Factors predictive of the short- and long-term efficacy of growth hormone treatment in prepubertal children with chronic renal failure. The German Study Group for Growth Hormone Treatment in Chronic Renal Failure

Longitudinal Relationship Between Anemia and Statural Growth Impairment in Children and Adolescents With Nonglomerular CKD: Findings From the Chronic Kidney Disease in Children (CKiD) Study

RATIONALE & OBJECTIVE

Anemia and statural growth impairment are both prevalent in children with nonglomerular chronic kidney disease (CKD) and are associated with poor quality of life and increased morbidity and mortality. However, to date no longitudinal studies have demonstrated a relationship between anemia and statural growth in this population.

STUDY DESIGN

The CKD in Children (CKiD) study is a multicenter prospective cohort study with over 15 years of follow-up observation.

SETTING & PARTICIPANTS

CKiD participants younger than 22 years with nonglomerular CKD who had not reached final adult height.

EXPOSURE

Age-, sex-, and race-specific hemoglobin z score.

OUTCOME

Age- and sex-specific height z score.

ANALYTICAL APPROACH

The relationship between hemoglobin and height was quantified using (1) multivariable repeated measures paired person-visit analysis, and (2) multivariable repeated measures linear mixed model analysis. Both models were adjusted for age, sex, body mass index, estimated glomerular filtration rate, acidosis, and medication use.

RESULTS

Overall, 67% of the 510 participants studied had declining hemoglobin z score trajectories over the follow-up period, which included 1,763 person-visits. Compared with average hemoglobin z scores of≥0, average hemoglobin z scores of less than -1.0 were independently associated with significant growth impairment at the subsequent study visit, with height z score decline ranging from 0.24 to 0.35. Importantly, in 50% of cases hemoglobin z scores of less than -1.0 corresponded to hemoglobin values higher than those used as cutoffs defining anemia in the KDIGO clinical practice guideline for anemia in CKD. When stratified by age, the magnitude of the association peaked in participants aged 9 years. In line with paired-visit analyses, our mixed model analysis demonstrated that in participants with baseline hemoglobin z score less than -1.0, a hemoglobin z score decline over the follow-up period was associated with a statistically significant concurrent decrease in height z score.

LIMITATIONS

Limited ability to infer causality.

CONCLUSIONS

Hemoglobin decline is associated with growth impairment over time in children with mild to moderate nonglomerular CKD, even before hemoglobin levels reach the cutoffs that are currently used to define anemia in this population.

[Chronic kidney disease and growth failure: Efficacy of growth hormone treatment]

Growth failure is a frequent complication observed in children with chronic kidney disease (CKD) and correlated to increased morbidity and mortality. To achieve a normal growth in children with CKD remains challenging for pediatric nephrologists. Growth failure in the setting of pediatric CKD is multifactorial and related to an impaired sensitivity to growth hormone and to a deficiency of IGF1 (insulin-like growth factor 1). Growth failure management has improved during the last two decades and consists of correcting any nutritional and metabolic abnormalities, of an improvement of dialysis for children on end-stage renal disease, and of an administration of a supraphysiologic dose of recombinant growth hormone to overcome GH insensitivity. This article summarizes the causes, outcomes and assessment tools of growth in children with CKD as well as the management of recombinant growth hormone.

Efficacy and safety of recombinant human growth hormone therapy in pediatric intestinal transplant recipients

BACKGROUND

Recombinant human growth hormone (rhGH) is widely used to treat growth retardation in children. We aimed to examine the effect of rhGH therapy on growth and its impact on allograft function in children with growth retardation after intestinal transplant (IT).

METHODS

We retrospectively included children younger than 19 years who had received an IT with or without the liver, were diagnosed with growth retardation, and have received rhGH between January 2010 and January 2021. Changes in the patient's anthropometric parameters between baseline and various time points were compared using the paired t-test or Wilcoxon signed-rank test, as appropriate.

RESULTS

Seven patients (all males and prepubertal) received rhGH for the median duration of 2.3 years. The median age at rhGH start was 9.5 years. The median growth velocity z-score improved from -0.95 before treatment to 2.3 (p = .04) and 1.9 (p = .06) after 1 and 2 years of treatment, respectively. The median height-for-age z-score significantly improved from -3.4 at rhGH start to -1.3 (p = .005) at rhGH stop and remained above baseline at the last visit (-2.4, p = .002). The change in the first-year growth velocity was negatively correlated with the change in the second-year growth velocity (r = -.90, p = .04). No serious adverse effects or worsening allograft function were observed.

CONCLUSIONS

Severely growth retarded children after IT could benefit from rhGH treatment. A larger, longitudinal study would be warranted to monitor the long-term effect and safety of rhGH and examine predictors of growth response to rhGH therapy in these pediatric IT recipients.

Growth Hormone and Insulin-Like Growth Factor Dysregulation in Pediatric Chronic Kidney Disease

Poor growth is a common finding in children with chronic kidney disease (CKD) that has been associated with poor long-term outcomes. The etiology of poor growth in this population is multifactorial and includes dysregulation of the growth hormone (GH) and insulin-like growth factor (IGF) axis. In this review, we describe the data on GH resistance or insensitivity and inappropriate levels or reduced bioactivity of IGF proposed as contributing factors of growth impairment in children with CKD. Additionally, we describe the theorized negative effect of metabolic acidosis, another frequent finding in pediatric CKD, on the GH/IGF axis and growth. Last, we present the current and potential therapies for the treatment of short stature in pediatric CKD that target the GH/IGF hormonal axis.

Peritoneal Loss of Growth Hormone in Children on Automated Peritoneal Dialysis

Objective

To provide quantitative data regarding the daily dialytic loss of growth hormone (GH) in children on peritoneal dialysis (PD).

Design

Prospective study involving 24-hour dialysate collections on 3 consecutive days in patients with and without recombinant human GH (rhGH) treatment.

Setting

Single-center outpatient PD program.

Patients

Twenty-six children undergoing automated PD (APD): 6 with and 20 without daily rhGH.

Main Outcome Measures

Daily peritoneal losses of GH, α1-, β2-microglobulin, transferrin, and albumin.

