Growth hormone deficiency and vascular risk

Old woman with Sheehan's syndrome suffered severe hyponatremia following percutaneous coronary intervention: a case report and review of literature

Glucocorticoid deficiency can lead to hypoglycemia, hypotension, and electrolyte disorders. Acute glucocorticoid deficiency under stress is very dangerous. Here, we present a case study of an elderly patient diagnosed with Sheehan's syndrome, manifesting secondary adrenal insufficiency and secondary hypothyroidism, managed with daily prednisone and levothyroxine therapy. She was admitted to our hospital due to acute non-ST segment elevation myocardial infarction. The patient developed nausea and limb twitching post-percutaneous coronary intervention, with subsequent diagnosis of hyponatremia. Despite initial intravenous sodium supplementation failed to rectify the condition, and consciousness disturbances ensued. However, administration of 50 mg hydrocortisone alongside 6.25 mg sodium chloride rapidly ameliorated symptoms and elevated blood sodium levels. Glucocorticoid deficiency emerged as the primary etiology of hyponatremia in this context, exacerbated by procedural stress during percutaneous coronary intervention. Contrast agent contributed to blood sodium dilution. Consequently, glucocorticoid supplementation emerges as imperative, emphasizing the necessity of stress-dose administration of glucocorticoid before the procedure. Consideration of shorter intervention durations and reduced contrast agent dosages may mitigate severe hyponatremia risks. Moreover, it is crucial for this patient to receive interdisciplinary endocrinologist management. In addition, Sheehan's syndrome may pose a risk for coronary atherosclerotic disease.

The modulation of platelet function by growth hormone in growth hormone deficient Hypopituitary patients

BACKGROUND

Growth hormone deficiency (GHD) has been implicated in increased cardiovascular and cerebrovascular disease risk seen in hypopituitarism, however the mechanism remains speculative. We hypothesise that platelet abnormalities may play a contributory role. Herein we examined platelet behaviour in GHD hypopituitary patients, pre- and post-growth hormone (GH) replacement.

METHODS

This study utilizes a physiological flow-based assay to quantify platelet function in whole blood from patient cohorts under arterial shear. Thirteen GH Naïve hypopituitary adults with GHD and thirteen healthy matched controls were studied. Patients were assessed before and after GH treatment. All other pituitary replacements were optimised before the study. In addition to a full endocrine profile, whole blood was labelled and perfused over immobilised von Willibrand factor (vWF). Seven parameters of dynamic platelet-vWF interactions were recorded using digital image microscopy and analysed by customised platelet tracking software.

RESULTS

We found a significantly altered profile of platelet-vWF interactions in GHD individuals compared to healthy controls. Specifically, we observed a marked increase in platelets shown to form associations such as tethering, rolling and adherence to immobilized vWF, which were reduced post GH treatment. Speed and distance platelets travelled across vWF was similar between controls and pre-therapy GHD patients, however, this was considerably increased post treatment. This may indicate reduced platelet signaling resulting in less stable adhesion of platelets post GH treatment.

CONCLUSIONS

Taken together observed differences in platelet behaviour may contribute to an increased risk of thrombosis in GHD which can in part be reversed by GH therapy.

Sheehan syndrome: Cardiovascular and metabolic comorbidities

Sheehan syndrome (SS) caused by postpartum hemorrhage leads to partial or complete pituitary hormone deficiency. In addition to lipid and glucose abnormalities, patients with SS have increased body fat, insulin resistance (IR), coagulation abnormalities, increased leptin concentration, low-grade inflammation, and endothelial dysfunction that predispose them to cardiovascular diseases. Untreated growth hormone (GH) deficiency, hypogonadism, and excess glucocorticoid use are considered risk factors for these abnormalities. Compared to other hypopituitary subjects, patients with SS are younger and have a longer duration of disease and severe GH deficiency. Replacement with GH in addition to standard hormone replacement improves their cardiometabolic profile.

Metabolic Profile and Echocardiographic Evaluation in Adults with Growth Hormone Deficiency

Adult growth hormone deficiency (AGHD) is associated with increased cardiovascular risks. The primary endpoint of this retrospective cohort study was to compare metabolic profile and echocardiographic parameters in childhood-onset (CO) and adulthood-onset (AO) AGHD patients. 26 patients with CO AGHD (19 males, 26.8±8.5 years) and 41 patients with AO AGHD (23 males, 35.1±6.8 years) were included. The standard deviation score of insulin-like growth factor-1 (IGF-1 SDS), metabolic profile, liver sonography and echocardiographic parameters were compared. The IGF-1 SDS were significantly lower in CO AGHD patients (p<0.05). AO AGHD patients showed much profound glycolipid aberrations, elevated C-reactive protein levels (p=0.012), and proportionally higher prevalence of non-alcoholic fatty liver disease (95.2% vs.8.3%, p<0.001). In all subjects, IGF-1 SDS was negatively related to low-density lipoprotein cholesterol, and positively related to total cholesterol and lipoprotein a (Lpa). There were significant differences between the two group with regard to the correlations between IGF-1 SDS and high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, LPa, uric acid and creatinine (all p for interaction<0.05). CO AGHD patients exhibited smaller heart, but similar ventricular ejection fraction compared to AO AGHD patients. AGHD may be a group of heterogenous entity based on the onset ages of disease. AO patients had prominent metabolic disorders, while CO patients had smaller heart but similar cardiac performance. Whether growth hormone replacement therapy will equally benefit both CO and AO AGHD patients needs further investigations.

Growth Hormone Secretory Capacity Is Associated with Cardiac Morphology and Function in Overweight and Obese Patients: A Controlled, Cross-Sectional Study

Obesity is associated with increased cardiovascular morbidity. Adult patients with growth hormone deficiency (GHD) show morpho-functional cardiological alterations. A total of 353 overweight/obese patients are enrolled in the period between 2009 and 2019 to assess the relationships between GH secretory capacity and the metabolic phenotype, cardiovascular risk factors, body composition and cardiac echocardiographic parameters. All patients underwent GHRH + arginine test to evaluate GH secretory capacity, DEXA for body composition assessment and transthoracic echocardiography. Blood samples are also collected for the evaluation of metabolic parameters. In total, 144 patients had GH deficiency and 209 patients had normal GH secretion. In comparing the two groups, we found significant differences in body fat distribution with predominantly visceral adipose tissue accumulation in GHD patients. Metabolic syndrome is more prevalent in the GHD group. In particular, fasting glycemia, triglycerides and systolic and diastolic blood pressure are found to be linearly correlated with GH secretory capacity. Epicardial fat thickness, E/A ratio and indexed ventricular mass are worse in the GHD group. In the population studied, metabolic phenotype, body composition, cardiovascular risk factors and cardiac morphology are found to be related to the GH secretory capacity. GH secretion in the obese patient seems to be an important determinant of metabolic health.

Standart diyet ile beslenen ratlarda aralıklı beslenmenin büyüme ve ghrelin hormonu üzerine etkisi

Aim: In this study, the effect of intermittent fasting on growth hormone (GH) and ghrelin was examined in rats that fed on a standard diet without any application that may cause the values to decrease or increase in order to see the net effect of intermittent fasting. Materials and Methods: 12 Wistar albino male rats were divided into the 1st group as Control (standard diet 2.8% crude fat. 23.1% crude protein. 5% crude fiber. 7.1% crude ash and 12.8% moisture) and the 2nd group as the intermittent fasting together with the diet group (with a 24-hour break from the non-consecutive diet for 2 days a week and all food restricted except water). Results: As a result of the analysis, it was found that the growth hormone in the intermittent fasting together with the standard diet group tended to increase compared to the control group, and while this value difference was not statistically significant, the ghrelin level was found to be statistically lower than the control group. Conclusion: As a result, it was found that intermittent fasting tends to increase the level of growth hormone, and to have a decreasing effect on ghrelin level, and it was concluded that it can be considered among the methods to be used to treat obesity and prevent its occurrence.

