Recombinant growth hormone (GH) therapy in GH-deficient adults: a long-term controlled study on daily versus thrice weekly injections

Weekly Lonapegsomatropin in Treatment-Naïve Children With Growth Hormone Deficiency: The Phase 3 heiGHt Trial

CONTEXT

For children with growth hormone deficiency (GHD), treatment burden with daily somatropin injections [human growth hormone (hGH)] is high, which may lead to poor adherence and suboptimal overall treatment outcomes. Lonapegsomatropin (TransCon hGH) is an investigational long-acting, once-weekly prodrug for the treatment of GHD.

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of once-weekly lonapegsomatropin vs daily somatropin.

DESIGN

The heiGHt trial was a randomized, open-label, active-controlled, 52-week Phase 3 trial (NCT02781727).

SETTING

This trial took place at 73 sites across 15 countries.

PATIENTS

This trial enrolled and dosed 161 treatment-naïve, prepubertal patients with GHD.

INTERVENTIONS

Patients were randomized 2:1 to receive lonapegsomatropin 0.24 mg hGH/kg/week or an equivalent weekly dose of somatropin delivered daily.

MAIN OUTCOME MEASURE

The primary end point was annualized height velocity (AHV) at week 52. Secondary efficacy end points included change from baseline in height SD scores (SDS).

RESULTS

Least squares (LS) mean (SE) AHV at 52 weeks was 11.2 (0.2) cm/year for lonapegsomatropin vs 10.3 (0.3) cm/year for daily somatropin (P = 0.009), with lonapegsomatropin demonstrating both noninferiority and superiority over daily somatropin. LS mean (SE) height SDS increased from baseline to week 52 by 1.10 (0.04) vs 0.96 (0.05) in the weekly lonapegsomatropin vs daily somatropin groups (P = 0.01). Bone age/chronological age ratio, adverse events, tolerability, and immunogenicity were similar between groups.

CONCLUSIONS

The trial met its primary objective of noninferiority in AHV and further showed superiority of lonapegsomatropin compared to daily somatropin, with similar safety, in treatment-naïve children with GHD.

Patient preferences for growth hormone treatment in Japanese children

BACKGROUND

There are not clear evidence to date evaluating patients' and caregivers' preferences for the recombinant-human growth hormone (r-hGH) injection in children in Japan. This study aimed to quantitatively evaluated the factors driving preferences for daily r-hGH injections among Japanese children with growth hormone deficiency (GHD) or their caregivers and to determine the relative importance of treatment delivery factors.

METHODS

This study was performed among Japanese children with GHD or their caregivers who visited a specialized clinic in Japan as part of their routine care. The participants were asked to complete a web-based discrete choice experiment (DCE) questionnaire.

RESULTS

Choice-based conjoint analysis was used to evaluate the relative importance of the attributes of the choice predictors and determine utility scores for each attribute. Of the 47 respondents who participated in this study, 41 were caregivers who responded on behalf of the patients, the remaining six were patients who completed the DCE themselves. The injection schedule was found to be the most important factor for both patients and caregivers; a once-weekly injection schedule was preferred over a daily injection schedule. Storage and preparation was deemed more important to patients than it was to caregivers, with patients preferring storage at room temperature even if it required additional mixing (reconstitution). Both patients and caregivers showed a clear preference for devices that offered a dose-setting memory.

CONCLUSIONS

A less frequent injection schedule may enhance adherence to r-hGH treatment and expected improve quality of life for GHD patients over the long term.

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.

Hydrogels For Peptide Hormones Delivery: Therapeutic And Tissue Engineering Applications

Peptides are the most abundant biological compounds in the cells that act as enzymes, hormones, structural element, and antibodies. Mostly, peptides have problems to move across the cells because of their size and poor cellular penetration. Therefore, a carrier that could transfer peptides into cells is ideal and would be effective for disease treatment. Until now, plenty of polymers, e.g., polysaccharides, polypeptides, and lipids were used in drug delivery. Hydrogels made from polysaccharides showed significant development in targeted delivery of peptide hormones because of their natural characteristics such as networks, pore sizes, sustainability, and response to external stimuli. The main aim of the present review was therefore, to gather the important usages of the hydrogels as a carrier in peptide hormone delivery and their application in tissue engineering and regenerative medicine.

Versatile biomanufacturing through stimulus-responsive cell-material feedback

Small-scale production of biologics has great potential for enhancing the accessibility of biomanufacturing. By exploiting cell-material feedback, we have designed a concise platform to achieve versatile production, analysis and purification of diverse proteins and protein complexes. The core of our technology is a microbial swarmbot, which consists of a stimulus-sensitive polymeric microcapsule encapsulating engineered bacteria. By sensing the confinement, the bacteria undergo programmed partial lysis at a high local density. Conversely, the encapsulating material shrinks responding to the changing chemical environment caused by cell growth, squeezing out the protein products released by bacterial lysis. This platform is then integrated with downstream modules to enable quantification of enzymatic kinetics, purification of diverse proteins, quantitative control of protein interactions and assembly of functional protein complexes and multienzyme metabolic pathways. Our work demonstrates the use of the cell-material feedback to engineer a modular and flexible platform with sophisticated yet well-defined programmed functions.

