The long-term ingestion of alcohol diminishes hypothalamic–pituitary–adrenal (HPA) axis reactivity in alcohol-dependent men, potentially altering future relapse risk. Although sex differences in HPA axis functioning are apparent in healthy controls, disruptions in this system have received little attention in alcohol-dependent women. In this study, we assessed the basal secretory profile of adrenocorticotropic hormone (ACTH) and cortisol, adrenocortical sensitivity in both the presence and absence of endogenous corticotropic pituitary activation, and feedback pituitary glucocorticoid sensitivity to dexamethasone.
Seven women 4- to 8-week abstinent alcohol-only dependent subjects and 10 age-matched female healthy controls were studied. All subjects were between 30 and 50 years old, not taking oral contraceptives, and were studied during the early follicular phase of their menstrual cycle. Circulating concentrations of ACTH and cortisol were measured in blood samples collected at frequent intervals from 2000 to 0800 hour. A submaximal dose of cosyntropin (0.01 μg/kg), a synthetic ACTH (1–24), was administered at 0800 hour to assess adrenocortical sensitivity. In a separate session, low-dose cosyntropin was also administered following high-dose dexamethasone (8 mg intravenous) to assess adrenocortical sensitivity in the relative absence of endogenous ACTH. In addition, the ACTH response to dexamethasone was measured to determine the pituitary glucocorticoid negative feedback. Sessions were 5 days apart, and blood draws were obtained every 5 to 10 minutes.
Mean concentrations and pulsatile characteristics of ACTH and cortisol over 12 hours were not statistically different between the 2 groups. Healthy controls had a somewhat higher (p < 0.08) net peak, but not net integrated, cortisol response to cosyntropin relative to the alcohol-dependent women. There were no significant group differences in either the ACTH or cortisol response to dexamethasone nor in the net cortisol response to cosyntropin following dexamethasone.
Significant differences in pituitary–adrenal function were not apparent between alcohol-dependent women and matched controls. Despite the small n, it appears that alcohol-dependent women do not show the same disruptions in HPA activity as alcohol-dependent men. These findings may have relevance for gender-specific treatment effectiveness.
Adrenal Cortex; Alcoholism; Cosyntropin; Dexamethasone; Pituitary-Adrenal System; Gender; Female
ACTH secretion is under hypothalamic stimulatory (feedforward) and adrenal inhibitory (feedback) control.
Assessment of overnight ACTH secretion during a hypocortisolemic clamp will permit the estimation of changing feedforward and feedback.
Seven healthy men.
An oral dose of placebo (PLAC), metyrapone (METY, 3 g), or ketoconazole (KTCZ, 1.2 g) was given at midnight (MN) to block glucocorticoid synthesis. Plasma ACTH was sampled every 10 min (MN to 0800 h).
Variable-waveform deconvolution analysis of ACTH secretion and approximate entropy (ApEn) analysis of pattern regularity.
Compared with PLAC, administration of METY and KTCZ reduced morning cortisol concentrations by ≥77 and 54% respectively (P<0.001). Hypocortisolemia elevated pulsatile ACTH secretion by 8.2- (METY) and 5.3-fold (KTCZ; both P<0.001). Basal ACTH secretion rose by 3.4-fold under METY-induced cortisol depletion (P = 0.020). ACTH secretory-burst shape and half-life were stable. ApEn of ACTH release declined overnight (P = 0.021) and with the drug (P = 0.001), denoting enhanced feedforward coordination.
The combined data predict overnight amplification and coordination of hypothalamic feedforward drive onto ACTH release. Therefore, disruption of either mechanism might contribute to clinical pathophysiology, such as late-day elevations of cortisol output in fasting, alcoholism, depression, or aging.
To test 3 theories of hypercortisolemia in depression – hypothalamic overdrive, impaired glucocorticoid feedback, or autonomous cortisol production.
We applied an overnight low cortisol feedback strategy by administering metyrapone to hypercortisolemic depressed inpatients and control subjects.
Under metyrapone, the increases of plasma ACTH concentrations and of basal and pulsatile ACTH secretion were not exaggerated in hypercortisolemic depressed patients compared with control subjects. ACTH approximate entropy (ApEn) did not differ at baseline or under metyrapone. Thus, neither hypothalamic overdrive nor irregular ACTH secretion was seen. We did not detect impaired cortisol feedback: the ACTH response was not reduced, and ApEn measures that are sensitive to feedback changes were comparable in both groups. Metyrapone disrupted cortisol secretory regularity in depressed and control subjects. On the baseline day, basal cortisol secretion was significantly increased and was highly irregular (high ApEn), and ACTH-cortisol cross-ApEn was markedly elevated in high-cortisol patients.
Classical feed forward overdrive and impaired feedback theories of hypercortisolemia in depression were not supported. Depressive hypercortisolemia may result from alternative pathophysiological mechanisms involving irregular basal hypersecretion of cortisol, associated with adrenal enlargement, possibly through splanchnic sympathetic activation of the adrenal cortex.
Adrenocorticotropic hormone; approximate entropy; cortisol; deconvolution; depressive disorder; major; feedback; physiological; metyrapone
To estimate the dose-dependence of endogenous ACTH’s stimulation of adrenal cortisol secretion overnight.
Ten-minute sampling for ACTH and cortisol over 8 and 24 hr (N=17), after metyrapone administration (N=6), during an insulin tolerance test (N=7).
ACTH dose-responsive estimates.
