經兩年的研究,每日服用大豆異黃酮片不能預防骨流失或更年期症狀

 

來源: Archives of Internal Medicine  Vol. 171, No. 15, August 8/22, 2011

http://archinte.ama-assn.org/cgi/content/short/171/15/1363

Soy Isoflavones in the Prevention of Menopausal Bone Loss and Menopausal Symptoms

A Randomized, Double-blind Trial

Silvina Levis, MD; Nancy Strickman-Stein, PhD; Parvin Ganjei-Azar, MD; Ping Xu, MPH; Daniel R. Doerge, PhD; Jeffrey Krischer, PhD

Arch Intern Med. 2011;171(15):1363-1369. doi:10.1001/archinternmed.2011.330

Background  Concerns regarding the risk of estrogen replacement have resulted in a significant increase in the use of soy products by menopausal women who, despite the lack of evidence of the efficacy of such products, seek alternatives to menopausal hormone therapy. Our goal was to determine the efficacy of soy isoflavone tablets in preventing bone loss and menopausal symptoms.

Methods  The study design was a single-center, randomized, placebo-controlled, double-blind clinical trial conducted from July 1, 2004, through March 31, 2009. Women aged 45 to 60 years within 5 years of menopause and with a bone mineral density T score of –2.0 or higher in the lumbar spine or total hip were randomly assigned, in equal proportions, to receive daily soy isoflavone tablets, 200 mg, or placebo. The primary outcome was changes in bone mineral density in the lumbar spine, total hip, and femoral neck at the 2-year follow-up. Secondary outcomes included changes in menopausal symptoms, vaginal cytologic characteristics, N -telopeptide of type I bone collagen, lipids, and thyroid function.

Results  After 2 years, no significant differences were found between the participants receiving soy tablets (n = 122) and those receiving placebo (n = 126) regarding changes in bone mineral density in the spine (–2.0% and –2.3%, respectively), the total hip (–1.2% and –1.4%, respectively), or the femoral neck (–2.2% and –2.1%, respectively). A significantly larger proportion of participants in the soy group experienced hot flashes and constipation compared with the control group. No significant differences were found between groups in other outcomes.

Conclusions  In this population, the daily administration of tablets containing 200 mg of soy isoflavones for 2 years did not prevent bone loss or menopausal symptoms.

Trial Registration  clinicaltrials.gov Identifier: NCT00076050