Adherence, Attitudes and Beliefs of Growth Hormone Deficient Patients - A Questionnaire-based Cohort Study

INTRODUCTION

GHD is a chronic and systemic disease requiring daily replacement of growth hormone (GHRT). Adherence and attitudes of adult GHD patients are not well known. We sought to assess patients' knowledge of growth hormone deficiency (GHD) in association with treatment adherence and attitudes regarding available and upcoming treatment options.

METHODS

We performed a cross-sectional survey with a custom-made questionnaire at a single centre assessing data on demographics, knowledge of GHD, adherence and attitudes towards GHRT.

RESULTS

Of 106 eligible patients actively followed for GHD 70 returned the completed survey (return-rate 66%, 34 m/36 f; age 56±14 years). 46 patients were actively treated, but almost one third (n=24) refused GHRT. 12 patients had participated in clinical trials with LAGH (long-acting growth hormone). Overall, patients with GHRT showed good adherence. Patients refusing GHRT mostly feared side effects and/or had a lack of information/perceived effect. Disease knowledge and level of education were higher in treated than untreated patients (p=0.023/0.017). Only 36% of respondents would initiate treatment with LAGH. Patients with prior LAGH experience and patients with childhood-onset GHD were more likely to adopt LAGH (p=0.048/0.031).

DISCUSSION

Most often, misinformation causes patients to refuse GHRT. Possibly the understanding of their condition and consequences of non-treatment is limited. To improve adherence more focused educational and behavioural strategies may be needed. Willingness to begin a therapy with LAGH was lower than expected (36%). The reasons for reluctance against LAGH need to be elucidated.

Pituitary Diseases and Bone

Neuroendocrinology of bone is a new area of research based on the evidence that pituitary hormones may directly modulate bone remodeling and metabolism. Skeletal fragility associated with high risk of fractures is a common complication of several pituitary diseases such as hypopituitarism, Cushing disease, acromegaly, and hyperprolactinemia. As in other forms of secondary osteoporosis, pituitary diseases generally affect bone quality more than bone quantity, and fractures may occur even in the presence of normal or low-normal bone mineral density as measured by dual-energy X-ray absorptiometry, making difficult the prediction of fractures in these clinical settings. Treatment of pituitary hormone excess and deficiency generally improves skeletal health, although some patients remain at high risk of fractures, and treatment with bone-active drugs may become mandatory. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary diseases.

More Favorable Metabolic Impact of Three-Times-Weekly versus Daily Growth Hormone Treatment in Naïve GH-Deficient Children

OBJECTIVE

To evaluate whether two different regimens of weekly injections could lead to similar auxological and metabolic effects in children with growth hormone deficiency (GHD).

DESIGN

32 GHD children (25 males, mean age 10.5 ± 2.2 yr) were randomly assigned to receive daily (group A, 16 patients) or TIW (group B, 16 patients) GHT for 12 months.

METHODS

Auxological parameters, insulin-like growth factor-I (IGF-I), glucose and insulin during OGTT, glycosylated hemoglobin (HbA1c), lipid profile, the oral disposition index (DIo), the homeostasis model assessment estimate of insulin resistance (Homa-IR), and the insulin sensitivity index (ISI).

RESULTS

After 12 months, both groups showed a significant and comparable improvement in height (p < 0.001) and IGF-I (p < 0.001). As regards the metabolic parameters, in both groups, we found a significant increase in fasting insulin (p < 0.001 and p = 0.026) and Homa-IR (p < 0.001 and p = 0.019). A significant increase in fasting glucose (p = 0.001) and a decrease in ISI (p < 0.001) and DIo (p = 0.002) were only found in group A.

CONCLUSIONS

The TIW regimen is effective and comparable with the daily regimen in improving auxological parameters and has a more favorable metabolic impact in GHD children. This trial is registered with ClinicalTrials.gov NCT03033121.

Management of GH treatment in adult GH deficiency

Growth hormone (GH) replacement therapy in adults with GH deficiency is still a challenge for the clinical endocrinologist and its implementation has still numerous difficulties and uncertainties. The decision to treat GH deficient adults requires a thoughtful and individualized evaluation of risks and benefits. Benefits have been found in body composition, bone health, cardiovascular risk factors, and quality of life. However, evidences for a reduction in cardiovascular events and mortality are still lacking, and treatment costs remain high. It is advisable to start treatment with low doses of GH, the goals being an appropriate clinical response, an avoidance of side effects, and IGF-I levels in the age-adjusted reference range. Although treatment appears to be overall safe, certain areas continue to require long-term surveillance, such as risks of glucose intolerance, pituitary/hypothalamic tumor recurrence, and cancer.

Is insulin-like growth factor-I a good marker for treatment adherence in growth hormone deficiency in adulthood?

OBJECTIVE

There is a paucity of studies on adherence to growth hormone treatment in growth hormone deficient (GHD) adults. Therefore, this study reports on adherence to GH-replacement therapy in adults with GHD, with a special focus on the course and potential predictors of nonadherence.

DESIGN

Retrospective single-centre cohort study.

PATIENTS

From the local patient database, 179 suitable patients with GHD were identified.

MEASUREMENTS

The primary outcome was adherence assessed by calculating the percentage of available prescription data in comparison with recommended GH dosages over a mean follow-up period of 92·4 months. Patients were categorized into five adherence categories ranging from <20% to >80%.

