Diagnosis of adult GH deficiency

The somatotroph pituitary gland function in high-aged multimorbid hospitalized patients with IGF-I deficiency

PURPOSE

It is unclear whether the age-related decline in the somatotropic axis stems from a reduced growth hormone (GH) production in the pituitary gland, or from a peripheral origin akin to an acquired GH resistance. With the help of a GHRH/arginine test, high-aged multimorbid hospitalized patients with IGF-I deficiency are to be tested to determine whether there is primarily a pituitary GH deficiency in the sense of a somatopause.

METHODS

Seventeen multimorbid patients (eleven men and six women) with a mean age of 82 years, with IGF-I concentrations below two standard deviations of 30-year-old men and women were identified. Patients suffered from a variety of common age-related stable diseases including coronary artery disease, chronic liver or kidney disease, chronic heart failure as well as acute conditions e.g., urosepsis or endocarditis. To assess the somatotropic axis they underwent a GHRH/arginine test. Results were evaluated using descriptive statistics.

RESULTS

In average, the peak concentration of GH after stimulation was 14.8 µg/L with a range from 2.76 to 47.4 µg/L. Taking into account both, gender and BMI (with a mean of 26.5 kg/m²) for each participant, the pituitary gland was adequately stimulated in 16 out of the 17 patients. No patient reported common side effects related to the GHRH/arginine test.

CONCLUSION

The somatotroph pituitary gland retains its secretory capacity in the advanced aged. Therefore, age does not seem to be the driving pacemaker for the functional decline of the somatotropic axis within the aged population.

Clinical and radiographic assessment of peripheral joints in controlled acromegaly

PURPOSE

Acromegalic arthropathy is a well-known phenomenon, occurring in most patients regardless of disease status. To date, solely hips, knees, hands, and spinal joints have been radiographically assessed. Therefore, this study aimed to assess the prevalence of joint symptoms and radiographic osteoarthritis (OA) of new, and established peripheral joint sites in well-controlled acromegaly.

METHODS

Fifty-one acromegaly patients (56% female, mean age 64 ± 12 years) in long-term remission for 18.3 years (median, IQR 7.2-25.4) were included. Nineteen patients currently received pharmacological treatment. Self-reported joint complaints were assessed using standardized interviews. Self-reported disability of the upper and lower limbs, and health-related quality of life (HR-QoL) were evaluated using validated questionnaires. Radiographic OA [defined as Kellgren & Lawrence (KL) ≥ 2] was scored using (modified) KL methods.

RESULTS

Radiographic signs of OA were present in 46 patients (90.2%) with ≥ 2 joints affected in virtually all of these patients (N = 44; 95.7%). Radiographic MTP1 OA was as prevalent as radiographic knee OA (N = 26, 51.0%), and radiographic glenohumeral OA was similarly prevalent as hip OA [N = 21 (41.2%) vs. N = 24 (47.1%)]. Risk factors for radiographic glenohumeral OA were higher pre-treatment IGF-1 levels [OR 1.06 (1.01-1.12), P = 0.021], and current pharmacological treatment [OR 5.01 (1.03-24.54), P = 0.047], whereas no risk factors for MTP1 joint OA could be identified.

CONCLUSION

Similar to previously-assessed peripheral joints, clinical and radiographic arthropathy of the shoulder and feet were prevalent in controlled acromegaly. Further studies on adequate management strategies of acromegalic arthropathy are needed.

Dynamic Tests in Pituitary Endocrinology: Pitfalls in Interpretation during Aging

Aging and age-related diseases represent hot topics of current research. Progressive damage in morphology and function of cells and tissue characterizes the normal process of aging that is influenced by both genetic and environmental factors. The ability of each individual to adapt to these stressors defines the type of aging and the onset of age-related diseases (i.e., metabolic syndrome, inflammatory disorders, cancer, and neurodegenerative diseases). The endocrine system plays a critical role in this process because of its complex relationships with brain, immune system, and skeletal muscle; thus, alterations in hormonal networks occur during aging to maintain homeostasis, with consequent under- or overactivity of specific hypothalamic-pituitary-peripheral hormone axes. On the other hand, the increase in life expectancy has led to increasing incidence of age-related diseases, including endocrine disorders, which may prompt assessment of endocrine function in aging individuals. In this context, there is growing awareness that natural changes of endocrine physiology and physiopathology occurring with increasing age may necessitate age-driven diagnostic cutoffs requiring validation in the elderly. This review aims to analyze the available literature on the hormone response to the most important dynamic tests currently used in the clinical practice for the screening of anterior pituitary-related diseases to underline pitfalls in interpretation during aging.

Prevalence of growth hormone deficiency in patients with unexplained chronic fatigue after undergoing bone marrow transplantation in adulthood

PURPOSE

Many patients who undergo bone marrow transplantation (BMT) in adulthood experience unexplained chronic fatigue which can have a major impact on their health-related quality of life (QoL). Pre-BMT treatment regimens increase the risk of developing acquired growth hormone deficiency (GHD), which results in a clinical syndrome with decreased energy and has additionally been linked to metabolic syndrome.

METHODS

Using the gold-standard insulin hypoglycemic test (IHT), we evaluated the prevalence of GHD in 18 post-BMT adult patients with unexplained chronic fatigue, as well as the correlation between peak serum GH response and QoL scores, the metabolic syndrome, and insulin resistance. Peak serum GH cut-point less than 3.0 ug/L was used for the diagnosis of severe GHD. The Fatigue Severity Scale and Quality of Life in Adult GHD Assessment questionnaires were used to quantify fatigue symptoms.

RESULTS

The prevalence of severe GHD within this sample of 18 patients was 50%. A trend between lower peak serum GH response and higher fatigue and QoL-AGHDA scores was observed.

CONCLUSIONS

GHD may represent a remediable contributor to post-BMT chronic fatigue in adults, further studies are needed to evaluate the potential role of screening and GH replacement therapy in this vulnerable patient population.

IMPLICATIONS FOR CANCER SURVIVORS

GHD may be a treatable explanation for disabling post-BMT fatigue pending results of intervention studies.

Untargeted LC/MS-Based Metabolic Phenotyping of Hypopituitarism in Young Males

Objective: Hypopituitarism (Hypo-Pit) is partial or complete insufficiency of anterior pituitary hormones. Besides hormone metabolism, the global metabolomics in Hypo-Pit are largely unknown. We aimed to explore potential biomarkers to aid in diagnosis and personalized treatment.

Methods: Using both univariate and multivariate statistical methods, we identified 72 differentially abundant features through liquid chromatography coupled to high-resolution mass spectrometry, obtained in 134 males with Hypo-Pit and 90 age matched healthy controls.

Results: Hypopituitarism exhibits an increased abundance of metabolites involved in amino acid degradation and glycerophospholipid synthesis, but decreased content of metabolites in steroid hormone synthesis and fatty acid beta-oxidation. Significantly changed metabolites included creatine, creatinine, L-alanine, phosphocholines, androstenedione, hydroprenenolone, and acylcarnitines. In Hypo-Pit patients, the increased ratio of creatine/creatinine suggested reduced creatine uptake and impaired creatine utilization, whereas the decreased level of beta-hydroxybutyrate, acetylcarnitine (C2) and a significantly decreased ratio of decanoylcarnitine (C10) to free carnitine suggested an impaired beta-oxidation. Furthermore, the creatine/creatinine and decanoylcarnitine/carnitine ratio were identified as diagnostic biomarkers for Hypo-Pit with AUCs of 0.976 and 0.988, respectively. Finally, we found that the creatinine and decanoylcarnitine/carnitine ratio could distinguish cases that were sensitive vs. resistant to human chorionic gonadotropin therapy.

Conclusion: We provided a global picture of altered metabolic pathways in Hypo-Pit, and the identified biomarkers in creatine metabolism and beta-oxidation might be useful for the preliminary screening and diagnosis of Hypo-Pit.

