title: GH response to oral and intravenous glucose load in acromegalic patients.
abstract: The lack of inhibition of Growth Hormone (GH) levels after glucose load is considered a marker of inappropriate GH secretion in acromegaly. In order to investigate the physiopathology of this phenomenon, we have studied the GH variations after an oral glucose load (0.75 g/kg BW per os, OGTT) or intravenous glucose bolus (25 g i.v., IVGTT), in a group of 12 acromegalic patients, aged 20 +/- 69 yr (mean 48), 5 males and 7 females, with basal GH levels ranging from 11 to 76.2 ng/ml. The results indicate that only a group of acromegalic patients (group 1) had a partial GH inhibition after OGTT (mean decrease: 56.4 +/- 4.2%), but in no patients GH levels were influenced by intravenous administration of glucose. It is possible that in group 1 patients, the gastroenteric response could partially influence the GH secretion by the pituitary tumor, probably due to an increased peripheral somatostatin release. The dissociation of the GH response to OGTT and IVTT could indicate a supersensitivity to peripheral somatostatin, related to a deficiency in central somatostatinergic tone and therefore represent a more unfavourable prognostic sign.
authors.affiliation: Chair of Internal Medicine II, Catholic University School of Medicine, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mancini
authors.forename: P
authors.initials: P
authors.lastname: Zuppi
authors.forename: C
authors.initials: C
authors.lastname: Fiumara
authors.forename: D
authors.initials: D
authors.lastname: Valle
authors.forename: G
authors.initials: G
authors.lastname: Conte
authors.forename: M L
authors.initials: ML
authors.lastname: Fabrizi
authors.forename: L
authors.initials: L
authors.lastname: Sammartano
authors.forename: C
authors.initials: C
authors.lastname: Anile
authors.forename: G
authors.initials: G
authors.lastname: Maira
authors.forename: L
authors.initials: L
authors.lastname: De Marinis
mesh_terms: D000172:Acromegaly / Q000097:blood* / Q000209:etiology; D000236:Adenoma / Q000150:complications / Q000378:metabolism; D000284:Administration, Oral; D000328:Adult; D005260:Female; D005947:Glucose / Q000008:administration & dosage; D005951:Glucose Tolerance Test; D013006:Growth Hormone / Q000097:blood*; D006728:Hormones / Q000097:blood / Q000652:urine; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000150:complications / Q000378:metabolism
chemical_list: D006728:Hormones; D013006:Growth Hormone; D005947:Glucose