Assessment of the Relationship Between Age and the Effect of Risedronate Treatment in Women with Postmenopausal Osteoporosis: A Pooled Analysis of Four Studies

Authors

  • Steven Boonen MD, PhD,

    1. From the *Bone Research Unit, Department of Experimental Medicine, Leuven University, Leuven, Belgium; Procter & Gamble Pharmaceuticals, Mason, Ohio; and Regional Bone Center, Helen Hayes Hospital, West Haverstraw, New York.
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  • Andrea B. Klemes DO,

    1. From the *Bone Research Unit, Department of Experimental Medicine, Leuven University, Leuven, Belgium; Procter & Gamble Pharmaceuticals, Mason, Ohio; and Regional Bone Center, Helen Hayes Hospital, West Haverstraw, New York.
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  • Xiaojie Zhou PhD,

    1. From the *Bone Research Unit, Department of Experimental Medicine, Leuven University, Leuven, Belgium; Procter & Gamble Pharmaceuticals, Mason, Ohio; and Regional Bone Center, Helen Hayes Hospital, West Haverstraw, New York.
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  • Robert Lindsay MD, PhD

    1. From the *Bone Research Unit, Department of Experimental Medicine, Leuven University, Leuven, Belgium; Procter & Gamble Pharmaceuticals, Mason, Ohio; and Regional Bone Center, Helen Hayes Hospital, West Haverstraw, New York.
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  • Portions of this research were presented as posters:
    Boonen S, Klemes A, Zhou X, Pack S, Delmas PD. Patients treated with risedronate have a fracture risk similar to patients 20 years younger in age. Presented at the 29th Annual Meeting of the American Society for Bone and Mineral Research; September 16–19, 2007; Honolulu, Hawaii.
    Lindsay R, Zhou X, James R, Boonen S. Non-vertebral fracture risk of risedronate treated patients is similar to that of untreated patients 10 years younger. IBMS_09. Presented at the 2nd Joint Meeting of the International Bone & Mineral Society and the Australian & New Zealand Bone & Mineral Society, March 21–25, 2009, Syndey, Australia.
    Lindsay R, Zhou X, James R, Boonen S. Non-vertebral fracture risk of risedronate treated patients is similar to that of untreated patients 10 years younger. Presented at the National Osteoporosis Foundation's 8th International Symposium on Osteoporosis; April 1–5, 2009; Washington, DC.

Address correspondence to Steven Boonen, Leuven University Center for Metabolic Bone Diseases and Division of Geriatric Medicine Katholieke Universiteit Leuven, Herestraat 49, B-3000 Leuven, Belgium. E-mail: steven.boonen@uz.kuleuven.ac.be

Abstract

OBJECTIVES: To quantify the effect of age on the incidence of osteoporosis-related fractures and of risedronate treatment on fracture risk in different age groups in women with postmenopausal osteoporosis.

DESIGN: Data from four randomized, double-blind, placebo-controlled, Phase III studies were pooled and analyzed.

PARTICIPANTS: The analysis population (N=3,229) consisted of postmenopausal women with osteoporosis as determined on the basis of prevalent vertebral fractures, low bone mineral density (BMD), or both.

INTERVENTION: Patients had received risedronate 5 mg daily or placebo for 1 to 3 years.

MEASUREMENTS: The endpoints of interest were the incidence of osteoporosis-related fractures, clinical fractures, nonvertebral fractures, and morphometric vertebral fractures. The effect of age on fracture risk and treatment benefit was examined using Cox regression models with age and treatment as explanatory variables. The 3-year fracture risk was estimated for patients in each treatment group at a given age.

RESULTS: Irrespective of treatment, fracture risks were greater in older patients (P<.001). On average, for every 1-year increase in age, a patient's risk for osteoporosis-related fracture increased 3.6% (95% confidence interval=2.3–5.0%). Irrespective of age, risedronate treatment reduced fracture risk 42%. Risedronate-treated patients had fracture risks similar to those of placebo-treated patients 10 to 20 years younger.

CONCLUSION: Patients treated with risedronate have a significantly lower fracture risk, similar to that of untreated patients 10 to 20 years younger.

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