Results

The mean (±SEM) daily dialytic GH loss was 2.18 ± 0.62 μg/1.73 m2 per day in rhGH-treated patients and 0.42 ± 0.28 μg/1.73 m2 per day in untreated patients, ( p < 0.05). The intraindividual coefficient of variation of daily GH loss was 65%. The peritoneal loss of GH was positively correlated with that of β2-microglobulin ( r = 0.77, p < 0.001) and α1-microglobulin ( r = 0.51, p < 0.01). The variability in β2-microglobulin and α1-microglobulin elimination, together with the use of rhGH, explained 66% of the total variability of daily GH excretion. In patients without rhGH therapy, the daily peritoneal GH loss was approximately 0.05% of the estimated daily endogenous production rate based on previous estimates in children with end-stage renal failure. In patients on rhGH therapy, less than 0.1% of the injected rhGH dose was eliminated by dialysis.

Conclusion

Peritoneal losses of GH in children on APD account only for a minute fraction of endogenous metabolic clearance, and do not explain the variability of the rhGH treatment response. The assessment of dialytic GH elimination may be used to estimate time-integrated mean plasma GH concentrations, and to monitor rhGH treatment compliance.

Long Term Experience with Growth Hormone Treatment in Children with Chronic Renal Failure

After a decade of experience with recombinant human growth hormone (rhGH) in children with chronic renal failure (CRF), the long-term efficacy and safety of the drug is now established. In prepubertal children, partial catch-up growth is achieved during the first three treatment years, followed by sustained percentile-parallel growth. Discontinuation of rhGH treatment results in catch-down growth in 75% of patients. Treatment efficacy is inversely correlated with age and baseline height velocity, and positively influenced by genetic target height and residual renal function. Skeletal maturation is not accelerated, suggesting a true increase in final height potential. Side effects are limited to a stimulation of insulin secretion, which is not associated with changes in glucose tolerance, and occasional cases of benign intracranial hypertension.

In summary, the advent of rhGH has opened a new era in the management of growth failure in CRF. Available evidence suggests that treatment should start in early childhood and early in the course of renal failure, and should be continued at least until renal transplantation. It remains to be seen whether the beneficial effect of rhGH on height observed during the prepubertal period will result in an eventual increase in adult height.

Strategies for Optimizing Growth in Children With Chronic Kidney Disease

Growth failure is a hallmark in children with chronic kidney disease (CKD). Therefore, early diagnosis and adequate management of growth failure is of utmost importance in these patients. The risk of severe growth retardation is the higher the younger the child is, which places an additional burden on patients and their families and hampers the psychosocial integration of these children. Careful monitoring of growth, and effective interventions are mandatory to prevent and treat growth failure in children with CKD at all ages and all stages of kidney failure. Early intervention is critical, as all therapeutic interventions are much more effective if they are started prior to the initiation of dialysis. Prevention and treatment of growth failure focuses on: (i) preservation of renal function, e.g., normalization of blood pressure and proteinuria by use of inhibitors of the renin-angiotensin aldosterone system, (ii) adequate energy intake, including tube feeding or gastrostomy in case of persisting malnutrition, (iii) substitution of water and electrolytes, especially in children with renal malformation, (iv) correction of metabolic acidosis, (v) control of parathyroid hormone levels within the CKD-dependent target range, (vi) use of recombinant human growth hormone in cases of persistent growth failure, and, (vii) early/preemptive kidney transplantation using steroid-minimizing immunosuppressive protocols in children with end-stage CKD. This review discusses these measures based on recent guidelines.

Gender-Dependent Growth and Insulin-Like Growth Factor-1 Responses to Growth Hormone Therapy in Prepubertal Growth Hormone-Deficient Children

Gender seems to be an important factor influencing the response to recombinant human growth hormone (rhGH) therapy in GH-deficient adolescents and adults. The results of studies evaluating gender-specific response to rhGH therapy in prepubertal GH-deficient children are divergent. The aim of this study was to determine the effect of gender on the growth and insulin-like growth factor-1 (IGF-1) responses in 75 prepubertal GH-deficient children during the first 2 years of rhGH therapy. There were no baseline gender differences in age, bone age, anthropometrical parameters, and IGF-1 SDS for bone age. After the initiation of rhGH therapy, there were no gender-specific differences concerning the reduction of height deficit. Serum IGF-1 levels were higher in the prepubertal GH-deficient girls than in the age-matched boys, but the difference was not significant when expressed as IGF-1 SDS for bone age. The increase in IGF-1 SDS for bone age was significantly greater in girls versus boys after the first 6 months of therapy, comparable between girls and boys after the first year of therapy, and tended to be higher in boys after the second year of therapy. In conclusion, prepubertal GH-deficient girls and boys do not differ significantly in growth response in the first 2 years of rhGH therapy.

Clinical practice recommendations for growth hormone treatment in children with chronic kidney disease

Achieving normal growth is one of the most challenging problems in the management of children with chronic kidney disease (CKD). Treatment with recombinant human growth hormone (GH) promotes longitudinal growth and likely enables children with CKD and short stature to reach normal adult height. Here, members of the European Society for Paediatric Nephrology (ESPN) CKD–Mineral and Bone Disorder (MBD), Dialysis and Transplantation working groups present clinical practice recommendations for the use of GH in children with CKD on dialysis and after renal transplantation. These recommendations have been developed with input from an external advisory group of paediatric endocrinologists, paediatric nephrologists and patient representatives. We recommend that children with stage 3–5 CKD or on dialysis should be candidates for GH therapy if they have persistent growth failure, defined as a height below the third percentile for age and sex and a height velocity below the twenty-fifth percentile, once other potentially treatable risk factors for growth failure have been adequately addressed and provided the child has growth potential. In children who have received a kidney transplant and fulfil the above growth criteria, we recommend initiation of GH therapy 1 year after transplantation if spontaneous catch-up growth does not occur and steroid-free immunosuppression is not a feasible option. GH should be given at dosages of 0.045–0.05 mg/kg per day by daily subcutaneous injections until the patient has reached their final height or until renal transplantation. In addition to providing treatment recommendations, a cost-effectiveness analysis is provided that might help guide decision-making.

This Evidence-Based Guideline developed by members of the European Society for Paediatric Nephrology CKD-MBD, Dialysis and Transplantation working groups presents clinical practice recommendations for the use of growth hormone in children with chronic kidney disease on dialysis and after renal transplantation.

