Underweight, overweight and obesity in paediatric dialysis and renal transplant patients

Body mass index in pediatric kidney transplant selection criteria

BACKGROUND

Obesity is associated with increased complications, rejection, and graft loss after kidney transplantation in adult and pediatric recipients. Elevated body mass index (BMI) is a common contraindication to transplant at adult kidney transplant programs; however, there is no data on such limitations for pediatric patients.

METHODS

Between October and December 2022, we conducted a survey of Pediatric Nephrology Research Consortium centers assessing the use of BMI in pediatric kidney transplant evaluation. Centers reporting utilization of BMI cutoffs were invited to submit patient-level data on children declined for active transplant listing due to BMI.

RESULTS

Thirty-nine centers responded to the survey (42% response rate); 51% include BMI in their written listing criteria, with a median BMI "cutoff" of 39 kg/m2 (range 30-50 kg/m2). Between January 1, 2016, and December 31, 2021, 30 children at 15 transplant centers were declined for listing status due to BMI. Patient-level data was provided for 19 children (63%) who were denied active listing status; median BMI was 42 kg/m2 (range 35.8-49.4 kg/m2) and 84% were on dialysis. One year after evaluation, seven patients (37%) had proceeded to active wait list status. Eight (42%) remained in inactive status and four (21%) were unlisted; ten of these 12 patients (83%) were on dialysis.

CONCLUSIONS

The use of BMI in pediatric kidney transplant evaluation and listing varies among centers, but BMI limits access to transplant for some children. More information is needed on the outcomes of obese pediatric kidney candidates who are and are not transplanted, to guide development of national and international consensus.

Nutritional management of the child with chronic kidney disease and on dialysis

While it is widely accepted that the nutritional management of the infant with chronic kidney disease (CKD) is paramount to achieve normal growth and development, nutritional management is also of importance beyond 1 year of age, particularly in toddlers, to support the delayed infantile stage of growth that may extend to 2-3 years of age. Puberty is also a vulnerable period when nutritional needs are higher to support the expected growth spurt. Inadequate nutritional intake throughout childhood can result in failure to achieve full adult height potential, and there is an increased risk for abnormal neurodevelopment. Conversely, the rising prevalence of overweight and obesity among children with CKD underscores the necessity for effective nutritional strategies to mitigate the risk of metabolic syndrome that is not confined to the post-transplant population. Nutritional management is of primary importance in improving metabolic equilibrium and reducing CKD-related imbalances, particularly as the range of foods eaten by the child widens as they get older (including increased consumption of processed foods), and as CKD progresses. The aim of this review is to integrate the Pediatric Renal Nutrition Taskforce (PRNT) clinical practice recommendations (CPRs) for children (1-18 years) with CKD stages 2-5 and on dialysis (CKD2-5D). We provide a holistic approach to the overall nutritional management of the toddler, child, and young person. Collaboration between physicians and pediatric kidney dietitians is strongly advised to ensure comprehensive and tailored nutritional care for children with CKD, ultimately optimizing their growth and development.

Exploring the Link between Oxidative Stress, Selenium Levels, and Obesity in Youth

Obesity is a worldwide increasing concern. Although in adults this is easily estimated with the body mass index, in children, who are constantly growing and whose bodies are changing, the reference points to assess weight status are age and gender, and need corroboration with complementary data, making their quantification highly difficult. The present review explores the interaction spectrum of oxidative stress, selenium status, and obesity in children and adolescents. Any factor related to oxidative stress that triggers obesity and, conversely, obesity that induces oxidative stress are part of a vicious circle, a complex chain of mechanisms that derive from each other and reinforce each other with serious health consequences. Selenium and its compounds exhibit key antioxidant activity and also have a significant role in the nutritional evaluation of obese children. The balance of selenium intake, retention, and metabolism emerges as a vital aspect of health, reflecting the complex interactions between diet, oxidative stress, and obesity. Understanding whether selenium status is a contributor to or a consequence of obesity could inform nutritional interventions and public health strategies aimed at preventing and managing obesity from an early age.

Management of pediatric obesity as a pathway towards kidney transplantation

Obesity is an increasing problem in pediatrics, leading to cardiovascular, metabolic and psychosocial complications. Additionally, for patients with chronic kidney disease (CKD), obesity can lead to CKD progression towards end-stage renal disease (ESRD) needing renal-replacement therapy (RRT). It is well-established that the optimal type of RRT for children with ESRD is kidney transplantation, as it provides significantly better life expectancy and quality of life. Unfortunately, pediatric patients with CKD/ESRD and obesity face barriers getting to kidney transplantation and often remain on dialysis for a long time, which negatively impacts their life expectancy and quality of life. One barrier to kidney transplant is that Body Mass Index (BMI) is still considered by most transplant centers as the main criterion for obesity assessment, although more recent evidence suggests that BMI is not the best measure of adiposity. Clearcut evidence is lacking that obesity has a long-term negative impact upon the graft. Another barrier to transplant can be bias on the part of referring providers that can deter or delay referral to an obesity treatment program. Our article describes the barriers that pediatric obese patients with CKD and ESRD face in their way towards kidney transplantation. In addition, our article encourages pediatric nephrologists to early refer their patients with CKD and ESRD who suffer from obesity to a specialized obesity treatment program and/or bariatric surgery. Our article also describes the treatment options for pediatric patients with CKD and ESRD who suffer from obesity in order to make them eligible for a kidney transplant.

Changes in graft outcomes in recipients <10 kg over 25 years of pediatric kidney transplantation in the United States

BACKGROUND

Kidney transplant (KT) was initially associated with poor outcomes, especially in smaller recipients. However, pediatric transplantation has evolved considerably over time. We investigated the impact of weight at the time of transplant and whether outcomes changed over 25 years for <10 kg recipients.

METHODS

Using the UNOS database, pediatric recipient outcomes were analyzed between 1/1/99 and 12/31/14. KT weight was stratified: <8.6 kg (mean weight of recipients <10 kg), 8.6-9.9 kg, 10-14.9 kg, 15-29.9 kg, and ≥30 kg. Outcomes in recipients <10 kg were then compared between 1990-1999 and 2000-2014.

RESULTS

17 314 pediatric KT recipients were included; 518 (3%) had a transplant weight <10 kg. The highest rates of allograft loss and death were in recipients <8.6 kg and ≥30 kg. Recipients <8.6 kg also had higher rates of delayed graft function, rejection, and longer hospital length of stay. In the multivariable Cox regression model, transplant weight was not a predictor of allograft loss. When compared with recipients <8.6 kg, patient survival hazard ratios associated with recipient weight of 10-14.9 kg, 15-29.9 kg, and ≥30 kg were 0.61 (95%CI: 0.4, 1), 0.42 (95%CI: 0.3, 0.7) and 0.32 (95%CI: 0.2, 0.6), respectively. In the later era of transplant, recipients <10 kg had improved outcomes on univariate analysis; however, the era of transplantation was not an independent predictor of allograft loss or patient survival in Cox regression models.

