Premium
Enhanced growth hormone (GH) responsiveness to GH‐releasing hormone after dietary restriction in patients with Cushing's syndrome
Author(s) -
Alfonso LealCerro,
Eva Venegas,
Felipe García-Pesquera,
Luís Jiménez,
R. Astorga,
F. F. Casanueva,
Carlos Diéguez
Publication year - 1998
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1046/j.1365-2265.1998.00363.x
Subject(s) - endocrinology , medicine , growth hormone , hormone , acromegaly , somatropin
OBJECTIVE In patients with Cushing's syndrome, decreased growth hormone (GH) secretion is observed although the basic mechanism is not yet understood. A short‐term hypocaloric diet is known to increase both spontaneous and GHRH‐stimulated GH secretion in normal subjects. In order to gain further insight into the altered GH secretion in patients with Cushing's syndrome, we assessed the effect of a short‐term hypocaloric diet on GH responses to GHRH in these patients. DESIGN Two GHRH tests (1 μg/kg i.v.) were performed, the first under basal conditions (normocaloric diet) and the second after a 3‐day hypocaloric diet (650 cal/day). PATIENTS Six female patients with untreated Cushing's disease. MEASUREMENTS Plasma GH levels were measured by immunoradiometric assay. RESULTS GHRH‐induced GH release was impaired in patients with Cushing's disease on a normal diet (mean peak 12.4 ± 6.4 mU/l, area under the curve (AUC) 744 ± 332 mU/l/120 min). Following a hypocaloric diet, GH responses to GHRH were markedly enhanced in the same group of patients (mean peak 46.2 ± 14.8 mU/l, AUC 3142 ± 1032 mU/l/120 min, P < 0.05). CONCLUSIONS This study demonstrates that in patients with Cushing's disease the somatotroph hyporesponsiveness to growth hormone releasing home is improved after a short‐term hypocaloric diet. Therefore, blunted growth‐hormone secretion in chronic hypercortisolism is a potentially reversible state and the secretory capacity of the somatotroph appears not to be severely compromised in patients with Cushing's disease.