Objective

Test the hypothesis that soy isoflavone supplementation preserves bone mineral density (BMD) in men and women.

Methods

We conducted a controlled, parallel-arm, double-blinded trial with 145 participants, 50-80 years, with random assignment to soy beverage daily for 12 months. Active treatment (+ISO) received soy protein containing 83 mg isoflavones (45.6 mg genistein, 31.7 mg daidzein), aglycone units; the comparison group (-ISO) received soy protein containing 3mg isoflavones. We measured BMD using dual-energy X-ray absorptiometry at the total hip and posterior-anterior spine (L1-L4) at baseline in 22 women and 123 men, and at 12 months in 13 women and 98 men. We used linear mixed models to test for an isoflavone effect on percentage BMD change from baseline in spine and hip.

Results

Among all participants, mean percent change in spine BMD (+/-S.E.) was 0.16+/-0.44 in -ISO (P=0.10) at 12 months. Treatment effects on spine BMD were significantly greater in women than men (P=0.01). At 12 months, in women, mean percent change was 0.58+/-0.70 in +ISO and -1.84+/-0.86 in -ISO (P=0.05); among men it was 1.32+/-0.53 in +ISO and 0.31+/-0.48 in -ISO (P=0.16). By comparison, percent change in hip BMD was similar in the treatment groups, and was not different between men and women. Mean percent change in hip BMD from baseline to 12 months was 0.54+/-0.38 in +ISO and -0.13+/-0.36 in -ISO (P=0.20) among all participants.

Conclusions

Soy protein containing isoflavones showed a modest benefit in preserving spine, but not hip BMD in older women.

To examine preventive health practices in older women, we conducted computer-assisted telephone interviews with 1082 women aged 50-80 who were enrollees of Group Health Cooperative of Puget Sound (June-November 1995; 80.3% response rate). We sought to describe the women's reasons for initiating, discontinuing, or not initiating hormone replacement therapy (HRT). HRT use was categorized as current (42.5%), past (20.9%), or never (36.6%) based on the interviews. The reasons most frequently cited by current users for initiating HRT were menopausal symptoms (47.3%), osteoporosis prevention (32.4%), and physician advice (30.3%). The most frequently cited reasons for quitting HRT were side effects (26.6%), physician's advice (22.9%), fear of cancer (15.4%), and not wanting menstrual periods or bleeding (15.2%). Of past users, 53.8% reported stopping HRT on their own, and 46.2% did so at their physician's advice. The reasons most commonly cited by never users for not initiating HRT were that hormones were not needed (49.9%) and that menopause is a natural event (17.9%). Among never users, 33.1% reported considering HRT, only 46.6% discussing it with their provider, and 5.0% being given an HRT prescription they did not fill. Many women made decisions about HRT independent of interactions with health care providers. Better understanding of the beliefs and decisions that influence women's choice to use or not use HRT is needed to develop more effective counseling strategies.

Objective

To ascertain the sources of information women use when making decisions about hormone replacement therapy (HRT).

Methods

A cross-sectional, population-based computer-assisted telephone survey of 1082 randomly selected women aged 50-80 years (80.3% response rate) was conducted at Group Health Cooperative of Puget Sound, a large staff-model health maintenance organization in Washington state.

Results

Overall, 460 participants (42.5%) were current HRT users, 226 (20.9%) were past users, and 396 (36.6%) were never users. Discussions with physicians dominated as the major source of information used in decision making by current (83.4%) and past (65.5%) users, but were less often cited by never users (44.4%); printed material was used by 44.5% of women. Although 72.1% of current users reported that the amount of information received from their physician about the benefits of HRT was about right, only 48.2% of past users and 33.6% of never users shared this view (P < .001 current versus never), and 13.3% of current users, 32.6% of past users and 58% of never users reported receiving no information from their physician about HRT's benefits.

Conclusion

Hormone replacement therapy use is strongly related to interactions between women and their physicians. Many women use written materials to make decisions about HRT. A large proportion of women feel inadequately informed about HRT's risks and benefits. Much work remains to be accomplished toward meeting the goal of the US Preventive Services Task Force that all perimenopausal and postmenopausal women be counseled about the potential benefits and risks of HRT.