Measurement of urinary free cortisol by current immunoassays: need for sex-dependent reference ranges to define hypercortisolism

Laboratory Testing for Endocrine Hypertension: Current and Future Perspectives

BACKGROUND

Secondary hypertension (SH) is a form of high blood pressure caused by an identifiable underlying condition. Although, it accounts for a small fraction of the overall hypertensive population, detection and management of SH is of utmost importance, because SH phenotypes carry a high cardiovascular risk and can possibly be cured by timely treatment.

CONTENT

This review focuses on the endocrine causes of SH, such as primary aldosteronism, Cushing syndrome, thyroid disease, pheochromocytoma and paraganglioma, acromegaly, and rare monogenic forms. It discusses current biomarkers, analytical methods, and diagnostic strategies, highlighting advantages and limitations of each approach. It also explores the emerging -omics technologies that can provide a comprehensive and multidimensional assessment of SH and its underlying mechanisms.

SUMMARY

Endocrine SH is a heterogeneous and complex condition that requires proper screening and confirmatory tests to avoid diagnostic delays and improve patient outcomes. Careful biomarker interpretation is essential due to potential interferences, variability, and method-dependent differences. Liquid chromatography-tandem mass spectrometry is a superior method for measuring low-concentration hormones and metabolites involved in SH, but it requires expertise. Omics approaches have great potential to identify novel biomarkers, pathways, and targets for SH diagnosis and treatment, especially considering its multifactorial nature.

Gender-affirming hormone therapy effect on cortisol levels in trans males and trans females

PURPOSE

Previous studies have shown differences in baseline and stimulated cortisol levels between men and women. Whether this difference is secondary to sex hormones or to other factors, such as genetic or epigenetic changes, is unknown. We investigated the effect of gender-affirming hormone treatment (GAHT) on the hypothalamo-pituitary-adrenal axis of transgender subjects in an effort to throw light on this question.

METHODS

Ten transgender males (TM) and eight transgender females (TF) underwent a low-dose (1 µg) adrenocorticotropic hormone (ACTH) stimulation test before and 6 months after GAHT initiation. Serum total, free and salivary cortisol (SC) levels were measured at baseline and at 20, 30 and 40 min.

RESULTS

For the TM, all three levels were significantly lower at several time points after ACTH injection compared to pretreatment levels following 6 months of treatment (p < .05). Likewise, the overall SC response as calculated by the area under the curve was significantly lower (p = .0053). For the TF, the basal total cortisol (TC) level increased after 6 months of treatment (p < .01) while ACTH-stimulated SC levels decreased significantly. The basal ACTH levels were significantly lower following hormonal therapy (p < .001).

CONCLUSION

Stimulated salivary cortisol levels decreased significantly after 6 months of GAHT in both male and female transgender subjects, possibly reflecting a decreased state of anxiety associated with treatment initiation. Additionally, basal and stimulated serum TC levels increased after hormonal treatment in the TF, probably secondary to the effect of oestrogen on cortisol-binding globulin.

Cortisol: Analytical and clinical determinants

Cortisol, the main human glucocorticoid, is synthesized from cholesterol in the adrenal cortex and predominantly metabolized by the liver. Interpretation of quantitative results from the analysis of serum, urine and saliva is complicated by variation in circadian rhythm, response to stress as well as the presence of protein-bound and free forms. Interestingly, cortisol is the only hormone routinely measured in serum, urine, and saliva. Preanalytical and analytical challenges arise in each matrix and are further compounded by the use of various stimulation and suppression tests commonly employed in clinical practice. Although not yet included in clinical guidelines, measurement of cortisol in hair may be of interest in specific situations. Immunoassays are the most widely used methods in clinical laboratories to measure cortisol, but they are susceptible to interference from synthetic and endogenous steroids, generally producing a variable overestimation of true cortisol results, especially in urine. Analysis by mass spectrometry provides higher specificity and allows simultaneous measurement of multiple steroids including synthetic steroids, thus reducing diagnostic uncertainty. An integrated review of cortisol in various disease states is also addressed.

