Dose-dependent effect of growth hormone on final height in children with short stature without growth hormone deficiency

Tackling access and payer barriers for growth hormone therapy in Saudi Arabia: a consensus statement for the Saudi Working Group for Pediatric Endocrinology

Prompt diagnosis and early treatment are key goals to optimize the outcomes of children with growth hormone deficiency (GHD) and attain the genetically expected adult height. Nonetheless, several barriers can hinder prompt diagnosis and treatment of GHD, including payer-related issues. In Saudi Arabia, moderate-to-severe short stature was reported in 13.1 and 11.7 % of healthy boys and girls, respectively. Several access and payer barriers can face pediatric endocrinologists during the diagnosis and treatment of GHD in Saudi Arabia. Insurance coverage policies can restrict access to diagnostic tests for GHD and recombinant human growth hormone (rhGH) due to their high costs and lack of gold-standard criteria. Some insurance policies may limit the duration of treatment with rhGH or the amount of medication covered per month. This consensus article gathered the insights of pediatric endocrinologists from Saudi Arabia to reflect the access and payer barriers to the diagnostic tests and treatment options of children with short stature. We also discussed the current payer-related challenges endocrinologists face during the investigations of children with short stature. The consensus identified potential strategies to overcome these challenges and optimize patient management.

Efficacy, safety, and patient satisfaction of norditropin and sogroya in patients with growth hormone deficiency: a systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Growth hormone deficiency occurs when the pituitary gland does not produce enough growth hormone. Norditropin®, a recombinant human growth hormone, and Sogroya®, an albumin-binding growth hormone derivative, are prescribed for patients with growth hormone deficiency. This systematic review assesses the efficacy, safety, and patient satisfaction associated with Norditropin and Sogroya.

METHODS

We systematically searched PubMed, Web of Science, and Scopus databases to identify eligible comparative studies. All studies published until June 2023 were included in our analysis. Our outcomes for children included height velocity and height velocity standard deviation score. In contrast, adult outcomes included adverse events, insulin-like growth factor 1-standard deviation score (IGF-1 SDS), and the Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9). Results are reported as odds ratio (OR) and mean difference (MD) with a 95% confidence interval (95% CI).

RESULTS

Ten studies involving 1058 participants (665 children and 393 adults) were included in the meta-analysis. In children, Norditropin at doses of 0.034 and 0.067 mg/kg/day was compared to Sogroya at doses of 0.04, 0.08, 0.16, and 0.24 mg/kg/week. The results showed that 0.034 mg/kg/day Norditropin had a favorable impact on height velocity (MD -2.01, 95% CI -3.7 to -2.12, p < 0.00001) and height velocity standard deviation score (Mean Difference -3.61, 95% CI -5.06 to -2.16, p < 0.00001) when compared to Sogroya 0.04 mg/kg/day. Other doses showed comparable results. In adults, the only significant side effect noted was rash, which favored Sogroya (OR 0.1, 95% CI 0.04-0.27, p < 0.00001). Additionally, IGF-1 SDS was significantly higher in the Sogroya group than in the Norditropin group (MD 0.25, 95% CI 0.02-0.48, p = 0.03). Furthermore, the overall score of the TSQM-9 questionnaire, which includes three domains: convenience, effectiveness, and satisfaction, was significantly higher in the Sogroya group compared to the Norditropin group (OR 6.36, 95% CI 3.92-8.8, p < 0.00001).

CONCLUSION

Norditropin and Sogroya showed comparable efficacy and safety profiles, except for the prevalence of rash in the Norditropin group, and Sogroya has higher satisfaction among adults. More high-quality studies with more patients are required to confirm these results.

Growth Hormone Treatment for Non-GHD Disorders: Excitement Tempered by Biology

The success of growth hormone (GH) replacement in children with classical GH deficiency has led to excitement that other causes of short stature may benefit similarly. However, clinical experience has shown less consistent and generally less dramatic effects on adult height, perhaps not surprising in light of increased understanding of GH and growth plate biology. Nonetheless, clinical demand for GH treatment continues to grow. Upon the 20th anniversary of the US Food and Drug Administration's approval of GH treatment for idiopathic short stature, this review will consider the factors underlying the expansion of GH treatment, the biological mechanisms of GH action, the non-GH-deficient uses of GH as a height-promoting agent, biological constraints to GH action, and future directions.

Normalization of puberty and adult height in girls with Turner syndrome: results of the Swedish Growth Hormone trials initiating transition into adulthood

Objective

To study the impact of GH dose and age at GH start in girls with Turner syndrome (TS), aiming for normal height and age at pubertal onset (PO) and at adult height (AH). However, age at diagnosis will limit treatment possibilities.

Methods

National multicenter investigator-initiated studies (TNR 87-052-01 and TNR 88-072) in girls with TS, age 3-16 years at GH start during year 1987-1998, with AH in 2003-2011. Of the 144 prepubertal girls with TS, 132 girls were followed to AH (intention to treat), while 43 girls reduced dose or stopped treatment prematurely, making n=89 for Per Protocol population. Age at GH start was 3-9 years (young; n=79) or 9-16 years (old; n=53). Treatment given were recombinant human (rh)GH (Genotropin^® Kabi Peptide Hormones, Sweden) 33 or 67 µg/kg/day, oral ethinyl-estradiol (2/3) or transdermal 17β-estradiol (1/3), and, after age 11 years, mostly oxandrolone. Gain in height_SDS, AH_SDS, and age at PO and at AH were evaluated.

Results

At GH start, height_SDS was -2.8 (versus non-TS girls) for all subgroups and mean age for young was 5.7 years and that of old was 11.6 years. There was a clear dose-response in both young and old TS girls; the mean difference was (95%CI) 0.66 (-0.91 to -0.26) and 0.57 (-1.0 to -0.13), respectively. The prepubertal gain_SDS (1.3-2.1) was partly lost during puberty (-0.4 to -2.1). Age/height_SDS at PO ranged from 13 years/-0.42 for GH_67young to 15.2 years/-1.47 for GH_33old. At AH, GH_67old group became tallest (17.2 years; 159.9 cm; -1.27 SDS; total gain_SDS, 1.55) compared to GH_67young group being least delayed (16.1 years; 157.1 cm; -1.73 SDS; total, 1.08). The shortest was the GH_33young group (17.3 years; 153.7 cm: -2.28 SDS; total gain_SDS, 0.53), and the most delayed was the GH_33old group, (18.5 years; 156.5 cm; -1.82 SDS; total gain_SDS, 0.98).

Conclusion

For both young and old TS girls, there was a GH-dose growth response, and for the young, there was less delayed age at PO and at AH. All four groups reached an AH within normal range, despite partly losing the prepubertal gain during puberty. Depending on age at diagnosis, low age at start with higher GH dose resulted in greater prepubertal height gain, permitting estrogen to start earlier at normal age and attaining normal AH at normal age, favoring physiological treatment and possibly also bone health, hearing, uterine growth and fertility, psychosocial wellbeing during adolescence, and the transition to adulthood.

Comparison of growth response and adverse reaction according to growth hormone dosing strategy for children with short stature: LG Growth Study

OBJECTIVE

Growth hormone (GH) dosage in children is conventionally determined either by body weight (BW) or body surface area (BSA). However, there is no consensus on the calculation method for proper GH treatment dose. We aimed to compare growth response and adverse reactions between BW- and BSA-based GH treatment doses for children with short statures.

DESIGN

Data from 2284 GH-treated children were analyzed. Distributions of BW- and BSA-based GH treatment doses and their association with growth response parameters, including changes in height, height standard deviation score (SDS), body mass index (BMI), and safety parameters, such as changes in insulin-like growth factor (IGF)-I SDS and adverse events, were investigated.

RESULTS

The mean BW-based doses were close to the recommended dose's upper limit in participants with GH deficiency and idiopathic short stature, while they were below the recommended dose in patients with Turner syndrome (TS). As age and BW increased, BW-based dose decreased, whereas BSA-based dose increased. Gain in height SDS was positively associated with BW-based dose in the TS group and negatively associated with BW in all groups. Despite having a lower BW-based dose, the overweight/obese groups had a higher BSA-based dose and higher frequencies of children with high IGF-I and adverse events than those of the normal-BMI group.

CONCLUSIONS

In children of older age or with high BW, BW-based doses can be overdosed in terms of BSA. and BW-based dose positively correlated with height gain only in the TS group. BSA-based doses represent an alternative dosing strategy in children who are overweight/obese.

