Depressive symptoms, bone loss, and fractures in postmenopausal women

BACKGROUND: Osteoporosis and depression may be associated through common physiologic systems or risk factors. OBJECTIVE: To assess the associations between depressive symptoms (Burnam's scale) or antidepressant use and bone outcomes. DESIGN: Prospective cohort study. PARTICIPANTS: A total of 93,676 postmenopausal women (50 to 79 years old) enrolled in the Women's Health Initiative Observational Study. MEASUREMENTS: Self-reported fractures (n=14,982) (hip [adjudicated], spine, wrist, and "other"). Analyses included 82,410 women with complete information followed on average for 7.4 years. Bone mineral density (BMD) of the hip (n=4539), spine (n=4417), and whole body (n=4502) was measured at baseline and 3 years in women enrolled at 3 densitometry study sites. RESULTS: Overall, there were no statistically significant associations between depressive symptoms or antidepressant therapy and 3-year change in BMD. In a subset of women not using antidepressants, there was a significant difference in whole-body BMD change between women with and without depressive symptoms (P=.05). Depressive symptoms (hazard ratio [HR] 1.08; 95% CI=1.02 to 1.14) and antidepressant therapy (HR=1.22; CI=1.15 to 1.30) independently increased risk of any fracture, the majority of which occurred at "other" anatomic sites. Antidepressant therapy increased the risk of spine fracture (HR=1.36; CI=1.14 to 1.63). No associations were observed between depressive symptoms or antidepressant therapy and hip or wrist fracture. CONCLUSIONS: In this study of postmenopausal women, average age 64, we observed minimal association between depressive symptoms and 3-year changes in either BMD or fracture risk. Antidepressant use was not associated with changes in BMD, but was associated with increased risk of fractures at the spine and "other" anatomic sites.