Improved left ventricular function after growth hormone replacement in patients with hypopituitarism: assessment with radionuclide angiography

Neonatal Risk Factors for Growth Retardation in Infants With Congenital Heart Disease

BACKGROUND

While the association of congenital heart disease (CHD) and growth retardation (GR) is known, data remain limited. This study investigated the incidence of GR and its neonatal risk factors in patients with CHD using nationwide population-based claims data.

METHOD

The study population was extracted from Korean National Health Insurance Service claims data from January 2002 to December 2020. We included patients diagnosed with CHD under one year of age. GR was defined as an idiopathic growth hormone deficiency or short stature on the claims data. We investigated the neonatal risk factors for GR.

RESULTS

The number of patients diagnosed with CHD within the first year of birth was 133,739. Of these, 2,921 newborns were diagnosed with GR. The cumulative incidence of GR was 4.8% at 19 years of age for individuals diagnosed with CHD at infancy. In the multivariable analysis, the significant risk factors for GR were preterm birth, small for gestational age, low birth weight, respiratory distress, bronchopulmonary dysplasia, bacterial sepsis, necrotizing enterocolitis, feeding problems and cardiac procedure.

CONCLUSION

Several neonatal conditions were significant risk factors for GR in CHD patients, and appropriate monitoring and treatment programs are required in CHD neonates with these factors. Considering this study is limited to claims data, further studies are warranted, including genetic and environmental factors affecting GR in CHD patients.

Insulin-like Growth Factor 1 (IGF-1) as a marker of cognitive decline in normal ageing: A review

Insulin-like Growth Factor 1 (IGF-1) and its signaling pathway play a primary role in normal growth and ageing, however serum IGF-1 is known to reduce with advancing age. Recent findings suggest IGF-1 is essential for neurogenesis in the adult brain, and this reduction of IGF-1 with ageing may contribute to age-related cognitive decline. Experimental studies have shown manipulation of the GH/GF-1 axis can slow rates of cognitive decline in animals, making IGF-1 a potential biomarker of cognition, and/or its signaling pathway a possible therapeutic target to prevent or slow age-related cognitive decline. A systematic literature review and qualitative narrative summary of current evidence for IGF-1 as a biomarker of cognitive decline in the ageing brain was undertaken. Results indicate IGF-1 concentrations do not confer additional diagnostic information for those with cognitive decline, and routine clinical measurement of IGF-1 is not currently justified. In cases of established cognitive impairment, it remains unclear whether increasing circulating or brain IGF-1 may reverse or slow down the rate of further decline. Advances in neuroimaging, genetics, neuroscience and the availability of large well characterized biobanks will facilitate research exploring the role of IGF-1 in both normal ageing and age-related cognitive decline.

Functional Changes after Recombinant Human Growth Hormone Replacement in Patients with Chronic Traumatic Brain Injury and Abnormal Growth Hormone Secretion

We explored the effects of recombinant human growth hormone (rhGH) replacement on physical and cognitive functioning in subjects with a moderate-to-severe traumatic brain injury (TBI) with abnormal growth hormone (GH) secretion. Fifteen individuals who sustained a TBI at least 12 months prior to study enrollment were identified as having abnormal GH secretion by glucagon stimulation testing (maximum GH response less than 8 ng/mL). Peak cardiorespiratory capacity, body composition, and muscle force testing were assessed at baseline and one year after rhGH replacement. Additionally, standardized neuropsychological tests that assess memory, processing speed, and cognitive flexibility, as well as self-report inventories related to depression and fatigue, were administered at baseline and 1 year after rhGH replacement. Comparison tests were performed with proper post hoc analyses. All analyses were carried out at α < 0.05. Peak O₂ consumption, peak oxygen pulse (estimate of cardiac stroke volume), and peak ventilation all significantly increased (p < 0.05). Maximal isometric and isokinetic force production were not altered. Skeletal muscle fatigue did not change but the perceptual rating of fatigue was reduced by ∼25% (p = 0.06). Cognitive performance did not change significantly over time, whereas self-reported symptoms related to depression and fatigue significantly improved. The observed changes suggest that rhGH replacement has a positive impact on cardiorespiratory fitness and a positive impact on perceptual fatigue in survivors of TBI with altered GH secretion.

Impact of adult growth hormone deficiency on metabolic profile and cardiovascular risk [Review]

Adult growth hormone deficiency (GHD) is a well defined clinical condition, which is characterized by abnormal body composition, impaired physical activity and decreased quality of life. In addition, in recent years, growing interest has been shown towards cardiovascular risks in adult patients affected by GHD. In this regard, GHD is widely known to be associated with increased mortality, likely due to the increase of risk factors, such as central obesity, impaired lipid and glucose profiles and other less-known risk factors, such as inflammatory cytokines, endothelial dysfunction and oxidative stress. However, very few papers have recently discussed this topic. In this review, the aim is to clarify this issue by discussing evidence regarding the effects of adult GHD on metabolic and cardiovascular profiles.

Growth hormone, insulin-like growth factor-1 and the aging brain

Growth hormone (GH) and insulin-like growth factor (IGF)-1 regulate the development and function of cells throughout the body. Several clinical diseases that result in a decline in physical and mental functions are marked by mutations that disrupt GH or IGF-1 signaling. During the lifespan there is a robust decrease in both GH and IGF-1. Because GH and IGF-1 are master regulators of cellular function, impaired GH and IGF-1 signaling in aging/disease states leads to significant alterations in tissue structure and function, especially within the brain. This review is intended to highlight the effects of the GH and IGF-1 on neuronal structure, function, and plasticity. Furthermore, we address several potential mechanisms through which the age-related reductions in GH and IGF-1 affect cognition. Together, the studies reviewed here highlight the importance of maintaining GH and IGF-1 signaling in order to sustain proper brain function throughout the lifespan.

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.

The GH/IGF-1 Axis and Heart Failure

The growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis regulates cardiac growth, stimulates myocardial contractility and influences the vascular system. The GH/IGF-1 axis controls intrinsic cardiac contractility by enhancing the intracellular calcium availability and regulating expression of contractile proteins; stimulates cardiac growth, by increasing protein synthesis; modifies systemic vascular resistance, by activating the nitric oxide system and regulating non-endothelial-dependent actions. The relationship between the GH/IGF-1 axis and the cardiovascular system has been extensively demonstrated in numerous experimental studies and confirmed by the cardiac derangements secondary to both GH excess and deficiency. Several years ago, a clinical non-blinded study showed, in seven patients with idiopathic dilated cardiomyopathy and chronic heart failure (CHF), a significant improvement in cardiac function and structure after three months of treatment with recombinant GH plus standard therapy for heart failure. More recent studies, including a small double-blind placebo-controlled study on GH effects on exercise tolerance and cardiopulmonary performance, have shown that GH benefits patients with CHF secondary to both ischemic and idiopathic dilated cardiomyopathy. However, conflicting results emerge from other placebo-controlled trials. These discordant findings may be explained by the degree of CHF-associated GH resistance. In conclusion, we believe that more clinical and experimental studies are necessary to exactly understand the mechanisms that determine the variable sensitivity to GH and its positive effects in the failing heart.