Clinical Indications for Growth Hormone Therapy

Growth hormone (GH) is an injectable medication originally used to replace the deficiency of the hormone, but has expanded to treating conditions that may reduce growth and adult height even when the body maintains endogenous GH production. In the United States, there are 8 Food and Drug Administration (FDA)-approved indications for pediatric GH therapy: GH deficiency, Prader-Willi Syndrome, small for gestational age (SGA) without catch-up growth, idiopathic short stature, Turner syndrome, SHOX gene haploinsufficiency, Noonan Syndrome, and chronic renal insufficiency. We characterize the growth patterns and effects of GH treatment in each of these indications. We also review patterns of growth that warrant referral to a pediatric endocrinologist, as well as safety updates. This review is intended to guide practitioners on the initial evaluation and management of patients with short stature, and the indications for GH therapy.

A Randomized Controlled Phase 3 Study on the Efficacy and Safety of Recombinant Human Growth Hormone in Children With Idiopathic Short Stature

BACKGROUND

To evaluate the safety and efficacy of daily somatropin (Jintropin^®), a recombinant human growth hormone, in prepubertal children with ISS in China.

METHODS

This study was a multicenter, randomized, controlled, open-label, phase 3 study. All subjects were randomized 3:1 to daily somatropin 0.05 mg/kg/day or no treatment for 52 weeks. A total of 481 subjects with a mean baseline age of 5.8 years were enrolled in the study. The primary endpoint was change in (△) height standard deviation score (HT-SDS) for chronological age (CA). Secondary endpoints included △height from baseline; △bone age (BA)/CA; △height velocity (HV) and △insulin-like growth factor 1 (IGF-1 SDS).

RESULTS

△HT-SDS at week 52 was 1.04 ± 0.31 in the treatment group and 0.20 ± 0.33 in the control group (P < 0.001). At week 52, statistical significance was observed in the treatment group compared with control for △height (10.19 ± 1.47 cm vs. 5.85 ± 1.80 cm; P < 0.001), △BA/CA (0.04 ± 0.09 vs. 0.004 ± 0.01; P < 0.001), △HV (5.17 ± 3.70 cm/year vs. 0.75 ± 4.34 cm/year; P < 0.001), and △IGF-1 SDS (2.31 ± 1.20 vs. 0.22 ± 0.98; P < 0.001). The frequencies of treatment-emergent adverse events (TEAEs) were similar for the treatment and the control groups (89.8% vs. 82.4%); most TEAEs were mild to moderate in severity and 23 AEs were considered study-drug related.

CONCLUSIONS

Daily subcutaneous administration of somatropin at 0.05 mg/kg/day for 52 weeks demonstrated improvement in growth outcomes and was well tolerated with a favorable safety profile.

TRIAL REGISTRATION

ClinicalTrials.gov (identifier: NCT03635580). URL: https://clinicaltrials.gov/ct2/show/NCT03635580.

GH Responsiveness in Children With Noonan Syndrome Compared to Turner Syndrome

BACKGROUND

Despite different genetic background, Noonan syndrome (NS) shares similar phenotype features to Turner syndrome (TS) such as short stature, webbed neck and congenital heart defects. TS is an entity with decreased growth hormone (GH) responsiveness. Whether this is found in NS is debated.

METHODS

Data were retrieved from combined intervention studies including 25 children diagnosed with NS, 40 diagnosed with TS, and 45 control children (all prepubertal). NS-children and TS-girls were rhGH treated after investigation of the GH/IGFI-axis. GH was measured with poly- and monoclonal antibodies; 24hGH-profile pattern analysed by PULSAR. The NS-children were randomly assigned to Norditropin^® 33 or 66 μg/kg/day, and TS-girls were consecutively treated with Genotropin^® 33 or 66 μg/kg/day.

RESULTS

Higher PULSAR-estimates of 24h-profiles were found in both NS-children and TS-girls compared to controls: Polyclonal GH_max24h-profile (Mean ± SD) was higher in both groups (44 ± 23mU/L, p<0.01 in NS; 51 ± 47, p<0.001 in TS; compared to 30 ± 23 mU/L in controls) as was GH-baseline (1.4 ± 0.6 mU/L in NS; 2.4 ± 2.4 mU/L in TS, p<0.01 for both, compared to 1.1 ± 1.2 mU/L in controls). Pre-treatment IGFI_SDS was 2.2 lower in NS-children (-1.7 ± 1.3) compared to TS-girls (0.6 ± 1.8, p<0.0001). GH_max, IGFI/IGFBP3-ratio_SDS, and chronological age at start of GH accounted for 59% of the variance in first-year growth response in NS.

CONCLUSION

Both prepubertal NS-children and TS-girls had a high GH secretion, but low IGFI/IGFBP3 levels only in NS-children. Both groups presented a broad individual response. NS-children showed higher response in IGFI and growth, pointing to higher responsiveness to GH treatment than TS-girls.

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.

A new type of pubertal height reference based on growth aligned for onset of pubertal growth

Objectives Growth references of today traditionally describe growth in relation to chronological age. Despite the broad variation in age of pubertal maturation, references related to biological age are lacking. To fill this knowledge gap, we aimed to develop a new type of pubertal height reference for improved growth evaluation during puberty, considering individual variation in pubertal timing. Methods Longitudinal length/height measures were obtained from birth to adult height in 1,572 healthy Swedish children (763 girls) born at term ∼1990 to nonsmoking mothers and Nordic parents, a subgroup of GrowUp1990Gothenburg cohort. A total height reference was constructed from Quadratic-Exponential-Puberty-Stop (QEPS)-function-estimated heights from individual height curves that had been aligned for time/age at onset of pubertal growth (5% of P-function growth). References that separated growth into specific pubertal heightSDS (P-function growth) and basic heightSDS (QES-function growth) were also generated. Results References (cm and SDS) are presented for total height, and height subdivided into that specific to puberty and to basic growth arising independently of puberty. The usefulness of the new pubertal growth reference was explored by identifying differences in the underlying growth functions that translate into differences in pubertal height gain for children of varying body mass, height, and with different pubertal timings. Conclusions A new type of height reference allowing alignment of individual growth curves, based on the timing of the pubertal growth spurt was developed using QEPS-model functions. This represents a paradigm shift in pubertal growth research and growth monitoring during the adolescent period.

Comparison of the efficacy and safety of recombinant human growth hormone in treating idiopathic short stature and growth hormone deficiency in children

PURPOSE

The present study aimed to compare the efficacy and safety of recombinant human growth hormone (rhGH) therapy between children with idiopathic short stature (ISS) and growth hormone deficiency (GHD).

METHODS

A total of 150 pediatric patients with ISS and 153 pediatric patients with GHD who received rhGH treatment for more than one year from 2005 to 2016 were enrolled. Growth velocity (GV); height standard deviation (HtSD); insulin-like growth factor-1 standard deviation (IGF-1SD); body mass index (BMI); and the incidence of fasting hyperglycemia, fasting hyperinsulinemia, and hypothyroidism were recorded and compared.

RESULTS

At the beginning of treatment, chronological age, bone age, height, and BMI were not statistically significant between the two groups. rhGH dosage in ISS was significantly higher compared with GHD (P = 0). GV from half a year to three years after rhGH therapy was higher in the GHD group compared with the ISS group, but the differences were not statistically significant (P > 0 .05). HtSD increased in the two groups after rhGH therapy. HtSD at the beginning and after three years of therapy was not different between groups except for after half a year of therapy. HtSD in patients with ISS was significantly higher compared with GHD (P < 0 .05). The incidence of hypothyroidism was significantly higher in the GHD group compared with the ISS group (13.72% vs. 6.0%; P < 0.05). Moreover, the incidence of hyperinsulinemia was significantly higher in the ISS group compared with the GHD group (15.33% vs. 7.84%; P < 0 .05).

CONCLUSIONS

rhGH increases growth in children with ISS and GHD. Fasting insulin and thyroid function were closely monitored for long-term follow up.

Efficacy and Safety Evaluation of Human Growth Hormone Therapy in Patients with Idiopathic Short Stature in Korea - A Randomised Controlled Trial

BACKGROUND

This trial evaluated the efficacy and safety of growth hormone (GH) therapy (Norditropin®; Novo Nordisk, Bagsværd, Denmark) in paediatric patients with idiopathic short stature (ISS) in Korea.