Twenty years of growth hormone treatment in dialyzed children in Poland-Results of national multicenter study

PURPOSE

The aim of the study was to analyze the effect of recombinant human growth hormone (rhGH) therapy and to establish factors influencing growth rate in dialyzed children in Poland.

METHODS

We retrospectively analyzed medical records of 81 children with end-stage renal disease (ESRD) on chronic dialysis treated with rhGH for ≥12 months between 1994 and 2014. The following data were recorded: cause of ESRD, dialysis modality, age at the dialysis and rhGH initiation [years]. In addition, growth [cm], [standard deviation score - SDS], body mass index [SDS], skeletal age [years], bone mineral density [SDS], hemoglobin, total protein, albumin, urea, creatinine, calcium, phosphorus, calcium phosphorus product, PTH, and alkaline phosphatase were measured at the baseline and after 12 months.

RESULTS

Growth velocity in 81 children during one-year rhGH treatment was 7.33 ± 2.63 cm (ΔSDS 0.36 ± 0.43). Height SDS increased significantly (-3.31 ± 1.12 vs. -2.94 ± 1.15, p < 0.001). Children on peritoneal dialysis (PD) (n = 51) were younger than children on hemodialysis (HD) (n = 30) (9.92 ± 3.72 vs. 12.32 ± 3.11 years, p = 0.003). ΔSDS did not differ between PD and HD children (0.40 ± 0.33 vs. 0.30 ± 0.47, p = 0.311). Growth velocity (ΔSDS) correlated with age at dialysis initiation (r=-0.30, p = 0.009), age at rhGH treatment initiation (r=-0.35, p = 0.002), skeletal age (r=-0.36, p = 0.002), BMI SDS (r=-0.27, p = 0.019), and PTH (r=-0.27, p = 0.017). No correlation between growth velocity and other parameters was observed.

CONCLUSIONS

Treatment with rhGH in children with ESRD is effective and safe irrespective of dialysis modality. Early initiation of rhGH therapy is a crucial factor determining response to the treatment in children with ESRD.

Pubertal development in children with chronic kidney disease

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

Growth hormone therapy for a patient with idiopathic Fanconi syndrome and growth hormone deficiency

Idiopathic Fanconi syndrome (FS) is characterized by a generalized dysfunction of the renal proximal tubules. Patients with FS often exhibit growth retardation due to complex factors, such as hypophosphatemia, metabolic acidosis, disturbed vitamin D metabolism and hypokalemia. To date, one FS patient has been reported to exhibit growth failure due to growth hormone deficiency (GHD), but the long-term clinical course of recombinant human GH (rhGH) therapy has not been reported. At 10 months of age, the patient was admitted to our hospital due to growth failure. Blood and urinary biochemical abnormalities, such as hypophosphatemia, metabolic acidosis, glycosuria and low-molecular-weight proteinuria, indicated a generalized dysfunction of the renal proximal tubules. The presence of cystinosis, collagen diseases, toxic agents and metabolic diseases were excluded. These features are compatible with idiopathic FS. Treatment with high-dose alkali, potassium citrate, phosphate buffer, hydrochlorothiazide and vitamin D supplement was initiated. The biochemical abnormalities achieved nearly normal values, and the patient's height was within -2.5 SD at the age of 2 years. However, his height did not continue to increase at the same rate and gradually declined to -2.9 SD at 4 years of age. GH stimulation test demonstrated GHD. After initiation of rhGH therapy, his height improved to -2.0 SD at the age of 9 years with no adverse effects. In conclusion, we report the case of a patient with FS and GHD who continued rhGH therapy for 5 years. The differential diagnosis of GHD should also be considered for FS patients with short stature.

Kidney transplantation fails to provide adequate growth in children with chronic kidney disease born small for gestational age

BACKGROUND

Children with chronic kidney disease are frequently born small for gestational age (SGA) and prone to disproportionately short stature. It is unclear how SGA affects growth after kidney transplantation (KTx).

METHODS

Linear growth (height, sitting height, and leg length) was prospectively investigated in a cohort of 322 pediatric KTx recipients, with a mean follow-up of 4.9 years. Sitting height index (ratio of sitting height to total body height) was used to assess body proportions. Predictors of growth outcome in KTx patients with (n = 94) and without (n = 228) an SGA history were evaluated by the use of linear mixed-effects models.

RESULTS

Mean z-scores for all linear body dimensions were lower in SGA compared with non-SGA patients (p < 0.001). SGA patients presented with higher target height deficit and degree of body disproportion (p < 0.001). The latter was mainly due to reduced leg growth during childhood. Pubertal trunk growth was diminished in SGA patients, and the pubertal growth spurt of legs was delayed in both groups, resulting in further impairment of adult height, which was more frequently reduced in SGA than in non-SGA patients (50 % vs 18 %, p < 0.001). Use of growth hormone treatment in the pre-transplant period, preemptive KTx, transplant function, and control of metabolic acidosis were the only potentially modifiable correlates of post-transplant growth in SGA groups. By contrast, living related KTx, steroid exposure, and degree of anemia proved to be correlates in non-SGA only.

CONCLUSIONS

In children born SGA, growth outcome after KTx is significantly more impaired and affected by different clinical parameters compared with non-SGA patients.

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.

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 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.

Growth in children with chronic kidney disease: role of nutrition, growth hormone, dialysis, and steroids

PURPOSE OF REVIEW

Children with chronic kidney disease (CKD) have impaired growth that leads to short stature in adulthood. The problem persists even with successful transplantation and steroid withdrawal protocols. The aim of this review is to provide an overview of the pressing issues related to growth failure in children with CKD both before and after transplantation.

RECENT FINDINGS

Although great strides have been made in dialysis and transplantation, the incidence of abnormal adult height in children growing up with CKD remains as high as 45-60%. The lack of catch-up growth and resultant short stature is a critical issue for self-esteem and quality of life in many children with CKD. Aggressive daily dialysis, improved nutrition, treatment of metabolic bone disease, and the use of recombinant human growth hormone provide some hope for catch-up growth in select patients.

SUMMARY

The causes of growth failure in the setting of CKD are multifactorial. Attention to all the details by optimizing nutritional, bone and mineral metabolism, correcting metabolic acidosis and anemia, achieving excellent blood pressure control, reversing cardiovascular complications such as left ventricular hypertrophy, and minimizing the use of corticosteroids is the current standard of care. Aggressive daily dialysis can reverse many of the uremic derangements. For patients not yet on dialysis or for those after renal transplant, early institution of recombinant human growth hormone can promote growth. Improved understanding of the mechanisms of hormone resistance may offer novel targets or measurements of treatment effectiveness.

