Common carotid intima-media thickness in growth hormone (GH)-deficient adolescents: a prospective study after GH withdrawal and restarting GH replacement

Serum afamin and its implications in adult growth hormone deficiency: a prospective GH-withdrawal study

Introduction

Adult growth hormone deficiency (AGHD) is associated with a high prevalence of metabolic syndrome (MS), which contributes to the unfavorable cardiovascular risk profile in these patients. Insulin like growth factor-1 (IGF-1) is a widely used biomarker, however it does not always reflect the cardiometabolic risk and has a poor relationship with clinical efficacy endpoints. Consequently, there is an unmet need for biomarkers to monitor responses to GH-replacement. Afamin is a hormone-like glycoprotein, expressed in the liver. Higher afamin levels are strongly associated with MS and insulin resistance (IR). Although both MS and IR are very common in AGHD, afamin has not been investigated in these patients.

Purpose

To investigate afamin as a potential biomarker in patients with AGHD.

Materials and methods

Participants included 20 AGHD patients (11 GH-substituted and 9 GH-unsubstituted) and 37 healthy controls. Subjects underwent routine laboratory examinations, anthropometric measurements, body composition analysis using multi-frequency bioelectrical impedance analysis (InBody720) and measurement of serum afamin concentrations. In GH-substituted subjects, GH-substitution was withdrawn for 2 months. Measurements were carried out right before GH-withdrawal, at the end of the 2-month withdrawal period, and 1 month after reinstituting GH-replacement therapy (GHRT).

Results

GH-unsubstituted patients demonstrated higher afamin levels compared to controls (p=0.03). Afamin positively correlated with skeletal muscle mass, bone mineral content, total body water, extracellular- and intracellular water content, insulin (all, p<0.01), HOMA-IR (p=0.01) and C-peptide (p=0.03) levels in AGHD but not in healthy controls. In GH-substituted patients 2-month of GH-withdrawal caused significant changes in body composition, including decreased fat-free mass, skeletal muscle mass, total body water, and intracellular water content (all, p<0.01); but these changes almost fully recovered 1 month after reinstituting GHRT. Unexpectedly, afamin levels decreased after GH-withdrawal (p=0.03) and increased with reinstitution (p<0.01). Changes of afamin levels during GH-withdrawal positively correlated with changes of HOMA-IR (r=0.80; p<0.01) and changes of insulin (r=0.71; p=0.02).

Conclusion

Higher afamin levels in unsubstituted AGHD patients might indicate severe metabolic dysregulation. Significant changes accompanying GH-withdrawal and reinstitution, along with strong correlations with measures of IR, suggest that afamin could be a promising biomarker to monitor GHRT-associated changes of insulin sensitivity.

Growth Hormone, Atherosclerosis and Peripheral Arterial Disease: Exploring the Spectrum from Acromegaly to Growth Hormone Deficiency

Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) are increasingly recognised for their role in cardiovascular (CV) physiology. The GH-IGF-1 axis plays an essential role in the development of the CV system as well as in the complex molecular network that regulates cardiac and endothelial structure and function. A considerable correlation between GH levels and CV mortality exists even among individuals in the general population without a notable deviation in the GHIGF- 1 axis functioning. In addition, over the last decades, evidence has demonstrated that pathologic conditions involving the GH-IGF-1 axis, as seen in GH excess to GH deficiency, are associated with an increased risk for CV morbidity and mortality. A significant part of that risk can be attributed to several accompanying comorbidities. In both conditions, disease control is associated with a consistent improvement of CV risk factors, reduction of CV mortality, and achievement of standardised mortality ratio similar to that of the general population. Data on the prevalence of peripheral arterial disease in patients with acromegaly or growth hormone deficiency and the effects of GH and IGF-1 levels on the disease progression is limited. In this review, we will consider the pivotal role of the GH-IGF-1 axis on CV system function, as well as the far-reaching consequences that arise when disorders within this axis occur, particularly in relation to the atherosclerosis process.