METHODS

This was an open-label, parallel-group, multicentre, interventional trial (ClinicalTrials.gov identifier: NCT01778023). Pre-pubertal patients (mean age 6.2 years; height, 107.1 cm) were randomised 2:1 to 12 months' GH treatment (0.469 mg/kg/week; group A, n=36) or 6 months untreated followed by 6 months' GH treatment (group B, n=18). Safety analysis was based on adverse events (AEs) in all GH-treated patients.

RESULTS

After 6 months, height velocity (Ht-V), change in both height standard deviation score (Ht-SDS) and insulin-like growth factor 1 (mean difference [95% confidence interval {CI}]: 5.15 cm/year [4.09, 6.21]; 0.57 [0.43, 0.71]; 164.56 ng/mL [112.04, 217.08], respectively; all p<0.0001) were greater in group A than in group B. Mean difference in Ht-V for 0-6 months versus 6-12 months was 2.80 cm/year (95% CI 1.55, 4.04) for group A and -4.60 cm/year (95% CI -6.12, -3.09; both p<0.0001) for group B. No unexpected AEs were reported.

CONCLUSIONS

During the first 6 months, height was significantly increased in GH-treated patients versus untreated patients with ISS. Safety of GH was consistent with the known safety profile.

Ten years with biosimilar rhGH in clinical practice in Sweden - experience from the prospective PATRO children and adult studies

BACKGROUND

In 2007, Omnitrope® was the first biosimilar recombinant human growth hormone (rhGH) to be approved in Sweden for treatment in adults and children. Over 10 years' safety and effectiveness data for biosimilar rhGH can now be presented.

METHODS

PATRO Children and PATRO Adults are multicenter, longitudinal, observational, post-marketing surveillance studies. Eligible patients include children 0-18 years and adults receiving biosimilar rhGH treatment. Adverse events (AEs) are monitored for safety evaluation. Growth variables in children and metabolic data in adults are recorded for effectiveness evaluation.

RESULTS

As of January 2019, data from 136 children (48% male) were reported from Swedish centers. Mean age in rhGH treatment-naïve patients at study entry (n = 114) was 7.5 years, with mean 3.6 years treatment duration. No severe AEs of diabetes, impaired glucose tolerance, or malignancy were reported. The most frequently reported AE was nasopharyngitis (n = 16 patients). No clinically relevant anti-hGH or neutralizing antibodies were observed. The mean change from baseline in height standard deviation score (SDS) in naïve prepubertal GH deficiency patients was + 0.79 at 1 year, + 1.27 at 2 years, and + 1.55 at 3 years. Data from 293 adults (44% rhGH-naïve, 51% male) were included. Fatigue was the most frequently reported AE (n = 26 patients). The incidence of new neoplasms or existing neoplasm progression was 23.8 patients per 1000 patient-years. Type 2 diabetes mellitus was reported in four patients. At baseline in rhGH-naïve adults, mean (SD) body mass index (BMI) was 29.1 (5.6) kg/m² and mean (SD) insulin-like growth factor (IGF)-I SDS was - 3.0 (1.4). Mean daily dose increased from 0.1 mg at baseline to 0.3 mg after 4 years. IGF-I SDS normalized during the first year of treatment. Mean BMI and glucose were unchanged over 4 years, while low-/high-density lipoprotein cholesterol ratio decreased.

CONCLUSIONS

For the first time, Swedish data from the PATRO Children and Adults studies are presented. The 10-year data suggest that biosimilar rhGH is well tolerated across pediatric and adult indications. Safety and effectiveness were similar to previous reports for other rhGH preparations. These results need to be confirmed in larger cohorts, highlighting the importance of long-term post-marketing studies.

Dilemmas of growth hormone treatment for GH deficiency and idiopathic short stature: defining, distinguishing, and deciding

Worrisome growth can be a sign of underlying pathology but usually reflects healthy variation. It is often recognized through short stature, which is defined by arbitrarily separating height, a physical trait on a continuum, into "normal" and "abnormal." In some cases of worrisome growth, recombinant human growth hormone (rhGH) treatment is indicated to hasten growth/increase height. This review addresses the two most frequently treated indications for rhGH, growth hormone deficiency (GHD) and idiopathic short stature (ISS). A review of worrisome growth itself, of the history of GH treatment, of the blurry line between partial GHD and ISS, of the GH stakeholders, and of the outside pressures involved in these cases demonstrates the ambiguous platform upon which treatment decisions are made. The rhGH treatment decision process can be examined further by considering the three most impactful factors on parental height-related medical decision-making: treatment characteristics, child health, and psychosocial function. While it is important to note that treatment for classical GHD is uncontroversial and supported, treatment decisions for partial GHD and ISS are more complicated and require careful evaluation of both patient needs and the supporting evidence. As the rhGH community grows, physicians, parents, and patients are encouraged to engage in a shared decision-making process to navigate the many challenges facing the GH field. Although this review addresses GHD and ISS specifically, the issues discussed are often applicable to pediatrics as a whole.

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.

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.

Genomic interrogation of familial short stature contributes to the discovery of the pathophysiological mechanisms and pharmaceutical drug repositioning

Background

Genetic factors, dysregulation in the endocrine system, cytokine and paracrine factors are implicated in the pathogenesis of familial short stature (FSS). Nowadays, the treatment choice for FSS is limited, with only recombinant human growth hormone (rhGH) being available.

Methods

Herein, starting from the identification of 122 genetic loci related to FSS, we adopted a genetic-driven drug discovery bioinformatics pipeline based on functional annotation to prioritize crucial biological FSS-related genes. These genes were suggested to be potential targets for therapeutics.

Results

We discovered five druggable subnetworks, which contained seven FSS-related genes and 17 druggable targerts.

Conclusions

This study provides a valuable drug repositioning accompanied by corresponding targetable gene clusters for FSS therapy.

Responses to growth hormone (GH) therapy in short children with normal GH secretion and no bone age delay: an analysis of potential factors affecting their response to rhGH therapy. A controlled study

Background: Variability still exist about the growth response to growth hormone (GH) therapy in children with idiopathic short stature (ISS). We describe the growth response to rhGH therapy for >2 years in 20 prepubertal children with idiopathic short stature (ISS) and 18 children with GH deficiency (GHD) and compared them with 15 children with ISS who did not receive rhGH therapy. Patients and methods: Our study included 35 prepubertal and peripubertal (Tanner 1 and 2) children with short stature (Ht-SDS <-2) and/or Ht-SDS >1SD below their mid parental height SD (MP-Ht-SDS) with slow growth velocity (<-1 SD), with normal peak GH response to provocation tests (15.5±6.5 ng/dl), normal IGF-I SDS (-0.9±0.6), and no bone age delay (± 1 year from chronological age) (ISS). 20 children were treated for 2.5±1.5 years with rhGH 0.05 mg/kg/day and 15 children were not treated with rhGH. 18 children with diagnosis of GHD, diagnosed in the same period, receiving rhGH therapy served as controls. We assessed the linear growth and IGF-I levels of all children for an average of 2 years. Results: Children with ISS on rhGH therapy had a height gain of 0.77 SD in 2 years versus 1.05 SD in GHD children, with significant increase in IGF-I and normal progression of bone age and puberty. Children with ISS who did not receive rhGH had no gain in the changes of Ht-SDS inspite of normal progression of bone age and puberty. The difference between children Ht-SDS and mid-parental height SDS (MP-Ht-SDS) changed significantly from -1.1±3 to -0.3±0.5 in the ISS group and from -1.35±0.5 to -0.3±0.25 in the GHD group, after an average of 2 years of treatment. In the treated ISS group, the Ht-SDS gain was correlated positively with the duration of rhGH therapy (r = 0.82, p<0.0001), negatively with the age at the start of treatment (r = -0.544, p = 0.01), and positively with the bone age (r =-0.44, p = 0.04). Discussion: The Ht-SDS of children with ISS on rhGH treatment closely approached their MP-Ht-SDS after 2 years of rhGH therapy while those who did not receive rhGH kept the same distance from their MP-Ht-SDS after 2 years. Analysis of possible factors affecting linear growth in children with ISS on rhGH therapy showed that children below 9 years with Ht-SDS <-2.5 SD and those with Ht-SDS >1SD below MP-Ht-SDS grew better on rhGH therapy compared to older children and those with Ht-SDS >-2.5 and were less than 1SD from their MP-HT-SD. Higher doses of rhGH (to keep IGF-I in high normal levels) and longer duration of therapy improved the Ht-SDS gain of these children. Conclusion: We report significant gain in Ht-SDS in prepubertal children with ISS on rhGH therapy and better response in younger children and in those with Ht-SDS > 1 SD below their MP-Ht-SDS. (www.actabiomedica.it)

