Dehydroepiandrosterone (DHEA) replacement reduces growth hormone (GH) dose requirement in female hypopituitary patients on GH replacement

GH Deficiency and Replacement Therapy in Hypopituitarism: Insight Into the Relationships With Other Hypothalamic-Pituitary Axes

GH deficiency (GHD) in adult patients is a complex condition, mainly due to organic lesion of hypothalamic-pituitary region and often associated with multiple pituitary hormone deficiencies (MPHD). The relationships between the GH/IGF-I system and other hypothalamic-pituitary axes are complicated and not yet fully clarified. Many reports have shown a bidirectional interplay both at a central and at a peripheral level. Signs and symptoms of other pituitary deficiencies often overlap and confuse with those due to GH deficiency. Furthermore, a condition of untreated GHD may mask concomitant pituitary deficiencies, mainly central hypothyroidism and hypoadrenalism. In this setting, the diagnosis could be delayed and possible only after recombinant human Growth Hormone (rhGH) replacement. Since inappropriate replacement of other pituitary hormones may exacerbate many manifestations of GHD, a correct diagnosis is crucial. This paper will focus on the main studies aimed to clarify the effects of GHD and rhGH replacement on other pituitary axes. Elucidating the possible contexts in which GHD may develop and examining the proposed mechanisms at the basis of interactions between the GH/IGF-I system and other axes, we will focus on the importance of a correct diagnosis to avoid possible pitfalls.

Management of Hypopituitarism

Hypopituitarism includes all clinical conditions that result in partial or complete failure of the anterior and posterior lobe of the pituitary gland’s ability to secrete hormones. The aim of management is usually to replace the target-hormone of hypothalamo-pituitary-endocrine gland axis with the exceptions of secondary hypogonadism when fertility is required, and growth hormone deficiency (GHD), and to safely minimise both symptoms and clinical signs. Adrenocorticotropic hormone deficiency replacement is best performed with the immediate-release oral glucocorticoid hydrocortisone (HC) in 2–3 divided doses. However, novel once-daily modified-release HC targets a more physiological exposure of glucocorticoids. GHD is treated currently with daily subcutaneous GH, but current research is focusing on the development of once-weekly administration of recombinant GH. Hypogonadism is targeted with testosterone replacement in men and on estrogen replacement therapy in women; when fertility is wanted, replacement targets secondary or tertiary levels of hormonal settings. Thyroid-stimulating hormone replacement therapy follows the rules of primary thyroid gland failure with L-thyroxine replacement. Central diabetes insipidus is nowadays replaced by desmopressin. Certain clinical scenarios may have to be promptly managed to avoid short-term or long-term sequelae such as pregnancy in patients with hypopituitarism, pituitary apoplexy, adrenal crisis, and pituitary metastases.

[Current aspects of diagnosis and treatment of adult GH-deficiency]

Adult growth hormone (GH) deficiency (AGHD) is a condition characterized by alterations in body composition, lipid and carbohydrate metabolism, bone mineral density and poor quality of life; however, clinical presentations of AGHD are mostly non-specific. Untreated AGHD is associated with increased cardiovascular morbidity and mortality. Stimulation tests are used for the diagnosis: insulin tolerance test, glucagon stimulation test, growth-hormone releasing hormone and arginine stimulation test. Moreover, in 2017 FDA approved the use of macimorelin (oral GH secretagogue) for the diagnosis of AGHD. In childhood GH-deficiency, apolipoprotein A-IV, CFHR4 (complement factor H-related protein 4) and PBP (platelet basic protein) were identified as potential biomarkers of the disease, however, this was not investigated in AGHD. GH treatment starts from the minimal dose, which allows minimizing the adverse effects. According to published meta-analyses, AGHD treatment generally does not lead to increased risk of malignancy and recurrence of sellar neoplasms in adult patients. Published data on GH receptor polymorphism associations with treatment efficacy remains controversial. Development of long-acting GH formulations is a currect perspective for the increase of treatment compliance.

