Effect of Intermittent Cyclical Etidronate Therapy on Corticosteroid Induced Osteoporosis in Japanese Patients with Connective Tissue Disease: 3 Year Followup

Objective. A 3 year prospective randomized study was conducted to clarify the efficacy of intermittent cyclical etidronate therapy on corticosteroid induced osteoporosis. Methods. A group of 102 Japanese patients were enrolled, each taking > 7.5 mg of prednisolone daily for at least 90 days. Patients were randomly divided into 2 treatment groups: Group E (etidronate) took 200 mg etidronate disodium per day for 2 weeks with 3.0 g calcium lactate and 0.75 μg alphacalcidol daily; Group C (control) took 3.0 g calcium lactate and 0. 75 μg alphacalcidol daily. Outcome measurements included changes from baseline in bone mineral density (BMD) of the lumbar spine and the rate of new vertebral fractures at 48 and 144 weeks. Results. The mean (± SD) lumbar spine BMD increased 3.7 ± 5.6% (p < 0.01) and 1.5 ± 4.1% (NS) from baseline at 48 weeks and 4.8 ± 6.9% (p < 0.005) and 0.4 ± 5.0% (NS) from baseline at 144 weeks in Group E and Group C, respectively. The improvement of BMD in Group E was significantly greater than in Group C at 144 weeks (p < 0.01). In 3 subgroups, men and premenopausal and postmenopausal women, the postmenopausal women showed the greatest improvement. Mean percentage change in this subgroup was 10.1 ± 8.0% and 1.35 ± 6. 4% in Group E and Group C, respectively. We noted that 2 patients in Group C had new vertebral fractures, whereas no fractures were observed in Group E. Conclusion. These results indicate that intermittent cyclical etidronate therapy is effective for the prevention and treatment of corticosteroid induced osteoporosis in patients with connective tissue diseases.