Etiology and treatment of growth retardation in children with chronic kidney disease and end-stage renal disease: a historical perspective

Patient, Parental, and Health Professional Perspectives on Growth in Children With CKD

RATIONALE & OBJECTIVE

Growth failure is a common problem among children with chronic kidney disease (CKD). Reduced height is associated with psychosocial burden, social stigma, and impaired quality of life. This study aimed to describe the aspects of growth impairment that are most impactful from the perspectives of children with CKD, their parents, and health professionals.

STUDY DESIGN

Qualitative study.

SETTINGS & PARTICIPANTS

120 children with CKD (aged 8-21 years), 250 parents, and 445 health professionals from 53 countries participated in 16 focus groups, two consensus workshops, and a Delphi survey.

ANALYTICAL APPROACH

A thematic analysis of all qualitative data concerning growth from the Standardized Outcomes in Nephrology - Children and Adolescents (SONG-Kids) initiative.

RESULTS

We identified five themes: diminishing psychological wellbeing (compared to and judged by peers, tired of explaining to others, damaging self-esteem), constrained life participation and enjoyment (deprived of normal school experiences, excluded from sports or competing at a disadvantage, impaired quality of life in adulthood); grappling with impacts of symptoms and treatment (difficulty understanding short stature and accessing help, lack of appetite, uncertainty regarding bone pains, medication side effects, burden of growth hormone treatment); facilitating timely interventions and optimizing outcomes (early indicator of disease, assessing management, maximizing transplant outcomes, minimizing morbidity); and keeping growth and health priorities in perspective (quality of life and survival of utmost priority, achieved adequate height).

LIMITATIONS

Only English-speaking participants were included.

CONCLUSIONS

Impaired growth may diminish psychological wellbeing, self-esteem, and participation in daily activities for children with CKD. Balancing different treatments that can affect growth complicates decision-making. These findings may inform the psychosocial support needed by children with CKD and their caregivers to address concerns about growth.

Over Three Decades of Growth Hormone Treatment in Children With Chronic Kidney Disease-Associated Growth Failure Before and After Kidney Transplantation

BACKGROUND

Growth retardation and short final height is a common complication of chronic kidney disease (CKD) beginning in childhood, with profound deleterious effects on quality of life, mental health, and social achievement. Despite optimal treatments of causative factors for growth retardation in children with CKD, more than 50% of patients reach end-stage renal failure with a height >2 SD below the mean, and most do not demonstrate "catch-up" growth after receiving a kidney transplant. Four decades ago, recombinant human growth hormone (rhGH) treatment was introduced after studies showed increased growth velocity and improved height SDS in uremic subjects. Since then, an abundance of published data showed significant improvements in health-related quality of life, and most studies revealed no significant adverse effects. Clinical practice guidelines recommended rhGH treatment in CKD Stages 3-5D and after transplantation. Despite these guidelines, this therapy remained underutilized. Most commonly cited barriers to the implementation of rhGH treatment were the need for daily injections, financial challenges, physicians' unfamiliarity with guidelines, and fear of adverse events.

CONCLUSIONS

rhGH has been shown to improve growth and final height in short children with CKD, with minimal adverse effects. Despite data of its successful use generated over 3 decades, this treatment is underutilized. More judicious utilization of the treatment should emphasize educating patients, their care givers, and members of the multidisciplinary treating team. Additional studies are needed to assess the longer-term rhGH treatment in larger cohorts of patients, leading to additional supportive data and clearer recommendations.

The Role of a Clinical Psychologist in Pediatric Nephrology

Renal disease in pediatric patients tends to have a broad clinical spectrum from milder disease to severe progressive renal dysfunction requiring renal replacement therapy. Patients with chronic kidney disease (CKD) can have additional comorbidities including hypertension, diabetes, and obesity, which can add to the disease burden. The psychosocial or the mental component of the pediatric CKD patient is often overlooked by health care professionals due to a lack of resources and training in identifying psychological disorders. In addition, many components of kidney disease like fatigue from anemia and cognitive impairment make it difficult for the untrained physician to identify underlying psychological disorders. This review explores the complex psychosocial issues in patients with kidney disease and the need of more comprehensive multidisciplinary approach for treatment.

Patterns of recombinant growth hormone therapy use and growth responses among children with chronic kidney disease

BACKGROUND

Recombinant growth hormone (rGH) is an efficacious therapy for growth failure in children with chronic kidney disease (CKD). We described rGH use and estimated its relationship with growth and kidney function in the Chronic Kidney Disease in Children (CKiD) cohort.

METHODS

Participants included those with growth failure, prevalent rGH users, and rGH initiators who did not meet growth failure criteria. Among those with growth failure, height z scores and GFR were compared between rGH initiators and non-initiators across 42 months. Inverse probability weights accounted for differences in baseline variables in weighted linear regressions.

RESULTS

Among 148 children with growth failure and no previous rGH therapy, 42 (28%) initiated rGH therapy. Of the initiators, average age was 8.9 years, height z score was 2.50 standard deviations (SDs) (0.6^th percentile), and GFR was 44 ml/min/1.73m². They were compared to 106 children with growth failure who never initiated therapy (8.8 years, -2.33 SDs, and 51 ml/min/1.73m²). At 30 and 42 months after rGH, height increased +0.26 (95%CI: -0.11, +0.62) and +0.35 (95%CI: -0.17, +0.87) SDs, respectively, relative to those who did not initiate rGH. rGH was not associated with GFR.

CONCLUSIONS

Participants with growth failure receiving rGH experienced significant growth, although this was attenuated relative to RCTs, and were more likely to have higher household income and lower GFR. A substantial number of participants, predominantly boys, without diagnosed growth failure received rGH and had the highest achieved height relative to mid-parental height. Since rGH was not associated with accelerated GFR decline, increasing rGH use in this population is warranted.

Feasibility of percutaneous endoscopic gastrostomy insertion in children receiving peritoneal dialysis

BACKGROUND

Peritoneal dialysis (PD) is the preferred dialysis modality for paediatric patients with end-stage kidney disease. Frequently, malnutrition is encountered. Percutaneous endoscopic gastrostomy (PEG) is the preferred mode of feeding because of its minimal invasive mode of placement and easy handling in daily life. However, reports of a high risk for early post-interventional peritonitis hampered this procedure during PD and controlled studies on the benefit of peri-interventional management to prevent peritonitis are lacking. Here, we report the safety profile of PEG insertion among a cohort of children on PD by using a prophylactic antibiotic and antifungal regimen as well as modification of the PD programme.

