Effect of growth hormone therapy and puberty on bone and body composition in children with idiopathic short stature and growth hormone deficiency

Impact of growth hormone therapy on bone and body composition in prepubertal children with idiopathic short stature

OBJECTIVES

Few studies have investigated the effect of growth hormone (GH) therapy on bone health and body composition in children with idiopathic short stature (ISS). Therefore, this study aimed to evaluate the short-term effects of GH treatment on bone mineral density (BMD) and prepubertal body composition in children with ISS.

METHODS

The study included 53 prepubertal children with ISS (mean age, 6.3 ± 1.5 years). Their BMD was compared to that of 20 healthy prepubertal children matched for chronological age. Of the 53 children with ISS, 11 received GH therapy for 1 year. Anthropometric measurements and bone age assessments were conducted, and body composition was analyzed using dual-energy X-ray absorptiometry at 6-month intervals.

RESULTS

At baseline, lumbar spine and femoral neck BMD Z scores, adjusted for height, showed no significant differences between the ISS and control groups. However, bone mineral apparent density (BMAD) Z scores were significantly lower in children with ISS compared to controls. Over 12 months of GH therapy, no significant changes were observed in lumbar spine or femoral neck height-adjusted BMD Z scores. Nevertheless, GH treatment led to a significant reduction in percent body fat for chronological age and an increase in lean body mass after 1 year.

CONCLUSIONS

Prepubertal children with ISS exhibited lower BMAD at the lumbar spine compared to healthy controls. Although short-term GH therapy did not significantly alter bone density, it positively impacted body composition. These findings provide valuable clinical insights into bone health and body composition in children with ISS.

Osteometabolic profile and bone mass in the transition phase: ethnic differences in Brazilians treated with somatropin during childhood

OBJECTIVE

The main growth hormone action is to promote linear growth increasing protein synthesis stimulation and osteoblastic activity. Peak bone mass extends from adolescence to 30 years of age. Several factors may influence this acquisition and prevent fracture risk in adulthood, such as genetic potential, GH, ethnicity, and lifestyle factors. This study aims to compare bone mass and osteometabolic profile of white and Afro-descendant Brazilian adolescents in the transition phase, who were treated with human recombinant growth hormone in childhood.

METHODS

The authors selected 38 adolescents from the Transition Outpatient Clinic of the University of São Paulo. Lumbar spine and total body bone mineral density (BMD) and bone mineral content (BMC), serum calcium, 25-OH-vitamin D and bone markers were analyzed at the rhGH withdrawal.

RESULTS

The mean age was 16.8 ± 1.6 years. There were 21 Afro-descendant and 17 whites. Thirty-four percent of the sample presented vitamin D insufficiency, 66% inadequate calcium intake and 44.7% physical inactivity. The Afro-descendants showed a lower lumbar spine and total body Z scores than those of the whites (p = 0.04 and p = 0.03, respectively), as well as their mean body weight (p = 0.03). There were no differences in the remaining osteometabolic parameters.

CONCLUSION

As most adolescents had vitamin D insufficiency, low calcium intake, and physical inactivity, calcium, and cholecalciferol supplementation and lifestyle changes should be encouraged. The Brazilian Afro-descendant may be a vulnerable group for low bone mass, requiring special strategies to increase bone accrual and body weight. More studies are necessary to compare ethnic differences in this population.

The influence of growth hormone on pediatric body composition: A systematic review

BACKGROUND

Growth hormone (GH) affects metabolism and regulates growth in childhood. The most prominent feature of GH deficiency (GHD) in children is diminished height velocity that eventually leads to short stature. In adult-onset GHD, lean body mass (LBM) is reduced, and visceral fat mass (FM) increased. Beneficial effects of GH treatment on body composition in adults with GHD, including an increase in muscle mass and a decrease in FM, are well established. Relatively few studies have investigated the effects of GH treatment on the body composition of pediatric patients with idiopathic or hypothalamic-pituitary disease-associated GH deficiency. This systematic review aimed to summarize available evidence relating to the effects of GH treatment on body composition in children with GHD.

METHODS

The PubMed, Science Direct, Cochrane Trials, and Embase databases, were searched with keywords including "GH", "body composition", "children", and "growth hormone" for English-language articles, published between January 1999 and March 2021. Two reviewers independently evaluated the search results and identified studies for inclusion based on the following criteria: participants had a confirmed diagnosis of GHD (as defined in each study); participants were pediatric patients who were receiving GH or had stopped GH treatment, regardless of whether they were pre- or post-pubertal; the intervention was recombinant human GH (rhGH; somatropin); and outcomes included changes in body composition during or after stopping GH therapy. Data extracted from each study included study quality, study sample characteristics, study interventions, and body composition. Data on fat-free mass and LBM were combined into a single category of LBM.

RESULTS

Sixteen studies reporting changes in body composition (i.e., FM and LBM) associated with GH treatment in children with GHD were identified and included in the review. Collectively, these studies demonstrated that FM decreased, and LBM increased in response to GH replacement therapy.

CONCLUSION

Despite study limitations (i.e., potential effects of diet and physical activity were not considered), we concluded that a periodic body composition assessment is required to ensure that a satisfactory body composition is achieved during GH replacement therapy in children with GHD.

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.

Impact of oral nutritional supplements (ONS) on growth outcomes and IGF-1 level in underweight older children and young adolescents (5-14 years) with short stature and no systemic disease: High versus normal calories density formula

Objectives:

This controlled trial investigated the effects of energy-dense pediatric oral nutritional supplements ONS versus standard ONS in pediatric patients requiring oral nutritional support for low body mass index (BMI) or weight gain per day (WGD) below the average for age and sex.

Patients and Methods:

34 children and adolescents (mean age 10.2 years) with faltering growth requiring ONS were randomized to cONS (n =22) or sONS (n = 12) for a year. We recorded their weight (WT), height (HT) and calculated height growth velocity (GV), Ht-SDS, BMI, WGD, every 3 months for a year.

Results:

The WGD, height growth velocity (GV: cm/year), and Ht-SDS increased significantly, in both groups, during the year of ONS. The use of the cONS resulted in significantly greater mean total WGD and BMI-SDS after 6 months and 1 year, compared to the sONS group. The increase in IGF1-SDS was significantly higher in the cONS groups versus the sONS group. Moreover, the WGD was correlated significantly with the height GV during the year of ONS intake.

Conclusions:

ONS improved the growth of underweight old children and adolescents who had no systemic illness. There was a significantly higher WGD and BMI-SDS in the group on cONS compared to those on sONS. In both groups, long-term use of ONS significantly improved Ht-SDS. (www.actabiomedica.it)

One Year of GH Treatment for Growth Failure in Children With Anorexia Nervosa: A Randomized Placebo-Controlled Trial

CONTEXT

Children with anorexia nervosa (AN) are at risk of adult height deficit due to prolonged low height velocity (HV).

OBJECTIVE

To investigate the effects of human growth hormone (GH) injections on HV in children with AN and severe growth impairment.

DESIGN AND PARTICIPANTS

In this prospective, randomized, double-blind, single-center, proof-of-concept trial, children with AN and low HV (≤2 cm/year) for at least 18 months, and a bone age ≤12 years for girls and ≤14 years for boys, were randomized to receive daily subcutaneous injections of human GH (0.050 mg/kg/day) or placebo for 12 months.

MAIN OUTCOME MEASURES

Change in HV after 12 months.

RESULTS

In total, 8 patients were assigned to the GH group and 6 to the placebo group. Patients had a median (25th-75th percentile) HV of 1.0 (0.5;1.5) cm/year. The effect of GH treatment increased strongly after 6 months, with a height gain after 12 months of 9.65 (8.0;11.6) cm for the GH group vs 3.85 (1.7;7.3) cm for the placebo group, with an absolute median (2.5th-97.5th percentile) difference between the groups of 5.8 (-1.85;9.68) cm after bootstrapping. The percentage of patients with a HV > 5 cm/year during the study period was higher in the GH group than in the placebo group (100% vs 50%, P = 0.05). Adverse events occurred in similar numbers in the 2 groups, were mild or nonfatal, and did not lead to treatment being stopped.

