SOUTHAMPTON, UK— New research showing that rheumatoid arthritis (RA) patients are at an increased risk of osteoporotic fractures due to a combination of disease activity, low body mass index (BMI), and oral glucocorticoid use suggests that rheumatologists step up to the plate and better identify and treat these problems.

"The long-term risks of fracture can be substantial, and further investigations, such as those involving bone densitometry, might be conveniently targeted to patients with higher absolute long-term fracture risk," Tjeerd-Pieter  van Staa, PhD, of the University of Southampton in the UK, and colleagues conclude in the October issue of Arthritis & Rheumatism.¹

The new study included 30,262 RA patients aged  40 years from the British General Practice Research Database. Each patient was matched with three controls and followed for a median of 7.6 years. Two thousand four hundred sixty patients had fractures during follow-up.

Novel Risk Score Can Help Predict At-Risk RA Patients

The study researchers created a risk score for each patient to estimate their 5- and 10-year risk of sustaining a fracture by converting beta coefficients in their final COX model into integer risk scores. Risk factors that determined the score included BMI, smoking, fracture history, fall history, and general risk factors.

According to the formula, a woman aged 65 years with longstanding RA whose risk factors also included low BMI, a history of fracture, and frequent use of oral glucocorticoids has a 5-year risk of hip fracture of 5.7%. Individuals with a risk score of 15 have about a 5% risk of sustaining a fracture within 10 years, RA patients with a risk score of 50 have a 30% risk of sustaining an osteoporotic fracture within 10 years.

Fracture risk was 50% higher in RA patients than in controls, and the risk was especially high at the hip (RR, 2.0) and spine (RR 2.4). Hip fracture risk was associated with RA duration (RR, 3.4 for >10 years RA), low body mass index (RR, 3.9), and use of oral glucocorticoids (RR, 3.4). However, increased risk was also seen in RA patients who did not take steroids. RA patients also had increased risk of pelvis or tibia/fibula fractures, but a lower risk of radius/ulna fractures. 

Onus on Rheumatologists

"Rheumatologists have a real challenge to ask their patients about low impact fractures and to be very diligent in treating patients with low bone mass and RA to prevent fractures," said CIAOMed editorial board member Nancy E. Lane, MD, director of the Aging Center and distinguished professor of medicine and rheumatology at the University of California at Davis Medical Center in Sacramento.

Dr. Lane advised clinicians to routinely ask RA patients about fracture risk factors, including use of steroids and history of a low impact fracture as an adult. "The ability to get out of a chair without using their hands is another physical performance risk factor for osteoporotic fractures," she said. "Taking a good history for osteoporotic risk factors will help identify RA patients who might benefit from treatment to prevent osteoporotic fractures."

Felicia Cosman, MD, clinical director of the National Osteoporosis Foundation in Washington, DC, medical director of the Clinical Research Center at Helen Hayes Hospital in West Haverstraw, New York, told CIAOMed that this "nicely done" study is  the most comprehensive Investigation of fracture risk in RA patients to date. Dr. Cosman said that the results highlight some key messages for clinicians.

"RA patients are at higher risk of osteoporotic-related fractures even if they haven't taken glucocorticoids, and we should be getting bone density at a younger age [in these patients]," Dr. Cosman said. "Women by age 65 should get bone density tests, and those women at age 50 or menopause with clinical risk factors should get bone density tests. RA should be considered a clinical risk factor."

Modifying risk factors and raising the threshold for treatment can also help decrease fracture risk in this population. "Looking at vitamin D and trying to optimize it in these patients is something that we should be pretty aggressive about," she said. "I would probably recommend treating many individuals with a T-score of -2 if they have RA, whereas I would not treat many people without RA [with a T score of -2] in the absence of other risk factors with this score."

Dr. Cosman also suggested maintaining good muscle strength and working on balance and coordination training—especially given the deformities and limitations associated with RA—as a means to helping prevent falls, which are usually the precipitants for fractures.

Reference

1. van Staa, TP, Geusens P, Bijlsma WJ, et al. Clinical assessment of the long-term risk of fracture on patients with rheumatoid arthritis. Arthritis Rheum. 2006;54:3104-3112.