Randomised trial of growth hormone in short normal girls

Effect of Growth Hormone Therapy on Pubertal Timing: Systematic Review and Meta-Analysis

INTRODUCTION

Recombinant human growth hormone (rhGH) therapy effectively increases height in various disorders of childhood growth. However, whether rhGH affects pubertal timing is unclear. We aimed to review systematically published evidence on the effect of rhGH on pubertal timing.

METHODS

Embase, MEDLINE, and Cochrane Library databases were searched until December 2021 on randomized and non-randomized controlled studies of rhGH in children.

RESULTS

Twenty-five articles (n = 1,433 children) were identified, describing 12 randomized and 13 non-randomized controlled studies in children with idiopathic short stature (ISS; 15 studies), small for gestational age (n = 6 studies), chronic renal failure (n = 3), Noonan syndrome (n = 1), and growth hormone deficiency (n = 1). Significant differences in the effects of rhGH on pubertal timing were found by clinical indication. Only among children with ISS, rhGH promoted earlier age at pubertal timing (mean difference = -0.46 years; 95% CI, -0.90 to -0.03; 9 studies; n total = 397) or higher relative risk for pubertal onset during study follow-up (1.26; 95% CI, 1.03 to 1.54; 6 studies; n total = 284).

CONCLUSIONS

Treatment with rhGH appears to promote earlier pubertal timing among children with ISS. Evidence was lacking in children with growth hormone deficiency due to the absence of studies with untreated controls.

Long-term GH Therapy Does Not Advance Skeletal Maturation in Children and Adolescents

Context

There is no consensus on the effect of recombinant human GH (rhGH) therapy on skeletal maturation in children despite the current practice of annual monitoring of skeletal maturation with bone age in children on rhGH therapy.

Aims

To investigate the effects of long-term rhGH therapy on skeletal age in children and explore the accuracy of bone age-predicted adult height (BAPAH) at different ages based on 13 years of longitudinal data.

Methods

A retrospective longitudinal study of 71 subjects aged 2 to 16 years, mean 9.9 ± 3.8 years, treated with rhGH for nonsyndromic short stature for a duration of 2 to 14 years, mean, 5.5 ± 2.6 years. Subjects with syndromic short stature and systemic illnesses such as renal failure were excluded.

Results

Bone age minus chronological age (BA-CA) did not differ significantly between baseline and the end of rhGH therapy (-1.05 ± 1.42 vs -0.69 ± 1.63, P = 0.09). Piecewise regression, however, showed a quantifiable catch-up phenomenon in BA of 1.5 months per year of rhGH therapy in the first 6.5 years (P = 0.017) that plateaued thereafter (P = 0.88). BAPAH overestimated near-adult height in younger subjects but became more accurate in older subjects (P < 0.0001). IGF-I levels correlated significantly with increases in child's height and BA-CA.

Conclusion

Long-term rhGH therapy demonstrated an initial catch-up phenomenon in skeletal maturation in the first 6.5 years that plateaued thereafter with no overall significant advancement in bone age. These findings are reassuring and support strategic, but not the insurance company mandated reflexive annual monitoring of skeletal maturation with bone age in children receiving rhGH therapy.

The effect of treatment with recombinant human growth hormone (rhGH) on linear growth and adult height in children with idiopathic short stature (ISS): a systematic review and meta-analysis

OBJECTIVES

Idiopathic short stature (ISS) is a recognized, albeit a controversial indication for treatment with recombinant human growth hormone (rhGH).The objective of the present study was to conduct a systematic review of the literature and meta-analyses of selected studies about the use of rhGH in children with ISS on linear growth and adult height (AH).

METHODS

A systematic literature search was conducted to identify relevant studies published till February 28, 2017 in the following databases: Medline (PubMed), Scopus and Cochrane Central Registry of Controlled Trials. After exclusion of duplicate studies, 3,609 studies were initially identified. Of those, 3,497 studies were excluded during the process of assessing the title and/or the abstract. The remaining 112 studies were evaluated further by assessing the full text; 21 of them fulfilled all the criteria in order to be included in the current meta-analysis.

RESULTS

Children who received rhGH had significantly higher height increment at the end of the first year, an effect that persisted in the second year of treatment and achieved significantly higher AH than the control group. The difference between the two groups was equal to 5.3 cm (95% CI: 3.4-7 cm) for male and 4.7 cm (95% CI: 3.1-6.3 cm) for female patients.

CONCLUSION

In children with ISS, treatment with rhGH improves short-term linear growth and increases AH compared with control subjects. However, the final decision should be made on an individual basis, following detailed diagnostic evaluation and careful consideration of both risks and benefits of rhGH administration.

Effect of growth hormone treatment on children with idiopathic short stature (ISS), idiopathic growth hormone deficiency (IGHD), small for gestational age (SGA) and Turner syndrome (TS) in a tertiary care center

OBJECTIVES

To assess the long-term effect of growth hormone (GH) therapy in a large cohort of short children with different etiologies.

PATIENTS AND METHODS

We evaluated retrospectively the anthropometric data of 252 short children [height SDS <-2: 154 children with growth hormone deficiency (GHD), 63 with idiopathic short stature (ISS), 26 with SGA, and 9 with Turner syndrome (TS)] who were treated, in our center, with GH between 1-2007 and 1-2018. Before and during recombinamt growth-hormone (recGH) treatment, auxological parameters including height (Ht), weight (Wt), Ht - Z score (HtSDS), body mass index (BMI) and BMISDS were recorded every 6 months; bone age (BA) was assessed every 12 months.

RESULTS

At the end of first year of rhGH therapy and after an average of 3 years treatment all groups of short children had significant increase in HtSDS, which was higher in GHD compared to other groups. Children with GHD, SGA, ISS and TS increased their HtSDS by an average of 2.2, 1.46, 0.6 and 0.99 SD, respectively at the end of follow up period (for all groups, p: <0.001). The bone age/chronological age (BA/CA) ratio did not differ significantly among ISS, GHD and SGA groups after GH therapy. The HtSDS gain was higher in children with GHD compared to other ISS, SGA and TS groups (p:< 0.01; p: 0.015 and p: 0.029, respectively).  HtSDS improvement occurred during the first 3 years of rhGH therapy. The BMISDS increased significantly in children with GHD, after 3 years of rhGH therapy (p: < 0.001). After rhGH treatment, the BMISDS decreased significantly in children with ISS and SGA (p: < 0.01 and < 0.001, respectively) but did not change in children with TS (p: 0.199).

CONCLUSIONS

Children with GHD, SGA, ISS and TS exhibited significant increases in HtSDS when treated with rhGH for 3 years. The HtSDS gain was higher in children with GHD compared to other groups.

