Effects of risedronate treatment on bone density and vertebral fracture inpatients on corticosteroid therapy

Men and women (n = 518) receiving moderate-to-high doses of corticosteroids were enrolled in two studies with similar protocols and randomly assigned to receive either placebo or risedronate (2.5 or 5 mg) for 1 year. All pati ents received daily calcium supplementation (500-1000 mg), and most also re ceived supplemental Vitamin D (400 Ill). The primary endpoint was the diffe rence between the placebo and active groups in lumbar spine bone mineral de nsity (BMD) at 1 year; changes in BMD at other sites, biochemical markers o f bone turnover, and the incidence of vertebral fractures were also assesse d. In the overall population, the mean (SE) lumbar spine BMD increased 1.9 +/- 0.38% from baseline in the risedronate 5 mg group (P < 0.001) and decre ased 1.0 +/- 0.4% in the placebo group (P = 0.005). BMD at the femoral neck , trochanter, and distal radius increased or was maintained with risedronat e 5 mg treatment, but decreased in the placebo group. Midshaft radius BMD d id not change significantly in either treatment group. The difference in BM D between the risedronate 5 mg and placebo groups was significant at all sk eletal sites (P < 0.05) except the midshaft radius at 1 year. The 2.5 mg do se also had a positive effect on BMD, although of a lesser magnitude than t hat seen with risedronate 5 mg. A significant reduction of 70% in vertebral fracture risk was observed in the risedronate 5 mg group compared with the placebo group (P = 0.01), Risedronate was efficacious in both men and wome n, irrespective of underlying disease and duration of corticosteroid therap y, and had a favorable safety profile, with a similar incidence of upper ga strointestinal adverse events in the placebo and active treatment groups. D aily treatment with risedronate 5 mg significantly increases BMD and decrea ses vertebral fracture risk in patients receiving moderate-to-high doses of corticosteroid therapy.