To study the effects of one year of high dose 6-methylprednisolone pulse therapy (MPPT) on bone mass, seric bone alkaline phosphatase (sBAP), and urinary deoxypyridinoline (uDpyr) in patients with active rheumatoid arthritis (RA), and to compare results with those of patients with active RA treated with oral methylprednisolone (OMP).
Thirty-one women with active RA were given 1000 mg of MP IV for 3 alternate days, with a mean interval of administration of 76 days (+/- 8.3 SD) for one year (MPPT group). Bone mineral density (BMD) (total body, lumbar spine, and femur neck), plasma levels of sBAP, and urinary concentrations of uDpyr were assessed at the beginning of the treatment and every 3 months until the end of the study. Moreover, erythrocyte sedimentation rate (ESR), Thompson joint score, and early morning stiffness were assessed at study entry and every month. The control group, 31 women with active RA treated with oral MP, was followed in the same way (OMP group).
In the MPPT group there was no significant reduction of BMD at any site compared to significant reductions in lumbar BMD at 6 and 12 months and total body BMD and femur neck BMD at 12 months in the OMP group. Also in the OMP group, a significant reduction in the mean sBAP was observed. The mean uDpyr levels were not significantly reduced in either group.
Our results show that MPPT, compared to continuous therapy with oral corticosteroids, preserves bone mass without modifying the biochemical markers of bone metabolism.