Cardiovascular risk factors in adult patients with growth hormone deficiency

COVID-19 and hypopituitarism

Besides the pulmonary manifestations caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), an emerging endocrine phenotype, which can heavily impact on the severity of the syndrome, has been recently associated with coronavirus disease 2019 (COVID-19). Patients with pituitary diseases or the pituitary gland itself may also be involved in COVID-19 clinical presentation and/or severity, causing pituitary apoplexy.Moreover, hypopituitarism is frequently burdened by several metabolic complications, including arterial hypertension, hyperglycemia, obesity and vertebral fractures, which have all been associated with poor outcomes and increased mortality in patients infected by SARS-CoV-2.This review will discuss hypopituitarism as a condition that might have a bidirectional relationship with COVID-19 due to the frequent presence of metabolic comorbidities, to the direct or indirect pituitary damage or being per se a potential risk factor for COVID-19. Finally, we will address the current recommendations for the clinical management of vaccines in patients with hypopituitarism and adrenal insufficiency.

The Long-Term Effects of Growth Hormone Replacement on Bone Mineral Density and Trabecular Bone Score: Results of the 10-Year Prospective Follow-up

There are only few studies concerning about long-term effect of growth hormone (GH) replacement therapy on bone mineral density and bone microstructure. To assess effect of GH replacement therapy on bone mineral density (BMD) and trabecular bone score (TBS) in adult GH deficient (AGHD) subjects over period of 10 years. From 2005 to 2018, a prospective study of AGHD patients was conducted in national referral center for treatment of GHD. All patients received subcutaneous recombinant human GH in an IGF 1-normalizing regimen once a day. Lumbar spine (L-spine) and total hip (TH) BMD using Hologic densitometers were measured at baseline and every two years during treatment with rhGH. TBS was derived from L1-L4 DXA using iNsight® software (Medimaps, France) at each time point. Periods of measurement were baseline, year 2; 4; 6; 8 and 10. In total, 63 patients (38 males, 25 females, mean age 25.1±16 years) were included in the study. After 10 years of GH treatment, IGF-1 significantly increased (~35 %), with greatest increase at year 2. During 10-year follow-up, L-spine BMD increased approximately of 7 % (NS). TH BMD increase of 11 % during follow-up (p=0.0003). The greatest increment of BMD was achieved at year 6 on both sites, L-spine (+6 %) and TH BMD (+13 %) (p<0.05). There was no significant change of TBS during whole follow-up. In this study, sustaining positive effect of GH replacement therapy on bone density in subjects with adult GH deficiency over 10 years of follow-up was observed. The study did not show effect on TBS, as indirect measure of trabecular bone microarchitecture.

Role of growth hormone in hepatic and intestinal triglyceride-rich lipoprotein metabolism

BACKGROUND

Elevated plasma concentrations of hepatic- and intestinally-derived triglyceride-rich lipoproteins (TRL) are implicated in the pathogenesis of atherosclerotic cardiovascular disease and all-cause mortality. Excess of TRL is the driving cause of atherogenic dyslipidemia commonly occurring in insulin-resistant individuals such as patients with obesity, type 2 diabetes and metabolic syndrome. Interestingly, growth hormone (GH)-deficient individuals display similar atherogenic dyslipidemia, suggesting an important role of GH and GH deficiency in the regulation of TRL metabolism.

OBJECTIVE

We aimed to examine the direct and/or indirect role of GH on TRL metabolism.

METHODS

We investigated the effect on fasting and postprandial hepatic-TRL and intestinal-TRL metabolism of short-term (one month) withdrawal of GH in 10 GH-deficient adults.

RESULTS

After GH withdrawal, we found a reduction in fasting plasma TRL concentration (significant decrease in TRL-TG, TRL-cholesterol, TRL-apoB-100, TRL-apoC-III and TRL-apoC-II) but not in postprandial TRL response. This reduction was due to fewer fasting TRL particles without a change in TG per particle and was not accompanied by a change in postprandial TRL-apoB-48 response. Individual reductions in TRL correlated strongly with increases in insulin sensitivity and decreases in TRL-apoC-III.

CONCLUSION

In this relatively short term 'loss of function' human experimental model, we have shown an unanticipated reduction of hepatic-TRL particles despite increase in total body fat mass and reduction in lean mass. These findings contrast with the atherogenic dyslipidemia previously described in chronic GH deficient states, providing a new perspective for the role of GH in lipoprotein metabolism.

Long-term neuroendocrine consequences of traumatic brain injury and strategies for management

Introduction: Traumatic brain injuries (TBI) are reported to cause neuroendocrine impairment with a prevalence of 15% with confirmatory testing. Pituitary dysfunction (PD) may have detrimental effects on vital parameters as well as on body composition, cardiovascular functions, cognition, and quality of life. Therefore, much effort has been made to identify predictive factors for post-TBI PD and various screening strategies have been offered.Areas covered: We searched PubMed and reviewed the recent data on clinical perspectives and long-term outcomes as well as predictive factors and screening modalities of post-TBI PD. Inconsistencies in the literature are overviewed and new areas of research are discussed.Expert opinion: Studies investigating biomarkers that will accurately predict TBI patients with a high risk of PD are generally pilot studies with a small number of participants. Anti-pituitary and anti-hypothalamic antibodies, neural proteins, micro-RNAs are promising in this field. As severity of TBI has been the most commonly associated risk factor for post-TBI PD, we suggest prospective screening based on severity of head trauma until new evidence emerges. There is also a need for more studies investigating the clinical effects of hormone replacement in TBI patients with PD.

Untreated adult GH deficiency is not associated with the development of metabolic risk factors: a long-term observational study

PURPOSE

Uncertainties exist about the predictors of the severity of the clinical picture of GH deficiency (GHD) syndrome. Aim of the study was to evaluate, in adult patients with GHD, the predictors of the development of hypercholesterolemia, hypertension, diabetes mellitus, and osteoporosis.

METHODS

We retrospectively studied 327 adult patients (age 47.1 ± 17.1 years) with untreated severe GHD (mean follow-up 110.9 ± 56.8 months). GHD was defined by GHRH + arginine test using BMI cut-offs. The possible development of hypercholesterolemia, hypertension, diabetes mellitus, and osteoporosis was investigated by Kaplan-Meier survival analysis. For each clinical outcome, either a univariate or multivariate analysis according to the Cox proportional-hazards model was performed to identify those factors that were associated with the development of the event.

RESULTS

GH secretion parameters were not associated with the outcomes. Hypercholesterolemia was positively and negatively predicted by a BMI ≥ 30 kg/m² (HR 2.50, p 0.00) and the dose of l-thyroxine possibly in place (HR 0.98, p 0.02), respectively. Hypertension was positively predicted by a BMI ≥ 30 kg/m² (HR 2.64, p 0.00) and IGF-I SDS values (HR 2.26, p 0.00). Diabetes mellitus was positively predicted by hypertension (HR 11.76, p 0.01). Osteoporosis was positively and negatively predicted by hypercholesterolemia (HR 3.25, p 0.01) and hypertension (HR 0.21, p 0.00), respectively.

CONCLUSIONS

The severity of the impairment of GH secretion does not predict the development of the clinical picture of GHD syndrome: untreated adult GHD does not increase the development of metabolic risk factors in hypopituitaric patients.

