Effective growth hormone replacement with once-weekly somapacitan in Japanese children with growth hormone deficiency: Results from REAL4, a phase 3 clinical trial

OBJECTIVE

Somapacitan is a long-acting growth hormone (GH) derivative developed for the treatment of GH deficiency (GHD). This study evaluates the efficacy and tolerability of somapacitan in Japanese children with GHD after 104 weeks of treatment and after switch from daily GH.

DESIGN

Subanalysis on Japanese patients from a randomised, open-labelled, controlled parallel-group phase 3 trial (REAL4, NCT03811535).

PATIENTS AND MEASUREMENTS

Thirty treatment-naïve patients were randomised 2:1 to somapacitan (0.16 mg/kg/week) or daily GH (0.034 mg/kg/day) up to Week 52, after which all patients received somapacitan. Height velocity (HV; cm/year) at Weeks 52 and 104 were the primary measurements. Additional assessments included HV SD score (SDS), height SDS, bone age, insulin-like growth factor-I (IGF-I) SDS, and observer-reported outcomes.

RESULTS

At Week 52, observed mean HV was similar between treatment groups (10.3 vs. 9.8 cm/year for somapacitan and daily GH, respectively). Similar HVs between groups were also observed at Week 104: 7.4 cm/year after continuous somapacitan treatment (soma/soma) and 7.9 cm/year after 1-year somapacitan treatment following switch from daily GH (switch). Other height-related endpoints supported continuous growth. IGF-I SDS increased in both groups with mean IGF-I SDS within -2 and +2 during the study. Somapacitan was well tolerated, one mild injection site reaction was reported, with no reports of injection site pain. Patient preference questionnaires showed that most patients and their caregivers (90.9%) who switched treatment at Week 52 preferred once-weekly somapacitan over daily GH treatment.

CONCLUSIONS

Somapacitan showed sustained efficacy in Japanese children with GHD over 104 weeks and for 52 weeks after switching from daily GH. Somapacitan was well tolerated and preferred over daily GH.

Meta-analysis of mortality in adults with growth hormone deficiency: Does growth hormone replacement therapy really improve mortality rates?

Growth hormone (GH) deficiency (GHD) is one of the most prevalent deficiencies in patients with hypopituitarism and several cohort studies have demonstrated an increased mortality risk in hypopituitary patients with a presumed GHD. The cause of the excess mortality is most likely multifactorial, including the etiology of the hypopituitarism, non-physiological replacement therapies (mostly glucocorticoid), tumor treatment and its side effects as well as untreated GHD. Several years later, other cohort studies that investigated life expectancy in patients with hypopituitarism on GH replacement therapy (GHRT) that showed a normalized mortality. By comparison of the distribution of characteristics of interest between cohorts, we discuss the existing literature to answer the following question: does growth hormone replacement really improve mortality rates in adult patients with hypopituitarism and GHD? We also conducted a meta-analysis of these studies. Since the literature suffers from selection and time bias (improvement of tumor management and other pituitary hormone replacement therapies), there is no high-quality evidence that replacement therapy for GHD really improves mortality. However, the available data does suggest that GHRT plays a significant part in the normalization of the mortality in patients with hypopituitarism.

Mild traumatic brain injury as a cause of adult growth hormone deficiency: Diagnosis and treatment

In recent years, mild traumatic brain injury (mTBI) has been recognized as a cause of acquired growth hormone deficiency (AGHD) and is likely much more prevalent than previous estimates. There is great overlap between persistent symptoms following mTBI and those of AGHD and it is possible that these persistent symptoms of mTBI are, at least in part, due to or aggravated by AGHD. This article reviews the current literature of AGHD following mTBI, and proposes practice recommendations for the screening, diagnosis, and management of patients with AGHD following mTBI.

Effective GH Replacement With Somapacitan in Children With GHD: REAL4 2-year Results and After Switch From Daily GH

CONTEXT

Somapacitan is a long-acting GH derivative for treatment of GH deficiency (GHD).

