Incidence of dementia in long-term hormone users.

Results from epidemiologic studies of postmenopausal hormone use and dementia have been conflicting. Investigators from the Women's Health Initiative Memory Study reported that the incidence of dementia in women aged >/=65 years assigned to hormone use was increased. Here the authors report results from a prospective cohort study of 2,906 dementia-free women (1,519 hormone users and 1,387 hormone nonusers) aged > or =75 years who were recruited from a Southern California health plan in 1999 and followed through 2003. Cognitive status was assessed annually using the Telephone Interview of Cognitive Status-modified, supplemented by the Telephone Dementia Questionnaire and medical record review. The mean self-reported age at initiation of hormone use was 48.3 years for users of estrogen alone (n = 1,072) and 54.9 years for users of estrogen plus progestin (n = 447); self-reported mean durations of hormone use were 30.5 years and 23.2 years, respectively. There were 283 incident dementia cases identified during follow-up. After adjustment for age, education, and medical history, hazard ratios for incident dementia were 1.34 (95% confidence interval: 0.95, 1.89) in estrogen/progestin users and 1.23 (95% confidence interval: 0.94, 1.59) in estrogen users. These findings do not provide support for an effect of estrogen or estrogen/progestin use in preventing dementia.