Impact of long-acting growth hormone replacement therapy in adult growth hormone deficiency: Comparison between adolescent, adult, and elderly patients

The predominant features of the adult growth hormone deficiency (GHD) syndrome may vary between patients of different age and age of onset of GHD. Evidence from clinical trials and long-term observational studies has informed our ability to understand the unique considerations regarding risks and benefits of daily growth hormone replacement therapy (GHRT) and specific dosing and monitoring strategies for these patient subgroups. High rates of nonadherence with daily GHRT presents a challenge to achieving optimal treatment outcomes and long-acting growth hormone (LAGH) formulations have been developed with the promise of improving treatment adherence resulting in improved therapeutic outcomes. While existing data from short-term studies have demonstrated noninferiority of efficacy and safety of LAGH compared to daily GHRT, long-term studies are needed to assess the full spectrum of outcomes of interest and long-term safety considerations specific to patients in adolescence, adulthood and the elderly GHD population. Since each LAGH formulation has a unique pharmacodynamic and pharmacokinetic profile optimal dosing and monitoring strategies will need to be developed to allow for the provision of individualized patient treatment.

Clinical, Diagnostic, and Therapeutic Aspects of Growth Hormone Deficiency During the Transition Period: Review of the Literature

The role of growth hormone (GH) during childhood and adulthood is well established. Once final stature is reached, GH continues to act during the transition, the period between adolescence and adulthood in which most somatic and psychological development is obtained. The achievement of peak bone mass represents the most relevant aspect of GH action during the transition period; however, equally clear is its influence on body composition and metabolic profile and, probably, in the achievement of a complete gonadal and sexual maturation. Despite this, there are still some aspects that often make clinical practice difficult and uncertain, in particular in evaluating a possible persistence of GH deficiency once final stature has been reached. It is also essential to identify which subjects should undergo re-testing and, possibly, replacement therapy, and the definition of unambiguous criteria for therapeutic success. Moreover, even during the transition phase, the relationship between GH substitution therapy and cancer survival is of considerable interest. In view of the above, the aim of this paper is to clarify these relevant issues through a detailed analysis of the literature, with particular attention to the clinical, diagnostic and therapeutic aspects.

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.

Growth Hormone (GH) and Cardiovascular System

This review describes the positive effects of growth hormone (GH) on the cardiovascular system. We analyze why the vascular endothelium is a real internal secretion gland, whose inflammation is the first step for developing atherosclerosis, as well as the mechanisms by which GH acts on vessels improving oxidative stress imbalance and endothelial dysfunction. We also report how GH acts on coronary arterial disease and heart failure, and on peripheral arterial disease, inducing a neovascularization process that finally increases flow in ischemic tissues. We include some preliminary data from a trial in which GH or placebo is given to elderly people suffering from critical limb ischemia, showing some of the benefits of the hormone on plasma markers of inflammation, and the safety of GH administration during short periods of time, even in diabetic patients. We also analyze how Klotho is strongly related to GH, inducing, after being released from the damaged vascular endothelium, the pituitary secretion of GH, most likely to repair the injury in the ischemic tissues. We also show how GH can help during wound healing by increasing the blood flow and some neurotrophic and growth factors. In summary, we postulate that short-term GH administration could be useful to treat cardiovascular diseases.

Cardiovascular risk factors and carotid intima media thickness in young adults born small for gestational age after cessation of growth hormone treatment: a 5-year longitudinal study

BACKGROUND

Growth hormone treatment reduces blood pressure and lipid concentrations. We assessed long-term changes in blood pressure, lipid concentrations, and carotid intima media thickness over a 5-year period after cessation of growth hormone treatment in adults born small for gestational age.

METHODS

We did a longitudinal observational study at a medical centre in the Netherlands between April 1, 2004, and April 1, 2016. We included adults born small for gestational age who were treated with growth hormone (1 mg/m² per day); treatment started during childhood until adult height. Participants were evaluated at cessation of treatment, and 6 months, 2 years, and 5 years later. We compared cardiovascular risk factors with untreated controls from the PROGRAM study.