METHODS

We performed a single-centre analysis of paediatric PD patients receiving PEG placement between 2015 and 2020. Demographic data, peri-interventional prophylactic antibiotic and antifungal treatment as well as modification of the PD programme were gathered and the incidence of peritonitis within a period of 28 days after PEG was calculated.

RESULTS

Eight PD patients (median weight 6.7 kg) received PEG insertion. Antibiotic and antifungal prophylaxis were prescribed for median time of 4.0 and 5.0 days, respectively. After individual reduction of PD intensity, all patients continued their regular PD programme after a median of 6 days. One patient developed peritonitis within 24 h after PEG insertion and simultaneous surgery for hydrocele.

CONCLUSIONS

Applying an antibiotic and antifungal prophylactic regime as well as an adapted PD programme may reduce the risk for peritonitis in paediatric PD patients who receive PEG procedure.

Ultrasound-Based Renal Parenchymal Area and Kidney Function Decline in Infants With Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract are the leading cause of chronic kidney disease in children. Noninvasive imaging biomarkers that predict chronic kidney disease progression in early infancy are needed. We performed a pilot study nested in the prospective Chronic Kidney Disease in Children cohort study to determine the association between renal parenchymal area (RPA) on first post-natal renal ultrasound and change in estimated glomerular filtration rate (eGFR) in children with congenital anomalies of the kidney and urinary tract. Among 14 participants, 78.6% were males, the median age at the time of the ultrasound was 3.4 months (interquartile range, 1.3-7.9 mo), and the median total RPA z-score at baseline was -1.01 (interquartile range, -2.39 to 0.52). After a median follow-up period of 7.4 years (interquartile range, 6.8-8.2 y), the eGFR decreased from a median of 49.4 mL/min per 1.73 m2 at baseline to 29.4 mL/min per 1.73 m2, an annual eGFR percentage decrease of -4.68%. Lower RPA z-scores were correlated weakly with a higher annual decrease in eGFR (Spearman correlation, 0.35; 95% confidence interval, -0.25 to 0.76). This pilot study shows the feasibility of obtaining RPA from a routine ultrasound and suggests that a lower baseline RPA may be associated with a greater decrease in eGFR over time. Further studies with larger patient cohorts are needed to confirm this association.

Kidney Outcomes and Hypertension in Survivors of Wilms Tumor: A Prospective Cohort Study

OBJECTIVE

To assess the prevalence of therapy-related kidney outcomes in survivors of Wilms tumor (WT).

STUDY DESIGN

This prospective cohort study included survivors of WT who were ≥5 years old and ≥1 year from completing therapy, excluding those with preexisting hypertension, prior dialysis, or kidney transplant. Participants completed 24-hour ambulatory blood pressure monitoring (ABPM). Abnormal blood pressure (BP) was defined as ≥90th percentile. Masked hypertension was defined as having normal office BP and abnormal ABPM findings. Urine was analyzed for kidney injury molecule-1, interleukin-18, epidermal growth factor, albumin, and creatinine. The estimated glomerular filtration rate (eGFR) was calculated using the bedside chronic kidney disease in children equation. Recent kidney ultrasound examinations and echocardiograms were reviewed for contralateral kidney size and left ventricular hypertrophy, respectively. Clinical follow-up data were collected for approximately 2 years after study enrollment.

RESULTS

Thirty-two participants (median age, 13.6 years [IQR, 10.5-16.3 years]; 75% stage 3 or higher WT) were evaluated at a median of 8.7 years (IQR, 6.5-10.8 years) after therapy; 29 participants underwent unilateral radical nephrectomy, 2 bilateral partial nephrectomy, and 1 radical and contralateral partial nephrectomy. In this cohort, 72% received kidney radiotherapy and 75% received doxorubicin. Recent median eGFR was 95.6 mL/min/1.73 m² (IQR, 84.6-114.0; 11 [34%] had an eGFR of <90 mL/min/1.73 m²). Abnormal ABPM results were found in 22 of 29 participants (76%), masked hypertension in 10 of 29 (34%), and microalbuminuria in 2 of 32 (6%). Of the 32 participants, 22 (69%) had abnormal epidermal growth factor; few had abnormal kidney injury molecule-1 or interleukin-18. Seven participants with previous unilateral nephrectomy lacked compensatory contralateral kidney hypertrophy. None had left ventricular hypertrophy.

CONCLUSIONS

In survivors of WT, adverse kidney outcomes were common and should be closely monitored.

SOCS2 Silencing Improves Somatic Growth without Worsening Kidney Function in CKD

BACKGROUND

Growth hormone (GH) resistance in CKD is partly due to increased expression of SOCS2, a GH signaling negative regulator. In SOCS2 absence, body growth is exaggerated. However, GH overexpression in mice causes glomerulosclerosis. Accordingly, we tested whether lack of SOCS2 improves body growth, but accelerates kidney damage in CKD.

METHODS

Eight-week-old mutant SOCS2-deficient high growth (HG) and normal wild-type mice (N) underwent 5/6 nephrectomy (CKD) or sham operation (C) and were sacrificed after 12 weeks, generating 4 groups: C-N, C-HG, CKD-N, CKD-HG.

RESULTS

Somatic growth, inhibited in CKD-N, increased significantly in CKD-HG. Liver p-STAT5, a key intracellular signal of GH receptor (GHR) activation, was decreased in CKD-N but not in CKD-HG. Serum Cr as well as histopathological scores of renal fibrosis were similar in both CKD groups. Kidney fibrogenic (TGF-β and collagen type IV mRNA) and inflammatory precursors (IL6, STAT3, and SOCS3 mRNA) were similarly increased in C-HG, CKD-HG, and CKD-N versus C-N. Renal GHR mRNA was decreased in C-HG, CKD-HG, and CKD-N versus C-N. Kidney p-STAT5 was decreased in CKD-N but not elevated in CKD-HG.

CONCLUSIONS

CKD-related growth retardation is overcome by SOCS2 silencing, in association with increased hepatic STAT5 phosphorylation. Renal insufficiency is not worsened by SOCS2 absence, as kidney GHR and STAT5 are not upregulated. This may be due to elevated kidney proinflammatory cytokines and their mediators, phospho-STAT3 and SOCS3, which may counteract for the absence in SOCS2 and explain the renal safety of prolonged GH therapy in CKD.

