Growth hormone decreases visceral fat and improves cardiovascular risk markers in women with hypopituitarism: a randomized, placebo-controlled study

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.

The GH/IGF-1 Axis Is Associated With Intrahepatic Lipid Content and Hepatocellular Damage in Overweight/Obesity

CONTEXT

Obesity is a state of relative growth hormone (GH) deficiency, and GH has been identified as a candidate disease-modifying target in nonalcoholic fatty liver disease (NAFLD) because of its lipolytic and anti-inflammatory properties. However, the GH/IGF-1 axis has not been well characterized in NAFLD.

OBJECTIVE

We aimed to investigate serum GH and IGF-1 levels in relation to intrahepatic lipid content (IHL) and markers of hepatocellular damage and fibrosis in NAFLD.

METHODS

This cross-sectional study included 102 adults (43% women; age 19-67; BMI ≥ 25 kg/m2) without type 2 diabetes. IHL was measured by magnetic resonance spectroscopy; NAFLD was defined by ≥ 5% IHL. Peak-stimulated GH in response to GH releasing hormone and arginine was assessed as was serum IGF-1 (LC/MS).

RESULTS

There was no difference in mean age, BMI, or sex distribution in NAFLD vs controls. Mean (± SD) IHL was higher in NAFLD vs controls (21.8 ± 13.3% vs 2.9 ± 1.1%, P < 0.0001). Mean peak-stimulated GH was lower in NAFLD vs controls (9.0 ± 6.3 vs 15.4 ± 11.2 ng/mL, P = 0.003), including after controlling for age, sex, visceral adipose tissue, and fasting glucose. In a stepwise model, peak-stimulated GH predicted 14.6% of the variability in IHL (P = 0.004). Higher peak-stimulated GH was also associated with lower ALT. Higher serum IGF-1 levels were associated with lower risk of liver fibrosis by Fibrosis-4 scores.

CONCLUSION

Individuals with NAFLD have lower peak-stimulated GH levels but similar IGF-1 levels as compared to controls. Higher peak-stimulated GH levels are associated with lower IHL and less hepatocellular damage. Higher IGF-1 levels are associated with more favorable fibrosis risk scores. These data implicate GH and IGF-1 as potential disease modifiers in the development and progression of NAFLD.

Expression of IGF-1 receptor and GH receptor in hepatic tissue of patients with nonalcoholic fatty liver disease and nonalcoholic steatohepatitis

OBJECTIVE

The GH and IGF-1 axis is a candidate disease-modifying target in nonalcoholic fatty liver disease (NAFLD) given its lipolytic, anti-inflammatory and anti-fibrotic properties. IGF-1 receptor (IGF-1R) and GH receptor (GHR) expression in adult, human hepatic tissue is not well understood across the spectrum of NAFLD severity. Therefore, we sought to investigate hepatic IGF-1R and GHR expression in subjects with NAFLD utilizing gene expression analysis (GEA) and immunohistochemistry (IHC).

DESIGN

GEA (n = 318) and IHC (n = 30) cohorts were identified from the Massachusetts General Hospital NAFLD Tissue Repository. GEA subjects were categorized based on histopathology as normal liver histology (NLH), steatosis only (Steatosis), nonalcoholic steatohepatitis (NASH) without fibrosis (NASH F0), and NASH with fibrosis (NASH F1-4) with GEA by the Nanostring nCounter assay. IHC subjects were matched for age, body mass index (BMI), sex, and diabetic status across three groups (n = 10 each): NLH, Steatosis, and NASH with fibrosis (NASH F1-3). IHC for IGF-1R, IGF-1 and GHR was performed on formalin-fixed, paraffin-embedded hepatic tissue samples.

RESULTS

IGF-1R gene expression did not differ across NAFLD severity while IGF-1 gene expression decreased with increasing NAFLD severity, including when controlled for BMI and age. GHR expression did not differ by severity of NAFLD based on GEA or IHC.

CONCLUSIONS

IGF-1R and GHR expression levels were not significantly different across NAFLD disease severity. However, expression of IGF-1 was lower with increasing severity of NAFLD. Additional research is needed regarding the contribution of the GH/IGF-1 axis to the pathophysiology of NAFLD and NASH.

Recombinant Human Growth Hormone Inhibits Lipotoxicity, Oxidative Stress, and Apoptosis in a Mouse Model of Diabetic Cardiomyopathy

Recombinant human growth hormone (rhGH), widely used in clinical studies, exerts protective effects against cardiac damage. Here, we investigated the effects and mechanisms underlying the effects of rhGH on cardiac functions in db/db mice. C57BL/6J and db/db mice were subjected to rhGH treatment. Metabolic parameters, cardiac function and morphology, oxidative stress, lipid metabolism, and apoptosis were evaluated 16 weeks after rhGH treatment. Although rhGH did not significantly affect fasting blood glucose levels in db/db mice, it protected against diabetic cardiomyopathy, by improving cardiac function and reducing oxidative stress in the heart. In addition, rhGH treatment exhibited anti-apoptotic effects in the heart of db/db mice. The rhGH treatment, besides inhibiting oxidative stress and apoptosis, ameliorated cardiac dysfunction by inhibiting lipotoxicity in mice with type 2 diabetes. These findings suggest that rhGH is a promising therapeutic agent for diabetic cardiomyopathy.

Safety and effectiveness of Omnitrope® in patients with growth hormone deficiency: snapshot analysis of PATRO Adults study in the Italian population

PURPOSE

PATRO adults is an ongoing, multicenter, observational, post-marketing surveillance study aimed at investigating the long-term safety (primary endpoint) and effectiveness (secondary endpoint) of the recombinant human growth hormone (rhGH) Omnitrope® during routine clinical practice. This report describes data from Italian participants in PATRO Adults with growth hormone deficiency (GHD), up to August 2017.

METHODS

Participants were adults (aged > 18 years) with GHD requiring rhGH therapy and were prescribed Omnitrope®, including those who had previously received another rhGH product. Adverse events (AEs) were evaluated in all study participants. Data were collected on insulin-like growth factor (IGF)-I levels and cardiovascular risk factors, including blood pressure, lipids, and anthropometric parameters.

RESULTS

From September 2007 to August 2017, 88 patients (mean age 48.9 years, 58.0% male) were enrolled at 8 sites in Italy. The mean treatment duration with Omnitrope® was 51.5 ± 37 months. AEs occurred in 54 patients; the most common were asthenia (20.5%), headache (14.8%), and arthralgia (13.6%). Serious AEs occurred in 22 patients (25%), including pneumonia (n = 2) and renal failure (n = 2). Neoplasms (2 benign and 1 malignant) developed in three patients, but none were considered to be drug-related. There were no significant changes in fasting glucose or glycosylated hemoglobin (HbA1c) during the study period. Long-term Omnitrope® therapy showed slight positive effects on lipid profile, while no significant changes were observed in body weight and BMI during the study.

CONCLUSION

This snapshot analysis of Italian participants in PATRO Adults confirmed the long-term safety and effectiveness of Omnitrope® in adults with GHD.

Adherence to growth hormone therapy guidelines in a real-world French cohort of adult patients with growth hormone deficiency

OBJECTIVE

Using real-world data from patients with growth hormone deficiency (GHD), we evaluated whether clinical practice in France adheres to international guidelines regarding somatropin dose adjustment, and assessed the long-term effectiveness and safety of somatropin.

METHODS

Data were obtained from a national prospective systematic longitudinal routine follow-up programme of naive/non-naive adults with childhood-onset (CO) or adult-onset (AO) GHD treated with Norditropin® (Novo Nordisk A/S).

RESULTS

Between 2003 and 2006, 331 treatment-naive and non-naive adults with severe GHD were enrolled and followed for a median duration of approximately 5 years; 328 patients were available for analysis. At baseline, mean patient age was 39.2 years; median standard deviation score (SDS) for insulin-like growth factor-1 (IGF-1) level was -2.2 in naive patients, subsequently fluctuating between -0.1 and +0.3 SDS during the study period. Mean GH doses ranged between 0.25 and 0.51mg/day (naive patients) and 0.39 and 0.46mg/day (non-naive patients). Despite generally receiving a higher somatropin dose, women (naive/non-naive) tended to have lower IGF-1 levels than men. Median somatropin dose was consistently higher in patients with CO-GHD than patients with AO-GHD. Extreme IGF-1 values (<-2 or >+2 SDS) were not systematically accompanied by somatropin dose adjustments. Waist circumference improved in approximately one third of patients, at a mean 3.5 years. Somatropin was well tolerated; there were no cardiovascular or cerebrovascular events during the 5-year analysis period.

