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

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

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

Global perspective on pediatric growth hormone registries: a systematic review

BACKGROUND

Registries are considered valuable data sources for identification of pediatric conditions treated with growth hormone (GH), and their follow-up. Currently, there is no systematic literature review on the scope and characteristics of pediatric GH registries. Therefore, the purpose of this systematic review is to identify worldwide registries reported on pediatric GH treatment and to provide a summary of their main characteristics.

CONTENT

Pediatric GH registries were identified through a systematic literature review. The search was performed on all related literature published up to January 30th, 2021. Basic information on pediatric GH registries, their type and scope, purpose, sources of data, target conditions, reported outcomes, and important variables were analyzed and presented.

SUMMARY

Twenty two articles, reporting on 20 pediatric GH registries, were included in this review. Industrial funding was the most common funding source. The main target conditions included in the pediatric GH registries were: growth hormone deficiency, Turner syndrome, Prader Willi syndrome, small for gestational age, idiopathic short stature, and chronic renal insufficiency. The main objectives in establishing and running pediatric GH registries were assessing the safety and effectiveness of the treatment, describing the epidemiological aspects of target growth conditions and populations, serving public health surveillance, predicting and measuring treatment outcomes, exploring new and useful aspects of GH treatment, and improving the quality of patient care.

OUTLOOK

This systematic review provides a global perspective on pediatric GH registries which can be used as a basis for the design and development of new GH registry systems at both national and international levels.

A Real-World Study of Recombinant Human Growth Hormone in the Treatment of Idiopathic Short Stature and Growth Hormone Deficiency

Objective

This study aimed to evaluate the clinical efficacy of recombinant human growth hormone (rhGH) in the treatment of children with idiopathic short stature (ISS) and growth hormone deficiency (GHD) and to explore the related factors affecting treatment efficacy.

Methods

The current research reflects a real-world study. A total of 79 patients with ISS and 95 patients with GHD (both groups pre-puberty) who had been treated with rhGH for more than one year from January 2010 to September 2019 were included in this study. The patients were divided into two groups, ie, an ISS and a GHD group, respectively. The growth indexes, such as chronological age (CA), bone age (BA), height standard deviation score (HtSDS), insulin-like growth factor-1 (IGF-1) SDS, and body mass index were recorded and compared between the two groups before and after treatment. The treatment efficacy was evaluated according to changes in HtSDS before and after treatment, and the influencing factors of clinical efficacy were analyzed using a multivariate regression model.

Results

At the start of treatment, the differences in CA, BA, height, weight, sexual development stage, HtSDS, mid-parental height SDS, and IGF-1 SDS between the two groups were not statistically significant (P > 0.05). However, the initial dose of rhGH in the GHD group was significantly lower than in the ISS group (P < 0.001). Following rhGH treatment, the differences in CA, BA, BA/CA ratio, and IGF-1 SDS measured at 6, 12, 18, and 24 months between the ISS and GHD groups were not statistically significant, while the difference in HtSDS measured at 6 months was statistically significant. With the extension of rhGH treatment time, the annual growth rate (GV) gradually decreased, and the difference between HtSDS and the baseline gradually increased; however, the differences between the ISS and GHD groups were not statistically significant. The most important factor affecting the treatment efficacy for patients with ISS was age at the start of treatment; the most important factors affecting the treatment efficacy for patients with GHD were age and IGF-1 SDS.

Conclusion

Recombinant human growth hormone treatment can significantly improve the height of patients with ISS and GHD. There was no significant difference in growth rate between patients with ISS and those with GHD at relatively high doses. The common factor affecting the treatment efficacy of the two groups was the age at the start of treatment. During treatment, monitored data indicated that rhGH treatment of GHD and ISS thyroid function showed a clinical phenomenon in the form of increased free triiodothyronine, rather than hypothyroidism, which was rarely reported in existing studies.