Glucocorticoid Replacement Affects Serum Adiponectin Levels and HDL-C in Patients With Secondary Adrenal Insufficiency

CONTEXT

Low serum adiponectin and high-density lipoprotein-cholesterol (HDL-C) levels are risk factors for cardiovascular disease. Patients with primary adrenal insufficiency are at higher risk of cardiovascular complications compared with healthy subjects. However, there is no information on the relationship between adiponectin and glucocorticoid replacement therapy in patients with secondary adrenal insufficiency (SAI).

OBJECTIVE

To determine the effects of intrinsic adrenal function and glucocorticoid replacement therapy on serum adiponectin levels and lipid profile in patients with SAI.

DESIGN

Part 1: a cross-sectional study. Part 2: a randomized, double-blind, crossover study.

SETTING

Osaka University Hospital, Osaka, Japan.

PATIENTS

Part 1: 58 patients diagnosed with nonfunctioning pituitary adenoma who underwent insulin tolerance test (ITT) for assessment of adrenal function. Part 2: 12 SAI patients randomly received hydrocortisone replacement therapy at a dose of 10, 20, or 30 mg/d for 4 weeks per term for three terms.

OUTCOME MEASUREMENTS

Part 1: we analyzed the relationship between serum cortisol levels during ITT and serum adiponectin levels and the lipid profile. Part 2: serum adiponectin levels and lipid profile were measured every 4 weeks.

RESULTS

Serum levels of adiponectin and HDL-C correlated significantly with peak cortisol levels after ITT. Serum adiponectin and HDL-C levels were significantly lower in patients with SAI than non-SAI. Serum levels of adiponectin and HDL-C increased in a hydrocortisone dose-dependent manner.

CONCLUSIONS

Glucocorticoid replacement therapy increased serum levels of adiponectin, an adipose-derived anti-atherogenic factor, and HDL-C in patients with SAI.

IGF-1 and cardiovascular disease

Atherosclerosis is an inflammatory arterial pathogenic condition, which leads to ischemic cardiovascular diseases, such as coronary artery disease and myocardial infarction, stroke, and peripheral arterial disease. Atherosclerosis is a multifactorial disorder and its pathophysiology is highly complex. Changes in expression of multiple genes coupled with environmental and lifestyle factors initiate cascades of adverse events involving multiple types of cells (e.g. vascular endothelial cells, smooth muscle cells, and macrophages). IGF-1 is a pleiotropic factor, which is found in the circulation (endocrine IGF-1) and is also produced locally in arteries (endothelial cells and smooth muscle cells). IGF-1 exerts a variety of effects on these cell types in the context of the pathogenesis of atherosclerosis. In fact, there is an increasing body of evidence suggesting that IGF-1 has beneficial effects on the biology of atherosclerosis. This review will discuss recent findings relating to clinical investigations on the relation between IGF-1 and cardiovascular disease and basic research using animal models of atherosclerosis that have elucidated some of the mechanisms underlying atheroprotective effects of IGF-1.

Metabolic syndrome as cardiovascular risk factor in childhood cancer survivors

Over the past decades, survival rates of childhood cancer have increased considerably from 5 to 30% in the early seventies to current rates exceeding 80%. This is due to the development of effective chemotherapy, surgery, radiotherapy and stem cell transplantation, combined with an optimized stratification of therapy and better supportive care regimens. As a consequence, active surveillance strategies of late sequelae have been developed to improve the quality of survival. Several epidemiological studies have reported an increased incidence of (components of) metabolic syndrome (MetS) and cardiovascular disease in childhood cancer survivors (CCS). Growth hormone deficiency (GHD) after cranial radiotherapy (CRT) has been previously described as an important cause of MetS. New insights suggest a role for abdominal radiotherapy as a determinant for MetS as well. The role of other risk factors, such as specific chemotherapeutic agents, steroids, gonadal impairment, thyroid morbidity and genetics, warrants further investigation. This knowledge is important to define subgroups of CCS that are at risk to develop (subclinical) MetS features. These survivors might benefit from standard surveillance and early interventions, for example lifestyle and diet advice and medical treatment, thereby preventing the development of cardiovascular disease.

Hypothalamic-Pituitary and Growth Disorders in Survivors of Childhood Cancer: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To formulate clinical practice guidelines for the endocrine treatment of hypothalamic-pituitary and growth disorders in survivors of childhood cancer.

PARTICIPANTS

An Endocrine Society-appointed guideline writing committee of six medical experts and a methodologist.

CONCLUSIONS

Due to remarkable improvements in childhood cancer treatment and supportive care during the past several decades, 5-year survival rates for childhood cancer currently are >80%. However, by virtue of their disease and its treatments, childhood cancer survivors are at increased risk for a wide range of serious health conditions, including disorders of the endocrine system. Recent data indicate that 40% to 50% of survivors will develop an endocrine disorder during their lifetime. Risk factors for endocrine complications include both host (e.g., age, sex) and treatment factors (e.g., radiation). Radiation exposure to key endocrine organs (e.g., hypothalamus, pituitary, thyroid, and gonads) places cancer survivors at the highest risk of developing an endocrine abnormality over time; these endocrinopathies can develop decades following cancer treatment, underscoring the importance of lifelong surveillance. The following guideline addresses the diagnosis and treatment of hypothalamic-pituitary and growth disorders commonly encountered in childhood cancer survivors.

THERAPY OF ENDOCRINE DISEASE: Growth hormone replacement therapy in adults: 30 years of personal clinical experience

The acute metabolic actions of purified human growth hormone (GH) were first documented in adult hypopituitary patients more than 50 years ago, and placebo-controlled long-term GH trials in GH-deficient adults (GHDA) surfaced in 1989 with the availability of biosynthetic human GH. Untreated GHDA is associated with excess morbidity and mortality from cardiovascular disease and the phenotype includes fatigue, reduced aerobic exercise capacity, abdominal obesity, reduced lean body mass, osteopenia and elevated levels of circulating cardiovascular biomarkers. Several of these features reverse and normalize with GH replacement. It remains controversial whether quality of life, assessed by questionnaires, improves. The known side effects are fluid retention and insulin resistance, which are reversible and dose dependent. The dose requirement declines markedly with age and is higher in women. Continuation of GH replacement into adulthood in patients with childhood-onset disease is indicated, if the diagnosis is reconfirmed. GH treatment of frail elderly subjects without documented pituitary disease remains unwarranted. Observational data show that mortality in GH-replaced patients is reduced compared to untreated patients. Even though this reduced mortality could be due to selection bias, GH replacement in GHDA has proven beneficial and safe.

Elevated (Pro)renin Receptor Expression Contributes to Maintaining Aerobic Metabolism in Growth Hormone Deficiency

Context

Growth hormone deficiency (GHD) leads to obesity and may induce tissue hypoxia. As (pro)renin receptor [(P)RR] is reported to contribute to the aerobic metabolism by stabilizing pyruvate dehydrogenase (PDH), it may play a substantial role in GHD.

Objective

We aimed to investigate serum soluble (P)RR [s(P)RR] concentration, the origin of s(P)RR, and significance of (P)RR in GHD.

Design, Setting, and Participants

Serum s(P)RR concentration was examined in 72 patients with pituitary diseases, including 32 patients with severe GHD (SGHD) and after GH replacement in 16 SGHD patients. Leptin-deficient ob/ob obese mice were treated with pegvisomant, a GH receptor antagonist, to explore the source of elevated serum s(P)RR in GHD. Adipocytes were cultured with 5% O₂ to examine the effects of hypoxia.

