Navajo Bone Health Study

描述（由申请人提供）：纳瓦霍族骨骼健康研究旨在开始对纳瓦霍族的骨骼健康进行监测。这些努力将及时使纳瓦霍民族能够计划筛查和文化上适当的教育和干预计划，针对那些最有可能骨折或骨质疏松症的人群。具体来说，我们假设纳瓦霍印第安人的骨密度（总骨矿物质密度（BMD）以及髋部和腰椎的骨密度）与高加索人不同。我们将通过使用双能x射线吸收仪（DXA）和足跟超声（宽带超声衰减（BUA）和声速（SOS）以及刚度指数（SI））测量骨密度（BMD）来检验这一假设，并将分布和z分数与NHANES III数据库中按年龄和性别分组的高加索人的分布和z分数进行比较。我们的目的是验证脚跟超声在纳瓦霍印第安人骨骼健康筛查中的应用，并为该人群的转诊创建临床相关的截止值。我们将研究报道的成人骨折与骨密度测量（DXA和BUA）之间的关系

DESCRIPTION (provided by applicant): The Navajo Bone Health Study aims to begin surveillance of bone health on the Navajo Nation. These efforts will in time enable the Navajo Nation to plan screening and culturally appropriate education and intervention programs targeted towards the segments of the population who are at greatest risk for fracture or osteoporosis. Specifically, we hypothesize that bone density (total bone mineral density (BMD), and BMD at the hip and lumbar spine) will be different in Navajo American Indians than Caucasians. We will examine this hypothesis by measuring bone mineral density (BMD) using dual energy x-ray absorptiometry (DXA) and heel ultrasound (broadband ultrasound attenuation (BUA) and speed of sound (SOS) as well as stiffness index (SI)) compare distributions and z-scores with those reported for Caucasians in the NHANES III database by age and gender groups. We aim to validate the use of heel ultrasound for bone health screening in Navajo Native Americans and create clinically relevant cutoffs for referral in this population. We will examine the association of reported adult fractures with BMD measures (DXA and BUA) to relate these measures to a relevant public health outcomes. In addition we will examine the association of body size, diet (nutrients relevant to bone formation including calcium, vitamin D, Vitamin A and protein), and lifestyle (physical activity) factors to and BMD in Navajo adults and children over the age of 18. Data will be collected in a cross-sectional design coincident with the Navajo EARTH cohort study. DXA will be measured in 1296 randomly selected Navajo men and women. We will select 112 men and 112 women in four 10 year age groups (30-39,40-49,50-59, and 60 and older) to assure that we can adequately estimate BMD in each of these gender specific age groups separately. Heel ultrasound will be measured in approximately 2500 Navajo men and women and associations with BMD measured using DXA, reported adult fractures, and diet and lifestyle factors will be explored. This study is an important first step in surveillance of bone health of Navajo American Indians and make efficient use of the Navajo EARTH Cohort Study which is currently in the field.