Daily Growth Hormone Injections Research Articles

Development and validation of a novel treatment adherence, satisfaction and knowledge questionnaire (TASK-Q) for adult patients with hypothalamic-pituitary disorders.

Successful treatment outcomes of adults with hypothalamic-pituitary disorders necessitate the adoption of intricate self-management behaviors, yet current scales for evaluating treatment adherence and satisfaction are inadequate for this patient group. This research introduces a novel treatment adherence, satisfaction and knowledge questionnaire (TASK-Q) developed specifically to identify patients' unmet needs in better assessing and managing these disorders. The study was conducted in three phases: (1) generating items and testing content validity, (2) refining these items through a pilot study, and (3) a main study evaluating the psychometric properties of the TASK-Q scale among 262 adults in a Pituitary Nurse-led Clinic, with 152 (58%) patients completing the questionnaire. Exploratory factor analysis was used to test the factor structure and construct validity of the TASK-Q, revealing a 22-item scale divided into Satisfaction and Knowledge (17 items) and Adherence (5 items) subscales, and exhibiting high internal consistency (Cronbach's α = 0.90). Significant correlations were identified between satisfaction and knowledge (r = 0.67, p < 0.001), satisfaction and adherence (r = 0.23, p = 0.005), and knowledge and adherence (r = 0.43, p < 0.001). Complex treatment regimens, like daily growth hormone injections and adjusting glucocorticoids during illness, negatively affected adherence (p < 0.001). The TASK-Q is a novel validated scale that can effectively evaluate patients' perspectives on adherence, knowledge and satisfaction. Our findings highlight the significant impact of Advanced Nurse Practitioners in improving patient self-management behaviors, which likely leads to better treatment outcomes for people with hypothalamic-pituitary disorders.

Once-Weekly Somapacitan as an Alternative Management of Growth Hormone Deficiency in Prepubertal Children: A Systematic Review and Meta-Analysis of Randomized Controlled Trial.

Growth hormone treatment has effectively restored normal growth in children with growth hormone deficiency (GHD); however, it poses challenges in compliance with a daily growth hormone injection regimen, leading to low adherence and persistence rates. Once-weekly Somapacitan is a potential alternative for treating children with GHD. This study aimed to evaluate the efficacy, safety, and adherence of once-weekly subcutaneous Somapacitan compared to daily growth hormone injection in prepubertal children with GHD. A search for the published records was carried out on 17 October 2023 utilizing the searching feature available on PubMed, Embase, and Scopus. Primary study outcomes included (1) efficacy, measured by height velocity (HV), standard deviation score (SDs), height SDs, insulin-like growth factor-SDs (IGF-I SDs), and bone age vs. chronological age ratio (BA vs. CA); (2) safety, assessed through adverse events and injection site reactions; and (3) adherence, determined by the percentage of the sample completing treatments. Secondary outcomes evaluated disease burden scores, divided into three subgroup domains: emotional well-being, physical functional, and social well-being scores. We retrieved 6 studies that were eligible for the systematic review (417 versus 186 for intervention and control, respectively). Only 2 of the total included studies were eligible for pooled analysis (175 versus 82 for intervention and control, respectively). The efficacy profile of Somapacitan was similar to daily growth hormones, indicated by HV (mean difference (MD = 0.04; p = 0.96), HV SDs (MD = -0.71; p = 0.09), height SDs (MD = 0.11; p = 0.69), IGF-I SDs (MD = 0.06; p = 0.70), and CA vs. BA (MD = 0.67; p = 0.70)), demonstrated similar and non-inferior outcomes. Treatment adherence is 3 times higher in the Somapacitan group as compared to control (OR = 3.02; p = 0.03) with adherence rates reaching 95% and 88% for Somapacitan and Norditropin®, respectively. The disease burden measurement is similar in Somapacitan and daily growth hormones (MD = -0.62; p = 0.83), as indicated by the Growth Hormone Deficiency-Child Impact Measure. In almost all outcomes, the level of confidence is strong. The confidence level in the data is generally strong, but for CA vs. BA and the subgroup of severe adverse events with heterogeneity >50%, the confidence level is moderate. Although the efficacy and safety profiles of Somapacitan were found to be similar to those of daily growth hormones, a reduced frequency of once-weekly Somapacitan injections led to increased adherence. PROSPERO registration: CRD42023473209.

