LinkThe research team established a correlation between low testosterone and elevated beta-amyloid (Aâ), a protein that accumulates abnormally in Alzheimer's disease patients. This finding, they say, suggests that testosterone depletion in aging men may be a risk factor for AD by promoting accumulation of Aâ in the brain. Testosterone, the primary male sex hormone, is one in a group of related steroid hormones referred to as androgens. Recent studies suggest that androgens may lower Aâ levels.