J Clin Endocrinol Metab. 2021 Apr 27;dgab279.doi: 10.1210/clinem/dgab279.
Context: Bone mineral density (BMD) decreases rapidly during the menopause transition (MT), and continues to decline in postmenopause.
Objective: To examine whether faster BMD loss during the combined MT and early postmenopause is associated with incident fracture, independent of starting BMD, before the MT.
Design and setting: The Study of Women’s Health Across the Nation (SWAN), a longitudinal cohort study.
Patients or participants: 451 women, initially pre- or early perimenopausal, and transitioned to postmenopause.
Main outcome measures: Time to first fracture after early postmenopause.
Results: In Cox proportional hazards regression, adjusted for age, body mass index, race/ethnicity, study site, use of vitamin D and calcium supplements, and use of bone–detrimental or beneficial medications, each SD decrement in lumbar spine (LS) BMD before the MT was associated with a 78% increment in fracture hazard (p=0.007). Each 1% per year faster decline in LS BMD was related to a 56% greater fracture hazard (p=0.04). Rate of LS BMD decline predicted future fracture, independent of starting BMD. Women with a starting LS BMD below the sample median, and a LS BMD decline rate faster than the sample median had a 2.7-fold greater fracture hazard (p=0.03). At the FN, neither starting BMD nor rate of BMD decline was associated with fracture.
Conclusions: At the LS, starting BMD before the MT and rate of decline during the combined MT and early postmenopause are independent risk factors for fracture. Women with below-median starting LS BMD and faster-than-median LS BMD decline have the greatest fracture risk.