Objective: To measure hand bone mineral content (BMC) by dual x-ray absorptiometry and to seek clinical correlates in patients with rheumatoid arthritis (RA), in a prospective, longitudinal study.
Methods: Eighty-one patients with non-steroid-treated RA were assessed at baseline and at month 12, for hand BMC and for disease activity and severity. Hand BMC in patients was compared with that in a control group of 95 normal volunteers, and rate of loss was compared with that in 37 controls.
Results: At the initial assessment, male and female patients with RA had lower hand BMC than controls, after correction for age, height, and weight (mean reduction 7.5% in men [P = 0.003] and 7.8% in women [P = 0.01]). After 1 year, there was a further loss of hand BMC in patients (median loss 3.25% in men [P = 0.001] and 1.46% in women [P = 0.05]), but normal controls did not have significant changes in their hand BMC. In patients with disease duration of < 2 years at study entry, the parameters of disease activity improved over 1 year, but they lost significant amounts of hand BMC. Hand BMC loss correlated with baseline C-reactive protein levels. In those with RA of > 2 years duration at entry, the Health Assessment Questionnaire scores and Larsen scores had worsened after 1 year, but there was no significant loss of hand BMC.
Conclusion: Patients with RA had low hand BMC compared with normal controls, even within 2 years of disease onset. The rate of loss was highest in patients with early disease and correlated with measures of initial disease activity. This loss continued despite clinical improvement.