RESULTS

Mean overall adherence was 74·0%, with 52·9% of patients falling into the adherence group of >80% and 8·8% of <20%. There was a significant drop in adherence (9·8%) between the first and second years of treatment (P < 0·001). Patients with childhood-onset GHD were significantly less adherent to GH treatment than patients with adult-onset GHD (62·0% vs 77·0%, P = 0·012); however, this finding was no longer significant after including age as a covariate. Frequency of IGF-1 levels lying outside the age- and sex-specific reference range was not a good indicator for adherence.

CONCLUSION

Although overall adherence was relatively high in our study sample, there is a significant amount of patients who should be regarded as nonadherent. This applies in particular to younger patients. Treating physicians should be aware of the fact that IGF-1 levels do not seem to be a good indicator for adherence.

Developments in our understanding of the effects of growth hormone on white adipose tissue from mice: implications to the clinic

Adipose tissue (AT) is a well-established target of growth hormone (GH) and is altered in clinical conditions associated with excess, deficiency and absence of GH action. Due to the difficulty in collecting AT from clinical populations, genetically modified mice have been useful in better understanding how GH affects this tissue. Recent findings in mice would suggest that the impact of GH on AT is beyond alterations of lipolysis, lipogenesis or proliferation/ differentiation. AT depot-specific alterations in immune cells, extracellular matrix, adipokines, and senescence indicate an expanded role for GH in AT physiology. This mouse data will guide additional studies necessary to evaluate the therapeutic potential and safety of GH for conditions associated with altering AT, such as obesity. In this review, we introduce several relatively new intricacies of GH's effect on AT, focusing on recent studies in mice. Finally, we summarize the clinical implications of these findings.

Comparative pharmacokinetics and pharmacodynamics of a PEGylated recombinant human growth hormone and daily recombinant human growth hormone in growth hormone-deficient children

Objective

Recombinant human growth hormone (rhGH) replacement therapy in children generally requires daily subcutaneous (sc) injections, which may be inconvenient for patients. Jintrolong^® is a PEGylated rhGH with the purpose of weekly sc injections. The aim of the current study was to examine the pharmacokinetics, pharmacodynamics, safety, and tolerability of multiple sc doses of Jintrolong^® vs daily doses of rhGH.

Design and methods

Twelve children with growth hormone deficiency participated in this single-center, open-label, crossover Phase I trial. All subjects received daily sc injections of rhGH at 0.0286 mg/kg/d for 7 days, followed by a 4-week washout period and six weekly doses of Jintrolong^® at 0.2 mg/kg/w.

Results

In comparison with rhGH, sc injection of Jintrolong^® produced a noticeably higher C_max, significantly longer half-life (t_1/2), and slower plasma clearance, signifying a profile suitable for long-term treatment. The ratio of the area under the concentration vs time curve (AUC) after the seventh and first injections (AUC_(0–∞)7th/AUC_(0–∞)1st) of rhGH was 1.02, while the AUC_(0–∞)6th/AUC_(0–∞)1st of Jintrolong ^® was 1.03, indicating no accumulation of circulating growth hormone. There was no significant difference in the change in insulin-like growth factor-1 expression produced by 7 days of sc rhGH and weekly Jintrolong^® injections. There were no severe adverse events during the trial.

Conclusion

The elimination rate of Jintrolong^® was slower than that of sc rhGH. No progressive serum accumulation of Jintrolong^® was found. The changes in insulin-like growth factor-1 expression produced by rhGH and Jintrolong^® were comparable, indicating similar pharmacodynamics. Our results demonstrate that Jintrolong^® is suitable for long-term growth hormone treatment in children with growth hormone deficiency.

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

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

A reversible albumin-binding growth hormone derivative is well tolerated and possesses a potential once-weekly treatment profile

CONTEXT

Human growth hormone (hGH) replacement therapy currently requires daily sc injections for years/lifetime, which may be both inconvenient and distressing for patients. NNC0195-0092 is a novel hGH derivative intended for once-weekly treatment of GH deficiency. A noncovalent albumin binding moiety is attached to the hGH backbone. Clearance is reduced as a consequence of a reversible binding to circulating serum albumin, which prolongs the pharmacodynamic (PD) effect.

OBJECTIVE

To evaluate safety, local tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of a single dose (SD) and multiple doses (MD) of NNC0195-0092.

SETTING AND DESIGN

Randomized, single-center, placebo-controlled, double-blind, SD/MD, dose-escalation trial of 105 healthy male subjects. NNC0195-0092 sc administration: Five cohorts of eight subjects received one dose of NNC0195-0092 (0.01-0.32 mg/kg) (n = 6) or placebo (n = 2). Sixteen subjects (equal numbers of Japanese and non-Asian) received once-weekly doses of NNC0195-0092 (0.02-0.24 mg/kg; n=12) or placebo (n=4) for 4 weeks. Blood samples were drawn for assessment of safety, PK, IGF-1, and IGF binding protein 3 profiles and anti-drug antibodies.