Effects of GH on the Aging Process in Several Organs: Mechanisms of Action

In order to investigate the possible beneficial effects of GH administration on the aging process, 24-month-old rats of both sexes and 10-month-old SAMP8 mice were used. Male rats showed increased fat content and decreased lean body mass together with enhanced vasoconstriction and reduced vasodilation of their aortic rings compared to young adult animals. Chronic GH treatment for 10 weeks increased lean body mass and reduced fat weight together with inducing an enhancement of the vasodilatory response by increasing eNOS and a reduction of the constrictory responses. Old SAMP8 male mice also showed insulin resistance together with a decrease in insulin production by the endocrine pancreas and a reduced expression of differentiation parameters. GH treatment decreased plasma levels and increased pancreatic production of insulin and restored differentiation parameters in these animals. Ovariectomy plus low calcium diet in rabbits induced osteoporosis Titanium implants inserted into these rabbit tibiae showed after one month lesser bone to implant (BIC) surface and bone mineral density (BMD). Local application of GH in the surgical opening was able to increase BIC in the osteoporotic group. The hippocampus of old rats showed a reduction in the number of neurons and also in neurogenesis compared to young ones, together with an increase of caspases and a reduction of Bcl-2. GH treatment was able to enhance significantly only the total number of neurons. In conclusion, GH treatment was able to show beneficial effects in old animals on all the different organs and metabolic functions studied.

Mortality in adults with hypopituitarism: a systematic review and meta-analysis

PURPOSE

Hypopituitarism is a rare disorder with significant morbidity. To study the evidence on the association of premature mortality and hypopituitarism.

METHODS

A comprehensive search of multiple databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus was conducted through August, 2015. Eligible studies that evaluated patients with hypopituitarism and reported mortality estimates were selected following a predefined protocol. Reviewers, independently and in duplicate, extracted data and assessed the risk of bias.

RESULTS

We included 12 studies (published 1996-2015) that reported on 23,515 patients. Compared to the general population, hypopituitarism was associated with an overall excess mortality (weighted SMR of 1.55; 95 % CI 1.14-2.11), I ²  = 97.8 %, P = 0.000. Risk factors for increased mortality included younger age at diagnosis, female gender, diagnosis of craniopharyngioma, radiation therapy, transcranial surgery, diabetes insipidus and hypogonadism.

CONCLUSION

Hypopituitarism may be associated with premature mortality in adults. Risk is particularly higher in women and those diagnosed at a younger age.

Cardiovascular alterations in adult GH deficiency

There is a growing body of evidence indicating that patients with adult GH deficiency (GHD) are characterized by a cluster of traditional and emerging cardiovascular risk factors and markers, which can significantly increase their cardiovascular morbidity and mortality possibly linked to aberrations in GH status. Patients with adult GHD present multiple different cardiovascular abnormalities. In addition, cardiovascular risk in adult GHD is increased due to altered body composition, abnormal lipid profile, insulin resistance and impaired glucose metabolism. Cardiovascular risk factors can be reversed, at least partially, after GH replacement. However, evidence on the effects of GH replacement on cardiovascular events and mortality is too limited in adult GHD patients. Aim of this review is to provide an at-a-glance overview of the role of the GH/IGF-I on the cardiovascular system and the state of art of the effects of GH replacement on cardiovascular system.

Low-dose hydrocortisone replacement is associated with improved arterial stiffness index and blood pressure dynamics in severely adrenocorticotrophin-deficient hypopituitary male patients

OBJECTIVE

Increased cardiovascular and cerebrovascular morbidity and mortality in hypopituitary subjects may be linked to inappropriate glucocorticoid exposure; however, the pathophysiology remains unclear. We aimed to examine the effect of three commonly prescribed hydrocortisone (HC) regimens on vascular risk factors.

DESIGN

An open crossover study randomising ten hypopituitary men with severe adrenocorticotrophic hormone deficiency to three HC dose regimens: dose A (20mg mane and 10mg tarde), dose B (10mg mane and 10mg tarde) and dose C (10mg mane and 5mg tarde).

METHODS

Following 6 weeks on each regimen, participants underwent 24-h serum cortisol sampling, 24-h ambulatory blood pressure (BP) measurements, calculation of the Ambulatory Arterial Stiffness Index (AASI), oral glucose tolerance testing and fasting serum osteoprotegerin (OPG) sampling.

RESULTS

There were no differences in 24-h BP between dose regimens and controls; however, low-dose HC replacement (dose C) was associated with the lowest AASI, indicating a less stiff arterial tree (P<0.05) compared with the other dose regimens. Loss of the physiologic nocturnal BP dip was more common in higher HC replacement regimens, although only significant for dose B compared with dose C (P=0.03). Twenty per cent of patients had abnormal glucose tolerance, but this was unrelated to dose regimen. OPG correlated strongly with 24-h BP in those on dose A only (r=0.65, P=0.04).

CONCLUSION

Currently prescribed HC replacement doses do not result in significant differences in absolute BP levels or improvements in insulin sensitivity. However, lower HC doses may result in lower arterial stiffness and a more physiological nocturnal BP dip. Long-term studies are required to confirm these findings and evaluate their impact on vascular morbidity in this patient group.

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Evaluation of left ventricular mass and function, lipid profile, and insulin resistance in Egyptian children with growth hormone deficiency: A single-center prospective case-control study

BACKGROUND

Growth hormone deficiency (GHD) in adults is associated with a cluster of cardiovascular risk factors that may contribute to an increased mortality for cardiovascular disease. In children, relatively few studies have investigated the effect of GHD and replacement therapy on cardiac performance and metabolic abnormalities that may place them at a higher risk of cardiovascular disease (CVD) at an early age.

AIM

This study was aimed to assess the left ventricular function, lipid profile, and degree of insulin resistance in Egyptian children with GHD before and after 1 year of GH replacement therapy.

SETTINGS AND DESIGN

Prospective case-control study, single-center study.

MATERIALS AND METHODS

Thirty children with short stature due to GHD were studied in comparison to 20 healthy age- and sex-matched children. All subjects were subjected to history, clinical examination, auxological assessment, and echocardiography to assess the left ventricular function. Blood samples were collected for measuring IGF-1, lipid profile (Total, LDL, HDL cholesterol, triglyceride, and atherogenic index (AI), fasting blood sugar, and fasting insulin levels. In addition, basal and stimulated GH levels were measured in children with suspected GHD.

STATISTICAL ANALYSIS USED

Student's t-test was used for parametric data, and the Mann-Whitney U-test was used for non-parametric data.

RESULTS

Total, LDL cholesterol, triglyceride, AI, and insulin were significantly higher in children with GHD than in healthy controls at baseline. After 12 months of GH replacement therapy, total, LDL cholesterol, triglyceride, AI and insulin were significantly decreased, while homeostatic model assessment for insulin resistance index (HOMA-IR) was significantly increased compared to both pre-treatment and control values. At baseline, the left ventricular mass (LVM) and left ventricular mass index (LVMi) were significantly lower in GHD children than in controls. After 12 months of GH replacement therapy, LVM and LVMi in GHD patients were significantly increased compared to pre-treatment values.

CONCLUSIONS

GHD in children is associated with a significantly reduced cardiac mass and impairment of lipid profile. GH replacement therapy exerts beneficial effects both on cardiac mass and lipid metabolism by normalizing cardiac size and improving the lipid profile. On the contrary, an increase in insulin resistance is observed after 12 months GH treatment. The study suggests that children with GH deficiency should have echocardiography and lipid profile monitoring before and during treatment with GH.