CONCLUSION

GH administration to improve HV is a potentially valid option for increasing HV in children with AN and prolonged severe growth failure.

Management of primary and secondary osteoporosis in children

Osteoporosis in children differs from adults in terms of definition, diagnosis, monitoring and treatment options. Primary osteoporosis comprises primarily of osteogenesis imperfecta (OI), but there are significant other causes of bone fragility in children that require treatment. Secondary osteoporosis can be a result of muscle disuse, iatrogenic causes, such as steroids, chronic inflammation, delayed or arrested puberty and thalassaemia major. Investigations involve bone biochemistry, dual-energy X-ray absorptiometry scan for bone densitometry and vertebral fracture assessment, radiographic assessment of the spine and, in some cases, quantitative computed tomography (QCT) or peripheral QCT. It is important that bone mineral density (BMD) results are adjusted based on age, gender and height, in order to reflect size corrections in children. Genetics are being used increasingly for the diagnosis and classification of various cases of primary osteoporosis. Bone turnover markers are used less frequently in children, but can be helpful in monitoring treatment and transiliac bone biopsy can assist in the diagnosis of atypical cases of osteoporosis. The management of children with osteoporosis requires a multidisciplinary team of health professionals with expertise in paediatric bone disease. The prevention and treatment of fragility fractures and improvement of the quality of life of patients are important aims of a specialised service. The drugs used most commonly in children are bisphosphonates, that, with timely treatment, can give good results in improving BMD and reshaping vertebral fractures. The data regarding their effect on reducing long bone fractures are equivocal. Denosumab is being used increasingly for various conditions with mixed results. There are more drugs trialled in adults, but these are not yet licenced for children. Increasing awareness of risk factors for paediatric osteoporosis, screening and referral to a specialist team for appropriate management can lead to early detection and treatment of asymptomatic fractures and prevention of further bone damage.

Combined therapy with GnRH analogue and growth hormone increases adult height in children with short stature and normal pubertal onset

OBJECTIVE

To investigate whether gonadotropin releasing hormone analogue (GnRHa) combined with recombinant human growth hormone (rhGH) can improve the adult height (AHt) of children with short stature and normal pubertal onset.

METHODS

In this retrospective study, GnRHa/rhGH treatment was given to children with normal pubertal onset and short stature. Patients were followed up to measure their AHt. The primary outcomes were the disparity between AHt standard deviation score (AHt SDS) and pre-treatment height standard deviation score (Ht SDS) and the disparity between AHt and target height (THt).

RESULTS

A total of 94 patients were included. Forty-nine boys were treated with GnRHa/rhGH for 24.84 ± 13.01 months, and 45 girls were treated for 23.89 ± 10.43 months. (2) Before treatment, the Ht SDS of boys and girls was -1.82 ± 1.30 and -1.10 ± 1.61, respectively, and the target height was 168.98 ± 3.51 cm and 157.90 ± 3.25 cm, respectively. (3) After treatment, for boys, the AHt SDS increased by 1.37 ± 1.28 (p = 0.000) and the disparity between AHt and THt was 0.98 ± 6.18 cm (p = 0.273); for girls, the AHtSDS increased by 1.28 ± 1.48 (p = 0.000), and the disparity between AHt and THt was 3.64 ± 4.86 cm (n = 45, p = 0.000). (4) Subgroup analysis showed that, for boys with idiopathic short stature (ISS) and non-ISS, AHt SDS increased by 2.00 ± 1.16 (p = 0.000) and 0.71 ± 1.06 (p = 0.003) respectively, compared with the pre-treatment HtSDS; The disparities between AHt and THt were -0.70 ± 6.54 cm and 2.73 ± 5.37 cm respectively. For girls with ISS and non-ISS, AHtSDS increased by 2.73 ± 1.21 (p = 0.000) and 0.748 ± 1.19 (p = 0.001), respectively; AHt increased by 2.63 ± 6.12 cm (p = 0.165) and 4.02 ± 4.37 cm (p = 0.000) compared with THt, respectively. (5) Multiple linear regression analysis showed that the baseline bone age (BA) (β = -0.200, p = 0.003), basal IGF-1(β = -0.002, p = 0.008) and HtSDS (β = -0.679, p = 0.000) had negative effects on increment of AHtSDS.

CONCLUSION

For adolescents with normal pubertal onset and short stature, with or without ISS, GnRHa/rhGH therapy can effectively improve AHtSDS. After treatment, ISS adolescents can reach the THts, and Non-ISS adolescents can exceed their THts.

Adherence to healthy diet is related to better linear growth with open growth plate in adolescent girls

Nutritional status can affect the linear growth of bones during puberty by affecting growth plate (GP) chondrocytes. We hypothesized that there is a relationship between dietary patterns and bone age on girls who have experienced height loss. This cross-sectional study was conducted on 350 girls aged 12-13 years with open GP, and major dietary patterns were determined using the factor analysis method. Dual-energy x-ray absorptiometry measurement of participant's wrist was performed to determine GP openness and bone age. In the present study, 70.3% of participants had bone age below chronological age. Three major dietary patterns-healthy, high sugar and salt, and Western diet-were identified using findings of dietary intake. Adherence to the healthy diet led to significant increase in height, weight, body mass index, and other components of body composition such as lean body mass (P < .001). Among these dietary patterns, we found only a significant association between healthy diet and difference between bone and chronological age (B = -0.106). In the present study, adherence to a healthy diet was associated with increase in bone age (P = .02). Healthy dietary pattern with an emphasis on enough intake of plant protein and white meat was associated with better linear growth.

Deficits in Bone Geometry in Growth Hormone-Deficient Prepubertal Boys Revealed by High-Resolution Peripheral Quantitative Computed Tomography

INTRODUCTION

Although growth hormone (GH) is essential for attainment of peak bone mass, bone health in prepubertal children with GH deficiency is not routinely evaluated. The objective of this study was to evaluate bone microarchitecture in GH-deficient (GHD) boys using high-resolution peripheral quantitative computed tomography (HR-pQCT).

METHODS

Fifteen control and fifteen GHD, GH naïve pre-pubertal boys were recruited for a case-control study at a major academic center. Subjects with panhypopituitarism, chromosomal pathology, chronic steroids, or stimulant use were excluded. Volumetric bone mineral density (vBMD; total, cortical, and trabecular), bone geometry (total, cortical and trabecular cross-sectional area, cortical perimeter), bone microarchitecture, and estimated bone strength of the distal radius and tibia were assessed by HR-pQCT. Areal BMD and body composition were assessed by DXA. Insulin-like growth factor 1 (IGF-1), osteocalcin, C telopeptide, and P1NP levels were measured.

RESULTS

GHD subjects had a significantly smaller cortical perimeter of the distal radius compared to controls (p < 0.001), with the difference in cortical perimeter persisting after adjusting for height z score, age, lean mass, and 25-hydroxyvitamin D level (p < 0.05).No significant differences were found in vBMD. No significant differences were found in microarchitecture, estimated strength, areal BMD, body composition, or bone turnover markers. Analysis showed significant positive correlations between IGF-1 levels and cortical parameters.

DISCUSSION/CONCLUSIONS

Prepubertal GHD boys had deficits in bone geometry not evident with DXA. Larger prospective/longitudinal HR-pQCT studies are needed to determine the extent of these deficits, the need for routine bone evaluation, and the timing of GH replacement for prevention or restoration of these deficits.

New Insights in Growth Hormone Stimulation Tests Protocols

Objective: The objective of this study was to analyze the performance of 2 stimulation tests used in the diagnosis of growth hormone deficiency.

