Impact of IGF(CA)19 gene polymorphism on the metabolic response to GH therapy in adult GH-deficient patients

OBJECTIVE

A polymorphism in the promoter region of the IGF1 gene has been linked to serum IGF1 levels, risk of diabetes, and cardiovascular diseases with conflicting results. The aim of this study was to investigate the impact of this polymorphism on the short-term (1 year, n=98) and long-term (5 years, n=50) metabolic response to recombinant human GH (rhGH) in GH-deficient (GHD) adults.

DESIGN AND METHODS

Prospective study on GHD adults. Different genotypes were studied by microsatellite method. According to the most frequent 192 bp allele (19 cytosine-adenosine-repeats), subjects were divided into homozygous (19/19), heterozygous (19/X), and noncarriers (X/X).

RESULTS

Basal characteristics of patients as well as their response to rhGH in terms of decrease in body fat percentage and increase in IGF1 levels were not different in the three genotype-groups. Conversely, after 1-year rhGH, a significant worsening of insulin sensitivity (i.e. increase in fasting glucose levels and homeostasis model assessment of insulin resistance) and a significant improvement in lipid profile (i.e. reduction in total cholesterol and LDL-cholesterol) were recorded only in homozygous subjects. In the long-term, insulin sensitivity was restored in all the patients, while a significant improvement in lipid profile was observed in homozygous and heterozygous subjects, but not in noncarrier subjects. No difference in rhGH dose among groups was recorded throughout the study.

CONCLUSIONS

In GHD adults, the presence of the WT allele in the IGF1 gene promoter may enhance sensitivity to either negative or positive metabolic changes induced by rhGH.

Epicardial fat thickness significantly decreases after short-term growth hormone (GH) replacement therapy in adults with GH deficiency

BACKGROUND AND AIM

Growth Hormone Deficiency (GHD) is characterized by increased visceral fat accumulation. Echocardiographic epicardial fat thickness is a new marker of visceral adiposity. Aim of the present study was to evaluate whether epicardial fat thickness can significantly change and therefore serve as a marker of visceral fat reduction after short-term rhGH replacement therapy in patients with adult-onset GHD.

METHODS AND RESULTS

Echocardiographic epicardial fat thickness was measured in 18 patients (10 M, 8 F, age 48 ± 11.8 yrs, BMI 29 ± 5.9 kg/m(2)) with adult-onset GHD, at baseline and after 6 and 12 months of rhGH therapy and in 18 healthy matched controls, at baseline. Echocardiographic epicardial fat thickness, conventional anthropometric and metabolic parameters, body fat percentage and quality of life were also evaluated. Epicardial fat thickness in adult GHD patients was higher than in controls (9.8 ± 2.8 vs 8 ± 3 mm, p < 0.05). Epicardial fat thickness significantly decreased after 6-months of rhGH replacement therapy (from 9.8 ± 2.8 to 7.0 ± 2.3 mm, P < 0.01, i.e. -29% from baseline). After 12 months of rhGH replacement therapy, epicardial fat thickness showed a further significant decrease (from 7.0 ± 2.3 to 5.9 ± 3.1 mm, P < 0.01, i.e. -40% from baseline). No significant changes in BMI or waist circumference after 6 or 12 months of rhGH therapy were observed.

CONCLUSIONS

Echocardiographic epicardial fat thickness may represent a valuable and easy marker of visceral fat and visceral fat changes during rhGH replacement treatment in patients with adult-onset growth hormone deficiency.

Increased risk for non-autoimmune hypothyroidism in young patients with congenital heart defects

CONTEXT

Newborns with congenital hypothyroidism (CH) have an increased risk for congenital heart defects (CHD) due to a common embryonic developmental program between thyroid gland and heart and great vessels.

OBJECTIVE

Our objective was to investigate the prevalence and origin of thyroid disorders in young patients with CHD.

DESIGN AND SETTING

We conducted a prospective observational study between January 2007 and January 2009 in academic Pediatric Cardiosurgery and Endocrinology.

PATIENTS

Patients included 324 children (164 males, 160 females, aged 0.2-15.4 yrs) with CHD.

INTERVENTION

Subjects underwent hormonal and genetic screening.

MAIN OUTCOME MEASURES

Serum TSH and thyroid hormone levels were assessed.

RESULTS

Two CHD patients were diagnosed with CH at the neonatal screening (1:162). Mild hypothyroidism (serum TSH > 4.0 μU/ml) was diagnosed and confirmed 6 months later [TSH = 5.4 ± 1.5 μU/ml; free T(4) = 1.3 ± 0.2 ng/dl (normal values 0.8-1.9)] in 37 children (11.5%) who were negative at neonatal screening. Hypothyroidism was not related to type of CHD, whereas TSH levels positively correlated with serum N-terminal pro-type B natriuretic peptide levels. Biochemical and ultrasound findings consistent with thyroid autoimmunity were present in three of 37 hypothyroid children (8.1%). One patient had hemiagenesis (2.7%). Variations in candidate genes were screened in CHD patients. NKX2.5 coding sequence was normal in all samples. A 3-Mb microdeletion in 22q11.2 was detected in three patients (8.3%), whereas only known polymorphisms were identified in TBX1 coding sequence.

CONCLUSIONS

CHD patients have an increased risk for both CH (10-fold higher) and acquired mild hypothyroidism (3-fold higher). Unrecognized mild hypothyroidism may negatively affect the outcome of CHD children, suggesting that thyroid function should be repeatedly checked. Thyroid autoimmunity and 22q11.2 microdeletions account for small percentages of these cases, and still unknown mechanisms underline such a strong association.

Relationship of thyroid function with body mass index and insulin-resistance in euthyroid obese subjects

BACKGROUND AND AIMS

It is recognized that overt thyroid dysfunction is associated with weight changes, but the influence of a minor alteration of thyroid function remains unclear. This study aimed to further investigate the relationship between obesity and thyroid function and to examine the possible role of insulin resistance on the hypothalamic-pituitary- thyroid axis.

METHODS AND RESULTS

Serum TSH and free T4 (FT4) levels, anthropometric and metabolic parameters were evaluated in 581 obese patients. In all patients TSH values progressively increased according to the severity of obesity and were positively correlated with body mass index (p=0.001, r=0.13) and waist circumference (p=0.02, r=0.11). Patients with insulin resistance showed higher TSH (1.8±1.0 vs 1.6±0.9 μUI/l; p=0.03) and lower FT4 levels (13.8±2.3 vs 15.0±2.2 pmol/l; p<0.001), as compared with patients with normal insulin sensitivity. Moreover, TSH was positively correlated with fasting insulin (p<0.001, r=0.152) and homeostasis model assessment of insulin resistance (HOMA-IR; p<0.001, r=0.148), and negatively correlated with Quantitative Insulin Sensitivity Check Index (QUICKI; p<0.001, r=-0.148); FT4 was negatively associated with fasting insulin (p<0.001, r=-0.287) and HOMA-IR (p<0.001, r=-0.295), and positively associated with QUICKI (p<0.001, r=0.295).

