Role of Endogenous Estrogen in Growth-Hormone Regulation in Postmenopausal Women
Status:
Completed
Trial end date:
2013-06-01
Target enrollment:
Participant gender:
Summary
Participants are being asked to take part in this research study to learn why growth
hormone(GH) levels decline when estrogen production falls at the time of menopause. GH is a
hormone released from the pituitary gland that affects bone, muscle, and fat. Estrogen is a
female hormone. Doctors believe that lower estrogen is one of the reasons that GH diminishes
in postmenopausal women. However, estrogen does not fall completely. This raises the question
whether the little bit of estrogen that is left is doing anything. Lack of GH makes bones
thinner, muscles weaker, and fat stores larger. To learn whether the low amount of the body's
own estrogen maintains GH secretion after menopause, the investigators need to stop any
estrogen you might be taking and then partially block the effect, if any, of your own
estrogen. The investigators will use a new estrogen-blocking drug (fulvestrant).
Fulvestrant(which also goes by the tradename, Faslodex) was recently approved by the Food and
Drug Administration (FDA) to treat breast cancer. Fulvestrant is being used in a non-FDA
approved manner in this study (not to treat breast cancer, but to study the effect on Growth
Hormone secretion). The drug interferes with how estrogen works in the body, except in the
brain. The study that you are considering now tests whether your own estrogen works outside
the brain to maintain GH secretion in postmenopausal women. This concept is important,
because the brain controls how the pituitary gland secretes GH.