CONCLUSION

Current clinical practice of physicians in France follows international guidelines regarding somatropin dose adjustment in adults with GHD. However, dose adjustments are not always sufficient, notably in women, and treatment effects may have been delayed due to low somatropin dose (Clinical trial registration NCT01580605).

Body fat distribution and circulating adipsin are related to metabolic risks in adult patients with newly diagnosed growth hormone deficiency and improve after treatment

OBJECTIVE

The relationships between body fat distribution, the adipokine adipsin and metabolic risks were assessed in patients with adult growth hormone deficiency (AGHD) before and after growth hormone (GH) treatment.

METHODS

Sixty newly diagnosed AGHD patients were included in our study, 24 of whom were evaluated after at least one year of GH treatment. Anthropometric parameters, glucolipid metabolism and the adipokine adipsin were measured. Visceral adipose tissue (VAT) and body composition were evaluated using a dual-energy X-ray-absorptiometry (DXA) scanner.

RESULTS

At baseline, the higher VAT group had worse glucolipid metabolism parameters. Basal GH was negatively associated with VAT (r=-0.277, p = 0.045), while minimal correlations were found with fat mass depots, such as limbs and trunk fat (all p > 0.05). Adipsin was correlated with total body fat (r = 0.543, p < 0.001), VAT (r = 0.563, p < 0.001) and insulin resistance (r = 0.353, p = 0.006). The effect of GH administration on fat distribution was mainly reflected in the reduction in VAT. Partial improvements were found in lipid profiles, including increased high-density lipoprotein (HDL) and decreases in triglycerides (TGs) and lipoprotein(a), while glucose metabolism showed little change. The adipsin level also decreased significantly. The best predictors of VAT at baseline were trunk fat and IGF-I, and after treatment, VAT was predicted by decreased adipsin and an increase in lean mass.

CONCLUSIONS

(1) VAT is an important metabolic risk factor for AGHD patients. (2) GH treatment decreased body fat predominantly in the visceral and central fat depots. (3) The lipid profiles partially improved after treatment, while glucose metabolism showed little change.

Visceral Obesity and Its Shared Role in Cancer and Cardiovascular Disease: A Scoping Review of the Pathophysiology and Pharmacological Treatments

The association between obesity, cancer and cardiovascular disease (CVD) has been demonstrated in animal and epidemiological studies. However, the specific role of visceral obesity on cancer and CVD remains unclear. Visceral adipose tissue (VAT) is a complex and metabolically active tissue, that can produce different adipokines and hormones, responsible for endocrine-metabolic comorbidities. This review explores the potential mechanisms related to VAT that may also be involved in cancer and CVD. In addition, we discuss the shared pharmacological treatments which may reduce the risk of both diseases. This review highlights that chronic inflammation, molecular aspects, metabolic syndrome, secretion of hormones and adiponectin associated to VAT may have synergistic effects and should be further studied in relation to cancer and CVD. Reductions in abdominal and visceral adiposity improve insulin sensitivity, lipid profile and cytokines, which consequently reduce the risk of CVD and some cancers. Several medications have shown to reduce visceral and/or subcutaneous fat. Further research is needed to investigate the pathophysiological mechanisms by which visceral obesity may cause both cancer and CVD. The role of visceral fat in cancer and CVD is an important area to advance. Public health policies to increase public awareness about VAT's role and ways to manage or prevent it are needed.

Diagnosis and Treatment of Growth Hormone Deficiency: A Position Statement from Korean Endocrine Society and Korean Society of Pediatric Endocrinology

Growth hormone (GH) deficiency is caused by congenital or acquired causes and occurs in childhood or adulthood. GH replacement therapy brings benefits to body composition, exercise capacity, skeletal health, cardiovascular outcomes, and quality of life. Before initiating GH replacement, GH deficiency should be confirmed through proper stimulation tests, and in cases with proven genetic causes or structural lesions, repeated GH stimulation testing is not necessary. The dosing regimen of GH replacement therapy should be individualized, with the goal of minimizing side effects and maximizing clinical improvements. The Korean Endocrine Society and the Korean Society of Pediatric Endocrinology have developed a position statement on the diagnosis and treatment of GH deficiency. This position statement is based on a systematic review of evidence and expert opinions.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY GUIDELINES FOR MANAGEMENT OF GROWTH HORMONE DEFICIENCY IN ADULTS AND PATIENTS TRANSITIONING FROM PEDIATRIC TO ADULT CARE

Objective: The development of these guidelines is sponsored by the American Association of Clinical Endocrinologists (AACE) Board of Directors and American College of Endocrinology (ACE) Board of Trustees and adheres with published AACE protocols for the standardized production of clinical practice guidelines (CPG). Methods: Recommendations are based on diligent reviews of clinical evidence with transparent incorporation of subjective factors, according to established AACE/ACE guidelines for guidelines protocols. Results: The Executive Summary of this 2019 updated guideline contains 58 numbered recommendations: 12 are Grade A (21%), 19 are Grade B (33%), 21 are Grade C (36%), and 6 are Grade D (10%). These detailed, evidence-based recommendations allow for nuance-based clinical decision-making that addresses multiple aspects of real-world care of patients. The evidence base presented in the subsequent Appendix provides relevant supporting information for the Executive Summary recommendations. This update contains 357 citations of which 51 (14%) are evidence level (EL) 1 (strong), 168 (47%) are EL 2 (intermediate), 61 (17%) are EL 3 (weak), and 77 (22%) are EL 4 (no clinical evidence). Conclusion: This CPG is a practical tool that practicing endocrinologists and regulatory bodies can refer to regarding the identification, diagnosis, and treatment of adults and patients transitioning from pediatric to adult-care services with growth hormone deficiency (GHD). It provides guidelines on assessment, screening, diagnostic testing, and treatment recommendations for a range of individuals with various causes of adult GHD. The recommendations emphasize the importance of considering testing patients with a reasonable level of clinical suspicion of GHD using appropriate growth hormone (GH) cut-points for various GH-stimulation tests to accurately diagnose adult GHD, and to exercise caution interpreting serum GH and insulin-like growth factor-1 (IGF-1) levels, as various GH and IGF-1 assays are used to support treatment decisions. The intention to treat often requires sound clinical judgment and careful assessment of the benefits and risks specific to each individual patient. Unapproved uses of GH, long-term safety, and the current status of long-acting GH preparations are also discussed in this document. LAY ABSTRACT This updated guideline provides evidence-based recommendations regarding the identification, screening, assessment, diagnosis, and treatment for a range of individuals with various causes of adult growth-hormone deficiency (GHD) and patients with childhood-onset GHD transitioning to adult care. The update summarizes the most current knowledge about the accuracy of available GH-stimulation tests, safety of recombinant human GH (rhGH) replacement, unapproved uses of rhGH related to sports and aging, and new developments such as long-acting GH preparations that use a variety of technologies to prolong GH action. Recommendations offer a framework for physicians to manage patients with GHD effectively during transition to adult care and adulthood. Establishing a correct diagnosis is essential before consideration of replacement therapy with rhGH. Since the diagnosis of GHD in adults can be challenging, GH-stimulation tests are recommended based on individual patient circumstances and use of appropriate GH cut-points. Available GH-stimulation tests are discussed regarding variability, accuracy, reproducibility, safety, and contraindications, among other factors. The regimen for starting and maintaining rhGH treatment now uses individualized dose adjustments, which has improved effectiveness and reduced reported side effects, dependent on age, gender, body mass index, and various other individual characteristics. With careful dosing of rhGH replacement, many features of adult GHD are reversible and side effects of therapy can be minimized. Scientific studies have consistently shown rhGH therapy to be beneficial for adults with GHD, including improvements in body composition and quality of life, and have demonstrated the safety of short- and long-term rhGH replacement. Abbreviations: AACE = American Association of Clinical Endocrinologists; ACE = American College of Endocrinology; AHSG = alpha-2-HS-glycoprotein; AO-GHD = adult-onset growth hormone deficiency; ARG = arginine; BEL = best evidence level; BMD = bone mineral density; BMI = body mass index; CI = confidence interval; CO-GHD = childhood-onset growth hormone deficiency; CPG = clinical practice guideline; CRP = C-reactive protein; DM = diabetes mellitus; DXA = dual-energy X-ray absorptiometry; EL = evidence level; FDA = Food and Drug Administration; FD-GST = fixed-dose glucagon stimulation test; GeNeSIS = Genetics and Neuroendocrinology of Short Stature International Study; GH = growth hormone; GHD = growth hormone deficiency; GHRH = growth hormone-releasing hormone; GST = glucagon stimulation test; HDL = high-density lipoprotein; HypoCCS = Hypopituitary Control and Complications Study; IGF-1 = insulin-like growth factor-1; IGFBP = insulin-like growth factor-binding protein; IGHD = isolated growth hormone deficiency; ITT = insulin tolerance test; KIMS = Kabi International Metabolic Surveillance; LAGH = long-acting growth hormone; LDL = low-density lipoprotein; LIF = leukemia inhibitory factor; MPHD = multiple pituitary hormone deficiencies; MRI = magnetic resonance imaging; P-III-NP = procollagen type-III amino-terminal pro-peptide; PHD = pituitary hormone deficiencies; QoL = quality of life; rhGH = recombinant human growth hormone; ROC = receiver operating characteristic; RR = relative risk; SAH = subarachnoid hemorrhage; SDS = standard deviation score; SIR = standardized incidence ratio; SN = secondary neoplasms; T3 = triiodothyronine; TBI = traumatic brain injury; VDBP = vitamin D-binding protein; WADA = World Anti-Doping Agency; WB-GST = weight-based glucagon stimulation test.