Overnight 1 mg dexamethasone suppression test and 24 h urine free cortisol-accuracy and pitfalls when screening for Cushing's syndrome

Diagnosis of Cushing's syndrome (CS) is often delayed due to variable clinical features and its rarity. Simple and accurate screening tests are required to enhance screening for hypercortisolism. Both overnight 1 mg dexamethasone suppression test (DST) and urinary free cortisol (UFC) demonstrate high sensitivity and specificity for the diagnosis of CS. However, each test has its own distinctive features, making it preferable in specific clinical conditions. This review will discuss the pitfalls for each of those tests.

Child maltreatment and hypothalamic-pituitary-adrenal axis functioning: A systematic review and meta-analysis

Alterations in hypothalamic-pituitary-adrenal (HPA) axis and its effector hormone cortisol have been proposed as one possible mechanism linking child maltreatment experiences to health disparities. In this series of meta-analyses, we aimed to quantify the existing evidence on the effect of child maltreatment on various measures of HPA axis activity. The systematic literature search yielded 1,858 records, of which 87 studies (k = 132) were included. Using random-effects models, we found evidence for blunted cortisol stress reactivity in individuals exposed to child maltreatment. In contrast, no overall differences were found in any of the other HPA axis activity measures (including measures of daily activity, cortisol assessed in the context of pharmacological challenges and cumulative measures of cortisol secretion). The impact of several moderators (e.g., sex, psychopathology, study quality), the role of methodological shortcomings of existing studies, as well as potential directions for future research are discussed.

Consensus on diagnosis and management of Cushing's disease: a guideline update

Cushing's disease requires accurate diagnosis, careful treatment selection, and long-term management to optimise patient outcomes. The Pituitary Society convened a consensus workshop comprising more than 50 academic researchers and clinical experts to discuss the application of recent evidence to clinical practice. In advance of the virtual meeting, data from 2015 to present about screening and diagnosis; surgery, medical, and radiation therapy; and disease-related and treatment-related complications of Cushing's disease summarised in recorded lectures were reviewed by all participants. During the meeting, concise summaries of the recorded lectures were presented, followed by small group breakout discussions. Consensus opinions from each group were collated into a draft document, which was reviewed and approved by all participants. Recommendations regarding use of laboratory tests, imaging, and treatment options are presented, along with algorithms for diagnosis of Cushing's syndrome and management of Cushing's disease. Topics considered most important to address in future research are also identified.

Biochemical diagnosis of Cushing's disease: Screening and confirmatory testing

Due to the variable clinical features and its rarity diagnosis of Cushing's disease (CD) is often delayed. Clearly, awareness for CD needs to be raised, accompanied by the availability of simple and accurate screening tests. Late-night salivary cortisol (LNSC), 1 mg dexamethasone suppression test (DST), and urinary free cortisol (UFC) have all been extensively studied, demonstrating high sensitivity and specificity for the diagnosis of Cushing's syndrome. However, each of those well-established tests has its own distinctive features, making it preferable in specific clinical conditions and patient groups. To choose the most appropriate test in individual patients, an expert endocrinologist should be consulted. This review will discuss the pitfalls for each of those tests.

Cortisol Measurements in Cushing's Syndrome: Immunoassay or Mass Spectrometry?

Determination of cortisol levels in the urine (24 hours urine free cortisol), saliva (late-night), or serum (total cortisol after dexamethasone suppression) is recommended to screen for Cushing's syndrome (CS). This review focuses on the differences between the frequently used cortisol-antibody immunoassay-based methods and the highly specific mass-spectrometry-based methods that are progressively being employed in clinical laboratories for CS screening. The particular characteristics of cortisol metabolism and the lack of specificity of the immunoassays cause marked differences between both methods that are in turn highly dependent on the biological matrix, in which the cortisol is measured. Understanding the origin of these differences is essential for the interpretation of these results. Although cross-reactivity with endogenous steroids leads to grossly inaccurate results of immunoassay measurements of cortisol in the saliva and urine, preliminary evidence suggests that the clinical sensitivity of CS screening using immunoassays may be similar to CS screening using mass spectrometry. However, mass spectrometry offers more accurate results and considerably reduced variation across laboratories, while avoiding false-positive results. Moreover, mass spectrometry can overcome some common diagnostic challenges, such as identification of exogenous corticosteroids or simultaneous assessment of appropriate dexamethasone levels in suppression tests. Further, comprehensive mass spectrometry-based profiling of several steroid metabolites may be useful for discriminating among different subtypes of CS. Finally, this review discusses the main preanalytical factors that could cause variations in cortisol measurements and their influence on the reliability of the results.

