Fractures and Falls More Common for Postmenopausal Women with Osteoarthritis

Newswise — CHICAGO – Postmenopausal women with osteoarthritis have a 20 percent higher risk of bone fractures and experience almost 30 percent more falls than those without the disease, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in Chicago.

Osteoarthritis, or OA as it is commonly called, is the most common joint disease affecting middle-aged and older people. It is characterized by progressive damage to the joint cartilage—the cushioning material at the end of long bones—and causes changes in the structures around the joint. These changes can include fluid accumulation, bony overgrowth, and loosening and weakness of muscles and tendons, all of which may limit movement and cause pain and swelling. Nearly 27 million Americans are affected by OA.

Although patients with OA have increased bone mass, there is no evidence that they have fewer fractures. And, researchers from the Hospital del Mar/IMIM in Spain and from the University of Oxford (United Kingdom), alongside investigators from nine other participating countries, recently set out to discover if there is an association between OA and risk of falls and fractures in postmenopausal women.

“Current knowledge suggests that patients with osteoarthritis have bigger bones, but this does not protect against fractures. According to our results, bigger bones might increase the risk of falling, joint pain and malfunction – leading to abnormal walking and body movement,” says Daniel Prieto-Alhambra, MD, MSC, PhD; post-doctoral research fellow at the Hospital del Mar and Municipal Institute of Medical Research in Spain and lead investigator of the study. “Women who have fractures experience poor quality of life, and are at increased risk of dying compared with the general population. As both osteoarthritis and fractures are very common in the elderly, finding an association between the two is relevant.”

Dr. Prieto-Alhambra’s team, in collaboration with the Global Longitudinal Study of Osteoporosis in Women investigators and the Center for Outcomes Research (University of Massachusetts), studied 60,393 women aged 55 years or older. Participants were selected using information from GLOW, which is an international yearly survey conducted for the past three years in a population of women from several countries, including the United States, Canada, Australia, United Kingdom, Spain and others.

At the beginning of the study, patients were mailed a questionnaire and asked to report if a doctor had ever diagnosed them with osteoarthritis or degenerative joint disease. Patients were also asked to report new falls and fractures. Based on questionnaire responses, patients were classified into two groups − having OA and not having it. An annual follow-up questionnaire was sent during a three-year period. The risk of fracture for both groups was then calculated using standard mathematical methods, and the difference in risk was accordingly estimated. Participants that failed to report OA and fracture information at the beginning of the study, and women with celiac disease or rheumatoid arthritis, were excluded.

Among the 51,386 women who responded to the annual questionnaires, 40 percent had osteoarthritis. Women with OA had a 20 percent higher risk of fracture, and experienced almost 30 percent more falls than those without OA. After measuring and adjusting for the existing differences between both groups at the beginning of the study, the increase in falls and fractures for osteoarthritis patients remained significant.

“Our results suggest that women with osteoarthritis are at increased risk of falls and fractures and, apparently, that increase in falls is actually the cause for the higher number of fractures they experience,” says Dr. Prieto-Alhambra. “If this can be confirmed in further studies, patients with osteoarthritis should be properly assessed for fracture risk, even when their bones look bigger and, according to some authors, stronger.”

The American College of Rheumatology is an international professional medical society that represents more than 8,000 rheumatologists and rheumatology health professionals around the world. Its mission is to advance rheumatology. The ACR/ARHP Annual Scientific Meeting is the premier meeting in rheumatology. For more information about the meeting, visit www.rheumatology.org/education. Follow the meeting on Twitter by using the official hashtag: #ACR2011.

Editor’s Notes: Daniel Prieto-Alhambra, MD, MSC, PhD, will present this research during the ACR Annual Scientific Meeting at McCormick Place Convention Center at 5:30 PM on Sunday, November 6 in Room W 196 A . Dr. Prieto-Alhambra will be available for media questions and briefing at 8:30 AM on Monday, November 7 in the on-site press conference room, W 175 C.

Learn more about living well with rheumatic disease as well as rheumatologists and the role they play in health care. Also, discover the ACR’s Simple Tasks campaign, which highlights how rheumatic diseases strike women disproportionately and in the prime of their lives.

