Growth in children with chronic kidney disease: a report from the Chronic Kidney Disease in Children Study

Long-term growth in children with posterior urethral valves

BACKGROUND

Posterior urethral valves (PUVs) are one of the leading causes of pediatric chronic kidney disease (CKD). Growth impairment is prevalent in pediatric CKD, and children with PUVs are at high risk for growth retardation.

OBJECTIVE

The objective of this study was to describe growth profiles in PUVs and to identify risk factors for stunting, defined as age-specific height standard deviation score (SDS) below -2.

PATIENTS AND METHODS

Medical records of 65 patients with PUVs and a minimum follow-up of two years were retrospectively reviewed. Chronic kidney disease stage 1-3 was considered mild CKD, whereas CKD stage 4-5 was considered advanced CKD. Age-specific height, weight, and body mass index (BMI) SDS were determined. Seven potential risk factors for stunting, namely timing of diagnosis, renal dysplasia, timing of surgery, requirement of urinary diversion, nadir serum creatinine after surgery, recurrent febrile urinary tract infection (UTI), and severity of CKD, were analyzed.

RESULTS

Median age at diagnosis, at surgery, and at last follow-up was 0.51, 0.75, and 7.53 years, respectively. All patients underwent valve ablation, and 33.8% required urinary diversion. Median nadir serum creatinine after surgery was 0.40 mg/dL and was higher in patients who underwent urinary diversion (P < 0.001). Growth profiles by CKD stage are displayed in Fig. 1. Median height SDS was -0.40 and was lower in patients with advanced CKD (P = 0.03). Stunting was diagnosed in 15.4%. Advanced CKD was an independent risk factor for stunting, with the odds ratio of 12.7. Urinary diversion and nadir creatinine more than 0.80 mg/dL were weakly associated with stunting but not significant. Timing of diagnosis and surgery, unilateral renal dysplasia, and recurrent febrile UTI were not associated with stunting. Median SDS of weight and BMI was -0.64 and -0.19, respectively. Patients who were thin, of normal weight, overweight, and obese comprised 26.2%, 58.5%, 10.8%, and 4.6%, respectively. There was no significant difference of SDS of weight and BMI across CKD stages (Fig. 1).

DISCUSSION

Deterioration in height began early in the course of disease and was worsening in relation to the decline of renal function. The impact of timing of diagnosis or surgery on height was controversial. Patients who underwent urinary diversion had high nadir creatinine and were likely to have severe PUVs. Although patients with severe baseline renal dysfunction may require urinary diversion, nadir serum creatinine and urinary diversion are not associated with stunting. Delaying progression of CKD could maximize linear growth potential in PUVs. A substantial proportion of patients were overweight or obese. Sufficient caloric intakes may be maintained in patients with PUVs.

Malnutrition in Children With Chronic Disease

Malnutrition occurs when nutrient intake does not meet the needs for normal body functions and as a consequence leads to alterations of growth and development in children. Chronic illness puts children at risk for developing malnutrition. Because of children's rapid periods of growth and development, early diagnosis, prevention, and management of malnutrition are paramount. The reasons for malnutrition in children with chronic disease are multifactorial and are related to the underlying disease and non-illness-associated factors. This review addresses the causes, evaluation, and management of malnutrition in pediatric congenital heart disease, chronic kidney disease, liver disease, and cystic fibrosis.

Causes of Chronic Kidney Disease in Iranian Children: A Meta-Analysis and Systematic Review

This study aimed to determine the causes of chronic kidney disease (CKD) in Iranian children. In this systematic review and meta-analysis study, international (PubMed, Web of Science, Scopus, and Google Scholar) and national (SID, Magiran) databases were searched for articles published through December 30, 2017. The quality of the studies was determined using the Hoy instrument. Out of 2,117 initial studies, 13 studies performed on a total of 3,596 children were included in the final stage of the study. Based on the results of the random effects method (95% CI), the main causes of chronic kidney disease in stages 1–4 (CKD) were CAKUT (37%) and glomerulonephritis (19.96%); in stage 5 (ESRD) they were CAKUT (40.82%) and urological disorders (27.44%). Considering the high prevalence of CAKUT, glomerulonephritis and urinary problems, the use of comprehensive approaches can be very effective in enhancing the knowledge of patients about the causes of kidney disease. The results obtained from the present study can assist policymakers in more accurately planning screenings of the causes of CKD in Iranian children.

