HARROGATE, ENGLAND — Age and frailty should not deter physicians from offering very elderly osteoporotic patients antiresorptive therapy, despite age-associated increases in comorbid conditions, said Steven Boonen, M.D.
The results of a pooled analysis from three randomized, double-blind controlled trials showed a significantly reduced risk of new vertebral fractures among 704 osteoporotic women aged 80 and older who received bisphosphonate therapy, compared with age and disease-matched patients randomized to placebo treatment, Dr. Boonen reported in a presentation at the annual conference of the National Osteoporosis Society.
“To the best of our knowledge, this study is the first to document a benefit of antiresorptive treatment in addition to that afforded by calcium and vitamin D in a population of women aged 80 and older with osteoporosis,” said Dr. Boonen of Leuven (Belgium) University Center for Metabolic Bone Disease, the study's principal investigator. “The findings tell us that, even in the very old, reducing bone resorption rates remains an effective treatment strategy.”
The three studies each looked at 3-year fracture end points and included women aged 80–100 years with documented osteoporosis. In each study, the women randomized to bisphosphonate therapy were prescribed 5 mg/day of risedronate (Actonel) for up to 3 years, and control group patients were given a placebo pill for the same duration. All participants received 1,000 mg calcium supplementation per day and, if baseline levels were low, up to 500 U of vitamin D per day.
At 1 year, the risedronate groups had a new vertebral fracture rate of 2.5%, compared with 10.9% for the control groups. At 3 years, the new vertebral fracture rates for the bisphosphonate and placebo groups were 18.2% and 24.6%, respectively, “representing a 44% reduction in risk for the women who took risedronate,” Dr. Boonen said.
The rates of nonvertebral fractures were not significantly different between the two groups, he said. At 3 years, the risedronate patients had a 14% risk, compared with the placebo group's 16.2% risk. The studies also showed risedronate to have a safety profile similar to that of placebo.
The early efficacy of the risedronate therapy was consistent across the three trials, Dr. Boonen said. The treatment was well tolerated, even among the oldest women in the study population, “despite the fact that evaluation of baseline characteristics showed these patients to have a higher prevalence of gastrointestinal diseases than younger patients.”
The findings are of particular relevance, considering the aging of the population. “The prevalence of vertebral deformities in women increases markedly between the ages of 50 and 90, and epidemiological data suggest that half or more of women aged 80 and older have vertebral fractures,” he said. “Our findings suggest that adding [bisphosphonate] treatment to calcium and vitamin D could significantly decrease the incidence of vertebral fractures in elderly women with osteoporosis and thus reduce the public health burden associated with these fractures.”
The hope is that these data will help increase the number of “very old” patients with osteoporotic fractures who are deemed eligible for and who receive treatment. “Despite the debilitating effects of osteoporotic fractures and the availability of therapies to reduce fracture recurrence, only a small percentage of women with osteoporotic fractures receive treatment, and this percentage decreases with age,” Dr. Boonen said. “Clinicians may presume that it is too late to alter the course of disease in its late stage, but these results tell us that is not so.”
Because each of the antiresorptive therapies used to treat osteoporosis has unique characteristics and side-effect profiles, the observations made in this study cannot be generalized to include other bisphosphonates, he cautioned.
Dr. Boonen disclosed that he has received research grants from Procter and Gamble Pharmaceuticals but has no other financial relationship with it or any other company that markets bisphosphonates.