Ja. Gusenoff et al., Cortisol and GH secretory dynamics, and their interrelationships, in healthy aged women and men, AM J P-ENDO, 280(4), 2001, pp. E616-E625
Citations number
70
Categorie Soggetti
Endocrinology, Nutrition & Metabolism
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM
We studied 130 healthy aged women (n = 57) and men (n = 73), age 65-88 yr,
with age-related reductions in insulin-like growth factor I and gonadal ste
roid levels to assess the interrelationships between cortisol and growth ho
rmone (GH) secretion and whether these relationships differ by sex. Blood w
as sampled every 20 min from 8:00 PM to 8:00 AM; cortisol was measured by R
IA and GH by immunoradiometric assay, followed by deconvolution analyses of
hormone secretory parameters and assessment of approximate entropy (ApEn)
and cross-ApEn. Cortisol mass/burst, cortisol production rate, and mean and
integrated serum cortisol concentrations (P < 0.0005), and overnight basal
GH secretion (P < 0.05), were elevated in women vs. men. Integrated cortis
ol concentrations were directly related to most measures of GH secretion in
women (P < 0.01) and with mean and integrated GH concentrations in men (P,
0.05). Integrated GH concentrations were directly related to mean and inte
grated cortisol levels in women (P < 0.005) and men (P, 0.05), with no sex
differences. There were no sex differences in cortisol or GH ApEn values; h
owever, the cross-ApEn score was greater in women (P, 0.05), indicating red
uced GH-cortisol pattern synchrony in aged women vs. men. There were no sig
nificant relationships of integrated cortisol secretion with GH ApEn, or vi
ce versa, in either sex. Thus postmenopausal women appear to maintain eleva
ted cortisol production in patterns that are relatively uncoupled from thos
e of GH, whereas mean hormone outputs remain correlated.