Desperately seeking stress: A pilot study of cortisol in archaeological tooth structures

OBJECTIVES

Cortisol is a glucocorticoid hormone produced through activation of the hypothalamic pituitary adrenal axis. It is known as the "stress hormone" for its primary role in the body's stress response and has been the focus of much modern clinical research. Within archaeology, only a few studies have analyzed cortisol in human remains and these have been restricted to hair (Webb et al., 2010; Webb, White, van Uum, & Longstaffe, 2015a; Webb, White, van Uum, & Longstaffe, 2015b). This study examines the utility of dentine and enamel, which survive well archaeologically, as possible reservoirs for detectable levels of cortisol.

MATERIALS AND METHODS

Then, 69 teeth from 65 individuals from five Roman and Post-Roman sites in France were tested via competitive enzyme-linked immunosorbent assay (ELISA) to assess and quantify the cortisol concentrations present within tooth dentine and enamel.

RESULTS

In both tooth dentine and enamel, detectable concentrations of cortisol were identified in multiple teeth. However, concentrations were low and not all teeth yielded results that were measurable through cortisol ELISA. Differences in cortisol values between dentine and enamel could suggest different uptake mechanisms or timing.

DISCUSSION

These results suggest that cortisol is incorporated within tooth structures and merits further investigation in both modern and archaeological contexts. Analysis of the results through liquid chromatographic-mass spectrometry would verify current results and might yield values that could be better integrated with published cortisol studies. Future studies of cortisol in tooth structures would greatly expand the research potential of cortisol in the past and could have implications for studies of human stress across deep time.

Accuracy of Laboratory Tests for the Diagnosis of Cushing Syndrome

CONTEXT

The diagnosis of Cushing syndrome (CS) can be challenging. It remains to be determined which diagnostic tests are the most accurate.

OBJECTIVE

To summarize the accuracy of diagnostic tests for CS using contemporary meta-analytic techniques (hierarchical models).

DATA SOURCES

PubMed, Embase, Scopus, Web of Science, and the Cochrane Database of Systemic Reviews (inception until August 3, 2018).

STUDY SELECTION

Studies performed in adults that determined the accuracy of one or more diagnostic tests: overnight 1-mg dexamethasone suppression test (DST), 2-day low-dose DST (2d DST), 24-hour urinary free cortisol (UFC), late-night salivary cortisol (LNSC), midnight serum cortisol (MSC), and the dexamethasone-suppressed CRH (dex-CRH) and desmopressin (dex-DDAVP) tests.

DATA EXTRACTION

Two authors independently extracted data and performed methodological assessments.

DATA SYNTHESIS

One hundred thirty-nine studies (14 140 participants) were included in the analysis. The respective sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio (95% confidence interval [CI]) estimates include the following: DST 98.6% (96.9%-99.4%), 90.6% (86.4%-93.6%), 10.5 (7.2-15.3), and 0.016 (0.007-0.035); 2d DST 95.3% (91.3%-97.5%), 92.8% (85.7%-96.5%), 13.2 (6.47-27.1), and 0.051 (0.027-0.095); UFC 94.0% (91.6%-95.7%), 93.0% (89.0%-95.5%), 13.3 (8.47-21.0), and 0.065 (0.046-0.092); LNSC 95.8% (93.%-97.2%), 93.4% (90.7%-95.4%), 14.6 (10.3-20.7), and 0.045 (0.030-0.066); MSC 96.1% (93.5%-97.6%), 93.2% (88.1%-96.3%), 14.2 (7.96-25.2), and 0.042 (0.026-0.069); and dex-CRH 98.6% (90.4%-99.8%), 85.9% (67.6%-94.7%), 7.0 (2.80-17.6), and 0.016 (0.002-0.118). A single study evaluated dex-DDAVP. Meta-regression and a novel network meta-analytic approach suggest that DST is the most sensitive while UFC is the least sensitive.

