Adrenal steroid responses to continuous intravenous adrenocorticotropin infusion compared to bolus injection in normal volunteers

Adrenocorticotropin Acutely Regulates Pregnenolone Sulfate Production by the Human Adrenal In Vivo and In Vitro

BACKGROUND

Dehydroepiandrosterone sulfate (DHEAS) is the most abundant steroid in human circulation, and adrenocorticotropic hormone (ACTH) is considered the major regulator of its synthesis. Pregnenolone sulfate (PregS) and 5-androstenediol-3-sulfate (AdiolS) have recently emerged as biomarkers of adrenal disorders.

OBJECTIVE

To define the relative human adrenal production of Δ5-steroid sulfates under basal and cosyntropin-stimulated conditions.

METHODS

Liquid chromatography-tandem mass spectrometry was used to quantify three unconjugated and four sulfated Δ5-steroids in (1) paired adrenal vein (AV) and mixed venous serum samples (21 patients) and (2) cultured human adrenal cells both before and after cosyntropin stimulation, (3) microdissected zona fasciculata (ZF) and zona reticularis (ZR) from five human adrenal glands, and (4) a reconstituted in vitro human 17α-hydroxylase/17,20-lyase/(P450 17A1) system.

RESULTS

Of the steroid sulfates, PregS had the greatest increase after cosyntropin stimulation in the AV (32-fold), whereas DHEAS responded modestly (1.8-fold). PregS attained concentrations comparable to those of DHEAS in the AV after cosyntropin stimulation (AV DHEAS/PregS, 24 and 1.3 before and after cosyntropin, respectively). In cultured adrenal cells, PregS demonstrated the sharpest response to cosyntropin, whereas DHEAS responded only modestly (21-fold vs 1.8-fold higher compared with unstimulated cells at 3 hours, respectively). Steroid analyses in isolated ZF and ZR showed similar amounts of PregS and 17α-hydroxypregnenolone in both zones, whereas DHEAS and AdiolS were higher in ZR (P < 0.05).

CONCLUSION

Our studies demonstrated that unlike DHEAS, PregS displayed a prominent acute response to cosyntropin. PregS could be used to interrogate the acute adrenal response to ACTH stimulation and as a biomarker in various adrenal disorders.

Liquid chromatography-tandem mass spectrometry analysis of human adrenal vein corticosteroids before and after adrenocorticotropic hormone stimulation

CONTEXT

Although steroid hormones produced by the adrenal gland play critical roles in human physiology, a detailed quantitative analysis of the steroid products has not been reported. The current study uses a single methodology (liquid chromatography-tandem mass spectrometry, LC-MS/MS) to quantify ten corticosteroids in adrenal vein (AV) samples pre- and post-adrenocorticotropic hormone (ACTH) stimulation.

DESIGN/METHODS

Three men and six women with a diagnosis of an adrenal aldosterone-producing adenoma (APA) were included in the study. Serum was collected from the iliac vein (IV) and the AV contralateral to the diseased adrenal. Samples were collected, before and after administration of ACTH. LC-MS/MS was then used to quantify serum concentrations of unconjugated corticosteroids and their precursors.

RESULTS

Prior to ACTH stimulation, the four most abundant steroids in AV were cortisol (90%), cortisone (4%), corticosterone (3%) and 11-deoxycortisol (0.8%). Post-ACTH administration, cortisol remained the major adrenal product (79%); however, corticosterone became the second most abundantly produced adrenal steroid (11%) followed by pregnenolone (2.5%) and 17α-hydroxypregnenolone (2%). ACTH significantly increased the absolute adrenal output of all ten corticosteroids measured (P < 0.05). The four largest post-ACTH increases were pregnenolone (300-fold), progesterone (199-fold), 17α-hydroxypregnenolone (187-fold) and deoxycorticosterone (82-fold).

CONCLUSION

Using LC-MS/MS, we successfully measured 10 corticosteroids in peripheral and AV serum samples under pre- and post-ACTH stimulation. This study demonstrates the primary adrenal steroid products and their response to ACTH.