Growth characterization in a cohort of renal allograft recipients

INTRODUCTION

Growth retardation is a common problem in children with CKD. This study aims to describe growth, prevalence of short stature before RTx, catch-up growth after RTx, and associated factors.

METHODS

We retrospectively reviewed 74 renal allograft recipients who underwent RTx at Fundación Cardioinfantil, Colombia, between January 2008 and September 2016 with follow-up for 2 years afterwards. Pre-RTx Height_SDS and demographic characteristics were compared between children with normal and short stature. Post-RTx Height_SDS at 1 and 2 years post-RTx and FAH, when available, were retrieved. Children were classified into catch-up growth and no catch-up growth groups depending on whether or not Height_SDS increased ≥0.5 per year within the first 2 years post-RTx. Possible associated factors were compared.

RESULTS

Seventy-four patients were included. Mean age at RTx was 11 ± 4.0 years, and 43.2% (32/74) were females. Mean Height_SDS for the entire study population at pre-RTx was -2.8 ± 1.5. Before RTx, 68.9% (51/74) had short stature, and 44.6% (33/74) had severe short stature. 37.2% presented catch-up growth post-RTx. Time on dialysis was associated with short pre-RTx stature (OR 1.66; 95% CI [1.15-2.39]; P = .006) and catch-up growth (OR 2.15; 95% CI [1.15-3.99]; P = .016). 44.59% (33/74) reached FAH, and 48.4% (16/33) presented short FAH.

CONCLUSIONS

Growth continues to be suboptimal after RTx. Given that pre-RTx height is a significantly associated factor, it is important to plan early interventions in terms of growth improvement in these children.

Growth plate alterations in chronic kidney disease

Growth retardation is a major feature of chronic kidney disease (CKD) of onset in infants or children and is associated with increased morbidity and mortality. Several factors have been shown to play a causal role in the growth impairment of CKD. All these factors interfere with growth by disturbing the normal physiology of the growth plate of long bones. To facilitate the understanding of the pathogenesis of growth impairment in CKD, this review discusses cellular and molecular alterations of the growth plate during uremia, including structural and dynamic changes of chondrocytes, alterations in their process of maturation and hypertrophy, and disturbances in the growth hormone signaling pathway.

Mental health and psychosocial adjustment in pediatric chronic kidney disease derived from the KNOW-Ped CKD study

BACKGROUND

Psychosocial development of pediatric chronic kidney disease (CKD) patients is substantially affected due to growth retardation, frequent school absences, and difficulties engaging in normal peer relationship activities. While many studies focus on specific issues such as depression, anxiety, or neurocognitive function, few evaluate prevalence of various types of mental health and psychosocial adjustment problems among children with CKD. This study aimed to investigate these within the KoreaN cohort study for Outcomes in patients With Pediatric Chronic Kidney Disease (KNOW-Ped CKD).

METHODS

One hundred sixty-six subjects who completed the Korean-Child Behavioral Checklist (K-CBCL) were included. The clinical group comprised subjects with scores indicating psychosocial adjustment or mental health problems using the T scores for the 14 subscales of the K-CBCL. We analyzed associations between mental health or adjustment problems in pediatric CKD and each variable.

RESULTS

Mean age was 11.1 (± 3.9) years, number of males was 117 (70.5%), and 20.5% and 22.3% of children had significant mental health problems and psychosocial adjustment problems, respectively. Overall, 33.1% were assigned to the clinical group, and exhibited short stature and higher rates of preterm birth history compared to the non-clinical group. Subjects with adjustment problems had higher comorbidities such as CNS disease, developmental delay, cardiovascular disease, and multi-organ involvement. Logistic regression analysis revealed preterm birth and developmental delay correlated highly with clinical group.

CONCLUSIONS

A significant proportion of children and adolescents with CKD experience mental health and adjustment problems. In particular, patients with developmental delay or preterm birth history require screening and targeted follow-up.

Assessment of prophylactic heparin infusion as a safe preventative measure for thrombotic complications in pediatric kidney transplant recipients weighing <20 kg

Small-sized kidney recipients (<20 kg) are at high risk of allograft vessel thrombosis. HP has been used to mitigate this risk but may infer an increase in bleeding risks. Therefore, we aim to determine whether HP is a safe means to prevent thrombosis in small kidney transplant patients by comparing those who have received HP and those who have NHP. A retrospective review of patients < 20 kg who underwent kidney transplant in our institution from 2000 to 2015 was performed. At our institution, unfractionated heparin 10 units/kg/hour is used as HP since 2009. Patients at increased risk of thrombosis (previous thrombosis, thrombophilia, nephrotic syndrome) and bleeding (therapeutic doses of heparin, diagnosis of coagulopathy) were excluded. Fifty-six patients were identified (HP n = 46; NHP n = 10). Baseline demographics were similar between HP and NHP. There was no statistical difference in frequency of transfusions, surgical re-exploration, or thrombotic events between HP and NHP. The HP group was more likely to have drop in Hb > 20 g/L (67.4% vs 30.0%, P = 0.038), and those who had drop in Hb > 20 g/L were more likely to also require pRBC transfusions (63.0% vs 20.0%, P = 0.017). Within the HP group, those who had bleeding complications had similar Hb levels as those who did not at baseline and post-transplant. Outcomes in the HP and NHP groups were no different with respect to thrombosis or significant bleeding complications requiring pRBC transfusions or surgical intervention. Future prospective studies are required to investigate the balance of preventing thrombosis and risks of pRBC transfusions for small-sized kidney recipients.

Estimated kidney function in children and young adults with spina bifida: A retrospective cohort study

AIMS

Current estimated glomerular filtration rate (eGFR) equations may be inaccurate in patients with spina bifida (SB) because of reduced muscle mass and stature. Cross-sectional and longitudinal variability of eGFR were analyzed in these patients across multiple equations, hypothesizing greater variability in creatinine-based than cystatin-C (Cys-C)-based equations.

METHODS

This retrospective cohort study included children (age, 1-17.9 years) and adults (≥18 years) with SB from 2002-2017 at a large SB clinic. Those without all data needed to calculate eGFR were excluded. Four pediatric and three adult eGFR equations were compared for cross-sectional outcomes of eGFR and elevated office blood pressures using chronic kidney disease (CKD) stage classification, and for longitudinal outcome of eGFR slope over time using covariance pattern models accounting for repeated measures.

