The loss of bone mass that occurs in the early years of menopause is a risk factor for osteoporosis in later life. We investigated the efficacy and safety of risedronate 35 mg dosed once a week in preventing bone loss in early postmenopausal women. In a one-year, double blind, placebo-controlled study, two hundred eighty subjects, 0.5 to 5 years post menopause, were randomly assigned to receive placebo or risedronate. Subjects also received 1000 mg elemental calcium and 400 IU vitamin D daily. Age, LS BMD at baseline and years since last menses were not significantly different between the treatment groups. For the overall study population, these were (mean [SD]) 53.6 years [4.0], 0.99 g/cm2 [0.14] (T-score -0.69), and 3.3 years [1.3], respectively. BMD changes were assessed at 6 and 12 months. The primary efficacy measurement was the percent change from baseline in LS BMD after one year of treatment. The primary analysis was the comparison of this parameter between the two treatment groups. This was evaluated in the two hundred sixty four subjects who received at least one dose of study medication and had a baseline and at least one post-baseline bone mineral density (BMD) test (modified intention-to-treat population) using the last observation carried forward principle. Secondary outcomes included percent changes in LS BMD at 6 months, and total proximal femur, femoral neck and trochanter BMD at 6 and 12 months and an assessment of the general safety and tolerability of risedronate. At the end of the study, the LS BMD in the placebo group had decreased by 1.05% (p<0.05) while the value in the risedronate-treated group had increased significantly by 1.83% (p<0.05). The difference between the risedronate and the placebo groups was 2.88% and highly significant (p<0.0001). Significant differences were apparent at 6 months. Similarly, at both 6 and 12 months, total proximal femur, femoral neck and trochanter BMD were significantly greater in subjects receiving risedronate compared with placebo (p<0.005 for all sites). Weekly risedronate therapy was well tolerated. The incidence of all adverse events (AEs) was comparable in the treated and placebo groups. Withdrawals due to an AE were also comparable (5.1% risedronate, 7.1% placebo). Upper GI AEs were reported in 10.9% of subjects in the risedronate group and 12.1% in the placebo group In conclusion, these data indicate that risedronate 35 mg once a week effectively prevents bone loss in early postmenopausal women, with tolerability and safety comparable to placebo.
Disclosure Information:
Faculty Member's Name: Michael R. McClung, M.D.
Grants/Research Support: Procter & Gamble Pharmaceuticals, Aventis Pharmaceuticals
Consultant: Procter & Gamble Pharmaceuticals, Aventis Pharmaceuticals
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