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

This study has been completed.
Information provided by:
Mayo Clinic Identifier:
First received: February 2, 2007
Last updated: January 26, 2010
Last verified: January 2010

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 Intervention Phase
Drug: Ketoconazole, Dexamethesone, Androgel,GnRH
Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double-Blind
Official Title: Steady-State Feedback Actions of Testosterone on Luteinizing Hormone Secretion in Young and Older Men

Resource links provided by NLM:

Further study details as provided by Mayo Clinic:

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

Secondary Outcome Measures:
  • Unknown

Estimated Enrollment: 40
Study Start Date: February 2004
Study Completion Date: December 2007
Primary Completion Date: December 2007 (Final data collection date for primary outcome measure)
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.


Ages Eligible for Study:   18 Years to 80 Years
Genders 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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT00431197

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

No publications provided Identifier: NCT00431197     History of Changes
Other Study ID Numbers: 344-03, Minn # 22270
Study First Received: February 2, 2007
Last Updated: January 26, 2010
Health Authority: United States: Food and Drug Administration processed this record on March 03, 2015