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Testosterone-Driven Growth-Hormone (GH) Secretion in Aging Men

This study has been completed.
Sponsor:
Collaborator:
GlaxoSmithKline
Information provided by:
Mayo Clinic
ClinicalTrials.gov Identifier:
NCT00309855
First received: March 31, 2006
Last updated: July 27, 2012
Last verified: July 2012
History of Changes
  Purpose

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.


Condition Intervention Phase
Aging
 Drug: Placebo
Drug: Testosterone
Drug: Anastrazole
Drug: Dutasteride
 Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Basic Science
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

Resource links provided by NLM:

U.S. FDA Resources

Further study details as provided by Mayo Clinic:

Primary Outcome Measures:
  • Growth Hormone concentration after injections [ Time Frame: 24 days ] [ Designated as safety issue: No ]
    GH will be measured 4 different times mornings within 16-21 days following the first testosterone injection (day 1).


Enrollment: 80
Study Start Date: December 2005
Study Completion Date: August 2008
Primary Completion Date: August 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Double Placebo
(i.m. vehicle 0.5 mL weekly x three injections and oral placebo once daily x 21 days)
 Drug: Placebo
im and orally
Testosterone IM and oral placebo
IM injections weekly x three injections and oral placebo once daily x 21 days
 Drug: Testosterone
injections
Testosterone and Oral Anastrozole
IM injections weekly x 3 injections and oral daily x 21 days
 Drug: Testosterone
injections
Drug: Anastrazole
orally x 21 days
Testosterone and Dutasteride
IM injections weekly x 3 injections and oral once daily x 21 days
 Drug: Testosterone
injections
Drug: Dutasteride
orally x 21 days

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

Ages Eligible for Study:   50 Years to 80 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
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.
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT00309855

Locations
United States, Minnesota
Mayo Clinic
Rochester, Minnesota, United States, 55905
Sponsors and Collaborators
Mayo Clinic
GlaxoSmithKline
Investigators
Principal Investigator: Johannes D. Veldhuis, M.D. Mayo Clinic
  More Information

No publications provided

Responsible Party: Johannes D. Veldhuis, M.D., Mayo Clinic
ClinicalTrials.gov Identifier: NCT00309855     History of Changes
Other Study ID Numbers: 319-03
Study First Received: March 31, 2006
Last Updated: July 27, 2012
Health Authority: United States: Food and Drug Administration

Additional relevant MeSH terms:
Testosterone
Testosterone enanthate
Testosterone undecanoate
Testosterone 17 beta-cypionate
Methyltestosterone
Anastrozole
Dutasteride
Androgens
Hormones
Hormones, Hormone Substitutes, and Hormone Antagonists
 Physiological Effects of Drugs
Pharmacologic Actions
Antineoplastic Agents, Hormonal
Antineoplastic Agents
Therapeutic Uses
Anabolic Agents
Aromatase Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
5-alpha Reductase Inhibitors

ClinicalTrials.gov processed this record on May 23, 2013