Results

Serum s(P)RR concentration was higher in patients with SGHD than in those without SGHD. Obesity was the important determinant of s(P)RR concentration. Serum s(P)RR concentration significantly decreased after GH replacement in SGHD patients. (P)RR mRNA expression was increased specifically in the adipose tissue (AT) of pegvisomant-treated obese mice compared with that of control obese mice. Hypoxia in cultured adipocytes increased (P)RR expression without affecting the PDH E1 β subunit (PDHB) expression; however, with (P)RR knockdown by small interfering RNA, hypoxia significantly decreased the expression of PDHB.

Conclusion

GHD patients showed increased serum s(P)RR concentration, possibly caused by obesity and hypoxia. (P)RR expression in AT of GHD patients may be elevated to help maintain aerobic metabolism under hypoxia. Thus, the elevated serum s(P)RR level may reflect hypoxia in ATs.

Long-Term Effect of Cranial Radiotherapy on Pituitary-Hypothalamus Area in Childhood Acute Lymphoblastic Leukemia Survivors

Survival rates of childhood cancer have improved markedly, and today more than 80 % of those diagnosed with a pediatric malignancy will become 5-year survivors. Nevertheless, survivors exposed to cranial radiotherapy (CRT) are at particularly high risk for long-term morbidity, such as endocrine insufficiencies, metabolic complications, and cardiovascular morbidity. Deficiencies of one or more anterior pituitary hormones have been described following therapeutic CRT for primary brain tumors, nasopharyngeal tumors, and following prophylactic CRT for childhood acute lymphoblastic leukemia (ALL). Studies have consistently shown a strong correlation between the total radiation dose and the development of pituitary deficits. Further, age at treatment and also time since treatment has strong implications on pituitary hormone deficiencies. There is evidence that the hypothalamus is more radiosensitive than the pituitary and is damaged by lower doses of CRT. With doses of CRT <50 Gy, the primary site of radiation damage is the hypothalamus and this usually causes isolated GH deficiency (GHD). Higher doses (>50 Gy) may produce direct anterior pituitary damage, which contributes to multiple pituitary deficiencies. The large group of ALL survivors treated with CRT in the 70–80-ties has now reached adulthood, and these survivors were treated mainly with 24 Gy, and the vast majority of these patients suffer from GHD. Further, after long-term follow-up, insufficiencies in prolactin (PRL) and thyroid stimulating hormone (TSH) have also been reported and a proportion of these patients were also adrenocoticotrophic hormone (ACTH) deficient. CRT to the hypothalamus causes neuroendocrine dysfunction, which means that the choice of GH test is crucial for the diagnosis of GHD.

Aerobic vs anaerobic exercise training effects on the cardiovascular system

Physical exercise is one of the most effective methods to help prevent cardiovascular (CV) disease and to promote CV health. Aerobic and anaerobic exercises are two types of exercise that differ based on the intensity, interval and types of muscle fibers incorporated. In this article, we aim to further elaborate on these two categories of physical exercise and to help decipher which provides the most effective means of promoting CV health.

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.

Plasma N-terminal Prosomatostatin and Risk of Incident Cardiovascular Disease and All-Cause Mortality in a Prospective Observational Cohort: the PREVEND Study

BACKGROUND

Somatostatin is a component of the well-known insulin-like growth factor-1/growth hormone (GH) longevity axis. There is observational evidence that increased GH is associated with an increased risk of cardiovascular disease (CVD). We aimed to investigate the potential association of plasma N-terminal fragment prosomatostatin (NT-proSST) with incident CVD and all-cause mortality in apparently healthy adults.

METHODS

We studied 8134 participants without history of CVD (aged 28-75 years; women, 52.6%) from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study in Groningen, the Netherlands. Plasma NT-proSST was measured in baseline samples. Outcomes were incidence of CVD and all-cause mortality.

RESULTS

In cross-sectional analyses, NT-proSST [mean (SD), 384.0 (169.3) pmol/L] was positively associated with male sex and age (both P < 0.001). During a median follow-up of 10.5 (Q1-Q3: 9.9-10.8) years, 708 (8.7%) participants developed CVD and 517 (6.4%) participants died. In univariable analyses, NT-proSST was associated with an increased risk of incident CVD and all-cause mortality (both P < 0.001). In multivariable analyses, these associations were independent of the Framingham risk factors, with hazard ratios (95% CI) per doubling of NT-proSST of 1.17 (1.03-1.34; P = 0.02) for incident CVD and of 1.28 (1.09-1.49; P = 0.002) for all-cause mortality. Addition of NT-proSST to the updated Framingham Risk Score improved reclassification (integrated discrimination improvement (P < 0.001); net reclassification improvement was 2.5% (P = 0.04)).

CONCLUSIONS

Plasma NT-proSST is positively associated with increased risk of future CVD and all-cause mortality, partly independent of traditional CVD risk factors. Further research is needed to address the nature of associations.

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.

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

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

Effect of growth hormone treatment on diastolic function in patients who have developed growth hormone deficiency after definitive treatment of acromegaly

OBJECTIVE

Although growth hormone (GH) replacement is prescribed for patients with hypopituitarism due to many etiologies, it is not routinely prescribed for patients with GH deficiency (GHD) after cure of acromegaly (acroGHD). This study was designed to investigate the effect of GH replacement on cardiac parameters in acroGHD.

DESIGN

We prospectively evaluated for 12months 23 patients with acroGHD: 15 subjects on GH replacement and eight subjects not on GH replacement. Main outcome measures included LV mass corrected for body surface area (LVM/BSA) and measures of diastolic dysfunction (E/A ratio and deceleration time), as assessed by echocardiography.

RESULTS

After 12months of follow-up, there were no differences between the GH-treated group and the untreated group in LVM/BSA (GH: 74.4±22.5g/m(2) vs untreated: 72.9±21.3g/m(2), p=0.89), E/A ratio (GH: 1.21±0.39 vs untreated: 1.08±0.39, p=0.50) or deceleration time (GH: 224.5±60.1ms vs untreated: 260±79.8ms, p=0.32). The overall degree of diastolic function was similar between the groups with 42.9% of untreated subjects and 50% of GH-treated subjects (p=0.76) classified as having normal diastolic function at follow-up.

CONCLUSIONS

There were no significant differences in LVM/BSA or parameters of diastolic function in patients with a history of acromegaly treated for GHD as compared to those who were untreated. These data are reassuring with respect to cardiovascular safety with GH use after treatment for acromegaly, although further longer term study is necessary to evaluate the safety and efficacy of GH treatment in this population.

Cardiovascular outcomes and conventional risk factors in non-diabetic adult patients with GH deficiency: A long-term retrospective cohort study

PURPOSE

To investigate the association between cardiovascular (CV) risk factors and cumulative CV events in patients with growth hormone deficiency (GHD) receiving GH replacement therapy (GHRT).

METHODS

53 non-diabetic adult GHD patients, aged 45.4±14.3years, 31 females, with a median follow up of 140months, were divided into two groups based on the presence (group A) or absence (group B) of systemic hypertension. Tertiles of age and LDL-cholesterol were considered as further potential prognosticators. Cumulative CV event rates were recorded and analyzed by Kaplan-Mayer method. Differences between patients with and without events were also evaluated.