RESULTS

One hundred and eighty two children and 75 adults had greater than or equal to 1 set of data measurements; 118 and 52, respectively, had greater than or equal to 2 sets. The pediatric bedside Schwartz equation had the highest median eGFR and coefficient of variation. CKD stage classification by eGFR showed large differences across equations in children, with rates of eGFR < 60 and <90 ml/min/1.73 m² ranging from 2%-9% and 5%-69%, respectively. Only one equation showed a significant inverse association between eGFR and blood pressure. Longitudinally, eGFR slopes over time were different across pediatric equations (P < .001) but not adult equations. The bedside Schwartz equation had a positive eGFR slope; the other Cys-C-containing equations had negative slopes.

CONCLUSIONS

Creatinine-based equations in children with SB vary considerably from cystatin-C-containing equations in calculating both single point-in-time eGFR values and eGFR trends over time.

Urologic care and progression to end-stage kidney disease: a Chronic Kidney Disease in Children (CKiD) nested case-control study

INTRODUCTION

Children with chronic kidney disease (CKD) risk progressing to end-stage kidney disease (ESKD). The majority of CKD causes in children are related to congenital anomalies of the kidney and urinary tract, which may be treated by urologic care.

OBJECTIVE

To examine the association of ESKD with urologic care in children with CKD.

STUDY DESIGN

This was a nested case-control study within the Chronic Kidney Disease in Children (CKiD) prospective cohort study that included children aged 1-16 years with non-glomerular causes of CKD. The primary exposure was prior urologic referral with or without surgical intervention. Incidence density sampling matched each case of ESKD to up to three controls on duration of time from CKD onset, sex, race, age at baseline visit, and history of low birth weight. Conditional logistic regression analysis was performed to estimate rate ratios (RRs) for the incidence of ESKD.

RESULTS

Sixty-six cases of ESKD were matched to 153 controls. Median age at baseline study visit was 12 years; 67% were male, and 7% were black. Median follow-up time from CKD onset was 14.9 years. Seventy percent received urologic care, including 100% of obstructive uropathy and 96% of reflux nephropathy diagnoses. Cases had worse renal function at their baseline visit and were less likely to have received prior urologic care. After adjusting for income, education, and insurance status, urology referral with surgery was associated with 50% lower risk of ESKD (RR 0.50 [95% confidence interval [CI] 0.26-0.997), compared to no prior urologic care (Figure). After excluding obstructive uropathy and reflux nephropathy diagnoses, which were highly correlated with urologic surgery, the association was attenuated (RR 0.72, 95% CI 0.24-2.18).

DISCUSSION

In this study, urologic care was commonly but not uniformly provided to children with non-glomerular causes of CKD. Underlying specific diagnoses play an important role in both the risk of ESKD and potential benefits of urologic surgery.

CONCLUSION

Within the CKiD cohort, children with non-glomerular causes of CKD often received urologic care. Urology referral with surgery was associated with lower risk of ESKD compared to no prior urologic care but depended on specific underlying diagnoses.

A Cross-Sectional Study of Growth and Metabolic Bone Disease in a Pediatric Global Cohort Undergoing Chronic Hemodialysis

OBJECTIVE

We sought to assess worldwide differences among pediatric patients undergoing hemodialysis. Because practices differ widely regarding nutritional resources, treatment practice, and access to renal replacement therapy, investigators from the Pediatric Investigation and Close Collaboration to examine Ongoing Life Outcomes, the pediatric subset of the MONitoring Dialysis Outcomes Cohort (PICCOLO MONDO) performed this cross-sectional study. We hypothesized that growth would be better in developed countries, possibly at the expense of bone mineral disease.

STUDY DESIGN

In this cross-sectional study, we analyzed growth by height z score and recommended age-specific bone mineral metabolism markers from 225 patients <18 years of age maintained on hemodialysis, between the years of 2000 to 2012 from 21 countries in different regions.

RESULTS

The patients' median age was 16 (IQR 14-17) years, and 45% were females. A height z score less than the third percentile was noted in 34% of the cohort, whereas >66% of patients reported normal heights, with patients from North America having the greatest proportion (>80%). More than 70% of the entire cohort had greater than the age-recommended levels of phosphorus, particularly in the Asia-Pacific and North America, where we also observed the greatest body mass index z score (0.99 ± 1.6) and parathyroid hormone levels (557.1 [268.4-740.5]). Below-recommended parathyroid hormone levels were noted in 26% and elevated levels in 61% of the entire sample, particularly in the Asia Pacific region. Lower-than-recommended calcium levels were noted in 36% of the entire cohort, particularly in Latin America.

CONCLUSIONS

We found regional differences in growth- and age-adjusted bone mineral metabolism markers. Children from North America had the best growth, received the most dialysis, but also had the worst phosphate control and body mass index z scores.

Skeletal manifestations of renal disease in childhood

PURPOSE OF REVIEW

This review summarizes recent findings on musculoskeletal health in three chronic renal conditions of childhood: chronic kidney disease stages 2-5D, nephrotic syndrome, and urolithiasis. Findings with important clinical implications warranting further investigation are highlighted.

RECENT FINDINGS

Recent cohort studies have demonstrated a high burden of fracture and progressive deficits of cortical bone in children with chronic kidney disease. Lower cortical density is associated with incident fracture and may be an important therapeutic target. Parathyroid hormone and calcium are independent correlates of cortical density, and modifiable factors for fracture include parathyroid hormone and phosphate binder use. Children with nephrotic syndrome, even with normal renal function, have evidence of abnormal bone metabolism and structure, and vitamin D deficiency may be an important modifiable risk factor in this population. Urolithiasis has been associated with reduced bone mineral density and is increasingly common in children and adolescents. Population-based data found a significantly increased risk of fracture in adolescent males and young women.

SUMMARY

Recent findings substantiate concern regarding the particular vulnerability of the growing skeleton to chronic renal disease. Studies are needed to determine how to optimize assessment and management of bone health in children with these conditions, particularly in terms of calcium and vitamin D requirements, with the goal of improving childhood bone accrual for lifelong fracture prevention.

Validity of self-reported weight and height: a cross-sectional study among Malaysian adolescents

Background

Self-reported weight and height are commonly used in lieu of direct measurements of weight and height in large epidemiological surveys due to inevitable constraints such as budget and human resource. However, the validity of self-reported weight and height, particularly among adolescents, needs to be verified as misreporting could lead to misclassification of body mass index and therefore overestimation or underestimation of the burden of BMI-related diseases. The objective of this study was to determine the validity of self-reported weight and height among Malaysian secondary school children.