Expression of the growth hormone receptor isoforms and its correlation with the metabolic profile in morbidly obese subjects

BACKGROUND AND AIM OF THE STUDY

Given the lipolytic effect of GH and its potential role in determining adipose tissue distribution, we evaluated the expression of the GH hormone receptor (GHR) isoforms in patients with morbid obesity seeking associations with metabolic parameters.

METHODS

262 morbidly obese subjects (mean age 42.5 ± 11 years, 75% women) underwent PCR-genotyping of the exon 3 GHR polymorphism. In 17 of these subjects, who proved to be heterozygous for the exon 3 genotype (+3/-3), subcutaneous and visceral adipose tissue was obtained during bariatric surgery; total RNA was extracted, reversely transcribed, and the different isoforms of the GHR (exon 3 containing and lacking flGHR as well as the trGHR) were PCR-amplified using specific primers.

RESULTS

27% were +3/+3 homozygous, 20% -3/-3 homozygous and 53% were +3/-3 heterozygous. Compared to subjects homozygous for the +3 genotype, homozygous and heterozygous carriers of the -3 genotype were significantly heavier and tended to have a higher HOMA 2-IR. Expression of the flGHR and trGHR mRNA was demonstrated in all evaluated samples of subcutaneous and visceral adipose tissue from the 17 patients. The exon 3+ isoform was expressed in all adipose tissue samples, whereas only six subjects expressed the 3- isoform as well. The only distinctive feature of these six patients was a higher HbA1c.

CONCLUSIONS

The heterozygous GHR +3/-3 genotype is more prevalent in subjects with morbid obesity. Patients expressing the exon +3 and exon -3 isoforms in adipose tissue had a higher HbA1c, than those expressing only the exon -3 isoform.

Growth hormone controls lipolysis by regulation of FSP27 expression

Growth hormone (GH) has long been known to stimulate lipolysis and insulin resistance; however, the molecular mechanisms underlying these effects are unknown. In the present study, we demonstrate that GH acutely induces lipolysis in cultured adipocytes. This effect is secondary to the reduced expression of a negative regulator of lipolysis, fat-specific protein 27 (FSP27; aka Cidec) at both the mRNA and protein levels. These effects are mimicked in vivo as transgenic overexpression of GH leads to a reduction of FSP27 expression. Mechanistically, we show GH modulation of FSP27 expression is mediated through activation of both MEK/ERK- and STAT5-dependent intracellular signaling. These two molecular pathways interact to differentially manipulate peroxisome proliferator-activated receptor gamma activity (PPARγ) on the FSP27 promoter. Furthermore, overexpression of FSP27 is sufficient to fully suppress GH-induced lipolysis and insulin resistance in cultured adipocytes. Taken together, these data decipher a molecular mechanism by which GH acutely regulates lipolysis and insulin resistance in adipocytes.

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

BACKGROUND AND OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

The effect of growth hormone on bioactive IGF in overweight/obese women

OBJECTIVE

Overweight/obesity is characterized by decreased growth hormone (GH) secretion whereas circulating IGF-I levels are less severely reduced. Yet, the activity of the circulating IGF-system appears to be normal in overweight/obese subjects, as estimated by the ability of serum to activate the IGF-I receptor in vitro (bioactive IGF). We hypothesized that preservation of bioactive IGF in overweight/obese women is regulated by an insulin-mediated suppression of IGF-binding protein-1 (IGFBP-1) and IGFBP-2, and by suppression of IGFBP-3, mediated by low GH. We additionally hypothesized that increases in bioactive IGF would drive changes in body composition with low-dose GH administration.

DESIGN

Cross-sectional analysis and 3-month interim analysis of a 6-month randomized, placebo-controlled study of GH administration in 50 overweight/obese women without diabetes mellitus. Bioactive IGF (kinase receptor activation assay) and body composition (DXA) were measured.

RESULTS

Prior to treatment, IGFBP-3 (r = -0.33, p = 0.02), but neither IGFBP-1 nor IGFBP-2, associated inversely with bioactive IGF. In multivariate analysis, lower IGFBP-3 correlated with lower peak stimulated GH (r = 0.45, p = 0.05) and higher insulin sensitivity (r = -0.74, p = 0.003). GH administration resulted in an increase in mean serum IGF-I concentrations (144 ± 56 to 269 ± 66 μg/L, p < 0.0001) and bioactive IGF (1.29 ± 0.39 to 2.60 ± 1.12 μg/L, p < 0.0001). The treatment-related increase in bioactive IGF, but not total IGF-I concentration, predicted an increase in lean mass (r = 0.31, p = 0.03) and decrease in total adipose tissue/BMI (r = -0.43, p = 0.003).

CONCLUSIONS

Our data suggest that in overweight/obesity, insulin sensitivity and GH have opposing effects on IGF bioactivity through effects on IGFBP-3. Furthermore, increases in bioactive IGF, rather than IGF-I concentration, predicted GH administration-related body composition changes.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00131378.

The Glycoproteomics-MS for Studying Glycosylation in Cardiac Hypertrophy and Heart Failure

With recent advancements of analytical techniques and mass spectrometric instrumentations, proteomics has been widely exploited to study the regulation of protein expression associated with disease states. Many proteins may undergo abnormal change in response to the stimulants, leading to regulation of posttranslationally modified proteins. In this review, the physiological and pathological roles of protein glycosylation in cardiac hypertrophy is discussed, and how the signal pathways regulate heart function and leading to heart failure. The analytical methods for analysis of protein glycosylation, including glycans, glycosite, occupancy, and heterogeneity is emphasized. The rationale on glycoproteins as disease biomarkers is also discussed. The authors also propose potential research in this field and challenges in the diagnosis and treatment of this disease.

Treatment of adult growth hormone deficiency with human recombinant growth hormone: an update on current evidence and critical review of advantages and pitfalls

Adult-onset growth-hormone (GH) deficiency (GHD) is a rare disorder, which most commonly results from pituitary or peripituitary tumors and their treatment, and is characterized by alterations in body composition, carbohydrate and lipid metabolism, bone mineral density, cardiovascular risk profile and quality of life, all of which may contribute to an increased morbidity and mortality. Since recombinant human GH (rhGH) became available in 1985, several studies have provided evidence of its beneficial effects, despite the potential risk of developing adverse effects, and much clinical experience has been accumulated. However, in adults, the precise therapeutic role of GH replacement therapy and the individual response to it remains highly variable and is still a matter of debate. In this article, we present a critical review of the available evidence on rhGH replacement therapy in GHD adults, emphasizing the pitfalls clinicians encounter in the diagnosis of GHD and monitoring of rhGH replacement therapy. We will cover all the relevant aspects regarding the potential usefulness of GH treatment, including the hot topic of mortality.