Regulation of GH and GH Signaling by Nutrients

Growth hormone (GH) and insulin-like growth factor-1 (IGF-I) are pleiotropic hormones with important roles in lifespan. They promote growth, anabolic actions, and body maintenance, and in conditions of energy deprivation, favor catabolic feedback mechanisms switching from carbohydrate oxidation to lipolysis, with the aim to preserve protein storages and survival. IGF-I/insulin signaling was also the first one identified in the regulation of lifespan in relation to the nutrient-sensing. Indeed, nutrients are crucial modifiers of the GH/IGF-I axis, and these hormones also regulate the complex orchestration of utilization of nutrients in cell and tissues. The aim of this review is to summarize current knowledge on the reciprocal feedback among the GH/IGF-I axis, macro and micronutrients, and dietary regimens, including caloric restriction. Expanding the depth of information on this topic could open perspectives in nutrition management, prevention, and treatment of GH/IGF-I deficiency or excess during life.

Progression of acromegalic arthropathy in long-term controlled acromegaly patients: 9 years of longitudinal follow-up

CONTEXT

Joint complaints in patients with acromegaly are common, although the long-term disease course is largely unknown.

OBJECTIVE

This study aims to evaluate the long-term course of acromegalic arthropathy.

DESIGN AND SETTING

A prospective longitudinal cohort study was conducted in controlled acromegaly patients followed at a tertial referral center, with 3 study visits: at baseline and after a median of 2.6 and 9.1 years.

PATIENTS

We included 31 patients with biochemically controlled acromegaly for 2 or more years (49% female; median age, 60 years) at baseline.

MAIN OUTCOME MEASURES

Radiographic arthropathy of the knee, hip, hand, and cervical and lumbar spine were evaluated using Kellgren and Lawrence (KL) scores, developed for assessment of primary osteoarthritis (OA). Radiographic progression was defined as a KL increase above the smallest detectable change. Joint symptoms were assessed using self-reported questionnaires. Progression was defined using existing clinically important cutoff values. Risk factors for progression were investigated using a multivariable model.

RESULTS

All patients had definite radiographic OA at 1 or more joints at baseline. Radiographic progression was observed in 29%, 48%, 84%, and 94% of patients in the knees, hips, hands, and axial joints, respectively. Deterioration in hand-related pain and function was observed in 10 (32.3%) and 11 patients (35.5%), respectively. Solely baseline KL scores of the hip were associated with hip OA progression (OR 1.88; 95% CI, 1.09-3.16).

CONCLUSIONS

Acromegalic arthropathy showed significant radiographic progression over 9.1 years of follow-up in patients in remission, whereas clinical progression was observed less frequently. Future studies should focus on adequate prevention and treatment strategies of acromegalic arthropathy.

GH Replacement in the Elderly: Is It Worth It?

Growth hormone (GH), once the age of linear growth is completed, continues to play a fundamental role for the human body. In adulthood, GH contributes to regulate muscle, cardiovascular and bone metabolism. The same happens in old age, although there is less data on the effect of GH in the elderly. Regardless the age of onset, a reduced quality of life (QoL), an increased cardiovascular risk and an accelerated age-related decline in physical strength have been demonstrated in the elderly with GH deficiency (EGHD). In adults with GH deficiency (AGHD), recent studies suggest a role of GH replacement therapy (GHrt) in improving lean/fat mass ratio, blood pressure, lipid profile, bone metabolism and QoL. Despite these recent studies, there is still a lack of randomized controlled trials proving these positive effects in EGHD. Moreover, the lack of a long-term positive outcome on mortality, and the cost of GHrt could often impact on treatment decision-making and lead to postpone or avoid the prescription. The aim of this mini-review is to summarize the available data on GHrt in EGHD, in order to highlight its weaknesses and strengths and to provide directions to clinicians that will help in the management of this specific set of patients.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Adult growth hormone deficiency in CEE region: Heterogeneity of the patient pathway

OBJECTIVES

Adult growth hormone deficiency (AGHD) is a rare disease characterised by abnormal body composition, reduced strength and exercise capacity and impaired psychological wellbeing. An advisory board of leading Central and Eastern European (CEE) endocrinologists was assembled to gain insights into the status of AGHD care in the CEE region. Topics of discussion included the position of adult hypopituitarism/AGHD in health system priorities, availability and affordability of treatments, awareness of AGHD, practice guidelines used in CEE countries and provisions for long-term care of patients.

DESIGN

Prior to the meeting, the advisors were asked to summarise, using an itemised survey questionnaire, the usual standards of care for patients with AGHD in their country. At the meeting, the panel of experts discussed the findings and thereby elucidated similarities and differences among CEE countries; these were compared with international guideline-recommended practices for AGHD.

RESULTS

All CEE countries involved reported having some type of infrastructure in place for care of patients with GHD transitioning from adolescence to adulthood. Most countries reported having at least one specialist centre for patients with AGHD. The main variations across the region included initial entry into healthcare systems, tests required to confirm AGHD diagnosis and medication reimbursement by health authorities. Most CEE countries relied on international society-led guidelines, while some countries have developed national guidelines.

CONCLUSION

The CEE Adult Endocrinology Advisory Board meeting recognised considerable diversity in the care and patient pathways for AGHD across CEE countries. Additional work is needed to optimise care of patients with AGHD in the CEE region.

Prevalence of low lean mass in patients with adult growth hormone deficiency with or without low-dose growth hormone therapy

OBJECTIVE

The importance of muscle mass has been emphasized in various studies, and growth hormone (GH) deficiency is tightly associated with lean mass loss. Therefore, we aimed to investigate the prevalence of low lean mass in patients with adult growth hormone deficiency (AGHD) who received or did not receive GH therapy.

METHODS

In this retrospective study, we included patients diagnosed with AGHD by using the insulin tolerance test (ITT) in our hospital. Patients without completed follow-up data were excluded, and data for 56 patients were analysed. Twenty-six patients who had received GH therapy for more than 6 months, based on the medical record, were included in the GH group and received recombinant human growth hormone (rhGH) at a dose of 0.5 IU/d. Thirty patients who had not previously received GH treatment were included in the non-GH group. Many anthropometric and blood biochemical indicators were measured. Body composition was measured on a dual-energy X-ray-absorptiometry (DXA) scanner. Low lean mass was defined as a skeletal muscle index (SMI) <7.0 kg/m² in males or 5.7 kg/m² in females. Statistical analyses were performed using GraphPad Prism 5.0.

RESULTS

Compared to the non-GH group, the patients who received GH therapy had significantly lower total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c) and fasting plasma glucose (FPG). The percentage of patients with low lean mass in GH and non-GH groups was 30.77% and 60%, respectively. The percentage of total lean was lower in the GH group than in the non-GH group, but the difference in total lean mass was not statistically significant. Conversely, patients with GH treatment had significantly lower fat mass and percentage than non-GH-treated patients (P < 0.05). The GH group had significantly higher serum levels of both IGF-1 and IGFBP3. Moreover, both IGF-1 and IGFBP3 were significantly correlated with SMI (r²  = 0.275, P = 0.003, and r²  = 0.138, P = 0.005, respectively).

CONCLUSIONS

Our data showed that AGHD patients who received low-dose GH treatment had a lower prevalence of low lean mass than those who did not receive GH treatment. Patients with GH treatment had significantly lower cardiovascular risk factors, especially the lipid profile.

Hormonal Replacement Therapy in Heart Failure: Focus on Growth Hormone and Testosterone

A growing body of evidence led to the hypothesis that heart failure (HF) could be considered a multiple hormone deficiency syndrome. Deficiencies in the main anabolic axes cannot be considered as mere epiphenomena, are very common in HF, and are clearly associated with poor cardiovascular performance and outcomes. Growth hormone deficiency and testosterone deficiency play a pivotal role and the replacement treatment is an innovative therapy that should be considered. This article appraises the current evidence regarding growth hormone and testosterone deficiencies in HF and reviews novel findings about the treatment of these conditions in HF.

Effects of discontinuation of growth hormone replacement in adult GH-deficient patients: a cohort study and a systematic review of the literature

BACKGROUND

Recombinant human growth hormone (rhGH) replacement is advocated in adult growth hormone-deficient (GHD) patients to increase bone mass and improve lipid profile, body composition, and quality of life. The long-term effects of discontinuation of rhGh replacement are unknown.

METHODS

This cohort study and systematic review aim to evaluate the long-term metabolic effects of discontinuation of rhGh replacement in adult GHD patients, with a subgroup analyses according to age (< or > 60 years). Data on anthropometry, lipids, glucose, and bone mass density (BMD) were assessed for 3 years after discontinuation.

