The Comparison of Tibolone and Hormone Replacement Therapy on Bone Densitometry and Bone Turnover in Postmenopausal Women

Osteoporosis is a prevalent disease related to menopause, and causes an increasing health problem. Our aim was to compare the effects of conventional estrogen replacement therapy and tibolone on the bone mineral density (BMD) and bone turn over in postmenopausal women. A total of 150 healthy non-surgical postmenopausal women in Iran were enrolled in a randomized controlled clinical trial. Fifty women received 2.5 mg tibolone plus one calcium + D tablet (500 mg Ca and 200 IU vitamin D) daily; 50 women received 0.625 mg conjugated equine estrogen and 2.5 mg medroxy progesterone acetate (CEE/MPA) plus one calcium + D tablet daily; 50 women received only one calcium + D tablet and served as a control group. Bone densitometry (DAX) of the lumbar spine and the proximal femoral neck and also bone turnover markers (serum alkaline phosphates (ALP) and urine Ca/Cr ratio) measured at baseline and after the nine months of entering into the study. After the treatments, ALP reduced significantly in the CEE/MPA and tibolone groups (P = 0.02, P = 0.002), but increased in the control group (P = 0.03) in comparison with the baseline. After the treatments with respect to femoral BMD, significantly increase occurred only in the tibolone group in comparison with the baseline (0.95 ± 0.13, 0.97 ± 0.12, P = 0.004). Tibolone may be considered as an alternative for preventing of osteoporosis in postmenopausal women.