CONCLUSIONS

Outcomes in children weighing 8.6-9.9 kg at the time of KT were similar to higher weight groups and improved over time; however, special precautions should be taken for recipients <8.6 kg at the time of transplant.

Estimating Total Energy Expenditure to Determine Energy Requirements in Free-Living Children With Stage 3 Chronic Kidney Disease: Can a Structured Approach Help Improve Clinical Care?

OBJECTIVE

Malnutrition and obesity are complex burdensome challenges in pediatric chronic kidney disease (CKD) management that can adversely affect growth, disease progression, wellbeing, and response to treatment. Total energy expenditure (TEE) and energy requirements in children are essential for growth outcomes but are poorly defined, leaving clinical practice varied and insecure. The aims of this study were to explore a practical approach to guide prescribed nutritional interventions, using measurements of TEE, physical activity energy expenditure (PAEE), and their relationship to kidney function.

DESIGN AND METHODS

In a cross-sectional prospective age-matched and sex-matched controlled study, 18 children with CKD (6-17 years, mean stage 3) and 20 healthy, age-matched, and gender-matched controls were studied. TEE and PAEE were measured using basal metabolic rate (BMR), activity diaries and doubly labeled water (healthy subjects). Results were related to estimated glomerular filtration rate (eGFR). The main outcome measure was TEE measured by different methods (factorial, doubly labeled water, and a novel device).

RESULTS

Total energy expenditure and PAEE with or without adjustments for age, gender, weight, and height did not differ between the groups and was not related to eGFR. TEE ranged from 1927 ± 91 to 2330 ± 73 kcal/d; 95 ± 5 to 109 ± 5% estimated average requirement (EAR), physical activity level (PAL) 1.52 ± 0.01 to 1.71 ± 0.17, and PAEE 24 to 34% EAR. Comparisons between DLW and alternative methods in healthy children did not differ significantly, except for 2 (factorial methods and a fixed PAL; and the novel device).

CONCLUSION

In clinical practice, structured approaches using supportive evidence (weight, height, BMI sds), predictive BMR or TEE values and simple questions on activity, are sufficient for most children with CKD as a starting energy prescription.

Childhood Obesity: Insight into Kidney Involvement

This review examines the impact of childhood obesity on the kidney from an epidemiological, pathogenetic, clinical, and pathological perspective, with the aim of providing pediatricians and nephrologists with the most current data on this topic. The prevalence of childhood obesity and chronic kidney disease (CKD) is steadily increasing worldwide, reaching epidemic proportions. While the impact of obesity in children with CKD is less pronounced than in adults, recent studies suggest a similar trend in the child population. This is likely due to the significant association between obesity and the two leading causes of end-stage renal disease (ESRD): diabetes mellitus (DM) and hypertension. Obesity is a complex, systemic disease that reflects interactions between environmental and genetic factors. A key mechanism of kidney damage is related to metabolic syndrome and insulin resistance. Therefore, we can speculate about an adipose tissue-kidney axis in which neurohormonal and immunological mechanisms exacerbate complications resulting from obesity. Adipose tissue, now recognized as an endocrine organ, secretes cytokines called adipokines that may induce adaptive or maladaptive responses in renal cells, leading to kidney fibrosis. The impact of obesity on kidney transplant-related outcomes for both donors and recipients is also significant, making stringent preventive measures critical in the pre- and post-transplant phases. The challenge lies in identifying renal involvement as early as possible, as it is often completely asymptomatic and not detectable through common markers of kidney function. Ongoing research into innovative technologies, such as proteomics and metabolomics, aims to identify new biomarkers and is constantly evolving. Many aspects of pediatric disease progression in the population of children with obesity still require clarification. However, the latest scientific evidence in the field of nephrology offers glimpses into various new perspectives, such as genetic factors, comorbidities, and novel biomarkers. Investigating these aspects early could potentially improve the prognosis of these young patients through new diagnostic and therapeutic strategies. Hence, the aim of this review is to provide a comprehensive exploration of the pathogenetic mechanisms and prevalent pathological patterns of kidney damage observed in children with obesity.

Associations of longitudinal height and weight with clinical outcomes in pediatric kidney replacement therapy: results from the ESPN/ERA Registry

BACKGROUND

Associations between anthropometric measures and patient outcomes in children are inconsistent and mainly based on data at kidney replacement therapy (KRT) initiation. We studied associations of height and body mass index (BMI) with access to kidney transplantation, graft failure, and death during childhood KRT.

METHODS

We included patients < 20 years starting KRT in 33 European countries from 1995-2019 with height and weight data recorded to the ESPN/ERA Registry. We defined short stature as height standard deviation scores (SDS) < -1.88 and tall stature as height SDS > 1.88. Underweight, overweight and obesity were calculated using age and sex-specific BMI for height-age criteria. Associations with outcomes were assessed using multivariable Cox models with time-dependent covariates.

RESULTS

We included 11,873 patients. Likelihood of transplantation was lower for short (aHR: 0.82, 95% CI: 0.78-0.86), tall (aHR: 0.65, 95% CI: 0.56-0.75), and underweight patients (aHR: 0.79, 95%CI: 0.71-0.87). Compared with normal height, patients with short and tall statures showed higher graft failure risk. All-cause mortality risk was higher in short (aHR: 2.30, 95% CI: 1.92-2.74), but not in tall stature. Underweight (aHR: 1.76, 95% CI: 1.38-2.23) and obese (aHR: 1.49, 95% CI: 1.11-1.99) patients showed higher all-cause mortality risk than normal weight subjects.

CONCLUSIONS

Short and tall stature and being underweight were associated with a lower likelihood of receiving a kidney allograft. Mortality risk was higher among pediatric KRT patients with a short stature or those being underweight or obese. Our results highlight the need for careful nutritional management and multidisciplinary approach for these patients. A higher resolution version of the Graphical abstract is available as Supplementary information.

Malnutrition Patterns in Children with Chronic Kidney Disease

Malnutrition is frequent in children with chronic kidney disease (CKD). Apart from undernutrition and protein energy wasting (PEW), overnutrition prevalence is rising, resulting in fat mass accumulation. Sedentary behavior and unbalanced diet are the most important causal factors. Both underweight and obesity are linked to adverse outcomes regarding renal function, cardiometabolic risk and mortality rate. Muscle wasting is the cornerstone finding of PEW, preceding fat loss and may lead to fatigue, musculoskeletal decline and frailty. In addition, clinical data emphasize the growing occurrence of muscle mass and strength deficits in patients with fat mass accumulation, attributed to CKD-related wasting processes, reduced physical activity and possibly to obesity-induced inflammatory diseases, leading to sarcopenic obesity. Moreover, children with CKD are susceptible to abdominal obesity, resulting from high body fat distribution into the visceral abdomen compartment. Both sarcopenic and abdominal obesity are associated with increased cardiometabolic risk. This review analyzes the pathogenetic mechanisms, current trends and outcomes of malnutrition patterns in pediatric CKD. Moreover, it underlines the importance of body composition assessment for the nutritional evaluation and summarizes the advantages and limitations of the currently available techniques. Furthermore, it highlights the benefits of growth hormone therapy and physical activity on malnutrition management.