FINDINGS

We included 199 participants born small for gestational age and treated with growth hormone along with 285 controls: 51 untreated short adults born small for gestational age, 92 untreated adults born small for gestational age with spontaneous catch-up growth, and 142 adults born appropriate for gestational age. In the 6 months after treatment cessation, systolic blood pressure increased temporarily from 113·00 mm Hg (95% CI 111·18-114·82) to 116·92 mm Hg (115·07 to 118·77; p<0·001) and diastolic blood pressure increased temporarily from 62·19 mm Hg (60·99-63·38) to 66·51 mm Hg (65·14-67·89; p<0·001). At 5 years after treatment cessation, mean systolic blood pressure was 109·2 mm Hg (105·5-113·0) and mean diastolic blood pressure was 63·4 mm Hg (60·9-65·9), similar to the values at cessation. Lipid concentrations were non-significantly higher 5 years after treatment cessation (p values 0·09-0·21) than at treatment cessation. Cessation of growth hormone had no effect on carotid intima media thickness. At 5 years after cessation, total cholesterol was lower in adults treated with growth hormone (mean 4·21 mmol/L, 95% CI 4·04-4·38) than in untreated short adults born small for gestational age (4·66 mmol/L, 4·42-4·92; p=0·0030), as was mean LDL cholesterol (2·28 mmol/L, 2·14-2·43 vs 2·85 mmol/L, 2·62-3·10; p<0·0001); blood pressure and carotid intima media thickness did not differ between these two groups (p values >0·12). At 5 years after cessation, systolic blood pressure, diastolic blood pressure, lipid concentrations, and carotid intima media thickness of adults treated with growth hormone were not different to those in adults born small for gestational age who had spontaneous catch-up growth or adults born appropriate for gestational age.

INTERPRETATION

Long-term growth hormone treatment in children born small for gestational age has no unfavourable effects on cardiovascular health in early adulthood and improves lipid profiles.

FUNDING

Novo Nordisk (Netherlands).

Growth hormone deficiency during young adulthood and the benefits of growth hormone replacement

Until quite recently, the management of children with growth hormone deficiency (GHD) had focussed on the use of recombinant human GH (rhGH) therapy to normalise final adult height. However, research over the past two decades that has demonstrated deficits in bone health and cardiac function, as well as impaired quality of life in adults with childhood-onset GHD (CO-GHD), has questioned this practice. Some of these studies suggested that there may be short-term benefits of rhGH in certain group of adolescents with GHD during transition, although the impact of GHD and replacement during the transition period has not been adequately investigated and its long-term benefits remain unclear. GH therapy remains expensive and well-designed long-term studies are needed to determine the cost effectiveness and clinical benefit of ongoing rhGH during transition and further into adulthood. In the absence of compelling data to justify widespread continuation of rhGH into adult life, there are several questions related to its use that remain unanswered. This paper reviews the effects of growth hormone deficiency on bone health, cardiovascular function, metabolic profile and quality of life during transition and young adulthood.

Subcutaneous adipose tissue plays a beneficial effect on subclinical atherosclerosis in young survivors of acute lymphocytic leukemia

Purpose

The aim of this study was to evaluate the relationship between body composition, metabolic profile, adipokines, and carotid intima-media thickness (cIMT) in young survivors of childhood acute lymphocytic leukemia (ALL).

Patients and methods

This cross-sectional study compared 55 ALL survivors, of chronological age between 15 years and 24 years, assigned into two groups according to the exposure to cranial radiation therapy (CRT; 25 irradiated and 30 nonirradiated) with 24 leukemia-free controls, and assessed body fat mass (dual-energy X-ray absorptiometry), computed tomography scan-derived abdominal adipose tissue, lipid profile, blood pressure (BP), adipokines, and cIMT by a multiple regression analysis.

Results

Treatment with CRT had an effect on all of the variables derived from the computed tomography scan: visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) (P<0.050). In a multiple linear regression model, cIMT positively correlated with exposure to CRT (P=0.029), diastolic BP (P=0.016), and leptin-to-adiponectin ratio (P=0.048), while negatively related to SAT (P=0.007).

