No bones about arthritis risk
Fractures are more likely to occur in Australian women who are suffering from rheumatoid arthritis, Deakin researcher Dr Sharon Brennan has found.
Surprisingly, Dr Brennan’s research has discovered that fractures are more likely to occur at the major osteoporotic sites - the hip, wrist and spine - rather than at the skeletal sites adjacent to the joints affected by rheumatoid arthritis (usually hands, feet, fingers and toes).
As Head of the Social Epidemiology Research Group within Deakin’s Epi-Centre for Healthy Ageing, Dr Brennan and her colleagues examined the likelihood of fracture over an eight-year period in all women aged 35 years and older who were resident within Geelong and/or surrounding areas. The collaborative project also included Professor Julie Pasco, Associate Professors Mark Kotowicz and Margaret Henry, Dr Hedley Griffiths and Leisje Toomey/Brice.
The research team investigated 173,430 women; 1,008 of whom had a clinical diagnosis of rheumatoid arthritis. Incident fractures were ascertained from the Geelong Osteoporosis Study Fracture Grid, which is directed by Deakin’s Professor Julie Pasco. The grid provides a comprehensive listing of all fractures in the Barwon region and documents patterns of fractures according to time, age, sex, fracture site and socioeconomic status.
“It is a concern that women with rheumatoid arthritis are twice as likely to sustain a fracture of the spine, compared to those without rheumatoid arthritis, even accounting for the role played by age in these associations,” Dr Brennan said.
While the causes of greater fracture risk for this group are unknown, Dr Brennan explains that it could be due to systemic factors associated with rheumatoid arthritis disease activity or duration. It could also be that those with rheumatoid arthritis may be less likely to be physically active, thereby weakening their musculoskeletal system, and increasing their likelihood of falls and fractures.
“Localised bone erosion around the joints affected by rheumatoid arthritis may have less influence on fracture risk than reduced bone density,” Dr Brennan said. “In order to reduce fracture risk, women with rheumatoid arthritis may be a suitable target population for anti-resorptive agents (drugs that decrease bone breakdown). This therapy is more commonly prescribed to patients with osteoporosis.”
Dr Brennan explained that rheumatoid arthritis and osteoporosis are both more prevalent in females. The research unit is currently undertaking further investigation into the role of inflammatory biomarkers in rheumatoid arthritis and bone fragility for both sexes.
- These findings have been published in the BMC Musculoskeletal Disorders Open Access Journal.