Evaluation of pulsatile plasma concentrations of growth hormone in healthy dogs and dogs with dilated cardiomyopathy

OBJECTIVE

To evaluate plasma concentrations of growth hormone (GH) and insulin-like growth factor I (IGF-I) in healthy dogs and large-breed dogs with dilated cardiomyopathy (DCM).

ANIMALS

8 dogs with DCM and 8 healthy control dogs of comparable age and body weight.

PROCEDURES

Blood samples for determination of the pulsatile plasma GH profile were collected from all dogs at 10-minute intervals between 8:00 am and 8:00 pm. Plasma IGF-I concentration was determined in the blood sample collected at 8:00 am.

RESULTS

No significant differences in plasma IGF-I concentrations, basal plasma GH concentration, GH pulse frequency, area under the curve above the zero line and above the baseline for GH, and GH pulse amplitude were found between dogs with DCM and control dogs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results did not provide evidence for an association between DCM in dogs and a reduction in plasma concentrations of GH or IGF-I. Therefore, reported positive effects of GH administration are most likely attributable to local effects in the heart.

Cardiovascular risk, cardiac function, physical activity, and quality of life with and without long-term growth hormone therapy in adult survivors of childhood acute lymphoblastic leukemia

CONTEXT

Long-term data are missing in GH-treated acute lymphoblastic leukemia (ALL) patients. GH therapy may result in poorer outcome regarding cardiovascular (CV) and particularly cardiac effects than in patients with hypothalamic-pituitary disease.

OBJECTIVE

Our objective was to evaluate GH therapy on CV risk, cardiac function, physical activity, and quality of life in ALL patients treated with cranial radiotherapy (18-24 Gy) and chemotherapy (anthracycline dose 120 mg/m2).

DESIGN AND SETTING

We conducted a 5- and 8-yr open nonrandomized prospective study in a university hospital clinic.

STUDY PARTICIPANTS

Two groups of GH-deficient ALL patients (aged 25 yr; range 19-32 yr) and matched population controls participated.

INTERVENTIONS

One ALL group (n=16) received GH for 5 yr, and the other ALL group (n=13) did not receive GH therapy.

MAIN OUTCOME MEASURES

We evaluated the prevalence of CV risk factors and metabolic syndrome (International Diabetes Federation consensus), cardiac function (echocardiography), and quality of life and physical activity questionnaires.

RESULTS

In comparison with 8 yr without, 5 yr with GH therapy resulted in significant positive changes in plasma glucose (-0.5 vs. 0.6 mmol/liter, P=0.002), apolipoprotein B/apolipoprotein A1 ratio (-0.1 vs. 0.0, P=0.03), and high-density lipoprotein-cholesterol (0.20 vs.-0.01 mmol/liter, P=0.008) and a significant reduction in the prevalence of metabolic syndrome (P=0.008). No significant difference in the left-ventricular systolic function or in physical activity and quality of life was recorded before and after 5 or 8 yr, respectively (all P>0.3).

CONCLUSION

GH therapy reduced the CV risk in this young ALL population but resulted in no clear benefit or deterioration in cardiac function.

Reduced cardiac functional reserve and quality of life in adults with GH deficiency

INTRODUCTION

Patients with severe GH deficiency (GHD) suffer with a reduced quality of life in addition to diverse changes in cardiac size and performance. So far, the cardiac reserve ability to maintain the circulation during peak exercise has not been measured. We tested the hypothesis that patients with severe GHD have reduced cardiac reserve function compared with healthy controls and that this could explain, in part, their reduced quality of life.

AIMS

Eighteen patients with severe GHD and an assessment of GHD in adults (AGHDA) score > or =11 (mean 20.0, range 12-25) were studied and compared with 18 age-, sex- and body mass index-matched healthy controls. Peak cardiac power and cardiorespiratory fitness were investigated using noninvasive haemodynamic measurements during maximal cardiopulmonary exercise testing.

RESULTS

Compared with matched controls, the cardiac power of GHD patients during exercise to volitional exhaustion was significantly reduced by 15% (mean +/- SD 4.4 +/- 1.0 W vs. 5.2 +/- 1.0 W, P = 0.02). Patients with GHD also had lower cardiac chronotropic reserve (peak heart rate 154 +/- 21/min vs. 174 +/- 11/min, P = 0.001) and a lower cardiac pressure-generating capacity (systolic blood pressure 160 +/- 25 mmHg vs. 200 +/- 15 mmHg, P < 0.0001). We found no correlation between any measure of peak cardiac power or function and the AGHDA score.

CONCLUSION

Using this robust noninvasive method of assessing functional cardiac pumping capacity, we have for the first time shown that, while patients with severe GHD have a significantly impaired cardiac functional reserve associated with chronotropic incompetence and impaired pressure-generating capacity, this does not correlate with their reduced quality of life assessed using the current standard AGHDA score.

[Efficacy, safety and compliance of long-term growth hormone (GH) replacement therapy in adults with GH deficiency]

AIM

To study efficacy, safety and compliance of GH therapy for 4 years in 18 GH deficient (GHD) adults [12 women; mean age 50.5 yrs (25-66 yrs)].

METHODS

Clinical, biochemical and body composition (DXA) measurements were performed before and every year after GH therapy. Ecocardiography was performed at baseline and after 4 years. Dose of GH was 0.2 mg/day during the first year with subsequent titration to attain normal IGF-1 levels.

RESULTS

There was a significant reduction of total body fat (mean 2.8 kg), truncal fat (mean 1.9 kg) and an increase of lean body mass (mean 0.8 kg) and bone mineral density (BMD) on lumbar spine and femur, particularly in sites with T-score<-1,0 at baseline. Insulin levels and HOMA index worsened in the first year, but at the end no changes were noted on glucose, insulin, HOMA index and glycosylated hemoglobin. Two patients with altered glucose tolerance at baseline developed type 2 diabetes during follow-up. Total and LDL-cholesterol were significantly lower after therapy, with changes directly associated with baseline values. Cardiac parameters did not change. Side effects were mild and disappeared spontaneously. Tumor recurrence was not observed. Low compliance (estimated by low IGF-1 levels) was observed in 4 (22%), 2 (11%) and 6 (33%) patients at the end of second, third and fourth year, respectively.

CONCLUSIONS

Four years of GH therapy in GHD adults had a positive impact on body composition, BMD and lipid profile, with no effects on insulin sensitivity and heart. Glucose tolerance should be monitored carefully during long-term GH therapy.

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.