An ethical analysis of obesity as a contraindication of pediatric kidney transplant candidacy

The inclusion of body mass index (BMI) as a criterion for determining kidney transplant candidacy in children raises clinical and ethical challenges. Childhood obesity is on the rise and common among children with kidney failure. In addition, obesity is reported as an independent risk factor for the development of CKD and kidney failure. Resultantly, more children with obesity are anticipated to need kidney transplants. Most transplant centers around the world use high BMI as a relative or absolute contraindication for kidney transplant. However, use of obesity as a relative or absolute contraindication for pediatric kidney transplant is controversial. Empirical data demonstrating poorer outcomes following kidney transplant in obese pediatric patients are limited. In addition, pediatric obesity is distributed inequitably among groups. Unlike adults, most children lack independent agency to choose their food sources and exercise opportunities; they are dependent on their families for these choices. In this paper, we define childhood obesity and review (1) the association and impact of obesity on kidney disease and kidney transplant, (2) existing adult guidelines and rationale for using high BMI as a criterion for kidney transplant, (3) the prevalence of childhood obesity among children with kidney failure, and (4) the existing literature on obesity and pediatric kidney transplant outcomes. We then discuss ethical considerations related to the use of obesity as a criterion for kidney transplant.

Effects of Body Mass Index Changes In Pediatric Kidney Transplant Patients

BACKGROUND

The negative effects of pretransplant obesity and post-transplant body mass index (BMI) increase on graft survival have been reported in recent years. The aim of this study is to evaluate the effects of BMI changes on post-transplant graft function, lipid profile, and blood pressure.

METHODS

The study included 133 pediatric patients transplanted between 1994 and 2019 in Ege University. BMI Z-scores (BMIZs) were calculated according to age and sex before and after transplantation using the World Health Organization criteria. Patients with BMIZs >+1 standard deviation (SD) were defined as overweight, and those with BMIZs >+2 SD were defined as obese: Group 1: Obese or overweight before transplantation; Group 2: Thin or normal weight before and 2 years after transplantation; and Group 3: Thin or normal weight before transplantation and obese or overweight 2 years after transplantation.

RESULTS

At the time of transplantation 8% of the patients were overweight, and 1% were obese. Overweight and obesity statistically significantly increased (31.6%) 2 years after renal transplantation (P = .001). Obese and overweight patients have lower high-density lipoprotein levels and were younger at the time of transplantation. Graft functions, lipid levels, and blood glucose levels of the groups were similar (P > .05). The only significant difference between the groups was that Group 1 patients were younger than Group 2.

CONCLUSIONS

Obesity develops at a significant rate in pediatric patients after renal transplantation. In this study, we could not demonstrate negative effects of obesity and being overweight in terms of post-transplant graft function, lipid profile, blood glucose, and blood pressure.

Malnutrition and immune cell subsets in children undergoing kidney transplantation

BACKGROUND

Malnutrition, including obesity and undernutrition, among children is increasing in prevalence and is common among children on renal replacement therapy. The effect of malnutrition on the pre-transplant immune system and how the pediatric immune system responds to the insult of both immunosuppression and allotransplantation is unknown. We examined the relationship of nutritional status with post-transplant outcomes and characterized the peripheral immune cell phenotypes of children from the Immune Development of Pediatric Transplant (IMPACT) study.

METHODS

Ninety-eight patients from the IMPACT study were classified as having obesity, undernutrition, or normal nutrition-based pre-transplant measurements. Incidence of infectious and alloimmune outcomes at 1-year post-transplantation was compared between nutritional groups using Gray's test and Fine-Gray subdistribution hazards model. Event-free survival was estimated by Kaplan-Meier method and compared between groups. Differences in immune cell subsets between nutritional groups over time were determined using generalized estimating equations accounting for the correlation between repeated measurements.

RESULTS

We did not observe that nutritional status was associated with infectious or alloimmune events or event-free survival post-transplant. We demonstrated that children with obesity had distinct T-and B-cell signatures relative to those with undernutrition and normal nutrition, even when controlling for immunosuppression. Children with obesity had a lower frequency of CD8 Tnaive cells 9-month post-transplant (p < .001), a higher frequency of CD4 CD57 + PD1- T cells, and lower frequencies of CD57-PD1+ CD8 and CD57-PD1- CD8 T cells at 12-month transplant (p < .05 for all).

CONCLUSIONS

Children with obesity have distinct immunophenotypes that may influence the tailoring of immunosuppression.

Increasing trends in hemodialysis and living donor kidney transplantation for children and young people in the United Kingdom

BACKGROUND

The UK Renal Registry is responsible for the national collection and reporting of data on all children receiving long-term kidney replacement therapy [KRT], including kidney transplantation.

METHODS

All 13 UK pediatric nephrology centers contributed to providing individual patient data from the pediatric population incident to and prevalent to KRT as per the date 31 December 2018. Data for children aged 16-<18 years were presented separately as some were managed under adult care settings with different methods of data collection. Demographics and biochemical data, including kidney function and prevalence of cardiovascular risk factors [hypertension, hypercholesterolemia, BMI] were reported.

RESULTS

Eight hundred and twenty-six children (65.4 per million age-related population [pmarp]) and 199 young people (139.4pmarp) in the United Kingdom were prevalent to KRT on 31 December 2018. Overall, the incidence of KRT during 2018 was 9.1 pmarp and 12.6 pmarp in children and young people, respectively. Congenital anomalies of the kidney and urinary tract (CAKUT) were the most prevalent primary diagnoses (52%). Living and deceased donor transplantation was the most common treatment modality (78%). Patients on dialysis had lower age standardized mean height and weight ranges recorded in comparison to transplant patients [median height z score -1.8 vs. -1.1]. 73.1% patients had one or more cardiovascular disease risk factors.

CONCLUSIONS

This study highlights increasing prevalence of hemodialysis and living donor transplantation as modalities for KRT. Of those incident to KRT, the highest patient survival was seen among 8-12 years and lowest <2 years. Moreover, there was a demographic shift from Caucasian toward Asian/other ethnicity and from CAKUT to other primary kidney diseases.

Plasma Netrin-1 & cardiovascular risk in children with end stage renal disease

Background: Cardiovascular disease (CVD) is the most common cause of mortality and morbidity in children with end stage kidney disease (ESKD) which arises from the interaction of several risk factors. The aim of the study is to assess CV risk of ESKD children and outline the impact of KTX on this CV risk. Also valuate the relation between plasma Netrin-1, chronic inflammatory markers and CV risk. Methods: Sixty ESKD (30 on regular hemodialysis (HD), 30 recipients of kidney transplant (KTX)) were assessed using 24 hour AMBP assessment, laboratory (including lipid profile and markers of chronic inflammation namely N/L and HsCRP) and echocardiographic data. Plasma netrin-1 was assessed by ELISA technique for all patients. Results: showed significant higher prevalence of hypertension, higher number of patients with 24hrs BP> 95th percentile by ABPM, more prevalence of nocturnal non-dipping BP, higher percentage of obese and overweight patients, worse biochemical analysis, higher chance of medical calcification by higher Po4 and Ca X Po4, higher triglyceride level and lower HDL level and higher N/L in HD than KTX group. Significant inverse relation was detected between plasma netrin 1 and Hs CRP and between netrin 1 and N/L (p<0.001).

