Eleven-Year Experience with Selective Adrenal Vein Sampling in Management of Primary Adrenal Hormonal Hypersecretion.

Introduction: Nearly half of the adult population in the United States has been diagnosed with hypertension. Adrenal hormonal hypersecretion is a leading cause of secondary hypertension. Adrenal vein sampling (AVS) may assist in differentiating between unilateral and bilateral adrenal hormonal hypersecretion to identify patients who are candidates for adrenalectomy. We reviewed the use of AVS at our institution along with associated outcomes after adrenalectomy. Materials and Methods: A retrospective chart review was conducted of patients with a diagnosis of primary hyperaldosteronism (PA) or adrenocorticotropic hormone-independent Cushing syndrome (AICS) and who underwent adrenalectomy between January 1, 2010, and December 1, 2021. Patient data of baseline characteristics, preoperative workup, including AVS, and postoperative outcomes were collected and analyzed. Results: Seventy-one patients were identified in the study period (48 PA and 23 AICS). Computed tomography scan identified unilateral adrenal nodules in 52 patients (29 left; and 23 right), bilateral nodules in 13 patients, and no nodules in 6 patients. AVS was performed in 45 patients with PA (93%) and 5 patients with AICS (21%). After surgery, the number of PA patients with hypokalemia or requiring potassium supplementation significantly decreased after adrenalectomy (before surgery: 33 [68.7%]; and after surgery: 5 [10.4%], P < .01). The number of medications required for hypertension in AICS patients also significantly decreased. No major adverse events were noted. Conclusions: Our long-term experience demonstrates the ongoing use of AVS during workup of patients with primary hyperaldosteronism and for select patients with adrenocorticotropic hormone-independent Cushing syndrome. However, a low level of discordance between imaging and AVS findings in PA patients suggests that there may be a subset of patients in whom preoperative AVS is not necessary.

Dysfunction in Sertoli cells participates in glucocorticoid-induced impairment of spermatogenesis.

The effect of stress on male fertility is a widespread public health issue, but less is known about the related signaling pathway. To investigate this, we established a hypercortisolism mouse model by supplementing the drinking water with corticosterone for four weeks. In the hypercortisolism mice, the serum corticosterone was much higher than in the control, and serum testosterone was significantly decreased. Moreover, corticosterone treatment induced decrease of sperm counts and increase of teratozoospermia. Increased numbers of multinucleated giant cells and apoptotic germ cells as well as downregulated meiotic markers suggested that corticosterone induced impaired spermatogenesis. Further, upregulation of macrophage-specific marker antigen F4/80 as well as inflammation-related genes suggested that corticosterone induced inflammation in the testis. Lactate content was found to be decreased in the testis and Sertoli cells after corticosterone treatment, and lactate metabolism-related genes were downregulated. In vitro phagocytosis assays showed that the phagocytic activity in corticosterone-treated Sertoli cells was downregulated and accompanied by decreased mitochondrial membrane potential, while pyruvate dehydrogenase kinase-4 inhibitor supplementation restored this process. Taken together, our results demonstrated that dysfunctional phagocytosis capacity and lactate metabolism in Sertoli cells participates in corticosterone-induced impairment of spermatogenesis.

Rationale and design of the cardiovascular status in patients with endogenous cortisol excess study (CV-CORT-EX): a prospective non-interventional follow-up study.

