Effect of hydrocortisone on the growth hormone response to growth hormone-releasing hormone in acromegaly.
Our recent data show that acute and sustained hypercortisolism decreases circulating growth hormone (GH) levels in acromegaly with respect to saline infusion. It has been hypothesized that in acromegalic patients, as well as in normal subjects, short-term increases in serum cortisol levels may be able to cause an enhancement of hypothalamic somatostatin secretion, which in turn may be responsible for the glucocorticoid mediated GH inhibition. The aim of our study was to investigate the acute effects of an intravenous infusion of hydrocortisone on the GH response to growth hormone-releasing hormone (GHRH) in acromegaly. We studied 6 adult patients with active acromegaly (3 M, 3 F; mean age 60.5 +/- 4.1 years; mean body mass index 27.1 +/- 0.6 kg/m2). All the patients underwent: (1) a bolus intravenous injection of 100 mg hydrocortisone succinate in 2 ml saline, at time -60 followed by a 120-min intravenous infusion of 250 mg hydrocortisone succinate in 250 ml saline, from -60 to 60 min; (2) a bolus intravenous injection of human GHRH 1-29NH2 100 micrograms in 1 ml saline, 60 min after initiation of a 2-hour hydrocortisone infusion; (3) a bolus intravenous GHRH injection 60 min after initiation of a 2-hour saline infusion. In all of the acromegalic patients during hydrocortisone succinate infusion, GH values clearly decreased with respect to basal levels (mean nadir 47 +/- 8.6%, p < 0.05 with respect to basal levels). After GHRH injection and saline infusion all the patients showed a significant increase in GH levels (mean peak 231.5 +/- 52.8%, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
Cattedra di Clinica Medica, University of Brescia, Italy.
A
A
Giustina
A R
AR
Bussi
M
M
Doga
W B
WB
Wehrenberg
D000172:Acromegaly / Q000097:blood / Q000188:drug therapy*; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D005938:Glucocorticoids / Q000502:physiology*; D013006:Growth Hormone / Q000097:blood*; D013007:Growth Hormone-Releasing Hormone; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D005938:Glucocorticoids; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone; D006854:Hydrocortisone