Nutrition and Wellness Research Center, Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50010-8281, USA.
Am J Clin Nutr. 2010 Jan;91(1):218-30. doi: 10.3945/ajcn.2009.28306. Epub 2009 Nov 11.
Our previous study indicated that soy protein with isoflavones lessened lumbar spine bone loss in midlife women.
We examined the efficacy of isoflavones (extracted from soy protein) on bone mineral density (BMD) in nonosteoporotic postmenopausal women. We hypothesized that isoflavone tablets would spare BMD, with biological (age, body weight, serum 25-hydroxyvitamin D) and lifestyle (physical activity, dietary intake) factors modulating BMD loss.
Our double-blind, randomized controlled trial (36 mo) included healthy postmenopausal women (aged 45.8-65.0 y) with intent-to-treat (n = 224) and compliant (n = 208) analyses. Treatment groups consisted of a placebo control group and 2 soy isoflavone groups (80 compared with 120 mg/d); women received 500 mg calcium and 600 IU vitamin D(3). Outcomes included lumbar spine, total proximal femur, femoral neck, and whole-body BMD.
Analysis of variance for intent-to-treat and compliant (> or =80%) models, respectively, showed no treatment effect for spine (P = 0.46, P = 0.21), femur (P = 0.86, P = 0.46), neck (P = 0.17, P = 0.14), or whole-body (P = 0.86, P = 0.78) BMD. From baseline to 36 mo, BMD declined regardless of treatment. In intent-to-treat and compliant models, respectively, BMD decreases were as follows: spine (-2.08%, -1.99%), femur (-1.43%, -1.38%), neck (-2.56%, -2.51%), and whole body (-1.66%, -1.62%). Regression analysis (compliant model) indicated that age, whole-body fat mass, and bone resorption were common predictors of BMD change. After adjustment for these factors, 120 mg (compared with placebo) was protective (P = 0.024) for neck BMD. We observed no treatment effect on adverse events, endometrial thickness, or bone markers.
Our results do not show a bone-sparing effect of extracted soy isoflavones, except for a modest effect at the femoral neck. This trial was registered at clinicaltrials.gov as NCT00043745.
我们之前的研究表明，富含异黄酮的大豆蛋白可减少中年女性的腰椎骨丢失。
我们研究了异黄酮（从大豆蛋白中提取）对非骨质疏松绝经后妇女骨密度（BMD）的疗效。我们假设异黄酮片会防止 BMD 丢失，而生物（年龄、体重、血清 25-羟维生素 D）和生活方式（体力活动、饮食摄入）因素会调节 BMD 丢失。
我们的双盲、随机对照试验（36 个月）包括有意愿接受治疗（n=224）和依从性（n=208）分析的健康绝经后妇女（年龄 45.8-65.0 岁）。治疗组包括安慰剂对照组和 2 个大豆异黄酮组（80 与 120mg/d）；女性每天接受 500mg 钙和 600IU 维生素 D3。结果包括腰椎、全近端股骨、股骨颈和全身 BMD。
意向治疗和符合率（>或=80%）模型的方差分析分别显示，脊柱（P=0.46，P=0.21）、股骨（P=0.86，P=0.46）、颈（P=0.17，P=0.14）或全身（P=0.86，P=0.78）BMD 无治疗效果。从基线到 36 个月，无论治疗与否，BMD 都在下降。意向治疗和符合率模型中，BMD 下降如下：脊柱（-2.08%，-1.99%）、股骨（-1.43%，-1.38%）、颈（-2.56%，-2.51%）和全身（-1.66%，-1.62%）。回归分析（符合率模型）表明，年龄、全身脂肪量和骨吸收是 BMD 变化的共同预测因素。在调整这些因素后，120mg（与安慰剂相比）对颈 BMD 有保护作用（P=0.024）。我们没有观察到治疗对不良事件、子宫内膜厚度或骨标志物的影响。
我们的结果并没有显示出提取大豆异黄酮对骨骼有保护作用，除了对股骨颈有适度的影响。该试验在 clinicaltrials.gov 上注册为 NCT00043745。