Effect of growth hormone on cardiac contractility in patients with adult onset growth hormone deficiency

This study was conducted to investigate the effect of growth hormone (GH) replacement on cardiac function assessed by standard or tissue Doppler echocardiography in GH deficiency. Ten patients (mean age 47+/-14 years) received GH at a dose of 1.0 IU/day (6 times/week). After 6 months of GH replacement, GH substitution was discontinued. Echocardiography was performed at baseline, after 6 months of therapy, and 1 year after the withdrawal of GH replacement. All parameters were compared with those from 11 healthy controls matched for age, gender, and left ventricular (LV) mass index. After GH replacement, LV ejection fractions were nonsignificantly increased. However, fractional shortening, LV dimensions, and LV volumes did not change. Compared with controls, peak strain (-18.9+/-4.8% vs -15.7+/-6.9%, p<0.01) and strain rate (-1.3+/-0.4/s vs -1.0+/-0.5/s, p<0.01) at baseline were significantly decreased in patients with GH deficiency. Strain and strain rate increased significantly after 6 months of replacement but returned to baseline levels after 12 months off therapy. In conclusion, GH replacement in adult-onset GH deficiency demonstrated beneficial effects on cardiac contractility assessed by strain and strain rate, but these parameters returned to baseline levels after the withdrawal of GH. Strain and strain rate can be used to evaluate subtle changes in myocardium after GH replacement.

Recombinant bovine growth hormone-induced reduction of atrial natriuretic peptide is associated with improved left ventricular contractility and reverse remodeling in cardiomyopathic UM-X7.1 hamsters with congestive heart failure

OBJECTIVE

To assess the effect of short-term treatment with GH on left ventricular contractility and remodeling, after the development of heart failure in cardiomyopathic hamsters (CMH).

DESIGN

Two groups of 200-day-old UM-X7.1 CMH received daily subcutaneous injections of recombinant bovine (rb) GH (1mg/kg/day) or 0.9% NaCl for 40 days. Golden Syrian hamsters (GSH) were used as controls. At 240-day-old, the hamsters were randomly subjected to (i) assessment of left ventricular systolic function in a Langendorff perfused mode followed by the determination of the passive diastolic pressure-volume relationship and morphometric measurements; (ii) assessment of left ventricular mRNA expression of genes belonging to the fetal gene program including atrial (ANP) and brain (BNP) natriuretic peptides and cardiac myosin heavy chain isoforms and of the circulating levels of the natriuretic peptides.

RESULTS

Hearts from CMH were hypertrophied and dilated (p<0.05) compared to hearts from GSH, along with a approximately 10-fold increase in the circulating ANP and BNP levels. Left ventricular BNP and ANP mRNAs were elevated by 2- and 3-fold, respectively, compared to GSH. rbGH reduced both ANP mRNA and ANP circulating levels by 34% (p<0.01) but did not significantly modulate BNP levels. This effect was associated with a preserved systolic function and reverse remodeling as assessed by a leftward shift of the passive diastolic pressure-volume relationship indicating reduced ventricular dilatation.

CONCLUSIONS

The data show that a short-term administration of GH in the terminal phase of the disease confers cardioprotection by attenuating systolic dysfunction and by inducing beneficial reverse remodeling.

Cardiovascular risk in patients with growth hormone deficiency: effects of growth hormone substitution

OBJECTIVE

To review the literature on the increased cardiovascular risk in patients with growth hormone (GH) deficiency and the positive effects of GH replacement.

METHODS

We analyze the factors that contribute to cardiovascular risk in GH deficiency, including body composition and lipid profile, and summarize GH treatment strategies and results described in the literature.

RESULTS

The prominent clinical finding in patients with GH deficiency is the increased abdominal fat, even in patients with normal weight. Cardiac ejection volume tends to be decreased, and arterial distensibility is diminished. The lipid status is also worsened, accompanied by increased inflammatory markers, such as highly sensitive C-reactive protein. Typically, GH treatment reduces visceral fat and increases muscle mass, changes that diminish cardiovascular risk. Because of direct effects as well as increased hemodynamic performance and increased blood volume, cardiac performance is improved. With GH therapy, total cholesterol and low-density lipoprotein levels decrease by 10% to 20%, and inflammatory markers such as C-reactive protein decline. Carbohydrate metabolism during moderate to long-term treatment is minimally affected, although obese patients with GH deficiency on rare occasion may have hyperglycemia or even diabetes.

CONCLUSION

The relevance of the beneficial effects of GH on the cardiovascular system is strongly suggested but not fully proved. The results in a large cohort of GH-treated patients (the KIMS or Pharmacia and Upjohn International Metabolic Surveillance database) demonstrated no difference in cardiovascular risk in comparison with that in a control population after a mean of 3 years of treatment.

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.

Influence of growth hormone on cardiovascular health and disease

Experimental and clinical studies indicate that growth hormone (GH) and insulin-like growth factor-1 (IGF-1) are involved in heart development. Impaired cardiovascular function, as recently demonstrated, could potentially reduce life expectancy both in GH deficiency (GHD) and excess. Patients with childhood- or adult-onset GHD may have both cardiac structural and functional abnormalities, i.e. reduced cardiac mass, reduced diastolic filling, and impaired left ventricular response to peak exercise. In addition, GHD patients may present with an increase in vascular intima-media thickness and a higher occurrence of atheromatous plaques that can further aggravate the hemodynamic conditions and contribute to the increased cardiovascular and cerebrovascular risk. However, some evidence has been provided to show that cardiovascular abnormalities can be partially reversed after somatropin (recombinant GH) therapy in patients with GHD. Recently, somatropin administration was shown to induce improvement in hemodynamics and clinical status in some patients with heart failure. Although these data need to be confirmed in more extensive studies, such promising results open new perspectives for somatropin therapy. The role of GH secretagogues in heart failure is still unknown.

Cardiovascular disease and risk factors: the role of growth hormone

Clinical studies in patients with acromegaly have shown that growth hormone (GH) exerts both short- and long-term effects on the structure and function of the heart. Moreover, chronic growth hormone deficiency (GHD) has been associated with impaired cardiac performance, low heart rate and impaired left ventricular systolic function. Exercise capacity in patients with GHD is significantly reduced and in some severely affected individuals, dilated cardiomyopathy and heart failure has been reported. GHD has also been associated with a number of risk factors for cardiovascular disease. Altered lipoprotein metabolism and elevated fibrinogen and plasminogen activator inhibitor-1 activity are associated with GHD, and the risk of hypertension is increased in GH-deficient men. Subcutaneous and intra-abdominal fat mass have also been found to be abnormally high in these patients. These effects may contribute to an increased risk of death from cardiovascular disease. GH is therefore an important factor in the development and function of the cardiovascular system. In this paper, the effects of GH on the physiological mechanisms of the cardiovascular system are discussed, including the effect of GHD on cardiovascular disease risk. We will also discuss the effects of long-term GH replacement therapy in this patient population.