Growth screening in children aged 3-5 years: a useful tool for public health programs in community pediatrics

Background About 90% of children grow up normally and attain a final height within their genetic target. In children with intrauterine growth restriction (IUGR), up to 10% will not catch up spontaneously. Turner syndrome is often diagnosed late, and a number of growth-stunted children go undiagnosed and untreated. Objectives Our primary aim was to evaluate the prevalence of stunted growth in preschool-aged children. Our secondary aim was to evaluate growth patterns in children belonging to four ethnic groups in Dreux district, France. Methods Body weight, height and body mass index (BMI) were collected for children aged 3-5 years during systematic community visits. Birth variables, family history of short stature, maternal smoking, ethnic origin, etc. were also recorded. Pubertal status was staged as per Tanner's method. Parents were instructed to attend the hospital growth clinics if their child's height was <-2.0 standard deviation score (SDS). Results Five hundred ninety-three children were screened (301 boys, 289 girls). The mean age was 4.33 ± 0.76 standard deviation (SD) years, and 48% were Caucasians, 13.7% were North Africans, 2.5% were Black Africans, 0.8% were Asians, 1.5% included others and the ethnicity was not specified in 33.5% of the cases. 91.5% of children were term-born and 8.5% were preterm. 84.2% of children were appropriate for gestational age (AGA) and 9.4% were small for gestational age (SGA). At 5 years of age, 22.2% of macrosomic North African children were overweight. Catch-up growth was complete in 98% children, 11/540 were short statured, 8/11 attended our growth clinics (seven short statured and one micropenis) and three were started on recombinant human growth hormone (rhGH). Conclusions Growth screening programs are important and useful tools for public health. There is a need for clear objectives, proper training and automated data collection tools, along with easy access to growth specialists.

GH Dose Reduction Maintains Normal Prepubertal Height Velocity After Initial Catch-Up Growth in Short Children

CONTEXT

GH responsiveness guides GH dosing during the catch-up growth (CUG) period; however, little is known regarding GH dosing during the prepubertal maintenance treatment period.

OBJECTIVE

To evaluate whether SD score (SDS) channel parallel growth with normal height velocity can be maintained after CUG by reducing the GH dose by 50% in children receiving doses individualized according to estimated GH responsiveness during the catch-up period.

DESIGN AND SETTINGS

Prepubertal children (n = 98; 72 boys) receiving GH during CUG (GH deficient, n = 33; non-GH deficient, n = 65), were randomized after 2 to 3 years to either a 50% reduced individualized dose (GHRID; n = 27; 20 boys) or unchanged individualized dose (GHUID; n = 38; 27 boys). Another 33 children (25 boys) continued a standard weight-based dose [43 µg/kg/d (GHFIX)].

MAIN OUTCOME MEASURES

The primary endpoint was the proportion of children with ΔheightSDS within ±0.3 at 1 year after GH dose reduction compared with two control groups: GHUID and GHFIX. The hypothesis was that heightSDS could be maintained within ±0.3 with a reduced individualized GH dose.

RESULTS

For the intention-to-treat population at 1 year, 85% of the GHRIDgroup maintained ΔheightSDS within ±0.3 vs 41% in the GHUIDgroup (P = 0.0055) and 48% in the GHFIXgroup (P = 0.0047). The ΔIGF-ISDS in the GHRID group was -0.75 ± 1.0 at 3 months (P = 0.003) and -0.72 ± 1.2 at 1 year compared with the GHUID group (0.15 ± 1.2; P = 0.005) and GHFIX group (0.05 ± 1.0; P = 0.02).

CONCLUSIONS

Channel parallel growth (i.e., normal height velocity) and IGF-ISDS levels within ±2 were maintained after completed CUG using a 50% lower individualized dose than that used during the CUG period.

Cost-Conscious Growth-Promoting Treatment: When Discretion Is the Better Part of Value

Assessing cost-effectiveness of human growth hormone (hGH) treatment to augment height is complicated by uncertainty about how best to measure its therapeutic effect. Cost-conscious growth promotion practice, however, is possible and likely an emerging practical requisite as health care payers increasingly deny the medical necessity of and restrict support for short stature treatment. The increase in denials is not surprising given the expansion and continued high cost of hGH treatment, debate about the value of such treatment, and universal need to restrain burgeoning health care costs. Renunciation of sweeping payer rejection of hGH-for-height treatment is strengthened by cost-conscious practices that (1) recommend no treatment for most short children and restrict treatment to severe, likely disabling short stature; (2) initiate hGH treatment only after evidence-based informed assent; (3) utilize alternative less costly and less invasive options when possible; (4) minimize hGH treatment duration and dosage; and (5) resist enhancement of normal adult stature. A new era of cost-conscious hGH prescribing that prompts thoughtful restraint in hGH use could help preserve hGH approval for children most in need of treatment.

GH and IGF-1 Replacement in Children

In this chapter, we want to give an overview on what we have learned from more than 30 years ago on the use of recombinant human growth hormone (rhGH) and later recombinant human IGF-1 which was introduced for the treatment of short children and what are the safety issues concerned with this treatment. However, rhGH is used not solely in conditions where short stature is the consequence of GH deficiency but also in various disorders without a proven GH deficiency. In clinical studies, growth responses to various forms of rhGH therapy were analyzed, adding to our concept about the physiology of growth. Most patients under rhGH treatment show a considerable short-term effect; however, the long-term gain of height in a child obtained by a year-long treatment until final height remains controversial in some of the growth disorders that have been treated with rhGH or IGF-1. Today the first studies on the long-term safety of rhGH treatment have been published and raising some questions whether this treatment is similarly safe for all the patient groups treated with rhGH. Although there is a long-standing safety record for these hormone replacement therapies, in the face of the considerable costs involved, the discussion about the risk to benefit ratio is continuing. Newer developments of rhGH treatment include long-term preparations, which have only to be injected once a week. Although some of these drugs already have proven their non-inferiority to conventional rhGH treatment, we have to await further results to see whether they show improvements in treatment adherence of the patients and prove their long-term safety.

Concerns and Expectations of Parents Seeking Subspecialist Care for Their Child's Short Stature

INTRODUCTION

Parents (PP) of children in primary care clinics previously reported factors influencing their height-related medical decision making. However, patients seeking height-related care in endocrine subspecialty clinics and their parents (EP) differ demographically from the general population.

OBJECTIVE

To determine EP height-related medical concerns and expectations, and to compare between EP and PP.

METHODS

EP completed a survey assessing their concerns in seeking medical care for their child's height with identical questions previously asked of PP and two additional questions about growth hormone (GH) treatment.

RESULTS

A greater proportion of the 166 EP (80% response rate) than the 1,820 PP (83% response rate) previously surveyed was Caucasian (75% EP, 41% PP) and privately insured (80% EP, 58% PP). Both groups rated treatment efficacy and risks most as having a bigor extreme impact on decision making (65% EP, 58% PP). The second most rated concern for EP was comparison of child's height to peers or growth chart (60% EP, 32% PP) versus child's health for PP (54% EP, 56% PP). Of the 166 EP surveyed, 76% rated GH treatment as potentially improving quality of life (QoL), with 88% reporting a minimum 3-inch height increase as necessary to improve QoL.

CONCLUSIONS

Height comparisons were more likely to impact EP than PP in seeking height-related medical care for their children. EP had high expectations of QoL improvement with GH treatment, which are unlikely to be met with treatment of idiopathic short stature. Thus, clinicians should be prepared to support families in other ways that promote positive development in children with short stature.

