Bone density changes during two years treatment with tibolone or conjugated estrogens and norgestrel, compared with untreated controls in postmenopausal women

Objective: To quantify and compare the effect of two different hormone repl acement therapy regimens on bone mineral density (BMD) and serum alkaline p hosphate levels against a group of no treatment control volunteers. Methods: An open 104-week comparative study of 113 early postmenopausal wom en. Fifty volunteered for the no treatment arm; the remainder were randomiz ed to tibolone (T) (n = 32) or conjugated estrogens plus sequential norgest rel (CEEP) (n = 31). BMD was measured at baseline and after 48 and 96 weeks by dual photon absorptiometry. Results: Baseline BMD was lower in nontherapy controls and with women assig ned to CEEP compared with the T group. Statistical significance was not rea ched. By 96 weeks, increased BMD was observed with both therapies at all si tes, whereas controls had lost bone compared with baseline. Changes from ba seline with both preparations were significantly different (p < 0.05) from changes in controls for all sites, except femoral neck where the change was significant only with CEEP (p < 0.05). Alkaline phosphatase was significan tly reduced in both treatment groups compared with controls (p < 0.05) at 4 8 and 96 weeks. Conclusions: The significant increases in BMD with T and CEEP confirm both regimens are effective in preventing osteoporosis. Without treatment, BMD d eclines postmenopausally. (Menopause 2000;7:327-333. (C) 2000, The North Am erican Menopause Society.).