To investigate the effects of tibolone on trabecular and cortical bone mineral density and on indices of calcium metabolism in postmenopausal women with previous fractures.Methods
In a 2-year, randomized, double-blind, placebo-controlled, bicenter study, 45 women were treated with tibolone and 43 with placebo. All subjects received 800 mg of calcium daily. Trabecular bone mineral density of lumbar spine (LI to L4) and cortical bone mass at the femoral neck were assessed by dual energy x-ray absorptiometry at baseline and at 6-month intervals. Serum and urinary bone biochemistry variables were also assessed.Results
After 2 years, subjects in the tibolone group gained 6.9% bone mass at lumbar spine and 4.5% at femoral neck, and respective increases from baseline in the placebo group were 2.7% and 1.4%. Tibolone-treated patients gained statistically significantly more bone mass than placebo-treated patients in the spine and femur. Urinary calcium: creatinine and hydroxyproline:creatinine ratios, as well as serum alkaline phosphatase and phosphate levels, were significantly reduced with tibolone compared with placebo.Conclusion
Tibolone induced a significant increase in trabecular (lumbar spine) and cortical (femoral neck) bone mass in postmenopausal osteoporotic women compared to placebo, suggesting its potential to treat postmenopausal osteoporosis.