Differences in Response to Recombinant Growth Hormone Therapy on Height Gain in Patients with Idiopathic Short Stature Vs. Patients with Growth Hormone Deficiency

Objective The use of recombinant human growth hormone (rhGH) in patients with idiopathic short stature (ISS) has been an area of concern since some studies reported less desired effects of the drug in this group of patients as compared to patients with growth hormone deficiency (GHD). In addition, there were no studies addressing the effects of rhGH in Saudi children. Therefore, we conducted a retrospective study to observe the effects one year of treatment with rhGH on the mean height gain in patients with ISS and GHD. Methods This retrospective study took place at King Abdulaziz Medical City in Jeddah. The study subjects included two groups of patients (GHD vs ISS). Patients' files were reviewed from January 2000 to January 2018 using the following parameters: chronological age, bone age, height, weight, body mass index (BMI), insulin-like growth factor (IGF-1), growth hormone stimulation test, and growth velocity (GV). After one year of treatment, the height, weight, and BMI of the study subjects were monitored and assessed. Results The total number of patients was 55, 36 of which were diagnosed with GHD while 19 were diagnosed with ISS. The mean age of patients with GHD and ISS were 10.7±2.38 and 10.91±2.74 years, respectively. Both groups showed a significant increase in height. The initial height for patients with GHD was 125.26±12.27 cm, and they achieved a mean height of 134.231±12.88 cm after one year of treatment. For the other group, the initial height for ISS patients was 125.51±10.94 cm, and they achieved a mean height of 134.04±10.90 cm after one-year therapy. However, after the treatment, there was no significant difference in the height gain between GHD and ISS patients (134.231±12.88, 134.04±10.90, respectively, P=0.437). Conclusion The short-term use of rhGH has a potent and similar effect on increasing the height of both patients diagnosed with ISS as well as GHD.

Height Gain and Safety Outcomes in Growth Hormone-Treated Children with Idiopathic Short Stature: Experience from a Prospective Observational Study

BACKGROUND/OBJECTIVES

Growth hormone (GH) treatment of idiopathic short stature (ISS) received US Food and Drug Administration approval in 2003. We assessed height gain and safety in 2,450 children with ISS treated with GH in US clinical practice.

METHODS

Short-term height gain, near-adult height (NAH), and safety outcomes were investigated using Genetics and Neuroendocrinology of Short Stature International Study data.

RESULTS

Compared to children with isolated idiopathic GH deficiency (IGHD), those with ISS were shorter at baseline but had similar age and GH dose. Mean ± SD height SD score (SDS) increase was similar for ISS and IGHD, with 0.6 ± 0.3 (first), 0.4 ± 0.3 (second), 0.3 ± 0.3 (third), and 0.1 ± 0.3 (fourth year) for ISS. Girls with ISS (27% of subjects) were younger and shorter than boys but had similar height gain over time. At NAH in the ISS group (n = 467), mean ± SD age, GH duration, and height SDS were 17.3 ± 2.3 years, 4.6 ± 2.7 years, and -1.2 ± 0.9, respectively. Height gain from baseline was 1.1 ± 1.0 SDS and was greater for boys than girls (1.2 ± 1.0 vs. 0.9 ± 0.9), but boys were treated longer (5.1 ± 2.8 vs. 3.6 ± 2.5 years). Adverse events were reported for 24% with ISS versus 20% with IGHD - most were common childhood conditions or previously reported in GH-treated patients.

CONCLUSIONS

GH-treated children with ISS achieved substantial height gain, similar to patients with IGHD. Fewer GH-treated girls were enrolled than boys, but with similar height SDS gain over time. No ISS-specific safety issues were identified. Thus, GH treatment of ISS appears to have a safety/effectiveness profile similar to that of IGHD.

Effect of Growth Hormone Therapy on Height Velocity in Korean Children with Idiopathic Short Stature: A Phase III Randomised Controlled Trial

BACKGROUND/AIMS

The SYNERGY (Saizen® for Your New Life and Brighter Tomorrow without Growth Deficiency) study is the first randomised multi-centre, open-label study to assess the short-term efficacy and safety of this recombinant human growth hormone (r-hGH) preparation for prepubertal children with idiopathic short stature in South Korea.

METHODS

The SYNERGY study (ClinicalTrials.gov NCT01746862) was conducted at 9 centres throughout South Korea between December 2012 and March 2015. The primary endpoint was difference in height velocity from baseline to 6 months in the treatment and control arms.

RESULTS

97 children were screened; 90 were randomly assigned: 60 children to 0.067 mg/kg/day r-hGH for 12 months (treatment) and 30 children to 6 months of no treatment followed by 0.067 mg/kg/day r-hGH for 6 months (control). The 6-month mean height velocity in the treatment group increased from 5.63 cm/year (SD 1.62) to 10.08 cm/year (SD 1.92) (p < 0.0001) and from 4.94 cm/year (SD 1.91) to 5.92 cm/year (SD 2.01) (p = 0.0938) in the control group (between-group difference 3.47 cm/year, 95% CI 2.17-4.78; p < 0.0001). Adherence was > 90% throughout the study. The safety profile was consistent with that already known for r-hGH.

CONCLUSION

Treatment with r-hGH in the SYNERGY study demonstrated a statistically significant increase in height velocity at 6 months.

The Rationale for Growth Hormone Therapy in Children with Short Stature

Growth hormone (GH) was first isolated from cadaver pituitary glands, requiring laborious and expensive collection of glands, followed by extraction and purification of the hormone. This limited supply restricted its use to children with severe GH deficiency who were treated with low dosages and suboptimal schedules. The development of recombinant DNA-derived GH, allowed the production of virtually unlimited amounts of GH, leading to the approval for therapy for a large number of childhood conditions characterized by non-GH deficient short stature. The aim of this review is to provide a critical overview on the daily use of GH in two paradigmatic conditions of non-GH deficient short stature which are children born small for gestational age and with idiopathic short stature, highlighting the available strength of evidence for efficacy and safety.

Effect of growth hormone treatment on children with idiopathic short stature and idiopathic growth hormone deficiency

PURPOSE

There are inconsistencies in the results reported in a small number of previous studies into growth hormone (GH) treatment in Korean children with idiopathic short stature (ISS) and idiopathic growth hormone deficiency (IGHD). Thus, the authors retrospectively compared the effects of GH in ISS and IGHD.

METHODS

From the medical records of 26 ISS and 30 IGHD children, auxological and biochemical changes including chronologic age (CA), bone age (BA), height standard deviation score (HT-SDS), predicted adult height (PAH), midparental height (MPH), insulin-like growth factor-1 (IGF-1), and insulin-like growth factor binding protein-3 (IGFBP-3) were compared.

RESULTS

Before treatment, IGHD group had younger BA, lower BA/CA ratio, and lower IGF-1 level than those in the ISS group. During GH treatment, the levels of IGF-1 and IGFBP-3 were not different. Although annual BA increment was higher in IGHD group, and annual PAH-SDS increment was higher in ISS group, annual HT-SDS increments were not different. Both HT-SDS and PAH-SDS in the ISS group increased significantly until the end of the second year, and then those were not significantly different from MPH-SDS. In the IGHD group, the HT-SDS showed a significant increase till the end of the second year, and the PAH-SDS was not significantly changed at each year, but both HT-SDS and PAH-SDS were not significantly different from MPH-SDS at the end of the third year.

CONCLUSION

During GH treatment, both HT-SDS and PAH-SDS approached the genetic target range of MPH-SDS after 2 years in ISS children and 3 years in IGHD children.

Efficacy of long-term growth hormone therapy in short non-growth hormone-deficient children

BACKGROUND

In recent years, several studies have been published showing different responses to growth hormone (GH) treatment in idiopathic short stature children. The aim of the present study was to investigate whether non-growth-hormone-deficient (non-GHD) short children could benefit from long-term GH treatment as GHD patients.

