Serum levels of estradiol and testosterone and performance in different cognitive domains in healthy elderly men and women.

Sex hormones could protect against age-related cognitive decline in elderly men and women. We investigated the relationships between serum total testosterone (TT), total estradiol (TE2) levels and cognitive function in 145 non-demented elderly volunteers (aged 61-91 years) who were not using hormone replacement therapy (HRT). Women (n=66) were better at verbal recall than men (n=79) and men were slightly better at naming. There was a positive relationship between serum levels of TE2 and verbal list recall but not with other verbal memory tests (e.g. Verbal Paired Associates) in women. There was a negative relationship of serum TT levels with verbal recall. Surprisingly, women who were in the upper age tertile (> 77 years of age) were better at verbal recall than men and than women younger than 72; this effect was independent of hormone levels. Men between 61 and 72 years of age showed a positive relationship between high TE2 levels and Spatial Span performance and between high TT levels and speed of information processing, while for women of this age-group, a negative relationship was found. These preliminary results were unchanged when controlling for education, sex hormone binding globulin levels, body mass index, depression, daily alcohol use and smoking. In sum, not all cognitive functions were better with higher levels of sex steroids and effects seemed to be modified by sex; the sex-sensitive tests showing the clearest effects. More research is required to investigate whether there is a window of time in which hormone therapy could be beneficial for middle-aged men.