Twenty-four hr ACTH-cortisol concentration pairs yielded an estimated EC50 (one-half maximally stimulatory ACTH concentration) of 5.1 (2.2–9.5) pmol/L [median (range)]. This did not differ from EC50’s based upon 8 or 6-hr data [5.9 (3.5–11) and 7.5 (3.7–41) pmol/L] in the same individuals. ACTH efficacy (maximally stimulatable cortisol secretion rate) was 8.4 (3.1–20), 11 (5.9–24) and 15 (5.9–22) nmol/L/min, when calculated over 24, 8 and 6 hr, respectively (P=NS). Adrenal sensitivity (slope term) was also consistent across sampling durations, viz., 14 (1.3–95), 18 (1.3–64) and 20 (1.3–64) slope units. Compared with placebo, metyrapone reduced ACTH efficacy from 11 (6.2–62) to 2.8 (1.5–4.5) nmol/L/min for cortisol (N=9, P<0.001), while increasing ACTH efficacy for 11-desoxycortisol from 2.3 (0.9–2.9) to 99 (70–218) nmol/L/min (N=6, P<0.01), thus affirming face validity. Combined ACTH and cortisol responses to hypoglycemia allowed an estimate of ACTH efficacy of 28 (22–81) nmol/L/min, compared with the control value of 8.7 (5.6–26), suggesting enhanced adrenal responsiveness.
The results suggest that endogenous ACTH-adrenal drive can be approximated from overnight 8-hr sampling of paired ACTH and cortisol concentrations. This strategy may have merit in clinical research in childhood, pregnancy, anxiety states, and frail elderly individuals, when ACTH injections are not desired.
corticotropic; feedback; human; adrenal
Autism is a disorder of early childhood characterized by social impairment, communication abnormalities and stereotyped behaviors. The hypothalamic-pituitary-adrenocortical (HPA) axis deserves special attention, since it is the basis for emotions and social interactions that are affected in autism.
To assess basal and stimulated plasma cortisol, and adrenocorticotropic hormone (ACTH) levels in autistic children and their relationship to disease characteristics.
Fifty autistic children were studied in comparison to 50 healthy age-, sex- and pubertal stage- matched children. All subjects were subjected to clinical evaluation and measurement of plasma cortisol (basal and stimulated) and ACTH. In addition, electroencephalography (EEG) and intelligence quotient (IQ) assessment were done for all autistic children.
Sixteen% of autistic patients had high ACTH, 10% had low basal cortisol and 10% did not show adequate cortisol response to ACTH stimulation. Autistic patients had lower basal (p = 0.032) and stimulated cortisol (p = 0.04) and higher ACTH (p = 0.01) than controls. Childhood Autism Rating Scale (CARS) score correlated positively with ACTH (r = 0.71, p = 0.02) and negatively with each of basal (r = -0.64, p = 0.04) and stimulated cortisol (r = -0.88, p < 0.001). Hormonal profile did not differ in relation to EEG abnormalities, IQ and self- aggressive symptoms.
The observed hormonal changes may be due to a dysfunction in the HPA axis in autistic individuals. Further studies are warranted regarding the role of HPA axis dysfunction in the pathogenesis of autism.
Available clinical data raise the possibility that stress-adaptive mechanisms differ by gender. However, this notion has not been rigorously tested in relation to cortisol-mediated negative feedback.
Degree of ACTH inhibition during and recovery from an experimental cortisol clamp was tested in 20 healthy older subjects (age 60 ± 2.2 y). Volunteers received oral placebo or ketoconazole (KTCZ) to inhibit adrenal steroidogenesis along with i.v. infusions of saline or a low vs high physiological dose of cortisol in a prospectively randomized double-blind, placebo-controlled design. ACTH and cortisol concentrations were measured every 10 min during the feedback-clamp phase and thereafter (recovery or escape phase). Corticosteroid-binding globulin (CBG) was measured, and free cortisol concentrations were calculated.
Gender did not determine mean ACTH concentrations during the saline or cortisol feedback-clamp phases per se. However, women had markedly impaired ACTH recovery after stopping both low- and high-dose cortisol infusions compared with men (P = 0.005, KTCZ/low-dose cortisol arm; and P = 0.006, KTCZ/high-dose cortisol arm). Decreased ACTH recovery in women was accompanied by lower total and free cortisol concentrations, pointing to heightened feedback inhibition of hypothalamo-pituitary drive of ACTH secretion as the main mechanism.
In summary, gender or a factor related to gender, such as sex steroids or body composition, determines recovery of ACTH secretion from cortisol-enforced negative feedback. Attenuated ACTH recovery in post-menopausal women may have relevance to sex differences in stress-related adaptations.
Aging; Feedback; Cortisol; Human
Both opioid antagonist administration and cigarette smoking acutely increase hypothalamic-pituitary-adrenal (HPA) axis activity as measured by adrenocorticotropic hormone (ACTH) and cortisol levels. However, male and female smokers may differ in their response to the opioid antagonist naltrexone, which may be partially mediated by sex differences in HPA axis function. Smokers, as a group, have frequently been shown to have HPA axis dysfunction, which may have relevance to the course and maintenance of nicotine dependence. The purpose of this study was to examine possible sex differences in HPA axis function by comparing stress-hormone response to naltrexone within healthy male and female smokers. Additionally, exploratory analyses compared the combined effects of naltrexone and cigarette smoking on hormonal responsivity between the sexes.
Thirty-eight healthy smokers (22 men) were tested in two separate morning sessions after 12 hours of smoking abstinence. For women, self reports of menstrual cycle information were obtained prior to each session (date of last menstruation, cycle length, reproductive phase, etc.). Each participant received 50 mg naltrexone or placebo capsule (in random order) and plasma levels of ACTH and cortisol were assessed at regular intervals for several hours. A subgroup of twelve participants underwent a similar, additional session in which they smoked a single cigarette three hours after naltrexone administration.