Adherence and quality of life in children receiving rhGH treatment

Short stature may have a major impact on quality of life (QoL), not only during adulthood but also during childhood. Treatment by growth hormone may induce improvement in QoL through height gain, as shown in recent articles, with an increase in general health-related and also height-specific QoL assessed by self-reports and parental reports. In a paper published by our team, we show altered general-health QoL in patients with very short stature (≤ -3 SD) and an improvement in general and height-specific scales in the complete population (≤ -2 SD) after one year of recombinant human growth hormone (rhGH) treatment, perceived both by children and their parents, with a moderate positive correlation with height gain. Adequate results in terms of height gain depend on different factors: the patient's age, underlying condition for which rhGH is prescribed and dose of rhGH treatment, among others. Daily injections may cause a significant burden for the child and family, and may alter adequate adherence to treatment. Identifying positive and negative factors in the patient and in the healthcare providers-patient team and encouraging a shared decision-making process are important for improving the patient's adherence to treatment. New long-acting forms of rhGH that will be available in the next few years may play an important part in improving treatment-related QoL and adherence to treatment. © 2022 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.

Yearly Height Gain Is Dependent on the Truly Received Dose of Growth Hormone and the Duration of Periods of Poor Adherence: Practical Lessons From the French Easypod™ Connect Multicenter Observational Study

Objective

To study the impact of the true mean daily dose and the true mean number of injections per week on the yearly height gain in short children treated with recombinant human growth hormone (rhGH).

Design and Methods

220 children from the French Easypod™ Connect Observational Study (ECOS) used the Easypod™ electronic device to record rhGH injections. The mean daily rhGH dose (the sum of the doses truly received divided by the number of days) and mean number of injections per week (the number of injections truly performed divided by the number of weeks) were calculated. Linear mixed models were used to study the impact of short (3-month) and long (1-year) variations in rhGH administration on the yearly height change [as a standard deviation score (SDS)], with time on treatment as a covariate. For each patient, several periods of 3 or 12 months were considered and designated as poorly adherence or fully adherence. We studied the impact of each of period on the height change.

Results

At treatment initiation, the mean ± SD age was 9.8 ± 3.7 years (females: 47%, prepubertal: 86%) and the mean height was -2.28 ± 0.92 SDS. The mean treatment duration was 3.2 ± 1.1 years (685.2 patient years). 122 patients were GH-deficient, 79 were small for gestational age, and 19 had Turner syndrome. When treatment was computed over 12-month periods, receiving a mean daily dose <0.03 mg/kg.d was associated with a 20% lower mean yearly height gain SDS when<3 injections/week were received (vs.>5 injections/week), whereas maintaining a mean daily dose >0.03 mg/kg.d with<3 injections/week was not associated with a lower yearly height gain SDS (vs.>5 injections/week). For 3-month periods, changes in the daily rhGH dose or the number of injections per week over such short period did not influence the yearly height gain SDS.

Conclusion

The 12-month treatment model showed that when poor adherence leads to a low true daily GH dose, the yearly height gain is low. The 3-month treatment model showed that poor adherence for short periods (<3 months) had no impact on the height SDS.

Growth response to growth hormone (GH) treatment in children with GH deficiency (GHD) and those with idiopathic short stature (ISS) based on their pretreatment insulin-like growth factor 1 (IGFI) levels and at diagnosis and IGFI increment on treatment

OBJECTIVES

Some idiopathic short stature (ISS) patients may have varying degrees of insulin-like growth factor 1 (IGFI) deficiency. Others with growth hormone deficiency (GHD) (peak GH < 7 ng/dL after provocation) have normal IGFI levels. Do children with ISS or those with GHD with variable pretreatment IGFI standard deviation score (IGFISDS) have different IGFI and growth responses to recombinant human growth hormone (rhGH) therapy?

METHODS

We studied the effect of GH therapy (0.035-0.06 mg/kg/day) on linear growth and weight gain per day (WGPD) in children with ISS (n=13) and those with GHD (n=10) who have low pretreatment IGFISDS (IGF SDS < -1.5) and compared them with age-matched prepubertal children with ISS (n=10) and GHD (n=17) who had normal pretreatment IGFISDS. An untreated group of children with ISS (n=12) served as a control group.

