The menopausal transition: a 9-year prospective population-based study. The Melbourne Women's Midlife Health Project

To describe the natural history of the menopause in Australian-born women. To determine the hormonal changes relating to the menopausal transition (MT) and how these affect quality of life, bone mineral density, body composition, cardiovascular disease (CVD) risk and memory.

A 9-year prospective, observational study of a population-based sample of 438 Australian-born women aged 45-55 years at baseline. By the 9th year, the retention rate was 88%. Interviews, blood sampling, menstrual calendars, quality of life and physical measures were taken annually, and bone mineral density was measured bi-annually.

The late MT coincides with changes in estradiol, follicle stimulating hormone, and free testosterone index, decreases in bone density and mastalgia, and increases in central adiposity, vasomotor symptoms, insomnia and vaginal dryness. Levels of total testosterone and dehydroepiandrosterone sulfate are unchanged by the MT. An increase in CVD risk was associated with increases in weight and free testosterone index and a decrease in estradiol. Depressed mood is increased by symptoms and by stressors occurring in the MT. Sexual functioning significantly deteriorates with the MT and aging, but relational factors have major effects. Menstrual cycles became more variable and longer closer to the final menstrual period.

As hormonal changes during the MT directly or indirectly adversely affect quality of life, body composition and CVD risk, maintenance of health parameters in the premenopausal years is crucial for a healthy postmenopause.