Abstract. Vasoactive intestinal polypeptide (VIP) was administered (75 μg iv over 12 min) to 14 patients with Cushing's disease, 1 patient with Nelson's syndrome, and 8 normal subjects. VIP induced a significant rise of plasma ACTH levels in 6 patients with Cushing's disease, from a baseline of 13.2 pmol/l (9.9–18.5 pmol/l) to a peak of 24.5 pmol/l (7.7–18.9 pmol/l), median and range (P < 0.05), and in the patient with Nelson's syndrome, from a baseline of 260.9 to 461.3 pmol/l. A significant elevation of cortisol levels was also observed, from a baseline of 567 nmol/l (185–842 nmol/l) to a peak of 727 nmol/l (364–1029 nmol/l); P < 0.05. No modifications in plasma ACTH and cortisol levels were noticed in the other 8 patients with Cushing's disease, or in the normal subjects. In the responsive patients, the median plasma ACTH level reached after VIP was found to be less than that induced by CRH administration. In 2 of the responsive patients, VIP was injected again after successful microadenomectomy and did not then cause changes in ACTH and cortisol concentration. These data demonstrate that VIP specifically stimulates ACTH release in some patients with corticotropinomas but not in normal subjects; the disappearance of such abnormal ACTH responses after successful adenomectomy suggests the presence of specific VIP receptors only on the adenomatous corticotropes.
Bruno Ambrosi, Domenico Bochicchio, Alessandro Sartorio, Francesco Morabito, and Giovanni Faglia
Alessandro Sartorio, Marco Narici, Antonio Conti, Marco Monzani, and Giovanni Faglia
Sartorio A, Narici M, Conti A, Monzani M, Faglia G. Quadriceps and hand-grip strength in adults with childhood-onset growth hormone deficiency. Eur J Endocrinol 1995;132:37–41. ISSN 0804–4643
The effects of chronic growth hormone (GH) deficiency on muscle size and strength of postural (quadriceps) and non-postural (hand-grip) muscle groups, as well as on vertical jump capacity, were evaluated in six adults with childhood-onset GH deficiency. Data obtained were compared to those recorded in an age-, sex- and exercise-matched healthy control group. Thigh muscle plus bone cross-sectional area (CSAM+B) of the dominant quadriceps was significantly lower (p < 0.001) than in controls, while the CSAM+B/Body height)2 ratio was similar to that of controls. The maximum voluntary contraction (MVC) of the quadriceps of patients was significantly lower (p < 0.002) than in controls, while no differences existed in the quadriceps force expressed per unit area (MVC/CSA) between patients and controls. As far as hand-grip was concerned, the CSAM+B of the dominant forearm was significantly lower (p < 0.003) than in controls, while the CSAM+B/Body height)2 ratio was no different. The hand-grip MVC of patients was significantly lower (p < 0.004) than in controls, while no differences existed in the MVC/CSA ratio. It is noteworthy also that no difference existed in the hand-grip to quadriceps MVC ratio of the two groups. Furthermore, no differences were found in the vertical jump capacity, because both Δ Height and Δ Height/Body weight of patients were not significantly different from those of controls. In conclusion, our study suggests that GH deficiency seems to reduce the size and strength of postural and non-postural muscle groups to the same extent. However, these findings are likely to be attributed to a simple dimensional scaling, because their CSA/ (Body height)2, MVC/CSA and vertical jump capacity were comparable to those of controls.
