MONOFLUOROPHOSPHATE INCREASES LUMBAR BONE-DENSITY IN OSTEOPENIC PATIENTS - A DOUBLE-MASKED RANDOMIZED STUDY

To assess the efficacy of combined sodium monofluorophosphate and calc ium therapy (FC) in increasing lumbar bone mineral density (BMD) in pa tients with low bone mass, we conducted a prospective double-masked ra ndomized study in 94 patients aged 50-70 years. Patients were selected on the basis of a lumbar BMD at least 2 standard deviations (SD) belo w the young adult mean (T-score) but without evidence of previous vert ebral fracture (severe osteopenia). They were randomly assigned to rec eive for 2 years, twice a day, either FC (13.2 mg F-, i.e. 100 mg sodi um monofluorophosphate, and 500 mg Ca2+) or C (500 mg Ca2+). Vertebral BMD was measured by dual photon absorptiometry from L2 to L4. Compari son at final assessment in the 76 eligible patients (Student's t-test) showed a statistically significant difference between the two groups in the mean BMD increase in favour of FC. Furthermore, Student's t-tes t showed a significantly greater increase in lumbar BMD in FC-treated patients at 1 year, at 18 months and after 2 years (mean increase of 7 .1%/year). These results were confirmed by ANOVA at 1 year, at 18 mont hs and after 2 years of treatment. Of the PC-treated patients, 71.4% w ere considered to have responded (i.e. they showed an increase in lumb ar BMD of more than 0.034 g/cm(2)). The dosage of 26.4 mg fluoride ion /day (i.e. 200 mg monofluorophosphate/day) therefore appears to be saf e and to increase the BMD effectively in patients with low bone mass p rior to vertebral fracture.