Methods

Both self-reported and directly measured weight and height of a subgroup of 663 apparently healthy schoolchildren from the Malaysian Adolescent Health Risk Behaviour (MyAHRB) survey 2013/2014 were analysed. Respondents were required to report their current body weight and height via a self-administrative questionnaire before they were measured by investigators. The validity of self-reported against directly measured weight and height was examined using intraclass correlation coefficient (ICC), the Bland-Altman plot and weighted Kappa statistics.

Results

There was very good intraclass correlation between self-reported and directly measured weight [r = 0.96, 95% confidence interval (CI): 0.93, 0.97] and height (r = 0.94, 95% CI: 0.90, 0.96). In addition the Bland-Altman plots indicated that the mean difference between self-reported and direct measurement was relatively small. The mean difference (self-reported minus direct measurements) was, for boys: weight, −2.1 kg; height, −1.6 cm; BMI, −0.44 kg/m² and girls: weight, −1.2 kg; height, −0.9 cm; BMI, −0.3 kg/m². However, 95% limits of agreement were wide which indicated substantial discrepancies between self-reported and direct measurements method at the individual level. Nonetheless, the weighted Kappa statistics demonstrated a substantial agreement between BMI status categorised based on self-reported weight and height and the direct measurements (kappa = 0.76, 95% CI: 0.67, 0.84).

Conclusion

Our results show that the self-reported weight and height were consistent with direct measurements and therefore can be used in assessing the nutritional status of Malaysian school children from the age of 13 to 17 years old in epidemiological studies and for surveillance purposes when direct measurements are not feasible, but not for assessing nutritional status at the individual level.

Bayesian joint modeling for assessing the progression of chronic kidney disease in children

Joint models are rich and flexible models for analyzing longitudinal data with nonignorable missing data mechanisms. This article proposes a Bayesian random-effects joint model to assess the evolution of a longitudinal process in terms of a linear mixed-effects model that accounts for heterogeneity between the subjects, serial correlation, and measurement error. Dropout is modeled in terms of a survival model with competing risks and left truncation. The model is applied to data coming from ReVaPIR, a project involving children with chronic kidney disease whose evolution is mainly assessed through longitudinal measurements of glomerular filtration rate.

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.

Impact of Pediatric Chronic Dialysis on Long-Term Patient Outcome: Single Center Study

Objective. Owing to a shortage of kidney donors in Israel, children with end-stage renal disease (ESRD) may stay on maintenance dialysis for a considerable time, placing them at a significant risk. The aim of this study was to understand the causes of mortality. Study Design. Clinical data were collected retrospectively from the files of children on chronic dialysis (>3 months) during the years 1995–2013 at a single pediatric medical center. Results. 110 patients were enrolled in the study. Mean age was 10.7 ± 5.27 yrs. (range: 1 month–24 yrs). Forty-five children (42%) had dysplastic kidneys and 19 (17.5%) had focal segmental glomerulosclerosis. Twenty-five (22.7%) received peritoneal dialysis, 59 (53.6%) hemodialysis, and 6 (23.6%) both modalities sequentially. Median dialysis duration was 1.46 years (range: 0.25–17.54 years). Mean follow-up was 13.5 ± 5.84 yrs. Seventy-nine patients (71.8%) underwent successful transplantation, 10 (11.2%) had graft failure, and 8 (7.3%) continued dialysis without transplantation. Twelve patients (10.9%) died: 8 of dialysis-associated complications and 4 of their primary illness. The 5-year survival rate was 84%: 90% for patients older than 5 years and 61% for younger patients. Conclusions. Chronic dialysis is a suitable temporary option for children awaiting renal transplantation. Although overall long-term survival rate is high, very young children are at high risk for life-threatening dialysis-associated complications.

Fracture Burden and Risk Factors in Childhood CKD: Results from the CKiD Cohort Study

Childhood chronic kidney disease (CHD) poses multiple threats to bone accrual; however, the associated fracture risk is not well characterized. This prospective cohort study included 537 CKD in Children (CKiD) participants. Fracture histories were obtained at baseline, at years 1, 3, and 5 through November 1, 2009, and annually thereafter. We used Cox regression analysis of first incident fracture to evaluate potential correlates of fracture risk. At enrollment, median age was 11 years, and 16% of patients reported a prior fracture. Over a median of 3.9 years, 43 males and 24 females sustained incident fractures, corresponding to 395 (95% confidence interval [95% CI], 293-533) and 323 (95% CI, 216-481) fractures per 10,000 person-years, respectively. These rates were 2- to 3-fold higher than published general population rates. The only gender difference in fracture risk was a 2.6-fold higher risk in males aged ≥15 years (570/10,000 person-years, adjusted P=0.04). In multivariable analysis, advanced pubertal stage, greater height Z-score, difficulty walking, and higher average log-transformed parathyroid hormone level were independently associated with greater fracture risk (all P≤0.04). Phosphate binder treatment (predominantly calcium-based) was associated with lower fracture risk (hazard ratio, 0.37; 95% CI, 0.15-0.91; P=0.03). Participation in more than one team sport was associated with higher risk (hazard ratio, 4.87; 95% CI, 2.21-10.75; P<0.001). In conclusion, children with CKD have a high burden of fracture. Regarding modifiable factors, higher average parathyroid hormone level was associated with greater risk of fracture, whereas phosphate binder use was protective in this cohort.

Calculating the Rate of Senescence From Mortality Data: An Analysis of Data From the ERA-EDTA Registry

The rate of senescence can be inferred from the acceleration by which mortality rates increase over age. Such a senescence rate is generally estimated from parameters of a mathematical model fitted to these mortality rates. However, such models have limitations and underlying assumptions. Notably, they do not fit mortality rates at young and old ages. Therefore, we developed a method to calculate senescence rates from the acceleration of mortality directly without modeling the mortality rates. We applied the different methods to age group-specific mortality data from the European Renal Association-European Dialysis and Transplant Association Registry, including patients with end-stage renal disease on dialysis, who are known to suffer from increased senescence rates (n = 302,455), and patients with a functioning kidney transplant (n = 74,490). From age 20 to 70, senescence rates were comparable when calculated with or without a model. However, when using non-modeled mortality rates, senescence rates were yielded at young and old ages that remained concealed when using modeled mortality rates. At young ages senescence rates were negative, while senescence rates declined at old ages. In conclusion, the rate of senescence can be calculated directly from non-modeled mortality rates, overcoming the disadvantages of an indirect estimation based on modeled mortality rates.