Kidney Transplantation in Small Children: Association Between Body Weight and Outcome-A Report From the ESPN/ERA-EDTA Registry

BACKGROUND

Many centers accept a minimum body weight of 10 kg as threshold for kidney transplantation (Tx) in children. As solid evidence for clinical outcomes in multinational studies is lacking, we evaluated practices and outcomes in European children weighing below 10 kg at Tx.

METHODS

Data were obtained from the European Society of Paediatric Nephrology/European Renal Association and European Dialysis and Transplant Association Registry on all children who started kidney replacement therapy at <2.5 y of age and received a Tx between 2000 and 2016. Weight at Tx was categorized (<10 versus ≥10 kg) and Cox regression analysis was used to evaluate its association with graft survival.

RESULTS

One hundred of the 601 children received a Tx below a weight of 10 kg during the study period. Primary renal disease groups were equal, but Tx <10 kg patients had lower pre-Tx weight gain per year (0.2 versus 2.1 kg; P < 0.001) and had a higher preemptive Tx rate (23% versus 7%; P < 0.001). No differences were found for posttransplant estimated glomerular filtration rates trajectories (P = 0.23). The graft failure risk was higher in Tx <10 kg patients at 1 y (graft survival: 90% versus 95%; hazard ratio, 3.84; 95% confidence interval, 1.24-11.84), but not at 5 y (hazard ratio, 1.71; 95% confidence interval, 0.68-4.30).

CONCLUSIONS

Despite a lower 1-y graft survival rate, graft function, and survival at 5 y were identical in Tx <10 kg patients when compared with Tx ≥10 kg patients. Our results suggest that early transplantation should be offered to a carefully selected group of patients weighing <10 kg.

Pediatric kidney transplant and cardiometabolic risk: a cohort study

INTRODUCTION

Patients with chronic kidney disease (CKD) are known to have increased cardiovascular risk but there are few data on the risk of pediatric kidney transplant recipients. We aimed to assess the impact of pre- and post-transplant overweight on allograft function and to characterize the evolution of several cardiovascular risk variables over time and their impact.

METHODS

A retrospective analysis of the records of 23 children/adolescents followed at a tertiary center after kidney transplant was conducted. Data on anthropometry and cardiometabolic variables were analyzed before transplant, six and 12 months after the transplant, and at the last follow-up visit. The impact of the variables on allograft function (glomerular filtration rate (GFR)) was estimated by creatinine-based revised Schwartz formula (Cr-eGFR) and was evaluated using nonparametric tests. Results: The 23 patients included in the study had a median age of 6.3 (4.4-10.1) years. Both systolic and diastolic BP z-score values significantly decreased between BMI groups [1.2 (-0.2 - 2.3) vs. 0.3 (-0.4 - 0.6), p=0.027 and 0.8 (-0.4 - 1.3) vs. 0.1 (-0.6 - 0.7), p=0.028, pre-transplant and at the final evaluation, respectively]. During follow-up, GFR values decreased (Cr-GFR: 68.9 (57.7-76.8) vs. 58.6 (48.9-72.9), p=0.033 at 6-months and at the end, respectively). Significant negative correlations between triglycerides and cystatin C-based eGFR (ρ=-0.47, p=0.028) and Cr-Cys-eGFR (ρ=-0.45, p=0.043) at the end of the study were found.

CONCLUSION

Our study showed a high number of overweight children undergoing kidney transplant. A negative correlation between triglycerides and GFR was found, which highlights the importance of managing nutritional status and regular blood lipids evaluation after kidney transplant.

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.

Obesity and chronic kidney disease: prevalence, mechanism, and management

The prevalence of childhood obesity is increasing worldwide at an alarming rate. While obesity is known to increase a variety of cardiovascular and metabolic diseases, it also acts as a risk factor for the development and progression of chronic kidney disease (CKD). During childhood and adolescence, severe obesity is associated with an increased prevalence and incidence of the early stages of kidney disease. Importantly, children born to obese mothers are also at increased risk of developing obesity and CKD later in life. The potential mechanisms underlying the association between obesity and CKD include hemodynamic factors, metabolic effects, and lipid nephrotoxicity. Weight reduction via increased physical activity, caloric restriction, treatment with angiotensin-converting enzyme inhibitors, and judicious bariatric surgery can be used to control obesity and obesity-related kidney disease. Preventive strategies to halt the obesity epidemic in the healthcare community are needed to reduce the widespread deleterious consequences of obesity including CKD development and progression.

Growth in children on kidney replacement therapy: a review of data from patient registries

Growth retardation is a major complication in children with chronic kidney disease (CKD) and on kidney replacement therapy (KRT). Conversely, better growth in childhood CKD is associated with an improvement in several hard morbidity-mortality endpoints. Data from pediatric international registries has demonstrated that improvements in the overall conservative management of CKD, the search for optimal dialysis, and advances in immunosuppression and kidney transplant techniques have led to a significant improvement of final height over time. Infancy still remains a critical period for adequate linear growth, and the loss of stature during the first years of life influences final height. Preliminary new original data from the European Society for Paediatric Nephrology/European Renal Association-European Dialysis and Transplant Association (ESPN/ERA-EDTA) Registry confirm an association between the final height and the height attained at 2 years in children on KRT.

Association Between Secondary Hyperparathyroidism and Body Composition in Pediatric Patients With Moderate and Advanced Chronic Kidney Disease