Dehydroepiandrosterone: a potential therapeutic agent in the treatment and rehabilitation of the traumatically injured patient

Severe injuries are the major cause of death in those aged under 40, mainly due to road traffic collisions. Endocrine, metabolic and immune pathways respond to limit the tissue damage sustained and initiate wound healing, repair and regeneration mechanisms. However, depending on age and sex, the response to injury and patient prognosis differ significantly. Glucocorticoids are catabolic and immunosuppressive and are produced as part of the stress response to injury leading to an intra-adrenal shift in steroid biosynthesis at the expense of the anabolic and immune enhancing steroid hormone dehydroepiandrosterone (DHEA) and its sulphated metabolite dehydroepiandrosterone sulphate (DHEAS). The balance of these steroids after injury appears to influence outcomes in injured humans, with high cortisol: DHEAS ratio associated with increased morbidity and mortality. Animal models of trauma, sepsis, wound healing, neuroprotection and burns have all shown a reduction in pro-inflammatory cytokines, improved survival and increased resistance to pathological challenges with DHEA supplementation. Human supplementation studies, which have focused on post-menopausal females, older adults, or adrenal insufficiency have shown that restoring the cortisol: DHEAS ratio improves wound healing, mood, bone remodelling and psychological well-being. Currently, there are no DHEA or DHEAS supplementation studies in trauma patients, but we review here the evidence for this potential therapeutic agent in the treatment and rehabilitation of the severely injured patient.

Central intracrine DHEA synthesis in ageing-related neuroinflammation and neurodegeneration: therapeutic potential?

It is a well-known fact that DHEA declines on ageing and that it is linked to ageing-related neurodegeneration, which is characterised by gradual cognitive decline. Although DHEA is also associated with inflammation in the periphery, the link between DHEA and neuroinflammation in this context is less clear. This review drew from different bodies of literature to provide a more comprehensive picture of peripheral vs central endocrine shifts with advanced age—specifically in terms of DHEA. From this, we have formulated the hypothesis that DHEA decline is also linked to neuroinflammation and that increased localised availability of DHEA may have both therapeutic and preventative benefit to limit neurodegeneration. We provide a comprehensive discussion of literature on the potential for extragonadal DHEA synthesis by neuroglial cells and reflect on the feasibility of therapeutic manipulation of localised, central DHEA synthesis.

Doping Status of DHEA Treatment for Female Athletes with Adrenal Insufficiency

OBJECTIVE

To review the doping status of dehydroepiandrosterone (DHEA) for female athletes with adrenal insufficiency within the framework of Therapeutic Use Exemption (TUE) applications for this proandrogen, which is included on the World Anti-Doping Agency (WADA)'s Prohibited List.

DATA SOURCES AND MAIN RESULTS

Current knowledge of adrenal pathophysiology with a focus on the physiological role and pharmacological effects of DHEA in female athletes including placebo-controlled clinical trials of DHEA and consensus clinical practice and prescribing guidelines.

CONCLUSIONS

Because there is no convincing clinical evidence to support the use of DHEA replacement therapy in women with adrenal failure, a TUE for DHEA is not justified by definite health benefit for either secondary or primary adrenal failure. This is consistent with the 2014 update of the US Endocrine Society guidelines, meta-analyses of DHEA treatment in women with or without adrenal failure, current WADA TUE guidance document for adrenal insufficiency and recent case law of WADA's Court of Arbitration for Sport.

Hypopituitarism

Hypopituitarism refers to deficiency of one or more hormones produced by the anterior pituitary or released from the posterior pituitary. Hypopituitarism is associated with excess mortality, a key risk factor being cortisol deficiency due to adrenocorticotropic hormone (ACTH) deficiency. Onset can be acute or insidious, and the most common cause in adulthood is a pituitary adenoma, or treatment with pituitary surgery or radiotherapy. Hypopituitarism is diagnosed based on baseline blood sampling for thyroid stimulating hormone, gonadotropin, and prolactin deficiencies, whereas for ACTH, growth hormone, and antidiuretic hormone deficiency dynamic stimulation tests are usually needed. Repeated pituitary function assessment at regular intervals is needed for diagnosis of the predictable but slowly evolving forms of hypopituitarism. Replacement treatment exists in the form of thyroxine, hydrocortisone, sex steroids, growth hormone, and desmopressin. If onset is acute, cortisol deficiency should be replaced first. Modifications in replacement treatment are needed during the transition from paediatric to adult endocrine care, and during pregnancy.

Diagnosis and management of adrenal insufficiency

Adrenal insufficiency continues to be a challenge for patients, their physicians, and researchers. During the past decade, long-term studies have shown increased mortality and morbidity and impaired quality of life in patients with adrenal insufficiency. These findings might, at least partially, be due to the failure of glucocorticoid replacement therapy to closely resemble physiological diurnal secretion of cortisol. The potential effect of newly developed glucocorticoid drugs is a focus of research, as are the mechanisms potentially underlying increased morbidity and mortality. Adrenal crisis remains a threat to lives, and awareness and preventative measures now receive increasing attention. Awareness should be raised in medical teams and patients about adrenal insufficiency and management of adrenal crisis to improve clinical outcome.