Method: A retrospective study was conducted on a non-random sample of 310 patients, between 2 and 20 years old, who were hospitalized in the Mureș County Hospital’s Endocrinology Department and in the National Institute of Endocrinology C.I. Parhon with short stature between 2009-2015. Inclusion criteria: all subjects who underwent growth hormone stimulation tests in accordance with the national protocol. Microsoft Office Excel was used for data collection and MedCalc v 12.5 was used for statistical analysis.

Results: From the total of 310 patients, 102 were diagnosed in Târgu Mureș and 208 in Bucharest. Sex ratio favored boys (boys:girls 1.64:1). In 173 subjects growth hormone deficiency was confirmed. For both tests the percentage of maximum response was the highest for the 60 minutes blood sample regardless if the test were positive or not. Both tests have 100% sensitivity and negative predictive value, with the highest specificity for the 60 minutes clonidine and 30 minutes insulin. The false positive rate was 60% for the insulin test and 27.2% for clonidine for Târgu Mureș sample and 86.9% for the insulin test and 62.5% for clonidine for Bucharest sample. The concordance of the 2 tests was 49.36%.

Conclusions: Stimulating growth hormone testing has a number of limitations but is still needed in some auxological circumstances. We recommend performing the clonidine test first to exclude idiopathic short stature and then the insulin tolerance test for the diagnosis of growth hormone deficiency.

Longitudinal Change in Peripheral Quantitative Computed Tomography Assessment in Older Adults: The Hertfordshire Cohort Study

There are few longitudinal data on change in bone structure and muscle mass, strength and function in later life. We report these, and consider bone-muscle interrelationships in older men and women. We studied 188 men and 166 women from the Hertfordshire Cohort Study, who underwent peripheral quantitative computed tomography (pQCT) of the radius and tibia in 2004-2005 and then again in 2011-2012. Grip strength and gait speed were also assessed at both timepoints. Percentage change per year was calculated for grip strength, gait speed, muscle cross-sectional area (mCSA), fat cross-sectional area (fCSA) and diaphyseal bone parameters [total area (Tt.Ar), cortical area (Ct.Ar), cortical density (cBMD) and trabecular density (tBMD)]. The mean (SD) age of men and women at baseline was 68.9 (2.5) and 69.2 (2.6) years, respectively. Rates of muscle area and strength loss did not differ by sex. Tt.Ar increased with age and faster in men [mean (SD) 1.78 (1.64) %/year] than women [mean (SD) 1.03 (1.69) %/year] in the radius (p < 0.001). In both the radius (p = 0.006) and tibia (p < 0.001), Ct.Ar reduced more rapidly in women than men. Change in Ct.Ar was associated with change in muscle area in the corresponding limb (radius; men: regression coefficient 0.36, 95% CI 0.20-0.52, p < 0.001; tibia; men: regression coefficient 0.14, 95% CI 0.00-0.27, p = 0.043, women: regression coefficient 0.16, 95% CI 0.01-0.30, p = 0.032). We have demonstrated that muscle strength and function decrease faster than muscle mass and have provided further evidence that changes in bone structure with age differ by sex.

Anabolic Therapy for the Treatment of Osteoporosis in Childhood

PURPOSE OF REVIEW

Numerous forms of osteoporosis in childhood are characterized by low bone turnover (for example, osteoporosis due to neuromuscular disorders and glucocorticoid exposure). Anti-resorptive therapy, traditionally used to treat osteoporosis in the young, is associated with further reductions in bone turnover, raising concerns about the long-term safety and efficacy of such therapy. These observations have led to increasing interest in the role of anabolic therapy to treat pediatric osteoporosis.

RECENT FINDINGS

While growth hormone and androgens appears to be relatively weak anabolic modulators of bone mass, emerging therapies targeting bone formation pathways (anti-transforming growth factor beta antibody and anti-sclerostin antibody) hold considerable promise. Teriparatide remains an attractive option that merits formal study for patients post-epiphyseal fusion, although it must be considered that adult studies have shown its effect is blunted when administered following bisphosphonate therapy. Mechanical stimulation of bone through whole body vibration therapy appears to be much less effective than bisphosphonate therapy for treating osteoporosis in children. New anabolic therapies which target important pathways in skeletal metabolism merit further study in children, including their effects on fracture risk reduction and after treatment discontinuation.

Influence of growth hormone replacement on neurological and psychomotor development. Case report

The height response to the use of growth hormone in short height cases has already been confirmed in the literature. The influence of the insulin-like growth factor 1 (GH-IGF1) axis components on development, function, regeneration, neuroprotection, cognition, and motor functions has been evaluated in experimental studies and in adults with central nervous system lesions. However, there is still little research on the clinical impact of hormone replacement on neurological and psychomotor development. This report presents the case of a patient with excellent weight-height recovery and, even more surprisingly, neurological and psychomotor development in response to use of growth hormone. The result strengthens the correlation between experimental and clinical findings related to cerebral plasticity response to growth hormone in children. A preterm male patient with multiple health problems during the neonatal and young infancy period, who for six years presented with a relevant deficit in growth, bone maturation, and neurological and psychomotor development. At six years of age, he had low stature (z-score −6.89), low growth rate, and low weight (z-score −7.91). He was incapable of sustaining his axial weight, had not developed fine motor skills or sphincter control, and presented with dysfunctional swallowing and language. Supplementary tests showed low IGF-11 levels, with no changes on the image of the hypothalamus-pituitary region, and bone age consistent with three-year-old children — for a chronological age of six years and one month. Growth hormone replacement therapy had a strong impact on the weight-height recovery as well as on the neurological and psychomotor development of this child.

Growth Hormone Improves Cardiopulmonary Capacity and Body Composition in Children With Growth Hormone Deficiency

CONTEXT

Growth hormone deficiency (GHD) in children may be associated with early cardiovascular risk factors and alterations in left ventricular (LV) structure and function; data on cardiopulmonary functional capacity are lacking.

OBJECTIVES

Aim of the study was to evaluate the effect of GHD and growth hormone (GH) therapy on cardiopulmonary functional capacity, left and right cardiac structure and function, and body composition in children and adolescents.

DESIGN

Prospective, case-control study.

PATIENTS AND METHODS

Twenty-one untrained GHD children (11.3 ± 0.8 years) underwent cardiopulmonary exercise testing, echocardiography and dual-energy x-ray absorptiometry, before and after 12 months of GH therapy. Twenty-one controls matched for sex, pubertal status, body mass index, and physical activity (PA) were evaluated at baseline and after 1 year.

RESULTS

At baseline, GHD patients showed reduced LV mass (LVM; 63.32 ± 7.80 vs 80.44 ± 26.29 g/m2, P = 0.006), peak oxygen consumption (VO2peak; 22.92 ± 4.80 vs 27.48 ± 6.71 mL/Kg/min, P = 0.02), peak workload (80.62 ± 29.32 vs 103.76 ± 36.20 W, P = 0.02), and O2 pulse (4.93 ± 1.30 vs 7.67 ± 2.93 mL/beat, P = 0.0003), compared with controls. GHD patients also exhibited lower lean body mass (LBM 65.36 ± 7.84% vs 76.13 ± 8.23%, P < 0.001), and higher fat mass (FM 30.84 ± 7.92% vs 22.19 ± 8.18%, P = 0.001) than controls. GH therapy resulted in a significant increase of LVM (72.01 ± 15.88, P = 0.03), VO2peak (26.80 ± 4.97; P = 0.01), peak workload (103.67 ± 32.24, P = 0.001), O2 pulse (6.64 ± 1.68, P = 0.0007), and LBM (75.36 ± 7.59%, P = 0.0001), with a reduction in FM (22.62 ± 7.73%, P = 0.001). No difference was found in either left or right ventricular function.

CONCLUSION

Our results suggest that cardiac structure, body composition and cardiopulmonary functional capacity are impaired in children with untreated GHD and can be restored after short-term GH replacement therapy.