RESULTS

Seventeen patients (32%) entered the group A and 36 (68%) the group B. A composite of fatal and non-fatal CV events occurred in 22.6% of patients, 47.1% in group A and 11% in group B (p=0.01), CV deaths in 3 patients (5.7%; annual death rate 0.49%), 2 of whom were in group A. At Kaplan-Mayer analysis, hypertension and age>55years were major prognosticators. The odds ratio was 7.1 (95% CI: 1.74-29.12, p<0.003) and 6.2 (95% CI: 1.54-25.04, p<0.006), respectively. LDL-cholesterol showed borderline statistical significance. Patients with CV events also had high prevalence of left ventricular hypertrophy, left atrial enlargement and subclinical systolic dysfunction.

CONCLUSIONS

In this study, outcomes were mainly related to hypertension and age (partially to LDL-cholesterol), confirming that management of GHD patients must be inclusive of treatment of conventional risk factors, being as important as GHRT. Optimal blood pressure control is crucial when a target organ damage is present and in patients older than 55years.

Effects of growth hormone-releasing hormone on visceral fat, metabolic, and cardiovascular indices in human studies

Increased visceral adipose tissue (VAT) is associated with reductions in endogenous GH secretion, possibly as a result of hyperinsulinemia, increased circulating free fatty acid, increased somatostatin tone, and reduced ghrelin. Reduced GH may, in turn, further exacerbate visceral fat accumulation because of decreased hormone-sensitive lipolysis in this depot. Data from multiple populations demonstrate that both reduced GH and increased VAT appear to contribute independently to dyslipidemia, increased systemic inflammation, and increased cardiovascular risk. The reductions in GH in states of visceral adiposity are characterized by reduced basal and pulsatile GH secretion with intact pulse frequency. Treatment with GH-releasing hormone (GHRH) provides a means to reverse these abnormalities, increasing endogenous basal and pulsatile GH secretion without altering pulse frequency. This review describes data from HIV-infected individuals and individuals with general obesity showing that treatment with GHRH significantly reduces visceral fat, ameliorates dyslipidemia, and reduces markers of cardiovascular risk. Further research is needed regarding the long-term efficacy and safety of this treatment modality.

GH and the cardiovascular system: an update on a topic at heart

In this review, the importance of growth hormone (GH) for the maintenance of normal cardiac function in adult life is discussed. Physiological effects of GH and underlying mechanisms for interactions between GH and insulin-like growth factor I (IGF-I) and the cardiovascular system are covered as well as the cardiac dysfunction caused both by GH excess (acromegaly) and by GH deficiency in adult hypopituitary patients. In both acromegaly and adult GH deficiency, there is also increased cardiovascular morbidity and mortality possibly linked to aberrations in GH status. Finally, the status of the GH/IGF-I system in relation to heart failure and the potential of GH as a therapeutic tool in the treatment of heart failure are reviewed in this article.

Long-term effects of growth hormone replacement therapy on liver function in adult patients with growth hormone deficiency

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) are frequently observed in patients with adult growth hormone deficiency (AGHD) and short-term GH replacement therapy (GHRT) has reportedly been efficacious in NAFLD and NASH. The aim of this study was to investigate whether long-term GHRT is an effective treatment for the hepatic comorbidities in AGHD.

DESIGN

This is a retrospective observational study. We recruited 54 consecutive hypopituitary patients with AGHD. Among them, 31 patients who had received GHRT for more than 24 months were compared with 19 age- and sex-matched patients without GHRT. We also analyzed the long term effect of GHRT on 14 patients diagnosed with NASH by liver biopsy. In addition, we subdivided the GHRT group into GH-responder and GH-non-responder groups and analyzed the factors associated with the efficacy of the treatment.

RESULTS

For a period of 24 months, the significant reduction of serum liver enzyme levels and a fibrotic marker was observed in patients receiving GHRT compared with the control group. Furthermore, GHRT also improved liver enzyme levels in AGHD patients with NASH. The GH-non-responder group showed a higher proportion of patients who gained weight during the study period.

CONCLUSIONS

These results indicate that GHRT is efficacious for improving serum liver enzyme levels for at least 24 months in patients with AGHD. To optimize this effect, it is important to avoid body weight gain during the treatment.

Extracellular water and blood pressure in adults with growth hormone (GH) deficiency: a genotype-phenotype association study

Objectives

Growth hormone deficiency (GHD) in adults is associated with decreased extracellular water volume (ECW). In response to GH replacement therapy (GHRT), ECW increases and blood pressure (BP) reduces or remains unchanged. Our primary aim was to study the association between polymorphisms in genes related to renal tubular function with ECW and BP before and 1 year after GHRT. The ECW measures using bioimpedance analysis (BIA) and bioimpedance spectroscopy (BIS) were validated against a reference method, the sodium bromide dilution method (Br⁻).

Design and Methods

Using a candidate gene approach, fifteen single-nucleotide polymorphisms (SNPs) in nine genes with known impact on renal tubular function (AGT, SCNN1A, SCNN1G, SLC12A1, SLC12A3, KCNJ1, STK39, WNK1 and CASR) were genotyped and analyzed for associations with ECW and BP at baseline and with their changes after 1 year of GHRT in 311 adult GHD patients. ECW was measured with the Br⁻, BIA, and BIS.

Results

Both BIA and BIS measurements demonstrated similar ECW results as the reference method. At baseline, after adjustment for sex and BMI, SNP rs2291340 in the SLC12A1 gene was associated with ECW volume in GHD patients (p = 0.039). None of the SNPs influenced the ECW response to GHRT. One SNP in the SLC12A3 gene (rs11643718; p = 0.024) and three SNPs in the SCNN1G gene [rs5723 (p = 0.02), rs5729 (p = 0.016) and rs13331086 (p = 0.035)] were associated with the inter-individual differences in BP levels at baseline. A polymorphism in the calcium-sensing receptor (CASR) gene (rs1965357) was associated with changes in systolic BP after GHRT (p = 0.036). None of these associations remained statistically significant when corrected for multiple testing.

Conclusion

The BIA and BIS are as accurate as Br⁻ to measure ECW in GHD adults before and during GHRT. Our study provides the first evidence that individual polymorphisms may have clinically relevant effects on ECW and BP in GHD adults.

Efficacy and safety of growth hormone treatment in adults with growth hormone deficiency: a systematic review of studies on morbidity

Due to the positive effects demonstrated in randomized clinical trials on cardiovascular surrogate markers and bone metabolism, a positive effect of growth hormone (GH) treatment on clinically relevant end-points seems feasible. In this review, we discuss the long-term efficacy and safety of GH treatment in adult patients with growth hormone deficiency (GHD) with emphasis on morbidity: fatal and nonfatal cardiovascular disease (CVD) and stroke, fractures, fatal and nonfatal malignancies and recurrences, and diabetes mellitus. A positive effect of GH treatment on CVD and fracture risk could be concluded, but study design limitations have to be considered. Stroke and secondary brain tumours remained more prevalent. However, other contributing factors have to be taken into account. Regrowth and recurrences of (peri)pituitary tumours were not increased in patients with GH treatment compared to similar patients without GH treatment. All fatal and nonfatal malignancies were not more prevalent in GH-treated adults compared to the general population. However, follow-up time is still relatively short. The studies on diabetes are difficult to interpret, and more evidence is awaited. In clinical practice, a more individualized assessment seems appropriate, taking into consideration the underlying diagnosis of GHD, other treatment regimens, metabolic profile and the additional beneficial effects of GH set against the possible risks. Large and thoroughly conducted observational studies are needed and seem the only feasible way to inform the ongoing debate on health care costs, drug safety and clinical outcomes.

