Alterations in hypothalamic-pituitary-adrenal function immediately after resection of adrenal adenomas in patients with Cushing's syndrome and others with incidentalomas and subclinical hypercortisolism

Distinct serum steroid profiles between adrenal Cushing syndrome and Cushing disease

Background

Differentiating between adrenal Cushing syndrome (adrenal CS) and Cushing disease (CD) can be challenging if there are equivocal or falsely elevated adrenocorticotropic hormone (ACTH) values. We aim to investigate the diagnostic value of serum steroid profiles in differentiating adrenal CS from CD.

Method

A total of 11 serum steroids in adrenal CS (n = 13) and CD (n = 15) were analyzed by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Age- and gender-specific steroid ratios were generated by dividing the actual steroid concentration by the upper limit of the relevant reference range. A principal component analysis (PCA) and an orthogonal partial least squares discriminant analysis (OPLS-DA) were performed.

Results

The PCA and OPLS-DA analyses showed distinct serum steroid profiles between adrenal CS and CD. Dehydroepiandrosterone sulfate (DHEA-S), dehydroepiandrosterone (DHEA), and androstenedione ratios were identified as biomarkers for discrimination by variable importance in projection (VIP) in combination with t-tests. The sensitivity and specificity of DHEA-S ratios <0.40 were 92.31% (95% CI 64.0%-99.8%) and 93.33% (95% CI 68.1%-99.8%), respectively, in identifying adrenal CS. The sensitivity and specificity of DHEA ratios <0.18 were 100% (95% CI 75.3%-100.0%) and 100% (95% CI 78.2%-100.0%), respectively, in identifying adrenal CS.

Conclusion

Our data support the clinical use of the DHEA-S and DHEA ratios in the differential diagnosis of adrenal CS and CD, especially when falsely elevated ACTH is suspected.

Biochemical assessment of adrenal insufficiency after adrenalectomy for non-cortisol secreting tumors: clinical correlation and recommendations

BACKGROUND

Data regarding changes in cortisol axis after adrenalectomy for non-cortisol secreting tumors and their correlation with adrenal insufficiency are limited. Our aim was to analyze these changes and their clinical correlations to guide management after adrenalectomy for non-Cushing's tumors.

METHODS

Following IRB approval, postoperative cortisol axis changes were analyzed in patients who underwent unilateral adrenalectomy for non-Cushing's tumors. A morning serum cortisol of ≥ 10 μg/dl was accepted as a sufficient adrenal response.

RESULTS

223 adrenalectomies were analyzed. In 63% of patients, POD1 serum cortisol was ≥ 10 μg/dl and in 37% < 10 μg/dl. No patient with a POD1 cortisol ≥ 10 μg/dl developed AI symptoms, whereas symptoms of AI were observed in 4% of those with < 10 μg/dl. In patients with a POD1 cortisol of < 10 μg/dl, the rate of steroid replacement therapy initiation was 100%, 8%, and 25% when the decision was based on serum cortisol, clinical symptoms, and serum cortisol plus ACTH stimulation test results, respectively. In 90% of asymptomatic patients, hypocortisolemia resolved uneventfully within a week on repeat morning cortisol testing. 75% of patients with hypocortisolemia on POD1 demonstrated an adequate cortisol response to ACTH stimulation test.

CONCLUSION

Although postoperative hypocortisolemia was observed in 37% of patients undergoing unilateral adrenalectomy for non-cortisol secreting tumors, majority did not develop symptoms of adrenal insufficiency. All three steroid initiation approaches appeared safe, with management based on clinical symptoms or selective ACTH stimulation testing sparing more patients from steroids compared to steroid initiation based on POD 1 cortisol levels alone.

GluN2A/ERK/CREB Signaling Pathway Involved in Electroacupuncture Regulating Hypothalamic-Pituitary-Adrenal Axis Hyperactivity

The hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis caused by stress will inevitably disrupt the homeostasis of the neuroendocrine system and damage physiological functions. It has been demonstrated that electroacupuncture (EA) can modulate HPA axis hyperactivity during the perioperative period. As the initiating factor of the HPA axis, hypothalamic corticotrophin-releasing hormone (CRH) is the critical molecule affected by EA. However, the mechanism by which EA reduces CRH synthesis and secretion remains unclear. Activated N-methyl-D-aspartate receptor (NMDAR) has been linked to over-secretion of hypothalamic CRH induced by stress. To determine whether NMDAR is involved in EA regulating the over-expression of CRH, a surgical model of partial hepatectomy (HT) was established in our experiment. The effect of EA on hypothalamic NMDAR expression in HT mice was examined. Then, we investigated whether the extracellular regulated protein kinases (ERK)/cyclic adenosine monophosphate response element-binding protein (CREB) signaling pathway mediated by NMDAR was involved in EA regulating HPA axis hyperactivity. It was found that surgery enhanced the expression of hypothalamic CRH and caused HPA axis hyperactivity. Intriguingly, EA effectively suppressed the expression of CRH and decreased the activation of GluN2A (NMDAR subunit), ERK, and CREB in HT mice. GluN2A, ERK, and CREB antagonists had similar effects on normalizing the expression of CRH and HPA axis function compared with EA. Our findings suggested that surgery enhanced the activation of the hypothalamic GluN2A/ERK/CREB signaling pathway, thus promoting the synthesis and secretion of CRH. EA suppressed the phosphorylation of GluN2A, ERK, and CREB in mice that had undergone surgery, indicating that the GluN2A/ERK/CREB signaling pathway was involved in EA alleviating HPA axis hyperactivity.