Is DHEA replacement beneficial in chronic adrenal failure?

Although dehydroepiandrosterone (DHEA) and its sulphate ester dehydroepiandrosterone sulphate (DHEAS) are the most abundant steroid hormones in the human circulation, its exact physiological role is not yet fully understood. In patients with adrenal insufficiency, secretion of DHEA is impaired, leading to decreased circulating DHEA and DHEAS levels, and to androgen deficiency in women. Replacement of DHEA in patients with adrenal insufficiency positively influence mood, sexuality and subjective health status. These effects are generally moderate and show high inter-individual variability. Limited evidence exists for immunomodulatory effects of DHEA. Although an increase of IGF-I levels has been documented, relevant effects on body composition, metabolic or cardiovascular parameters has not been observed in patients with adrenal insufficiency receiving DHEA. Larger-scale phase III studies are still lacking; therefore, initiation of DHEA replacement is decided on an individual basis, focussing on those patients with impaired well-being associated with signs and symptoms of androgen deficiency.

Scavenger receptor class B type I and immune dysfunctions

PURPOSE OF REVIEW

To summarize the recent findings about the roles of scavenger receptor class B type I (SR-BI) in immunity and discuss the underlying mechanisms by which SR-BI prevents immune dysfunctions.

RECENT FINDINGS

SR-BI is well known as a high-density lipoprotein (HDL) receptor playing key roles in HDL metabolism and in protection against atherosclerosis. Recent studies have indicated that SR-BI is also an essential modulator in immunity. SR-BI deficiency in mice causes immune dysfunctions, including increased atherosclerosis, elevated susceptibility to sepsis, impaired lymphocyte homeostasis, and autoimmune disorders. SR-BI exerts its protective roles through a variety of HDL-dependent and HDL-independent mechanisms. SR-BI is also involved in hepatitis C virus cell entry. A deficiency of SR-BI in humanized mice has been shown to decrease hepatitis C virus infectivity.

SUMMARY

SR-BI regulates immunity via multiple mechanisms and its deficiency causes numerous diseases. A comprehensive understanding of the roles of SR-BI in protection against immune dysfunctions may provide a therapeutic target for intervention against its associated diseases.

Effects of dehydroepiandrosterone sulphate (DHEAS) replacement on insulin action and quality of life in hypopituitary females: a double-blind, placebo-controlled study

OBJECTIVE

Addition of dehydroepiandrosterone sulphate (DHEAS) to standard pituitary replacement may improve quality of life and glucose metabolism. Conflicting results from the previous work probably relate to differences in populations studied and assessment techniques used. We examined the effects of DHEAS on insulin action and the quality of life in female patients with hypopituitary hypoadrenalism.

DESIGN

Randomized, double-blind, placebo-controlled, crossover design was used. Patients received either DHEAS 50 mg daily or placebo for 12 weeks.

PATIENTS

Fourteen hypopituitary females on stable standard replacement therapy and with low DHEAS were enrolled.

MEASUREMENTS

Insulin action by euglycaemic hyperinsulinaemic clamp and extensive quality of life parameters were assessed after each treatment.

RESULTS

Serum DHEAS (DHEAS 5·4 ± 0·8 vs placebo <0·8 ± 0·0 μm; P < 0·001) and androstenedione (DHEAS 4·1 ± 0·8 vs placebo 1·3 ± 0·2 nm; P < 0·05) rose to within the normal range after DHEAS 50 mg daily. There were no differences between treatments in testosterone, sex hormone-binding globulin (SHBG) or IGF-1. Quality of life measures were unchanged after DHEAS. There were no differences between treatments in fasting glucose, serum insulin, HbA1c or in insulin action (glucose infusion rates required to maintain euglycaemia; DHEAS 21·9 ± 2·5 vs placebo 24·5 ± 2·1 μmol/kg/min; P = 0·4). Triglyceride concentrations were lower following DHEAS (DHEAS 1·24 ± 0·18 vs placebo 1·41 ± 0·19 mm; P < 0·05) but other lipid parameters remained unchanged.

CONCLUSION

There were no differences compared with placebo in quality of life or insulin action after DHEAS replacement therapy for 12 weeks. These results do not provide evidence for the addition of DHEAS to standard hypopituitary replacement therapy.