RESULTS

SD and MD of NNC0195-0092 were well tolerated at all dose levels. No safety concerns or local tolerability issues were identified. A dose-dependent IGF-1 response was observed. IGF-1 profiles suggest that NNC0195-0092 may be suitable for once-weekly dosing, with a clinically relevant dose ≤0.08 mg/kg/week. No differences in PK and PD were observed between Japanese and non-Asian subjects.

CONCLUSIONS

SD and MD of NNC0195-0092 administered to healthy Japanese and non-Asian male subjects were well tolerated at all doses. The present trial suggests that NNC0195-0092 has the potential for an efficacious, well-tolerated, once-weekly GH treatment.

Efficacy and safety of sustained-release recombinant human growth hormone in Korean adults with growth hormone deficiency

PURPOSE

The administration of recombinant human growth hormone in adults with growth hormone deficiency has been known to improve metabolic impairment and quality of life. Patients, however, have to tolerate daily injections of growth hormone. The efficacy, safety, and compliance of weekly administered sustained-release recombinant human growth hormone (SR-rhGH, Declage™) supplement in patients with growth hormone deficiency were evaluated.

MATERIALS AND METHODS

This trial is 12-week prospective, single-arm, open-label trial. Men and women aged ≥20 years with diagnosed growth hormone deficiency (caused by pituitary tumor, trauma and other pituitary diseases) were eligible for this study. Each subject was given 2 mg (6 IU) of SR-rhGH once a week, subcutaneously for 12 weeks. Efficacy and safety at baseline and within 30 days after the 12th injection were assessed and compared. Score of Assessment of Growth Hormone Deficiency in Adults (AGHDA score) for quality of life and serum IGF-1 level.

RESULTS

The IGF-1 level of 108.67±74.03 ng/mL was increased to 129.01±68.37 ng/mL (p=0.0111) and the AGHDA QoL score was decreased from 9.80±6.51 to 7.55±5.76 (p<0.0001) at week 12 compared with those at baseline. Adverse events included pain, swelling, erythema, and warmth sensation at the administration site, but many adverse events gradually disappeared during the investigation.

CONCLUSION

Weekly administered SR-rhGH for 12 weeks effectively increased IGF-1 level and improved the quality of life in patients with GH deficiency without serious adverse events.

Relationship between serum circulating insulin-like growth factor-1 and liver fat in the United States

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD), circulating insulin-like growth factor-1 (IGF-1), and IGF-1/IGF-binding protein-3 (IGFBP-3) concentrations are associated with adiposity and insulin resistance. We aimed to determine whether serum IGF-1, IGFBP-3, and IGF-1/IGFBP-3 are associated with presence or severity of NAFLD independent of potential confounding.

METHODS

We performed a cross-sectional analysis of data from the Third National Health and Nutrition Examination Survey, 1988–1994, a representative sample of the United States adult population. Among participants who had a fasting blood draw and ultrasound examination, we excluded those with missing data, viral hepatitis, iron overload, excessive alcohol intake, pregnancy, or taking glucose-lowering therapy, yielding 4172 adults for this analysis.

RESULTS

In logistic regression analyses adjusted for age, gender, and race/ethnicity, higher IGF-1 and IGF-1/IGFBP-3 quartiles were associated with lower likelihood of NAFLD and lower grade steatosis. These associations became non-significant when further adjusted for adiposity (body mass index, waist circumference) with the exception of the association between IGF-1/IGFBP-3 and severity of NAFLD which remained significant after adjustment for homeostasis model assessment for insulin resistance (HOMA-IR) (odds ratio [95% CI]: Q3: 0.71 [0.53–0.96], Q4: 0.62 [0.43–0.89]) and adiposity (Q4: 0.67 [0.47–0.96]). Full adjustment (age, gender, race/ethnicity, adiposity, HOMA-IR, A1C%) further attenuated associations between IGF-1 or IGF-1/IGFBP-3 and liver fat such that they were no longer significant.

CONCLUSIONS

Adiposity explains much of the observed association between IGF-1 or IGF-1/IGFBP-3 and liver fat. These findings do not support a direct role for the growth hormone-IGF-1/IGFBP-3 axis in the pathophysiology of NAFLD.

Multiple doses of pegylated long-acting growth hormone are well tolerated in healthy male volunteers and possess a potential once-weekly treatment profile

OBJECTIVES

Recombinant human growth hormone (rhGH) replacement therapy in children and adults currently requires daily subcutaneous injections for several years or lifelong. The current study examined safety, tolerability, pharmacokinetic and pharmacodynamic response parameters after single and multiple doses of a long-acting rhGH preparation (NNC126-0083).

DESIGN

Randomized, double-blinded, placebo-controlled, multiple-dose, dose-escalating (0·02, 0·04, 0·08 and 0·16 mg protein/kg), sequential dose group trial.

SUBJECTS

Forty adult Japanese healthy male volunteers (aged 20-45; body mass index: 18·0-27·0 kg/m(2)). Five groups (n = 8) were randomized to receive multiple doses of NNC126-0083 (n = 6) or placebo (n = 2).

METHODS

Primary outcome was safety, and tolerability of multiple doses of NNC126-0083 compared with placebo. Blood samples for the assessment of pharmacokinetics (PK) and pharmacodynamics response [insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3)] were taken after multiple ascending doses.