Pre-weaning growth hormone treatment reverses hypertension and endothelial dysfunction in adult male offspring of mothers undernourished during pregnancy

Maternal undernutrition results in elevated blood pressure (BP) and endothelial dysfunction in adult offspring. However, few studies have investigated interventions during early life to ameliorate the programming of hypertension and vascular disorders. We have utilised a model of maternal undernutrition to examine the effects of pre-weaning growth hormone (GH) treatment on BP and vascular function in adulthood. Female Sprague-Dawley rats were fed either a standard control diet (CON) or 50% of CON intake throughout pregnancy (UN). From neonatal day 3 until weaning (day 21), CON and UN pups received either saline (CON-S, UN-S) or GH (2.5 ug/g/day)(CON-GH, UN-GH). All dams were fed ad libitum throughout lactation. Male offspring were fed a standard diet until the end of the study. Systolic blood pressure (SBP) was measured at day 150 by tail cuff plethysmography. At day 160, intact mesenteric vessels mounted on a pressure myograph. Responses to pressure, agonist-induced constriction and endothelium-dependent vasodilators were investigated to determine vascular function. SBP was increased in UN-S groups and normalised in UN-GH groups (CON-S 121±2 mmHg, CON-GH 115±3, UN-S 146±3, UN-GH 127±2). Pressure mediated dilation was reduced in UN-S offspring and normalised in UN-GH groups. Vessels from UN-S offspring demonstrated a reduced constrictor response to phenylephrine and reduced vasodilator response to acetylcholine (ACh). Furthermore, UN-S offspring vessels displayed a reduced vasodilator response in the presence of L-NG-Nitroarginine Methyl Ester (L-NAME), carbenoxolone (CBX), L-NAME and CBX, Tram-34 and Apamin. UN-GH vessels showed little difference in responses when compared to CON and significantly increased vasodilator responses when compared to UN-S offspring. Pre-weaning GH treatment reverses the negative effects of maternal UN on SBP and vasomotor function in adult offspring. These data suggest that developmental cardiovascular programming is potentially reversible by early life GH treatment and that GH can reverse the vascular adaptations resulting from maternal undernutrition.

Overall and cause-specific mortality in GH-deficient adults on GH replacement

OBJECTIVE

Hypopituitarism is associated with an increased mortality rate but the reasons underlying this have not been fully elucidated. The purpose of this study was to evaluate mortality and associated factors within a large GH-replaced population of hypopituitary patients.

DESIGN

In KIMS (Pfizer International Metabolic Database) 13,983 GH-deficient patients with 69,056 patient-years of follow-up were available.

METHODS

This study analysed standardised mortality ratios (SMRs) by Poisson regression. IGF1 SDS was used as an indicator of adequacy of GH replacement. Statistical significance was set to P<0.05.

RESULTS

All-cause mortality was 13% higher compared with normal population rates (SMR, 1.13; 95% confidence interval, 1.04-1.24). Significant associations were female gender, younger age at follow-up, underlying diagnosis of Cushing's disease, craniopharyngioma and aggressive tumour and presence of diabetes insipidus. After controlling for confounding factors, there were statistically significant negative associations between IGF1 SDS after 1, 2 and 3 years of GH replacement and SMR. For cause-specific mortality there was a negative association between 1-year IGF1 SDS and SMR for deaths from cardiovascular diseases (P=0.017) and malignancies (P=0.044).

CONCLUSIONS

GH-replaced patients with hypopituitarism demonstrated a modest increase in mortality rate; this appears lower than that previously published in GH-deficient patients. Factors associated with increased mortality included female gender, younger attained age, aetiology and lower IGF1 SDS during therapy. These data indicate that GH replacement in hypopituitary adults with GH deficiency may be considered a safe treatment.

Myths and truths of growth hormone and testosterone therapy in heart failure

Heart failure is a chronic clinical syndrome with very poor prognosis. Despite being on optimal medical therapy, many patients still experience debilitating symptoms and poor quality of life. In recent years, there has been a great interest in anabolic hormone replacement therapy - namely, growth hormone and testosterone - as an adjunctive therapy in patients with advanced heart failure. It has been observed that low levels of growth hormone and testosterone have been associated with increased mortality and morbidity in patients with heart failure. Animal studies and clinical trials have shown promising clinical improvement with hormonal supplementation. Growth hormone has been shown to increase ventricular wall mass, decrease wall stress, increase cardiac contractility, and reduce peripheral vascular resistance, all of which might help to enhance cardiac function, resulting in improvement in clinical symptoms. Likewise, testosterone has been shown to improve hemodynamic parameters via reduction in peripheral vascular resistance and increased coronary blood flow through vasodilation, thereby improving functional and symptomatic status. To date, growth hormone and testosterone therapy have shown some positive benefits, albeit with some concerns over adverse effects. However, large randomized controlled trials are still needed to assess the long-term safety and efficacy.

Endocrine parameters and phenotypes of the growth hormone receptor gene disrupted (GHR-/-) mouse

Disruption of the GH receptor (GHR) gene eliminates GH-induced intracellular signaling and, thus, its biological actions. Therefore, the GHR gene disrupted mouse (GHR-/-) has been and is a valuable tool for helping to define various parameters of GH physiology. Since its creation in 1995, this mouse strain has been used by our laboratory and others for numerous studies ranging from growth to aging. Some of the most notable discoveries are their extreme insulin sensitivity in the presence of obesity. Also, the animals have an extended lifespan, which has generated a large number of investigations into the roles of GH and IGF-I in the aging process. This review summarizes the many results derived from the GHR-/- mice. We have attempted to present the findings in the context of current knowledge regarding GH action and, where applicable, to discuss how these mice compare to GH insensitivity syndrome in humans.

Update: Systemic Diseases and the Cardiovascular System (II). The endocrine system and the heart: a review

Normal endocrine function is essential for cardiovascular health. Disorders of the endocrine system, consisting of hormone hyperfunction and hypofunction, have multiple effects on the cardiovascular system. In this review, we discuss the epidemiology, diagnosis, and management of disorders of the pituitary, thyroid, parathyroid, and adrenal glands, with respect to the impact of endocrine dysfunction on the cardiovascular system. We also review the cardiovascular benefits of restoring normal endocrine function.

Update: Systemic Diseases and the Cardiovascular System (II). The endocrine system and the heart: a review

Normal endocrine function is essential for cardiovascular health. Disorders of the endocrine system, consisting of hormone hyperfunction and hypofunction, have multiple effects on the cardiovascular system. In this review, we discuss the epidemiology, diagnosis, and management of disorders of the pituitary, thyroid, parathyroid, and adrenal glands, with respect to the impact of endocrine dysfunction on the cardiovascular system. We also review the cardiovascular benefits of restoring normal endocrine function.

Cardiological aging in SAM model: effect of chronic treatment with growth hormone

The purpose of this study was to investigate the effect of aging on different parameters related to inflammation, oxidative stress and apoptosis in hearts from two types of male mice models: senescence-accelerated mice (SAM-P8) and senescence-accelerated-resistant (SAM-R1), and the influence of chronic administration of Growth Hormone (GH) on old SAM-P8 mice. Forty male mice were used. Animals were divided into five experimental groups: two 10 month old untreated groups (SAM-P8/SAM-R1), two 2 month old young groups (SAM-P8/SAM-R1) and one 10 month old group (SAM-P8) treated with GH for 30 days. The expression of tumor necrosis factor-alpha, interleukin 1, interleukin 10, heme oxygenases 1 and 2, endothelial and inducible nitric oxide synthases, NFkB, Bad, Bax and Bcl-2 were determined by real-time reverse transcription polymerase chain reaction (RT-PCR). Results were submitted to a two way ANOVA statistical evaluation using the Statgraphics program. Inflammation, as well as, oxidative stress and apoptosis markers were increased in the heart of old SAM-P8 males, as compared to young controls and this situation was not observed in the old SAM-R1 mice. Exogenous GH administration reverted the effect of aging in the described parameters of old SAM-P8 mice. Our results suggest that inflammation, apoptosis and oxidative stress could play an important role in the observed cardiovascular alterations related to aging of SAM-P8 mice and that GH may play a potential protective effect on the cardiovascular system of these animals.

