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Role of Endogenous Estrogen in Growth-Hormone Regulation in Postmenopausal Women

NCT01186796 · Status: COMPLETED · Phase: PHASE1 · Type: INTERVENTIONAL · Enrollment: 30

Last updated 2015-03-27

Study results available
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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.

Conditions

  • Healthy

Interventions

DRUG

Fulvestrant

Secretagogue combinations are assigned in randomized double-blind order within-subject to include the following four conditions: (i)L-arginine (30 gm i.v. over 30 min from 0930 h to 1000 h) followed by 5 mL bolus of NS at 1000 h; (ii) L-arginine (30 gm i.v. over 30 min from 0930 h to 1000 h) followed by GHRH and Ghrelin (both at dose of 0.3 mcg/kg bolus i.v.) at 1000 h; (iii) L-arginine (30 gm i.v. over 30 min from 0930 h to 1000 h) followed by GHRH (0.3 μg/kg bolus i.v.) at 1000 h; (iv) L-arginine infusion (30 gm i.v. over 30 min from 0930 h to 1000 h) followed by Ghrelin (0.3 μg/kg bolus i.v.) at 1000 h. \*\*Ghrelin dosage is based on 70 kg subject.Total exposure of Ghrelin will be 42 mcg total dose for 2 subject visits (21 mcg per visit).

Sponsors & Collaborators

  • National Institutes of Health (NIH)

    collaborator NIH

  • AstraZeneca

    collaborator INDUSTRY

  • Mayo Clinic

    lead OTHER

Principal Investigators

  • Johannes Veldhuis, M.D. · Mayo Clinic

Study Design

Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Model
PARALLEL

Eligibility

Min Age
50 Years
Max Age
80 Years
Sex
FEMALE
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2009-06-30
Primary Completion
2013-06-30
Completion
2013-06-30

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT01186796 on ClinicalTrials.gov