Steady-State Feedback Actions of Testosterone on Luteinizing Hormone Secretion in Young and Older Men

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00431197
Recruitment Status : Completed
First Posted : February 5, 2007
Last Update Posted : January 28, 2010
National Institutes of Health (NIH)
Information provided by:
Mayo Clinic

Brief Summary:
This study is being done to learn how the male hormone , testosterone, affects pituitary hormones in younger and older men. The pituitary is a gland in the brain that secretes hormones, some of which normally control growth and fertility.

Condition or disease Intervention/treatment Phase
Hypogonadism Drug: Ketoconazole, Dexamethesone, Androgel,GnRH Phase 1

Detailed Description:
Concentrations of bioavailable testosterone decline by 1.0-1.5% annually as men age. Reduced systemic testosterone availability is associated with decreased muscle mass, strength and aerobic capacity, decreased bone-mineral density and increased risk of hip fracture, waning sexual interest, inpaired spatial cognition and increased risk of visceral obesity, impaired glucose tolerance and coronary artery disease. Luteinizing hormone (LH) secretion often fails in healthy older individuals. In addition, aging is marked by an acceleration of LH pulse frequency, loss of high-amplitude LH pulses and disorderly release of LH and testosterone, as measured by the approximate entropy statistic. The mechanisms that underlie such complex adaptations are not known, but appear to involve multiple loci of regulatory failure.

Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 40 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double
Official Title: Steady-State Feedback Actions of Testosterone on Luteinizing Hormone Secretion in Young and Older Men
Study Start Date : February 2004
Actual Primary Completion Date : December 2007
Actual Study Completion Date : December 2007

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Hormones
U.S. FDA Resources

Primary Outcome Measures :
  1. LH and Testosterone levels will be evaluated after 4 study visits

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Senior)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
  • Healthy Men Ages 18-80
  • All ethnicities eligible
  • Men with indeterminate erectile dysfunction eligible with normal serum gonadotropin, total testosterone, prolactin and TSH concentrations and documented integrity of the neurovascular, cardiovascular, hepatorenal systems

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00431197

United States, Minnesota
Mayo Clinic and Foundation
Rochester, Minnesota, United States, 55905
Sponsors and Collaborators
Mayo Clinic
National Institutes of Health (NIH)
Principal Investigator: Johannes D. Veldhuis, M.D. Mayo Clinic Identifier: NCT00431197     History of Changes
Other Study ID Numbers: 344-03
Minn # 22270
First Posted: February 5, 2007    Key Record Dates
Last Update Posted: January 28, 2010
Last Verified: January 2010

Additional relevant MeSH terms:
Gonadal Disorders
Endocrine System Diseases
Testosterone enanthate
Testosterone undecanoate
Testosterone 17 beta-cypionate
Hormones, Hormone Substitutes, and Hormone Antagonists
Physiological Effects of Drugs
Antineoplastic Agents, Hormonal
Antineoplastic Agents
Anabolic Agents
Antifungal Agents
Anti-Infective Agents
14-alpha Demethylase Inhibitors
Cytochrome P-450 Enzyme Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Steroid Synthesis Inhibitors
Hormone Antagonists
Cytochrome P-450 CYP3A Inhibitors