RESULTS

Cohort study included 64 patients who had discontinued rhGh replacement for >12 months. Fat percentage increased from 31.5±9.5% to 33.8±9.0% (mean difference 2.3, P=0.003). BMI decreased only in subjects <60 years (P=0.014). Glucose, total cholesterol, and LDL-cholesterol levels did not change; however, the percentage of patients on statins increased slightly from 39% to 44%. HDL-C concentration increased only in patients <60 years (mean difference 0.2, P=0.043). Lumbar spine BMD did not change; however, femoral neck BMD and bone turnover markers decreased in subjects <60 years (P=0.001). Systematic review included eight studies (n=166 patients) with a follow-up duration of 6-18 months. Of the Please check the edit of the sentence 'Of the eight studies "'.eight studies, three qualified as low risk of bias and five as having an intermediate risk of bias. None of the studies reported handling of statins, bisphosphonates, and glucose-lowering medication or excluded patients using these medications.

CONCLUSIONS

In this study, discontinuation of rhGh replacement resulted in metabolic changes only in patients <60 years after 3 years. Further research warrants to determine the optimal strategies for (dis)continuation of rhGh replacement in adult patients with GHD.

Insulin-like growth factor binding-protein-3 (IGFBP-3)

The IGF system comprises two IGFs (IGF-1, IGF-2), two IGF-receptors (IGF-R1, IGF-R2), and six IGF binding proteins (IGFBPs) with a high affinity for IGFs. The IGFBPs, of which IGFBP-3 is the most abundant in postnatal blood, link with IGFs and prevent them from being degraded; they also facilitate IGF transport through body compartments. The interaction between IGFs and their specific receptors is partly regulated by structural modifications inherent to the IGFBPs. IGFBPs also have IGF-independent biological effects. Since serum IGFBP-3 is GH-dependent and correlates quantitatively with GH secretion, its measurement is useful in tests of abnormal GH secretion. Particularly during childhood, IGFBP-3 values play an important role in ascertaining alterations in GH secretion and action (i.e., primary IGF deficiency states). A new role for IGFBP-3 and other IGFBPs with natural or altered structures is likely to be established through current studies investigating their application in promoting apoptotic processes in malignancies.

Relationship between pituitary stalk (PS) visibility and the severity of hormone deficiencies: PS interruption syndrome revisited

CONTEXT

Pituitary stalk interruption syndrome (PSIS) is a rare cause of combined pituitary hormone deficiency characterized by a triad shown in pituitary imaging, yet it has never been evaluated due to the visibility of pituitary stalk (PS) in imaging findings.

OBJECTIVE

The major objective of the study was to systematically describe the disease including clinical presentations, imaging findings and to estimate the severity of anterior pituitary hormone deficiency based on the visibility of the PS.

METHODS

This was a retrospective study including 74 adult patients with PSIS in Shanghai Clinical Center for Endocrine and Metabolic Diseases between January 2010 and June 2014. Sixty had invisible PS according to the findings on MRI, while the rest had a thin or intersected PS. Basic characteristics and hormonal status were compared.

RESULTS

Of the 74 patients with PSIS, age at diagnosis was 25 (22-28) years. Absent pubertal development (97·3%) was the most common presenting symptom, followed by short stature. Insulin tolerance test (ITT) and gonadotrophin-releasing hormone (GnRH) stimulation test were used to evaluate the function of anterior pituitary. The prevalence of isolated deficiency in growth hormone (GH), gonadotrophins, corticotrophin and thyrotrophin were 100%, 97·2%, 88·2% and 70·3%, respectively. Although the ratio of each deficiency did not vary between patients with invisible PS and with visible PS, panhypopituitarism occurred significantly more frequent in patients with invisible PS. Patients with invisible PS had significantly lower levels of luteinizing hormone (LH), follicle stimulation hormone (FSH) and hormones from targeted glands including morning cortisol, 24-h urine free cortisol, free triiodothyronine (FT3), free thyroxine (FT4) and testosterone (T) in male than patients with visible PS. Moreover, patients with invisible PS had lower peak LH and FSH in GnRH stimulation test, and higher peak cortisol in ITT while peak GH remained unchanged between two groups.

CONCLUSIONS

The prevalence of multiple anterior pituitary hormone deficiency was high in adult patients with PSIS. And more importantly, we found the visibility of PS shown on MRI might be an indication of the severity of PSIS.

Pituitary dysfunction after aneurysmal subarachnoid haemorrhage: course and clinical predictors—the HIPS study

OBJECTIVE

We describe the occurrence and course of anterior pituitary dysfunction (PD) after aneurysmal subarachnoid haemorrhage (SAH), and identify clinical determinants for PD in patients with recent SAH.

METHODS

We prospectively collected demographic and clinical parameters of consecutive survivors of SAH and measured fasting state endocrine function at baseline, 6 and 14 months. We included dynamic tests for growth-hormone function. We used logistic regression analysis to compare demographic and clinical characteristics of patients with SAH with and without PD.

RESULTS

84 patients with a mean age of 55.8 (±11.9) were included. Thirty-three patients (39%) had PD in one or more axes at baseline, 22 (26%) after 6 months and 6 (7%) after 14 months. Gonadotropin deficiency in 29 (34%) patients and growth hormone deficiency (GHD) in 26 (31%) patients were the most common deficiencies. PD persisted until 14 months in 6 (8%) patients: GHD in 5 (6%) patients and gonadotropin deficiency in 4 (5%). Occurrence of a SAH-related complication was associated with PD at baseline (OR 2.6, CI 2.2 to 3.0). Hydrocephalus was an independent predictor of PD 6 months after SAH (OR 3.3 CI 2.7 to 3.8). PD was associated with a lower score on health-related quality of life at baseline (p=0.06), but not at 6 and 14 months.

CONCLUSIONS

Almost 40% of SAH survivors have PD. In a small but substantial proportion of patients GHD or gonadotropin deficiency persists over time. Hydrocephalus is independently associated with PD 6 months after SAH.

TRIAL REGISTRATION NUMBER

NTR 2085.

Impaired Pituitary Axes Following Traumatic Brain Injury

Pituitary dysfunction following traumatic brain injury (TBI) is significant and rarely considered by clinicians. This topic has received much more attention in the last decade. The incidence of post TBI anterior pituitary dysfunction is around 30% acutely, and declines to around 20% by one year. Growth hormone and gonadotrophic hormones are the most common deficiencies seen after traumatic brain injury, but also the most likely to spontaneously recover. The majority of deficiencies present within the first year, but extreme delayed presentation has been reported. Information on posterior pituitary dysfunction is less reliable ranging from 3%-40% incidence but prospective data suggests a rate around 5%. The mechanism, risk factors, natural history, and long-term effect of treatment are poorly defined in the literature and limited by a lack of standardization. Post TBI pituitary dysfunction is an entity to recognize with significant clinical relevance. Secondary hypoadrenalism, hypothyroidism and central diabetes insipidus should be treated acutely while deficiencies in growth and gonadotrophic hormones should be initially observed.

Effects of up to 15 years of recombinant human GH (rhGH) replacement on bone metabolism in adults with growth hormone deficiency (GHD): the Leiden Cohort Study

BACKGROUND

Growth hormone deficiency (GHD) in adulthood may be associated with a decreased bone mineral density (BMD), a decreased bone mineral content (BMC) and an increased fracture risk. Recombinant human GH (rhGH) replacement induces a progressive increase in BMD for up to 5-7 years of treatment. Data on longer follow-up are, however, scarce.

METHODS

Two hundred and thirty-adult GHD patients (mean age 47·1 years, 52·6% female), of whom 88% patients had adult-onset (AO) GHD, receiving rhGH replacement for ≥5 years were included in the study. Most patients had multiple pituitary hormone deficiencies. Bone turnover markers, BMC and BMD and T-scores at the lumbar spine and femoral neck were evaluated at baseline, and after 5, 10 and 15 years of rhGH replacement. In addition, clinical fracture incidence was assessed.

RESULTS

Mean lumbar spine BMD, lumbar spine BMC and T-scores gradually increased during the first 10 years of rhGH replacement and remained stable thereafter. Largest effects of rhGH supplementation were found in men. In the small subset of patients using bisphosphonates, use of bisphosphonates did not impact additional beneficial effects in the long term. Low baseline BMD positively affected the change in BMD and BMC over time, but there was a negative effect of high GH dose at 1 year on the change in BMD and BMC over time. Clinical fracture incidence during long-term rhGH replacement was 20.1/1000 py.