CONCLUSIONS

A relationship between thyroid function and overweight/ obesity condition seems to exist, mainly influenced by insulin resistance. Whether variations in TSH and/or thyroid hormones, within a normal range, can influence body weight or whether obesity per se can alter thyroid function cannot be stated so far. Further studies are needed to assess the link between thyroid function and body weight, by considering not only changes in thyroid hormones, but also body fat distribution, obesity duration and low-grade inflammation.

[Thyroid function and obesity]

A relationship between thyroid function and obesity seems likely, mainly influenced by the insulin resistance. Whether variations in TSH and/or thyroid hormones, within a normal range, can influence body weight or if obesity per se can alter thyroid function has not been clarified so far. Further studies are necessary to assess the link between thyroid function and body weight, that must consider not only changes of thyroid hormones, but also body fat distribution, obesity duration and the state of low grade inflammation. It is recognized that thyroid function is linked not only to body mass index, but also to body composition and, particularly, to the amount and percentage of fat mass.

Subclinical hypercortisolism: correlation between biochemical diagnostic criteria and clinical aspects

OBJECTIVE

Subclinical hypercortisolism (SH) has been associated with increased prevalence of hypertension, type 2 diabetes mellitus, dyslipidaemia, central obesity, osteoporosis and vertebral fractures. We aimed to investigate the accuracy of different SH diagnostic criteria in predicting the presence of complications.

DESIGN

This was a retrospective study.

PATIENTS

We evaluated data from 231 patients (120 women and 111 men) affected with adrenal incidentalomas (AI).

MEASUREMENTS

We studied the accuracy of different SH diagnostic criteria (cortisol after 1 mg overnight dexamethasone suppression test - 1mg-DST - at different cut-off such as 49.7, 82.8, 137.9 nmol/l, elevated urinary free cortisol, reduced adrenal corticotroph hormone (ACTH) levels alone or various combination of these parameters) in predicting the concomitant presence of the following three complications: hypertension, type 2 diabetes and vertebral fractures.

RESULTS

The criterion characterized by the presence of two of 1mg-DST >82.8 nmol/l, elevated UFC and reduced ACTH struck the best balance between sensitivity and specificity, reaching a good accuracy in predicting the cluster of complications (61.9%; 77.1% and 75.8%, respectively). The presence of this cluster was associated with this criterion (OR 4.75, 95%CI 1.8-12.7, P = 0.002) regardless of gonadal status, body mass index (BMI) and age.

CONCLUSIONS

The SH criterion characterized by the presence of two of 1mg-DST >82.8 nmol/l, elevated UFC and reduced ACTH seems the best in predicting the presence of chronic manifestations of subtle cortisol excess.

Peripheral insulin-like factor 3 concentrations are reduced in men with type 2 diabetes mellitus: effect of glycemic control and visceral adiposity on Leydig cell function

BACKGROUND AND AIM

Hypogonadism frequently occurs in men with type 2 diabetes mellitus (T2DM), while the role of glycemic control and visceral obesity is still unclear. This study aimed to assess the Leydig cell function, including the new sensitive marker insulin-like factor 3 (INSL3), in T2DM patients without overt hypogonadism and the influence of either glycemic control or visceral adiposity.

SUBJECTS AND METHODS

Thirty T2DM patients (age 57.1+/-6.2 years, body mass index (BMI) 28.0+/-4.3) without overt hypogonadism and 30 age- and BMI-matched controls were studied. Anthropometric, glycometabolic parameters and testosterone, SHBG, LH, INSL3 levels, bioavailable and free testosterone (BT and cFT) were evaluated. The human chorionic gonadotrophin (hCG) test was also performed.

RESULTS

Patients had lower total testosterone (452.6+/-130.0 vs 512.6+/-117.3 ng/dl, P=0.06), BT (189.7+/-36.4 vs 237.1+/-94.1 ng/dl, P=0.002), cFT (8.1+/-1.6 vs 10.1+/-4.0 ng/dl, P=0.002), and higher LH levels (3.5+/-1.6 vs 2.6+/-1.2 mU/ml, P=0.01) versus controls. Serum INSL3 concentrations were also lower in patients (1.1+/-0.3 vs 1.5+/-0.7 ng/ml, P=0.01). These hormonal parameters, including INSL3, did not differ between T2DM patients with poor or good glycemic control (HbA1c>9 or <7% respectively). In patients, waist circumferences (97.9+/-12.4 cm) negatively correlated with INSL3 (P=0.03) and basal, as well as hCG-stimulated testosterone levels (P=0.04 and 0.004 respectively). Basal or stimulated hormonal levels and INSL3 concentrations were not different between patients with (40%) or without erectile dysfunction.

CONCLUSIONS

An early impairment of the overall Leydig cell function is present in men with T2DM, mainly related to visceral adiposity rather than to glycemic control.

Prevalence of GH deficiency in cured acromegalic patients: impact of different previous treatments

OBJECTIVE

Radiotherapy (RT) for pituitary adenomas, including GH-secreting ones, frequently leads to GH deficiency (GHD). Data on the effects of surgery alone (S) on dynamic GH secretion are limited. The aim of the study was to investigate the occurrence of GHD in acromegalic patients treated with different therapeutic options.

DESIGN AND METHODS

Fifty-six patients in remission from acromegaly, (33 F & 23 M, age: 54+/-13 years, body mass index (BMI): 28.4+/-4.1 kg/m(2), 21 with adequately substituted pituitary deficiencies) treated by S alone (n=33, group 1) or followed by RT (n=23, group 2), were investigated for GHD by GHRH plus arginine testing, using BMI-adjusted cut-offs. Several metabolic and cardiovascular parameters (waist circumference, body fat percentage, blood pressure, fasting and post-oral glucose tolerance test glucose, HbA1c, insulin resistance and lipid profile) were evaluated in all the patients and 28 control subjects with known diagnosis of GHD.

RESULTS

Serum GH peak after challenge was 8.0+/-9.7 microg/l, without any correlation with post-glucose GH nadir and IGF-1 levels. The GH response indicated severe GHD in 34 patients (61%) and partial GHD in 15 patients (27%). IGF-1 were below the normal range in 14 patients (25%). The frequency of GHD was similar in the two treatment groups (54% in group 1 and 70% in group 2). No significant differences in metabolic parameters were observed between acromegalic patients and controls with GHD.

CONCLUSIONS

Severe GHD may occur in about 60% of patients treated for acromegaly, even when cured after S alone. Thus, a stimulation test (i.e. GHRH plus arginine) is recommended in all cured acromegalic patients, independently from previous treatment.

Analysis of GNAS1 and PRKAR1A gene mutations in human cardiac myxomas not associated with multiple endocrine disorders

Cardiac myxomas are rare tumors that usually occur as sporadic lesions or,more rarely, in the familial form,mostly in the context of Carney complex (CNC). The molecular basis for the development of cardiac myxomas is unclear. However, somatic activating mutations in the GNAS1 gene (the gsp oncogene) are detected in the myocardium ofMcCune-Albright syndrome patients while germ-line mutations in the PRKAR1A gene are associated with CNC and familial myxomas. We investigated the presence of activating missense mutations in the GNAS1 gene as well as of inactivating mutations in PRKAR1A in 29 sporadically occurring cardiac myxomas. No gsp and no PRKAR1A mutations were found by direct sequencing of PCR products amplified from tumoral DNA. This is the first study including a large series of sporadic, isolated cardiac myxomas and showing that these cardiac neoplasms do not share the same mutations found in familial forms.

