdrawal and maintenance immunosuppression in pediatric kidney transplantation

BACKGROUND

Corticosteroids have been an integral part of maintenance immunosuppression for pediatric kidney transplantation. However, prolonged steroid therapy is associated with significant toxicities resulting in several SW/avoidance strategies in recent years.

METHOD/OBJECTIVE

This comprehensive review aims to discuss steroid-related toxicities and the safety, efficacy, and benefit of steroid avoidance/withdrawal immunosuppression in pediatric kidney transplant recipients.

RESULTS

Initial studies of SW/avoidance conducted in the setting of CSA and AZA showed an increased incidence of AR but no increase in graft loss or mortality with SW/avoidance maintenance immunosuppression. Studies performed under modern immunosuppression (induction therapy, Tac, and MMF) show no significant increase in AR or graft loss with SW/avoidance immunosuppression. Furthermore, SW/avoidance immunosuppression is associated with significant improvement in growth, BMI, BP control, and lipid profile in pediatric kidney transplant recipients. Despite these data, SW/avoidance remains controversial, and only 40% of pediatric kidney transplant recipients in the United States are currently on SW/avoidance maintenance immunosuppression.

CONCLUSION

SW/avoidance maintenance immunosuppression is safe and associated with fewer side effects compared with steroid-inclusive maintenance immunosuppression in pediatric kidney transplant recipients.

Assessment and management of obesity and metabolic syndrome in children with CKD stages 2-5 on dialysis and after kidney transplantation-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

Obesity and metabolic syndrome (O&MS) due to the worldwide obesity epidemic affects children at all stages of chronic kidney disease (CKD) including dialysis and after kidney transplantation. The presence of O&MS in the pediatric CKD population may augment the already increased cardiovascular risk and contribute to the loss of kidney function. The Pediatric Renal Nutrition Taskforce (PRNT) is an international team of pediatric renal dietitians and pediatric nephrologists who develop clinical practice recommendations (CPRs) for the nutritional management of children with kidney diseases. We present CPRs for the assessment and management of O&MS in children with CKD stages 2-5, on dialysis and after kidney transplantation. We address the risk factors and diagnostic criteria for O&MS and discuss their management focusing on non-pharmacological treatment management, including diet, physical activity, and behavior modification in the context of age and CKD stage. The statements have been graded using the American Academy of Pediatrics grading matrix. Statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs based on the clinical judgment of the treating physician and dietitian. Research recommendations are provided. The CPRs will be periodically audited and updated by the PRNT.

Assessments of left ventricular systolic and diastolic functions with tissue Doppler imaging and myocardial performance index in children with chronic kidney disease

BACKGROUND

This study aimed to document early left ventricular (LV) dysfunction in chronic kidney disease (CKD) using methods such as tissue Doppler imaging and the myocardial performance index (MPI).

METHODS

A total of 40 patients diagnosed with CKD (mean age, 10.1 ± 4.1 years) and 40 sex- and age-matched healthy controls (mean age, 9.6 ± 4.3 years) were examined. In the patient group, 20 patients had early stage (Stage 2-3) CKD and 20 patients had late-stage (stage 4-5) CKD, and 18 patients had hypertension.

RESULTS

The pulmonary artery systolic pressure (PAPs) and LV mass index (LVMI) were significantly higher in the patient group (P < 0.05). The LV septal and lateral margins of the mitral annulus E'/A' ratio, E/E' ratio and MPI results were significantly different between the groups (P < 0.05). The MPI scores were higher in late-stage CKD than in early stage CKD (P < 0.05). The E'/A' ratio was lower and the MPI was higher in the hypertensive CKD group compared with the normotensive CKD group (P < 0.05). The E/E' ratio was correlated positively with the LVMI, and the PAPs, and negatively with glomerular filtration rate, S' value, E'/A' ratio. The MPI was correlated positively with blood pressure, LVMI, PAPs, and the S value, and negatively with the E'/A' ratio.

CONCLUSIONS

The E'/A' ratio, the E/E' ratio, and the isovolumetric relaxation time measured by tissue Doppler imaging is highly accurate and easily applicable for detecting diastolic LV function, and the MPI is suitable for detecting both systolic and diastolic LV dysfunction. Their routine use may be useful in evaluating LV functions in children with CKD.

Nutritional Assessment and Management in Paediatric Chronic Kidney Disease

Nutrition in paediatrics has always been one of the most important factors for optimal growth. Children with chronic kidney disease (CKD) need special consideration for better long-term outcomes, including nutritional status, optimal height, and cognitive function. Nonetheless, there are many obstacles to overcome to attain optimal linear growth and nutritional status in children with CKD. This review highlights the need for tools to assess the growth parameters in CKD. In addition, recommendations for dietary intake play a major role in controlling electrolyte disturbances in patients with CKD. For example, it is still unclear whether it is better to restrict phosphate sources in inorganic, organic, or food additives. The review also summarises different factors such as fluid intake, route of feeding, and essential nutrients that require particular attention in paediatric patients with CKD. In summary, a multidisciplinary team is needed to devise individual nutritional plans to achieve the best outcome and improve the quality of life of patients.