Mortality in patients with pituitary disease

Pituitary disease is associated with increased mortality predominantly due to vascular disease. Control of cortisol secretion and GH hypersecretion (and cardiovascular risk factor reduction) is key in the reduction of mortality in patients with Cushing's disease and acromegaly, retrospectively. For patients with acromegaly, the role of IGF-I is less clear-cut. Confounding pituitary hormone deficiencies such as gonadotropins and particularly ACTH deficiency (with higher doses of hydrocortisone replacement) may have a detrimental effect on outcome in patients with pituitary disease. Pituitary radiotherapy is a further factor that has been associated with increased mortality (particularly cerebrovascular). Although standardized mortality ratios in pituitary disease are falling due to improved treatment, mortality for many conditions are still elevated above that of the general population, and therefore further measures are needed. Craniopharyngioma patients have a particularly increased risk of mortality as a result of the tumor itself and treatment to control tumor growth; this is a key area for future research in order to optimize the outcome for these patients.

The influence of growth hormone replacement on peripheral inflammatory and cardiovascular risk markers in adults with severe growth hormone deficiency

BACKGROUND

Adult GHD syndrome is associated with clustering of adverse cardiovascular (CV) risk factors such as abnormal body composition, dyslipidemia, insulin resistance and abnormal haemostatic factors. There is a wealth of evidence linking CV events with elevated levels of inflammatory markers (hs-CRP and IL-6) in the general population; however data on their abnormalities in GHD and specially the effects of GH replacement (GHR) on these inflammatory markers are limited.

OBJECTIVE

To study the effects of GHR on inflammatory markers, glucose homeostasis and body composition in a cohort of adults with recently diagnosed severe GHD due to hypothalamic pituitary disease.

DESIGN

Fifteen hypopituitary adults (11 males, mean age 48.5 years) with recently diagnosed, severe GHD were recruited. Patients received GHR (in addition to other pituitary hormone replacements) titrated to clinical response and to normalize age and gender adjusted IGF-1 levels. Weight, waist hip ratio (WHR), body composition, fasting plasma glucose and insulin, insulin resistance index (HOMA-IR), fasting serum lipid levels, hs-CRP, IL-6 and TNF-alpha were measured at baseline and following a minimum 6 months of stable maintenance GHR.

RESULTS

GHR resulted in a physiological increase in IGF-1 SDS [median -0.6 to +0.39, P<0.0001], improved quality of life (mean pre-treatment AGHDA score 16 vs. post-treatment score 7, P<0.0001) and reduction in WHR (0.94 vs. 0.92, P=0.01). There were no significant changes in body weight and composition. Levels of hs-CRP (log transformed, mean (SD)) were significantly reduced following GHR (pre 1.21 (0.9) vs. post 0.27 (0.9), P<0.0001) but TNF-alpha and IL-6 levels remained unchanged. Fasting glucose (mmol/L) [4.6 (0.1) vs. 5.1 (0.1), P=0.003], fasting insulin (muU/mL) [9.4 (8.1) vs. 12.1 (9.2), P=0.03] and HOMA-IR [1.2 (1.0) vs. 1.5 (1.1) P=0.02] (all pre-GHR vs. post-GHR and mean (SD)) significantly increased following GHR indicating increased insulin resistance. Significant improvements were noted in fasting LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) levels following GHR [3.4 (0.9) vs. 2.9 (0.7), P=0.03 and 1.2 (0.2) vs. 1.3 (0.2), P=0.02, respectively] (all pre-GHR vs. post-GHR and mean (SD)). Levels of total cholesterol and triglycerides did not change following GHR.

CONCLUSIONS

Physiological GHR for at least 6 months in hypopituitary adults with recently diagnosed severe GHD resulted in favourable changes in hs-CRP, WHR, fasting LDL-C and HDL-C levels all of which are recognised CV risk markers. However, there remains a high prevalence of obesity in this population and given the worsening of insulin sensitivity in the short term with GHR, monitoring and aggressive treatment of established CV risk factors is essential to reduce premature atherosclerotic CVD in this patient population.

Metabolic, cardiovascular, and cerebrovascular outcomes in growth hormone-deficient subjects with previous cushing's disease or non-functioning pituitary adenoma

CONTEXT

Previous exposure to hypercortisolism due to Cushing's disease (CD) may adversely affect long-term metabolic and cardiovascular outcomes. In particular, metabolic and cardiovascular outcomes of patients with previous CD who require GH replacement have not been fully established.

OBJECTIVE

The aim of the study was to compare the prevalence and incidence of metabolic syndrome (Adult Treatment Panel III criteria), diabetes mellitus, cardiovascular disease, and cerebrovascular disease in GH-treated subjects with previous CD with GH-treated subjects with previous nonfunctioning pituitary adenoma (NFPA).

DESIGN

We conducted post hoc analysis of the observational Hypopituitary Control and Complications Study conducted at 362 international centers (1995-2006).

SUBJECTS

We studied adult-onset GH-deficient subjects with previous CD (n = 160) or NFPA (n = 879). All subjects received GH replacement therapy and were GH naive at enrollment. Multiple pituitary deficits were prevalent in both groups.

MAIN OUTCOME MEASURES

We measured the prevalence and incidence of metabolic syndrome, diabetes mellitus, cardiovascular disease, and cerebrovascular disease at baseline and at 3 yr, standardized for age and sex differences between groups.

RESULTS

Compared with subjects with previous NFPA, subjects with previous CD had a significantly greater 3-yr incidence of metabolic syndrome (CD, 23.4%; NFPA, 9.2%; P = 0.01), baseline (CD, 6.3%; NFPA, 2.2%; P < 0.01) and 3-yr (CD, 7.6%; NFPA, 3.9%; P = 0.04) prevalence of cardiovascular disease, and baseline (CD, 6.4%; NFPA, 1.8%; P = 0.03) and 3-yr (CD, 10.2%; NFPA, 2.9%; P = 0.01) prevalence of cerebrovascular disease.

CONCLUSIONS

Previous hypercortisolism may predispose GH-treated, GH-deficient subjects with prior CD to an increased risk of metabolic syndrome, cardiovascular disease, and cerebrovascular disease.

IGF-I replacement therapy in children with congenital IGF-I deficiency (Laron syndrome) maintains heart dimension and function

OBJECTIVE

Untreated patients with congenital growth hormone deficiency (GHD) and IGF-I deficiency are characterized not only by dwarfism but also by acromicria and organomicria, such as the heart. We assessed cardiac dimensions and function in very young patients with Laron syndrome (LS) undergoing IGF-I replacement therapy.

DESIGN

Two to seven echocardiographic measurements were performed during IGF-I replacement therapy on male (n=4) and female (n=4) LS -patients, mean+/-SD age of 7.1+/-3.6 years (range 1.6-11.6 years), weight 16.1+/-9.7 kg, and height 89.9+/-18.5 cm. As aged- and gender-matched controls served 44 healthy children, age: 8.7+/-5.5 years, weight: 36.1+/-22.4 kg, and height: 129.7+/-33.1cm. Data of LS patients were normalized to body surface area and compared to the control group as well as nomograms of normal echocardiographic parameters for this age group.

