Bone loss in patients with rheumatoid arthritis: results from a population-based cohort of 366 patients followed up for two years

OBJECTIVE: To evaluate the extent of and risk factors for bone loss in a population-based cohort of patients with rheumatoid arthritis (RA) receiving conventional health care. METHODS: In a longitudinal study, clinical data were collected and bone mineral density (BMD) measurements were performed at baseline and after 2 years. Dual-energy x-ray absorptiometry was used for hip and spine BMD measurements. At baseline, patients received advice about lifestyle adjustments and calcium and vitamin D supplementation; during the followup period they were treated with antirheumatic and bone-sparing drugs, according to clinical judgment. RESULTS: After a mean +/- SD of 2.2 +/- 0.2 years, 366 (298 women, 68 men) of the 488 patients who were examined at baseline were reexamined. At that time, 47.9% were current users of corticosteroids and 37.0% were using antiresorptive drugs (hormone replacement therapy, bisphosphonates, or calcitonin). The mean BMD reduction was -0.64% in the femoral neck, -0.77% in the total hip, and -0.29% in the spine at L2-4. BMD was increased at all measurement sites in current users of antiresorptive drugs (0.16-1.64%) but was decreased in patients using calcium and vitamin D alone (-1.99% to -1.39%) and in patients not using any osteoporosis treatment (-1.20% to -0.43%). Current use of corticosteroids was independently associated with increased risk for BMD loss in the total hip (odds ratio [OR] 2.63, 95% confidence interval [95% CI] 1.38-5.00) and spine at L2-4 (OR 2.70, 95% CI 1.30-5.63), whereas current use of antiresorptive drugs was associated with decreased risk for bone loss in the total hip (OR 0.43, 95% CI 0.20-0.89). CONCLUSION: Results of this population-based, 2-year followup study indicate that adequate management of patients with RA, addressing both the rheumatic disease and osteoporosis, protects against bone loss.