Cross-sectional and longitudinal relation of IGF1 and IGF-binding protein 3 with lipid metabolism

BACKGROUND

Previous intervention studies in patients with GH disorders suggested an impact of IGF1 and IGF-binding protein 3 (IGFBP3) on lipid metabolism, whereas population-based studies revealed conflicting results. Therefore, we aimed to assess the cross-sectional and longitudinal associations between IGF1 or IGFBP3 serum levels and lipids (total, LDL, or HDL cholesterol and triglycerides) in a large-scale study.

METHODS

Data of 2935 subjects (1356 women) from the population-based Study of Health in Pomerania (SHIP) were used. ANOVA, quantile regression, and logistic regression models adjusted for age, waist circumference, physical activity, and alcohol consumption were performed.

RESULTS

In cross-sectional analyses, we detected that IGF1 and IGFBP3 levels were positively related to total and LDL cholesterol and inversely related to HDL cholesterol in both sexes. Furthermore, IGFBP3 levels showed a positive relationship to triglycerides. In total, IGFBP3 levels were more strongly associated to lipids than IGF1. In longitudinal analysis, we found no influence of baseline IGF1 or IGFBP3 serum concentration on incidentally elevated or reduced lipid levels. However, the positive relationship between IGFBP3 and incidentally elevated triglycerides barely missed statistical significance in women.

CONCLUSION

The present study showed strong cross-sectional associations between IGF1 or IGFBP3 and lipids, whereas no longitudinal relationships were revealed. Therefore, our findings suggest IGF1 and IGFBP3 as a risk marker rather than a risk factor for alterations in lipid metabolism. Further studies are needed to elucidate the mechanisms underlying the association between the GH/IGF axis and lipid metabolism.

Metabolic syndrome and cardiovascular risk among long-term survivors of acute lymphoblastic leukaemia - From the St. Jude Lifetime Cohort

Adult survivors of childhood acute lymphoblastic leukaemia (ALL) have a four-fold excess risk of mortality from cardiovascular disease. This cardiovascular risk has not been fully characterized. ALL survivors [n = 784, median age 31·7 years (18·9-59·1)] in the St. Jude Lifetime Cohort Study underwent evaluation for cardiovascular risk and metabolic syndrome (MetS) according to National Cholesterol Education Program - Adult Treatment Panel III criteria. Comparisons were made to 777 age-, sex-, and race-matched controls from the National Health and Nutrition Examination Survey (NHANES). MetS was identified in 259 survivors (33·6%) and associated with older age in 5-year increments (relative risk [RR] 1·13, 95% confidence interval [CI] 1·06-1·19) and prior cranial radiotherapy (CRT) (with craniospinal radiation: RR 1·88, 95%CI 1·32-2·67; without: RR 1·67, 95%CI 1·26-2·23). Measures of obesity were highly prevalent among female survivors and CRT recipients. Compared to NHANES controls, ALL survivors had a higher risk of MetS (RR 1·43, 95%CI 1·22-1·69), hypertension (RR 2·43, 95%CI 2·06-2·86), low high-density lipoprotein (RR 1·40, 95%CI 1·23-1·59), obesity (RR 1·47, 95%CI 1·29-1·68) and insulin resistance (1·64, 95%CI 1·44-1·86). This large study of clinically evaluated ALL survivors identified a high prevalence of MetS, obesity and cardiovascular risk, particularly in CRT recipients, underscoring the need for screening and aggressive reduction of modifiable risks.

Revisiting the relationship between blood pressure and insulin-like growth factor-1

Conflicting evidence exists on the relationship between blood pressure (BP) and insulin-like growth factor-1 (IGF-1). We reviewed available articles and pooled extrapolated regression coefficients for the association between BP and total IGF-1 as reported in the literature and included additional data from 912 individuals from the general population. We identified 20 studies including 11 704 subjects. We also measured total IGF-1, insulin-like binding protein-3, and BP in 912 black and white men and women from South Africa (aged 20-70 years). When plotting positive and negative weighed regression coefficients (29 data points) against IGF-1, we found a significant positive relationship (r=0.31; P<0.001; n=11 704) intercepting the 0 point at 191 ng/mL IGF-1, suggesting an inverse BP/IGF-1 relationship in low IGF-1 conditions, and a positive relationship in overtly high IGF-1 conditions. In conclusion, our findings suggest that the relationship between BP and IGF-1 is dependent on, or related to, IGF-1 concentrations, as an expression of direct or reverse causality. Low IGF-1 bioavailability (associated with aging and vascular deterioration), resistance to IGF-1, and the complex interplay between IGF-1 and other vasoactive hormones could mask the vasoprotective functions of IGF-1 in cross-sectional studies or could modify their functions in prospective studies.

Impact of the growth hormone replacement on bone status in growth hormone deficient adults

INTRODUCTION

Growth hormone deficiency (GHD) is associated with reduced bone mineral density (BMD). GH replacement has positive effect on BMD but the magnitude of this effect and its mechanism are debated.

OBJECTIVES

The objectives of this study was first, to assess the effect of GH replacement on BMD, and second, to evaluate the effect of GH treatment on bone turnover and microarchitecture and to assess the factors influencing the effect of the therapy on BMD.

PATIENTS AND METHODS

Adult GHD (AO-GHD) and childhood onset GHD (CO-GHD) patients treated with GH using IGF-I normalization GH replacement regimen were prospectively followed during 2 years. Lumbar spine (L1-L4) and total femur BMD by Hologic discovery, in the subset of patients also bone turnover markers; osteocalcin and carboxy-terminal collagen crosslinks (CTx) were assessed at baseline and at months 3, 6, 12 and 24, respectively. The trabecular bone score (TBS) derived from lumbar spine DXA by the iNsight® software was assessed in a subset of study population at baseline and months 12 and 24.

RESULTS

In total, 147 GHD patients (age 35.1 years, 84 males/63 females, 43 of childhood onset GHD/104 AO-GHD) were included. BMD of lumbar spine and femur increased significantly during the treatment (14% and 7% increase at 2 years, respectively; p<0.0001). Bone markers increased during the first 12 months of treatment with subsequent decrease of CTx. At month 24, significant increase in TBS was observed (4%, p=0.02). BMD increase was significantly higher in males (15% increase in males vs. 10% in females, p=0.037) and childhood onset GHD (CO-GHD) patients (13% increase in CO-GHD, p=0.004).

CONCLUSION

GH supplementation leads to an increase of BMD with corresponding changes in bone turnover markers and changes in microarchitecture as assessed by trabecular bone score. Positive effect of GH on bone status is more pronounced in males and CO-GHD adults.

Abnormal metabolic phenotype in middle-aged GH-deficient adults despite long-term recombinant human GH replacement

BACKGROUND

Adult GH deficiency (GHD) is associated with increased cardiovascular mortality. Recombinant human GH (rhGH) replacement has beneficial short-term metabolic effects. Although these positive effects sustain during longer follow-up, the prevalence of the metabolic syndrome (MS) remains increased in comparison with population data not adjusted for the higher mean BMI in GHD adults.

OBJECTIVE

To explore whether middle-aged patients with proposed physiological rhGH replacement have been normalized with respect to MS and its individual components in comparison with the general population, adjusted for age, sex, and BMI.