RESULTS

At presentation, the height standard deviation score (HtSDS) of children with ISS who had low pretreatment IGFISDS was significantly lower compared to the normal IGFI group. The age, body mass index (BMI), BMISDS, peak GH response to clonidine provocation and bone age did not differ between the two study groups. After 1 year of treatment with rhGH (0.035-0.06 mg/kg/day) IGFISDS increased significantly in both groups (p<0.05). Both had significantly increased HtSDS (catch-up growth). The increase in the HtSDS and WGPD were significantly greater in the lower pretreatment IGFISDS group. The IGFSDS, BMISDS, HtSDS and difference between HtSDS and mid-parental HtSDS were significantly greater in the rhGH treated groups vs. the not treated group. In the GHD groups (normal and low IGFISDS), after 1 year of GH therapy (0.03-0.05 mg/kg/day), the HtSDS increased significantly in both, (p<0.01). The WGPD and increment in BMI were significantly greater in children who had low pretreatment IGFISDS. There was a significant increase in the IGFSDS in the two treated groups (p<0.05), however, the WGPD was greater in the pretreatment low IGFISDS.

CONCLUSIONS

IGFI deficiency represents a low anabolic state. Correction of IGFI level (through rhGH and/or improved nutrition) in short children (ISS and GHD) was associated with increased linear growth and WGPD denoting significant effect on bone growth and muscle protein accretion.

Pharmacogenomics applied to recombinant human growth hormone responses in children with short stature

We present current knowledge concerning the pharmacogenomics of growth hormone therapy in children with short stature. We consider the evidence now emerging for the polygenic nature of response to recombinant human growth hormone (r-hGH). These data are related predominantly to the use of transcriptomic data for prediction. The impact of the complex interactions of developmental phenotype over childhood on response to r-hGH are discussed. Finally, the issues that need to be addressed in order to develop a clinical test are described.

Genetic Screening for Growth Hormone Therapy in Children Small for Gestational Age: So Much to Consider, Still Much to Discover

Children born small for gestational age (SGA), and failing to catch-up growth in their early years, are a heterogeneous group, comprising both known and undefined congenital disorders. Care for these children must encompass specific approaches to ensure optimal growth. The use of recombinant human growth hormone (rhGH) is an established therapy, which improves adult height in a proportion of these children, but not with uniform magnitude and not in all of them. This situation is complicated as the underlying cause of growth failure is often diagnosed during or even after rhGH treatment discontinuation with unknown consequences on adult height and long-term safety. This review focuses on the current evidence supporting potential benefits from early genetic screening in short SGA children. The pivotal role that a Next Generation Sequencing panel might play in helping diagnosis and discriminating good responders to rhGH from poor responders is discussed. Information stemming from genetic screening might allow the tailoring of therapy, as well as improving specific follow-up and management of family expectations, especially for those children with increased long-term risks. Finally, the role of national registries in collecting data from the genetic screening and clinical follow-up is considered.

The long-term safety and effectiveness of growth hormone treatment in Japanese children with short stature born small for gestational age

This study aimed to characterize the safety and effectiveness of GH treatments, in usual clinical practice, in children with short stature born small for gestational age (SGA). This was a multicenter, open-label, non-interventional study (NCT01110928) conducted at 150 sites in Japan (2009–2018). The primary objective was to assess the type and frequency of serious adverse drug reactions (SADRs) associated with long-term GH use. Overall, 452 naïve and 46 non-naïve (previously treated) children were enrolled. GH treatment was well‑tolerated, with SADRs occurring in 1.3% (6/452) and 0% (0/46) of naïve and non-naïve children, respectively. No new safety concerns or notable changes in glucose metabolism were identified during long-term treatment. Altogether, 57 children (32 naïve and 25 non-naïve) reached near adult height (NAH). In naïve and non-naïve children, mean ± standard deviation (SD) height standard deviation score (SDS) at NAH were –2.03 ± 0.77 and –1.53 ± 0.81, respectively, representing a change of +0.85 ± 0.72 and +1.24 ± 0.66 from baseline height SDS, respectively. Mean treatment duration to NAH was 4.29 (naïve) and 7.26 (non-naïve) yr. Thus, long-term GH treatment for short stature in children born SGA was confirmed to have a good safety profile and was effective for improving adult height.