The Immune System in Obesity: Developing Paradigms Amidst Inconvenient Truths

PURPOSE OF REVIEW

Adipose tissue (AT) houses both innate and adaptive immune systems that are crucial for preserving AT function and metabolic homeostasis. In this review, we summarize recent information regarding progression of obesity-associated AT inflammation and insulin resistance. We additionally consider alterations in AT distribution and the immune system in males vs. females and among different racial populations.

RECENT FINDINGS

Innate and adaptive immune cell-derived inflammation drives insulin resistance both locally and systemically. However, new evidence also suggests that the immune system is equally vital for adipocyte differentiation and protection from ectopic lipid deposition. Furthermore, roles of anti-inflammatory immune cells such as regulatory T cells, "M2-like" macrophages, eosinophils, and mast cells are being explored, primarily due to promise of immunotherapeutic applications. Both immune responses and AT distribution are strongly influenced by factors like sex and race, which have been largely underappreciated in the field of metabolically-associated inflammation, or meta-flammation. More studies are required to recognize factors that switch inflammation from controlled to uncontrolled in obesity-associated pathogenesis and to integrate the combined effects of meta-flammation and immunometabolism. It is critical to recognize that the AT-associated immune system can be alternately beneficial and destructive; therefore, simply blocking immune responses early in obesity may not be the best clinical approach. The dearth of information on gender and race-associated disparities in metabolism, AT distribution, and the immune system suggest that a greater understanding of such differences will be critical to develop personalized treatments for obesity and the associated metabolic dysfunction.

Hormonal factors in the control of the browning of white adipose tissue

Adipose tissue has been historically classified into anabolic white adipose tissue (WAT) and catabolic brown adipose tissue (BAT). Recent studies have revealed the plasticity of WAT, where white adipocytes can be induced into 'brown-like' heat-producing adipocytes (BRITE or beige adipocytes). Recruiting and activating BRITE adipocytes in WAT (so-called 'browning') is believed to provide new avenues for the treatment of obesity-related diseases. A number of hormonal factors have been found to regulate BRITE adipose development and activity through autocrine, paracrine and systemic mechanisms. In this mini-review we will discuss the impact of these factors on the browning process, especially those hormonal factors identified with direct effects on white adipocytes.

Impact of Growth Hormone on Regulation of Adipose Tissue

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

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.

Metabolic alterations in paediatric GH deficiency

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

Hormonal Replacement in Hypopituitarism in Adults: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To formulate clinical practice guidelines for hormonal replacement in hypopituitarism in adults.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of six experts, a methodologist, and a medical writer. The American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology co-sponsored this guideline.

EVIDENCE

The Task Force developed this evidence-based guideline using the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The Task Force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Committees and members of the Endocrine Society, the American Association for Clinical Chemistry, the Pituitary Society, and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines.

CONCLUSIONS

Using an evidence-based approach, this guideline addresses important clinical issues regarding the evaluation and management of hypopituitarism in adults, including appropriate biochemical assessments, specific therapeutic decisions to decrease the risk of co-morbidities due to hormonal over-replacement or under-replacement, and managing hypopituitarism during pregnancy, pituitary surgery, and other types of surgeries.

Liver fat in adults with GH deficiency: comparison to matched controls and the effect of GH replacement

CONTEXT

Existing data regarding the association between growth hormone deficiency (GHD) and liver fat content are conflicting.

OBJECTIVE

We aimed (i) to assess intrahepatocellular lipid (IHCL) content in hypopituitary adults with GHD compared to matched controls and (ii) to evaluate the effect of growth hormone (GH) replacement on IHCL content.

DESIGN

Cross-sectional comparison and controlled intervention study.

PATIENTS, PARTICIPANTS

Cross-sectional comparison: Twenty-two hypopituitary adults with GHD and 44 healthy controls matched for age, BMI, gender and ethnicity. Intervention study: nine GHD patients starting GH replacement (GH Rx group) and nine GHD patients not starting replacement therapy (non-GH Rx group).

INTERVENTION

Intervention study: GH replacement for 6 months in the GH Rx group, dosage was titrated to achieve normal IGF-1 levels.

MAIN OUTCOME MEASURES

HCL content determined by proton magnetic resonance spectroscopy ((1) H MRS).

RESULTS

Cross-sectional Comparison: There was no difference in IHCL content between GHD patients and healthy controls (1·89% (0·30, 4·03) vs 1·14% (0·22, 2·32); P = 0·2), and the prevalence of patients with hepatic steatosis (IHCL of ≥ 5·56%) was similar in the two groups (22·7% vs 15·9%; chi-square probability = 0·4). Intervention study: The change in IHCL content over 6 months did not differ between the GH Rx group and the non-GH Rx group (-0·63 ± 4·53% vs + 0·11 ± 1·46%; P = 0·6).

CONCLUSIONS

In our study, liver fat content and the prevalence of hepatic steatosis did not differ between hypopituitary adults with GHD and matched controls. In GHD patients, GH replacement had no effect on liver fat content.

Growth hormone receptor expression in human gluteal versus abdominal subcutaneous adipose tissue: Association with body shape

OBJECTIVE

Growth hormone (GH) administration reduces abdominal, but not lower body, fat mass. To gain insight into the underlying mechanisms, this study examined the expression of the GH receptor (GHR) and some of its targets in abdominal and gluteal adipose tissue.

METHODS

GHR and GH targets in the lipolytic pathway were assessed (quantitative PCR/Western blotting) in adipose aspirates from premenopausal women [n = 15, age 26.9 ± 6.1 years, body mass index (BMI) 28.0 ± 6.8 kg/m(2) ] and men (n = 28, age 29.2 ± 7.0 years, BMI 26.9 ± 3.7 kg/m(2) ).

RESULTS

GHR mRNA expression was lower in the gluteal depot when compared with the abdominal depot (P = 0.01). Abdominal GHR correlated negatively with age and BMI, whereas gluteal GHR was associated with lower waist-to-hip ratio (WHR), that is, pear shape. In both sites, GHR mRNA correlated strongly with genes important for the regulation of lipolysis: adipose tissue triglyceride lipase (ATGL), hormone-sensitive lipase, perilipin, and CIDEA (all P < 0.001), independently of BMI, WHR, age, and sex. GHR protein was lower in the gluteal fat when compared with the abdominal fat (P = 0.03) and correlated with ATGL protein in the gluteal depot (P < 0.001).

CONCLUSIONS

GHR levels correlate with levels of lipases and lipid droplet-associated proteins crucial for lipolysis. Thus, higher GHR expression in the abdominal depot when compared with the gluteal depot may underlie the in vivo effect of GH to specifically reduce abdominal adipose tissue mass.

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.

Unintended positive and negative effects of drugs on lipoproteins

PURPOSE OF REVIEW

Dyslipidaemia is an important cardiovascular disease risk factor. Many drugs affect lipid profile and lipoprotein metabolism. We reviewed unintended effects of nonlipid modifying, commonly used medications on lipid profile and lipoprotein metabolism.

RECENT FINDING

Several detrimental effects of many drug classes such as diuretics, antidepressant, anticonvulsant and antiretroviral drugs have been reported, whereas other drug classes such as antiobesity, alpha 1-blockers, oestrogens and thyroid replacement therapy were associated with positive effects.

SUMMARY

Dyslipidaemia is a common side-effect of many medications. This should be taken into consideration, especially in patients at high risk of cardiovascular disease. Other drugs demonstrated positive effects on circulating lipids and lipoproteins. The impact of these unintended effects on atherosclerotic disease risk and progression is unclear.

Effects of low dose versus high dose human growth hormone on body composition and lipids in adults with GH deficiency: a meta-analysis of placebo-controlled randomized trials

PURPOSE

Doses of growth hormone in adults with growth hormone deficiency are now lower than previously. However, it is not clear they are as effective as higher doses. The objective of this meta-analysis was to assess efficacy of low to moderate dose (LD) GH replacement on standard endpoints of GH compared to higher doses.

METHODS

A meta-analysis was carried out using PubMed, Cochrane and Embase databases from 1960 to 9/23/12. Three reviewers identified randomized double-blind, placebo-controlled trials of 6 months duration. Of 173 publications, 28 representing 22 trials (591 GH-treated patients and 562 placebo) were included. Data were independently extracted by three reviewers. Endpoints were analyzed if ≥4 studies per dose group reported baseline and 6 month data.

