Final height of short subjects of low birth weight with and without growth hormone treatment

[Short stature due to intrauterine growth retardation. Clinical and hormonal-metabolic features, possibilities of growth-stimulating therapy]

The article presents data about short stature due to intrauterine development delay. This type of short stature - separate nosology, unites children born small for gestation age. The majority of them in the first years of life have accelerated growth rates, allowing the child to normalize their weight-growth indicators and catch up in the development of peers. In the absence of an accelerated growth rates, children have a high risk of lagging behind in physical development throughout childhood, achieving low final growth and becoming short adults. In addition, the fact of birth with small body sizes is associated with a number of hormonal and metabolic features, a risk of metabolic syndrome in adult years.It is assumed that the absence of postnatal growth acceleration is due to various damages to the GH-IGF1 axis (partial GH deficiency, partial resistance to GH, partial resistance to IGF1). Growth hormone therapy, initiated early in life, is able to normalize growth rates in childhood and ultimately significantly improve or normalize the final growth of short stature children born small for gestational age.

Growth and metabolic effects of long-term recombinant human growth hormone (rhGH) treatment in short children born small for gestational age: GH-RAST study

Objectives To study the efficacy and influence on metabolism of recombinant human growth hormone (rhGH) treatment in short children born small for gestational age (SGA). Methods Retrospective, observational, multicenter study in 305 short children born SGA, treated with rhGH during a mean ± SD of 5.03 ± 1.73 years at a mean ± SD dose of 37 ± 8 μg/kg/day. Auxological and metabolic assessment including glucose and lipids profile were collected. Results Mean ± SD age at the start of treatment was 7.11 ± 2.78 years. Height and weight improved significantly until the end of treatment from mean -2.72 (CI95%: -2.81 to -2.63) standard deviation score (SDS) to -1.16 (CI95%: -1.44 to -0.88) SDS and from -1.62 (CI95%: -1.69 to -1.55) SDS to -0.94 (CI95%: -1.14 to -0.74) SDS respectively. Mean height gain was 1.27 (CI95%: 0.99-1.54) SDS. Prepubertal patients showed higher height gain than pubertal children (mean [CI95%] = 1.44 [CI95%: 1.14-1.74] vs. 0.73 [CI95%: 0.22-1.24], p=0.02). Height gain SDS during treatment negatively correlated with chronological age (CA) and bone age (BA) delay and positively correlated with duration of treatment, height gain during first year of treatment, years on prepubertal treatment and height SDS from target height (TH). Glucose, insulin, and triglycerides increased significantly but remained within the normal range. Total and LDL-cholesterol decreased significantly, and HDL-cholesterol remained unchanged. Conclusions rhGH treatment in short SGA children effectively normalized height in most of the patients and showed a safe metabolic profile. Children who benefit the most are those with greater height SDS distance from TH, BA delay, longer duration of treatment and prepubertal treatment initiation.

Adult height in short children born small for gestational age treated with growth hormone

BACKGROUND AND OBJECTIVE

Recombinant human growth hormone (rhGH) treatment in small for gestational age (SGA) children has been effective, although there is significant variability in the response. Adult height and the factors that determine the long-term response are evaluated.

PATIENTS AND DESIGN

A retrospective study of 80 patients born SGA with short stature treated with rhGH and followed until adult height (23 males).

RESULTS

The group starting treatment pre-puberty reached a higher Adult height (-1.4±0.6 vs. -1.9±.6 in pubertal children), the highest final height gain was achieved in those treated for at least 2years prepuberty (1.32±.5 SDS). Factors associated with greater adult height gain were: a) less height, weight and BMI at start of treatment, b) lower chronological and bone age with lower IGF-I before treatment, c) greater distance to target height, d) higher growth velocity the first and second year of treatment, and higher height gain before and during puberty. The percentage of patients with good response in the first year ranged from 46.6% to 81.6% depending on the criteria. Growth velocity increase ≥3cm/ first year correlated best with long-term response.