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

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

Near-Adult Height After Growth Hormone Treatment in Children Born Prematurely-Data From KIGS

CONTEXT

Children born prematurely have been treated with growth hormone (GH), and a significant improvement in height during the first years of treatment has been described.

OBJECTIVE

To evaluate the influence of prematurity on near-adult height (NAH) after GH treatment.

DESIGN

KIGS (Pfizer International Growth Database) was queried for children born preterm treated with GH.

SETTING

KIGS database.

PATIENTS

A total of 586 children short in stature born preterm with various GH status and with available gestational age (GA), birth weight, and NAH, all treated with GH.

INTERVENTION

GH treatment.

MAIN OUTCOME MEASURE

NAH.

RESULTS

Values were expressed as median. From the 586 children included, 482 born appropriate for GA (AGA; median age 8.26 years) and 104 born small for gestational age (SGA) (median age 8.54 years); 66.6% of preterm AGA had GH peak < 7 µg/L during a provocation test, whereas only 8.6% of preterm SGA. Change in height standard deviation scores (SDS) from GH start to NAH after 8.04 years of GH treatment was 1.82 in preterm AGA. Respective values were 7.08 years and 1.08 SDS for preterm SGA (P < 0.001); 57% of the variability of the growth response to NAH could be explained, and the distance to parental height was the strongest predictor. No significant changes in height SDS were observed from puberty start to NAH. No correlation was found with GA. GH treatment was well tolerated.

CONCLUSION

GH treatment resulted in significant improvement in height in children born preterm, particularly during prepubertal years and for those with GH deficiency. The degree of prematurity did not influence the growth response.

Korean reference for full-term birth length by sex: data from the 4th Korean National Health and Nutrition Examination Survey (KNHANES-IV; 2007-2009)

PURPOSE

The purpose of this study was to construct reference data for birth length of full-term and preterm Korean infants by sex and to define a sex-specific birth length cut-off to identify small for gestational age (SGA).

METHODS

Data were collected from the 4th Korean National Health and Nutrition Examination Survey (2007-2009), comprising 843 children with birth length data and birth history.

RESULTS

References for the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles of birth length and weight were created using singleton neonates of gestational age (GA) 36-37 weeks and 38-41 weeks by sex. The birth length cutoff value for SGA (&lt;10th percentile) was 48 cm in both male and female neonates, and the ≤3rd percentile cutoff was 47 cm in males and 46 cm in females born at a GA of 38-41 weeks.

CONCLUSION

New Korean reference data were created for birth length and differed from those of other ethnicities. Further research on short-term and long-term health outcomes of SGA infants based on the new reference data is needed.

Treatment of Children With GH in the United States and Europe: Long-Term Follow-Up From NordiNet® IOS and ANSWER Program

CONTEXT

Understanding real-world prescribing of GH may help improve treatment of eligible patients.

OBJECTIVE

Overall: to assess real-world effectiveness and safety of GH (Norditropin). This analysis: to compare clinical characteristics of GH-treated children in the United States and Europe.

DESIGN

The American Norditropin Studies: Web-Enabled Research Program (ANSWER; 2002 to 2016, United States) and the NordiNet International Outcome Study (NordiNet IOS; 2006 to 2016, Europe) were multicenter longitudinal observational cohort studies.

SETTING

Data were recorded in 207 (United States) and 469 (Europe) clinics.

PARTICIPANTS

Patients with GH deficiency, Turner syndrome, Noonan syndrome, idiopathic short stature, Prader-Willi syndrome, or born small for gestational age, who commenced GH treatment aged <18 years.

INTERVENTION

GH was prescribed by treating physicians according to local practice.

