Bone mineral density and biomarkers in rheumatoid arthritis patients

Abstract EN

Objective: Reduced bone mineral density (BMD) is a frequent complication in rheumatoid arthritis (RA).

However, the mechanism and possible risk factors of this reduction are not exactly known.

The aim of this study was to evaluate the bone mineral status in RA patients using dual energy x-ray absorptiometry (DEXA) and biomarkers of bone formation and resorption, as well as to determine the possible risk factors.

Methodology: We studied 32 RA patients (21 with active disease and 11 were 1:0 inactive) and 10 healthy controls.

BMD was measured by DEXA in the lumbar spine (LS) and femoral neck (FN).

Osteocalcin (DC) and carboxyterminal cross linked telopeptide of type I collagen (ICTP) were measured in the serum with radioimmunoassay.

Results: BMD in LS, but not in FN; was significantly reduced in RA than controls.

Meanwhile, BMD in both sites was significantly reduced in active than non-active disease.

Parameters having high relative risk (RR) included disease activity (RR = 9.6), menopause (RR = 5.9), steroids (RR = 4.9), [n radiological erosions (RR = 3.2), functional disability (odds = 2.97), CRP f " (odds = 2.16) and Ritchie articular index (odds = 1.63).

ICTP, but not DC was; significantly higher in RA patients than in controls, whereas both markers were significantly higher in active than non-active RA.

Conclusion: These results confirm the diminished BMD in RA, particularly in trabecular bone.

This reduction may be mainly due to increased bone resorption rather than decreased bone formation.

Important risks include disease activity, menopause, steroid therapy and functional disability.