Testosterone-Driven Growth-Hormone (GH) Secretion in Aging Men
Information source: Mayo Clinic
Information obtained from ClinicalTrials.gov on October 19, 2009
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Aging
Intervention: anastrazole or dutasteride (Drug)
Phase: N/A
Status: Recruiting
Sponsored by: Mayo Clinic Official(s) and/or principal investigator(s):
Johannes D. Veldhuis, M.D., Principal Investigator, Affiliation: Mayo Clinic
Overall contact:
Johannes D. Veldhuis, M.D., Phone: (507) 284-2511
Summary
This study is being done to understand how testosterone, the major male sex hormone,
controls the pituitary gland's secretion of growth hormone (GH). GH is an important
metabolic hormone, which controls sugar; fat and protein use in the body and maintains
muscle strength and bone calcium content. Both testosterone and GH decline in older men. The
age-related fall in these hormones probably contributes to relative frailty, reduced quality
of life, bone loss, muscle wasting and impaired sexual function.
Clinical Details
Official title: Mechanisms of Testosterone-Driven Growth-Hormone (GH) Secretion in Aging Men: Modulation of GHRH, GHRP and Somatostatin Action by Estrogenic Versus Androgenic Steroids
Study design: Randomized, Double-Blind, Placebo Control, Parallel Assignment
Primary outcome: How testosterone, controls the pituitary gland's secretion of growth hormone (GH).
Detailed description:
Repletion of testosterone in older men drives pulsatile GH secretion via conjoint
facilitation of feedforward by the primary secretagogues GHRH and GHRP and repression of
feedback by the dominant inhibitor, somatostatin; and, in corollary, testosterone acts via
aromatization to estradiol and/or reduction to 5 alpha-dihydrotestosterone
Eligibility
Minimum age: 50 Years.
Maximum age: 80 Years.
Gender(s): Male.
Criteria:
Inclusion Criteria:
- healthy men between the ages of 50 and 80;
- normal weight (within 30% of ideal body weight defined by New York Metropolitan Life
tables); and
- normal hematocrit (greater than 38%);
- community dwelling; and
- voluntarily consenting
Exclusion Criteria:
- recent use of psychotropic or neuroactive drugs (within five biological half-live);
- obesity (outside weight range above);
- anemia (hematocrit < 38%);
- drug or alcohol abuse, psychosis, depression, mania or severe anxiety;
- acute or chronic organ-system disease;
- endocrinopathy, other than primary thyroidal failure receiving replacement;
- nightshift work or recent transmeridian travel (exceeding 3 time zones within 7 days
of admission);
- acute weight change (loss or gain of > 2 kg in 6 weeks);
- allergy to administered compounds; and
- unwillingness to provide written informed consent.
Locations and Contacts
Johannes D. Veldhuis, M.D., Phone: (507) 284-2511
Mayo Clinic, Rochester, Minnesota 55905, United States; Recruiting
Kristi L. Mielke, Phone: 507-255-1294, Email: mielke.kristi@mayo.edu
Additional Information
Starting date: December 2005
Last updated: March 31, 2006
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