MAIN OUTCOMES MEASURES

Baseline data and drug doses were recorded. Data on effectiveness and safety were collected.

RESULTS

ANSWER had 19,847 patients in the full analysis set (FAS; patients with birthdate information and one or more GH prescription) and 12,660 in the effectiveness analysis set (EAS; GH-naive patients with valid baseline information). NordiNet IOS had 17,711 (FAS) and 11,967 (EAS). Boys accounted for 69% (ANSWER) and 57% (NordiNet IOS). Treatment start occurred later than optimal to improve growth. The proportion of boys treated was generally larger, children were older at treatment start, and GH doses were higher in the United States vs Europe. No new safety signals of concern were noted.

CONCLUSIONS

In most indications, more boys than girls were treated, and treatment started late. Earlier diagnosis of GH-related disorders is needed. The data support a favorable benefit-risk profile of GH therapy in children.

Children Born Small for Gestational Age: Differential Diagnosis, Molecular Genetic Evaluation, and Implications

Children born small for gestational age (SGA), defined as a birth weight and/or length below -2 SD score (SDS), comprise a heterogeneous group. The causes of SGA are multifactorial and include maternal lifestyle and obstetric factors, placental dysfunction, and numerous fetal (epi)genetic abnormalities. Short-term consequences of SGA include increased risks of hypothermia, polycythemia, and hypoglycemia. Although most SGA infants show catch-up growth by 2 years of age, ∼10% remain short. Short children born SGA are amenable to GH treatment, which increases their adult height by on average 1.25 SD. Add-on treatment with a gonadotropin-releasing hormone agonist may be considered in early pubertal children with an expected adult height below -2.5 SDS. A small birth size increases the risk of later neurodevelopmental problems and cardiometabolic diseases. GH treatment does not pose an additional risk.

Still too little, too late? Ten years of growth hormone therapy baseline data from the NordiNet® International Outcome Study

BACKGROUND

We investigated time trends in age, gender, growth hormone (GH) dose and height standard deviation score (SDS) in children with GH deficiency (GHD), born small for gestational age (SGA) or with Turner syndrome (TS) starting GH treatment.

METHODS

Data were obtained from children enrolled in the NordiNet® International Outcome Study (IOS) between 2006 and 2015 in the Czech Republic, France, Germany, Serbia and Montenegro (all indications), and Switzerland and the UK (GHD only). Trends were analyzed by linear regression. Patients were divided by age into early-, medium- or late-start groups in three different time periods.

RESULTS

Approximately one-third of children starting treatment for GHD were girls, with no apparent increase in proportion over time. The mean baseline age for starting treatment decreased significantly (p<0.001) for both GHD and SGA in the Czech Republic and Germany. In the other countries studied, over 40% of children started treatment for GHD and SGA late (girls >10, boys >11 years) between 2013 and 2015. The mean baseline GH doses were largely within recommended ranges for GHD and SGA, but below the lowest recommended starting dose for TS in almost every year since 2011 except in France.

CONCLUSIONS

Approximately one-third of children starting treatment for GHD were girls. Between 2013 and 2015, more than 40% of children started treatment for GHD and SGA late except in Germany and the Czech Republic. TS patients received below-recommended doses. These results highlight the need for earlier identification of short stature in children, particularly girls, and for dose optimization in TS.

Growth Hormone Research Society perspective on biomarkers of GH action in children and adults

OBJECTIVE

The Growth Hormone Research Society (GRS) convened a Workshop in 2017 to evaluate clinical endpoints, surrogate endpoints and biomarkers during GH treatment of children and adults and in patients with acromegaly.

PARTICIPANTS

GRS invited 34 international experts including clinicians, basic scientists, a regulatory scientist and physicians from the pharmaceutical industry.

EVIDENCE

Current literature was reviewed and expert opinion was utilized to establish the state of the art and identify current gaps and unmet needs.