METHODS

We enrolled 22 prepubertal children and 22 age- and sex-matched GHD patients, with comparable height, body mass index (BMI), bone age, and insulin-like growth factor 1 (IGF-I) circulating levels. The patients were treated with recombinant human GH (rhGH) and followed until they reach adult height.

RESULTS

During GH treatment, the two groups grew in parallel, reaching the same final height-standard deviation score (SDS) and the same height gain. On the contrary, we found significantly lower IGF-I serum concentrations in non-GHD patients than in GHD ones, at the end of therapy (p=0.0055).

CONCLUSIONS

In our study, the response to GH treatment in short non-GHD patients proved to be similar to that in GHD ones. However, a careful selection of short non-GHD children to be treated with GH would better justify the cost of long-term GH therapy.

Growth Pattern in Paediatric Crohn Disease Is Related to Inflammatory Status

OBJECTIVES

The respective role of disease activity and steroid therapy in growth impairment in paediatric-onset Crohn disease (CD) is still debated. Our aim was to investigate whether the growth pattern of children with CD was correlated with the inflammatory status during the disease course, regardless the cumulative duration of steroid therapy.

METHODS

One hundred and seven patients with a diagnosis of CD <17 years, followed during ≥2 years and for whom ≥2 height measures were available during follow-up, were identified between 1998 and 2010. Height, C-reactive protein (CRP), orosomucoid, and steroid therapy duration were collected at each visit. The relationship between the evolution of growth velocity and inflammatory status during follow-up was investigated using a linear mixed model with random coefficients.

RESULTS

Median age at diagnosis was 11.7 years (Q1-Q3: 9.8-13.5). Mean height for age (H/A) z score was 0.14 ± 1.29 at diagnosis and 0.05 ± 1.23 among the 75 patients who had reached their final height at maximal follow-up (median: 4.9 years; Q1-Q3: 3.8-6.4). Growth failure (H/A z score <-2) was present in 7 (8%) patients at diagnosis and 5 (5%) at maximal follow-up. Growth velocity was negatively correlated with the evolution of CRP (P < 0.0001) and orosomucoid (P < 0.0001) during follow-up. After adjustment for the cumulative duration of steroid therapy, these 2 correlations remained significant (CRP: P = 0.0008; orosomucoid: P < 0.0001).

CONCLUSIONS

Children with CD with uncontrolled inflammatory status have a lower growth velocity. The inflammatory status should be kept as close to normal as possible in paediatric-onset patients with CD to optimize their growth pattern.

A randomized pilot trial of growth hormone with anastrozole versus growth hormone alone, starting at the very end of puberty in adolescents with idiopathic short stature

BACKGROUND

When given during the course of puberty, anastrozole (A), an aromatase inhibitor, has been shown to increase the predicted adult height (PAH) of GH-deficient (GHD) boys treated with recombinant human growth hormone (rhGH). Our study questioned whether this treatment could retain some of its effects in non-GHD adolescent boys if started only at the very end of puberty, a time when rhGH treatment is denied to short adolescents who have almost reached their final height.

OBJECTIVE

To explore the effect on adult height of a combination of rhGH and A, compared with rhGH alone, at the end of puberty in boys with idiopatic short stature (ISS).

METHODS

A prospective randomized study comparing rhGH + A and rhGH was conducted in 24 healthy adolescent boys aged 15.2 ± 1.2 yrs with serum testosterone at adult levels and a faltering growth velocity <3.5 cm/yr leading to a predicted adult height (PAH) <2.5 SDS. Treatments were stopped when growth velocity became <10 mm in 6 months or when height was close to 170 cm. A historical group of ISS adolescents (N = 17) matched for puberty and growth was used for comparison.

RESULTS

IGF1 levels remained within normal limits in all treated patients. Mean treatment duration was 19 months in the rhGH + A group and 11.5 months in the rhGH group (P = 6.10(-4)). Adult height reached 168.4 ± 2.6 cm in the rhGH + A group and 164.2 ± 5.6 cm in the rhGH group (P < 0.02). Adult height was 160.1 ± 2.8 cm in the historical controls.

CONCLUSION

A combination of rhGH and A, started at the very end of puberty, seems to allow boys with ISS to reach a greater adult height than rhGH alone. Larger trials are needed to confirm this preliminary observation.

Outcomes for patients with the same disease treated inside and outside of randomized trials: a systematic review and meta-analysis

BACKGROUND

It is unclear whether participation in a randomized controlled trial (RCT), irrespective of assigned treatment, is harmful or beneficial to participants. We compared outcomes for patients with the same diagnoses who did ("insiders") and did not ("outsiders") enter RCTs, without regard to the specific therapies received for their respective diagnoses.

METHODS

By searching the MEDLINE (1966-2010), Embase (1980-2010), CENTRAL (1960-2010) and PsycINFO (1880-2010) databases, we identified 147 studies that reported the health outcomes of "insiders" and a group of parallel or consecutive "outsiders" within the same time period. We prepared a narrative review and, as appropriate, meta-analyses of patients' outcomes.

RESULTS

We found no clinically or statistically significant differences in outcomes between "insiders" and "outsiders" in the 23 studies in which the experimental intervention was ineffective (standard mean difference in continuous outcomes -0.03, 95% confidence interval [CI] -0.1 to 0.04) or in the 7 studies in which the experimental intervention was effective and was received by both "insiders" and "outsiders" (mean difference 0.04, 95% CI -0.04 to 0.13). However, in 9 studies in which an effective intervention was received only by "insiders," the "outsiders" experienced significantly worse health outcomes (mean difference -0.36, 95% CI -0.61 to -0.12).

INTERPRETATION

We found no evidence to support clinically important overall harm or benefit arising from participation in RCTs. This conclusion refutes earlier claims that trial participants are at increased risk of harm.

Comparison of growth hormone treatment in patients with idiopathic short stature and idiopathic growth hormone deficiency

After recombinant human growth hormone (rhGH) was introduced in the treatment of patients with growth hormone deficiency (GHD) and idiopathic short stature (ISS), many studies have addressed the effect of GH treatment and changes in the height standard deviation score (SDS) after GH treatment. However, few studies comparing the effect of GH in Korean patients with idiopathic GHD and ISS have been designed. Therefore, this study focused on the difference in effect of GH treatment between the two groups. We retrospectively reviewed the height SDS of 34 patients with idiopathic GHD and 12 patients with ISS. The mean ages of the patients with idiopathic GHD and ISS were 9.84±2.09 and 10.72±1.48 years, respectively. All patients were treated with GH for 1 year and body parameters were recorded before and after the GH treatment. Change in height SDS in patients with idiopathic GHD was significantly higher than that in patients with ISS (0.62±0.33 vs. 0.40±0.27, p=0.03). However, body mass index, insulin-like growth factor-1, and insulin-like growth factor binding protein-3 were not significantly different between the two groups after GH treatment. These results suggest that GH treatment has a more powerful effect on increasing height SDS in patients with idiopathic GHD than in patients with ISS.

Growth hormone significantly increases the adult height of children with idiopathic short stature: comparison of subgroups and benefit

BACKGROUND

Children with Idiopathic Short Stature do not attain a normal adult height. The improvement of adult height with treatment with recombinant human growth hormone (rhGH), at doses of 0.16 to 0.28 mg/kg/week is modest, usually less that 4 cm, and they remain short as adults. The benefit obtained seems dose dependent and benefits of 7.0 to 8.0 cm have been reported with higher doses of 0.32 to 0.4 mg/kg/week, but the number of studies is limited. The topic has remained controversial.