Diagnosis of Idiopathic GHD in Children Based on Response to rhGH Treatment: The Importance of GH Provocative Tests and IGF-1

Purpose: Serum IGF-1 (Insulin like growth factor 1) and Growth Hormone (GH) provocative tests are reasonable tools for screening and diagnosis of idiopathic GH Deficiency (IGHD). However, the average cut-off points applied on these tests have a lower level of evidence and produce large amounts of false results. The aim of this study is to evaluate the sensitivity, specificity, and accuracy of IGF-1 and GH stimulation tests as diagnostic tools for IGHD, using clinical response to recombinant human GH (rhGH) treatment as diagnostic standard [increase of at least 0.3 in height standard deviation (H-SD) in 1 year]. Methods: We performed a prospective study with 115 children and adolescents presenting short stature (SS), without secondary SS etiologies such as organic lesions, genetic syndromes, thyroid disorders. They were separated into Group 1 [patients with familial SS or constitutional delay of growth and puberty (CDGP), not treated with rhGH], Group 2 (patients with suspicion of IGHD with clinical response to rhGH treatment), and Group 3 (patients with suspicion of IGHD without growth response to rhGH treatment). Then, they were assessed for diagnostic performance of IGF-1, Insulin Tolerance Test (ITT) and clonidine test (CT) alone and combined at different cut-off points. Results: Based on the ROC curve, the best cut-off points found for IGF-1, ITT, and CT when they were used isolated were -0.492 SDS (sensitivity: 50%; specificity: 53.8%; accuracy: 46.5%), 4.515 μg/L (sensitivity: 75.5%; specificity: 45.5%; accuracy: 52.7%), and 4.095 μg/L (sensitivity: 54.5%; specificity: 52.6%; accuracy: 56.9%), respectively. When we had combined IGF-1 with-2SD as cut-off alongside ITT or CT, we found 7 μg/L as the best cut-off point. In this situation, ITT had sensitivity, specificity and accuracy of 93.9, 81.8, and 90.1%, while CT had 93.2, 68.4, and 85.7%, respectively. Conclusion: Our data suggest that diagnosis of IGHD should be established based on a combination of clinical expertise, auxologic, radiologic, and laboratorial data, using IGF-1 at the -2SD threshold combined, with ITT or CT at the cut-off point of 7 μg/L. Additional studies, similar to ours, are imperative to establish cut-off points based on therapeutic response to rhGH in IGHD, which would be directly related to a better treatment outcome.

CHALLENGES OF SECURING GROWTH HORMONE COVERAGE FOR IDIOPATHIC SHORT STATURE: REVIEW OF THE 7-YEAR EXPERIENCE AT ONE INSTITUTION

OBJECTIVE

Despite U.S. Food & Drug Administration (FDA) approval of growth hormone (GH) for idiopathic short stature (ISS), many providers face challenges obtaining insurance coverage. We reviewed the insurance coverage experience for ISS at our hospital to identify factors predictive of approval or denial.

METHODS

We reviewed charts of patients who underwent GH stimulation testing from July 1, 2009, to April 30, 2017, to identify ISS patients (height <-2.25 SD, subnormal predicted adult height (PAH) and peak GH >10 ng/mL).

RESULTS

Eighty-seven patients met ISS criteria, of whom 47 (29 male/18 female) had a GH request submitted to insurance. Mean age, height, and growth velocity were 8.6 ± 2.7 years, 2.83 ± 0.4 SD, and 4.4 ± 1.7 cm/year, respectively. Mean PAH based on bone age was -2.50 ± 0.9 SD, equaling 62 inches for males and 58 inches for females. Most had private managed care insurance (74%). Overall, 17/47 (36%) received treatment approval, 7 immediately and 10 more on appeal. There were no differences in age, height SD, growth rate, insurance type, or PAH between the 17 who were approved and the 30 denied. For 21 patients who were treated, a mean increase in 0.6 SD in height was seen after 1 year.

CONCLUSION

At our institution, GH coverage requests for ISS included very short children mostly ages 6 to 11, with heights well below -2.25 SD and poor PAH. Only 36% were approved even after appeal. This highlights the challenge in our area to secure GH treatment for a FDA-approved indication. Collaboration between pediatric endocrinologists and insurers focusing on height SD and PAH, may improve cost-effective coverage to deserving short children who meet FDA guidelines for ISS treatment.

ABBREVIATIONS

FDA = Food and Drug Administration; GH = growth hormone; IGF-1 = insulin-like growth factor 1; ISS = idiopathic short stature; PAH = predicted adult height.

Variation of bone acquisition during growth hormone treatment in children can be explained by proteomic biomarkers, bone formation markers, body composition and nutritional factors

OBJECTIVE

Growth hormone (GH) regulates both longitudinal growth and bone acquisition in children, and has profound metabolic effects. The aim was to investigate the association between proteomic biomarkers, body fat, nutrition and bone formation markers, and longitudinal growth in response to GH during the first year of treatment. The degree to which changes in these factors could explain variations in GH-dependent longitudinal growth and bone mineralization was also assessed.

METHODS

The individualized GH dose trial included 128 short prepubertal children with either normal (non-GH-deficient) or reduced levels of GH secretion (GH-deficient) (mean age ± SD, 8.6 ± 2.6 years; 90 boys), i.e., with a broad range of GH-secretion and GH-responsiveness, receiving GH treatment (mean 43 μg/kg/day). Blood samples were taken and dual-energy X-ray absorptiometry (DXA) measured at baseline and 1 year of treatment. Step-wise multiple regression models were constructed including three steps with different independent variables added at each step to explain the variance in outcome variables (height_SDS, bone mineral content (BMC) and bone mineral density (BMD). Independent variables included in Step I were previously identified proteomic markers related to GH treatment response, bone formation markers (intact PINP, bone-specific alkaline phosphatase and osteocalcin), variables at treatment start (GH dose mU/kg/day, GH maximum secretion, and difference between child's current and mid-parental height_SDS). Step II explored the added influence of body composition data (body mass index or DXA). Step III explored the added influence of serum nutritional markers and hormones.

RESULTS

Step I variables explained 71% of the variation in first year height_SDS gain, median (minimum-maximum) 0.8 (0.24-1.67); and the proportion explained rose to 73% following inclusion of step II variables and 75% following step III. Corresponding values for total body BMC were 58%, 78%, and 80%, respectively. Proportions fell by approximately 20% when BMC was adjusted for height; 33%, 57%, and 57% for steps I, II, and III, respectively. Corresponding values for total body BMD were 29%, 39%, and 45%, respectively.

CONCLUSION

For total BMC, as much as 80% of the variation during the first year of GH treatment could be explained by proteomic biomarkers, body fat, nutrition and bone formation markers, whereas for height-adjusted BMC 57% could be explained. The inclusion of information about either body composition (fat/lean mass) or nutritional markers contributed with approximately 20%. The variation in height_SDS gain could be explained to 75%. Hence, information of fat or nutrition markers was needed for explaining the variation in bone acquisition to the same magnitude as explaining the variation in height response.

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.

Once-Weekly Administration of Sustained-Release Growth Hormone in Korean Prepubertal Children with Idiopathic Short Stature: A Randomized, Controlled Phase II Study

BACKGROUND/AIMS

To determine the optimal dose of LB03002, a sustained-release, once-weekly formulation of recombinant human growth hormone (rhGH), and to compare its efficacy and safety with daily rhGH in children with idiopathic short stature (ISS).

METHODS

This multicenter, randomized, open-label, phase II study included GH-naïve, prepubertal children with ISS, randomized to receive daily rhGH 0.37 mg/kg/week (control, n = 16), LB03002 0.5 mg/kg/week (n = 14), or LB03002 0.7 mg/kg/week (n = 16). The primary endpoint was height velocity (HV) change at week 26.

RESULTS

At week 26, the least square (LS) means for HV change (cm/year) with control, LB03002 0.5 mg/kg/week, and LB03002 0.7 mg/kg/week were 5.08, 3.65, and 4.38, and the LS means for the change in height standard deviation score were 0.65, 0.49, and 0.58, respectively. The lower bound of the 90% confidence interval for the difference between LB03002 0.7 mg/kg/week and the control in the LS mean for HV change (-1.72) satisfied the noninferiority margin (-1.75). Adverse events were generally mild and short-lived.

CONCLUSION

A once-weekly regimen of LB03002 0.7 mg/kg demonstrated noninferiority to the daily regimen of rhGH 0.37 mg/kg/week in terms of HV increments. LB03002 was well tolerated and its safety profile was comparable with that of daily rhGH.

A genetic approach to evaluation of short stature of undetermined cause

Short stature is a common presentation to paediatric endocrinologists. After exclusion of major endocrine or systemic disease, most children with short stature are diagnosed based on a description of their growth pattern and the height of their parents (eg, familial short stature). Height is a polygenic trait and genome-wide association studies have identified many of the associated genetic loci. Here we review the application of genetic studies, including copy number variant analysis, targeted gene panels, and whole-exome sequencing in children with idiopathic short stature. We estimate 25-40% of children diagnosed with idiopathic short stature could receive a molecular diagnosis using these technologies. A molecular diagnosis for short stature is important for affected individuals and their families and might inform treatment decisions surrounding use of growth hormone or insulin-like growth factor 1 therapy.

