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

Aging Clinical Trial

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00309855
• Other study ID #: 319-03
• Status: Completed
• Phase: Phase 1
• First received: March 31, 2006
• Last updated: July 27, 2012
• Start date: December 2005
• Est. completion date: August 2008

Study information

• Verified date: July 2012
• Source: Mayo Clinic
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Food and Drug Administration
• Study type: Interventional

Clinical Trial 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.

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

Recruitment information / eligibility

• Status: Completed
• Enrollment: 80
• Est. completion date: August 2008
• Est. primary completion date: August 2008
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 50 Years to 80 Years

Eligibility

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.

Study Design

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

Related Conditions & MeSH terms

• Aging

Intervention

Drug:
• Placebo
im and orally
• Testosterone
injections
• Anastrazole
orally x 21 days
• Dutasteride
orally x 21 days

Locations

Country	Name	City	State
United States	Mayo Clinic	Rochester	Minnesota

Sponsors (2)

Lead Sponsor	Collaborator
Mayo Clinic	GlaxoSmithKline

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Growth Hormone concentration after injections	GH will be measured 4 different times mornings within 16-21 days following the first testosterone injection (day 1).	24 days	No