Purpose: To compare the bone-mass effects of intermittent cyclic etidronate administration in patients of various rheumatic disease patients with corticosteroid-induced osteoporosis.
Patients and methods: We evaluated bone mineral density (BMD) of lumbar spine in 34 female patients (mean age: 46.4 +/- 13.7 y. o. 17-71) treated with long term corticosteroid (> 6 months). Eighteen patients cyclically received etidronate orally (400 mg or 200 mg etidronate daily for 2 weeks, followed by 10-12 weeks drug-free periods). Twelve in these 18 patients received 400 mg (group A) and another 6 patients were treated with 200 mg/day (group B). Sixteen patients free from etidronate administrations were analysed as a control group.
Results: Cyclical etidronate therapy showed significant increase in BMD. The BMD of lumbar spine increased from 0.760 +/- 0.10 g/cm 2 to 0.783 +/- 0.11 g/cm 2 (%change from baseline 2.91 +/- 2.56%/year) in group A treated patients after 12 months. Reduced BMD (%change from baseline 1.55 +/- 2.48%) was observed in 16 control group patients (P < 0.0012). The BMD in group A was significantly high compared to group B or control after the etidronate treatment. In 7 of group A, BMD increased significantly on 6 months but no more significant increase was shown on 12 months compared to the value on 6 months. On the other hand the BMD tend to increased for after 2 years in intermittent cyclic etidronate treatment in 8 cases of group A. There were no adverse effects and abnormal laboratory data related to the administration of etidronate. Although only 2 cases of group A showed the findings of compression fracture before the study, but no new compression fracture appeared in any group during this study.
Conclusion: It was shown that cyclical etidronate therapy is effective for steroid induced osteoporosis.