Presentation Number: 829

Osteoarthritis Is Related to An Increased Risk of Falls and Fractures: A Prospective Multinational Cohort Study (the GLOW study)

Daniel Prieto-Alhambra (URFOA-IMIM, Parc de Salut Mar; Idiap Jordi Gol i Gurina-Institut Català de la Salut; Oxford NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, UK, Barcelona, Spain,)Xavier Nogués (Hospital del Mar-IMIM, Universitat Autònoma de Barcelona, Barcelona and RETICEF, ISCIII Madrid; Spain, Barcelona, United Kingdom)M. Kassim Javaid (Oxford NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, UK, Oxford, United Kingdom)Nigel K. Arden (Oxford NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, UK, Oxford, United Kingdom)Cyrus Cooper (Southampton General Hospital, Southampton, United Kingdom)Allison Wyman (Center for Outcomes Research, UMass Medical School, Worcester, MA)Adolfo Díez-Pérez (Hospital del Mar-IMIM, Universitat Autònoma de Barcelona, Barcelona; and RETICEF, ISCIII Madrid; Spain, Barcelona, Spain) GLOW Investigators

Background/Purpose: Although patients with osteoarthritis (OA) have increased bone mass, no corresponding decrease in fractures has been observed. We therefore studied the association between OA and incident falls and fractures in postmenopausal women.

Method: The Global Longitudinal Study of Osteoporosis in Women (GLOW) is a prospective, multinational, observational cohort study. Practices that were typical of each region were identified through primary care networks organized for administrative, research, or educational purposes. Non-institutionalized women aged ≥55 years who visited a practice within the previous 2 years were eligible. A total of 60,393 women agreed to participate. Participants were mailed a self-administered questionnaire at baseline; follow-up questionnaires were sent at 12-month intervals for 3 years. Patients were classified as having OA or not according to their answer to the following question in the baseline survey: “Has a doctor or other health provider ever said that you had osteoarthritis or degenerative joint disease?” Information on incident falls and fractures, and potential confounders were self-reported by participants. For this analysis, women with missing baseline OA or fracture information, as well as those with celiac disease or rheumatoid arthritis, were excluded. The cumulative fracture incidence was calculated by the Kaplan-Meier method. Unadjusted and multivariable Cox models for incident fractures and falls were used to compute hazard ratios (HRs) according to baseline OA status. A Kaplan-Meier curve was computed on the subset of women with complete follow-up data.

Result: Of 51,386 women who were followed up for a median time of 1072 days (interquartile range 772 to 1095 days), 20,409 (39.7%) were classified as having OA. The unadjusted HR for fracture among OA patients was 1.40 (95% CI 1.32-1.48; p<0.0001), and this remained significant after multivariable adjustment (HR 1.21; 95% CI 1.13-1.30; p<0.0001; Figure). Falls were also more likely in women with OA (adjusted HR 1.27; 95% CI 1.23-1.30; p<0.0001). The association between OA and fracture remained significant even after adjusting for baseline falls (HR 1.16; 95% CI 1.08-1.25; p<0.0001).

Conclusion: Postmenopausal women with OA have a 20% higher risk of fracture and experience almost 30% more falls than those without OA. Although incident falls may partially explain the increased risk of fracture observed in women with OA, our data suggest that the association between OA and fracture is independent of the number of falls.

Disclosures: D. Prieto-Alhambra, None. X. Nogués, Eli Lilly, 5 M. K. Javaid, Novartis, Alliance for Better Health and Lilly, 9 N. K. Arden, Merck, MSD, Roche, Novartis, Smith and Nephew, Q-MED, Nicox, Servier, GSK, Schering-Plough, Pfizer and Rottapharm, 9 C. Cooper, Alliance for Better Bone Health, Amgen, Novartis, MSD, Servier, Eli Lilly and GSK, 9 A. Wyman, the Alliance for Better Bone Health:Sanofi-Aventis and Warner Chilcott, 9 A. Díez-Pérez, Eli Lilly, Amgen, Procter & Gamble, Servier, and Daiichi-Sankyo, 5, Merck, Novartis, Eli Lilly, Amgen, and Procter & Gamble; has received honoraria from Novartis, Lilly, Amgen, Procter & Gamble, and Roche, 9