Risedronate rapidly reduces the risk for nonvertebral fractures in women with postmenopausal osteoporosis

Abstract

Prevention of nonvertebral fractures, which account for a substantial proportion of osteoporotic fractures, is an important goal of osteoporosis treatment. Risedronate, a pyridinyl bisphosphonate, significantly reduces clinical vertebral fracture incidence within 6 months. To determine the effect of risedronate on osteoporosis-related nonvertebral fractures, data from four large, randomized, double-blind, placebo-controlled, Phase III studies were pooled and analyzed. The population analyzed consisted of postmenopausal women, with and without vertebral fractures, who had low bone mineral density (lumbar spine T-score <-2.5). Patients received placebo (N = 608) or risedronate 5 mg daily (N = 564) for 1 to 3 years. At baseline, 58% had at least one prevalent vertebral fracture, and the mean lumbar spine T-score was -3.4. Among placebo-treated patients, the presence of prevalent vertebral fractures did not increase the risk of incident nonvertebral fractures overall, although fractures of the humerus and hip and pelvis were more common in patients who had prevalent vertebral fractures than in those who did not. Risedronate 5 mg significantly reduced the incidence of nonvertebral fractures within 6 months compared with control. After 1 year, nonvertebral fracture incidence was reduced by 74% compared with control ( P = 0.001), and after 3 years, the incidence was reduced by 59% ( P = 0.002). The results indicate that risedronate significantly reduces the incidence of osteoporosis-related nonvertebral fractures within 6 months.