Born Small for Gestational Age and Poor School Performance - How Small Is Too Small?

AIM

To assess the relationship between severity of small for gestational age (SGA) and the risk of poor school performance, and to investigate whether adult stature modifies this risk.

METHODS

1,088,980 Swedish children born at term between 1973 and 1988 were categorized into severe SGA (less than -3 standard deviations (SD) of expected birth weight), moderate SGA (-2.01 to -3 SD), mild SGA (-1.01 to -2 SD), and appropriate for gestational age (-1 to 0.99 SD). The risk of poor school performance at the time of graduation from compulsory school (grades <10th percentile) was calculated using unconditional logistic regression models and adjusted for socio-economic factors. In a sub-analysis, we stratified boys by adult stature, and adjusted for maternal but not paternal height.

RESULTS

All SGA groups were significantly associated with an increased risk of poor school performance, with adjusted odds ratios and 95% confidence intervals ranging from 1.85 (1.65-2.07) for severe SGA to 1.25 (1.22-1.28) for mild SGA. In the sub-analysis, all birth weight groups were associated with an increased risk of poor school performance among boys with short stature compared to those with non-short stature.

CONCLUSION

Mild SGA is associated with a significantly increased risk of poor school performance, and the risk increases with severity of SGA. Further, this risk diminishes after adequate catch-up growth.

Broad variability in pharmacokinetics of GH following rhGH injections in children

OBJECTIVE

Daily subcutaneous self-injection of GH is used worldwide to treat short stature in childhood; longitudinal data on the impact of this regimen on GH-uptake are lacking.

DESIGN

Children with/without GH-deficiency participating in clinical trials were followed prospectively (≤8 times). Blood was sampled pre-GH-injection (dose GH³³/GH⁶⁷ μg/kg) and either every 30 min thereafter for 24 h (Experimental-setting; 59 GH-curves/15 children); or every 2 h thereafter for 16 h (Clinical-setting; 429 GH-curves/117 children). Pharmacokinetics were estimated by time T_max (h) of maximal GH-concentration (C_max, mU/L) and area under the curve for 16 h (AUC, mU/L ∗ h).

RESULTS

In the Clinical-setting, median C_max was 71 mU/L and AUC was 534 mU/L ∗ h, with coefficients of variation for intra-individual variation of 39% and 36%, respectively, and inter-individual variation of 44% and 42%, respectively. 43% of C_max and AUC variability was explained by GH-dose and proxies for injection depth (baseline GH-level, GH_peakwidth, BMI_SDS). In the Experimental- versus Clinical-setting, 85% and 40% of GH-curves, respectively, reached zero-levels within 24 h. A longer duration was found following a more superficial GH-injection. Spontaneous GH-peaks were identified already 6 h after the GH-injection in about half of the curves of both GHD and non-GHD patients.

CONCLUSION

Very broad intra-individual and inter-individual variability was found. A high GH-peak will optimize growth effects; the highest C_max was found after a deep injection of GH at the higher dose and concentration. In as many as 60% of the children, GH remained detectable in serum after 24 h; a constant GH-level will promote IGF-I and metabolic effects.

Recombinant growth hormone therapy for prepubertal children with idiopathic short stature in Korea: a phase III randomized trial

PURPOSE

Several studies have evaluated the effects of growth hormone (GH) on auxological and biochemical parameters in children with non-GH-deficient, idiopathic short stature (ISS). This study evaluated the efficacy and safety of Growtropin^®-II (recombinant human GH) in Korean patients with ISS.

METHODS

This was a 1-year, open-label, multicenter, phase III randomized trial of Growtropin^®-II in Korean patients with ISS. In total, 70 prepubertal subjects (39 males, 31 females) between 4 and 12 years of age were included in the study. All patients were naive to GH treatment.

RESULTS

Annual height velocity was significantly higher in the treatment group (10.68 ± 1.95 cm/year) than the control group (5.72 ± 1.72, p < 0.001). Increases in height and weight standard deviation scores (SDSs) at 26 weeks were 0.63 ± 0.16 and 0.64 ± 0.46, respectively, for the treatment group, and 0.06 ± 0.15 and 0.06 ± 0.28, respectively, for the control group (p < 0.001). Serum insulin-like growth factor (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) increased significantly in the treatment group at week 26 compared to baseline. However, the SDS for body mass index (BMI) at 26 weeks did not change significantly in either group. Growtropin^®-II was well tolerated and safe over 1 year of treatment.

CONCLUSIONS

One-year GH treatment for prepubertal children with ISS demonstrated increased annualized velocity, height and weight SDSs, and IGF-1 and IGFBP-3 levels, with a favorable safety profile. Further evaluations are needed to determine the optimal dose, final adult height, and long-term effects of ISS treatment.

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.

Clinical and laboratory parameters predicting a requirement for the reevaluation of growth hormone status during growth hormone treatment: Retesting early in the course of GH treatment

OBJECTIVE

We aimed to define the predictive criteria, in the form of specific clinical, hormonal and radiological parameters, for children with growth hormone deficiency (GHD) who may benefit from the reevaluation of GH status early in the course of growth hormone (GH) treatment.

DESIGN AND METHODS

Two hundred sixty-five children with growth hormone deficiency were retested by GH stimulation at the end of the first year of GH treatment. The initial clinical and laboratory characteristics of those with a normal (GH≥10ng/ml) response and those with a subnormal (GH<10ng/ml) response were compared to predict a normal GH status during reassessment.

RESULTS

Sixty-nine patients (40.6%) out of the 170 patients with isolated growth hormone deficiency (IGHD) had a peak GH of ≥10ng/ml during the retest. None of the patients with multiple pituitary hormone deficiency (MPHD) had a peak GH of ≥10ng/ml. Puberty and sex steroid priming in peripubertal cases increased the probability of a normal GH response. Only one patient with IGHD who had an ectopic posterior pituitary without stalk interruption on MRI analysis showed a normal GH response during the retest. Patients with a peak GH between 5 and 10ng/ml, an age at diagnosis of ≥9years or a height gain below 0.61 SDS during the first year of treatment had an increased probability of having a normal GH response at the retest.

CONCLUSION

Early reassessment of GH status during GH treatment is unnecessary in patients who have MPHD with at least 3 hormone deficiencies. Retesting at the end of the first year of therapy is recommended for patients with IGHD who have a height gain of <0.61 SDS in the first year of treatment, especially those with a normal or 'hypoplastic' pituitary on imaging. Priming can increase the likelihood of a normal response in patients in the pubertal age group who do not show overt signs of pubertal development.

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.

Clinical Characterization of Patients With Autosomal Dominant Short Stature due to Aggrecan Mutations

CONTEXT

Heterozygous mutations in the aggrecan gene (ACAN) cause autosomal dominant short stature with accelerated skeletal maturation.

OBJECTIVE

We sought to characterize the phenotypic spectrum and response to growth-promoting therapies.

PATIENTS AND METHODS

One hundred three individuals (57 females, 46 males) from 20 families with autosomal dominant short stature and heterozygous ACAN mutations were identified and confirmed using whole-exome sequencing, targeted next-generation sequencing, and/or Sanger sequencing. Clinical information was collected from the medical records.

RESULTS

Identified ACAN variants showed perfect cosegregation with phenotype. Adult individuals had mildly disproportionate short stature [median height, -2.8 standard deviation score (SDS); range, -5.9 to -0.9] and a history of early growth cessation. The condition was frequently associated with early-onset osteoarthritis (12 families) and intervertebral disc disease (9 families). No apparent genotype-phenotype correlation was found between the type of ACAN mutation and the presence of joint complaints. Childhood height was less affected (median height, -2.0 SDS; range, -4.2 to -0.6). Most children with ACAN mutations had advanced bone age (bone age - chronologic age; median, +1.3 years; range, +0.0 to +3.7 years). Nineteen individuals had received growth hormone therapy with some evidence of increased growth velocity.

