DHEA: why, when, and how much--DHEA replacement in adrenal insufficiency

Increased Resting-State Functional Connectivity in Patients With Autoimmune Addison Disease

CONTEXT

Individuals with autoimmune Addison disease (AAD) take replacement medication for the lack of adrenal-derived glucocorticoid (GC) and mineralocorticoid hormones from diagnosis. The brain is highly sensitive to these hormones, but the consequence of having AAD for brain health has not been widely addressed.

OBJECTIVE

The present study compared resting-state functional connectivity (rs-fc) of the brain between individuals with AAD and healthy controls.

METHODS

Fifty-seven patients with AAD (33 female) and 69 healthy controls (39 female), aged 19 to 43 years were scanned with 3-T magnetic resonance imaging (MRI).

RESULTS

Independent component and subsequent dual regression analyses revealed that individuals with AAD had stronger rs-fc compared to controls in 3 networks: the bilateral orbitofrontal cortex (OFC), the left medial visual and left posterior default mode network. A higher GC replacement dose was associated with stronger rs-fc in a small part of the left OFC in patients. We did not find any clear associations between rs-fc and executive functions or mental fatigue.

CONCLUSION

Our results suggest that having AAD affects the baseline functional organization of the brain and that current treatment strategies of AAD may be one risk factor.

Brain structure in autoimmune Addison's disease

Long-term disturbances in cortisol levels might affect brain structure in individuals with autoimmune Addison's disease (AAD). This study investigated gray and white matter brain structure in a cohort of young adults with AAD. T1- and diffusion-weighted images were acquired for 52 individuals with AAD and 70 healthy controls, aged 19-43 years, using magnetic resonance imaging. Groups were compared on cortical thickness, surface area, cortical gray matter volume, subcortical volume (FreeSurfer), and white matter microstructure (FSL tract-based spatial statistics). Individuals with AAD had 4.3% smaller total brain volume. Correcting for head size, we did not find any regional structural differences, apart from reduced volume of the right superior parietal cortex in males with AAD. Within the patient group, a higher glucocorticoid (GC) replacement dose was associated with smaller total brain volume and smaller volume of the left lingual gyrus, left rostral anterior cingulate cortex, and right supramarginal gyrus. With the exception of smaller total brain volume and potential sensitivity of the parietal cortex to GC disturbances in men, brain structure seems relatively unaffected in young adults with AAD. However, the association between GC replacement dose and reduced brain volume may be reason for concern and requires follow-up study.

Young adult Swedish patients with autoimmune Addison's disease report difficulties with executive functions in daily life despite overall good cognitive performance

OBJECTIVES

Sub-optimal replacement of glucocorticoids (GC) in autoimmune Addison's disease (AAD) may affect cognitive functioning. The present study therefore sought to investigate cognitive performance and self-reported problems with executive functions in a cohort of young adult patients with AAD.

DESIGN AND METHODS

67 patients with AAD (39 females), mean age 32 yrs. (range 19-41), and 80 control participants (43 females), mean age 29 yrs. (range 19-43), completed neuropsychological tests estimating verbal and non-verbal intellectual ability, learning, memory and executive functioning, in addition to self-report scales assessing problems with executive functions, fatigue and symptoms of anxiety and depression.

RESULTS

Patients performed within the average range on all cognitive tests compared to population norms. However, female AAD patients reported more problems than controls with both hot (emotion regulation) and cold (cognitive regulation) executive functions in daily life. Moreover, experienced problems with executive functions in both male and female patients were associated with increased mental fatigue and lower GC replacement doses.

CONCLUSIONS

Despite average performance in neuropsychological tests by both sexes, young adult female patients with AAD experience problems with executive functions in daily life. Coping with mental fatigue and optimization of pharmacotherapy may be important factors to be addressed in order to provide timely support for patients. Future research is needed to further determine other risk factors for experiencing executive function impairments in AAD.