Towards cardiovascular risks in children with chronic kidney disease: a prospective cohort study

Background: Children with chronic kidney disease (CKD) are at substantially high risk of morbidity and mortality from cardiovascular disease (CVD). Although this issue has been extensively studied in adults, little is known whether similar associations exist in the paediatric population. We therefore aimed to evaluate the cardiac structure and function in children with CKD, and investigate the factors that contribute to the development of CVD. Methods: A prospective cohort was established following 40 children with CKD treated in the nephrology unit at a high-volume, tertiary, teaching hospital and compared to age- and gender-matched controls of the same number.  We reviewed the patients’ medical records, assessed growth parameters, measured blood pressure, took blood samples, and performed echocardiography. Results: More than half of the CKD patients are hypertensive (N = 22; 55%) and were found to have a higher proportion of increased left ventricular mass index (LVMI) (75.5%; P = 0.001). In contrast, we did not find any significant association between CKD and both valvular calcification & left ventricular (LV) fractional shortening (FS) in children (P = 0.314). Furthermore, high LVMI is found to be correlated well with the following: anaemia, hypertension, CKD duration > one year, hyperparathyroidism, estimated glomerular filtration rate (eGFR) < 15ml/minute/1.73 m2 and death (P < 0.05). Conclusions: Despite the fact that LV systolic function is preserved and valvular calcification is usually absent, left ventricular hypertrophy (LVH) is common in children with CKD. Hypertension, anaemia, hyperparathyroidism, as well as the severity and duration of renal impairment, are amongst the additional risk factors that predispose to LVH. We contribute this study to the growing information of the review articles regarding the association between CKD and CVD in paediatrics.

Waist-to-height ratio, body mass index, and cardiovascular risk profile in children with chronic kidney disease

BACKGROUND

Cardiovascular (CV) risk is high in children with chronic kidney disease (CKD), and further compounded in those who are overweight. Children with CKD have a unique body habitus not accurately assessed by body mass index (BMI). Waist-to-height ratio (WHr), a better predictor of CV risk in populations with short stature, has not been investigated in children with CKD.

METHODS

Analysis of 1723 visits of 593 participants enrolled in the Chronic Kidney Disease in Children (CKiD) study was conducted. CKiD participants had BMI and WHr measured and classified as follows: (1) lean (WHr ≤ 0.49, BMI < 85th percentile); (2) WHr-overweight (WHr > 0.49, BMI < 85th percentile); (3) BMI-overweight (WHr ≤ 0.49, BMI ≥ 85th percentile); or (4) overweight by both BMI and WHr. Left ventricular mass index (LVMI), fasting lipids, fibroblast growth factor 23 (FGF23), blood pressure, and glucose were measured as markers of CV risk. Linear mixed-effects regression was used to evaluate differences in CV markers between overweight and lean groups.

RESULTS

Participants were 12.2 years old, 60% male, and 17% African-American. Approximately 15% were overweight by WHr but not by BMI. Overweight status by WHr-only or both WHr and BMI was associated with lower high-density lipoprotein (HDL) and higher LVMI, triglycerides, and non-HDL cholesterol compared to lean. CV markers of participants overweight by BMI-only were similar to those of lean children.

CONCLUSIONS

WHr-adiposity is associated with an adverse CV risk profile in children with CKD. A significant proportion of children with central adiposity are missed by BMI. WHr should be utilized as a screening tool for CV risk in this population.

Nutrition imbalance in Chinese chronic kidney disease children

BACKGROUND

Nutrition imbalance is common in chronic kidney disease (CKD) children. This study evaluated the nutrition status of CKD children at different stages using bioimpedance analysis (BIA) compared with anthropometry.

METHODS

Fifty-five CKD children at stages III, IV, V and 19 age- and sex-matched healthy controls were recruited. Fat, protein and mineral composition on BIA were analyzed together with anthropometry for height, weight and body mass index (BMI). Biochemistry was also checked in CKD children.

RESULTS

Of the CKD children, 23.6%, 10.9% and 56.3% were underweight, overweight/obese and stunted, respectively. On BIA, 52.7%, 70.9%, 14.5% and 40.0% of the CKD children had protein reduction, fat reduction, fat enhancement and mineral reduction, respectively. Growth retardation and nutrition reduction became remarkable at stages IV and V. Approximately 65% of healthy-weight children had nutrition reduction. In the underweight and healthy-weight groups, fat reduction rates were higher than protein reduction rate. In the overweight/obese group, fat enhancement was most notable. Mineral reduction was less remarkable.

CONCLUSIONS

The nutrition imbalance in CKD children on BIA correlated well with anthropometry and disease process, supporting BIA as an auxiliary diagnosis tool.

Optimizing Enteral Nutrition for Growth in Pediatric Chronic Kidney Disease (CKD)

Growth in pediatric Chronic Kidney Disease is important for long-term outcomes including final adult height and cognitive function. However, there are many barriers for children with chronic kidney disease to achieve adequate nutritional intake to optimize growth. This review highlights these unique concerns, including route of nutrition, dialysis contributions and biochemical indices. Fitting the enteral feeding to the patients' needs involves choosing an appropriate product or products, limiting harmful nutrients in excess, notably aluminum, and altering for electrolyte and micronutrient needs. Unique adjustments to the enteral regimen include accommodating volume needs, optimizing macronutrient ratios, specific electrolyte adjustments, the blending of products together, and adjustments made to consider patient and family psychosocial needs. When a holistic approach to medical nutrition therapy is applied, taking the above factors into consideration, adequate intake for growth of the child with CKD is achievable.

