Untreated postmenopausal women with osteoporosis are at risk for first spinal fracture within one year

Results of a new analysis found that, without treatment, one out of 13 postmenopausal osteoporotic women who were initially fracture-free were likely to experience a spinal fracture within one year. This risk of fracture was present despite these patients taking supplemental calcium, and if necessary, Vitamin D. Data were presented today at the annual meeting of the American Association of Clinical Endocrinologists (AACE).

Additionally, a statistical model was presented that predicted the progression over time of subsequent spinal fractures in a population of osteoporotic women who were initially fracture-free. The model was based upon data from the placebo arms of Phase III fracture trials for Actonel® (risedronate sodium tablets), and it included data for 2,326 patients whose fracture status (i.e. number of spinal fractures) was assessed at baseline and at yearly intervals. The model showed that the prevalence of spinal fractures rapidly increased over time if the population of osteoporotic women was not treated, and projected that therapy which reduced the risk of a first fracture within one year could substantially reduce the risk of future fracture.

"We previously established in another analysis that a postmenopausal osteoporotic woman who has already suffered a spinal fracture has a one in five risk of having another spinal fracture within one year; therefore, intervening before that first fracture occurs is important," said Dr. Robert Lindsay, Chief of Internal Medicine at Helen Hayes Hospital, West Haverstraw, NY and principal investigator on this study. "With one in 13 osteoporotic women at risk of that first spinal fracture within the year, choosing a therapy proven to act rapidly is important."

About the Analysis
Data for the analysis were from patients in the placebo arms of the Actonel fracture trials (VERT-MN, VERT-NA, HIP). The women had lumbar spine or femoral neck bone mineral density T-scores of less than -2.5 or had one or more prevalent spinal fractures. All patients received 1,000 mg daily calcium and, if baseline levels were low, up to 500 IU Vitamin D daily.

The data were used to estimate the probabilities of having zero, one, or multiple spinal fractures within one year for patients having any number (0-13) of prevalent spinal fractures. Using these one year risk estimates, a simple Markov model was constructed to model the progression of spinal fractures over time in a population of untreated osteoporotic women who were initially fracture-free.

About Osteoporosis
Osteoporosis is a disease characterized by reduced bone strength predisposing a person to an increased risk of fracture. According to the National Osteoporosis Foundation (NOF), 8 million women in the U.S. have osteoporosis, and 1.2 million osteoporotic fractures occur annually. The NOF estimates that every 20 seconds an osteoporosis-related fracture occurs. Risk factors for osteoporosis in postmenopausal women include age, personal history or family history of fracture, low bone mineral density, cigarette use, and race.

Studies show that among postmenopausal women with osteoporosis who experience a spinal fracture, one out of five will suffer their next spinal fracture within just one year, potentially leading to a fracture cascade. Fractures can progress quickly if osteoporosis is left untreated. The NOF, National Institutes of Health, and American Association of Clinical Endocrinologists agree that fracture risk reduction is the efficacy endpoint by which osteoporosis therapies should be evaluated.

Preventive measures, such as not smoking, maintaining a balanced diet supplemented with calcium and vitamin D, if needed, and engaging in weight-bearing exercise, like walking, can reduce an individual's chances of developing osteoporosis. However, in some women, these preventive measures may not be enough, and prescription medications such as Actonel may be beneficial.

About Actonel® (risedronate sodium tablets)
Actonel is developed by Procter & Gamble Pharmaceuticals and co-marketed by Procter & Gamble Pharmaceuticals and Aventis. Actonel 35 mg Once-a-Week and Actonel 5 mg daily are indicated for the prevention and treatment of osteoporosis in postmenopausal women. Actonel 5 mg daily is also indicated for the prevention and treatment of glucocorticoid-induced osteoporosis (GIO) in men and women either initiating or continuing systemic glucocorticoid treatment (≥7.5 mg/d prednisone or equivalent) for chronic diseases.

In clinical trials, Actonel was generally well tolerated. Actonel is contraindicated in patients with hypocalcemia, known hypersensitivity to any component of this product, or inability to stand or sit upright for at least 30 minutes. Hypocalcemia and other disturbances of bone and mineral metabolism should be effectively treated before starting Actonel therapy. Actonel is not recommended for use in patients with severe renal impairment (creatinine clearance < 30 mL/min).

Bisphosphonates may cause upper gastrointestinal disorders such as dysphagia, esophagitis and esophageal or gastric ulcer. Patients should pay particular attention to the dosing instructions, as failure to take the drug according to instructions may compromise clinical benefits and may increase the risk of adverse events.

In clinical trials, the overall incidence of adverse events with Actonel 5 mg daily was comparable to placebo. The most commonly reported adverse events regardless of causality were infection (primarily upper respiratory, placebo 29.7 percent vs. Actonel 5 mg 29.9 percent), back pain (23.6 percent vs. 26.1 percent), and arthralgia (21.1 percent vs. 23.7 percent).

In a one-year clinical trial comparing Actonel 35 mg Once-a-Week and Actonel 5 mg daily, the overall incidence of adverse events with the two dosing regimens was similar. The most commonly reported adverse events regardless of causality were infection (Actonel 35 mg 20.6 percent vs. Actonel 5 mg 19.0 percent), arthralgia (14.2 percent vs. 11.5 percent) and constipation (12.2 percent vs. 12.5 percent). Please visit www.actonel.com for full prescribing information for Actonel.