CONSENSUS PROCESS

Following plenary presentations, breakout groups discussed questions framed by the planning committee. The attendees re-convened after each breakout session to share the group reports. A writing team compiled the breakout session reports into a document that was subsequently discussed and revised by participants. This was edited further and circulated for final review after the meeting. Participants from pharmaceutical companies were not part of the writing process.

CONCLUSIONS

The clinical endpoint in paediatric GH treatment is adult height with height velocity as a surrogate endpoint. Increased life expectancy is the ideal but unfeasible clinical endpoint of GH treatment in adult GH-deficient patients (GHDA) and in patients with acromegaly. The pragmatic clinical endpoints in GHDA include normalization of body composition and quality of life, whereas symptom relief and reversal of comorbidities are used in acromegaly. Serum IGF-I is widely used as a biomarker, even though it correlates weakly with clinical endpoints in GH treatment, whereas in acromegaly, normalization of IGF-I may be related to improvement in mortality. There is an unmet need for novel biomarkers that capture the pleiotropic actions of GH in relation to GH treatment and in patients with acromegaly.

Adult Height after Growth Hormone Treatment at Pubertal Onset in Short Adolescents Born Small for Gestational Age: Results from a Belgian Registry-Based Study

OBJECTIVES

Information on the efficacy of GH treatment in short SGA children starting their treatment in adolescence is limited. Therefore, adult height (AH), total height gain, and pubertal height gain were evaluated in short SGA children who started GH treatment at pubertal onset.

PATIENT AND METHODS

Growth data of 47 short SGA adolescents (22 boys) who started GH treatment at pubertal onset (PUB group) were compared with results from 27 short SGA patients (11 boys) who started GH therapy at least 1 year before pubertal onset (PrePUB group).

RESULTS

The PUB group achieved a mean (±SD) total height gain of 0.8 ± 0.7 SDS and an AH of -2.5 ± 0.7 SDS after 4.1 ± 1.1 years of GH treatment with a dosage of 41.8 ± 8.4 μg/kg/day. These results were comparable with those in the PrePUB group, which was treated for a longer duration (5.8 ± 2.1 years), resulting in a total height gain of 1.1 ± 0.7 SDS and an AH of -2.1 ± 1.0 SDS. Multiple regression analysis showed a significantly lower height gain in pubertal patients, females, and patients weighing less at start of GH treatment. An AH above -2 SDS and above the parent-specific lower limit of height was, respectively, reached in 28% and 70% of PUB and 44% and 67% of PrePUB patients (NS). AH SDS was positively correlated with the height SDS at start of GH.

CONCLUSIONS

Short SGA adolescents starting GH therapy at an early pubertal stage have a modest and variable height gain. A normal AH can be expected in one third of the patients, especially in those with a smaller height deficit at onset of GH 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.

Individualised growth response optimisation (iGRO) tool: an accessible and easy-to-use growth prediction system to enable treatment optimisation for children treated with growth hormone

BACKGROUND

Growth prediction models (GPMs) exist to support clinical management of children treated with growth hormone (GH) for growth hormone deficiency (GHD), Turner syndrome (TS) and for short children born small for gestational age (SGA). Currently, no prediction system has been widely adopted.

CONTENT

The objective was to develop a stand-alone web-based system to enable the widespread use of an 'individualised growth response optimisation' (iGRO) tool across European endocrinology clinics. A modern platform was developed to ensure compatibility with IT systems and web browsers. Seventeen GPMs derived from the KIGS database were included and tested for accuracy.

SUMMARY

The iGRO system demonstrated prediction accuracy and IT compatibility. The observed discrepancies between actual and predicted height may support clinicians in investigating the reasons for deviations around the expected growth and optimise treatment.

CONCLUSIONS

This system has the potential for wide access in endocrinology clinics to support the clinical management of children treated with GH for these three indications.