The Growth Hormone Deficiency (GHD) Reversal Trial: effect on final height of discontinuation versus continuation of growth hormone treatment in pubertal children with isolated GHD—a non-inferiority Randomised Controlled Trial (RCT)

Background Growth hormone deficiency (GHD) is the commonest endocrine cause of short stature and may occur in isolation (I-GHD) or combined with other pituitary hormone deficiencies. Around 500 children are diagnosed with GHD every year in the UK, of whom 75% have I-GHD. Growth hormone (GH) therapy improves growth in children with GHD, with the goal of achieving a normal final height (FH). GH therapy is given as daily injections until adult FH is reached. However, in many children with I-GHD their condition reverses, with a normal peak GH detected in 64–82% when re-tested at FH. Therefore, at some point between diagnosis and FH, I-GHD must have reversed, possibly due to increase in sex hormones during puberty. Despite increasing evidence for frequent I-GHD reversal, daily GH injections are traditionally continued until FH is achieved.Methods/designEvidence suggests that I-GHD children who re-test normal in early puberty reach a FH comparable to that of children without GHD. The GHD Reversal study will include 138 children from routine endocrine clinics in twelve UK and five Austrian centres with I-GHD (original peak GH < 6.7 mcg/L) whose deficiency has reversed on early re-testing. Children will be randomised to either continue or discontinue GH therapy. This phase III, international, multicentre, open-label, randomised controlled, non-inferiority trial (including an internal pilot study) will assess whether children with early I-GHD reversal who stop GH therapy achieve non-inferior near FH SDS (primary outcome; inferiority margin 0.55 SD), target height (TH) minus near FH, HRQoL, bone health index and lipid profiles (secondary outcomes) than those continuing GH. In addition, the study will assess cost-effectiveness of GH discontinuation in the early retesting scenario.DiscussionIf this study shows that a significant proportion of children with presumed I-GHD reversal generate enough GH naturally in puberty to achieve a near FH within the target range, then this new care pathway would rapidly improve national/international practice. An assumed 50% reversal rate would provide potential UK health service cost savings of £1.8–4.6 million (€2.05–5.24 million)/year in drug costs alone. This new care pathway would also prevent children from having unnecessary daily GH injections and consequent exposure to potential adverse effects.Trial registrationEudraCT number: 2020-001006-39

Cost-effectiveness and cost-utility analysis of somatrogon once-weekly injections vs. daily growth hormone injection for treating paediatric growth hormone deficiency in Ireland

ObjectivesPaediatric growth hormone deficiency (pGHD) manifests as growth failure associated with inadequate growth hormone (GH) production. Daily injections of recombinant human GH (dGH) [somatropin] is the current standard of care, which has been shown to be well tolerated and effective, but associated with suboptimal adherence, leading to reduced effectiveness. Somatrogon, a once-weekly injectable long-acting human GH, has demonstrated clinical non-inferiority and significantly lower life interference (i.e. treatment burden) vs. somatropin in two Phase 3 studies. This work evaluated cost-effectiveness and cost-utility of somatrogon vs dGHs from an Irish payer perspective.MethodsA Markov model was developed for patients starting somatrogon or dGHs treatment at 3–12 years and continuing up to achievement of near adult height (NAH), with growth driven by trial-based height velocity (HV) and treatment-specific adherence. Patients could discontinue treatment at the end of Year 1 (4%). DGH adherence (95.3%–65% over treatment duration) and adherence-growth relationship were based on published evidence. Higher Year 1 adherence of 4%, tapering over time, for somatrogon vs. dGHs was based on clinical consultation. Treatment costs, monitoring costs and costs due to different wastage types (device setting and adherence) were sourced from local data. Health utilities based on height and injection frequency were derived from published literature. Scenario analysis, deterministic and probabilistic sensitivity analysis were performed.ResultsSomatrogon treatment led to 1.87–3.66 cm greater NAH gain and 0.21–0.50 higher quality adjusted life years (QALYs) vs. dGHs, across the base case and scenarios evaluated. Somatrogon treatment was associated with cost savings of €5,699–€21,974 and lower cost per cm gained vs. dGHs (€197–€527), per patient. Somatrogon was cost-effective vs. dGHs, with the result consistent across the sensitivity analyses conducted.ConclusionSomatrogon weekly injections were estimated to result in higher NAH, higher QALYs, lower overall costs and lower costs per cm gained than dGHs, in pGHD.

Treatment burden, adherence, and quality of life in children with daily GH treatment in France.

