Association of tibolone and fluoride displays a pronounced effect on bone mineral density in postmenopausal osteoporotic women

A double-blind, placebo-controlled, randomized, prospective two-center stud y was carried out to assess the effects of tibolone + fluoride versus place bo + fluoride therapy on trabecular and cortical bone in postmenopausal ost eoporotic women. Ninety-four subjects (mean age 61.1 years, postmenopausal 13.5 years on average) with low bone mineral density (BMD) at baseline were randomized to 2.5 mg of tibolone (Org OD14, Livial (R)) plus 26.4 mg of fl uoride (Fluocalcic (R)) or placebo plus 26.4 mg of fluoride daily over 2 ye ars; 55 (58.5%) subjects completed the study, the main reason for discontin uation being untoward gastrointestinal effects. BMD at the lumbar spine was measured by both dual photon absorptiometry (DPA) and dual-energy X-ray ab sorptiometry (DXA), and at the hip by DXA at 6-month intervals. Baseline va lues (DXA, g/cm(2)) for tibolone + fluoride and placebo + fluoride groups w ere 0.733 and 0.744 for the lumbar spine, and 0.761 and 0.788 for the hip. Change from baseline and percentage change from baseline were calculated fo r the intent-to-treat and completers groups. An analysis of variance (ANOVA ) model or Wilcoxon test was used for statistical evaluation. There was a m ean increase in BMD at the lumbar spine measured by DPA of 25.3% and 12.3% in tibolone + fluoride and placebo + fluoride groups, respectively (p = 0.0 1); with DXA, respective changes were 32.6% and 14.0% (p = 0.013). Data on BMD at the hip showed mean increases of 7.9% and 2.6% for the tibolone + fl uoride and placebo + fluoride groups, respectively. We conclude that combin ed tibolone + fluoride treatment induces a highly significant increase in B MD at the lumbar spine without simultaneous loss of the cortical bone allow ing for a meaningful reduction of the fluoride dose when given in combinati on with tibolone.