The severity of growth hormone deficiency correlates with the severity of cardiac impairment in 100 adult patients with hypopituitarism: an observational, case-control study

In 100 patients with hypopituitarism and 80 sex- and age-matched healthy subjects, we correlated the severity of cardiac impairment to the severity of GH deficiency (GHD). By the GH peak after arginine plus GHRH test (normal > 16.5 microg/liter), the patients were classified as severe GHD (n = 56), partial GHD (n = 27), and non-GHD (n = 17). Compared with controls, decreased left ventricular ejection fraction at rest was found only in severe GHD patients (55.0 +/- 8.8 vs. 63.4 +/- 4.5%, P < 0.001); decreased left ventricular ejection fraction response on effort in severe (-4.6 +/- 17.4 vs. 15.2 +/- 9.1%, P < 0.001) and partial GHD patients (3.6 +/- 6.6 vs. 14.6 +/- 8.3%, P < 0.001); decreased diastolic filling at rest in severe (2.53 +/- 0.68 vs. 3.01 +/- 0.48 end-diastolic volume per second, P < 0.001) and partial GHD (2.61 +/- 0.45 vs. 2.89 +/- 0.54 end-diastolic volume per second, P = 0.004) patients; and decreased exercise duration and capacity in all the patient groups. A normal systolic performance on effort was found in 21.4% of severe GHD, 55.6% of partial GHD, all non-GHD, and 93.7% of controls. A normal diastolic filling at rest was found in 57.1% of severe GHD, 74.1% of partial GHD, 76.5% of non-GHD, and 90% of controls. In conclusion, cardiac performance is correlated with the GH status because significant impairment was found in patients with severe and partial GHD but not in non-GHD hypopituitary patients.

Cardiovascular Effects of Growth Hormone Treatment: Potential Risks and Benefits

Growth hormone (GH) and insulin-like growth factor-I are involved in heart development and in maintaining cardiac structure and performance. Cardiovascular disease has been reported to reduce life expectancy both in GH deficiency (GHD) and in GH excess. Patients with GHD suffer from abnormalities of left ventricular performance, i.e. reduced diastolic filling and impaired response to peak exercise. Patients with GHD also have increased intima-media thickness at the common carotid arteries, associated with a higher occurrence of atherosclerotic plaques, which may further aggravate the haemodynamic conditions. This may contribute to increased cardiovascular and cerebrovascular risk. These cardiovascular abnormalities can be reversed, at least partially, with GH replacement therapy. In recent years, GH therapy has been used to increase cardiac mass in ischaemic or dilated cardiomyopathy, but the results have produced contradictory data.

The effects of GH replacement therapy on cardiac morphology and function, exercise capacity and serum lipids in elderly patients with GH deficiency

OBJECTIVES

To assess effects of GH replacement therapy on cardiac structure and function, exercise capacity as well as serum lipids in elderly patients with GH deficiency (GHD).

PATIENTS AND METHODS

Thirty-one patients (six females, 25 males), aged 60-79 years (mean 68 years) with GHD on stable cortisone and thyroxine substitution were studied. All men with gonadotropin deficiency had testosterone and one woman had oestrogen replacement. They were randomized in a double-blind manner to GH or placebo treatment for 6 months, followed by another 12 months GH (Humatrope, Eli Lilly & Co, Uppsala, Sweden). GH dose was 0.017 mg/kg/week for 1 month and then 0.033 mg/kg/week divided into daily subcutaneous injections at bedtime. Echocardiography, exercise capacity tests and serum lipid measurements were performed at 0, 6, 12 and 18 months.

RESULTS

During the 6-month placebo-controlled period there were no significant changes in the placebo group, but in the GH-treated group there was a significant increase in IGF-I to normal levels for age, with median IGF-I from 6.9 to 18.5 nmol/l, increase in resting heart rate and maximal working capacity. During the open GH study, IGF-I increased from 8.7 to 19.2 nmol/l at 6 months and 18.8 nmol/l at 12 months (P </= 0.001). At 6 months, in the open GH study group, a minor decrease in aortic outflow tract integral (VTI) from 21.8 to 20.7 cm (P = 0.031) and an increase in heart rate at rest from 63 to 67 bpm (P = 0.017), heart rate at maximum exercise from 138 to 144 bpm (P = 0.005) and maximum load at exercise from 142 to 151 Watts (P = 0.014) were seen. These changes were temporary and returned at 12 months with no significant difference from baseline values. Left ventricular dimensions and blood pressure showed no significant changes. At 6 months, in the open GH study group, there was a significant decrease in serum low-density lipoprotein (LDL) cholesterol from 3.7 to 3.4 mmol/l (P = 0.006), a decrease in LDL/HDL ratio from 3.4 to 3.1 (P = 0.036) and a decrease in serum total cholesterol from 5.6 to 5.3 mmol/l (P = 0.036). At 12 months, serum lipids showed same changes with a significant decrease in serum LDL cholesterol (P = 0.0008), in LDL/HDL ratio (P = 0.0005) and in serum total cholesterol (P = 0.049). Serum HDL cholesterol showed no significant change at 6 months, at 12 months a significant increase was seen from 1.2 to 1.4 mmol/l (P = 0.007). There were no significant changes in serum triglycerides.

CONCLUSIONS

GH substitution to elderly patients with GHD caused only a transient increase in heart rate. At the end of the 12 months there were no significant changes on cardiac noninvasive structural and functional parameters. Maximal working capacity transiently improved. Thus, the therapy was safe without negative effects on cardiac structural and functional noninvasive parameters. Lipid profiles improved with reduction of serum LDL cholesterol accompanied by significant improvement of LDL/HDL ratio and serum HDL cholesterol after 12 months treatment.

Structural, functional and autonomic changes in the cardiovascular system in growth hormone deficient patients

BACKGROUND

Growth hormone deficiency (GHD) is known to cause higher rates of cardiovascular mortality. The purpose of the study was to analyze the structural and functional changes in the heart and investigate their relation to autonomic function as assessed with heart rate variability (HRV).

METHODS

Eleven untreated GHD patients (mean age 50.4 +/- 10.7 years, M/F: 3/8) and 15 age- and sex-matched healthy persons (mean age 45.3 +/- 10.4 years, M/F: 5/10) were compared. Both groups were examined with echocardiography, HRV, and exercise testing and findings were analyzed.

RESULTS

The groups were similar in height, weight, body mass index, body surface area, systolic and diastolic blood pressure, heart rate. The GHD patients had lower exercise duration and metabolic equivalent (MET) compared to controls (7.94 +/- 1.26 vs. 9.8 +/- 1.9 min, P < 0.001, for MET 8.85 +/- 0.86 vs. 10.7 +/- 2.23, P = 0.03). On echocardiography, GHD patients had lower interventricular septum diastolic diameter (9 +/- 0.89 vs. 10.7 +/- 0.88 mm, P < 0.001) and posterior wall thickness (8.4 +/- 0.93 vs. 9.8 +/- 0.91 mm, P = 0.002), and lower left ventricle mass index (90.9 +/- 20 vs. 112 +/- 8 g/m2, P = 0.01). Left ventricular ejection fraction was lower in the GHD patients (57.4 +/- 5.12% vs. 65.5 +/- 4.1%, P < 0.001). Time and frequency domain heart rate variability parameters, SDNN, SDANN, VLF, LF ve LF/HF were lower in GHD patients compared to controls. There was a significant correlation between left ventricle diastolic diameter and LF (r = 0.62, P = 0.02).