Objective: This single center cross-sectional study aims to investigate the association between secondary hyperparathyroidism and body composition in pediatric patients with moderate (stage 3) and advanced (stage 4-5) chronic kidney disease (CKD). Methods: 61 patients (median age: 13.4 years) were included. Body composition indices, including lean tissue index (LTI) and fat tissue index (FTI), were measured using multi-frequency bio-impedance spectroscopy. Muscle wasting was defined as LTI adjusted to height-age (HA) z-score < -1.65 SD and high adiposity as FTI z-score > 1.65 SD. Serum mineral metabolism parameters, including serum intact parathormone (iPTH), calcium, phosphorus and 25-hydroxyvitamin D, as well as serum leptin were measured in each patient. In advanced CKD patients, the mean values of serum mineral laboratory parameters of the 6 months prior to body composition assessment were recorded, and alfacalcidol index, defined as weekly alfacalcidol dose (mcg/week) per pg/ml of iPTH × 1,000, was calculated. Results: In moderate CKD (31 patients), high iPTH (>90 ng/ml) was observed in 10 (32.3%) patients and was associated with higher FTI z-score (p = 0.022). Moreover, serum iPTH was negatively correlated to LTI HA z-score (rs = -0.486, p = 0.006), and positively correlated to serum leptin levels (rs = 0.369, p = 0.041). The positive correlation between FTI z-score and iPTH (rs = 0.393, p = 0.039) lost significance after adjustment for serum leptin. iPTH was positively associated with high adiposity (12 patients, 38.7%) after adjustment for the other mineral metabolism parameters (OR 1.023, 95% CI 1.002-1.045, p = 0.028). In advanced CKD (30 patients), no significant correlation was observed between iPTH and body composition indices and serum leptin levels. Eleven (36.7%) patients with muscle wasting presented lower alfacalcidol index (p = 0.017). Alfacalcidol index ≤ 24 was strongly associated with muscle wasting after adjustment for CKD stage and other mineral metabolism parameters (OR 7.226, 95% CI 1.150-45.384, p = 0.035). Conclusion: Secondary hyperparathyroidism is associated with high adiposity in moderate but not in advanced CKD, with leptin acting as a potential contributive factor. In advanced CKD, targeting higher alfacalcidol weekly dose per each unit of serum PTH seems beneficial for preventing muscle wasting.

Long-term outcomes of peritoneal dialysis started in infants below 6 months of age: An experience from two tertiary centres

BACKGROUND

Little data are available for infants who started renal replacement therapy before 6 months of age. Because of extra-renal comorbidities and uncertain outcomes, whether renal replacement therapy in neonates is justified remains debatable.

METHODS

We performed a retrospective analysis of all patients who began chronic peritoneal dialysis below 6 months between 2007 and 2017 in two tertiary centres. Results are presented as median (min;max).

RESULTS

Seventeen patients (10 boys) were included (8 prenatal diagnoses, 6 premies), with the following diagnoses: congenital anomalies of kidney and urinary tract (n=9), oxalosis (n=5), congenital nephrotic syndrome (n=2) and renal vein thrombosis (n=1). Five patients had associated comorbidities. At peritoneal dialysis initiation, age was 2.6 (0.1;5.9) months, height-standard deviation score (SDS) -1.3 (-5.7;1.6) and weight-SDS -1.4 (-3.6;0.6). Peritoneal dialysis duration was 12 (2;32) months, and at peritoneal dialysis discontinuation height-SDS was -1.0 (-4.3;0.7) weight-SDS -0.7 (-3.2;0.2), parathyroid hormone 123 (44;1540) ng/L, and hemoglobin 110 (73;174) g/L. During the first 6 months of peritoneal dialysis, the median time of hospitalisation stay was 69 (15;182) days. Ten patients presented a total of 27 peritonitis episodes. Reasons for peritoneal dialysis discontinuation were switch to hemodialysis (n=6), transplantation (n=6), recovery of renal function (n=2) and death (n=1). After a follow-up of 4.3 (1.7;10.3) years, 12 patients were transplanted, 2 patients were still on peritoneal dialysis, 2 patients were dialysis free with severe chronic kidney disease and 1 patient had died. Seven patients displayed neurodevelopmental delay, of whom five needed special schooling.

CONCLUSION

We confirm that most infants starting peritoneal dialysis before 6 months of age will be successfully transplanted and will have a favourable growth outcome. Their quality of life will be impacted by recurrent hospitalisations and neurodevelopmental delay is frequent.

Changes in body mass index after pediatric renal transplantation

Significant weight gain following renal transplantation is common in adult and pediatric recipients and mostly depends on receiving higher doses of steroids, changes in mood and feelings, as well as their level of physical activities. This study was performed to evaluate body weight and body mass index (BMI) before and after kidney transplantation in children and adolescents. In this cross-sectional study, 71 pediatric renal transplant recipients (42 boys and 29 girls) were included. World Health Organization criteria were used for comparing Z-score BMI for age in our cases. Overweight was defined as Z-score BMI >+1 SD (standard deviation) and obesity as >+2 SD. At the time of transplantation, the mean age was 10.8 ± 3 years (5-16 years) and based on BMIZ-score, the patients were found to be thin (BMIZs <-2 SD) in 16.9%, normal (BMIZs = -2 to +1 SD) in 67.6%, overweight (>+1 SD to +2 SD) in 9.9%, and obese (BMIZs >+2 SD) in 5.6%.The mean follow-up duration after transplantation was 3.57 ± 1.68 years (1-7 years) and at the time of reevaluation after transplant, their mean age was 14.4 years (6-18 years). The mean BMI was 22 ± 5.3 kg/m², and for BMI grouping, the patients were thin in 7%, normal in 54.9%, overweight in 21.1%, and obese in 17%. Pretransplant thinness (BMIZs <-2 SD) was found in 12 patients (16.9%), equally in boys and girls, and in most of them (83.3%), BMIZs changed to normal or even >+1 SD after transplant. Chronic continuous decrease of glomerular filtration rate (CCD/GFR) was found in 27 cases (38%); 74.1% were male (P = 0.045), hypertriglyceridemia was found in 74.1% (P = 0.023%), hypercholesterolemia in 63% (P = 0.032),and obesity in 18.5% (p = 0.5). The incidence of obesity has tripled after kidney transplantation. It was not a risk factor for graft or patient survival in our experience, whereas pretransplant obesity had some effects on long-term graft outcome.

Long-term all-cause mortality and cardiovascular outcomes in Scottish children after initiation of renal replacement therapy: a national cohort study

BACKGROUND

Data on long-term outcomes in children who have received renal replacement therapy (RRT) for end-stage renal disease are limited.

METHODS

We studied long-term survival and incidence of fatal and nonfatal cardiovascular disease (CVD) events and determinants of these outcomes in children who initiated RRT between 1961 and 2013 using data from the Scottish Renal Registry (SRR). Linkage to morbidity records was available from 1981.

RESULTS

A total of 477 children of whom 55% were boys, almost 50% had congenital urinary tract disease (CAKUT), 10% received a transplant as the first mode of RRT and almost 60% were over 11 years of age at start of RRT were followed for a median of 17.8 years (interquartile range (IQR) 8.7-26.6 years). Survival was 87.3% (95% confidence interval (CI) 84.0-90.1) at 10 years and 77.6% (95% CI 73.3-81.7) at 20 years. During a median follow-up of 14.96 years (IQR 7.1-22.9), 20.9% of the 381 patients with morbidity data available had an incident of CVD event. Age < 2 years at start of RRT, receiving dialysis rather than a kidney transplant and primary renal disease (PRD) other than CAKUT or glomerulonephritis (GN), were associated with a higher risk of all-cause mortality. Male sex, receiving dialysis rather than a kidney transplant and PRD other than CAKUT or GN, was associated with a higher risk of CVD incidence.

CONCLUSIONS

Mortality and CVD incidence among children receiving RRT are high. PRD and RRT modality were associated with increased risk of both all-cause mortality and CVD incidence.