RESULTS

Left ventricular diastolic and systolic dimensions (LVDD/ LVSD, mm) and LV mass (gr) were significantly smaller in boys and girls with IGF-I treated LS compared with controls while the shortening fraction (%) and intraventricular septum thickness (mm) were similar. When compared with standard values for this age group, all treated LS patients were within 1 standard deviation of the mean.

CONCLUSION

IGF-I therapy of young patients with Laron syndrome maintain LV dimensions and function within the normal range of aged-matched controls.

Metabolic co-morbidities revealed in patients with childhood-onset adult GH deficiency after cessation of GH replacement therapy for short stature

GH therapy was approved in 2006 for treatment of adult growth hormone deficiency (GHD) in Japan. Until then, GH was used only to treat short stature in children with GHD and the treatment was stopped when the final height was reached. In the present study, we investigated metabolic co-morbidities experienced by adults with childhood-onset (CO) GHD after the cessation of GH. Forty-two patients with COGHD (M/F 22/20, age at follow up when the retrospective analysis was carried out: 18-52 yr) treated with GH in childhood were studied. We reviewed the medical records of these patients to determine the metabolic co-morbidities that developed after cessation of GH. The median age was 19 yrs (range: 14-38) at cessation of GH, and the following co-morbidities were observed: hypertriglyceridemia in 15 (41%) patients, non-alcoholic fatty liver disease (NAFLD) in 11 (29%) patients, hypercholesterolemia in 10 (26%) patients, diabetes mellitus (DM) in 4 (10%) patients, and hypertension in 1 (2.4%) patient. The median BMI when these complications became overt was 23.5 kg/m(2) for those with hypertriglyceridemia, 26.0 kg/m(2) for those with NAFLD, 20.9 kg/m(2) for those with hypercholesterolemia, and 27.2 kg/m(2 ) for those with DM. More than two co-morbidities were experienced by 32% of men and 30% of women. In conclusion, adults with COGHD after the cessation of GH have multiple metabolic co-morbidities. Lifelong GH replacement might be important for improving the overall metabolic profiles in these 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.

Current and future perspectives on recombinant growth hormone for the treatment of obesity

The similarities between patients with untreated growth hormone (GH) deficiency and those with the cardiometabolic syndrome and the beneficial effects of recombinant human GH (rhGH) on body composition have led to the hypothesis that rhGH treatment may have utility in obesity. GH release is reduced in the setting of obesity, primarily due to hyperinsulinism and increased free fatty acid levels. We reviewed the outcomes of 23 clinical studies carried out between 1987 and 2006 that examined the effects of rhGH administration in the obese state. Typically, changes in overall body weight do not occur with rhGH therapy; however, assessment of body composition demonstrates reductions in visceral abdominal fat. Data on the effects of rhGH on lipid and carbohydrate metabolic profiles in obese patients are less clear-cut, with a subset of studies showing a beneficial effect and others a neutral effect. Given the increasing burden of obesity in the general population and the current paucity of effective therapies, it is useful to consider the data on rhGH and obesity from a clinical perspective to highlight potential treatment strategies that harness the somatotropic axis.

Growth hormone receptor deficiency in mice results in reduced systolic blood pressure and plasma renin, increased aortic eNOS expression, and altered cardiovascular structure and function

To study the role of the growth hormone receptor (GHR) in the development of cardiovascular structure and function, female GHR gene-disrupted or knockout (KO) and wild-type (WT) mice at age 18 wk were used. GHR KO mice had lower plasma renin levels (12 +/- 2 vs. 20 +/- 4 mGU/ml, P < 0.05) and increased aortic endothelial NO synthase (eNOS) expression (146%, P < 0.05) accompanied by a 25% reduction in systolic blood pressure (BP, 110 +/- 4 vs. 147 +/- 3 mmHg, P < 0.001) compared with WT mice. Aldosterone levels were unchanged, whereas the plasma potassium concentration was elevated by 14% (P < 0.05) in GHR KO. Relative left ventricular weight was 14% lower in GHR KO mice (P < 0.05), and cardiac dimensions as analyzed by echocardiography were similarly reduced. Myograph studies revealed a reduced maximum contractile response in the aorta to norepinephrine (NE) and K(+) (P < 0.05), and aorta media thickness was decreased in GHR KO (P < 0.05). However, contractile force was normal in mesenteric arteries, whereas sensitivity to NE was increased (P < 0.05). Maximal acetylcholine-mediated dilatation was similar in WT and GHR KO mice, whereas the aorta of GHR KO mice showed an increased sensitivity to acetylcholine (P < 0.05). In conclusion, loss of GHR leads to low BP and decreased levels of renin in plasma as well as increase in aortic eNOS expression. Furthermore, GHR deficiency causes functional and morphological changes in both heart and vasculature that are beyond the observed alterations in body size. These data suggest an important role for an intact GH/IGF-I axis in the maintenance of a normal cardiovascular system.

Cardiovascular disease, hypertension, dyslipidaemia and obesity in patients with hypothalamic-pituitary disease

OBJECTIVE

Adults with hypothalamic-pituitary disease have increased morbidity and mortality from cardiovascular disease (CVD). Therefore, the prevalence of CVD and adequacy of treatment of cardiovascular risk factors (according to current treatment guidelines) was studied in a large group of patients with hypothalamic-pituitary disease.

STUDY DESIGN

In 2005, 152 consecutive adult patients with hypothalamic-pituitary disease attending our neuro-endocrine centre were clinically examined and blood pressure (BP), lipid profile, type 2 diabetes mellitus, body composition and smoking status were assessed.

RESULTS

Of the 152 patients, 36.8% had treated hypertension and 28.2% had treated dyslipidaemia. Many of these patients had inadequate BP control (BP >140/85 mm Hg, 44.6%) and undesirable lipid levels (total cholesterol >4.0 mmol/l, 69%). Also, many of the untreated patients had BP and lipid levels which should have been considered for treatment (26 patients (27%) and 83 patients (76%), respectively). Smoking was admitted in 18% of patients. Central adiposity was present in 86% and obesity (body mass index > or =30) was present in 50%.

CONCLUSIONS

Cardiovascular risk factors are highly prevalent and often inadequately treated in adult patients with hypothalamic-pituitary disease. Aggressive treatment of these factors is essential to reduce mortality and morbidity from CVD in these patients.

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.

Metabolic risk factors for vascular disease in obstructive sleep apnea: a matched controlled study

RATIONALE

Obstructive sleep apnea (OSA) is reported to have a metabolic profile predisposing to cardiovascular disease. However, previous case-control studies have not adequately controlled for confounders.

OBJECTIVES

To determine whether OSA is associated with increased insulin resistance and related metabolic risk factors.

METHODS

We performed a matched case-control study (n = 42) examining putative metabolic risks among men with OSA attending a sleep clinic (apnea-hypopnea index [AHI] > 15] compared with no OSA (AHI < 5). Participants were matched for age +/- 5 yr, body mass index +/- 10%, and current smoking status. They were free of diabetes, clinically demonstrable cardiovascular disease, marked hypertension, and dyslipidemia.

