Novel agents to treat adrenal insufficiency: findings of preclinical and early clinical trials.

INTRODUCTION: Adrenal insufficiency currently affects over 300/million population, with higher morbidity and mortality compared to the general population. Current glucocorticoid replacement therapy is limited by a lack of reliable biomarkers to guide dosing, inter-patient variation in metabolism and narrow therapeutic window. Increased morbidity and mortality may relate to unappreciated under- or over-exposure to glucocorticoids and impaired cortisol circadian rhythm. New agents are required to emulate physiological cortisol secretion and individualize glucocorticoid dosing. AREAS COVERED: History of glucocorticoid therapy, current limitations, and novel chronotherapeutic glucocorticoid delivery mechanisms. Literature search incorporated searches of PubMed and Embase utilizing terms such as adrenal insufficiency, Chronocort, Plenadren, continuous subcutaneous hydrocortisone infusion (CHSI), and glucocorticoid receptor modulator. EXPERT OPINION: Glucocorticoid chronotherapy is necessary to optimize glucocorticoid exposure and minimize complications. Current oral chronotherapeutics provide improved dosing functionality, but are modifiable only in specific increments and cannot accommodate ultradian cortisol variation. Current data show improvement in quality of life but not morbidity or mortality outcomes. CHSI has significant potential for individualized glucocorticoid dosing, but would require a suitable biomarker of glucocorticoid adequacy to be implementable. Avenues for future research include determining a glucocorticoid sufficiency biomarker, development of interstitial or systemic cortisol monitoring, or development of glucocorticoid receptor modulators.

The Hypothalamus-pituitary-adrenocortical Response to Critical Illness: A Concept in Need of Revision.

Based on insights obtained during the past decade, the classical concept of an activated hypothalamus-pituitary-adrenocortical axis in response to critical illness is in need of revision. After a brief central hypothalamus-pituitary-adrenocortical axis activation, the vital maintenance of increased systemic cortisol availability and action in response to critical illness is predominantly driven by peripheral adaptations rather than by an ongoing centrally activated several-fold increased production and secretion of cortisol. Besides the known reduction of cortisol-binding proteins that increases free cortisol, these peripheral responses comprise suppressed cortisol metabolism in liver and kidney, prolonging cortisol half-life, and local alterations in expression of 11ßHSD1, glucocorticoid receptor-α (GRα), and FK506 binding protein 5 (FKBP51) that appear to titrate increased GRα action in vital organs and tissues while reducing GRα action in neutrophils, possibly preventing immune-suppressive off-target effects of increased systemic cortisol availability. Peripherally increased cortisol exerts negative feed-back inhibition at the pituitary level impairing processing of pro-opiomelanocortin into ACTH, thereby reducing ACTH-driven cortisol secretion, whereas ongoing central activation results in increased circulating pro-opiomelanocortin. These alterations seem adaptive and beneficial for the host in the short term. However, as a consequence, patients with prolonged critical illness who require intensive care for weeks or longer may develop a form of central adrenal insufficiency. The new findings supersede earlier concepts such as "relative," as opposed to "absolute," adrenal insufficiency and generalized systemic glucocorticoid resistance in the critically ill. The findings also question the scientific basis for broad implementation of stress dose hydrocortisone treatment of patients suffering from acute septic shock solely based on assumption of cortisol insufficiency.

Adult-born proopiomelanocortin neurons derived from Rax-expressing precursors mitigate the metabolic effects of congenital hypothalamic proopiomelanocortin deficiency.