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.

Growth and Nutrition in Pediatric Chronic Kidney Disease

Children with chronic kidney disease (CKD) feature significant challenges to the maintenance of adequate nutrition and linear growth. Moreover, the impaired nutritional state contributes directly to poor growth. Therefore, it is necessary to consider nutritional status in the assessment of etiology and treatment of sub-optimal linear growth. The major causes of poor linear growth including dysregulation of the growth hormone/insulin-like growth factor-I (IGF-I) axis, nutritional deficiency, metabolic acidosis, anemia, renal osteodystrophy/bone mineral disease, and inflammation. This review summarizes the causes and assessment tools of growth and nutrition while providing a summary of state of the art therapies for these co-morbidities of pediatric CKD.

Intradialytic Parenteral Nutrition in Pediatrics

Children with end-stage renal disease (ESRD) on hemodialysis are at increased risk for malnutrition. Aggressive nutrition intervention such as intradialytic parenteral nutrition (IDPN) should be considered to prevent further co-morbidities and mortality associated with malnutrition when other interventions fail. IDPN is a non-invasive method of providing nutrition to malnourished hemodialysis (HD) patients via the HD access throughout the HD treatment. Although the evidence on the long-term benefits of IDPN is scant in pediatrics, there is evidence that it improves metabolic parameters and nutritional status. In this paper, therapy with IDPN including indications, goals of therapy, and elements to monitor will be described. In addition, a practice guideline for prescribing IDPN is provided.

Association of Serum Soluble Urokinase Receptor Levels With Progression of Kidney Disease in Children

Importance

Conventional methods to diagnose and monitor chronic kidney disease (CKD) in children, such as creatinine level and cystatin C-derived estimated glomerular filtration rate (eGFR) and assessment of proteinuria in spot or timed urine samples, are of limited value in identifying patients at risk of progressive kidney function loss. Serum soluble urokinase receptor (suPAR) levels strongly predict incident CKD stage 3 in adults.

Objective

To determine whether elevated suPAR levels are associated with renal disease progression in children with CKD.

Design, Setting, and Participants

Post hoc analysis of 2 prospectively followed up pediatric CKD cohorts, ie, the ESCAPE Trial (1999-2007) and the 4C Study (2010-2016), with serum suPAR level measured at enrollment and longitudinal eGFR measured prospectively. In the 2 trials, a total of 898 children were observed at 30 (ESCAPE Trial; n = 256) and 55 (4C Study; n = 642) tertiary care hospitals in 13 European countries. Renal diagnoses included congenital anomalies of the kidneys and urinary tract (n = 637 [70.9%]), tubulointerstitial nephropathies (n = 92 [10.2%]), glomerulopathies (n = 69 [7.7%]), postischemic CKD (n = 42 [4.7%]), and other CKD (n = 58 [6.5%]). Total follow-up duration was up to 7.9 years, and median follow-up was 3.1 years. Analyses were conducted from October 2016 to December 2016.

Exposures

Serum suPAR level was measured at enrollment, and eGFR was measured every 2 months in the ESCAPE Trial and every 6 months in the 4C Study. The primary end point of CKD progression was a composite of 50% eGFR loss, eGFR less than 10 mL/min/1.73 m2, or initiation of renal replacement therapy.

Main Outcomes and Measures

The primary end point in this study was renal survival, defined as a composite of 50% loss of GFR that persisted for at least 1 month, the start of renal replacement therapy, or an eGFR less than 10 mL/min/1.73 m2.

Results

Of the 898 included children, 560 (62.4%) were male, and the mean (SD) patient age at enrollment was 11.9 (3.5) years. The mean (SD) eGFR was 34 (16) mL/min/1.73 m2. The 5-year end point-free renal survival was 64.5% (95% CI, 57.4-71.7) in children with suPAR levels in the lowest quartile compared with 35.9% (95% CI, 28.7-43.0) in those in the highest quartile (P < .001). By multivariable analysis, the risk of attaining the end point was higher in children with glomerulopathies and increased with age, blood pressure, proteinuria, and lower eGFR at baseline. In patients with baseline eGFR greater than 40 mL/min/1.73 m2, higher log-transformed suPAR levels were associated with a higher risk of CKD progression after adjustment for traditional risk factors (hazard ratio, 5.12; 95% CI, 1.56-16.7; P = .007).

Conclusions and Relevance

Patients with high suPAR levels were more likely to have progression of their kidney disease. Further studies should determine whether suPAR levels can identify children at risk for future CKD.

