Sensitivity and specificity of the macimorelin test for diagnosis of AGHD

Diagnosing and treating the elderly individual with hypopituitarism

Hypopituitarism in the elderly is an underestimated condition mainly due to the non-specific presentation that can be attributed to the effects of aging and the presence of comorbidities. Diagnosis and treatment of hypopituitarism often represent a challenging task and this is even more significant in the elderly. Diagnosis can be insidious due to the physiological changes occurring with aging that complicate the interpretation of hormonal investigations, and the need to avoid some provocative tests that carry higher risks of side effects in this population. Treatment of hypopituitarism has generally the goal to replace the hormonal deficiencies to restore a physiological balance as close as possible to that of healthy individuals but in the elderly this must be balanced with the risks of over-replacement and worsening of comorbidities. Moreover, the benefit of some hormonal replacement therapies in the elderly, including sex hormones and growth hormone, remains controversial.

Pitfalls in the lab assessment of hypopituitarism

The diagnostic approach to hypopituitarism involves many disciplines. Clinical symptoms rarely are specific. Imaging techniques are helpful but cannot prove the specific functional defects. Therefore, the definitive diagnosis of pituitary insufficiency is largely based on laboratory tests. However, also laboratory methods come with inherent limitations, and it is essential for the clinician to know and recognize typical pitfalls. Most factors potentially impairing the quality of hormone measurements are introduced in the preanalytical phase, i.e. before the hormones are measured by the laboratory. For example, the timing of blood drawing with respect to circadian rhythm, stress, and medication can have an influence on hormone concentrations. During the actual analysis of the hormones, cross-reactions with molecules present in the sample presenting the same or similar epitopes than the intended analyte may affect immunoassays. Interference can also come from heterophilic or human anti-animal antibodies. Unexpected problems can also be due to popular nutritional supplements which interfere with the measurement procedures. An important example in this respect is the interference from biotin. It became only clinically visible when the use of this vitamin became popular among patients. The extreme serum concentrations reached when patients take it as a supplement can lead to incorrect measurements in immunoassays employing the biotin-streptavidin system. To some extent, hormone analyses using liquid chromatography mass spectrometry (LCMS) can overcome problems, although availability and cost-effectiveness of this method still imposes restrictions. In the post-analytical phase, appropriateness of reference intervals and cut-offs with respect to the specific analytical method used is of outmost importance. Furthermore, for interpretation, additional biological and pharmacological factors like BMI, age and concomitant diseases must be considered to avoid misinterpretation of the measured concentrations. It is important for the clinician and the laboratory to recognize when one or more laboratory values do not match the clinical picture. In an interdisciplinary approach, the search for the underlying cause should be initiated.

Long-term pituitary function and functional and patient-reported outcomes in severe acquired brain injury

OBJECTIVE

Assessment of posttraumatic hypothalamic-pituitary dysfunctions is expected to be the most relevant assessment to offer patients with severe intracranial affection. In this study, we aim to investigate the prevalence of hypopituitarism in patients with severe acquired traumatic brain injury (TBI) compared with nontraumatic brain injury (NTBI) and to relate pituitary insufficiency to functional and patient-reported outcomes.

DESIGN

This is a prospective study.

METHODS

We included patients admitted for inpatient neurorehabilitation after severe TBI (N = 42) and NTBI (N = 18). The patients underwent a pituitary function assessment at a mean of 2.4 years after the injury. Functional outcome was assessed by using Functional Independence Measure and Glasgow Outcome Scale-Extended (both 1 year after discharge from neurorehabilitation) and patient-reported outcome was assessed by using Multiple Fatigue Inventory-20 and EQ-5D-3L.

RESULTS

Hypopituitarism was reported in 10/42 (24%) patients with TBI and 7/18 (39%) patients with NTBI (P = .23). Insufficiencies affected 1 axis in 14/17 (82%) patients (13 hypogonadotropic hypogonadism and 1 growth hormone [GH] deficiency) and 2 axes in 3/17 (18%) patients (1 hypogonadotropic hypogonadism and GH deficiency, and 2 hypogonadotropic hypogonadism and arginin vasopressin deficiency). None had central hypoadrenalism or central hypothyroidism. In patients with both TBI and NTBI, pituitary status was unrelated to functioning and ability scores at 1 year and to patient-reported outcome scores at a mean of 2.4 years after the injury.

CONCLUSION

Patients with severe acquired brain injury may develop long-term hypothalamus-pituitary insufficiency, with an equal occurrence in patients with TBI and NTBI. In both types of patients, mainly isolated deficiencies, most commonly affecting the gonadal axis, were seen. Insufficiencies were unrelated to functional outcomes and patient-reported outcomes, probably reflecting the complexity and heterogeneous manifestations in both patient groups.

