Led by neuroscientists at the UCLA Alzheimer Disease Research Center and detailed in an early online release of the peer-reviewed journal Archives of Neurology, the double blind, placebo-controlled study used caregiver assessments to evaluate quality of life and used a battery of tests administrated by clinicians to evaluate cognitive skills.
Alzheimer patients treated with testosterone showed significant improvement on a quality-of-life instrument that encompasses memory, interpersonal relationships, physical health, energy, living situation and overall well-being compared with patients who received a placebo, or inactive, medication. However, researchers found no significant differences in memory or other cognitive skills as assessed by tests administered by clinicians.
"The results suggest that testosterone replacement therapy holds potential for improving quality of life of Alzheimer patients and merits further testing with a larger group of patients and with a longer treatment period," said Dr. Po H. Lu, lead author and assistant clinical professor of neurology at the research center and the David Geffen School of Medicine at UCLA.
An estimated 4 million Americans are affected by Alzheimer disease, which causes memory loss, behavior changes and difficulties with thinking.
The 24-week study included 16 male patients diagnosed with mild Alzheimer disease and 22 healthy male control subjects. Each group was randomly subdivided into two treatment arms. One group received daily testosterone treatment in the form of hydroalcoholic gel (75 mg) and other received a gel with no active medication.
The research team assessed cognitive function using the Alzheimer Disease Assessment Scale -- Cognitive Subscale, California Verbal Learning Test, Block Design Subtest, Judgment of Line Orientation and Development Test of Visual-Motor Integration; neuropsychiatric symptoms using the Neuropsychiatric Inventory; global functioning using Clinician's Interview-based Impression of Change; and quality of life using the Quality of Life -- Alzheimer Disease Scale.
Among patients with the disease, the testosterone-treated group had significantly greater improvements in the scores on the caregiver version of the quality-of-life scale than those who received placebo. No statistically significant differences were seen in cognitive or other scores at the end of the study, though numerically greater improvement or less decline in measures of visual-spatial abilities were found in the group treated with testosterone.
In the healthy control group, a non-significant trend toward greater improvement in self-rated quality of life was observed in the testosterone-treated group compared with placebo treatment.
Primary funding was provided by the John Douglas French Alzheimer's Foundation. Additional funding was provided by the National Institute on Aging; the UCLA Alzheimer Disease Research Center; the Los Angeles-based Sidell-Kagan Foundation; the University of California, Irvine, Alzheimer's Disease Research Center; and the Memory and Aging Center at the University of California, San Francisco.
Testosterone and placebo gel were supplied by Marietta, Ga.-based Unimed Pharmaceuticals Inc.
In addition to Lu, other researchers involved in the study were Dr. Donna A. Masterman, Dr. Verna Porter, Dr. Jeffrey L. Cummings and Erin Rebak of UCLA; Ruth Mulnard and Carl Cotman of the University of California, Irvine; Dr. Bruce Miller and Dr. Kristine Yaffe of the University of California, San Francisco; and Dr. Ronald Swerdloff of Harbor-UCLA Medical Center.
The UCLA Department of Neurology encompasses more than a dozen research, clinical and teaching programs. These programs cover brain mapping and neuroimaging, movement disorders, Alzheimer disease, multiple sclerosis, neurogenetics, nerve and muscle disorders, epilepsy, neuro-oncology, neurotology, neuropsychology, headaches and migraines, neurorehabilitation, and neurovascular disorders. The department ranks No. 2 among its peers nationwide in National Institutes of Health funding.
The Alzheimer Disease Research Center (ADRC) at UCLA, directed by Dr. Jeffrey L. Cummings, was established in 1991 by a grant from the National Institute on Aging. Together with grants from the Alzheimer Disease Research Center of California grant and the Sidell Kagan Foundation, the center provides a mechanism for integrating, coordinating and supporting new and ongoing research by established investigators in Alzheimer disease and aging. The Memory Disorders and Alzheimer's Disease Clinic of the ADRC is an evaluation clinic for individuals over the age of 45 who are experiencing mild but gradually progressing cognitive or memory declines that are not related to other brain diseases such as strokes, tumors, infection, metabolic abnormalities, psychiatric disease or trauma.
Additional online resources:
Journal
Archives of Neurology