Peripheral nerve decline: an underappreciated cause of injurious falls

描述(申请人提供)：这项老年队列中周围神经功能的竞争性更新将首次确定感觉运动周围神经功能是否差， 一种新的潜在风险因素，与老年人的跌伤、骨折、医疗保险利用率、医疗保险支出和死亡率的主要临床结局有关。在这个项目的最初资助期间，我们证明了感觉运动周围神经功能的丧失在糖尿病和非糖尿病老年人中都是非常常见的。我们发现了显著的和独立的神经功能下降的预测因素，如身高、白人和老年，以及可预防的疾病相关因素，如糖尿病、肾损害(高胱抑素C)、亚临床周围血管疾病和低维生素B12。神经功能低下可以在表现为临床周围神经病之前很久就被发现，我们已经建立了与较低的骨矿密度、肌肉力量和体能表现的联系。糖尿病并不能解释这些联系。这些肌肉骨骼因素可能导致跌伤、骨折和死亡率增加。与老年人周围神经衰退相关的利用和支出没有特征性。我们将把我们的队列数据与医疗保险服务中心的数据联系起来，以确定感觉运动周围神经功能是否可以预测跌倒损伤，并与更高的利用率、总支出和死亡率相关。具体目标是确定外周感觉和运动神经功能不良是否与1)治疗跌倒损伤(包括骨折)有关，2)总体和跌倒相关的医疗保险利用率、医疗保险支出和死亡率更高。Health ABC研究是一项由NIA支持的大型队列研究，包括1997-98年基线的3075名黑人和白人男性和女性(42%是黑人；52%是女性)，并在2000-01年对神经功能进行了初步评估。在本项目的第一阶段，我们重新评估了2007年至2008年的周围神经功能(N=1 175例，年龄80-，平均83.3±2.7岁)，以确定感觉和运动神经功能下降的比率和下降的危险因素。在这次更新中，我们将采取下一步措施，前瞻性地评估与神经功能不良相关的主要老年结果。我们最初的R01没有评估跌倒伤害或骨折，也不包括医疗使用和支出，这些都是最近才与健康ABC数据联系在一起的。相关医疗保险数据的可获得性丰富了我们充分描述这些结果的机会。该项目将确定周围神经功能的主要临床结果：治疗的跌倒损伤、骨折、医疗用途、费用和死亡。我们特征良好的流行病学队列与相关的医疗保险数据为这项工作提供了理想的机会。我们将产生一种有效的方法，可以应用于医疗保险数据，以检查我们其他大型流行病学队列中的伤害跌倒结果。最终目标是确定周围神经测试是否识别出跌倒损伤、骨折和死亡的风险较高的老年人，这些老年人可能受益于神经衰退的预防措施或临床结果。

DESCRIPTION (provided by applicant): This competing renewal of Peripheral nerve function in an aged cohort will determine for the first time if poor sensorimotor peripheral nerve function, a novel potential risk factor, is associated with major clinical outcomes of fall injuries requirin medical care, fractures, Medicare utilization, Medicare expenditures, and mortality in older adults. In the initial funding period of this project, we demonstrated that loss of sensorimotor peripheral nerve function is very common in both diabetic and non-diabetic older adults. We found significant and independent predictors for nerve function decline, such as taller height, white race, and older age, and preventable, disease-related factors such as diabetes, renal impairment (high cystatin C), subclinical peripheral vascular disease, and low vitamin B12. Poor nerve function can be detected long before presenting as overt clinical peripheral neuropathy and we have established associations with lower bone mineral density, muscle strength and physical performance. These associations are not explained by diabetes. These musculoskeletal factors likely contribute to fall injuries, fractures, and increased mortality. Utilization and expenditures associated with peripheral nerve decline in older adults are not characterized. We will link our cohort data to Centers for Medicare Services data to determine if sensorimotor peripheral nerve function predicts fall injuries and is associated with higher utilization, total expenditures, and mortality. The specific aims are to determine if poor peripherl sensory and motor nerve function is associated with 1) treated fall injuries, including fractures, and 2) greater total and fall-related Medicare utilization, Medicare expenditures, and mortality. The Health ABC Study is a large NIA supported cohort study that included 3075 black and white men and women (42% Black; 52% women) at baseline in 1997-98, with an initial assessment of nerve function in 2000-01. In the first stage of this project, we reassessed peripheral nerve function in 2007-2008 (N=1175, aged 80-89 and mean 83.3¿2.7 years) to determine rates of sensory and motor nerve function decline and risk factors for decline. In this renewal we will take the next step and prospectively assess the major geriatric outcomes associated with poor nerve function. Our initial R01 did not assess fall injuries or fractures and did not include medical utilization and expenditures, which have been only recently linked to the Health ABC data. The availability of linked Medicare data enriches our opportunities to fully characterize these outcomes. This project will define the major clinical outcomes of peripheral nerve function: treated fall injuries, fractures, medical utilization, expenditures and death. Our well characterizd epidemiologic cohort with linked Medicare data provides the ideal opportunity for this work. We will generate a validated approach that may be applied to Medicare data to examine injurious fall outcomes in our other large epidemiologic cohorts. The ultimate goal is to determine if peripheral nerve testing identifies older adults at higher risk for fall injuries, fractures and deth that may benefit from preventive measures for nerve decline or clinical outcomes.