Rapid ACTH test with plasma aldosterone levels. Improved diagnostic discrimination

Impaired aldosterone response to ACTH without hypoaldosteronism: An unrecognized secretory pattern in search of clinical implications

CONTEXT

Aldosterone has been recently characterized as a 'stress hormone'. Stress per se elicits a sizable rise in aldosterone secretion, which could be replicated by the administration of a low dose (0.03-1 μg, IV) of adrenocorticotropic hormone (ACTH). Whether or not the aldosterone response to ACTH could be selectively impaired, that is, in association with intact cortisol response, is presently unknown.

OBJECTIVE

To determine whether or not the aldosterone response to low dose of ACTH is impaired in subjects referred to assess the hypothalamic-pituitary-adrenal axis (HPA).

DESIGN

Retrospective analysis.

SETTING

Outpatient referral endocrine day care centre.

PATIENTS

One hundred and ninety-five consecutive subjects who underwent the low dose (1 μg) ACTH test, in whom decreased cortisol reserve was suspected due to former/present glucocorticoid excess, pituitary disease or/and unexplained weakness.

MAIN OUTCOME MEASURES

The outcome was the detection of lack of aldosterone response, defined as a rise <111 pmol/l.

RESULTS

In all, 46/195 subjects had subnormal aldosterone response as compared with 52/195 subjects showing diminished cortisol response. Nine subjects had combined deficient aldosterone and cortisol response. In the 37 subjects with isolated subnormal aldosterone response common associations were the use of exogenous glucocorticoids, mostly prednisone (n = 16); former Cushing disease (n = 2); nonfunctioning pituitary adenoma (n = 8); hypothyroidism (n = 11); the use of statins (n = 11), angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (n = 6), sex steroids in transgenders and orthostatic hypotension (n = 3). Twenty-seven percent (25/93) of the subjects with recent exposure to glucocorticoids had impaired aldosterone response to ACTH.

CONCLUSION

Blunted aldosterone response to ACTH in the absence of hypoaldosteronism was seen in ~27% of subjects referred for HPA assessment using the low dose 1 μg ACTH test. Exposure to glucocorticoid excess was often linked to this impairment, independent of the cortisol response to ACTH.

Endocrine Toxicity of Cancer Immunotherapy Targeting Immune Checkpoints

Immune checkpoints are small molecules expressed by immune cells that play critical roles in maintaining immune homeostasis. Targeting the immune checkpoints cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed death 1 (PD-1) with inhibitory antibodies has demonstrated effective and durable antitumor activity in subgroups of patients with cancer. The US Food and Drug Administration has approved several immune checkpoint inhibitors (ICPis) for the treatment of a broad spectrum of malignancies. Endocrinopathies have emerged as one of the most common immune-related adverse events (irAEs) of ICPi therapy. Hypophysitis, thyroid dysfunction, insulin-deficient diabetes mellitus, and primary adrenal insufficiency have been reported as irAEs due to ICPi therapy. Hypophysitis is particularly associated with anti-CTLA-4 therapy, whereas thyroid dysfunction is particularly associated with anti-PD-1 therapy. Diabetes mellitus and primary adrenal insufficiency are rare endocrine toxicities associated with ICPi therapy but can be life-threatening if not promptly recognized and treated. Notably, combination anti-CTLA-4 and anti-PD-1 therapy is associated with the highest incidence of ICPi-related endocrinopathies. The precise mechanisms underlying these endocrine irAEs remain to be elucidated. Most ICPi-related endocrinopathies occur within 12 weeks after the initiation of ICPi therapy, but several have been reported to develop several months to years after ICPi initiation. Some ICPi-related endocrinopathies may resolve spontaneously, but others, such as central adrenal insufficiency and primary hypothyroidism, appear to be persistent in most cases. The mainstay of management of ICPi-related endocrinopathies is hormone replacement and symptom control. Further studies are needed to determine (i) whether high-dose corticosteroids in the treatment of ICPi-related endocrinopathies preserves endocrine function (especially in hypophysitis), and (ii) whether the development of ICPi-related endocrinopathies correlates with tumor response to ICPi therapy.

Endocrine dysfunction induced by immune checkpoint inhibitors: Practical recommendations for diagnosis and clinical management

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy. However, because ICIs block coinhibitory molecules on T cells and other immune cells, unleashing them to mediate tumor cell killing, they also can disrupt the maintenance of immunological tolerance to self-antigens. Compared with chemotherapy, ICIs have a different toxicity profile, especially the occurrence of autoimmune-like manifestations against multiple organ systems, including endocrine glands, commonly referred to as immune-related adverse events. The aim of this review was to provide practical recommendations regarding the proper assessment and clinical management related to the new onset of endocrinopathies after the use of ICIs in patients with cancer. Cancer 2018;124:1111-21. © 2018 American Cancer Society.

Adrenal Insufficiency in the Intensive Care Setting

In the intensive care setting, the question of adrenal insufficiency arises most frequently in patients whose endogenous adrenal function may be suppressed by pre ceding glucocorticoid therapy or in patients with the acquired immunodeficiency syndrome. Less often the question arises in patients whose adrenal tissue may have been destroyed by autoimmune disease, tuber culosis, meningococcal or other infection, hemorrhage, or replacement by malignancy, or in patients whose adrenal function has been suppressed by certain drugs. Measurements of plasma adrenocorticotrophic hor mone (ACTH), cortisol, aldosterone, and renin levels and the response of cortisol and aldosterone to exoge nously administered ACTH form the basis for clinically evaluating the adequacy of a patient's adrenal function. The naturally occurring glucocorticoid, hydrocortisone, remains the cornerstone of adrenal replacement therapy along with appropriate fluid and electrolyte administra tion. In rare instances the addition of a mineralocor ticoid is necessary. A brief review of the use of mega- dose glucocorticoids in the treatment of sepsis, shock, and the adult respiratory distress syndrome is included.

