Bone density changes in postmenopausal women with the administration of ipriflavone alone or in association with low-dose ERT

Abstract

Ipriflavone is a synthetic flavonoid that has been shown to exert a direct inhibitory effect on osteoclastic activity and possibly stimulate the osteoblast activity in different experimental models. The aim of the present study was to evaluate the effects of either ipriflavone alone or ipriflavone plus low dose hormone replacement therapy (HRT) in the prevention of postmenopausal bone loss. Patients were randomly allocated to different treatment groups receiving calcium (500 mg/day, control group), continuous HRT (25 or 50 micrograms/day of transdermal 17 beta-estradiol) plus medrogestone 5 mg/day for 12 days/month, ipriflavone at the standard dose of 600 mg/day, or finally ipriflavone 600 mg/day plus 17 beta-estradiol 25 micrograms/day plus medrogestone 5 mg/day for 12 days/month. No significant differences in basal levels of biochemical markers of bone turnover or in basal bone mineral density (BMD) values were evident in the different groups. In the control group after 12 months, spine BMD showed a significant (p < 0.05) 3.41% decrease. The pattern of BMD modification was significantly different from controls in the high dose HRT group (+1.84%), the ipriflavone group (+0.11%), and the combined ipriflavone/HRT group (-0.22%). Conversely, the BMD pattern in the low dose HRT group (-0.55%) was similar to that observed in controls. Thus, present results confirm that ipriflavone and 50 micrograms/day of transdermal 17 beta-estradiol are effective measures in the prevention of postmenopausal osteopenia. A lower transdermal estrogen dose is unable to increase the antiresorptive effect of ipriflavone and did not exert any further action in the prevention of postmenopausal osteopenia.