MEASUREMENTS AND MAIN RESULTS

Mean +/- SD AHI was higher in patients with OSA (40 +/- 27) than in control subjects (3 +/- 1.3, p = 0.02), and median (interquartile range) nocturnal oxygen saturation was lower (OSA, 83 [76-88]; control, 91 [90-93]%; p < 0.001). Patients with OSA had a higher median (interquartile range) homeostasis model assessment score for insulin resistance (OSA, 1.7 [0.8-4.1]; control, 1.0 [0.7-1.8] mU.mmol/L(2); p = 0.02), total cholesterol (OSA, 5.6 [4.8-6.2]; control, 4.8 [4.3-5.4] mmol/L; p = 0.049), and low-density-lipoprotein cholesterol (OSA, 3.8 [2.9-4.2]; control, 3.1 [2.6-3.6] mmol/L; p = 0.04). Patients with OSA had higher 24-h and nocturnal (12-h) urinary norepinephrine excretion and plasma leptin levels, and lower insulin-like growth factor (IGF)-1 levels (all, p < or = 0.02). Multiple linear regression, adjusting for central obesity, age, and alcohol consumption, confirmed an independent association between OSA and metabolic risks (all, p < 0.05), with a trend for IGF-1 (p = 0.053).

CONCLUSIONS

In a sleep clinic population, men with OSA and no identifiable cardiovascular disease have increased insulin resistance and other metabolic changes that act to increase the risk of vascular disease, compared with age- and body mass index-matched attendees without OSA.

Understanding and meeting the needs of those using growth hormone injection devices

BACKGROUND

Recombinant human growth hormone (r-hGH) is used to treat: growth hormone deficiency in children and adults; children born small for gestational age; Turner's syndrome; and chronic renal failure. r-hGH is administered by daily subcutaneous injection and may be given using a number of different administration devices. The aim of this survey was, firstly, to identify which attributes of an r-hGH administration device are considered most important to physicians, teenage patients, parents of young children requiring GH and nurses who have experience of r-hGH administration, and, secondly, to determine how they rate existing devices in each of these key attributes.

METHODS

The opinions of 67 individuals with experience in r-hGH administration were captured in discussion sessions. Parents, physicians and nurses were asked to rate 19 device attributes by completing a questionnaire, and to rank four different r-hGH administration devices (including a conceptual electronic device) in order of preference.

RESULTS

Reliability, ease of use, lack of pain during injection, safety in use, storage, and number of steps in preparation before use, during use and after were considered to be the five most desirable attributes of an r-hGH administration device. An electronic device was preferred to an automatic, multi-dose injection device, a needle-free injection device or a manual, ready-to-use, disposable injection device.

CONCLUSION

In the opinion of physicians, nurses and parents using r-hGH injection devices, an ideal device must combine reliability with simplicity, while delivering treatment with minimal pain. An electronic device, which combines many of the most useful features of existing devices with novel functions, was the preferred option for r-hGH administration.

Effects of ovariectomy and growth hormone administration on body composition and vascular function and structure in old female rats

Aging and estrogen-deprivation induce deleterious effects on body composition and vascular function in females. On the other hand, growth hormone (GH), whose production is reduced by age, exerts several vascular effects. The aim of this study was to investigate the effect of long-term estrogen deprivation and GH administration on body composition, vascular function and structure in aged female rats.

METHODS

Twelve female Wistar rats were ovariectomized at 10 months of age. At 20 months of age, half of the ovariectomized rats were treated with GH for 4 weeks. The remaining ovariectomized rats animals and one group of six intact females were used as control groups. After the treatment period, animals were sacrificed and Specific Gravity Index (SGI) and periuterine fat weigh, as well as vascular reactivity and morphometry in aortic rings, were studied.

RESULTS

No significant differences were found in SGI and periuterine fat weigh between ovariectomized and intact control rats. SGI was significantly increased by GH, and periuterine fat was reduced by the treatment. Dose-dependent relaxing responses to acetylcholine and isoproterenol were significantly diminished in ovariectomized rats as compared with intact animals, and GH treatment improved these responses. Ovariectomized animals showed significantly higher contracting responses to phenylephrine, acetylcholine + L-NAME and angiotensin-I than intact rats, and treatment with GH reduced them significantly. Media cross-sectional area was increased in ovariectomized rats as compared to intact animals, and GH reduced this area, but differences did not reach significance.

CONCLUSION

GH has beneficial effects in body composition and endothelial function in old ovariectomized female rats.

Growth hormone and its disorders

Growth hormone (GH) is synthesised and secreted by the somatotroph cells of the anterior lobe of the pituitary gland. Its actions involve multiple organs and systems, affecting postnatal longitudinal growth as well as protein, lipid, and carbohydrate metabolism. GH hypersecretion results in gigantism or acromegaly, a condition associated with significant morbidity and mortality, while GH deficiency results in growth retardation in children and the GH deficiency syndrome in adults. This article, aimed at non-paediatric physicians, examines the clinical features, diagnosis, and current concepts in the management of these conditions.

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.

Persisting effects on fasting glucose levels and insulin sensitivity after 6 months of discontinuation of a very low-dose GH therapy in adults with severe GH deficiency

OBJECTIVE

We recently reported that, in contrast to the standard GH (SGH) replacement dose titrated to normalize serum IGF-I levels, 12-month treatment with a fixed low GH dose (LGH) (0.1 mg/day) decreased fasting glucose levels and improved insulin sensitivity with little effect on body composition in severely GH-deficient adults. In this study, we have subsequently examined the effects after 6 months of discontinuation of these variable GH doses (LGH: n = 8; fixed dose 0.10 mg/day and SGH: n = 8; mean dose 0.50 mg/day) on glucose metabolism, body composition and other surrogate cardiovascular risk markers.

METHODS

Fasting insulin sensitivity using the homeostasis model assessment, and body composition using dual-energy X-ray absorptiometry scans were assessed at baseline, after 12 months of therapy (month 12) and after 6 months following discontinuation of therapy (month 18).

RESULTS

At month 12, the LGH decreased fasting glucose levels and improved insulin sensitivity without altering body composition, whereas the SGH improved body composition without modifying insulin sensitivity. Six months after discontinuation of the LGH treatment (month 18), fasting glucose levels remained decreased and the enhanced insulin sensitivity persisted. In contrast, after discontinuation of SGH treatment (month 18), body composition reverted to baseline without changes in either fasting glucose levels or insulin sensitivity. CONCLUSION In contrast to the SGH, the LGH induces effects on fasting glucose levels and insulin sensitivity, which persist after 6 months of discontinuation of therapy. The exact molecular mechanisms are unclear but may involve the modulation of hepatic and muscle insulin sensitivity, possibly by altering insulin and IGF-I receptor responsiveness and/or density.

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.

Genetic variation at the growth hormone (GH1) and growth hormone receptor (GHR) loci as a risk factor for hypertension and stroke

An increased prevalence of both hypertension and cerebrovascular stroke is apparent in growth hormone (GH) deficiency whilst hypertension is a frequent complication in acromegaly. This has suggested a possible link between GH, stature and arterial function. Since the risk of both hypertension and stroke also appears to be inversely correlated with adult height, we have instigated an exploratory study to assess whether inter-individual variation in the genes encoding human growth hormone (GH1) and the GH receptor (GHR) might be associated with an increased risk of hypertension and stroke. GH1 promoter haplotypes were found to differ significantly not only between hypertensive patients (n = 111) and controls (n = 121) but also between stroke patients (n = 155) and controls (n = 158). Intriguingly, the association between GH1 promoter haplotype and risk of hypertension was much greater in females than in males. An inverse correlation between height and central systolic blood pressure was apparent in both hypertensive patients and normal controls but was much stronger in individuals carrying at least one GH1 promoter risk haplotype. The GH1 genotype therefore constitutes a risk factor for hypertension that interacts with stature. A strong association was found between the presence of at least one GH1 risk haplotype and a family history of stroke at an early age (odds ratio: 9.07, 95% confidence interval: 1.14-72.22). Three novel GH variants (Arg16His, Phe176Cys, Cys189Arg) were identified during the course of this study. Although two exhibited markedly reduced biological activity in vitro, their clinical significance remains unclear. No association was found between GHR genotype and either hypertension or stroke, nor was any interaction noted between GHR and GH1 genotypes in terms of a disease association. However, an association between GHRd3 genotype and hypertension was observed among stroke patients, particularly females. Elevated HDL was found to be a risk factor for hypertension in individuals lacking a copy of the GHRd3 allele. Weak associations with GHR genotype were also noted for peripheral systolic and diastolic blood pressure in hypertensive patients. Although the underlying mechanisms are still unclear, our findings are consistent with a complex relationship between height, hypertension, GH1 promoter haplotype, GHR polymorphism and the risk of stroke.

