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

Biological effects of recombinant human growth hormone therapy on metabolism in children with growth hormone deficiency: a review

INTRODUCTION

Recombinant human growth hormone (rhGH) therapy (GHT) for short stature resulting from growth hormone deficiency (GHD) is effective in promoting optimal growth velocity and achieving an appropriate final height. However, the specific metabolic changes in children during replacement GHT remain unclear.

CONTENT

The study aimed to evaluate the effects of GHT on metabolism in children with GHD. This is a review of the literature published at PubMed/MEDLINE between January 2010 and August 2024, including original articles. The authors searched Medline using the following keywords: growth hormone therapy in children OR growth hormone treatment in children AND metabolism OR glycemia OR glycated hemoglobin OR insulin OR lipid profile OR blood pressure OR bone mineral density OR body mass index OR waist circumference OR hip circumference OR waist-to-hip ratio OR lean body mass OR visceral fat OR muscle strength OR physical activity OR exercise.

SUMMARY AND OUTLOOK

GHT in children positively affects the lipid profile and body composition. Nevertheless, rhGH treatment may increase fasting glucose, glycated hemoglobin, and indices of insulin resistance. GHT in children has not been associated with an increased risk of diabetes. No changes in blood pressure during GHT were observed. The results of our review show that GHT impacts lipid profiles, carbohydrate metabolism, and body composition. Further studies are needed to clarify the molecular mechanisms by which GH regulates substrate metabolism.

Vascular Function and Intima-Media Thickness in Children and Adolescents with Growth Hormone Deficiency: Results from a Prospective Case-Control Study

INTRODUCTION

Growth hormone deficiency (GHD) may be associated with subtle cardiovascular abnormalities, reversible upon starting GH treatment. Data on vascular morphology and function in GHD children are scanty and inconclusive. The aim of our study was to evaluate the effects of GHD and GH treatment on endothelial function and intima-media thickness (IMT) in children and adolescents.

METHODS

We enrolled 24 children with GHD (10.85 ± 2.71 years) and 24 age-, sex-, and BMI-matched controls. We evaluated anthropometry, lipid profile, asymmetric dimethylarginine (ADMA), brachial flow-mediated dilatation (FMD), and IMT of common (cIMT) and internal (iIMT) carotid artery at study entry in all subjects and after 12 months of treatment in GHD children.

RESULTS

At baseline GHD, children had higher total cholesterol (163.17 ± 18.66 vs. 149.83 ± 20.68 mg/dL, p = 0.03), LDL cholesterol (91.18 ± 20.41 vs. 77.08 ± 19.73 mg/dL, p = 0.019), atherogenic index (AI) (2.94 ± 0.71 vs. 2.56 ± 0.4, p = 0.028), and ADMA (215.87 ± 109.15 vs. 164.10 ± 49.15 ng/mL, p < 0.001), compared to controls. GHD patients also exhibited increased higher waist-to-height ratio (WHtR) compared to controls (0.48 ± 0.05 vs. 0.45 ± 0.02 cm, p = 0.03). GH therapy resulted in a decrease in WHtR (0.44 ± 0.03 cm, p = 0.001), total (151.60 ± 15.23 mg/dL, p = 0.001) and LDL cholesterol (69.94 ± 14.40 mg/dL, p < 0.0001), AI (2.28 ± 0.35, p = 0.001), and ADMA (148.47 ± 102.43 ng/mL, p < 0.0001). GHD showed lower baseline FMD than controls (8.75 ± 2.44 vs. 11.85 ± 5.98%, p = 0.001), which improved after 1-year GH treatment (10.60 ± 1.69%, p = 0.001). Baseline cIMT and iIMT were comparable between the two groups, but slightly reduced in GHD patients after treatment.

CONCLUSION

GHD children may exhibit endothelial dysfunction in addition to other early atherosclerotic markers like visceral adiposity, and altered lipids, which can be restored by GH treatment.