OBJECTIVE: Proopiomelanocortin (POMC) neurons of the hypothalamic arcuate nucleus are essential regulators of energy balance. Selective loss of POMC production in these cells results in extreme obesity and metabolic comorbidities. Neurogenesis occurs in the adult hypothalamus, but it remains uncertain whether functional POMC neurons emerge in physiologically significant numbers during adulthood. Here, we tested whether Rax-expressing precursors generate POMC neurons in adult mice and rescue the metabolic phenotype caused by congenital hypothalamic POMC deficiency. METHODS: Initially, we identified hypothalamic Rax-expressing cell types using wild-type and Rax-CreERT2:Ai34D mice. Then we generated compound Rax-CreERT2:ArcPomcloxTB/loxTB mice in which endogenous hypothalamic Pomc expression is silenced, but can be restored by tamoxifen administration selectively in neurons derived from Rax+ progenitors. The number of POMC neurons generated by Rax+ progenitors in adult mice and their axonal projections was determined. The metabolic effects of these neurons were assessed by measuring food intake, bodyweight, and body composition, along with glucose and insulin levels. RESULTS: We found that Rax is expressed by tanycytes and a previously unrecognized cell type in the hypothalamic parenchyma of adult mice. Rax+ progenitors generated ~10% of the normal adult hypothalamic POMC neuron population within two weeks of tamoxifen treatment. The same rate and steady state of POMC neurogenesis persisted from young adult to aged mice. These new POMC neurons established terminal projections to brain regions that were involved in energy homeostasis. Mice with Rax+ progenitor-derived POMC neurons had reduced body fat mass, improved glucose tolerance, increased insulin sensitivity, and decreased bodyweight in proportion to the number of new POMC neurons. CONCLUSIONS: These data demonstrate that Rax+ progenitors generate POMC neurons in sufficient numbers during adulthood to mitigate the metabolic abnormalities of hypothalamic POMC-deficient mice. The findings suggest that adult hypothalamic neurogenesis is a robust phenomenon in mice that can significantly impact energy homeostasis.

Latent Adrenal Insufficiency: Concept, Clues to Detection, and Diagnosis.

In 1855, Thomas Addison described an illness now known as Addison disease (AD) caused by damage to the adrenal cortex and manifesting in weakness, weight loss, hypotension, gastrointestinal disturbances, and brownish pigmentation of the skin and mucous membranes. Corticosteroid supplementation, corticotropin (adrenocorticotropic hormone [ACTH] of medicinal use) test, and anti-adrenal auto-antibodies (AA) have come into use in the 100 years since Addison's death. Following the methodological innovations, 4 disorders which share impaired response to corticotropin in common have been discovered (i.e., partial AD, apigmented adrenal insufficiency [AI], subclinical AI, and the AA-positive state exclusively in subjects proven to have an impaired response to corticotropin). As they are hidden, potentially serious conditions, these disorders are bound together as latent AI (LAI). Diagnosis of AD is often delayed, which may lead to adrenal crisis. If LAI were widely recognized, such delays would not exist and crises would be averted. The 3 existing guidelines do not refer much to LAI patients outside those in acute situations. To address this, information relevant to clinical manifestations and diagnostic tests of LAI was sought in the literature. Signs and symptoms that are useful clues to begin a diagnostic workup are presented for endocrinologists to identify patients with suspected LAI. The utility of 2 corticotropin test protocols is reviewed. To endorse LAI shown by the corticotropin test, monitoring items following corticosteroid supplementation are cited from the guidelines and supplemented with the author's observations. ABBREVIATIONS: AA = anti-adrenal auto-antibodies; Ab = antibodies; ACA = AA detected by immunofluorescence; ACTH = adrenocorticotropic hormone; AD = Addison disease; AI = adrenal insufficiency; DHEA = dehydroepiandrosterone; GC = glucocorticoid; IFA = immunofluorescence assay; LAI = latent AI; LDT = low-dose test; MC = mineralocorticoid; 21OHAb = anti-21-hydroxylase Ab; ST = standard test; URI = upper respiratory infection.

Hypothalamic-specific proopiomelanocortin deficiency reduces alcohol drinking in male and female mice.

