CT EVALUATION OF DIABETIC TIBIAL ARTERY CALCIFICATION

描述（由申请人提供）：糖尿病患者截肢的终生风险比非糖尿病人群高15倍。一旦患者发展为终末期外周血管疾病（PVD），糖尿病足溃疡的治疗选择就变得有限，截肢是常见的结果。开发新的方法来检测和治疗糖尿病患者的早期PVD仍然是我们限制糖尿病相关截肢的最大希望。目前的非侵入性研究不能敏感地识别早期血管疾病或跟踪其进展。基于研究人员对冠状动脉钙化的研究，我们试图回答以下问题：在II型糖尿病患者中，胫动脉钙化量与PVD严重程度之间是否存在类似的关系？如果是这种情况，那么胫骨钙化可以作为动脉粥样硬化闭塞性疾病严重程度的替代标志物，并用于识别高危患者。我们将检验一个假设，即多层螺旋CT得出的胫动脉钙化评分与糖尿病患者人群血管疾病的临床严重程度相关。我们将首先（具体目标1）探索II型糖尿病患者中胫动脉钙化与PVD临床分类之间的关系，然后（具体目标2）检查这些患者中胫动脉钙化评分与血管造影确定的胫动脉闭塞性疾病数量之间的相关性。我们将招募三组II型糖尿病患者：第1组-无PVD临床证据，第2组-有PVD临床证据但无足缺血，第3组-有PVD和足缺血临床证据。 我们还将招募一个年龄和性别匹配的对照组，以更全面地了解II型糖尿病对胫骨钙化的具体影响。对于目标1，将使用病例对照设计和ANOVA统计方法比较各组的平均TAC评分。对于目标2，患者将通过CT血管造影术对其血管解剖结构进行评价，我们将计算相关系数（r）和预测值（P）。初步调查的结果将支持更大规模的病例对照研究，队列研究和随机试验，以测试使用TAC评分在II型糖尿病患者护理中的效用。我们的最终目标是预防糖尿病的大血管并发症，并减少导致患者残疾的下肢截肢的发生率。

DESCRIPTION (provided by applicant): The lifetime risk of amputation in patients with diabetes is 15-fold higher than that of the non-diabetic population. Once patients develop end-stage peripheral vascular disease (PVD), the treatment options for diabetic foot ulcers become limited and amputation is commonly the result. Developing new methods to detect and treat early-stage PVD in patients with diabetes remains our best hope for limiting diabetes-related amputation. Current non-invasive studies do not sensitively identify early-stage vascular disease or serve to track its progression. Based on work done by investigators studying coronary calcification, we seek to answer the following question: Is there a similar relationship between the amount of calcification found in tibial arteries and the severity of PVD in patients with type II diabetes? If this is the case, then tibial calcification could be used as a surrogate marker for the severity of athero-occlusive diseases and for the identification of high risk patients. We will test the hypothesis that tibial artery calcification scores derived by multi-slice CT are related to the clinical severity of vascular disease in a diabetic patient population. We will first (specific aim 1) explore the relationship between tibial artery calcification and clinical category of PVD in patients with type II diabetes, and then (specific aim 2) examine the correlation between the tibial artery calcification score and the amount of angiographically-determined tibial artery occlusive disease in these patients. We will recruit three groups of patients with type II diabetes: Group 1- no clinical evidence of PVD, Group 2 -- clinical evidence of PVD but no pedal ischemia, and Group 3 -clincial evidence of PVD and pedal ischemia. We will also recruit an age and gender matched control group to more fully understand the specific effect of type II diabetes on tibial calcification. For Aim 1, mean TAC scores in each of these groups will be compared using a case-contol design and ANOVA statistical methods. For Aim 2, patients will undergo evaluation of their vascular anatomy by CT angiography and we will calculate a correlation coefficient (r) and predictive value (P). Results from this preliminary inquiry would support larger case-control studies, cohort studies, and randomized trials to test the utility of using TAC scoring in the care of patients with type II diabetes. Our ultimate goal is to prevent the marco-vascular complications of diabetes, and to decrease the incidence of lower extremity amputation that causes disability in our patients.