Forearm bone mineral density in patients with rheumatoid arthritis

The aims of the present study were to determine whether patients with rheumatoid arthritis (RA) show significantly lower forearm bone mineral density (BMD) than sex- and age-matched healthy controls, and to identify significant factors that are associated with their BMD loss. One hundred eighty-four patients with RA and 185 sex- and age-matched healthy controls were enrolled in the study: 71 men 37-68 years of age (RA, 31; controls, 40), 129 premenopausal women 30-48 years of age (RA, 67; controls, 62), and 169 postmenopausal women 48-69 years of age (RA, 86; controls, 83). The correlation of forearm BMD, measured by dual energy X-ray absorptiometry with anatomic grade in the wrist, functional class, duration of disease, steroid use, modified health assessment questionnaire (HAQ) score for the upper and lower extremities, levels of serum C-reactive protein and rheumatoid factor, erythrocyte sedimentation rate, and years since menopause (YSM) were examined by multiple regression analysis. In men with RA, no clinical factors were significantly correlated with forearm BMD, and the BMD did not differ significantly from that in controls (0.329 +/- 0.060 [mean +/- SD] vs. 0.351 +/- 0.069 g/cm(2)). In premenopausal women with RA, the HAQ score for the upper extremities was positively correlated with forearm BMD ( P < 0.05), but the BMD did not differ significantly from that in controls (0.298 +/- 0.085 vs. 0.324 +/- 0.088 g/cm(2)); in postmenopausal women with RA, YSM and anatomic grade in the wrist were negatively correlated with forearm BMD ( P < 0.01 and P < 0.05), and the BMD was significantly lower than in controls (0.192 +/- 0.063 vs. 0.223 +/- 0.076 g/cm(2), P < 0.01). These findings suggest that forearm BMD loss in patients with RA may be accelerated in women after menopause, and that YSM and disuse of the wrist may be significant determinants of their forearm BMD loss.