Growth hormone therapy in children with chronic renal failure

Growth is impaired in a chronic renal failure. Anemia, acidosis, reduced intake of calories and protein, decreased synthesis of vitamin D and increased parathyroid hormone levels, hyperphosphatemia, renal osteodystrophy and changes in growth hormone-insulin-like growth factor and the gonadotropin-gonadal axis are implicated in this study. Growth is adversely affected by immunosuppressives and corticosteroids after kidney transplantation. Treating metabolic disorders using the recombinant human growth hormone is an effective option for patients with inadequate growth rates.

Growth impairment in children with pre-dialysis chronic kidney disease in Japan

BACKGROUND

Growth impairment is a major complication of chronic kidney disease (CKD) in children. However, no cohort studies have examined the growth of Asian children with pre-dialysis CKD.

METHODS

We sent cross-sectional surveys to 113 Japanese medical institutions that were treating 447 children with CKD stages 3-5 in 2010 and 2011. Of 447 children included in our survey conducted in 2010, height and CKD stage were evaluable for 297 children in 2011, and height standard deviation score (height SDS) was calculated in these children.

RESULTS

Height SDS decreased with increasing CKD stage (P < 0.001) in boys and girls. Height SDS also decreased significantly with increasing CKD stage among patients with congenital anomalies of the kidney and urinary tract (P < 0.001). Risk factors for growth impairment included CKD stages 4 and 5 (relative to stage 3), being small-for-date, and asphyxia at birth. Among children with a height SDS ≤-2.0, growth hormone was used in 19.5, 31.0, and 25.0 % of children with CKD stages 3, 4, and 5, respectively.

CONCLUSIONS

This prospective cohort study revealed marked growth impairment in Japanese children with CKD stages 3-5 relative to healthy children. CKD-related risk factors for growth impairment included advanced CKD (stages 4 and 5), being small-for-date, and asphyxia at birth. Growth hormone was infrequently used in this cohort of children with pre-dialysis CKD.

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.

Growth, chronic kidney disease and pediatric kidney transplantation: is it useful to use recombinant growth hormone in Colombian children with renal transplant?

Kidney transplantation has become the best treatment for children with chronic kidney disease (CKD). In recent times, knowledge concerning the effect of CKD and kidney transplantation over the normal growth rate has increased; now it is known that 40% of children with CKD do not reach the expected height for age. Growth retardation has been associated with the type of nephropathy, metabolic and endocrine disorders that are secondary to kidney disease, immunosuppressive therapy with glucocorticoids, and suboptimal function of renal allograft. Nowadays, we know better the role of the growth hormone/insulin-like growth factor 1 axis in growth retardation we can see it in children with CKD or recipients of renal allograft. Several studies have shown that administration of recombinant growth hormone (rhGH) has a positive effect on the longitudinal growth of children and teenagers who have received a kidney transplant. On the other hand, there have been reported side effects associated with using rhGH; however, these are not statistically significant. In this article, we show a small review about growth in children with CKD and/or recipients of renal allografts the growth pattern of three children who were known by the Transplant Group of National University of Colombia, and the results obtained with the use of rhGH in one of these cases. We want to show the possibility of achieving a secure use of rhGH in children with CKD and its use as a therapeutic option for treating the growth retardation in children with kidney transplantation, and set out the need of typifying the growth pattern of Colombian children with CKD and/or who are recipients of renal allografts through multicenter studies to propose and analyze the inclusion of rhGH in the therapeutic scheme of Colombian children with these two medical conditions. rhGH could be a useful tool for treating children with CKD or kidney transplantation who have not reached the expected longitudinal growth for age. However, it is necessary to know the growth pattern standards for Colombian children with CKD or kidney transplant in Bogotá-Colombia to include the rhGH in clinical protocols for treatment of these patients.

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.

Growth hormone, insulin-like growth factor-1, and the kidney: pathophysiological and clinical implications

Besides their growth-promoting properties, GH and IGF-1 regulate a broad spectrum of biological functions in several organs, including the kidney. This review focuses on the renal actions of GH and IGF-1, taking into account major advances in renal physiology and hormone biology made over the last 20 years, allowing us to move our understanding of GH/IGF-1 regulation of renal functions from a cellular to a molecular level. The main purpose of this review was to analyze how GH and IGF-1 regulate renal development, glomerular functions, and tubular handling of sodium, calcium, phosphate, and glucose. Whenever possible, the relative contributions, the nephronic topology, and the underlying molecular mechanisms of GH and IGF-1 actions were addressed. Beyond the physiological aspects of GH/IGF-1 action on the kidney, the review describes the impact of GH excess and deficiency on renal architecture and functions. It reports in particular new insights into the pathophysiological mechanism of body fluid retention and of changes in phospho-calcium metabolism in acromegaly as well as of the reciprocal changes in sodium, calcium, and phosphate homeostasis observed in GH deficiency. The second aim of this review was to analyze how the GH/IGF-1 axis contributes to major renal diseases such as diabetic nephropathy, renal failure, renal carcinoma, and polycystic renal disease. It summarizes the consequences of chronic renal failure and glucocorticoid therapy after renal transplantation on GH secretion and action and questions the interest of GH therapy in these conditions.

Effect of growth hormone on plasminogen activator and inhibitor activity in rat

Growth retardation is one of the significant changes in chronic kidney disease (CKD) and is associated with increased morbidity and mortality. Disturbances in growth hormone (GH) are held responsible for several complications in CKD. GH is a protein based peptide hormone which directly or indirectly regulates renal functions to ensure homeostasis. We investigated the effects of growth hormone on plasminogen activators (PA) in rat kidney, PA and plasminogen activator inhibitor (PAI), glucose and fibrinogen in plasma and serum lipid profile. Rats were injected daily with 250 mU GH kg-1 body weight subcutaneously for one week. Growth hormone treatment increased PA activity significantly in rat kidneys as compared to controls. No changes were seen in PA, PAI and fibrinogen levels in the plasma of two groups of rats. There was significant decrease in plasma glucose, total cholesterol and LDL-cholesterol levels in serum of treated group resulting in the decrease of HDL/LDL and total cholesterol/cholesterol ratios. However, triglycerides and VLDL showed significant higher activity in the serum of treated group as compared to controls. Our data suggests that GH administration might improve renal function by increasing PA activity in kidney as well as by reducing the cholesterol content in blood. GH may be effective in improving growth failure as it helps to maintain the normal homeostatic balance.