Possible effects of an early diagnosis and treatment in patients with growth hormone deficiency: the state of art

Growth hormone deficiency (GHD) is a relatively uncommon and heterogeneous endocrine disorder presenting in childhood with short stature. However, during the neonatal period, the metabolic effects of GHD may to require prompt replacement therapy to avoid possible life-threatening complications. An increasing amount of data suggests the importance of an early diagnosis and treatment of GHD because of its auxological, metabolic, and neurodevelopmental features with respect to the patients diagnosed and treated later in life.

The available results show favourable auxological outcomes for patients with GHD diagnosed and treated with r-hGH early in life compared with those from patients with GHD who do not receive this early diagnosis and treatment. Because delayed referral for GHD diagnosis and treatment is still frequent, these results highlight the need for more attention in the diagnosis and treatment of GHD.

Despite these very encouraging data regarding metabolic and neurodevelopmental features, further studies are needed to better characterize these findings. Overall, the importance of early diagnosis and treatment of GHD needs to be addressed.

Bone Mineral Density After Cessation of GH Treatment in Young Adults Born SGA: A 5-Year Longitudinal Study

CONTEXT

Short children born small for gestational age (SGA) have below-average bone mineral density (BMD). Growth hormone (GH) treatment improves height and BMD in short SGA children. Longitudinal data on BMD in adults born SGA, after GH cessation (GH-stop), are lacking.

OBJECTIVE

To determine BMD in young adults born SGA during 5 years after GH-stop.

METHODS

In 173 GH-treated adults born SGA (SGA-GH), BMD of total body (BMDTB) and bone mineral apparent density of lumbar spine (BMADLS) were measured longitudinally at adult height (AH) and 6 months, 2 years, and 5 years thereafter. At 5 years after GH-stop (age 21 years), data were compared with 45 untreated short SGA adults (SGA-S), 59 SGA adults with spontaneous catch-up (SGA-CU), and 81 adults born appropriate for gestational age (AGA).

RESULTS

At GH-stop (mean age 16.4 years), estimated mean (standard error) BMDTB standard deviation score (SDS) was -0.40 (0.1) in males and -0.51 (0.1) in females, followed by a trend toward a decrease of BMDTB in males to -0.59 (0.1) at 5 years after GH-stop (P = 0.06), whereas it remained stable in females [-0.57 (0.1); P = 0.33]. At GH-stop, BMADLS SDS was -0.01 (0.1) in males and -0.29 (0.1) in females, followed by a decrease in males and females to -0.38 and -0.55, respectively, at 5 years after GH-stop (P < 0.001). At 5 years after GH-stop, BMDTB and BMADLS in SGA-GH were similar compared with SGA-S, SGA-CU, and AGA.

CONCLUSION

After GH-stop, there is a gradual decline of BMADLS, but at the age of 21 years, BMDTB and BMADLS are similar as in untreated short SGA adults.

Body Mass Disorders in Healthy Short Children and in Children with Growth Hormone Deficiency

The aim of the study was to determine the degree of adiposity and the incidence of body mass disorders, including abdominal obesity, in healthy short children and children with growth hormone deficiency. The study included 134 short children (height < 10th percentile) aged 7-15. In this cohort there were 63 (31 boys and 32 girls) children without diagnosed hormonal disorders and 71 patients (35 boys and 36 girls) with growth hormone deficiency. Basic somatic features were assessed and the study participants were categorized according to the percentage of body fat (%FAT), body mass index (BMI), and waist-to-height ratio (WHtR). We found that there were no significant differences in %FAT and the incidence of body weight disorders depending on gender or diagnosis. %FAT deficit was observed in 12-21% of the participants and underweight in almost every fourth child. Overweight involved 3-14% of the participants and obesity was diagnosed in isolated cases (0-3%); both were considerably lower compared to the estimates based on %FAT. Using the cut-off points of WHtR, abdominal adiposity was observed in 3-15% of the participants. In conclusion, quite a large number of short children (between 25 and 50%) are characterized by abnormal body fat or body mass index values. The results indicate a limited usefulness of BMI in evaluating the incidence of overweight and obesity in children characterized by a height deficit.

Astragalus Extract Mixture HT042 Improves Bone Growth, Mass, and Microarchitecture in Prepubertal Female Rats: A Microcomputed Tomographic Study

Astragalus extract mixture HT042 is a standardized multiherbal mixture comprising Astragalus membranaceus, Eleutherococcus senticosus, and Phlomis umbrosa, which has proven to promote children's height growth. The aim of this study was to investigate the effects of HT042 on longitudinal bone growth, bone mass, and bone microstructure in growing rats using a high-resolution microcomputed tomography system. Four-week-old female rats were fed an HT042-containing diet for 2 weeks. Tibial length was measured at baseline and weekly in vivo. At the end of the study, volumetric bone mineral density (vBMD) and microarchitectural parameters were estimated in the trabecular and cortical bone of the tibia. Tibial length gain was significantly increased by HT042 compared to that reported with the control diet. In the proximal tibial metaphysis, HT042-treated rats had significantly higher trabecular vBMD, bone volume fraction, and trabecular number and lower trabecular separation, trabecular pattern factor, and structure model index values than control rats did. Total cross-sectional area and bone area of the cortical bone in the tibial diaphysis also increased. These findings suggest that HT042 increases longitudinal bone growth rate, improves trabecular bone mass, and enhances the microarchitecture of trabecular and cortical bone during growth.

Muscle and skeletal health in children and adolescents with GH deficiency

In addition to promoting linear growth, GH plays a key role in the regulation of bone and muscle development and metabolism. Although GH deficiency is frequently listed among the causes of secondary osteoporosis in children, its impact on bone and muscle health and on fracture risk is still not completely established. Current data suggest that childhood-onset GH deficiency can affect bone and muscle mass and strength, with GH replacement therapy exerting beneficial effects. Moreover, GH withdrawal at final height can result in reduced peak bone and muscle mass, potentially leading to increased fracture risk in adulthood. Thus, the muscle-bone unit in GH deficient subjects should be monitored during childhood and adolescence in order to prevent osteoporosis and increased fracture risk and GH replacement should be tailored to ensure an optimal bone and muscle health.

Baseline Body Composition in Prepubertal Short Stature Children with Severe and Moderate Growth Hormone Deficiency

Objective. To compare body composition parameters in short children with severe versus moderate and no growth hormone deficiency (GHD). Design and Method. 61 children (40 boys) were studied. Height SDS, BMI Z-score, waist/height ratio (W/HtR), and body composition parameters (BIA) as fat tissue (FAT%), fat-free mass (FFM%), predicted muscle mass (PMM%), and total body water (TBW%) were evaluated. GH secretion in the overnight profile and two stimulation tests and insulin-like growth factor 1 (IGF-1) level were measured. Results. Overall, in 16 (26%) moderate (7.0 > peak GH < 10 ng/mL) and in 11 (18%) severe (GH ≤ 7.0 ng/mL) GHD was diagnosed. In children with sGHD BMI Z-score, W/HtR and FAT% were significantly higher, while FFM%, PMM%, and TBW% were significantly lower versus mGHD and versus noGHD subgroups. No significant differences between mGHD and noGHD were found. There were no differences in height SDS and IGF-1 SDS between evaluated subgroups. Night GH peak level correlated significantly with FAT%, FFM%, PMM%, and TBW%, (p < 0.05) in the entire group. Conclusions. Only sGHD is associated with significant impairment of body composition. Body composition analysis may be a useful tool in distinguishing between its severe and moderate form of GHD.

Advances in pubertal growth and factors influencing it: Can we increase pubertal growth?