CONCLUSIONS

All of the included diagnostic tests for CS are highly sensitive and specific. It appears that the DST is the most sensitive while the UFC is less sensitive. The specificity of all first-line tests appears comparable.

Dynamic Pituitary-Adrenal Interactions in the Critically Ill after Cardiac Surgery

CONTEXT

Patients with critical illness are thought to be at risk of adrenal insufficiency. There are no models of dynamic hypothalamic-pituitary-adrenal (HPA) axis function in this group of patients and thus current methods of diagnosis are based on aggregated, static models.

OBJECTIVE

To characterize the secretory dynamics of the HPA axis in the critically ill (CI) after cardiac surgery.

DESIGN

Mathematical modeling of cohorts.

SETTING

Cardiac critical care unit.

PATIENTS

20 male patients CI at least 48 hours after cardiac surgery and 19 healthy (H) male volunteers.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Measures of hormone secretory dynamics were generated from serum adrenocorticotrophic hormone (ACTH) sampled every hour and total cortisol every 10 min for 24 h.

RESULTS

All CI patients had pulsatile ACTH and cortisol profiles. CI patients had similar ACTH secretion (1036.4 [737.6] pg/mL/24 h) compared to the H volunteers (1502.3 [1152.2] pg/mL/24 h; P = .20), but increased cortisol secretion (CI: 14 447.0 [5709.3] vs H: 5915.5 [1686.7)] nmol/L/24 h; P < .0001). This increase in cortisol was due to nonpulsatile (CI: 9253.4 [3348.8] vs H: 960 [589.0] nmol/L/24 h, P < .0001), rather than pulsatile cortisol secretion (CI: 5193.1 [3018.5] vs H: 4955.1 [1753.6] nmol/L/24 h; P = .43). Seven (35%) of the 20 CI patients had cortisol pulse nadirs below the current international guideline threshold for critical illness-related corticosteroid insufficiency, but an overall secretion that would not be considered deficient.

CONCLUSIONS

This study supports the premise that current tests of HPA axis function are unhelpful in the diagnosis of adrenal insufficiency in the CI. The reduced ACTH and increase in nonpulsatile cortisol secretion imply that the secretion of cortisol is driven by factors outside the HPA axis in critical illness.

UTILITY OF A SINGLE LATE-NIGHT PLASMA CORTISOL AND ACTH FOR THE DIAGNOSIS OF CUSHING SYNDROME

OBJECTIVE

To evaluate the diagnostic efficacy of various screening tests for the diagnosis of Cushing syndrome (CS).

METHODS

Thirty-five patients with CS and 16 patients of pseudo-CS were enrolled. Assessment of 24-h urinary free cortisol (UFC), late-night salivary cortisol (LNSC), overnight dexamethasone suppression test (ONDST), late-night plasma cortisol (LNPC), and adrenocorticotropic hormone (ACTH) on outpatient basis, and during sleep as well as in awake state after 48 hours of hospital admission.

RESULTS

We found that 24-h UFC performed the best among the screening tests with sensitivity, specificity and areas under the curve (AUCs) of 96.0%, 99%, and 0.988, respectively, at a cut-off of 144.6 μg/24 h. A cut-off of 10.5 nmol/L for LNSC had sensitivity 85.7%, specificity 88.2%, and an AUC of 0.897. A cut-off of 412.4 nmol/L for LNPC on outpatient basis had sensitivity 88.2%, specificity 91.2%, and an AUC of 0.957. Cut-offs of 215 and 243.3 nmol/L for LNPC during sleep and awake states after acclimatization had sensitivity, specificity, and an AUC of 94.1%, 88.2%, and 0.958, respectively. An ONDST cut-off of 94.6 nmol/L provided sensitivity, specificity, and an AUC of 96.0%, 99.03% and 0.995, respectively. A cut-off of 30.3 pg/mL for late-night ACTH on outpatient basis had sensitivity 67.6%, specificity 99.9%, and an AUC 0.796.A cut-off of 22.6 pg/mL for ACTH during sleep state after acclimatization had sensitivity, specificity, and an AUC of 73.5%, 99.2%, and 0.827, respectively.