CONCLUSION

GHD seemed to cause decreased left ventricle mass and decreases in the sympathetic components of HRV that may have a bearing on the increased cardiovascular risk seen in these patients.

Evidence of early impairments in both right and left ventricular inotropic reserves in children with Duchenne's muscular dystrophy

In Duchenne's muscular dystrophy (DMD), cardiac function deteriorates with time and heart failure is one of the major causes of death. The aim of the study was to determine if a decrease in the ventricular inotropic reserves could be an early sign of cardiac dysfunction in these children. Nineteen children with DMD (aged 9 to 18 years, mean age 13.6 +/- 2.4) underwent equilibrium radionuclide angiography at rest and during an inotropic stimulation with low-dose dobutamine perfusion (7.5 to 15 microg. kg(-1). min(-1)). In all patients, this investigation was short (<30 minutes), successful, and uncomplicated. At rest, left ventricular (LV) ejection fraction (EF) was normal (>0.50) in 79% of patients, and right ventricular (RV) EF was normal (>0.45) in 95%. There was a trend toward a decrease with age for rest LVEF (p = 0.051) but not for rest RVEF (p = 0.8). By contrast, marked declines with age could be documented for the increases (Delta) in LVEF and RVEF during dobutamine perfusion (p = 0.002 for DeltaLVEF and p = 0.015 for DeltaRVEF). Thus, by multivariate analysis, the sole best indicator of decline in cardiac function with age was LVEF determined with dobutamine. In children with DMD, low-dose dobutamine radionuclide angiography gives evidence of an early decline with age of the inotropic reserves of both ventricles.

Cardiac Abnormalities in Acromegaly

Cardiovascular disease is claimed to be one of the most severe complications of acromegaly, contributing significantly to mortality in this disease. In fact, an excess of growth hormone (GH) and insulin-like growth factor 1 (IGF-I) causes a specific derangement of cardiomyocytes, leading to abnormalities in cardiac muscle structure and function, inducing a specific cardiomyopathy. In the early phase of acromegaly the excess of GH and IGF-I induces a hyperkinetic syndrome, characterized by increased heart rate and increased systolic output. Concentric hypertrophy is the most common feature of cardiac involvement in acromegaly, found in more than two thirds of patients at diagnosis. This abnormality is commonly associated with diastolic dysfunction and eventually with impaired systolic function ending in heart failure, if the GH/IGF-I excess is left untreated. In addition, abnormalities of cardiac rhythm and of heart valves have also been described in acromegaly. The coexistence of other complications, such as arterial hypertension and diabetes mellitus, aggravates acromegalic cardiomyopathy. Successful control of acromegaly induces a decrease in left ventricular mass and an improvement in diastolic function, while the effects of GH/IGF-I suppression on systolic function are more variable. However, since cardiovascular alterations in young patients with short disease duration are milder than in those with longer disease duration, it is likely to be easier to reverse and/or arrest acromegalic cardiomyopathy in young patients with early-onset disease. In conclusion, careful assessments of cardiac function, morphology, and activity are required in patients with acromegaly. An early diagnosis and prompt effective treatment are important in order to reverse acromegalic cardiomyopathy.

Long-Term Challenges in Growth Hormone Treatment

Growth hormone deficiency (GHD) is defined biochemically as a response to hypoglycaemia with a peak GH concentration of less than 5 microg/l. The 'GHD syndrome' is a range of psychological and physical symptoms that are associated with GHD, which include increased central adiposity, decreased bone mineral density, abnormal lipid profiles, decreased cardiovascular performance, reduced lean body mass (LBM), social isolation, depressed mood and increased anxiety. Importantly, the combination of physical and psychological problems can often result in a reduced quality of life. A number of trials have shown that GH replacement therapy can lead to a substantial improvement in GHD associated symptoms. Following up to 12 months of treatment with GH, LBM increased, left ventricular systolic function improved and the mean volume of adipose tissue fell. After only 4 months of treatment, a rise in exercise capacity was recorded, and after 2 years' treatment, isokinetic and isometric muscle strength had normalized in proximal muscle groups. Feelings of well-being and vitality also improved significantly. However, studies on the effects of treatment on insulin sensitivity in GH-deficient patients have had conflicting results. In this paper, we will discuss the long-term consequences of GHD and the effects of GH replacement therapy.

Cardiac effects of growth hormone in adults with growth hormone deficiency: a meta-analysis

BACKGROUND

Growth hormone (GH) treatment may improve morphological and functional cardiac parameters in adults with GH deficiency (GHD). However, clinical trials reported to date involved few patients and yielded variable effects.

METHODS AND RESULTS

We systematically reviewed blinded, placebo-controlled, randomized clinical trials of GH treatment in adults with GHD and open studies in patients with GHD before and after GH treatment, evaluating the effects of GH on cardiac parameters assessed by echocardiography. Sixteen trials (9 blinded and 7 open), involving a total of 468 patients, were identified in 3 bibliographic databases. GH dosage, duration of treatment, and study populations varied among the studies. We conducted a combined analysis of effects on left ventricular mass (LVM), interventricular septum thickness (IVS), left ventricular posterior wall (LVPW), left ventricular end-systolic (LVESD) and diastolic (LVEDD) diameters, stroke volume, E/A ratio, isovolumic relaxation time (IRT), and fractional shortening. Overall effect size was used to evaluate significance, and weighted mean difference between GH and control was given to appreciate size of the effect. GH treatment was associated with a significant increase in LVM: +10.8 (SD: 9.3) g (P=0.02); IVS: +0.28 (0.38) mm (P<0.001), LVPW: 0.98 (0.22) mm (P=0.05), LVEDD: +1.34 (1.13) mm (P<0.001), and stroke volume: +10.3 (8.7) mL (P<0.001). A trend toward a difference in fractional shortening was observed: +1.1 (1.1)% (P=0.06). Overall effect sizes were not significant for LVESD, E/A, and IRT.

CONCLUSIONS

GH treatment is associated with a significant positive effect on LVM, IVS, LVPW, LVEDD, and stroke volume, as assessed by echocardiography, in adults with GHD.