[Epidemiology of pediatric chronic kidney disease]

Major advances have been made in the management of children with chronic kidney disease over the past 30 years. However, existing epidemiology data are primarily from kidney replacement therapy registries, and information available at earlier stages of chronic kidney disease is limited. The incidence and prevalence of chronic kidney disease stages 2 to 5 remain poorly understood. However, rare population-based studies suggest that the prevalence of all-stage chronic kidney disease may be as high as 1% of the pediatric population. Congenital disorders including congenital abnormalities of the kidney and urinary tract and hereditary nephropathies account for one-half to two-thirds of pediatric chronic kidney disease cases in middle and high-income countries, whereas acquired nephropathies seem to predominate in low-income countries. The progression of chronic kidney disease is slower in children with congenital disorders than in those with acquired nephropathy, particularly glomerular disease, resulting in a lower proportion of congenital abnormalities of the kidney and urinary tract as a cause of end-stage kidney disease compared to less advanced stages of chronic kidney disease. The incidence of kidney replacement therapy in the pediatric population ranged by country from 1 to 14 per million children of the same age in 2018 (approximately 8 per million children in France) in patients younger than 20 years. The prevalence of kidney replacement therapy in children under 20 years of age in 2018 ranged from 15-30 per million children in some Eastern European and Latin American countries to 100 per million children in Finland and the United States (56 per million children in France). Most children with end-stage kidney disease initiate kidney replacement therapy with dialysis (more frequently hemodialysis than peritoneal dialysis). In about 20% of cases, the initial kidney replacement therapy modality is a pre-emptive kidney transplantation. In high-income countries, 60-80% of prevalent children with end-stage kidney disease live with a functioning transplant (75% in France). While the survival of children with chronic kidney disease has continuously improved over time, mortality remains about 30 times higher than in the general pediatric population.

Hemodiafiltration maintains a sustained improvement in blood pressure compared to conventional hemodialysis in children-the HDF, heart and height (3H) study

BACKGROUND

Hypertension is prevalent in children on dialysis and associated with cardiovascular disease. We studied the blood pressure (BP) trends and the evolution of BP over 1 year in children on conventional hemodialysis (HD) vs. hemodiafiltration (HDF).

METHODS

This is a post hoc analysis of the "3H - HDF-Hearts-Height" dataset, a multicenter, parallel-arm observational study. Seventy-eight children on HD and 55 on HDF who had three 24-h ambulatory BP monitoring (ABPM) measures over 1 year were included. Mean arterial pressure (MAP) was calculated and hypertension defined as 24-h MAP standard deviation score (SDS) ≥95th percentile.

RESULTS

Poor agreement between pre-dialysis systolic BP-SDS and 24-h MAP was found (mean difference - 0.6; 95% limits of agreement -4.9-3.8). At baseline, 82% on HD and 44% on HDF were hypertensive, with uncontrolled hypertension in 88% vs. 25% respectively; p < 0.001. At 12 months, children on HDF had consistently lower MAP-SDS compared to those on HD (p < 0.001). Over 1-year follow-up, the HD group had mean MAP-SDS increase of +0.98 (95%CI 0.77-1.20; p < 0.0001), whereas the HDF group had a non-significant increase of +0.15 (95%CI -0.10-0.40; p = 0.23). Significant predictors of MAP-SDS were dialysis modality (β = +0.83 [95%CI +0.51 - +1.15] HD vs. HDF, p < 0.0001) and higher inter-dialytic-weight-gain (IDWG)% (β = 0.13 [95%CI 0.06-0.19]; p = 0.0003).

CONCLUSIONS

Children on HD had a significant and sustained increase in BP over 1 year compared to a stable BP in those on HDF, despite an equivalent dialysis dose. Higher IDWG% was associated with higher 24-h MAP-SDS in both groups.

Reducing the burden of cardiovascular disease in children with chronic kidney disease: prevention vs. damage limitation

Cardiovascular disease (CVD) is a life-limiting condition in patients with chronic kidney disease (CKD) and is rapidly progressive, especially in those with stage 5 CKD and on dialysis. Cardiovascular mortality, although reducing, remains at least 30 times higher than in the general pediatric population. The American Heart Association guidelines for cardiovascular risk reduction in high-risk pediatric patients has stratified pediatric CKD patients in the "high risk" category for the development of CVD, with associated pathological and/or clinical evidence for manifest coronary disease before 30 years of age. While improving patient survival is a key priority, other patient-related outcomes, such as psychosocial development, quality of life and growth are of major importance to children and their caregivers. Once vascular damage or calcification has developed, there are no data to suggest that they can be reversed. Treatments such as intensified dialysis and transplantation may attenuate the progression of subclinical cardiovascular disease, but no treatment to date has shown that the inexorable progression of CVD in CKD can be reversed. Thus, our management must focus on early diagnosis and robust preventative strategies to give our patients the best chance of optimal cardiovascular health and survival. In this review, the pathophysiology and importance of preventing the development of CVD in CKD is discussed.

High Fibroblast Growth Factor 23 as a Biomarker for Severe Cardiac Impairment in Children with Chronic Kidney Disease: A Single Tertiary Center Study

INTRODUCTION

Left ventricular hypertrophy (LVH) is the most common cardiac abnormality in chronic kidney disease (CKD). Changes in cardiac geometry and functions may occur in an early stage and worsen as CKD progresses. Recently, the role of fibroblast growth factor 23 (FGF23) is being highlighted and investigated in CKD-related cardiomyopathy. However, only a few studies have reviewed the utilization of FGF23 as a diagnostic biomarker in the pediatric CKD population.

PURPOSE

This study aimed to identify the role of FGF23 as a biomarker in assessing cardiac changes in children with CKD.

PATIENTS AND METHODS

We conducted a cross-sectional study that involved children aged 2 to 18 years old with CKD stages 2 to 5D in Dr. Sardjito General Hospital, Yogyakarta, Indonesia. The level of FGF23 was measured using an immunometric enzyme-linked immunosorbent assay. LVMI, RWT, and left ventricular ejection fraction (LVEF) were assessed with echocardiography. Receiver-operating characteristic (ROC) analyses were conducted to assess the diagnostic performance of FGF23 in detecting LVH with impaired contractility.

RESULTS

A total of 43 children with CKD stages 2 to 5D were included, among whom the prevalence of LVH diagnosis was 95.35%. The area under the curve (AUC) of FGF23 to assess LVH and systolic dysfunction was 0.82 (95% CI 0.62-1.0), and the optimal cutoff point was 1413 RU/mL (sensitivity 80%, specificity 78.95%). The median concentration of FGF23 increased with the decreasing eGFR and the increasing LVMI although the systolic and diastolic functions were preserved.