Naltrexone significantly increased ACTH and cortisol levels in women, but not men (Drug*Sex*Time, p<0.05). A post hoc analysis suggested that women at an estimated ‘high estrogen’ phase had a greater cortisol response (Dose*Estrogen Level, p<0.05) than those at an estimated ‘low estrogen’ phase. Exploratory analyses showed that smoking a single cigarette potentiated naltrexone-induced increases in ACTH (p<0.05) and cortisol (p<0.01) in all participants.
The findings support the hypothesis that women are more sensitive to opioid antagonism at the level of the HPA axis. Although further studies are needed to examine mechanisms underlying these responses, both results may have clinical implications for the use of naltrexone as a treatment for nicotine dependence.
hypothalamic-pituitary-adrenal (HPA) axis; ACTH; cortisol; naltrexone; cigarette smoking; sex differences
Hypercortisolism as a sign of hypothamamus-pituitary-adrenocortical (HPA) axis overactivity and sleep EEG changes are frequently observed in depression. Closely related to the HPA axis is the renin-angiotensin-aldosterone system (RAAS) as 1. adrenocorticotropic hormone (ACTH) is a common stimulus for cortisol and aldosterone, 2. cortisol release is suppressed by mineralocorticoid receptor (MR) agonists 3. angiotensin II (ATII) releases CRH and vasopressin from the hypothalamus. Furthermore renin and aldosterone secretion are synchronized to the rapid eyed movement (REM)-nonREM cycle.
Here we focus on the difference of sleep related activity of the RAAS between depressed patients and healthy controls. We studied the nocturnal plasma concentration of ACTH, cortisol, renin and aldosterone, and sleep EEG in 7 medication free patients with depression (1 male, 6 females, age: (mean +/-SD) 53.3 ± 14.4 yr.) and 7 age matched controls (2 males, 5 females, age: 54.7 ± 19.5 yr.). After one night of accommodation a polysomnography was performed between 23.00 h and 7.00 h. During examination nights blood samples were taken every 20 min between 23.00 h and 7.00 h. Area under the curve (AUC) for the hormones separated for the halves of the night (23.00 h to 3.00 h and 3.00 h to 7.00 h) were used for statistical analysis, with analysis of co variance being performed with age as a covariate.
No differences in ACTH and renin concentrations were found. For cortisol, a trend to an increase was found in the first half of the night in patients compared to controls (p < 0.06). Aldosterone was largely increased in the first (p < 0.05) and second (p < 0.01) half of the night. Cross correlations between hormone concentrations revealed that in contrast to earlier findings, which included only male subjects, in our primarily female sample, renin and aldosterone secretion were not coupled and no difference between patients and controls could be found, suggesting a gender difference in RAAS regulation. No difference in conventional sleep EEG parameters were found in our sample.
Hyperaldosteronism could be a sensitive marker for depression. Further our findings point to an altered renal mineralocorticoid sensitivity in patients with depression.
Metabolic syndrome (MetS) is characterized by central obesity, hypertension, insulin resistance, and hypercholesterolemia. Hypothalamic-pituitary-adrenal (HPA) axis activity is frequently abnormal in MetS, and excessive cortisol exposure may be implicated in metabolic derangements. We investigated the hypothesis that cortisol and adrenocorticotropic hormone (ACTH) responses to a standardized neuroendocrine challenge test would be associated with indices of MetS in a community sample of healthy adults. Healthy adults, 125 men and 170 women, without significant medical problems or chronic medications were recruited from the community. Participants completed the dexamethasone/corticotropin-releasing hormone (Dex/CRH) test, and anthropometric measurements, blood pressure, glycosylated hemoglobin (HbA1c), and cholesterol were measured. Participants reported on their history of early life stress and recent stress, as well as mood and anxiety symptoms. Cortisol and ACTH responses to the Dex/CRH test were negatively associated with measures of central adiposity (p < 0.001) and blood pressure (p < 0.01), and positively associated with HDL cholesterol (p < 0.01). These findings remained significant after controlling for body mass index (BMI). Measures of stress and anxiety and depressive symptoms were negatively correlated with cortisol and ACTH responses in the Dex/CRH test but were not related to MetS indices. That altered HPA axis function is linked to MetS components even in a healthy community sample suggests that these processes may be involved in the pathogenesis of MetS. Identification of premorbid risk processes might allow for detection and intervention prior to the development of disease.
metabolic syndrome; HPA axis; cortisol; ACTH; corticotrophin-releasing hormone
Corticotropin-releasing hormone (CRH), through the hypothalamic pituitary adrenal (HPA) axis and other brain stress systems, is involved in the emotional dysregulation associated with cocaine dependence. Little is known about the response of cocaine-dependent individuals to CRH administration.
The primary objective was to examine the HPA axis, subjective and physiologic response to CRH in cocaine-dependent individuals and controls.
Subjects were admitted to a General Clinical Research Center (GCRC) for testing and abstinence verified with urine drug screening.
Participants were control males (n=23), control females (n=24), cocaine-dependent males (n=28), and cocaine-dependent females (n=25). Individuals with dependence on other substances (except caffeine, nicotine) or with major depression, PTSD, bipolar, psychotic and eating disorders were excluded.
Subjects received i.v. CRH (1ug/kg).
Main Outcome Measures
Primary outcomes included plasma ACTH and cortisol, heart rate, and subjective measurements.
Cocaine-dependent individuals exhibited higher stress (P < 0.001) and craving to CRH compared to controls. A positive correlation (rs=.51, P=0.0002) between stress and craving was found in cocaine dependent subjects. CRH elevated heart rates in all groups, however cocaine dependent females, demonstrated a significantly higher heart rate at all time points (P=0.05). Women had higher cortisol response to CRH (P=0.028). No effect of cocaine status was observed. ACTH response to CRH was independent of gender and cocaine. Cortisol and ACTH were positively correlated in the controls and cocaine-dependent males, but not in cocaine-dependent females (rs = 0.199; P = 0.4).