The cardiovascular risk of adult GH deficiency (GHD) improved after GH replacement and worsened in untreated GHD: a 12-month prospective study

Increased cardiovascular morbidity and mortality were reported in GH deficiency (GHD), and GH replacement can ameliorate cardiac abnormalities of adult GHD patients. To test the potential progression of untreated GHD on the cardiovascular risk and cardiac function, cardiovascular risk factors, cardiac size, and performance were prospectively evaluated in 15 GHD patients (age, 18-56 yr) who were treated with recombinant GH at the dose of 0.15-1.0 mg/d, 15 GHD patients (age, 18-56 yr) who refused GH replacement, and 30 healthy subjects (age, 18-53 yr). Electrocardiogram, systolic and diastolic blood pressure, and heart rate measurement, serum IGF-I, total cholesterol, low- and high-density lipoprotein (LDL, HDL) cholesterol, triglycerides, and fibrinogen level assay, echocardiography, and equilibrium radionuclide angiography were performed basally and after 12 months. At study entry, low IGF-I levels, unfavorable lipid profile, and inadequate cardiac and physical performance were found in GHD patients compared with controls. After 12 months of GH treatment, IGF-I levels normalized; HDL-cholesterol levels, left ventricular (LV) mass index (LVMi), left ventricular ejection fraction (LVEF) at peak exercise, peak filling rate, exercise duration and capacity significantly increased; total- and LDL-cholesterol levels significantly decreased. After 12 months in GH-untreated GHD patients, IGF-I levels remained stable, and HDL-cholesterol levels, LVEF both at rest and at peak exercise, and exercise capacity were further reduced; total- and LDL-cholesterol levels increased slightly. LVEF at rest and its response at peak exercise normalized in 60 and 53.3%, respectively, of GH-treated patients and in none of the GH-untreated patients. In conclusion, 12 months of GH replacement normalized IGF-I and improved lipid profile and cardiac performance in adult GHD patients. A similar period of GH deprivation induced a further impairment of lipid profile and cardiac performance. This finding strongly supports the need of GH replacement in adult GHD patients.

Low individualized growth hormone (GH) dose increased renal and cardiac growth in young adults with childhood onset GH deficiency

OBJECTIVE

In childhood onset GH deficiency (GHD) a reduction in left ventricular mass (LV-mass) and impairment of systolic function as well an impairment in glomerular filtration rate (GFR) has been shown. The aim of the present study was to assess if a low GH dose resulted in an improvement in morphological and functional parameters of these organs.

DESIGN AND PATIENTS

Eleven patients with childhood onset GHD were investigated before and after 10 months of GH treatment at a dose of 1.5 IU/day (range 1-2), corresponding to 0.02 IU/kg/day or 7 microg/ kg/day. The GH dose resulted in a serum IGF-I level in the normal range in all but one patient.

MEASUREMENTS

Doppler echocardiography of the heart and ultrasound examination of the kidneys was performed. Glomerular filtration rate (GFR) was estimated with iohexol clearance and urinary proteinuria was measured with 24-h urinary samples collected for analyses of albumin, alpha-1-microglobulin, IgG and albumin/creatinine clearance ratio. Body composition was measured by bioelectric impedance analysis.

RESULTS

L V-mass index increased significantly after GH treatment (P = 0.04), and there was a clear trend for a positive correlation between the increase in serum IGF-I and the increase in LV-mass index, although it did not reach significance (r= 0.57, P = 0.07). GH treatment did not increase cardiac fractional shortening. Kidney length increased significantly (P = 0.02) with an average increase of 1 cm (range - 0.5-1.5 cm). No significant changes in median GFR or serum creatinine were recorded. Three patients with subnormal GFR before GH treatment normalized after 10 months of treatment. Urine analysis showed no abnormalities before or after GH treatment. A significant decrease in percentage fat mass was recorded (P = 0.03).

CONCLUSION

A low individualized GH dose to adults with childhood onset GHD resulted in an increase in LV-mass index and kidney length. Re-establishing GH treatment with a low dose in this patient group can lead to a further somatic maturation of these organs, probably not accomplished previously.

Commencing growth hormone replacement in adults with a fixed low dose. Effects on serum lipoproteins, glucose metabolism, body composition, and cardiovascular function

The safety and effects of a fixed low dose of growth hormone (GH), 0.17 mg/day was evaluated for 3 months, on glucose metabolism, serum lipids, body composition and cardiac function in 53 GH deficient adults aged 18-78 years. Body composition was determined by dual energy X-ray absorptiometry and total body water was determined by bioelectrical impedance. Echocardiography was used to assess cardiac function and bicycle ergonometry was used to determine exercise capacity. All investigations were performed at baseline and after 3 months. At 3 months, serum levels of insulin-like growth factor (IGF)-I, IGF binding protein (IGFBP)-3 and lipoprotein (a) and lean body mass were increased (P<0.05). Total and low density lipoprotein cholesterol levels and fat mass were reduced (P<0.05). There was an increase in the serum glucose value at 120 min after an oral glucose tolerance test performed at 3 months (P<0.05), no other changes in glucose metabolism or in cardiac function were noted. Side-effects were few and mild. This fixed low-dose regime resulted in improvements in body composition and lipid profile, without causing serious side effects. This is therefore a valid method to institute GH replacement in adults.

Growth hormone and the heart

Impaired cardiovascular function has recently been demonstrated to potentially reduce life expectancy both in GH deficiency and excess. Experimental and clinical studies have supported the evidence that GH and IGF-I are implicated in cardiac development. In most patients with acromegaly a specific cardiomyopathy, characterized by myocardial hypertrophy with interstitial fibrosis, lympho-mononuclear infiltration and areas of monocyte necrosis, results in biventricular concentric hypertrophy. In contrast, patients with childhood or adulthood-onset GH deficiency (GHD) may suffer both from structural cardiac abnormalities, such as narrowing of cardiac walls, and functional impairment, that combine to reduce diastolic filling and impair left ventricular response to peak exercise. In addition, GHD patients may have an increase in vascular intima-media thickness and a higher occurrence of atheromatous plaques, that can further aggravate the haemodynamic conditions and contribute to increased cardiovascular and cerebrovascular risk. However, several lines of evidence have suggested that the cardiovascular abnormalities can be partially reversed by suppressing GH and IGF-I levels in acromegaly or after GH replacement therapy in GHD patients. Recently, much attention has been focussed on the ability of GH to increase cardiac mass suggesting its possible use in the treatment of chronic nonendocrine heart failure. In fact, GH administration can induce an improvement in haemodynamic and clinical status in some patients. Although these data need to be confirmed in more extensive studies, such promising results seem to open new perspectives for GH treatment in humans.

Growth hormone replacement in adults with growth hormone deficiency: assessment of current knowledge

The recent availability of recombinant human growth hormone (GH) has led to intense investigation of the consequences of adult GH deficiency (GHD) and the effects of GH replacement. These studies have led to the identification of a characteristic syndrome of GHD consisting of decreased mood and well-being, with alterations in body composition and substrate metabolism. In both placebo-controlled and open studies, GH replacement therapy has consistently been shown to reverse or correct these features. Whether long-term GH replacement will result in a reduction of osteoporotic fractures, cardiovascular morbidity and mortality is not yet known. To date, no permanent serious adverse effects have been associated with GH replacement in GHD, and although currently expensive, it is anticipated that GH replacement will become routine in the treatment of the severely hypopituitary adult.