Serum dehydroepiandrosterone sulfate concentration as an indicator of adrenocortical suppression in asthmatic children treated with inhaled steroids

ACTH regulates adrenal androgen production, which may thus be reduced during glucocorticosteroid therapy. Dehydroepiandrosterone sulfate is the most abundant androgen secreted by the adrenals. We wished to evaluate whether serum levels of dehydroepiandrosterone sulfate can be used as an indicator of adrenal suppression during inhaled steroid treatment in children. Sixty school-aged children with newly diagnosed asthma were randomly divided into budesonide (n = 30) and fluticasone propionate (n = 30) groups. Fifteen cromone-treated children served as a control group. The budesonide dose was 800 microg/d during the first 2 months and 400 microg/d thereafter. The respective fluticasone propionate doses were 500 and 200 microg/d. Serum dehydroepiandrosterone sulfate concentrations were measured before and after 2 and 4 months of treatment. In the budesonide group, serum dehydroepiandrosterone sulfate decreased from the baseline by a mean of 21% (95% confidence interval, 13-29%; P < 0.001) after 2 months of high dose treatment and by 16% (95% confidence interval, 8-25%; P < 0.001) after 4 months of treatment. In the fluticasone propionate group, the respective figures were 10% (95% confidence interval, 4-16%; P < 0.01) and 6% (95% confidence interval, 16% decrease-3% increase; P = NS). A low dose ACTH test indicated adrenocortical suppression at 4 months in 14 (23%) steroid-treated children. In these children, dehydroepiandrosterone sulfate decreased by a mean of 21% (95% confidence interval, 14-28%), whereas in those 46 steroid-treated children with normal ACTH test results, dehydroepiandrosterone sulfate decreased by 8% (95% confidence interval, 0-16%; P < 0.05 between these groups). In the control group, dehydroepiandrosterone sulfate levels tended to increase (by a mean of 26%), reflecting the normal physiological change at this age. In conclusion, inhaled steroid treatment suppresses dehydroepiandrosterone sulfate production in a dose-dependent manner. Monitoring of serum dehydroepiandrosterone sulfate concentrations can be used as a practical method to follow adrenocortical function and to detect its suppression during inhaled steroid treatment in children.

Cognitive function in patients with Cushing syndrome: a longitudinal perspective

The purposes of this study were to examine the level of improvement of cognitive function 12 months posttreatment in adult patients with Cushing syndrome (CS), the relationships of cognitive function to duration of CS or recovery of the hypothalamic pituitary adrenal (HPA) axis, and depression and improved cognitive functioning. Thirty-three patients with CS and a matched comparison group were enrolled. IQ, depression, and endocrine factors were measured during the active phase of CS and at 12 months posttreatment for CS. Results show no group differences in cognitive function across time but a trend for CS patients to have lower IQ scores at baseline. Individual differences in performance were striking. For some subscales of IQ there was a positive relationship with recovery of the HPA axis and a negative relationship with duration of CS as well as an improvement if depression had decreased. Limitations of the study are cited along with clinical implications and directions for future research.

Repetitive graded ACTH stimulation test for adrenal insufficiency

ACTH stimulation is useful in assessing the hypothalamo-pituitary-adrenal axis. However, there is still some debate about the proper dose and interpretation. We designed a new protocol using repetitive graded ACTH stimulation. Thirty-two patients with the diagnosis of adrenal insufficiency (Al) were studied. After taking samples for baseline ACTH and cortisol, 1 microg fresh-prepared ACTH (Synacthen (1-24)) was injected intravenously, then 5, 50 and 100 microg at hourly interval. Cortisol responses were measured at 30, 60, 120, 180 and 240 min. The secondary Al group (26 subjects) had cortisol responses in between those of the control group (8 subjects) and the primary Al group (6 subjects). The minimal overlap between the secondary Al group and the control group occurred at a 30-min cortisol response after 1 microg ACTH stimulation, using 20 microg/dl as the cut-off level. There was only one exception which showed an episodic release at 30 min. There were 5, 10 and 9 patients with secondary Al who responded normally to 5, 50 and 100 microg ACTH stimulation, respectively. Maximal cortisol increments of the primary Al group were all below 4 microg/dl. Although there were 11 cases of secondary Al whose cortisol responses overlapped with those of primary Al, only two of them had a cortisol increment less than 4 microg/dl. Our new protocol combines the advantage of the low dose ACTH stimulation test, a sensitive method for detecting mild Al, and the ACTH infusion test, a longer test to mimic surgical stress.

