Patients with inflammatory myositis are at increased risk for osteoporosis and fracture, according to study results published in BMC Musculoskeletal Disorders.
Researchers aimed to determine the prevalence of low bone mineral density (BMD) and fracture risk in patients with inflammatory myositis compared with those with rheumatoid arthritis (RA).
Data were obtained for 52 patients with myositis (82.7% women) and 43 patients with RA (95.3% women) treated at the National Myositis Center at the University of Debrecen in Debrecan, Hungary. Fracture risk was assessed using the Fracture Risk Assessment Tool (FRAX), and physical function and quality of life were evaluated using the FRAX Health Assessment Questionnaire and Short Form-36 questionnaire, respectively.
Researchers identified osteopenia in 60% of patients with myositis and 39.5% of patients with RA. Osteoporosis occurred significantly more frequently in patients with myositis (13.5%) than those with RA (7%; P =.045). Without accounting for BMD, femoral neck fracture risk was found to be significantly higher in patients with RA vs myositis (15.58% vs 9.68%; P =.008). Similar results were observed for other major fracture risk (6.23% vs 3.06%; P =.022). This difference was attenuated after accounting for differences in BMD and was further decreased after correcting for glucocorticoid use.
Overall 40 patients with myositis and 35 with RA received vertebral x-ray examinations. A total of 194 vertebral fractures were identified in 54 patients, including 115 fractures in 30 patients with myositis and 79 fractures in 24 patients with RA; however, the difference in fracture frequency was not significantly different between the groups. Compared with patients without fractures, patients with vertebral fractures were older in both patients with myositis (mean age, 55.4 vs 62.83 years; P =.034) and RA (mean age, 52.0 vs 63.25; P =.022). Age was an independent predictor of vertebral fracture in patients with myositis (P =.042).
Physical function scores were proportional to the number of vertebral fractures in patients with myositis (correlation coefficient [r]=0.457; P =.008) and RA (r=0.376; P =.041). Decreases in quality of life scores were also proportional to the number of vertebral fractures in myositis (r=0.538; P <.001).
Investigators noted that the small number of participants in the study obtained from a single center in Hungary may limit the generalizability of results.
“It can be concluded that osteoporosis and consequential fractures in myositis are common and probably underestimated, and that their examination is often neglected,” the researchers concluded. “Therefore, it would be important to pay greater attention to the recognition of low BMD and high fracture risk and adherence to preventive measures.”
Vincze A, Bodoki L, Szabó K, et al. The risk of fracture and prevalence of osteoporosis is elevated in patients with idiopathic inflammatory myopathies: cross-sectional study from a single Hungarian center. BMC Musculoskelet Disord. 2020;21(1):426.