End-stage kidney disease in infancy: an educational review

An increasing number of infants with end-stage kidney disease (ESKD) are surviving and receiving renal replacement therapy (RRT). Unique clinical issues specific to this age group of patients influence their short- and long-term outcomes. This review summarizes current epidemiology, clinical characteristics, ethical dilemmas, management concerns, and outcomes of infants requiring chronic dialysis therapy. Optimal care during infancy requires a multidisciplinary team working closely with the patient's family. Nutritional management, infection prevention, and attention to cardiovascular status are important treatment targets. Although mortality rates remain higher among infants on dialysis compared to older pediatric dialysis patients, outcomes have improved over time. Most importantly, infants who subsequently receive a kidney transplant are now experiencing graft survival rates that are comparable to older pediatric patients.

Cardiovascular risk factors in children on dialysis: an update

Cardiovascular disease (CVD) is a life-limiting comorbidity in patients with chronic kidney disease (CKD). In childhood, imaging studies have demonstrated early phenotypic characteristics including increases in left ventricular mass, carotid artery intima-media thickness, and pulse wave velocity, which occur even in young children with early stages of CKD. Vascular calcifications are the signature of an advanced phenotype and are mainly found in adolescents and young adults treated with dialysis. Association studies have provided valuable information regarding the significance of a multitude of risk factors in promoting CVD in children with CKD by using intermediate endpoints of measurements of surrogate parameters of CVD. Dialysis aggravates pre-existing risk factors and accelerates the progression of CVD with additional dialysis-related risk factors. Coronary artery calcifications in children and young adults with CKD accumulate in a time-dependent manner on dialysis. Identification of risk factors has led to improved understanding of principal mechanisms of CKD-induced damage to the cardiovascular system. Treatment strategies include assessment and monitoring of individual risk factor load, optimization of treatment of modifiable risk factors, and intensified hemodialysis if early transplantation is not possible.

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.

Association of nutritional status and health-related quality of life in children with chronic kidney disease

PURPOSE

Health-related quality of life (HRQoL) is an important, patient-centred measure. Although nutritional status is altered in children with CKD, the impact of nutritional status on HRQoL in this population has not been explored. The aims of this study are to report the HRQoL scores as assessed by the validated PedsQL™ questionnaire and to explore the relationship of HRQoL scores to markers of nutritional status. It will also examine the concordance between the scores of the child and their parent/carer.

METHODS

A single-centre, cross-sectional, observational study was performed exploring the markers of nutritional status (anthropometry-including presence of obesity, micronutrient status and appetite) and HRQoL and assessed by the PedsQL™ questionnaire in children aged 3-18 years with pre-dialysis, conservatively managed CKD.

RESULTS

A total of 46 children were recruited, with a mean age of 10.5 years. HRQoL scores were lower than in healthy controls throughout all domains. Lower scores were associated with short stature and poor appetite. Markers of obesity or micronutrient status were not associated with HRQoL scores.

DISCUSSION

Nutritional status impacts upon HRQoL. Further study is needed to evaluate how changing nutritional status may affect HRQoL in children with CKD, and this may be used to facilitate the development of patient-centred treatment goals and plans.

Global Variation of Nutritional Status in Children Undergoing Chronic Peritoneal Dialysis: A Longitudinal Study of the International Pediatric Peritoneal Dialysis Network

While children approaching end-stage kidney disease (ESKD) are considered at risk of uremic anorexia and underweight they are also exposed to the global obesity epidemic. We sought to investigate the variation of nutritional status in children undergoing chronic peritoneal dialysis (CPD) around the globe. The distribution and course of body mass index (BMI) standard deviation score over time was examined prospectively in 1001 children and adolescents from 35 countries starting CPD who were followed in the International Pediatric PD Network (IPPN) Registry. The overall prevalence of underweight, and overweight/obesity at start of CPD was 8.9% and 19.7%, respectively. Underweight was most prevalent in South and Southeast Asia (20%), Central Europe (16.7%) and Turkey (15.2%), whereas overweight and obesity were most common in the Middle East (40%) and the US (33%). BMI SDS at PD initiation was associated positively with current eGFR and gastrostomy feeding prior to PD start. Over the course of PD BMI SDS tended to increase on CPD in underweight and normal weight children, whereas it decreased in initially overweight patients. In infancy, mortality risk was amplified by obesity, whereas in older children mortality was markedly increased in association with underweight. Both underweight and overweight are prevalent in pediatric ESKD, with the prevalence varying across the globe. Late dialysis start is associated with underweight, while enteral feeding can lead to obesity. Nutritional abnormalities tend to attenuate with time on dialysis. Mortality risk appears increased with obesity in infants and with underweight in older children.

Factors Associated With Anthropometric Indicators of Nutritional Status in Children With Chronic Kidney Disease Undergoing Peritoneal Dialysis, Hemodialysis, and After Kidney Transplant

OBJECTIVE

The objective of the study was to demonstrate that there are differences in the factors associated with anthropometric indicators of nutritional status, with particular emphasis on arm indicators, in children with end-stage kidney disease undergoing peritoneal dialysis (PD), hemodialysis (HD), and after kidney transplant (KT).

METHODS

An analytical cross-sectional study of consecutive cases included 130 children and adolescents with end-stage kidney disease undergoing substitutive treatment: 49 patients who underwent KT, 33 undergoing PD, and 47 undergoing HD. Socioeconomic data were obtained from all the 3 groups; anthropometric indicators of nutritional status were calculated. Student's t-test and analysis of variance were used for parametric variables. Chi-square test, Mann-Whitney U test, Kruskal-Wallis test, and odds ratio (OR) were used for nonparametric variables.

RESULTS

The number of parents living as couples was higher for patients who underwent KT (OR = 3.5 [95% confidence interval {CI} 1.34-9.0]) and undergoing PD (OR = 3.0 [95% CI 1.06-8.8]) than those undergoing HD. The number of mothers who worked outside the home was higher for patients who underwent KT and undergoing PD than the mothers of patients undergoing HD (OR = 13.7 [95% CI: 4.56-41.05]; OR = 15.4 [CI 95% 4.8-49], respectively). Family income was higher for patients who underwent KT and undergoing PD (P = .019, P = .093, respectively). More than 40% of patients in all the 3 groups had growth impairment. Body mass index, mid-upper arm circumference, tricipital and subscapular skinfolds, total arm area, and arm fat area were affected in HD and PD groups (9 to 40%), while of the patients who underwent KT, 36.7% were overweight or obese. More than 50% of patients who underwent KT and undergoing HD and PD had involvement in the arm muscular area.

CONCLUSIONS

Socioeconomic conditions are more influential for children in the HD program. The nutritional status of children after KT improves; however, not all anthropometric indicators are fully recovered. Children after KT are up to 9 times more likely to be overweight or obese.