There is an increased subjective and heart rate response to CRH and a relationship between stress and craving in cocaine-dependent individuals. The lack of difference in HPA axis response between the cocaine and control groups suggests that the heart rate and subjective responses in the cocaine group may be mediated by sensitization of non-hypothalamic stress-responsive CRH systems.
A dynamic systems model was used to generate parameters describing a phenotype of Hypothalamic–Pituitary–Adrenal (HPA) behavior in a sample of 36 patients with chronic fatigue syndrome (CFS) and/ or fibromyalgia (FM) and 36 case-matched healthy controls. Altered neuroendocrine function, particularly in relation to somatic symptoms and poor sleep quality, may contribute to the pathophysiology of these disorders. Blood plasma was assayed for cortisol and ACTH every 10 min for 24 h. The dynamic model was specified with an ordinary differential equation using three parameters: (1) ACTH-adrenal signaling, (2) inhibitory feedback, and (3) non-ACTH influences. The model was ‘‘personalized’’ by estimating an individualized set of parameters from each participant’s data. Day and nighttime parameters were assessed separately. Two nocturnal parameters (ACTH-adrenal signaling and inhibitory feedback) significantly differentiated the two patient subgroups (“fatigue-predominant” patients with CFS only versus ‘‘pain-predominant’’ patients with FM and comorbid chronic fatigue) from controls (allp’s < .05), whereas daytime parameters and diurnal/nocturnal slopes did not. The same nocturnal parameters were significantly associated with somatic symptoms among patients (p’s < .05). There was a significantly different pattern of association between nocturnal non-ACTH influences and sleep quality among patients versus controls (p < .05). Although speculative, the finding that patient somatic symptoms decreased when more cortisol was produced per unit ACTH, is consistent with cortisol’s anti-inflammatory and sleep-modulatory effects. Patients’ HPA systems may compensate by promoting more rapid or sustained cortisol production. Mapping “behavioral phenotypes” of stress–arousal systems onto symptom clusters may help disentangle the pathophysiology of complex disorders with frequent comorbidity.
Psychoneuroendocrinology; Stress–arousal; Cortisol; Glucocorticoid resistance; Feedback sensitivity; Dynamical systems; Systems medicine; Personalized medicine; Sleep quality; Somatic symptoms; Functional somatic disorders; Fibromyalgia; Chronic fatigue syndrome
Clinical and preclinical studies indicate that maternal stress during pregnancy may exert long-lasting adverse effects on offspring. This investigation sought to identify factors mediating the relationship between maternal and neonatal hypothalamic–pituitary–adrenal (HPA) axes in pregnant women with past or family psychiatric history.
Two hundred and five pairs of maternal and umbilical cord blood samples from a clinical population were collected at delivery.
Maternal and neonatal HPA axis activity measures were plasma adrenocorticotrophic hormone (ACTH), total cortisol, free cortisol and cortisol-binding globulin concentrations. The effects of maternal race, age, body mass index, psychiatric diagnosis (DSM-IV), birth weight, delivery method and estimated gestational age (EGA) at delivery on both maternal and neonatal HPA axis measures were also examined. Incorporating these independent predictors as covariates where necessary, we evaluated whether neonatal HPA axis activity measures could be predicted by the same maternal measure using linear regression.
Delivery method was associated with umbilical cord plasma ACTH and both total and free cord cortisol concentrations (T = 10·53–4·21; P < 0·0001–0·010). After accounting for method of delivery and EGA, we found that maternal plasma ACTH concentrations predicted 23·9% of the variance in foetal plasma ACTH concentrations (T = 6·76; P < 0·0001), and maternal free and total plasma cortisol concentrations predicted 39·8% and 32·3% of the variance in foetal plasma free and total cortisol concentrations (T = 5·37–6·90; P < 0·0001), respectively.
These data suggest that neonatal response is coupled with maternal HPA axis activity at delivery. Future investigations will scrutinize the potential long-term sequelae for the offspring.
Objective: To assess basal function and responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis in patients with ankylosing spondylitis during dynamic testing.
Methods: Insulin induced hypoglycaemia (IIH) (Actrapid HM 0.1 IU/kg, as intravenous bolus) was induced in 17 patients and 11 healthy controls matched for age, sex, and body mass index. Concentrations of glucose, adrenocorticotrophic hormone (ACTH), cortisol, insulin, dehydroepiandrosterone sulphate (DHEAS), 17α-hydroxyprogesterone, interleukin 6 (IL-6), and tumour necrosis factor α (TNFα) were determined in plasma.
Results: Comparable basal cortisol levels were found in the two groups, with a trend to be lower in ankylosing spondylitis. In the ankylosing spondylitis group, there were higher concentrations of IL-6 (mean (SEM): 16.6 (2.8) pg/ml v 1.41 (0.66) pg/ml in controls; p<0.001) and TNFα (8.5 (1.74) pg/ml v 4.08 (0.42) pg/ml in controls; p<0.01). Glucose, insulin, ACTH, DHEAS, and 17α-hydroxyprogesterone did not differ significantly from control. The IIH test was carried out successfully in 11 of the 17 patients with ankylosing spondylitis, and the ACTH and cortisol responses were comparable with control. General linear modelling showed a different course of glycaemia (p = 0.041) in the ankylosing spondylitis patients who met the criteria for a successful IIH test compared with the controls.
Conclusions: The results suggest there is no difference in basal HPA axis activity and completely preserved responsiveness of the HPA axis in patients with ankylosing spondylitis. The interpretation of the different course of glycaemia during IIH in ankylosing spondylitis requires further investigation.