Effects of serotonin antagonists in sexually impotent men

Thirty-one men affected with sexual impotence were studied. Since sexual function in the male seems to be controlled by both dopaminergic stimulatory and serotoninergic inhibitory mechanisms, the patients were treated with serotonin antagonists. In basal conditions mean serum LH, FSH, PRL and testosterone did not significantly differ from those found in normal subjects; no significant variations, except for PRL reduction, were observed after treatment. Both methysergide, in association with bromocriptine or mesterolone, and metergoline, either alone or in association with mesterolone, were ineffective in significantly improving sexual activity.

Echocardiographic alterations in patients with non-functioning adrenal incidentaloma

OBJECTIVE

While left ventricular (LV) dysfunction has been described in patients with Cushing's syndrome (CS), data concerning morphologic and functional cardiac alterations in patients with incidentally discovered adrenal masses [adrenal "incidentaloma" (AI)], without overt hypercortisolism, are lacking. In this study the echocardiographic characteristics of patients with AI were evaluated and then compared with those of lean and obese normotensive subjects.

SUBJECTS AND METHODS

Twenty-one patients with AI, without clinical or subclinical hypercortisolism, 18 normotensive obese subjects matched for gender and body mass index (BMI) and 20 normotensive lean subjects were studied. Echocardiography was performed in all subjects. In all patients plasma ACTH, serum cortisol, and DHEA-S levels were measured.

RESULTS

Patients with AI showed greater impairment of several echocardiographic indices of LV hypertrophy and diastolic dysfunction compared to normotensive lean subjects (p<0.05), but did not differ from those in obese subjects. Hypertensive AI patients showed a greater alteration of echocardiographic parameters (p<0.05) and higher BMI (p<0.01) and cortisol values (p<0.05) than normotensive ones. Plasma ACTH and serum cortisol were similar in AI patients and in obese controls, while DHEA-S levels were lower in AI (p<0.05). No correlations between cortisol secretion and echocardiographic parameters were found.

CONCLUSION

In patients with non-functioning AI there is an impairment of cardiac morphology and function. These data suggest that patients with AI should be carefully screened also by means of echocardiographic studies.

Soluble adhesion molecules levels in patients with Cushing's syndrome before and after cure

OBJECTIVE

Patients with Cushing's syndrome (CS) show a high prevalence of cardiovascular risk factors and atherosclerosis, persisting even after cure. Soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) are surrogate markers of endothelial function involved in the initiation of atherosclerosis. This study aimed to evaluate sICAM-1 and sVCAM-1 levels in patients with CS before and after successful cure.

SUBJECTS AND METHODS

sICAM-1 and sVCAM-1 levels were evaluated in 28 patients with active CS and in 12 patients with Cushing's disease (CD), 6-12 months after disease remission. Body mass index (BMI), blood pressure, glucose, serum lipids, ACTH, cortisol and urinary free cortisol (UFC) were measured in basal conditions in all patients.

RESULTS

At baseline, sICAM-1 levels positively correlated with BMI (r=0.443, p<0.01), while no correlations between sICAM/sVCAM levels and ACTH, cortisol or UFC were found. Plasma ACTH, serum cortisol, and UFC levels significantly decreased in 12 cured patients, but ICAM-1 and VCAM-1 levels were unchanged (12.7+/-1.8 vs 10.1+/-0.9 ng/ml and 33.5+/-4.4 vs 35.8+/-4.0 ng/ml, respectively). Obesity, hypertension, and impaired glucose metabolism persisted 1 yr after the biochemical cure of hypercortisolism. A significant reduction in ICAM-1 levels was observed in 4 out of 12 cured patients as well as a remission from diabetes, hypertension or obesity.

CONCLUSIONS

ICAM/VCAM-1 levels show a great variability in patients with active CS, not correlated with cortisol levels, and are slightly modified in some cured patients with CD. The persistence of obesity, hypertension, and impaired glucose metabolism may be responsible for the maintenance of a subclinical endothelial dysfunction, making these subjects still at high cardiovascular risk and needing a long-term follow-up.

Evaluation of proopiomelanocortin mRNA in the peripheral blood from patients with Cushing's syndrome of different origin

ACTH-dependent Cushing's syndrome is due to ACTH overproduction originating from a pituitary corticotroph adenoma (Cushing's disease) or from ectopic tumors (ectopic ACTH syndrome). Due to difficulties in the differential diagnosis between these two forms of hypercortisolism it would be important to have molecular tools able to discriminate the two conditions. It is known that proopiomelanocortin (POMC) gene transcription can originate messengers of different length. ACTHomas show the normal 1072 nucleotides (nt) transcript, whereas ectopic tumors seem to be associated with a longer mRNA form (1450 nt). In order to analyse the presence of different POMC transcripts, we extracted total RNA from peripheral lymphocytes of 10 patients with Cushing's disease, 10 with ectopic Cushing syndrome, and 20 controls as well as from pituitary tissues (2 ACTH-omas and a normal pituitary polyA+ sample). Northern blot analysis correctly revealed a 1072 nt mRNA molecule in pituitary ACTH-oma and in the normal pituitary polyA+ RNA samples, whereas neither this molecule nor other alternative transcripts were detected in blood samples from patients and controls. These data were confirmed by the more sensitive RT-PCR technique. This study further underlines the need for alternative approaches in the diagnosis of ACTH-dependent Cushing's syndrome.

A Primary Adrenal Non-Hodgkin's Lymphoma Presenting as an Incidental Adrenal Mass

The primary adrenal localization of a non-Hodgkin's lymphoma (NHL) is a rare event. We report the case of a 70-yr-old woman, who was admitted at our Institute for a hormonal evaluation after the incidental discovery of a right adrenal mass during ultrasonography (US) performed for cardiovascular disease. At the physical examination, no sign of adrenal hyperfunction was present. She showed only an androgenetic alopecia and her blood pressure was 180/70 mm Hg, with an arrhythmic heart rate of 100 beats/min. No alterations in hormonal and biochemical data were observed. US studies showed a right adrenal mass (major diameter 16 mm), and an abdominal computed tomography (CT) scan confirmed this solid lesion (major diameter 15 mm) with a high density. [75Se] methylnorcholesterol adrenal scintigraphy exhibited a normal symmetrical radiotracer uptake. After 8 months of follow-up, an abdominal CT scan demonstrated a significant increase of the right adrenal mass (major diameter: 40 mm), with a solid tissue density and enhancement after i.v. contrast. [75Se] methylnorcholesterol adrenal scintigraphy showed an absent uptake on the right side versus the contralateral side. The hematological, hormonal and radiological evaluation did not reveal any sign of malignancy. Owing to the mass enlargement and the modification of scintigraphic pattern, the patient underwent unilateral adrenalectomy. Histological examination revealed a primary diffuse large B-cell NHL (REAL classification) of the adrenal gland. After surgery, she underwent a combined polychemotherapy (cyclophospamide, adriamycin, vincristine and prednisone) and subsequently one cycle of radiotherapy. At present, the patient is in good conditions and there are no signs or symptoms of recurrent disease.