The utility of the IGF-I generation test in children with chronic kidney disease

BACKGROUND

To determine if the insulin-like-growth factor (IGF-I) generation test is a marker for growth hormone (GH) sensitivity in children with chronic kidney disease (CKD).

METHODS

This was a randomized cross-over study in which children with CKD received low-dose (0.025 mg/kg/day) and high-dose (0.05 mg/kg/day) GH therapy in the framework of a 7-day IGF-I generation test. Blood samples were collected on day 1 (D1; pre-dose) and on day 8 (D8; post 7 doses) of GH therapy. All subjects received GH for 12 months at 0.05 mg/kg/day. Serum IGF-I was measured by radioimmunometric assay. Normative historic data from healthy children and those with idiopathic short stature were used for comparison.

RESULTS

Sixteen subjects (age 2-13 years) with creatinine clearances of between 25 and 75 ml/min/1.73 m(2) were enrolled. Annualized height velocity for all subjects was 10.3 ± 1.1 cm/year (mean ± standard deviation), with an annual change in height Z score of 0.7 ± 1.0. No correlation was found between the generated serum IGF-I levels (D8 - D1) and creatinine clearances, and with changes in height Z scores. Serum IGF-I levels on D1 and D8 in CKD subjects were lower than normative data, but with adequate IGF-I generation on D8.

CONCLUSIONS

Children with CKD were able to respond to GH therapy with both growth and an increase in serum IGF-I levels, but the IGF-I generation test was not a good predictor of growth response in this cohort.

Paediatric reference values for the C-terminal fragment of fibroblast-growth factor-23, sclerostin, bone-specific alkaline phosphatase and isoform 5b of tartrate-resistant acid phosphatase

BACKGROUND

Paediatric reference values for novel markers of phosphate homeostasis, bone formation and resorption and their putative relationship to growth are lacking.

METHODS

A total of 424 healthy children, adolescents and young adults (221 males) aged 0.1-21 y, were enrolled in this cross-sectional study. Height, weight and height velocity were assessed. Plasma/serum samples for determination of C-terminal fragment of fibroblast growth factor-23 (cFGF-23), sclerostin, bone alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase 5b (TRAP5b) were available from 222, 264, 352 and 338 individuals, respectively. Calculation of cross-sectional centiles and z-scores was based on median (M), standard coefficient of variation (S) and the Box-Cox power (L) of transformation (LMS method) per age cohort. Correlations between variables as well as with growth were assessed.

RESULTS

cFGF-23, BAP and TRAP5b were significantly correlated with age (each P < 0.01), with highest values during infancy and adolescence. Serum levels of BAP and TRAP5b were significantly higher in adolescent boys compared with girls (each P < 0.01). In contrast, sclerostin levels were independent of age and gender. BAP and TRAP5b were strongly correlated and both were significantly associated with cFGF-23 and sclerostin as well (each P < 0.01). cFGF-23 was positively correlated with serum phosphate and renal phosphate threshold concentration (each P < 0.01). Height, weight, body mass index and height velocity were weakly correlated with BAP and TRAP5b (each P < 0.05).

CONCLUSIONS

This study provides age- and gender-related centile charts and z-scores for cFGF-23, BAP, TRAP5b and sclerostin and highlights the link between phosphate homeostasis and markers of bone metabolism during growth.

Insulin-like growth factors in normal and diseased kidney

This article reviews the physiology of the insulin-like growth factor (IGF) system in the kidney and the changes and potential role of this system in selected renal diseases. The potential therapeutic uses of recombinant human IGF-I for the treatment of acute and chronic kidney failure are briefly discussed.

Predicting response to growth hormone treatment

Despite extensive experience over the past 25 y in managing growth failure with growth hormone (rhGH), predicting treatment efficacy in individual children remains a challenge. In this paper, the authors present the methods that are currently available to clinicians for predicting the growth response, and other more sophisticated techniques which have the potential to pave the way for individualised therapy in the future.

Peritoneal dialysis in children with end-stage renal disease

Peritoneal dialysis is the preferred chronic dialysis modality for most children owing to its almost universal applicability and superior compatibility with lifestyle over other modalities. Although technological advances and increasing clinical experience have impacted favorably on patient and technique survival, clinical research in pediatric peritoneal dialysis has been hampered by the low incidence of end-stage renal disease (ESRD) in the pediatric population. To overcome this limitation, several international registries have emerged in the past few years to complement other long-standing registries, which together have provided useful information regarding technique-specific complications and comorbidities associated with ESRD in children undergoing chronic peritoneal dialysis. In this Review, we summarize the most relevant findings from these studies, highlighting the substantial variation in patient conditions, peritoneal dialysis practices and management of comorbidities encountered in different parts of the world.

Factors influencing the one- and two-year growth response in children treated with growth hormone: analysis from an observational study

To assess gender-, pubertal-, age-related differences in change from baseline height standard deviation score (ΔHSDS), data from 5,797 growth hormone (GH) naïve pediatric patients (<18 years) with growth hormone deficiency (GHD), multiple pituitary hormone deficiency (MPHD), Turner syndrome (TS), small for gestational age (SGA), Noonan syndrome (NS), and idiopathic short stature (ISS) were obtained from the ANSWER (American Norditropin Studies: Web-enabled Research) Program registry. For patients with SGA, ΔHSDS at year 1 was significantly greater for males versus females (P = .016), but no other gender differences were observed. For patients with GHD, ΔHSDS was greater in prepubertal than in pubertal patients. Younger patients for both genders (<11 years for boys; <10 years for girls) showed a greater ΔHSDS (P < .05 for GHD, MPHD, and ISS). Overall, positive ΔHSDSs were observed in all patients, with greater growth responses in younger prepubertal children, emphasizing the importance of starting GH treatment early.