CONCLUSIONS

Heterozygous ACAN mutations result in a phenotypic spectrum ranging from mild and proportionate short stature to a mild skeletal dysplasia with disproportionate short stature and brachydactyly. Many affected individuals developed early-onset osteoarthritis and degenerative disc disease, suggesting dysfunction of the articular cartilage and intervertebral disc cartilage. Additional studies are needed to determine the optimal treatment strategy for these patients.

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.

The direction of human mesenchymal stem cells into the chondrogenic lineage is influenced by the features of hydrogel carriers

Low back pain is a major public health issue in the Western world, one main cause is believed to be intervertebral disc (IVD) degeneration. To halt/diminish IVD degeneration, cell therapy using different biomaterials e.g. hydrogels as cell carriers has been suggested. In this study, two different hydrogels were examined (in vitro) as potential cell carriers for human mesenchymal stem cells (hMSCs) intended for IVD transplantation. The aim was to investigate cell-survival and chondrogenic differentiation of hMSCs when cultured in hydrogels Puramatrix^® or Hydromatrix^® and potential effects of stimulation with growth hormone (GH). hMSCs/hydrogel cultures were investigated for cell-viability, attachment, gene expression of chondrogenic markers SOX9, COL2A1, ACAN and accumulation of extracellular matrix (ECM). In both hydrogel types, hMSCs were viable for 28days, expressed integrin β1 which indicates adhesion of hMSCs. Differentiation was observed into chondrocyte-like cells, in a higher extent in hMSCs/Hydromatrix^® cultures when compared to hMSCs/Puramatrix^® hydrogel cultures. Gene expression analyses of chondrogenic markers verified results. hMSCs/hydrogel cultures stimulated with GH displayed no significant effects on chondrogenesis. In conclusion, both hydrogels, especially Hydromatrix^® was demonstrated as a promising cell carrier in vitro for hMSCs, when directed into chondrogenesis. This knowledge could be useful in biological approaches for regeneration of degenerated human IVDs.

A 4-Year, Open-Label, Multicenter, Randomized Trial of Genotropin® Growth Hormone in Patients with Idiopathic Short Stature: Analysis of 4-Year Data Comparing Efficacy, Efficiency, and Safety between an Individualized, Target-Driven Regimen and Standard Dosing

BACKGROUND/AIMS

Growth hormone (GH) treatment regimens for children with non-GH-deficient, idiopathic short stature (ISS) have not been optimized. To compare the efficacy, efficiency, and safety of an individualized, target-driven GH regimen with standard weight-based dosing after 4 years of treatment.

METHODS

This is a 4-year, open-label, multicenter, randomized trial comparing individualized, formula-based dosing of Genotropin® versus a widely used ISS dose of Genotropin®. Subjects were prepubertal, had a bone age of 3-10 years for males and 3-9 years for females, were naive to GH treatment, and had a height standard deviation score (Ht SDS) of -3 to -2.25, a height velocity <25th percentile for their bone age, and peak stimulated GH >10 ng/ml. After the first 2 years, the individualized-dosing group was further randomized to either 0.18 or 0.24 mg/kg/week.

RESULTS

At 4 years, subjects in all treatment regimens achieved similar average height gains of +1.3 SDS; however, the individualized dosing regimen utilized less GH to achieve an equivalent height gain.

CONCLUSION

Individualized, formula-based GH dosing, followed by a dose reduction after 2 years, provides a more cost-effective growth improvement in patients with ISS than currently employed weight-based regimens.

Psychometric performance of the Quality of Life in Short Stature Youth (QoLISSY) questionnaire in the Netherlands

The European Quality of Life in Short Stature Youth (QoLISSY) questionnaire is a disease-specific instrument assessing quality of life (QoL) in children with short stature from the child and parent perspectives. In order to use the QoLISSY in Dutch samples, a translation process and psychometric testing is needed. Children diagnosed with short stature (8 to 18 years) and their parents were recruited from a Dutch growth clinic. Reliability was assessed using Cronbach's α and intraclass correlation coefficients (ICCs). Pearsons' correlations with the generic KIDSCREEN and a confirmatory factor analysis (CFA) were performed to test validity. Scales showed good internal consistency with α ranging from 0.80 to 0.94 (child report) and from 0.85 to 0.95 (parent report). Test-retest reliability (ICC) ranged from 0.15 to 0.91 (child report) and from 0.14 to 0.83 (parent report). Correlations with the KIDSCREEN in the mean range indicated criterion validity. The models' goodness of fit was confirmed by CFA results in the Dutch and in comparison with the European sample.

CONCLUSION

The Dutch QoLISSY is a psychometrically reliable and valid short stature-specific QoL measure. It is now available for use in clinical research and practice to evaluate well-being and possible effects of growth hormone treatment and psychological interventions in the Netherlands.

The Effect of Recombinant Growth Hormone Treatment in Children with Idiopathic Short Stature and Low Insulin-Like Growth Factor-1 Levels

OBJECTIVE

Idiopathic short stature (ISS) constitutes a heterogeneous group of short stature which is not associated with an endocrine or other identifiable cause. Some ISS patients may have varying degrees of insulin-like growth factor-1 (IGF-1) deficiency. Recombinant growth hormone (rGH) treatment has been used by some authors with variable results. Reports on long-term rGH treatment are limited.

METHODS

In this study, 21 slowly growing, non-GH-deficient ISS children who received rGH treatment for 3.62±0.92 years were evaluated at the end of a 5.42±1.67-year follow-up period. The study group included patients with low IGF-1 levels who also responded well to an IGF generation test. The patients were divided into two groups as good responders [height increment >1 standard deviation (SD)] and poor responders (height increment <1 SD) at the end of the follow-up period.

RESULTS

The height of the patients improved from -3.16±0.46 SD score (SDS) to -1.9±0.66 SDS. At the end of the follow-up period, mean height SDS was -1.72. Eleven of the patients showed a good response to treatment. Clinical parameters were essentially similar in the good responders and the poor responders groups. A female preponderance was noted in the good responders group.

CONCLUSION

rGH treatment can safely be used in ISS children. Long-term GH treatment will ameliorate the height deficit and almost 40% of patients may reach their target height.

Seasonal variations in vitamin D in relation to growth in short prepubertal children before and during first year growth hormone treatment

PURPOSE

This study investigated the relationship between seasonal variations in 25-hydroxyvitamin D (25(OH)D) levels and growth in prepubertal children during both the pretreatment year and the first year of GH treatment.

METHODS

The study included 249 short prepubertal children with a broad range of GH secretion, GH(max) during a 24 h profile median 23; range 1-127 mU/L, 191 boys (mean age ± SD, 8.6 ± 2.6 years), 58 girls (7.5 ± 1.9 years) receiving GH treatment (mean 43 µg/kg/day; range 17-99 µg/kg/day). Serum 25(OH)D was measured using an automated IDS-iSYS immunoassay.

RESULTS

25(OH)D levels showed seasonal variation, and decreased significantly during GH treatment. 25(OH)D levels at start and first year reduction in 25(OH)D, correlated (-) with the first year growth response during treatment. The degree of GH secretion capacity within our study population of mainly non-GH deficient children and 25(OH)D sufficient (67 ± 29 nmol/L) had no influence on 25(OH)D levels. Growth during GH treatment were independent of seasonal variations in 25(OH)D. Multiple regression analysis showed that 25(OH)D levels at treatment start, together with auxological data and IGF-binding protein-(3)SDS, explained 61 % of the variation in first year gain in heightSDS.

CONCLUSION

25(OH)D levels were associated with first year growth response to GH and may be a useful contribution to future growth prediction models.

Short and tall stature: a new paradigm emerges

In the past, the growth hormone (GH)-insulin-like growth factor 1 (IGF-1) axis was often considered to be the main system that regulated childhood growth and, therefore, determined short stature and tall stature. However, findings have now revealed that the GH-IGF-1 axis is just one of many regulatory systems that control chondrogenesis in the growth plate, which is the biological process that drives height gain. Consequently, normal growth in children depends not only on GH and IGF-1 but also on multiple hormones, paracrine factors, extracellular matrix molecules and intracellular proteins that regulate the activity of growth plate chondrocytes. Mutations in the genes that encode many of these local proteins cause short stature or tall stature. Similarly, genome-wide association studies have revealed that the normal variation in height seems to be largely due to genes outside the GH-IGF-1 axis that affect growth at the growth plate through a wide variety of mechanisms. These findings point to a new conceptual framework for understanding short and tall stature that is centred not on two particular hormones but rather on the growth plate, which is the structure responsible for height gain.