The objective of this study was to describe in a real-life setting the treatment burden and adherence and quality of life (QOL) of children treated with daily injections of growth hormone and their relationship with treatment duration. This non-interventional, multicenter, cross-sectional French study involved children aged 3-17 years treated with daily growth hormone injections. Based on a recent validated dyad questionnaire, the mean overall life interference total score (100 = most interference) was described, with treatment adherence and QOL, using the Quality of Life of Short Stature Youth questionnaire (100 = best). All analyses were performed according to treatment duration prior to inclusion. Among the 275/277 analyzed children, 166 (60.4%) had only growth hormone deficiency (GHD). In the GHD group, the mean age was 11.7 ± 3.2 years; median treatment duration was 3.3 years (interquartile range 1.8-6.4). The mean overall life interference total score was 27.7 ± 20.7 (95% CI (24.2; 31.2)), with non-significant correlation with treatment duration (P = 0.1925). Treatment adherence was good (95.0% of children reported receiving >80% of planned injections over the last month); it slightly decreased with treatment duration (P = 0.0364). Children's overall QOL was good (81.5 ± 16.6 and 77.6 ± 18.7 according to children and parents, respectively), but subscores of the coping and treatment impact domains were <50. Similar results were observed in all patients independently of the condition requiring treatment. This real-life French cohort confirms the treatment burden of daily growth hormone injections, as previously reported in an interventional study.

EE27 Cost-Effectiveness and Cost-Utility Analysis of Somatrogon Once-Weekly Injectable vs Daily Growth Hormones for Treating Pediatric Growth Hormone Deficiency

Pediatric growth hormone deficiency (pGHD) is defined as growth failure associated with inadequate growth hormone (GH) production. Daily injections of recombinant human GH (dGH) [somatropin] is the current standard of care, which has been shown to be safe and effective, however with suboptimal adherence, leading to reduced effectiveness. Somatrogon, a once-weekly injectable long-acting human GH, has demonstrated clinical non-inferiority and significantly lower life interference vs. somatropin. This work aimed to evaluate cost-effectiveness and cost-utility of somatrogon vs dGHs across 5 countries (United States, Canada, Spain, Sweden, Ireland)

Association of Daily Growth Hormone Injection Adherence and Height Among Children With Growth Hormone Deficiency

ObjectiveRecombinant human growth hormone (somatropin) is recommended for children with growth hormone deficiency (GHD) to normalize adult height. Prior research has indicated an association between adherence to somatropin and height velocity. Further research is needed using real-world data to quantify this relationship; hence the objective of this study was to investigate the association between adherence to somatropin and change in height among children with GHD. MethodsThis retrospective cohort study included patients in the IQVIA PharMetrics Plus and Ambulatory Electronic Medical Records databases aged 3 to 15 years, with ≥1 GHD diagnosis code claim and newly initiated on somatropin between January 1, 2007 and November 30, 2019. Adherence was measured over the follow-up using the medication possession ratio (MPR); patients were classified as adherent (MPR ≥ 0.8) or nonadherent (MPR < 0.8). ResultsAmong 201 patients initiated on somatropin, 74.6% were male, mean age was 11.4 years, and the mean follow-up was 343.3 days. Approximately 76.6% of patients were adherent to somatropin over the follow-up period. Adjusted growth trajectories were similar between adherent and nonadherent patients pre-treatment initiation (P = .15). Growth trajectories post-initiation were significantly different (P = .001). On average, adherent patients gained an additional 1.8 cm over 1 year compared with nonadherent patients, adjusted for covariates. ConclusionGreater adherence to somatropin therapy is associated with improved height velocity. As suboptimal adherence to daily somatropin therapy is an issue for children with GHD, novel strategies to improve adherence may improve growth outcomes.

Efficacy and safety of long-acting growth hormone in adult growth hormone deficiency: A systematic review and meta-analysis

