The Testosterone-Alzheimer's Disease Link

Study results appearing in the just-released September issue of the Journal of Alzheimer's Disease show that the onset of Alzheimer’s disease is associated, in older men, with low testosterone levels, adding to previous findings in older Caucasian men that low testosterone levels are associated with impaired thinking and Alzheimer’s disease.

"Having low testosterone may make you more vulnerable to Alzheimer's disease," said co-author John E. Morley, MD, director, division of geriatric medicine, Saint Louis University. "The take-home message is we should pay more attention to low testosterone, particularly in people who have memory problems or other signs of cognitive impairment."

For the study—led by Leung-Wing Chu, MD, chief, division of geriatric medicine, Queen Mary Hospital, University of Hong Kong—the researchers recruited 153 Chinese men age 55 years or older who lived in the community and did not have dementia (47 experienced mild cognitive impairment).

Of the 47 men with mild cognitive impairment, 10 developed probably Alzheimer’s disease within a year. Each of the 10 had low testosterone levels, elevated ApoE 4 protein levels, and high blood pressure.

"It's a very exciting study because we've shown that a low level of testosterone is one of the risk factors for Alzheimer's disease," Morley said. Morley and colleagues believe that testosterone may have a protective value against the disease.

A large-scale study that looks at the use of testosterone in preventing Alzheimer’s disease will be the next step, according to Morley, who along with his fellow researchers, advocates the study of the effectiveness of testosterone replacement therapy to help ward off Alzheimer’s disease in elderly men with mild memory issues and low testosterone levels.

Are these findings enough to convince you to prescribe testosterone replacement therapy in your elderly male patients with cognitive impairment, or do you need more evidence? Are Morley, Chu, and colleagues onto something with a study looking at prevention of Alzheimer’s with testosterone therapy? Share your thoughts and get a conversation started!

More on Alzheimer’s Disease around the Web:

• Cerebral Microhemorrhage and Iron Deposition in Mild Cognitive Impairment: Susceptibility-weighted MR Imaging Assessment
• Diabetes-Associated SorCS1 Regulates Alzheimer's Amyloid-β Metabolism: Evidence for Involvement of SorL1 and the Retromer Complex
• Family Detect Alzheimer's Signs Better than Common Tests
• New Gene Linked to Alzheimer's Risk
• New Alzheimer's Disease Target Found
• Native Functions of the Androgen Receptor Are Essential to Pathogenesis in a Drosophila Model of Spinobulbar Muscular Atrophy