ESTROGEN DEFICIENCY AND RISK OF ALZHEIMERS-DISEASE IN WOMEN

The authors explored the possibility that estrogen loss associated wit h menopause may contribute to the development of Alzheimer's disease b y using a case-control study nested within a prospective cohort study. The Leisure World Cohort includes 8,877 female residents of Leisure W orld Laguna Hills, a retirement community in southern California, who were first mailed a health survey in 1981. From the 2,529 female cohor t members who died between 1981 and 1992, the authors identified 138 w ith Alzheimer's disease or other dementia diagnoses likely to represen t Alzheimer's disease (senile dementia, dementia, or senility) mention ed on the death certificate. Four controls were individually matched b y birth date (+/-1 year) and death date (+1 year) to each case. The ri sk of Alzheimer's disease and related dementia was less in estrogen us ers relative to nonusers (odds ratio = 0.69, 95 percent confidence int erval 0.46-1.03). The risk decreased significantly with increasing est rogen dose and with increasing duration of estrogen use. Risk was also associated with variables related to endogenous estrogen levels; it i ncreased with increasing age at menarche and (although not statistical ly significant) decreased with increasing weight. This study suggests that the increased incidence of Alzheimer's disease in older women may be due to estrogen deficiency and that estrogen replacement therapy m ay be useful for preventing or delaying the onset of this dementia.