Chronic Kidney Disease (CKD): An Observational Study of Etiology, Severity and Burden of Comorbidities

OBJECTIVES

To study the etiology and burden of comorbidities across stages of chronic kidney disease (CKD).

METHODS

Children, 2-16 y of age with CKD Stages II- IV were recruited over 12 mo. The etiology, clinical presentation and severity of complications were studied.

RESULTS

Among 78 children [Stage II (n = 21), Stage III (n = 26), Stage IV (n = 31)], congenital anomalies of the kidney and urinary tract (CAKUT) was the commonest etiology and 28 were newly diagnosed in Stage III /IV. High prevalence of comorbidities was observed with growth retardation (65%), hypertension (59%), hyperphosphatemia (32%), vitamin D deficiency (92%), dyslipidemia (64%), left ventricular hypertrophy (45%) and hyperparathyroidism (56%). While most comorbidities correlated with the estimated glomerular filtration rate and severity of CKD, hypertension, vitamin D deficiency and cardiovascular morbidity were prevalent even in early stages.

CONCLUSIONS

CAKUT was the commonest cause of CKD. Late detection and high prevalence of comorbidities even in early stages of CKD were observed.

Cluster analysis for family management of Chinese children with chronic kidney diseases

This study aimed to identify patterns of family management and its predictors based on the perception of the care experience from 339 caregivers of Chinese children with chronic kidney disease in multiple medical centers. Each caregiver completed the Family Management Measure questionnaires. Cluster analysis generated five patterns: effective (12.7%), impaired (14.5%), burdensome (21.2%), disorganized (27.7%), and concerning (23.9%). Multinomial logistic regression indicated that child's age, disease duration, family income, and paternal employment predicted cluster membership. Findings assist healthcare providers to distinguish families that need more help and the areas in which to intervene to promote families' overall coping and adaptation.

Metabolic acidosis is common and associates with disease progression in children with chronic kidney disease

Recent studies in adult chronic kidney disease (CKD) suggest that metabolic acidosis is associated with faster decline in estimated glomerular filtration rate (eGFR). Alkali therapies improve the course of kidney disease. Here we investigated the prevalence and determinants of abnormal serum bicarbonate values and whether metabolic acidosis may be deleterious to children with CKD. Associations between follow-up serum bicarbonate levels categorized as under 18, 18 to under 22, and 22 or more mmol/l and CKD outcomes in 704 children in the Cardiovascular Comorbidity in Children with CKD Study, a prospective cohort of pediatric patients with CKD stages 3-5, were studied. The eGFR and serum bicarbonate were measured every six months. At baseline, the median eGFR was 27 ml/min/1.73m² and median serum bicarbonate level 21 mmol/l. During a median follow-up of 3.3 years, the prevalence of metabolic acidosis (serum bicarbonate under 22 mmol/l) was 43%, 60%, and 45% in CKD stages 3, 4, and 5, respectively. In multivariable analysis, the presence of metabolic acidosis as a time-varying covariate was significantly associated with log serum parathyroid hormone through the entire follow-up, but no association with longitudinal growth was found. A total of 211 patients reached the composite endpoint (ESRD or 50% decline in eGFR). In a multivariable Cox model, children with time-varying serum bicarbonate under 18 mmol/l had a significantly higher risk of CKD progression compared to those with a serum bicarbonate of 22 or more mmol/l (adjusted hazard ratio 2.44; 95% confidence interval 1.43-4.15). Thus, metabolic acidosis is a common complication in pediatric patients with CKD and may be a risk factor for secondary hyperparathyroidism and kidney disease progression.

Cardiovascular effects of metabolic syndrome after transplantation: convergence of obesity and transplant-related factors

Children are at increased risk of developing metabolic syndrome (MS) after kidney transplantation, which contributes to long-term cardiovascular (CV) morbidities and decline in allograft function. While MS in the general population occurs due to excess caloric intake and physical inactivity, additional chronic kidney disease and transplant-related factors contribute to the development of MS in transplant recipients. Despite its significant health consequences, the interplay of the individual components in CV morbidity in pediatric transplant recipients is not well understood. Additionally, the optimal methods to detect early CV dysfunction are not well defined in this unique population. The quest to establish clear guidelines for diagnosis is further complicated by genetic differences among ethnic groups that necessitate the development of race-specific criteria, particularly with regard to individuals of African descent who carry the apolipoprotein L1 variant. In children, since major CV events are rare and traditional echocardiographic measures of systolic function, such as ejection fraction, are typically well preserved, the presence of CV disease often goes undetected in the early stages. Recently, new noninvasive imaging techniques have become available that offer the opportunity for early detection. Carotid intima-media thickness and impaired myocardial strain detected by speckle tracking echocardiography or cardiac magnetic resonance are emerging as early and sensitive markers of subclinical CV dysfunction. These highly sensitive tools may offer the opportunity to elucidate subtle CV effects of MS in children after transplantation. Current knowledge and future directions are explored in this review.