RESULTS

NNC126-0083 was well tolerated and not associated with any local injection-site reactions or lipoatrophy. Following administration, NNC126-0083 levels increased rapidly and remained elevated for several days, returning to baseline before each weekly injection. Steady-state PK was achieved after the third dosing. A more than dose-proportional exposure was observed at the highest NNC126-0083 dose (0·16 mg protein/kg). A strong dose-dependent pharmacodynamic response in circulating concentrations of both IGF-I and IGFBP-3 compared with placebo (P < 0·0001) was observed during the administration of all doses.

CONCLUSIONS

Multiple administration of NNC126-0083 in healthy male volunteers indicates that NNC126-0083 has the potential for an efficacious, well-tolerated, once-weekly rhGH compound in the treatment of GH deficiency.

Disrupted corticosterone pulsatile patterns attenuate responsiveness to glucocorticoid signaling in rat brain

Chronically elevated circulating glucocorticoid levels are although to enhance vulnerability to psychopathology. Here we hypothesized that such sustained glucocorticoid levels, disturbing corticosterone pulsatility, attenuate glucocorticoid receptor signaling and target gene responsiveness to an acute challenge in the rat brain. Rats were implanted with vehicle or 40 or 100% corticosterone pellets known to flatten ultradian and circadian rhythmicity while maintaining daily average levels or mimic pathological conditions. Additionally, recovery from constant exposure was studied in groups that had the pellet removed 24 h prior to the challenge. Molecular markers for receptor responsiveness (receptor levels, nuclear translocation, promoter occupancy, and target gene expression) to an acute challenge mimicking the stress response (3 mg/kg ip) were studied in the hippocampal area. Implantation of 40 and 100% corticosterone pellets dose-dependently down-regulated glucocorticoid receptor and attenuated mineralocorticoid receptor and glucocorticoid receptor translocation to the acute challenge. Interestingly, whereas target gene Gilz expression to the challenge was already attenuated by tonic daily average levels (40%), Sgk-1 was affected only after constant high corticosterone exposure (100%), indicating altered receptor responsiveness due to treatment. Washout of 100% corticosterone recovered all molecular markers (partial), whereas removal of the 40% corticosterone pellet still attenuated responsiveness to the challenge. We propose that corticosteroid pulsatility is crucial in maintaining normal responsiveness to glucocorticoids. Whereas the results with 100% corticosterone are likely attributed to receptor saturation, subtle changes in the pattern of exposure (40%) induces changes at least as severe for glucocorticoid signaling as overt hypercorticism, suggesting an underlying mechanism sensitive to the pattern of hormone exposure.

N-terminal propeptide of type III procollagen as a biomarker of anabolic response to recombinant human GH and testosterone

CONTEXT

Biomarkers that predict musculoskeletal response to anabolic therapies should expedite drug development. During collagen synthesis in soft lean tissue, N-terminal propeptide of type III procollagen (P3NP) is released into circulation. We investigated P3NP as a biomarker of lean body mass (LBM) and muscle strength gains in response to testosterone and GH.

DESIGN

Community-dwelling older men received GnRH agonist plus 5 or 10 g testosterone gel plus 0, 3, or 5 microg recombinant human GH daily. P3NP levels were measured at baseline and wk 4, 8, 12, and 16. LBM and appendicular skeletal muscle mass (ASM) were measured by dual-energy x-ray absorptiometry.

RESULTS

One hundred twelve men completed treatment; 106 underwent serum P3NP measurements. P3NP levels were higher at wk 4 than baseline (6.61 +/- 2.14 vs. 4.51 +/- 1.05, P < 0.0001) and reached plateau by wk 4 in men receiving testosterone alone. However, wk 8 P3NP levels were higher than wk 4 levels in men receiving testosterone plus recombinant human GH. Increases in P3NP from baseline to wk 4 and 16 were significantly associated with gains in LBM (r = 0.26, P = 0.007; r = 0.53, P < 0.001) and ASM (r = 0.17, P = 0.07; r = 0.40, P < 0.0001). Importantly, for participants receiving only testosterone, P3NP increases at wk 4 and 16 were related to muscle strength gains (r = 0.20, P = 0.056 and r = 0.36, P = 0.04). In stepwise regression, change in P3NP explained 28 and 30% of the change in ASM and LBM, respectively, whereas change in testosterone but not IGF-I and age provided only small improvements in the models.

CONCLUSION

Early changes in serum P3NP levels are associated with subsequent changes in LBM and ASM during testosterone and GH administration. Serum P3NP may be a useful early predictive biomarker of anabolic response to GH and testosterone.

Testosterone and growth hormone improve body composition and muscle performance in older men

CONTEXT

Impairments in the pituitary-gonadal axis with aging are associated with loss of muscle mass and function and accumulation of upper body fat.

OBJECTIVES

We tested the hypothesis that physiological supplementation with testosterone and GH together improves body composition and muscle performance in older men.

DESIGN, SETTING, AND PARTICIPANTS

One hundred twenty-two community-dwelling men 70.8 +/- 4.2 yr of age with body mass index of 27.4 +/- 3.4 kg/m2, testosterone of 550 ng/dl or less, and IGF-I in lower adult tertile (< or =167 ng/dl) were randomized to receive transdermal testosterone (5 or 10 g/d) during a Leydig cell clamp plus GH (0, 3, or 5 microg/kg . d) for 16 wk.