Opioid receptor antagonist naltrexone reduces alcohol consumption and relapse in both humans and rodents. This study investigated whether hypothalamic proopiomelanocortin (POMC) neurons (producing beta-endorphin and melanocortins) play a role in alcohol drinking behaviors. Both male and female mice with targeted deletion of two neuronal Pomc enhancers nPE1 and nPE2 (nPE-/-), resulting in hypothalamic-specific POMC deficiency, were studied in short-access (4-h/day) drinking-in-the-dark (DID, alcohol in one bottle, intermittent access (IA, 24-h cycles of alcohol access every other day, alcohol vs. water in a two-bottle choice) and alcohol deprivation effect (ADE) models. Wild-type nPE+/+ exposed to 1-week DID rapidly established stable alcohol drinking behavior with more intake in females, whereas nPE-/- mice of both sexes had less intake and less preference. Although nPE-/- showed less saccharin intake and preference than nPE+/+, there was no genotype difference in sucrose intake or preference in the DID paradigm. After 3-week IA, nPE+/+ gradually escalated to high alcohol intake and preference, with more intake in females, whereas nPE-/- showed less escalation. Pharmacological blockade of mu-opioid receptors with naltrexone reduced intake in nPE+/+ in a dose-dependent manner, but had blunted effects in nPE-/- of both sexes. When alcohol was presented again after 1-week abstinence from IA, nPE+/+ of both sexes displayed significant increases in alcohol intake (ADE or relapse-like drinking), with more pronounced ADE in females, whereas nPE-/- did not show ADE in either sex. Our results suggest that neuronal POMC is involved in modulation of alcohol 'binge' drinking, escalation and 'relapse', probably via hypothalamic-mediated mechanisms, with sex differences.

Global and Targeted Metabolomics Evidence of the Protective Effect of Chinese Patent Medicine Jinkui Shenqi Pill on Adrenal Insufficiency after Acute Glucocorticoid Withdrawal in Rats.

Glucocorticoids are commonly used in anti-inflammatory and immunomodulatory therapies, but glucocorticoid withdrawal can result in life-threatening risk of adrenal insufficiency. Chinese patented pharmaceutical product Jinkui Shenqi pill (JKSQ) has potent efficacy on clinical adrenal insufficiency resulting from glucocorticoid withdrawal. However, the underlying molecular mechanism remains unclear. We used an animal model to study JKSQ-induced metabolic changes under adrenal insufficiency and healthy conditions. Sprague-Dawley rats were treated with hydrocortisone for 7 days with or without 15 days of JKSQ pretreatment. Sera were collected after 72 h hydrocortisone withdrawal and used for global and free fatty acids (FFAs)-targeted metabolomics analyses using gas chromatography/time-of-flight mass spectrometry and ultraperformance liquid chromatography/quadruple time-of-flight mass spectrometry. Rats without hydrocortisone treatment were used as controls. JKSQ pretreatment normalized the significant changes of 13 serum metabolites in hydrocortisone-withdrawal rats, involving carbohydrates, lipids, and amino acids. The most prominent effect of JKSQ was on the changes of FFAs and some [product FFA]/[precursor FFA] ratios, which represent estimated desaturase and elongase activities. The opposite metabolic responses of JKSQ in adrenal insufficiency rats and normal rats highlighted the "Bian Zheng Lun Zhi" (treatment based on ZHENG differentiation) guideline of TCM and suggested that altered fatty acid metabolism was associated with adrenal insufficiency after glucocorticoid withdrawal and the protective effects of JKSQ.

Different cut-off values of the insulin tolerance test, the high-dose short Synacthen test (250 µg) and the low-dose short Synacthen test (1 µg) in assessing central adrenal insufficiency.