CONCLUSION

FGF23 might be used as an early biomarker to detect cardiac changes in pediatric CKD patients, particularly for LVH and impaired systolic function among children with CKD stage 2 and higher.

Bone Disease in CKD in Children

This manuscript discusses mineral and bone disorders of chronic kidney disease (MBD-CKD) in pediatric patients with special emphasis on the underlying pathophysiology, the causes and clinical profile of growth retardation, the alterations in the growth plate, the strategies to optimize growth and the medical recommendations for prevention and treatment.

"Removal of nitrate and nitrite by hemodialysis in end-stage renal disease and by sustained low-efficiency dialysis in acute kidney injury"

BACKGROUND & PURPOSE

It is well established that end-stage renal disease (ESRD) is associated with increased cardiovascular morbidity and mortality both in the adult and pediatric population. Although the underlying molecular mechanisms are poorly understood, compromised nitric oxide (NO) bioactivity has been suggested as a contributing factor. With this in mind, we investigated the effects of hemodialysis on NO homeostasis and bioactivity in blood.

METHODS & RESULTS

Plasma and dialysate samples were obtained before and after hemodialysis sessions from adults (n = 33) and pediatric patients (n = 10) with ESRD on chronic renal replacement therapy, and from critically ill adults with acute kidney injury (n = 12) at their first sustained low-efficiency dialysis session. Levels of nitrate, nitrite, cyclic guanosine monophosphate (cGMP) and amino acids relevant for NO homeostasis were analyzed. We consistently found that nitrate and cGMP levels in plasma were significantly reduced after hemodialysis, whereas post-dialysis nitrite and amino acids coupled to NO synthase activity (i.e., arginine and citrulline) were only significantly reduced in adults with ESRD. The amount of excreted nitrate and nitrite during dialysis were similar to daily endogenous levels that would be expected from endothelial NO synthase activity.

CONCLUSIONS

Our results show that hemodialysis significantly reduces circulating levels of nitrate and cGMP, indicating that this medical procedure may impair NO synthesis and potentially NO signaling pathways.

Vitamin D and cardiovascular disease in chronic kidney disease

Chronic kidney disease (CKD) is considered an independent risk factor for cardiovascular disease, with increased cardiovascular morbidity and mortality seen even in the early stages of CKD. Several studies have shown a high prevalence of vitamin D deficiency in individuals with CKD. Low vitamin D levels upregulate the renin-angiotensin-aldosterone system (RAAS), cause endothelial dysfunction, and increase inflammation. Epidemiological studies show an association between vitamin D deficiency and risk factors for cardiovascular disease, but a causal relationship has not been established. The high cardiovascular morbidity and mortality associated with CKD in adults requires therapies to decrease this elevated risk. However, results from several meta-analyses and randomized clinical trials in adults have not shown convincing evidence for the use of vitamin D therapy in improving cardiovascular outcomes. Lack of high-quality evidence from randomized clinical trials in children regarding the effectiveness and long-term safety of vitamin D treatment precludes any recommendations on its use to mitigate the cardiovascular burden of CKD.

Changes in cardiac function after renal transplantation in children: Significance of pre-transplantation left ventricular hypertrophy

LVH is a significant risk factor for the development of cardiovascular morbidity. However, few studies have evaluated the changes in cardiac function that occur in pediatric patients with ESRD undergoing RTx. Therefore, we assessed the changes in parameters associated with LVH in children within the first year after RTx. We retrospectively evaluated patients aged < 18 years who underwent initial RTx from April 2014 to December 2016. The patients were divided into 2 groups according to the presence of LVH before RTx. Clinical, biochemical, and echocardiographic parameters including the LVMI before and 1 year after RTx were evaluated in both groups. Twenty-six patients were included in this study. Seven of the 26 patients had LVH before RTx. Among the echocardiographic parameters, the LVMI was significantly improved 1 year after RTx in the initial LVH group (57.79 ± 11.86 vs 42.20 ± 6.03 g/cm^2.7 , P = .018), while no change was observed in the initial non-LVH group (32.66 ± 7.52 vs 35.17 ± 12.86 g/cm^2.7 , P = .376). Improvement of the ejection fraction was also observed only in the initial LVH group (66.5% ± 5.3% vs 72.2% ± 5.2%, P = .042). Children who had LVH before RTx showed significant improvements in the LVMI and ejection fraction even within 1 year after RTx. To minimize aggravation of cardiac function, early RTx should be considered for patients with LVH.

Body composition and arterial stiffness in pediatric patients with chronic kidney disease

BACKGROUND

This study investigated the impact of body composition in the arterial stiffness of children with chronic kidney disease (CKD).

METHODS

Fat mass (FM), fat tissue index (FTI), fat-free mass (FFM), fat-free tissue index (FFTI), and FFTI/FTI were measured in 26 patients and 25 healthy controls by bio-impedance analysis. Data on patient's body mass index (BMI) for height-age, serum albumin, glomerular filtration rate (GFR), blood pressure status, and pulse wave velocity (PWV) were collected in patients.

RESULTS

Patients presented lower levels of FM and FFM compared to healthy controls (p = 0.04 and p = 0.055 respectively). In patient group, BMI height-age z-score was positively correlated to FTI (r² = 0.574, p < 0.001) and FFTI (r² = 0.338, p = 0.001) and negatively correlated to FFTI/FTI (r² = 0.263, p = 0.007). Serum albumin was positively correlated only with FFM among body composition data (r² = 0.169, p = 0.037). PWV z-score was positively correlated to FFTI (r² = 0.421, p = 0.006) and inversely correlated to FFTI/FTI ≥ 2.5 (r² = 0.317, p = 0.003). Patients with FFTI/FTI ≥ 2.5 presented lower levels of PWV regardless the need for antihypertensive treatment. Serum albumin ≥ 3.8 mg/dl and FFTI/FTI ≥ 2.5 were independently associated with a lower risk for high PWV, after adjustment for age, sex, and GFR (OR 0.009, 95% CI 0.000-0.729 and OR 0.039, 95% CI 0.002-0.680). All underweight [2 (7.7%)] and overweight [4 (15.4%)] patients presented high PWV. Among normal weight patients, FFTI/FTI ratio ≥ 2.5 was significantly associated with lower PWV z-score (p = 0.013).