Background: A study was undertaken to assess the function of the hypothalamic-pituitary-adrenal axis (HPA) in a group of asthmatic children before and after treatment with inhaled corticosteroids.
Methods: Thirty prepubertal patients of mean (SD) age 6.7 (1.8) years were treated with inhaled corticosteroids. All children underwent a corticotrophin releasing hormone (CRH) test with evaluation of serum cortisol and adrenocorticotrophin hormone (ACTH) levels before and after 3 months of treatment. Twenty four hour urine samples were also collected to measure free cortisol (UFC) excretion.
Results: Subjects showed no difference between basal serum cortisol levels (mean change –18; 95% CI –41 to 5; p=0.118) and delta (peak minus basal) levels (mean change –13; 95% CI –38 to 12; p=0.308) before and after treatment, whereas the peak cortisol level (mean change –31; 95% CI –55 to –7; p=0.013) and area under the curve (AUC) (mean change –175; 95% CI –288 to –63; p=0.003) after CRH were significantly lower following treatment. Basal, peak and AUC ACTH were significantly lower after treatment (p<0.05, p=0.004 and p=0.003, respectively), while delta ACTH was similar before and after treatment ((mean change –12; 95% CI – 31 to –7; p=0.199). No significant reduction in 24 hour UFC was observed after the treatment period (before 14.9 (7.1), after 15.0 (11.6); mean change 0.1, 95% CI –5.2 to 5.4; p=0.967). No correlation was found between UFC and any of the parameters of cortisol excretion following the CRH test, either before or after treatment.
Conclusions: These data suggest that, at the dosage and for the treatment period used, inhaled steroids do not seem to suppress the HPA axis in the majority of patients. The CRH test may be more sensitive than 24 hour UFC and morning plasma cortisol levels in evaluating systemic activity of inhaled corticosteroid treatment.
The mu-opioid receptor encoded by the gene OPRM1 plays a primary role in opiate, alcohol, cocaine and nicotine addiction. Studies using opioid antagonists demonstrate that the mu-opioid receptor (MOP-r) also mediates the hypothalamic–pituitary–adrenal (HPA) axis stress response. A common polymorphism in exon one of the MOP-r gene, A118G, has been shown to significantly alter receptor function and MOP-r gene expression; therefore, this variant likely affects HPA-axis responsivity. In the current study, we have investigated whether the presence of the 118AG variant genotype affects HPA axis responsivity to the stressor metyrapone, which transiently blocks glucocorticoid production in the adrenal cortex. Forty-eight normal and healthy volunteers (32 men, 16 women) were studied, among whom nine men and seven women had the 118AG genotype. The 118G allele blunted the adrenocorticotropic hormone (ACTH) response to metyrapone. Although there was no difference in basal levels of ACTH, subjects with the 118AG genotype had a more modest rise and resultant significantly lower ACTH levels than those with the prototype 118AA at the 8-hour time point (P < 0.02). We found no significant difference between genders. These findings suggest a relatively greater tonic inhibition at hypothalamic–pituitary sites through the mu-opioid receptor and relatively less cyclical glucocorticoid inhibition in subjects with the 118G allele.
ACTH; genetics; HPA axis; metyrapone; mu-opioid receptor; OPRM1
Studies show that the hypothalamic–pituitary–adrenal (HPA) axis is dysregulated in depression. Some studies suggest that variation in the serotonin transporter genotype (hereafter 5HTT) modulates both risk for depression and psychopathological HPA axis responsiveness. Rhesus monkeys are well suited to model such relationships. Rhesus macaque models of human psychopathology have assessed the effect of the serotonin transporter (rh5HTT) on levels of cortisol in stressed subjects. These studies show that that under conditions of stress, heterozygous females (Ls) reared under adversity exhibit high levels of cortisol. Studies have not to our knowledge, however, assessed the potential additive effect on the cortisol response in a number of macaque subjects homozygous for the serotonin transporter short allele (ss). Moreover, little is known about the level of the central or peripheral nervous system at which the 5HTT genotype acts to modulate the cortisol response.
This study assesses a relatively large number of subjects homozygous and heterozygous for the rh5HTT short and long alleles (a) during stress; (b) following a dexamethasone suppression test; and (c) following an adrenocorticotropic hormone (ACTH) challenge. Subjects included 190 infant rhesus macaques (Macaca mulatta – 84 males and 106 females; 118 LL, 60 Ls, and 12 ss subjects), obtaining two blood plasma samples during the stress of separation from their mothers. Then on the following day, we obtained a blood sample following a dexamethasone test, and later that day we obtained a blood sample after an ACTH challenge test. Subjects ranged in age between 90 and 128 days, with a mean age of 107 days.
Subjects homozygous for the short allele had significantly higher levels of cortisol across all test conditions, when compared to those homozygous for the long allele, or those heterozygous with Ls alleles. Subsequent analyses showed a high correlation between individual cortisol levels across the three different tests.
These data suggest that subjects homozygous for the short allele are more likely to show dysregulated cortisol levels in response to stress. Given the correlation in individual responses of the HPA axis across the different tests, our data suggest that the effect of the 5HTT genotype shows some commonality in its regulation of stress, feedback, and ACTH-stimulated cortisol output. Our data suggest that under conditions of stress, the serotonin transporter may modulate HPA axis psychopathology.