MAIN OUTCOME MEASURES

Body composition by dual-energy x-ray absorptiometry, muscle performance, and safety tests were conducted.

RESULTS

Total lean body mass increased (1.0 +/- 1.7 to 3.0 +/- 2.2 kg) as did appendicular lean tissue (0.4 +/- 1.4 to 1.5 +/- 1.3 kg), whereas total fat mass decreased by 0.4 +/- 0.9 to 2.3 +/- 1.7 kg as did trunk fat (0.5 +/- 0.9 to 1.5 +/- 1.0 kg) across the six treatment groups and by dose levels for each parameter (P < or = 0.0004 for linear trend). Composite maximum voluntary strength of upper and lower body muscles increased by 14 +/- 34 to 35 +/- 31% (P < 0.003 in the three highest dose groups) that correlated with changes in appendicular lean mass. Aerobic endurance increased in all six groups (average 96 +/- 137 sec longer). Systolic and diastolic blood pressure increased similarly in each group with mean increases of 12 +/- 14 and 8 +/- 8 mm Hg, respectively. Other predictable adverse events were modest and reversible.

CONCLUSIONS

Supplemental testosterone produced significant gains in total and appendicular lean mass, muscle strength, and aerobic endurance with significant reductions in whole-body and trunk fat. Outcomes appeared to be further enhanced with GH supplementation.

Age-related changes in body composition of bovine growth hormone transgenic mice

GH has a significant impact on body composition due to distinct anabolic and catabolic effects on lean and fat mass, respectively. Several studies have assessed body composition in mice expressing a GH transgene. Whereas all studies report enhanced growth of transgenic mice as compared with littermate controls, there are inconsistencies in terms of the relative proportion of lean mass to fat mass in these animals. The purpose of this study was to characterize the accumulation of adipose and lean mass with age and according to gender in a bovine (b) GH transgenic mouse line. Weight and body composition measurements were assessed in male and female bGH mice with corresponding littermate controls in the C57BL/6J genetic background. Body composition measurements began at 6 wk and continued through 1 yr of age. At the conclusion of the study, tissue weights were determined and triglyceride content was quantified in liver and kidney. Although body weights for bGH mice were significantly greater than their corresponding littermate controls at all time points, body composition measurements revealed an unexpected transition midway through analyses. That is, younger bGH mice had relatively more fat mass than nontransgenic littermates, whereas bGH mice became significantly leaner than controls by 4 months in males and 6 months in females. These results reveal the importance in timing and gender when conducting studies related to body composition or lean and fat tissue in GH transgenic mice or in other genetically manipulated mouse strains in which body composition may be impacted.

Role of the GH/IGF-1 axis in lifespan and healthspan: lessons from animal models

Animal models are fundamentally important in our quest to understand the genetic, epigenetic, and environmental factors that contribute to human aging. In comparison to humans, relatively short-lived mammals are useful models as they allow for rapid assessment of both genetic manipulation and environmental intervention as related to longevity. These models also allow for the study of clinically relevant pathologies as a function of aging. Data associated with more distant species offers additional insight and critical consideration of the basic physiological processes and molecular mechanisms that influence lifespan. Consistently, two interventions, caloric restriction and repression of the growth hormone (GH)/insulin-like growth factor-1/insulin axis, have been shown to increase lifespan in both invertebrates and vertebrate animal model systems. Caloric restriction (CR) is a nutrition intervention that robustly extends lifespan whether it is started early or later in life. Likewise, genes involved in the GH/IGF-1 signaling pathways can lengthen lifespan in vertebrates and invertebrates, implying evolutionary conservation of the molecular mechanisms. Specifically, insulin and insulin-like growth factor-1 (IGF-1)-like signaling and its downstream intracellular signaling molecules have been shown to be associated with lifespan in fruit flies and nematodes. More recently, mammalian models with reduced growth hormone (GH) and/or IGF-1 signaling have also been shown to have extended lifespans as compared to control siblings. Importantly, this research has also shown that these genetic alterations can keep the animals healthy and disease-free for longer periods and can alleviate specific age-related pathologies similar to what is observed for CR individuals. Thus, these mutations may not only extend lifespan but may also improve healthspan, the general health and quality of life of an organism as it ages. In this review, we will provide an overview of how the manipulation of the GH/IGF axis influences lifespan, highlight the invertebrate and vertebrate animal models with altered lifespan due to modifications to the GH/IGF-1 signaling cascade or homologous pathways, and discuss the basic phenotypic characteristics and healthspan of these models.

Growth hormone, insulin-like growth factors, and the skeleton

GH and IGF-I are important regulators of bone homeostasis and are central to the achievement of normal longitudinal bone growth and bone mass. Although GH may act directly on skeletal cells, most of its effects are mediated by IGF-I, which is present in the systemic circulation and is synthesized by peripheral tissues. The availability of IGF-I is regulated by IGF binding proteins. IGF-I enhances the differentiated function of the osteoblast and bone formation. Adult GH deficiency causes low bone turnover osteoporosis with high risk of vertebral and nonvertebral fractures, and the low bone mass can be partially reversed by GH replacement. Acromegaly is characterized by high bone turnover, which can lead to bone loss and vertebral fractures, particularly in patients with coexistent hypogonadism. GH and IGF-I secretion are decreased in aging individuals, and abnormalities in the GH/IGF-I axis play a role in the pathogenesis of the osteoporosis of anorexia nervosa and after glucocorticoid exposure.