Approach to growth hormone therapy in children with chronic kidney disease varies across North America: the Midwest Pediatric Nephrology Consortium report

Background

Growth impairment remains common in children with chronic kidney disease (CKD). Available literature indicates low level of recombinant human growth hormone (rhGH) utilization in short children with CKD. Despite efforts at consensus guidelines, lack of high-level evidence continues to complicate rhGH therapy decision-making and the level of practice variability in rhGH treatment by pediatric nephrologists is unknown.

Methods

Cross-sectional online survey electronically distributed to pediatric nephrologists through the Midwest Pediatric Nephrology Consortium and American Society of Pediatric Nephrology.

Results

Seventy three pediatric nephrologists completed the survey. While the majority (52.1%) rarely involve endocrinology in rhGH management, 26.8% reported that endocrinology managed most aspects of rhGH treatment in their centers. The majority of centers (68.5%) have a dedicated renal dietitian, but 20.6% reported the nephrologist as the primary source of nutritional support for children with CKD. Children with growth failure did not receive rhGH most commonly because of family refusal. Differences in initial work-up for rhGH therapy include variable use of bone age (95%), thyroid function (58%), insulin-like growth factor-1 (40%), hip/knee X-ray (36%), and ophthalmologic evaluation (7%). Most pediatric nephrologists (95%) believe that rhGH treatment improves quality of life, but only 24% believe that it improves physical function; 44% indicated that rhGH improves lean body mass.

Conclusions

There is substantial variation in pediatric nephrology practice in addressing short stature and rhGH utilization in children with CKD. Hence, there may be opportunities to standardize care to study and improve growth outcomes in short children with CKD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0599-1) contains supplementary material, which is available to authorized users.

Obesity in children with congenital adrenal hyperplasia in the Minnesota cohort: importance of adjusting body mass index for height-age

OBJECTIVES

To evaluate obesity and overweight in children with congenital adrenal hyperplasia (CAH) and associations with glucocorticoids, fludrocortisone and disease control. Adjusting body mass index-for-height-age (BMI_HA ) percentile is proposed to correct misclassification of obese/overweight status in CAH children with advanced bone age and tall-for-age stature.

DESIGN

Longitudinal.

PATIENTS

One hundred and ninety-four children with CAH seen from 1970 to 2013: 124 salt wasting (SW); 70 simple virilizing (SV); 102 females.

MEASUREMENTS

Body mass index (BMI) end-points were overweight (85-94 percentile) and obese (≥95 percentile).

RESULTS

Approximately 50% of the children had at least one BMI measurement ≥95 percentile and about 70% had at least one ≥85 percentile. Using BMI_HA percentiles, obesity incidence decreased slightly in SW children (47-43%) and markedly in SV children (50-33%); however, overweight status was not reduced. Only 6% of SW and 1% of SV children were persistently obese (≥3 clinic visits) when BMI_HA was applied, whereas overweight status persisted in 35% of SW and 33% of SV children. Most obesity or overweight when using BMI_HA occurred before age 10 and there was no association with hydrocortisone (HC) or fludrocortisone dosing. Adiposity rebound for SW children occurred by 3·3 years and in SV females by age 3·8 years, over a year earlier than the adiposity rebound for healthy children.

CONCLUSION

Children with CAH are at higher risk for early onset obesity and overweight with or without using BMI_HA but rates of persistent obesity were lower than previously reported. Careful HC dosing during early childhood is needed to prevent increased weight gain and an early adiposity rebound.

Lack of hepcidin ameliorates anemia and improves growth in an adenine-induced mouse model of chronic kidney disease

Growth delay is common in children with chronic kidney disease (CKD), often associated with poor quality of life. The role of anemia in uremic growth delay is poorly understood. Here we describe an induction of uremic growth retardation by a 0.2% adenine diet in wild-type (WT) and hepcidin gene (Hamp) knockout (KO) mice, compared with their respective littermates fed a regular diet. Experiments were started at weaning (3 wk). After 8 wk, blood was collected and mice were euthanized. Adenine-fed WT mice developed CKD (blood urea nitrogen 82.8 ± 11.6 mg/dl and creatinine 0.57 ± 0.07 mg/dl) and were 2.1 cm shorter compared with WT controls. WT adenine-fed mice were anemic and had low serum iron, elevated Hamp, and elevated IL6 and TNF-α. WT adenine-fed mice had advanced mineral bone disease (serum phosphorus 16.9 ± 3.1 mg/dl and FGF23 204.0 ± 115.0 ng/ml) with loss of cortical and trabecular bone volume seen on microcomputed tomography. Hamp disruption rescued the anemia phenotype resulting in improved growth rate in mice with CKD, thus providing direct experimental evidence of the relationship between Hamp pathway and growth impairment in CKD. Hamp disruption ameliorated CKD-induced growth hormone-insulin-like growth factor 1 axis derangements and growth plate alterations. Disruption of Hamp did not mitigate the development of uremia, inflammation, and mineral and bone disease in this model. Taken together, these results indicate that an adenine diet can be successfully used to study growth in mice with CKD. Hepcidin appears to be related to pathways of growth retardation in CKD suggesting that investigation of hepcidin-lowering therapies in juvenile CKD is warranted.