CONCLUSIONS

Fifteen years of rhGH replacement in GHD adults resulted in a sustained increase in BMD values at the lumbar spine, particularly in men, and stabilization of BMD values at the femoral neck. Clinical fracture incidence was suggested not to be increased during long-term rhGH replacement.

High prevalence of metabolic syndrome features in patients previously treated for nonfunctioning pituitary macroadenoma

OBJECTIVE

Patients treated for nonfunctioning pituitary macroadenoma (NFMA) with suprasellar extension show disturbed sleep characteristics, possibly related to hypothalamic dysfunction. In addition to hypopituitarism, both structural hypothalamic damage and sleep restriction per se are associated with the metabolic syndrome. However, the prevalence of the metabolic syndrome in patients with NFMA is not well established. Our objective was to study the prevalence and risk factors for (components of) the metabolic syndrome in patients treated for NFMA.

DESIGN

The metabolic syndrome (NCEP-ATP III criteria) was studied in an unselected cohort of 145 NFMA patients (aged 26-88yr, 44% female) in long-term remission after treatment, receiving adequate stable hormone replacement for any pituitary deficiencies. The results were compared to population data of 63,995 Dutch inhabitants by standardization (LifeLines cohort study).

RESULTS

NFMA patients showed increased risk for reduced HDL-cholesterol (SMR 1.59, 95% CI 1.13-2.11), increased triglyceride levels (SMR 2.31, 95% CI 1.78-2.90) and the metabolic syndrome (SMR 1.60, 95% CI 1.22-2.02), but not for increased blood pressure, waist circumference or hyperglycemia. Preoperative visual field defects independently affected the risk for increased blood pressure (OR 6.5, 95% CI 1.9-22.2), and hypopituitarism was associated with a body mass index - dependent risk for increased waist circumference (OR 1.6, 95% CI 1.2-2.2) and the metabolic syndrome (OR 1.4, 95% CI 1.0-1.9).

CONCLUSIONS

Patients treated for NFMA are increased at risk for developing the metabolic syndrome, mainly due to decreased HDL-cholesterol and increased triglycerides. Risk factors included hypopituitarism and preoperative visual field defects. Hypothalamic dysfunction may explain the metabolic abnormalities, in addition to intrinsic imperfections of hormone replacement therapy. Additional research is required to explore the relation between derangements in circadian rhythmicity and metabolic syndrome in these patients.

Consensus document of the Neuroendocrinology area of the Spanish Society of Endocrinology and Nutrition on management of hypopituitarism during transition

The transition period from child to adult represents a crucial phase in the growth process where multiple physical and psychosocial changes occur. It has been arbitrarily defined as the period extending from late puberty to full adult maturity (i.e., from mid to late teenage years until 6-7 years after achievement of final height). The aim of this guideline is to emphasize the importance of adequate hormone replacement during this period and to review reassessment of pituitary function. In patients with GH deficiency diagnosed in childhood, an attempt is made to answer when to retest GH secretion, when to treat and how they should be monitored. Thyroxine, glucocorticoid, and sex steroid replacement are also reviewed.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Acute presentation of craniopharyngioma in children and adults in a Danish national cohort

We aimed to study the occurrence of acute-onset symptoms at initial presentation in a national Danish cohort of patients with childhood- or adult-onset craniopharyngioma, and to investigate potential risk factors for acute presentation. Medical records of 189 consecutive patients (39 children, 150 adults) presenting with craniopharyngioma during the period 1985-2004 were reviewed, and data regarding initial symptoms, neuroimaging results, vision and pituitary function were systematically collected. Acute symptoms preceding hospital admission were noted. Subgroup analyses were based on age, gender and calendar year period. Potential risk factors for acute presentation were analysed through uni- and multivariate analyses. Acute symptoms were reported in 24 (13%) patients. Acute visual symptoms, headache, nausea or vomiting were most frequently reported, and acute symptoms were more frequent among children (28%) than among adults (9%) (P < 0.01). There were no differences according to sex or calendar year period. Hydrocephalus was present in half of childhood cases and one-fifth of adult patients (P < 0.001). Intra-tumour haemorrhage was seen in two cases. Acute symptoms were more frequent among patients with tumours occupying the third ventricle (P < 0.01), radiologic signs of calcification (P < 0.05) or hydrocephalus (P < 0.01). In multivariate analysis, however, only childhood onset (P < 0.05) and calcification (P < 0.05) were independent risk factors for acute presentation. Craniopharyngioma presented with acute symptoms in 13% of patients. Childhood onset and radiologic signs of calcification were independent risk factors for acute presentation. Intra-tumour haemorrhage was rare.

Comparison of two growth hormone stimulation tests and their cut-off limits in healthy adults at an outpatient clinic

OBJECTIVE

A peak GH less than 3 μg/L to insulin tolerance test (ITT) is commonly used as a threshold indicating severe adult GH deficiency (GHD). This cut-off is based on results obtained by polyclonal radioimmunoassays preferably under standard conditions at hospital. Our aim was to evaluate the validity of this cut-off limit using two currently used immunometric GH assays and to compare GH responses in the ITT and the GH releasing hormone + arginine (GHRH + ARG) test in healthy adults at our outpatient endocrine unit.

DESIGN

ITT was performed on 73 subjects and the GHRH + ARG test on those 28 who showed insufficient response to the ITT.

METHODS

GH was measured by an immunofluorometric and immunochemiluminometric assay.

RESULTS

GH peak above 3 μg/L was observed in 56% of the healthy volunteers with adequate hypoglycemia in the ITT. Among the 28 subjects with a peak GH below 3 μg/L, only two overweight men had a GH peak response below the commonly used cut-off limit of 9.1 μg/L in the GHRH + ARG test.

CONCLUSIONS

Lean healthy adults could erroneously be classified as GH deficient by the ITT while their results in the GHRH + ARG test were normal. The GH results are highly dependent on the immunoassay used, but false positive results in the ITT are often obtained even if lower cutoff limits determined on the basis on the calibration of the GH assay are used. Confounding factors seemed to blunt the GH response to the ITT more than to the GHRH + ARG test at our outpatient clinic.

Diagnostic value of a ghrelin test for the diagnosis of GH deficiency after subarachnoid hemorrhage

OBJECTIVE

To determine the diagnostic value of a ghrelin test in the diagnosis of GH deficiency (GHD) shortly after aneurysmal subarachnoid hemorrhage (SAH).

DESIGN

Prospective single-center observational cohort study.

METHODS

A ghrelin test was assessed after the acute phase of SAH and a GH-releasing hormone (GHRH)-arginine test 6 months post SAH. Primary outcome was the diagnostic value of a ghrelin test compared with the GHRH-arginine test in the diagnosis of GHD. The secondary outcome was to assess the safety of the ghrelin test, including patients' comfort, adverse events, and idiosyncratic reactions.

RESULTS

Forty-three survivors of SAH were included (15 males, 35%, mean age 56. 6 ± 11.7). Six out of 43 (14%) SAH survivors were diagnosed with GHD by GHRH-arginine test. In GHD subjects, median GH peak during ghrelin test was significantly lower than that of non-GHD subjects (5.4 vs 16.6, P=0.002). Receiver operating characteristics analysis showed an area under the curve of 0.869. A cutoff limit of a GH peak of 15 μg/l corresponded with a sensitivity of 100% and a false-positive rate of 40%. No adverse events or idiosyncratic reactions were observed in subjects undergoing a ghrelin test, except for one subject who reported flushing shortly after ghrelin infusion.

CONCLUSION

Owing to its convenience, validity, and safety, the ghrelin test might be a valuable GH provocative test, especially in the early phase of SAH.

Partially reversible hypopituitarism in an adolescent with a rathke cleft cyst

Rathke cleft cysts are remnants of the Rathke pouch. Most of them are asymptomatic, but sometimes they can grow enough to cause compression of structures within and/or close to the sella, thus eliciting symptoms such as visual disturbance, pituitary defects, and headache. Asymptomatic cysts can safely be followed up with serial imaging, while the standard treatment for symptomatic lesions is surgical removal. We describe a 14-yr-old boy, admitted for anorexia, fatigue, weight loss, recurrent headache and vomiting. Magnetic resonance imaging showed an intra- and suprasellar cystic lesion, which was surgically removed. Histology was consistent with Rathke’s cleft cyst. Diabetes insipidus and multiple anterior pituitary defects (GH, ACTH and TSH) were found preoperatively, and substitutive therapy was started. No additional hormonal defect appeared after surgery. After 4 yr of follow up, pituitary function was retested, and there were no confirmed GH or ACTH defects, allowing a partial withdrawal of replacement therapy. Our report confirms that pituitary defects, in patients with a Rathke cleft cyst, may recover even year after surgery. Thus, retesting of pituitary axes is indicated during long-term follow up.