RESULTS

Mean lean body mass (LBM) increased by 2.61 kg in GH-treated subjects versus 0.04 in the placebo group (P < 0.0001). Fat mass (FM) was reduced by -2.19 kg versus 0.31 (GH vs. placebo) (P = 0.0002). Changes in LBM and FM were dose-related (P = 0.02 and 0.007, respectively), high dose (HD) being more effective than low dose (LBM P = 0.03 and FM P = 0.04). In contrast, treatment with GH reduced total cholesterol -0.38 mmol/L versus. 0.01 (placebo) (P < 0.0001), and low density lipoprotein cholesterol (LDL-C) -0.42 mmol/L versus -0.1 (P = 0.0009), but there were no differences between LD and HD GH.

CONCLUSIONS

LDs of hGH improve total- and LDL-C, and body composition. Higher doses are more effective on body composition, but not lipids.

Insulin resistance, metabolic syndrome and chronic low grade inflammation in Sheehan's syndrome on standard replacement therapy: a case control study

BACKGROUND

Increased clustering of metabolic risk factors has been demonstrated in patients with hypopituitarism on standard replacement therapy. This usually has been attributed to persistent growth hormone deficiency, though contribution from underlying etiology of hypopituitarism cannot be underestimated. We, therefore, studied conventional metabolic risk factors and pro inflammatory markers in a cohort of hypopituitary patients in whom the etiology was Sheehan's syndrome.

MATERIAL & METHODS

We studied 30 GH naive patients with Sheehan's syndrome (SS) on standard replacement therapy and compared with healthy age, BMI and parity matched controls. All subjects were normotensive, non-diabetic, non-smokers and none had history of any acute or chronic illness. We recorded height, weight, BMI, waist circumference and waist hip ratio, besides measuring biochemical parameters like lipid profile, fasting plasma glucose and insulin, sVCAM-1, ICAM-1 and hsCRP.

RESULTS

Metabolic syndrome and impaired glucose tolerance were more common with SS patients. Similarly total cholesterol (mean ± SD, 5.21 ± 0.98 vs 4.57 ± 0.88, P = 0.00), LDL-cholesterol (3.15 ± 0.90 vs 2.67 ± 0.75, P = 0.02), triglycerides (2.14 ± 1.00 vs 1.43 ± 0.45, P = 0.00) and pro-inflammatory markers i.e. hsCRP (3.95 ± 2.58 vs 1.45 ± 2.77, P = 0.00) were significantly higher in patients with SS. hsCRP positively correlated with fasting insulin (r = 0.40, P = 0.02), HOMA-IR (r = 0.38, P = 0.03) and negatively with HDL (r = - 0.33, P = 0.05).

CONCLUSIONS

GH naïve SS patients on standard replacement therapy have increased clustering of metabolic and pro-inflammatory risk factors.

Analysis of short- and long-term metabolic effects of growth hormone replacement therapy in adult patients with craniopharyngioma and non-functioning pituitary adenoma

PURPOSE

Adult patients operated for craniopharyngioma develop more frequently GH deficiency (GHD) than patients operated for non-functioning pituitary adenoma (NFPA). The aim of the study was to compare both short- (1 year) and long-term (5 years) effects of rhGH in 38 GHD adult patients (19 operated for Craniopharyngioma (CP) and 19 for NFPA).

METHODS

IGF-I levels, body composition (BF%), BMI, lipid profile and glucose homeostasis were evaluated in all patients. Pituitary MRI was performed at baseline and during follow-up, as needed.

RESULTS

At baseline no difference between the two groups was observed, apart from a higher prevalence of diabetes insipidus in CP patients (79 vs 21%). After 12 months, IGF-I SDS normalized and BF% significantly decreased only in the NFPA group. During long-term treatment, decrease in BF% and improvement in lipid profile shown by reduction in total- and LDL-cholesterol were present in NFPA group only, while increase in insulin levels and HbA1c and decrease of QUICKI were observed in CP patients only. Accordingly, after long-term therapy, the prevalence of metabolic syndrome (MS) was significantly higher in CP than in NFPA group (37% in CP and in 5% in NFPA group; p < 0.05).

CONCLUSION

The present data suggest that CP patients are less sensitive to the positive rhGH effects on lipid profile and BF% and more prone to insulin sensitivity worsening than NFPA patients, resulting in increased prevalence of MS in CP only.

Correlation of increased plasma osteoprotegerin and cardiovascular risk factors in patients with adult growth hormone deficiency

Adult growth hormone deficiency (AGHD) is correlated to many adverse effects on metabolism and increases cardiovascular risk. 40 patients with AGHD and 40 healthy subjects were included. Anthropometric parameters such as body mass index, waist circumference, and waist-hip ratio were measured. Meanwhile, plasma levels of total cholesterol, triglyceride, high sensitivity C-relative protein, interleukin-6 and OPG were determined. Homeostasis model assessments for insulin resistance (HOMA-IR) and β-cell function (HOMA-β) were calculated using homeostasis model. Plasma OPG concentrations of AGHD patients were significantly higher than those in healthy subjects (131.82 ± 45.04 versus 81.02 ± 45.04, P < 0.01). Plasma OPG levels were positively correlated with age, body mass index, waist circumference, hip circumference, waist-hip ratio, fasting insulin, total cholesterol, triglyceride, high sensitivity C-relative protein and interleukin-6 (P < 0.05), but negatively correlated with high-density lipoprotein cholesterol (P < 0.05). Multiple linear stepwise regression analysis demonstrated that body mass index, triglyceride, and interleukin-6 were independently related to plasma OPG levels (P < 0.05). The levels of plasma OPG were increased in AGHD patients and were closely correlated with glycolipid metabolism and chronic inflammation. OPG might play an important role in the occurrence and development of cardiovascular diseases in AGHD patients.

Growth hormone deficiency in treated acromegaly

Growth hormone deficiency (GHD) of the adult is characterized by reduced quality of life (QoL) and physical fitness, skeletal fragility, and increased weight and cardiovascular risk. Hypopituitarism may develop in patients after definitive treatment of acromegaly, but an exact prevalence of GHD in this population is still uncertain owing to limited awareness and the scarce and conflicting data available on this topic. Because acromegaly and GHD may yield adverse consequences on similar target systems, the final outcomes of some complications of acromegaly may be further affected by the occurrence of GHD. However, it is still largely unknown whether patients with post-acromegaly GHD may benefit from GH replacement. We review the diagnostic, clinical, and therapeutic aspects of GHD in adult patients treated for acromegaly.

Is growth hormone treatment in children associated with weight gain?--longitudinal analysis of KIGS data

OBJECTIVE

Growth hormone (GH) increases lean body mass and reduces fat mass. However, the long-term changes in weight status during growth hormone treatment, according to age and weight status at onset of treatment, have not previously been reported in large data sets.

METHODS

Changes in BMI-SDS between starting GH treatment and attaining near adult height (NAH) were analysed in 2643 children with idiopathic GH deficiency (IGHD), 281 children small for gestational age (SGA), 1661 girls with Turner syndrome (TS), and 142 children with Prader-Willi syndrome (PWS) in the KIGS database.

RESULTS

BMI-SDS increased significantly between onset of GH treatment and NAH (IGHD:+0·29, SGA:+0·69, TS:+0·48) except in PWS (-0·02). These increases were greater in children with younger age at onset of GH treatment (significant in all indications) and with lower doses of GH treatment (significant in IGHD & TS) in multiple linear regression analyses also including gender, duration of GH treatment, BMI-SDS and height-SDS at onset of treatment, and birth weight-SDS. Obese children at onset of GH treatment decreased their BMI-SDS, while underweight and normal weight children at onset of GH treatment increased their BMI-SDS independently of GH treatment indication.

CONCLUSIONS

Long-term GH treatment was associated with changes in weight status, which were beneficial for underweight and obese children independent of the indication for GH. However, the increase in BMI-SDS in normal weight children treated with GH needs to be investigated in future prospective longitudinal studies to analyse whether this represents an increase of fat mass, lean body mass or both.

Fasting levels of high-sensitivity growth hormone predict cardiovascular morbidity and mortality: the Malmö Diet and Cancer study

BACKGROUND

Both pathological excess and deficiency of growth hormone (GH) are associated with cardiovascular mortality.