Growth hormone therapy in children with CKD after more than two decades of practice

This review focuses on the evidence for the efficacy and safety of recombinant human growth hormone (rhGH) therapy in children with all stages of chronic kidney disease (CKD) and at all ages. It describes the improving height prognosis for our patients both with and without rhGH; explains the underlying hormonal abnormalities that provide the rationale for rhGH use in CKD and the endocrine changes that accompany treatment; and views on who warrants treatment, with what dose, and how long for.

Chronic kidney disease in children

Chronic kidney disease (CKD) is a major health problem worldwide. Although relatively uncommon in children, it can be a devastating illness with many long-term consequences. CKD presents unique features in childhood and may be considered, at least in part, as a stand-alone nosologic entity. Moreover, some typical features of paediatric CKD, such as the disease aetiology or cardiovascular complications, will not only influence the child's health, but also have long-term impact on the life of the adult that they will become. In this review we will focus on the unique issues of paediatric CKD, in terms of aetiology, clinical features and treatment. In addition, we will discuss factors related to CKD that start during childhood and require appropriate treatments in order to optimize health outcomes and transition to nephrologist management in adult life.

PROGRESSION OF CHRONIC KIDNEY DISEASE AFTER ACUTE KIDNEY INJURY

The incidence of chronic kidney disease (CKD) in children and adults is increasing. Cardiologists have become indispensable members of the care provider team for children with CKD. This is partly due to the high incidence of CKD in children and adults with congenital heart disease, with current estimates of 30-50%. In addition, the high incidence of acute kidney injury (AKI) due to cardiac dysfunction or following pediatric cardiac surgery that may progress to CKD is also well documented. It is now apparent that AKI and CKD are uniquely intertwined as interconnected syndromes. Furthermore, the well-known long-term cardiovascular morbidity and mortality associated with CKD require the joint attention of both nephrologists and cardiologists. Children with both congenital heart disease and CKD are increasingly surviving to adulthood, with synergistically negative medical, financial, and quality of life impact. An improved understanding of the epidemiology, mechanisms, early diagnosis, and preventive measures is of importance to cardiologists, nephrologists, scientists, economists, and policy makers alike. Herein, we report the current definitions, epidemiology, and complications of CKD in children, with an emphasis on children with congenital heart disease. We then focus on the clinical and experimental evidence for the progression of CKD after episodes of AKI commonly encountered in children with heart disease, and explore the role of novel biomarkers for the prediction of CKD progression.

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.

KNOW-Ped CKD (KoreaN cohort study for outcomes in patients with pediatric CKD): Design and methods

Background

The global prevalence of chronic kidney disease (CKD) is increasing. In children, CKD exhibits unique etiologies and can have serious impacts on children’s growth and development. Therefore, an aggressive approach to preventing the progression of CKD and its complications is imperative. To improve the understanding and management of Asian pediatric patients with CKD, we designed and launched KNOW-Ped CKD (KoreaN cohort study for Outcome in patients With Pediatric Chronic Kidney Disease), a nationwide, prospective, and observational cohort study of pediatric CKD with funding from the Korean government.

Methods/design

From seven major centers, 450 patients <20 years of age with CKD stages I to V are recruited for the comprehensive assessment of clinical findings, structured follow-up, and bio-specimen collection. The primary endpoints include CKD progression, defined as a decline of estimated glomerular filtration rate by 50 %, and a requirement for renal replacement therapy or death. The secondary outcomes include the development of left ventricular hypertrophy or hypertension, impairment of growth, neuropsychological status, behavioral status, kidney growth, and quality of life.

Discussion

With this study, we expect to obtain more information on pediatric CKD, which can be translated to better management for the patients.

Trial registration

NCT02165878 (ClinicalTrials.gov), submitted on June 11, 2014.

Chronic kidney disease in children and adolescents in Brunei Darussalam

AIM: To determine epidemiology of Bruneian paediatric chronic kidney disease (CKD) patients and factors that affect growth and progression of disease.