OBJECTIVE

Evaluate the efficacy and tolerability of somapacitan in children with GHD after 2 years of treatment and after the switch from daily GH.

DESIGN

A randomized, multinational, open-labelled, controlled parallel group phase 3 trial, comprising a 52-week main phase and 3-year safety extension (NCT03811535).

SETTING

Eighty-five sites across 20 countries.

PATIENTS

A total of 200 treatment-naïve prepubertal patients were randomized and exposed; 194 completed the 2-year period.

INTERVENTIONS

Patients were randomized 2:1 to somapacitan (0.16 mg/kg/wk) or daily GH (0.034 mg/kg/d) during the first year, after which all patients received somapacitan 0.16 mg/kg/wk.

MAIN OUTCOME MEASURES

Height velocity (HV; cm/year) at week 104. Additional assessments included HV SD score (SDS), height SDS, IGF-I SDS, and observer-reported outcomes.

RESULTS

HV was sustained in both groups between 52 and 104 weeks. At week 104, mean (SD) for HV between weeks 52 and 104 was 8.4 (1.5) cm/year after continuous somapacitan treatment and 8.7 (1.8) cm/year after 1 year of somapacitan treatment following switch from daily GH. Secondary height-related endpoints also supported sustained growth. Mean IGF-I SDS during year 2 was similar between groups and within normal range (-2 to +2). Somapacitan was well tolerated, with no safety or tolerability issues identified. GH patient preference questionnaire results show that most patients and their caregivers (90%) who switched treatment at year 2 preferred once-weekly somapacitan over daily GH treatment.

CONCLUSIONS

Somapacitan in children with GHD showed sustained efficacy and tolerability for 2 years, and after switching from daily GH. Patients/caregivers switching from daily GH expressed a preference for somapacitan.

CLINICAL TRIAL REGISTRATION

NCT03811535.

Sex Differences in Long-Term Safety and Tolerability of GH Replacement Therapy in GH Deficient Adults

CONTEXT

Previous studies report that outcomes of growth hormone (GH) replacement therapy (GHRT) might be less beneficial in growth hormone deficient (GHD) women compared with men.

OBJECTIVE

This study investigated possible contributing factors regarding this previously found sex difference.

METHODS

This retrospective cohort study, conducted at a nationwide outpatient clinic (the Dutch National Registry of GH Treatment in Adults), included Dutch adult GHD men (n = 1335) and women (n = 1251) treated with GHRT. The patients' baseline characteristics, details of GHRT, and the tolerability and long-term safety of GHRT were measured.

RESULTS

During treatment, sensitivity analysis showed that insulin-like growth factor-1 (IGF-1) SD scores remained subnormal more often in women (P < 0.001), while scores above normal were more frequent in men (P < 0.001). Women reported more adverse events (P < 0.001), especially symptoms related to fluid retention, and more often needed a dose reduction or temporary stop of GHRT (P = 0.001). In percentages, both sexes equally discontinued GHRT, as was also true for the risk in developing type 2 diabetes mellitus, benign neoplasms, and tumor recurrence. The risk of developing malignant neoplasms was higher in men (P = 0.012).

CONCLUSION

Data obtained from the Dutch National Registry of GH Treatment in Adults indicate that GHD women might be treated suboptimally, reflected as lower IGF-1 status and lower GHRT tolerability, leading to more frequent changes in treatment regimen but not discontinuation of GHRT. Regarding long-term safety, we found a higher risk for development of malignancies in GHD men.

Long-term Effectiveness and Safety of GH Replacement Therapy in Adults ≥60 Years: Data From NordiNet® IOS and ANSWER

Context

Effectiveness and safety data on GH replacement therapy (GHRT) in older adults with adult GH deficiency (AGHD) are limited.

Objective

To compare GHRT safety and clinical outcomes in older (≥60 years and, for some outcomes, ≥75 years) and middle-aged (35-<60 years) patients with AGHD.

Design/setting

Ten-year follow-up, real-world data from 2 large noninterventional studies-NordiNet® International Outcome Study (IOS) and the American Norditropin® Studies: Web-Enabled Research (ANSWER) Program-were analyzed.

