Is addition of sodium fluoride to cyclical etidronate beneficial in the treatment of corticosteroid induced osteoporosis?

OBJECTIVE To investigate whether administration of sodium fluoride (NaF) in addition to cyclical etidronate has a positive effect on bone mineral density (BMD) in patients with established osteoporosis during continued treatment with corticosteroids. PATIENTS AND METHODS 47 patients who were receiving treatment with corticosteroids were included in a two year randomised, double blind, placebo controlled trial. Established osteoporosis was defined as a history of a peripheral fracture or a vertebral deformity, or both, on a radiograph. All patients were treated with cyclical etidronate, calcium, and either NaF (25 twice daily) or placebo. Vitamin D was supplemented in the case of a low serum 25 (OH) vitamin D concentration. BMD of the lumbar spine and hips was measured at baseline and at 6, 12, 18, and 24 months. RESULTS After two years of treatment, the BMD of the lumbar spine in the etidronate/NaF group had increased by +9.3% (95% confidence intervals (CI): +2.3% to +16.2%, p < 0.01), while the BMD in the etidronate/placebo group was unchanged: +0.3% (95% CI: -2.2% to +2.8%). The difference in the change in BMD between groups was +8.9% (95% CI: +1.9% to +16.0%, p < 0.01). For the hips, no significant changes in BMD were observed in the etidronate/NaF group after two years: -2.5% (95% CI: -6.8% to +1.8%); in the etidronate/placebo group BMD had significantly decreased: -4.0% (95% CI: -6.6% to -1.4%; p < 0.01). The difference between the groups was not significant: +1.5% (95% CI: -3.4% to +6.4%). No significant differences in number of vertebral deformities and peripheral fractures were observed between the two groups. CONCLUSION The effect of combination treatment with NaF and etidronate on the BMD of the lumbar spine in corticosteroid treated patients with established osteoporosis is superior to that of etidronate alone.