Does the age of onset of growth hormone deficiency affect cardiac performance? A radionuclide angiography study

BACKGROUND

GH and IGF-I seem to play a relevant role in cardiac development and performance. Long-standing GH deficiency (GHD) causes several abnormalities in cardiac structure and performance which ultimately determine an increased cardiovascular morbidity and mortality.

OBJECTIVE

To investigate whether the age of onset of GHD plays a role in determining the negative effects on the heart.

DESIGN

Open cross-sectional

PATIENTS

55 patients with adulthood-onset GHD and 36 healthy sex- and age-matched controls. Patients and controls were divided into 2 groups in line with age: 32 patients and 16 controls, were aged </= 35 years (young); while 23 patients and 20 controls were aged between 36 and 60 years (middle-aged). The estimated disease duration was similar in young (6.7 +/- 0.5 years) and middle-aged patients (8.1 +/- 1.2 years, P = 0.2).

STUDY PROTOCOL

All subjects underwent ECG, blood pressure and heart rate measurement, plasma IGF-I level assay, and equilibrium radionuclide angiography.

RESULTS

Plasma IGF-I levels were significantly lower in patients than in controls (P < 0.0001). When considered as a whole, no difference in systolic (SBP) and diastolic blood pressure (DBP) at peak exercise was found between patients and controls. However, a significant decrease of SBP at rest was found in young patients as compared to age-matched controls (P = 0.009), while a significant increase of DBP at rest was found in middle-aged patients as compared to age-matched controls (P = 0.03). In addition, in young patients, both resting (P = 0.02) and exercise heart rate (P = 0.01) were significantly lower than in controls. Diastolic filling when measured as end-diastolic volume (EVD/sec), was significantly reduced in middle-aged patients (P = 0.04). An impaired peak filling rate (PFR) (< 2.5 EDV/sec) was found in 30 patients (54.5%) and 10 controls (27.7%, chi2 = 5.3, P = 0.02): 17 young (53.1%) and 13 middle-aged patients (56.5%). A significant decrease of left ventricular (LV) ejection fraction (EF) at peak exercise was found in both patients groups (P < 0.0001) while LVEF at rest was lower only in middle-aged patients (P = 0.004). An impaired LVEF at rest (< 50%) was found in 13 patients (23.6%) and in none of controls (chi2 = 8.1, P = 0.004). The exercise induced changes in LVEF (DeltaEF) were significantly lower in both patients groups than in age-matched controls (P < 0.0001). Impaired LVEF response to exercise (< 5% increase vs. basal value) was found in 36 patients (65.4%) and in 5 controls (13.8%, chi2 = 21.3, P < 0.000): 21 young (65.6%) and 15 middle-aged patients (65.2%). The peak ejection rate (PER) was also significantly lower in young GHD patients than in controls (P < 0.001). Exercise duration and capacity were significantly reduced in both groups of GHD patients. In the patient group, age was significantly correlated with SBP and DBP levels both at rest (r = 0.612, and r = 0.516, respectively, P < 0.001) and at peak exercise (r = 0.4, P < 0.005 and r = 0.34, P < 0. 01, respectively), with exercise duration (r = - 0.383, P < 0.005) and capacity (r = - 0.355, P = 0.005). Disease duration was also correlated with IGF-I levels (r = - 0.319, P < 0.01), SBP levels at peak exercise (r = 0.352, P = 0.005), and LVEF at rest (r = - 0.254, P < 0.05). Finally, a significant correlation was found between IGF-I levels and DBP at peak exercise (r = 0.3, P < 0.05) and between GH peak at ARG + GHRH test and LVEF at rest (r = 0.232, P < 0.05). Exercise-induced changes in LVEF were significantly correlated with SBP levels at peak exercise (r = - 0.401, P < 0.005), PFR expressed as EDV/sec (r = - 0.306, P < 0.05) and SV/sec (r = - 0.292, P < 0.05). At multiple regression analysis in the patient group, age was the strongest predictor of SBP both at rest (t = 4.17, P < 0.0001) and at peak exercise (t = 2.32, P = 0.025), and capacity (t = - 2.84, P = 0.007). IGF-I levels were the strongest predictor of DBP at peak exercise (t = 2.2, P = 0.

Impaired cardiac performance in elderly patients with growth hormone deficiency

Several evidences indicate that GH and/or insulin-like growth factor I (IGF-I) are involved in the regulation of cardiovascular function. In patients with childhood and adulthood-onset GH deficiency (GHD), the impairment of cardiac performance is manifest primarily as a reduction in the left ventricular (LV) mass (LVM), inadequacy of LV ejection fraction both at rest and at peak exercise, and abnormalities of LV diastolic filling. No study has been reported to date in elderly GHD patients that investigated cardiac function. In particular, it is unknown whether cardiac function is modified in accordance with patients' age as a physiological response to aging, as in normal subjects the rate and extent of LV filling are reduced with age. This study was designed to evaluate heart morphology and function, by echocardiography and equilibrium radionuclide angiography, respectively, in rigorously selected elderly patients with GHD but without evidence of other complications able to affect cardiac performance. Eleven patients with hypopituitarism (6 men and 5 women, aged 60-72 yr) and 11 sex- age- and body mass index-matched healthy subjects entered this study. None of the patients and controls presented with or had previously suffered from other concomitant diseases, such as diabetes mellitus, coronary artery diseases, long-standing hypertension, and hyperthyroidism, which could affect cardiac function. All patients had been previously operated on via the transsphenoidal and/or transcranic route for nonfunctioning pituitary adenoma, meningioma, or craniopharyngioma, and 6 of them had been irradiated. Eight patients had FSH/LH insufficiency, 5 had TSH insufficiency, and 6 had ACTH insufficiency, appropriately replaced. All subjects were tested with the combined arginine plus GHRH test showing a GH response below 9 microg/L. No significant difference was found in plasma IGF-I levels (49.2 +/- 8.5 vs. 71.8 +/- 7.5 microg/L) between patients and controls. However, IGF-I levels were lower than the normal range in 8 patients and 3 controls. Interventricular septum thickness (9.1 +/- 0.2 vs. 9.1 +/- 0.2 mm), LV posterior wall thickness (9.1 +/- 0.2 vs. 9.0 +/- 0.2 mm), and LVM after correction for body surface area (97.6 +/- 1.8 vs. 99.9 +/- 1.5 g/m2) were similar in patients and controls. Similarly, the LV ejection fraction at rest was similar in patients and controls (57.1 +/- 2% vs. 63.2 +/- 2.5%; P = NS), and it was normal (> or = 50%) in all controls and in 10 of 11 patients. By contrast, the LV ejection fraction at peak exercise was markedly depressed in elderly GHD patients compared to age-matched controls (51 +/- 2.5% vs. 73.3 +/- 3%; P < 0.001). A normal response (> or = 5% increase compared to basal value) of LV ejection fraction at peak exercise was found in 8 controls (72.7%) and in 2 of 11 patients (18.2%). No difference was found in the peak rate of LV filling, whether peak filling rate was normalized to end-diastolic volume (2.5 +/- 0.2 vs. 2.6 +/- 0.2 end-diastolic volume/s) or stroke volume (4.3 +/- 0.3 vs. 4.0 +/- 0.3 stroke volume/s), between patients and controls. Finally, exercise duration was significantly shorter in elderly GHD patients than in age-matched controls (7.2 +/- 2.1 vs. 9.1 +/- 0.2 min; P < 0.01). In the patient group, the GH peak after arginine plus GHRH test was significantly correlated with the LV ejection fraction at rest (r = 0.822; P < 0.01), whereas IGF-I was significantly correlated with the peak rate of LV filling whether the peak filling rate was normalized to end-diastolic volume (r = -0.863; P < 0.001) or stroke volume (r = -0.616; P < 0.05) or expressed as the ratio of peak filling rate to peak ejection fraction rate (r = -0.736; P < 0.01). Disease duration was significantly correlated with heart rate at peak exercise (r = 0.614; P < 0.05) and with systolic and diastolic blood pressures both at rest (r = 0.745; P < 0.01 and r = 0.650; P < 0.05) and at peak exercise (r = 0.684; P < 0.05 and r =