Therapeutic proteins: developments, progress, challenges, and future perspectives

Proteins are considered magic molecules due to their enormous applications in the health sector. Over the past few decades, therapeutic proteins have emerged as a promising treatment option for various diseases, particularly cancer, cardiovascular disease, diabetes, and others. The formulation of protein-based therapies is a major area of research, however, a few factors still hinder the large-scale production of these therapeutic products, such as stability, heterogenicity, immunogenicity, high cost of production, etc. This review provides comprehensive information on various sources and production of therapeutic proteins. The review also summarizes the challenges currently faced by scientists while developing protein-based therapeutics, along with possible solutions. It can be concluded that these proteins can be used in combination with small molecular drugs to give synergistic benefits in the future.

Hypopituitarism after traumatic brain injury in adults: Clinical guidelines of the neuroendocrinology area of the Spanish Society of Endocrinology and Nutrition (SEEN)

Traumatic brain injury (TBI) is associated with hypopituitarism with a variable incidence, depending on the time and methods used to diagnosis, and on factors related to the trauma, such as its severity, its anatomical location and the drugs used in the acute phase. The pituitary gland can be damaged directly by the impact or secondary to factors such as ischemia, inflammation, excitotoxicity or immunity. In acute phases ACTH deficiency is the most relevant, since failure to detect and treat it can compromise the patient's life. Clinical manifestations are typical of each hormone deficient axes, although the combination hypopituitarism-trauma has been associated with cognitive deterioration, worse metabolic profile and greater impairment of quality of life. One of the clinical challenges is to determine which patients benefit from a systematic hormonal evaluation, and therefore from hormone replacement, and what is the appropriate time to do so and the most suitable diagnostic methods.

Pilot clinical trial of macimorelin to assess safety and efficacy in patients with cancer cachexia

BACKGROUND

Cancer cachexia is associated with reduced body weight, appetite and quality of life (QOL) with no approved treatments. Growth hormone secretagogues like macimorelin have potential to mitigate these effects.

METHODS

This pilot study assessed the safety and efficacy of macimorelin for 1 week. Efficacy was defined a priori as 1-week change in body weight (≥0.8 kg), plasma insulin-like growth factor (IGF)-1 (≥50 ng/mL) or QOL (≥15%). Secondary outcomes included food intake, appetite, functional performance, energy expenditure and safety laboratory parameters. Patients with cancer cachexia were randomized to 0.5 or 1.0 mg/kg macimorelin or placebo; outcomes were assessed non-parametrically.

RESULTS

Participants receiving at least one of either macimorelin dose were combined (N = 10; 100% male; median age = 65.50 ± 2.12) and compared with placebo (N = 5; 80% male; median age = 68.00 ± 6.19). Efficacy criteria achieved: body weight (macimorelin N = 2; placebo N = 0; P = 0.92); IGF-1 (macimorelin N = 0; placebo N = 0); QOL by Anderson Symptom Assessment Scale (macimorelin N = 4; placebo N = 1; P = 1.00) or Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F; macimorelin N = 3; placebo N = 0; P = 0.50). No related serious or non-serious adverse events were reported. In macimorelin recipients, change in FACIT-F was directly associated with change in body weight (r = 0.92, P = 0.001), IGF-1 (r = 0.80, P = 0.01), and caloric intake (r = 0.83, P = 0.005), and inversely associated with change in energy expenditure (r = -0.67, P = 0.05).

CONCLUSIONS

Daily oral macimorelin for 1 week was safe and numerically improved body weight and QOL in patients with cancer cachexia compared with placebo. Longer term administration should be evaluated for mitigation of cancer-induced reductions in body weight, appetite and QOL in larger studies.

Treating Hypopituitarism in the Over 65s: Review of Clinical Studies

The current increase of life expectancy is associated with the presence of endocrine diseases in the elderly. The management of hypopituitarism in this group of patients is a challenging task. A correct diagnosis, which represents an essential requisite for an appropriate medical treatment, can be difficult because of the physiological changes occurring in pituitary function with aging, which may lead to challenges in the interpretation of laboratory results. Furthermore, the treatment requires several careful considerations: the need to restore the hormonal physiology with replacement therapies must be balanced with the need to avoid the risks of the over-replacement, especially in the presence of concomitant cardiovascular and metabolic disease. Interactions with other drugs able to modify the absorption and/or the metabolism of hormonal replacement therapies should be considered, in particular for the treatment of hypoadrenalism and hypothyroidism. The most important challenges stem from the lack of specific studies focused on the management of hypopituitarism in older people.