Echocardiographic assessment of subclinical left ventricular eccentric hypertrophy in adult-onset GHD patients by geometric remodeling: an observational case-control study

BACKGROUND

Most patients with growth hormone deficiency (GHD) show high body mass index. Overweight subjects, but GHD patients, were demonstrated to have high left ventricular mass index (LVMi) and abnormal LV geometric remodeling. We sought to study these characteristics in a group of GHD patients, in an attempt to establish the BMI-independent role of GHD.

METHODS

Fifty-four patients, 28 F and 26 M, aged 45.9 +/- 13.1, with adult-onset GHD (pituitary adenomas 48.2%, empty sella 27.8%, pituitary inflammation 5.5%, cranio-pharyngioma 3.7%, not identified pathogenesis 14.8%) were enrolled. To minimize any possible interferences of BMI on the aim of this study, the control group included 20 age- and weight-matched healthy subjects. The LV geometry was identified by the relationship between LVMi (cut-off 125 g/m2) and relative wall thickness (cut-off 0.45) at echocardiography.

RESULTS

There was no significant between-group difference in resting cardiac morphology and function, nor when considering age-related discrepancy. The majority of patients had normal-low LVM/LVMi, but about one fourth of them showed higher values. These findings correlated to relatively high circulating IGF-1 and systolic blood pressure at rest. The main LV geometric pattern was eccentric hypertrophy in 22% of GHD population (26% of with severe GHD) and in 15% of controls (p = NS).

CONCLUSION

Though the lack of significant differences in resting LV morphology and function, about 25% of GHD patients showed high LVMi (consisting of eccentric hypertrophy), not dissimilarly to overweight controls. This finding, which prognostic role is well known in obese and hypertensive patients, is worthy to be investigated in GHD patients through wider controlled trials.

Metabolic syndrome and growth hormone deficiency in adult survivors of childhood acute lymphoblastic leukemia

BACKGROUND

The purpose of the study was to determine the prevalence of metabolic syndrome, growth hormone deficiency, and cardiovascular risk factors among adult survivors of childhood acute lymphoblastic leukemia (ALL) treated with or without cranial irradiation.

METHODS

Follow-up was undertaken of 75 randomly selected long-term childhood ALL survivors. Testing included fasting insulin, glucose, lipids, and growth hormone (GH) releasing hormone plus arginine stimulation test. The prevalence of metabolic syndrome was compared with population norms from 1999-2002 National Health and Nutrition Examination Study (NHANES) data, and internally between those with and without past cranial irradiation and those with normal (>16.5 microg/L) versus insufficient (9-16.5 microg/L) versus deficient (<9 microg/L) peak GH secretion.

RESULTS

The mean subject age was 30 years and the mean time since ALL diagnosis was 25 years. The prevalence of metabolic syndrome did not differ statistically (P = .87) between study subjects (16.6%) and same-age, same-sex population norms (17.5%). However, 60% of subjects treated with cranial irradiation, compared with 20% of those who were not, had 2 or more of the 5 components of metabolic syndrome. Untreated abnormally low GH was present in 64% of subjects overall and 85% of those who received past cranial irradiation. Cranial irradiation was strongly related to GH deficiency, and in turn lower insulin-like growth factor 1 (IGF-1), higher fasting insulin, abdominal obesity, and dyslipidemia, particularly in women.

CONCLUSIONS

Hematologists who treat childhood ALL patients, and particularly those who provide primary care to adult survivors, should be aware of the potential for long-term GH deficiency and adverse cardiovascular and diabetes risk profiles as a consequence of leukemia treatment.

Massive cardiac thrombosis in a patient with Sheehan's syndrome

Growth hormone deficiency (GHD) is a risk factor for increased cardiovascular disease, and it has been recently demonstrated that abnormalities in coagulation system might contribute to the increased cardiovascular morbidity and mortality. However, there is not enough data related to the major thrombotic events in GH-deficient patients. We describe the case of a 62-year-old woman with Sheehan's syndrome who developed massive cardiac thrombosis. She was hospitalized with acute pulmonary edema. ECG revealed high ventricular responsive atrial fibrillation (AF) and T-wave inversion on precordial leads. The ejection fraction of left ventricle (LVEF) was measured as 60% by transthoracic echocardiography (TTE) and there was 2nd degree mitral regurgitation with concentric hypertrophic LV walls. Transesophagial echocardiography (TEE) established thrombi both at right atrium and left atrial appendix. Before anticoagulant therapy several hemostatic and fibrinolytic markers were measured. Except increased D-dimer concentration (763.14 mug/L (0-325)) we did not observe any pathological finding in these parameters. After 14 days of discharge, the patient was admitted to the intensive care unit with upper gastrointestinal bleeding. The warfarin and salicylate were stopped for two months. At the end of two months, the patient was again hospitalized with congestive heart failure and there was a high ventricular responsive AF on ECG. TEE was performed and three thrombi were demonstrated at right atrium (RA), left atrium (LA) and left ventricle (LV). There was no active bleeding on upper GIS endoscopy and anticoagulant therapy was restarted. In this particular case massive cardiac thrombi involving three chambers (LA, RA, LV) were more extensive than expected in AF. Moreover, there was a 2nd degree mitral regurgitation in the patient, and based on previous studies mitral regurgitation has been associated with less prevalent LA spontaneous echo contrast and fewer thromboembolic events. Therefore we hypothesized that severe GHD in the present case might be the major contributing factor in massive cardiac thrombosis. In summary, based on previous data there is increased risk of thromboembolic events in GHD although the mechanism is unclear yet. Our case is the first case showing massive cardiac thrombosis in a severe GH-deficient patient with Sheehan's syndrome. Therefore, patients with GHD should be screened carefully for thrombus in clinical practice, and further studies need to be done to understand the relation between GHD and coagulation system.

Short-term administration of growth hormone (GH) lowers blood pressure by activating eNOS/nitric oxide (NO)-pathway in male hypophysectomized (Hx) rats

Background

The aim of the study was to evaluate the acute and continuous (up to 14 days of treatment) effect of growth hormone (GH) on blood pressure (BP) regulation and to investigate the interplay between GH, nitric oxide (NO) and BP.

In un-supplemented and GH supplemented hypophysectomized (Hx) male rats as well as intact rats, continuous resting mean arterial blood pressure (MAP) was measured using telemetry. Baroreceptor activity and the influences of NO on BP control were assessed during telemetric measurement. Furthermore, basal plasma and urine nitrate levels and aortic endothelial nitric oxide synthase (eNOS) expression were analysed. Endothelial function as well as vascular structure in the hindquarter vascular bed was estimated using an in vivo constant-flow preparation.

Results

Hypophysectomy was associated with decreased MAP (Hx: 83 ± 3 vs Intact: 98 ± 6 mmHg, p < 0.05) and heart rate (HR) (Hx: 291 ± 4 vs Intact: 351 ± 7 beat/min, p < 0.05). Endothelial dysfunction and reduced vasculature mass in the hindquarter vascular bed was found in Hx rats. GH substitution caused a further transient decrease in MAP and a transient increase in HR (14% and 16% respectively, p < 0.05). The reduction in MAP appeared to be NO dependent. Aortic eNOS expression was unchanged. GH substitution resulted in an impaired baroreceptor function. Two weeks of GH treatment did not normalise the BP, vascular structure and the endothelial function in the resistance vessels.