Clinical applications of recombinant human growth hormone in adults

The main function of growth hormone (GH) is to promote linear growth during childhood; however, GH secretion persists throughout life after cessation of skeletal growth. This hormone has important physiological functions apart from growth stimulation. Many aspects of the physiological and pharmacological actions of GH have been recently clarified. Accordingly, in the last years, especially since the introduction of recombinant human GH (rhGH), GH therapeutical applications have increased. In the last years, the main clinical application of rhGH has been to stimulate growth of growth-retarded GH deficient (GHD) children. More recently, rhGH therapy has been approved for other conditions associated with short stature, including Turner syndrome and end stage renal disease. In adults, the only therapeutic indications approved are the adult GHD syndrome and the AIDS-associated wasting. This review outlines the present knowledge of the physiological effects, clinical applications, therapeutic perspectives, side effects, precautions and contraindications of rhGH therapy in adults.

Cardiac effects of hexarelin in hypopituitary adults

Growth hormone (GH)-releasing peptides possess specific pituitary, hypothalamic, and myocardial receptors. Seven adult male patients with GH deficiency (GHD) (age, mean+/-S.E.M.: 42.0+/-4.0 year) were studied by equilibrium radionuclide angiocardiography after i.v. administration of hexarelin, a peptide GH secretagogue. Data for these patients were compared with those for nine adult male controls (37.0+/-2.7 year). The GH response to hexarelin was negligible in patients with GHD compared to control subjects (CS) (peak: 1.9+/-0.9 vs. 45.7+/-3.6 microg/l, P<0.001). Basal left ventricular ejection fraction (LVEF) in patients with GHD was lower than that in CS (50+/-1% vs. 63+/-2%, P<0.001). Hexarelin administration increased LVEF both in patients with GHD and in CS (peak: 57+/-2 vs. 70+/-2, respectively, P<0.05 vs. baseline) without changing catecholamine levels, mean blood pressure (MBP), or cardiac output in either group. In conclusion, the acute administration of hexarelin exerts a short-lasting positive inotropic effect in humans, probably GH-independent and mediated by specific myocardial receptors for GH secretagogues.

Recombinant growth hormone therapy in patients with ischemic cardiomyopathy : effects on hemodynamics, left ventricular function, and cardiopulmonary exercise capacity

BACKGROUND

We studied the effects of recombinant growth hormone (rhGH) on exercise capacity and cardiac function in patients with ischemic cardiomyopathy.

METHODS AND RESULTS

Seven patients (aged 55+/-9 years) with mild to moderate congestive heart failure (ejection fraction 31+/-4%) who were on standard therapy were included. The patients were studied at baseline, after 3 months of rhGH treatment, and 3 months after rhGH discontinuation. Cardiac function was assessed by exercise capacity, right heart catheterization at rest and after submaximal exercise, MRI, echocardiography, and Holter monitoring. When administered at a dose of 2 IU/d, rhGH doubled the serum concentration of insulin-like growth factor-I. rhGH improved clinical symptoms and exercise capacity significantly (New York Heart Association class 2.4+/-0.5 initially versus 1.4+/-0.5 at 3 months [mean+/-SD], P<0.05; VO2max 13.6+/-3.8 versus 17.4+/-5.4 mL. kg-1. min-1, P<0.05). Additionally, pulmonary capillary wedge pressures at rest and after submaximal exercise were reduced significantly. Cardiac output increased, particularly at rest (5.0+/-1.1 versus 5.8+/-1.3 L/min; P<0.05). Posterior wall thickness was increased (1.08+/-0.1 versus 1. 24+/-0.3 cm; P<0.05), and the end-diastolic and end-systolic volume indexes decreased significantly after rhGH treatment. There was no significant increase in left ventricular ejection fraction. The improvements were partially reversed 3 months after rhGH discontinuation.

CONCLUSIONS

The administration of rhGH for 3 months in patients with ischemic cardiomyopathy results in significant improvement in hemodynamics and clinical function. The attenuation of left ventricular remodeling persisted 3 months after discontinuation of treatment.

Growth hormone: a new therapy for heart failure?

There is now little doubt that growth hormone (GH) and insulin-like growth factor-1 (IGF-1) play a role in cardiac development and in cardiovascular physiology in adult life. Congenital lack of GH is associated with defective cardiac growth, ventricular wall thinning, and impaired systolic function. These abnormalities limit exercise capacity and contribute to the poor quality of life in patients with GH deficiency. In addition, studies with in vitro muscle preparations have shown that IGF-1 affects myocardial contractility by a direct mechanism. These findings suggested that GH would benefit patients affected by heart failure. Indeed, GH and/or IGF-1 have proven beneficial in various models of experimental heart failure. Tested in patients with classes II-IV heart failure, they improved cardiac performance and clinical status. These effects were associated with improved myocardial energetics and de-activation of the neurohormonal system. Because of the uncontrolled nature of the studies and the small number of cases examined, conclusions as to the effectiveness of GH and IGF-1 must await the results from larger trials.

Recombinant growth hormone: a new cardiovascular drug therapy

GH has an important role in normal cardiovascular physiologic functioning, working indirectly through effects on IGF-1. An excess or deficiency of GH causes an increased rate of cardiovascular disease, including cardiomyopathy. A relative GH deficiency in older subjects may also increase cardiovascular morbidity and mortality risk. In replacement doses, GH can enhance myocardial contractility; can decrease peripheral vascular resistance; and can reduce total cholesterol and LDL-cholesterol values and fibrinogen and PAI levels. These effects of GH, coupled with the ability to improve skeletal muscle function and reduce adiposity, make it an attractive treatment for patients with CHF and a potential maintenance drug for elderly people. Clinical trials, including studies with GHRH that may reduce the adverse effects of GH therapy, such as hyperglycemia and hypertension, are now in progress.