Design of the long-term observational cohort study with recombinant human growth hormone in Korean children: LG Growth Study

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.

Development and validation of a nomogram to predict poor short-term response to recombinant human growth hormone treatment in children with growth disorders

PURPOSE

The purpose of this study was to develop and validate a clinical predictive model for predicting the likelihood of a poor therapeutic response during the first year of recombinant human growth hormone (rhGH) treatment in children with growth disorders.

METHODS

A total of 627 pediatric patients with growth disorders (GHD, ISS, TS, SGA) from The LG Growth Study cohort were evaluated. Restricted cubic splines (RCS) were utilized to investigate the association between predictors and the risk of poor rhGH response. Variables were selected using LASSO regression, and multivariate logistics regression models were established. Receiver operating characteristic (ROC) curves, calibration curves, decision curve analysis (DCA), and clinical impact curves (CIC) were used to assess the predictive model's accuracy and clinical value. The predictive accuracy of the model was validated on the testing set.

RESULTS

Two predictive models containing 8 baseline predictors (diagnosis, age, height SDS, bone age minus chronological age, rhGH dosage, distance from mid-parental height in SDS, weight SDS, IGF-1 SDS) and 1 post-treatment predictor (height SDS gain at 6 months) were constructed by multivariate logistic regression analyses. The nomogram was built based on the multivariate predictive model and showed good discrimination and model fit effects in both the training set and the testing set. DCA and CIC analyses presented good clinical usability.

CONCLUSION

The clinical predictive model for predicting the probability of poor short-term response of rhGH treatment in pediatric patients with growth disorders is useful and can assist physicians in making clinical decisions.

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.

Long-term effectiveness of growth hormone therapy in children born small for gestational age: An analysis of LG growth study data

Purpose

Growth hormone (GH) treatment has been used to improve growth in short children who were born small for gestational age (SGA). The aim of this study was to investigate the long-term efficacy of GH treatment in these children.

Methods

Data from a multicenter observational clinical trial (ClinicalTrials.gov NCT01604395, LG growth study) were analyzed for growth outcome and prediction model in response to GH treatment. One hundred fifty-two children born SGA were included.

Results

The mean age of patients born SGA was 7.13 ± 2.59 years. Height standard deviation score (SDS) in patients born SGA increased from -2.55 ± 0.49 before starting treatment to -1.13 ± 0.76 after 3 years of GH treatment. Of the 152 patients with SGA, 48 who remained prepubertal during treatment used model development. The equation describing the predicted height velocity during 1st year of GH treatment is as follows: the predictive height velocity (cm) = 10.95 + [1.12 x Height SDS at initial treatment (score)] + [0.03 x GH dose (ug/kg/day)] + [0.30 x TH SDS at initial treatment (score)] + [0.05 x age (year)] + [0.15 x Weight SDS at initial treatment (score)] ± 1.51 cm.

Conclusions

GH treatment improved growth outcome in short children born SGA. We also developed a prediction model that is potentially useful in determining the optimal growth outcome for each child born SGA.

Trial registration

ClinicalTrials.gov Identifier: NCT01604395.

Growth Responses During 3 Years of Growth Hormone Treatment in Children and Adolescents With Growth Hormone Deficiency: Comparison Between Idiopathic, Organic and Isolated Growth Hormone Deficiency, and Multiple Pituitary Hormone Deficiency

BACKGROUND

The study aimed to compare the growth responses to 3 years of growth hormone (GH) treatment in children and adolescents with GH deficiency (GHD) according to idiopathic, organic, isolated (IGHD), and multiple pituitary hormone deficiency (MPHD).

METHODS

Total 163 patients aged 2-18 years (100 males and 63 females; 131 idiopathic and 32 organic GHD; 129 IGHD and 34 MPHD) were included from data obtained from the LG Growth Study. Parameters of growth responses and biochemical results were compared during the 3-year GH treatment.

