The purpose of this study is to determine if an aromatase inhibitor (a drug that inhibits the conversion of testosterone to estrogen) is as effective as testosterone replacement in improving muscle mass, muscle strength, sexual function, memory, and bone health.

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 testoterone 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.

Ages Eligible for Study:  65 Years and above,  Genders Eligible for Study:  Male

Criteria

Inclusion Criteria:

• Male
• 65 years of age or older
• Testosterone level less than 350 ng/dl (we will check this level at the screening visit)
• Able to complete an informed consent

Exclusion Criteria:

• History of Stroke
• History of Dementia
• History of Diabetes
• Blood Pressure at rest of > 155/90 mm Hg
• Chronic medical condition (i.e. heart failure, rheumatoid arthritis)
• On osteoporosis medications
• On steroids (prednisone, cortisone)
• History of gastric surgery
• History of any Cancer (except non-melanoma skin cancers)
• Drink more than 2 beers OR 1 glass of wine or cocktail daily
• Smoke any tobacco product
• Started a new medication within the past three months
• History of joint replacement