Patients

GH-naïve and non-naïve patients with AGHD.

Intervention

Norditropin® (somatropin).

Main outcome measures

Outcomes included GH exposure, IGF-I standard deviation scores (SDS), body mass index (BMI), glycated hemoglobin (HbA_1c), serious and nonserious adverse reactions (SARs and NSARs, respectively), and serious adverse events (SAEs). Adverse reactions were events with possible/probable causal relationship to GHRT.

Results

The effectiveness analysis set comprised 545 middle-aged and 214 older patients (19 aged ≥75 years) from NordiNet® IOS. The full analysis set comprised 1696 middle-aged and 652 older patients (59 aged ≥75 years) from both studies. Mean GH doses were higher in middle-aged vs older patients. For both age groups and sexes, mean IGF-I SDS increased following GHRT, while BMI and HbA_1c changes were similar and small.Incidence rate ratios (IRRs) did not differ statistically between older and middle-aged patients for NSARs [IRR (mean, 95% confidence interval) 1.05 (.60; 1.83)] or SARs [.40 (.12; 1.32)]. SAEs were more frequent in older than middle-aged patients [IRR 1.84 (1.29; 2.62)].

Conclusion

Clinical outcomes of GHRT in AGHD were similar in middle-aged and older patients, with no significantly increased risk of GHRT-related adverse reactions in older patients.

Weekly Somapacitan is Effective and Well Tolerated in Children With GH Deficiency: The Randomized Phase 3 REAL4 Trial

CONTEXT

Somapacitan, a once-weekly reversible albumin-binding GH derivative, is evaluated in children with GH deficiency (GHD).

OBJECTIVE

To demonstrate efficacy and safety of somapacitan vs daily GH.

METHODS

REAL4 is a randomised, multinational, open-labeled, active-controlled parallel group phase 3 trial, comprising a 52-week main trial and 3-year extension (NCT03811535).

SETTING

Eighty-six sites across 20 countries.

PATIENTS

200 treatment-naïve patients were randomized and exposed.

INTERVENTIONS

Patients were randomized 2:1 to somapacitan (0.16 mg/kg/wk) or daily GH (Norditropin; 0.034 mg/kg/d), administered subcutaneously.

MAIN OUTCOME MEASURES

The primary endpoint was annualized height velocity (HV; cm/y) at week 52. Additional assessments included HV SD score (SDS), height SDS, bone age, IGF-I SDS, patient-reported outcomes, and safety measures.

RESULTS

Estimated mean HV at week 52 was 11.2 and 11.7 cm/y for somapacitan and daily GH, respectively. Noninferiority was confirmed. Changes in HV SDS, height SDS, bone age, and IGF-I SDS from baseline to week 52 were similar between treatment groups. At week 52, mean IGF-I SDS values were similar between treatment groups and within normal range (-2 to +2). Safety of somapacitan was consistent with the well-known daily GH profile. Low proportions of injection-site reactions were reported for somapacitan (5.3%) and daily GH (5.9%). Both treatments similarly reduced disease burden from baseline to week 52, whereas a greater treatment burden reduction was observed for somapacitan.

CONCLUSIONS

Similar efficacy for somapacitan compared to daily GH was demonstrated over 52 weeks of treatment with comparable safety and mean IGF-I SDS levels in treatment-naïve children with GHD.

Safety and Efficacy of Lonapegsomatropin in Children With Growth Hormone Deficiency: enliGHten Trial 2-Year Results

PURPOSE

The objectives of the ongoing, Phase 3, open-label extension trial enliGHten are to assess the long-term safety and efficacy of weekly administered long-acting growth hormone lonapegsomatropin in children with growth hormone deficiency.

