Background: To perform a systematic review, completed with a meta-analysis, of the published evidences about the effect of oral alendronate on bone mineral density and the incidence of fractures in postmenopausal women with low bone mass.
Methods: We search for all alendronate clinical trials in postmenopausal women with low bone mass which were randomized, double blind, placebo controlled, with a duration of one year or more and with bone mineral density measurement and/or fractures as outcomes. We used the weighted average of individual study results as an estimation of the global effect.
Results: Seven studies meet all the inclusion criteria. Relative Risks (RR) with 95% Confidence Intervals (CI 95%) for the combined effect under fixed effects model were: RR 0.54 (CI 95%: 0.45 to 0.66) for vertebral fractures, RR 0.81 (CI 95%: 0.72 to 0.92) for non vertebral fractures and RR 0.64 (CI 95%: 0.40 to 1.01) for hip fractures.
Conclusions: Our results demonstrate that alendronate reduces the risk of vertebral, non vertebral and hip fractures in postmenopausal women with low bone mass. This meta-analysis allows the classification of alendronate anti-fracture evidences in the highest level.