Conclusion

GH substitution seems to have a short lasting effect on lowering blood pressure via activation of the NO-system. An interaction between GH, NO-system and BP regulation can be demonstrated.

Effect of Recombinant Human Growth Hormone Administration on Body Composition and Vascular Function and Structure in Old Male Wistar Rats

The process of ageing affects negatively both cardiovascular system and body composition. On the other hand, the hormones of the somatotrophic axis, growth hormone (GH) and insulin-like growth factor-I (IGF-I), whose production is reduced by age, are involved in the regulation of the cardiovascular system. The aim of this study was to investigate the effect of GH on body composition, vascular function and structure in old male rats. Old (20 months) and adult (4 months) male Wistar rats were used. One group of old animals was treated with GH for 4 weeks. Periepididimary fat weight, Specific Gravity Index (SGI), dose responses to Acetylcholine (ACh), Isoproterenol (Iso), Phenylephrine (Phe) and ACh in the presence of NG-nitro-L: -arginine metylester (L-NAME; ACh + L-NAME), as well as vascular morphology in aortic rings, were studied. Old rats showed increased fat weight and decreased SGI as compared to adult animals. GH increased SGI and tended to reduce fat weight. Old rats showed an impairment in the vasodilator response to ACh and Iso; GH significantly improved the vasodilatation induced by Iso, whereas the response to ACh was not significantly enhanced by GH treatment. There were no significant differences between adult and old rats in the contractile response to Phe, and GH did not show any effect. Contraction induced by ACh + L-NAME was higher in old rats as compared to adults, and treatment with GH significantly reduced this response. Aortic media area was increased in old rats, and GH administration reduced this parameter. In conclusion, GH shows beneficial effects on body composition, as well as on vascular function and morphology in old male rats.

Combined dietary and pharmacological weight management in obese hypopituitary patients

OBJECTIVE

The high prevalence of obesity and cardiovascular risk factors in hypopituitarism affirms the need for effective weight loss intervention. In this study, we investigated the combined effect of sibutramine, diet, and exercise in obese hypopituitary patients (HPs).

RESEARCH METHODS AND PROCEDURES

In an open-label prospective intervention trial, 14 obese well-substituted nondiabetic HPs and 14 matched simple obese controls were allocated to 11-month treatment with sibutramine (10 to 15 mg), diet (600 kcal/d deficit), and exercise. Anthropometric indices and body composition (obtained from DXA scan) were assessed monthly for the first 5 months and thereafter every second month for the next 6 months.

RESULTS

Mean (+/-SD) weight loss at 11 months was 11.3 +/- 4.8 kg in patients vs. 10.7 +/- 4.7 kg in controls. The HPs exhibited the same improvements in body composition, waist circumference, blood lipids, and fasting glucose as the simple obese. In a multivariate model, baseline weight, duration of growth hormone replacement therapy, and duration of pituitary disease explained 79% (p = 0.001) of the variation in weight loss at 4 months in the HPs. Only baseline weight and waist circumference could predict weight loss at 11 months.

DISCUSSION

HPs are not resistant to weight loss therapy. Almost all will achieve at least 5% weight loss, and 60% can lose >10% weight within 11 months. However, the long-term effect on risk factors associated with type 2 diabetes and cardiovascular disease as well as on mortality needs to be established.

Carotid artery intima-media thickness and lipid profile in adults with growth hormone deficiency after long-term growth hormone replacement

To investigate the effects of growth hormone (GH) replacement on carotid artery intima-media thickness (IMT) and lipid profile, 29 adults with GH deficiency (GHD), mean age 42.5 +/- 10.1 years, were studied and compared with 29 control subjects matched for sex, age, body mass index, and smoking habits. Lipid profile (total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein cholesterol, apolipoproteins A and B, and lipoprotein), serum insulin-like growth factor 1 (IGF-1) levels, and ultrasonography of the carotid arteries were performed at baseline and at 6, 12, and 24 months during GH therapy on maintenance dose. At baseline, when compared with the control group, patients presented increased carotid artery IMT (P < .05) and triglyceride levels (P < .001) and lower HDL concentrations (P < .01). In a linear regression analysis, age and known mean duration of GHD were correlated with carotid artery IMT. After 24 months of GH replacement, a reduction in the mean of carotid artery IMT was observed (P < .01). The apolipoprotein B levels decreased significantly after the first 3 months of GH treatment (P < .001) and remained stable thereafter. Women also presented an increase in HDL cholesterol levels (P < .01). No differences were observed in the other lipids measured. Carotid artery IMT at baseline was inversely correlated with the change in carotid artery IMT (Delta = 24 months - baseline), r = 0.63, P < .001. In conclusion, 24 months of GH replacement therapy promoted favorable effects on carotid artery IMT and lipid profile in patients with GHD. Long-term follow-up studies are required to show whether these beneficial effects will result in reduction of morbidity and mortality from vascular disease.

A rare case of adulthood-onset growth hormone deficiency presenting as sporadic, symptomatic hypoglycemia

Symptomatic hypoglycemia is described in children with severe GH deficiency (GHD), but is rare in adults with GHD. We describe the case of a 62- yr-old man, referred for recurrent hypoglycemic events. He reported a previous head trauma at the age of 20 yr and a diagnosis of reactive hypoglycemia at the age of 50 yr. In the last months, during a period of job-related stress, the hypoglycemic episodes became more frequent and severe (glucose <2.2 mmol/l), finally requiring hospitalization. On admission, the patient was in good general health, with normal renal and hepatic function. During hospitalization, no hypoglycemic episodes were recorded, also during a 72-h fasting test. Biochemical data and abdominal computed tomography (CT) excluded insulinoma. A tumor-induced hypoglycemia was ruled out. The 4-h oral glucose tolerance test (OGTT) showed an impaired glucose tolerance with a tendency toward asymptomatic hypoglycemia. Hormonal study disclosed low levels of GH (0.2 ng/ml) and IGF-I (51 ng/ml); the response of GH to GHRH plus arginine confirmed a severe GHD (GH peak 2.7 ng/ml). Other pituitary and counterregulation hormones were within the normal range and magnetic resonance imaging (MRI) of the pituitary gland was normal. Replacement therapy with a low dose of rhGH induced an increase of IGF-I up to low-normal values, accompanied by lasting regression of hypoglycemic events. In conclusion, hypoglycemia was the main clinical symptom of isolated adult onset GHD, in the present case. The possible pathogenesis of isolated adult onset GHD and the association of GHD with conditions predisposing to hypoglycemia are considered and discussed.

Proinflammatory parameters as CRP and IL-6 do not discriminate between post-PCI cardiac patients with and without exercise-induced ischemia as indicated by Tl-201 myocardial scintigraphy

INTRODUCTION

Atherosclerosis is looked upon as an inflammatory disease. The production of proinflammatory markers may indicate activity in this inflammatory state.

METHODS

We prospectively evaluated a range of proinflammatory serum parameters in 136 cardiac patients who had previously undergone percutaneous coronary intervention (PCI).

RESULTS

By means of myocardial scintigraphy, an ischemia group (A; n=49) and a group with stable cardiovascular disease without exercise induced ischemia (B; n=87) were distinguished. Risk factors and lipoprotein profile of both groups were comparable. Serum levels of serum C-reactive protein (CRP), IL-6, sTNF-RI, IGF-I, neopterin, serotonin and prolactin did not present any significant difference between the two groups.

CONCLUSIONS

We conclude that measurement of these (inflammatory) parameters does not help to delineate post-PCI cardiac patients with and without exercise-induced ischemia.