OBJECTIVE: The short Synacthen test (SST) is widely used as alternative test to the insulin tolerance test (ITT) to investigate central adrenal insufficiency (CAI), but the methodology and cut-off values of the SST are controversial. Our aim was to evaluate the cut-off value of the ITT in normal subjects and to assess the different cut-off values of the high-dose SST (250 µg, HDT) and the low-dose SST (1 µg, LDT) in subjects with suspected CAI. SUBJECTS AND METHODS: We conducted ITTs in 208 normal subjects to establish the cut-off value for the ITT, and 28 of those subjects underwent the HDT and LDT. From 1999 to 2007, 182 patients with suspected CAI were recruited and underwent ITTs, LDTs and HDTs to establish cut-off values and compare the diagnostic accuracy between the LDT and HDT. RESULTS: The 95th percentile of the peak cortisol level during the ITT in the normal control subjects was 14·8 µg/dl. Receiver operator characteristics (ROC) analysis revealed that the optimal cut-off values of peak cortisol in the LDT and HDT in patients with suspected CAI were 15·8 and 17·4 µg/dl, respectively. However, the cut-off values from normative data (mean - 2 SD) were 18·3 µg/dl for the LDT and 20·5 µg/dl for the HDT in normal control. CONCLUSIONS: The optimal cut-off values of SSTs needed to be individualized according to the type of SST and tested patient population.

Diagnosis of secondary adrenal insufficiency in patients with hypothalamic-pituitary disease: comparison between serum and salivary cortisol during the high-dose short synacthen test.

OBJECTIVE: Accurate assessment of adrenal function is essential in patients with hypothalamic-pituitary-adrenal (HPA) disease. The measurement of salivary cortisol (SaC) instead of serum cortisol (SeC) offers several advantages, such as the determination of the free hormone. We evaluated the diagnostic value of SeC and SaC both unstimulated and during a high-dose short synacthen test (HDT) in comparison to the insulin tolerance test (ITT). DESIGN: Comparative study between 2005 and 2007. METHODS: Fifty-five patients with HPA impairment and 21 healthy controls were enrolled. Samples were collected in the early morning and over 120 min during the HDT. Receiver operating characteristic analysis revealed individual thresholds for four HDT periods (0-30, 0-60, 0-90, and 0-120 min). RESULTS: The ITT identified 30 subjects as adrenal insufficient. With respect to the four HDT periods, sensitivity and specificity were 67-79% and 71-88% for SeC, compared with 63-72% and 72-86% for SaC. If upper and lower thresholds (with specificities >95%) were applied, patients were diagnosed in 40-45% by SeC and in 25-31% by SaC. The combination of basal cortisol and HDT allowed a diagnosis in 47-49% (SeC) and in 42-45% (SaC) respectively. CONCLUSION: We suggest the determination of basal SeC or SaC as first-line test. In comparison to the ITT, the HDT has only limited value in screening for alterations of the HPA axis. If the HDT is performed, sampling may be limited to 30 min post-synacthen, using either SeC or SaC. Due to the ease of collection and the independence of binding proteins, SaC may be preferable.

[Adrenopause]. / Adrenopauza.

The hypothalamic-pituitary-adrenal axis activity in the aging people is characterised by an unexplained reduction of dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) secretion while ACTH and cortisol production remains relatively unchanged. This decline in the biological activity of the zona reticularis, referred to as 'adrenopause', may contribute to the physiology of human aging. The reduced endogenous concentrations of DHEA and DHEAS found in advancing age have been correlated with a constellation of health problems. Because these steroids seem to play a role in the maintenance of immunity, musculoskeletal integrity, and cardiovascular health, age-associated declines in adrenal androgen production may lead to decreased immune function, osteoporosis, and atherosclerosis. Despite clear benefits of DHEA administration in patients with adrenal insufficiency, the results of DHEA supplementation in healthy euadrenal subjects are not so clear-cut. Studies assessing its action on sexual function, metabolism and cardiovascular functions have provided conflicting results. This paper summarises the present state of knowledge on the age-related changes in adrenal androgen production and discusses pros and cons of DHEA use in older people.

The effect of synacthen on acute necrotizing pancreatitis in rats.