Growth and body composition in very young SGA children

Infants with a very low birth weight are at risk of a reduced number of nephrons predisposing to kidney disorder, hypertension, and metabolic syndrome. Approximately 3% of infants are born small for gestational age (SGA), defined as birth weight and/or length at least 2 SD below the mean for gestational age (GA), independently of whether these children are born prematurely or at term. About 10% of these children do not show postnatal catch-up growth and remain of short stature during childhood. Most of these infants are not growth hormone (GH)-deficient, but may have GH resistance. Although GH-resistant, the majority of patients benefit from GH therapy, normalize height during childhood, maintain a normal growth velocity during puberty, and attain a normal adult height. To date, GH has been shown to be safe and no significant adverse effects have been demonstrated. Children with congenital chronic kidney disease (CKD) are born with subnormal birth weight and length and about 25% are born SGA. Shortness and need for GH treatment is highly correlated with weight at birth and gestational age. Primary renal disorders modify the response to GH treatment. Analysis of whether SGA is an additional risk factor for CKD regarding the development of hypertension, metabolic syndrome and cardiovascular complications is required.

A review of the effects of growth hormone changes on symptoms of frailty in the elderly with chronic kidney disease

The incidence and prevalence of chronic kidney disease (CKD) is increasing worldwide, especially in the elderly. Recently, functional impairment and frailty have been recognized as factors affecting the quality of life, and outcomes in elderly patients with CKD and therapeutic interventions to improve function and reduce frailty are therefore being considered. Growth hormone (GH) levels decrease with age and GH actions are impaired in CKD patients. GH stimulates protein synthesis, bone, and glucose metabolism, and affects body composition by reducing body fat and increasing lean body mass. An increase in lean body mass may reduce frailty and thus avoid functional impairment. Thus, providing GH to elderly CKD patients could potentially improve outcomes and quality of life by lowering the risk of frailty and associated functional impairment. There are few studies assessing the long-term effects of GH administration on symptoms of frailty in elderly patients with CKD. In this review we will try to shed some light on the trials assessing the administration of GH to elderly subjects and to patients with CKD and focus on the possible role GH administration may play to improve frailty and quality of life in those patients.

Predicting the response to growth hormone treatment in short children with chronic kidney disease

CONTEXT

Short stature in children with chronic kidney disease (CKD) is due to various underlying congenital or acquired renal disorders resulting in variable impairment of renal function and variable response to GH treatment.

OBJECTIVE

It was the aim to develop a mathematical model that allows the prediction of the individual growth response and to identify nonresponders.

DESIGN

Data from 208 prepubertal children on conservative or dialysis treatment in a large pharmaco-epidemiological survey, the KIGS (Pfizer International Growth Database), were used for the model and data from 67 similar CKD patients registered at the Dutch Growth Research Foundation for validation.

RESULTS

Annualized height velocity (centimeters per year) during the first year of GH treatment was best predicted by age at start, weight sd score, underlying renal disorder (hereditary kidney disorder), glomerular filtration rate (at baseline), and GH dosage. Using these parameters, the final model explained 37% of the overall variability of growth response. Standard error of the estimates was 1.6 cm. Age was the most important predictor of growth response (20.3% of variability) followed by weight sd score at start, and 27.2% of the variability of the second-year response could be predicted by the first-year response and glomerular filtration rate. Nonresponders of the validation group could be correctly identified.

CONCLUSION

Based on simple clinical variables, a robust prediction model was developed that provides realistic expectations of individual growth response to GH in short children with CKD. The model will help in identifying nonresponders and to tailor treatment strategies.

Growth hormone treatment of infants with chronic kidney disease: requirement, efficacy, and safety

Growth failure is still a challenge in infants suffering from chronic kidney disease (CKD). Persistent growth failure is associated with the excessive mortality rate seen in these patients and markedly hampers later psychosocial integration. Infancy is an extremely sensitive period of growth, since physiological growth rates are several times higher than in later life. Growth failure in infants with CKD has multiple reasons, originating preferentially from malnutrition and, to a lesser extent, from water and electrolyte losses, metabolic acidosis, anemia, and renal osteodystrophy. Although, recombinant human growth hormone (rhGH) has been proven to be safe and effective for treatment of uremic growth failure in later childhood, its usage has not been adequately investigated in infants. Mencarelli et al. (Pediatric Nephrology 24:1039-1046, 2009) reported on their retrospective analysis of the longitudinal growth of 27 infants with early onset CKD that were receiving either standard therapy or additional rhGH treatment. Although their results were encouraging with respect to a sustained catch-up growth in rhGH-treated children, this issue has to be further addressed in prospective randomized controlled trials. In these trials special emphasis has to be given to the safety of this treatment modality, since rhGH might induce insulin resistance and glucose intolerance, especially in infants on high caloric intake and peritoneal dialysis.

Growth hormone treatment in short children with chronic kidney disease

Growth hormone (GH) has been used for treatment of impaired growth in children with chronic kidney disease (CKD) for nearly 17 years. Controlled and open-label studies have shown that GH is highly effective in improving growth velocity and adult height. The growth response is negatively correlated with age and height at start and time spent on dialysis treatment; it is positively correlated with dose and duration of treatment and the primary renal disease (renal hypodysplasia). In children with renal transplants, corticosteroid treatment is an additional factor negatively influencing spontaneous growth rates. However, GH treatment is able to compensate corticosteroid-induced growth failure. GH treatment improved final height by 0.5-1.7 standard deviation score (SDS) in various studies, whereas the control group lost about 0.5 SDS in comparable time intervals. These variable results are explained in part by the factors mentioned above. The adverse events are comparable to those in non-CKD children treated with GH.

CONCLUSION

GH treatment is safe and highly effective in improving growth and final height of short children with all stages of CKD. The highest treatment success is obtained if treatment is started at an early age and with relatively well-preserved residual renal function and continued until final height.

Factors predicting the near-final height in growth hormone-treated children and adolescents with chronic kidney disease

CONTEXT

GH therapy is an accepted measure to increase adult height in young prepubertal patients suffering from growth failure related to chronic kidney disease (CKD). The impact of GH therapy on final height (FH) in CKD patients of pubertal age is unclear.

OBJECTIVE

This study set out to analyze near-FH in a cohort of GH-treated CKD patients.

DESIGN, SETTINGS, AND PATIENTS

Of 240 evaluable patients in the Pfizer International Growth Database (KIGS) with CKD, 39% were prepubertal and 61% were pubertal at baseline; 45% were on conservative treatment for CKD, 28% were on dialysis, and 27% were in the period after renal transplantation.

