Bone mineral density and frequency of osteoporosis among Vietnamese women with early rheumatoid arthritis

Generalised bone mineral density (BMD) reduction often occurs in established rheumatoid arthritis (RA); however, in early RA, there is a disagreement with regard to BMD in the femoral neck and lumbar spine, and there is no available information for the whole body. Therefore, the aims of this study were to investigate the BMD, frequency of osteoporosis and the risk factors for BMD reduction in Vietnamese women with early RA. BMD in the femoral neck, lumbar spine L1–4 and whole body was measured in 105 women with early RA (disease duration ≤3 years) and 105 age-matched healthy women (26–73 years) using a dual energy X-ray absorptiometry. Femoral neck and whole body BMD in women with RA were lower (p < 0.05) than controls, while lumbar spine BMD was similar between two groups. The frequency of osteoporosis in the femoral neck, lumbar spine and whole body in women with RA aged ≥50 were higher (p < 0.05) than controls: 41.8% versus 29.5%, 42.2% versus 37.7% and 37.1% versus 28%, respectively. There were associations between the frequencies of osteoporosis at all sites with postmenopausal status, glucocorticoid use, rheumatoid factor positivity and disease activity with lumbar spine BMD and disease disability with femoral neck and whole body BMD. In conclusion, women with early RA had significantly lower femoral neck and whole body BMD, but had similar lumbar spine BMD compared with controls. The frequency of osteoporosis at all sites was significantly higher in women with RA than controls, suggesting that assessment of BMD should be considered in women with early RA.