The bisphosphonate risedronate significantly reduced the risk of hip fracture in elderly men with a history of stroke, in the first randomized, double-blind study on this topic.
Risedronate sodium, an inhibitor of bone resorption, previously was shown to decrease the risk of nonvertebral fractures in postmenopausal women with osteoporosis and of hip fractures in women who had a stroke.
The current study randomized 280 consecutive ambulatory men aged 65 years or older with a previous stroke to a daily dosage of 2.5 mg risedronate or placebo for 18 months. By the study's end, 10 patients in the placebo group and 2 in the risedronate group had sustained hip fractures, representing an 80% reduction in risk of fracture in the risedronate group, reported Dr. Yoshihiro Sato of Mitate Hospital, Tagawa, Japan, and his associates (Arch. Intern. Med. 2005;165:1743–8).
The investigators estimated that 16 elderly men who had previous strokes would need to be treated with risedronate to prevent one hip fracture.
All of the hip fractures were on the patient's hemiplegic side. In addition to hip fractures, wrist or ankle fractures occurred in two patients in the risedronate group, and six patients in the placebo group sustained other fractures—two at the proximal femur, two at the ribs, one at the proximal humerus, and one at the pelvis.
Bone mineral density on the hemiplegic side increased by 2.5% in men in the risedronate group, compared with baseline measurements, but decreased by 3.5% in men in the placebo group, compared with baseline, a significant difference.
On the nonhemiplegic side, bone density increased by more than 3% in the risedronate group and decreased by 2% in the placebo group. Bone density was significantly lower on the hemiplegic side in both groups. A key marker of bone resorption—urinary deoxypyridinoline—decreased by 59% in the risedronate group and by 37% in the placebo group. Bone resorption typically increases during the first year after a stroke in both men and women, studies have shown.
Patients in the current study were advised to take risedronate with water 30–60 minutes before breakfast and not to take any other drugs that could affect bone or calcium metabolism. Patients were asked to return pills not taken, which were counted to check adherence to therapy. A single physician who was blinded to treatment assignment did the follow-up assessments of all patients, evaluating them every 4 weeks for falls or possible hip fractures and performing hematologic and biochemical tests.
Six patients in the risedronate group and seven in the placebo group dropped out of the study or were lost to follow-up, illness, or death.