Researchers emphasize the importance of assessing osteoporosis risk factors in RA

Researchers in a new study have compiled a set of considerations for assessing the risk of falls in patients with rheumatoid arthritis (RA), a disease that puts patients at greater risk of weakened bones and fractures.

The risk of osteoporosis and fractures in RA arises from disease-specific causes, disease treatment and factors exposed to the general population, the study said, emphasizing the importance of assessing risk factors in these patients.

“Unfortunately, osteoporosis is underdiagnosed and undertreated in the RA patient population. Although RA is included in fracture risk calculators (such as the FRAX), the binary representation of RA in such algorithms does not adequately capture the complexity of the disease (severity, duration, and treatments). The increased risk of osteoporosis in RA has been attributed to inflammation, medications (particularly glucocorticoids), and decreased physical activity and altered body composition. In addition to these disease-specific risk factors, traditional risk factors for osteoporosis also need to be considered in people with RA.”

Risk factors for low bone mineral density (BMD) in RA outlined by the group included autoantibodies – present in about half of patients with this disease – thought to contribute to RA pathogenesis and with a associated with more severe illness. For example, anti-citrullinated protein antibodies (ACPAs) have been shown to bind to and stimulate osteoclasts and have been implicated in local joint erosions and systemic bone loss in RA.

Increased inflammation — common in people with active disease — contributes to osteoporosis and can also contribute to the loss of muscle mass and muscle function, which lowers BMD and ultimately increases the risk of frailty and falls.

BMD can also be affected by glucocorticoids (GCs), which have been shown to increase the risk of low BMD and poor bone quality, and subsequent falls and fractures.

“Nonetheless, GCs remain a common drug in the treatment of RA, reducing inflammation, joint pain and stiffness, which may counteract the deleterious effects of GCs on BMD. It is unclear what the optimal dose of GCs is in the balance between treating RA disease and minimizing damage to bone density and quality,” the researchers described. “Because excess GC, even at low doses, can be detrimental to skeletal health and there are many non-GC treatment options for RA, the 2020 American College of Rheumatology (ACR) RA guideline recommends conditionally to follow a “treatment”-targeting strategy that avoids GCs.”

In addition to GC, selective serotonin reuptake inhibitors and opiates have been associated with an increased risk of fracture in patients. It has been found that patients with RA who take both GCs and a proton pump inhibitor have an increased risk of osteoporotic fractures compared to patients who take neither drug or both. Using multiple drugs also exacerbates the risk, the researchers explained, noting that data in elderly patients showed a 14% increase in the risk of falls with each drug added to a 4-drug regimen.

Risk of falls and fractures has been associated with several patient characteristics, including age and body composition. The researchers pointed to the risk of lower BMD associated with sarcopenia, which is independently associated with an increased risk of falls.

Relation

Baker R, Narla R, Baker J, Wysham K. Risk factors for osteoporosis and fractures in rheumatoid arthritis. Best Practice Res Clin Rheumatol. Published online October 5, 2022. doi:10.1016/j.berh.2022.101773