OBJECTIVES: This study investigates the hypothesis that an adrenocorticotropic hormone-analog therapy may ameliorate relative adrenal insufficiency in the early phase of acute necrotizing pancreatitis (NP) by boosting endogenous glucocorticoid production. METHODS: Forty Wistar rats with taurocholate-induced NP were divided into 5 groups: the first group received low-dose Synacthen (0.5 mg/kg); the second, high-dose Synacthen (5mg/kg); the third,low-dose cortisol (10 mg/kg); the fourth, high-dose cortisol (100 mg/kg); and the fifth, the control group, received no treatment. All animals were killed after 6 hours: concentrations of plasma corticosterone, interleukin 1 (IL-1), IL-6, IL-10, tumor necrosis factor alpha, amylase, and lipase in ascites, myeloperoxidase activity in the pancreas, and a histological score were evaluated. RESULTS: Corticosterone increased neither in the low-dose nor in the high-dose Synacthen group. Synacthen did not improve the early course of NP in terms of laboratory and histological results. A reduction of pancreatic necrosis and inflammation was observed in the low-dose cortisol group. CONCLUSIONS: Endogenous glucocorticoid release seemed to be at its maximum during the early stage of NP and could not be further increased by Synacthen. Low-dose exogenous cortisol ameliorated the disease. These findings support the existence of relative adrenal insufficiency in the early phase of acute NP.

Effects of dehydroepiandrosterone (DHEA) supplementation on hormonal, metabolic and behavioral status in patients with hypoadrenalism.

Oral DHEA administration to patients with hypoadrenalism, in addition to glucocorticoid and mineralcorticoid replacement, may improve both well-being and hormonal/metabolic parameters. Twenty patients (13 men, 7 women, 26-76 yr, 11 with Addison's disease, 9 with central hypoadrenalism) were recruited in a placebo-controlled, randomized study. Hormone levels, carbohydrate and lipid parameters, bone metabolism, body composition and psychological parameters were evaluated at baseline and after treatment with DHEA 50 mg/day or placebo for 4 months. After 4 months of DHEA administration, serum DHEAS levels raised both in men (from 0.71+/-0.18 to 8.28+/-1.66 micropmol/l, p<0.005) and in women (from 0.25+/-0.07 to 5.65+/-1.93 micromol/l, p<0.05). Only in hypoadrenal women an increase in testosterone (T; from 0.4+/-0.1 to 1.45+/-0.26 nmol/l, p<0.05) and androstenedione (A; from 0.86+/-0.34 to 2.05+/-0.29 nmol/l, p<0.05) levels was observed. In men no significant modifications in T and 17-hydroxyprogesterone (17-OHP) levels were found, whereas serum SHBG significantly decreased. As far as the metabolic parameters are concerned, only in patients with Addison's disease a significant decrease in total cholesterol and in low-density lipoproteins after 4 months of DHEA administration was found. No changes in glucose metabolism and insulin sensitivity were observed. In basal conditions, mean serum osteocalcin (OC) was normal and significantly decreased after DHEA treatment. A significant reduction in body fat mass percentage (BF%) after DHEA administration was observed. As far as well-being is concerned, DHEA replacement did not cause any relevant variation of subjective health scales and sexuality in both sexes. Our study confirms that DHEA may be beneficial for female patients with hypoadrenalism, mainly in restoring androgen levels. Concerning the health status, more sensitive and specific instruments to measure the effects of DHEA treatment could be necessary.

[Effect of glutamic acid on the course of recovery processes in the adrenal cortex]. / Vliianie glutaminovoi kisloty na techenie vosstanovitel'nykh protsessov v kore nadpochechnikov.

Glutamic acid in a dose of 1/100 of the LD50 was injected in the form of sodium salt into male and female Wistar rats for 7 days after 8- and 12-day injections of dexazone. During the first 3 days of injections, female rats received a low dexazone dose (5 micrograms/100 g bw). Injection of glutamic acid in conjunction with dexazone reduced the inhibitory effect of the latter drug on the adrenals but did not avert its inhibitory effect on the central nervous system. Prolonged injections of glutamic acid after dexazone treatment promoted more rapid and more complete recovery of adrenal function.