Postoperative adrenal insufficiency in Conn's syndrome-does it occur frequently?

Primary aldosteronism (PA) is the most frequent form of endocrine hypertension. Recently, frequent clinically significant adrenal insufficiency after adrenalectomy in subjects with PA has been reported, which may make the early postsurgical management difficult. We retrospectively searched for possible adrenal insufficiency in subjects who underwent adrenalectomy for PA and have measured cortisol in the early postoperative course. We included subjects with confirmed diagnosis of PA who underwent either posture testing (blood draw at 06:00 and 08:00) and/or adrenal venous sampling (AVS) (blood draw between 08:00 and 09:00) and have also measured cortisol after surgery (cortisol measured approximately at 07:00). Cortisol was measured by immunoassay. In this study, we identified 150 subjects (age 48.5 ± 10.3 years) with available cortisol values in the early postoperative course (median [25th percentile, 75th percentile]) 6 [5,6] days. Postoperative cortisol values (551 ± 148 nmol/l) were normal and significantly higher, compared to preoperative standing cortisol values (404 ± 150 nmol/l; (P < 0.001) and AVS cortisol values (493 ± 198 nmol/l; P = 0.009), and did not significantly differ from preoperative supine cortisol values. Postsurgical cortisol values were not different among subjects with or without abnormal dexamethasone suppression test or elevated urinary free cortisol pre-surgery, and were significantly higher in subjects with abnormal diurnal cortisol variability compared with subjects with normal diurnal variability. No patient presented with adrenocortical crisis in the later follow-up. In conclusion, postoperative cortisol values did not indicate any suspicion of possible adrenal insufficiency. To exclude possible adrenal insufficiency, it may be sufficient to measure morning cortisol in the early postoperative course.

Perioperative Glucocorticoid Therapy for Patients with Adrenal Insufficiency: Dosing Based on Pharmacokinetic Data

BACKGROUND

Perioperative glucocorticoid therapy for patients with adrenal insufficiency (AI) is currently based on anecdotal reports, without supporting pharmacokinetic data.

METHODS

We determined the half-life, clearance, and volume of distribution of 2 consecutive intravenously (IV)-administered doses of hydrocortisone (15 or 25 mg every 6 hours) to 22 dexamethasone-suppressed healthy individuals and used the data to develop a novel protocol to treat 68 patients with AI who required surgical procedures. Patients received 20 mg of hydrocortisone orally 2 to 4 hours before intubation and were started on 25 mg of IV hydrocortisone every 6 hours for 24 hours and 15 mg every 6 hours during the second day. Nadir cortisol concentrations were repeatedly measured during that period.

RESULTS

In healthy individuals, cortisol half-life was longer when the higher hydrocortisone dose was administered (2.02 ± 0.15 vs 1.81 ± 0.11 hours; P < 0.01), and in patients with AI, the half-life was longer than in healthy individuals given the same hydrocortisone dose. In both populations, the cortisol half-life increased further with the second hormone injection. Prolongation of cortisol half-life was due to decreased hydrocortisone clearance and an increase in its volume of distribution. Nadir cortisol levels determined throughout the 48 postoperative hours were within the range of values and often exceeded those observed perioperatively in patients without adrenal dysfunction.

CONCLUSIONS

Cortisol pharmacokinetics are altered in the postoperative period and indicate that lower doses of hydrocortisone can be safely administered to patients with AI undergoing major surgery. The findings of this investigation call into question the current practice of administering excessive glucocorticoid supplementation during stress.

Increased androgen secretion in patients with prolactinomas: the impact of altered HPA function

BACKGROUND AND OBJECTIVES

Earlier studies suggested that hyperprolactinemia was associated with elevated serum DHEA-S levels. The importance of DHEA-S measurements in the diagnosis of adrenal insufficiency prompted us to assess adrenal androgen levels in hyperprolactinemic subjects with normal or impaired function.

METHODS

Prospective study including 122 medically treated and 26 surgically patients with prolactinomas. Serum PRL, DHEA and DHEA-S levels were measured before and repeatedly after cabergoline therapy and also in the perioperative period of surgically treated patients.

RESULTS

Serum PRL levels decreased (P < 0.001) in all 101 medically treated patients with normal HPA function from 728.3 ± 1507 reaching 29.1 ± 39 and 14.9 ± 24.4 µg/L at 3 and 12 months, respectively. Concurrently serum DHEA-S levels decreased (P < 0.001) from 245.9 ± 196 to 216.2 ± 203.3 and to 169.7 ± 121.1 µg/dl at 3 and 12 months, respectively. These effects were reversed in 19 patients who discontinued treatment and were re-demonstrated after therapy resumption. Among the 22 surgically treated patients with normal HPA, peri-operative PRL levels decreased rapidly (P < 0.001) with a parallel decline in serum DHEA-S levels (P = 0.03). Strong correlations were noted between PRL and DHEA-S decrements observed with medical or surgical therapy. Medically (n = 21) and surgically (n = 4) patients with impaired HPA function had very low DHEA-S values that were unchanged despite marked reductions in PRL secretion.

CONCLUSION

Hyperprolactinemia is associated with a reproducible and reversible increase in serum DHEA-S that was observed in medically- and surgically-treated patients with normal HPA function. Thus, a normal age- and gender-adjusted serum DHEA-S level continues to imply normal HPA function even among hyperprolactinemic subjects.