ENDOCRINE OBESITY: Pituitary dysfunction in obesity

Obesity, the growing pandemic of the 21st century, is associated with multiple organ dysfunction, either by a direct increase in fatty organ content or by indirect modifications related to general metabolic changes driven by a specific increase in biologic products. The pituitary gland is not protected against such a situation. Different hypothalamic-pituitary axes experience functional modifications initially oriented to an adaptive situation that, with years of obesity, turn to maladaptive dynamics that contribute to perpetuating obesity and specific symptoms of their hormonal nature. This paper reviews the recent knowledge on obesity-related pituitary dysfunction and its pathogenic mechanisms and discusses potential therapeutic actions aimed at contributing to ameliorating the complex treatment of severe cases of obesity.

Safety of growth hormone replacement in survivors of cancer and intracranial and pituitary tumours: a consensus statement

Growth hormone (GH) has been used for over 35 years, and its safety and efficacy has been studied extensively. Experimental studies showing the permissive role of GH/insulin-like growth factor 1 (IGF-I) in carcinogenesis have raised concerns regarding the safety of GH replacement in children and adults who have received treatment for cancer and those with intracranial and pituitary tumours. A consensus statement was produced to guide decision-making on GH replacement in children and adult survivors of cancer, in those treated for intracranial and pituitary tumours and in patients with increased cancer risk. With the support of the European Society of Endocrinology, the Growth Hormone Research Society convened a Workshop, where 55 international key opinion leaders representing 10 professional societies were invited to participate. This consensus statement utilized: (1) a critical review paper produced before the Workshop, (2) five plenary talks, (3) evidence-based comments from four breakout groups, and (4) discussions during report-back sessions. Current evidence reviewed from the proceedings from the Workshop does not support an association between GH replacement and primary tumour or cancer recurrence. The effect of GH replacement on secondary neoplasia risk is minor compared to host- and tumour treatment-related factors. There is no evidence for an association between GH replacement and increased mortality from cancer amongst GH-deficient childhood cancer survivors. Patients with pituitary tumour or craniopharyngioma remnants receiving GH replacement do not need to be treated or monitored differently than those not receiving GH. GH replacement might be considered in GH-deficient adult cancer survivors in remission after careful individual risk/benefit analysis. In children with cancer predisposition syndromes, GH treatment is generally contraindicated but may be considered cautiously in select patients.

Advances in the Development of Nonpeptide Small Molecules Targeting Ghrelin Receptor

Ghrelin is an octanoylated peptide acting by the activation of the growth hormone secretagogue receptor, namely, GHS-R1a. The involvement of ghrelin in several physiological processes, including stimulation of food intake, gastric emptying, body energy balance, glucose homeostasis, reduction of insulin secretion, and lipogenesis validates the considerable interest in GHS-R1a as a promising target for the treatment of numerous disorders. Over the years, several GHS-R1a ligands have been identified and some of them have been extensively studied in clinical trials. The recently resolved structures of GHS-R1a bound to ghrelin or potent ligands have provided useful information for the design of new GHS-R1a drugs. This perspective is focused on the development of recent nonpeptide small molecules acting as GHS-R1a agonists, antagonists, and inverse agonists, bearing classical or new molecular scaffolds, as well as on radiolabeled GHS-R1a ligands developed for imaging. Moreover, the pharmacological effects of the most studied ligands have been discussed.

Advances in differential diagnosis and management of growth hormone deficiency in children

Growth hormone (GH) deficiency (GHD) in children is defined as impaired production of GH by the pituitary gland that results in growth failure. This disease might be congenital or acquired, and occurs in isolation or in the setting of multiple pituitary hormone deficiency. Isolated GHD has an estimated prevalence of 1 patient per 4000-10,000 live births and can be due to multiple causes, some of which are yet to be determined. Establishing the correct diagnosis remains key in children with short stature, as initiating treatment with recombinant human GH can help them attain their genetically determined adult height. During the past two decades, our understanding of the benefits of continuing GH therapy throughout the transition period from childhood to adulthood has increased. Improvements in transitional care will help alleviate the consequent physical and psychological problems that can arise from adult GHD, although the consequences of a lack of hormone replacement are less severe in adults than in children. In this Review, we discuss the differential diagnosis in children with GHD, including details of clinical presentation, neuroimaging and genetic testing. Furthermore, we highlight advances and issues in the management of GHD, including details of transitional care.

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.