Primary vs secondary adrenal insufficiency: ACTH-stimulated aldosterone diagnostic cut-off values by tandem mass spectrometry

OBJECTIVES

To validate the diagnostic utility of Cortrosyn(™) stimulated aldosterone in the differentiation of primary (PAI) and secondary adrenal insufficiency (SAI) and to evaluate the effect of urine sodium levels and posture on test performance.

DESIGN

Cross-sectional study.

METHODS

Healthy volunteers (HV; n = 46) and patients with PAI (n = 26) and SAI (n = 29) participated in the study. Testing included cortisol and aldosterone (by liquid-chromatography tandem mass spectrometry) measurements at baseline and 30 and 60 min after 250 μg Cortrosyn(™). Plasma corticotropin (ACTH), renin activity (PRA) and urine spot sodium as a proxy for 24-h urine sodium excretion were measured at baseline. The effect of a sitting or semifowlers posture was evaluated in healthy volunteers.

RESULTS

A Cortrosyn(™)-stimulated aldosterone level of 5 ng/dl (0·14 nmol/l) had 88% sensitivity and positive predictive value and 89·7% specificity and negative predictive value for distinguishing PAI from SAI. Spot urine sodium levels showed a strong correlation with peak aldosterone levels (r = -0·55, P = 0·02, n = 18) in the SAI but not PAI or HV groups. Posture did not have a significant effect on results.

CONCLUSIONS

Once diagnosed with adrenal insufficiency, a stimulated aldosterone value of 5 ng/dl (0·14 nmol/l) works well to differentiate PAI from SAI. However, clinicians should be aware of the possible effect of total body sodium as reflected by spot urine sodium levels on aldosterone results. A 24-h urine sodium measurement may be helpful in interpretation.

Physiological basis for the etiology, diagnosis, and treatment of adrenal disorders: Cushing's syndrome, adrenal insufficiency, and congenital adrenal hyperplasia

The hypothalamic-pituitary-adrenal (HPA) axis is a classic neuroendocrine system. One of the best ways to understand the HPA axis is to appreciate its dynamics in the variety of diseases and syndromes that affect it. Excess glucocorticoid activity can be due to endogenous cortisol overproduction (spontaneous Cushing's syndrome) or exogenous glucocorticoid therapy (iatrogenic Cushing's syndrome). Endogenous Cushing's syndrome can be subdivided into ACTH-dependent and ACTH-independent, the latter of which is usually due to autonomous adrenal overproduction. The former can be due to a pituitary corticotroph tumor (usually benign) or ectopic ACTH production from tumors outside the pituitary; both of these tumor types overexpress the proopiomelanocortin gene. The converse of Cushing's syndrome is the lack of normal cortisol secretion and is usually due to adrenal destruction (primary adrenal insufficiency) or hypopituitarism (secondary adrenal insufficiency). Secondary adrenal insufficiency can also result from a rapid discontinuation of long-term, pharmacological glucocorticoid therapy because of HPA axis suppression and adrenal atrophy. Finally, mutations in the steroidogenic enzymes of the adrenal cortex can lead to congenital adrenal hyperplasia and an increase in precursor steroids, particularly androgens. When present in utero, this can lead to masculinization of a female fetus. An understanding of the dynamics of the HPA axis is necessary to master the diagnosis and differential diagnosis of pituitary-adrenal diseases. Furthermore, understanding the pathophysiology of the HPA axis gives great insight into its normal control.

Changes in steroid concentrations with the timing of corticotropin stimulation testing in participants with adrenal sufficiency

OBJECTIVE

To determine whether the time of day at which corticotropin stimulation testing is performed influences the steroid concentrations observed in persons with normal adrenal function.

METHODS

In this retrospective, secondary analysis, participants with normal adrenal function were studied to determine whether the time of corticotropin stimulation testing influenced results. Participants consisted of 2 groups: healthy volunteers who were not suspected of having adrenal insufficiency and patients being tested for adrenal insufficiency as part of their standard of care who were subsequently shown to have normal adrenal function on the basis of a peak cortisol value of at least 20 μg/dL. A high-dose corticotropin stimulation test was performed in all participants. Baseline, peak, and delta steroid concentrations were documented after corticotropin injection. Steroid concentrations were measured by tandem mass spectrometry. Multivariate analyses adjusted for patient age, sex, and baseline steroid concentrations.

RESULTS

With progression through the day for the time of testing, the baseline cortisol concentration decreased, while the peak and delta cortisol concentration increased (P values: <.001, .007, .007, respectively). For 11-deoxycortisol, the baseline decreased, while peak and delta values increased with later testing (P values: .017, .012, .02, respectively). Peak aldosterone concentrations increased according to their baseline values (P<.001), but were unaffected by time. Peak and delta dehydroepiandrosterone concentrations increased with time (P = .015 and .021, respectively). Referring to the various criteria for adequate steroid responses to corticotropin available in the literature, the time-related differences in this small group of patients were insufficient to draw different conclusions about results of testing.

CONCLUSIONS

Cortisol, 11-deoxycortisol, and dehydroepiandrosterone values were most influenced by testing times. In patients with borderline adrenal function who are tested at different times of the day, the modest differences we observed may be sufficient to affect conclusions about whether adrenal insufficiency is present.

Pomc knockout mice have secondary hyperaldosteronism despite an absence of adrenocorticotropin

Aldosterone production is controlled by angiotensin II, potassium, and ACTH. Mice lacking Pomc and its pituitary product ACTH have been reported to have absent or low aldosterone levels, suggesting that ACTH is required for normal aldosterone production. However, this is at odds with the clinical finding that human aldosterone deficiency is not a component of secondary adrenal insufficiency. To resolve this, we measured plasma and urine electrolytes, together with plasma aldosterone and renin activity, in Pomc(-/-) mice. We found that these mice have secondary hyperaldosteronism (elevated aldosterone without suppression of renin activity), indicating that ACTH is not required for aldosterone production or release in vivo. Exogenous ACTH stimulates a further increase in aldosterone in Pomc(-/-) mice, whereas angiotensin II has no effect, and the combination of angiotensin II and ACTH is no more potent than ACTH alone. These data suggest that aldosterone production and release in vivo do not require the action of ACTH during development or postnatal life and that secondary hyperaldosteronism in Pomc(-/-) mice is a consequence of glucocorticoid deficiency.