Serotonin; stress; cortisol; HPA axis; serotonin transporter genotype; depression; dexamethasone; Nonhuman primate; Rhesus monkey
There are likely to be gender differences in determinants of relapse to drug use following abstinence in cocaine-dependent individuals. Cocaine-dependent women are more likely to attribute relapse to negative emotional states and interpersonal conflict. Cocaine dependence has also been linked to dysregulation of stress response and the hypothalamic pituitary adrenal (HPA) axis which may differ between genders. Subjective and HPA axis responses to a social evaluative stressor, the Trier Social Stress Test (TRIER), and in vivo cocaine-related cues were examined in the present study.
There were no gender differences in magnitude of craving responses to the TRIER or the CUE. Both genders had a greater craving response to the CUE than to the TRIER, but the magnitude of the difference was greater for men than women (p=0.04). Cocaine-dependent subjects, compared to the control group, had significantly higher response throughout the TRIER (p<0.0001) and CUE (p<0.0001) testing sessions. There were no gender differences and no gender by cocaine interaction for ACTH responses to the TRIER, although women had lower baseline ACTH (p=0.049). On the CUE task, in contrast, female cocaine-dependent subjects had a more blunted ACTH response than did the other three groups (p=0.02). Female cocaine-dependent subjects also had a lower odds of a positive cortisol response to the TRIER as compared to the other three groups (OR=0.84, 95% CI=[0.02, 1.01]). During the CUE task, cocaine-dependent subjects had overall higher mean cortisol levels (p=0.0001), and higher odds of demonstrating a positive cortisol response to the CUE (OR=2.61, 95% CI=[1.11, 6.11]). No gender differences were found in ACTH responses to the CUE. The results are reviewed in the context of the existing literature on gender differences in cocaine dependence and potential implications for treatment are discussed.
HPA axis; substance use disorder; gender differences; stress reactivity; cue reactivity; drug craving
Hypothalamic-pituitary-adrenal (HPA) axis responses following naloxone administration have been assumed to provide a measure of opioid receptor activity. Employing positron emission tomography (PET) using the mu opioid receptor (MOR) selective ligand [11C] Carfentanil (CFN), we demonstrated that cortisol responses to naloxone administration were negatively correlated with MOR availability (Wand et al, 2011). In this study we examined whether naloxone-induced cortisol and ACTH responses in 15 healthy control and 20 recently detoxified alcohol dependent subjects correlated with delta opioid receptor (DOR) availability in 15 brain regions using the DOR-selective ligand [11C] methyl-naltrindole (MeNTL) and PET imaging. The day after the scan, cortisol responses to cumulative doses of naloxone were determined. Peak cortisol and adrenocorticotropin (ACTH) levels and area under the cortisol and ACTH curve did not differ by group. There were negative relationships between cortisol AUC to naloxone and [11C] MeNTL BPND in the ventral striatum, anterior cingulate, fusiform cortices, temporal cortex, putamen and a trend in the hypothalamus of healthy control subjects. However, in alcohol dependent subjects, cortisol responses did not correlate with [11C]MeNTL BPND in any brain region. Plasma ACTH levels did not correlate with [11C]MeNTL BPND in either group. The study demonstrates that naloxone provides information about individual differences in DOR availability in several mesolimbic structures. The data also show that the HPA axis is intimately connected with mesolimbic stress pathways through opioidergic neurotransmission in healthy subjects but this relationship is disrupted during early abstinence in alcohol dependent subjects.
mu opioid receptors; naloxone; PET imaging; HPA axis; cortisol
A central problem in posttraumatic stress disorder (PTSD) is the inability to suppress fear under safe conditions. We have previously shown that PTSD patients cannot inhibit conditioned fear. Another relevant finding in PTSD is the hypersensitivity of the hypothalamic-pituitary adrenal (HPA) axis feedback. Given their common neurobiological pathways, alterations in HPA function in PTSD may be associated with impaired fear inhibition. The present study examined the relationship between HPA axis function and fear-potentiated startle and inhibition of conditioned fear in trauma-exposed individuals. We used a conditional discrimination procedure (AX+/BX−), in which one set of shapes (AX+) was paired with aversive airblasts to the throat (danger signal), and the same X shape with a different shape (BX−) were presented without airblasts (safety signal). The paradigm also included a transfer of fear inhibition test (AB). In addition to fear-potentiated startle, blood was drawn for neuroendocrine analysis and the dexamethasone suppression test (DEX) was performed; cortisol and ACTH were assessed at baseline and post-DEX. Ninety highly traumatized individuals recruited from Grady Hospital in Atlanta, GA participated in the study. The sample was divided into those who met DSM-IV criteria for PTSD (n=29) and Non-PTSD controls (n=61) using the PTSD symptom scale (PSS). Both groups showed significant reduction in cortisol and ACTH levels after DEX. Subjects with PTSD had higher fear-potentiated startle to the safety signal, BX− (F(1,88)=4.44, p<0.05) and fear inhibition trials, AB (F(1,88)=5.20, p<0.05), both indicative of less fear inhibition in the presence of B, compared to control subjects. In addition, fear-potentiated startle to AX+, BX−, and AB was positively correlated with baseline and post-DEX ACTH in PTSD subjects. These results suggest that impaired fear inhibition and associated alterations in HPA feedback may reflect amygdala hyperactivity in subjects with PTSD.
PTSD; Trauma; Physiology; Startle Response; HPA; Cortisol
Subarachnoid haemorrhage (SAH) may damage the hypothalamo-pituitary-adrenal gland (HPA) axis and disturb cortisol metabolism. There are no available data that relates to the response of the HPA axis in the acute phase of SAH. We aimed to characterise the behavior of serum adrenocorticotropic hormone (ACTH), total cortisol, stimulated total cortisol and free cortisol concentrations in acute aneurysmal SAH.