Adrenal androgen production in response to adrenocorticotropin infusions in men

The responses of several adrenal steroids to adrenocorticotropin (ACTH) were investigated in a group of healthy young men. The protocol consisted of overnight adrenal suppression with dexamethasone followed by 1 hr infusions of ACTH in increasing (4X) doses ranging from 30-30,720 ng/1.5M2 followed by 0.25 mg ACTH/1.5M2. Whereas cortisol, androstenedione and androstenediol concentrations tended to plateau at the higher ACTH infusion rates, those of dehydroepiandrosterone (DHEA) and 17-hydroxyprogesterone (17-OH P) did not. The cortisol concentration achieved after the highest dose of ACTH was over 50 fold higher than that at baseline. DHEA levels rose to values about 13 times baseline whereas the other steroids increased to lesser extents (3-5 fold). The ACTH infusion rate required to significantly increase each steroid over the baseline level was extrapolated from dose response curves and was considered to be an index of the sensitivity of each steroid to ACTH. Cortisol was the most sensitive, rising significantly at approximately 35 ng ACTH/1.5M2, followed by androstenediol, DHEA, androstenedione and 17-OH P.

delta 5-Androstene-3 beta,17 beta-diol in healthy eumenorrheic women: relationship to body mass and hormonal profile

OBJECTIVE

To determine whether delta 5-Androstene-3 beta,17 beta-diol or androstenediol secretion increases with body mass.

DESIGN

A prospective study.

SETTING

University-based clinical research center.

PATIENTS

Twenty healthy, nonhirsute, eumenorrheic women, 10 with a body mass index (BMI) < 31 kg/m2 and 10 with a BMI > 31 kg/m2 were studied.

INTERVENTIONS

All patients had blood sampled before (0 minute) and 60 minute after acute administration of 1 mg ACTH-(1-24) i.v. Body circumferences were obtained, and the BMI and waist-hip ratio was calculated.

MAIN OUTCOME MEASURES

Total T, androstenedione (A), E2, sex hormone binding globulin, DHEA, DHEAS, and androstenediol were measured at 0 minutes (steroid 0): and DHEA, A and androstenediol were also measured after stimulation (steroid 60). The net steroid increment (delta) from 0 to 60 minute was calculated.

RESULTS

Compared with thin women, obese subjects had higher levels of androstenediol 60 (95.8 +/- 20.3 versus 130.7 +/- 40.7 ng/dL, respectively [conversion factor to SI units, 0.03443]) and delta androstenediol (17.4 +/- 8.7 versus 37.8 +/- 29.0 ng/dL, respectively [conversion factor to SI units, 0.03443]). Neither the BMI, height, nor the body circumference measures correlated with any of the steroid levels or responses to adrenal stimulation, except for a weak positive correlation between BMI and estrone (E1) (r = 0.38) and a negative correlation between waist-hip ratio and delta androstenediol (r = -0.51). The basal level of T, E1, and DHEA0, but not A or DHEAS, correlated with androstenediol 0 (r = 0.65, 0.62, and 0.67, respectively) and delta androstenediol (r = 0.66, 0.63, and 0.63 to 0.005, respectively).

CONCLUSIONS

Although the unstimulated morning androstenediol level did not differ between obese and thin euandrogenic healthy women, the response of androstenediol to ACTH-(1-24) stimulation was greater in obese individuals. The present findings, together with our previous data demonstrating an increased adrenal secretion of the E1 precursor A in response to ACTH in obese women, suggests that the adrenal cortex in overweight women may further enhance the estrogenic milieu of these women.