Puberty is a period of development characterized by partially concurrent changes which includes growth acceleration, alteration in body composition and appearance of secondary sex characteristics. Puberty is characterized by an acceleration and then deceleration in skeletal growth. The initiation, duration and amount of growth vary considerably during the growth spurt. Pubertal growth and biological maturation are dynamic processes regulated by a variety of genetic and environmental factors. Changes in skeletal maturation and bone mineral accretion concomitant with the stage of pubertal development constitute essential components in the evaluation of growth during this pubertal period. Genetic, endocrine and nutritional factors and ethnicity contribute variably to the amount of growth gained during this important period of rapid changes. Many studies investigated the possibility of increasing pubertal growth to gain taller final adult height in adolescents with idiopathic short stature (ISS). The pattern of pubertal growth, its relation to sex maturity rating and factors affecting them has been addressed in this review. The results of different trials to increase final adult height of adolescents using different hormones have been summarized. These data enables Endocrinologists to give in-depth explanations to patients and families about the efficacy and clinical significance as well as the safety of using these therapies in the treatment of adolescents with ISS.

Effect of growth hormone treatment on quality of life in Japanese children with growth hormone deficiency: an analysis from a prospective observational study

The aim of this study was to assess changes in quality of life (QoL) in Japanese children with GH deficiency (GHD) after 12 mo of GH treatment or with idiopathic short stature (ISS) after 12 mo without treatment. Children with GHD were treated with GH after enrollment. Outcome measures included the parent-rated Child Behavior Checklist (CBCL), the Youth Self-Report Form (YSR), and height standard deviation scores (SDS). Total CBCL scores significantly decreased in children with GHD (n = 152, mean change (standard deviation [SD]) = –3.42 [11.21]) and ISS (n = 129, mean change = –4.82 [10.09]) after 12 mo (p < 0.001). Total YSR scores (mean change = –9.21 [14.07]) and height SDS (mean change = 0.35 [0.38]) significantly decreased in children with GHD (p < 0.001), but were unchanged in children with ISS. The change in total YSR score was significantly correlated with the change in height SDS in children with GHD (r = –0.516, p = 0.003). Our findings demonstrate that GH treatment can improve QoL in Japanese children with GHD. The correlation between the changes in total YSR score and height SDS demonstrated that increased height resulted in improved QoL.

Isolated growth hormone deficiency (GHD) in childhood and adolescence: recent advances

The diagnosis of GH deficiency (GHD) in childhood is a multistep process involving clinical history, examination with detailed auxology, biochemical testing, and pituitary imaging, with an increasing contribution from genetics in patients with congenital GHD. Our increasing understanding of the factors involved in the development of somatotropes and the dynamic function of the somatotrope network may explain, at least in part, the development and progression of childhood GHD in different age groups. With respect to the genetic etiology of isolated GHD (IGHD), mutations in known genes such as those encoding GH (GH1), GHRH receptor (GHRHR), or transcription factors involved in pituitary development, are identified in a relatively small percentage of patients suggesting the involvement of other, yet unidentified, factors. Genome-wide association studies point toward an increasing number of genes involved in the control of growth, but their role in the etiology of IGHD remains unknown. Despite the many years of research in the area of GHD, there are still controversies on the etiology, diagnosis, and management of IGHD in children. Recent data suggest that childhood IGHD may have a wider impact on the health and neurodevelopment of children, but it is yet unknown to what extent treatment with recombinant human GH can reverse this effect. Finally, the safety of recombinant human GH is currently the subject of much debate and research, and it is clear that long-term controlled studies are needed to clarify the consequences of childhood IGHD and the long-term safety of its treatment.

Effect of body composition on bone mineral density in Moroccan patients with juvenile idiopathic arthritis

Introduction

The link between bone mass and body composition is widely recognized, but only few works were selectively performed on subjects with juvenile idiopathic arthritis. The aim of our study was to investigate the effect of body composition on bone mineral density (BMD) in Moroccan patients with juvenile idiopathic arthritis.

Methods

Thirty three children with juvenile idiopathic arthritis (JIA) were included in a cross-sectional study. The diagnosis of JIA was made according to the criteria of the International League of Association of Rheumatology (ILAR). Body mass index (BMI) was calculated from the ratio of weight/height²(kg/m²). Pubertal status was determined according to the Tanner criteria. Bone status, body composition and bone mineral content (BMC) were analyzed by using dual-energy X-ray absorptiometry (DXA). BMD was assessed at the lumbar spine (L1-L4) and at total body in (g/cm²). Total body fat tissue mass (FTM) and lean tissue mass (LTM) were also analyzed by DXA and expressed in kilograms. In children, low BMD was defined as a Z-score less than -2 and osteoporosis was defined as a Z-score less than -2 with a fracture history.

Results

A cross-sectional study was conducted in 33 Moroccan patients with JIA aged between 4 and 16 years, Fat mass was not related to bone density; in contrast, BMD was positively associated to LTM in total body(r = =0.41, p= 0.04) but not in lumbar spine (r = 0.29, p= 0.17). There exist significant correlation between BMC and BMD in total body (r = 0.51, p = 0.01).

Conclusion

This study suggests that the LTM is a determining factor of the BMD during adolescence. Other studies with a broader sample would be useful to confirm this relation.

Low bone mineral content and challenges in interpretation of dual-energy X-ray absorptiometry in children with mucopolysaccharidosis types I, II, and VI

Osteoporosis has been described in animal models of mucopolysaccharidosis (MPS). Whether clinically significant osteoporosis is common among children with MPS is unknown. Therefore, cross-sectional data from whole body (WB; excluding head) and lumbar spine (LS) bone mineral density (BMD) compared with sex-, chronologic age-, and ethnicity-matched healthy individuals (Zage), height-for-age (HAZ) Z-score (ZHAZ) and bone mineral content (BMC) measured by dual-energy X-ray absorptiometry (DXA) in 40 children with MPS were analyzed. A subset of these children (n=24) was matched 1:3 by age and sex to a group of healthy children (n=72) for comparison of BMC adjusted for Tanner stage, race, lean body mass, height, and bone area. Low BMD Z-score was defined as Z-score of -2 or less. In children with MPS, 15% had low WB Zage and 48% had low LS Zage; 0% and 6% had low WB ZHAZ and low LS ZHAZ, respectively. Adjusted WB BMC was lower in MPS participants (p=0.009). In conclusion, children with MPS had deficits in WB BMC after adjustments for stature and bone area. HAZ adjustment underestimated bone deficits (i.e., overestimated WB BMD Z-scores) in children with MPS likely owing to their abnormal bone shape. The influence of severe short stature and bone geometry on DXA measurements must be considered in children with MPS to avoid unnecessary exposure to antiresorptive treatments.

Effect of one-year growth hormone therapy on body composition and cardio-metabolic risk in Indian children with growth hormone deficiency

Growth hormone (GH) deficiency in children manifests as short stature but is also associated with metabolic disturbances. Paucity of GH is also likely to be associated with increased intima media thickness. Data on body composition (BC) and carotid intima media thickness (cIMT) in children with growth hormone deficiency (GHD) from developing countries are very scarce. Therefore, objectives of present study were to assess effect of 1 year of rhGH therapy on (i) BC and lipid profile (LP) in a cohort of Indian GHD children and (ii) effect on atherosclerotic markers - cIMT in subsample. Anthropometry, BC [% body fat (BF), % lean body mass (LBM), bone mineral content (BMC)] (DXA) and LP were measured in 49 pre-pubertal GHD-children (9.3 ± 3.1 years) at baseline and after 1 year of rhGH therapy. On subset of 20 children, cIMT of right common carotid artery was also measured. Baseline BC parameters were compared with age-gender matched healthy controls (n = 49). At baseline % BF was 23 ± 9 %, LBM was 9 ± 3 kg and BMC was 0.306 ± 0.15 kg in GHD- children; BF was comparable, while lean and bone were less than controls (p < 0.05). Post therapy, significant reduction in fat (15%), and cIMT (7%) and increase in LBM and BMC by 40% and 44%, respectively (p < 0.05) was seen. Our cohort of untreated GHD children had abnormal BC and cIMT as compared to controls. rhGH therapy for 1 year had beneficial effect on BC and cardiovascular risk factors.