METHODS: A cross-sectional study conducted on all children below 18 years old who were diagnosed with CKD over a ten year period (2004 to 2013). The reference population was all children (< 18 years old) suffering from CKD and attending the tertiary paediatric nephrology clinic in Brunei Darussalam. Demographic (current age, age of diagnosis, gender, ethnicity), anthropometric (weight and height), diagnosis, laboratory data (serum creatinine and haemoglobin, urinalysis) and blood pressure were extracted from the patients’ clinical case notes and recorded using a data collection form.

RESULTS: The study revealed a high national prevalence [736 per million child population (pmcp)] and incidence (91 pcmp) of CKD. If CKD was defined at Stage 1, 2, 3, 4 or 5, the associated prevalence figures were 736, 132, 83, 50 and 33 pmcp. Glomerulonephritis accounted for 69% of all prevalent cases, followed by congenital abnormalities of kidney and urinary tract (20%) and tubulointerstitial diseases (8%). Minimal change disease being the most common histological diagnosis. The median age of diagnosis was 4.5 years, with congenital disease patients experiencing an earlier onset of diagnosis. A large proportion of patients were below the 5% percentile for height and weight. Non-glomerular diseases, adolescent and female patients were significantly associated with poor growth, but not glomerular filtration rate, age of diagnosis or steroid usage.

CONCLUSION: Brunei has a high prevalence of chronic kidney disease in the paediatric population with glomerulonephritis being the most common disease.

Growth and nutritional status in children with chronic kidney disease on maintenance dialysis in Poland

PURPOSE

Despite vast availability of modern methods of treatment of chronic kidney disease and its complications, the short stature still is a major point of concern in adolescents with chronic kidney disease. The aim of the study was to assess changes in growth and nutritional status of Polish children on renal replacement therapy in the decade, 2004-2013.

MATERIAL AND METHODS

The study was designed as a cross-sectional analysis of anthropometric values and selected indices of growth status amongst children receiving dialysis in Poland between the years 2004 and 2013. Data were acquired during two different multicentre studies on hypertension in dialyzed children in Poland. Basic anthropometric parameters (body weight, body height/length, body mass index - BMI), dialysis adequacy and duration of RRT were assessed.

RESULTS

The study showed that anthropometric parameters of children undergoing renal replacement therapy had not significantly changed in the last 10 years of observation. Children on RRT were still of short stature despite availability of modern methods of hormonal therapy and nutrition. Median of height z-score was -2.10 in 2004 and -2.19 in 2013. Expected clinical improvement in these measures was not proven.

CONCLUSIONS

The cause of chronic kidney disease, method of dialysis, time on dialysis or dialysis adequacy did not influence the anthropometric parameters significantly in dialyzed children in Poland.

Growth in Children with Autosomal Recessive Polycystic Kidney Disease in the CKiD Cohort Study

BACKGROUND

Previous studies have suggested that some children with autosomal recessive polycystic kidney disease (ARPKD) have growth impairment out of proportion to their degree of chronic kidney disease (CKD). The objective of this study was to systematically compare growth parameters in children with ARPKD to those with other congenital causes of CKD in the chronic kidney disease in Children (CKiD) prospective cohort study.

METHODS

Height SD scores (z-scores), proportion of children with severe short stature (z-score < -1.88), rates of growth hormone use, and annual change in height z-score were analyzed in children with ARPKD (n = 22) compared with two matched control groups: children with aplastic/hypoplastic/dysplastic kidneys (n = 44) and obstructive uropathy (OU) (n = 44). Differences in baseline characteristics were tested by Wilcoxon rank-sum test or Fisher's exact test. Matched differences in annual change in height z-score were tested by Wilcoxon signed-rank test.

RESULTS

Median height z-score in children with ARPKD was -1.1 [interquartile range -1.5, -0.2]; 14% of the ARPKD group had height z-score < -1.88, and 18% were using growth hormone. There were no significant differences in median height z-score, proportion with height z-score < -1.88, growth hormone use, or annual change in height z-score between the ARPKD and control groups.

CONCLUSION

Children with ARPKD and mild-to-moderate CKD in the CKiD cohort have a high prevalence of growth abnormalities, but these are similar to children with other congenital causes of CKD. This study does not support a disease-specific effect of ARPKD on growth, at least in the subset of children with mild-to-moderate CKD.

Chronic Kidney Disease in Children: Recent Update

The incidence of end stage of renal disease (ESRD) in US children age 0-19 years is 12.9 per million/year (2012). The economic and social burden of diagnosing, treating and preventing chronic kidney disease (CKD) in children and adults remains substantial. Advances in identifying factors that predict development of CKD and its progression, as well as advances in the management of co-morbid conditions including anemia, cardiovascular disease, growth, mineral and bone disorder, and neurocognitive function are discussed. Despite recent reports from retrospective registry data analysis and multi-center prospective studies which have significantly advanced our knowledge of CKD, and despite advances in the understanding of the pathogenesis, diagnosis and treatment of CKD much work remains to be done to improve the long term outcome of this disease.