OBJECTIVE

The objective was to conduct a retrospective analysis of our experience with 123 children with ISS treated with 0.32 ± 0.03 mg/kg/week of rhGH, with the aim of comparing the different subgroups of non-familial short stature, familial short stature, normal puberty, and delayed puberty and to assess the benefit by comparison with 305 untreated historical controls, from nine different randomized and nonrandomized controlled studies.

RESULTS

Eighty eight of our children (68 males and 20 females) attained an adult height or near adult height of -0.71 SDS (0.74 SD) (95% CI, -0.87 to -0.55) with a benefit over untreated controls of 9.5 cm (7.4 to 11.6 cm) for males and 8.6 cm (6.7 to 10.5 cm) for females. In the analysis of the subgroups, the adult height and adult height gain of children with non-familial short stature were significantly higher than of familial short stature. No difference was found in the cohorts with normal or delayed puberty in any of the subgroups, except between the non-familial short stature and familial short stature puberty cohorts. This has implications for the interpretation of the benefit of treatment in studies where the number of children with familial short stature in the controls or treated subjects is not known. The treatment was safe. There were no significant adverse events. The IGF-1 values were essentially within the levels expected for the stages of puberty.

CONCLUSION

Our experience was quite positive with normalization of the heights and growth of the children during childhood and the attainment of normal adult heights, the main two aims of treatment.

Growth hormone treatment in non-growth hormone-deficient children

Until 1985 growth hormone (GH) was obtained from pituitary extracts, and was available in limited amounts only to treat severe growth hormone deficiency (GHD). With the availability of unlimited quantities of GH obtained from recombinant DNA technology, researchers started to explore new modalities to treat GHD children, as well as to treat a number of other non-GHD conditions. Although with some differences between different countries, GH treatment is indicated in children with Turner syndrome, chronic renal insufficiency, Prader-Willi syndrome, deletions/mutations of the SHOX gene, as well as in short children born small for gestational age and with idiopathic short stature. Available data from controlled trials indicate that GH treatment increases adult height in patients with Turner syndrome, in patients with chronic renal insufficiency, and in short children born small for gestational age. Patients with SHOX deficiency seem to respond to treatment similarly to Turner syndrome. GH treatment in children with idiopathic short stature produces a modest mean increase in adult height but the response in the individual patient is unpredictable. Uncontrolled studies indicate that GH treatment may be beneficial also in children with Noonan syndrome. In patients with Prader-Willi syndrome GH treatment normalizes growth and improves body composition and cognitive function. In any indication the response to GH seems correlated to the dose and the duration of treatment. GH treatment is generally safe with no major adverse effects being recorded in any condition.

Height gain at adult-height age in 184 short patients treated with growth hormone from prepubertal age to near adult-height age is not related to GH secretory status at GH therapy onset

BACKGROUND

GH release after stimuli classifies short children as severe idiopathic isolated GH deficiency (IIGHD), mild IIGHD, dissociated GH release (DGHR) and normal GH release (NGHR) and anthropometric birth data as adequate for gestational age (AGA) or small for gestational age (SGA). GH release after stimuli classifies AGA patients as IIGHD or as idiopathic short stature (ISS).

AIM

To compare height gain induced by GH therapy (31.8 ± 3.5 µg/kg/day, 7.7 ± 1.6 years) started at prepubertal age and stopped at near adult-height age.

METHODS

A retrospective longitudinal multicenter study including 184 short patients classified as severe IIGHD n = 25, mild IIGHD n = 75, DGHR n = 55 and NGHR n = 29; or as IIGHD n = 78, ISS n = 57 and SGA n = 49. Height gain was evaluated throughout GH therapy and at adult-height age.

RESULTS

Height-SDS gain at adult-height age was similar among severe IIGHD (1.8 ± 0.8 SDS), mild IIGHD (1.6 ± 0.6 SDS), DGHR (1.7 ± 0.7 SDS) and NGHR (1.6 ± 0.7 SDS), or among IIGHD (1.7 ± 0.7 SDS), ISS (1.7 ± 0.6 SDS) and SGA (1.6 ± 0.8 SD).

CONCLUSION

GH-release stimuli are of little help for deciding on GH therapy in the clinical management of prepubertal children with IIGHD, ISS or SGA.

Treatment of children and adolescents with idiopathic short stature

Idiopathic short stature (ISS) is defined as shortness in childhood without a specific cause. ISS may be familial or nonfamilial and may be associated with or without delay of pubertal development. Treatment can be considered in an attempt to reduce the psychological burden caused by short stature in childhood and adult life. If counselling alone is not sufficient, medical modifications of the growth process can be attempted. In cases with pubertal delay, sex steroids, such as testosterone and oxandrolone, can favourably influence height velocity and growth tempo, although adult height is not affected. Medications that prolong the process of growth--for example, gonadotropin-releasing hormone agonists or aromatase inhibitors--might increase adult height, but findings to date are still experimental. Growth hormone therapy is approved for the treatment of very short children with reduced adult height expectation, as evidence has accumulated that this therapy can increase height in childhood and in adult life. Sensitivity to growth hormone is impaired in patients with ISS; therefore, doses higher than a replacement dose have to be applied. This treatment still needs to be optimized in terms of efficacy, cost-effectiveness and long-term safety. A debate is ongoing concerning the psychological benefit of height increase, with clinicians warning against the medicalization of a deviation in height.

A mathematical model in the analysis of the response to growth hormone treatment in pediatric patients with diagnosis of growth hormone deficiency

In the literature, few studies analyze the effect of GH therapy on height, preferring a more indirect approach, where factors influencing the total pubertal and pre-pubertal growth in GH-deficient patients are evaluated and subsequently used to estimate the overall effect at the end of the therapy; unfortunately, this approach does not quantify the real growth gain in treated patients. Using a non-parametric Empirical Bayes approach, our study analyzes the growth response to GH treatment in a homogeneous cohort of 317 patients with pituitary GH deficiency who were enrolled during their pre-pubertal stage in the GH Piedmont Registry (Italy), between January 2000-October 2008, and have at least 2 yr of follow-up. To estimate the growth curve for males and females, a non-parametric regression model was fitted, applying Empirical Bayes techniques. A validation of the model was also performed. Improvement was evident in both genders, since both males and females mean growth curve, which started below the 3rd percentile at the beginning of the therapy, reached the 10th percentile of the Tanner curve at the end of observation (17 yr old for males and 14 yr old for females); the estimation procedure achieved a good precision. The methodological approach allows for fitting a model able to evaluate longitudinally the response to GH treatment, by means of estimating the overall growth curve, even in presence of sparse information about children heights.

Growth hormone use in children: necessary or designer therapy?

Society often rewards the beautiful, the smart, and the intelligent. The possibility that children with idiopathic short stature (ISS) will sustain psychological damage as a result of ridicule from their peers is a concern. The desire for children to become tall adults provides a difficult quandary for parents and caregivers. Growth hormone (GH) treatment in children requires subcutaneous injections six to seven times weekly. The cost of treating with GH can be more than $52,000, and many third-party payers do not cover the cost of GH treatment. Research to date would indicate that while the administration of GH may improve final adult height in children with ISS, children treated with GH will remain short when compared with peers. More research is needed to study whether the administration of GH is beneficial for children with ISS. This article will discuss ISS and the use of GH in children.

