THE MENOPAUSE TRANSITION

The menopause transition is defined as the permanent cessation of mens truation resulting from the loss of ovarian follicular activity. Termi nation of ovarian function and menses is not an acute physiologic even t; rather, the physiologic antecedents associated with the transition from premenopausal to postmenopausal follicular function occurs in the perimenopause (menopause transition). The proposed model of hormonal changes at the time of the transition has been expanded to include not only estrogen declines but also a broader range of hormones and alter ations in the pattern and frequency of changes in hormone levels. The expanded menopause model also incorporates comorbid medical and psychi atric conditions and environmental influences and behaviors as covaria tes that influence the expression of menopause-related events. This br oader view is likely to elucidate previously confusing data, as the pr oper understanding of potentially complex exposures, effect modifiers, and confounders is more likely to provide clearer answers to critical research questions.