Growth hormone replacement therapy in patients with traumatic brain injury

In patients with severe traumatic brain injury (TBI), a growth hormone deficiency (GHD) is frequent and may contribute to the cognitive sequelae and reduction in quality of life (QoL). Recent studies have suggested that GH replacement therapy (GHRT) can improve processing speed and memory. The aim of the study was to analyze the efficacy of GHRT on cognition, activities of daily living (ADL), and QoL and the factors that predicted and contributed to these effects. We included patients at least 1 year after their TBI and assessed pituitary functions (with stimulation tests), cognition (attention, memory, and executive function), participation in ADL and QoL. GHD was treated for at least 1 year in 23 patients, who were compared with 27 non-treated patients. Other deficiencies were also treated. Measurements were performed at baseline and 1 year later. An analysis of variance of the factors group and session (p ≤ 0.05) showed that most cognitive parameters had improved at 1 year (evidencing a session effect). A stronger effect of GHRT (i.e. a group x session interaction) was found for Rey Osterrieth complex figure recall and 2/6 domains in the QoL questionnaire ("personal" and "functional"). Trends (p ≤ 0.07) were also found for spatial orientation and immediate recall in the verbal memory test. Greatest improvements were associated with lower performance before treatment. The magnitude of the improvements in ADL and QoL was moderately correlated with the improvement in cognition. In conclusion, replacement therapy can improve cognition and QoL in patients with TBI who have GHD, especially in those with severe disabilities.

Low and Normal IGF-1 Levels in Patients with Chronic Medical Disorders (CMD) is Independent of Anterior Pituitary Hormone Deficiencies: Implications for Treating IGF-1 Abnormal Deficiencies with CMD

Over time, based on evidence-based medicine, a number of hormonal test levels including IGF-1 had been raised or lowered to meet new criteria standards. In particular, IGF-1 plasma levels have been shown in several studies to be an independent diagnostic tool in Adult Growth Hormone Deficiency (AGHD). Many endocrinology studies link low IGF-1 plasma levels with low levels of other anterior pituitary hormones (i.e., LH, FSH, and TSH). Low IGF-1 is considered by most to be between 84-100 µ/l and numerous studies recommend that raising IGF-1 to high normal range reverses Chronic Medical Diseases (CMD), improves bone mineral density (BMD), and fibromyalgia. Moreover, some studies suggest that low levels of IGF-1 by itself independent of anterior pituitary deficiencies is sufficient to determine AGHD in humans. In order to determine the relationship of low IGF-1 with that of LH, FSH, and TSH levels in subjects with CMD, we evaluated these levels (± SD) in 944 patients. Patients with IGF-1 below 84 µ/l, 100 µ/l, and 150 µ/l were accessed. 9.22% had less than 84 µ/l (SD ± 12.52); 19.9% had less than 100 µ/l (SD ± 9.54); and 51.6 had less than 150 µ/l (SD ± 26.0). Specifically, the percentages found for low LH, FSH, and TSH were only 4.2%, 4.8%, and 6.5%. We conclude that IGF-1 deficiencies occur independent of comorbid deficiencies of LH, FSH, and TSH. Finally, we propose that based on the present investigation, IGF-1 low levels between the range of 84-100 µ/l may be too low to be considered as an independent diagnostic marker to treat AGHD with CMD.

The arginine and GHRP-2 tests as alternatives to the insulin tolerance test for the diagnosis of adult GH deficiency in Japanese patients: a comparison

The arginine + GHRH test has been established as an alternative to the insulin tolerance test (ITT) for the diagnosis of adult GH deficiency (AGHD). However, the glucagon, arginine, and GH releasing peptide-2 (GHRP-2) test are recommended as alternatives in Japan. The objective of this study was to evaluate the arginine and GHRP-2 tests as alternatives to the ITT for the diagnosis of AGHD in a Japanese population. Three stimulation tests (ITT, arginine test, and GHRP-2 test) were conducted in 71 pre-operative adult patients with pituitary tumors (age, 18-65 years). The peak GH responses to each test were examined. The peak GH responses were significantly lower with the ARG test (median 4.43 μg/L) (p < 0.0001) than with the ITT (median 9.38 μg/L), and the peak GH responses with the GHRP-2 test (median 28.88 μg/L) were higher (p < 0.0001). However, among the AGHD patients, there was no significant difference between the peak GH responses to the ARG test and the ITT. The sensitivities and specificities of the ARG / GHRP-2 tests compared to the ITT for the diagnosis of severe AGHD (peak GH responses to ITT ≤ 1.8 μg/L) were 93.8% / 81.3% and 85.5% / 94.5%, respectively. The arginine and GHRP-2 stimulation tests are acceptable alternatives to the ITT for the diagnosis of AGHD in Japanese patients. The method and criterion for the diagnosis of AGHD should be reconsidered and adjusted to each population.

The limited screening value of insulin-like growth factor-I as a marker for alterations in body composition in very long-term adult survivors of childhood cancer

BACKGROUND

The clinical relevance of low IGF-I levels, caused by cranial radiotherapy, in adult childhood cancer survivors has not been studied extensively. We evaluated whether IGF-I is a useful marker for altered body composition and growth hormone deficiency (GHD) in this group.

PROCEDURE

We analyzed retrospective data from 610 adult childhood cancer survivors, retrieved from the late effects clinic. Median age at diagnosis was 6 years (interquartile range 3-11) and follow-up time was 18 years (13-24). We assessed IGF-I standard deviation scores (SDS), anthropometrical measures, growth hormone stimulation tests in patients with clinical signs of GHD, and measures of body composition (assessed by dual X-ray absorptiometry, Lunar Prodigy).

RESULTS

In 58 cranially irradiated acute leukemia survivors (25 Gy (24-25)) and 56 locally irradiated brain tumor survivors (42 Gy (35-54)) we found significantly lower IGF-I SDS (P < 0.001), lower height SDS (P < 0.001), higher body mass index (P = 0.01), higher waist-hip ratio (WHR; P = 0.001), higher total fat percentage SDS (P < 0.001), and lower lean body mass SDS (P < 0.001), as compared to 452 not cranially irradiated survivors. IGF-I showed a weak inverse correlation with BMI (r = -0.12, P = 0.04), WHR (r = -0.15, P = 0.01), total fat percentage (r = - 0.14, P = 0.02), and a positive correlation with lean body mass (r = 0.15, P = 0.01). In patients with low IGF-I levels, IGF-I did not significantly differ between subjects with and without GHD as determined by GH-stimulation testing (P = 0.39).

CONCLUSION

This study shows that IGF-I has limited value as a marker for alterations in body composition in adult childhood cancer survivors.

Testing for growth hormone deficiency in adults: doing without growth hormone-releasing hormone

PURPOSE OF REVIEW

This article summarizes recent advances in testing for growth hormone deficiency (GHD) in adults, focusing on critical appraisal of existing growth hormone (GH) provocative tests as well as newer tests in development.

RECENT FINDINGS

The diagnosis of GHD can be challenging and often requires the use of GH provocative testing. The most widely validated of these is insulin-induced hypoglycemia (ITT), which requires close supervision and has significant contraindications and side-effects. The arginine-growth hormone-releasing hormone (GHRH) test had become widely used as a safe and accurate alternative to the ITT, but GHRH is currently unavailable for clinical use in the USA. On the basis of review of recent literature we recommend that in the absence of GHRH, glucagon stimulation testing should be the preferred alternative to ITT. Several synthetic GH secretagogues that mimic the gastric peptide ghrelin are currently in development and may become available for use in the diagnosis of GHD in the near future. Other GH provocative tests suitable for use in children lack adequate specificity for the diagnosis of GHD in adults.