Secondary hypoadrenalism

Secondary adrenal insufficiency (SAI) is a clinical disorder that results from hypothalamic or hypophyseal damage or from prolonged administration of supraphysiological doses of glucocorticoids. Since glucocorticoids are widely used for a variety of diseases, the prevalence of SAI is by far exceeding that of primary adrenal insufficiency. Although the presentation of adrenal insufficiency may be insidious and difficult to recognize, an appropriate adrenocortical hormone replacement could lead to a normal quality of life and longevity can be achieved. The spectrum of adrenal insufficiency ranges from overt adrenal crises to subtle dysfunctions in asymptomatic patients who may be at risk of developing acute adrenal insufficiency since their hypothalamic-pituitary-adrenal (HPA) axis cannot appropriately react to stress. Thus, identification of patients with subtle abnormalities of the HPA is mandatory for avoiding this life-threatening event in stressful conditions. The optimal tests and the optimal testing sequence for adrenal insufficiency are still matter of debate. Insulin tolerance test (ITT) could be the gold standard, as it tests the whole HPA axis, but there are some patients who pass the ITT failing the ACTH test. Various alternatives to the ITT, including the standard cosyntropin stimulation test (SST) and low-dose SST, have been proposed since the adrenal gland in SAI loses the capacity for a prompt response to ACTH stimulation. The standard ACTH dose, but not the 1 microg dose, increases adrenal blood flow and this may contribute to produce an early cortisol response of greater magnitude. Moreover, the loss of the early cortisol response to ACTH stimulation could be a specific property of adrenal insufficiency, thus being a sensitive and early marker of failing adrenal function. While the results of the SSTs are often positive in patients with long-standing and severe disease, in patients with mild or recent-onset SAI these tests, using either 250 microg or 1 microg ACTH, tend to give normal results; thus, a negative cosyntropin test result does not rule out the possibility of SAI. Further studies with a systematic comparison of the different tests in large series of patients submitted to a prolonged follow-up are needed to solve the controversy of the optimal diagnostic strategy of SAI.

Use of steroid profiles in determining the cause of adrenal insufficiency

HYPOTHESIS

A cortisol response to adrenocorticotropin injection is the standard test for diagnosing adrenal insufficiency. Multiple steroid hormones can now be accurately measured by tandem mass spectrometry in a single sample. The study objective was to determine whether a steroid profile, created by simultaneous measurement of 10 steroid hormones by tandem mass spectrometry, would help determine the cause of adrenal insufficiency.

DESIGN

A 10-steroid profile was measured by tandem mass spectrometry during the performance of a standard high dose cortrosyn stimulation test. The steroids were measured at baseline, 30, and 60min following synthetic adrenocorticotropin injection. Adrenal insufficiency was defined as a peak cortisol level of less than 20microg/dL. Testing was conducted in the general clinical research center of a university medical center. Normal volunteers, patients suspected of having adrenal insufficiency, and patients with known adrenal insufficiency participated.

RESULTS

Our results showed that adrenal insufficiency of any cause was adequately diagnosed using the response of 11-deoxycortisol, dehydroepiandrosterone, or these analytes combined in a two-steroid profile. A three-steroid profile yielded a test with 100% accuracy for discriminating primary adrenal insufficiency from normal status. Primary adrenal insufficiency was well separated from secondary adrenal insufficiency using only a single aldosterone value. 11-Deoxycortisol, dehydroepiandrosterone, and a two-steroid profile each provided fair discrimination between secondary adrenal insufficiency and normal status.

CONCLUSIONS

We conclude that stimulated levels of aldosterone, 11-deoxycortisol, dehydroepiandrosterone, and a two- or three-steroid profile provided additional discrimination between states of adrenal sufficiency and insufficiency. It is proposed that a steroid profile measuring cortisol, aldosterone, 11-deoxycortisol, and dehydroepiandrosterone would potentially improve the ability to determine the cause of adrenal insufficiency.

The hypothalamic-pituitary-adrenal axis in pregnancy: challenges in disease detection and treatment

Pregnancy dramatically affects the hypothalamic-pituitary-adrenal axis leading to increased circulating cortisol and ACTH levels during gestation, reaching values in the range seen in Cushing's syndrome (CS). The cause(s) of increased ACTH may include placental synthesis and release of biologically active CRH and ACTH, pituitary desensitization to cortisol feedback, or enhanced pituitary responses to corticotropin-releasing factors. In this context, challenges in diagnosis and management of disorders of the hypothalamic-pituitary-adrenal axis in pregnancy are discussed. CS in pregnancy is uncommon and is associated with fetal morbidity and mortality. The diagnosis may be missed because of overlapping clinical and biochemical features in pregnancy. The proportion of patients with primary adrenal causes of CS is increased in pregnancy. CRH stimulation testing and inferior petrosal sinus sampling can identify patients with Cushing's disease. Surgery is a safe option for treatment in the second trimester; otherwise medical therapy may be used. Women with known adrenal insufficiency that is appropriately treated can expect to have uneventful pregnancies. Whereas a fetal/placental source of cortisol may mitigate crisis during gestation, unrecognized adrenal insufficiency may lead to maternal or fetal demise either during gestation or in the puerperium. Appropriate treatment and management of labor are reviewed.