Adrenal insufficiency

Adrenal insufficiency (AI) is a condition characterized by an absolute or relative deficiency of adrenal cortisol production. Primary AI (PAI) is rare and is caused by direct adrenal failure. Secondary AI (SAI) is more frequent and is caused by diseases affecting the pituitary, whereas in tertiary AI (TAI), the hypothalamus is affected. The most prevalent form is TAI owing to exogenous glucocorticoid use. Symptoms of AI are non-specific, often overlooked or misdiagnosed, and are related to the lack of cortisol, adrenal androgen precursors and aldosterone (especially in PAI). Diagnosis is based on measurement of the adrenal corticosteroid hormones, their regulatory peptide hormones and stimulation tests. The goal of therapy is to establish a hormone replacement regimen that closely mimics the physiological diurnal cortisol secretion pattern, tailored to the patient's daily needs. This Primer provides insights into the epidemiology, mechanisms and management of AI during pregnancy as well as challenges of long-term management. In addition, the importance of identifying life-threatening adrenal emergencies (acute AI and adrenal crisis) is highlighted and strategies for prevention, which include patient education, glucocorticoid emergency cards and injection kits, are described.

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: growth hormone and corticotropin deficiency

This article presents an overview of adult growth hormone deficiency (AGHD) and corticotropin deficiency (central adrenal failure, CAI). Both conditions can result from various ailments affecting the hypothalamus or pituitary gland (most frequently a tumor in the area or its treatment). Clinical manifestations are subtle in AGHD but potentially life-threatening in CAI. The diagnosis needs dynamic testing in most cases. Treatment of AGHD is recommended in patients with documented severe deficiency, and treatment of CAI is mandatory in all cases. Despite significant progress in replacement hormonal therapy, more physiologic treatments and more reliable indicators of treatment adequacy are still needed.

Applied Healthspan engineering

According to the Homeric Hymn to Aphrodite, when Eos asked Zeus for Tithonus to be granted immortality, she forgot to ask for eternal youth. Applied Healthspan Engineering (AHE) seeks to address this problem. All organisms have a minimal level of functional reserve required to sustain life that eventually declines to a point incompatible with survival at death. AHE seeks to maintain or restore optimal functional reserve of critical tissues and organs. Tissue reserve correlates with well being. Diet, physical exercise, and currently available small-molecule-based therapeutics may attenuate the rate of decline of specific organs or organ systems, but are unlikely to restore lost reserve. Inherent evolutionary-derived limitations in tissue homeostasis and cell maintenance necessitate the development of therapies to enhance regenerative processes and possibly replace whole organs or tissues. AHE supports the study of cell, tissue, and organ homeostatic mechanisms to derive new regenerative and tissue replacement therapies to extend the period of human health.

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.

Genome-wide analysis of DHEA- and DHT-induced gene expression in mouse hypothalamus and hippocampus

Dehydroepiandrosterone (DHEA) is the most abundant steroid in humans and a multi-functional neuroactive steroid that has been implicated in a variety of biological effects in both the periphery and central nervous system. Mechanistic studies of DHEA in the periphery have emphasized its role as a prohormone and those in the brain have focused on effects exerted at cell surface receptors. Recent results demonstrated that DHEA is intrinsically androgenic. It competes with DHT for binding to androgen receptor (AR), induces AR-regulated reporter gene expression in vitro, and exogenous DHEA administration regulates gene expression in peripheral androgen-dependent tissues and LnCAP prostate cancer cells, indicating genomic effects and adding a level of complexity to functional models. The absence of information about the effect of DHEA on gene expression in the CNS is a significant gap in light of continuing clinical interest in the compound as a hormone replacement therapy in older individuals, patients with adrenal insufficiency, and as a treatment that improves sense of well-being, increases libido, relieves depressive symptoms, and serves as a neuroprotective agent. In the present study, ovariectomized CF-1 female mice, an established model for assessing CNS effects of androgens, were treated with DHEA (1mg/day), dihydrotestosterone (DHT, a potent androgen used as a positive control; 0.1mg/day) or vehicle (negative control) for 7 days. The effects of DHEA on gene expression were assessed in two regions of the CNS that are enriched in AR, hypothalamus and hippocampus, using DNA microarray, real-time RT-PCR, and immunohistochemistry. RIA of serum samples assessed treatment effects on circulating levels of major steroids. In hypothalamus, DHEA and DHT significantly up-regulated the gene expression of hypocretin (Hcrt; also called orexin), pro-melanin-concentrating hormone (Pmch), and protein kinase C delta (Prkcd), and down-regulated the expression of deleted in bladder cancer chromosome region candidate 1 (Dbccr1) and chitinase 3-like 3 (Chi3l3). Two-step real-time RT-PCR confirmed changes in the expression of three genes (Pmch, Hcrt and Prkcd) using the same RNA sample employed in the microarray experiment. Immunohistochemistry showed augmentation of prepro-hypocretin (pHcrt) neuropeptide protein expression by DHEA and DHT in hypothalamus, consistent with the localization of orexin neurons. In hippocampus, DHT down-regulated the expression of Prkcd, while DHEA did not have significant effects. RIA results supported the view that DHEA-induced effects were mediated through AR. The current study identified neurogenomic effects of DHEA treatment on a subset of genes directly implicated in the regulation of appetite, energy utilization, alertness, apoptosis, and cell survival. These changes in gene expression in the CNS represent a constellation of effects that may help explain the diverse benefits attributed to replacement therapy with DHEA. The data also provide a new level of detail regarding the genomic mechanism of action of DHEA in the CNS and strongly support a central role for the androgen receptor in the production of these effects. More broadly, the results may be clinically significant because they provide new insights into processes that appear to mediate the diverse CNS effects attributed to DHEA.