METHODS

Eligible subjects completing a prior Phase 3 lonapegsomatropin parent trial (heiGHt or fliGHt) were invited to participate. All subjects were treated with lonapegsomatropin. Subjects in the United States switched to the TransCon hGH Auto-Injector when available. Endpoints were long-term safety, annualized height velocity, pharmacodynamics [insulin-like growth factor-1 SD score (SDS) values], and patient- and caregiver-reported assessments of convenience and tolerability.

RESULTS

Lonapegsomatropin treatment during enliGHten was associated with continued improvements in height SDS through week 104 in treatment-naïve subjects from the heiGHt trial (-2.89 to -1.37 for the lonapegsomatropin group; -3.0 to -1.52 for the daily somatropin group). Height SDS also continued to improve among switch subjects from the fliGHt trial (-1.42 at fliGHt baseline to -0.69 at week 78). After 104 weeks, the average bone age/chronological age ratio for each treatment group was 0.8 (0.1), showing only minimal advancement of bone age relative to chronological age with continued lonapegsomatropin treatment among heiGHt subjects. Fewer local tolerability reactions were reported with the TransCon hGH Auto-Injector compared with syringe/needle.

CONCLUSIONS

Treatment with lonapegsomatropin continued to be safe and well-tolerated, with no new safety signals identified. Children treated with once-weekly lonapegsomatropin showed continued improvement of height SDS through the second year of therapy without excess advancement of bone age.

Effective GH Replacement With Once-weekly Somapacitan vs Daily GH in Children with GHD: 3-year Results From REAL 3

CONTEXT

Current GH therapy requires daily injections, which can be burdensome. Somapacitan is a long-acting GH derivative in development for treatment of GH deficiency (GHD).

OBJECTIVE

Evaluate the efficacy, safety, and tolerability of once-weekly somapacitan after 3 years of treatment.

DESIGN

A multicenter, randomized, controlled, phase 2 study comparing somapacitan and once-daily GH for 156 weeks (NCT02616562).

SETTING

Twenty-nine sites in 11 countries.

PATIENTS

Fifty-nine children with GHD randomized (1:1:1:1) and exposed to treatment. Fifty-three children completed the 3-year period.

INTERVENTIONS

Patients received somapacitan (0.04 [n = 14], 0.08 [n = 15], or 0.16 [n = 14] mg/kg/wk) or daily GH (n = 14) (0.034 mg/kg/d, equivalent to 0.238 mg/kg/wk) subcutaneously during the first year, after which all patients on somapacitan received 0.16 mg/kg/wk.

MAIN OUTCOME MEASURES

Height velocity (HV) at year 3; changes from baseline in height SD score (HSDS), HVSDS, and IGF-I SDS.

RESULTS

The estimated treatment difference (95% CI) in HV for somapacitan 0.16/0.16 mg/kg/wk vs daily GH at year 3 was 0.8 cm/y (-0.4 to 2.1). Change in HVSDS from baseline to year 3 was comparable between somapacitan 0.16/0.16 mg/kg/wk, the pooled somapacitan groups, and daily GH. A gradual increase in HSDS from baseline was observed for all groups. At year 3, mean HSDS was similar for the pooled somapacitan groups and daily GH. Change from baseline to year 3 in mean IGF-I SDS was similar across treatments.

CONCLUSIONS

Once-weekly somapacitan in children with GHD showed sustained efficacy over 3 years in all assessed height-based outcomes with similar safety and tolerability to daily GH. A plain language summary (1) is available for this study.

CLINICAL TRIAL INFORMATION

This study has been registered at ClinicalTrials.gov, number NCT02616562 (REAL 3).

MRI Assessment of Cardiac Function and Morphology in Adult Patients With Growth Hormone Deficiency: A Systematic Review and Meta-Analysis

BACKGROUND

Adult GH deficiency (GHD) has been described as a heterogeneous condition characterized by many clinical modifications, such as metabolic alterations, impaired quality of life, and increased mortality. The clinical relevance of cardiac involvement remains, however, only partially elucidated.

METHODS

PubMed/Medline, EMBASE, Cochrane library, OVID and CINAHL databases were systematically searched until February 2022 for studies evaluating cardiac function and morphology by magnetic resonance imaging in adult patients with GHD. Effect sizes were pooled through a random-effect model.

