Effect of glucocorticoids on the paradoxical growth hormone response to thyrotropin-releasing hormone in patients with acromegaly.
It has been hypothesized that in acromegalic patients, as well as in normal subjects, acute increases in serum cortisol levels may cause an enhancement of hypothalamic somatostatin secretion, which in turn may be responsible for the glucocorticoid-mediated growth hormone (GH) inhibition. The aim of this study was to investigate short-term effects of an intravenous (i.v.) infusion of hydrocortisone on the GH response to thyrotropin-releasing hormone (TRH) in acromegaly. We studied six adult patients with active acromegaly. The group was composed of four women and two men with a mean age of 55.8 +/- 6.4 years (range, 27 to 68) and a mean body mass index of 26.7 +/- 1 kg/m2 (range, 23.3 to 30). All patients underwent the following treatments: (1) hydrocortisone alone: a bolus i.v. injection of hydrocortisone succinate 100 mg in 2 mL saline at time -60 minutes, followed by a 120-minute i.v. infusion of hydrocortisone succinate 250 mg in 250 mL saline from -60 to 60 minutes; (2) TRH+hydrocortisone: a bolus i.v. injection of TRH 200 micrograms 60 minutes after initiation of a 2-hour hydrocortisone infusion; (3) TRH alone: a bolus i.v. injection of TRH at time 0, 60 minutes after initiation of a 2-hour saline infusion. In all six patients, TRH induced large GH increases (absolute peak GH level, 58.1 +/- 23.2 micrograms/L; maximum % GH change with respect to baseline, 1,397.8% +/- 807.8%; range, 205% +/- 5,219%).(ABSTRACT TRUNCATED AT 250 WORDS)
Giustina
A
A
Cattedra di Clinica Medica, University of Brescia, Italy.
Doga
M
M
Bresciani
E
E
Bussi
A R
AR
Chiesa
L
L
Misitano
V
V
Giustina
G
G
D000172:Acromegaly / Q000097:blood*; D000328:Adult; D000368:Aged; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology*; D007262:Infusions, Intravenous; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology*
D013973:Thyrotropin-Releasing Hormone; D013006:Growth Hormone; D006854:Hydrocortisone