BACKGROUND: Endogenous Cushing's syndrome (CS) results in increased cardiovascular (CV) morbidity and mortality. So far, most studies focussed on distinct disease entities rather than the integrity of the CV system. We here describe the design of the Cardiovascular Status in Endogenous Cortisol Excess Study (CV-CORT-EX), a study aiming to comprehensively investigate the health status of patients with endogenous CS (with a particular focus on CV phenotypes, biochemical aspects, quality of life, and psychosocial status). METHOD: A prospective non-interventional cohort study performed at a German tertiary referral centre. At the time of enrolment, patients will be categorised as: (1) newly diagnosed overt CS, (2) recurrent overt CS, (3) CS in remission, (4) presence of mild autonomous cortisol excess (MACE). The target cohorts will be n = 40 (groups 1 + 2), n = 80 (group 3), and n = 20 (group 4). Patients with overt CS at the time of enrolment will be followed for 12 months after remission (with re-evaluations after 6 and 12 months). At each visit, patients will undergo transthoracic echocardiography, cardiac magnetic resonance imaging, 24-h electrocardiogram, 24-h blood pressure measurement, and indirect evaluation of endothelial function. Furthermore, a standardised clinical investigation, an extensive biochemical workup, and a detailed assessment of quality of life and psychosocial status will be applied. Study results (e.g. cardiac morphology and function according to transthoracic echocardiography and cardiac magnetic resonance imaging; e.g. prevalence of CV risk factors) from patients with CS will be compared with matched controls without CS derived from two German population-based studies. DISCUSSION: CV-CORT-EX is designed to provide a comprehensive overview of the health status of patients with endogenous CS, mainly focussing on CV aspects, and the holistic changes following remission. TRAIL REGISTRATION: ClinicalTrials.gov ( https://clinicaltrials.gov/ ) NCT03880513, registration date: 19 March 2019 (retrospectively registered). Protocol Date: 28 March 2014, Version 2.

Ectopic ACTH syndrome of different origin-Diagnostic approach and clinical outcome. Experience of one Clinical Centre.

PURPOSE: Ectopic Cushing Syndrome (EAS) is a rare condition responsible for about 5-20% of all Cushing syndrome cases. It increases the mortality of affected patients thus finding and removal of the ACTH-producing source allows for curing or reduction of symptoms and serum cortisol levels. The aim of this study is to present a 20-year experience in the diagnosis and clinical course of patients with EAS in a single Clinical Centre in Southern Poland as well as a comparison of clinical course and outcomes depending on the source of ectopic ACTH production-especially neuroendocrine tumors with other neoplasms. METHODS: Twenty-four patients were involved in the clinical study with EAS diagnosed at the Department of Endocrinology between years 2000 and 2018. The diagnosis of EAS was based on the clinical presentation, hypercortisolemia with high ACTH levels, high dose dexamethasone suppression test and/or corticotropin-releasing hormone tests. To find the source of ACTH various imaging studies were performed. RESULTS: Half of the patients were diagnosed with neuroendocrine tumors, whereby muscle weakness was the leading symptom. Typical cushingoid appearance was seen in merely a few patients, and weight loss was more common than weight gain. Patients with neuroendocrine tumors had significantly higher midnight cortisol levels than the rest of the group. Among patients with infections, we observed a significantly higher concentrations of cortisol 2400 levels in gastroenteropancreatic neuroendocrine tumors. Chromogranin A correlated significantly with potassium in patients with neuroendocrine tumors and there was a significant correlation between ACTH level and severity of hypokalemia. CONCLUSION: EAS is not common, but if it occurs it increases the mortality of patients; therefore, it should be taken into consideration in the case of coexistence of severe hypokalemia with hypertension and muscle weakness, especially when weight loss occurs. Because the diagnosis of gastroenteropancreatic neuroendocrine tumor worsens the prognosis-special attention should be paid to these patients.

Late-Pregnancy Salivary Cortisol Concentrations of Ghanaian Women Participating in a Randomized Controlled Trial of Prenatal Lipid-Based Nutrient Supplements.