Effects of sodium bicarbonate correction of metabolic acidosis on regional tissue oxygenation in very low birth weight neonates

OBJECTIVE

To determine the effects of sodium bicarbonate (NaHCO3) correction of metabolic acidosis on cardiopulmonary, laboratory, and cerebral, renal and splanchnic regional oxygen saturation (rSO2) and fractional tissue oxygen extraction (FTOE) in extremely premature neonates during the first postnatal week.

STUDY DESIGN

Observational cohort data were collected from 500 to 1250 g neonates who received NaHCO3 'half' corrections (0.3 * Weight (kg) * Base Deficit (mmol l(-1))) for presumed renal losses.

RESULT

Twelve subjects with normal blood pressure and heart rate received 17 NaHCO3 corrections. Mean (±s.d.) gestational age was 27±2 week and birth weight was 912±157 g. NaHCO3 corrections provided a mean (±s.d.) 4.5±1.0 ml kg(-1) fluid bolus, shifted mean (±s.d.) base deficit from 7.6±1.8 to 3.4±2.1 mmol l(-1) (P<0.05), and increased median (±s.d.) pH from 7.23±0.06 to 7.31±0.05 (P<0.05). No significant changes in blood pressure, pulse oximetry, PCO2, lactate, sodium, blood urea nitrogen, creatinine or hematocrit were observed. Cerebral, renal and splanchnic rSO2 (74%, 66% and 44%, respectively, at baseline) and FTOE (0.21, 0.29 and 0.52, respectively, at baseline) were unchanged following NaHCO3 correction.

CONCLUSION

NaHCO3 infusions decreased base deficits and increased pH though produced no discernible effects or benefits on cardiopulmonary parameters including rSO2 and FTOE. These findings warrant further prospective evaluation in larger populations with more significant metabolic acidosis to determine the utility of tissue oxygenation monitoring in differentiating metabolic acidosis due to oxygen delivery/consumption imbalance versus renal bicarbonate losses.

Anthropometric and biochemical profile of children and adolescents with chronic kidney disease in a predialysis pediatric interdisciplinary program

This is longitudinal retrospective observational cohort study that evaluated anthropometric and biochemical variables of children and adolescents admitted to a Predialysis Interdisciplinary Management Program (PDIMP) responsible for the follow-up of children and adolescents at stages 2 to 4 of chronic kidney disease (CKD) at a tertiary center. One hundred thirty-eight patients with CKD on predialysis treatment with median age at admission of 9 years and the median follow-up time of 5 years were evaluated. Seventy-four (53%) had CKD stage 3 at admission and 70 (51%) reached CKD stage 5 at the end of the follow-up. There was no significant difference between the mean initial and final hemoglobin and serum albumin. However, the final serum bicarbonate presented a significant improvement. Analyses stratified according to clinical variables of interest showed a significant improvement in body mass index (BMI) Z score, especially in the subgroup of children admitted under two years of age. In relation to stature-for-age Z score, data show a significant improvement in stature SD at the end of the study. In conclusion, the present study showed improvement of nutritional status of CKD patients and that the deterioration of renal function was not correlated with BMI-for-age Z score.

Medication adherence and growth in children with CKD

BACKGROUND AND OBJECTIVES

Poor growth is a consequence of CKD, but can often be partially or fully prevented or corrected with the use of a number of medications. The extent of nonadherence with medications used to treat or mitigate growth failure in CKD has not been examined prospectively in children with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The prevalence of both prescription of and nonadherence to recombinant human growth hormone (rhGH), phosphate binders, alkali, active vitamin D, nutritional vitamin D, iron, and erythrocyte-stimulating agents was summarized over the first seven visits of the Chronic Kidney Disease in Children cohort study. The association between self-reported nonadherence to each medication group and the mean annual change in age- and sex-specific height z score was quantified using seven separate linear regression models with generalized estimating equations.

RESULTS

Of 834 participants, 597 reported use of at least one of these medication groups and had adherence data available. Nonadherence ranged from 4% over all visits for erythrocyte-stimulating agents to 22% over all visits for nutritional vitamin D. Of the study participants, 451 contributed data to at least one of the analyses of adherence and changes in height z score. Children nonadherent to rhGH had no change in height z score, whereas those adherent to rhGH had a significant improvement of 0.16 SDs (95% confidence interval, 0.05 to 0.27); the effect size was slightly larger and remained significant after adjustment. Among participants with height≤3rd percentile and after adjustment, adherence to rhGH was associated with a 0.33 SD (95% confidence interval, 0.10 to 0.56) greater change in height z score. Nonadherence with other medication groups was not significantly associated with a change in height z score.

CONCLUSIONS

Self-reported nonadherence to rhGH was associated with poorer growth velocity in children with CKD, suggesting an opportunity for intervention and improved patient outcome.