Conclusion

In young survivors of childhood ALL, CRT modified the distribution of fat and played a critical role in determining cIMT. Leptin-to-adiponectin ratio, a biomarker of abdominal obesity and metabolic syndrome, and diastolic BP also influenced cIMT, a marker of subclinical atherosclerosis. Nonetheless, adiposity-associated vascular disease might be attenuated by SAT. Changes in body fat must be evaluated in this group of patients in the early course of survivorship in order to avoid premature cardiovascular disease associated with atherosclerosis. Yet, further research as regards the possible protective effect of SAT on vascular disease is warranted.

Growth hormone treatment of adolescents with growth hormone deficiency (GHD) during the transition period: results of a survey among adult and paediatric endocrinologists from Italy. Endorsed by SIEDP/ISPED, AME, SIE, SIMA

Treatment of adolescents with growth hormone deficiency (GHD) during the transition period is a controversial issue. This paper is a contribution from the Italian community of paediatric and adult endocrinologists surveyed in a Delphi panel. The Delphi method is a structured communication technique, originally developed as a systematic, interactive forecasting method that relies on a panel of experts. The experts answer questionnaires in two or more rounds. There was substantial agreement on the definition of the problems associated with the diagnosis and treatment of adolescents with GHD in the transition period, as well as on the identification of the controversial issues which need further studies. There is general consensus on the need of re-testing all isolated idiopathic GHD after at least 30-day withdrawn from treatment, while in patients with multiple pituitary deficiency and low IGF-I levels there is generally no need to re-test. In patients with permanent or confirmed GHD, a starting low rhGH dose (0.01-0.03 mg per day) to be adjusted according to IGF-I concentrations is also widely accepted. For those continuing treatment, the optimal therapeutic schedule to obtain full somatic maturation, normalization of body composition and bone density, cardiovascular function and Quality of Life, need to be evaluated.

The cardiovascular system in growth hormone excess and growth hormone deficiency

The clinical conditions associated with GH excess and GH deficiency (GHD) are known to be associated with an increased risk for the cardiovascular morbidity and mortality, suggesting that either an excess or a deficiency in GH and/or IGF-I is deleterious for cardiovascular system. In patients with acromegaly, chronic GH and IGF-I excess commonly causes a specific cardiomyopathy characterized by a concentric cardiac hypertrophy associated with diastolic dysfunction and, in later stages, with systolic dysfunction ending in heart failure if GH/IGF-I excess is not controlled. Abnormalities of cardiac rhythm and anomalies of cardiac valves can also occur. Moreover, the increased prevalence of cardiovascular risk factors, such as hypertension, diabetes mellitus, and insulin resistance, as well as dyslipidemia, confer an increased risk for vascular atherosclerosis. Successful control of the disease is accompanied by a decrease of the cardiac mass and improvement of cardiac function and an improvement in cardiovascular risk factors. In patients with hypopituitarism, GHD has been considered the under- lying factor of the increased mortality when appropriate standard replacement of the pituitary hormones deficiencies is given. Either childhood-onset or adulthood-onset GHD are characterized by a cluster of abnormalities associated with an increased cardiovascular risk, including altered body composition, unfavorable lipid profile, insulin resistance, endothelial dysfunction and vascular atherosclerosis, a decrease in cardiac mass together with an impairment of systolic function mainly after exercise. Treatment with recombinant GH in patients with GHD is followed by an improvement of the cardiovascular risk factors and an increase in cardiac mass together with an improvement in cardiac performance. In conclusion, acromegaly and GHD are associated with an increased risk for cardiovascular morbidity and mortality, but the control of GH/IGF-I secretion reverses cardiovascular abnormalities and restores the normal life expectancy.

Growth hormone and the cardiovascular system

Growth hormone (GH) exerts its effects through insulin-like growth factor-1, and although ubiquitous in human tissues, it has a significant role in cardiovascular function. In recent years, there has been a great deal of interest in GH as an etiologic factor in many cardiovascular disease states. Acromegaly, a state of endogenous GH excess, results in myocardial hypertrophy and decreased cardiac performance with increased cardiovascular mortality. Additional insight into the role of excess GH on the cardiovascular system has been gained from data collected in athletes doping with GH. Likewise, GH deficiency is associated with increased mortality, possibly from the associated increase in atherosclerosis, lipid abnormalities, and endothelial dysfunction. However, further research is required to clarify the benefit of GH treatment in both deficient states and in heart failure patients.

