Osteoporosis is a known complication of rheumatoid arthritis (RA). This prospective study aimed to evaluate whether disease activity, disability, and glucocorticoid (GC) treatment in early RA were risk factors for loss of bone mineral density (BMD).
We followed 97 women (mean age 58 years), for 24 months, with a history of RA of less than 12 months. At baseline, 77 women were receiving standard treatment with disease-modifying antirheumatic drugs (DMARDs) and 20 were receiving no treatment. Risk factors for osteoporosis were recorded. Disease activity score (DAS28), Health Assessment Questionnaire (HAQ) score, and medications were registered at baseline and every 6 months and calculated as areas under the curve (AUCs). Femoral neck and lumbar spine BMD were measured at baseline and after 2 years and compared to BMD in age- and gender-matched controls. Risk factors were analysed by linear regression models.
BMD loss was comparable to that of age-matched women in both the lumbar spine and the femoral neck, although neither was significantly different from baseline. In multivariate analyses the AUC for DAS28 was an independent predictor of changes in lumbar spine BMD (p = 0.003) and that for HAQ of changes in femoral neck BMD (p = 0.018). GC use was not an overall predictor of BMD loss.
BMD loss was predicted by high disease activity and disability but not by GC treatment. With the DMARD, GC, hormone replacement therapy (HRT), and bisphosphonate treatment strategies used during the study period, the general outcome seems favourable concerning loss of BMD in patients with early RA.