Pharmacogenomics related to growth disorders

Growth disorders resulting in short stature are caused by a wide range of underlying pathophysiological processes. To improve height many of these conditions are treated with recombinant human growth hormone (rhGH). However, substantial inter-individual variability in growth response both in the short and long-term is recognised. Over the last decade, disease-specific growth prediction models have been developed that the clinician can use to define a child's potential response to rhGH and to optimise starting and maintenance doses of rhGH. These models, however, are not able to predict all the variations in treatment response. There has, therefore, been recent interest in using genetic information to contribute to the evaluation of responses to rhGH, including high-throughput technologies for assessing DNA markers (genome) and mRNA transcripts (transcriptome) as pharmacogenomic tools. This review will focus on how these pharmacogenomic approaches are being applied to growth disorders.

New Korean reference for birth weight by gestational age and sex: data from the Korean Statistical Information Service (2008-2012)

PURPOSE

To construct new Korean reference curves for birth weight by sex and gestational age using contemporary Korean birth weight data and to compare them with the Lubchenco and the 2010 United States (US) intrauterine growth curves.

METHODS

Data of 2,336,727 newborns by the Korean Statistical Information Service (2008-2012) were used. Smoothed percentile curves were created by the Lambda Mu Sigma method using subsample of singleton. The new Korean reference curves were compared with the Lubchenco and the 2010 US intrauterine growth curves.

RESULTS

Reference of the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles birth weight by gestational age were made using 2,249,804 (male, 1,159,070) singleton newborns with gestational age 23-43 weeks. Separate birth weight curves were constructed for male and female. The Korean reference curves are similar to the 2010 US intrauterine growth curves. However, the cutoff values for small for gestational age (<10th percentile) of the new Korean curves differed from those of the Lubchenco curves for each gestational age. The Lubchenco curves underestimated the percentage of infants who were born small for gestational age.

CONCLUSION

The new Korean reference curves for birth weight show a different pattern from the Lubchenco curves, which were made from white neonates more than 60 years ago. Further research on short-term and long-term health outcomes of small for gestational age babies based on the new Korean reference data is needed.

Dose-sparing and safety-enhancing effects of an IGF-I-based dosing regimen in short children treated with growth hormone in a 2-year randomized controlled trial: therapeutic and pharmacoeconomic considerations

CONTEXT AND OBJECTIVE

Titrating the dosage of growth hormone (GH) to serum levels of insulin-like growth factor-I (IGF-I) is a feasible treatment strategy in children with GH deficiency (GHD) and idiopathic short stature (ISS). The objective was to assess the dose-sparing effect and theoretical safety of IGF-I-based GH therapy.

DESIGN, SETTING AND PATIENTS

This was a post hoc analysis of a previously described 2-year, multicenter, open-label, randomized, outpatient, controlled clinical trial in 172 prepubertal short children [age 7·5 ± 2·4 years; height standard deviation score (HSDS) -2·64 ± 0·61] classified by baseline peak GH levels as GHD (<7 ng/ml) or ISS (≥7 ng/ml).

INTERVENTION

Conventional weight-based dosing of GH (0·04 mg/kg/day) (n = 34) or GH dosing titrated to an IGF-I target of 0 SDS (IGF0T; n = 70) or an IGF-I target of +2 SDS (IGF2T; n = 68).

MAIN OUTCOME MEASURES

Change in HSDS per GH mg/kg/day dose (∆HSDS/GH dose ratio) and proportion of IGF-I levels above +2 SDS at the end of 2 years.

RESULTS

GH dosing titrated to an IGF-I target of 0 SDS was the most dose-sparing treatment regimen for GHD or ISS children (mean±SE ∆HSDS/GH dose ratios 48·1 ± 4·4 and 32·5 ± 2·8, respectively) compared with conventional dosing (30·3 ± 6·6 and 21·3 ± 3·5, respectively; P = 0·02, P = 0·005) and IGF2T (32·7 ± 4·8 and 16·3 ± 2·8, respectively; P = 0·02, P < 0·0001). IGF0T also resulted in the fewest IGF-I excursions above +2 SDS (6·8% vs 30·0% for conventional dosing; P < 0·01).

CONCLUSIONS

IGF-I-based GH dosing, targeted to age- and gender-adjusted means, may offer a more dose-sparing and potentially safer mode of therapy than traditional weight-based dosing.

