Effects of 8 years of treatment with tibolone 2.5 mg daily on postmenopausal bone loss

The objective of this study was to assess the long-term effects of tibolone 2.5 mg daily (Livial(R) Organon) on bone mineral density In recently postm enopausal women. An 8-year, open, nonrandomized, prospective study was desi gned to compare the effects of tibolone 2.5 mg daily (n = 59) with an untre ated control group (n = 51). The subjects of this study were 110 recently p ostmenopausal women (6-36 months since last menstrual period). The main out come measures were hone mineral density of the spine and femur, measured by duel-energy X-ray absorptiometry, and assessment of biochemical markers of bone metabolism. After 8 years of tibolone use, the mean (+/- SEM) increas e in bone mineral density compared with baseline was 4.1% +/- 0.8% (p<0.000 1) in the spine and 4.6% +/- 1.8% (P = 0.015) in the femoral neck. Over the same period, bone mineral density In the control group decreased in the sp ine by -7.5% +/- 1.1%, (p<0.0001) and in the femur by -6.7% +/- 1.2% (p<0.0 001). The bone resorption marker, calcium/creatinine ratio, decreased in th e tibolone group but not in the control group. Serum bone formation markers decreased (alkaline phosphatase) or stayed approximately the same (osteoca lcin) in the tibolone group. Adherence was high, with 58% (34 of 59) of the tibolone group continuing treatment far 8 years. We conclude that tibolone 2.5 mg daily prevents bone lass in the lumbar spine and femoral neck over 8 years and adherence to treatment is high. The greater bone density compar ed with untreated women would be expected to reduce the risk of bone fractu res.