OBJECTIVES

The goal of this study was to test whether fasting levels of growth hormone measured with a high-sensitivity assay (hs-GH) predict cardiovascular morbidity and mortality at the population level.

METHODS

We studied 4,323 participants (age 46 to 68 years; mean age 58 years; 59% women) of the Swedish, population-based Malmö Diet and Cancer study examined in 1991 to 1994. Using multivariate-adjusted Cox proportional hazards models, we related baseline levels of fasting hs-GH to incidence of coronary artery disease, stroke, congestive heart failure, all-cause mortality, and cardiovascular mortality.

RESULTS

During a median follow-up of 16.2 years, hs-GH (hazard ratio [HR]/SD increment of natural logarithm of fasting hs-GH) was independently associated with increased risk of coronary artery disease (397 events; HR: 1.11; 95% confidence interval [CI]: 1.01 to 1.23; p = 0.04), stroke (251 events; HR: 1.18; 95% CI: 1.04 to 1.34; p = 0.01), congestive heart failure (107 events; HR: 1.25; 95% CI: 1.03 to 1.52; p = 0.02), all-cause mortality (645 events; HR: 1.17; 95% CI: 1.08 to 1.26; p < 0.001) and cardiovascular mortality (186 events; HR: 1.43; 95% CI: 1.24 to 1.66; p < 0.001). The addition of hs-GH to a model with conventional cardiovascular risk factors significantly reclassified risk, with a category-free net reclassification improvement (>0) of 0.542 (95% CI: 0.205 to 0.840) in cardiovascular mortality.

CONCLUSIONS

Higher values of hs-GH were associated with an increased risk of cardiovascular morbidity and mortality.

Short-term, low-dose GH therapy improves insulin sensitivity without modifying cortisol metabolism and ectopic fat accumulation in adults with GH deficiency

CONTEXT

Low-dose GH (LGH) therapy has been reported to improve insulin sensitivity in GH-deficient adults; however, the mechanism is unclear.

HYPOTHESIS

Effects of LGH therapy on insulin sensitivity are mediated through changes in cortisol metabolism and ectopic fat accumulation.

DESIGN AND SETTING

This was a double-blind, placebo-controlled, parallel, 3-month study.

PARTICIPANTS AND INTERVENTION

Seventeen GH-deficient adults were randomized to receive either daily LGH or placebo injections. Fasting blood samples were collected at baseline, and months 1 and 3, whereas hyperinsulinemic-euglycemic clamps, magnetic resonance spectroscopy scans, 24-hour cortisol production rates (CPRs), and sc abdominal fat biopsies were performed at baseline and month 3.

MAIN OUTCOME MEASURES

Clamp glucose infusion rate, intramyocellular, extramyocellular, and intrahepatic lipid content, 24-hour CPRs, adipocyte size, and adipocyte 11β-hydroxysteroid dehydrogenase activity in adults with GH deficiency were evaluated.

RESULTS

At month 1, LGH did not alter fasting levels of glucose, insulin, C-peptide, free fatty acid, adiponectin, total IGF-1, IGF-1 bioactivity, IGF-2, IGF binding protein (IGFBP)-2, or IGF-1 to IGFBP-3 molar ratio. At month 3, LGH increased clamp glucose infusion rates (P < .01) and IGF-1 to IGFBP-3 molar ratio (P < .05), but fasting glucose, insulin, C-peptide, free fatty acid, adiponectin, IGF-1 bioactivity, IGF-2, IGFBP-2, 24-hour CPRs, adipocyte size, adipocyte 11β-hydroxysteroid dehydrogenase activity, intrahepatic lipid, extramyocellular, or intramyocellular were unchanged. In the placebo group, all within-group parameters from months 1 and 3 compared with baseline were unchanged.

CONCLUSIONS

Short-term LGH therapy improves insulin sensitivity without inducing basal lipolysis and had no effect on cortisol metabolism and ectopic fat accumulation in GH-deficient adults. This may reflect an LGH-induced increase in IGF-1 to IGFBP-3 molar ratio exerting insulin-like effects through the abundant muscle IGF-1 receptors, but this hypothesis requires confirmation with further studies.

Mechanism of repression of 11β-hydroxysteroid dehydrogenase type 1 by growth hormone in 3T3-L1 adipocytes

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is an NADPH-dependent reductase that converts cortisone to cortisol in adipose tissue. We previously reported that GH and IGF-I decrease 11β-HSD1 activity and mRNA levels in adipocytes. Hexose-6-phosphate dehydrogenase (H6PDH) is involved in the production of NADPH, which is a coenzyme for 11β-HSD1. The aim of the present study was to clarify further the mechanism of repression of 11β-HSD1 activity by GH using linsitinib, an IGF-I receptor inhibitor. The suppression of 11β-HSD1 mRNA by IGF-I was attenuated in the presence of 1 μM linsitinib (17.2% vs. 53.3% of basal level, P<0.05). 11β-HSD1 mRNA levels in cells treated with GH in the presence of 1 μM linsitinib were not different from those in absence of linsitinib (35.9% vs. 33.9%). The increase in IGF-I mRNA levels with GH and 1 μM linsitinib was not different from that in the absence of linsitinib (359% vs. 347%). H6PDH mRNA levels were significantly decreased in cells treated with IGF-I for 8 and 24 h (55.6% and 33.7%, P<0.05). In the presence of 1 μM linsitinib, there was no repression of H6PDH mRNA (111.4%). H6PDH mRNA levels were significantly decreased in cells treated with GH in the absence of linsitinib for 24 h (55.9%, P<0.05), but not for 8 h (89.5%). The presence of 1 μM linsitinib also prevented repression of H6PDH mRNA by GH over 24 h (107.8%). These results suggest that GH directly represses 11β-HSD1 mRNA rather than acting via the IGF-I receptor, and that GH represses H6PDH through locally produced IGF-I.

Effects of GH on body composition and cardiovascular risk markers in young men with abdominal obesity

CONTEXT

Visceral adiposity is associated with increased cardiometabolic risk and decreased GH secretion.

OBJECTIVE

Our objective was to determine the effects of GH administration in abdominally obese young men on body composition, including liver fat, mitochondrial function, and cardiovascular (CV) risk markers.

DESIGN AND PARTICIPANTS

This was a 6-month, randomized, double-blind, placebo-controlled study with 62 abdominally obese men (IGF-1 below the mean, no exclusion based on GH level), 21 to 45 years of age.

MAIN OUTCOME MEASURES

We evaluated abdominal fat depots, thigh muscle and fat (computed tomography), fat and lean mass (dual-energy x-ray absorptiometry), intramyocellular and intrahepatic lipids (proton magnetic resonance spectroscopy), mitochondrial function (dynamic phosphorous magnetic resonance spectroscopy), CV risk markers, carotid intimal-medial thickness, and endothelial function.

RESULTS

GH administration resulted in a mean IGF-1 SD score increase from -1.9 ± 0.08 to -0.2 ± 0.3 in the GH group and a decrease in visceral adipose tissue (VAT), VAT/sc adipose tissue, trunk/extremity fat, intrahepatic lipids, high-sensitivity C-reactive protein and apolipoprotein B/low-density lipoprotein vs placebo after controlling for the increase in weight observed in both groups. There were inverse associations between change in IGF-1 levels and change in VAT, VAT/sc adipose tissue, trunk fat, trunk/extremity fat, high-sensitivity C-reactive protein, and apolipoprotein B. Mitochondrial function improved in the GH group compared with placebo after controlling for change in glucose. There was no change in thigh fat, muscle mass, intramyocellular lipids, cholesterol, fibrinogen, intimal-medial thickness, or endothelial function. There was no increase in fasting glucose or hemoglobin A1c in the GH vs placebo group, although glucose during the 2-hour oral glucose tolerance test increased slightly.

CONCLUSION

GH replacement in abdominally obese men improves body composition, including liver fat, mitochondrial function, and markers of CV risk. Although fasting glucose was unchanged, a slight increase in 2-hour glucose during an oral glucose tolerance test was noted.