RESULTS

Four studies were considered in the meta-analysis. With respect to the left ventricle, GHD patients were characterized by a lower stroke-volume-index (-3.6 ml/m², standardized mean difference (SMD) -0.60, 95%CI [-1.15,-0.05], p=0.03), lower end-diastolic-volume-index (-6.2 ml/m², SMD -0.54, 95%CI [-0.97,-0.10], p=0.02) and, after accounting for possible biases, lower mass-index (-15.0 g/m², SMD -1.03, 95%CI [-1.89,-0.16], p=0.02). With respect to the right ventricle, a lower end-diastolic-volume-index (-16.6 ml/m², SMD -1.04, 95%CI [-2.04,-0.03], p=0.04) and a borderline-significant lower stroke-volume-index (-5.0 ml/m², SMD -0.84, 95%CI [-1.77,0.08], p=0.07) could be observed. Data about the effect of GH replacement therapy highlighted a significant increase in left ventricular mass-index after treatment initiation (+3.7 g/m², 95%CI [1.6,5.7], p<0.01).

CONCLUSION

With respect to the left ventricle, our results confirmed those retrieved by echocardiographic studies. In addition, significant alterations were demonstrated also for the right ventricle, for which echocardiographic data are nearly absent. This supports the thesis of a biventricular cardiac involvement in patients with GHD, with a similar pattern of morphological and functional alterations in both ventricles.

GH Replacement in the Elderly: Is It Worth It?

Growth hormone (GH), once the age of linear growth is completed, continues to play a fundamental role for the human body. In adulthood, GH contributes to regulate muscle, cardiovascular and bone metabolism. The same happens in old age, although there is less data on the effect of GH in the elderly. Regardless the age of onset, a reduced quality of life (QoL), an increased cardiovascular risk and an accelerated age-related decline in physical strength have been demonstrated in the elderly with GH deficiency (EGHD). In adults with GH deficiency (AGHD), recent studies suggest a role of GH replacement therapy (GHrt) in improving lean/fat mass ratio, blood pressure, lipid profile, bone metabolism and QoL. Despite these recent studies, there is still a lack of randomized controlled trials proving these positive effects in EGHD. Moreover, the lack of a long-term positive outcome on mortality, and the cost of GHrt could often impact on treatment decision-making and lead to postpone or avoid the prescription. The aim of this mini-review is to summarize the available data on GHrt in EGHD, in order to highlight its weaknesses and strengths and to provide directions to clinicians that will help in the management of this specific set of patients.

Xia-Gibbs Syndrome: A Review of Literature

Xia-Gibbs syndrome (XGS) is a rare genetic disorder that has been discovered as a distinct clinical entity in the recent past. The occurrence has been attributed to the mutation of AT Hook DNA binding motif Containing 1 (AHDC1) gene that is carried on chromosome 1p36. The concerned gene participates in deoxyribonucleic acid (DNA) repair apart from other crucial functions. The mutation results in dysfunction that leads to neurodevelopmental delay. The spectrum of manifestations constitutes intellectual disabilities, hypotonia, expressive language delay, sleep difficulties, and short stature. Dysmorphic facial features include depressed nasal bridge, hypertelorism, down-slanting or up-slanting palpebral fissures, horizontal eyebrows, dysplastic dentition, thin upper lip vermilion, and micrognathia. The phenotype is still expanding. The condition may range from mild to severe dysfunction depending on the area and site of genetic aberration but variation is evident. Thus, the correlation between genotype and phenotype is largely unclear. XGS should be considered as a differential diagnosis for patients presenting with intellectual as well as developmental disabilities. Whole-exome sequencing (WES) is the genetic test that is largely used for the confirmation of diagnosis. Less is known about the natural history as only a few adults with XGS have been documented in the literature. Age-appropriate cancer screening is recommended for patients with XGS as the gene mutation alters DNA repair mechanisms that may trigger tumour formation. The management of patients diagnosed with XGS is an area that needs investigation. Though use of growth hormone replacement therapy and physiotherapy intervention have been reported as effective in previous studies, research on effective means of care of these patients is warranted on a larger number of patients. We present a review of current literature on what is known about XGS that would facilitate to identify knowledge gaps for paving a way for further studies. This, in turn, will help in provision of early and effective rehabilitation services for patients with XGS.