RESULTS

The baseline age, bone age (BA), height (Ht) standard deviation score (SDS), weight SDS, mid-parental Ht SDS, predicted adult Ht (PAH) SDS, and insulin like growth factor-1 (IGF-1) SDS were significantly higher in the organic GHD patients than in the idiopathic GHD patients, but peak GH on the GH-stimulation test, baseline GH dose, and mean 3-year-GH dosage were higher in the idiopathic GHD patients than in the organic GHD patients. The prevalence of MPHD was higher in the organic GHD patients than in the idiopathic GHD patients. Idiopathic MPHD subgroup showed the largest increase for the ΔHt SDS and ΔPAH SDS during GH treatment, and organic MPHD subgroup had the smallest mean increase after GH treatment, depending on ΔIGF-1 SDS and ΔIGF binding protein-3 (IGFBP-3) SDS. The growth velocity and the parental-adjusted Ht gain were greater in the idiopathic GHD patients than the organic GHD patients during the 3-year GH treatment, which may have been related to the different GH dose, ΔIGF-1 SDS, and ΔIGFBP-3 SDS between two groups. Multiple linear regression analysis revealed that baseline IGF-1 SDS, BA, and MPH SDS in idiopathic group and baseline HT SDS in organic group are the most predictable parameters for favorable 3-year-GH treatment.

CONCLUSION

The 3-year-GH treatment was effective in both idiopathic and organic GHD patients regardless of the presence of MPHD or underlying causes, but their growth outcomes were not constant with each other. Close monitoring along with appropriate dosage of GH and annual growth responses, not specific at baseline, are more important in children and adolescents with GHD for long-term treatment.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01604395.

Response to growth hormone according to provocation test results in idiopathic short stature and idiopathic growth hormone deficiency

PURPOSE

To investigate growth response in children with either idiopathic short stature (ISS) or growth hormone (GH) deficiency (GHD).

METHODS

The data of prepubertal GHD or ISS children treated using recombinant human GH were obtained from the LG Growth Study database. GHD children were further divided into partial and complete GHD groups. Growth response and factors predicting growth response after 1 and 2 years of GH treatment were investigated.

RESULTS

This study included 692 children (98 with ISS, 443 partial GHD, and 151 complete GHD). After 1 year, changes in height standard deviation score (ΔHt-SDS) were 0.78, 0.83, and 0.96 in ISS, partial GHD, and complete GHD, respectively. Height velocity (HV) was 8.72, 9.04, and 9.52 cm/yr in ISS, partial GHD, and complete GHD, respectively. ΔHt-SDS and HV did not differ among the 3 groups. Higher initial body mass index standard deviation score (BMI-SDS) and midparental height standard deviation score (MPH-SDS) were predictors for better growth response after 1 year in ISS and the partial GHD group, respectively. In the complete GHD group, higher Ht-SDS and BMI-SDS predicted better growth response after 1 year. After 2 years of GH treatment, higher BMI-SDS and MPH-SDS predicted a better growth outcome in the partial GHD group, and higher MPH-SDS was a predictor of good growth response in complete GHD.

CONCLUSION

Clinical characteristics and growth response did not differ among groups. Predictors of growth response differed among the 3 groups, and even in the same group, a higher GH dose would be required when poor response is predicted.

Association between uric acid and height during growth hormone therapy in children with idiopathic short stature

BACKGROUND

Serum uric acid (UA) within appropriate levels is reported to be beneficial in patients with idiopathic short stature (ISS). This study aimed to evaluate the association between serum UA levels and height standard deviation scores (SDS) in patients with ISS during growth hormone (GH) therapy.

METHODS

A longitudinal study (LG Growth Study) of 182 children (mean age: 7.29±2.60 years) with ISS was performed. All participants were in the prepubertal stage and treated with GH, and the data within a treatment period of 30 months were analyzed.

RESULTS

In the adjusted Pearson's correlation, UA was significantly correlated with height SDS after controlling for sex, age, and body mass index (BMI) SDS (r=0.22, p=0.007). In the adjusted multiple regression analyses, the height SDS was significantly associated with UA after controlling for sex, age, and BMI SDS (β=0.168, p=0.007). Within the 30-month treatment period, the UA levels significantly increased as the height SDS increased, and the mean UA levels at baseline and 30 months after treatment were 3.90±0.64 mg/dL and 4.71±0.77 mg/dL, respectively (p=0.007).

DISCUSSION

In conclusion, UA is related to height SDS, and GH treatment leads to a significant increase in UA without hyperuricemia. Elevated UA is considered a favorable outcome of GH therapy, and further studies are needed to determine its role as a monitoring tool.