SUMMARY

Due to the current unavailability of the arginine-GHRH test in the USA, when ITT is contraindicated or impractical we recommend the glucagon stimulation testing as the GH provocative test of choice. There remains a need for a simple, safe and accurate test for the diagnosis of GHD.

Depth and duration of hypoglycaemia achieved during the insulin tolerance test

CONTEXT

The insulin tolerance test (ITT) is the gold standard for assessment of the pituitary adrenal axis but its use is limited because of concerns relating to the risk of hypoglycaemia.

OBJECTIVE

This study examined the depth and duration of hypoglycaemia achieved during the test in a large cohort of patients.

DESIGN

Two hundred and twenty ITTs were performed from 2005 to 2010.

SETTING

A 1200-bed University Teaching Hospital.

PATIENTS

Two hundred and twenty ITTs were carried out in patients with suspected or known pituitary disorders.

INTERVENTIONS

Intravenous insulin was administered to achieve nadir plasma glucose (NPG) of 2.2 mmol/l (39.6 mg/dl). Blood chemistry to show the cortisol and GH response to hypoglycaemic stress was measured.

MAIN OUTCOME MEASURES

Predictors of depth and duration of hypoglycaemia, adverse events and within-subject variability of nadir glucose, peak cortisol and peak GH were studied.

RESULTS

Thirty percent of the cohort achieved a nadir glucose of <2.0 mmol/l (36 mg/dl) that lasted for 60 min or more. The NPG correlated positively with fasting plasma glucose (FPG; r=0:56; P<0.0005), insulin dose (r=0.27; P<0.0005) and weight (r=0.21; P<0.004). The within subject variability of nadir glucose was 15.2%, peak cortisol was 11.7% and peak GH was 6.4%. The factors determining nadir blood glucose were FPG (b=0.56, P<0.0005, 20% contribution) and weight (b=0.14, P<0.05, 2% contribution). The five patients with adverse events had NPG and insulin dose comparable with the rest of the population.

CONCLUSIONS

The hypoglycaemia achieved during the ITT is much lower than the target required. However, adverse events are few and do not relate to the depth of hypoglycaemia.

Peripheral bone mineral density in correlation to disease-related predisposing conditions in patients with multiple endocrine neoplasia type 1

BACKGROUND AND AIM

Patients with multiple endocrine neoplasia type 1 (MEN1) often have low bone mineral density (BMD) attributed to primary hyperparathyroidism (pHPT). However, in MEN1 patients, other endocrine dysfunctions and conditions such as hypercortisolism, hypogonadism, and GH deficiency due to pituitary manifestation, and surgery on the upper gastrointestinal tract may affect BMD.

SUBJECTS AND METHODS

In 23 patients with MEN1 (10 females, 13 males; 46±12 yr), BMD was determined by quantitative computed tomography at the forearm (pqCT), compared to a reference population and related to different conditions suspected to affect bone metabolism in MEN1.

RESULTS

In this cohort, Z-score for trabecular BMD was -0.85±1.18 and for total BMD -1.16±1.04. There was a similar trend towards lower BMD in uncontrolled hyperparathyroidism, hypercortisolism, hypogonadism/GH deficiency and the state after surgery at the upper gastrointestinal tract.

CONCLUSIONS

These data while confirming previous observations on reduced BMD in patients with MEN1, however, challenge its only or even predominant association with pHPT. Other conditions such as hypercortisolism, somatotrophic/ gonadotrophic pituitary insufficiency, and previous upper gastrointestinal surgery seem to be factors contributing to the risk of developing osteoporosis.

Lasting pituitary hormone deficiency after traumatic brain injury

Pituitary deficiencies have been reported after traumatic brain injury (TBI) and may contribute to lasting cognitive disorders in this context. In a population of TBI patients with persistent cognitive and/or behavioral disorders, we sought to determine the prevalence of lasting pituitary deficiency and relationships with TBI severity, cognitive disorders, and impairments in activities of daily living (ADL). Fifty-five patients were included (mean age 36.1 years; 46 men) at least 1 year after TBI. They underwent a comprehensive evaluation of pituitary function (basic tests and stimulation), initial TBI severity, and long-term outcomes (cognitive performance, Glasgow Outcome Scale score, impact on ADL, and quality of life [QoL]). We used chi-squared and Mann-Whitney tests to probe for significant (p≤0.05) relationships between pituitary disorders and other parameters. Thirty-eight (69%) patients had at least one pituitary hormone deficiency. Growth hormone deficiency was more prevalent (severe: 40.0%; partial: 23.6%) than corticotropin (27.3%) or thyrotropin (21.8%) deficiencies. Other deficiencies were rare. Growth hormone deficiency was associated with attention and verbal memory disorders and reduced involvement in ADL. We did not find any relationship between pituitary deficiency and the TBI's initial severity. In a multivariate analysis, the TBI severity was introduced as a first factor, and pituitary deficits as a secondary factor for explaining the late outcome (ADL and QoL). In conclusion, TBI patients with cognitive sequelae must undergo pituitary screening because growth hormone, corticotropin, and thyrotropin deficits are particularly common and can adversely affect ADL and reduce QoL.

[Growth hormone therapy in adult patients: a review]

Growth hormone deficiency (GHD) can frequently be expected in hypopituitarism of adult patients. If GHD is proven by dynamic testing of the somatotrophic axis, growth hormone substitution is useful for improving quality of life, body composition, bone and lipid metabolism, and myocardial function according to the criteria of evidence-based medicine and is admitted by most national health authorities. There are no other reasonable indications for growth hormone treatment in adulthood.

Impact of different cut-off limits of peak GH after GHRH-arginine stimulatory test, single IGF1 measurement, or their combination in identifying adult patients with GH deficiency

OBJECTIVE

To evaluate the impact of different peak GH cut-off limits after GHRH-Arg test, IGF1 measurement, or their combination in identifying patients with GH deficit (GHD).

DESIGN AND PATIENTS

Totally, 894 normal subjects (used for determining IGF1 normative limits) and 302 patients with suspected GHD were included. Different peak GH cut-off limits (used by European (depending on body mass index (BMI)) or North American (4.1 μg/l) Endocrine Societies, by HypoCCs (2.5 μg/l), or with 95% specificity (based on BMI), Method 1, 2, 3, or 4 respectively) and IGF1 were considered.

METHODS

Peak GH after GHRH-Arg and IGF1.

RESULTS

Different peak GH cut-off limits recognized different proportions of GHD (range, 24.8-62.9%). Methods 1 and 2 with high sensitivity recognized a higher proportion (95.5 and 92.5% respectively) of GHD among patients with three (T) pituitary hormone deficits (HD), whereas Method 4 (with high specificity) identified 96.7% normal subjects among those without pituitary HD; on the contrary, Method 4 identified only 75% GHD among patients with THD, whereas Method 1 recognized a high proportion (40%) of GHD among subjects without HD. Of the total patients, 82% with THD and 84.5% without HD were recognized as GHD or normal respectively by IGF1. Among the remaining patients with THD and normal IGF1, 75% was recognized as GHD by Method 1; among patients without HD and abnormal IGF1, 87.5% was identified as normal by Method 4. Overall, combination of IGF1 and Method 1 or Method 4 identified 95.5% GHD among patients with THD and 98.1% normal subjects among those without HD.

CONCLUSIONS

Single peak GH cut-offs have limits to sharply differentiate GHD from normal subjects; IGF1 may be used for selecting patients to be submitted to the GHRH-Arg test; the peak GH cut-off limits to be used for identifying healthy or diseased patients depend mainly on the clinical context.

Serum IGF-1 concentrations in a sample of patients with traumatic brain injury as a diagnostic marker of growth hormone secretory response to glucagon stimulation testing

OBJECTIVE

The diagnosis of growth hormone deficiency (GHD) in adults is established through growth hormone (GH) stimulation testing, which is often complex, expensive, time-consuming and may be associated with adverse side effects. The decision to perform GH provocative testing is influenced by clinical findings, medical history and biochemical evidence. We report in this study our experience using the glucagon stimulation test (GST) in assessing GHD in adult patients with traumatic brain injury (TBI) as it relates to baseline serum insulin-like growth factor-1 (IGF-1) concentrations.

DESIGN

A receiver operating characteristic (ROC) curve analysis was performed to determine the optimal IGF-1 cut-off for diagnosis of GHD at different potential diagnostic GST cut-off values (<3, <5, & <10 μg/l).