CONCLUSION

UFC is the best screening test for CS. Furthermore, single measurements of LNPC and ACTH help to establish the diagnosis and ACTH dependency of CS in the majority of patients with CS.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone AUC = area under the curve CRH = corticotropin-releasing hormone CS = Cushing syndrome ECLIA = electrochemiluminescence immuno-assay LDDST = low-dose dexamethasone suppression test LNPC = late-night plasma cortisol LNSC = late-night salivary cortisol ONDST = overnight dexamethasone suppression test RIA = radio-immuno assay UFC = urinary free cortisol.

How useful is urinary-free cortisol in the clinic?

Measurement of 24-h urine-free cortisol is frequently employed as a first-line screening and disease-monitoring test in Cushing's syndrome (CS). The quest for ‘cortisol specificity’ has seen the emergence of mass spectrometry (MS) based assays, particularly liquid chromatography/tandem mass spectrometry. In contrast to traditional immunoassays, liquid chromatography/tandem mass spectrometry ‘free cortisol’ measurement is less susceptible to ‘interference’ from cortisol precursors and metabolites. However, detection of these conjugates is important in mild CS and therefore, missed by MS if cortisol alone is measured. MS assays nevertheless are capable of measuring broad steroid profiles, including the potential to distinguish benign from malignant adrenal-based CS and detection of exogenous glucocorticoids. Until this is routine practice, we recommend against abandoning immunoassays measurement of urine-free cortisol.

Factors predicting the duration of adrenal insufficiency in patients successfully treated for Cushing disease and nonmalignant primary adrenal Cushing syndrome

Successful treatment of Cushing syndrome causes transient or permanent adrenal insufficiency deriving from endogenous hypercortisolism-induced hypothalamus-pituitary-adrenal-axis suppression. We analyzed pre-treatment factors potentially affecting the duration of adrenal insufficiency. We conducted a retrospective analysis on patients successfully treated for Cushing disease (15 patients) who underwent transsphenoidal surgery, and nonmalignant primary adrenal Cushing syndrome (31 patients) who underwent unilateral adrenalectomy, divided into patients with overt primary adrenal Cushing syndrome (14 patients) and subclinical primary adrenal Cushing syndrome (17 patients). Epidemiological data, medical history, and hormonal parameters depending on the etiology of hypercortisolism were collected and compared to the duration of adrenal insufficiency. The median duration of follow-up after surgery for Cushing disease and primary adrenal Cushing syndrome was 70 and 48 months, respectively. In the Cushing disease group, the median duration of adrenal insufficiency after transsphenoidal surgery was 15 months: younger age at diagnosis and longer duration of signs and symptoms of hypercortisolism before diagnosis and surgery were associated with longer duration of adrenal insufficiency. The median duration of adrenal insufficiency was 6 months for subclinical primary adrenal Cushing syndrome and 18.5 months for overt primary adrenal Cushing syndrome. The biochemical severity of hypercortisolism, the grade of hypothalamus-pituitary-adrenal-axis suppression, and treatment with ketoconazole before surgery accounted for longer duration of adrenal insufficiency. In patients with Cushing disease, younger age and delayed diagnosis and treatment predict longer need for glucocorticoid replacement therapy after successful transsphenoidal surgery. In patients with primary adrenal Cushing syndrome, the severity of hypercortisolism plays a primary role in influencing the duration of adrenal insufficiency after unilateral adrenalectomy.

