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 replacement therapy regimens on bone mineral density (BMD) and serum alkaline phosphate levels against a group of no treatment control volunteers.


METHODS
An open 104-week comparative study of 113 early postmenopausal women. Fifty volunteered for the no treatment arm; the remainder were randomized to tibolone (T) (n = 32) or conjugated estrogens plus sequential norgestrel (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 assigned to CEEP compared with the T group. Statistical significance was not reached. By 96 weeks, increased BMD was observed with both therapies at all sites, whereas controls had lost bone compared with baseline. Changes from baseline 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 significantly reduced in both treatment groups compared with controls (p < 0.05) at 48 and 96 weeks.


CONCLUSIONS
The significant increases in BMD with T and CEEP confirm both regimens are effective in preventing osteoporosis. Without treatment, BMD declines postmenopausally.
Milner
M
M
Department of Obstetrics and Gynaecology, Cavan General Hospital, Ireland.
Harrison
R F
RF
Gilligan
E
E
Kelly
A
A
D000469:Alkaline Phosphatase / Q000097:blood; D015519:Bone Density / Q000187:drug effects*; D004966:Estrogens, Conjugated (USP) / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D008875:Middle Aged; D009644:Norgestrel / Q000494:pharmacology* / Q000627:therapeutic use; D009652:Norpregnenes / Q000494:pharmacology* / Q000627:therapeutic use; D015663:Osteoporosis, Postmenopausal / Q000517:prevention & control*
D004966:Estrogens, Conjugated (USP); D009652:Norpregnenes; D009644:Norgestrel; D000469:Alkaline Phosphatase; C027385:tibolone