Muscle size, strength, and physical performance and their associations with bone structure in the Hertfordshire Cohort Study

Sarcopenia is associated with a greater fracture risk. This relationship was originally thought to be explained by an increased risk of falls in sarcopenic individuals. However, in addition, there is growing evidence of a functional muscle-bone unit in which bone health may be directly influenced by muscle function. Because a definition of sarcopenia encompasses muscle size, strength, and physical performance, we investigated relationships for each of these with bone size, bone density, and bone strength to interrogate these hypotheses further in participants from the Hertfordshire Cohort Study. A total of 313 men and 318 women underwent baseline assessment of health and detailed anthropometric measurements. Muscle strength was measured by grip strength, and physical performance was determined by gait speed. Peripheral quantitative computed tomography (pQCT) examination of the calf and forearm was performed to assess muscle cross-sectional area (mCSA) at the 66% level and bone structure (radius 4% and 66% levels; tibia 4% and 38% levels). Muscle size was positively associated with bone size (distal radius total bone area β = 17.5 mm2 /SD [12.0, 22.9]) and strength (strength strain index (β = 23.3 mm3 /SD [18.2, 28.4]) amongst women (p < 0.001). These associations were also seen in men and were maintained after adjustment for age, height, weight-adjusted-for-height, limb-length-adjusted-for-height, social class, smoking status, alcohol consumption, calcium intake, physical activity, diabetes mellitus, and in women, years since menopause and estrogen replacement therapy. Although grip strength showed similar associations with bone size and strength in both sexes, these were substantially attenuated after similar adjustment. Consistent relationships between gait speed and bone structure were not seen. We conclude that although muscle size and grip strength are associated with bone size and strength, relationships between gait speed and bone structure and strength were not apparent in this cohort, supporting a role for the muscle-bone unit.

Protein markers predict body composition during growth hormone treatment in short prepubertal children

OBJECTIVE

A high-throughput pharmaco-proteomic approach has previously been successfully used to identify lipoprotein biomarkers related to changes in longitudinal growth and bone mass in response to growth hormone (GH) treatment. The aim of this study was to identify protein markers involved in the diverse anabolic and lipolytic remodelling of body composition during GH treatment.

DESIGN, PATIENTS AND MEASUREMENTS

The study population consisted of 128 prepubertal children receiving GH treatment. Thirty-nine were short as a result of GH deficiency, and 89 had idiopathic short stature (ISS). Serum protein expression profiles at study start and after 1 year of GH treatment were analysed using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). Body composition was analysed by dual-energy X-ray absorptiometry (DXA), reliably estimating muscle mass from appendicular (arms and legs) lean soft tissue mass (LST). DXA was also used to estimate appendicular bone mineral content (BMC) and fat mass for the total body.

RESULTS

Specific protein expression patterns associated with GH response in different body compartments were identified. Among identified proteins, different isoforms of nutrition markers such as apolipoproteins (Apo) were recognized: Apo C-I, Apo A-II, serum amyloid A4 (SAA4) and transthyretin (TTR). In addition, unidentified peaks were associated with GH effects on specific body compartments.

CONCLUSIONS

Our results suggest that unique protein markers are associated with remodelling of different body compartments during GH treatment, which in the future might be useful to optimize GH treatment not only with regard to longitudinal growth.

Enhanced effect of zinc and calcium supplementation on bone status in growth hormone-deficient children treated with growth hormone: a pilot randomized controlled trial

Reduced bone mineral content in growth hormone-deficient children (GHD) has been reported. Calcium, zinc, and vitamin D play an important role in bone formation. Hence, the aim of this pilot randomized controlled study was to evaluate the effect of calcium, vitamin D, and zinc supplementation in prepubertal GHD children treated with GH on bone health parameters. After 1 year of treatment with GH (20 mg/m(2)/week), 31 GHD (mean age 8.7 ± 2.8 years, 18 boys) prepubertal children were randomised to receive calcium (500 mg/day) and vitamin D (60,000 IU/3 months) [Group A] or a similar supplement of calcium, vitamin D, and zinc (as per Indian Recommended Allowance) [Group B] along with GH therapy for the next 12 months. The two groups were similar in anthropometric and body composition parameters at baseline (p > 0.1). After 1 year of GH therapy, height-adjusted % gain was similar in both groups, 48 % in bone mineral content (BMC) and 45 % in bone area (BA). Height-adjusted % increase in BMC was significantly (p < 0.05) higher in the second year than in the first in both the groups. This % increase in BMC and BA was greater in Group B (51 and 36 % respectively) than in Group A (49 and 34 %), although marginally (p < 0.05). Supplementation of calcium and vitamin D along with GH therapy in GHD Indian children has the potential for enhancing bone mass accrual; this effect was further enhanced through the addition of zinc supplement.

The effect of growth hormone deficiency on size-corrected bone mineral measures in pre-pubertal children

Growth hormone deficiency (GHD) in children has been frequently perceived to be a cause of low bone mass accrual. The confounding effects of poor growth limit the interpretation of prior studies of bone health in GHD. We studied size-corrected bone mineral measures in 30 pre-pubertal GHD children and 75 healthy controls. Our study shows that size-corrected whole-body bone mineral content of GHD children were comparable with controls.

INTRODUCTION

The purpose of this study is to evaluate the effects of GHD on size-corrected bone measures at the lumbar spine (LS) and the whole body (WB).

METHODS

LS bone area (BA), LS bone mineral content (BMC), WB BA, WB BMC, and lean body mass (LBM) were measured in 30 pre-pubertal GHD children and 75 controls by dual-energy X-ray absorptiometry. Multiple linear regressions were used to calculate size-corrected (Sc) LS BA(Sc), LS BMC(Sc), WB BA(Sc), and WB BMC(Sc) from control subjects using height and age as independent variables. Furthermore, the relationship between muscle and bone was studied by first assessing LBM for height (LBM(Ht)) and then determining WB BMC for LBM (WB BMC(LBM)). All values were converted to Z-scores and compared with the control.

RESULTS

At diagnosis, WB BMC(Sc) Z-score of GHD children was not significantly different from controls. However, mean Z-scores of LS BA(Sc) (-0.89 ± 0.84, p < 0.0001), LS BMC(Sc) (-0.70 ± 1.1, p < 0.001), WB BA(Sc) (-0.65 ± 1.0, p < 0.006), and LBM(Ht) (-0.66 ± 1.7, p < 0.01) were significantly reduced, and WB BMC(Lbm) (0.78 ± 1.5, p < 0.003) was significantly higher in GHD children than controls.

CONCLUSION

Size-corrected WB BMC of GHD children were comparable with controls, and bones were normally adapted for muscle mass. Determinants of bone strength which may primarily be affected by GHD are muscle mass, bone size, and geometry rather than bone mass.

Growth hormone effects on cortical bone dimensions in young adults with childhood-onset growth hormone deficiency

Growth hormone (GH) treatment in young adults with childhood-onset GH deficiency has beneficial effects on bone mass. The present study shows that cortical bone dimensions also benefit from GH treatment, with endosteal expansion and increased cortical thickness leading to improved bone strength.

INTRODUCTION

In young adults with childhood-onset growth hormone deficiency (CO GHD), GH treatment after final height is reached has been shown to have beneficial effects on spine and hip bone mineral density. The objective of the study was to evaluate the influence of GH on cortical bone dimensions.

METHODS

Patients (n = 160; mean age, 21.2 years; 63% males) with CO GHD were randomised 2:1 to GH or no treatment for 24 months. Cortical bone dimensions were evaluated by digital x-ray radiogrammetry of the metacarpal bones every 6 months.

