ORIGINAL CONTRIBUTION Reproductive Period and Risk of Dementia in Postmenopausal Women

AFTER MENOPAUSE, ESTROGENlevels decrease dramatically inwomen. This decrease in en-dogenous estrogen is associ-ated with increased risk of osteoporosis and cardiovascular disease.1-3 Decreas-ing estrogen levels also have been hy-pothesized to be associated with in-creased risk of dementia. A relationship between estrogen levels and dementia is biologically plausible4-6 and, if present, may have major implications for preven-tion or delay of dementia onset. In ovari-ectomized rats, estrogen increases cho-line acetyltransferase activity in the basal forebrain and hippocampus, regions in the brain that are acetylcholine-deficient in patients with Alzheimer dis