Background & aimsNo meta-analysis has analysed efficacy and safety of long-acting growth hormone (GH) therapy in adult GH deficiency. We undertook this meta-analysis to address this gap in knowledge MethodsElectronic databases were searched for RCTs involving adult GH deficiency patients receiving weekly long-acting GH as compared to daily GH/placebo controls. Primary outcome was to evaluate changes in body-composition parameters. Secondary outcomes were to evaluate alterations in glycaemia and adverse-events. ResultsData from 5 studies involving 648 patients were analysed (4 studies having daily GH as active controls; 1 study having placebo as passive controls). Over 24–34 weeks clinical use, patients receiving long-acting GH had comparable change in lean mass [MD-0.28 kg (95%CI: 0.94 – 0.38); P = 0.41; I2 = 29% (low heterogeneity)] and fat mass [MD-0.10 kg (95%CI: 1.97–1.78); P = 0.92; I2 = 77%(considerable heterogeneity)] as compared to daily GH injections. Long-acting GH use was associated with significantly lower visceral adipose tissue [MD-1.75 cm2(95%CI: 2.14 to −1.35); P < 0.01; I2 = 0% (low heterogeneity)] and higher gynoid fat-mass [MD 0.14 kg(95%CI:0.02–0.26); P = 0.03] compared to daily GH injections. Total adverse events [Risk ratio (RR) 1.65 (95% CI: 0.83–3.29); P = 0.15; I2 = 68%] and severe adverse events [RR 0.60 (95% CI: 0.30–1.19); P = 0.14; I2 = 0%] were not significantly different in long-acting GH group compared to controls. Occurrence of headache, arthralgia, nasopharyngitis, new onset diabetes, anti-GH antibodies were comparable among groups. Long-acting GH users had significantly higher treatment adherence compared to controls [OR 4.80 (95%CI:3.58–6.02); P < 0.01; I2 = 0%]. ConclusionLong-acting GH has comparable beneficial impact on body composition parameters in adult GH deficiency, is well tolerated without any increased adverse events.

POSA351 Dyadic Evaluation of Patient and Caregiver Treatment Burden with Once Weekly Growth Hormone (GH) Injection Schedule (SOMATROGON) vs. Once Daily GH Injection Schedule (SOMATROPIN) By Baseline Burden Subgroup in Paediatric Growth Hormone Deficiency (GHD)

To evaluate patient and caregiver perceptions of the treatment burden associated with weekly somatrogon compared to daily somatropin injection in subgroups identified as ‘Not Burdened’ or ‘Burdened’ at baseline (BL).

Lipoatrophy associated with daily growth hormone injections.

SummaryRecombinant human growth hormone therapy (rhGH) has been available since 1985 for a variety of conditions and has expanded the indications for rhGH therapy and the number of patients receiving therapy. The very nature of the therapy exposes individuals to years of injections. There are a number of well-known adverse events, however, a lesser-known and rarely reported adverse event of rhGH therapy is localized lipoatrophy. We report nine cases of localized lipoatrophy during rhGH therapy accounting for 14.5% of patients taking rhGH presenting to a single centre for routine follow-up over just a 2-month period. The development of localized lipoatrophy does not appear to be age, indication or dose-related but rather related to repeated administration of rhGH into a limited number of sites. The most likely putative mechanism is the local lipolytic action of growth hormone (GH) itself, although the possibility of an excipient-based interaction cannot be excluded. Given the high prevalence of this adverse event and the potential to prevent it with adequate site rotation, we can recommend that patients be informed of the possible development of localized lipoatrophy. Doctors and nurses should closely examine injection sites at each visit, and site rotation should be emphasized during injection technique education.Learning pointsThere are a number of well-known adverse events, however, a lesser-known and rarely reported adverse event of rhGH therapy is localized lipoatrophy.Examination of the injection sites at each visit by the treating healthcare practitioner.To advise the parents/caregivers/patients to change their injection site with each injection.To advise the parents/caregivers/patients to change the needles after every use.For parents, caregivers and patients to self-inspect their injection sites and have a high alert for the development of lipoatrophy and to then immediately report it to their doctor.

Using Deep Learning for Individual-Level Predictions of Adherence with Growth Hormone Therapy.

The problem of consistent therapy adherence is a current challenge for health informatics, and its solution can increase the success rate of treatments. Here we show a methodology to predict, at individual-level, future therapy adherence for patients receiving daily injections of growth hormone (GH) therapy for GH deficiency. Our proposed model is able to generate predictions of future adherence using a recurrent neural network with adherence data recorded by easypodTM, a connected autoinjection device. The model was trained with a multi-year long dataset with 2500 patients, from January 2007 to June 2019. When testing, the model reached an average sensitivity of 0.70 and a specificity of 0.88 per patient when predicting non-adherence (<85%) periods. When evaluated with thousands of therapy segments extracted from a test set, our model reached an AUC-PR score of 0.79 and AUC-ROC of 0.90; both metrics were consistently better than traditional approaches, such as simple average model. Using this model, we can perform precise early identification of patients who are likely to become non-adherent patients. This opens a path for healthcare practitioners to personalize GH therapy at any stage of the patients' journey and improve shared decision making with patients and caregivers to achieve optimal outcomes.