RESULTS

After 24 months, cortical thickness was increased compared with the controls (6.43%, CI 3.34 to 9.61%; p = 0.0001) and metacarpal index (MCI) (6.14%, CI 3.95 to 8.38%; p < 0.0001), while the endosteal diameter decreased (-4.64%, CI -7.15 to -2.05; p < 0.001). Total bone width did not change significantly (0.68%, CI -1.17 to 2.57%; not significant (NS)). A gender effect was seen on bone width (p < 0.0001), endosteal diameter (p < 0.01) and cortical thickness (p < 0.01), but not with MCI (NS).

CONCLUSIONS

Cortical bone reacts promptly to reinstitution of GH beyond the attainment of final height by increasing the cortical thickness through endosteal bone growth. This leads to a higher peak bone mass and may reduce the risk of cortical bone fragility later in life.

Comparison of response to 2-years' growth hormone treatment in children with isolated growth hormone deficiency, born small for gestational age, idiopathic short stature, or multiple pituitary hormone deficiency: combined results from two large observational studies

Background

Few studies have compared the response to growth hormone (GH) treatment between indications such as isolated growth hormone deficiency (IGHD), born small for gestational age (SGA), idiopathic short stature (ISS), and multiple pituitary hormone deficiency (MPHD). The aim of this analysis of data, collected from two large ongoing observational outcome studies, was to evaluate growth and insulin-like growth factor-I (IGF-I) response data for children of short stature with IGHD, MPHD, SGA, or ISS following two years of treatment with the recombinant GH product Norditropin® (Novo Nordisk A/S, Bagsværd, Denmark).

Methods

Analysis of auxologic data from two ongoing prospective observational studies, NordiNet® International Outcomes Study (NordiNet® IOS) and NovoNet®/American Norditropin® Studies: Web-enabled Research (ANSWER) Program®.

Results

4,582 children aged <18 years were included: IGHD, n = 3,298; SGA, n = 678; ISS, n = 334; and MPHD, n = 272. After two years’ GH treatment, change in height standard deviation score (SDS) was +1.03 in SGA and +0.84 in ISS vs. +0.97 in IGHD (p = 0.047; p < 0.001 vs. IGHD, respectively). Height gain was comparable between IGHD and MPHD. In pre-pubertal children vs. total population, height SDS change after two years was: IGHD, +1.24 vs. +0.97; SGA, +1.17 vs. +1.03; ISS, +1.04 vs. +0.84; and MPHD, +1.16 vs. +0.99 (all p < 0.001).

Conclusions

After two years’ GH treatment, change in height SDS was greater in SGA and less in ISS, compared with IGHD; the discrepancy in responses may be due to the disease nature or confounders (i.e. age). Height SDS increase was greatest in pre-pubertal children, supporting early treatment initiation to optimize growth outcomes.

Obesity is a risk factor for fracture in children but is protective against fracture in adults: a paradox

With the rise in obesity worldwide, an important debate has developed as to whether excess fat has a detrimental or protective effect on skeletal health in children and adults. Obese children appear to be over represented in fracture groups and recent evidence suggests that fat may be detrimental to bone accrual in children, although this effect may be confined to adolescence during rapid skeletal growth. Fat induced alterations in hormonal factors and cytokines during growth may play a pivotal role in disturbing bone accrual. In contrast, the widely accepted opinion is that fat appears to be protective of bone in adults and minimises bone loss in postmenopausal women. Recent evidence suggests that in adults, site specific fat depots may exert differing effects on bone (with visceral fat acting as a pathogenic fat depot and subcutaneous fat exerting protective effects), and that the effects of fat mass on bone and fracture risk may vary by skeletal site; obesity protects against hip and vertebral fractures but is a risk factor for fractures of the humerus and ankle. The incidence of fracture during adolescence is rising and osteoporosis remains a considerable health burden in older adults. Understanding the effects of fat mass on bone during growth and early adulthood is vital in informing future health strategies and pharmacotherapies to optimise peak bone mass and prevent fracture.

Childhood growth hormone deficiency, bone density, structures and fractures: scrutinizing the evidence

Childhood-onset growth hormone deficiency (GHD) is frequently perceived to cause low bone density, fractures and osteoporosis. This article critically reviews the evidence behind these perceptions. Inherent limitations of current bone imaging techniques have caused many artefacts and misconceptions about bone density and structure. Using appropriate size-corrections, bone density is normal in children and adults with isolated GHD. Cortical density, trabecular density and trabecular volume are normal when measured by peripheral quantitative computerized tomography and histomorphometry. The only verifiable deficit affects cortical thickness (periosteal expansion), both in human and animal studies. However, short limb bones cannot be expected to have an average-sized shaft, as bone elongation and widening could be proportionally impaired in GHD. In addition, GH and IGF-1 have indisputable anabolic actions not only on bone, but also on muscle tissue. In fact, compared with all other bone-related variables, muscle size is the lowest at diagnosis of GHD. During GH therapy, muscle enlargement precedes and exceeds any gain in bone mass. The mechanostat theory suggests that the GHD-induced deficit in muscle force secondarily causes low cortical thickness. There is no evidence that isolated childhood-onset GHD, or severe GH resistance, causes an increased fracture risk in children or adults. Only adults with organic hypopituitarism appear to have a slightly greater risk of fractures. Using current transition guidelines, short children and adults with GHD are at risk of being misdiagnosed with low bone mass and may consequently receive inappropriate treatment. As neither reports of increased fracture risk nor low bone density can stand up against scrutiny, these misconceptions should no longer influence clinical practice. In this respect, GHD should not be listed as a cause of osteoporosis in children and there is a need to review current transition guidelines.

Influence of birth size on body composition in early adulthood: the programming factors for growth and metabolism (PROGRAM)-study

BACKGROUND/OBJECTIVES

Several studies have investigated the relationship of birth size with fat mass and lean body mass (LBM), but the findings differed greatly due to different ways of measuring FM and LBM, different study populations and age groups. We hypothesized that birth size has no influence on adult body composition, whereas weight gain during childhood has.

METHODS

In the programming factors for growth and metabolism (PROGRAM)-study, a cohort of 312 young adults, aged 18-24 years, FM and LBM were determined by dual energy X-ray absorptiometry (DXA). Subsequently, differences in FM and LBM were analysed in four subgroups, young adults either born small for gestational age with short stature (SGA-S) or with catch-up growth (SGA-CU), or born appropriate for gestational age (AGA) with idiopathic short stature (ISS) or with normal stature (controls).

RESULTS

Age, gender, adult height SDS and adult weight SDS were significant positive determinants of FM and LBM, whereas weight gain during childhood was positively significant for FM and negatively for LBM. Birth weight SDS tended to be significant and birth length SDS was not. Weight gain during childhood was positively correlated with waist : hip ratio and trunk fat : total fat ratio. SGA-CU subjects had significantly higher FM and significantly lower LBM than controls.

CONCLUSION

Weight gain during childhood is an important determinant of body composition in young adulthood, whereas birth size is less important. In clinical practice, too much weight gain in childhood should be prevented as it results in a relatively high fat mass, especially in children with catch-up growth in weight, like SGA-CU subjects.

Anastrozole increases predicted adult height of short adolescent males treated with growth hormone: a randomized, placebo-controlled, multicenter trial for one to three years

CONTEXT

The process of epiphyseal fusion during puberty is regulated by estrogen, even in males.

OBJECTIVE

Our objective was to investigate whether anastrozole, a potent aromatase inhibitor, could delay bone age acceleration and increase predicted adult height in adolescent boys with GH deficiency.

METHODS

Fifty-two adolescent males with GH deficiency treated with GH were randomized to cotreatment with anastrozole or placebo daily for up to 36 months.

RESULTS

Fifty subjects completed 12 months, 41 completed 24 months, and 28 completed 36 months. Linear growth was comparable between groups; however, there was a significantly slower increase in bone age advancement from baseline in the anastrozole group vs. placebo group after 2 yr (+1.8+/-0.1 vs. +2.7+/-0.1 yr, P<0.0001) and after 3 yr (+2.5+/-0.2 vs. +4.1+/-0.1 yr, P<0.0001). This resulted in a net increase in predicted adult height of +4.5+/-1.2 cm in the anastrozole group at 24 months and +6.7+/-1.4 cm at 36 months as compared with a 1-cm gain at both time points in the placebo group. Estradiol and estrone concentrations increased less in the anastrozole group compared with placebo group. All boys on the aromatase inhibitor had normal tempo of virilization. Safety data, including glucose, and plasma lipid concentrations were comparable between groups.

