The earliest radiological change in rheumatoid arthritis (RA) is periarticular osteopenia, which occurs prior to the appearance of erosions and clinically apparent deformities. The aim of the study was to measure periarticular bone mineral density (BMD) in the hands of patients with early RA, using dual energy X-ray absorptiomentry (DEXA) and to correlate this with markers of disease activity and radiological progression.
The study population (n = 50) of patients with RA of < 3 years duration underwent measurement of BMD of the non-dominant hand, femoral neck and lumbar spine and clinical assessment at baseline, 6 and 12 months. Hand radiographs were performed at baseline and 12 months. Thirty age- and sex-matched controls also underwent measurement of BMD of the non-dominant hand, femoral neck and lumbar spine.
Hand BMD correlated strongly with sex, height, weight and lumbar and femoral neck BMD in both RA subjects and controls. Baseline hand BMD in RA subjects correlated with baseline serum C-reactive protein (r = -0.36, P = 0.01) and 12-month radiographic score (r = 0.36, P = 0.02). There were small non-significant decreases in hand, femoral neck and lumbar spine BMD over the 12-month period.
Hand BMD measurement using DEXA is a reproducible, well-tolerated procedure that warrants further investigation as a component of routine assessment in early RA.