An Observational Study on Response to Growth Hormone Therapy in Indian Patients of Short Stature with Special Emphasis on Biochemical Parameters and Bone Biomarkers

Introduction

There is a lack of Indian data on short stature treatment using recombinant human growth hormone (rhGH). We explored the effects of such treatment in eastern Indian patients, with emphasis on biochemical parameters and bone biomarkers in addition to basic anthropometry.

Methods

Our descriptive study covered 50 short stature patients of varied aetiology attending endocrine outpatient department (OPD) of a tertiary care teaching hospital. Patients were followed up for 1 year after the index visit, and prospective data were reconciled with past medical records. A dose of rhGH used was 0.18-0.375 mg/kg as standard, starting dose mostly being 0.2 mg/kg. Dosing was adjusted if the physician judged the clinical outcome to be less favourable than expected. Anthropometric parameters (height, weight, body mass index (BMI) and skeletal age) were recorded clinically, and various biochemical parameters and bone biomarkers were estimated from blood.

Results

Among 50 subjects, 60% had idiopathic growth hormone (GH) deficiency and 26% had Turner's syndrome. The median age at treatment start was 10 years, and the median treatment duration was 25.5 months. The height increased more in the first year of therapy. In the last 6 months, the height velocity was approximately 0.5 cm/month. Although the weight increased significantly, the increment slowed down in the last 6 months. Both remained less than age- and gender-matched references throughout. The skeletal age was on average 2 years behind chronological age (CA)-being 8.7, 9.6 and 11.3 years, respectively, at therapy start, after one year and at study end. Fasting blood glucose (FBG), total cholesterol and calcium level changes were not statistically significant. Serum cortisol and phosphate showed a modest but statistically significant rise, while thyroid-stimulating hormone (TSH) level declined. Insulin-like growth factor 1 (IGF-1) increase was relatively pronounced. Among bone biomarkers, a decrease in CTx and an increase in vitamin D were significant. Dual-energy X-ray absorptiometry (DEXA) data indicated that bone mineral density was less than that of age-matched controls despite treatment. The therapy was well tolerated.

Conclusions

rhGH treatment leads to significant improvement in anthropometry in Indian children comparable with Western data. Bone biomarker changes indicate decreased bone resorption and increased bone formation although bone mineral density still lags behind age-matched controls.

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.

Comprehensive assessment of cardiovascular disease risk in children with short stature due to isolated growth hormone deficiency: a case-control study

OBJECTIVES

Growth hormone deficiency (GHD) in adults is associated with an increased risk of cardiovascular morbidity and mortality. Although children with GHD are also believed to have a similar cardiovascular disease (CVD) risk beginning at an early age, the available data in children is scarce. We aimed to determine the various CVD risk parameters in children with isolated GHD (IGHD).

METHODS

A cross-sectional case-control study was conducted at a tertiary care centre in North India comparing various auxological, biochemical, and echocardiographic parameters between 20 IGHD children aged 5-15 years and their age and sex-matched healthy controls.

RESULTS

The mean age of children with IGHD and controls was similar (10.5 ± 2.6 yr vs. 9.9 ± 2.7 yr, p=0.48). Children with IGHD had significantly higher waist-hip-ratio (p=0.01), total cholesterol (p=0.02), non-high-density lipoprotein-cholesterol (p=0.02), serum homocysteine (p<0.001), C-reactive protein (CRP) (p=0.01) and pro-brain natriuretic peptide (pro-BNP) (p=0.04) levels as compared to healthy controls. Left ventricular mass (LVM) and interventricular septal thickness were significantly lower (p=0.04; p=0.02) in IGHD children. Correlation analysis showed that pro-BNP and CRP levels had negative correlation (p<0.001, r=-0.70; and p=0.04, r=-0.44, respectively) and LVM had a positive correlation (p=0.02, r=0.53) with height SDS among IGHD children.

CONCLUSIONS

Children with IGHD showed abnormalities in several biochemical and cardiac parameters that may be associated with an increased CVD risk in later life. More extensive studies, including younger children with IGHD, are needed to determine the lower ages at which the CVD risk is detectable.