Comparison of different regimens of glucocorticoid replacement therapy in patients with hypoadrenalism

Since the optimal glucocorticoid replacement needs to avoid over and under treatment, the adequacy of different daily cortisone acetate (CA) doses was assessed in 34 patients with primary and central hypoadrenalism. The conventional twice CA 37.5 mg/day dose was administered to all patients (A regimen: 25 mg at 07:00 h, 12.5 mg at 15:00 h), while in 2 subgroups of 12 patients the dose was shifted on 2 thrice daily regimens (B: 25 mg at 07:00, 6.25 mg at 12: 00, 6.25 mg at 17:00; C: 12.5 mg, 12.5 mg, 12.5 mg). In other 12 patients the conventional dose was reduced to a thrice 25 mg/day administration (D regimen: 12.5 mg, 6.25 mg, 6.25 mg). In all patients, urinary free cortisol (UFC) excretion and cortisol day curves were evaluated. During the CA 37.5 mg administration, nadir cortisol levels were significantly higher with the thrice daily regimens (143 +/- 31 on B and 151 +/- 34 nmol/l on C) than with the conventional twice (85 +/- 16 nmol/l). Moreover, UFC, morning cortisol levels and mean cortisol day curves were similar in each group. Finally, during D regimen nadir cortisol levels were higher than in A and similar to B and C regimens. No difference in UFC and in cortisol day curves by reducing the CA dose was found. In conclusion, the thrice daily cortisone regimens, in which more physiological cortisol levels are achieved, perform better as replacement therapy. The administration of 25 mg/day CA confirms that replacement therapy is more adequate with a lower dose, particularly in patients with central hypoadrenalism.

Effects of dehydroepiandrosterone (DHEA) supplementation on hormonal, metabolic and behavioral status in patients with hypoadrenalism

Oral DHEA administration to patients with hypoadrenalism, in addition to glucocorticoid and mineralcorticoid replacement, may improve both well-being and hormonal/metabolic parameters. Twenty patients (13 men, 7 women, 26-76 yr, 11 with Addison's disease, 9 with central hypoadrenalism) were recruited in a placebo-controlled, randomized study. Hormone levels, carbohydrate and lipid parameters, bone metabolism, body composition and psychological parameters were evaluated at baseline and after treatment with DHEA 50 mg/day or placebo for 4 months. After 4 months of DHEA administration, serum DHEAS levels raised both in men (from 0.71+/-0.18 to 8.28+/-1.66 micropmol/l, p<0.005) and in women (from 0.25+/-0.07 to 5.65+/-1.93 micromol/l, p<0.05). Only in hypoadrenal women an increase in testosterone (T; from 0.4+/-0.1 to 1.45+/-0.26 nmol/l, p<0.05) and androstenedione (A; from 0.86+/-0.34 to 2.05+/-0.29 nmol/l, p<0.05) levels was observed. In men no significant modifications in T and 17-hydroxyprogesterone (17-OHP) levels were found, whereas serum SHBG significantly decreased. As far as the metabolic parameters are concerned, only in patients with Addison's disease a significant decrease in total cholesterol and in low-density lipoproteins after 4 months of DHEA administration was found. No changes in glucose metabolism and insulin sensitivity were observed. In basal conditions, mean serum osteocalcin (OC) was normal and significantly decreased after DHEA treatment. A significant reduction in body fat mass percentage (BF%) after DHEA administration was observed. As far as well-being is concerned, DHEA replacement did not cause any relevant variation of subjective health scales and sexuality in both sexes. Our study confirms that DHEA may be beneficial for female patients with hypoadrenalism, mainly in restoring androgen levels. Concerning the health status, more sensitive and specific instruments to measure the effects of DHEA treatment could be necessary.

Assessing the presence of abnormal regulation of cortisol secretion by membrane hormone receptors: in vivo and in vitro studies in patients with functioning and non-functioning adrenal adenoma

Regulation of cortisol secretion by aberrant hormone receptors may play a role in the pathogenesis of ACTH-independent Cushing's syndrome. In this study, the topic was evaluated by combining in vivo and in vitro approaches. Cortisol responses to various stimuli (standard meal, GnRH + TRH, cisapride, vasopressin, glucagon) were assessed in 6 patients with clinical or subclinical adrenal Cushing's syndrome, and non-functioning adrenal adenoma in two cases. Abnormal responses were observed in three patients with Cushing's syndrome; one patient showed a gastric inhibitory polypeptide (GIP)-dependent cortisol rise after meal, together with responses after GnRH and cisapride; the second patient showed an LH-dependent cortisol response to GnRH, and in the third cortisol rose after cisapride. The pattern of receptor expression performed by RT-PCR showed that while GIP-R was only expressed in tumor from the responsive patient, 5-hydroxytryptamine type 4 receptor and LH-R were also present in normal adrenal tissues and tissues from non-responsive patients. Interestingly, an activating mutation of Gsalpha gene was identified in one of these tumors. Therefore, cortisol responses to agents operating via Gs protein coupled receptors (in one case associated with Gsalpha mutation) were found in Cushing's patients, while these responses were absent in the others. The finding of receptor expression in normal and non-responsive tumors suggests that different mechanisms are probably involved in inducing in vivo cortisol responses.

Anthropometric, hormonal and biochemical differences in lean and obese women before and after menopause

The menopausal status is associated with an increased risk of metabolic and cardiovascular diseases. Since the post-menopausal modifications have not been clearly investigated in obese women, we evaluated the influences of menopausal status on anthropometric, hormonal and biochemical characteristics in selected groups of normal-weight and obese women. We studied 92 female outpatients: 24 normal-weight pre-menopausal (Pre-NW) [body mass index (BMI) 23.6 +/- 0.48, age 44.8 +/- 0.68], 24 normal-weight post-menopausal (Post-NW) (BMI 23.7 +/- 0.44, age 55.5 +/- 0.69), 24 obese pre-menopausal (pre-OB) (BMI 32.3 +/- 0.45, age 44.6 +/- 0.75), 20 obese post-menopausal women (Post-OB) (BMI 32.9 +/- 0.57, age 55.2 +/- 0.82). All the subjects were non smokers and free from hypertension, diabetes or impaired glucose tolerance (IGT). Anthropometric parameters, body composition, 17 beta-estradiol, LH, FSH, androstenedione, SHBG, testosterone and leptin were determined. Free androgen index (FAI) and insulin resistance index (HOMA) were calculated. In comparison with Pre-OB, Post-OB had higher values of waist circumferences (p < 0.02), while Post-NW showed no difference. Total and LDL-cholesterol were high in Post-NW women, whereas in the obese subjects they were already elevated in the premenopausal period. SHBG levels declined and FAI increased in Post-OB in comparison with Pre-OB. SHBG levels showed an inverse correlation with BMI, waist and waist-to-hip ratio (WHR), while FAI positively correlated with waist values. Serum leptin levels were higher in Post-OB than in Pre-OB, whereas they were similar in normal-weight women. The rise of leptin levels may be related to the greater abdominal fat deposition. In addition, menopausal status of uncomplicated obese women is associated with a greater abdominal fat deposition and with higher values of free androgen index, which may be considered as factors of cardiovascular risk.