CONCLUSION

rhGH treatment in children born SGA produced a varying increase in adult height that allowed them to reach their adult height. The best results occurred in the prepubertal group and did not depend on pituitary GH response.

Environmental and birth characteristics as predictors of short stature in early childhood

AIM

To evaluate for environmental and birth characteristic predictors of short stature in a large nationally representative sample.

METHODS

We evaluated 10 127 children from the Early Childhood Longitudinal Study-Kindergarten 2011 cohort, using univariate and multivariable linear and logistic regression to evaluate factors associated with short stature (height <3rd percentile) at kindergarten through second grade. Predictors included birthweight, preterm status, sex, parental education, parental income and race/ethnicity.

RESULTS

Lower birthweight was associated with short stature, with each decreasing kilogram having a 2.45 adjusted odds ratio (aOR; 95% confidence interval [CI] 1.81, 3.33) of short stature for term children in second grade. Preterm children (compared to term children) had an aOR of 2.23 (CI 1.32, 3.78) for short stature. Other predictors of short stature included female sex and lower parental income. African American children had a lower risk of short stature (aOR 0.34, CI 0.14, 0.82) compared to white children.

CONCLUSION

Predictors of short stature include lower birthweight, preterm status, female sex and parental income. Socio-economic disparities and race/ethnicity further influenced height. These data may assist paediatricians in considering contributors to stature outcomes by early school age.

Clinical response to growth hormone in children with intrauterine growth retardation without catch-up growth in Castilla y León (Spain)

INTRODUCTION AND OBJECTIVES

Growth hormone (rhGH) is used in children with intrauterine growth retardation without catch-up growth. The Advisory Committee of Castilla y León was implemented in 2010 to watch for consistent application of the criteria for using rhGH. The aim is to assess anthropometric and clinical changes in children treated with growth hormone.

PATIENTS AND METHODS

A retrospective, longitudinal study of patients diagnosed with intrauterine growth retardation without catch-up growth in Castilla y León since 2010 who have received treatment for at least 3 years. Changes in anthropometric, clinical, and laboratory parameters were assessed.

RESULTS

Forty-three children with a mean age of 6.06 years (58.14%<5 years) were enrolled and treated with a mean dose of 0.038mg/kg/day. A significant increase was seen in height (-3.05 to -1.58SD). Both weight and BMI (14.51 to 15.80kg/m²) increased throughout the study. Growth rate peaked during the first year of treatment (0.74SD). IGF-1 levels increased throughout the study (99.96 to 392.88ng/mL). There were significant increases in glycosylated hemoglobin levels in the first year, and in basal blood glucose and insulin levels during the second year. The LDL/HDL ratio decreased during the study period (1.70 to 1.50).

CONCLUSION

Treatment with rhGH promotes growth in children with intrauterine growth retardation. Peak effect occurs in the first 12 months of treatment, and is greater when growth hormone is started before the age of 5 years.

Efficacy and safety of growth hormone treatment for children born small for gestational age

Recombinant growth hormone (GH) is an effective treatment for short children who are born small for gestational age (SGA). Short children born SGA who fail to demonstrate catch-up growth by 2-4 years of age are candidates for GH treatment initiated to achieve catch-up growth to a normal height in early childhood, maintain a normal height gain throughout childhood, and achieve an adult height within the normal target range. GH treatment at a dose of 35-70 µg/kg/day should be considered for those with very marked growth retardation, as these patients require rapid catch-up growth. Factors associated with response to GH treatment during the initial 2-3 years of therapy include age and height standard deviation scores at the start of therapy, midparental height, and GH dose. Adverse events due to GH treatment are no more common in the SGA population than in other conditions treated with GH. Early surveillance in growth clinics is strongly recommended for children born SGA who have not caught up. Although high dose of up to 0.067 mg/kg/day are relatively safe for short children with growth failure, clinicians need to remain aware of long-term mortality and morbidity after GH treatment.

