Estrogens exert route- and dose-dependent effects on insulin-like growth factor (IGF)-binding protein-3 and the acid-labile subunit of the IGF ternary complex.
J Clin Endocrinol Metab
; 85(5): 1918-22, 2000 May.
Article
em En
| MEDLINE
| ID: mdl-10843175
ABSTRACT
We have previously shown that exogenous estrogens exert route-dependent effects on serum GH and insulin-like growth factor I (IGF-I) levels. IGF-I circulates as a ternary complex with IGF-binding protein-3 (IGFBP-3) and the acid-labile subunit (ALS). It is not known whether IGFBP-3 and ALS in blood are regulated by estrogen and, if so, whether this is also route dependent. In the present study we investigate the effects on IGFBP-3 and ALS of oral and transdermal estrogens (study 1), of different oral estrogen formulations (ethinyl estradiol, conjugated estrogen, and estradiol valerate; study 2), of different estrogen dosages (study 3) in normal postmenopausal women, and of oral estrogen in hypogonadal GH-deficient women (study 4). Administration of oral, but not transdermal, estrogen in normal postmenopausal women significantly decreased serum levels of IGFBP-3 and ALS (P < or = 0.005). The suppressive effects were similar with different oral estrogen formulations, and the degree of suppression increased with estrogen dosage. In hypogonadal GH-deficient women, oral estrogen treatment also significantly reduced IGFBP-3 and ALS (P = 0.02). The changes in IGF-I in each of the four studies paralleled the changes in both IGFBP-3 and ALS. In conclusion, exogenous estrogens suppress serum IGFBP-3 and ALS in a route- and dose-dependent manner, which are in parallel with the effects on serum IGF-I. These actions of oral estrogen are independent of endogenous GH status.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fator de Crescimento Insulin-Like I
/
Terapia de Reposição de Estrogênios
/
Estrogênios Conjugados (USP)
/
Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina
/
Hormônio do Crescimento Humano
/
Estradiol
Tipo de estudo:
Clinical_trials
Limite:
Aged
/
Female
/
Humans
/
Middle aged
Idioma:
En
Revista:
J Clin Endocrinol Metab
Ano de publicação:
2000
Tipo de documento:
Article