Induced multiple follicular growth and ongoing twin pregnancy by IVF in a woman with premature menopause

Menopause, natural or premature, was long been considered to be incompatible with conception with the own eggs of the women affected. Here we describe a case of a 32-year-old woman with premature menopause, characterized by amenorrea, the absence of antral follicles in the ovaries, high basal follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels and extremely low antimullerian hormone (AMH) levels. After preliminary treatment with contraceptive pill for two months, and an injection of recombinant human chorionic gonadotropin (HCG) to boost intrinsic androgen production, ovarian stimulation, using a customized protocol with a patient-tailored combination of recombinant FSH and LH, in addition to daily injections of growth hormone, resulted in the recovery of 3 metaphase II eggs after double triggering with recombinant HCG. After transfer of two embros, obtained by intracytoplasmic sperm injection, an ongoing twin clinical pregnancy was achieved. These data show that oocyte recovery, fertilization, embryo development and pregnancy can be achieved, with the use of a customized ovarian stimulation protocol, even in young women with clear signs of advanced premature menopause.

Efficacy and safety of long-acting growth hormone in children with short stature: a systematic review and meta-analysis.

Long-acting growth hormone (GH) has been developed to address the noncompliance and decreased efficacy associated with daily GH injections. We aimed to evaluate the efficacy and safety of long-acting GH replacement therapy in children with short stature. Randomized controlled trials (RCTs) that investigated the efficacy and safety of long-acting GH therapy in children with short stature in comparison with daily GH injections were searched in Medline, Embase, and the Cochrane Central Register of Controlled Trials. A random-effect model was used to pool data using mean difference and odds ratios (OR). (PROSPERO registration number: CRD42018111105). Seven relevant studies were finally included. Meta-analysis found there was no significant difference between high-dose long-acting GH and daily GH in terms of height velocity (HV) (mean difference (MD) = -0.10, 95% CI, -0.79 to 0.60, P = 0.79). Moreover, no significant difference was observed in height standard deviation scores (Ht SDS) between high-dose long-acting GH and daily GH (MD = -0.07, 95% CI, -0.18 to 0.03, P = 0.17). Treatment with high-dose long-acting GH significantly increased IGF-1 SDS when compared with daily GH (MD = 0.31, 95% CI, 0.06-0.56, P = 0.02). In safety assessment, no significant difference was observed in the incidence of adverse events between high-dose long-acting GH and daily GH (OR 1.42, 95% CI, 0.65-3.11, P = 0.38). There is no evidence to support differences in the effects of long-acting GH compared with those of daily GH. More RCTs that focus on the safety of high-dose long-acting GH treatment, especially the detection of adverse events caused by elevated levels of serum IGF-1, are needed in the future.

Gamification Concepts to Promote and Maintain Therapy Adherence in Children with Growth Hormone Deficiency

Growth hormone (GH) deficiency affects up to one in 4000 children and is usually treated with daily injections of GH whilst the child is still growing. With children typically diagnosed at around five years old, this can mean over 10 years of therapy, which can place a considerable burden on the child and the parent. Over three-quarters of children are estimated to be not fully compliant with therapy, which can compromise their chances of attaining their target height. In recent years, interactive mobile health (smart phone or tablet) interventions using game-like concepts, so called ‘gamification’, have increased in popularity and have demonstrated success in promoting positive self-management behaviour in children with chronic conditions, such as diabetes. The application of gamified interventions has the potential to support adherence to therapy and positive behaviour in children with GH deficiency in a number of ways: (1) By providing education in a format that the child understands and accepts (e.g., using behavioural constructs to facilitate explaining why adherence is important); (2) By providing a mechanism to reduce the anxiety and stress associated with administering the injection (e.g., diversion with a virtual pet); and (3) By providing feedback to encourage ongoing engagement (e.g., rewards, progression through levels).

Growth Hormone Research Society perspective on the development of long-acting growth hormone preparations.

ObjectiveThe Growth Hormone (GH) Research Society (GRS) convened a workshop to address important issues regarding trial design, efficacy, and safety of long-acting growth hormone preparations (LAGH).ParticipantsA closed meeting of 55 international scientists with expertise in GH, including pediatric and adult endocrinologists, basic scientists, regulatory scientists, and participants from the pharmaceutical industry.EvidenceCurrent literature was reviewed for gaps in knowledge. Expert opinion was used to suggest studies required to address potential safety and efficacy issues.Consensus processFollowing plenary presentations summarizing the literature, breakout groups discussed questions framed by the planning committee. Attendees reconvened after each breakout session to share group reports. A writing team compiled the breakout session reports into a draft document that was discussed and revised in an open forum on the concluding day. This was edited further and then circulated to attendees from academic institutions for review after the meeting. Participants from pharmaceutical companies did not participate in the planning, writing, or in the discussions and text revision on the final day of the workshop. Scientists from industry and regulatory agencies reviewed the manuscript to identify any factual errors.ConclusionsLAGH compounds may represent an advance over daily GH injections because of increased convenience and differing phamacodynamic properties, providing the potential for improved adherence and outcomes. Better methods to assess adherence must be developed and validated. Long-term surveillance registries that include assessment of efficacy, cost-benefit, disease burden, quality of life, and safety are essential for understanding the impact of sustained exposure to LAGH preparations.

