Calcium Foods and Bone Health of Adolescent Girls

描述（由申请人提供）：骨质疏松症是一种主要的健康问题。年轻时骨骼的最佳发育对预防骨质疏松症至关重要，骨质疏松症是一种由于骨量和骨质量减少而导致晚年骨折的疾病。如果骨骼发育可以在成长过程中最大化，年轻人将以最佳的骨骼健康开始成年，并且在以后的岁月中不太可能患骨质疏松症。然而，年轻人的骨骼健康问题还没有得到充分的解决。在这个应用中，我们建议延长我们对高钙饮食对青春期女孩骨质量影响的四年干预研究。本实验研究的目的是测试将膳食钙摄入量增加到1500毫克/天对青春期女性骨质量增加的影响。要测试的假设是：通过密度测量和超声波测量，摄入高钙饮食的青春期女性比摄入正常饮食的青春期女性骨骼质量有更大的提高。该研究采用了一种实验设计，其中58名参与者（26名治疗组和32名对照组）将被额外随访4.5年，总计8.5年。参与者是一个方便的样本，他们在登记时年龄为9岁。治疗组的女孩将继续摄入至少1500毫克/天的高钙食物，而对照组的女孩将被要求继续摄入正常的饮食。在基线、每六个月和研究结束时进行的测量包括身高、体重、坦纳病分期、病史和社会史。通常的体育活动和饮食摄入量将每三个月确定一次。下一个周期的项目资助将使我们能够持续跟踪这些年轻女性从9岁到18.5岁。据我们所知，这将是第一个评估最佳钙摄入量在骨量和骨质量最高时期对骨骼健康影响的干预措施。这群热情的青少年参与者给了我们信心，我们可以成功地完成这个雄心勃勃的项目。从食物中增加钙摄入量对青春期女性骨骼质量有积极影响的证据将为针对青春期女性、父母和护理人员的教育努力提供强有力的支持。阴性结果将为进一步研究其他最大化骨骼发育的伴随方法提供支持。

DESCRIPTION (provided by applicant): Osteoporosis is a major health problem. Optimum development of the skeleton during youth is crucial in prevention of osteoporosis, a condition that fractures bone late in life because of reduced bone mass and bone quality. If skeletal development can be maximized during growth, young people will begin adulthood with optimal bone health and be less likely to develop osteoporosis in later years. Yet bone health in youth has not been adequately addressed. In this application, we propose to extend our four-year intervention study of the effects of a high calcium diet on bone quality in pubertal girls. The aim of this experimental study is to test the effect of increasing dietary calcium intake to 1500 mg/day on increases in bone quality in adolescent females. The hypothesis to be tested is: adolescent females who consume a high calcium diet will have a greater increase in bone quality, as measured by densitometry and ultrasound, then adolescent females who consume their usual dietary calcium intake. The study uses an experimental design in which 58 participants (26 treatment and 32 control) will be followed for an additional 4.5 years for a total of 8.5 years. Participants are a convenience sample who were age 9 when enrolled. Girls in the treatment group will continue to be given high calcium foods to supply at least 1500 mg/day while girls in the control group will be asked to continue consuming their usual diet. Measurements to be made at baseline, every six months, and at the end of the study include height, weight, Tanner stage, and medical and social history. Usual physical activity and dietary intake will be determined every three months. Funding of this project in the next cycle would enable us to follow these young females continuously from age 9 to age 18.5. To our knowledge, this would be the first intervention to evaluate the effects of optimal calcium intake on bone health through out the period of highest bone mass and bone quality accrual. This enthusiastic group of adolescent participants provides us with confidence that we can successfully complete this ambitious project. Evidence of a positive effect of increased calcium intake from food sources on bone quality in adolescent females would provide strong support for educational efforts targeted at adolescent females, parents and care providers. Negative findings would provide support for further research into other methods of concomitant methods of maximizing skeletal development.