CONCLUSIONS

Both underweight and overweight are associated with arterial stiffness. Targeting FFTI/FTI ≥ 2.5 could be protective against cardiovascular disease in normal weight children.

Interdialytic weight gain and vasculopathy in children on hemodialysis: a single center study

BACKGROUND

Increased interdialytic weight gain (IDWG) has been associated with poor outcomes in adults, but its impact on hemodialysis vasculopathy in children is unknown.

METHODS

Nineteen patients (age 9 to 19 years old) with a median hemodialysis duration of 10.4 months were enrolled. Cardiovascular evaluation included left ventricular mass index (LVMI), pulse wave velocity (PWV), and carotid intima-media thickness (cIMT) measurements. PWV and cIMT were expressed as z-scores based on reference values in healthy children. Blood pressure (BP) evaluation consisted in a 24-h ambulatory BP monitoring. Mean IDGW and residual urine output during the 6 months prior to cardiovascular examination were calculated.

RESULTS

Increased cIMT, LVMI, and PWV was observed in 11 (57.9%), 7 (36.8%), and 5 (26.3%) patients respectively, while BP was normal in all patients. Median IDWG was 3.5% (1.8-6.7). Residual urine output and BP status did not significantly differ between patients with IDWG ≥ or < 4%. After linear regression, IDWG was correlated to cIMT z-score (r² = 0.485, p = 0.001), but not to PWV z-score (r² = 0.04, p = 0.415) and LVMI (r² = 0.092, p = 0.206). After univariate logistic regression, IDWG ≥ 4% was significantly associated to increased cIMT (above 1.65 SDS) (odds ratio 12.25, 95% confidence interval 1.08-138.988). The trend toward an increased cIMT with IDWG ≥ 4% was observed in both patients with short and long dialysis vintage.

CONCLUSIONS

High IDWG is associated with increased cIMT in hemodialyzed children independently of BP control and dialysis vintage. This observation reinforces the importance of interventions to avoid IDWG in hemodialyzed children.

Intimal and medial arterial changes defined by ultra-high-frequency ultrasound: Response to changing risk factors in children with chronic kidney disease

BACKGROUND

Patients with chronic kidney disease (CKD) are exposed to both traditional 'Framingham' and uremia related cardiovascular risk factors that drive atherosclerotic and arteriosclerotic disease, but these cannot be differentiated using conventional ultrasound. We used ultra-high-frequency ultrasound (UHFUS) to differentiate medial thickness (MT) from intimal thickness (IT) in CKD patients, identify their determinants and monitor their progression.

METHODS

Fifty-four children and adolescents with CKD and 12 healthy controls underwent UHFUS measurements using 55-70MHz transducers in common carotid and dorsal pedal arteries. Annual follow-up imaging was performed in 31 patients.

RESULTS

CKD patients had higher carotid MT and dorsal pedal IT and MT compared to controls. The carotid MT in CKD correlated with serum phosphate (p<0.001, r = 0.42), PTH (p = 0.03, r = 0.36) and mean arterial pressure (p = 0.03, r = 0.34). Following multivariable analysis, being on dialysis, serum phosphate levels and mean arterial pressure remained the only independent predictors of carotid MT (R2 64%). Transplanted children had lower carotid and dorsal pedal MT compared to CKD and dialysis patients (p = 0.02 and p = 0.01 respectively). At 1-year follow-up, transplanted children had a decrease in carotid MT (p = 0.01), but an increase in dorsal pedal IT (p = 0.04) that independently correlated with annualized change in BMI.

CONCLUSIONS

Using UHFUS, we have shown that CKD is associated with exclusively medial arterial changes that attenuate when the uremic milieu is ameliorated after transplantation. In contrast, after transplantation intimal disease develops as hypertension and obesity become prevalent, representing rapid vascular remodeling in response to a changing cardiovascular risk factor profile.

Clinical outcomes and survival in pediatric patients initiating chronic dialysis: a report of the NAPRTCS registry

BACKGROUND

The 2011 annual report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) registry comprises data on 6482 dialysis patients over the past 20 years of the registry.

METHODS

The study compared clinical parameters and patient survival in the first 10 years of the registry (1992-2001) with the last decade of the registry (2002-2011).

RESULTS

There was a significant increase in hemodialysis as the initiating dialysis modality in the most recent cohort (42% vs. 36%, p < 0.001). Patients in the later cohort were less likely to have a hemoglobin <10 g/dl [odds ratio (OR) 0.68; confidence interval (CI) 0.58-0.81; p < 0.001] and height z-score <2 standard deviations (SD) below average (OR 0.68, CI 0.59-0.78, p < 0.0001). They were also more likely to have a parathyroid hormone (PTH) level two times above the upper limits of normal (OR 1.39, CI 1.21-1.60, p < 0.0001). Although hypertension was common regardless of era, patients in the 2002-2011 group were less likely to have blood pressure >90th percentile (OR 1.39, CI 1.21-1.60, p < 0.0001), and a significant improvement in survival at 36 months after dialysis initiation was observed in the 2002-2011 cohort compared with the 1992-2001 cohort (95% vs. 90%, respectively). Cardiopulmonary causes were the most common cause of death in both cohorts. Young age, growth deficit, and black race were poor predictors of survival.

CONCLUSIONS

The survival of pediatric patients on chronic dialysis has improved over two decades of dialysis registry data, specifically for children <1year.

