Effects of Aromatase Inhibition Versus Testosterone in Older Men With Low Testosterone: Randomized-Controlled Trial.

Approximately 20% of men over the age of 70 have low testosterone levels. In some studies, testosterone replacement has resulted in improvement in bone mass, muscle strength, quality of life and memory function. In the body, testosterone is converted into estrogen. Hence, it is unclear whether these beneficial effects are due to testosterone or estrogen. Research has shown that inhibition of estrogen production in men results in an increase in testosterone levels. In this study, patients will be assigned to one of three groups: one group will receive testosterone gel and a placebo tablet, one group will receive a 1mg Anastrozole tablet and a placebo gel, and one group will receive a placebo tablet and placebo gel. Each group will receive a daily dose of calcium with vitamin D. The study requires 6 visits over a 12-month period for testing and evaluation. Two of the 6 visits will require an overnight stay in the hospital so that an intravenous (IV) line can be placed in the arm to allow samples to be drawn throughout the night. Testing will include a cardiac stress test, a glucose tolerance test, bone and muscle tests, evaluation of memory function, etc. For the safety of the prostate, we will perform a prostate ultrasound at the start and end of the study and we will monitor urinary symptoms, prostate specific antigen (PSA) levels and the prostate exam throughout the study.