Controversies in the definition and treatment of idiopathic short stature (ISS)

The term idiopathic short stature (ISS) refers to short children with no identifiable disorder of the growth hormone (GH)/insulin like growth factor (IGF) axis and no other endocrine, genetic or organ system disorder. This heterogeneous group of short children without GH deficiency (GHD) includes children with constitutional delay of growth and puberty, familial short stature, or both, as well as those with subtle cartilage and bone dysplasias. In rare cases, ISS is due to IGF molecular abnormalities. In this review we tackle the major challenges in the definition and treatment of ISS.

[Growth hormone and idiopathic short stature]

Idiopathic short stature is defined by height below 3rd percentile, in a child with normal birth height and weight, lack of dysmorphy, endocrine deficiency or systemic disease. Food and Drugs administration approved GH treatment in this indication in the United States, because it induces height gain, and sometimes may increase quality of life. There is no consensus in terms of duration, monitoring parameters, benefits and risks of long term GH treatment in these patients. Cost effectiveness of such a treatment is under debate, and ethical considerations also have to be taken into account. Recombinant IGF1 should not be proposed in this indication at the moment, due to the lack of sufficient data on potential GH insensitivity in a subgroup of these patients.

Outcomes of patients who participate in randomized controlled trials compared to similar patients receiving similar interventions who do not participate

BACKGROUND

Some people believe that patients who take part in randomised controlled trials (RCTs) face risks that they would not face if they opted for non-trial treatment. Others think that trial participation is beneficial and the best way to ensure access to the most up-to-date physicians and treatments. This is an updated version of the original Cochrane review published in Issue 1, 2005.

OBJECTIVES

To assess the effects of patient participation in RCTs ('trial effects') independent both of the effects of the clinical treatments being compared ('treatment effects') and any differences between patients who participated in RCTs and those who did not. We aimed to compare similar patients receiving similar treatment inside and outside of RCTs.

SEARCH STRATEGY

In March 2007, we searched The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, The Cochrane Methodology Register, SciSearch and PsycINFO for potentially relevant studies. Our search yielded 7586 new references. In addition, we reviewed the reference lists of relevant articles.

SELECTION CRITERIA

Randomized studies and cohort studies with data on clinical outcomes of RCT participants and similar patients who received similar treatment outside of RCTs.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed studies for inclusion, assessed study quality and extracted data.

MAIN RESULTS

We identified 30 new non-randomized cohort studies (45 comparisons): no new RCTs were found. This update now includes five RCTs (yielding 6 comparisons) and 80 non-randomized cohort studies (130 comparisons), with 86,640 patients treated in RCTs and 57,205 patients treated outside RCTs. In the randomised studies, patients were invited to participate in an RCT or not; these comparisons provided limited information because of small sample sizes (a total of 412 patients) and the nature of the questions they addressed. When the results of RCTs and non-randomized cohorts that reported dichotomous outcomes were combined, there were 98 comparisons; there was also heterogeneity (P < 0.00001, I(2) = 42.2%) between studies. No statistical significant differences were found for 85 of the 98 comparisons. Eight comparisons reported statistically significant better outcomes for patients treated within RCTs, and five comparisons reported statistically significant worse outcomes for patients treated within RCTs. There was significant heterogeneity (P < 0.00001, I(2) = 58.2%) among the 38 continuous outcome comparisons. No statistically significant differences were found for 30 of the 38 comparisons. Three comparisons reported statistically significant better outcomes for patients treated within RCTs, and five comparisons reported statistically significant worse outcomes for patients treated within RCTs.

AUTHORS' CONCLUSIONS

This review indicates that participation in RCTs is associated with similar outcomes to receiving the same treatment outside RCTs. These results challenge the assertion that the results of RCTs are not applicable to usual practice.

Idiopathic short stature: management and growth hormone treatment

In the management of ISS auxological, biochemical, psychosocial and ethical elements have to be considered. In boys with constitutional delay of growth and puberty androgens are effective in increasing height and sexual characteristics, but adult height is unchanged. GH therapy is efficacious in increasing height velocity and adult height, but the inter-individual variation is considerable. The effect on psychosocial status is uncertain. Factors affecting final height gain include GH dose, height deficit in comparison to midparental height, age and first year height velocity. In case of a low predicted adult height at the onset of puberty, addition of a GnRH analogue can be considered. Although GH therapy appears safe, long-term monitoring is recommended.

Recombinant growth hormone for idiopathic short stature in children and adolescents

BACKGROUND

Idiopathic short stature (ISS) refers to children who are very short compared with their peers for unknown or hereditary reasons. Recombinant human growth hormone (GH) has been used to increase growth and final height in children with ISS.

OBJECTIVES

To assess the effects of recombinant human GH on short-term growth and final height in children with ISS.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE, The Cochrane Library, Science Citation Index, BIOSIS and Current Controlled Trials. Article reference lists were assessed for trials and experts and pharmaceutical companies were contacted.

SELECTION CRITERIA

Randomised controlled trials were included if they were carried out in children with ISS with normal GH secretion. GH had to be administered for a minimum of six months and be compared with placebo or no treatment. A growth or height outcome measure had to be assessed.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed studies for inclusion criteria and for methodological quality. Data were extracted by one reviewer and checked by a second. The primary outcome was final height and secondary outcomes included short term growth, health related quality of life and adverse effects. To estimate summary treatment effects, data were pooled, when appropriate using a random effects model.

MAIN RESULTS

Ten RCTs were included. One trial reported near final height in girls and found that girls treated with GH were 7.5 cm taller than untreated controls (GH group, 155.3 cm +/- 6.4; control, 147.8 cm +/- 2.6; P = 0.003); another trial which reported adult height standard deviation score found that children treated with GH were 3.7 cm taller than children in a placebo-treated group (95% confidence intervals 0.03 to 1.10; P < 0.04). The other trials reported short term outcomes. Results suggest that short-term height gains can range from none to approximately 0.7 SD over one year. One study reported health related quality of life and showed no significant improvement in GH treated children compared with those in the control group, whilst another found no significant evidence that GH treatment impacts psychological adaptation or self-perception in children with ISS. No serious adverse effects of treatment were reported.

AUTHORS' CONCLUSIONS

GH therapy can increase short-term growth and improve (near) final height. Increases in height are such that treated individuals remain relatively short when compared with peers of normal stature. Large, multicentre RCTs are required which should focus on final height and address quality of life and cost issues.

Outcomes of patients who participate in randomised controlled trials compared to similar patients receiving similar interventions who do not participate

BACKGROUND

Some people believe that patients who take part in randomised controlled trials (RCTs) face risks that they would not face if they opted for non-trial treatment. Others think that trial participation is beneficial and the best way to ensure access to the most up to date physicians and treatments.

OBJECTIVES

To assess the effects of patient participation in RCTs ('trial effects') independent both of the effects of the clinical treatments being compared ('treatment effects') and any differences between patients who participated in RCTs and those who did not.

SEARCH STRATEGY

In May 2001, we searched The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, The Cochrane Methodology Register, SciSearch and PsycINFO for potentially relevant studies. Our search yielded over 10,000 references. In addition, we reviewed the reference lists of relevant articles and wrote to over 250 investigators to try to obtain further information.

