Shieh A, et al. - This study was undertaken to determine if estradiol (E2), or follicle stimulating hormone (FSH), measured in pre- and perimenopausal women, could anticipate significant bone loss by the next year. The authors utilized information from 1,559 candidates in the Study of Women's Health Across the Nation and examined E2 and FSH as separate predictors using repeated measures modified Poisson regression. Based on the results of this study, tracking an in-individual change in either hormone did not predict onset of bone loss superior to a single measure. Prediction in pre- or early perimenopause was better vs late perimenopause when hormones were measured. FSH was more informative than E2 in identifying women, particularly in the lumbar spine (LS), who were more likely to start losing bone. The investigators recommended that measuring FSH in the MT can help identify women with imminent or ongoing bone loss in the LS prospectively.