Effects of growth hormone on exercise capacity and cardiopulmonary performance in patients with chronic heart failure

BACKGROUND

Because GH exerted beneficial effects in various experimental models of heart failure, we investigated the effects of GH on physical exercise capacity and cardiopulmonary performance in patients with dilated cardiomyopathy and chronic heart failure (CHF).

METHODS

Twenty-two patients with CHF (New York Heart Association functional class II-III) underwent spirometry and a symptom-limited, cardiopulmonary exercise testing before and after 3 months of GH (n = 11; seven males; seven idiopathic; 57 +/- 11 yr; 4 IU sc every other day) or placebo (n = 11; eight males; six idiopathic; 54 +/- 10 yr) administration, in a randomized, double-blind trial. Background CHF therapy remained unchanged.

RESULTS

GH, but not placebo, increased IGF-I serum concentration (from 144 +/- 35 to 293 +/- 58 ng/ml; P < 0.005) and improved New York Heart Association functional class (from 2.4 +/- 0.5 to 1.8 +/- 0.4; P < 0.005), exercise duration (from 831 +/- 273 to 925 +/- 266 sec; P < 0.005), peak power output (from 245 +/- 127 to 280 +/- 132 W; P < 0.05), peak minute ventilation (from 52.5 +/- 16.1 to 61.3 +/- 17.3 liters/min; P < 0.05), peak oxygen consumption (from 19.8 +/- 5.6 to 25.1 +/- 5.6 ml/kg.min; P < 0.005), and anaerobic threshold (from 14.9 +/- 4.8 to 20.0 +/- 4.5 ml/kg.min; P < 0.005) without affecting lung function parameters. Furthermore, the slope of the relationship between minute ventilation and pulmonary carbon dioxide production (ventilatory efficiency) decreased from 34.7 +/- 5.1 to 31.7 +/- 5.3 (P < 0.005), whereas the slope of the relation between percent predicted heart rate reserve used and percent observed metabolic reserve used (chronotropic index) rose from 0.57 +/- 0.20 to 0.69 +/- 0.18 (P < 0.005).

CONCLUSION

Given the predictive value of physical exercise capacity and cardiopulmonary performance in CHF progression, these data provide additional insights into the mechanisms by which GH may potentially benefit CHF patients.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Hormonal regulators of muscle and metabolism in aging (HORMA): design and conduct of a complex, double masked multicenter trial

BACKGROUND

Older persons often lose muscle mass, strength, and physical function. This report describes the challenges of conducting a complex clinical investigation assessing the effects of anabolic hormones on body composition, physical function, and metabolism during aging.

METHODS

HORMA is a multicenter, randomized double masked study of 65-90-year-old community dwelling men with testosterone levels of 150-550 ng/dL and IGF-1 < 167 ng/dL. Subjects were randomized to transdermal testosterone (5 or 10 g/day) and rhGH (0, 3, or 5 microg/kg/day) for 16 weeks. Outcome measures included body composition by DEXA, MRI, and (2)H(2)O dilution; muscle performance (strength, power, and fatigability), VO2peak, measures of physical function, synthesis/breakdown of myofibrillar proteins, other measures of metabolism, and quality of life.

RESULTS

Major challenges included delay in startup caused by need for 7 institutional contracts, creating a 142-page manual of operations, orientation and training, creating a 121-page CRF; enrollment inefficiencies; scheduling 16 evaluations/ subject; overnight admissions for invasive procedures and isotope infusions; large data and image management and transfer; quality control at multiples sites; staff turnover; and replacement of a clinical testing site. Impediments were largely solved by implementation of a web-based data entry and eligibility verification; electronic scheduling for multiple study visits; availability of research team members to educate and reassure subjects; more frequent site visits to validate all source documents and reliability of data entry; and intensifying quality control in testing and imaging. The study exceeded the target goal of 108 (n = 112) completely evaluable cases. Two interim DSMB meetings confirmed the lack of excessive adverse events, lack of center effects, comparability of subjects, and that distribution of subjects and enrollment will not jeopardize outcomes or generalizability of results.

CONCLUSIONS

Flexibility and rapidly solving evolving problems is critical when conducting highly complex multicenter metabolic studies.

Prospects for the Development of Long-Acting Formulations of Human Somatropin

In healthy humans, growth hormone (GH) is secreted in distinct pulses with an underlying nyctohemeral pattern. Current forms of somatropin replacement are unable to closely mimic such a release pattern, but are still able to exert the beneficial action of GH. A limited number of short-term studies in rodents and humans suggest that longitudinal growth may be superior when somatropin is given with a pulsatile mode of administration, whereas hepatic insulin-like growth factor-I generation and beneficial changes in body composition appear to be equal or even enhanced with continuous somatropin administration.Recent developments in drug delivery technology have allowed the use of slow-release preparations of somatropin in humans. The most successful technology so far has been the encapsulation of somatropin molecules in poly(D,L-lactic-co-glycolic acid) biodegradable microspheres. Pharmacokinetic and pharmacodynamic data have been published on two such preparations; Nutropin Depot((R)) and hGH-Biosphere((R)). The latter has a superior release profile, but outcomes data from multicenter trials in both children and adults have been presented for the former: catch-up growth was observed in children, although to a lesser degree than historic comparative data obtained with the use of daily somatropin injections and the effects on metabolic derangements in GH-deficient patients appeared similar to those observed with daily injections. Improved sustained-release somatropin preparations will need further study of their long-term efficacy, but, if successful, will be highly attractive in terms of patient compliance and convenience.

