One-Year Spinal Bone Change in Pre- and Perimenopausal Japanese Women

Background: This prospective observational study was designed to determine whether the bone mineral density (BMD) of the lumbar spine decreases before menopause. Methods: The change in BMD of the second through fourth lumbar vertebrae (Δ%L2–4BMD) over the course of 12 months was measured in 197 pre- and perimenopausal Japanese women aged 48.2 ± 2.3 (mean ± SD) years. Results: Overall, Δ%L2–4BMD decreased significantly, with a greater decrease seen in perimenopausal women. This group also had a significantly higher level of FSH (p < 0.05, t = 7.356), a significantly lower level of estradiol (p < 0.05, t = 4.245), and significantly higher levels of the bone metabolic markers, alkaline phosphatase (p < 0.05, t = 3.841), calcium (p < 0.05, t = 3.939), and osteocalcin (p < 0.05, t = –3.295). Overall, there was a significant positive correlation between osteocalcin and Δ%L2–4BMD (r = –0.194, p = 0.0479). Conclusion: A subset of perimenopausal women with transient decreases in ovarian function that do not respond to increased FSH may be at increased risk for abnormally low BMD, and may benefit from early management of bone mass.