Double-blind, placebo-controlled study of the effects of tibolone on bone mineral density in postmenopausal osteoporotic women with and without previous fractures

A 2-year placebo-controlled, randomized, two-center prospective study was c arried out to assess the effects of tibolone (Org OD14, Livial(R)) on trabe cular and cortical bone mass and bone biochemistry parameters in elderly po stmenopausal women with and without previous fractures. In total, 107 subje cts, 71 with fractures and 36 without fractures, were randomized to tibolon e (n = 64) or placebo (n = 43). Their mean age was 63.1 years. Bone mineral density (BMD) (g/cm(2)) was assessed at baseline and every 6 months for 2 years by dual-energy X-ray absorptiometry (DXA). Mean baseline values were 0.79 and 0.80 for the lumbar spine in the tibolone 0.64 in both groups. Ser um and urinary bone biochemistry parameters were measured concurrently. An analysis of variance (ANOVA) model including center and group was applied. The completers' group was the primary subset for the analysis; the intentio n-to-treat (ITT) group was also analyzed. Results are expressed as the perc entage change at 24 months and the annual rate of change percentage year. T he tibolone group showed an overall mean increase (vs. placebo) in BMD at t he lumbar spine of 7.2% (p < 0.001) and for the femoral neck 2.6% (p < 0.00 1). In subjects with previous fractures increases neck, while in those with no fractures, respective changes were 8.9% and 1.1%. Overall changes in th e placebo group were 0.9% and -1.6% for the lumbar spine and femoral neck, respectively. A significant fall in bone biochemistry parameters showed tha t tibolone inhibits osteoclastic activity. In conclusion we have found that tibolone 2.5 mg induces significant increases of trabecular and cortical b one mass in elderly postmenopausal osteoporotic women with and without prev ious fractures.