Investigating whether serum IGF-1 and IGFBP-3 levels reflect the height outcome in prepubertal children upon rhGH therapy: LG growth study database

Serum insulin-like growth factor-1 (IGF-I) and IGF binding protein-3 (IGFBP-3) levels can be used to monitor the safety of recombinant human growth hormone (rhGH) therapy. In this study, we evaluated the changes in serum IGF-I and IGFBP-3 levels during rhGH therapy as a marker of height outcome in prepubertal children. Totally, 705 prepubertal children with short stature were enrolled from the LG Growth Study Database. Data for three groups of subjects were obtained as follows: Idiopathic GH deficiency (IGHD; n = 486); idiopathic short stature (n = 66); small for gestational age (n = 153). Serum IGF-I and IGFBP-3 levels at the baseline and after the 1st and 2nd year of rhGH therapy, as well as the Δheight standard deviation score (SDS), were obtained. Δheight SDS after the 1st and 2nd year of rhGH therapy had notably increased compared to that at the baseline for all three groups. IGF-I and IGFBP-3 levels in all three groups were significantly increased compared to those at the baseline (p <0.001). Δheight SDS was positively correlated with ΔIGF-1 SDS after the 1st year of therapy, ΔIGFBP-3 SDS after the 2nd year of therapy in the IGHD group, and ΔIGF-I SDS and ΔIGFBP-3 SDS after the 2nd year of therapy (p < 0.05), regardless of whether the height at the baseline was a covariate. The increase in IGF-I and IGFBP-3 levels during rhGH therapy was related to the growth response in children with IGHD. Therefore, it may be valuable to measure the change in serum IGF-I and IGFBP-3 levels, especially the latter, during rhGH treatment to predict the growth response upon long-term treatment.

Factors affecting IGF-I level and correlation with growth response during growth hormone treatment in LG Growth Study

Growth hormone treatment strategies to achieve the goal include the titration of GH doses according to serum insulin-like growth factor I (IGF-I) concentrations. However, IGF-I levels do not always correlate well with the growth response. This study aims to identify the factors affecting the IGF-I concentration and identify the relationship between IGF-I and the treatment response. The data of prepubertal children treated with recombinant human GH for more than one year were obtained from the LG Growth Study (LGS) Database. This study includes patients with idiopathic growth hormone deficiency (IGHD), organic growth hormone deficiency (OGHD), or Turner syndrome (TS) or small for gestational age (SGA). Among 2,021 participants registered in LGS, 366 subjects were selected, 252 had IGHD, 16 had OGHD, 31 had TS, and 67 were SGA. In the IGHD and SGA groups, IGF-I levels had a positive correlation with weight SDS. There was no significant relationship between the pre-treatment IGF-I level and growth response. However, in the IGHD group, the growth response was significantly higher when the change in the IGF-I SDS value was 1 or more (p = 0.0013). Therefore, IGF-I concentrations should be used as an indicator to monitor the treatment compliance rather than for efficacy determination in Korean children of short stature with GH treatment.

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

Context

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

Aims

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

Methods

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

Results

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

Conclusion

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

Predicting First-Year Growth in Response to Growth Hormone Treatment in Prepubertal Korean Children with Idiopathic Growth Hormone Deficiency: Analysis of Data from the LG Growth Study Database

BACKGROUND

The first-year growth in response to growth hormone (GH) treatment seems to be the most important factor in determining the overall success of GH treatment.

METHODS

Data from children (n = 345) who were in the LG Growth Study Database were used to develop a model. All subjects had been diagnosed with idiopathic growth hormone deficiency (GHD) and presented in a prepubertal state during the first year of GH treatment.

RESULTS

The Δheight standard deviation score (SDS) during 1st year of GH treatment was correlated positively with weight-SDS (β = 0.304, P < 0.001), body mass index (BMI)-SDS (β = 0.443, P < 0.001), paternal height-SDS (β = 0.296, P = 0.001), MPH-SDS (β = 0.421, P < 0.001) and MPH SDS minus baseline height SDS (β = 0.099, P < 0.001) but negatively with chronological age (β = -0.294, P < 0.001), bone age (β = -0.249, P < 0.001). A prediction model of 1st year growth in response to GH treatment in prepubertal Korean children with idiopathic GHD is as follows: Δheight SDS during 1st year of GH treatment = 1.06 - 0.05 × age + 0.09 × (MPH SDS minus baseline height SDS) + 0.05 × BMI SDS. This model explained 19.6% of the variability in the response, with a standard error of 0.31.

CONCLUSION

The present model to predict first-year response to GH treatment might allow more tailored and personalized GH treatment in Korean prepubertal children with idiopathic GHD.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01604395.

