Bone microarchitecture, diabetes and change in bone mineral density in Puerto Rican adults

项目总结 最近的国家数据表明，与非西班牙裔美国人相比，西班牙裔美国人中骨质疏松症(OP)的患病率更高 西班牙裔白人或黑人。作为美国人口中增长最快的群体之一，这一群体 预计从2005年到2025年，与OP相关的骨折的增长幅度最大。加勒比海的西班牙裔成年人 与非西班牙裔白人相比，Origin的骨骼质量更差。尤其是波多黎各人， 有比之前认为的更高的OP患病率。尽管较高的骨矿密度(BMD) 在2型糖尿病(T2D)患者中已被注意到，T2D有助于降低骨强度、皮质 缺陷和皮质孔隙率增加增加了骨折的风险。这是波多黎各特别关注的问题。 患有T2D的高患病率的里约人。T2D患者骨质质量差的一个机制是 晚期糖基化终末产物(AGE)的积累，影响骨骼的机械性能。动物 研究表明，维生素B6的抗氧化活性可能会抑制AGE的形成。更大的血浆吡哆醇- 5‘-磷酸(PLP，维生素B6)浓度和维生素B6的摄入量与骨骼减少有关 随着时间的推移，损失和减少骨折的风险；但机制尚不清楚。一种新的骨小梁评分(TBS) 测量腰椎的小梁微结构，可以指示脆性骨折的风险，即使在 那些骨密度正常的人；然而，TBS用于评估骨质量的研究有限且迫切需要。 此外，通过新的微压痕评估骨强度可以阐明骨质量的差异。 在面临OP风险的T2D中。因此，我们的中心假设是患有T2D的波多黎各成年人将会有 骨强度差(微压痕)，脊柱TBS和脊柱和髋部骨密度损失更大 与没有T2D的个体相比，这将被高血浆AGE浓度所缓和。我们的 第二个假设是，较高的血浆PLP与较低的血浆年龄相关，因此 更高的骨强度(微压痕)，随着时间的推移，TBS和BMD的损失更少。所有有空位的860波多黎各 参与波士顿波多黎各骨质疏松症研究的拥有有效BMD数据的波多黎各成年人将是 邀请参加拟议的研究。参与者将完成一份问卷，重复进行DXA扫描， 接受骨微压痕、皮肤自发荧光测量年龄并提供空腹血液 样本。这项拟议的研究在纳入TBS作为衡量骨骼质量的指标方面具有创新性， 评估骨骼强度的压痕，检查年龄作为联系糖尿病和骨骼的效果修饰物 健康，以及在纵向研究中将PLP作为年龄因素的考虑。这项工作是迫切需要的 增进我们对影响骨骼健康的复杂危险因素的了解，并为 制定未来的干预措施，以预防骨丢失和骨折风险，特别是在高危人群中 健康差距很大。

PROJECT SUMMARY Recent national data indicate a higher prevalence of osteoporosis (OP) among Hispanics, compared with non- Hispanic whites or blacks. As one of the fastest growing segments of the U.S. population, this group is projected to have the largest increase in OP-related fracture from 2005 to 2025. Hispanic adults of Caribbean origin have been shown to have poorer bone quality than non-Hispanic whites. Puerto Ricans, in particular, have higher prevalence of OP than previously appreciated. Although higher bone mineral density (BMD) has been noted in those with type 2 diabetes (T2D), T2D contributes to compromised bone strength, cortical defects and increased cortical porosity increasing risk of fracture. This is of particular concern for Puerto Ricans who have a high prevalence of T2D. One mechanism for poor bone quality among those with T2D is the accumulation of advanced glycation end-products (AGE), which affect bone mechanical properties. Animal studies suggest that antioxidant activity from vitamin B6 may inhibit AGE formation. Greater plasma pyridoxyl- 5'-phosphate (PLP, vitamin B6) concentration and intake of vitamin B6 has been associated with less bone loss over time and reduced risk of fracture; but mechanisms are unclear. Trabecular bone score (TBS), a novel measure of trabecular microarchitecture of the lumbar spine, is indicative of fragility fracture risk, even among those with normal BMD; however, research on TBS for assessing bone quality is limited and urgently needed. Further, assessment of bone strength by novel micro-indentation may elucidate differences in bone quality among T2D at risk for OP. Therefore, our central hypothesis is that Puerto Rican adults with T2D will have poor bone strength (micro-indentation), and greater loss of TBS at the spine and of BMD at the spine and hip compared to individuals without T2D; and that this will be moderated by high plasma AGE concentration. Our secondary hypothesis is that greater plasma PLP will be associated with lower plasma AGE and therefore higher bone strength (micro-indentation), and less loss of TBS and BMD over time. All available 860 Puerto Rican adults who participated in the Boston Puerto Rican Osteoporosis Study with valid BMD data will be invited to participate in the proposed study. Participants will complete a questionnaire, a repeat DXA scan, undergo bone micro-indentation, skin autofluorescence measurement of AGES and provide a fasting blood sample. The proposed research is innovative in the inclusion of TBS as a measure of bone quality, micro- indentation to evaluate bone strength, the examination of AGE as an effect modifier linking diabetes and bone health, and the consideration of PLP as a factor in AGE in a longitudinal study. This work is urgently needed to improve our understanding of complex risk factors for bone health, and to provide important information for the development of future interventions to prevent bone loss and fracture risk, particularly in high-risk populations with health disparities.