Abstract
Objectives: To assess the association between testosterone levels and APOEε4 in cases with AD and controls.Method: We included 61 men with definite or probable Alzheimer's disease (AD) and 55 elderly male controls from the Oxford Project to Investigate Memory and Ageing (OPTIMA). Testosterone was measured using a competitive enzyme immunoassay (Bayer®).Results: We found that both low serum testosterone and the interaction between testosterone and APOEε4 were associated with AD. Furthermore, testosterone levels were lower in APOEε4‐positive controls (mean: 11.3 nmol/L) than in controls without the allele (19.1 nmol/L).Conclusions: Low testosterone is potentially a modifiable risk factor, which may prove relevant to APOEε4 carriers who are at risk of AD. Copyright © 2002 John Wiley & Sons, Ltd.