Machine learning-based prediction of response to growth hormone treatment in Turner syndrome: the LG Growth Study

Background Growth hormone (GH) treatment has become a common practice in Turner syndrome (TS). However, there are only a few studies on the response to GH treatment in TS. The aim of this study is to predict the responsiveness to GH treatment and to suggest a prediction model of height outcome in TS. Methods The clinical parameters of 105 TS patients registered in the LG Growth Study (LGS) were retrospectively reviewed. The prognostic factors for the good responders were identified, and the prediction of height response was investigated by the random forest (RF) method, and also, multiple regression models were applied. Results In the RF method, the most important predictive variable for the increment of height standard deviation score (SDS) during the first year of GH treatment was chronologic age (CA) at start of GH treatment. The RF method also showed that the increment of height SDS during the first year was the most important predictor in the increment of height SDS after 3 years of treatment. In a prediction model by multiple regression, younger CA was the significant predictor of height SDS gain during the first year (32.4% of the variability). After 3 years of treatment, mid-parental height (MPH) and the increment of height SDS during the first year were identified as significant predictors (76.6% of the variability). Conclusions Both the machine learning approach and the multiple regression model revealed that younger CA at the start of GH treatment was the most important factor related to height response in patients with TS.

Long-term safety and effectiveness of growth hormone therapy in Korean children with growth disorders: 5-year results of LG Growth Study

PURPOSE

The aim of this registry study was to analyze the long-term safety and effectiveness of recombinant human growth hormone (rhGH) in South Korean pediatric patients (≥2 years of age) with growth hormone deficiency GHD) of idiopathic or organic etiology, idiopathic short stature, Turner syndrome, small for gestational age and chronic renal failure.

METHODS

The study patients were followed-up till two years after the epiphyseal closure, with visits scheduled every six months. The outcome measures included the incidence of adverse events (AEs, in particular, neoplasia, glucose intolerance and hypothyroidism), as well as height standard deviation score (Ht SDS) and annual height velocity. The results of the interim analysis of a 5-year accumulated data for 2,024 patients (7,342 patient-years, PY) are presented.

RESULTS

A total of 14 neoplasms were diagnosed (191/100,000 PY); 7 out of 9 malignancies were recurrent craniopharyngioma found in patients with organic GHD. Seven cases of glucose intolerance (95/100,000 PY) and 22 cases of hypothyroidism (300/100,000 PY) were detected; about half of the cases (4 and 10 cases each) were considered to be related with rhGH treatment. Most of the growth-retarded patients showed continuous improvement in Ht SDS, with the most prominent effect observed within a year of treatment initiation. The beneficial effect of rhGH on Ht SDS gain was maintained for 2-4 years.

CONCLUSIONS

The incidence of AEs of interest in rhGH-treated patients was low, and most of the neoplasms were benign and/or non-related to rhGH. Most patients benefited from the therapy in terms of height increment.

Factors affecting bone age maturation during 3 years of growth hormone treatment in patients with idiopathic growth hormone deficiency and idiopathic short stature: Analysis of data from the LG growth study

To investigate the progression rate of bone age (BA) and associated factors during the first 3 years of growth hormone (GH) treatment in children with idiopathic GH deficiency (iGHD) and idiopathic short stature (ISS).Data for prepubertal children with iGHD and ISS who were treated with recombinant human GH were obtained from the LG Growth Study Database and analyzed. Height, weight, BA, insulin-like growth factor-1 (IGF-1) level, and GH dose were recorded every 6 months. Differences between BA and chronological age (CA), BA-CA, were calculated at each measurement. This study included 92 (78 iGHD and 14 ISS) subjects.After 3 years of GH treatment, the height z-score was -1.09 ± 0.71 (P < .001 compared to baseline), BA-CA was -1.21 ± 1.18 years (P < .001), and IGF-1 standard deviation score (SDS) was 0.43 ± 1.21 (P < .001) in the iGHD subjects; the change in BA over the 3 years was 3.68 ± 1.27 years. In the ISS subjects, the height z-score was -1.06 ± 0.59 (P < .001), BA-CA was -0.98 ± 1.23 years (P = .009), and IGF-1 SDS was 0.16 ± 0.76 (P = .648); the change in BA over the 3 years was 3.88 ± 1.36 years. The only significant factor associated with the BA progression was the BA-CA at 1 year of GH treatment (OR = 2.732, P = .001). The baseline BA-CA, IGF-1 SDS, and GH dose did not influence BA progression.Prepubertal subjects with iGHD and ISS showed height improvement and mild BA acceleration over the first 3 years of GH treatment. However, because the BA progression rate was considered to be clinically acceptable, GH treatment may increase the predicted adult height during this period.