Relationship between early bone mineral density changes and long-term function and radiographic progression in rheumatoid arthritis.

OBJECTIVE

To ascertain whether bone mineral density loss during the first year of treatment for early rheumatoid arthritis (RA) as assessed by dual x-ray absorptiometry (DXA) is associated with long-term function, quality of life, and radiographic progression.

METHODS

Early RA patients, prior to commencing disease-modifying antirheumatic drug therapy, underwent evaluation with DXA scans of both hands, femoral neck, and lumbar spine at the time of diagnosis, then at 1 year and final followup at >6 years. Clinical and laboratory data and hands and feet radiographs were obtained at baseline and final followup.

RESULTS

Sixty-four patients were assessed. At baseline, median disease duration was 6 months, mean 28-joint Disease Activity Score was 5.85, and median Health Assessment Questionnaire score was 1.38. Median followup was 6.4 years (range 5.1-7.2 years). For erosion scores, 86% of patients with hand bone density loss above the smallest detectable change after 1 year progressed versus 55% of those with no hand bone density loss (P = 0.006). However, baseline radiographs showed a similar strength of association. Eighty-four percent of patients with erosions at baseline had erosion progression versus 57% of those with no baseline erosions (P = 0.021). Additionally, first-year bone density loss was not associated with function and quality of life status at followup.

CONCLUSION

Hand bone loss during the first year of treatment in early RA, as assessed with DXA, was associated with a high likelihood of radiographic progression; however, in the current study this was not superior to baseline radiographs. Furthermore, it was not associated with patient-reported outcomes.