MAIN OUTCOME MEASURES

Near-FH, relation to pubertal stage, and factors predictive of growth response were the main outcome measures.

RESULTS

Mean height sd scores increased continuously during GH treatment until near-FH by 1.2 and 1.6 in boys and girls, respectively. Mean near-FH differed significantly from prepubertal patients showing severely delayed puberty (-3.6), late pubertal patients (-2.9), early pubertal patients (-2.2), and prepubertal patients with normal onset of puberty (-2.0). The initial degree of stunting, degree of bone age retardation, duration of GH therapy, time spent on conservative treatment/dialysis, pubertal delay (>2 sd), gender, and age at start of GH treatment were significant predictors of growth response to GH therapy, explaining between 33 and 61% of the overall variability.

CONCLUSIONS

Long-term GH therapy of CKD patients in prepubertal and pubertal age results in an increased adult height, but response is diminished in patients on dialysis and/or with severely delayed puberty.

Growth of prepubertal children on dialysis

Growth failure is a common and significant clinical problem for children on dialysis and often remains a major impediment to their rehabilitation. Early referral to a paediatric nephrology centre and appropriate management before the initiation of dialysis may significantly prevent growth deterioration. Growth in children on dialysis can be affected by nutritional, metabolic, and hormonal changes. Early diagnosis of malnutrition and aggressive management should be a priority. Gastrostomy feeding should be used when adequate oral intake to maintain normal height and weight velocity cannot be achieved. Active vitamin D metabolites should be used carefully, to prevent low-turnover bone disease. All children should have an adequate regimen of dialysis and an appropriate management of malnutrition, renal osteodystrophy, metabolic acidosis, salt wasting and anaemia, before recombinant human growth hormone (rhGH) administration is considered. The current challenge of reversing growth impairment in children on dialysis can only be achieved by optimization of their care.

Short stature and growth hormone use in pediatric hemodialysis patients

End-stage renal disease (ESRD) causes growth retardation in children, and poor growth has been linked to worse outcomes. Recombinant human growth hormone (rhGH) can increase growth velocity and final adult height in pediatric ESRD patients. We aimed to identify clinical predictors of short stature (height standard deviation score (Ht SDS) <-1.88) and rhGH use in short stature pediatric hemodialysis patients. In 2002, the Centers for Medicare & Medicaid Services (CMS) Clinical Performances Measures (CPM) ESRD Project collected demographic, clinical and laboratory data as well as rhGH use on all in-center hemodialysis patients in the US aged <18 years. The odds ratios (OR) of short stature and rhGH use for individual predictors were determined by multivariate logistic regression modeling. Six-hundred and fifty-one (92%) of 710 eligible patients were included for analysis. Of these, 266 (41%) had Ht SDS <-1.88. After adjustment, short stature was predicted by congenital/urologic causes of ESRD ((OR 5.4; 95% confidence interval [CI], 2.1-13.8; p <0.001) in patients aged 10-14 years; (OR 2.8; 95% CI, 1.5-5.4; p <0.01) in patients aged 15-18 years) and increasing years on dialysis ((OR 1.2; 95% CI, 1.1-1.4; p <0.01) in patients aged 10-14 years; (OR 1.2; 95% CI, 1.1-1.4; p <0.001) in patients aged 15-18 years). Of 266 short stature patients, 214 (80.5%) had data on rhGH use. Of these, 80 (37%) had been prescribed rhGH. After adjustment, use of rhGH in short-stature patients was predicted by white race (OR 2.1; 95% CI, 1.1-4.0; p <0.05), increasing years on dialysis (OR 1.13; 95% CI, 1.05-1.22; p <0.01) and patients with BMI <16.6 kg/m(2) (OR 3.1; 95% CI, 1.2-8.4; p <0.05). Increasing age and level of intact parathyroid hormone were not associated with rhGH use among short stature patients. A significant proportion of pediatric hemodialysis patients have short stature. The majority of short-stature patients are not receiving rhGH. Patients with short stature who are white, have longer durations on dialysis and have lower BMI are more likely to receive rhGH.

Growth hormone for children with chronic renal failure and on dialysis

We studied all children with CRF who received recombinant human growth hormone (rhGH) for more than a year (mean+/-SD duration of therapy 3.7+/-2.5 years) over an 11-year period. There were 32 children. Twenty-one children were conservatively managed, with a mean glomerular filtration rate (GFR) of 24+/-12 mL min(-1)/1.73 m2 at the start of rhGH. Their height standard deviation score improved from -2.5+/-1.4 to -2.1+/-0.7 at 1 year (P=0.3), -2.0+/-0.7 at 2 years (P=0.01), and -1.6+/-0.6 at 3 years (P=0.001). After that there was no improvement. Eleven children were on dialysis, six on haemodialysis (HD) and five on peritoneal (PD). Ht SDS improved from -2.7+/-0.5 to -2.3+/-0.5 at 1 year (P=0.02). Thereafter there was no further improvement. RhGH was stopped because of transplantation in 29 patients at a mean+/-SD age of 12.1+/-4.0 years. Mean Ht SDS was -1.8+/-0.8 at transplant and there was no change over the following 5 years. In conclusion, treatment with rhGH resulted in improvement in Ht SDS in conservatively managed CRF for up to 3.0 years and for 1 year in children on dialysis. Discontinuation of rhGH after transplantation resulted in little change in Ht SDS.

Long-term recombinant human growth hormone use in Australian children with renal disease

BACKGROUND

Recombinant human growth hormone (rhGH) has been used for 15 years to treat Australian children with short stature caused by chronic kidney disease. The Australia-wide growth hormone database, OZGROW, has prospectively collected data for all patients treated with rhGH. The impact of rhGH therapy on linear growth in patients with chronic renal failure (CRF) was assessed by retrospectively analysing this data.

METHODS

Growth data prior to and during treatment, bone age, and pubertal data were recorded from the database. Questionnaire data provided further information on underlying renal disease, medication use, bone disease, and final height. Patients were classified according to treatment modality; conservative management of CRF, haemodialysis or peritoneal dialysis, and transplant.

