Fracture incidence and risk associated with rheumatoid arthritis
Rheumatoid arthritis (RA) is the most common type of autoimmune arthritis. It is triggered by a faulty immune system and affects the wrist and small joints of the hand, including knuckles and middle joints of the fingers. Rheumatoid patients have high risk for developing osteoporosis and fracture. To identify the incidence rate and risk factors in Asian RA patients, study was conducted.
A total of 3557 RA patients in the Korean Observational Study Network for Arthritis (KORONA) were included and observed over a mean follow-up of 18 months. A fracture was assessed as total, major or minor fractures; major fracture was defined as a vertebral or hip fracture and the other fractures were classified as minor fractures. The standardized incidence ratio (SIR) of fracture in RA patients was calculated compared with general population and possible risk factors for fractures were explored using multi-variable logistic regression analyses.
In the analyses, a total of 194 patients with 215 fractures were observed and the SIR of the total fracture in RA patients was 2.2. The SIRs of major and minor fractures were 1.5 and 3.0. Advanced age and having history of prior fracture were risk factors for total fractures. In addition, higher HAQ increased fracture risk, whereas the use of bis-phosphonate showed protective effect for future fractures in patients with osteoporosis. RA patients had a 2.2 fold increased risk of fractures as compared to general population. In Asian RA patients, advanced age and history of prior fracture were the most important risk factors for new fractures.