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.

A Retrospective Analysis of Patients with Short Stature in Eastern China between 2013 and 2019

Objective

To identify the aetiology of growth and development diseases and assess the long-term effectiveness of recombinant human growth hormone (rhGH) therapy in a real-life clinical setting and provide better guidance in clinical strategy and decision making.

Methods

This retrospective study included 1145 children and adolescents with short stature admitted to the Department of Endocrinology, Affiliated Hospital of Jining Medical University, from January 2013 to December 2019, of whom 484 received rhGH treatment. The related anthropometrics and laboratory examinations were assessed in all participants.

Results

A total of 1145 children and adolescents with short stature aged 10.5 ± 3.3 years, including 740 boys and 405 girls, were analysed in this study. The number of children and adolescents with short stature gradually increased per year from 2013 to 2019. The mean pretreatment height standard deviation score (SDS) and insulin-like growth factor-1 SDS were −2.93 ± 1.05 and -1.01 (-1.83--0.16), respectively. The majority of the children (658, 57.47%) were prepubescent. In total, 484 subjects aged 10.6 ± 3.2 years received rhGH and were followed up, and among them, 292 children were treated for more than one year. As the treatment time increased, the children's height SDS gradually increased, and most of them attained a height SDS within the normal range. The mean height SDS in children who were treated for more than one year was −3.0 ± 1.0 at baseline and gradually increased to −0.8 ± 0.3 by year 6. The results were consistent across subgroups of different aetiologies of short stature.

Conclusions

Increasing attention has been given to the height of children during the period of 2013–2019 in eastern China. The present findings indicate that children with short stature need to be referred to a specialist centre to diagnose the cause of growth failure and that short children receiving rhGH therapy show a significant increase in height over time.

Effect of One-Year Growth Hormone Therapy on Cardiometabolic Risk Factors in Boys with Obesity

It has been recognized that people with obesity are more likely to have low growth hormone secretion. Recent studies have also confirmed that the abnormalities of the growth hormone/insulin-like growth factor 1 axis were associated with cardiovascular complications in people with obesity. However, little is known about whether recombinant human growth hormone therapy could improve cardiovascular and metabolic risks in obese children. This study aims to evaluate the effect of one-year growth hormone therapy on obesity-related comorbidities and to assess the safety in Chinese boys with obesity. Eighteen boys with obesity were treated with recombinant human growth hormone for one year. Anthropometric measurements, endocrine testing, and cardiovascular risk markers were performed in all obese boys in baseline, and follow-up visits were performed at 3 months, 6 months, 9 months, and one year, respectively. After one year of recombinant human growth hormone treatment, the body mass index standard deviation scores decreased (P < 0.001) and insulin-like growth factor 1 levels increased (P < 0.001). GH treatment also reduced low density lipoprotein cholesterol (P < 0.001), total cholesterol (P < 0.001), triglycerides (P=0.042), and alanine aminotransferase (P=0.027) when compared with the baseline. One-year of recombinant human growth hormone treatment could improve cardiometabolic risk markers, without adverse effects on glucose homeostasis in boys with obesity.

Effect of growth hormone treatment on energy expenditure and its relation to first-year growth response in children

PURPOSE

The effects of growth hormone (GH) treatment on linear growth and body composition have been studied extensively. Little is known about the GH effect on energy expenditure (EE). The aim of this study was to investigate the effects of GH treatment on EE in children, and to study whether the changes in EE can predict the height gain after 1 year.

METHODS

Total EE (TEE), basal metabolic rate (BMR), and physical activity level (PAL) measurements before and after 6 weeks of GH treatment were performed in 18 prepubertal children (5 girls, 13 boys) born small for gestational age (n = 14) or with growth hormone deficiency (n = 4) who were eligible for GH treatment. TEE was measured with the doubly labelled water method, BMR was measured with an open-circuit ventilated hood system, PAL was assessed using an accelerometer for movement registration and calculated (PAL = TEE/BMR), activity related EE (AEE) was calculated [AEE = (0.9 × TEE) - BMR]. Height measurements at start and after 1 year of GH treatment were analysed. This is a 1-year longitudinal intervention study, without a control group for comparison.