DHEA, important source of sex steroids in men and even more in women

A major achievement from 500 million years of evolution is the establishment of a high secretion rate of dehydroepiandrosterone (DHEA) by the human adrenal glands coupled with the indroduction of menopause which stops secretion of estrogens by the ovary. Cessation of estrogen secretion at menopause eliminates the risks of endometrial hyperplasia and cancer which would result from non-opposed estrogen stimulation during the post-menopausal years. In fact, from the time of menopause, DHEA becomes the exclusive and tissue-specific source of sex steroids for all tissues except the uterus. Intracrinology, a term coined in 1988, describes the local formation, action and inactivation of sex steroids from the inactive sex steroid precursor DHEA. Over the past 25 years most, if not all, the genes encoding the human steroidogenic and steroid-inactivating enzymes have been cloned and sequenced and their enzymatic activity characterized. The problem with DHEA, however, is that its secretion decreases from the age of 30 years and is already decreased, on average, by 60% at time of menopause. In addition, there is a large variability in the circulating levels of DHEA with some post-menopausal women having barely detectable serum concentrations of the steroid while others have normal values. Since there is no feedback mechanism controlling DHEA secretion within 'normal' values, women with low DHEA will remain with such a deficit of sex steroids for their remaining lifetime. Since there is no other significant source of sex steroids after menopause, one can reasonably believe that low DHEA is involved, in association with the aging process, in a series of medical problems classically associated with post-menopause, namely osteoporosis, muscle loss, vaginal atrophy, fat accumulation, hot flashes, skin atrophy, type 2 diabetes, memory loss, cognition loss and possibly Alzheimer's disease. A recent randomized, placebo-controlled study has shown that all the signs and symptoms of vaginal atrophy, a classical problem recognized to be due to the hormone deficiency of menopause, can be rapidly improved or corrected by local administration of DHEA without systemic exposure to estrogens. In addition, the four domains of sexual dysfucntion are improved. For the other problems of menopause, although similar large scale, randomized and placebo-controlled studies usually remain to be performed, the available evidence already strongly suggests that they could be improved, corrected or even prevented by exogenous DHEA. In men, the contribution of adrenal DHEA to the total androgen pool has been measured at 40% in 65-75-year-old men. Such data stress the necessity of blocking both the testicular and adrenal sources of androgens in order to achieve optimal benefits in prostate cancer therapy. On the other hand, the comparable decrease in serum DHEA levels observed in both sexes has less consequence in men who continue to receive a practically constant supply of testicular sex steroids during their whole life. In fact, in men, the appearance of hormone-deficiency symptoms common to women is observed at a later age and with a lower degree of severity. Consequently, DHEA replacement has shown much more easily measurable beneficial effects in women. Most importantly, despite the non-scientific and unfortunate availability of DHEA as a food supplement in the United States, a situation that discourages rigorous clinical trials on the crucial physiological and therapeutic role of DHEA, no serious adverse event related to DHEA has ever been reported in the world literature (thousands of subjects exposed) or in the monitoring of adverse events by the FDA (millions of subjects exposed), thus indicating, as expected from its known physiology, the excellent safety profile of DHEA. With today's knowledge, one can reasonably suggest that DHEA offers the promise of a safe and efficient replacement therapy for the multiple problems related to hormone deficiency after menopause without the risks associated with estrogen-based or any other treatments.

Dehydroepiandrosterone sulfate linked to physiologic response against hot spring immersion

The steroid dehydroepiandrosterone sulfate (DHEA-S) is associated with longevity and adaptation against external stress in humans. The aim of the study was to investigate the acute effect of a 30-min hot spring immersion at 41 degrees C on insulin resistance measures of 16 male subjects, in relation to DHEA-S level. To elucidate the role of DHEA-S in the coping against the heat stress, all subjects were evenly divided into lower and upper halves according to their baseline DHEA-S concentrations. The levels of glucose, insulin, blood pressure, and stress hormones (growth hormone, testosterone, and cortisol) in both groups were compared before and after hot spring immersion. The result shows that hot spring immersion significantly increased heart rate and reduced diastolic blood pressure, both of which were paralleled with a drop of DHEA-S concentration. Homeostasis model assessment for insulin resistance (HOMA-IR) and area under curve of glucose (GAUC) of oral glucose tolerance test were significantly increased by the hot spring immersion only in the Low DHEA-S group. Likewise, hot spring immersion caused an opposing effect on cortisol changes for the Low and High DHEA-S groups (+95% vs. -33%, p<0.05), respectively. In conclusion, hot spring bathing induced insulin resistance confined only to those Low DHEA-S individuals. This response may be associated with a stress response such as increased cortisol levels.

