PURPOSE: Early menopause (EM, age at menopause < 45 years) and premature ovarian insufficiency (POI, age at menopause < 40 years) are associated with an increased risk of osteoporosis. However, their association with increased fracture risk has not been established, with studies yielding conflicting results. The primary aim of this systematic review and meta-analysis was to synthesize studies evaluating the association between age at menopause and fracture risk. The secondary aim was to evaluate this effect concerning the site of fractures.
METHODS: A comprehensive search was conducted in PubMed, CENTRAL and Scopus, up to 31 January 2018. Data were expressed as odds ratio (OR) with 95% confidence intervals (CI). The I index was employed for quantifying heterogeneity.
RESULTS: Eighteen studies were included in the qualitative and quantitative analysis (462,393 postmenopausal women, 12,130 fractures). Compared with women with age at menopause > 45 years, women with EM demonstrated higher fracture risk (OR 1.36, 95% CI 1.11-1.66, p < 0.002, I² 81.5%). Women with POI did not display any difference in fracture risk compared either with women with age at menopause > 40 (OR 1.23, 95% CI 0.72-2.09, p = 0.436, I² 62.5%) or >45 years (OR 0.54, 95% CI 0.22-1.29, p = 0.17, I 0%). No difference was evident when a separate analysis was performed for vertebral, non-vertebral and hip fractures.
CONCLUSIONS: This is the first meta-analysis showing that EM is associated with increased fracture risk compared with normal age at menopause, without any distinct effect on the site of the fracture.