BACKGROUND: High circulating cortisol is associated with miscarriage, preterm birth, and low birth weight. Research in nonpregnant individuals suggests that improved nutrition may lower cortisol concentrations. It is unknown whether nutritional supplementation during pregnancy lowers cortisol. OBJECTIVE: Our objective was to determine whether women receiving a lipid-based nutrient supplement (LNS) throughout pregnancy would have lower salivary cortisol at 36 wk gestation compared with women receiving other nutrient supplements. METHODS: We conducted a randomized controlled trial in 1320 pregnant Ghanaian women at ≤20 wk gestation who were assigned to receive daily throughout pregnancy: 1) 60 mg iron + 400 µg folic acid (IFA), 2) multiple micronutrients (MMNs), or 3) 20 g LNS (containing 118 kcal, 22 micronutrients, and protein). Morning salivary cortisol was collected from a subsample at baseline and at 28 and 36 wk gestation. RESULTS: A total of 758 women had cortisol measurements at 28 or 36 wk gestation. Salivary cortisol at 36 wk gestation did not differ between groups and was (mean ± SE) 7.97 ± 0.199 in the IFA group, 7.84 ± 0.191 in the MMN group, and 7.77 ± 0.199 nmol/L in the LNS group, when adjusted for baseline cortisol, time of waking, and time between waking and saliva collection (P = 0.67). There was an interaction between supplementation group and women's age (continuous variable, P-interaction = 0.03); and when age was dichotomized by the median, significant differences in salivary cortisol concentrations between groups were seen in women ≤26 y of age (IFA = 8.23 ± 0.284 nmol/L, MMN = 8.20 ± 0.274 nmol/L, and LNS = 7.44 ± 0.284 nmol/L; P = 0.03) but not in women >26 y old (IFA = 7.71 ± 0.281 nmol/L, MMN = 7.50 ± 0.274 nmol/L, and LNS = 8.08 ± 0.281 nmol/L; P = 0.13). CONCLUSIONS: We conclude that supplementation with LNSs or MMNs during pregnancy did not affect the cortisol concentration in the study population as a whole, in comparison with IFA, but that LNS consumption among younger women may lead to lower cortisol at 36 wk gestation. This trial was registered at clinicaltrials.gov as NCT00970866.

Vitamin D status before and after hypophysectomy in dogs with pituitary-dependent hypercortisolism.

Both spontaneous hypercortisolism and chronic glucocorticoid treatment are associated with osteoporosis and low circulating concentrations of 1,25-dihydroxy-vitamin D in humans. Pituitary-dependent hypercortisolism (PDH) is a common disorder in dogs, but little is known about the vitamin D status of affected dogs. Pituitary-dependent hypercortisolism in dogs can be treated effectively by hypophysectomy and subsequent hormone supplementation. Because hormone supplementation does not include GH, dogs that have undergone hypophysectomy have low circulating concentrations of GH and IGF-1, which may result in low plasma 1,25-dihydroxy-vitamin D concentrations and consequently increased parathyroid hormone secretion. The aim of this study was to determine whether dogs with PDH need vitamin D supplementation before and/or after hypophysectomy. To this end, we measured plasma concentrations of GH, IGF-1, parathyroid hormone, calcium, phosphate, and vitamin D metabolites in 12 dogs with PDH before and 8 wk after hypophysectomy and in 12 control dogs. Although plasma GH concentrations were lower in dogs with PDH than in control dogs both before and after hypophysectomy, the vitamin D status was similar. In conclusion, there is no need for vitamin D supplementation in dogs with PDH, either before or after hypophysectomy.

Prevalence of subclinical Cushing's syndrome in 70 patients with adrenal incidentaloma: clinical, biochemical and surgical outcomes.

Subclinical Cushing's syndrome (SCS) is being detected with increased frequency in patients with adrenal incidentaloma. In the current study, we evaluated the prevalence of SCS in 70 patients with adrenal incidentaloma and compared the main findings on them with other patients with nonfunctional adrenal incidentaloma (NFA). Overnight 3 mg dexamethasone (DXM) suppression test to exclude cortisol hypersecretion, and high dose DXM suppression test to find out patients with SCS, were applied to all subjects. Afterwards, biochemical and clinical findings of patients with SCS were compared with the other patients with NFA. Four of the 70 patients with adrenal incidentaloma were found to have SCS, with a prevalence of 5.7%. Basal ACTH and DHEA-S levels were significantly lower (p < 0.05 and p < 0.01, respectively), and midnight cortisol and 24-hour urinary free cortisol levels were significantly higher in patients with SCS (p < 0.001 and p < 0.05, respectively). Biochemical and metabolic bone parameters were similar in patients with SCS and in patients with NFA. Hypertension, diabetes mellitus, and obesity were more common in patients with SCS. One of the patients with SCS developed adrenocortical insufficiency following unilateral adrenalectomy which lasted for about 6 months. Suppressed ACTH and DHEA-S levels, and high midnight cortisol levels may be some clues for SCS in patients with adrenal incidentaloma. Since patients with SCS frequently have risk factors for atherosclerosis such as hypertension, diabetes, and obesity, and the surgical management of SCS with adrenalectomy may offer an advantage. Patients undergoing adrenalectomy should be followed for the development of adrenal insufficiency.