Translational Neuroendocrinology: Control of Human Growth

Human growth is driven by both basic cell processes as well as hormones, in particular the growth hormone (GH)-insulin-like growth factor (IGF)-1 axis. Understanding how these mechanisms are coordinated is not only critical to achieving a normal growth rate, but also to recognising potential new causes of disordered growth and how they might be treated. We have demonstrated in healthy children that height is gained by periods of rapid growth interspersed by periods of very slow growth or even stasis. We have also shown that a lower order organism, Caenorhabditis elegans, grows in a similar manner. By contrast, secretion of GH from somatotrophs occurs on a daily basis in discrete pulses over a 24-h period. We have used the measurement of GH in urine as a surrogate marker of GH secretion to show that there are rhythms of GH output with frequencies of several days. We then assessed which attributes of these GH profiles were related to growth and found that disorderliness in the GH profile (as measured by approximate entropy) was related to better growth rate. This feature was then tested in the dwarf rat using different GH regimens to introduce variation into the administration of daily GH injections. Better long bone growth was associated with week-to-week or even random dose variation compared to the same amount of GH delivered as a standard daily dose. Understanding the control of growth has implications in clinical practice for modelling GH treatment regimens based on physiological principles.

Effect of growth hormone on aging connective tissue in muscle and tendon: gene expression, morphology, and function following immobilization and rehabilitation

It is unknown whether loss in musculotendinous tissue during inactivity can be counteracted by growth hormone (GH), and whether GH accelerate rehabilitation in aging individuals. Elderly men (65-75 yr; n = 12) had one leg immobilized 2 wk followed by 6 wk of retraining and were randomly assigned to daily injections of recombinant GH (rhGH; n = 6) or placebo (Plc; n = 6). Cross-sectional area (CSA), muscle strength (MVC), and biomechanical properties of m. quadriceps and patellar tendon were determined. Muscle and tendon biopsies were analyzed for gene expressions (mRNA) of collagen (COL1A1/3A1) and insulin-like growth factors (IGF-1Ea/Ec). Fibril morphology was analyzed by transmission electron microscope (TEM). In tendon, CSA and biomechanical properties did not change following immobilization, but an increase in CSA was found after 6 wk of rehabilitation in both groups. The changes were more pronounced when GH was injected. Furthermore, tendon stiffness increased in the GH group. Muscle CSA declined after immobilization in the Plc but not in the GH group. Muscle CSA increased during retraining, with a significantly larger increase in the GH group compared with the Plc group. Both a time and a group effect were seen for IGF-1Ea/Ec and COL1A1/3A1 mRNA expression in muscle, with a difference between GH and Plc. IGF-1Ea/Ec and COL-1A1/3A1 mRNA expression increased in muscle following immobilization and retraining in subjects receiving GH, whereas an increase in IGF-1Ec mRNA expression was seen in the Plc group only after retraining. In conclusion, in elderly humans, GH seems to have a matrix stabilizing effect during inactivity and rehabilitation by stimulating collagen expression in the musculotendinous tissue and increasing tendon CSA and stiffness.

Growth Hormone Does Not Stimulate Early Healing in Rat Tendons

Growth Hormone stimulates bone growth and fracture repair. It acts mainly by increasing the systemic levels of IGF-1. Local treatment with IGF-1 appears to stimulate tendon healing. We therefore hypothesized that systemic treatment with Growth Hormone would also stimulate tendon healing. Rat Achilles tendons were transected and left to heal. 4 groups were studied. Intramuscular injections of botulinum toxin A (Botox) were used to reduce loading in 2 groups. The animals were randomized to twice daily injections of Growth Hormone (n=2×10) or saline (n=2×10), and killed after 10 days. Healing was assessed by mechanical testing. Muscle paralysis induced by Botox reduced the strength of the healing tendon by two thirds. Growth Hormone increased femoral and tibial length in the unloaded, and femoral and tibial weight in the loaded group. Body weight and muscle weight were increased in both. In contrast, there was no increase in the strength of the healing tendons, regardless of mechanical loading status. An increase in peak force of the loaded healing tendons by more than 5% could be excluded with 95% confidence. In spite of its stimulatory effects on other tissues, Growth Hormone did not appear to stimulate tendon or tendon repair.

