Gender differences in cognitive function with age: The Rancho Bernardo Study

BACKGROUND: Estrogen deficiency has been proposed as a cause of memory loss in postmenopausal women. If true, men should have less memory loss with age than women. The present study is designed to examine the postulated effect of estrogen on memory by studying the effect of gender on the age-related decline in cognitive function. METHODS: Cross-sectional study of 800 women and 551 men aged 65 to 95 years, members of the community-based Rancho Bernardo Study (begun in 1972 and 1974) who completed the Beck Depression Inventory in 1984-1987 and 12 standardized tests of cognitive function in 1988-1991. All participants were white, middle to upper-middle class, relatively well educated, and ambulatory. At all visits, use of estrogen therapy was ascertained and validated. RESULTS: Test performance worsened with age in both sexes, with similar patterns in men compared with women who were current, past, or never users of estrogen. Between-gender comparisons of the slope for age on each cognitive function test after adjustment for education, depressed mood, and estrogen use (in women) indicated that men had a significantly steeper decrement with age than women on the Buschke total recall and long-term memory tests (P <.001), on the immediate and delayed recall tasks of the visual reproduction tests (P <.01 and .05, respectively), and on category fluency (P <.05). Similar results were obtained when gender comparisons included only women who had never used estrogen. CONCLUSION: These weak or absent gender differences in decline in cognitive function with age do not support the thesis that estrogen deficiency is associated with a decline in cognitive function in postmenopausal women.