Obesity and bone development in young girls

年轻女孩的肥胖和骨骼发育

• 批准号: 8416920
• 负责人: Scott B Going
• 金额: $ 52.2万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8416920
• 关键词: 3-Dimensional; Abdomen; Adipose tissue; Adolescence; Adolescent; Adult; Animals; Architecture; Attention; Body Composition; Bone Development; C-reactive protein; Childhood; Chronic; Comorbidity; Conflict (Psychology); Development; Diet; Drug or chemical Tissue Distribution; Epidemic; Equation; Failure; Fasting; Fatty acid glycerol esters; Fracture; Glucose; Glucose Intolerance; Growth; Height; Imaging Techniques; Impairment; Inflammation; Insulin; Insulin Resistance; Intervention; Leg; Life; Link; Magnetic Resonance Imaging; Measures; Mechanics; Metabolic; Methods; Minerals; Modeling; Muscle; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Osteoporosis; Outcome; Overweight; Peripheral; Phase; Physical activity; Physiologic calcification; Prevalence; Prevention strategy; Public Health; Relative (related person); Reporting; Research Personnel; Risk; Risk Factors; Sampling; Site; Skeletal Muscle; Structure; Technology; Thick; Time; Visceral; Weight; Weight-Bearing state; X-Ray Computed Tomography; Youth; abdominal fat; animal data; bone; bone mass; bone strength; cost effective; density; design; girls; indexing; interest; longitudinal design; mineralization; obesity risk; public health relevance; soft tissue; two-dimensional

DESCRIPTION (provided by applicant): Obesity and osteoporosis are major public health concerns. Mounting evidence supports that they are linked. Whereas overweight per se may augment bone mineralization, animal studies and studies in adults suggest that the metabolic impairment that accompanies obesity is detrimental to bone. Obesity during adolescence, a critical time for bone development, likely has profound and lasting effects on bone strength and fracture risk. This notion has received little attention in adolescents and results are mixed, with studies reporting that mineral accrual is enhanced or impaired by obesity. The proposed project is designed to clarify the relationship of obesity, fat distribution (visceral adipose tissue and tigh muscle fat content), insulin resistance (HOMA-IR) and inflammation (hsCRP) with bone mass, density, structure and strength in 450 normal weight, overweight and obese premenarcheal girls. Unlike other studies with surrogates for body composition, we plan to measure soft tissue composition and adipose tissue (AT) distribution directly, using dual energy x-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and peripheral quantitative computed tomography (pQCT). While DXA also provides a measure of whole body bone mineral mass, the primary bone parameters of interest, cortical and trabecular density (vBMD), structure (e.g., cortical thickness, periosteal and endosteal circumferences), and especially strength (strength-strain index; bone strength index), will be measured by pQCT at weight-bearing and non-weight-bearing sites. pQCT provides 3-dimensional estimates of bone parameters that are not confounded by changes in bone size, a significant confounder of most past studies which have relied on 2-dimensional imaging techniques during growth. Fasting levels of insulin, glucose, and C-reactive protein (CRP) will be measured to assess how insulin resistance (HOMA-IR) and inflammation (hsCRP) are related to bone. Repeat measures (2 years from initial assessment) of all variables will be obtained in a subsample (n=150) of normal weight (n=50), obese (n=50), and obese/high IR (n=50) girls to assess the effects of adiposity, insulin resistance and inflammation on changes in bone mass, density, structure and strength. The proposed mixed (cross-sectional and longitudinal) design in premenarcheal girls provides excellent power to examine associations between adiposity, metabolic risk factors and bone, as well as assess their effects on mineral accrual and changes in structure and strength during a critical phase of bone development. We expect to clarify the currently controversial relationships and provide critical information needed to develop efficacious interventions for optimal bone development.

描述（由申请人提供）：肥胖和骨质疏松症是主要的公共卫生问题。越来越多的证据支持它们已连接。尽管超重本身可能会增加骨矿化，而在成年人中进行动物研究和研究表明伴随肥胖症的代谢障碍对骨骼有害。青春期的肥胖症，骨骼发育的关键时刻，可能对骨骼强度和骨折风险产生深远而持久的影响。这个概念在青少年中很少受到关注，结果混合在一起， 研究报告说，肥胖症会增强或受损矿物质。拟议的项目旨在阐明肥胖，脂肪分布（内脏脂肪组织和tigh肌肉脂肪含量），胰岛素抵抗（HOMA-IR）和炎症（HSCRP）与骨骼质量，密度，结构和强度的关系，450正常体重，超重，肥胖和肥胖前女孩。与其他有关人体组成替代物的研究不同，我们计划使用双能X射线吸收仪（DXA），磁共振成像（MRI）和外周定量计算机层表（PQCT）直接测量软组织组成和脂肪组织（AT）分布。虽然DXA还提供了全身骨骼矿物质的度量，而感兴趣的主要骨头参数，皮质和小梁密度（VBMD），结构（例如，皮质厚度，骨膜厚度，骨膜和内膜周长），尤其是强度（尤其是强度构型（强度构造索引；骨骼强度）），将通过pQct和非质量来测量。 PQCT提供了骨头参数的3维估计，这些估计并非被骨骼大小的变化混淆，骨骼大小是过去研究的重要混杂因素，在生长过程中依赖于二维成像技术。将测量胰岛素，葡萄糖和C反应蛋白（CRP）的禁食水平，以评估胰岛素抵抗（HOMA-IR）和炎症（HSCRP）与骨骼的关系。在正常体重（n = 50），肥胖（n = 50）和肥胖/高IR（n = 50）的子样本（n = 150）中，将获得所有变量的重复度量（距初步评估2年），以评估肥胖性，胰岛素抵抗和炎症对骨骼质量，密度，结构和强度变化的影响。结构前女孩中提出的混合（横截面和纵向）设计为检查肥胖，代谢危险因素和骨骼之间的关联提供了出色的功能，并评估了它们对骨骼发育关键阶段的矿物应计和结构和强度变化的影响。我们希望阐明当前有争议的关系，并提供开发有效干预措施以进行最佳骨骼发育所需的关键信息。