Cushing's syndrome due to ACTH-independent bilateral adrenocortical macronodular hyperplasia.

ACTH-independent macronodular adrenocortical hyperplasia (AIMAH) is a rare cause of Cushing's syndrome in which adrenal glands become very enlarged, occupied and distorted by multiple cortical nodules. We report on such two patients, a 44-year-old man and a 40-year-old woman. Physical examination revealed in both cases a classic cushingoid habit. Laboratory studies showed overt hypercortisolism with high urinary free cortisol excretion and elevated serum cortisol with loss of the circadian rhythm. Serum cortisol levels were not modified after high dose dexamethasone. ACTH levels were undetectable both in baseline conditions and following CRH or metyrapone. In both cases, abdominal CT demonstrated bilaterally enlarged adrenal glands which were distorted by multiple bumps. 131I-Norcholesterol scintiscan showed bilateral uptake of the radionuclide. Pituitary region was normal at neuroradiologic imaging. Bilateral adrenalectomy was performed in both cases. In patient I, adrenal glands weighted 77 and 90 g, respectively, while in patient II they were of 90 and 55 g, respectively. At histological examination, the adrenal cortex was occupied by multiple nodular lesions composed mostly of clear cells. In the internodular regions, no evidence of cortical architecture was observed. At the immunohistochemical evaluation, both cases displayed KI-67 staining comparable with that of ACTH-dependent diffuse hyperplasia. Postoperative course was uneventful and signs of Cushing's syndrome resolved in about three months. At the last follow up, the patients are going well on glucocorticoid and mineralocorticoid supplementation. Plasma ACTH levels are 65 and 107 pg/ml, respectively.

Lysine vasopressin stimulation of cortisol secretion in patients with adrenocorticotropin-independent macronodular adrenal hyperplasia.

We present two patients with Cushing's syndrome due to ACTH-independent macronodular adrenal hyperplasia who showed marked plasma cortisol response to lysine-8-vasopressin (LVP) injection (from 930 and 731 pmol/L to 2177 and 1920 pmol/L, respectively), while plasma ACTH levels remained undetectable. The ACTH independence of cortisol secretion in the two patients was determined from the following endocrinological findings. Plasma cortisol levels were not increased by corticotropin-releasing hormone injections and were not suppressed by high dose (16 mg) dexamethasone administrations. The plasma ACTH levels, measured by two independent sensitive immunoassays, were persistently undetectable even after corticotropin-releasing hormone injection, metyrapone administration, and bilateral adrenalectomy. The particular pathological finding of the two cases, atrophic lesions in nonnodular parts of the adrenal cortexes, also indicated ACTH independence of the macronodular hyperplasia. In vitro examination revealed a direct effect of LVP on cortisol secretion from the adrenal cells of the macronodules. We also examined seven patients with Cushing's syndrome caused by adrenal adenoma and found a statistically significant plasma cortisol response to LVP injection. The direct effect of LVP was also demonstrated in cultured adenoma cells. In conclusion, we discovered a direct adrenal effect of LVP on cortisol secretion in patients with ACTH-independent macronodular hyperplasia and, to a lesser extent, in patients with cortisol-producing adrenal adenoma. The cortisol response to LVP may serve to facilitate their diagnosis and choice of therapy.

Growth hormone releasing hormone priming increases growth hormone secretion in patients with Cushing's syndrome.