Alessandro Sartorio, Laboratorio Sperimentale di Ricerche Endocrinologiche, Centro Auxologico Italiano, IRCCS, via Ariosto 13, 1-20145 Milan, Italy
Bruno Ambrosi, Susanna Peverelli, Elena Passini, Tiziana Re, Riccardo Ferrario, Paolo Colombo, Alessandro Sartorio, and Giovanni Faglia
Ambrosi B, Peverelli S, Passini E, Re T, Ferrario R, Colombo P, Sartorio A, Faglia G. Abnormalities of endocrine function in patients with clinically "silent" adrenal masses. Eur J Endocrinol 1995;132:422–8. ISSN 0804–4643
Because, in recent years, patients with incidentally discovered adrenal masses have been encountered increasingly, their endocrine function was investigated in basal conditions and after dynamic tests. Thirty-two patients (23 women and 9 men, aged 28–74 years) were studied. Lesion diameter, as documented by computed tomography and/or nuclear magnetic resonance imaging, ranged between 5 and 65 mm; the tumors were localized on the right in 22 patients, on the left in 5 and bilaterally in 5 cases. In basal conditions, urinary free cortisol (UFC) excretion, plasma adrenocorticotropin (ACTH) and cortisol levels were normal, except for 4 patients who showed high UFC and ACTH levels in the low–normal range. Ovine corticotropin-releasing hormone (CRH, 1 μg/kg iv) was given to 18 patients, inducing normal ACTH and cortisol responses in 12, blunted responses in 4 and no response in 2 cases. No reduction in ACTH and cortisol levels after suppression tests was observed in 4 of 29 patients after dexamethasone (1 mg overnight) or in 6 of 29 after loperamide. The 4 patients who were unresponsive to both tests did not show any further inhibition after high-dose dexamethasone administration, had low plasma ACTH levels and showed impaired or absent responses to the CRH test: they were diagnosed as affected with preclinical Cushing's syndrome. An exogenous ACTH test performed in 30 patients caused a normal cortisol rise. Basal mean 17-hydroxyprogesterone (17-OHP) levels were not different from those in normal subjects. After ACTH the 17-OHP rate increase was higher than in normal subjects (17-OHP(30–)/30 min = 0.31 ±0.04 vs 0.07 ± 0.01 nmol·1−1·min−1; mean±SEM, p < 0.01); in particular, this parameter was elevated in 18 of 30 patients (17-OHP(30–0)/30 min range = 0.23–1.07 vs 0.01–0.19 nmol·1−1·min−1 in normal subjects). In a subset of 11 patients, serum markers of bone (bone-GLA protein (BGP) and carboxyterminal cross-linked telopeptide of type I collagen (ICTP) and collagen turnover (aminoterminal propeptide of type III procollagen (PIIINP)) were significantly (p < 0.01) lower than in normal subjects: in particular, in 2 preclinical Cushing's patients they were markedly reduced and rose after unilateral adrenalectomy. Of these 2 patients who underwent surgery, 1 showed a secondary hypoadrenalism. The histological study in 7 operated patients revealed the presence of benign adenoma in 4 cases and carcinoma, myelolipoma and hematoma in the others. In conclusion, in patients with incidentalomas endocrine testing is recommended because about two-thirds of them show subtle signs of adrenal overactivity. In patients with enzymatic defects of steroidogenesis a surgical approach is not suggested. On the contrary, the existence of a preclinical Cushing's syndrome has to be investigated carefully and followed up in order to disclose the possible appearance of clinical and/or metabolic features induced by the hypercortisolism and to suggest a surgical treatment.
B Ambrosi, Institute of Endocrine Sciences, Ospedale Maggiore, IRCCS, via F Sforza 35, 20122 Milan, Italy
Giorgio Radetti, Antonio Fanolla, Fiorenzo Lupi, Alessandro Sartorio, and Graziano Grugni
Carla Bizzarri, Antonello E Rigamonti, Antonella Luce, Marco Cappa, Silvano G Cella, Jenny Berini, Alessandro Sartorio, Eugenio E Müller, and Alessandro Salvatoni
Background and aims
Ghrelin is an orexigenic 28-amino acid peptide produced by the stomach. Circulating ghrelin levels rise shortly before and fall shortly after every meal. Peptide YY (PYY), an anorexigenic 36-amino acid peptide, is secreted primarily from the intestinal mucosa of the ileum and large intestine. Plasma PYY levels begin to rise within 15 min after starting to eat and plateau within ∼90 min, remaining elevated for up to 6 h. Recently, some studies have tried to evaluate the potential role of ghrelin and PYY in the hyperphagia of patients with Prader–Willi syndrome (PWS). While hyperghrelinemia is well characterized in PWS, conflicting results have been reported for PYY. The aim of the study was to investigate ghrelin and PYY responses to a standard liquid high-fat meal in children with PWS.
Patients and methods
Circulating levels of total ghrelin and PYY levels were assayed by RIA after overnight fasting and 45, 60, 90, and 180 min following a standard meal (Ensure 6 ml/kg) in 16 patients with PWS (11 boys and five girls, aged 4.6–10.7 years, including ten receiving 0.02 mg/kg per day rhGH for 2–18 months; body mass index (BMI) z-score: 0.6±0.2 and 1.6±0.5 for children treated or not treated with rhGH respectively), ten obese (eight boys and two girls, aged 9.2–15.6 years; BMI z-score: 2.4±0.2, i.e. BMI >97th centile for chronological age and sex) subjects, and 16 normal-weight controls (five boys and 11 girls, aged 5.8–17.3 years; BMI z-score: 0.6±0.2).