Prediction models for short children born small for gestational age (SGA) covering the total growth phase. Analyses based on data from KIGS (Pfizer International Growth Database)

BACKGROUND

Mathematical models can be developed to predict growth in short children treated with growth hormone (GH). These models can serve to optimize and individualize treatment in terms of height outcomes and costs. The aims of this study were to compile existing prediction models for short children born SGA (SGA), to develop new models and to validate the algorithms.

METHODS

Existing models to predict height velocity (HV) for the first two and the fourth prepubertal years and during total pubertal growth (TPG) on GH were applied to SGA children from the KIGS (Pfizer International Growth Database)--1st year: N = 2340; 2nd year: N = 1358; 4th year: N = 182; TPG: N = 59. A new prediction model was developed for the 3rd prepubertal year based upon 317 children by means of the all-possible regression approach, using Mallow's C(p) criterion.

RESULTS

The comparison between the observed and predicted height velocity showed no significant difference when the existing prediction models were applied to new cohorts. A model for predicting HV during the 3rd year explained 33% of the variability with an error SD of 1.0 cm/year. The predictors were (in order of importance): HV previous year; chronological age; weight SDS; mid-parent height SDS and GH dose.

CONCLUSIONS

Models to predict growth to GH from prepubertal years to adult height are available for short children born SGA. The models utilize easily accessible predictors and are accurate. The overall explained variability in SGA is relatively low, due to the heterogeneity of the disorder. The models can be used to provide patients with a realistic expectation of treatment, and may help to identify compliance problems or other underlying causes of treatment failure.

Impact of growth hormone therapy on adult height of children born small for gestational age

CONTEXT

Use of growth hormone (GH) therapy to promote growth in short children born small for gestational age (SGA) was recently approved in the United States and Europe, but there is still disagreement about the magnitude of effectiveness of GH.

OBJECTIVE

To determine the impact of GH therapy on adult height in short SGA children by a meta-analysis of randomized, controlled trials (RCTs).

METHODS

We performed a systematic review of controlled studies using as data sources the Cochrane Central Register of Controlled Trials, Medline, and the bibliographic references from all retrieved articles describing RCTs up to November 2008. A meta-analysis of all RCT studies conducted up to the achievement of adult height was performed. Inclusion criteria were birth weight and/or length below -2 SD score (SDS), initial height less than -2 SDS, and GH dose range of 33 to 67 microg/kg per day. Adult height SDS and overall height gain SDS were the primary outcome measures.

RESULTS

Four RCTs (391 children) met the inclusion criteria. The adult height of the GH-treated group significantly exceeded controls by 0.9 SDS. Mean height gain was 1.5 SDS in treated versus 0.25 SDS in untreated SGA subjects. No significant difference in adult height was observed between the 2 GH dose regimens.

CONCLUSIONS

GH therapy seems to be an effective approach to partially reduce the adult height deficit in short SGA children. However, the response to therapy is highly variable, and additional studies are needed to identify the responders.

Growth hormone treatment for short stature in children born small for gestational age

Children born small for gestational age (SGA) who do not show catch-up in the first 2 years generally remain short for life. Although the majority of children born SGA are not growth hormone (GH) deficient, GH treatment is known to improve average growth in these children.Early studies using GH in children born SGA demonstrated increased height velocity, but these effects tended to be short-term with effects decreasing when GH treatment stopped. With refined GH regimens, significant effects on height have been shown, with gains of approximately 1 standard deviation score after 2 years. Studies have also shown that long-term continuous GH therapy can significantly increase final height to within the normal range. GH treatment of children born SGA does not appear to unduly affect bone age or pubertal development. Growth prediction models have been used to identify various factors involved in the response to GH therapy with age at start, treatment duration, and GH dose showing strong effects. Genetic factors such as the exon 3 deletion of the GH receptor may contribute to short stature of children born SGA and may also be involved in the responsiveness to GH treatment, but there remain other unknown genetic and/or environmental factors. No unexpected safety concerns have arisen in GH therapy trials. In particular, no long-term adverse effects have been seen for glucose metabolism, and positive effects have been shown for lipid profiles and blood pressure.GH treatment in short children born SGA has shown a beneficial, growth-promoting effect in both the short-and long-term, and has become a recognized indication in both the US and Europe. Further studies on individualized treatment regimens and long-term safety are ongoing.