Influence of the Method of Definition on the Prevalence of Left-Ventricular Hypertrophy in Children with Chronic Kidney Disease: Data from the Know-Ped CKD Study

BACKGROUND/AIMS

Children with chronic kidney disease (CKD) have a high risk of cardiovascular disease. Left-ventricular (LV) hypertrophy (LVH) is an early marker of cardiovascular disease in pediatric CKD, and the prevalence of LVH in pediatric CKD is approximately 20-30% in pre-dialysis CKD patients. However, there is no consensus on the ideal method of defining LVH in pediatric CKD patients. Previous studies have typically used the LV mass index (LVMI), which is calculated as LV mass in grams divided by height in meters to the 2.7th power ≥ 38 g/m2.7, to diagnose LVH in children with CKD. Recently, age-specific reference values for LVMI ≥ 95th percentile and LV wall-thickness z-score > 1.64 in children were addressed. The aim of this study was to assess the prevalence and contributing factors of LVH in pediatric CKD patients according to each measurement and evaluate the concordance between each measurement.

METHODS

We used the baseline data of the KoreaN cohort study for Outcome in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD), which is a nationwide, 10-year, prospective, observational cohort study of pediatric CKD. A total of 469 patients were enrolled, and 458 patients were included in the final analysis. Univariate and multiple logistic regression analysis were performed to evaluate the association of the variables with LVH. Kappa statistics were used to analyze the concordance.

RESULTS

According to an LVH diagnosis of LVMI ≥ 38 g/m2.7, 188 patients (41.0%) were diagnosed with LVH, and the prevalence of LVH was high in younger patients (< 2 years of age). Using the age-specific reference values, 116 patients (25.3%) were diagnosed with LVH, and there was no difference in the prevalence of LVH according to age. Thirty-one patients (6.8%) were diagnosed with LVH using an LV wall-thickness z-score > 1.64. There is poor concordance between the diagnosis of LVH using the LV wall-thickness z-score and the LVMI method.

CONCLUSIONS

The results of this study show that there is poor concordance between the diagnosis of LVH using the wall-thickness z-score and the LVMI2.7 criteria. Further investigation is needed to estimate the correlation between LVH and cardiac dysfunction and to find a better method for defining LVH in the pediatric CKD cohort and thereby predicting cardiac dysfunction.

Non-Medical Risk Factors as Avoidable Determinants of Excess Mortality in Children with Chronic Kidney Disease. A Prospective Cohort Study in Nicaragua, a Model Low Income Country

Background

The widely recognized clinical and epidemiological relevance of the socioeconomic determinants of health-disease conditions is expected to be specifically critical in terms of chronic diseases in fragile populations in low-income countries. However, in the literature, there is a substantial gap between the attention directed towards the medical components of these problems and the actual adoption of strategies aimed at providing solutions for the associated socioeconomic determinants, especially in pediatric populations. We report a prospective outcome study on the independent contribution and reciprocal interaction of the medical and socioeconomic factors to the hard end-point of mortality in a cohort of children with chronic kidney disease in Nicaragua.

Methods and Findings

Every child (n = 309) diagnosed with chronic kidney disease (CKD) and referred to the tertiary unit of Pediatric Nephrology in Managua (Nicaragua) from a network of nine hospitals serving 80% of the country’s pediatric population was registered between January 2005 and December 2013. The three main socioeconomic determinants evaluated were family income, living conditions and the family’s level of education. Further potential determinants of the outcomes included duration of exposure to disease, CKD stage at the first visit as suggested by the KDOQI guidelines in children, the time it took the patients to reach the reference centre and rural or urban context of life. Well-defined and systematically collected medical and socioeconomic data were available for 257 children over a mean follow-up period of 2.5±2.5 years. Mortality and lost to follow-up were considered as outcome end-points both independently and in combination, because of the inevitably progressive nature of the disease. A high proportion (55%) of children presented in the advanced stages of CKD (CKD stage IV and V) at the first visit. At the end of follow-up, 145 (57%) of the 257 cohort children were alive, 47 (18%) were lost to follow-up and 65 (25%) had died. Cox regression analysis showed an independent contribution to mortality of CKD stage at diagnosis and of level of education, with overlapping HR values (HR and 95%CI: 2.66; 1.93–3.66 and 2.72; 1.71–4.33, respectively).

Conclusions

The unfavourable socioeconomic and cultural background of the pediatric study cohort and the severity of kidney damage at diagnosis were the key determinants of the clinical risk conditions at baseline and of the mortality outcome. Long-term structural interventions on such backgrounds must be adopted to assure effectiveness of medical care and to assure an earlier diagnosis of CKD in these patients. The translation-extension of our results is currently underway with an agenda which includes: 1) better integration of chronic pediatric conditions into primary care strategies to promote prevention and early timely referral; 2) the consideration of socioeconomic conditions as a mandatory component of the packages of best-care; 3) the formulation and flexible adaptation of guidelines and educational programs, based on the information generated by a context-specific, epidemiological monitoring of needs and outcomes, guaranteed by an effective database.

Nephron Sparing Surgery Associated With Better Survival Than Radical Nephrectomy in Patients Treated for Unforeseen Benign Renal Tumors

OBJECTIVE

To evaluate the role of the surgical technique used for the treatment of benign renal tumors, with regard to renal function and overall survival (OS) in patients without cancer-related mortality.

PATIENTS AND METHODS

The study included 506 patients, mean age of 63.3 years, with histologically proven benign renal lesions originating from 5 European centers. Retrospective data from each hospital were retrieved and merged into a common database for analyses. OS, American Society of Anesthesiology score, and renal functions were measured in relation to surgical technique. The Mann-Witney U-test, the paired t-test, and Cox's multivariate analysis were used.