METHODS

One hundred and sixty-one GHD patients (aged 40-70 years) were studied before the start and after 5 years of rhGH replacement, and were compared with 1671 subjects (aged 45-66 years) from the general population (NEO Study).

RESULTS

MS PROPORTION IN GHD PATIENTS WAS 41.0% BEFORE THE START OF RHGH SUPPLETION, INCREASING TO 53.4% AFTER 5 YEARS (P=0.007). DESPITE CHRONIC RHGH REPLACEMENT, GHD PATIENTS HAD A 1.3-TIMES HIGHER MS PROPORTION THAN THE GENERAL POPULATION, INDEPENDENTLY OF AGE, SEX, AND BMI (95% CI 1.11.5, P=0.008). THE GHD POPULATION SHOWED A DIFFERENT METABOLIC PROFILE THAN THE GENERAL POPULATION WITH SIMILAR BMI: an increased risk of hypertriglyceridemia (adjusted prevalence ratio (PR) 2.0, 95% CI 1.7-2.3) and low HDL-C (adjusted PR 1.8, 95% CI 1.5-2.2), but less hyperglycemia (adjusted PR 0.5, 95% CI 0.4-0.7).

CONCLUSIONS

Despite 5 years of rhGH replacement, GHD patients still have a different metabolic profile and more frequently MS than the general population. These differences were independent of BMI, and resemble the unfavorable metabolic profile of untreated GHD patients, pointing to question the long-term benefits of rhGH replacement.

Growth hormone replacement normalizes impaired fibrinolysis: new insights into endothelial dysfunction in patients with hypopituitarism and growth hormone deficiency

BACKGROUND

Cardiovascular morbidity in adult patients with growth hormone deficiency (GHD) and hypopituitarism is increased. Clustering of cardiovascular risk factors leading to endothelial dysfunction and impaired fibrinolysis has also been reported and may account for progression to overt vascular changes in these patients. However, effect of long lasting GH replacement therapy on fibrinolytic capacity in GH deficient patients has not been investigated so far.

OBJECTIVE

To investigate fibrinolysis before and after challenge with venous occlusion in GHD patients with hypopituitarism before and during one year of growth hormone replacement.

DESIGN

Hospital based, interventional, prospective study.

INVESTIGATED SUBJECTS

Twenty one patient with GHD and fourteen healthy control subjects matched for age, sex and body mass index (BMI).

METHODS

Anthropometric, metabolic and fibrinolytic parameters were measured at the start and after three, six and twelve months of treatment with human recombinant GH.

RESULTS

At baseline GHD patients had significantly impaired fibrinolysis compared to healthy persons. During treatment with GH, significant changes were observed in insulin like growth factor 1(IGF-1) [from baseline 6.9(2.4-13.5) to 22.0(9.0-33.0) nmol/l after one month of treatment; p<0.01] and fibrinolysis. Improvement in fibrinolysis was mostly attributed to improvement of stimulated endothelial tissue plasminogen activator (t-PA) release in response to venous occlusion [from baseline 1.1(0.4-2.6) to 1.9(0.5-8.8) after one year of treatment; p<0.01].

CONCLUSION

Growth hormone replacement therapy has favorable effects on t-PA release from endothelium and net fibrinolytic capacity in GHD adults, which may contribute to decrease their risk of vascular complications.

Pituitary disease mortality: is it fiction?

During the last 20 years a tremendous improvement in the care of patients with pituitary tumors and of hypopituitarism has been achieved. If we resolve most of the possible causes of the increased cardiovascular disease and stroke mortality a normal survival is expected in these patients. Recently, a large population based study showed a decline in the risk of non-fatal stroke and of non-fatal cardiac events in GH deficient patients. This improvement was achieved by complete hormone replacement, including long term GH replacement, together with prescription of cardio protective drugs. If we follow the latest achievements in pituitary imaging, surgery techniques, hormone substitutions, cardio protective medications, we would expect a normal longevity in these patients. This review will focus on; (1) pituitary insufficiencies and hormone substitutions, (2) modes of cranial radiotherapy, and (3) new techniques in the surgery of a pituitary adenoma.

Pituitary function and functional outcome in adults after severe traumatic brain injury: the long-term perspective

Post-traumatic hypopituitarism (PTHP) has been linked to disability and decreased quality of life. However, no studies have addressed the long-term consequences of PTHP in adults with severe traumatic brain injury (TBI) only. In this study, we evaluated the relationship between pituitary function, quality of life, and functioning in 51 patients (16-65 years of age) with severe TBI who were admitted to Sahlgrenska University Hospital, Gothenburg from 1999 to 2002. The patients were assessed once, 2-10 years after trauma. Data from the time of injury were collected retrospectively to adjust for injury severity. Outcome measures included hormonal testing, the Short Form-36 Health Survey, the Glasgow outcome scale-extended, and a self-report questionnaire specifically designed for this study and based on the International Classification of Functioning, Disability and Health. Of 51 patients, 14 (27.5%) presented with PTHP, and 11 (21.6%) had isolated growth hormone deficiency. Patients with PTHP were more often overweight at follow-up (p=0.01); the higher body mass index was partially explained by PTHP (R2 change=0.07, p=0.001). Otherwise no significant correlation was found among PTHP, functioning, or patient-reported quality of life. This study-which is unique in the homogeneity of the patients, the long follow-up time, and the use of injury severity as an outcome predictor-did not confirm results from previous studies linking PTHP to a worse outcome. Therefore, screening for PTHP might be restricted to specific subgroups such as overweight patients, indicating growth hormone deficiency.

Psychosocial health and levels of employment in 851 hypopituitary Swedish patients on long-term GH therapy

CONTEXT

The psychosocial health and working capacity in hypopituitary patients receiving long-term growth hormone (GH) therapy are unknown.

OBJECTIVE

Psychosocial health and levels of employment were compared between GH deficient (GHD) patients on long-term replacement and the general population.

DESIGN AND PARTICIPANTS

In a Swedish nationwide study, 851 GHD patients [101 childhood onset (CO) and 750 adult onset (AO)] and 2622 population controls answered a questionnaire regarding current living, employment and educational level, alcohol consumption and smoking habits. The median time on GH therapy for both men and women with CO GHD was 9 years and for AO GHD 6 years, respectively.

RESULTS

As compared to the controls, the GHD patients were less often working full time, more often on sick leave/disability pension, and to a larger extent alcohol abstainers and never smokers (all; P<0.05). Predominantly CO GHD women and men, but to some extent also AO GHD women and men, lived less frequently with a partner and more often with their parents. Particularly AO GHD craniopharyngioma women used more antidepressants, while AO GHD men with a craniopharyngioma used more analgesics.

CONCLUSIONS

A working capacity to the level of the general population was not achieved among hypopituitary patients, although receiving long-term GH therapy. Patients were less likely to use alcohol and tobacco. The CO GHD population lived a less independent life.

Imaging of serotonin transporters with [123I]FP-CIT SPECT in the human hypothalamus

BACKGROUND

Serotonergic neurons in the rodent hypothalamus are implicated in key neuroendocrine and metabolic functions, including circadian rhythmicity. However, the assessment of the serotonergic system in the human hypothalamus in vivo is difficult as delineation of the hypothalamus is cumbersome with conventional region-of-interest analysis. In the present study, we aimed to develop a method to visualize serotonin transporters (SERT) in the hypothalamus. Additionally, we tested the hypothesis that hypothalamic SERT binding ratios are different between patients with hypothalamic impairment (HI), pituitary insufficiency (PI), and control subjects (C).