PWS children showed higher fasting levels of ghrelin than obese and lean controls. Postprandial ghrelin drop was more pronounced in PWS than in the other study groups. No significant difference on fasting levels of PYY was found among groups. PWS showed a higher postprandial PYY rise than obese and lean controls. PWS patients treated and not treated with GH showed similar fasting and postprandial levels of ghrelin and PYY. Fasting PYY levels correlated negatively (P<0.05; r=−0.68) with those of ghrelin only in PWS.
The results of this study confirm fasting hyperghrelinemia in PWS. Since in PWS adults an impaired postprandial suppression of plasma ghrelin was previously reported to be associated with a blunted postprandial PYY response, the finding of a meal-induced decrease and increase in ghrelin and PYY levels respectively in PWS children would imply that the regulation of appetite/satiety of these peptides is operative during childhood, and it progressively deteriorates and vanishes in adulthood when hyperphagia and obesity worsen.
Antonello E Rigamonti, Silvano G Cella, Sara M Bonomo, Giuseppe Mancia, Guido Grassi, Mario Perotti, Fiorenza Agosti, Alessandro Sartorio, Eugenio E Müller, and Angela I Pincelli
Changes in many gastrointestinal peptides, including the anorexigenic peptide YY (PYY), which is produced by L cells, occur in both anorexia nervosa (AN) and obesity (OB). High PYY levels are present in AN, whereas in morbid OB fasting and postprandial PYY secretion is blunted. Somatostatin (somatotropin release-inhibiting factor (SRIF)) reportedly inhibits plasma PYY concentrations in animals and healthy humans, but the effect of a SRIF infusion on spontaneous PYY secretion in AN and OB is unknown.
A total of 18 young women, seven with acute AN (A-AN), four with AN in the recovery phase (R-AN), and seven with morbid OB, were studied. All subjects underwent an infusion of SRIF (9 μg/kg i.v./h, over 60 min), with blood samples drawn before and at different time intervals after SRIF administration. Plasma PYY levels were measured at each time point.
SRIF significantly inhibited plasma PYY concentrations in R-AN and OB, without affecting PYY titers in A-AN. In OB, the inhibitory effect of SRIF also persisted at 90 min. Withdrawal of SRIF infusion in R-AN resulted in a prompt restoration of basal plasma PYY levels, whereas termination of SRIF infusion in OB was followed by a slower increase of PYY titers toward baseline levels. After infusion, PYY Δ area under the curve (ΔAUC) in R-AN was significantly higher than those in A-AN and OB patients. A significant difference in PYY ΔAUC between A-AN and OB was present.
These results suggest the existence of a hypo- and hyper-sensitivity of L cells to the inhibitory effect of SRIF in A-AN and OB respectively.
Luigi Di Luigi, Antonello E Rigamonti, Fiorenza Agosti, Monica Mencarelli, Paolo Sgrò, Nicoletta Marazzi, Silvano G Cella, Eugenio E Müller, and Alessandro Sartorio
To detect exogenous recombinant human GH (rhGH) abuse in female athletes.
GH-dependent markers were assayed in serum of 100 female athletes (control group) and in a subgroup of nine female subjects treated with rhGH (0.09 IU/kg body weight, 6 days/week for 3 weeks).
Cut-off values (mean+2 s.d.) for IGF1, N-terminal propeptide of type III procollagen (PIIINP) and C-terminal telopeptide of type I collagen (ICTP) were calculated and arbitrary scores (1.5 or 2.0) were assigned to abnormal markers. By using the sum of individual marker scores, positive (≥3) or negative (<3) scores were obtained.
None of the control group obtained a positive score (≥3). Abnormal IGF1, PIIINP and ICTP levels were found in 61.4, 54.5 and 11.4% samples of the treated group. Overall, positive cases were present in 43.2% blood samples drawn in subjects treated with rhGH and in 26% of samples after rhGH withdrawal. The sensitivity of the detection approach was 66.6% at the end of 3-week rhGH treatment and 11.1% at the 15th day of rhGH withdrawal, while the specificity was 100%.
Detection test for rhGH administration appears less sensitive in female (66.6%) than in male athletes (previous observation, 100% after 3 weeks of comparable rhGH dose), but shows a similar specificity (98.5–100%). Since athletes supposedly use very high doses and long-term administration of rhGH for doping purposes, it is foreseen that the here-in detection test would in future increase its strength.