Attaining genetic height potential: Analysis of height outcomes from the ANSWER Program in children treated with growth hormone over 5 years

OBJECTIVE

This study aimed to assess attainment of genetic height potential after long-term growth hormone (GH) treatment in GH-naïve children diagnosed with isolated growth hormone deficiency (IGHD), multiple pituitary hormone deficiency (MPHD), born small for gestational age (SGA), or idiopathic short stature (ISS) enrolled in the American Norditropin®

STUDIES

Web-enabled Research (ANSWER) Program.

DESIGN

Children with IGHD (n=2884), MPHD (n=200), SGA (n=481), or ISS (n=733) with baseline height standard deviation score (HSDS)≤-2 were assessed over 5 years of GH treatment for mean HSDS, change in HSDS (ΔHSDS), and corrected HSDS (HSDS-target HSDS).

RESULTS

Mean HSDS and corrected HSDS significantly increased to close to target height across all diagnostic groups after 5 years of GH treatment (P<0.0001). ∆HSDS at year 5 increased for all groups (IGHD: 1.8; MPHD: 2.1; SGA: 1.8; ISS: 1.6). Among patients who continued GH for 5 years, mean insulin-like growth factor-I (IGF-I) SDS increased to within normal range across all groups. Body mass index (BMI) SDS remained relatively stable in all diagnostic groups. Bone age (BA) increased, and the mean BA to chronological age (BA/CA) ratio reached or approached 1 across diagnostic groups over 5 years of GH treatment.

CONCLUSIONS

Long-term GH therapy resulted in a significant increase in mean HSDS and corrected HSDS from baseline values in all diagnostic groups. The observed increase in mean corrected HSDS is consistent with growth that approached the patients' genetic height potential, although complete height gains will be evaluated at the attainment of final height.

Can school health check-ups serve as screening tool for growth anomalies and obesity in children?

OBJECTIVE

To evaluate the prevalence of growth disorders and obesity in schoolchildren and determine whether school health check-ups are effective in their screening. Subjects-methods: Analysis of anonymized growth and body mass index (BMI) data from 2887 children attending the 3rd grade from 2008 to 2009 after selection of 75 elementary schools in Paris.

RESULTS

Linear growth velocity was abnormal in 198 children. Height and weight were above the French reference values (+ 0.9 ± 1.2 SD and + 1 ± 1.7 SD, respectively). BMI was higher, compared to reference values (+ 0.4 ± 1.4 SD). At their last check-up, 20.9% of children had a BMI > + 2 SD.

CONCLUSIONS

School health check-ups constitute a good screening tool for growth and obesity. However, further work is needed to determine the most effective modality. The reference values currently used in France are no longer suitable and new reference charts need to be established. The high prevalence of obesity in schoolchildren remains a public health challenge.

Efficacy and Safety of Human Growth Hormone in Idiopathic Short Stature

OBJECTIVE

To explore the efficacy and safety of medium dose of recombinant human growth hormone (rhGH) in the treatment of prepubescent girls with idiopathic short stature (ISS).

METHODS

Fifty-one prepubescent girls with ISS were recruited into the study and divided into the treatment group (n = 27) and the control group (n = 24) depending on whether or not they accepted rhGH therapy respectively. A therapeutic dose of 0.35-0.42 mg of rhGH·(kg·wk)(-1) was administered for 2 y. The control group patients did not receive rhGH treatment. The height, growth rate, height standard deviation score (HtSDS), bone age (BA), the expected adult height (PAH), and potential side effects of rhGH treatment were analysed and compared between the groups.

RESULTS

The growth rate and htSDS during years 1 and 2 were significantly higher in the treatment group than in the control group. The expected adult height was significantly higher after 2 y of treatment as compared to the corresponding value in the control group. The BA after years 1 and 2 did not significantly differ between the two groups.

CONCLUSIONS

Thus, short-term therapy with a medium dose of rhGH was found to have a precise effect on prepubertal children with ISS. At this dose, it can significantly increase the growth rate of children and improve the expected adult height without accelerating bone maturation. No serious adverse reactions were found in association with rhGH use during the two-year study period.

Genetic and Epigenetic Modulation of Growth Hormone Sensitivity Studied With the IGF-1 Generation Test

CONTEXT

Like all hormones, GH has variable physiological effects across people. Many of these effects initiated by the binding of GH to its receptor (GHR) in target tissues are mediated by the expression of the IGF1 gene. Genetic as well as epigenetic variation is known to contribute to the individual diversity of GH-dependent phenotypes through two mechanisms. The first one is the genetic polymorphism of the GHR gene due to the common deletion of exon 3. The second, more recently reported, is the epigenetic variation in the methylation of a cluster of CGs dinucleotides located within the proximal part of the P2 promoter of the IGF-1 (IGF1) gene, notably CG-137.

OBJECTIVE

The current study evaluates the relative contribution of these two factors controlling individual GH sensitivity by measuring the response of serum IGF-1 to a GH injection (IGF-1 generation test) in a sample of 72 children with idiopathic short stature.

RESULTS

Although the d3 polymorphism of the GHR contributed 19% to the variance of the IGF-1 response, CG-137 methylation in the IGF-1 promoter contributed 30%, the combined contribution of the two factors totaling 43%.

CONCLUSION

Our observation indicates that genetic and epigenetic variation at the GHR and IGF-1 loci play a major role as independent modulators of individual GH sensitivity.

The growth hormone receptor exon 3-deleted/full-length polymorphism and response to growth hormone therapy in prepubertal idiopathic short children

OBJECTIVE

The primary aim of the study was to evaluate d3-GHR as a possible cause of increased GH sensitivity in children with delayed infancy-childhood transition (DICT). The secondary aim was to investigate the impact of the GHR exon 3 deleted/full-length (d3/fl) polymorphism on GH treatment response in prepubertal children classified as having idiopathic short stature (ISS).

DESIGN

Study subjects included 167 prepubescent longitudinally followed children classified as having ISS. Children were randomized to standard-dose GH treatment (33 μg kg(-1) day(-1)), to double-dose treatment (67 μg kg(-1) day(-1)), or to an untreated control group. Growth and metabolic outcome were evaluated at birth (n = 166), after one year of treatment (n = 59) and at adult height (n = 145). Genotyping of the GHR d3/fl polymorphism was performed using TaqMan SNP genotyping of tagSNP rs6873545.

RESULTS

Birth and early growth data did not reach the predetermined level of statistical significance for difference between genotypes. Growth and IGF-1 response after one year of GH treatment did not differ between genotypes. IGFBP-3SDS was higher in untreated d3-GHR carriers than in untreated fl/fl individuals, whereas there was insufficient evidence for higher IGFBP-3SDS in treated d3-GHR carriers. Genotype did not explain the growth response to treatment, and no differences in heightSDS, height gain, or difference in height to midparental heightSDS between genotype groups were found at adult height.

CONCLUSION

The common GHR d3/fl polymorphism is probably not a cause of DICT in children with ISS, and our results do not suggest that the d3-GHR genotype is associated with increased sensitivity to GH in children with ISS.

Hormone replacement therapy in children: The use of growth hormone and IGF-I

Recombinant human GH (rhGH) has been available since 1985. This article gives an overview, what has been achieved over the past 30 years in respect to optimization of rhGH treatment for the individual child with GH deficiency and what are the safety issues concerned with this treatment. In the last twenty years significant scientific progress has been made in the diagnosis of GH deficiency, the genetic disorders that are associated with pituitary GH deficiency and the genetics that influence growth in general. On the other hand rhGH is not only used in states of GH deficiency but also various conditions without a proven GH deficiency by classical standards. Clinical studies that investigated both the genetics of growth and the individual responses to rhGH therapy in these patient populations were able to refine our concept about the physiology of normal growth. In most patients under rhGH treatment there is a considerable short-term effect, however the overall gain in growth obtained by a long-term treatment until final height still remains a matter of debate in some of the conditions treated. Also first studies on the long-term safety risks of rhGH treatment have raised the question whether this treatment is similarly safe for all the patient groups eligible for such a treatment. Therefore even in the face of a longstanding safety record of this drug replacement therapy the discussion about the right cost and risk to benefit ratio is continuing. Consequently there is still a need for carefully conducted long-term studies that use modern anthropometric, genetic, and laboratory techniques in order to provide the necessary information for clinicians to select the patients that will benefit best from this valuable treatment without any long term risk.