A prospective cohort study was conducted of patients with acute aneurysmal SAH (n = 30) admitted to a tertiary university hospital. Patients admitted for elective aneurysmal surgery (n = 16) served as the control group. An ACTH stimulation test was performed twice during the first week and at three months. The main outcome measure was description of the ACTH-cortisol response by calculating serum free cortisol and measuring total cortisol and ACTH concentrations. A mixed models method was used for testing between the groups, allowing heterogeneity between the groups.
Patients with SAH had higher initial serum total cortisol (mean +/- SD; 793 +/- 312 nmol/L) and free cortisol concentrations (83 +/- 55 nmol/L) than control patients (535 +/- 193 nmol/L, p = 0.001 and 33 +/- 18 nmol/L, p < 0.001, respectively). Thereafter, there were no differences in this respect. Serum free and total cortisol concentrations correlated but were unaffected by the severity of SAH. ACTH concentrations were comparable between SAH and control groups. Patients with Hunt-Hess grades IV to V had higher ACTH concentrations at day one (10.7 +/- 7.1 pmol/l/L) and day five (8.2 +/- 7.7 pmol/L) than patients with grade I-III (day one: 3.8 +/- 2.0 pmol/L, p = 0.002; day five: 4.7 +/- 1.8 pmol/L, p = 0.04).
Calculation of serum free cortisol concentration was not helpful in identifying patients with potential hypocortisolism. SAH severity did not affect cortisol concentrations, possibly indicating relative pituitary-adrenal insufficiency in patients with more severe bleeding.
ClinicalTrials.gov Identifier NCT00614887.
Cushing's syndrome (CS) is a rare but severe clinical condition represented by an excessive endogenous cortisol secretion and hence excess circulating free cortisol, characterized by loss of the normal feedback regulation and circadian rhythm of the hypothalamic-pituitary axis due to inappropriate secretion of ACTH from a pituitary tumor (Cushing's disease, CD) or an ectopic source (ectopic ACTH secretion, EAS). The remaining causes (20%) are ACTH independent. As soon as the diagnosis is established, the therapeutic goal is the removal of the tumor. Whenever surgery is not curative, management of patients with CS requires a major effort to control hypercortisolemia and associated symptoms. A multidisciplinary approach that includes endocrinologists, neurosurgeons, oncologists, and radiotherapists should be adopted. This paper will focus on traditional and novel medical therapy for aggressive ACTH-dependent CS. Several drugs are able to reduce cortisol levels. Their mechanism of action involves blocking adrenal steroidogenesis (ketoconazole, metyrapone, aminoglutethimide, mitotane, etomidate) or inhibiting the peripheral action of cortisol through blocking its receptors (mifepristone “RU-486”). Other drugs include centrally acting agents (dopamine agonists, somatostatin receptor agonists, retinoic acid, peroxisome proliferator-activated receptor γ “PPAR-γ” ligands) and novel chemotherapeutic agents (temozolomide and tyrosine kinase inhibitors) which have a significant activity against aggressive pituitary or ectopic tumors.
Smith-Lemli-Opitz syndrome (SLOS) is a multiple malformation syndrome due to mutations of the 7-dehydrocholesterol reductase gene (DHCR7), which leads to a deficiency of cholesterol synthesis and an accumulation of 7-dehydrocholesterol and related metabolites. The SLOS clinical spectrum ranges from multiple major malformations to a mild phenotype with dysmorphic features, intellectual disability and a specific behavioral presentation. Several cases of SLOS with adrenal insufficiency have been described. We performed ovine corticotropin (oCRH) testing in 35 SLOS patients and 16 age- and gender-matched controls. We reviewed prior ACTH stimulation tests of our SLOS patients (19 of 35 available) and reviewed ACTH stimulation tests from additional 10 other SLOS patients. Results from oCRH testing showed that patients with SLOS had significantly higher ACTH baseline values than healthy controls (24.8 ± 15.3 pg/mL vs. 17.8 ± 7.5 pg/mL, p=0.034). However, no statistically significant differences were noted for peak ACTH values (74.4 ± 35.0 pg/mL vs. 64.0 ± 24.9 pg/mL, p=0.303) and for baseline (14.2 ± 7.8 mcg/dL vs. 14.2 ± 6.3 mcg/dL, p=0.992) and peak cortisol values (28.2 ± 7.9 mcg/dL vs. 24.8 ± 8.1 mcg/dL, p=0.156). The area-under-the-curve (AUC) was not significantly different in SLOS patients compared to controls for both ACTH (250.1 ± 118.7 pg/mL vs. 195.3 ± 96.6 pg/mL, p=0.121) as well as cortisol secretion (83.1 ± 26.1 mcg/dL vs. 77.8 ± 25.9 mcg/dL, p=0.499). ACTH stimulation test was normal in 28 of 29 tests. The individual with the abnormal ACTH stimulation test had a normal oCRH test during the same evaluation. The slightly increased baseline ACTH level seen during oCRH testing may be due to compensated mild adrenocortical insufficiency. However, we were able to show that our cohort affected with SLOS had an adequate stress response and that in mild to moderate cases of SLOS stress steroid coverage should not be required.
adrenal gland; adrenocortical insufficiency; pituitary gland; adrenocorticotropin (ACTH); cortisol; Smith-Lemli-Opitz Syndrome (SLOS); inborn error of cholesterol synthesis; corticotrophin releasing hormone (CRH)
Thalassemia major patients with repeated blood transfusion have high prevalence of endocrinopathies due to iron overload.
Materials and Methods:
We examined the adrenocortical function in 23 thalassemic patients (10 children and 13 young adults) aged 8-26 years. Serum cortisol and dehydroepiandrosterone sulfate (DHEA-S) concentrations were determined in each subject before blood transfusion both in basal condition and after low dose (LD) (1 μg), followed by standard dose (SD) (250 μg, respectively) with synthetic corticotrophin beta 1-24 ACTH (Synacthen, Ciba). Normal controls were a group of 13 age- and sex-matched normal subjects.