OBJECTIVE: In patients with Cushing's syndrome, decreased growth hormone (GH) secretion is observed though the basic mechanism is unknown. In states of chronic deficiency of hypothalamic growth hormone releasing hormone (GHRH) release, a blunted GH response to exogenous GHRH has been reported; such impairment can be partially normalized by repetitive GHRH administration (priming). In order to clarify whether a deficit in hypothalamic release of GHRH is the basis of the decreased GH secretion in patients with Cushing's syndrome, GHRH plus pyridostigmine tests were undertaken, both before and after GHRH priming. DESIGN: GHRH (200 micrograms/day as a single s.c. injection) was given daily over 7 days. Two pyridostigmine (120 mg p.o.) plus GHRH (100 micrograms i.v.) tests were performed before and after priming to assess GH response. PATIENTS: Eight patients (seven women, one man), with untreated Cushing's syndrome (six Cushing's disease, one autonomous bilateral adrenal hyperplasia, one adrenal adenoma), were studied. MEASUREMENTS: Plasma GH levels were measured by immunoradiometric assay. RESULTS: GHRH plus pyridostigmine-induced GH release was impaired in patients with untreated Cushing's syndrome (mean peak 5.2 +/- 1.4 mU/l, area under the curve (AUC) 472 +/- 96). Repetitive administration of GHRH over 7 days partially restored the GH response to the second pyridostigmine-GHRH test (mean peak 15.0 +/- 2.1 mU/l. AUC 1016 +/- 104), both P < 0.05. All of the eight Cushing's syndrome patients studied presented a higher GHRH plus pyridostigmine-induced GH secretion after priming. CONCLUSIONS: Repetitive administration of GHRH increases the pyridostigmine-GHRH-induced GH secretion in patients with Cushing's syndrome. This suggests that impaired hypothalamic release of GHRH is a contributing factor to the decreased GH secretion observed in chronic hypercortisolism.

Mechanism of impaired growth hormone secretion in patients with Cushing's disease.

The function of the growth hormone-releasing hormone (GHRH)-growth hormone (GH) axis in Cushing's disease was studied by monitoring (a) the GH responses to GHRH loading and L-dopa loading, (b) the GHRH response to L-dopa loading, and (c) the daytime profiles of plasma GH concentration. GH release following GHRH and L-dopa was blunted in patients as compared to that in age-matched control subjects. However, GHRH release following L-dopa was similar in patients and controls. The plasma GH levels in four patients measured every 20 min by a highly sensitive immunoradiometric assay for GH showed pulsatile GH secretion at low levels during the observation period. These results indicate that GHRH release from the hypothalamus is preserved in patients with Cushing's disease, and support the hypothesis that glucocorticoid inhibits GH secretion by altering the hypothalamic somatostatin tone.

Hypothalamic abnormalities in patients with pituitary-dependent Cushing's syndrome.

OBJECTIVE: We aimed to investigate the pattern of 24-hour ACTH and cortisol secretion in pituitary-dependent Cushing's syndrome and to evaluate the pituitary and hypothalamic contributions to the disease. PATIENTS: Five women with Cushing's disease (mean age 35 +/- 5 (SEM) years) and five normal female controls (mean age 25 +/- 2 years) were studied. DESIGN AND MEASUREMENTS: Plasma ACTH and cortisol levels were measured every 15 minutes for 24 hours using established IRMA and RIA respectively. ACTH and cortisol mean and trough levels, pulse number and amplitude were calculated using established computer software, programmed to identify ACTH and cortisol peaks. RESULTS: Patients with Cushing's disease had a twofold increase in 24-hour mean cortisol levels and a threefold increase in 24-hour mean ACTH levels (Cushing's 5.9 +/- 1.0, controls 1.9 +/- 0.2 pmol/l, P less than 0.01). This was predominantly mediated by an increase in ACTH pulse amplitude. However, 24-hour ACTH pulse number was also increased (Cushing's 15.2 +/- 2.6, controls 10.6 +/- 1.7, P less than 0.05) due to an increase in pulse number between 1800 and 2400 h. ACTH trough levels were also higher in patients with Cushing's disease (Cushing's 5.3 +/- 1.3, controls 2.3 +/- 0.2 pmol/l, P less than 0.05). CONCLUSIONS: Twenty-four-hour mean plasma cortisol and ACTH levels are elevated two to three-fold in patients with Cushing's disease. The increase in ACTH pulse amplitude suggests a pituitary abnormality in patients with Cushing's disease. However, the increased ACTH pulse frequency together with elevated trough levels is interpreted as indicating coexisting hypothalamic stimulation (or loss of inhibition).

Endogenous natriuretic factors: atrial natriuretic hormone and digitalis-like substance in Cushing's syndrome.