Early versus late initiation of GH replacement in adult-onset hypopituitarism

INTRODUCTION

Adult-onset growth hormone deficiency (AGHD) is usually the last deficiency to be substituted in hypopituitarism. In children with documented GH deficiency, treatment without delay is crucial for achieving optimal effects on growth and development. In adults, it is not known whether a delay in treatment initiation influences biochemical response and the favourable physiological effects resulting from GH replacement therapy (GHRT).

METHODS

A total of 1085 GH-deficient adults from KIMS (Pfizer International Metabolic Database) were included, adequately replaced with all pituitary hormones except for GH at baseline. Patients were stratified by sex and age (20-50 years and ≥50 years) and subsequently divided into two groups below and above the median duration of unsubstituted AGHD for that subgroup. The median time of unsubstituted GHD for the total cohort was 2.53 years (P5 = 0.35, P95 = 24.42).

RESULTS

Beneficial effects of 4 years of GHRT were observed on lipids and quality of life in all subgroups. A decrease in waist circumference was observed only in older (>50 years) patients. There was no difference in IGF-I SDS and in GH dose required to normalize IGF-I in patients with a duration of unsubstituted AGHD above or below the median. No relevant differences were found between the groups for anthropometric measures, cardiovascular risk factors and quality of life scores.

CONCLUSION

In contrast to GHD in children and adolescents, no difference could be established in treatment response between early or late initiation of GHRT in AGHD in terms of required GH dose, IGF-I, metabolic health and quality of life.

Once-Weekly Somapacitan vs Daily GH in Children With GH Deficiency: Results From a Randomized Phase 2 Trial

CONTEXT

Daily growth hormone (GH) injections can be burdensome for patients and carers. Somapacitan is a long-acting, reversible albumin-binding GH derivative in development for once-weekly administration in patients with growth hormone deficiency (GHD).

OBJECTIVE

The objective of this study is to evaluate the efficacy, safety, and tolerability of once-weekly somapacitan vs once-daily GH.

DESIGN

REAL 3 is a multicenter, randomized, controlled, double-blind (somapacitan doses), phase 2 study with a 26-week main and 26-week extension phase (NCT02616562).

SETTING

This study took place at 29 sites in 11 countries.

PATIENTS

Fifty-nine GH treatment-naive prepubertal children with GHD were randomly assigned; 58 completed the trial.

INTERVENTIONS

Interventions comprised 3 somapacitan doses (0.04 [n = 16], 0.08 [n = 15], or 0.16 mg/kg/wk [n = 14]) and daily GH (0.034 mg/kg/d [n = 14]), administered subcutaneously.

MAIN OUTCOME MEASURES

The primary end point was height velocity (HV) at week 26. Secondary efficacy end points included HV SD score (SDS) and insulin-like growth factor-I (IGF-I) SDS.

RESULTS

At week 26, mean (SD) annualized HV for the somapacitan groups was 8.0 (2.0), 10.9 (1.9), and 12.9 (3.5) cm/year, respectively, vs 11.4 (3.3) cm/year for daily GH; estimated treatment difference (somapacitan 0.16 mg/kg/week-daily GH): 1.7 [95% CI -0.2 to 3.6] cm/year. HV was sustained at week 52, and significantly greater with somapacitan 0.16 mg/kg/week vs daily GH. Mean (SD) change from baseline in HV SDS at week 52 was 4.72 (2.79), 6.14 (3.36), and 8.60 (3.15) for the somapacitan groups, respectively, vs 7.41 (4.08) for daily GH. Model-derived mean (SD) IGF-I SDS for the somapacitan groups was -1.62 (0.86), -1.09 (0.78), and 0.31 (1.06), respectively, vs -0.40 (1.50) observed for daily GH. Safety and tolerability were consistent with the profile of daily GH.