SELECTION CRITERIA

Randomised studies and cohort studies with data on clinical outcomes of RCT participants and similar patients who received similar treatment outside of RCTs.

DATA COLLECTION AND ANALYSIS

At least two reviewers independently assessed studies for inclusion, assessed study quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

We included five randomised studies (yielding 6 comparisons) and 50 non-randomised cohort studies (85 comparisons), with 31,140 patients treated in RCTs and 20,380 patients treated outside RCTs. In the randomised studies, patients were invited to participate in an RCT or not; these comparisons provided limited information because of small sample sizes (a total of 412 patients) and the nature of the questions they addressed. There was statistically significant heterogeneity (P < 0.002, I(2) = 36.2%) among the 73 dichotomous outcome comparisons; none of the potential explanatory factors we investigated helped to explain this heterogeneity. No statistically significant differences were found for 63 of the 73 comparisons. Eight comparisons reported statistically significant better outcomes for patients treated within RCTs, and two comparisons reported statistically significant worse outcomes for patients treated within RCTs. There were no statistically significant differences in heterogeneity (P = 0.53, I(2) = 0%) or in outcomes (SMD 0.01, 95% CI -0.10 to 0.12) of patients treated within and outside RCTs in the 18 comparisons which had used continuous outcomes.

AUTHORS' CONCLUSIONS

This review indicates that participation in RCTs is not associated with greater risks than receiving the same treatment outside RCTs. These results challenge the assertion that the results of RCTs are not applicable to usual practice.

Systematic review to determine whether participation in a trial influences outcome

OBJECTIVE

To systematically compare the outcomes of participants in randomised controlled trials (RCTs) with those in comparable non-participants who received the same or similar treatment.

DATA SOURCES

Bibliographic databases, reference lists from eligible articles, medical journals, and study authors.

REVIEW METHODS

RCTs and cohort studies that evaluated the clinical outcomes of participants in RCTs and comparable non-participants who received the same or similar treatment.

RESULTS

Five RCTs (six comparisons) and 50 cohort studies (85 comparisons) provided data on 31,140 patients treated in RCTs and 20,380 comparable patients treated outside RCTs. In the five RCTs, in which patients were given the option of participating or not, the comparisons provided limited information because of small sample sizes (a total of 412 patients) and the nature of the questions considered. 73 dichotomous outcomes were compared, of which 59 reported no statistically significant differences. For patients treated within RCTs, 10 comparisons reported significantly better outcomes and four reported significantly worse outcomes. Significantly heterogeneity was found (I2 = 89%) among the comparisons of 73 dichotomous outcomes; none of our a priori explanatory factors helped explain this heterogeneity. The 18 comparisons of continuous outcomes showed no significant differences in heterogeneity (I2 = 0%). The overall pooled estimate for continuous outcomes of the effect of participating in an RCT was not significant (standardised mean difference 0.01, 95% confidence interval -0.10 to 0.12).

CONCLUSION

No strong evidence was found of a harmful or beneficial effect of participating in RCTs compared with receiving the same or similar treatment outside such trials.

Growth hormone treatment in non-growth hormone-deficient short children

The unlimited availability of GH obtained by recombinant DNA technology has allowed optimization of treatment in GH-deficient (GHD) children. At the same time it has prompted a number of studies in conditions not characterized by GHD such as Turner syndrome, intrauterine growth retardation, chronic renal failure and other chromosomal and genetic abnormalities associated with short stature. Several controlled and uncontrolled studies have now reported the adult height of patients with short stature and normal GH secretion. Critical reviewing of the data shows that some short non-GHD children may benefit from a prolonged treatment with GH. However, further studies are needed in order to be able to identify the subjects for whom treatment is really beneficial.

Growth hormone (GH) treatment to final height in children with idiopathic short stature: evidence for a dose effect

OBJECTIVES

To investigate in an open-label randomized study, the effect of two doses of growth hormone (GH) on final height and height velocity during the first 2 years of treatment of children with idiopathic short stature (mean baseline height standard deviation score [SDS] -3.2).

STUDY DESIGN

Patients were treated with GH at 0.24 mg/kg/week, 0.24 mg/kg/week for the first year and at 0.37 mg/kg/week thereafter (0.24-->0.37), or 0.37 mg/kg/week. Final height was evaluated in 50 patients at study completion (mean treatment duration, 6.5 years).

RESULTS

Patients who received 0.37 mg/kg/week (n = 72) experienced a significantly greater increase in height velocity than those who received 0.24 mg/kg/week (n = 70) (treatment difference = 0.8 cm/year; P = .003) or 0.24-->0.37 mg/kg/week (n = 67) (treatment difference = 0.9 cm/year; P = .001). For the 50 patients for whom final height measurements were available, mean height SDS increased by 1.55, 1.52, and 1.85 SDS, respectively, for the three dose groups. For the primary comparison between the 0.37 mg/kg/week and 0.24 mg/kg/week dose groups, the mean treatment difference (adjusted for differences in baseline predicted height SDS) was 0.57 SDS (3.6 cm; P = .025). Mean overall height gains (final height minus baseline predicted height) were 7.2 cm and 5.4 cm for the 0.37 mg/kg/week and 0.24 mg/kg/week dose groups, respectively, without dose effects on safety parameters. Final height measurements were within the normal adult height range for 94% of patients randomized to 0.37 mg/kg/week who continued to final height.

CONCLUSION

GH treatment dose-dependently increases height velocity and final height in children with idiopathic short stature.

Growth Hormone Use in Children with Idiopathic Short Stature

OBJECTIVE:

To review the indication, pharmacology, pharmacokinetics, efficacy, and adverse effects of recombinant human growth hormone in children with idiopathic short stature (ISS).

DATA SOURCES:

A MEDLINE search (1966–December 2003) was performed using the key words human growth hormone, somatropin, Humatrope, normal children, somatrem, and idiopathic short stature. Food and Drug Administration Advisory Committee Meeting minutes were also reviewed.

STUDY SELECTION AND DATA EXTRACTION:

The data presented in this review were obtained from published literature, abstracts presented at scientific meetings, and information on file with the manufacturer. Additional articles from these sources were also identified. Current issues of pediatric and endocrinology journals were reviewed for the most recent articles. Articles only addressing the use of growth hormone in normal, healthy children were used.

DATA SYNTHESIS:

Somatropin is indicated for use in children with ISS. Studies have shown modest benefit to final height achieved and, at the doses used for ISS, there have been no adverse effects associated with somatropin. Many questions still exist, however, concerning the most appropriate age to initiate treatment and duration of treatment. There are also many ethical concerns surrounding patient selection criteria and potential for increased off-label use.

CONCLUSIONS:

Growth hormone has been found to have modest efficacy in improving final height in children with ISS. The specific patient population likely to achieve maximal benefit, optimal dosage regimens, and the long-term adverse effects of extended duration of therapy are unknown.

Growth hormone secretory pattern and response to treatment in children with short stature followed to adult height

OBJECTIVE

To compare the relative utility of GH stimulation tests and assays of spontaneous GH secretion as predictors of change in height standard deviation score at the end of GH treatment in children with short stature.