Novel View on Stem Cell Compartment and Aging - a Number of Pluripotent Very Small Embryonic Like Stem Cells and Hematopoietic Stem Cells in Murine Bone Marrow Is High in Several Long-Living and Reduced in Short-Living Murine Strains and Unexpectedly Inversely Correlates in These Animals with Plasma Growth Hormone/Insulin-Like Growth Factor-1 Level

Abstract LBA-5 Background:It is known that an increase in caloric intake leads to increase in plasma growth hormone (GH) level that subsequently induces secretion of insulin-like growth factor-1 (IGF-1) from liver, what leads to accelerated aging (Nature 2010;464:504). On the other hand, caloric restriction and a resulting decrease in plasma IGF-1 level has the opposite effect and extends lifespan. It also known that adult tissues contain a population of pluripotent very small embryonic like stem cells (VSELs) that play as postulated an important role in rejuvenation of long term hematopoietic stem cells (LT-HSCs) in bone marrow (BM) Leukemia 2011; doi:10.1038/leu.2011.73, Exp. Hematology 2011;39:225–237). As we observed previously, the number of these cells in murine BM decreases with age and VSELs are kept quiescent in BM and protected from premature depletion by erasure of the somatic imprint in differentially methylated regions (DMRs) of some paternally imprinted genes involved in insulin/insulin growth factors signaling (IIS) such as e.g., Igf2-H19 and RasGRF1 (Leukemia 2009;23:2042). Hypothesis:To explain and connect these phenomena together, we hypothesized that prolonged insulin/insulin growth factors signaling (IIS) prematurely depletes VSELs from the adult tissues and in BM may negatively impact on population of HSCs. Material and Methods:The number of VSELs and HSCs in long living murine strains with inborn low level of circulating IGF-1 (Laron- and Ames- dwarfs) as well as in short living mice with high levels of circulating IGF-1 (e.g., transgenic mice that overexpress bovine growth hormone; bGH) was evaluated by FACS. VSELs were isolated and epigenetic status of genes regulating pluripotency (e.g., Oct-4) as well as imprinted genes regulating IIS was evaluated by employing bisulfate modification of DNA followed by sequencing and by COBRE assay. We also challenged long living mice with low IGF-1 plasma level by daily injections of recombinant GH or IGF-1. Results:We found that the number of VSELs and HSCs residing in BM inversely correlates with plasma GH/IGF-1 level. To support this, mice with low circulating plasma IGF-1 levels (Laron- and Ames-dwarf mice) have higher numbers of VSELs and HSCs in BM that, in contrast to aged-matched normal littermates, are maintained at high levels even into advanced age. The analysis of molecular signature of VSELs in these animals revealed prolonged retention of hypomethylation in the DMRs within the Igf2-H19 and RasGRF1 loci, which attenuates IIS signaling in these cells. The number of VSELs, however, decreased in these animals after prolonged treatment with GH or recombinant IGF-I. Conversely, mice with elevated IGF-I level in plasma due to expression of the GH transgene or normal wild type mice injected for a sustained period with recombinant GH both exhibit significant decreases in the number of VSELs and HSCs in BM compared to control animals. These decreases were paralleled by epigenetic changes in Igf2-H19 and RasGRF1 loci in which DMRs became hypermethylated over time. These changes in methylation lead to increases in IGF-2 and RasGRF1 expression and may explain why GH transgenic mice have an increase in IIS that leads to shortening of life span in these animals. Conclusions:Our data shed new light on the relationships between senescence, GH/IGF-1 level, prolonged IIS, and number of VSELs and LT-HSCs. Accordingly, we propose a new paradigm in which a decrease in IIS (e.g., due to caloric restriction that lowers plasma IGF-1 level) may delay the age-dependent elimination of VSELs from adult tissues. By contrast, chronic IIS (e.g., due to chronic high caloric intake and the resulting elevated GH and IGF-1 levels) prematurely depletes VSELs residing in adult organs, which for example in BM leads to a decrease in the number of LT-HSCs. This study also indicates that GH-based anti-aging therapies need careful re-evaluation of their potentially uncontrolled stimulation of VSELs in BM that may lead to development of hematological malignancies. In support of this, elevated GH and IIS lead to hematological malignancies, while, by contrast, Laron dwarf mice and Laron dwarf patients, which have a low plasma IGF-1 levels, do not develop leukemias. Disclosures:Ratajczak:Neostem Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Novel View on Stem Cell Compartment and Aging - a Number of Pluripotent Very Small Embryonic Like Stem Cells and Hematopoietic Stem Cells in Murine Bone Marrow Is High in Several Long-Living and Reduced in Short-Living Murine Strains and Unexpectedly Inversely Correlates in These Animals with Plasma Growth Hormone/Insulin-Like Growth Factor-1 Level