CONCLUSIONS

Anastrozole increases adult height potential of adolescent boys on GH therapy while maintaining normal pubertal progression after 2-3 yr. This treatment offers an alternative in promoting growth in GH-deficient boys in puberty. Long-term follow up is needed to elucidate fully the safety and efficacy of this approach.

Pediatric dual-energy X-ray absorptiometry: technique, interpretation, and clinical applications

This article reviews the dual-energy x-ray absorptiometry (DXA) technique, its interpretation, and clinical applications with emphasis on the considerations unique to pediatrics. Specifically, the use of DXA in children requires the radiologist to be a "clinical pathologist," monitoring the technical aspects of the DXA acquisition, a "statistician" knowledgeable in the concepts of Z-scores and least significant changes, and a "bone specialist," aware of the DXA findings in a large number of clinical diseases, providing the referring clinician with a meaningful context for the numeric result obtained with DXA.

Growth hormone treatment in adolescent males with idiopathic short stature: changes in body composition, protein, fat, and glucose metabolism

CONTEXT

Cross-sectional observations show an inverse relationship between pubertal increase in GH and insulin sensitivity, suggesting that pubertal insulin resistance may be mediated by GH.

OBJECTIVE

Our objective was to assess longitudinally the effects of short-term GH supplementation in adolescent males with non-GH-deficient idiopathic short stature (ISS) on body composition, substrate metabolism, and insulin sensitivity. Children with ISS were studied to simulate the pubertal increase in GH secretion.

PARTICIPANTS AND SETTING

Eight males with ISS (10.8-16.5 yr) were recruited from pediatric endocrinology clinics at an academic medical center.

STUDY DESIGN

Participants were evaluated in the General Clinical Research Center before and after 4 months of GH supplementation (0.3 mg/kg.wk). Body composition was assessed with dual-energy x-ray absorptiometry. Whole-body glucose, protein, and fat turnover were measured using stable isotopes. In vivo insulin action was assessed during a 3-h hyperinsulinemic (40 mU/m(2).min) euglycemic clamp.

RESULTS

GH supplementation led to 1) increase in hepatic glucose production and fasting insulin levels, 2) increase in lean body mass and decrease in fat mass, and 3) improvement in cardiovascular lipid risk profile. Plasma IGF-I levels correlated positively with insulin levels.

CONCLUSIONS

Four months of GH supplementation in adolescent males with ISS is associated with significant body composition changes and hepatic insulin resistance.

Pediatric DXA: clinical applications

Normal bone mineral accrual requires adequate dietary intake of calcium, vitamin D and other nutrients; hepatic and renal activation of vitamin D; normal hormone levels (thyroid, parathyroid, reproductive and growth hormones); and neuromuscular functioning with sufficient stress upon the skeleton to induce bone deposition. The presence of genetic or acquired diseases and the therapies that are used to treat them can also impact bone health. Since the introduction of clinical DXA in pediatrics in the early 1990s, there has been considerable investigation into the causes of low bone mineral density (BMD) in children. Pediatricians have also become aware of the role adequate bone mass accrual in childhood has in preventing osteoporotic fractures in late adulthood. Additionally, the availability of medications to improve BMD has increased with the development of bisphosphonates. These factors have led to the increased utilization of DXA in pediatrics. This review summarizes much of the previous research regarding BMD in children and is meant to assist radiologists and clinicians with DXA utilization and interpretation.

Bone quality assessed by phalangeal quantitative ultrasonography in children and adolescents with isolated idiopathic growth hormone deficiency

OBJECTIVE

Some observations indicate that GH deficiency (GHD) may have little impact on bone mineralization in contrast to its effects on bone growth and maturation. The aim of the present study was to evaluate the effects of isolated GHD and GH-replacement therapy on bone quality assessed by a quantitative ultrasound (QUS) technique at the proximal phalanges of the hand.

DESIGN

Growth and QUS data of 68 subjects (50 males and 18 females) aged 5-18 yr with isolated GHD were retrospectively examined. A cross-sectional series of 120 observations was collected and compared with data obtained from a control population (1227 healthy children, 641 males and 586 females, aged 3-16 yr).

METHODS

QUS variables amplitude- dependent speed of sound (AD-SoS) and bone transmission time (BTT) were assessed by the sonographic device DBM Sonic BP IGEA. Height and weight measurements were performed according to standard techniques. In patients, skeletal age (SA) was determined by Tanner-Whitehouse method (3rd version).

RESULTS

Before treatment height, SA, ADSoS and BTT were reduced in patients. Height SD score (SDS), SA SDS, AD-SoS SDS, and BTT SDS improved during treatment. Significant associations of both AD-SoS and BTT with age, SA, height, and therapy duration were observed. Using multivariate regression models the disease state, SA, and height proved to be significant variables in predicting BTT and AD-SoS.

CONCLUSIONS

QUS measurements adjusted for body size and skeletal maturity in GHD patients seem to be only slightly reduced. A body size and skeletal maturity adjustment should be incorporated in studies on bone mass in GHD children and adolescents. A non-invasive technique such as QUS technology opens new perspectives.

Metabolic effects of growth hormone (GH) replacement in children and adolescents with severe isolated GH deficiency due to a GHRH receptor mutation

BACKGROUND

The interpretation of the true effect of GH replacement therapy (GHRT) on metabolic status in GH deficiency (GHD) is often complicated by differing aetiologies of GHD and by the presence of additional hormone deficits.

OBJECTIVE

To study the growth and response of the lipid profile and body composition to GHRT in a cohort of children with the same mutation in the GHRH receptor gene. Design Nine GH-deficient subjects (mean age 12.8 years, range 5-17.5 years; three male) in a rural community in Northeast Brazil were treated with GHRT for 2 years and compared with indigenous normal controls.

MAIN OUTCOME MEASURES

Total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), triglycerides (TG) and body composition were measured at baseline and after 3, 12 and 24 months of GHRT.

RESULTS

At baseline, the subjects with GHD had an adverse lipid profile, including elevated TC, elevated LDL-C and elevated TG. GHRT normalized TG in 3 months, LDL-C in 12 months and TC in 24 months. At baseline, older pubertal subjects with GHD had adverse body composition, including higher percentage fat mass (%FM), and GHRT induced a reduction in %FM that was maintained after 24 months. By contrast, younger prepubertal subjects did not have an adverse body composition.

CONCLUSIONS

Lipid profile was abnormal at baseline, while abnormal body composition was only seen in older subjects in late puberty, indicating that body composition is less sensitive to the effect of GHD than lipid profile. GHRT improves lipid profile at all ages, while it affects body composition only towards the end of growth, emphasizing its importance in achieving normal somatic development in the transition period.

Growth hormone treatment of non-growth hormone-deficient growth disorders

Although a large body of data on efficacy and safety of growth hormone (GH) treatment for various non-growth hormone-deficient (GHD) growth disorders has accumulated from a combination of clinical trial and postmarketing sources in the last 20 years or more, there remain limitations. Clinical trial data have the advantage of direct comparison of well-matched, randomized patient groups receiving treatment (or not) under comparable conditions and, as such, provide the highest quality evidence of efficacy. Clinical trials, however, are typically too small for any statistically valid assessment for safety, which is more comprehensively addressed using postmarketing data. Consequently, while the efficacy of GH treatment in children with non-GHD growth disorders has been solidly established and, based on the combination of the rigor of the clinical trial data and numerical power of the postmarketing data, no major concerns exist regarding safety, additional long-term data are required.