Efficacy of risedronate on clinical vertebral fractures within six months.

OBJECTIVE

Postmenopausal osteoporotic women with pre-existing or new incident vertebral fractures are at high risk for future fracture, so prompt treatment is warranted. Risedronate has been shown to reduce the incidence of radiographically-defined vertebral fractures by approximately two-thirds within 1 year.

RESEARCH

DESIGN

This study examined the effects of risedronate treatment on the time course of the reduction in the risk of clinical vertebral fractures (i.e., symptomatic fractures), on the risk of moderate-to-severe radiographic vertebral fractures, and on height.

RESULTS

In 2442 postmenopausal women with prevalent vertebral fractures from the Vertebral Efficacy with Risedronate Therapy (VERT) studies who received either risedronate 5 mg or placebo, daily risedronate reduced the risk of clinical vertebral fractures within 6 months (RR = 0.08, 95% CI 0.01-0.63), and by 69% at 1 year (RR = 0.31, 95% CI 0.12, 0.78). At 1 year, risedronate also reduced the risk of moderate-to-severe radiographically-defined vertebral fractures by 71% (RR = 0.29 95% CI 0.16, 0.54). Height loss was attenuated with treatment, most notably in patients who experienced new vertebral fractures, with a median difference of 0.73 cm compared with subjects receiving placebo (p = 0.005).

CONCLUSION

Risedronate reduces the risk of clinical vertebral fractures in postmenopausal women with osteoporosis within 6 months of commencing treatment.