Bone Mineral Density Changes During the Menopause Transition in a Multiethnic Cohort of Women

Bone loss accelerates after menstruation ends, but it is not clear when bone loss begins or at what rate bone is lost at various stages of the transition to menopause. Such knowledge would help to determine when to screen for osteoporosis and when to consider treatment. The SWAN (Study of Women’s Health Across the Nation), a longitudinal multiethnic cohort study of menopausal transition, provided an opportunity to track bone mineral density (BMD) at the lumbar spine and proximal femur in 1902 African American, Caucasian, Chinese, and Japanese women who, at baseline, were premenopausal or at the early perimenopausal stage and ranged in age from 42 to 52 years. The women were evaluated at up to 6 annual visits.