In order to investigate the effect of chronic hypercortisolaemia on endogenous natriuretic factors (atrial natriuretic hormone (ANH) and the Na+/K+ pump inhibitor) digitalis-like substance (DLS), and their relation to hypertension, 28 patients with pituitary- or adrenal-dependent Cushing's syndrome and six patients on high-dose prednisone treatment were studied. Plasma ANH levels were increased in patients with Cushing's syndrome (36.0 +/- 1.4 (S.E.M.) ng/l) compared with those in healthy controls (28.6 +/- 1.3 ng/l, P less than 0.01). In prednisone-treated patients, ANH levels (43.8 +/- 4.5 ng/l) were higher than those in patients with Cushing's syndrome and in controls (P less than 0.05 and P less than 0.01 respectively). DLS measured by radioimmunoassay and binding of [3H]ouabain to erythrocytes was not altered in patients with hypercortisolaemia. Slightly decreased DLS activity in the erythrocyte 86Rb uptake inhibition assay was found in patients with Cushing's syndrome (52.9 +/- 2.7%) compared with that in controls (60.9 +/- 1.8%, P less than 0.02). With the exception of cortisol (r = 0.52, P less than 0.01), none of the other factors determined correlated with the mean arterial pressure in patients with Cushing's syndrome. Thus, a chronic excess of endogenous and exogenous glucocorticoids increases plasma levels of ANH, but does not substantially influence DLS activity or plasma levels. Neither natriuretic factor is directly related to hypertension in Cushing's syndrome.

Treatment of iatrogenic Cushing's syndrome in dogs with electroacupuncture stimulation of stomach 36.

This study was conducted to evaluate the effectiveness of electroacupuncture (EA) on the recovery of adrenocortical function from Iatrogenic Cushings Syndrome (ICS) in dogs. Experiment I: Selection of the most effective Acupuncture point to treat ICS--Six healthy adult female dogs were treated bilaterally with EA for 15 minutes at loci BL22 + BL23 + BL24, ST36, or a non-locus control point on M. brachialis. Each dog was tested at all three sites in rotation. Blood samples were collected before and 0, 15 and 60 minutes after EA, and the serum cortisol levels were measured by radioimmunoassay. The data showed that EA at ST36 resulted in the highest response of serum cortisol levels among the three treatments. Experiment II: Evaluation of the effectiveness of EA ST36 in the treatment of ICS in dogs--Eight healthy adult female dogs were given prednisolone acetate 2mg/kg/day IM for 3 weeks. They were then randomly divided into ST36 and control groups of 4 dogs each. In the ST36 group, ST36 was treated bilaterally with EA for 30 minutes, 3 times per week, for 3 consecutive weeks. For the control, a non-locus point on M. brachialis was treated bilaterally with the same protocol. After the first week of EA, the serum cortisol levels of the ST36 and control groups were 0.9 +/- 0.1 and 0.5 +/- 0.1 micrograms/dl (P less than 0.005) baseline and 2.5 +/- 0.2 and 1.4 +/- 0.4 micrograms/dl (p less than 0.05) and after ACTH stimulation test, respectively. After the third week of EA treatment, the results were 1.0 +/- 0.1 and 0.6 +/- 0.2 micrograms/dl (p less than 0.05) baseline and 4.0 +/- 0.5 and 1.7 +/- 0.5 micrograms/dl (p less than 0.001) after ACTH stimulation respectively. These data indicated that EA at ST36 could restore the adrenocortical hypofunction resulting from ICS in dogs.

An evaluation of the distinction of ectopic and pituitary ACTH dependent Cushing's syndrome by clinical features, biochemical tests and radiological findings.

The efficiency of various laboratory and radiological investigations in the differentiation of ectopic from pituitary dependent Cushing's syndrome was studied, based on findings in 23 patients with verified Cushing's disease and seven patients with the ectopic ACTH syndrome. Clinical features strongly favouring the ectopic type were male sex and history for less than 18 months. Basal biochemical features strongly indicating the ectopic syndrome included plasma K+ less than 3.0 mmol/l and HCO3 greater than 30 mmol/l; serum cortisol at 9 a.m. or midnight of greater than 800 nmol/l; urine free cortisol greater than 1300 nmol/24 hours; plasma ACTH greater than 100 ng/l. In the high-dose dexamethasone suppression test, suppression by less than 50 per cent of 9 a.m. serum cortisol, urine free cortisol or 17-oxogenic steroids was usually indicative of an ectopic source of ACTH. A mean suppressed value of greater than 450 nmol/l for the 9 a.m. and midnight cortisol combined occurred in all of those with the ectopic syndrome, but in none of the 23 patients with Cushing's disease. For urine free cortisol, a mean suppressed value of less than 1000 nmol/24 hours was found in all patients with Cushing's disease, but in none of those in the ectopic group. In the metyrapone test, there was an increase of less than or equal to 3-fold in 11-deoxycortisol at 24 hours in patients with ectopic ACTH; the increase was greater than 3-fold in all but one of the patients with Cushing's disease. Failure to respond to either dexamethasone or metyrapone was found in only one of the patients with Cushing's disease (Patient 16); in the ectopic group, all patients except Patient D failed to respond to either test. It is concluded that patients presenting with clinically obvious Cushing's syndrome along with measurable plasma ACTH can be reliably divided by conventional tests into those that are driven from the pituitary and those driven by ectopic ACTH.

