Effects of sex and age on the 24-hour profile of growth hormone secretion in man: Importance of endogenous estradiol concentrations

K. Y. Ho, W. S. Evans, R. M. Blizzard, Johannes D Veldhuis, G. R. Merriam, E. Samojlik, R. Furlanetto, A. D. Rogol, D. L. Kaiser, M. O. Thorner

Research output: Contribution to journalArticle

767 Citations (Scopus)

Abstract

We undertook a study of the separate and combined effects of age and sex on the pulsatile pattern of GH secretion. The 24-h secretory profile of GH was generated by 20-min sampling in 10 young women (aged 18-33 yr), 10 young men (aged 18-33 yr), 8 postmenopausal women (aged >55 yr), and 8 older men (aged >55 yr). A computer-assisted pulse analysis program was used to assess both total GH secretion, as reflected in the 24-h integrated GH concentrations (IGHC), and pulsatile secretion, as denoted by pulse frequency, duration, amplitude, and the fraction of GH secreted in pulses during the 24-h period (FGHP). IGHC was significantly greater in women than in men (P<0.025) and greater in the young than in the old (P<0.003). The mean pulse amplitude, duration, and FGHP were each greater in the young (P<0.006, P<0.03, and P<0.0001, respectively), but not significantly different between the sexes. The mean pulse frequency was not affected by sex or age. The serum concentration of free estradiol, but not free testosterone, correlated with IGHC (r = 0.46; P<0.005), pulse amplitude (r = 0.53, P<0.001), and FGHP (r = 0.59; P<0.0002). After correcting for the effects of estradiol, neither sex nor age influenced IGHC or mean pulse amplitude, while the effect of age on FGHP was reduced from 81% to 29%. Of the indices of GH secretion, FGHP had the strongest correlation (r = 0.43; P<0.006) with somatomedin-C. Somatomedin-C declined significantly with age in both sexes. Our results indicate that sex and age have independent and interrelated effects on GH secretion. These effects can be largely accounted for by corresponding variations in endogenous estradiol levels. These observations suggest an amplifying action of estradiol on the neuroendocrine regulation of pulsatile GH release.

Original languageEnglish (US)
Pages (from-to)51-58
Number of pages8
JournalJournal of Clinical Endocrinology and Metabolism
Volume64
Issue number1
StatePublished - 1987
Externally publishedYes

Fingerprint

Growth Hormone
Estradiol
Insulin-Like Growth Factor I
Testosterone
Sampling
Serum

ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology, Diabetes and Metabolism

Cite this

Ho, K. Y., Evans, W. S., Blizzard, R. M., Veldhuis, J. D., Merriam, G. R., Samojlik, E., ... Thorner, M. O. (1987). Effects of sex and age on the 24-hour profile of growth hormone secretion in man: Importance of endogenous estradiol concentrations. Journal of Clinical Endocrinology and Metabolism, 64(1), 51-58.

Effects of sex and age on the 24-hour profile of growth hormone secretion in man : Importance of endogenous estradiol concentrations. / Ho, K. Y.; Evans, W. S.; Blizzard, R. M.; Veldhuis, Johannes D; Merriam, G. R.; Samojlik, E.; Furlanetto, R.; Rogol, A. D.; Kaiser, D. L.; Thorner, M. O.

In: Journal of Clinical Endocrinology and Metabolism, Vol. 64, No. 1, 1987, p. 51-58.

Research output: Contribution to journalArticle

Ho, KY, Evans, WS, Blizzard, RM, Veldhuis, JD, Merriam, GR, Samojlik, E, Furlanetto, R, Rogol, AD, Kaiser, DL & Thorner, MO 1987, 'Effects of sex and age on the 24-hour profile of growth hormone secretion in man: Importance of endogenous estradiol concentrations', Journal of Clinical Endocrinology and Metabolism, vol. 64, no. 1, pp. 51-58.
Ho, K. Y. ; Evans, W. S. ; Blizzard, R. M. ; Veldhuis, Johannes D ; Merriam, G. R. ; Samojlik, E. ; Furlanetto, R. ; Rogol, A. D. ; Kaiser, D. L. ; Thorner, M. O. / Effects of sex and age on the 24-hour profile of growth hormone secretion in man : Importance of endogenous estradiol concentrations. In: Journal of Clinical Endocrinology and Metabolism. 1987 ; Vol. 64, No. 1. pp. 51-58.
@article{f97eac70a89d4ba8b5b5b0b9854f84d8,
title = "Effects of sex and age on the 24-hour profile of growth hormone secretion in man: Importance of endogenous estradiol concentrations",
abstract = "We undertook a study of the separate and combined effects of age and sex on the pulsatile pattern of GH secretion. The 24-h secretory profile of GH was generated by 20-min sampling in 10 young women (aged 18-33 yr), 10 young men (aged 18-33 yr), 8 postmenopausal women (aged >55 yr), and 8 older men (aged >55 yr). A computer-assisted pulse analysis program was used to assess both total GH secretion, as reflected in the 24-h integrated GH concentrations (IGHC), and pulsatile secretion, as denoted by pulse frequency, duration, amplitude, and the fraction of GH secreted in pulses during the 24-h period (FGHP). IGHC was significantly greater in women than in men (P<0.025) and greater in the young than in the old (P<0.003). The mean pulse amplitude, duration, and FGHP were each greater in the young (P<0.006, P<0.03, and P<0.0001, respectively), but not significantly different between the sexes. The mean pulse frequency was not affected by sex or age. The serum concentration of free estradiol, but not free testosterone, correlated with IGHC (r = 0.46; P<0.005), pulse amplitude (r = 0.53, P<0.001), and FGHP (r = 0.59; P<0.0002). After correcting for the effects of estradiol, neither sex nor age influenced IGHC or mean pulse amplitude, while the effect of age on FGHP was reduced from 81{\%} to 29{\%}. Of the indices of GH secretion, FGHP had the strongest correlation (r = 0.43; P<0.006) with somatomedin-C. Somatomedin-C declined significantly with age in both sexes. Our results indicate that sex and age have independent and interrelated effects on GH secretion. These effects can be largely accounted for by corresponding variations in endogenous estradiol levels. These observations suggest an amplifying action of estradiol on the neuroendocrine regulation of pulsatile GH release.",
author = "Ho, {K. Y.} and Evans, {W. S.} and Blizzard, {R. M.} and Veldhuis, {Johannes D} and Merriam, {G. R.} and E. Samojlik and R. Furlanetto and Rogol, {A. D.} and Kaiser, {D. L.} and Thorner, {M. O.}",
year = "1987",
language = "English (US)",
volume = "64",
pages = "51--58",
journal = "Journal of Clinical Endocrinology and Metabolism",
issn = "0021-972X",
publisher = "The Endocrine Society",
number = "1",

