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Completed

NCT Number: NCT00309855

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

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.

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Key information

Conditions

Aging

Age range

50 year–80 year

Sex eligibility

Male

Study type

Interventional

Phase

Phase 1

Primary location

Mayo Clinic

Rochester, Minnesota, 55905, United States

About this study

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

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Placebo

Drug

im and orally

Testosterone

Drug

injections

Anastrazole

Drug

orally x 21 days

dutasteride

Drug

orally x 21 days

Primary outcomes

  1. Growth Hormone concentration after injections

    Time frame: 24 days

    GH will be measured 4 different times mornings within 16-21 days following the first testosterone injection (day 1).

Sponsors and collaborators

Lead sponsor

Mayo Clinic

Other

Collaborators

  • GlaxoSmithKline

Registry information

Official study title

Mechanisms of Testosterone-Driven Growth-Hormone (GH) Secretion in Aging Men: Modulation of GHRH, GHRP and Somatostatin Action by Estrogenic Versus Androgenic Steroids

Important dates

Study start
2005
Primary completion
2008
Study completion
2008
First posted
Apr 3, 2006
Registry last updated
Jul 31, 2012

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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