Role of low levels of endogenous estrogen in regulation of bone resorption in late postmenopausal women.
J Bone Miner Res
; 17(1): 172-8, 2002 Jan.
Article
em En
| MEDLINE
| ID: mdl-11771665
ABSTRACT
Although median levels of bone turnover are increased in postmenopausal women, it is unclear whether the low circulating levels of endogenous estrogen exert a regulatory role on these levels. This issue was evaluated by assessing the effect of a blockade of estrogen synthesis on bone turnover markers in 42 normal women (mean age +/- SD, 69 +/- 5 years) randomly assigned to groups receiving the potent aromatase inhibitor letrozole or placebo for 6 months. Letrozole treatment reduced serum estrone (E1) and estradiol (E2) to near undetectable levels (p < 0.0001). This treatment did not affect bone formation markers but, as compared with the placebo group, increased bone resorption markers (urine 24-h pyridinoline [PYD] by 13.3% [p < 0.05] and 24-h urine deoxypyridinoline [DPD] by 14.2% [p < 0.05]) and decreased serum parathyroid hormone (PTH) by 22% (p = 0.002). These data indicate that in late postmenopausal women even the low serum estrogen levels present exert a restraining effect on bone turnover and support the concept that variations in these low levels may contribute to differences in their rate of bone loss.
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Base de dados:
MEDLINE
Assunto principal:
Reabsorção Óssea
/
Estrogênios
Tipo de estudo:
Clinical_trials
/
Observational_studies
Limite:
Aged
/
Female
/
Humans
/
Middle aged
Idioma:
En
Ano de publicação:
2002
Tipo de documento:
Article