Pituitary gland and pregnancy

The hypothalamic-pituitary-adrenal axis is central to mammalian reproductive function, including conception, pregnancy maintenance, parturition, and breastfeeding. Pregnancy is associated with substantial physiologic changes within this endocrine axis to meet the demands of pregnancy, which include support of the fetus (volume support, nutritional and oxygen supply, clearance of fetal waste), protection of the fetus (from starvation, drugs, toxins), preparation of the uterus for labor, and protection of the mother from potential cardiovascular injury at delivery. This article reviews the anatomy, embryology, and physiology of the pituitary. The effect of pregnancy on pituitary structure and function, in health and disease, also is discussed.

Adrenal insufficiency in high-risk surgical ICU patients

STUDY OBJECTIVES

To examine the incidence and response to treatment of adrenal insufficiency (AI) in high-risk postoperative patients.

DESIGN

Prospective observational case series.

SETTING

Large urban tertiary-care surgical ICU (SICU).

PARTICIPANTS

Adults > 55 years of age who required vasopressor therapy after adequate volume resuscitation in the immediate postoperative period.

INTERVENTIONS

Each patient underwent a cosyntropin (ACTH) stimulation test; at the discretion of the clinical team, some patients were empirically given hydrocortisone (100 mg IV q8h for three doses) before serum cortisol values became available.

MEASUREMENTS

Adrenal dysfunction (AD), defined as serum cortisol < 20 microg/dL at all time points, with Delta cortisol (60 min post-ACTH minus baseline) of < or = 9 microg/dL; functional hypoadrenalism (FH), defined as serum cortisol < 30 microg/dL at all time points or Delta cortisol (60 min post-ACTH minus baseline) < or = 9 microg/dL; and AI, as the presence of either AD or FH.

RESULTS

One hundred four patients were enrolled with a mean age (SD) of 65.2 +/- 16.9 years. AI (AD plus FH) was found in 34 of 104 patients (32.7%): AD was found in 9 patients (8.7%), FH in 25 patients (24%), and normal adrenal function in 70 patients (67.3%). The absolute eosinophil count was significantly higher in the combined AD and FH groups compared with the group with normal adrenal function (p < 0.05). Forty-six of 104 patients (44.2%) received hydrocortisone; 29 (63%) could be weaned from treatment with vasopressors within 24 h. This beneficial effect of hydrocortisone reached statistical significance in the FH group when compared with untreated patients (p < 0.031); a similar trend was seen in the AD group (p = 0.083). Mortality was also lower in the hydrocortisone-treated AI patients (5 of 23 [21%] vs 5 of 11 [45%] in those not receiving hydrocortisone; p < 0.01).

CONCLUSION

There is a high incidence of AI among SICU patients > 55 years of age with postoperative hypotension requiring vasopressors. There is also a significant association between hydrocortisone replacement therapy, resolution of vasopressor requirements, and improved survival.

Adrenal dysfunction in hemodynamically unstable patients in the emergency department

OBJECTIVE

Adrenal failure, a treatable condition, can have catastrophic consequences if unrecognized in critically ill ED patients. The authors' objective was to prospectively study adrenal function in a case series of hemodynamically unstable (high-risk) patients from a large, urban ED over a 12-month period.

METHODS

In a prospective manner, critically ill adult patients presenting to the ED were enrolled when presenting with a mean arterial blood pressure < or =60 mm Hg requiring vasopressor therapy for more than one hour after receiving fluid resuscitation (central venous pressure of 12-15 mm Hg or a minimum of 40 mL/kg of crystalloid). Patients were excluded if presenting with hemorrhage, trauma, or AIDS, or if steroids were used within the previous six months. An adrenocorticotropic hormone (ACTH) stimulation test was performed and serum cortisol was measured. Treatment for adrenal insufficiency was not instituted.

RESULTS

A total of 57 consecutive patients were studied. Of these, eight (14%) had baseline serum cortisol concentrations of <20 microg/dL (<552 nmol/L), which was considered adrenal insufficiency (AI). Three additional patients (5%) had subnormal 60-minute post-ACTH-stimulation cortisol responses (<30 microg/dL) and a delta cortisol < or =9 microg/dL, which is the difference between the baseline and 60-minute levels. This is functional hypoadrenalism (FH). There were no laboratory abnormalities that distinguished patients with AI or FH from those with preserved adrenal function (PAF). Rates of survival to discharge did not differ between the AI group (7 of 8) and PAF patients (21 of 46; p = 0.052).

CONCLUSIONS

Adrenal dysfunction is common in high-risk ED patients. Overall, it has a frequency of 19% among a homogeneous population of hemodynamically unstable vasopressor-dependent patients. The effect of physiologic glucocorticoid replacement in this setting remains to be determined.

Plasma cortisol responses after intramuscular corticotropin 1-24 in healthy men

Intravenous infusion of corticotropin 1-24 (ACTH 1-24) followed by a plasma cortisol measurement after 60 minutes of less than 20 microg/dL indicates clinically important glucocorticoid deficiency. In this study, we evaluated the morning plasma cortisol response to an intramuscular (IM) injection of ACTH 1-24 (250 microg) in 64 healthy men. Plasma cortisol increased significantly 30 and 60 minutes after IM ACTH 1-24 (P < .0001). In most subjects, a maximal response was obtained at 60 minutes. The cortisol response correlated positively with the morning basal cortisol concentration. The lowest cortisol peak and the lowest increment observed after IM ACTH 1-24 were, respectively, 12.6 and 3.5 microg/dL after 30 minutes and 16.3 and 5.3 microg/dL after 60 minutes. We conclude that a plasma cortisol level less than 16.0 microg/dL 60 minutes after IM ACTH 1-24 can be used as an index of glucocorticoid deficiency.

Tuberculous Addison's disease: lack of normalization of adrenocortical function after anti-tuberculous chemotherapy

OBJECTIVE

Tuberculosis of the adrenal glands is a common cause of Addison's disease in developing countries. We conducted a study to determine if treatment of such patients with modern anti-tuberculous chemotherapy would lead to an improvement in plasma cortisol and aldosterone levels.

DESIGN

Prospective study.

PATIENTS

5 patients with Addison's disease secondary to tuberculosis.