PATIENTS

One hundred and thirty-eight patients (98 men and 40 women) with a documented history of moderate to severe TBI were assessed for GHD using serum IGF-1 concentrations and the GST.

MEASUREMENTS

IGF-1 values were compared with peak GH values obtained following the GST.

RESULTS

An IGF-1 cut-off value of 175 μg/l minimized the misclassification of GHD patients and GH-sufficient patients and provided a sensitivity of 83% and specificity of 40%, as well as a negative predictive power of 90% considering a criterion for peak GH response of <3 μg/l.

CONCLUSIONS

Our current findings are consistent with previous work assessing peak GH response using the insulin tolerance test (ITT) in a non-TBI sample, suggesting that diagnostic accuracy may be optimized if the GST is used when obtained serum IGF-1 concentrations are below 175 μg/l. While the decision to perform provocative testing to assess GHD in adult patients should be based on the clinician's clinical impression, the findings from this retrospective study can provide useful clinical information and serve as a guide.

Pituitary stalk interruption syndrome: diagnostic delay and sensitivity of the auxological criteria of the growth hormone research society

OBJECTIVES

To study the diagnostic delay for pituitary stalk interruption syndrome (PSIS) with growth hormone deficiency (GHD) and the sensitivity of the auxological criteria of the Growth Hormone Research Society (GHRS) consensus guidelines.

METHODS

A single-center retrospective case-cohort study covering records from January 2000 through December 2007 evaluated the performance of each GHRS auxological criterion for patients with GHD and PSIS. Diagnostic delay was calculated as the difference between the age at which the earliest GHRS criterion could have been observed and the age at diagnosis of PSIS with GHD. A diagnostic delay exceeding one year was defined as late diagnosis.

RESULTS

The study included 21 patients, 16 (76%) of whom had isolated GHD and 5 (24%) multiple pituitary hormone deficiencies. The median age at diagnosis was 3.6 years (interquartile range, IQR, 2.6-5.5). The median diagnostic delay was 2.3 years (range 0-12.6; IQR 1.5-3.6), with late diagnosis for 17 patients (81%). Height more than 1.5 SDS below target height was the most effective criterion: 90% of the patients met the criterion before diagnosis at a median age of 1 year, and it was the first criterion to be fulfilled for 84%.

CONCLUSION

In our cohort, the delay for diagnosis of PSIS with GHD was long and could have been reduced by using the GHRS criteria, in particular, height more than 1.5 SDS below the target height. The specificity of such a strategy needs to be tested in healthy populations.

Clinical characteristics of Japanese adults with growth hormone deficiency: a HypoCCS database study

The clinical characteristics of Caucasian adults with growth hormone (GH) deficiency (GHD) have been well defined. However, no large-scale clinical practice study has examined the clinical characteristics of Japanese adults with GHD. The aim of our study was to describe the clinical characteristics of Japanese adults with GHD by reviewing the records of participants who were GH-naive at the time of enrollment in the Hypopituitary Control and Complications Study (N = 349). The majority of participants (280 of 349; 80.2%) had adult-onset rather than childhood-onset GHD. Hypothalamo-pituitary tumors were the most common cause of GHD in Japanese adults (247 of 349; 70.8%); these tumors were primarily pituitary adenomas in participants with adult-onset GHD (156 of 243; 64.2%), and germ cell tumors (19 of 40; 47.5%) and craniopharyngiomas (18 of 40; 45.0%) in participants with childhood-onset GHD. Most participants (310 of 349; 88.8%) had multiple pituitary hormone deficiencies. Dyslipidemia (195 of 349; 55.9%), visual field loss (67 of 349; 19.2%), hypertension (59 of 349; 16.9%), and liver disease (54 of 349; 15.5%) were the most common pre-existing conditions in Japanese adults with GHD. Quality of life was decreased in seven of the eight short form-36 domains in participants with GHD compared with age- and sex-matched healthy Japanese individuals. Our findings confirm that the clinical characteristics of Japanese adults with GHD are similar to those of Caucasian adults with GHD. Confirmation of these clinical characteristics will enhance the ability of clinicians to identify and treat Japanese adults with GHD.

The diagnosis and treatment of growth hormone deficiency in adults

PURPOSE OF REVIEW

This review summarizes the recent published information regarding efficacy and complications of growth hormone replacement therapy. Several recent reports have monitored patients for periods of up to 10 years. Additionally, a consensus conference has been held regarding needed improvements in diagnostic testing and the recommendations of consensus panels regarding diagnostic criteria and laboratory test utilization are summarized.

RECENT FINDINGS

Long-term studies show growth hormone can be administered safely and that muscle strength and function as well as lipoprotein abnormalities and low-bone mineral density show sustained improvement over extended periods of time. The complications that occur are generally dose-dependent and once attenuated do not tend to recur. Long-term safety studies regarding improvement in cardiovascular mortality and/or worsening prognosis for patients who develop malignancies are available only in the form of observational studies and randomized controlled long-term trial information is not yet available. The studies reported provide a means for clinicians to ascertain the patients who are likely to derive the greatest benefit from growth hormone when the appropriate diagnostic testing and treatment paradigms are utilized.

SUMMARY

The studies that are summarized provide useful information for assessing the response to treatment, selecting patients who are candidates for long-term replacement therapy and for selecting those in whom the need for therapy may need to be reassessed.

Comparative validation of the growth hormone-releasing hormone and arginine test for the diagnosis of adult growth hormone deficiency using a growth hormone assay conforming to recent international recommendations

CONTEXT

The GHRH plus arginine (GHRH+Arg) test is a promising alternative to the insulin tolerance test (ITT) for diagnosis of adult GH deficiency (AGHD).

OBJECTIVES

The objectives of the study were to validate the GHRH+Arg test for diagnosis of AGHD, using the ITT as comparator and a GH assay calibrated according to recent international recommendations, and to study the repeatability and tolerance of both tests.

DESIGN

This was a multicenter, randomized, open-label, phase III study.

SETTING

The study was conducted at 10 French university hospitals.

SUBJECTS

Sixty-nine subjects (38 and 15 with high and low probability of GH deficiency, respectively, and 16 healthy controls) were randomized: 35 to the GHRH+Arg-GHRH+Arg-ITT test sequence and 34 to the ITT-ITT-GHRH+Arg test sequence.

INTERVENTIONS

Each subject underwent three tests of GH secretion separated by 24 h or more.

MAIN OUTCOME MEASURES

The primary variable used for response assessments was serum peak GH response. Test results were compared with the final AGHD diagnosis.

RESULTS

Peak GH responses in the two tests were strongly correlated. A cutoff value of 7.89 microg/liter for GHRH+Arg corresponding to 3 microg/liter for ITT was calculated. The cutoff value leading to 95% specificity with the GHRH+Arg test was measured at about 3.67 microg/liter (sensitivity 79.0%). Intermethod agreement and repeatability were high. Both tests were well tolerated. A preference for the GHRH+Arg test was expressed by 74% of subjects.

CONCLUSIONS

The GHRH+Arg test demonstrated good accuracy and repeatability, was at least as sensitive as the ITT, and was associated with better subject acceptability. The GHRH+Arg test represents a good alternative to the ITT for the diagnosis of AGHD.

The rational use of pituitary stimulation tests

BACKGROUND

Diseases of the pituitary gland can lead to the dysfunction of individual hormonal axes and to the corresponding clinical manifestations. The diagnostic assessment of pituitary function has not yet been standardized.

METHODS

The members of the Neuroendocrinology Section and the Pituitary Study Group of the German Society for Endocrinology (Deutsche Gesellschaft für Endokrinologie) prepared outlines of diagnostic methods for the evaluation of each of the pituitary hormonal axes. These outlines were discussed in open session in recent annual meetings of the Section and the Study Group.

RESULTS

For the evaluation of the thyrotropic axis, basal TSH and free T4 usually suffice. For the evaluation of the gonadotropic axis in men, the testosterone level should be measured; if the overall testosterone level is near normal, then calculating the free testosterone level may be additionally useful. In women, an intact menstrual cycle is sufficient proof of normal function. In the absence of regular menstruation, measurement of the basal estradiol and gonadotropin levels aids in the diagnosis of the disturbance. For the evaluation of the adrenocorticotropic axis, the basal cortisol level may be helpful; provocative testing is in many cases necessary for precise characterization. The evaluation of the somato-tropic axis requires provocative testing. Aside from the insulin tolerance test, the GHRH-arginine test has become well established. Reference ranges normed to the body mass index (BMI) are available.