GENDER DETERMINES SERUM FREE CORTISOL: HIGHER LEVELS IN MEN

OBJECTIVE

Because only the free fraction of serum cortisol can readily access glucocorticoid receptors, we investigated whether or not a gender-related difference in serum free cortisol (FC) exists in the basal and adrenocorticotropic hormone (ACTH)-stimulated state.

METHODS

Serum total cortisol (TC) and FC were measured in 323 subjects (175 men; 148 women). Additionally, the low-dose 1-μg ACTH test was performed in 56 subjects (30 women, 26 men). Subjects were healthy volunteers, recruited in a preventive medicine screening program and an outpatient clinic.

RESULTS

Overall, basal serum TC and FC level were ~18 and ~33%, respectively, higher in men than in women (TC, 14.5 ± 0.33 μg/dL vs. 12.3 ± 0.33 μg/dL; P<.0001; FC, 0.68 ± 0.02 μg/dL vs. 0.51 ± 0.02 μg/dL; P<.0001). The higher FC in men relative to women was apparent across a wide age range (17 to 86 years) and persisted after adjustment for age and body mass index. The FC fraction (%FC, out of TC) was concordantly higher in men (5.4 ± 0.09% vs. 4.8 ± 0.3%; P = .046). FC was not related to the estimated menopausal status (women age below and above 47, 50, or 53 years). ACTH-stimulated FC levels were significantly higher in men compared to women, as reflected by the area under the response curve (49.4 ± 3.4 μg × min vs. 39.6 ± 2.2 μg × min; P = .0014).

CONCLUSION

Gender is an unrecognized determinant of serum FC in humans. The possibility of lifelong exposure to the higher bioactive fraction of cortisol under basal conditions or daily stress involving ACTH stimulation should be further investigated in the context of gender-related phenotypic features such as "android" (visceral) fat deposition and longevity.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone BMI = body mass index CBG = cortisol-binding globulin FC = free cortisol HPA = hypothalamic-pituitary-adrenal TC = total cortisol.

Recommendations of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism for the diagnosis of Cushing's disease in Brazil

Although it is a rare condition, the accurate diagnosis and treatment of Cushing's disease is important due to its higher morbidity and mortality compared to the general population, which is attributed to cardiovascular diseases, diabetes mellitus and infections. Screening for hypercortisolism is recommended for patients who present multiple and progressive clinical signs and symptoms, especially those who are considered to be more specific to Cushing's syndrome, abnormal findings relative to age (e.g., spinal osteoporosis and high blood pressure in young patients), weight gain associated with reduced growth rate in the pediatric population and for those with adrenal incidentalomas. Routine screening is not recommended for other groups of patients, such as those with obesity or diabetes mellitus. Magnetic resonance imaging (MRI) of the pituitary, the corticotropin-releasing hormone (CRH) test and the high-dose dexamethasone suppression test are the main tests for the differential diagnosis of ACTH-dependent Cushing's syndrome. Bilateral and simultaneous petrosal sinus sampling is the gold standard method and is performed when the triad of initial tests is inconclusive, doubtful or conflicting. The aim of this article is to provide information on the early detection and establishment of a proper diagnosis of Cushing's disease, recommending follow-up of these patients at experienced referral centers. Arch Endocrinol Metab. 2016;60(3):267-86.

Variability in laboratory parameters used for management of Cushing's syndrome

The progress in assay methodology, from the use of radioactive tracers to chemiluminescent signals, from competitive to chromatographic techniques and from serum or urine to saliva has considerably impacted on hormonal measurements. The clinician now may choose among multiple tests but the inherent variability in cortisol and ACTH secretion, coupled to lack of harmonization among assay procedures and normal ranges mandates careful interpretation of any result. The present review will examine factors which affect interpretation of cortisol and ACTH measurements and their impact on tests used for management of Cushing's syndrome.