MEASUREMENTS

Basal and ACTH stimulated plasma cortisol and aldosterone levels were measured prior to instituting anti-tuberculous chemotherapy, as well as one month after its conclusion. Four patients were again studied over the next 2-5 years.

RESULTS

Peak plasma cortisol levels prior to treatment were markedly reduced (range, < 14-110 mumol/l). There was no improvement one month (< 14-143 mumol/l) or 2-5 years (< 14-69 mumol/l) after completing anti-tuberculous chemotherapy. Peak plasma aldosterone at diagnosis was < 56-210 pmol/l; it was undetectable in 4 patients. No improvement was observed one month (< 56-210 pmol/l), or 2-5 years (< 56-389 pmol/l) after stopping anti-tuberculous chemotherapy. Plasma aldosterone levels at both these time points were far lower than those in control subjects (median 736 pmol/l, 560-1512 pmol/l; p < 0.01). One patient had an increase in peak aldosterone from < 56 pmol/l to 389 pmol/l, though peak cortisol actually declined in this subject (from 110 mumol/l to 69 mumol/l).

CONCLUSIONS

Treatment of tuberculous Addison's disease with anti-tuberculous chemotherapy does not lead to normalization of ACTH stimulated plasma cortisol or aldosterone levels during the 2-5 year period of study. However, prolonged follow up with regular adrenal function tests is warranted in all such patients.

Giant-Cell Granulomatous Hypophysitis

OBJECTIVE

To describe the clinical features of giant-cell granulomatous hypophysitis and to report on the results of corticosteroid treatment.

METHODS

A case of giant-cell granulomatous hypophysitis is presented, and the pertinent literature is reviewed.

RESULTS

A 41-year-old woman with anterior pituitary dysfunction had a pituitary mass that was 18 by 16 by 13 mm by magnetic resonance imaging. The pituitary stalk was thickened and enhanced after intravenous administration of gadolinium. A biopsy specimen that was obtained at transsphenoidal pituitary exploration revealed that the patient had giant-cell granulomatous hypophysitis, a rare inflammatory pituitary disorder. High-dose corticosteroid therapy failed to reverse her anterior pituitary dysfunction.

CONCLUSION

The coincidence of a contrast-enhancing pituitary mass with a thickened pituitary stalk and the awareness of the rare occurrence of endocrine inactive tumors in women of childbearing age should suggest an inflammatory pituitary condition. Such lesions should also be suspected in otherwise healthy young women with hypopituitarism and no evidence of hormone hypersecretion. On the basis of the literature and our experience, corticosteroid treatment does not seem to improve anterior pituitary function.

Mineralocorticoid insufficiency due to suramin therapy

BACKGROUND

During a Phase I trial of suramin, a novel antineoplastic agent with activity against hormone-refractory prostate carcinoma, the authors observed two patients with clinical mineralocorticoid insufficiency in spite of hydrocortisone replacement therapy.

METHODS

The authors retrospectively assessed adrenal cortical function in 20 such patients via adrenocorticotropic stimulation testing, measuring both cortisol and aldosterone responses, either at the time or treatment of immediately after discontinuation of treatment.

RESULTS

Two of 9 patients (22%) treated at relatively low dose levels (< or = 1200 mg/m2 on Day 1) demonstrated adrenal cortical insufficiency, as compared with 9 of 11 patients (32%) treated with relatively high doses (> 1200 mg/m2 on Day 1) (P = 0.03 by 1-tailed Fisher's exact test). There appeared to be a cumulative dose-response relationship to the development of glucocorticoid insufficiency, with no instances being observed at doses < 4.8 g/m2 and uniform toxicity occurring at doses > 7.6 g/m2. Long term glucocorticoid insufficiency was present in 1 of 5 patients (20%) tested at an interval of > 90 days after discontinuation of suramin treatment. All instances of glucocorticoid insufficiency were associated with mineralocorticoid insufficiency. Suramin did not affect the absorption or excretion of exogenously administered glucocorticoid in one patient.

CONCLUSIONS

Suramin causes both primary mineralocorticoid and primary glucocorticoid insufficiency. This may occur in a dose-dependent manner. Long term glucocorticoid insufficiency appears to occur in a minority of patients treated with low doses of suramin. Patients receiving high doses of suramin for treatment of advanced carcinoma should receive at least physiologic replacement doses of both mineralocorticoid and glucocorticoid. Higher doses of glucocorticoid may be required in selected patients.

A comparison between short synacthen test and depot synacthen test in the evaluation of cortisol reserve of adrenal gland in normal subjects

Synacthen test has been widely used as a screening test for evaluation of adrenal cortisol reserve. We investigated whether depot Synacthen test can be used in place of short Synacthen test in the evaluation of cortisol reserve of the adrenal gland. The study included 20 healthy volunteers of both sexes. We examined plasma cortisol response 30, 60, 90, and 120 min after administration of plain Synacthen, 250 micrograms, iv (Group 1), and depot Synacthen, 1000 micrograms, im (Group 2). Peak cortisol values were statistically similar between the groups. The increment in cortisol levels following Synacthen was also similar between the groups. A plasma cortisol value above 550 or 600 nmol/L was achieved in both groups during the test of 90 or 120 minutes duration, respectively. We think that depot Synacthen test, im 1000 micrograms, may be used in place of plain Synacthen, iv 250 micrograms, for evaluation of adrenal cortisol reserve.

Responses of plasma adrenocortical steroids to low dose ACTH in normal subjects

OBJECTIVE

The standard ACTH test in clinical use employs a pharmacological dose of ACTH which assesses the maximum secretory capacity of the adrenal cortex. We have investigated the responses of plasma adrenocortical steroids including cortisol, aldosterone and dehydroepiandrosterone (DHEA) to physiological doses of ACTH (ACTH 1-24, tetracosactide, Cortrosyn) and determined the minimal dose which induces a response equivalent to that induced by a pharmacological dose of ACTH.