CONCLUSION

The diagnostic evaluation of pituitary insufficiency should proceed in stepwise fashion, depending on the patient's clinical manifestations and underlying disease. For some pituitary axes, measurement of basal hormone levels suffices; for others, stimulation tests are required. In general, the performance of combined pituitary tests should be viewed with caution.

The effect of in vivo growth hormone treatment on blood gene expression in adults with growth hormone deficiency reveals potential biomarkers to monitor growth hormone therapy

OBJECTIVE

Growth hormone (GH) replacement therapy is presently utilized in the treatment of adult GH deficiency (AGHD). Adult responses to GH treatment are highly variable and, apart from measurement of IGF-I, few tools are currently available for monitoring GH treatment progress. As GH receptors are expressed in certain blood cell types, changes in gene expression in peripheral blood can reflect perturbations induced as a result of GH therapy.

DESIGN/PATIENTS

We have carried out a pilot study to identify GH-responsive genes in blood, and have assessed the utility of GH-responsive genes in monitoring GH therapy in AGHD. Blood was collected from ten women diagnosed with AGHD syndrome both before and 4 weeks after initiation of GH substitutive therapy. RNA was extracted from peripheral blood mononuclear cells (PBMCs) and changes in response to GH were detected using microarray-based gene analysis.

RESULTS

All patients responded to GH replacement therapy, with serum levels of IGF-I increasing by an average of 307% (P = 0.0003) while IGFBP-3 increased by an average of 182% (P = 0.0002). Serum levels of triglycerides, LDL-C, HDL-C, APOA1 or APOB did not change after 1 month of GH treatment. By contrast, we detected an increase in Lp(a) serum levels (P = 0.0149). Using a stringent selection cutoff of P <or= 0.05, paired analysis identified a set of transcripts that correlated with GH administration. We applied the multivariate statistical technique PLS-DA to the changes in gene expression, demonstrating their utility in differentiating untreated patients and those undergoing GH replacement therapy.

CONCLUSION

This study shows that GH-dependent effects on gene expression in PBMCs can be detected by microarray-based gene analysis, and our results establish a foundation for the further exploration of peripheral blood as a surrogate to detect exposure to GH therapy.

The growth hormone-insulin-like growth factor axis in glycogen storage disease type 1: evidence of different growth patterns and insulin-like growth factor levels in patients with glycogen storage disease type 1a and 1b

OBJECTIVES

To investigate the growth hormone (GH)-insulin-like growth factor (IGF) system in patients with glycogen storage disease type 1 (GSD1).

STUDY DESIGN

This was a prospective, case-control study. Ten patients with GSD1a and 7 patients with GSD1b who were given dietary treatment and 34 sex-, age-, body mass index-, and pubertal stage-matched control subjects entered the study. Auxological parameters were correlated with circulating GH, either at basal or after growth hormone releasing hormone plus arginine test, insulin-like growth factors (IGF-I and IGF-II), and anti-pituitary antibodies (APA).

RESULTS

Short stature was detected in 10.0% of patients with GSD1a, 42.9% of patients with GSD1b (P = .02), and none of the control subjects. Serum IGF-I levels were lower in patients with GSD1b (P = .0001). An impaired GH secretion was found in 40% of patients with GSD1a (P = .008), 57.1% of patients with GSD1b (P = .006), and none of the control subjects. Short stature was demonstrated in 3 of 4 patients with GSD1b and GH deficiency. The prevalence of APA was significantly higher in patients with GSD1b than in patients with GSD1a (P = .02) and control subjects (P = .03). The GH response to the provocative test inversely correlated with the presence of APA (P = .003). Compared with levels in control subjects, serum IGF-II and insulin levels were higher in both groups of patients, in whom IGF-II levels directly correlated with height SD scores (P = .003).

CONCLUSION

Patients with GSD1a have an impaired GH secretion associated with reference range serum IGF-I levels and normal stature, whereas in patients with GSD1b, the impaired GH secretion, probably because of the presence of APA, was associated with reduced IGF-I levels and increased prevalence of short stature. The increased IGF-II levels, probably caused by increased insulin levels, in patients with GSD1 are presumably responsible for the improved growth pattern observed in patients receiving strict dietary treatment.

Normal growth hormone secretion in overweight young adults with Down syndrome

Down syndrome (DS) is associated with short stature and obesity. Adults with DS have several features in common with growth hormone (GH) deficient adult subjects. The aim of this study was to investigate GH secretion in young adults with DS and its relation to body composition as well as glucose and lipid metabolism. Ten young adults with DS (aged 24-32 years; 5 F) and ten controls matched for age and sex were examined regarding spontaneous nocturnal GH secretion and body composition. Stable isotope tracers were used to study glucose and lipid metabolism in the DS subjects. There was no difference in secretion of GH between the DS subjects and controls. The DS subjects had a higher BMI, fat mass proportion and HOMA (homeostasis model assessment) index compared with the controls. The rates of production of glucose and glycerol (reflecting lipolysis) in the DS subjects were increased (15.5+/-5.07 and 3.5+/-1.68 micromol/kg/min, respectively). The DS subjects showed normal GH secretion despite increased BMI and fat mass. The increased HOMA index and high rate of glucose production indicate peripheral and hepatic insulin resistance in adult DS subjects.

Hypopituitarism following traumatic brain injury: prevalence is affected by the use of different dynamic tests and different normal values

OBJECTIVE

Traumatic brain injury (TBI) has emerged as an important cause of hypopituitarism. However, considerable variations in the prevalence of hypopituitarism are reported. These can partly be explained by severity of trauma and timing of hormonal evaluation, but may also be dependent on endocrine tests and criteria used for diagnosis of hypopituitarism.

METHODS

Systematic review of studies reporting prevalence of hypopituitarism in adults >or=1 year after TBI focusing on used (dynamic) tests and biochemical criteria.

RESULTS

We included data from 14 studies with a total of 931 patients. There was considerable variation in definition of hypopituitarism. Overall, reported prevalences of severe GH deficiency varied between 2 and 39%. Prevalences were 8-20% using the GHRH-arginine test (cutoff <9 microg/l), 11-39% using the glucagon test (cutoff 1-5 microg/l), 2% using the GHRH test (no cutoff), and 15-18% using the insulin tolerance test (ITT; cutoff <3 microg/l). Overall, the reported prevalence of secondary adrenal insufficiency had a broad range from 0 to 60%. This prevalence was 0-60% with basal cortisol (cutoff <220 or <440 nmol/l), 7-19% using the ACTH test, and 5% with the ITT as first test (cutoff <500 or <550 nmol/l). Secondary hypothyroidism was present in 0-19% (free thyroxine) or 5-15% (thyroid-releasing hormone stimulation). Secondary hypogonadism was present in 0-29%.

CONCLUSION

The reported variations in the prevalence rates of hypopituitarism after TBI are in part caused by differences in definitions, endocrine assessments of hypopituitarism, and confounding factors. These methodological issues prohibit simple generalizations of results of original studies on TBI-associated hypopituitarism in the perspective of meta-analyses or reviews.

Treatment of adult growth hormone deficiency: who, why and how? A review

Adult growth hormone deficiency (AGHD) is nowadays recognized as a distinct clinical entity and replacement therapy has become a standard practice. Reflecting on the accumulated evidence, questions nevertheless arise. Should all AGHD patients be treated? What dose of GH should be given and for how long? What are the real long-term benefits, in particular regarding life expectancy? if the diagnosis of severe GHD is firmly established and if there is no contra-indication (such as an active cancer or uncontrolled diabetes), it is worthwile initiating GH replacement therapy. Treatment can indeed correct the abnormal body composition, improve various adverse cardiovascular parameters and risk factors, increase muscle strength and bone mineral density and, although to a variable degree, improve the patient's quality of life and psychological well-being. Treatment should be started with very low doses to avoid side-effects related to fluid retention and should then be gradually titrated against IGF-I values, clinical response and individual tolerance.There is unfortunately no confirmed predictive factor for the overall therapeutic response in a given individual. Thus, the decision to whether or not pursue the therapy will depend on the ratio of perceived and expected benefits over cost and risks of treatment, as well as on the persistent motivation of the patient.