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.

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.

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]. / La funzione tiroidea in corso di obesità.

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.

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.

Dopamine D2 receptor gene polymorphisms and response to cabergoline therapy in patients with prolactin-secreting pituitary adenomas.

Dopamine-agonist cabergoline (CB) reduces prolactin (PRL) secretion and tumor size in 80% of patients with prolactin-secreting adenomas (PRL-omas) by binding type 2 dopamine receptor (DRD2). The mechanisms responsible for resistance to CB remain largely unknown. To assess the association of DRD2 with sensitivity to CB, TaqI-A1/A2, TaqI-B1/B2, HphI-G/T and NcoI-C/T genotypes were determined in a cross-sectional retrospective study, including 203 patients with PRL-oma. DRD2 alleles frequencies did not differ between patients and 212 healthy subjects. Conversely, NcoI-T allele frequency was higher in resistant rather than responsive patients, considering both PRL normalization (56.6 vs 45.3%, P=0.038) and tumor shrinkage (70.4 vs 41.4%, P=0.006). Finally, [TaqI A1-/TaqI B1-/HphI T-/NcoI T-] haplotype was found in 34.5% of patients normalizing PRL with < or =3 mg/week of CB vs 11.3% of resistants (P=0.021). In conclusion, resistance to CB was associated with DRD2 NcoI-T+ allele, consistent with evidence suggesting that this variant may lead to reduction and instability of DRD2 mRNA or protein.

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.

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.

Effect of sulpiride-induced hyperprolactinemia on serum testosterone response to HCG in normal men.

In six normal volunteers hyperprolactinemia was induced by sulpiride (150 mg/day) for 10 days. Both before and during sulpiride hCG was injected; the higher testosterone response to hCG, when PRL levels were enhanced, suggests a possible stimulatory role of PRL on Leydig cells.

Influence of L-prolyl-L-leucyl-glycine amide on growth hormone secretion in normal and acromegalic subjects.

Melanocyte Release-Inhibiting Peptide (MRIP-I) did not affect circulating levels of ACTH, LH, FSH, TSH,ORL, betaMSH and insulin when iv infused (5.0 mg in 5 min plus 0.4 mg/min for 70-115 min), while it significantly reduced serum GH response to hypoglycemia in normal subjects and lowered serum GH levels in acromegalics. There was no correlation between the fall in serum GH after MRIP and after dopaminergic drugs in acromegaly. These data are compatible with either a direct suppressive action exerted by MRIP-I at pituitary level or an extra-pituitary effect not involving dopaminergic pathways. It can be spec-lated that since labelled MRIP-I accumualtes in the pineal and melatonin blunts GH response to hypoglycemia, the pineal gland might be involved in the MRIP-I-induced suppression of GH secretion.

Thyrotropin secretion in patients with central hypothyroidism: evidence for reduced biological activity of immunoreactive thyrotropin.

TSH concentration was measured in plasma before and after TRH administration (200 micrograms, iv) in 89 patients with documented hypothyroidism consequent to various hypothalamic-pituitary disorders. Basal plasma TSH was less than 1.0 microI/ml in 34.8%, between 1.0-3.6 microU/ml in 40.5% and slightly elevated (3.7-9.7 microU/ml) in 24.7% of the cases. The plasma TSH response to TRH was absent in 13.5%, impaired in 16.8%, normal in 47.2%, and exaggerated in 22.5% of the cases, with delayed and/or prolonged pattern of response in 65% of the cases. The dilution curves of several plasmas drawn before and after TRH were parallel to those obtained with TSH standard preparation. After gel filtration, the elution pattern of TRH-stimulated plasmas from 4 patients did not show any major difference from that of pooled plasmas from normal subjects given TRH or from that of patients with primary hypothyroidism. Plasma TSH values determined by cytochemical bioassay on both basal and TRH-stimulated samples of 5 patients were markedly lower than those obtained by RIA. The serum T3 response to TRH was absent or low in 40 out of 53 patients in whom it was evaluated. The administration of T3 (100 micrograms/day for 3 days) or dexamethasone (3 mg/day for 5 days) respectively suppressed or reduced both basal and TRH-induced plasma TSH levels. Two patients became hypothyroid shortly after pituitary surgery in spite of basal and TRH-induced plasma TSH levels similar to or higher than those before surgery. Though thyroid atrophy due to chronic understimulation could explain the low T3 response to TRH in secondary hypothyroidism, it is difficult to reconcile thyroid understimulation with normal or increased plasma TSH unless the immunoreactive material has low biological activity. Present data suggest that several patients with hypothyroidism consequent to hypothalamic-pituitary diseases secrete a material which is immunologically similar to pituitary standard TSH and responds to stimulatory and suppressive agents in a manner similar to normal TSH but has low or absent biological activity. Thus, hypothyroidism due to insufficient TSH stimulation can be termed central hypothyroidism and can be due 1) to pituitary insufficiency (secondary hypothyroidism), 2) to a hypothalamic defect (tertiary hypothyroidism), or 3) to the secretion of biologically inactive TSH.

In vivo detection of somatostatin receptors in patients with functionless pituitary adenomas by means of a radioiodinated analog of somatostatin ([123I]SDZ 204-090).

The recent availability of a Tyr3-substituted octreotide (SDZ 204-090) for radioiodination has allowed somatostatin (SRIH) receptor binding to be studied in vivo, and receptor-positive tumors of different origins to be visualized with a gamma-camera. This prompted us to investigate whether this compound could be used for external imaging of functionless pituitary adenomas displaying SRIH receptors. Eight patients with functionless pituitary adenomas, three patients with acromegaly, and three with macroprolactinoma were injected iv with 123I-labeled Tyr3-octreotide and then scanned with a gamma-camera. Positive scans were obtained in the three acromegalics and in two of the eight patients with functionless pituitary tumors. The patients with macroprolactinoma had negative scans. The diagnosis of functionless pituitary adenomas was confirmed by light and electron microscopic examination as well as immunocytochemical studies. In vitro binding of [125I]Tyr11-SRIH to cell membranes was evaluated in four functionless and three GH-secreting adenomas removed from seven of the patients. All of the GH-secreting as well as one of the four functionless adenomas had high affinity SRIH-binding sites, without differences in number or affinity, whereas SRIH-binding sites were not detected in the others. Positive scans were observed only in patients bearing tumors with high affinity SRIH-binding sites. In conclusion, [123I]Tyr3-octreotide appears to be a promising tool for singling out, in vivo, patients with functionless pituitary tumors displaying SRIH receptors who might potentially benefit from octreotide treatment.

A syndrome of primary gonadal failure, short stature, mitral valve prolapse, and mental retardation.

Two brothers referred for hypogonadism presented with short stature, mild mental retardation, and minor anomalies. In addition, both patients had hypogonadism due to primary gonadal failure and mitral valve prolapse, in the absence of other heart defects. A complete hormonal evaluation in one of the patients showed abnormal growth hormone (GH) and gonadotropin responses to different stimuli, findings suggestive of a disorder of hypothalamic-pituitary regulation. Both patients had normal chromosomes (46,XY) as did their mother (46,XX), who had some of the clinical manifestations found in her sons but in a milder form. We propose that this is a new syndrome.