Pediatric perspective on pharmacogenomics

The advances in high-throughput genomic technologies have improved the understanding of disease pathophysiology and have allowed a better characterization of drug response and toxicity based on individual genetic make up. Pharmacogenomics is being recognized as a valid approach used to identify patients who are more likely to respond to medication, or those in whom there is a high probability of developing severe adverse drug reactions. An increasing number of pharmacogenomic studies are being published, most include only adults. A few studies have shown the impact of pharmacogenomics in pediatrics, highlighting a key difference between children and adults, which is the contribution of developmental changes to therapeutic responses across different age groups. This review focuses on pharmacogenomic research in pediatrics, providing examples from common pediatric conditions and emphasizing their developmental context.

Personalized approach to growth hormone treatment: clinical use of growth prediction models

The goal of growth hormone (GH) treatment in a short child is to attain a fast catch-up growth toward the target height (TH) standard deviation score (SDS), followed by a maintenance phase, a proper pubertal height gain, and an adult height close to TH. The short-term response variable of GH treatment, first-year height velocity (HV) (cm/year or change in height SDS), can either be compared with GH response charts for diagnosis, age and gender, or with predicted HV based on prediction models. Three types of prediction models have been described: the Kabi International Growth Hormone Study models, the Gothenburg models and the Cologne model. With these models, 50-80% of the variance could be explained. When used prospectively, individualized dosing reduces the variation in growth response in comparison with a fixed dose per body weight. Insulin-like growth factor-I-based dose titration also led to a decrease in the variation. It is uncertain whether adding biochemical, genetic or proteomic markers may improve the accuracy of the prediction. Prediction models may lead to a more evidence-based approach to determine the GH dose regimen and may reduce the drug costs for GH treatment. There is a need for user-friendly software programs to make prediction models easily available in the clinic.

Towards optimal treatment with growth hormone in short children and adolescents: evidence and theses

Treatment with growth hormone (GH) has become standard practice for replacement in GH-deficient children or pharmacotherapy in a variety of disorders with short stature. However, even today, the reported adult heights achieved often remain below the normal range. In addition, the treatment is expensive and may be associated with long-term risks. Thus, a discussion of the factors relevant for achieving an optimal individual outcome in terms of growth, costs, and risks is required. In the present review, the heterogenous approaches of treatment with GH are discussed, considering the parameters available for an evaluation of the short- and long-term outcomes at different stages of treatment. This discourse introduces the potential of the newly emerging prediction algorithms in comparison to other more conventional approaches for the planning and evaluation of the response to GH. In rare disorders such as those with short stature, treatment decisions cannot easily be deduced from personal experience. An interactive approach utilizing the derived experience from large cohorts for the evaluation of the individual patient and the required decision-making may facilitate the use of GH. Such an approach should also lead to avoiding unnecessary long-term treatment in unresponsive individuals.

Update: consequences of abnormal fetal growth

Intrauterine growth restriction (IUGR) is prevalent worldwide and affects children and adults in multiple ways. These include predisposition to type 2 diabetes mellitus, the metabolic syndrome, cardiovascular disease, persistent reduction in stature, and possibly changes in the pattern of puberty. A review of recent literature confirms that the metabolic effects of being born small for gestational age are evident in the very young, persist with age, and are amplified by adiposity. Furthermore, the pattern of growth in the first few years of life has a significant bearing on a person's later health, with those that show increasing weight gain being at the greatest risk for future metabolic dysfunction. Treatment with exogenous human GH is used to improve height in children who remain short after being small for gestational age at birth, but the response of individuals remains variable and difficult to predict. The mechanisms involved in the metabolic programming of IUGR children are just beginning to be explored. It appears that IUGR leads to widespread changes in DNA methylation and that specific "epigenetic signatures" for IUGR are likely to be found in various fetal tissues. The challenge is to link such alterations with modifications in gene expression and ultimately the metabolic abnormalities of adulthood, and it represents one of the frontiers for research in the field.