Using a peak total cortisol cutoff level of 550 nmol/L and increments of 200 μg above basal cortisol, adrenal insufficiency (AI) was demonstrated in 8 patients (34.7%) after the LD ACTH and in 2 patients (8.7%) after SD cosyntropin (ACTH) test, but none of the controls. Using a peak total cortisol cutoff level of 420 nmol/L and increments of 200 μg above basal cortisol, AI was demonstrated in 5 patients (21.7%) after the LD ACTH and in 2 patients after SD ACTH test (8.7%), but none of controls. All patients with biochemical AI were asymptomatic with normal serum sodium and potassium concentrations and had no history suggestive of adrenal pathology. The peak cortisol concentrations in thalassemic patients with impaired adrenal function both after 1 μg and 250 μg cosyntropin (294 ± 51 nmol/L and 307 ± 58.6) were significantly lower than those with patients with normal (454 ± 79.7 nmol/L and 546.1 ± 92.2 nmol/L, respectively) and controls (460.2 ± 133.4 nmol/L and 554.3 ± 165.8 nmol/L, respectively). Adolescents and young adults, but not children with thalassaemia, had significantly lower peak cortisol concentration after SD ACTH versus controls. Peak cortisol response to LD ACTH was correlated significantly with peak cortisol response to SD in all patients (r = 0.83, P < 0.0001). In adolescents and young adults with thalassemia, DHEA-S levels before and after LD ACTH stimulation were significantly lower and the cortisol/DHEA-S ratios were significantly higher than the controls.
The use of LD ACTH test diagnoses more adrenal abnormalities versus SD ACTH in thalassemic patients. The relatively high prevalence of AI in thalassemic adolescents and young adults necessitates that these patients have to be investigated for AI before major surgery and those with impaired cortisol secretion should receive stress doses of corticosteroids during the stressful event.
Cortisol; dehydroepiandrosterone sulfate; low dose adrenocorticotropic hormone test; standard dose adrenocorticotropic hormone test; thalassemia
The endogenous opioid system is involved in modulating a number of behavioral and physiological systems, including the hypothalamic-pituitary-adrenal (HPA) axis. In humans, a functional variant in the OPRM1 gene (OPRM1 A118G) is associated with a number of outcomes, including attenuated HPA axis responses to stress. A nonsynonymous variant (OPRM1 C77G) in the rhesus macaque has been shown to have similar effects in vivo to the human variant. The current study investigated whether OPRM1 C77G influences HPA axis response to stress in rhesus macaques. We analyzed plasma adrenocorticotropic hormone (ACTH) and cortisol levels measured in response to three different stressors: 1) maternal separation in infant subjects at 6 months of age, 2) acute ethanol administration in adolescent subjects at 4 years of age, and 3) postpartum HPA axis function in adult rhesus macaque females. For the maternal separation paradigm, ACTH and cortisol levels were determined at baseline as well as peak levels during each of 4 consecutive separation episodes. For the acute ethanol administration paradigm, hormone levels were determined at baseline and again at 5 minutes, 10 minutes, and 60 minutes following the ethanol infusion. For postpartum sampling, hormone levels were determined at postpartum days 7, 14, 21, 30, 60, 90, 120, and 150. Infants carrying the 77G allele exhibited lower levels of cortisol across all 4 separation episodes. Furthermore, adolescents carrying the 77G allele exhibited lower cortisol levels at 5 and 10 minutes following acute ethanol administration. Adult females with prior reproductive experience and who carry the 77G allele exhibited lower cortisol levels across the postpartum period. No significant genotype effects were found for ACTH, although there were some trends for lower ACTH levels in 77G allele carriers. These data are consistent with human studies that have demonstrated attenuated cortisol responses to stress among carriers of the OPRM1 118G allele, lending further support to the argument that the rhesus and human allelic variants are functionally similar. Our results also suggest that OPRM1 variation may influence coping style, as well as alcohol-induced and postpartum levels of HPA axis activity and, as such, may modify vulnerability to alcohol use disorders and postpartum depression.
Opioids; Hypothalamic-Pituitary-Adrenal (HPA) Axis; Cortisol; Stress; Nonhuman Primate; Separation; Alcohol; Postpartum Depression
Despite observations of age-dependent sexual dimorphisms in hypothalamic-pituitary-adrenal (HPA) axis activity, the role of androgens in the regulation of HPA axis activity in men has not been examined. We assessed this role by performing CRH stimulation tests in ten men (ages 18–45) during gonadal suppression with leuprolide acetate and during testosterone addition to leuprolide. CRH-stimulated cortisol levels as well as peak cortisol and greatest cortisol excursion were significantly lower (p < .05, .005, and .01, respectively) during testosterone replacement compared with the induced hypogonadal condition (leuprolide plus placebo); cortisol area under the curve was lower at a trend level (p < .1). Paradoxically, CRH-stimulated ACTH was increased significantly during testosterone replacement (p < .05). The cortisol:ACTH ratio, a measure of adrenal sensitivity, was lower during testosterone replacement (p < .1). A mixed effects regression model showed that testosterone but not estradiol or CBG significantly contributed to the variance of cortisol. These data demonstrate that testosterone regulates CRH-stimulated HPA axis activity in men, with the divergent effects on ACTH and cortisol suggesting a peripheral (adrenal) locus for the suppressive effects on cortisol. Our results further demonstrate that the enhanced stimulated HPA axis activity previously described in young men compared with young women cannot be ascribed to an activational upregulation of the axis by testosterone.
testosterone; cortisol; HPA axis; ACTH; CRH; men