RESULTS

BMR and TEE increased significantly (resp. 5% and 7%). Physical activity (counts/day), PAL, and AEE did not change. 11 out of 13 patients (85%) with an increased TEE after 6 weeks of GH treatment had a good first-year growth response (∆height SDS > 0.5).

CONCLUSIONS

GH treatment showed a positive effect on EE in prepubertal children after 6 weeks. No effect on physical activity was observed. The increase in TEE appeared to be valuable for the prediction of good first-year growth responders to GH treatment.

Effect of recombinant human growth hormone therapy on blood lipid and carotid intima-media thickness in children with growth hormone deficiency

BackgroundReports on the association between growth hormone deficiency (GHD) and cardiovascular risk factors in children are limited. We aim to investigate the effect of different doses of recombinant human growth hormone (rhGH) therapy on blood lipid and carotid intima-media thickness (cIMT) in Chinese GHD children.MethodsNinety children, including sixty isolated GHD children and thirty healthy children, were enrolled. GHD children were randomly divided into two groups (A and B) according to the rhGH dose given: group A received 0.23 mg/kg/week and group B received 0.35 mg/kg/week for 12 months. The TC, TG, LDL-C, HDL-C, and cIMT at baseline and after treatment were measured.ResultsThe height, weight, and height velocity improved significantly over 12 months of rhGH therapy in all GHD children. At baseline, GHD children in both the treatment groups showed significantly higher total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), cIMT, and lower high-density lipoprotein-cholesterol (HDL-C) than healthy children (all P≤0.033). After the 12-month rhGH therapy, a significant decrease in the TC, TG, LDL-C, and cIMT, as well as a significant increase in the HDL-C (P≤0.046), was observed in the GHD children, with change in the group B being even more marked.ConclusionsThe RhGH replacement therapy in GHD children can improve both the blood lipid profile and carotid intima-media thickness, with higher-dose rhGH therapy showing superior effects.

Causes of low peak bone mass in women

Peak bone mass is the maximum bone mass that accrues during growth and development. Consolidation of peak bone mass normally occurs during early adulthood. Low peak bone mass results from failure to achieve peak bone mass genetic potential, primarily due to bone loss caused by a variety of conditions or processes occurring at younger ages than usual. Recognized causes of low peak bone mass include genetic causes, endocrine disorders, nutritional disorders, chronic diseases of childhood or adolescence, medications, and idiopathic factors.

GH Supplementation Effects on Cardiovascular Risk in GH Deficient Adult Patients: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVE

The current meta-analysis aims at evaluating whether the existing clinical evidence may ascertain the effects of growth hormone (GH) replacement therapy on cardiovascular risk, both in isolated GH deficiency (GHD) and in compensated panhypopituitarism including GH deficit.

METHODS

Original articles published from 1991 to 2015 were searched on Medline (Pubmed). Among an overall number of 181 potentially suitable studies, 24 fulfilled the selection criteria and were included in the analysis. Data aggregation was carried out through the calculation of the absolute risk reduction. The meta-analysis was then conducted by means of a fixed-effects model, according to the heterogeneity test (Chi-square statistic).

RESULTS

Fat-free mass (FFM) increase and fat mass (FM) reduction were found, together with a C-LDL reduction, a wide variation in glycaemia and a neutral effect on glycated haemoglobin (HbA1c) and blood pressure. These effects were valid both for isolated GHD patients and for those with compensated panhypopituitarism. The global outcome D showed a nonsignificant reduction of the overall cardiovascular risk (0.53; 95% C.I. -1.23, 2.85).

CONCLUSION

Our meta-analysis shows no signnificatly positive trend in cardiovascular risk after both short and long-term GH supplementation therapy in adult GHD patients. However, a reduction of LDL cholesterol levels has been found. No differences were found between isolated GHD participants and those affected by panhypopituitarism well compensated since at least 3 months.