CONCLUSIONS

In children with GHD, once-weekly somapacitan 0.16 mg/kg/week provided the closest efficacy match with similar safety and tolerability to daily GH after 26 and 52 weeks of treatment. A short visual summary of our work is available (1).

Personalized approach to growth hormone replacement in adults

Growth hormone (GH) deficiency (GHD) in adults is well-characterized and includes abnormal body composition, reduced bone mass, an adverse cardiovascular risk profile, and impaired quality of life. In the early 1990s, it was also shown that patients with hypopituitarism without GH replacement therapy (GHRT) had excess mortality. Today, GHRT has been shown to decrease or reverse the negative effects of GHD. In addition, recent papers have shown that mortality and morbidity are approaching normal in hypopituitary patients with GHD who receive modern endocrine therapy including GHRT. Since the first dose-finding studies, it has been clear that efficacy and side effects differ substantially between patients. Many factors have been suggested as affecting responsiveness, such as sex, age, age at GHD onset, adherence, and GH receptor polymorphisms, with sex and sex steroid replacement having the greatest impact. Therefore, the individual tailoring of GH dose is of great importance to achieve sufficient efficacy without side effects. One group that stands out is women receiving oral estrogen replacement, who needs the highest dose. Serum insulin-like growth factor-1 (IGF-1) is still the most used biochemical biomarker for GH dose titration, although the best serum IGF-1 target is still debated. Patients with GHD due to acromegaly, Cushing's disease, or craniopharyngioma experience similar effects from GHRT as others. Arch Endocrinol Metab. 2019;63(6):592-600.

Thyroid function in children with growth hormone deficiency during long-term growth hormone replacement therapy

Aim of the study

The aim of this study was to investigate the effects of growth hormone (GH) therapy on thyroid function in a group of euthyroid children with isolated idiopathic growth hormone deficiency (GHD).

Material and methods

The study was retrospective and included 117 children treated with GH for 1-4 years. Anthropometric measurements and serum concentrations of insulin-like growth factor-1 (IGF-1), thyroid-stimulating hormone (TSH), and free thyroxine (fT4) were analysed at baseline and during GH therapy.

Results

TSH levels did not change significantly after the initiation of GH treatment, while fT4 levels decreased after the second year of GH treatment (p < 0.01) and remained lower than baseline until the end of observation (p < 0.01, after both the third and fourth year of therapy) in the whole group. Analysis according to baseline pubertal status revealed significant changes in TSH and fT4 levels during GH treatment, but only in the prepubertal children. Multiple regression analysis confirmed that mean GH doses administered in the first two years of GH therapy were independently (R = 0.218, p < 0.05) associated with changes in fT4 levels in this period (∆fT4_{2 years – baseline}), even when taking into account changes in height SDS and bone age.

Conclusions

FT4 levels decreased during GH replacement therapy, while TSH levels appeared to be unaffected by GH therapy. Prepubertal children seem to be more predisposed to thyroid function alterations during such therapy in comparison to pubertal children. Changes in fT4 levels during GH replacement therapy are related to GH doses.

Improved adipose tissue metabolism after 5-year growth hormone replacement therapy in growth hormone deficient adults: The role of zinc-α2-glycoprotein

