SWAN is providing many interesting findings about the health and aging of mid-life women from diverse communities and racial and ethnic backgrounds. By collecting, analyzing, and publishing information on health status, physical measures, symptoms, lifestyles, attitudes, and health care utilization, SWAN has begun to describe the timing of, and the normal variation in, the biologic and psychological characteristics of the mid-life transition as well as in normal aging.
The scientific areas of study in SWAN’s longitudinal cohort are outlined below:
Bone mineral density and body composition.
Bone mineral density (BMD) measurements are obtained annually at five study sites. These measures include low energy X rays of the lumbar spine, hip, and whole body, which will provide an indication of bone strength, and predisposition to sustain fractures. Blood and urine samples that were obtained at baseline and at the first two annual follow-up visits are being studied to assess biochemical markers of bone turnover. Bone turnover markers provide an indication of how quickly bone breakdown and formation is taking place and may help to predict subsequent bone loss. Body composition (lean and fat mass) and its changes are also assessed annually in these same study participants.
Cardiovascular measures/risk factors.
Physical measures (waist and hip measurements, height and weight) and cardiovascular measures are obtained annually at all seven study sites in all ethnic groups. Lipids, lipoproteins, glucose, insulin and clotting factors are measured from blood samples every other year. SWAN investigators look for change in these cardiovascular factors as women age, and how examine changes vary by ethnicity and other health and psychosocial factors.
Markers of ovarian aging, including follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), inhibin-B and estrone (E1) are being assessed. Additional biochemical determinations include dehydroepiandrosterone sulfate (DHEAS), sex hormone-binding globulin and testosterone. All of these assessments are performed annually in all ethnic groups. Thyroid stimulating hormone is also measured periodically but not at every visit.
At each annual visit, participants are surveyed about psychosocial issues, such as quality of life, depression, stress, social support and life events. Information pertaining to sexual function is obtained via a confidential self-administered questionnaire.
Factors measured at baseline included demographic descriptors such as race/ethnicity, education, income, occupation (job title, activities, and industry) and marital status. Other factors assessed were health care utilization, active and passive smoke exposure, physical activity, menstrual characteristics, pregnancy/infertility and menstrual history (including cycle length and variability, and premenstrual symptoms), family history, medical history (including chronic diseases, fractures, urinary incontinence and surgeries), medication use, weight history, physical and psychological/emotional symptoms of midlife, initiation and discontinuation of hormone replacement therapy (HRT), and use of complementary and alternative therapies. Most of these factors, except those (such as family history) that are unlikely to change are assessed annually. Information pertaining to diet is obtained periodically.