PATIENTS AND METHODS

We retrospectively studied 116 children (67 boys and 49 girls) with subnormal growth rates and short stature, defined as a height of more than 2SD below the mean for age and sex. The patients were classified according to their pattern of findings on baseline pharmacological GH stimulation tests and a 12-h assay of nocturnal spontaneous GH secretion. Twenty-eight patients (24%) had normal hormone levels by both methods (group I); 14 (12%) had normal levels by stimulation tests but subnormal levels by the physiological assay (group II); 48 (41%) had subnormal levels on pharmacological stimulation, with normal physiologic levels (group III); and 26 (22%) had subnormal levels by both methods (group IV). All children in groups II and IV, and 27 in group III, designated IIIb, were treated with recombinant GH at 0.7 U (0.23 mg/kg) of body weight per week. GH secretory patterns were related to final height SD scores and other growth parameters, after the patients had attained their adult stature 6.7 +/- 2.2 years (SD) after GH evaluation.

RESULTS

The five groups were similar with respect to mean baseline height SD scores for chronological as well as bone age. Whether assessed as absolute or parentally adjusted (relative) values, mean gains in height SD scores were significantly greater in treated patients with physiological hormone deficiency (groups II and IV) than in those with normal hormone levels (group I, untreated controls). Relative height gains were 1.03 +/- 1.45 cm (6.6 +/- 9.28 cm) and 1.85 +/- 1.21 cm (SDS; 11.8 +/- 7.74 cm) in groups II and IV respectively, compared with only 0.11 +/- 0.42 cm (0.7 +/- 2.68 cm) in group I (P < 0.01 and P < 0.001). GH treatment failed to improve either the absolute or parentally adjusted final height of patients with GH deficiency by stimulation tests but normal levels by physiological assay.

CONCLUSION

Long-term administration of GH to short children with normal spontaneous GH secretion is not associated with an appreciable increase in adult height.

Recombinant growth hormone for idiopathic short stature in children and adolescents

BACKGROUND

Idiopathic short stature (ISS) refers to children who are very short compared with their peers for unknown or hereditary reasons. Recombinant human growth hormone has been used to increase growth and final height in children with idiopathic short stature.

OBJECTIVES

To assess the effects of recombinant human growth hormone on short-term growth and final height in children with idiopathic short stature.

SEARCH STRATEGY

Randomised controlled trials (RCTs) were sought by searching The Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, PubMed, Science Citation Index, BIOSIS and Current Controlled Trials (date of last search 10 December 2002). Article reference lists were assessed for trials and experts and pharmaceutical companies were contacted.

SELECTION CRITERIA

Randomised controlled trials were included if they were carried out in children with ISS with normal growth hormone secretion. Growth hormone (GH) had to be administered for a minimum of six months and be compared with placebo or no treatment. A growth or height outcome measure had to be assessed.

DATA COLLECTION AND ANALYSIS

Two reviewers assessed studies for inclusion criteria and for methodological quality. Data were extracted by one reviewer and checked by a second. The primary outcome was final height and secondary outcomes included short term growth, health related quality of life and adverse effects. To estimate summary treatment effects, data were pooled, when appropriate using a random effects model.

MAIN RESULTS

Nine randomised controlled trials were included. One trial reported near final height in girls and found that girls treated with growth hormone were 7.5 cm taller than untreated controls (GH group, 155.3 cm +/- 6.4; control, 147.8 cm +/- 2.6; p = 0.003). The other trials reported short term outcomes. Results suggest that short-term height gains can range from none to approximately 0.7 SD over one year. One study reported health related quality of life and showed no significant improvement in growth hormone treated children compared with those in the control group. No serious adverse effects of treatment have been reported.

REVIEWER'S CONCLUSIONS

Results suggest that growth hormone therapy can increase short-term growth and improve (near) final height. Increases in height are such that treated individuals remain relatively short when compared with peers of normal stature. Further research in the form of large, multicentre RCTs are required. These should focus on final height, which is the best outcome for assessing the effects of growth hormone, and address quality of life and cost issues.

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.

High dose growth hormone treatment induces acceleration of skeletal maturation and an earlier onset of puberty in children with idiopathic short stature

BACKGROUND

Long term growth hormone (GH) treatment in children with idiopathic short stature (ISS) results in a relatively small mean gain in final height of 3-9 cm, which may not justify the cost of treatment. As it is unknown whether GH treatment during puberty adds to final height gain, we sought to improve the cost-benefit ratio, employing a study design with high dose GH treatment restricted to the prepubertal period.

AIMS

To assess the effect of short term, high dose GH treatment before puberty on growth, bone maturation, and pubertal onset.

METHODS

Five year results of a randomised controlled study are reported. Twenty six boys and nine girls were randomly assigned to a GH treatment group (n = 17) or a control group (n = 18). Inclusion criteria were: no signs of puberty, height less than -2 SDS, age 4-8 years for girls or 4-10 years for boys, GH concentration >10 micro g/l after provocation, and normal body proportions. To assess GH responsiveness, children assigned to the GH treatment group received GH treatment for two periods of three months (1.5 IU/m2/day and 3.0 IU/m2/day), separated by three month washout periods, during the first year of study. High dose GH treatment (6.0 IU/m2/day) was then started and continued for at least two full years. When puberty occurred, GH treatment was discontinued at the end of a complete year's treatment (for example, three or four years of GH treatment).

RESULTS

In response to at least two years on high dose GH treatment, mean (SD) height SDS for chronological age increased significantly in GH treated children from -2.6 (0.5) to -1.3 (0.5) after two years and -1.4 (0.5) SDS after five years of study. No changes in height SDS were observed in controls. A rapid rate of bone maturation of 3.6 years/2 years in treated children compared to 2 years/2 years in controls was observed in response to two years high dose GH treatment. Height SDS for bone age was not significantly different between groups during the study period. GH treated children entered into puberty at a significantly earlier age compared to controls.

CONCLUSIONS

High dose GH treatment before puberty accelerates bone age and induces an earlier onset of puberty. This may limit the potential therapeutic benefit of this regimen in ISS.

Short children with familial short stature show enhancement of somatotroph secretion but normal IGF-I levels

The aim of the present study was to evaluate the GH status in children with familial, idiopathic short stature (FSS). To this goal we evaluated the GH response to GHRH (1 microg/kg iv) + arginine (ARG) (0.5 g/kg iv) test which is one of the most potent and reproducible provocative tests of somatotroph secretion, in 67 children with FSS [50 boys and 17 girls, age 10.8+/-0.4 yr, pubertal stages I-III, height between -3.6 and -1.6 standard deviation score (SDS), target height <10 degrees centile, normality of both spontaneous and stimulated GH secretion as well as of IGF-I levels]. The results in FSS were compared with those in groups of children of normal height (NHC) (42 NHC, 35 boys and 7 girls, age 12.0+/-0.5 yr, pubertal stages I-III, height between -1.3 and 1.4 SDS, height velocity standard deviation score (HVSDS)>25 degrees centile, GH peak >20 microg/l after GHRH+ARG test, mean GH concentration [mGHc]>3 microg/l) and children with organic GH deficiency (GHD) (38 GHD, 29 boys and 9 girls, age 11.2+/-3.7 yr, pubertal stages I-III, height between -5.7 and -1.3 SDS, GH peak <20 microg/l after GHRH +ARG test, mGHc <3 mg/l). Basal IGF-I levels and mGHc were also evaluated in each group over 8 nocturnal hours. IGF-I levels in FSS (209.2+/-15.6 microg/l) were similar to those in NHC (237.2+/-17.2 microg/l) and both were higher (p<0.0001) than those in GHD (72.0+/-4.0 microg/l). The GH response to GHRH +ARG test in FSS (peak: 66.4+/-5.6 microg/l) was very marked and higher (p<0.01) than that in NHC (53.3+/-4.5 microg/l) which, in turn, was higher (p<0.01) than in GHD (8.2+/-0.8 microg/l). Similarly, the mGHc in FSS was higher than in NHC (6.7+/-0.5 microg/l vs 5.1+/-0.7 microg/l, p<0.05) which, in turn, was higher than in GHD (1.5+/-0.2 microg/l, p<0.0001). In conclusion, our present study demonstrates that short children with FSS show enhancement of both basal and stimulated GH secretion but normal IGF-I levels. These findings suggest that increased somatotroph function would be devoted to maintain normal IGF-I levels thus reflecting a slight impairment of peripheral GH sensitivity in FSS.