Impact of Growth Hormone on Regulation of Adipose Tissue

Increasing prevalence of obesity and obesity-related conditions worldwide has necessitated a more thorough understanding of adipose tissue (AT) and expanded the scope of research in this field. AT is now understood to be far more complex and dynamic than previously thought, which has also fueled research to reevaluate how hormones, such as growth hormone (GH), alter the tissue. In this review, we will introduce properties of AT important for understanding how GH alters the tissue, such as anatomical location of depots and adipokine output. We will provide an overview of GH structure and function and define several human conditions and cognate mouse lines with extremes in GH action that have helped shape our understanding of GH and AT. A detailed discussion of the GH/AT relationship will be included that addresses adipokine production, immune cell populations, lipid metabolism, senescence, differentiation, and fibrosis, as well as brown AT and beiging of white AT. A brief overview of how GH levels are altered in an obese state, and the efficacy of GH as a therapeutic option to manage obesity will be given. As we will reveal, the effects of GH on AT are numerous, dynamic and depot-dependent. © 2017 American Physiological Society. Compr Physiol 7:819-840, 2017.

Endocrine status of patients with septo-optic dysplasia: fourteen Japanese cases

A clinical diagnosis of septo-optic dysplasia (SOD) is made when two or more of the classical triad of optic nerve hypoplasia, pituitary hormone abnormalities or midline brain defects. To date, a clinical study of SOD, regarding its endocrinological features in particular, has not been undertaken in Japan. We retrospectively evaluated 14 SOD patients at our institution. Hormonal dysfunction was present in 78% of cases: ten cases presented combined hypopituitarism and one case presented precocious puberty. GHD and hypothyroidism were the most common endocrinopathies. A thin pituitary stalk and a gradual decrease in hormone secretion were the main characteristics. SOD patients usually visited ophthalmologists during early infancy because of eye problems; however, the medical examination did not always lead to endocrine assessments being made. Consequently, children who have eye problems with optic nerve hypoplasia should undergo head MRI imaging. If diagnosed with SOD, it is very important to evaluate pituitary functions. Their endocrinological status should be followed for a long time, even if they do not exhibit any endocrinological problems at evaluation.

Growth Hormone Deficiency in Prepubertal Children: Predictive Markers of Cardiovascular Disease

BACKGROUND

Cardiovascular (CV) risk factors have been identified in adults with untreated growth hormone deficiency (GHD). Existing evidence suggests that the development of the atheromatous plaque begins early in childhood. Previous reports have shown that GHD children are prone to increased CV risks including impaired cardiac function, dyslipidemia and abnormalities in body composition. Recent studies in epigenetics and metabolomics have defined specific fingerprints that might be associated with an increased risk of CV disease.

AIM

The aim of this review is to point out the most significant biochemical and clinical predictive markers of CV disease in prepubertal children and to evaluate the effect of recombinant human growth hormone therapy on most of these alterations. The novel findings in epigenetics and metabolomics are also reviewed, with a particular focus on translating them into clinical practice.

Metabolic alterations in paediatric GH deficiency

Growth hormone (GH) has a large number of metabolic effects, involving lipid and glucose homoeostasis, lean and fat mass. Growth hormone deficiency (GHD) is associated with a metabolic profile similar to the Metabolic Syndrome which is characterized by dyslipidemia, insulin resistance, haemostatic alterations, oxidative stress, and chronic inflammation. GH replacement treatment in GHD children improves these cardiovascular risk factors, while cessation of GH is associated with a deterioration of most of these risk factors. However, it is unclear whether the changes of these risk factors are associated with an increased risk of cardiovascular diseases especially after discontinuing GH treatment. GH treatment itself can lead to insulin resistance, which probably also influences the cardiovascular health status. Therefore, longitudinal studies with the primary outcome cardiovascular diseases are needed in GHD children. Furthermore, new approaches such as metabolomic studies might be helpful to understand the relationship between GHD, GH treatment, and cardiovascular diseases.