DESIGN

Rapid ACTH tests at various physiological (0-1, 0.5, 1 and 5 micrograms) and standard pharmacological (250 micrograms) intravenous doses.

SUBJECTS

Seven healthy normal volunteers.

MEASUREMENTS

Plasma cortisol, aldosterone and DHEA were measured. Peak value and the increment from basal value were used as indices of responses.

RESULTS

Each steroid responded to physiological doses of ACTH in a dose dependent manner. The minimum dose inducing an equivalent response to 250 micrograms ACTH was 0.5 micrograms for peak and incremental values in cortisol and DHEA, while that for aldosterone was 0.1 microgram. The time to peak for each steroid was delayed as the dose increased. Plasma aldosterone and DHEA peaked significantly earlier than plasma cortisol in 1-5 micrograms and 0.5-5-micrograms ACTH tests, respectively.

CONCLUSIONS

These results suggest that the sensitivity of secretion to physiological doses of ACTH in descending order is aldosterone > DHEA = cortisol. When peak and incremental values are used, sufficient doses of ACTH are 0.1 microgram for plasma aldosterone and 0.5 microgram for plasma cortisol and DHEA in the rapid ACTH test.

Therapeutic outcome of primary aldosteronism: adrenalectomy versus enucleation of aldosterone-producing adenoma

Our followup study of 48 patients with primary aldosteronism concerns the results of 2 different operative methods. After preoperative localization of the unilateral solitary tumor 22 patients underwent unilateral adrenalectomy and 26 underwent enucleation of aldosterone-producing adenoma. Both operative methods improved hypertension, hypokalemia, the low urinary sodium-to-potassium ratio, suppressed plasma renin activity, high plasma aldosterone concentration, high urinary aldosterone excretion and high urinary kallikrein excretion in similar orders of magnitude for 5 years. Levels of plasma cortisol and plasma adrenocorticotropic hormone following respective operations were also identical. Five years postoperatively, ambulation and furosemide administration under low sodium diet stimuli remarkably enhanced plasma renin activity and plasma aldosterone concentration in the aldosterone-producing adenoma enucleation group (p < 0.001), almost similar to that of normal subjects but increment magnitudes were slight (p < 0.05 to < 0.01) in the adrenalectomy group. Preoperatively, angiotensin II infusion failed to increase plasma aldosterone concentration in patients with primary aldosteronism. After respective operations, responses of plasma aldosterone concentration to angiotensin II infusion and of plasma cortisol to adrenocorticotropic hormone administration in the aldosterone-producing adenoma enucleation group were more sensitive than those in the adrenalectomy group. There was no remission of recurrent hyperaldosteronism in either group throughout the study. These results suggest that angiotensin II induces aldosterone release by an activation of tumor uninvolved cortical cells and that the enucleation of aldosterone-producing adenoma is more preferable than unilateral adrenalectomy.

Addison's disease. How to improve patients' quality of life

Modern adrenal function studies can facilitate both diagnosis and management in patients with chronic adrenal insufficiency. These tests are readily available at commercial laboratories and can be conveniently carried out in the physician's office during working hours. As use of these adrenal function studies becomes more common, patients with chronic adrenal insufficiency can expect to have a great improvement in quality of life.

Yohimbine and aldosterone responsiveness to angiotensin II or corticotrophin in normal subjects

In normal man the sympathetic nervous system exerts an inhibitory influence on aldosterone responsiveness to angiotensin II. The possible role of alpha-2 adrenoceptors was assessed by studying the changes of plasma aldosterone during an angiotensin II infusion at the dose of 1, 2, 5 and 10 ng/kg. min or after corticotrophin infusion, 0.25 mg, in 8 normal subjects before and after treatment with the selective alpha-2 adrenoceptor antagonist, yohimbine, at a maximal dosage of 60 mg daily. Yohimbine did not modify blood pressure, body weight, the supine levels of angiotensin II, renin and aldosterone, the pressor response to angiotensin II and the correlation relating plasma aldosterone to plasma angiotensin II obtained during infusion studies. These findings suggest that the inhibitory influence of the sympathetic nervous system on aldosterone responsiveness to angiotensin II.

Diseases of the adrenal cortex

The adrenal cortex is functionally a three-dimensional gland that secretes glucocorticoids, mineralocorticoids, and sex steroids. Of these three classes of steroids only the gluco- and mineralocorticoid hormones are necessary to sustain life. The availability of sensitive and specific radioimmunoassays has permitted accurate measurement of practically every steroid hormone secreted by the adrenal cortex. As in other endocrinopathies, suppression studies are employed when hyperfunction is suspected, while provocative tests are used to detect hypofunction. These dynamic studies enable the clinician to evaluate the functional status of the adrenal cortex. The anatomic configuration of the adrenal cortices is delineated by high-resolution computed tomography (and magnetic resonance imaging), obviating the need for invasive procedures such as venography or arteriography. The disorders of the adrenal cortex can be viewed from the dual perspectives of hyperfunction and hypofunction. Clinical expressions of hyperfunctional adrenocortical syndromes include Cushing's syndrome, primary hyperaldosteronism, and the adrenogenital syndrome. The expressions of hypofunctional syndromes include Addison's disease and selective hypoaldosteronism. The diagnosis and treatment of these disorders are outlined in this issue.

Hyporeninemic hypoaldosteronism associated with acquired immune deficiency syndrome

Four patients with the acquired immune deficiency syndrome (AIDS) and persistent unexplained hyperkalemia were studied. Testing with cosyntropin (0.25 mg intravenously) revealed normal baseline and stimulated cortisol levels and adequate aldosterone stimulation. The baseline aldosterone level was low for the degree of hyperkalemia. Renin/aldosterone stimulation testing was performed by intravenous injection of 80 mg of furosemide followed by four hours of upright posture. This study showed low baseline renin and aldosterone levels and inadequate renin and aldosterone stimulation. Three patients were subsequently treated with fludrocortisone (0.1 to 0.2 mg per day), with normalization of serum potassium levels. It is concluded that hyporeninemic hypoaldosteronism is responsible for hyperkalemia in some patients with AIDS and that treatment with fludrocortisone is effective in these cases.

