THE EFFECT OF SHORT-TERM CORTISOL CHANGES ON GROWTH-HORMONE RESPONSESTO THE PYRIDOSTIGMINE-GROWTH-HORMONE-RELEASING-HORMONE TEST IN HEALTHY-ADULTS AND PATIENTS WITH SUSPECTED GROWTH-HORMONE DEFICIENCY
M. Andersen et al., THE EFFECT OF SHORT-TERM CORTISOL CHANGES ON GROWTH-HORMONE RESPONSESTO THE PYRIDOSTIGMINE-GROWTH-HORMONE-RELEASING-HORMONE TEST IN HEALTHY-ADULTS AND PATIENTS WITH SUSPECTED GROWTH-HORMONE DEFICIENCY, Clinical endocrinology, 49(2), 1998, pp. 241-249
BACKGROUND AND AIMS The interaction between cortisol and growth hormon
e (GH)-levels may significantly influence GH-responses to a stimulatio
n test. In order to systematically analyse the interaction in a paired
design, it is necessary to use a test, which has been proven safe and
reliable such as the pyridostigmine-growth-hormone-releasing-hormone
(PD-GHRH) test, Three groups of subjects with a different GH-secretory
capacity were included, STUDY A Eight healthy adults were tested seve
n times, once with placebo throughout the examination and six times wi
th the PD-GHRH test following no glucocorticoid pretreatment, pretreat
ment with hydrocortisone (HC) (30 mg/day and 80 mg/day for 1 and 3 day
s) or pretreatment with 15 mg prednisolone for 1 day. HC (80 mg/day fo
r 1 day) in combination with PD significantly stimulated GH-levels com
pared to PD alone, 18.9 mU/l +/- 6.1 vs 3.0 mU/l +/- 0.8 (P< 0.05). Ho
wever, peak GH-responses to PC in combination with GHRH were reduced d
uring HC (80 mg/day for 1 day) compared to no glucocorticoid pretreatm
ent in all healthy adults. Conventional HC therapy (30 mg/day for 1 an
d 3 days) did not significantly affect peak GH-responses, STUDY B 16 p
atients with suspected GH-deficiency (GHD) (seven with known ACTH-defi
ciency and nine with an intact pituitary-adrenal axis) were tested fiv
e times with the PD-GHRH test following no pretreatment or pretreatmen
t with HC (30 mg/day and 80 mg/day for 1 and 3 days), Peak GH-response
s were not significantly affected by conventional HC therapy (30 mg/da
y for 1 and 3 days). However, peak GH-responses to PO in combination w
ith GHRH were reduced during HC (80 mg/day for 1 day) compared to no g
lucocorticoid pretreatment in all patients, Short-term hypocortisolism
did not significantly affect peak GH-responses, CONCLUSION The GH-res
ponses to a PD-GHRH test were reduced in all individuals during acute
stress-appropriate cortisol levels and the percentage reduction in GH-
levels was independent of the GH-secretory capacity, Clinically, we fo
und that peak GH-responses were not significantly affected by a short
break in conventional HC therapy nor by conventional HC therapy itself
. However, our results also demonstrated that a GH-stimulation test sh
ould not be performed on patients, suffering from acute stress.