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.

Cardiovascular Risk in Growth Hormone Deficiency: Beneficial Effects of Growth Hormone Replacement Therapy

Growth hormone deficiency (GHD) in adulthood is associated with an increased risk of developing adverse cardiovascular events and with reduced life expectancy. Cardiovascular and metabolic abnormalities have so far been evaluated only in a small number of children with GHD and adolescents. In this article we review these abnormalities and their underlying mechanisms and discuss the beneficial effect of growth hormone treatment in subjects with GHD.

Growth hormone and the risk of atherosclerosis in growth hormone-deficient children

OBJECTIVE

Growth hormone-deficient (GHD) children have been found to have higher cardiovascular mortality rates and an increased carotid intima-media thickness (CIMT). This study investigated the risk of atherosclerosis and the effect of recombinant growth hormone (rhGH) replacement therapy on the lipid profile and CIMT in GHD children.

DESIGN

A total of 40 GHD children (mean age: 12.3±2.04 years) were investigated before and after 1 year of rhGH therapy at a dosage of 0.03 mg/kg/day and 40 age- and sex-matched healthy children (mean age: 12.1±2.23 years) were enrolled as a control group, in the same pubertal stage. Fasting blood samples were obtained for lipid profile, IGF-1, and IGFBP-3 analyses. The patients and controls underwent CIMT measurements before and after 1 year of rhGH treatment.

RESULTS

The growth velocity and height standard deviation scores increased significantly over 1 year of treatment in all patients. The total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and atherogenic index (Ai) values were increased while the high-density lipoprotein (HDL) cholesterol value was decreased in the GHD children, as compared to the controls; however, the triglyceride (TG) level was comparable. After 1 year of treatment, a significant decrease in the TC, LDL cholesterol, and Ai values as well as a significant increase in the HDL value were observed in the GHD patients, with the values becoming similar to those in the control group. The mean CIMT was significantly greater in the GHD subjects than in the controls. After 1 year of therapy, the CIMT in the GHD subjects had decreased significantly; however, it was still greater than that in the control group. IGF-1 was negatively correlated with TC, LDL cholesterol, Ai, right CIMT, and left CIMT.

CONCLUSIONS

GHD is associated with increased atherosclerotic risk in children. An improved lipid profile and CIMT were detected after 1 year of hormone replacement therapy.

Modified Clonidine Testing for Growth Hormone Stimulation Reveals α2-Adrenoreceptor Sub Sensitivity in Children with Idiopathic Growth Hormone Deficiency

Introduction

The association between short stature and increased risk of ischemic heart disease has been subject to studies for decades. The recent discussion of cardiovascular risk during growth hormone therapy has given new importance to this question. We have hypothesized that the autonomic system is a crucial element relating to this subject.

Methods

Heart rate variability calculated from 24-hour electrocardiogram data is providing insight into the regulatory state of the autonomous nervous system and is an approved surrogate parameter for estimating cardiovascular risk. We have calculated heart rate variability during clonidine testing for growth hormone stimulation of 56 children. As clonidine is a well-known effector of the autonomous system, stimulating vagal tone and decreasing sympathetic activity, we compared the autonomous reactions of children with constitutional growth delay (CGD), growth hormone deficiency (GHD) and former small for gestational age (SGA).

Results

During clonidine testing children with CGD showed the expected α₂-adrenoreceptor mediated autonomous response of vagal stimulation for several hours. This vagal reaction was significantly reduced in the SGA group and nearly non- existent in the GHD group.

Discussion

Children with GHD show a reduced autonomous response to clonidine indicating α₂-adrenoreceptor sub sensitivity. This can be found prior to the start of growth hormone treatment. Since reduction of HRV is an approved surrogate parameter, increased cardiovascular risk has to be assumed for patients with GHD. In the SGA group a similar but less severe reduction of the autonomous response to clonidine was found. These findings may enrich the interpretation of the data on growth hormone therapy, which are being collected by the SAGhE study group.