Safety and efficacy of growth hormone treatment in small for gestational age children

PURPOSE OF REVIEW

Approximately 100,000 infants are born small for gestational age (birth weight <2 standard deviation) annually in the US alone. Because of catch-up growth, 10-20% of all children born small for gestational age will be eligible for growth hormone therapy. Growth hormone has been approved by the Food and Drug Administration in 2003 and by the European Agency for the Evaluation of Medical Products though at different enrollment and treatment criteria. Benefits and risks of growth hormone therapy for small for gestational age children are the purpose of the present review.

RECENT FINDINGS

Mean height increased by as much as two standard deviation over 3 years of treatment in infants born small for gestational age. Rapid catch-up growth is desirable and will only be achieved with higher growth hormone doses (0.48 mg/kg/week) Treatment should be continuous and not interrupted. The safety profile of growth hormone treatment is excellent. Transient elevation of insulin levels returned to near normal after growth hormone treatment was discontinued.

SUMMARY

Growth hormone treatment in small for gestational age children has been found to be well tolerated and is an important advance in the treatment of short stature in pediatrics. Treatment of short prematurely born infants with growth hormone may offer similar efficacy and safety as growth hormone treatment in small for gestational age infants.

[Growth hormone therapy for short children born small for gestational age]

Approximately 10% of all children born small for gestational age (SGA) fail to achieve sufficient catch-up growth and remain with short stature throughout childhood and adult life. Abnormalities of the GH/IGF-1 axis are not always identified. Several studies have demonstrated that GH is an effective and well-tolerated therapy and most children will reach a normal adult height. In this review, it can be seen the encouraging results of GH treatment in growth-retarded children born SGA highlighting the benefits of early treatment.

Optimal use of growth hormone therapy for maximizing adult height in children born small for gestational age

Growth retardation is a well-known complication of being born small for gestational age (SGA). Approximately 10% of children born SGA do not experience postnatal catch-up growth and are at risk for short adult height. The use of growth hormone (GH) therapy in these short children appears to increase their adult height, but modalities of GH administration remain controversial. Numerous therapeutic strategies have been developed to optimize the efficacy of GH treatment. Data concerning the influence of age at start of GH treatment, duration of GH treatment, GH dosage and method of GH administration on height gain and adult height are reported in this chapter. Longitudinal studies addressing the safety of GH treatment in SGA children are reassuring, but long-term follow-up remains necessary. Recommendations on the management of SGA children during GH treatment are given.

Individualization of growth hormone therapy

Short children born small for gestational age account for 20% of patients with short stature. These children should be investigated individually to identify treatable causes of their short stature and any associated neurodevelopmental problems. Randomized controlled growth hormone therapy trials demonstrate growth acceleration in childhood and improved adult height. The individualization of therapy is increasingly possible with insight from the available prediction models. These identify the main modifiable factors such as dose of growth hormone and age at the start of therapy. Non-modifiable factors including target height standard deviation score (SDS), weight SDS at the start of therapy, and first year response to therapy also play a significant role.

Growth and growth hormone in children born small for gestational age

Although most children born small for gestational age catch up in growth by age 2 y, up to 14% remain more than 2 standard deviations below the mean for height. Recombinant growth hormone is approved by the US Food and Drug Administration and by the European Agency for Evaluation of Medicinal Products for the treatment of children born small for gestational age who fail to manifest catch-up growth by 2 y or 4 y, respectively.

CONCLUSION

We conclude from clinical studies that growth hormone therapy can induce catch-up growth in these children.