Hypopituitarism: clinical features, diagnosis, and management

Hypopituitarism is characterized by loss of function of the anterior pituitary gland. It is a rare condition that can present at any age and is caused by pathology of the hypothalamic-pituitary axis or one of many gene mutations. The symptoms and signs of hypopituitarism may evolve over several years and be nonspecific or related to the effects of the underlying disease process or to hormone deficiencies. Investigation of patients requires a combination of basal hormone levels and dynamic function tests; management requires regular monitoring. The goal of physicians managing patients who have hypopituitarism is to improve their health and long-term outcome.

Management of growth hormone deficiency in adults

Growth hormone (GH) deficiency in adults is a recognised clinical entity. There is still, however, an ongoing debate of the clinical need and the importance of replacing GH in adults with severe GH deficiency. This review will focus on the overall management of adults with GH deficiency and highlight published data on dose management and treatment goals for various age groups. The efficacy data on quality of life and well-being is discussed and available and growing experience on long-term effects of GH replacement in adults and safety in terms of diabetes mellitus, pituitary tumour recurrence/regrowth and malignancy risk will be reviewed.

Psychosocial impairment in patients treated for pituitary disease: a controlled study

OBJECTIVE

To verify whether patients with pituitary disorders in remission and on appropriate treatment display significant differences in psychological distress compared to healthy controls and other patients treated for nonpituitary endocrine disorders.

DESIGN

A single-centred, controlled study.

PATIENTS

Eighty-six outpatients cured or in remission for at least 9 months following appropriate treatment by surgery, irradiation and/or pharmacological interventions for pituitary disease were compared with 86 healthy subjects. A sample comprising 60 outpatients cured or in remission from nonpituitary endocrine disorders was also compared.

MEASUREMENTS

(1) A modified version of the Structural Clinical Interview for DSM-IV; (2) a shortened version of the structured interview for the Diagnostic Criteria for Psychosomatic Research (DCPR); (3) the Psychosocial Index (PSI); and (4) the Medical Outcomes Study (MOS) short form General Health Survey (SF-20) were employed.

RESULTS

Patients with pituitary disease displayed a higher prevalence of psychiatric disease (P < 0.001) compared to controls, but not when compared to nonpituitary endocrine patients. They also showed a higher prevalence of DCPR clusters compared to controls (P < 0.001), but not when compared to nonpituitary endocrine patients. At PSI and MOS (SF-20), patients with endocrine disease, whether pituitary or not, reported more psychological distress, and less well-being (P < 0.001) compared to controls.

CONCLUSIONS

At follow-up after appropriate treatment, we documented a high prevalence of psychopathology in patients with pituitary disease, which was however, similar to that found in nonpituitary endocrine patients. This is consistent with an increasing body of literature that reports difficulties in obtaining full recovery in patients treated for endocrine disorders.

Serum IGF-I levels in the diagnosis and monitoring of acromegaly

Insulin-Like Growth Factor-I (IGF-I) is a reliable marker of disease activity and growth hormone (GH) status in acromegaly, but its clinical utility has been hampered over the years by various issues including a lack of robust reference range data and variability in assay sensitivity and specificity. In acromegaly IGF-I correlates well with GH activity and nadir GH on oral glucose tolerance test (OGTT) and is the most sensitive and specific test in diagnosis, where serum IGF-I is persistently seen to be elevated to a range that is distinct from that in healthy individuals. However it should not be relied on exclusively for diagnosis or used as the sole indication of disease severity and GH burden. Successful medical or surgical treatment of acromegaly is usually associated with normalisation of serum IGF-I but there is discordance between GH and IGF-I in some patients. Patients with a normal IGF-I but an abnormal GH suppression to OGTT are at risk of relapse and therefore it should not be used alone to establish disease remission. In contrast to the diagnosis of acromegaly, there is also considerable overlap in serum IGF-I with normality after primary treatment of disease, even in the presence of persisting GH excess. Gender, age and prior radiotherapy alters the relationship between GH and IGF-I and reliance on one marker of disease activity such as IGF-I is particularly precarious in certain disease states. However an elevated serum IGF-I has been shown to be associated with excess mortality and normalising IGF-I normalises mortality making it a useful marker. The tightening up of the assays means that establishing absolute concentrations as well as standard deviation scores are essential to allow cross-study comparisons. This becomes especially important in the use of Pegvisomant, where IGF-I becomes the sole biochemical marker of disease activity.