The effects of stress on salt and water balance

The effect of 'stress' on salt and water balance is largely determined by intrinsic renal factors supported by a series of inter-related neuro-humoral mechanisms which serve to enhance salt and water reabsorption and to maintain arterial pressure. As shown by acute hypovolaemic stress, the hormone response is characterized by increased renin-angiotensin production and associated hyperaldosteronism, which is further augmented by states of Na+ depletion. As well as increasing aldosterone secretion, angiotensin II has a direct renal effect to increase Na+ retention, and may stimulate both thirst and arginine vasopressin secretion. Additional support to volume homeostasis is provided by increased secretion of hypothalamic hormones (arginine vasopressin and corticotrophin releasing factor) and activation of the sympathetic nervous system, which further enhances renin secretion. These mechanisms, in restoring extracellular fluid volume and renal perfusion pressure, eventually diminish the stimuli to renin once normovolaemia is achieved. A variety of other acute 'stressors', not associated with major changes in ECF volume or hypotension, also stimulate adrenocortical hormones (cortisol and aldosterone), renin and arginine vasopressin. The biological significance of these changes is uncertain, but their brief duration make it unlikely that the responses contribute significantly to changes in salt or water balance. Atrial peptide hormones could also be important in ECF volume regulation. However, recent studies show little if any change in basal plasma atrial natriuretic peptide levels during acute hypovolaemic stress, whereas severe treadmill exercise (but not surgical stress or acute hypoglycaemia) stimulates venous levels in man. The relevance of these findings to the regulation of salt and water balance during stress clearly requires further study.

Adrenergic activity and aldosterone regulation: no evidence for an alpha-1 adrenoceptor-mediated influence in normal subjects

In normal man the sympathetic nervous system could exert an inhibitory influence on aldosterone responsiveness to angiotensin II. The possible role of alpha-1 adrenoceptors in the modulation of aldosterone response was assessed by studying the changes of plasma aldosterone during infusion of angiotensin II at the doses of 1, 2, 5 and 10 ng/kg.min or after corticotrophin injection, 0.25 mg, in 9 normal subjects before and after treatment with the selective alpha-1 adrenoceptor antagonist, prazosin. Prazosin, given during 3 weeks, did not modify supine arterial pressure, heart rate and the plasma levels of angiotensin II, renin, aldosterone or adrenaline but caused a significant (P less than 0.05) increase of plasma noradrenaline. The correlation relating plasma aldosterone to plasma angiotensin II levels before and during angiotensin II infusion and the response of plasma aldosterone to corticotrophin was not modified by prazosin. These findings suggest that in normal man there is no inhibitory influence of the noradrenergic system on aldosterone responsiveness to angiotensin II mediated by an alpha-1 dependent mechanism.

Adrenal function following coronary bypass surgery

Little is known about adrenocortical function after coronary bypass surgery in which moderate to deep hypothermia and cardiopulmonary bypass are used particularly with intraoperative steroid administration. Therefore, we performed a pilot study in which immediately preoperative and 18-hour postoperative serum cortisol levels were determined in eight patients who received 1.0 to 1.5 gm of methylprednisolone intravenously during surgery; postoperative serum cortisol (3 +/- 1 microgram%) levels were lower than preoperative levels (15 +/- 3 microgram%, p less than 0.05). To determine the possible cause of these striking findings, the effects of moderate to profound hypothermia and cardiopulmonary bypass upon adrenocortical functioning were investigated without the influence of intraoperative steroid administration. Serum cortisol and aldosterone levels and their response to adrenocorticotropic hormone (ACTH) (Cortrosyn) were determined before coronary bypass surgery and at various postoperative intervals in seven patients. Postoperative cortisol and aldosterone levels increased markedly over their preoperative values, reaching a maximum at 6 to 12 hours (cortisol 16 +/- 8 vs 63 +/- 23 micrograms%, p less than 0.05, aldosterone 15 +/- 5 vs 51 +/- 22 ng%, p less than 0.05). Adrenal response to ACTH was normal preoperatively, during rewarming from hypothermia, and 18 hours, and 7 days postoperatively. In summary, normal adrenal responsiveness occurs after coronary bypass surgery, in spite of hypothermic cardiopulmonary bypass and the effects of anesthesia, and a single dose of methylprednisolone during surgery is associated with markedly lower serum cortisol levels and prevents the usual adrenal stress response to bypass surgery for at least 18 hours postoperatively.

Investigation of hypothalamic-pituitary disease

It can be readily appreciated from the preceding discussion that many endocrine and non-endocrine tests are available for the evaluation of patients with suspected hypothalamic-pituitary disease. The endocrine evaluation of these subjects should be tailored according to the type and extent of pathology suspected (see Tables 2 and 3). For patients with pituitary adenomas and clinical features of hyperpituitarism, such as hyperprolactinaemia, Cushing's disease or acromegaly, the initial tests should be directed at the hormone whose excess is suspected. For example, a glucose suppression test for acromegaly or dexamethasone suppression test for Cushing's disease should be performed early in the evaluation. The possibility of deficiencies of the other pituitary hormones should then be addressed in patients with secretory tumours, but initially in those with apparent non-functioning adenomas. In patients with large macroadenomas pituitary hormone deficiencies are almost invariable with GH and FSH/LH being the most commonly affected, followed by TSH and ACTH in that order (Snyder et al, 1979a; Valenta et al, 1982). Basal thyroid function tests, serum oestradiol or testosterone, and basal gonodotrophins should be routinely obtained in patients with macroadenomas. Additionally, the integrity of the pituitary-adrenal axis should be determined and an overnight water deprivation test for assessment of neurohypophyseal function is also recommended. GH stimulation testing is valuable as a test of pituitary function in patients with suspected pituitary tumours since GH reserve is lost very early in the development of hypopituitarism. Evaluation of the pituitary-thyroid axis with TRH or the pituitary gonadal axis with LHRH generally provides limited additional information of diagnostic value in individual patients with macroadenomas. However, the 'paradoxical' responses to TRH and LHRH may be useful as a biological marker following therapy in patients with GH- or ACTH-secreting tumours. In patients with microadenomas, pituitary hormone deficiencies are uncommon (Valenta et al, 1982). Despite this observation, it may be beneficial to determine basal thyroid levels, gonadotrophin levels, serum testosterone or oestradiol levels, and the response to an overnight metyrapone test in such patients to provide a baseline for future care.(ABSTRACT TRUNCATED AT 400 WORDS)