RESULTS

Patients treated with radical nephrectomy had significantly reduced renal function postoperatively compared with nephron sparing surgery (NSS). OS was significantly reduced after radical nephrectomy compared with NSS (P = .012), a survival difference that remained significant [hazard ratio (HR) 0.042, 95% confidence interval (CI) 0.221-0.972, P = .042] in multivariate analysis, together with age at diagnosis (HR 1.065, 95% CI 1.026-1.106, P = .001) and American Society of Anesthesiology score (HR 2.361, 95% CI 1.261-4.419, P = .007). Also renal function assessed by estimated glomerular filtration rate significantly correlated to survival in univariate analysis, but did not remain independent after multivariate analysis. Oncocytoma was the most frequent benign lesion, followed by angiomyolipoma.

CONCLUSION

The present study in patients with benign renal tumors shows that the remaining renal function and OS correspond to the choice of surgical procedure. Our results support the recommendation to perform NSS whenever possible when surgery is performed for patients with renal masses. The limitations of the study are the retrospective design and the selection bias for the surgical approach.

Improved cardiovascular risk factors in pediatric renal transplant recipients on steroid avoidance immunosuppression: A study of the Midwest Pediatric Nephrology Consortium

Several centers have examined the implementation of immunosuppression protocols that minimize steroid exposure. This study retrospectively examined cardiovascular risk factors in 70 pediatric renal transplant recipients on steroid avoidance-based immunosuppression over three yr compared to matched pediatric patients maintained on chronic corticosteroids. Although higher rates of acute rejection were noted in the steroid-avoidant group (22% vs. 16%, p = 0.034), graft function was similar (67 + 10 mL/min/1.73 m(2) vs. 72 + 12 mL/min/1.73 m(2)) (p = 0.053). The steroid-avoidant group demonstrated improved growth (height z-score -0.41 + 5.9 vs. -1.1 + 0.041) with a decrease in the prevalence of obesity (24% vs. 34%, p = 0.021). Indexed systolic blood pressures were lower beginning at six months post-transplant in the steroid-avoidant group (1.21 + 0.15 vs. 1.51 + 0.22, p = 0.020). Indexed diastolic blood pressures were lower beginning at 12 months post-transplant (0.91 + 0.11 vs. 1.12 + 0.18, p = 0.037). Differences in total serum cholesterol values and serum glucose values were not statistically significant. Beginning at 12 months, a statistically significant decrease in left ventricular mass index (39.2 + 11.3 vs. 49.4 + 14.5, p = 0.014) was noted in patients on steroid-avoidant immunosuppression, which corresponded to a significant decrease in the prevalence of left ventricular hypertrophy in these patients by two yr post-transplant (35% vs. 48%, p = 0.012). Systolic blood pressure and BMI were independent predictors of left ventricular hypertrophy.

Decreased arterial elasticity in children with nondialysis chronic kidney disease is related to blood pressure and not to glomerular filtration rate

We compared large artery mechanical properties in children with nondialysis stages of chronic kidney disease with those in children with normal renal function, examining the potential effect of blood pressure (BP) components and level of renal dysfunction. Common carotid artery mechanical properties, carotid-femoral pulse wave velocity, and carotid and peripheral BP were measured in children (n=226) with nondialysis chronic kidney disease (n=188; 11.9±3.7 years; 26%, 25%, 30%, 16%, and 3% in stages 1, 2, 3, 4 and 5, respectively) and healthy controls (n=38; 11.5±3.3 years). In children with nondialysis chronic kidney disease when compared with healthy controls, at similar levels of peripheral and carotid BP, carotid artery diastolic diameter and wall thickness were similar. In those with suboptimal BP (≥75th percentile), indices of arterial elasticity indicated greater stiffness than in healthy normotensive controls (distensibility: 92±31 versus 114±33 kPa(-1)×10(-3), P=0.03; compliance: 2.1±0.7 versus 2.6±0.7 m(2) kPa(-1)×10(-6), P=0.02; Young elastic modulus: 0.151±0.068 versus 0.109±0.049 kPa×10(3), P=0.02; and wall stress: 83.6±23.5 versus 68.7±14.9 kPa, P=0.02). In all children, mechanical properties were independently related to carotid and peripheral BP components but not to estimated glomerular filtration rate. In children with nondialysis chronic kidney disease, changes in elastic properties of the carotid artery are primarily related to BP and not to glomerular renal function.

Elevated Ejection-Phase Myocardial Wall Stress in Children With Chronic Kidney Disease

Myocardial wall stress (MWS) is thought to be the mechanical stimulus to ventricular hypertrophy. The objective of this study was to examine whether MWS is elevated in children with chronic kidney disease (CKD) who are at high risk of developing adverse cardiovascular events related to left ventricular (LV) hypertrophy. MWS, a function of left ventricular pressure, myocardial wall volume, and cavity volume, was obtained using carotid tonometry to estimate ventricular pressure and 2-dimensional transthoracic echocardiographic wall-tracking to obtain LV cavity and wall volumes. Ninety-two children (50 boys) aged 11.2±3.2 (mean±SD) years, including healthy controls (n=16), and those with CKD disease divided into 3 groups according to estimated glomerular filtration rate (mL/min per 1.73 m 2 ) >90 (CKD 1, n=26), 60 to 90 (CKD 2, n=23), and <60 (CKD≥3, n=27) were studied. There was no significant difference in age, height, weight, central or peripheral blood pressure, LV mass, or mass index in the 4 study groups. By contrast, peak, mean, and end-systolic MWS were higher in children with CKD and increased across stages of CKD (peak MWS, 338.8±18.5 and 397.5±14.3 s/cm 2 in controls and CKD≥3, respectively; P =0.01). Higher systolic MWS was explained by a form of LV dysfunction whereby dynamic values of the ratio of wall volume/cavity size during systole were lower in children with CKD than in those without ( P =0.001). Children with CKD exhibit blood pressure–independent LV dysfunction which results in increased systolic MWS and which may predispose to LV hypertrophy in later life.

