Project Summary (1995-2000)

The objectives of this project are to explore the hypothesis that lead mobilization accompanies menopause and is associated with subclinical neuropsychological dysfunction. In addition, the effect of estrogen replacement therapy on lead levels and on neuropsychological functioning is assessed. Blood and plasma lead levels, bone lead concentration (¹⁰⁹Cd K X-ray fluorescence), bone density (DXA), serum ferritin and hormone levels, standardized questionnaire data, menopausal symptoms, mood and neuropsychological function are being assessed in about 200 women residing in New York City who are scheduled to undergo a surgically induced menopause (bilateral oophorectomy). The difference between the pre- and post-oophorectomy total bone lead provides an estimate of total postmenopausal lead exposure from skeletal sources. Blood and bone levels are evaluated at baseline (preoperatively) and again at 6 months and 18 months after surgery. Bone mineral density is evaluated at baseline and at the 18-month visit. Assessment of neuropsychological function is performed preoperatively and 18 months after surgery.

Measures of subclinical neuropsychological effects include both computer-administered and manually administered tests that asses a range of functions including memory, cognition, psychomotor abilities, attention, executive functioning and mood. Menopausal symptoms are evaluated by the menopausal index. Changes in neuropsychological function over the interval of observation is compared with changes in blood and bone lead levels. In particular, changes in neuropsychological function are correlated with the total quantity of lead released from bone.

Data from this study may shed light on the role that lead and other environmental toxins have in the genesis of dementia and other chronic neurologic and psychologic impairment among aging women.