Abstract LBA-5 Background: It is known that an increase in caloric intake leads to increase in plasma growth hormone (GH) level that subsequently induces secretion of insulin-like growth factor-1 (IGF-1) from liver, what leads to accelerated aging (Nature 2010;464:504). On the other hand, caloric restriction and a resulting decrease in plasma IGF-1 level has the opposite effect and extends lifespan. It also known that adult tissues contain a population of pluripotent very small embryonic like stem cells (VSELs) that play as postulated an important role in rejuvenation of long term hematopoietic stem cells (LT-HSCs) in bone marrow (BM) Leukemia 2011; doi:10.1038/leu.2011.73, Exp. Hematology 2011;39:225–237). As we observed previously, the number of these cells in murine BM decreases with age and VSELs are kept quiescent in BM and protected from premature depletion by erasure of the somatic imprint in differentially methylated regions (DMRs) of some paternally imprinted genes involved in insulin/insulin growth factors signaling (IIS) such as e.g., Igf2-H19 and RasGRF1 (Leukemia 2009;23:2042). Hypothesis: To explain and connect these phenomena together, we hypothesized that prolonged insulin/insulin growth factors signaling (IIS) prematurely depletes VSELs from the adult tissues and in BM may negatively impact on population of HSCs. Material and Methods: The number of VSELs and HSCs in long living murine strains with inborn low level of circulating IGF-1 (Laron- and Ames- dwarfs) as well as in short living mice with high levels of circulating IGF-1 (e.g., transgenic mice that overexpress bovine growth hormone; bGH) was evaluated by FACS. VSELs were isolated and epigenetic status of genes regulating pluripotency (e.g., Oct-4) as well as imprinted genes regulating IIS was evaluated by employing bisulfate modification of DNA followed by sequencing and by COBRE assay. We also challenged long living mice with low IGF-1 plasma level by daily injections of recombinant GH or IGF-1. Results: We found that the number of VSELs and HSCs residing in BM inversely correlates with plasma GH/IGF-1 level. To support this, mice with low circulating plasma IGF-1 levels (Laron- and Ames-dwarf mice) have higher numbers of VSELs and HSCs in BM that, in contrast to aged-matched normal littermates, are maintained at high levels even into advanced age. The analysis of molecular signature of VSELs in these animals revealed prolonged retention of hypomethylation in the DMRs within the Igf2-H19 and RasGRF1 loci, which attenuates IIS signaling in these cells. The number of VSELs, however, decreased in these animals after prolonged treatment with GH or recombinant IGF-I. Conversely, mice with elevated IGF-I level in plasma due to expression of the GH transgene or normal wild type mice injected for a sustained period with recombinant GH both exhibit significant decreases in the number of VSELs and HSCs in BM compared to control animals. These decreases were paralleled by epigenetic changes in Igf2-H19 and RasGRF1 loci in which DMRs became hypermethylated over time. These changes in methylation lead to increases in IGF-2 and RasGRF1 expression and may explain why GH transgenic mice have an increase in IIS that leads to shortening of life span in these animals. Conclusions: Our data shed new light on the relationships between senescence, GH/IGF-1 level, prolonged IIS, and number of VSELs and LT-HSCs. Accordingly, we propose a new paradigm in which a decrease in IIS (e.g., due to caloric restriction that lowers plasma IGF-1 level) may delay the age-dependent elimination of VSELs from adult tissues. By contrast, chronic IIS (e.g., due to chronic high caloric intake and the resulting elevated GH and IGF-1 levels) prematurely depletes VSELs residing in adult organs, which for example in BM leads to a decrease in the number of LT-HSCs. This study also indicates that GH-based anti-aging therapies need careful re-evaluation of their potentially uncontrolled stimulation of VSELs in BM that may lead to development of hematological malignancies. In support of this, elevated GH and IIS lead to hematological malignancies, while, by contrast, Laron dwarf mice and Laron dwarf patients, which have a low plasma IGF-1 levels, do not develop leukemias. Disclosures: Ratajczak: Neostem Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees.