Both cardiovascular diseases (CVD) and osteoporosis are common comorbidities in rheumatoid arthritis (RA) patients. Although accumulating evidence indicates a link between CVD and osteoporotic fracture, whether CVD contributes to osteoporotic fracture risk in RA has yet to be explored. We examined the incidence rate and risk factors of osteoporotic vertebral fracture in RA patients with new-onset CVD (RA-CVD) and evaluated the effects of medications on such fracture risk.
A retrospective study was conducted using a nationwide database from 2000 to 2010: 1267 RA-CVD and 1267 non-CVD patients were enrolled from 30,507 patients with newly diagnosed RA. The main outcome was the development of osteoporotic vertebral fracture. After being adjusted for age, gender, and comorbidities, the Cox proportional hazard model was used to identify independent factors contributing to osteoporotic vertebral fracture.
The adjusted hazard ratio (aHR) of developing osteoporotic vertebral fracture was 1.47-fold greater in RA-CVD group than in non-CVD group (95% confidence interval 1.19-1.81, p < 0.001). Both the age above 40 years and female gender were significant risk factors for developing osteoporotic vertebral fracture in RA-CVD patients. Using patients not taking medication as a reference group, the aHR of osteoporotic vertebral fracture was significantly lower in those receiving statins (0.50), low-dose corticosteroids (0.57), or hydroxychloroquine (0.12).
The risk of osteoporotic vertebral fracture was significantly increased in RA-CVD patients, particularly women above 40 years of age, and could be reduced by statin therapy. However, the protective effect of low-dose corticosteroids or hydroxychloroquine on osteoporotic vertebral fracture risk needs further validation.