Limited adrenal reserve in paracoccidioidomycosis: cortisol and aldosterone responses to 1-24 ACTH

Adrenal function in twenty-three patients with paracoccidioidomycosis (South American Blastomycosis) has been assessed by measuring the response to adrenocortical stimulation with 1-24 ACTH. Two patients with overt Addison's disease showed very low basal levels and the complete absence of an increase in either cortisol or aldosterone secretion. Six patients showed probable diminished adrenal reserve in terms of cortisol and three patients showed diminished reserve in terms of aldosterone function. These findings indicate an incidence of significant hypoadrenalism in 44% of hospitalized patients with disseminated paracoccidioidomycosis.

Recognition of adrenal insufficiency in the postoperative patient

The signs and symptoms of adrenal insufficiency in the postoperative patient are generally nonspecific, and the diagnosis is usually made at postmortem examination. Two patients in whom adrenal insufficiency developed in the postoperative period are reported on (one had metastatic carcinoma to the adrenal glands and in the other bilateral adrenal hemorrhage developed during anticoagulant treatment). Both patients survived multiple, successive stressful episodes before the diagnosis of adrenal insufficiency was established by the alpha1-24 corticotropin stimulation test.

Use and abuse of systemic corticosteroid therapy

Steroid-responsive acute dermatoses should be treated with a single morning dose of prednisone for approximately 2 weeks. It is necessary to "taper" a short course of oral prednisone given by this method. Chronic dermatoses should be treated whenever possible with prednisone used in the morning and on alternate days. This method is effective, is free of most side effects, and suppresses the HPA axis minimally. There are few real advantages in using intramuscular corticosteroids. TAC is an unusually strong suppressor of the HPA axis. For chronic dermatoses, a less suppressive preparation might best be chosen if the physician feels that the intramuscular route is the most reasonable one. In any event TAC should never be used more often than every two months. Finally, the time-course of HPA recovery following short courses of steroids is presently unknown. Nonetheless, some astute critics of steroid metabolism have felt obliged to advise us that individuals who have received from 1 to 4 weeks of suppressive steroid treatment should be suspect as to the integrity of their HPA axis in stressful situations for up to one year. The withdrawal from, as well as the use of, systemic corticosteroids requires a creative and critical physician.

Hyporeninemic hypoaldosteronism--case report and observation of dissociated renin and erythropoietin activity

A case is reported of hyporeninemic hypoaldosteronism, diagnosed during an evaluation of hyperkalemia. Urine and plasma aldosterone concentrations were depressed despite hyperkalemia and were not responsive to ACTH, cosyntropin, and angiotensin 2. Adrenal glucocorticoid function was normal. Plasma renin activity also was low, and was hyporesponsive to stimulation, including intravascular volume contraction and potassium depletion. Autonomic nervous function was intact. Of the 32 previously reported cases of selective hypoaldosteronism, plasma renin activity was low in the majority of cases in which it was measured. A classification of the types of selective hypoaldosteronism is presented. It is of interest that the serum erythropoietin activity in this case was increased while plasma renin activity was markedly depressed.

Adrenal insufficiency after unilateral radical nephrectomy

A case of adrenal insufficiency occurring after unilateral radical nephrectomy is presented. Recommendations for identification and treatment of this condition are discussed.

Clinical testing of the hypothalamic-pituitary-adrenocortical system in states of hypo- and hypercortisolism

Cortisol production is appropriately maintained by a complex control system which involves primarily the hypothalamus, the pituitary, and the adrenal cortices. Very small quantities of ACTH stimulate cortisol production, and maximum stimulation occurs with serum concentrations of only 3 mU/100 ML. Under normal circumstances, cortisol is secreted in bursts about ten times each day and circulates predominately bound to a specific binding protein which is rather completely saturated. Radioimmunoassay of plasma cortisol is now generally available and is the assay method of choice, but because of the episodic nature of its secretion, random values of plasma cortisol must be interpreted with great reservation, and even the comparison of morning and evening values in assessing circadian rhythmicity is not often helpful. Urinary free cortisol determinations provide excellent discrimination between normal function and all forms of hypercortisolism. Although the response of the adrenal cortices to ACTH may be evaluated in a number of different ways, the simplest but most definitive procedure involves continuous intravenous administration over a 48-hr period. Of the various tests which indirectly assess the potential for ACTH secretion, the use of metyrapone is most helpful. In the test of greatest utility, plasma cortisol and 11-desoxycortisol are determined the morning after a single midnight oral dose of 30 mg/kg. The detection of all forms of pathologic hypercortisolism is still best accomplished by the oral administration of dexamethasone. Plasma cortisol can be determined the morning after a single midnight dose of 1 mg, or urinary 17-hydroxycorticosteroids can be determined after 2 days in which 0.5 mg is given at 6-hr intervals. Patients with hypercortisolism of hypothalamic-pituitary origin usually evidence appropriate suppression of urinary steroids if the dose is increased to 2.0 mg every 6 hr for another 48 hr. In patients who do not suppress on this or even higher doses of dexamethasone, the distinction between those with adrenal tumor and those with the ectopic ACTH syndrome can be accomplished most definitively by the assay of plasma ACTH where this determination is available.