- pyridinyl bisphosphonate which is indicated in osteoporosis;
- increases bone mineral density;
- in the study by McClung, et al, the authors studied 5445 women 70 to 79 years old who had osteoporosis (indicated by a T score for bone mineral density at the femoral neck that was more than 4 SD below the mean peak value in young adults [-4] or lower than -3 plus a nonskeletal risk factor for hip fracture, such as poor gait or a propensity to fall)...
... and 3886 women at least 80 years old who had at least one nonskeletal risk factor for hip fracture or low bone mineral density at the femoral neck (T score, lower than -4 or lower than -3 plus a hip-axis length of 11.1 cm or greater);
- women were randomly assigned to receive treatment with oral risedronate (2.5 or 5.0 mg daily) or placebo for three years. The primary end point was the occurrence of hip fracture;
- incidence of hip fracture among all the women assigned to risedronate was 2.8 %, as compared with 3.9 % among those assigned to placebo (relative risk, 0.7; 95 % CI, 0.6 to 0.9; P=0.02);
- in the group of women with osteoporosis (those 70 to 79 years old), the incidence of hip fracture among those assigned to risedronate was 1.9 %, as compared with 3.2 % among those assigned to placebo (relative risk, 0.6; 95 percent CI, 0.4 to 0.9; P=0.009);
- in the group of women selected primarily on the basis of nonskeletal risk factors (those at least 80 years of age), the incidence of hip fracture was 4.2 % among those assigned to risedronate and 5.1 % among those assigned to placebo (P=0.35);
- the authors concluded that risedronate significantly reduces the risk of hip fracture among elderly women with confirmed osteoporosis but not among elderly women selected primarily on the basis of risk factors other than low bone mineral density.
- Effect of risedronate on the risk of hip fracture in elderly women. Hip Intervention Program Study Group.
- Outside Links:
osteoporosis and bone physiology at Washington University
References for Osteoporosis