Associations between Fatness, Fitness, IGF and IMT among Obese Korean Male Adolescents

BACKGROUND

The purpose of this study was to investigate the association between obesity, fitness levels and cardiovascular (CVD) risk factors, and to identify the correlation between of insulin-like growth factor (IGF)-1, IGF binding protein-3 (IGFBP-3), and carotid intima media thickness (IMT) in Korean adolescents.

METHODS

A total of 225 high school males with a mean age of 16.96±0.23 years participated in this study, and their fatness and fitness levels, fasting glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), blood lipids, IGF-1, IGFBP-3, and IMT were measured.

RESULTS

The results showed that total cholesterol (TC), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), fasting insulin, HOMA-IR, IGF-1, and IGFBP-3 levels were significantly higher in the most obese group than in the other two groups (tertiles). Muscular and cardiopulmonary fitness were negatively associated with weight, body mass index (BMI), fat mass, body fat, waist circumference (WC), fasting insulin, HOMA-IR, and IMT. IGF-1 and IGFBP-3 levels were correlated with WC, hip circumference (HC), fasting glucose, TG, HDL-C, fasting insulin, and HOMA-IR. IMT levels were significantly associated with weight, BMI, muscle mass, fat mass, percent body fat, WC, HC, systolic blood pressure, diastolic blood pressure and high-sensitivity C-reactive protein.

CONCLUSION

There was a significant association between increased obesity and decreased fitness and HOMA-IR, IGF, and IMT among adolescents.

Association of a functional polymorphism (C59038T) in GTP cyclohydrolase 1 gene and Type 2 diabetic macrovascular disease in the Chinese population

Nitric oxide (NO) unavailability plays an important role in the progression of macrovascular diseases in Type 2 diabetes (T2DM). C59038T polymorphism in GTP cyclohydrolase 1 (GCH1) gene is a functional mutation involved in NO metabolism and cardiovascular risk in a multiethnic population. To clarify the relationship between C59038T polymorphism and macrovascular disease in T2DM, an association study was performed among 611 unrelated T2DM patients. C59038T polymorphism was detected by polymerase chain reaction (PCR) restriction fragment length polymorphism. The PCR products after digestion displayed three genotypes, including CC, CT, and TT. The prevalence of cardiovascular disease, cerebrovascular disease, and peripheral vascular disease was significantly higher in T2DM patients with TT genotype than those with CC or CT genotype (P<.001). Compared with CC or CC+CT genotype, T2DM patients with TT genotype had a significantly increased risk of macrovascular disease (P<.001, P=.001), with odds ratio for 4.717 [95% confidence interval: 3.056-7.370] and 4.082 (2.716-5.868), respectively. Subjects with TT genotype showed lower levels of plasma NOx (nitrite and nitrate), flow-mediated artery dilatation and activities of superoxide dismutase but higher levels of plasma malonaldehyde and intima-media thickness of carotid artery than those with CC or CT genotype (P<.05). This study demonstrated that in Chinese T2DM population, C59038T polymorphism was associated with an increased risk of macrovascular disease, which was likely due to its effects on NO metabolism, oxidative stress, and subsequently vascular dysfunction.

Vasoprotective effects of life span-extending peripubertal GH replacement in Lewis dwarf rats