Factors affecting growth and final adult height after pediatric renal transplantation

BACKGROUND

Growth retardation is a common problem for children with chronic kidney disease. Although renal transplantation (RTx) resolves endocrine metabolic and uremic disturbances, growth continues to be suboptimal. This study aims to describe changes in height from diagnosis to final adult height (FAH) in Korean renal allograft recipients and determine factors associated with posttransplantation growth.

METHODS

We retrospectively reviewed 63 renal allograft recipients who underwent RTx at <15 years of age with regular follow-up for >3 years afterwards. Pre- and post-RTx growth was analyzed by height Z scores (Ht_Z) at RTx, 2 and 5 years follow-up, and at FAH.

RESULTS

Ht_Z decreased from diagnosis to dialysis by -0.8 (P = .009) and from dialysis to RTx by -0.46 (P < .001). The mean baseline Ht_Z at RTx was -1.62 ± 1.36. The change in Ht_Z at 2 and 5 years after transplantation was 0.68 ± 0.88 and 0.48 ± 0.86, respectively. Both variables were negatively correlated with baseline age at RTx. Mean FAH was -1.22 ± 1.11 and was positively correlated with baseline height at RTx. Height at start of dialysis and dialysis duration were significant determinants of baseline height at RTx (P < .001).

CONCLUSIONS

Although there is significant posttransplant catch-up growth among younger recipients and among those with greater baseline height deficit, catch-up growth is not sustained and greater FAH is attained in those who are taller at RTx. Achieving greater height before dialysis and decreasing dialysis duration leads to maximal height at RTx as well as greater FAH.

Longitudinal growth on an everolimus- versus an MMF-based steroid-free immunosuppressive regimen in paediatric renal transplant recipients

Concerns have been raised that mammalian target of rapamycin inhibitors in pediatric transplant recipients might interfere with longitudinal bone growth by inhibition of growth factor signaling and growth plate chondrocyte proliferation. We therefore undertook a prospective nested, case-control study on longitudinal growth over 2 years in steroid-free pediatric renal transplant recipients. Fourteen patients on a steroid-free maintenance immunosuppressive regimen consisting of low-dose everolimus (EVR) in conjunction with low-dose cyclosporine (CsA) were compared to a matched cohort of 14 steroid-free patients on a standard dose mycophenolate mofetil (MMF) regimen in conjunction with a standard dose calcineurin inhibitor (CNI). The mean change in height standard deviation (SD) score in the first study year was 0.31 ± 0.71 SD score in the EVR group compared to 0.31 ± 0.64 SD score in the MMF group (P = 0.20). For the entire study period of 2 years, the change in height SD score in the EVR group was 0.43 ± 0.81 SDS compared to 0.75 ± 0.85 SDS in the MMF group (P = 0.32). The percentage of prepubertal patients experiencing catch-up growth, defined as an increase in height SD score ≥0.5 in 2 years, was similar in the EVR group (5/8, 65%) and the MMF group (6/8, 75%; P = 1.00). Longitudinal growth over 2 years in steroid-free pediatric patients on low-dose EVR and CsA is not different to that of a matched steroid-free control group on an immunosuppressive regimen with standard-dose CNI and MMF. Hence, low-dose EVR does not appear to negatively impact short-term growth in pediatric renal transplant recipients.

Final adult height in kidney recipients who underwent highly successful transplantation as children: a single-center experience

BACKGROUND

Achieving a normal final adult height (FH) remains a challenge in the field of pediatric kidney transplantation (KTx). To examine the optimal approach to assuring normal FH following KTx, we retrospectively examined the post-transplant growth and FH of pediatric KTx recipients.

METHODS

Since the relevant factors affecting the FH of children following KTx are multifactorial and notably complex, KTx recipients with persistent good graft function and successful steroid minimization until FH attainment were selected for this study.

RESULTS

Thirteen patients were enrolled in this study. The mean estimated glomerular filtration rate was 72.1 ± 15.3 ml/min/1.73 m(2), and the mean corticosteroid dose was 0.05 ± 0.05 mg/kg on alternate days at the time of FH attainment. Despite highly successful KTx, four (30.8 %) patients (one who underwent KTx before puberty and three during puberty) showed a decrease in the height standard deviation score (hSDS) from the time of KTx until FH attainment. Moreover, of these, two male patients had an FH with an SD <-2.

CONCLUSION

FH remained suboptimal despite highly successful KTx. Not only highly successful KTx but also further treatment such as steroid avoidance, early steroid withdrawal or using rhGH might be necessary to assure a normal FH in some pubertal patients.

Skeletal effects and growth in children with chronic kidney disease: a 5-year prospective study

This study was designed to follow the evolving process of growth, bone modeling and remodeling in children with chronic kidney disease (CKD) who are at risk of developing CKD-mineral bone disorder (CKD-MBD). Fifteen patients, 4-15 years, were included with a median glomerular filtration rate of 46 (range 12-74) mL/min/1.73 m(2). Growth, bone mineral density (BMD) and markers of bone and mineral metabolism were investigated over a 5-year period. The median height standard deviation score was -0.65 at the start and 0.1 after 5 years, with a range from -1.7 to 1.7, which implies that growth was acceptable. Total body, femoral neck, and lumbar spine BMD increased over the study period (p < 0.0001). None had total body BMD Z-scores and lumbar spine Z-scores below -2.0 at follow-up. Most bone markers were within the reference intervals, but the formation markers of alkaline phosphatase and type I procollagen intact amino-terminal propeptide (PINP) were slightly increased in about one-third of the patients after 5 years. Eleven out of 15 CKD patients had increased parathyroid hormone levels at baseline and 10 patients after 5 years had increased parathyroid hormone levels. Taken together, this is the first 5-year longitudinal study of skeletal effects, growth and bone turnover in children with CKD. Growth and BMD Z-scores were well preserved on a group basis; however, these parameters varied significantly on an individual basis. We suggest, therefore, that it is difficult to state an overall recommendation and growth, bone mass, and markers of bone and mineral metabolism should be monitored and treated individually in CKD children.