METHODS

SERT availability was determined in 17 subjects (6 HI, 5 PI, and 6 healthy controls), 2 h after injection of 123I-N-ω-fluoropropyl-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane ([123I]FP-CIT), using single-photon emission computed tomography (performed on a brain-dedicated system) fused with individual magnetic resonance imaging (MRI) scans of the brain. The hypothalamus (representing specific SERT binding) and cerebellum (representing nonspecific binding) were manually delineated on each MRI to assess [123I]FP-CIT binding and specific-to-nonspecific binding ratios.

RESULTS

In each healthy subject, [123I]FP-CIT binding was higher in the hypothalamus than in the cerebellum, and the mean hypothalamic binding ratio of SERT was 0.29 ± 0.23. We found no difference in hypothalamic binding ratios between HI, PI, and control subjects (HI 0.16 ± 0.24, PI 0.45 ± 0.39, C 0.29 ± 0.23, p value 0.281).

CONCLUSIONS

We were able to demonstrate SERT binding in the human hypothalamus in vivo. However, we did not find altered hypothalamic SERT binding in patients with hypothalamic impairment.

TRIAL REGISTRATION

Netherlands Trial Register: NTR2520.

Systemic hypertension counteracts potential benefits of growth hormone replacement therapy on left ventricular remodeling in adults with growth hormone deficiency

BACKGROUND

Systemic Hypertension (SH) is the main cause of left ventricular (LV) hypertrophy in the general population, but only scanty data are available on LV geometric remodeling (LVGR) in hypertensive patients with GH deficiency (GHD).

AIM

We investigated hypertensive LVGR in adult-onset GHD patients, before (T0) and after 55±16 months (T1) of individualized GH replacement therapy (GHRT).

SUBJECTS

Fifty-one patients, aged 45±15 yr, 29 women, were enrolled. Fifteen patients met criteria for SH (group A) whereas 36 were normotensive (group B).

METHODS

An echocardiogram was performed on all patients, at least twice (at T0 and T1). LV geometric remodeling as a relationship between LV mass (LVM) index and relative wall thickness (RWT), LV volumes, and ejection fraction were measured.

RESULTS

At T0, group A showed higher LV mass and LVM index values than group B; LV hypertrophy was found in 40% and 22% of patients, respectively (p=0.06). At T1, IGF-I levels had increased significantly in both groups. LV hypertrophy rate consistently increased in group A (from 40 to 60%, p<0.05), whereas slightly decreased in group B (from 22 to 19%, ns). Body surface area (p<0.001), age (p<0.05), and systolic blood pressure (p<0.05) were main determinants of LVM at multivariate analysis.

CONCLUSIONS

Along with body surface area and age, SH was significantly related to abnormal LVGR (LV hypertrophy) in GHD patients. As a result, blood pressure management and caloric intake restrictions are deemed necessary for this subset of patients.

Serum IGF1, metabolic syndrome, and incident cardiovascular disease in older people: a population-based study

OBJECTIVE

High as well as low levels of IGF1 have been associated with cardiovascular diseases (CVD). The relationship of IGF1 with (components of) the metabolic syndrome could help to clarify this controversy. The aims of this study were: i) to investigate the association of IGF1 concentration with prevalent (components of) the metabolic syndrome; and ii) to examine the role of (components of) the metabolic syndrome in the relationship between IGF1 and incident CVD during 11 years of follow-up.

METHODS

Data were used from the Longitudinal Aging Study Amsterdam, a cohort study in a representative sample of the Dutch older population (≥65 years). Data were available in 1258 subjects. Metabolic syndrome was determined using the definition of the US National Cholesterol Education Program Adult Treatment Panel III. CVD were ascertained by self-reports and mortality data.

RESULTS

Levels of IGF1 in the fourth quintile were associated with prevalent metabolic syndrome compared with the lowest quintile (odds ratio: 1.59, 95% confidence interval (CI) 1.09-2.33). The middle up to the highest quintile of IGF1 was positively associated with high triglycerides in women. Metabolic syndrome was not a mediator in the U-shaped relationship of IGF1 with CVD. Both subjects without the metabolic syndrome and low IGF1 levels (hazard ratio (HR) 1.75, 95% CI 1.12-2.71) and subjects with the metabolic syndrome and high IGF1 levels (HR 2.28, 95% CI 1.21-4.28) demonstrated increased risks of CVD.

CONCLUSIONS

In older people, high-normal IGF1 levels are associated with prevalent metabolic syndrome and high triglycerides. Furthermore, this study suggests the presence of different pathomechanisms for both low and high IGF1 levels and incident CVD.

The Challenge of Growth Hormone Deficiency Diagnosis and Treatment during the Transition from Puberty into Adulthood

In children with childhood-onset growth hormone deficiency, replacement GH therapy is effective in normalizing height during childhood and achieving adult height within the genetic target range. GH has further beneficial effects on body composition and metabolism through adult life. The transition phase, defined as the period from mid to late teens until 6-7 years after the achievement of final height, represents a crucial time for reassessing children's GH secretion and deciding whether GH therapy should be continued throughout life. Evidence-based guidelines for diagnosis and treatment of growth hormone deficient children during transition are lacking. The aim of this review is to critically review the up-to-date evidence on the best management of transition patients in order to ensure the correct definitive diagnosis and establish the appropriate therapeutic regimen.

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.

Effects on insulin sensitivity and body composition of combination therapy with GH and IGF1 in GH deficient adults with type 2 diabetes

OBJECTIVE

The aim of this trial was to evaluate the effect on insulin sensitivity and body composition of combination therapy with GH and IGF1 in adults with GH deficiency (GHD) and diabetes.

DESIGN, PATIENTS AND METHODS

A 6-month randomised placebo-controlled pilot study. Fourteen adults with GHD and type 2 diabetes were included. All received rhGH (0.15 mg/day for 1 month and 0.3 mg/day for 5 months) and were randomised to rhIGF1 (15 μg/kg per day for 1 month and 30 μg/kg per day for 5 months) or placebo. Insulin sensitivity was evaluated with euglycaemic hyperinsulinaemic clamp and body composition by computed tomography of abdominal and thigh fat, as well as bioimpedance.

RESULTS

Twelve patients completed the study. They were overweight and obese; at baseline, insulin sensitivity (M-value) was low. IGF1 and IGF1 SDS increased in both groups, with the highest increase in the GH and IGF1 group. Positive changes in M-value by +1.4 mg/kg per min, in subcutaneous abdominal fat by -60.5 ml and in fat-free mass by +4.4% were seen in the GH and IGF1 group. Corresponding values in the GH and placebo-treated group were -1.5 mg/kg per min, +23 ml and -0.04% respectively (P=0.02, P=0.04 and P=0.03 for delta values between groups). No safety issues occurred.

CONCLUSIONS

Combined GH and IGF1 treatment resulted in positive, but rather small effects, and might be a treatment option in a few selected patients.

Effects of growth hormone deficiency on body composition and biomarkers of cardiovascular risk after definitive therapy for acromegaly

BACKGROUND

Both growth hormone (GH) excess and GH deficiency are associated with abnormalities in body composition and biomarkers of cardiovascular risk in patients with pituitary disorders. However, the effects of developing GH deficiency after definitive treatment of acromegaly are largely unknown.