Radioimmunoassay of corticotropin-releasing hormone: methodology and clinical application.

Corticotropin-releasing hormone (CRH) levels in the human plasma and cerebrospinal fluid (CSF), and those in the rat hypothalamus, peripheral and hypophyseal portal plasma were studied by a specific h/r CRH RIA and an immunoaffinity procedure. CRH levels in the plasma and CSF were low in patients with hypercortisolemia and those with hypothalamic hypopituitarism, but high in patients with hypocortisolemia except for patients with hypothalamic hypopituitarism. Plasma CRH responded to insulin-induced hypoglycemia (ITT) those with Addison's disease and those with primary hypopituitarism, but not in patients with Cushing's syndrome or in patients with hypothalamic hypopituitarism. The results suggest that the major component of plasma CRH may be of hypothalamic origin, but other extrahypothalamic tissues cannot be ruled out as minor sources of plasma CRH. In addition, the measurement of CRH levels in the plasma and CSF seems to be of value in evaluating the hypothalamic function. The short negative feedback mechanism regulating CRH release was demonstrated in humans and rats. In the absence of the long negative feedback control of ACTH secretion by glucocorticoids, ACTH originating from the pituitary may regulate ACTH secretion form the pituitary through inhibition of CRH release.

Diagnosis and management of ACTH-dependent Cushing's syndrome: comparison of the features in ectopic and pituitary ACTH production.

The clinical features, diagnosis and management of 16 consecutive patients with ectopic ACTH production are described and biochemical data are compared with those of 48 consecutive patients with pituitary-dependent Cushing's disease. In 10 cases the ectopic ACTH secreting tumour was completely occult to routine clinical and radiological investigation, and no basal or dynamic investigation of adrenal-pituitary function was able clearly to differentiate these patients from those with Cushing's disease. High dose dexamethasone suppression testing assessed by plasma cortisol was usually helpful but unexpected responses were seen in both diagnostic groups; the metyrapone test yielded no useful information and should now be abandoned. Hypokalaemia was seen in all patients with ectopic ACTH production but in only 10% of those with Cushing's disease who were not on diuretics at presentation. Successful diagnosis and tumour localization was most frequently achieved by a combination of CT scanning of the chest and abdomen and venous catheter sampling for ACTH. All patients in whom the ectopic ACTH-secreting tumour was obvious at presentation died of their primary tumour within 8 months, whereas seven of the 10 patients with occult tumours at presentation are alive 1.5-16.5 years later, and appear cured. Occult ectopic ACTH secretion may be impossible to distinguish from pituitary Cushing's disease. Multiple and repeated investigations are often required to make this differential diagnosis, essential for appropriate therapy.

Serum osteocalcin is increased in patients with hyperthyroidism and decreased in patients receiving glucocorticoids.

Osteocalcin (OC) is a vitamin K-dependent protein which is synthesized by osteoblasts and is present in the circulation. We measured serum OC concentrations in 10 patients receiving corticosteroids (CS) for chronic obstructive pulmonary disease and in 9 hyperthyroid (HT) patients. Mean values ( +/- SE) were as follows: There was a significant correlation between OC and alkaline phosphatase (r = 0.607; P = 0.006) when CS and HT groups were combined. Elevated serum OC concentrations in hyperthyroid patients may reflect increased osteoblastic activity, while decreased levels in corticosteroid-treated patients may reflect decreased osteoblastic activity.