Advanced Parameters of Cardiac Mechanics in Children with CKD: The 4C Study

BACKGROUND AND OBJECTIVES

Newer parameters of cardiac mechanics provide additional insights on cardiac dysfunction in adult patients with CKD. The aim of this study was to identify prevalence of subclinical abnormalities in cardiac function through the analysis of novel indices of cardiac mechanics in a large population of children with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Between 2009 and 2011, the prospective observational Cardiovascular Comorbidity in Children with CKD Study enrolled patients with CKD ages 6-17 years old with eGFR=10-45 ml/min per 1.73 m(2) in 14 European countries. Cardiac morphology and function were assessed through echocardiography. The analysis presented encompasses global radial, longitudinal, and circumferential strains as well as time to peak analysis. Data were compared with 61 healthy children with comparable age and sex.

RESULTS

Data on 272 patients with CKD with complete echocardiographic assessment are reported (age =12.8±3.5 years old; 65% boys). Patients with CKD showed mildly higher office BP values and higher prevalence of left ventricular hypertrophy, but no differences were observed among groups in left ventricular ejection fraction. Strain analysis showed significantly lower global radial strain (29.6%±13.3% versus 35.5%±8.9%) and circumferential strain components (-21.8%±4.8% versus -28.2%±5.0%; both P<0.05) in patients with CKD without significant differences observed in longitudinal strain (-15.9%±3.4% versus -16.2%±3.7%). Lower values of global radial strain were associated with lower circumferential endocardial-to-epicardial gradient (r=0.51; P<0.01). This association remained significant after adjusting for BP, eGFR, and presence of left ventricular hypertrophy. Eventually, patients with CKD also showed higher delay in time to peak cardiac contraction (58±28 versus 37±18 milliseconds; P<0.05).

CONCLUSIONS

A significant proportion of children with CKD show impaired systolic mechanics. Impaired systolic function is characterized by lower radial strain, transmural circumferential gradient, and mild cardiac dyssynchrony. This study suggests that analysis of cardiac strain is feasible in a large multicenter study in children with CKD and provides additional information on cardiac pathophysiology of this high-risk population.

Is peritoneal dialysis still an equal option? Results of the Berlin pediatric nocturnal dialysis program

BACKGROUND

Peritoneal dialysis (PD) or conventional hemodialysis (HD) are considered to be equally efficient dialysis methods in children and adolescents. The aim of our study was to analyze whether an intensified, nocturnal HD program (NHD) is superior to PD in an adolescent cohort.

METHODS

Thirteen patients were prospectively enrolled in a NHD program. We measured uremia-associated parameters, parameters for nutrition, medication and blood pressure and analyzed the data. These data were compared to those of 13 PD controls, matched for gender, age and weight at the beginning the respective dialysis program and after 6 months of treatment.

RESULTS

Serum phosphate levels decreased significantly in the NHD group and remained unchanged in the PD group. Arterial blood pressure in the NHD was significantly lower despite the reduction of antihypertensive treatment, whereas blood pressure levels remained unchanged in the PD controls. Preexisting left ventricular hypertrophy resolved and albumin levels improved with NHD. Dietary restrictions could be lifted for those on NHD, whereas they remained in place for the patients on PD treatment. Residual diuresis remained unchanged after 6 months of either NHD or PD. NHD patients experienced fewer days of hospitalization than the PD controls.

CONCLUSIONS

Based on our results, NHD results in significantly improved parameters of uremia and nutrition. If individually and logistically possible, NHD should be the treatment modality of preference for older children and adolescents.

17-Year-Old Boy with Renal Failure and the Highest Reported Creatinine in Pediatric Literature

The prevalence of chronic kidney disease (CKD) is on the rise and constitutes a major health burden across the world. Clinical presentations in early CKD are usually subtle. Awareness of the risk factors for CKD is important for early diagnosis and treatment to slow the progression of disease. We present a case report of a 17-year-old African American male who presented in a life threatening hypertensive emergency with renal failure and the highest reported serum creatinine in a pediatric patient. A brief discussion on CKD criteria, complications, and potential red flags for screening strategies is provided.

Hypervitaminosis A is prevalent in children with CKD and contributes to hypercalcemia

BACKGROUND

Vitamin A accumulates in renal failure, but the prevalence of hypervitaminosis A in children with predialysis chronic kidney disease (CKD) is not known. Hypervitaminosis A has been associated with hypercalcemia. In this study we compared dietary vitamin A intake with serum retinoid levels and their associations with hypercalcemia.

METHODS

We studied the relationship between vitamin A intake, serum retinoid levels, and serum calcium in 105 children with CKD stages 2-5 on dialysis and posttransplant. Serum retinoid measures included retinol (ROH), its active retinoic acid (RA) metabolites [all-trans RA (at-RA) and 13-cis RA] and carrier proteins [retinol-binding protein-4 (RBP4) and transthyretin (TTR)]. Dietary vitamin A intake was assessed using a food diary.

RESULTS

Twenty-five children were in CKD 2-3, 35 in CKD 4-5, 23 on dialysis and 22 posttransplant; 53 % had vitamin A intake above the Reference Nutrient Intake (RNI) value. Children receiving supplemental feeds compared with diet alone had higher vitamin A intake (p = 0.02) and higher serum ROH (p < 0.001). Notably, increased ROH was seen as early as CKD stage 2. For every 10 ml/min/1.73 m(2) fall in estimated glomerular filtration rate (eGFR), there was a 13 % increase in ROH. RBP4 levels were increased in CKD 3-5 and dialysis patients. The lowest ratios of ROH:RBP4 were seen in dialysis compared with CKD 2-3 (p = 0.03), suggesting a relative increase in circulating RBP4. Serum ROH, RBP4 and at-RA were associated with serum calcium. On multivariable analysis RBP4 levels and alfacalcidol dose were significant predictors of serum calcium (model R (2) 32 %) in dialysis patients.

CONCLUSIONS

Hypervitaminosis A is seen in early CKD, with highest levels in children on supplemental feeds compared with diet alone. Serum retinoid levels significantly predict hypercalcemia.

