Soy Proteins and Isoflavones Impact Bone Mineral Density in Older Women
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 发起方
- 入组人数
- 97
- 试验地点
- 2
- 主要终点
- Bone turnover markers
研究概览
简要总结
The purpose of this study is to test the effect of 1 year of added dietary soy protein and/or soy isoflavones on bone mineral density in late postmenopausal women.
详细描述
Although soy foods contain several components (isoflavones and amino acids) that could potentially have positive effects on bone health, there are few long term, large, clinical trials using soy as a means of improving bone mineral density. The objective of this study is to provide daily soy protein and isoflavones to healthy older women in order to answer three major questions:
- Does soy protein alone affect bone metabolism?
- Do isoflavones, given with soy protein, affect bone metabolism?
- What dose of isoflavones affects bone in older women?
We hypothesize that soy protein will have a beneficial effect on bone in older women compared to control protein. Further, we hypothesize that there will be an additional benefit to bone in women who receive soy protein plus isoflavones (at both doses) compared to soy protein alone.
Both control and soy proteins used in the study were isolates, meaning they were the highest concentration of protein (85-90% by weight) in order to minimize the volume of protein supplement that each woman was asked to ingest on a daily basis. The soy protein was an alcohol-washed, soy protein isolate containing 90% protein and negligible isoflavone (0.2 mg/g product). The control protein was a mix consisting of 50% protein from sodium caseinate, 25% protein from whey protein and 25% from egg white protein. The use of a mix of proteins as a control provides a more balanced level of amino acids, mimics the real life mix of proteins that humans typically consume, and avoids the unique characteristics of one source of protein. In order to maintain the dietary protein intake constant, the participant was counseled to decrease her intake of other sources of protein from primarily animal sources by approximately 3 ounces per day (the approximate equivalent of the protein powders). The isoflavones tablets each contained 57 mg of total isoflavone from primarily genistein, glycitein, and daidzein and their beta-glycosides.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Factorial
- 主要目的
- Treatment
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 65 Years 至 —（Older Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Postmenopausal women 65 years old or older
- •Able to travel to the clinical sites for follow-up visits
排除标准
- •History of disease that may affect bone metabolism (including Paget's disease, primary hyperparathyroidism, osteomalacia, untreated hyperthyroidism, or multiple myeloma)
- •Cancer of any kind (except basal or squamous cell of skin) in past 5 years
- •Use of any of the following medications within the past 2 years: calcitonin, calcitriol, heparin, phenytoin, phenobarbital
- •Use at any time of bisphosphonates, long-term corticosteroids (over 6 months), methotrexate, or fluoride
- •Estimated creatinine clearance less than 50 ml/min
- •History of chronic liver disease or evidence of liver disease on screening
- •History of hip fracture
- •Known vertebral fracture within the past year
结局指标
主要结局
Bone turnover markers
时间窗: baseline, 3 months, and 1 year
次要结局
- Bone Mineral Density(Baseline, 6 and 12 months)
- Quality of life measured by Medical Outcomes Short Form(Baseline, 6 and 12 months)
- Medication Side Effects(3 , 6, 9, and 12 months)
- Adherence to dietary intervention through the use of 24-hour recall(3, 6, 9, and 12 months)
- Long-term medication behavior self-efficacy scale(3, 6, 9, and 12 months)