Muscle wasting in chronic kidney disease

Loss of lean body mass is a relevant component of the cachexia, or protein energy wasting (PEW), syndrome. Reduced muscle mass seems to be the most solid criterion for the presence of cachexia/PEW in patients with chronic kidney disease (CKD), and those with greater muscle mass loss have a higher risk of death. Children with CKD have many risk factors for lean mass and muscle wasting, including poor appetite, inflammation, growth hormone resistance, and metabolic acidosis. Mortality risks in patients with CKD increases as body mass index (BMI) and weight decreases. However, data regarding cachexia/PEW and muscle wasting in children with CKD is scarce due to lack of consensus in diagnostic criteria and an appropriate investigative methodology. Further research is urgently needed to address this important complication in the pediatric CKD setting, which may have fundamental impact on clinical outcomes.

Unacylated ghrelin and obestatin: promising biomarkers of protein energy wasting in children with chronic kidney disease

BACKGROUND

Impairment in orexigenic/anorexigenic hormone balance may be key in the pathogenesis of protein energy wasting in children with chronic kidney disease (CKD). Measurement of ghrelin and obestatin concentrations in children with CKD would help assess the potential contribution of these hormones to uremic protein energy wasting.

METHODS

This was a cross-sectional case-control study. Acylated and unacylated ghrelin and obestatin were measured in 42 children on conservative treatment (CT), 20 children on hemodialysis, 48 pediatric renal transplant (RTx) recipients and 43 controls (CTR) (mean age 11.9, range 5-20 years). Weight, height and bicipital, tricipital, subscapular and suprailiac folds were measured, and the body mass index-standard deviation score (BMI-SDS), percentage of fat mass and fat-free mass were calculated. Urea and creatinine were measured and the glomerular filtration rate (GFR) calculated.

RESULTS

Unacylated ghrelin level was higher in patients than controls (p = 0.0001), with the highest levels found in hemodialysis patients (p = 0.001 vs. CKD-CT, p = 0.0001 vs. RTx, p < 0.0001 vs. CTR). Obestatin level was significantly higher in patients on hemodialysis than those on conservative treatment, RTx recipients and controls (p < 0.0001 in each case). Unacylated ghrelin negatively correlated with weight-SDS (p < 0.0001), BMI-SDS (p = 0.0005) and percentage fat mass (p = 0.004) and positively correlated with percentage fat-free mass (p = 0.004). Obestatin concentration negatively correlated with weight-SDS (p = 0.007). Unacylated ghrelin and obestatin concentrations positively correlated with creatinine and urea and inversely with eGFR, even after adjustments for gender, age, puberty and BMI-SDS (p < 0.0001 for each model).

CONCLUSIONS

Unacylated ghrelin and obestatin, negatively related to renal function, seem to be promising inverse indicators of nutritional status in children with CKD. Potential therapeutic implications in terms of optimization of their removal in patients on hemodialysis could be hypothesized.

Cachexia in children with chronic kidney disease: challenges in diagnosis and treatment

PURPOSE OF REVIEW

Although cachexia is highly prevalent in adult patients with chronic kidney disease (CKD), it is understudied and less well characterized in children. Recent evidence suggests that cachexia is also prevalent in children with CKD but presents challenges in diagnosis and treatment.

RECENT FINDINGS

A study from the CKD in children cohort showed that CKD cachexia or protein-energy wasting, using modified pediatric diagnostic criteria, such as lack of expected weight gain instead of weight loss and BMI for height age, had a prevalence of 7-20%. When growth indices such as height SD score (SDS)/height velocity SDS was included in the criteria, cachexia or PEW correlated with the morbidity outcome of increased hospitalization risk in children with CKD. Conversely, aggressive nutritional supplementation in children with advanced CKD, with nasogastric or gastric tube feeding, led to prevalence of obesity over that of cachexia. Body habitus of underweight and obesity have been shown to be associated with the worst clinical outcomes in both adults and children with CKD.

SUMMARY

Optimal nutritional therapy remains the mainstay of treatment of cachexia in CKD children with therapeutic goals of maintaining BMI as well as linear growth within the normal range.

Obesity in pediatric kidney transplant recipients and the risks of acute rejection, graft loss and death

BACKGROUND

Obesity is prevalent in children with chronic kidney disease (CKD), but the health consequences of this combination of comorbidities are uncertain. The aim of this study was to evaluate the impact of obesity on the outcomes of children following kidney transplantation.

METHODS

Using data from the ANZDATA Registry (1994-2013), we assessed the association between age-appropriate body mass index (BMI) at the time of transplantation and the subsequent development of acute rejection (within the first 6 months), graft loss and death using adjusted Cox proportional hazards models.

RESULTS

Included in our analysis were 750 children ranging in age from 2 to 18 (median age 12) years with a total of 6597 person-years of follow-up (median follow-up 8.4 years). Overall, at transplantation 129 (17.2%) children were classified as being overweight and 61 (8.1%) as being obese. Of the 750 children, 102 (16.2%) experienced acute rejection within the first 6 months of transplantation, 235 (31.3%) lost their allograft and 53 (7.1%) died. Compared to children with normal BMI, the adjusted hazard ratios (HR) for graft loss in children who were underweight, overweight or diagnosed as obese were 1.05 [95% confidence interval (CI) 0.70-1.60], 1.03 (95% CI 0.71-1.49) and 1.61 (95% CI 1.05-2.47), respectively. There was no statistically significant association between BMI and acute rejection [underweight: HR 1.07, 95% CI 0.54-2.09; overweight: HR 1.42, 95% CI 0.86-2.34; obese: HR 1.83, 95% CI 0.95-3.51) or patient survival (underweight: HR 1.18, 95% CI 0.54-2.58, overweight: HR 0.85, 95% CI 0.38-1.92; obese: HR 0.80, 95% CI 0.25-2.61).

CONCLUSIONS

Over 10 years of follow-up, pediatric transplant recipients diagnosed with obesity have a substantially increased risk of allograft failure but not acute rejection of the graft or death.

Pubertal development in children with chronic kidney disease

Impairment of pubertal growth and sexual maturation resulting in reduced adult height is an significant complication in children suffering from chronic kidney disease (CKD). Delayed puberty and reduced pubertal growth are most pronounced in children with pre-existing severe stunting before puberty, requiring long-term dialysis treatment, and in transplanted children with poor graft function and high glucocorticoid exposure. In pre-dialysis patients, therapeutic measures to improve pubertal growth are limited and mainly based on the preservation of renal function and the use of growth hormone treatment. In patients with end-stage CKD, early kidney transplantation with steroid withdrawal within 6 months of renal transplantation allows for normal pubertal development in the majority of patients. This review focuses on the underlying pathophysiology and strategies for improving height and development in these patients.

