Objective: The objective of this study was to examine 5-year change in cortical hand BMD in female RA patients with established disease. Further, possibly baseline predictors of 5-year loss in digital X-ray radiogrammetry (DXR)-BMD were studied.
Methods: This 5-year multicentre, longitudinal study included patients from Amsterdam (the Netherlands), Truro (UK) and Oslo (Norway). At baseline, 50 patients were consecutively included per centre. Inclusion criteria were: female sex, age 50-70 years and disease duration >or=5 years. This study presents 5-year follow-up data for 85 of these 150 patients (29 patients from Amsterdam; 26 from Truro; and 30 from Oslo). Clinical examination, blood test and radiographs were taken at baseline and 5-year follow-up. Cortical hand BMD was measured by DXR from hand radiographs.
Results: The mean (95% CI) baseline DXR-BMD for all patients was 0.46 (0.44, 0.48) g/cm(2) and the median 5-year DXR-BMD change was -6.7% (-11.2, -2.82%). Five-year DXR-BMD loss was associated with baseline measurements of age, RF, CRP, HAQ and 28-joint disease activity score (DAS-28) in univariate linear regression analyses. DAS-28 at baseline was an independent predictor of 5-year DXR-BMD loss in multivariate linear regression analyses corrected for centre, age and use of bone-protective agents.
Conclusion: High disease activity measured by DAS-28 was an independent predictor of cortical hand bone loss over 5 years in established, destructive RA. This finding supports that increased disease activity leads to localized bone loss in long-standing RA and underlines the importance of tight control and aggressive anti-inflammatory treatment in these patients.