OBJECTIVE

To determine whether development of GH deficiency after definitive therapy for acromegaly is associated with increased visceral adiposity and biomarkers of cardiovascular risk compared with GH sufficiency after definitive therapy for acromegaly.

DESIGN

Cross-sectional.

PATIENTS

We studied three groups of subjects, all with a history of acromegaly (n = 76): subjects with subsequent GH deficiency (GHD; n = 31), subjects with subsequent GH sufficiency (GHS; n = 25) and subjects with active acromegaly (AA; n = 20). No study subjects were receiving somatostatin analogues, dopamine agonists or hGH.

MEASUREMENTS

Body composition (by DXA), abdominal adipose tissue depots (by cross-sectional CT), total body water (by bioimpedance analysis) and carotid intima-media thickness (IMT) were measured. Fasting morning serum was collected for high-sensitivity C-reactive protein (hsCRP), lipids and lipoprotein levels. An oral glucose tolerance test was performed, and homoeostasis model of assessment-insulin resistance (HOMA-IR) was calculated.

RESULTS

Abdominal visceral adipose tissue, total adipose tissue and total body fat were higher in subjects with GHD than GHS or AA (P < 0·05). Subcutaneous abdominal fat was higher, and fibrinogen and IMT were lower in GHD (but not GHS) than AA (P < 0·05). Patients with GHD had the highest hsCRP, followed by GHS, and hsCRP was lowest in AA (P < 0·05). Fasting glucose, 120-min glucose, fasting insulin, HOMA-IR and per cent total body water were lower in GHD and GHS than AA (P < 0·05). Triglycerides were higher in GHS than AA (P < 0·05). Lean body mass, mean arterial pressure, total cholesterol, HDL and LDL were comparable among groups.

CONCLUSIONS

Development of GHD after definitive treatment of acromegaly may adversely affect body composition and inflammatory biomarkers of cardiovascular risk but does not appear to adversely affect glucose homoeostasis, lipids and lipoproteins, or other cardiovascular risk markers.

Growth hormone and the cardiovascular system

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

Hepatic steatosis, GH deficiency and the effects of GH replacement: a Liverpool magnetic resonance spectroscopy study

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is reported to be more common in patients with GH deficiency (GHD) than in the general population. we aimed to determine: i) liver fat in patients with GHD compared with age and body mass index (BMI)-matched controls; and ii) effect of 6 months of GH replacement (GHR) on liver fat.

PARTICIPANTS AND METHODS

The study included 28 GHD patients and 24 controls. 12 patients were studied before and after 6 months of GHR. Anthropometry, liver enzymes and lipid profiles were measured, and body composition and intrahepatocellular lipid (IHCL) were determined by magnetic resonance imaging and spectroscopy.

RESULTS

Age and BMI (median (inter-quartile range)) of patients and controls were 52.6 (14) vs 52.6 (12) years (P=0.9) and 27.8 (24.7, 34.7) vs 27.9 (25.1, 32.1) kg/m(2) (P=0.9). IGF1 was lower in the patients (11.5 vs 16.0 nmol/l, P=0.002). There was no difference in liver transaminases, lipids or IHCL between patients and controls (2.8 (1.3, 8.6) vs 5.0 (1.5, 12.7), P=0.72), despite significantly higher visceral fat in GHD patients. Thirty-two percent of patients and 50% of controls had NAFLD (defined as IHCL >5.6%), and the relationship between IHCL and BMI was the same in each group. GHR significantly reduced abdominal subcutaneous and visceral fat in all patients; however, GHR did not reduce liver fat.

CONCLUSIONS

NAFLD is equally common in patients with GHD and matched controls. GHR is associated with a hierarchical reduction in fat deposition (fat loss: visceral > subcutaneous > liver). Further studies involving GHD patients with NAFLD are required to conclude the role of GHR in treating NAFLD.

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.

Does pituitary radiotherapy increase the risk of stroke and, if so, what preventative actions should be taken?

Radiotherapy for pituitary adenomas is a well-established and effective treatment, but it has been linked to a number of complications, including an increased risk of cerebrovascular disease and mortality. Possible underlying mechanisms include the direct effects of radiation on cerebral vasculature and deficiencies in specific pituitary hormones. Higher administered dose of radiotherapy is one of the main predictors of stroke. Although treatment strategies for stroke prevention in patients treated with pituitary radiotherapy have not been studied, using the lowest effective radiation dose and ensuring hormone deficiencies are adequately treated may be beneficial in reducing the risk of stroke.

Does growth hormone replacement therapy reduce mortality in adults with growth hormone deficiency? Data from the Dutch National Registry of Growth Hormone Treatment in adults

CONTEXT

Adults with GH deficiency (GHD) have a decreased life expectancy. The effect of GH treatment on mortality remains to be established.

OBJECTIVE

This nationwide cohort study investigates the effect of GH treatment on all-cause and cause-specific mortality and analyzes patient characteristics influencing mortality in GHD adults.

DESIGN, SETTING, AND PATIENTS

Patients in the Dutch National Registry of Growth Hormone Treatment in Adults were retrospectively monitored (1985-2009) and subdivided into treatment (n = 2229), primary (untreated, n = 109), and secondary control (partly treated, n = 356) groups.

MAIN OUTCOME MEASURES

Standardized mortality ratios (SMR) were calculated for all-cause, malignancy, and cardiovascular disease (CVD) mortality. Expected mortality was obtained from cause, sex, calendar year, and age-specific death rates from national death and population counts.

RESULTS

In the treatment group, 95 patients died compared to 74.6 expected [SMR 1.27 (95% confidence interval, 1.04-1.56)]. Mortality was higher in women than in men. After exclusion of high-risk patients, the SMR for CVD mortality remained increased in women. Mortality due to malignancies was not elevated. In the control groups mortality was not different from the background population. Univariate analyses demonstrated sex, GHD onset, age, and underlying diagnosis as influencing factors.

CONCLUSIONS

GHD men receiving GH treatment have a mortality rate not different from the background population. In women, after exclusion of high-risk patients, mortality was not different from the background population except for CVD. Mortality due to malignancies was not elevated in adults receiving GH treatment. Next to gender, the heterogeneous etiology is of influence on mortality in GHD adults with GH treatment.

The brazilian version of the Quality of Life Assessment of Growth Hormone Deficiency in Adults (QoL-AGHDA): Four-stage translation and validation

OBJECTIVE

This study reports on the Brazilian Portuguese adaptation of the QoL-AGHDA (Quality of Life Assessment of Growth Hormone Deficiency in Adults) for use in adult growth hormone deficient (GHD) patients.

MATERIALS AND METHODS

The translation process adopted the dual panel methodology. The questionnaire was tested through field-test interviews (16 GHD patients). In the final stage, data from 120 GHD patients (81 included in a test-retest analysis) were analyzed for internal consistency, test-retest reliability, convergent validity and validity among known groups.

RESULTS

The translation panels were successful and the draft version was amended to improve the wording as a result of the field-test interviews. Cronbach's alpha was 0.90 and test-retest reliability 0.88. QoL-AGHDA scores had the expected pattern of association with NHP scale scores and QoL-AGHDA was able to differentiate significantly between patients based on patient-reported general health (p < 0.01) and QoL (p < 0.01).

CONCLUSIONS

The adaptation of the QoL-AGHDA for a Brazilian population was successful and the adapted questionnaire was shown to be reliable and valid.