Effects of two doses of tibolone on trabecular and cortical bone loss in early postmenopausal women: a two-year randomized, placebo-controlled study.
The present randomized, double-blind, placebo-controlled, 2-year study is the first to evaluate the effect of 1.25 and 2.5 mg tibolone daily oral administration on trabecular and cortical bone loss in early postmenopausal women. Ninety-four healthy, normal weight, nonsmoking women participated 1-3 years following spontaneous menopause. Twenty-three subjects were randomized to the placebo group, 36 to the 1.25 mg/day tibolone group, and 35 to the 2.5 mg/day tibolone group. Bone density was assessed at 6 month intervals. Spinal trabecular bone density (BD) was measured with quantitative computed tomography. Phalangeal cortical BD was measured by radiographic absorptiometry. The 2-year change vs. baseline in the placebo group for trabecular BD was -6.4% (95% confidence interval -8.1 to -4.7). Cortical BD did not change significantly. At 24 months both tibolone groups showed a statistically significantly higher trabecular [9.4% (6.6-12.2) for the 1.25 mg group and 14.7% (11.8-17.5%) for the 2.5 mg group] and phalangeal BD [4.4% (1.5-7.4) for the 1.25 mg group and 6.8% (3.8-9.8) for the 2.5 mg group] as compared to the placebo group. After 2 years of tibolone in both regimes, trabecular and phalangeal BD was significantly higher as compared to pretreatment values. At 24 months the 2.5 mg group showed a significantly higher trabecular (p < 0.001) but not phalangeal (p = 0.064) BD compared to the 1.25 mg group. Tibolone prevents early postmenopausal bone loss by inducing an increase in trabecular and phalangeal BD.
Department of Obstetrics and Gynaecology, Dijkzigt Academic Hospital, Rotterdam, The Netherlands.
B
B
Berning
C V
CV
Kuijk
J W
JW
Kuiper
H J
HJ
Bennink
P M
PM
Kicovic
B C
BC
Fauser
D015502:Absorptiometry, Photon; D045930:Anabolic Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000187:drug effects*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D009652:Norpregnenes / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy / Q000517:prevention & control*
D045930:Anabolic Agents; D015415:Biomarkers; D009652:Norpregnenes; C027385:tibolone