INCREASED BONE MASS WITH PAMIDRONATE TREATMENT IN RHEUMATOID-ARTHRITIS - RESULTS OF A 3-YEAR RANDOMIZED, DOUBLE-BLIND TRIAL

Objective. Osteoporosis is a frequent complication of rheumatoid arthr itis (RA). We therefore investigated the effect of oral pamidronate th erapy as a specific bone-sparing agent in RA. Methods. The study desig n was a 3-year randomized, double-blind trial of 300 mg oral pamidrona te/day compared with placebo in 105 RA patients. Bone mineral density (BMD) measured at 12-month intervals was the primary efficacy paramete r. Results. In 3 years, lumbar spine and forearm BMD increased signifi cantly in the pamidronate-treated group (by 8.4 +/- 6.9% [mean +/- SEM ] [P < 0.0001] and 5.2 +/- 6.5% [P < 0.005], respectively), compared w ith nonsignificant changes in the placebo-treated patients (increase o f 0.6 +/- 5.2% and decrease of 1.2 +/- 5.8%, respectively). Femoral ne ck BMD increased in the pamidronate-treated group (by 2.6 +/- 8.6%) an d decreased significantly in the placebo-treated group (by 4.0 +/- 1.3 % [P < 0.005]). The changes in BMD with time at all 3 measurement site s were significantly different between the treatment groups (P < 0.000 1). Changes in radiographic signs of joint damage and in disease activ ity were similar in the 2 groups. Conclusion. The present study provid es the first evidence that long-term treatment with an orally administ ered bisphosphonate overcomes bone loss and increases bone mass when c ompared with placebo. This finding may have significance with regard t o the treatment of patients with RA.