}

TY - JOUR

T1 - Effects of sex and age on the 24-hour profile of growth hormone secretion in man

T2 - Importance of endogenous estradiol concentrations

AU - Ho, K. Y.

AU - Evans, W. S.

AU - Blizzard, R. M.

AU - Veldhuis, Johannes D

AU - Merriam, G. R.

AU - Samojlik, E.

AU - Furlanetto, R.

AU - Rogol, A. D.

AU - Kaiser, D. L.

AU - Thorner, M. O.

PY - 1987

Y1 - 1987

N2 - We undertook a study of the separate and combined effects of age and sex on the pulsatile pattern of GH secretion. The 24-h secretory profile of GH was generated by 20-min sampling in 10 young women (aged 18-33 yr), 10 young men (aged 18-33 yr), 8 postmenopausal women (aged >55 yr), and 8 older men (aged >55 yr). A computer-assisted pulse analysis program was used to assess both total GH secretion, as reflected in the 24-h integrated GH concentrations (IGHC), and pulsatile secretion, as denoted by pulse frequency, duration, amplitude, and the fraction of GH secreted in pulses during the 24-h period (FGHP). IGHC was significantly greater in women than in men (P<0.025) and greater in the young than in the old (P<0.003). The mean pulse amplitude, duration, and FGHP were each greater in the young (P<0.006, P<0.03, and P<0.0001, respectively), but not significantly different between the sexes. The mean pulse frequency was not affected by sex or age. The serum concentration of free estradiol, but not free testosterone, correlated with IGHC (r = 0.46; P<0.005), pulse amplitude (r = 0.53, P<0.001), and FGHP (r = 0.59; P<0.0002). After correcting for the effects of estradiol, neither sex nor age influenced IGHC or mean pulse amplitude, while the effect of age on FGHP was reduced from 81% to 29%. Of the indices of GH secretion, FGHP had the strongest correlation (r = 0.43; P<0.006) with somatomedin-C. Somatomedin-C declined significantly with age in both sexes. Our results indicate that sex and age have independent and interrelated effects on GH secretion. These effects can be largely accounted for by corresponding variations in endogenous estradiol levels. These observations suggest an amplifying action of estradiol on the neuroendocrine regulation of pulsatile GH release.

AB - We undertook a study of the separate and combined effects of age and sex on the pulsatile pattern of GH secretion. The 24-h secretory profile of GH was generated by 20-min sampling in 10 young women (aged 18-33 yr), 10 young men (aged 18-33 yr), 8 postmenopausal women (aged >55 yr), and 8 older men (aged >55 yr). A computer-assisted pulse analysis program was used to assess both total GH secretion, as reflected in the 24-h integrated GH concentrations (IGHC), and pulsatile secretion, as denoted by pulse frequency, duration, amplitude, and the fraction of GH secreted in pulses during the 24-h period (FGHP). IGHC was significantly greater in women than in men (P<0.025) and greater in the young than in the old (P<0.003). The mean pulse amplitude, duration, and FGHP were each greater in the young (P<0.006, P<0.03, and P<0.0001, respectively), but not significantly different between the sexes. The mean pulse frequency was not affected by sex or age. The serum concentration of free estradiol, but not free testosterone, correlated with IGHC (r = 0.46; P<0.005), pulse amplitude (r = 0.53, P<0.001), and FGHP (r = 0.59; P<0.0002). After correcting for the effects of estradiol, neither sex nor age influenced IGHC or mean pulse amplitude, while the effect of age on FGHP was reduced from 81% to 29%. Of the indices of GH secretion, FGHP had the strongest correlation (r = 0.43; P<0.006) with somatomedin-C. Somatomedin-C declined significantly with age in both sexes. Our results indicate that sex and age have independent and interrelated effects on GH secretion. These effects can be largely accounted for by corresponding variations in endogenous estradiol levels. These observations suggest an amplifying action of estradiol on the neuroendocrine regulation of pulsatile GH release.

UR - http://www.scopus.com/inward/record.url?scp=0023098492&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023098492&partnerID=8YFLogxK

M3 - Article

C2 - 3782436

AN - SCOPUS:0023098492

VL - 64

SP - 51

EP - 58

JO - Journal of Clinical Endocrinology and Metabolism

JF - Journal of Clinical Endocrinology and Metabolism

SN - 0021-972X

IS - 1

ER -