Growth retardation in children with kidney disease

Growth failure is almost inextricably linked with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Growth failure in CKD has been associated with both increased morbidity and mortality. Growth failure in the setting of kidney disease is multifactorial and is related to poor nutritional status as well as comorbidities, such as anemia, bone and mineral disorders, and alterations in hormonal responses, as well as to aspects of treatment such as steroid exposure. This review covers updated management of growth failure in these children including adequate nutrition, treatment of metabolic alterations, and early administration of recombinant human growth hormone (GH).

The consequences of chronic kidney disease on bone metabolism and growth in children

Growth retardation, decreased final height and renal osteodystrophy (ROD) are common complications of childhood chronic kidney disease (CKD), resulting from a combination of abnormalities in the growth hormone (GH) axis, vitamin D deficiency, hyperparathyroidism, hypogonadism, inadequate nutrition, cachexia and drug toxicity. The impact of CKD-associated bone and mineral disorders (CKD-MBD) may be immediate (serum phosphate/calcium disequilibrium) or delayed (poor growth, ROD, fractures, vascular calcifications, increased morbidity and mortality). In 2012, the clinical management of CKD-MBD in children needs to focus on three main objectives: (i) to provide an optimal growth in order to maximize the final height with an early management with recombinant GH therapy when required, (ii) to equilibrate calcium/phosphate metabolism so as to obtain acceptable bone quality and cardiovascular status and (iii) to correct all metabolic and clinical abnormalities that can worsen bone disease, growth and cardiovascular disease, i.e. metabolic acidosis, anaemia, malnutrition and 25(OH)vitamin D deficiency. The aim of this review is to provide an overview of the mineral, bone and vascular abnormalities associated with CKD in children in terms of pathophysiology, diagnosis and clinical management.

Growth hormone in chronic renal disease

Severe growth retardation (below the third percentile for height) is seen in up to one-third children with chronic kidney disease. It is thought to be multifactorial and despite optimal medical therapy most children are unable to reach their normal height. Under-nutrition, anemia, vitamin D deficiency with secondary hyperparathyroidism, metabolic acidosis, hyperphosphatemia, renal osteodystrophy; abnormalities in the growth hormone/insulin like growth factor system and sex steroids, all have been implicated in the pathogenesis of growth failure. Therapy includes optimization of nutritional and metabolic abnormalities. Failure to achieve adequate height despite 3-6 months of optimal medical measures mandates the use of recombinant GH (rGH) therapy, which has shown to result in catch-up growth, anywhere from 2 cm to 10 cm with satisfactory liner, somatic and psychological development.

Validation of The Health Improvement Network (THIN) database for epidemiologic studies of chronic kidney disease

PURPOSE

Chronic kidney disease (CKD) is a prevalent and important outcome and covariate in pharmacoepidemiology. The Health Improvement Network (THIN) in the UK represents a unique resource for population-based studies of CKD. We compiled a valid list of Read codes to identify subjects with moderate to advanced CKD.

METHODS

A cross-sectional validation study was performed to identify codes that best define CKD Stages 3-5. All subjects with at least one non-zero measure of serum creatinine after 1 January 2002 were included. Estimated glomerular filtration rate (eGFR) was calculated according to the Schwartz formula for subjects aged < 18 years and the Modification of Diet in Renal Disease formula for subjects aged ≥ 18 years. CKD was defined as an eGFR <60 mL/minute/1.73 m² on at least two occasions, more than 90 days apart.

RESULTS

The laboratory definition identified 230,426 subjects with CKD, for a period prevalence in 2008 of 4.56% (95%CI, 4.54-4.58). A list of 45 Read codes was compiled, which yielded a positive predictive value of 88.9% (95%CI, 88.7-89.1), sensitivity of 48.8%, negative predictive value of 86.5%, and specificity of 98.2%. Of the 11.1% of subjects with a code who did not meet the laboratory definition, 83.6% had at least one eGFR <60. The most commonly used code was for CKD Stage 3.

CONCLUSIONS

The proposed list of codes can be used to accurately identify CKD when serum creatinine data are limited. The most sensitive approach for the detection of CKD is to use this list to supplement creatinine measures.

Growth of kidney-transplanted pediatric patients treated with sirolimus

Experimental findings indicate that sirolimus (SRL) inhibits longitudinal growth by mechanisms potentially related to its inhibitory effects on both cell proliferation and expression of vascular endothelial growth factor (VEGF). The aim of this study was to investigate the growth pattern of kidney-transplanted children treated with SRL in a multicenter observational clinical study. Height, change in height SD (Δ height) and growth velocity of pediatric patients with renal transplant were calculated at 0, 6, 12, and 24 months after starting SRL. Controls of kidney-transplanted children not treated with SRL were matched by age, gender, renal function, and dose of corticosteroids. Sixty-eight children (34 SRL, 34 controls) were enrolled in the study. Nephrotoxicity was the most frequent indication to start therapy with SRL. SRL exerted an adverse effect on growth as demonstrated by significantly lower (p < 0.05) growth velocity (cm/year) and smaller change in height SD in the SRL group after 6 (4.08 vs. 6.56 and -0.05 vs. 0.14), 12 (4.44 vs. 6.11 and -0.03 vs. 0.28) and 24 (4.53 vs. 6.03 and -0.04 vs. 0.53) months of treatment. This study suggests that SRL therapy may interfere with growth of kidney-transplanted children. This undesirable effect needs to be taken into account when considering a switch to SRL and confirmed in further prospective trials including larger number of patients.

Dialysis strategies to improve growth in children with chronic kidney disease

Despite major advances in the understanding and management of uremic growth failure, 35% to 50% of children with chronic kidney disease still grow up to become adults of small stature. The final adult height achieved is correlated with the height deficit recorded at the time of kidney transplantation. A degree of catch-up growth does occur after kidney transplantation in childhood, but it is often limited. Growth retardation in children with chronic kidney disease causes significant difficulties in their daily lives, often limiting psychosocial integration. Additionally, growth retardation is associated with a greater number of hospital admissions and an increased risk of mortality. Growth failure is the common endpoint of a variety of pathologies, including growth hormone resistance. In children on chronic dialysis, linear growth may be improved by ensuring that optimal clinical care is provided. This includes maximizing nutritional support (e.g., tube feeding in cases of anorexia) so as to prevent malnutrition. Further management options include the administration of recombinant human growth hormone (rhGH) treatment and the use of more frequent and intensive dialysis sessions, such as daily on-line hemodiafiltration, which combines increased dialysis convective flow with ultrapure dialysate, to limit cachexia.