Growth hormone (GH) supplementation therapy to adults with GH deficiency has beneficial effects on adipose tissue lipid metabolism, improving thus adipocyte functional morphology and insulin sensitivity. However, molecular nature of these effects remains unclear. We therefore tested the hypothesis that lipid-mobilizing adipokine zinc-α2-glycoprotein is causally linked to GH effects on adipose tissue lipid metabolism. Seventeen patients with severe GH deficiency examined before and after the 5-year GH replacement therapy were compared with age-, gender- and BMI-matched healthy controls. Euglycemic hyperinsulinemic clamp was used to assess whole-body and adipose tissue-specific insulin sensitivity. Glucose tolerance was determined by oGTT, visceral and subcutaneous abdominal adiposity by MRI, adipocyte size morphometrically after collagenase digestion, lipid accumulation and release was studied in differentiated human primary adipocytes in association with GH treatment and zinc-α2-glycoprotein gene silencing. Five-year GH replacement therapy improved glucose tolerance, adipose tissue insulin sensitivity and reduced adipocyte size without affecting adiposity and whole-body insulin sensitivity. Adipose tissue zinc-α2-glycoprotein expression was positively associated with whole-body and adipose tissue insulin sensitivity and negatively with adipocyte size. GH treatment to adipocytes in vitro increased zinc-α2-glycoprotein expression (>50%) and was paralleled by enhanced lipolysis and decreased triglyceride accumulation (>35%). Moreover, GH treatment improved antilipolytic action of insulin in cultured adipocytes. Most importantly, silencing zinc-α2-glycoprotein eliminated all of the GH effects on adipocyte lipid metabolism. Effects of 5-year GH supplementation therapy on adipose tissue lipid metabolism and insulin sensitivity are associated with zinc-α2-glycoprotein. Presence of this adipokine is required for the GH action on adipocyte lipid metabolism in vitro.

The NordiNet® International Outcome Study and NovoNet® ANSWER Program®: rationale, design, and methodology of two international pharmacoepidemiological registry-based studies monitoring long-term clinical and safety outcomes of growth hormone therapy (Norditropin®)

Objective

Randomized controlled trials have shown that growth hormone (GH) therapy has effects on growth, metabolism, and body composition. GH therapy is prescribed for children with growth failure and adults with GH deficiency. Carefully conducted observational study of GH treatment affords the opportunity to assess long-term treatment outcomes and the clinical factors and variables affecting those outcomes, in patients receiving GH therapy in routine clinical practice.

Design

The NordiNet® International Outcome Study (IOS) and the American Norditropin® Studies: Web Enabled Research (ANSWER Program®) are two complementary, non-interventional, observational studies that adhere to current guidelines for pharmacoepidemiological data.

Patients

The studies include pediatric and adult patients receiving Norditropin®, as prescribed by their physicians.

Measurements

The studies gather long-term data on the safety and effectiveness of reallife treatment with the recombinant human GH, Norditropin®. We describe the origins, aims, objectives, and design methodology of the studies, as well as their governance and validity, strengths, and limitations.

Conclusion

The NordiNet® IOS and ANSWER Program® studies will provide valid insights into the effectiveness and safety of GH treatment across a diverse and large patient population treated in accordance with real-world clinical practice and following the Good Pharmacoepidemiological Practice and STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) guidelines.

Favorable Impacts of Growth Hormone (GH) Replacement Therapy on Atherogenic Risks in Japanese Children with GH Deficiency

Growth hormone (GH) affects body composition and atherogenic risk factors. Severe hyperlipidemia may develop in GH-deficient adults as a consequence of continuous GH deficiency. We investigated changes in lipid profiles in 158 Japanese children (103 boys and 55 girls) with GH deficiency who had been enrolled in the Pfizer International Growth Database Japan during 3 yr of GH replacement therapy to evaluate whether GH treatment has beneficial effects on atherogenic risk factors. Total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), low-density lipoprotein cholesterol (LDLC) and atherogenic index were evaluated before treatment and then once a year during treatment. The mean baseline TC was within the normal range in both boys and girls. Seventeen (16.5%) of the 103 boys and 18 (32.7%) of the 55 girls, however, had a TC level over 200 mg/dl before treatment. The mean TC level showed a significant decrease in girls. In a separate analysis, patients of both sexes with a TC level > 200 mg/dl showed significantly decreased TC. LDLC decreased significantly only in girls, while HDLC showed no change in either sex. The atherogenic index decreased significantly in girls. GH replacement therapy in children with GH deficiency had beneficial effects on lipid metabolism and atherogenic risk in both sexes. Early GH treatment would produce lipid metabolism benefits in these patients.