The interrelationship between bone and fat: from cellular see-saw to endocrine reciprocity

The number of mature osteoblasts and marrow adipocytes in bone is influenced by the differentiation of the common mesenchymal progenitor cell towards one phenotype and away from the other. Consequently, factors which promote adipogenesis not only lead to fatty marrow but also inhibit osteoblastogenesis, resulting in decreased osteoblast numbers, diminished bone formation and, potentially, inadequate bone mass and osteoporosis. In addition to osteoblast and bone adipocyte numbers being influenced by this skewing of progenitor cell differentiation towards one phenotype, mature osteoblasts and adipocytes secrete factors which may evoke changes in the cell fate and function of each other. This review examines the endogenous factors, such as PPAR-γ2, Wnt, IGF-1, GH, FGF-2, oestrogen, the GP130 signalling cytokines, vitamin D and glucocorticoids, which regulate the selection between osteoblastogenesis and adipogenesis and the interrelationship between fat and bone. The role of adipokines on bone, such as adiponectin and leptin, as well as adipose-derived oestrogen, is reviewed and the role of bone as an energy regulating endocrine organ is discussed.

Adult growth hormone deficiency - benefits, side effects, and risks of growth hormone replacement

Deficiency of growth hormone (GH) in adults results in a syndrome characterized by decreased muscle mass and exercise capacity, increased visceral fat, impaired quality of life, unfavorable alterations in lipid profile and markers of cardiovascular risk, decrease in bone mass and integrity, and increased mortality. When dosed appropriately, GH replacement therapy (GHRT) is well tolerated, with a low incidence of side effects, and improves most of the alterations observed in GH deficiency (GHD); beneficial effects on mortality, cardiovascular events, and fracture rates, however, remain to be conclusively demonstrated. The potential of GH to act as a mitogen has resulted in concern over the possibility of increased de novo tumors or recurrence of pre-existing malignancies in individuals treated with GH. Though studies of adults who received GHRT in childhood have produced conflicting reports in this regard, long-term surveillance of adult GHRT has not demonstrated increased cancer risk or mortality.

Diagnosis and treatment of growth hormone deficiency in adults

The availability of synthetic recombinant human growth hormone (GH) in potentially unlimited quantities since the 1980s has improved understanding of the many nonstatural effects of GH on metabolism, body composition, physical and psychological function, as well as the consequences of GH deficiency in adult life. Adult GH deficiency is now recognized as a distinct if nonspecific syndrome with considerable adverse health consequences. GH replacement therapy in lower doses than those used in children can reverse many of these abnormalities and restore functional capacities toward or even to normal; if dosed appropriately, GH therapy has few adverse effects. Although some doubts remain about possible long-term risks of childhood GH therapy, most registries of adult GH replacement therapy, albeit limited in study size and duration, have not shown an increased incidence of cancers or of cardiovascular morbidity or mortality.

Effects of growth hormone withdrawal in obese premenopausal women

OBJECTIVE

We previously reported improved body composition and cardiovascular risk markers plus a small decrease in glucose tolerance with GH administration vs placebo for 6 months to abdominally obese premenopausal women. The objective of this study was to determine whether the effects of GH treatment on cardiovascular risk markers, body composition and glucose tolerance in obese women persist 6 months after GH withdrawal.

DESIGN AND PATIENTS

Fifty abdominally obese premenopausal women completed a trial of rhGH vs placebo for 6 months; thirty-nine women completed a subsequent 6-month withdrawal observation period.

MEASUREMENTS

IGF-I, body composition by CT, (1) H-MRS and DXA, serum cardiovascular risk markers, oral glucose tolerance test (OGTT).

RESULTS

IGF-I standard deviation scores (SDS) within the GH group were -1.7 ± 0.1 (pretreatment),-0.1 ± 0.3 (after 6 months of GH) and -1.7 ± 0.1 (6 months post-GH withdrawal). Six months after GH withdrawal, total abdominal and subcutaneous adipose tissue, total fat, trunk fat, trunk/extremity fat, hsCRP, apoB, LDL, and tPA were higher than at the 6-month (GH discontinuation) timepoint (P ≤ 0.05). All body composition and cardiovascular risk markers that had improved with GH returned to baseline levels by 6 months after GH discontinuation, as did fasting and 2-h OGTT glucose levels.

CONCLUSION

The effects of GH administration to abdominally obese premenopausal women have a short time-course. The beneficial effects on body composition and cardiovascular risk markers, and the side effect of altered glucose tolerance returned to pretreatment levels after GH withdrawal. There was no suppression of endogenous IGF-I levels, which returned to baseline after GH withdrawal.

Pathophysiology of human visceral obesity: an update

Excess intra-abdominal adipose tissue accumulation, often termed visceral obesity, is part of a phenotype including dysfunctional subcutaneous adipose tissue expansion and ectopic triglyceride storage closely related to clustering cardiometabolic risk factors. Hypertriglyceridemia; increased free fatty acid availability; adipose tissue release of proinflammatory cytokines; liver insulin resistance and inflammation; increased liver VLDL synthesis and secretion; reduced clearance of triglyceride-rich lipoproteins; presence of small, dense LDL particles; and reduced HDL cholesterol levels are among the many metabolic alterations closely related to this condition. Age, gender, genetics, and ethnicity are broad etiological factors contributing to variation in visceral adipose tissue accumulation. Specific mechanisms responsible for proportionally increased visceral fat storage when facing positive energy balance and weight gain may involve sex hormones, local cortisol production in abdominal adipose tissues, endocannabinoids, growth hormone, and dietary fructose. Physiological characteristics of abdominal adipose tissues such as adipocyte size and number, lipolytic responsiveness, lipid storage capacity, and inflammatory cytokine production are significant correlates and even possible determinants of the increased cardiometabolic risk associated with visceral obesity. Thiazolidinediones, estrogen replacement in postmenopausal women, and testosterone replacement in androgen-deficient men have been shown to favorably modulate body fat distribution and cardiometabolic risk to various degrees. However, some of these therapies must now be considered in the context of their serious side effects. Lifestyle interventions leading to weight loss generally induce preferential mobilization of visceral fat. In clinical practice, measuring waist circumference in addition to the body mass index could be helpful for the identification and management of a subgroup of overweight or obese patients at high cardiometabolic risk.

Increase in serum pregnancy-associated plasma protein-A is correlated with increase in cardiovascular risk factors in adult patients with growth hormone deficiency

Adult Growth Hormone Deficiency (AGHD) is correlated to many adverse effects on metabolism and increased cardiovascular risk. Pregnancy-associated plasma protein-A (PAPP-A) is a protease that promotes IGF-I availability in vascular tissues in recent study, and PAPP-A levels have been proposed as an early predictor of cardiac events. The aim of our study was to compare PAPP-A levels in AGHD patients with that of healthy adult subjects to determine if there is a relationship between serum PAPP-A and glucose and lipid metabolism. Twenty AGHD patients and 20 healthy, age-matched and weight-matched persons were chosen for the study. Their weight, height, blood pressure, body mass index (BMI), body fat percentage, waist and hip circumference, and waist-hips ratio were assessed. An oral glucose tolerance test was performed and venous blood was collected from the each patient's cubital vein for biochemical analysis. Serum PAPP-A level in AGHD patients was significantly higher than that of the control group [(7.62 ± 1.62 vs. 6.54 ± 1.31) p < 0.05], and PAPP-A was positively correlated to age, BMI, waist circumference and so on. After adjusting for the waist circumference, waist-hip ratio, 2 h postprandial blood glucose, triglycerides, the serum PAPP-A in AGHD patients was positively correlated to the BMI (r = 0.728, p < 0.05) and fasting insulin (r = 0.433, p < 0.05). In a multiple step-wise regression analysis, BMI, 2 h postprandial glucose, fasting insulin, HOMA-IR were independently associated with serum PAPP-A in AGHD patients. The increase in serum PAPP-A levels is associated with abnormal glucose metabolism and increased risk of atherosclerosis in AGHD 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.

Effect of growth hormone replacement therapy on the quality of life in women with growth hormone deficiency who have a history of acromegaly versus other disorders

OBJECTIVE

To compare the response in quality of life (QoL) to growth hormone (GH) replacement in women with GH deficiency (GHD) and a history of acromegaly with that in women with GHD of other causes.

METHODS

Fifty-five women with GHD were studied: 17 with prior acromegaly and 38 with other causes of GHD. We compared two 6-month, randomized, placebo-controlled studies of GH therapy in women with hypopituitarism conducted with use of the same design-one in women with a history of acromegaly and one in women with no prior acromegaly. QoL was assessed with the following questionnaires: the QoL-Assessment of Growth Hormone Deficiency in Adults (AGHDA), the Symptom Questionnaire, and the 36-Item Short-Form Health Survey (SF-36).

