Sodium fluoride prevents bone loss in primary biliary cirrhosis

Low-bone-turnover osteoporosis is a common complication of primary biliary cirrhosis (PBC). Since sodium fluoride stimulates bone formation we assessed the effect of this drug on bone mass in a 2-year, prospective, double-blind trial including 22 women with PBC who were randomly assigned to receive sodium fluoride (50 mg/day) or placebo. All received calcium supplements and low doses of vitamin D. Bone mineral density of the lumbar spine was measured by dual-photon absorptiometry initially and every 6 months. Vertebral fractures were evaluated in thoracic and lumbar spine initially, and after 1 and 2 years. Seven patients in the fluoride group and eight in the placebo group completed the trial. In the fluoride group, bone mineral density did not change after 2 years (initial 1.05 +/- 0.07, final 1.07 +/- 0.06 g/cm2; p = n.s.). In the placebo group, however, bone mineral density decreased significantly (initial 1.00 +/- 0.07, final 0.93 +/- 0.06 g/cm2; p = 0.03). Moreover, in the fluoride group bone mineral density increased by 2.9 +/- 3.6%, and in the placebo group decreased by 6.6 +/- 2.6% (p = 0.04). None of the patients developed new vertebral or non-vertebral fractures. Treatment with sodium fluoride did not impair liver function or cholestasis in PBC. These results indicate that sodium fluoride prevents bone loss in PBC and therefore might be considered as a possible therapeutic agent for osteoporosis associated with this liver disease. Since a small number of patients completed the trial, further studies are required.