The effect of low-dose methotrexate on bone mineral density in patients with early rheumatoid arthritis

The intent of this study was to assess the effect of low-dose methotrexate treatment on bone mineral density (BMD) in patients with early rheumatoid arthritis (RA).

Forty-six premenopausal women with early RA not previously treated with disease-modifying antirheumatic drugs or corticosteroid were randomized to 7.5 mg/week of methotrexate or 2 g/day of sulphasalazine for 18 months. Bone mineral density of the lumbar spine, femoral neck, and trochanter was measured using dual-energy X-ray absorptiometry (DEXA). Biochemical studies included serum calcium, phosphorus, total alkaline phosphatase, beta-2 microglobulin, parathyroid hormone and 25-hydroxyvitamin D(3) concentrations, spot urinary calcium, and 24-h urinary calcium excretion. Disease activity was assessed by modified disease activity score (DAS 28), and functional impairment was estimated by the Health Assessment Questionnaire.

No significant difference in BMD of the lumbar spine, femur neck, or trochanter was observed at 18 months in either group. There was also no significant change in the biochemical parameters of both groups.

Our findings suggest that low-dose methotrexate has no negative effect on BMD in premenopausal RA patients.