RESULTS

The 2 groups had comparable mean pretreatment age, body mass index, and QoL scores and comparable mean GH dose at 6 months (0.61 ± 0.30 versus 0.67 ± 0.27 mg daily). After 6 months of GH replacement therapy, women with GHD and prior acromegaly demonstrated a greater improvement in AGHDA score, four SF-36 sub-scales (Role Limitations due to Physical Health, Energy or Fatigue, Emotional Well-Being, and Social Functioning), and the Somatic Symptoms subscale of the Symptom Questionnaire than did women with GHD of other causes. Poorer pretreatment QoL was associated with a greater improvement in QoL after administration of GH.

CONCLUSION

In this study, GH replacement therapy improved QoL in women with GHD and a history of acromegaly but not in women with GHD due to other hypothalamic and pituitary disorders. Further studies are needed to determine the long-term risks versus benefits of GH replacement in patients who develop GHD after definitive treatment for acromegaly.

Effects of GH in women with abdominal adiposity: a 6-month randomized, double-blind, placebo-controlled trial

OBJECTIVE

Abdominal adiposity is associated with increased cardiovascular risk and decreased GH secretion. The objective of our study was to determine the effects of GH on body composition and cardiovascular risk markers in abdominally obese women.

MATERIALS AND METHODS

In this randomized, double-blind, placebo-controlled study, 79 obese premenopausal women received GH vs placebo for 6 months. Primary endpoints were i) total abdominal (total abdominal adipose tissue, TAT) fat by computed tomography (CT) (body composition) and ii) high-sensitivity C-reactive protein (hsCRP) (cardiovascular risk marker). Body composition was assessed by CT, dual-energy X-ray absorptiometry, and proton MR spectroscopy. Serum cardiovascular risk markers, carotid intima-media thickness, and endothelial function were measured.

RESULTS

Mean 6-month GH dose was 1.7±0.1 mg/day, resulting in a mean IGF1 SDS increase from -1.7±0.08 to -0.1±0.3 in the GH group. GH administration decreased TAT and hsCRP compared with placebo. In addition, it increased thigh muscle mass and lean body mass and decreased subcutaneous abdominal and trunk fat, tissue plasminogen activator, apoB, and apoB/low-density lipoprotein compared with placebo. Visceral adipose tissue (VAT) decreased and intramyocellular lipid increased within the GH group. Six-month change in IGF1 levels was negatively associated with 6-month decrease in TAT and VAT. One subject had a 2 h glucose >200 mg/ml at 3 months; four subjects, three of whom were randomized to GH, had 2 h glucose levels >200 mg/ml at the end of the study.

CONCLUSION

GH administration in abdominally obese premenopausal women exerts beneficial effects on body composition and cardiovascular risk markers but is associated with a decrease in glucose tolerance in a minority of women.

A systematic review and meta-analysis of the effect of aerobic vs. resistance exercise training on visceral fat

It is increasingly recognized that the location of excess adiposity, particularly increased deposition of visceral adipose tissue (VAT), is important when determining the adverse health effects of overweight and obesity. Exercise therapy is an integral component of obesity management, but the most potent exercise prescription for VAT benefit is unclear. We aimed to evaluate the independent and synergistic effects of aerobic exercise (AEx) and progressive resistance training (PRT) and to directly compare the efficacy of AEx and PRT for beneficial VAT modulation. A systematic review and meta-analysis was performed to assess the efficacy of exercise interventions on VAT content/volume in overweight and obese adults. Relevant databases were searched to November 2010. Included studies were randomized controlled designs in which AEx or PRT in isolation or combination were employed for 4 weeks or more in adult humans, where computed tomography (CT) or magnetic resonance imaging (MRI) was used for quantification of VAT pre- and post-intervention. Of the 12196 studies from the initial search, 35 were included. After removal of outliers, there was a significant pooled effect size (ES) for the comparison between AEx therapy and control (-0.33, 95% CI: -0.52 to -0.14; P < 0.01) but not for the comparison between PRT therapy and control (0.09, 95% CI: -0.17 to -0.36; P = 0.49). Of the available nine studies which directly compared AEx with PRT, the pooled ES did not reach statistical significance (ES = 0.23, 95% CI: -0.02 to 0.50; P = 0.07 favouring AEx). The pooled ES did not reach statistical significance for interventions that combined AEx and PRT therapy vs. control (-0.28, 95% CI: -0.69 to 0.14; P = 0.19), for which only seven studies were available. These data suggest that aerobic exercise is central for exercise programmes aimed at reducing VAT, and that aerobic exercise below current recommendations for overweight/obesity management may be sufficient for beneficial VAT modification. Further investigation is needed regarding the efficacy and feasibility of multi-modal training as a means of reducing VAT.

Body composition and quality of life in adults treated with GH therapy: a systematic review and meta-analysis

OBJECTIVE

To summarise the evidence about the efficacy and safety of using GH in adults with GH deficiency focusing on quality of life and body composition.

DATA SOURCES

We searched MEDLINE, EMBASE, Cochrane CENTRAL, Web of Science and Scopus through April 2011. We also reviewed reference lists and contacted experts to identify candidate studies.

STUDY SELECTION

Reviewers, working independently and in duplicate, selected randomised controlled trials (RCTs) that compared GH to placebo.

DATA SYNTHESIS

We pooled the relative risk (RR) and weighted mean difference (WMD) by the random effects model and assessed heterogeneity using the I(2) statistic.

RESULTS

Fifty-four RCTs were included enrolling over 3400 patients. The quality of the included trials was fair. GH use was associated with statistically significant reduction in weight (WMD, 95% confidence interval (95% CI): -2.31 kg, -2.66 and -1.96) and body fat content (WMD, 95% CI: -2.56 kg, -2.97 and -2.16); increase in lean body mass (WMD, 95% CI: 1.38, 1.10 and 1.65), the risk of oedema (RR, 95% CI: 6.07, 4.34 and 8.48) and joint stiffness (RR, 95% CI: 4.17, 1.4 and 12.38); without significant changes in body mass index, bone mineral density or other adverse effects. Quality of life measures improved in 11 of the 16 trials although meta-analysis was not feasible.

RESULTS

GH therapy in adults with confirmed GH deficiency reduces weight and body fat, increases lean body mass and increases oedema and joint stiffness. Most trials demonstrated improvement in quality of life measures.

OPPORTUNITY&trade;: a large-scale randomized clinical trial of growth hormone in hemodialysis patients

BACKGROUND

Adult maintenance hemodialysis (MHD) patients experience high mortality and morbidity and poor quality of life (QoL). Markers of protein-energy wasting are associated with these poor outcomes. The OPPORTUNITY™ Trial examined whether recombinant human growth hormone (hGH) reduces mortality in hypoalbuminemic MHD patients. Secondary end points were effects on number of hospitalizations, cardiovascular events, lean body mass (LBM), serum proteins, exercise capacity, QoL and adverse events.

METHODS

We performed a randomized, double-blind, placebo-controlled, multicenter multinational trial stratified for diabetic status. Clinically, stable adult MHD patients with serum albumin <4.0 g/dL were randomized to subcutaneous injections of hGH, 20 μg/kg/day, or placebo. Planned treatment duration was 24 months for 2500 patients. The trial was terminated early due to slow recruitment.

RESULTS

Seven hundred and twelve patients were randomized until trial termination; 695 patients received at least one dose of trial medication. Mean treatment duration was 20 weeks (no completers). There were no differences between groups in all-cause mortality, cardiovascular morbidity or mortality, serum albumin, LBM, physical exercise capacity or QoL. The hGH group, compared to placebo, displayed a reduction in body weight, total body fat, serum high-sensitivity C-reactive protein and possibly homocysteine and an increase in serum high-density lipoprotein-cholesterol and transferrin levels.

CONCLUSIONS

Although the OPPORTUNITY™ Trial was terminated early, treatment with hGH, compared to placebo, improved certain cardiovascular risk factors but did not reduce mortality, cardiovascular events or improve nutritional factors or QoL. The power for showing differences was substantially reduced due to the marked decrease in treatment duration and sample size.