Neurobiological and neuropsychiatric effects of dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS)

DHEA and DHEAS are steroids synthesized in human adrenals, but their function is unclear. In addition to adrenal synthesis, evidence also indicates that DHEA and DHEAS are synthesized in the brain, further suggesting a role of these hormones in brain function and development. Despite intensifying research into the biology of DHEA and DHEAS, many questions concerning their mechanisms of action and their potential involvement in neuropsychiatric illnesses remain unanswered. We review and distill the preclinical and clinical data on DHEA and DHEAS, focusing on (i) biological actions and putative mechanisms of action, (ii) differences in endogenous circulating concentrations in normal subjects and patients with neuropsychiatric diseases, and (iii) the therapeutic potential of DHEA in treating these conditions. Biological actions of DHEA and DHEAS include neuroprotection, neurite growth, and antagonistic effects on oxidants and glucocorticoids. Accumulating data suggest abnormal DHEA and/or DHEAS concentrations in several neuropsychiatric conditions. The evidence that DHEA and DHEAS may be fruitful targets for pharmacotherapy in some conditions is reviewed.

Dehydroepiandrosterone supplement increases malate dehydrogenase activity and decreases NADPH-dependent antioxidant enzyme activity in rat hepatocellular carcinogenesis

Beneficial effects of dehydroepiandrosterone (DHEA) supplement on age-associated chronic diseases such as cancer, cardiovascular disease, insulin resistance and diabetes, have been reported. However, its mechanism of action in hepatocellular carcinoma in vivo has not been investigated in detail. We have previously shown that during hepatocellular carcinogenesis, DHEA treatment decreases formation of preneoplastic glutathione S-transferase placental form-positive foci in the liver and has antioxidant effects. Here we aimed to determine the mechanism of actions of DHEA, in comparison to vitamin E, in a chemically-induced hepatocellular carcinoma model in rats. Sprague-Dawley rats were administered with control diet without a carcinogen, diets with 1.5% vitamin E, 0.5% DHEA and both of the compounds with a carcinogen for 6 weeks. The doses were previously reported to have anti-cancer effects in animals without known toxicities. With DHEA treatment, cytosolic malate dehydrogenase activities were significantly increased by ~5 fold and glucose 6-phosphate dehydrogenase activities were decreased by ~25% compared to carcinogen treated group. Activities of Se-glutathione peroxidase in the cytotol was decreased significantly with DHEA treatment, confirming its antioxidative effect. However, liver microsomal cytochrome P-450 content and NADPH-dependent cytochrome P-450 reductase activities were not altered with DHEA treatment. Vitamin E treatment decreased cytosolic Se-glutathione peroxidase activities in accordance with our previous reports. However, vitamin E did not alter glucose 6-phosphate dehydrogenase or malate dehydrogenase activities. Our results suggest that DHEA may have decreased tumor nodule formation and reduced lipid peroxidation as previously reported, possibly by increasing the production of NADPH, a reducing equivalent for NADPH-dependent antioxidant enzymes. DHEA treatment tended to reduce glucose 6-phosphate dehydrogenase activities, which may have resulted in limited supply for de novo synthesis of DNA via inhibiting the hexose monophophaste pathway. Although both DHEA and vitamin E effectively reduced preneoplastic foci in this model, they seemed to function in different mechanisms. In conclusion, DHEA may be used to reduce hepatocellular carcinoma growth by targeting NADPH synthesis, cell proliferation and anti-oxidant enzyme activities during tumor growth.