Baseline and CRH-stimulated ACTH and cortisol levels after administration of the peroxisome proliferator-activated receptor-gamma ligand, rosiglitazone, in Cushing's disease

The ability of acute rosiglitazone administration in influencing ACTH/cortisol secretion in basal conditions and after CRH stimulation was studied in patients with Cushing's disease. Ten patients (8 women and 2 men, aged 18-65 yr) with Cushing's disease were enrolled in the study: 6 of them had previously undergone unsuccessful surgery and 4 were untreated. Plasma ACTH and serum cortisol levels were evaluated at serial time points for 3 h during saline infusion and after the administration of rosiglitazone (8 mg, po) and for 1 h after the injection of CRH (1 microg/kg iv) given alone or 30 min following rosiglitazone administration. The 4 tests were performed in all subjects in randomized order on different days. No significant difference was observed between the pattern of hormone secretion during saline alone and after rosiglitazone, as evaluated by two-way analysis of variance (ANOVA). The integrated areas under the curves (AUCs) were also not significantly different (ACTH: 5683 +/- 1038 vs 6111 +/- 1007 pg/ml/180 min; cortisol: 2333 +/- 267 vs 2902 +/- 486 microg/dl/180 min). In addition, there was no difference for ACTH and cortisol responses to CRH given either alone or after rosiglitazone, when evaluated as peak, increment or AUC; the pattern of the responses analyzed by two-way ANOVA was also similar.

IN CONCLUSION

1) the administration of a single dose of rosiglitazone did not decrease ACTH/cortisol levels or blunt their response after CRH injection; 2) the activation of PPAR-gamma receptors by rosiglitazone seems unable to affect ACTH and cortisol secretion, at least in acute conditions, in patients with ACTH-secreting pituitary adenomas.

Long-term results of treatment in patients with ACTH-secreting pituitary macroadenomas

OBJECTIVE

Since Cushing's disease due to large pituitary tumors is rare, we evaluated biochemical characteristics at entry and the results of first surgical approach and of adjuvant therapeutic strategies during a long-term follow-up period.

DESIGN

We studied 26 patients (nine male, 17 female; 42.5+/-12.7 years, mean+/-s.e.) with ACTH-secreting pituitary macroadenoma (tumor diameter: 11-40 mm).

METHODS

At entry, plasma ACTH, serum cortisol and 24-h urinary free cortisol (UFC) levels were measured in all patients, a high-dose dexamethasone (dexa) suppression test was evaluated in 22 cases and a corticotrophin releasing hormone (CRH) test in 20 cases. Patients were re-evaluated after operation and, when not cured, they underwent second surgery, radiotherapy and/or ketoconazole treatment. The follow-up period was 78+/-10 months.

RESULTS

Before surgery, dexa decreased ACTH (>50% of baseline) in only 14/22 patients. The CRH-stimulated ACTH/cortisol response was normal in six patients, impaired in six patients and exaggerated in eight patients. After operation eight patients were cured, nine had normalized cortisol levels and nine were not cured. Pre-surgery, mean ACTH values were significantly higher in the not cured patients than in those normalized (P<0.05) and cured (P<0.01); the ACTH response to CRH was impaired in only six patients of the not cured group. The tumour diameter was significantly less in cured patients (P<0.02) and in normalized patients (P<0.05) than in the not cured ones. Magnetic resonance imaging (MRI) showed invasion of the cavernous sinus in 2/9 normalized, and in 6/9 not cured patients. After surgery, ACTH, cortisol and UFC were significantly lower than at entry in cured and in normalized patients, but not in not cured patients. In the cured group, the disease recurred in one patient who was unsuccessfully treated with ketoconazole. In the normalized group, a relapse occurred in eight patients: radiotherapy and ketoconazole induced cortisol normalization in one case, hypoadrenalism in one case and were ineffective in another one, while five patients were lost at follow-up. In the not cured group, eight patients underwent second surgery, radiotherapy and/or ketoconazole, while one patient was lost at follow-up. These therapies induced cortisol normalization in two patients and hypoadrenalism in one.

CONCLUSIONS

(i) A sub-set of patients with ACTH-secreting pituitary macroadenoma showed low sensitivity to high doses of dexamethasone and to CRH, (ii) pituitary surgery cured Cushing's disease in a minority of patients, (iii) high baseline ACTH levels, impaired ACTH response to CRH, increased tumor size or invasion of the cavernous sinus were unfavourable prognostic factors for surgical therapy, and (iv) second surgery, radiotherapy and/or ketaconazole cured or normalized hypercortisolism in half of the patients with recurrence or not cured.

Diagnosis and management of Addison's disease during pregnancy

Although primary adrenal failure is considered a rare condition, recent epidemiological studies indicate a rising incidence of the disease owing to the increase of autoimmune disorders. Addison's disease may be a life-threatening condition and the occurrence of pregnancy has been considered as a dangerous event. Nowadays, adrenal insufficiency during pregnancy is associated with high incidence of serious fetal and maternal complications, as fetal death in utero and post-partum adrenal crises, only if the disorder is not recognized and adequately treated. In this article pathophysiological aspects, clinical features and guidelines of management of pregnancy in Addison's disease are reviewed.

Impaired estrogen-induced negative feedback on gonadotropin secretion in patients with gonadotropin-secreting and nonfunctioning pituitary adenomas

BACKGROUND

Several in vitro studies suggest that gonadotropin-secreting pituitary adenomas (Gn-omas) and non functioning pituitary adenomas (NFPA) originate from gonadotroph cells. Patients with Gn-oma and NFPA frequently show abnormal gonadotropin response to TRH. The aim of the study was to investigate whether the estrogen-induced negative feedback is operating in either patients with Gn-oma or NFPA.

MATERIALS AND METHODS

Serum gonadotropin levels were evaluated at 24 h after ethinylestradiol administration (1 mg per os; EE2 test) in seven patients with a diagnosis of Gn-oma, based on the presence of high follicle-stimulating hormone (FSH) and/or lutenising hormone (LH) levels with normal or high levels of sex steroids, in 22 patients with NFPA with normal or low levels of gonadotropin and sex steroids, and 30 sex- and age-matched healthy subjects. A normal response to EE2 test was arbitrarily defined as a serum LH and FSH decrease of at least 40 and 30% below basal levels.

RESULTS

Among patients with Gn-oma, only one had a normal FSH inhibition and another, a normal LH inhibition. Among the 22 patients with NFPA, the EE2 test caused a normal FSH or LH reduction in 10 and 15, respectively, while a normal reduction of both FSH and LH was observed in nine.

CONCLUSIONS

The study demonstrates that estrogen-induced negative feedback of gonadotropin secretion is disrupted in almost all patients with Gn-oma and in half of those with NFPA. This defective feedback is reminiscent of the resistance to thyroid hormones and glucocorticoids observed in patients with thyroid-stimulating hormone- (TSH-) and adrenocorticotropic hormone- (ACTH-)secreting adenomas, respectively.