RESULTS

Data on 183 patients were analysed. The duration of rhGH therapy ranged from 1.2 to 10.5 years (mean 5.3 years). The height standard deviation score (Ht SDS) in each patient group at the start and end of rhGH treatment were as follows: Predialysis: -2.6 to -2.1; dialysis: -2.7 to -2.3; transplant: -3.1 to -2.8 (P = 0.0001). Thirty-nine patients achieved final adult height, with mean Ht SDS before rhGH therapy being -2.65, and at final height it was 2.3. The mean final height for the males was 161.8 cm and for the females, it was 149.5 cm.

CONCLUSION

The effect of treatment with rhGH was less dramatic than reported in the literature. However, the positive benefit of rhGH therapy was apparent both in the short and long-term. Therapy with rhGH maintained a steady Ht SDS with time; without rhGH, it would be anticipated that many children would show a steady decline in Ht SDS. The maximum benefit was seen in preterminal renal failure, and early therapy (before dialysis or transplantation) is recommended before an irrecoverable loss of height potential occurs.

Growth hormone therapy before and after pediatric renal transplant

Children undergoing successful renal transplantation anticipate optimal growth and development. The use of rhGH pre- and post-Tx has been evaluated and supported by randomized control trials. Several strategies are required to maximize the potential benefit of this treatment in the renal population including provision of adequate nutrition intake, following bone parameters with appropriate interventions, and strategies to reduce steroid therapy including utilization of alternate day steroid treatment. Studies are required to further assess the impact of rhGH on renal allograft function, rejection risk, and allograft ultrastructural changes.

Growth in children with chronic renal failure on intermittent versus daily calcitriol

Calcitriol (C) treatment strategies for secondary hyperparathyroidism remain controversial regarding efficacy and safety. In children, intermittent C administration has been suspected of impairing body growth. In a prospective, randomized multicenter study, we compared the effect of daily versus twice weekly C on plasma intact parathyroid hormone (iPTH) levels and growth in 24 prepubertal children with chronic renal insufficiency (mean creatinine clearance 20+/-9 ml/min per 1.73 m(2)). After a 3-week washout period, the patients were randomly assigned to 10 ng/kg per day or 35 ng/kg twice a week oral C. The C dose was kept constant for 2 months and could then be adapted to maintain an iPTH target range of 140-280 pg/ml. Median (range) baseline iPTH levels were 567 (114-1209) pg/ml in the daily and 332 (93-614) pg/ml in the intermittent treatment group ( P=NS). After 12 months, iPTH had decreased to 255 (85-710) and 179 (51-443) pg/ml ( P<0.01). The average weekly dose of C was 76+/-34 and 62+/-34 ng/kg ( P=NS). Five episodes of calcium phosphate product>/=70 occurred in the daily group and four in the intermittent group. The change in height standard deviation score during the study period was not affected by either treatment modality (-0.18+/-0.34 vs. -0.05+/-0.52, P=NS). Daily and intermittent C do not differentially affect growth rate and are equally effective in controlling secondary hyperparathyroidism in children with chronic renal failure.

Preservation of bone mass in pediatric dialysis and transplant patients

Renal osteodystrophy continues to be a major challenge to the physician treating the child with end-stage renal disease (ESRD). The gold standard for the assessment of bone status is bone histomorphometry, which divides bone pathology into 3 main types; high-turnover, low-turnover, and mixed disease. The high-turnover disease, related to hyperparathyroidism, has been the one most extensively investigated; however, optimal therapy, especially in the growing child, is yet unclear. Overzealous treatment might result in adynamic bone disease (an extreme example of low-turnover disease), and further interference with statural growth. Pre-existent bone disease after kidney transplantation seems to worsen immediately, probably because of the high dose of corticosteroids used. In children who attain normal kidney function in the allograft, bone status seems to improve over time. Little is known about bone in transplanted patients with reduced glomerular filtration rate (GFR). The correlation between bone histology and its main surrogates, bone remodeling markers and bone mineral density, is yet unclear, but it might serve to follow the progress of an individual patient. New therapeutic modalities aimed at suppressing hyperparathyroidism, and consequently bone resorption, as well as agents directly attenuating bone resorption, should be further investigated for their effect on bone in patients with ESRD or after transplantation. Similarly, agents stimulating bone formation, particularly growth hormone, require further attention for their potential to improve bone status. Bone health and the child's somatic growth at ESRD or after kidney transplantation are closely related, and therapy should be aimed at achieving optimal results for both.

Long-term treatment with growth hormone in short children with nephropathic cystinosis

OBJECTIVE

The objective was to assess the efficacy and safety of growth hormone (GH) treatment in severely growth retarded children with nephropathic cystinosis during conservative treatment and during renal replacement therapy.

STUDY DESIGN

The design was an open-labeled prospective trial with a run-in period of 1 year.

RESULTS

A total of 74 children with cystinosis (age 3.0 to 18 years) were treated with GH over a mean period of 3.1 years (range 1 to 10 years); 52 patients were receiving conservative treatment (mean age 7.1 years), 7 were receiving dialysis (12.5 years), and 15 had received a renal transplant (14.8 years). The mean standardized height (SD score) was -4.0 in the conservative treatment group, -4.4 in the dialysis group, and -4.9 in the renal transplant group. During the first treatment year, height velocity doubled in the conservative treatment group, increased by 80% in the dialysis group, and increased by 45% in renal transplant group. Within 3 years the height SD score increased by +1.6 (P <.001) in prepubertal patients receiving conservative treatment, and percentile parallel growth was maintained thereafter. These effects of GH were less expressed in peripubertal patients receiving renal replacement therapy. No major side effects were observed.

CONCLUSION

Long-term GH treatment is safe and effective in young children with nephropathic cystinosis. GH treatment should be started early in the course of the disease if adequate nutrition and cysteamine treatment do not prevent growth retardation.

Growth factor insensitivity in renal failure

Advanced chronic renal failure is associated with multiple endocrine and metabolic abnormalities that result from changes in the secretion and metabolism of hormones and growth factors and the target organ sensitivity to their physiological actions. As a consequence, growth retardation, bone disease, pertubations in lipid, carbohydrate and protein metabolism are commonly seen in patients with chronic renal failure. The recent availability of recombinant growth factors has provided new therapeutic opportunities for correcting these abnormalities. However because of the presence of end-organ resistance relatively high dose therapy is required and this carries an increased risk of side effects. One logical approach to this problem would be to prevent or treat the underlying resistance and thus restore sensitivity to endogenous GH or low doses of the recombinant molecule. To achieve this goal, a better understanding of the mechanism of growth factor resistance is required. In this lecture, in honor of the memory of Frank Carone. I review our current state of knowledge of the impact of advanced renal failure on the tissue sensitivity to insulin, growth hormone and insulin-like-growth factor I.