Hemodiafiltration in a pediatric nocturnal dialysis program

BACKGROUND

To overcome the deleterious consequences of conventional dialysis, intensified dialysis programs have been developed and their feasibility and beneficial effects in children demonstrated. To investigate whether such a program can be further improved, we implemented hemodialfiltration within an established pediatric in-center, nocturnal hemodialysis program.

METHODS

After being started on conventional hemodialysis (HD), seven patients were switched to intermittent nocturnal hemodialysis (NHD) for 3 months, then to intermittent nocturnal online-hemodiafiltration (NHDF) for a further 3 months and finally back to NHD. Uremia-associated parameters, predialytic blood pressure, intradialytic events, protein catabolic rate and levels of albumin, vitamins and trace elements were investigated. Dialysis-related medication and dietary restrictions were also registered.

RESULTS

Phosphate and intact parathyroid hormone levels were reduced after the switch from HD to NHD and NHDF. Dialysis dose (Kt/V) was increased in patients on NHD and NHDF; however, Kt/V was significantly higher with NHDF than NHD. Blood pressure was significantly reduced in patients on NHD and NHDF despite the reduction in antihypertensive medication; albumin levels were significantly higher on NHD and NHDF, indicating improved nutritional status; protein catabolic rate was also increased. Vitamins and trace elements remained unchanged. All dietary restrictions could be lifted in patients on NHD and NHDF.

CONCLUSIONS

The introduction of a nocturnal dialysis program to an existing intensified HD program significantly improved the uremia-associated parameters, nutrition and hemodynamic stability of our seven patients. At least during our observational period, hemodiafiltration was able to further improve the existing HD program by increasing the Kt/v.

Left ventricular mass and cardiac function in a population of children with chronic kidney disease

BACKGROUND

Cardiovascular disease (CVD) is a common cause of morbidity and mortality in children with chronic kidney disease (CKD). Left ventricular hypertrophy (LVH) and diastolic dysfunction (LVDD) are early markers. The aims of this study were to evaluate (1) LVH and LVDD, using both conventional echocardiographic evaluation and Tissue Doppler Imaging (TDI), and (2) the correlation between cardiac disease and possible risk factors, in children with CKD.

METHODS

The study cohort comprised 34 paediatric patients with CKD and 34 healthy children (mean ± standard deviation: age 9 ± 4.6 and 8.2 ± 4.3 years, respectively). Thirteen (38 %) patients were in CKD stage 2, 15 (44 %) in stage 3 and six (18 %) in stage 4-5. LVH was defined as a left ventricular mass index (LVMI) of >95th percentile (38 g/h(2.7)).

RESULTS

Left ventricular hypertrophy was present in 13 patients (38 %). Diastolic function evaluated with TDI (E'/A' = early/late diastolic myocardial velocity) worsened with the reduction of glomerular filtration rate (p = 0.020). There was a positive correlation between LVMI and body mass index-standard deviation score (p = 0.020) and a negative correlation between E'/A' and serum phosphorus and calcium levels and their respective product (p = 0.004, p = 0.017, p < 0.001). The relaxation index E' was reduced in 68 % of patients.

CONCLUSION

Based on our results, TDI is a simple procedure and would appear to be a more accurate diagnostic tool than conventional echocardiography in the early diagnosis of LVDD.

Paricalcitol downregulates myocardial renin-angiotensin and fibroblast growth factor expression and attenuates cardiac hypertrophy in uremic rats

BACKGROUND

Vitamin D attenuates uremic cardiac hypertrophy, possibly by suppressing the myocardial renin-angiotensin system (RAS) and fibroblast growth factors (FGFs). We compared the suppression of cardiac hypertrophy and myocardial expression of RAS and FGF receptor genes offered by the vitamin D analog paricalcitol (Pc) or the angiotensin-converting enzyme inhibitor enalapril (E) in experimental uremia.

METHODS

Rats with 5/6 nephrectomy received Pc or E for 8 weeks. Renal function, systolic blood pressure, and cardiac hypertrophy were evaluated. Myocardial expression of RAS genes, brain natriuretic peptide (BNP), and FGF receptor-1 (FGFR-1) were determined using quantitative reverse-transcription (pRT)-PCR.

RESULTS

Blood pressure, proteinuria, and serum creatinine were significantly higher in untreated uremic animals. Hypertension was significantly reduced by E but only modestly by Pc; however, cardiac hypertrophy in the untreated group was similarly attenuated by Pc or E. Upregulation of myocardial expressions of renin, angiotensinogen, FGFR-1, and BNP in untreated uremic animals was reduced similarly by Pc and E, while the angiotensin II type 1 receptor was downregulated only by E.

CONCLUSIONS

Uremic cardiac hypertrophy is associated with activation of the myocardial RAS and the FGFR-1. Downregulation of these genes induced by Pc and E results in similar amelioration of left ventricular hypertrophy despite the different antihypertensive effects of these drugs.

Pediatric cardiomyopathies: causes, epidemiology, clinical course, preventive strategies and therapies

Pediatric cardiomyopathies, which are rare but serious disorders of the muscles of the heart, affect at least one in every 100,000 children in the USA. Approximately 40% of children with symptomatic cardiomyopathy undergo heart transplantation or die from cardiac complications within 2 years. However, a significant number of children suffering from cardiomyopathy are surviving into adulthood, making it an important chronic illness for both pediatric and adult clinicians to understand. The natural history, risk factors, prevalence and incidence of this pediatric condition were not fully understood before the 1990s. Questions regarding optimal diagnostic, prognostic and treatment methods remain. Children require long-term follow-up into adulthood in order to identify the factors associated with best clinical practice including diagnostic approaches, as well as optimal treatment approaches. In this article, we comprehensively review current research on various presentations of this disease, along with current knowledge about their causes, treatments and clinical outcomes.