Abstract
Elevated levels of gonadotropins have been observed in patients with Alzheimer's disease and have been associated with poorer cognition in women, but not men. The aim of this study was to explore the relationship between gonadotropins and cognition in a cohort of 585 healthy, community-dwelling men aged 70–87 years. Cognitive function was assessed with the California Verbal Learning Test Second Edition (CVLT-II) and the Standardized Mini-Mental State Examination (SMMSE). Testosterone, sex hormone binding globulin, and luteinizing hormone levels were assayed from early morning sera. Free testosterone was calculated using mass action equations. In linear regression analyses, neither total nor free testosterone levels were associated with measures of immediate or delayed recall. Higher levels of luteinizing hormone were associated with poorer performance on a measure of immediate recall (CVLT-II trials 1–5 total score) independent of total and free testosterone levels. The association remained after adjustment for age, educational attainment, and depression. In contrast, only total and free testosterone levels were associated with SMMSE score. These findings suggest a role for both androgens and gonadotropins in differing cognitive domains, and that gonadotropins may influence cognition independent of sex steroids.