Results of early reevaluation of growth hormone secretion in short children with apparent growth hormone deficiency

OBJECTIVE

To test the hypothesis that normalization of the growth hormone (GH) response to stimulation in patients with GH deficiency (GHD) and normal magnetic resonance imaging (MRI) of the hypothalamic-pituitary area might occur earlier than at attainment of final height.

STUDY DESIGN

Prepubertal children with short stature (21 boys and 12 girls; age, 5.2-10 years), in whom a diagnosis of GHD was based on a GH response <10 microg/L after 2 pharmacologic tests (clonidine, arginine, or insulin hypoglycemia), and normal MRI of the hypothalamic-pituitary area were studied. After 1 to 6 months, all children underwent reevaluation of GH secretion by means of one of the provocative tests previously used. During that time, none of the children received GH therapy or entered puberty.

RESULTS

A GH response > or =10 microg/L after retesting was found in 28 patients, and a GH response <10 microg/L was found in 5. In 9 patients, the peak GH response at diagnosis was <7 microg/L to both tests used. In 8, the GH response at retesting was > or =10 microg/L and was 9.0 microg/L in the remaining child.

CONCLUSIONS

We suggest that patients with pathologic GH responses to provocative tests but normal MRI should be reevaluated and followed up before a diagnosis of GHD is firmly established.

Effect of growth hormone treatment on testicular function, puberty, and adrenarche in boys with non-growth hormone-deficient short stature: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To evaluate the effect of growth hormone (GH) therapy on pubertal onset, pubertal pace, adult testicular function, and adrenarche in boys with non-GH-deficient short stature.

STUDY DESIGN

Randomized, double-blind, placebo-controlled trial. GH (0.074 mg/kg, subcutaneously, 3 times per week) or placebo treatment was initiated in prepubertal or early pubertal boys and continued until near final height was reached (n = 49). Statistical significance was assessed by survival analysis, repeated-measures analysis of variance, and Student t test.

RESULTS

GH therapy did not affect the age at pubertal onset, defined either by testicular volume >4 mL or by testosterone concentration >1.0 nmol/L (30 ng/dL). GH treatment also did not affect the pace of puberty, defined either by the rate of change in testicular volume or testosterone concentration during the 4 years after pubertal onset. In boys followed up to age > or =16 years during the study, there were no significant differences in final testicular volume or in plasma testosterone, luteinizing hormone, or follicle-stimulating hormone concentrations. The pace of adrenarche, assessed by change in dehydroepiandrosterone sulfate levels over time, also did not differ significantly between the GH and placebo groups.

CONCLUSION

Our findings suggest that GH treatment does not cause testicular damage, alter the onset or pace of puberty, or alter the pace of adrenarche in boys with non-GH-deficient short stature.

Growth hormone treatment of children with brain tumors and risk of tumor recurrence

GH is increasingly used for treatment of children and adults. It is mitogenic, however, and there is therefore concern about its safety, especially when used to treat cancer patients who have become GH deficient after cranial radiotherapy. We followed 180 children with brain tumors attending three large hospitals in the United Kingdom and treated with GH during 1965-1996, and 891 children with brain tumors at these hospitals who received radiotherapy but not GH. Thirty-five first recurrences occurred in the GH-treated children and 434 in the untreated children. The relative risk of first recurrence in GH-treated compared with untreated patients, adjusted for potentially confounding prognostic variables, was decreased (0. 6; 95% confidence interval, 0.4-0.9) as was the relative risk of mortality (0.5; 95% confidence interval, 0.3-0.8). There was no significant trend in relative risk of recurrence with cumulative time for which GH treatment had been given or with time elapsed since this treatment started. The relative risk of mortality increased significantly with time since first GH treatment. The results, based on much larger numbers than previous studies, suggest that GH does not increase the risk of recurrence of childhood brain tumors, although the rising trend in mortality relative risks with longer follow-up indicates the need for continued surveillance.

Adult height in children with idiopathic short stature treated with growth hormone

Idiopathic short stature (ISS) includes a heterogeneous group of patients with common characteristics to those of familial short stature and constitutional delay. Some authors state that these children can often respond to GH treatment, thus increasing their adult height. The aims of this study were to determine the effect of GH treatment (0.5-0.7 IU/kg/week) and the influence of some initial variables on adult height in patients with ISS. It was a non-randomized, observational study of 30 boys with ISS and a historical control group of 42 patients. The patients were followed until achieving their adult height. The mean height gain of the treated group attributable to GH was 4.5 cm. A stepwise regression model considering predicted adult height and target height as independent variables and final height as dependent variable gave an R2 coefficient of 0.38. We conclude that GH significantly increases final height in boys with ISS.

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.

Effect of growth hormone treatment on adult height of children with idiopathic short stature. Genentech Collaborative Group

BACKGROUND

Short-term administration of growth hormone to children with idiopathic short stature results in increases in growth rate and standard-deviation scores for height. However, the effect of long-term growth hormone therapy on adult height in these children is unknown.

METHODS

We studied 121 children with idiopathic short stature, all of whom had an initial height below the third percentile, low growth rates, and maximal stimulated serum concentrations of growth hormone of at least 10 microg per liter. The children were treated with growth hormone (0.3 mg per kilogram of body weight per week) for 2 to 10 years. Eighty of these children have reached adult height, with a bone age of at least 16 years in the boys and at least 14 years in the girls, and pubertal stage 4 or 5. The difference between the predicted adult height before treatment and achieved adult height was compared with the corresponding difference in three untreated normal or short-statured control groups.

RESULTS

In the 80 children who have reached adult height, growth hormone treatment increased the mean standard-deviation score for height (number of standard deviations from the mean height for chronologic age) from -2.7 to -1.4. The mean (+/-SD) difference between predicted adult height before treatment and achieved adult height was +5.0+/-5.1 cm for boys and +5.9+/-5.2 cm for girls. The difference between predicted and achieved adult height among treated boys was 9.2 cm greater than the corresponding difference among untreated boys with initial standard-deviation scores of less than -2, and the difference among treated girls was 5.7 cm greater than the difference among untreated girls.

CONCLUSION

Long-term administration of growth hormone to children with idiopathic short stature can increase adult height to a level above the predicted adult height and above the adult height of untreated historical control children.