Official Title: “A Pilot Study of the Effect of Testosterone on Cerebral Glucose Metabolism in Hypogonadal Males With Alzheimer's Disease”

Treatment with testosterone can improve performance on tests of spatial ability in men with low testosterone levels and Alzheimer's disease. Improved performance on these tests may mean an improved ability to get around in one's environment without getting lost or injured. This could have a positive impact on both patients and those who care for them. We will investigate what areas of the brain are involved in these improvements in spatial ability.

This will be done using a PET scan, which creates a 3-dimensional image of the brain that can allow us to see how the brain functions.

Study Type: Interventional

Study Design: Treatment, Non-Randomized, Open Label, Uncontrolled, Single Group Assignment, Pharmacokinetics Study

Study Primary Completion Date: June 2009

Volunteers will be treated with a prescription testosterone gel applied to the shoulder or other body area each day. This treatment will continue for 6 months. Subjects will undergo a PET scan at the beginning of the study and after approximately 2 months of treatment.

Subjects will undergo some cognitive testing throughout the study.

Intervention(s) in this Clinical Trial

• Drug: Testosterone replacement therapy: AndroGel 1% 5g packets (Solvay Pharmaceuticals)
  • AndroGel 1% 5g packets (Solvay Pharmaceuticals). Initial dosage: 5g daily (1 packet). Patients who do not achieve eugonadal levels of 400-600 mg/dL within 2 weeks will be raised to 10g daily.

Primary Measures

• Calculated difference image of pre-treatment and on-treatment PET scans.

Secondary Measures

• Change in cognitive function at 8-week intervals over a 6-month period.

Inclusion Criteria:

• Alzheimer's disease diagnosis, based on Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-V)
• Total testosterone < 300 ng/dL and/or calculated free testosterone < 50 pg/ml
• Sufficient English to perform cognitive testing
• Stable on concomitant medications for 1 month prior to starting study

Exclusion Criteria:

• history of prostate cancer
• history of breast cancer
• gonadal endocrine disorders
• current major psychiatric illness (excluding depression)
• significant uncontrolled systemic illness
• recent myocardial infarction (within 6 months)
• renal or hepatic disease, sleep apnea
• history of alcoholism or substance abuse within the past year
• history of head injury with loss of consciousness greater than 1 hour
• testosterone or other androgen treatment within past 3 months
• history of taking other drugs that might interfere with the results of the study (ie, spironolactone, cimetidine, antiandrogens, estrogens, p450 enzyme inducers, barbiturates)
• symptomatic BPH: prostatic symptoms, prostatic masses or induration on rectal examination
• prostate specific antigen (PSA) >4.0 mg/mL
• hemoglobin > 17 mg/dL
• generalized skin disease that could affect the absorption of testosterone gel (ie, psoriasis).
• potentially agitated or uncooperative for procedures

Gender Eligibility for this Clinical Trial: Male

Minimum Age for this Clinical Trial: 55 Years

Maximum Age for this Clinical Trial: N/A

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Sponsor: VA Medical Center, Houston

Overall Clinical Trial Officials and Contacts

Robert S. Tan, MD Principal Investigator Michael E. DeBakey VA Medical Center, Houston, TX  

Overall Contact: Robert S. Tan, MD 713-794-7382 Robert.Tan@med.va.gov

Information obtained from ClinicalTrials.gov on August 29, 2008

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00392912

Study ID Number: GR-294

ClinicalTrials.gov Identifier: NCT00392912

Health Authority: United States: Institutional Review Board