In humans, growth hormone deficiency (GHD) and low circulating levels of insulin-like growth factor 1 (IGF-1) significantly increase the risk for cerebrovascular disease. Genetic growth hormone (GH)/IGF-1 deficiency in Lewis dwarf rats significantly increases the incidence of late-life strokes, similar to the effects of GHD in elderly humans. Peripubertal treatment of Lewis dwarf rats with GH delays the occurrence of late-life stroke, which results in a significant extension of life span. The present study was designed to characterize the vascular effects of life span-extending peripubertal GH replacement in Lewis dwarf rats. Here, we report, based on measurements of dihydroethidium fluorescence, tissue isoprostane, GSH, and ascorbate content, that peripubertal GH/IGF-1 deficiency in Lewis dwarf rats increases vascular oxidative stress, which is prevented by GH replacement. Peripubertal GHD did not alter superoxide dismutase or catalase activities in the aorta nor the expression of Cu-Zn-SOD, Mn-SOD, and catalase in the cerebral arteries of dwarf rats. In contrast, cerebrovascular expression of glutathione peroxidase 1 was significantly decreased in dwarf vessels, and this effect was reversed by GH treatment. Peripubertal GHD significantly decreases expression of the Nrf2 target genes NQO1 and GCLC in the cerebral arteries, whereas it does not affect expression and activity of endothelial nitric oxide synthase and vascular expression of IGF-1, IGF-binding proteins, and inflammatory markers (tumor necrosis factor alpha, interluekin-6, interluekin-1β, inducible nitric oxide synthase, intercellular adhesion molecule 1, and monocyte chemotactic protein-1). In conclusion, peripubertal GH/IGF-1 deficiency confers pro-oxidative cellular effects, which likely promote an adverse functional and structural phenotype in the vasculature, and results in accelerated vascular impairments later in life.

A reappraisal of diagnosing GH deficiency in adults: role of gender, age, waist circumference, and body mass index

OBJECTIVE

The objective of the study was to reevaluate the diagnostic accuracy of GH peak after GHRH plus arginine test (GHRH+ARG) according to patients' age, body mass index (BMI), and waist circumference to diagnose GH deficiency (GHD).

OUTCOME MEASURES

GH peak after GHRH+ARG and IGF-I levels reported as sd score.

SUBJECTS

Subjects included 408 controls (218 women, 190 men, aged 15-80 yr) and 374 patients with hypopituitarism (167 women, 207 men, aged 16-83 yr).

RESULTS

In the (elderly) healthy subjects 15-25 yr old (young), 26-65 yr old (adults) and older than 65 yr, GH cutoffs were 15.6, 11.7, and 8.5 microg/liter, 11.8, 8.1, and 5.5 microg/liter, and 9.2, 6.1, and 4.0 microg/liter, respectively, in the lean, overweight, and obese subjects. Waist circumference was the best predictor of GH peak (t = -7.6, P < 0.0001) followed by BMI (t = -6.7, P < 0.0001) and age (t = -5.7, P < 0.0001). Based on the old (<9.1 microg/liter) and new GH cutoff, 286 (76.5%) and 276 (73.8%) of 374 hypopituitary patients had severe GHD. The receiving-operator characteristic analysis showed GH cutoffs in line with the third percentile or slightly higher results so that the prevalence of GHD increased to 90.1%.

CONCLUSIONS

The results of the current study show that waist circumference and BMI are the strongest predictors of GH peak after GHRH+ARG followed by age. However, the old cutoff value of 9.0 microg/liter was in line with the new cutoffs in 95% of patients.

The GH-IGF-I axis and the cardiovascular system: clinical implications

BACKGROUND

GH and IGF-I affect cardiac structure and performance. In the general population, low IGF-I has been associated with higher prevalence of ischaemic heart disease and mortality. Both in GH deficiency (GHD) and excess life expectancy has been reported to be reduced because of cardiovascular disease.

OBJECTIVE

To review the role of the GH-IGF-I system on the cardiovascular system.

RESULTS

Recent epidemiological evidence suggests that serum IGF-I levels in the low-normal range are associated with increased risk of acute myocardial infarction, ischaemic heart disease, coronary and carotid artery atherosclerosis and stroke. This confirms previous findings in patients with acromegaly or with GH-deficiency showing cardiovascular impairment. Patients with either childhood- or adulthood-onset GHD have cardiovascular abnormalities such as reduced cardiac mass, diastolic filling and left ventricular response at peak exercise, increased intima-media thickness and endothelial dysfunction. These abnormalities can be reversed, at least partially, after GH replacement therapy. In contrast, in acromegaly chronic GH and IGF-I excess causes a specific cardiomyopathy: concentric cardiac hypertrophy (in more than two-thirds of the patients at diagnosis) associated to diastolic dysfunction is the most common finding. In later stages, impaired systolic function ending in heart failure can occur, if GH/IGF-I excess is not controlled. Abnormalities of cardiac rhythm and of cardiac valves can also occur. Successful control of acromegaly is accompanied by decrease of the left ventricular mass and improvement of cardiac function.