Anthropometric measures and risk of death in children with end-stage renal disease

We evaluated the association between anthropometric measurements and death among pediatric patients with end-stage renal disease (ESRD) using data from the Pediatric Growth and Development Special Study (PGDSS) from the US Renal Data System. Height, growth velocity, and body mass index (BMI) were used for the analysis of 1,949 patients in the PGDSS. To standardize these measurements, SD scores (SDSs) were calculated using population data from the Third National Health and Nutrition Examination Survey. Using Cox proportional hazards models, we assessed the association between anthropometric measures and death, controlling for demographic factors and stratifying by age. Multivariate analysis showed that each decrease by 1 SDS in height was associated with a 14% increase in risk for death (adjusted relative risk [aRR], 1.14; 95% confidence interval [CI], 1.02 to 1.27; P = 0.017). For each 1 SDS decrease in growth velocity among patients in our sample, the risk for death increased by 12% (aRR, 1.12; 95% CI, 1.00 to 1.25; P = 0.043). There was a statistically significant U-shaped association between BMI and death (P = 0.001), with relatively low and high BMIs associated with an increased risk for death. In children with ESRD, growth delay and extremes in BMI are associated with an increased risk for mortality.

Effect of growth hormone treatment on the adult height of children with chronic renal failure. German Study Group for Growth Hormone Treatment in Chronic Renal Failure

BACKGROUND

Growth hormone treatment stimulates growth in short children with chronic renal failure. However, the extent to which this therapy increases final adult height is not known.

METHODS

We followed 38 initially prepubertal children with chronic renal failure treated with growth hormone for a mean of 5.3 years until they reached their final adult height. The mean (+/-SD) age at the start of treatment was 10.4+/-2.2 years, the mean bone age was 7.1+/-2.3 years, and the mean height was 3.1+/-1.2 SD below normal. Fifty matched children with chronic renal failure who were not treated with growth hormone served as controls.

RESULTS

The children treated with growth hormone had sustained catch-up growth, whereas the control children had progressive growth failure. The mean final height of the growth hormone-treated children was 165 cm for boys and 156 cm for girls. The mean final adult height of the growth hormone-treated children was 1.6+/-1.2 SD below normal, which was 1.4 SD above their standardized height at base line (P< 0.001). In contrast, the final height of the untreated children (2.1+/-1.2 SD below normal) was 0.6 SD below their standardized height at base line (P<0.001). Although prepubertal bone maturation was accelerated in growth hormone-treated children, treatment was not associated with a shortening of the pubertal growth spurt. The total height gain was positively associated with the initial target-height deficit and the duration of growth hormone therapy and was negatively associated with the percentage of the observation period spent receiving dialysis treatment.

CONCLUSIONS

Long-term growth hormone treatment of children with chronic renal failure induces persistent catch-up growth, and the majority of patients achieve normal adult height.

Effects of recombinant human growth hormone in catabolic adults with chronic renal failure

Growth hormone (GH) has been used for the treatment of catabolism in a few pilot studies and in two placebo-controlled studies of 6 months duration. Treatment with GH in doses of 2-4 IU/m2/day (0.67-1.33 mg/m2/day) resulted in clear anabolic effects and a significant change in body composition. Lean body mass increased by more than 3 kg within 6 months, whereas fat mass was decreased by the same amount, resulting in a constant total body weight. As there were no major side-effects, controlled long-term studies are justified.

Dialysis for end-stage renal disease

Peritoneal dialysis is the major renal replacement therapy for children with end-stage renal disease, with hemodialysis used for a substantial number of pediatric patients. Reduction of morbidity and mortality is a major goal with the use of these modalities. Adequacy of dialysis and maintenance of peritoneal membrane function are important considerations for children on long term dialysis. Both adequacy and function are important to ensure optimal growth and nutrition and improve morbidity in this population. Use of supplemental gastrostomy tube feeds has improved calorie-protein malnutrition. Therapy advancements, such as growth hormone and erythropoietin, have improved the quality of life for dialysis patients. As the survival of the pediatric patient with end-stage renal disease improves, issues regarding cardiovascular disease and other factors that increase mortality in the adult population will need to be addressed.

Peritoneal transport properties and dialysis dose affect growth and nutritional status in children on chronic peritoneal dialysis. Mid-European Pediatric Peritoneal Dialysis Study Group

To evaluate a possible effect of peritoneal transport properties and dialysis dose on the physical development of children on chronic peritoneal dialysis, a cohort of 51 children was prospectively followed for 18 mo. Peritoneal transport characteristics were assessed by serial peritoneal equilibration tests (PET), dialysis efficacy by dialysate and residual renal clearance measurements, and growth and nutritional status by the longitudinal changes (delta) of height SD score (SDS), body mass index (BMI) SDS, and serum albumin. delta height SDS was negatively correlated with the creatinine equilibration rate observed in the initial PET (r = -0.31, P < 0.05). Multiple regression analysis confirmed the negative effect of the high transporter state (partial r2 = 0.07), and disclosed an additional positive effect of dialytic C(Cr) (partial r2 = 0.11) and a weak negative effect of daily dialysate volume (partial r2 = 0.04) on delta height SDS. delta BMI SDS was strongly age-dependent (r = -0.48, P < 0.001); while relative body mass gradually increased below 4 yr of age, it remained stable in older children. Positive changes in BMI SDS were associated with rapid PET creatinine equilibration rates (univariate r = 0.35, P < 0.05) and/or large dialysate volumes (multivariate partial r2 = 0.11), suggesting a role of dialytic glucose uptake in the development of obesity. The change in serum albumin concentrations was positively correlated with dialysate volume (partial r2 = 0.14), and negatively affected by dialytic protein losses (partial r2 = 0.06). In conclusion, the peritoneal transporter state is a weak but significant determinant of growth and body mass gain in children on chronic peritoneal dialysis. Rapid small solute equilibration contributes to impaired growth but enhanced acquisition of body mass. Dialytic small solute clearance has a weak positive effect on statural growth independent of the transporter state, but does not affect body mass gain.