Three weekly injections (TWI) of low-dose growth hormone (GH) restore low normal circulating IGF-I concentrations and reverse cardiac abnormalities associated with adult onset GH deficiency (GHD)

GH replacement therapy given 3 times weekly (TWI) and adjusted to allow serum IGF-I concentrations in the mid-normal range for sex and age has been shown to be as effective as the daily regimen in improving lipid profile, body composition, bone mass and turnover in adult GH deficient (GHD) patients. Only one study has investigated so far the short-term (6 months) effect of a fixed weight-based TWI dosing schedule on heart structure and function in childhood onset (CO) GHD patients, whereas such a schedule in adult onset (AO) GHD patients has not been studied as yet. Aim of this study was to investigate whether a 1-yr low-dose titrated TWI GH-replacement regimen aimed at achieving and maintaining IGF-I levels within the low normal limits for age and sex is able to affect cardiovascular and heart parameters in a group of AO GHD patients. Eight adult patients (4 women and 4 men, age 35.8 +/- 3.37 yr, body mass index, BMI, 28.7 +/- 2.62 kg/m2) with AO GHD were included in the study, along with 10 healthy subjects, matched for age, sex, BMI and physical activity (6 women and 4 men, age 35.2 +/- 4.05 yr, BMI 28.4 +/- 2.34 kg/m2). M- and B- mode ecocardiography and pulsed doppler examination of transmitral flow were performed in GHD patients at baseline and after 3 and 12 months of GH therapy (mean GH dose 6.7 +/- 0.8 microg/kg/day given thrice a week), while normal subjects were studied once. Treatment with GH for 1 yr induced a significant increase in left ventricular (LV) diastolic and systolic volumes (+11.1 and +16.5%, respectively). Systolic LV posterior wall thickness and LV mass were increased (+10.2 and +7.7%, respectively) by GH administration. Systemic vascular resistance was significantly decreased by 1-yr GH therapy (-13.8% after 1 yr), while stroke volume, cardiac output and cardiac index were increased (+9.4, +11.6 and + 11.9%, respectively). LV end-systolic stress was decreased at the end of GH therapy (-11.2%). E and A wave, significantly reduced at baseline, were increased by 1 yr of GH therapy (+23.3% and +28.1%, respectively); likewise, the abnormally high E peak deceleration time was partially reversed by GH administration (-10.7%). Our study, though conducted in a small sample size, demonstrates that a TWI GH treatment schedule is able to reverse the cardiovascular abnormalities in AO GHD patients and to improve body composition and lipid profile. The maintenance of circulating IGF-I concentrations within the low normal range allows to avoid most of the side-effects reported with higher GH doses while being cost-effective and improving the patient's compliance.

Effect of growth hormone (GH) and/or testosterone replacement on the prostate in GH-deficient adult patients

The prostate is a target organ of the GH and IGF-I axis because prostate hypertrophy is found in acromegaly, reduced prostate size is found in GH deficiency (GHD) patients, and additionally, IGF-I is reported to be a positive predictor factor of prostate cancer. To investigate whether GH replacement therapy in adult patients with GHD has adverse effects on the prostate, we studied the effect of 12-month GH or GH plus testosterone replacement on prostate pathophysiology in 24 adult patients with GHD (11 euandrogenemic and 13 hypoandrogenemic), compared with 24 age-matched healthy controls. At study entry, GHD patients had lower prostate volume than controls (19.4 +/- 1.7 vs. 24.9 +/- 1.7 ml; P = 0.03). After 12 months of treatment, all hypoandrogenemic patients achieved normal testosterone levels, and prostate volume increased in the patients to the same level as controls (25.0 +/- 1.9 ml). The percentage increase in prostate volume was greater in hypoandrogenemic patients receiving both GH and testosterone replacement (51 +/- 11%) than in those receiving GH replacement alone (15 +/- 3%; P < 0.0009). At baseline, prostate volume was similar in GHD patients below or above 60 yr of age (16.8 +/- 1.3 vs. 23 +/- 3.6 ml; P = 0.08), whereas after treatment it was higher in the latter patients (21.8 +/- 1.2 vs. 29.5 +/- 3.9 ml; P = 0.04). Prostate-specific antigen (PSA) and free PSA did not change, whereas PSA density was significantly reduced after treatment in hypoandrogenemic patients; there was also no change in calcifications, cysts, or nodules. In conclusion, GH replacement restores prostate size to normal in both young and elderly patients, with no increase in prostate abnormalities. Because the simultaneous treatment with GH and testosterone induces an increase of prostate size by 50% of baseline on average, care is suggested in elderly patients with prostate hyperplasia to avoid any risk of prostate symptoms. In these cases, GH replacement might be performed sequentially to reduce the hypertrophic effect of combining GH and testosterone.

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

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