CONCLUSION

The cardiovascular system is a target organ for GH and IGF-I. Subtle dysfunction in the GH-IGF-I axis are correlated with increased prevalence of ischaemic heart disease. Acromegaly and GHD are associated with several abnormalities of the cardiovascular system and control of GH/IGF-I secretion reverses (or at least stops) cardiovascular abnormalities.

Growth hormone treatment on atherosclerosis: results of a 5-year open, prospective, controlled study in male patients with severe growth hormone deficiency

BACKGROUND

Severe GH deficiency (GHD) is associated with, increased cardiovascular risk and intima-media thickness (IMT) at major arteries.

OBJECTIVE

The objective of the study was to investigate the 5-yr effects of GH replacement on common carotid IMT and insulin resistance syndrome (IRS) (at least two of the following: triglycerides levels > or = 1.7 mmol/liter, high-density lipoprotein-cholesterol levels < or = 1.0 mmol/liter, blood pressure above 130/85 mm Hg, fasting glucose 6.1-7 or 2 hr after glucose 7.7-11.1 mmol/liter).

DESIGN

This was an interventional, open, prospective, controlled study.

PATIENTS

Patients included 35 men with severe GHD and 35 age-matched healthy men as controls.

INTERVENTION

All patients received standard replacement therapy; GH replacement was added in 22 patients (group A) and refused by 13 others (group B).

MEASUREMENTS

Five-year changes in IMT and IRS prevalence were measured.

RESULTS

At baseline, IMT was higher in the patients with (P < 0.001) and without IRS (P = 0.004) than in controls. Eighteen patients (51.4%) and two controls (5.7%; P < 0.0001) had IRS. At study end, use of lipid-lowering drugs (92.3, vs. 13.6 and 34.3%, P < 0.0001), glucose-lowering drugs (69.2 vs. 31.4 and 22.7%; P = 0.016), and antihypertensive drugs (61.5 vs. 20.0 and 4.5%; P < 0.0001) was higher in group B patients than controls and group A patients. IGF-I levels normalized in all group A patients and remained lower than -1 sd score in 77% of group B patients. IMT significantly decreased only in group A and significantly increased in controls and nonsignificantly in group B patients. IRS prevalence significantly reduced only in group A patients.

CONCLUSIONS

Severely hypopituitary GHD men have more frequently increased IMT at common carotid arteries and IRS than controls. After 5 years, only in GH replaced patients, IMT and prevalence of IRS decreased.

Detection of metabolic syndrome features among childhood cancer survivors: a target to prevent disease

Along with the growing epidemic of obesity, the risk of atherosclerosis, cardiovascular disease morbidity, and mortality are increasing markedly. Several risk factors for cardiovascular disease, such as visceral obesity, glucose intolerance, arterial hypertension, and dyslipidemia commonly cluster together as a condition currently known as metabolic syndrome. Thus far, insulin resistance, and endothelial dysfunction are the primary events of the metabolic syndrome. Several groups have recommended clinical criteria for the diagnosis of metabolic syndrome in adults. Nonetheless, in what concerns children and adolescents, there are no unified definitions, and modified adult criteria have been suggested by many authors, despite major problems. Some pediatric disease states are at risk for premature cardiovascular disease, with clinical coronary events occurring very early in adult life. Survivors of specific pediatric cancer groups, particularly acute lymphocytic leukemia, central nervous system tumors, sarcomas, lymphomas, testicular cancer, and following bone marrow transplantation, may develop metabolic syndrome traits due to: hormonal deficiencies (growth hormone deficiency, thyroid dysfunction, and gonadal failure), drug or radiotherapy damage, endothelial impairment, physical inactivity, adipose tissue dysfunction, and/or drug-induced magnesium deficiency. In conclusion, some primary and secondary prevention remarks are proposed in order to reduce premature cardiovascular disease risk in this particular group of patients.