Assessment of cure and recurrence after pituitary surgery for Cushing's disease

BACKGROUND

The treatment of choice in Cushing's disease is transsphenoidal adenomectomy with a recurrence rate ranging 9-23%. We investigated whether abnormal hormonal responses may predict the relapse in "operated" patients followed-up for a long period.

METHOD

Sixty-eight surgically treated patients with Cushing's disease were followed-up for 12-252 months. Forty-eight patients underwent selective adenomectomy, 17 enlarged adenomectomy and 3 underwent total hypophysectomy. After surgery ACTH and cortisol levels were measured after stimulatory (desmopressin and CRH) and inhibitory tests (dexamethasone and loperamide).

FINDINGS

After operation 46 patients were cured (group A), 15 patients only normalized cortisol levels (group B), 7 patients were surgical failures. During the follow-up, a disease-free condition was maintained in 48 of 61 cases (79%), while a recurrence occurred in 13 patients (21%, 5 of group A and 8 of group B). In 5/13 patients who relapsed an absent inhibition after dexamethasone and an exaggerated response to CRH test preceded the recurrence. In 5 other patients the relapse was suspected by loperamide test. In the 3 remaining cases, positive responses to desmopressin preceded the recurrence. In 7/13 patients who relapsed the pituitary tumour was visualized by MRI/CT imaging.

INTERPRETATION

During the follow-up a careful assessment of ACTH dynamics is needed. Although no single test can reliably predict the late outcome, individual patients at risk for relapse may be identified by abnormal responses to desmopressin, CRH and loperamide tests; particularly, the persistent responsiveness to desmopressin may be a criterion of risk for recurrence in patients who only normalized cortisol levels after surgery.

Comparison between buserelin and dexamethasone testing in the assessment of hirsutism

Many hirsute women may present a form of functional ovarian hyperandrogenism (FOH), since they show an exaggerated 17-hydroxyprogesterone (17-OHP) response to GnRH agonists administration. As the failure of dexamethasone to reduce testosterone levels may be indicative of an ovarian source of androgen secretion, we evaluated the usefulness of dexamethasone suppression test, in comparison with buserelin challenge, in the assessment of hirsutism. Twenty-seven hirsute women (aged 15-42 yr) underwent ACTH and buserelin tests: 4 patients were heterozygotes for 21-OH deficiency and 8 patients were affected with FOH: 2 of the patients with hyperresponse to buserelin also had 21-hydroxylase deficiency. The results of the dexamethasone suppression test (2 mg/day for 7 days) were compared to those obtained after buserelin test. Basal T and delta4 levels (mean+/-SE) were higher than in controls (4.2+/-0.5 vs 2.2+/-0.2 nmol/l and 10.9+/-0.9 vs 5.9+/-0.6 nmol/l, p<0.02), while no differences were found in 17-OHP and DHEAS levels. A significant reduction (p<0.001) in T (1.8+/-0.4 nmol/l), delta4 (3.2+/-0.5 nmol/l) and DHEAS levels (2.4+/-0.3 micromol/l) was observed at the 3rd day of dexamethasone administration and no differences between sampling at 3rd, 5th and 7th day were found. Serum T was not suppressed in 6 cases, delta4 and DHEAS levels in 3 and 1 of them, respectively. Buserelin injection caused an excessive 17-OHP response in 8 patients, only 4 of them did not reduce T levels during dexamethasone. The sensitivity and specificity of the dexamethasone suppression test, with respect to the buserelin test, were 50% and 89%, respectively. In conclusion, 37% of hirsute patients had an abnormal responsiveness to buserelin and/or ACTH tests, indicating that hormonal investigations are mandatory. An ovarian origin of hirsutism was identified by buserelin test in 30% of patients and by dexamethasone in 22% of cases; only 4 of 8 patients showed concordant results to both tests. Therefore, buserelin challenge seems a more useful, cost-effective and less time consuming tool than dexamethasone administration in order to recognize the possible ovarian origin of hyperandrogenism.

Androgen secretion in ectopic ACTH syndrome and in Cushing's disease: modifications before and after surgery

The role of ACTH in the control of adrenal androgen secretion is known, although the possible existence of other regulatory factors has been also suggested. While some data concerning Cushing's disease have been reported, only few studies concerned androgen levels in ectopic ACTH secretion. The aim of this study was to evaluate serum DHEA-S, androstenedione (A) and testosterone (T) levels in 36 women with ACTH-dependent Cushing's syndrome (30 with Cushing's disease and 6 with ectopic ACTH secretion) before and after surgery. Two men with ectopic ACTH production were also studied. In 30 women with Cushing's disease serum DHEA-S (9.6 +/- 0.9 micromol/l), A (15.2 +/- 1.2 nmol/l) and T (4.1 +/- 0.5 nmol/l) were higher than in controls (p < 0.01): elevated DHEA-S, A and T values were found in 8, 18 and 17 cases, respectively. After adenomectomy in 15 apparently cured patients DHEA-S, A and T levels were low at 1 - 3 months and at 6 - 12 months after surgery. At 18 - 24 months, DHEA-S remained low in spite of cortisol normalisation. In ectopic Cushing's syndrome, A levels were significantly higher (23.1 +/- 4.9 nmol/l) than in Cushing's disease (p < 0.05), while no differences were found in DHEA-S and T levels. Two patients had elevated DHEA-S values, 3 women had high T levels and 7 of the 8 patients had very high A concentration that was lowered in 3 operated cases. In conclusion, the pattern of adrenal androgen secretion is rather different in patients with pituitary or with ectopic Cushing's syndrome. While the frequency of DHEA-S and T alterations is similar, androstenedione secretion is greatly increased in the latter condition. It is suggested that in ACTH-secreting non-pituitary tumours, the production of a POMC-derived peptide, although unidentified, may lead to preferentially stimulated androstenedione secretion, without affecting other enzymatic pathways.

A comparative evaluation of effectiveness of medical and surgical therapy in patients with macroprolactinoma

BACKGROUND

The surgical success rate in macroprolactinomas is quite low, while medical treatment is more effective in reducing PRL levels and tumour mass. In this study the effectiveness of surgical, medical and radiant approaches on clinical symptoms, PRL levels and tumour size were compared in a large series of patients with macroprolactinomas.

METHODS

One hundred and thirty-two patients (63 males and 69 females) were followed-up. Eighty-three patients were operated by trans-sphenoidal (TSS) approach: 18 underwent only TSS, 10 were operated and then irradiated; 30 patients underwent TSS and dopamine agonists, 25 were treated by TSS, radiotherapy and dopamine agonists. One hundred and four patients were treated by medical therapy: 49 patients were only administered dopamine agonists and 55 were given dopamine agonists after unsuccessful surgery and/or radiotherapy.