Relationship Among Viremia/Viral Infection, Alloimmunity, and Nutritional Parameters in the First Year After Pediatric Kidney Transplantation

The Immune Development in Pediatric Transplantation (IMPACT) study was conducted to evaluate relationships among alloimmunity, protective immunity, immune development, physical parameters, and clinical outcome in children undergoing kidney transplantation. We prospectively evaluated biopsy-proven acute rejection (BPAR), de novo donor-specific antibody (dnDSA) formation, viremia, viral infection, T cell immunophenotyping, and body mass index (BMI)/weight Z scores in the first year posttransplantation in 106 pediatric kidney transplant recipients. Outcomes were excellent with no deaths and 98% graft survival. Rejection and dnDSAs occurred in 24% and 22%, respectively. Pretransplant cytomegalovirus (CMV) and Epstein-Barr virus (EBV) serologies and subsequent viremia were unrelated to BPAR or dnDSA. Viremia occurred in 73% of children (EBV, 34%; CMV, 23%; BMK viremia, 23%; and JC virus, 21%). Memory lymphocyte phenotype at baseline was not predictive of alloimmune complications. Patients who developed viral infection had lower weight (-2.1) (p = 0.028) and BMI (-1.2) (p = 0.048) Z scores at transplantation. The weight difference persisted to 12 months compared with patients without infection (p = 0.038). These data indicate that there is a high prevalence of viral disease after pediatric kidney transplantation, and underweight status at transplantation appears to be a risk factor for subsequent viral infection. The occurrence of viremia/viral infection is not associated with alloimmune events.

Timing of renal replacement therapy does not influence survival and growth in children with congenital nephrotic syndrome caused by mutations in NPHS1: data from the ESPN/ERA-EDTA Registry

BACKGROUND

Congenital nephrotic syndrome (CNS) of the Finnish type, NPHS1, is the most severe form of CNS. Outcomes of renal replacement therapy (RRT) in NPHS1 patients in Europe were analysed using data from the ESPN/ERA-EDTA Registry. As NPHS1 is most prevalent in Finland and the therapeutic approach differs from that in many other countries, we compared outcomes in Finnish and other European patients.

METHODS

NPHS1 mutations were confirmed in 170 children with CNS who initiated RRT (dialysis or renal transplantation) between 1991 and 2012. Finnish (n = 66) and non-Finnish NPHS1 patients (n = 104) were compared with respect to treatment policy, age at first RRT and renal transplantation (RTX), patient and graft survival, estimated glomerular filtration rate (eGFR) and growth. Age-matched patients with congenital anomalies of the kidney and urinary tract (CAKUT) served as controls.

RESULTS

Finnish NPHS1 patients were significantly younger than non-Finnish patients, both at the start of RRT and at the time of RTX. We found similar overall 5-year patient survival on RRT (91 %) and graft survival (89 %) in both NPHS1 groups and CAKUT controls. At the start of RRT, height standard deviation score (SDS) was higher in Finnish patients than in non-Finnish patients (mean [95 % CI]: -1.31 [-2.13 to -0.49] and -3.0 [-4.22 to -1.91], p < 0.01 respectively), but not at 5 years of age. At 5 years of age height and body mass index (BMI) SDS were similar to those of CAKUT controls.

CONCLUSIONS

Overall, 5-year patient and graft survival of both Finnish and non-Finnish NPHS1 patients on RRT were excellent and comparable with CAKUT patients with equally early RRT onset and was independent of the timing of RRT initiation and RTX.

Lessons learned from the ESPN/ERA-EDTA Registry

End-stage renal disease (ESRD) in children is a medically challenging condition. Due to its rarity and special features, methodologically sound collaborative studies are required. In 2007, a new European registry of pediatric renal replacement therapy (RRT), the ESPN/ERA-EDTA Registry, was launched. In recent years, the Registry has provided comprehensive data on incidence, prevalence, patient characteristics, RRT modalities, and mortality in pediatric ESRD, along with relevant insights into cardiovascular risk, anemia, nutrition and growth, transplantation outcomes, and rare diseases. In this review, we describe the study design and structure underlying the ESPN/ERA-EDTA Registry, summarize the major research findings from more than 20 publications, and discuss current limitations and the future challenges to overcome.

Perceived appetite and clinical outcomes in children with chronic kidney disease

BACKGROUND

Children with chronic kidney disease (CKD) may have impaired caloric intake through a variety of mechanisms, with decreased appetite as a putative contributor. In adult CKD, decreased appetite has been associated with poor clinical outcomes. There is limited information about this relationship in pediatric CKD.

METHODS

A total of 879 participants of the Chronic Kidney Disease in Children (CKiD) study were studied. Self-reported appetite was assessed annually and categorized as very good, good, fair, or poor/very poor. The relationship between appetite and iohexol or estimated glomerular filtration rate (ieGFR), annual changes in anthropometrics z-scores, hospitalizations, emergency room visits, and quality of life were assessed.

RESULTS

An ieGFR < 30 ml/min per 1.73 m(2) was associated with a 4.46 greater odds (95 % confidence interval: 2.80, 7.09) of having a worse appetite than those with ieGFR >90. Appetite did not predict changes in height, weight, or BMI z-scores. Patients not reporting a very good appetite had more hospitalizations over the next year than those with a very good appetite. Worse appetite was significantly associated with lower parental and patient reported quality of life.

CONCLUSIONS

Self-reported appetite in children with CKD worsens with lower ieGFR and is correlated with clinical outcomes, including hospitalizations and quality of life.

Inflammation and nutrition in children with chronic kidney disease

Chronic inflammation and nutritional imbalance are important comorbid conditions that correlate with poor clinical outcomes in children with chronic kidney disease (CKD). Nutritional disorders such as cachexia/protein energy wasting, obesity and growth retardation negatively impact the quality of life and disease progression in children with CKD. Inadequate nutrition has been associated with growth disturbances in children with CKD. On the other hand, over-nutrition and obesity are associated with poor outcomes in children with CKD. The exact mechanisms leading to these unfavorable conditions are not fully elucidated and are most likely multifactorial. In this review, we focus on the pathophysiology of nutrition disorders and inflammation and their impact on clinical outcomes in children with CKD.

Treatment Strategies to Prevent Renal Damage in Hypertensive Children

Hypertension secondary to chronic kidney disease prevails in earlier childhood and obesity-related primary hypertension in adolescence. Both are associated with a high risk of renal and cardiovascular morbidity. In children with chronic kidney disease, uncontrolled hypertension may accelerate progression to end-stage renal disease before adulthood is reached and increase a child’s risk of cardiac death a thousand-fold. Obesity-related hypertension is a slow and silent killer, and though early markers of renal damage are recognized during childhood, end-stage renal disease is a risk in later life. Renal damage will be a formidable multiplier of cardiovascular risk for adults in whom obesity and hypertension tracks from childhood. Management options to prevent renal damage will vary for these different target groups. This review provides a summary of the available renoprotective strategies in order to aid physicians involved in the care of this challenging group of children.

Chronic kidney disease: Obesity in children with end-stage renal disease

A recent publication by Bonthuis et al. shows a high prevalence of overweight or obesity in children with end-stage renal disease, particularly in renal transplant recipients. Underweight is more prevalent in infants than in other age groups. This study highlights the need to evaluate and implement interventional strategies in this patient population.