Growth hormone replacement throughout life: insights into age-related responses to treatment

The adult growth hormone deficiency (GHD) syndrome is a well-defined clinical entity. Although the symptoms of GHD are not age specific, their relative importance differs depending on the patient's age, and the impact of GHD varies throughout adult life. Ceasing growth hormone (GH) therapy soon after final height in patients with severe GHD potentially limits somatic development by reducing accrual of bone and muscle mass. It is now recognized that the continuation of GH therapy in the transition years is required to achieve adult levels of somatic development. In middle age, the most worrying feature of GHD is the increase in cardiovascular risk, an important component of which is GHD-related dyslipidemia. One of the most profound effects of GH therapy in this age group is the durable reduction in cholesterol levels. Elderly GH-deficient patients experience the symptoms of GHD over and above the signs of normal aging. Perhaps most importantly, these patients have impaired quality of life, with fatigue as a major component. Evidence is growing for improved quality of life with GH therapy in the elderly. This review describes the diagnosis, symptoms and treatment of GHD specific to the different age groups.

Beginning to end: cardiovascular implications of growth hormone (GH) deficiency and GH therapy

Both growth hormone (GH) and insulin-like growth factor I (IGF-I) are involved in heart development and in maintenance of cardiac structure and performance. Cardiovascular disease has been reported to reduce life expectancy in both GH deficiency (GHD) and GH excess. Patients with GHD suffer from a cluster of abnormalities associated with increased cardiovascular risk, including abnormal body composition, unfavorable lipid profile, increased fibrinogen and C-reactive protein levels, insulin resistance, early atherosclerosis and endothelial dysfunction, and impaired left ventricular (LV) performance (i.e., reduced diastolic filling and impaired response to peak exercise). Long-term GH replacement therapy reverses most of these abnormalities. More consistently, GH replacement reduces body fat and visceral adipose tissue, reduces low-density lipoprotein cholesterol and triglyceride levels, and improves endothelial function. GH replacement also reduces intima media thickness at major arteries and improves LV performance, but these results have been observed only in small series of patients treated on a short-term basis. This review discusses the roles of GHD and GH replacement therapy in the development of cardiovascular disease.

Improvement of cardiac performance and cardiovascular risk factors in children with GH deficiency after two years of GH replacement therapy: an observational, open, prospective, case-control study

CONTEXT

GH deficiency (GHD) in adults is associated with a cluster of cardiovascular risk factors that may contribute to an increased mortality for cardiovascular disease.

OBJECTIVE

The aim of this study was to evaluate the effect of GHD and GH replacement therapy on cardiac performance, lipid profile, and insulin resistance in children.

DESIGN

This was a 2-yr case-control prospective study.

PATIENTS

Thirty children with GHD aged 9.3 +/- 0.5 yr and 30 healthy matched controls were studied.

INTERVENTION

Children were studied before and after 1 and 2 yr of GH replacement (GHD children) or no treatment (controls).

MAIN OUTCOME MEASURES

Lipid profile, serum insulin levels, homeostasis model of assessment (HOMA) index, and left ventricular (LV) mass and function by echocardiography were the main outcome measures.

RESULTS

At study entry, the LV mass index was significantly lower in GHD children (50.2 +/- 1.7) than in controls (60.3 +/- 2.5 g/m(2); P < 0.002), whereas LV systolic and diastolic function, lipid profile, insulin levels, and HOMA index were similar. In GHD children LV mass index significantly increased (66.3 +/- 2.4 g/m(2); P < 0.0001) after 1 yr of GH replacement and remained stable thereafter. LV systolic and diastolic function did not change during treatment. After 2 yr of GH replacement, total cholesterol (P < 0.007) and the atherogenic index (P < 0.0001) significantly decreased, whereas fasting insulin levels (P < 0.001) and HOMA index (P < 0.0001) significantly increased compared with both pretreatment and control values.

CONCLUSIONS

GHD in children is associated with a reduced cardiac size but with a normal cardiac function, lipid profile, and insulin sensitivity. Two years of GH replacement normalizes cardiac morphology, improves lipid profile, and slightly impairs insulin sensitivity.