Abstract |
The objective of this study was to investigate the relationship between growth hormone (GH) dynamic tests ( thyrotropin-releasing hormone [TRH] test and oral glucose tolerance test [OGTT]), insulin-like growth factor-I ( IGF-I) plasma values, tumor size, and clinical outcome in patients with GH-secreting pituitary adenomas. Furthermore, we investigated the potential prognostic utility of the above biochemical parameters in the follow-up of patients with acromegaly. We studied 50 acromegalic patients (18 males and 32 females; mean age, 40 years; range, 16 to 69) who underwent trans-sphenoidal removal of a GH-secreting pituitary adenoma from 1990 to 1994. Preoperatively, we evaluated (1) GH plasmatic levels after an oral glucose load (OGTT) (blood samples were drawn at -15, 0, 30, 60, 90, 120, 150, and 180 minutes after oral administration of 0.75 g/kg body weight [BW] of glucose), (2) GH plasma levels after a TRH test (200 microg as an intravenous [IV] bolus), and (3) basal IGF-I plasma levels after an overnight fast. From 3 to 12 months after surgery we evaluated (1) GH plasma values after an OGTT, and (2) basal plasma IGF-I, free triiodothyronine (FT(3)), free thyroxine (FT(4)), thyroid-stimulating hormone (TSH), and urinary free cortisol. The same tests were performed every year for 5 years. All of the patients were classified into 4 subgroups according to the system of Hardy and Vezina. Preoperatively, "controlled" patients (n = 29) had a GH paradoxical response to TRH (n = 28) and an unresponsiveness to OGTT (n = 29); 23 of them belonged to the I and II classes. Only 5 poorly controlled patients (n = 21) showed a preoperative paradoxical response to TRH and 9 had a preoperative GH partial inhibition after OGTT; 19 of them belonged to the III and IV classes. Our data suggest that in the preoperative period in acromegalic patients the simultaneous presence of a GH paradoxical response to TRH and lack of GH inhibition after OGTT is inversely related to the tumor size and therefore more likely to be restored to normal by surgical treatment.
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Authors | L De Marinis, A Mancini, A Bianchi, R Gentilella, D Valle, A Giampietro, P Zuppi, C Anile, G Maira, A Giustina |
Journal | Metabolism: clinical and experimental
(Metabolism)
Vol. 51
Issue 5
Pg. 616-21
(May 2002)
ISSN: 0026-0495 [Print] United States |
PMID | 11979395
(Publication Type: Journal Article)
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Copyright | Copyright 2002, Elsevier Science (USA). All rights reserved. |
Chemical References |
- Triiodothyronine
- Human Growth Hormone
- Thyrotropin-Releasing Hormone
- Insulin-Like Growth Factor I
- Thyrotropin
- Thyroxine
- Hydrocortisone
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Topics |
- Acromegaly
(blood, surgery)
- Adenoma
(metabolism, pathology, surgery)
- Adult
- Female
- Glucose Tolerance Test
- Human Growth Hormone
(blood, metabolism)
- Humans
- Hydrocortisone
(urine)
- Insulin-Like Growth Factor I
(analysis)
- Male
- Middle Aged
- Pituitary Neoplasms
(metabolism, pathology, surgery)
- Postoperative Period
- Preoperative Care
- Prognosis
- Retrospective Studies
- Thyrotropin
(blood)
- Thyrotropin-Releasing Hormone
- Thyroxine
(blood)
- Triiodothyronine
(blood)
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