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.
Berning
B
B
Department of Obstetrics and Gynaecology, Dijkzigt Academic Hospital, Rotterdam, The Netherlands.
Kuijk
C V
CV
Kuiper
J W
JW
Bennink
H J
HJ
Kicovic
P M
PM
Fauser
B C
BC
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