Adult height of prepubertal short children born small for gestational age treated with GH

OBJECTIVE

Human GH (hGH) treatment leads to catch-up growth in children with short stature born small for gestational age (SGA). However, long-term efficacy and safety results in this patient group remain scarce. The present study assessed the efficacy and safety of late childhood treatment with biosynthetic hGH (Humatrope) in a group of short children born SGA (height <-2 standard deviation scores (SDS)).

DESIGN

Patients in this open-label, Phase III, multicenter study received a daily hGH dose of 0.067 mg/kg for 2 years, and then received no treatment for the following 2 years. After the fourth year on study, patients whose height had decreased more than 0.5 SDS but who still showed growth potential based on bone age were allowed to resume treatment until they reached adult height.

METHODS

Height gain SDS was assessed for 11 girls and 24 boys (mean age+/-s.d. 9.6+/-0.9 years) at the end of the 2 years of hGH treatment, during the subsequent 2-year off-treatment period, and upon reaching adult height.

RESULTS

At the end of the initial 2-year treatment period, 83% of patients had reached a height within the normal range, with a mean increase in height SDS vs baseline of 1.3+/-0.3 (P <0.001). Adult heights (n = 20) were within the normal range for 50% of patients, and mean height gain from baseline was statistically significant (0.7+/-0.8 SDS, P <0.001). Fasting glucose and glycosylated hemoglobin levels were not significantly modified during treatment.

CONCLUSIONS

High-dose hGH treatment for a minimum of 2 years in short children born SGA was well tolerated and resulted in a significant increase in adolescent and adult height.

Should recombinant human growth hormone therapy be used in short small for gestational age children?

Short small for gestational age (SGA) children represent 20% of all children with short stature and therefore constitute a significant portion of the caseload in a growth clinic. The recent approval of recombinant human growth hormone (GH) for the treatment of short stature in SGA children by the European Union's Committee on Proprietary Medicinal Products offers a new licensed therapeutic option. This article examines the role of GH therapy in short SGA children with particular reference to selection of patients, effectiveness, safety, and its potential metabolic implications.

Long term outcome of small versus appropriate size for gestational age co-twins/triplets

BACKGROUND

Small for gestational age (SGA) extremely low birthweight (ELBW < 1000 g) survivors often remain small and/or have subnormal school performance. Some are twins/triplets with larger appropriate size for gestational age (AGA) co-twins/triplets.

OBJECTIVE

To assess whether SGA ELBW twins/triplets remain different from their AGA co-twins/triplets.

DESIGN, SETTING

During 1981-1999, 353 SGA ELBW neonates were admitted to our neonatal intensive care unit: 267 survived, 54/267 were twins/triplets, and 36/54 had AGA surviving co-twins/triplets. This longitudinal study describes the growth, neurodevelopmental outcome, and school performance of these 36 sets (3-17 years). The children were classified as normal, or having minor, moderate, or severe deficiencies.

RESULTS

Values for birth weight (mean intrapair z score difference 2.26), length (2.74), and head circumference (2.62) were lower in SGA neonates than in AGA co-twins/triplets. SGA survivors remained smaller at 3-6 years of age: mean intrapair z score difference in weight, 1.37, height, 1.54, head circumference, 1.21. From 6 to 17 years, smaller differences persisted. Former SGA children had a tendency to have motor deficiencies (nine SGA v three AGA) and mental retardation (seven v four), same hearing loss (two v two), but significantly more visual abnormalities (15 v 11), behavioural disturbances (14 v five), and speech problems (14 v eight). Twenty four sets were in the same normal level class, often supported by familial/professional help.

CONCLUSIONS

Although raised in the same environment, SGA ELBW survivors remained smaller and had more visual/behavioural/speech problems, but most maintained grade level parity with their AGA siblings, with appropriate help.