Medical therapy for Cushing's disease: adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers

Morbidity and mortality in Cushing's disease (CD) patients are increased if patients are not appropriately treated. Surgery remains the first line therapy, however the role of medical therapy has become more prominent in patients when biochemical remission is not achieved/or recurs after surgery, while waiting effects of radiation therapy or when surgery is contraindicated. Furthermore, use of preoperative medical therapy has been also recognized. In addition to centrally acting therapies (reviewed elsewhere in this special issue), adrenal steroidogenesis inhibitors, and glucocorticoid receptor antagonists are frequently used. A PubMed search of all original articles or abstracts detailing medical therapy in CD, published within 12 months (2013-2014), were identified and pertinent data extracted. Although not prospectively studied, ketoconazole and metyrapone have been the most frequently used medical therapies. A large retrospective ketoconazole study showed that almost half of patients who continued on ketoconazole therapy achieved biochemical control and clinical improvement; however almost 20% discontinued ketoconazole due to poor tolerability. Notably, hepatotoxicity was usually mild and resolved after drug withdrawal. Etomidate remains the only drug available for intravenous use. A new potent inhibitor of both aldosterone synthase and 11β-hydroxylase, following the completion of a phase II study LCI699 is being studied in a large phase III with promising results. Mifepristone, a glucocorticoid receptor antagonist, has been approved for hyperglycemia associated with Cushing's syndrome based on the results of a prospective study where it produced in the majority of patients' significant clinical and metabolic improvement. Absence of both a biochemical marker for remission and/or diagnosis of adrenal insufficiency remain, however, a limiting factor. Patient characteristics and preference should guide the choice between different medications in the absence of clinical trials comparing any of these therapies. Despite significant progress, there is still a need for a medical therapy that is more effective and with less adverse effects for patients with CD.

Adrenal insufficiency in pregnancy: challenging issues in diagnosis and management

Adrenal insufficiency (AI) in pregnancy is relatively rare, but it is associated with significant maternal and fetal morbidity and mortality if untreated during gestation or in the puerperium. Hence, timely diagnosis and decisive treatment by the clinician are critical. However, due to pregnancy-induced metabolic and endocrine changes and the resemblance of symptomatology of AI to those of pregnancy, the diagnosis is often difficult to recognize and challenging to confirm. Normal pregnancy is a state of glucocorticoid excess particularly in the latter stages, and normative values for serum cortisol levels are not well-established. Furthermore, testing the hypothalamic-pituitary-adrenal axis using validated stimulation tests during pregnancy are lacking. Therefore, it is the aim of the present review to discuss and to summarize the current knowledge, focussing on the challenges in recognizing AI in pregnancy and interpreting the diagnostic tests, and to propose a clinical approach for optimizing the management of AI in women diagnosed before or during pregnancy.

Medical management of Cushing's disease: what is the future?

Cushing's disease (CD) is caused by a corticotroph, adrenocorticotropic-hormone (ACTH)-secreting pituitary adenoma resulting in significant morbidity and mortality. Transsphenoidal surgery is the initial treatment of choice in almost all cases. Remission rates for microadenomas are good at 65-90 % (with an experienced neurosurgeon) but remission rates are much lower for macroadenomas. However, even after postoperative remission, recurrence rates are high and can be seen up to decades after an initial diagnosis. Repeat surgery or radiation can be useful in these cases, although both have clear limitations with respect to efficacy and/or side effects. Hence, there is a clear unmet need for an effective medical treatment. Currently, most drugs act by inhibiting steroidogenesis in the adrenal glands. Most is known about the effects of ketoconazole and metyrapone. While effective, access to ketoconazole and metyrapone is limited in many countries, experience with long-term use is limited, and side effects can be significant. Recent studies have suggested a role for a pituitary-directed therapy with new multireceptor ligand somatostatin analogs (e.g., pasireotide, recently approved in Europe for treatment of CD), second-generation dopamine agonists, or a combination of both. Mifepristone (a glucocorticoid receptor antagonist) is another promising drug, recently approved by the FDA for treatment of hyperglycemia associated with Cushing's syndrome. We review available medical treatments for CD with a focus on the two most recent compounds referenced above. Our aim is to expand awareness of current research, and the possibilities afforded by available medical treatments for this mesmerizing, but often frightful disease.