"Studies suggest that bone quality may be an important contributor to bone strength and fracture resistance. These new data provide value in learning how therapies such as risedronate affect bone quality," said principal investigator Eleftherios P. Paschalis, PhD, Ludwig Boltzmann Institute for Osteology, Vienna. "However, additional studies are necessary to fully understand how the different aspects of bone quality relate to fracture risk."
One aspect of bone quality is the integrity of the material components of bone. Bone is a living tissue composed of calcium-based mineral crystals that are embedded in a network of protein fibers, called collagen. In osteoporotic bone, the calcium-based mineral crystals enlarge and the integrity of the collagen deteriorates compared to what is found in normal bone. Actonel, as shown in study biopsies, maintained the size of the calcium crystals and the integrity of the collagen structure over five years of treatment. Actonel is the only osteoporosis therapy for which these aspects of bone quality have been evaluated in bone biopsies taken from the same patients before and after five years of treatment.
About the Study
The study analyzed paired iliac crest biopsies from eight postmenopausal women with osteoporosis who received Actonel (5mg/day) over a 5-year period. The biopsies were analyzed with a novel imaging technique called Fourier Transform Infrared Spectroscopic Imaging (FTIRI), which provides microscopic information on the size of the calcium-based mineral crystals (crystallinity) and the structure of the collagen (collagen cross-link ratio, pyr/deH-DHLNL).