Trajectory Clustering of Estradiol and Follicle-Stimulating Hormone during the Menopausal Transition among Women in the Study of Women's Health across the Nation (SWAN)
CONTEXT: Variability in the pattern of change in estradiol (E2) and FSH levels over the menopause transition has not been well defined. OBJECTIVE: The current study aimed to determine whether different trajectories of E2 and FSH could be identified and whether race/ethnicity and body mass index were related to the different trajectories. DESIGN: The Study of Women's Health Across the Nation is a longitudinal observational study of the menopausal transition. SETTING: Women aged 42-52 yr from seven participating sites were recruited and underwent up to 11 annual visits. PARTICIPANTS: Postmenopausal women with 12 or more months of amenorrhea that was not due to hysterectomy/oophorectomy and who were not using hormone therapy before the final menstrual period participated in the study. MAIN OUTCOME MEASURES: Annual serum E2 and FSH levels anchored to final menstrual period were measured. RESULTS: Four distinct E2 trajectories and three distinct FSH trajectories were identified. The E2 trajectories were: slow decline (26.9%), flat (28.6%), rise/slow decline (13.1%), and rise/steep decline (31.5%). The FSH trajectories were: low (10.6%), medium (48.7%), and high (41.7%) rising patterns. Obesity increased the likelihood of a flat E2 and low FSH trajectory for all race/ethnic groups. Normal-weight Caucasian and African-American women tended to follow the rise/steep decline E2 and high FSH trajectories. Normal-weight Chinese/Japanese women tended to follow the slow decline E2 and the high/medium FSH trajectories. CONCLUSIONS: E2 and FSH trajectories over the menopausal transition are not uniform across the population of women. Race/ethnicity and body mass index affect the trajectory of both E2 and FSH change over the menopausal transition.