RESULTS

In 83 patients serum PRL levels decreased from 1873+/-319.9 ng/ml to 831.6+/-297.8 ng/ml after trans-sphenoidal surgery: a significant PRL reduction was obtained in 18 cases (22%) and a full PRL normalization was found in 15 patients (18%). The pituitary adenoma was completely removed in the 15 cases, in whom serum PRL normalized. Sexual function was restored in 57 percent; of women and in 29 percent; of men. In contrast, dopaminergic drugs normalized PRL levels (from 1590.5+/-232.7 to 19.2+/-4.8 ng/ml) in 93/104 patients (89 percent;). Sexual function was restored in 74 percent; of women and in 75 percent; of men. Radiotherapy, performed after unsuccessful TSS, was ineffective in normalizing PRL levels.

CONCLUSIONS

Medical therapy should be considered the first choice treatment in macroprolactinomas, while the surgical approach is recommended when neurological compressive symptoms are present and in patients resistant or intolerant to dopamine agonists. Radiotherapy may be indicated only in the patients in whom medical and surgical therapy have not been successful.

Blunted vascular and renal effects of exogenous atrial natriuretic peptide in patients with cushing's disease

The role of atrial natriuretic peptide (ANP) in glucocorticoid hypertension is still controversial, as glucocorticoids enhance the secretion of ANP in vivo, but reduce its biological activity in vitro. In isolated cells, for example, the cGMP response to ANP is suppressed by dexamethasone. We tested the in vivo relevance of this observation by comparing the cGMP, endocrine, and renal responses to exogenous ANP in patients with Cushing's disease (CD; n = 10) and in a matched group of essential hypertensives (EH; n = 8) and normotensive controls (N; n = 4). alpha-human-ANP was infused at 0.01 microg/kg/min for 120 min with a 30-min recovery period; hormonal and arterial pressure measurements were performed at 30-min intervals, and renal parameters were measured at baseline and after infusion. There was a 4-fold increase in plasma ANP in all groups, but the increments in plasma cGMP were about 50% lower in CD than in N and EH; urinary cGMP was similarly lower in CD (247 +/- 61 vs. 529 +/- 146 and 384 +/- 54 nmol/150 min, respectively). This was associated with a reduced peak increase in hematocrit in CD (+2.6 +/- 0.9%) compared with N (+6.6 +/- 0.9%) and EH (+7.1 +/- 0.7%; P < 0.05 CD vs. both); the diuretic and natriuretic effects of ANP were also lower in CD than in EH with very similar systemic pressure levels (382 +/- 63 vs. 848 +/- 130 mL/150 min, and 61 +/- 14 vs. 113 +/- 14 mmol/150 min, respectively; P < 0.05 for both). The increments in plasma and urinary cGMP in response to physiological doses of ANP are thus blunted in CD patients compared with those in N and EH. This biochemical defect is associated with reduced capillary permeability and a lesser diuretic and natriuretic effect. These data are compatible with an impairment of the biological activity of ANP in glucocorticoid hypertension in humans.

Evaluation of haemostatic and fibrinolytic markers in patients with Cushing's syndrome and in patients with adrenal incidentaloma

It is known that either chronic glucocorticoid administration or endogenous hypercortisolism frequently induce an hypercoagulable condition. Since little is known about the evaluation of markers of haemostatic and fibrinolytic systems in other adrenal disorders, we studied plasminogen activator inhibitor (PAI-1), tissue-plasminogen activator (t-PA), fibrinogen and von Willebrand factor antigen (vWF-Ag) levels in 11 patients with Cushing's syndrome and in 12 patients with adrenal incidentaloma. In patients with Cushing's syndrome mean PAI-1, t-PA and vWF-Ag levels did not significantly differ from those found in 50 age- and sex-matched controls, while mean fibrinogen levels were significantly higher in patients (337.0+/-39.1 mg/dl) than in normal subjects (278.9+/-8.4 mg/dl). Patients with adrenal incidentaloma showed PAI-1, t-PA and vWF-Ag mean levels superimposable to those in controls, while fibrinogen (319.7+/-27.9 mg/dl) was slightly, although not significantly, higher than in normals. Considering the limits of normal values (as mean+/-2 SD) obtained in the control group, high PAI-1 levels were found in 2 patients with Cushing's syndrome and in 3 patients with incidentaloma. An elevation of fibrinogen levels was found in 3 patients with Cushing's syndrome and in 3 with incidentaloma. Increased vWF-Ag levels were found only in 1 patient with Cushing's syndrome. An increased t-PA level was occasionally observed only in the patient with adrenal carcinoma. On the whole, an alteration of at least one of haemostatic and fibrinolytic parameters was detected in 55% of the patients with Cushing's syndrome and in 42% of those with adrenal incidentaloma. In conclusion, early alterations of coagulation and fibrinolytic systems may be found in some patients with adrenal disorders, thus suggesting the opportunity of an accurate follow-up in order to identify possible risk factors for cardiovascular disease and thromboembolism.

Usefulness of the desmopressin test in the postoperative evaluation of patients with Cushing's disease

OBJECTIVE

To evaluate the plasma ACTH and serum cortisol responses to desmopressin in patients with Cushing's disease either before or after pituitary adenomectomy during long-term follow-up, and to compare the results with those obtained after corticotrophin-releasing hormone (CRH) testing.

DESIGN

Plasma ACTH and serum cortisol concentrations were evaluated after the administration of desmopressin (10 microg i.v.) or CRH (1 microg/kg i. v.) in 34 patients with Cushing's disease. Twenty-four patients with active Cushing's disease were evaluated both before and after transsphenoidal pituitary surgery (TSS); these patients were followed up for 1-36 months. Ten patients were studied only after a long-term period (1-19 years, median 4 years) after TSS (six patients), TSS plus external pituitary irradiation (three patients) and TSS plus radiosurgery (one patient).

RESULTS

In 24 patients with active Cushing's disease a significant ACTH/cortisol response (P<0.001) was induced by either desmopressin (ACTH from a baseline of 15.3+/-2.7 pmol/l to a peak of 40.9+/-7.3 pmol/l; cortisol from 673+/-59 nmol/l to 1171+/-90 nmol/l) or CRH (ACTH from a basal of 14. 2+/-2.5 pmol/l to a peak of 47.2+/-7.7 pmol/l; cortisol from 672+/-50 nmol/l to 1192+/- 80 nmol/l). In all patients a positive cortisol response to desmopressin was found. After pituitary adenomectomy the 14 'cured' patients were followed up for 1-36 months; desmopressin administration never induced ACTH or cortisol responsiveness in any patient. In contrast, a progressive recovery of ACTH and cortisol responses after CRH was observed at different intervals of time in all patients but one. Five patients, in whom the cortisol concentration only normalized after surgery, showed a persistent responsiveness to desmopressin, and two of them relapsed 12 and 24 months later. In five patients who were not cured, the hormonal responsiveness to either CRH or desmopressin was similar before and after operation. Of 10 patients studied only after long-term follow-up, six were cured and a normal response to CRH was present, whereas no changes in ACTH/cortisol concentrations were induced by desmopressin. The other four unsuccessfully operated patients underwent pituitary irradiation and showed different and equivocal hormonal responses to desmopressin and to CRH.

CONCLUSIONS

During the postoperative follow-up of patients with Cushing's disease, the maintenance or the disappearance of the hormonal response may be related to the persistence or the complete removal of adenomatous corticotrophs, respectively. It is suggested that desmopressin test should be performed in the preoperative evaluation and follow-up of patients with ACTH-dependent Cushing's syndrome.

