Steady-State Feedback Actions of Testosterone on Luteinizing Hormone Secretion in Young and Older Men
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.
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
|Official Title:||Steady-State Feedback Actions of Testosterone on Luteinizing Hormone Secretion in Young and Older Men|
- LH and Testosterone levels will be evaluated after 4 study visits
|Study Start Date:||February 2004|
|Study Completion Date:||December 2007|
|Primary Completion Date:||December 2007 (Final data collection date for primary outcome measure)|
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.
|United States, Minnesota|
|Mayo Clinic and Foundation|
|Rochester, Minnesota, United States, 55905|
|Principal Investigator:||Johannes D. Veldhuis, M.D.||Mayo Clinic|