International Small for Gestational Age Advisory Board consensus development conference statement: management of short children born small for gestational age, April 24-October 1, 2001

OBJECTIVE

To provide pediatric endocrinologists, general pediatricians, neonatologists, and primary care physicians with recommendations for the management of short children born small for gestational age (SGA).

METHODS

A 13-member independent panel of pediatric endocrinologists was convened to discuss relevant issues with respect to definition, diagnosis, and clinical management of short children born SGA. Panel members convened over a series of 3 meetings to thoroughly review, discuss, and come to consensus on the identification and treatment of short children who are born SGA.

CONCLUSIONS

SGA is defined as birth weight and/or length at least 2 standard deviations (SDs) below the mean for gestational age (<or=-2 SD). Accurate gestational dating and measurement of birth weight and length are crucial for identifying children who are born SGA. Comprehensive pregnancy, perinatal, and immediate postnatal data may help to confirm the diagnosis. Maternal, placental, and fetal causes of SGA should be sought, although the cause is often not clear. Most children who are SGA experience catch-up growth and achieve a height >2 SD below the mean; this catch-up process is usually completed by the time they are 2 years of age. A child who is SGA and older than 3 years and has persistent short stature (ie, remaining at least 2 SD below the mean for chronologic age) is not likely to catch up and should be referred to a pediatrician who has expertise in endocrinology. Bone age is not a reliable predictor of height potential in children who are SGA. Nevertheless, a standard evaluation for short stature should be performed. A diagnosis of SGA does not exclude growth hormone (GH) deficiency, and GH assessment should be performed if there is clinical suspicion or biochemical evidence of GH deficiency. At baseline, insulin-like growth factor-I, insulin-like growth factor binding protein-3, fasting insulin, glucose, and lipid levels as well as blood pressure should be measured, and all aspects of SGA-not just stature-should be addressed with parents. The objectives of GH therapy in short children who are SGA are catch-up growth in early childhood, maintenance of normal growth in childhood, and achievement of normal adult height. GH therapy is effective and safe in short children who are born SGA and should be considered in those older than 2 to 3 years. There is long-term experience of improved growth using a dosage range from 0.24 to 0.48 mg/kg/wk. Higher GH doses (0.48 mg/kg/wk [0.2 IU/kg/d]) are more effective for the short term. Whether the higher GH dose is more efficacious than the lower dose in terms of adult height results is not yet known. Only adult height results of randomized dose-response studies will give a definite answer. Monitoring is necessary to ensure safety of medication. Children should be monitored for changes in glucose homeostasis, lipids, and blood pressure during therapy. The frequency and intensity of monitoring will vary depending on risk factors such as family history, obesity, and puberty.

Growth hormone therapy

Since 1958 growth hormone (GH) has been used as substitution treatment for children with GH deficiency. At present, it is clear that a dose of 0.23 mg/kg/week can lead to a final height close to target height, but in view of the wide inter-individual variation, alternative regimens based on invidualizing the dosage with the help of prediction models are being investigated. The best strategy during puberty (increase the dosage, delay puberty) is still uncertain. The value of GH in idiopathic short stature is still heavily debated, although the average final height gain on 0.33 mg/kg/week is 5-7 cm. GH is efficacious in short stature due to chronic renal failure and Prader-Willi syndrome. In other conditions insufficient data are available. There are few side-effects.

Expanded spectrum of recombinant human growth hormone therapy

The efficacy of recombinant human growth hormone in the treatment of growth hormone deficiency is well established. In recent years, the use of recombinant human growth hormone as a therapeutic modality has greatly increased and has expanded beyond the realm of replacement for growth hormone deficiency. Recombinant human growth hormone has been employed to ameliorate growth failure in multiple other disorders. For some, like Turner syndrome, recombinant human growth hormone has become the standard of care. For others, the ultimate benefit of recombinant human growth hormone remains to be determined. Although recent investigations provide encouraging short-term data, it is important to recognize that the impact of recombinant human growth hormone therapy on adult height has not been established in a number of conditions.