The one microgram adrenocorticotropin test in the assessment of hypothalamic-pituitary-adrenal function

The possibility of assessing hypothalamic-pituitary-adrenal (HPA) function by the standard ACTH test (250 microg) has been widely discussed in the past years and compared with the role of the insulin tolerance test (ITT). Recently, it was shown that low doses of ACTH, such as 1 microg i.v., induce a maximal adrenal response and, by reducing the discrepancies compared with the ITT also allow one to detect mild forms of secondary hypoadrenalism. In the present study the 1 microg ACTH test was performed in patients with hypothalamic-pituitary disease in order to assess adrenal function, and the results have been compared with those obtained after the insulin test. Fifty-seven patients (31 men and 26 women, aged 19-73 years) with hypothalamic-pituitary diseases were studied: 51 patients were affected with pituitary tumor and 6 patients had hypothalamic disorders. All these patients and 18 healthy volunteers (7 men and 11 women, aged 19-46 years) received 1 microg i.v. ACTH injection. In addition, the ITT (0.1-0.15 U/kg body weight) was performed in all patients. In normal subjects mean cortisol levels significantly (P<0.001) increased from a baseline of 393+/-43 nmol/l to a peak of 770+/-41 nmol/l after 1 microg ACTH. In 44 patients with hypothalamic-pituitary disease 1 microg ACTH caused a cortisol rise similar to that of normal subjects (from 332+/-17 to 769+/-24 nmol/l; P<0.001), while an impaired response (from 124+/-23 to 312+/-46 nmol/l) was observed in 13 cases (23%), 7 of them with low morning cortisol levels (10-127 nmol/l) and 6 with basal values at the lower limit of normality. The cortisol response to ITT was compared with that obtained after the 1 microg ACTH test: 10 patients failed both challenges, 4 patients who passed the ACTH test failed the ITT, while 3 patients who failed the ACTH test passed the ITT. The 23 out of 57 patients (40%) who showed a cortisol peak greater than 750 nmol/l after 1 microg ACTH had a normal response to ITT. A positive correlation between cortisol peaks after ACTH and after insulin was also found (r = 0.68, P<0.001). Assuming a 100% accuracy of ITT, the low dose ACTH test yielded a 71% sensitivity and a 93% specificity. In conclusion, the low-dose ACTH test is a useful, safe and inexpensive tool for the initial assessment of HPA function in patients with hypothalamic-pituitary disease. In fact, the ITT is unnecessary when cortisol peaks are greater than 750 nmol/l after 1 microg ACTH and also when very low cortisol basal levels indicate an overt hypoadrenalism. Within these limits the ITT is mandatory and its important role in the recognition of secondary adrenal failure is further confirmed.

Evaluation of markers of bone and collagen turnover in patients with active and preclinical Cushing's syndrome and in patients with adrenal incidentaloma

Although steroid-induced negative effects on bone and collagen have been well described in corticosteroid-treated patients, few studies have extensively evaluated bone and collagen turnover in patients with endogenous Cushing's syndrome. In this work serum bone-Gla protein (BGP), C-terminal cross-linked telopeptide of type I collagen (ICTP) and N-terminal propeptide of type III procollagen (PIIINP) levels were determined in patients with active (n = 12) and preclinical (n = 6) Cushing's syndrome, adrenal incidentalomas (n = 35) and in healthy controls (n = 28). In patients with overt Cushing's syndrome, serum BGP (0.9+/-0.2 ng/ml), ICTP (2.7+/-0.2 ng/ml) and PIIINP (1.9+/-0.2 ng/ml) levels were significantly lower (P < 0.0001) than in controls (5.5+/-0.2, 3.9+/-0.2 and 3.2+/-0.2 ng/ml respectively). In preclinical Cushing's syndrome, serum BGP (2.5+/-0.8 ng/ml), ICTP (2.2+/-0.1 ng/ml) and PIIINP (2.2+/-0.2 ng/ml) levels were significantly lower than in normal subjects (P < 0.0001, P < 0.0001 and P < 0.02 respectively), being similar to those recorded in overt Cushing's syndrome. In patients with adrenal incidentaloma, serum BGP (4.2+/-0.5 ng/ml) and ICTP (2.9+/-0.2 ng/ml) levels were significantly lower than those found in controls (P < 0.05 and P < 0.001 respectively), while serum PIIINP levels (3.6+/-0.2 ng/ml) did not differ from those of normals. In particular, 9/35 patients with adrenal incidentaloma had markedly depressed BGP levels (<2.0 ng/ml; mean 0.8+/-0.1 ng/ml): all patients of this subgroup showed an exaggerated 17-hydroxyprogesterone increase after ACTH administration. In the same patients, serum ICTP (3.0+/-0.4 ng/ml) and PIIINP (3.6+/-0.2 ng/ml) levels did not differ from those found in the incidentaloma group. In conclusion, our study indicates that bone and collagen turnover are markedly affected in patients with overt and preclinical Cushing's syndrome. Although patients with adrenal incidentaloma do not show any signs or symptoms of overt hypercortisolism, the presence of reduced BGP and ICTP levels might be considered a further index of an 'abnormal' pattern of steroid secretion in some of them. As a consequence, the presence of early alterations in markers of bone turnover might be useful for selecting those patients who need more accurate follow-up of the adrenal mass.

Loperamide test: a simple and highly specific screening test for hypercortisolism in children and adolescents

The overnight dexamethasone (DXM) test can give false-positive results in a few conditions (e.g. stress, strenuous exercise, depression, anorexia, anxiety, anticonvulsive therapy) in diagnosing simple obesity and hypercortisolism (HC). The loperamide (LP; a peripheral opioid agonist) test has proven useful in such conditions in adults. Thirty-one obese subjects (age 10.0-19.7 y) were studied by both overnight DXM test and LP test (8 mg orally, samples for cortisol at 0, 90, 150, 180 and 210 min) on 2 separate days. LP suppressed cortisol (< or = 138 nmol l-1) at a dose of 0.1 mg kg-1 bw (half the minimum recommended dose for the drug's antidiarrhoea effect) in 14 subjects who had normal urinary (< 4970 nmol l-1) and serum (< 552 nmol l-1) cortisol, in the absence of signs and symptoms of HC (group A). The DXM test failed to suppress cortisol in three subjects in group A, two of whom were on anticonvulsive treatment. The LP test suppressed cortisol in all of 13 subjects with elevated urinary and/or serum cortisol and/or with signs or symptoms of HC (but in whom HC was subsequently excluded on clinical grounds) (group B), while the DXM test failed to suppress cortisol in three subjects of this group. One of these was under anticonvulsive treatment and one suffered from anxiety and depression. In four patients with Cushing's syndrome (group C) neither DXM nor LP could suppress cortisol levels. Therefore, the sensitivity was 100% for both DXM and LP, while the specificity was 84% for DXM and 100% for LP. No side-effects were observed with either drug. In conclusion, LP is a useful alternative to DXM in those particular conditions that can affect its specificity in children.