糖尿病患者颈动脉粥样硬化多因素研究

目的 研究糖尿病患者颈动脉粥样硬化与血糖、血脂、凝血谱等多因素之间的关系。方法 对39例糖尿病患者行颈动脉超声检查，同时检测血糖、血脂、凝血谱等项目。34例非糖尿病患者作为对照组，两组的结果进行比较。结果 糖尿病组颈动脉粥样斑块发生率74．35％，对照组11．76％，差异有显著性（P〈0．01）。糖尿病组粥样斑块以颈总动脉分叉部位最多，占40％。糖尿病组血糖、胆固醇、载脂蛋白B、纤维蛋白原、高血压发生率与对照组比较差异有显著性（P〈0．05）。结论 糖尿病能促进颈动脉粥样硬化的形成，其形成还与脂质代谢紊乱、凝血谱异常、高血压等因素有关。     

Magnetic resonance imaging of atherosclerosis by targeting extracellular matrix deposition with Gadofluorine M

As previously reported, Gadofluorine M‐enhanced magnetic resonance imaging clearly demarcates atherosclerotic plaques from the normal vessel wall. To date, the underlying mechanism has remained unknown. Gadofluorine M is a gadolinium‐containing macrocyclic contrast agent containing hydrophilic and hydrophobic moieties. To elucidate the mechanism of accumulation, fluorescently labeled and radioactively labeled derivates of Gadofluorine M were used to determine affinity and specificity of Gadofluorine M binding to blood serum and plaque components in vitro and for the distribution within the plaque of WHHL rabbits in vivo. Gadofluorine M binds to serum albumin, leading to a breakdown of micelles after intravenous injection. The affinity of Gadofluorine M to serum albumin is k_D = 2 µmol/l. Gadofluorine then penetrates the atherosclerotic plaque while bound to albumin and then accumulates within the extracellular, fibrous parts of the plaque by binding to collagens, proteoglycans and tenascin, having the same affinity to these plaque constituents as to albumin. In contrast, weak binding was determined to LDL (k_D = 2 mmol/l) and even no binding to hyaluronic acid. The driving force of binding and accumulation is the hydrophobic moiety of the molecules interacting with hydrophobic plaque materials. Thus, Gadofluorine M accumulates within the fibrous plaque or in the fibrous cap of a plaque containing high amounts of extracellular matrix components, but not in the lipid‐rich areas. In combination with high‐resolution MRI, Gadofluorine M might enable the detection of thin‐cap fibroatheromas, also named the vulnerable plaque. Copyright © 2007 John Wiley & Sons, Ltd.     

Sonographic Carotid Plaque Morphologic Characteristics and Vascular Risk Factors

Objective. The role of vascular risk factors in atherosclerosis development is well established, whereas risk factors involved in determining plaque vulnerability are still a matter of debate. We investigated the vascular risk factor distribution in patients with carotid plaques. Methods. We consecutively assessed sonographic plaque morphologic characteristics, the degree of stenosis, and the common carotid artery intima‐media thickness (IMT) in 1655 patients. Demographic data, a documented history of symptomatic cerebrovascular disease (CVD), and the presence of vascular risk factors were collected. According to literature, heterogeneous hypoechoic plaques with an irregular surface or ulcerations and those with a severe degree of stenosis (≥70%) have been considered “complex” plaques at “major” risk of stroke; homogeneous hyperechoic plaques with smooth surface lesions have been considered “simple” plaques at minor risk. Results. Univariate analysis showed that all vascular risk factors were associated with the presence of carotid atherosclerotic lesions. Multiple logistic regression showed an independent association of hypertension and diabetes with complex plaques, which also had a thicker IMT. A history of CVD was observed more frequently in complex plaques, which had a higher stenosis percentage even after patients with a severe degree of stenosis (≥70%) and indications for carotid surgery were excluded. Conclusions. Hypertension and diabetes are related to a thicker IMT and more severe complex plaques, which may reflect the instability of atherosclerotic process. Because two‐thirds of the patients with complex plaques were asymptomatic for CVD, this raises the importance of surveillance sonography to monitor plaque evolution for prevention of symptomatic CVD.     

Heritability of flow-mediated dilation: a twin study

BACKGROUND: Endothelial dysfunction assessed by brachial artery flow-mediated dilation (FMD) is a marker for early atherosclerotic vascular disease and future cardiovascular events. OBJECTIVE: To estimate the heritability of brachial artery FMD using a twin design. METHODS: We estimated the heritability of FMD using 94 middle-aged male twin pairs. FMD was measured by ultrasound, and traditional coronary heart disease risk factors were measured. Genetic modeling techniques were used to determine the relative contributions of genes and environment to the variation in FMD. RESULTS: The mean age of the twin participants was 54.9 +/- 2.8 years. The mean FMD was 0.047 +/- 0.030. The intraclass correlation coefficient was higher in MZ twins [0.38, 95% confidence interval (CI) 0.32-0.43] than in DZ twins (0.19, 95% CI 0.11-0.26), suggesting a role of genetic influence in FMD variation. Structural equation modeling showed that both genetic and unique environmental factors contributed significantly to the variation in FMD. The crude FMD heritability was 0.37 (95% CI 0.15-0.54). After adjustment for traditional cardiovascular risk factors, including age, total cholesterol, blood pressure, and body mass index, the heritability of FMD was 39% (95% CI 0.18-0.56). The remaining variation in FMD could be explained by individual-specific environment. CONCLUSION: This is the first study using twins to estimate the relative contributions of genetics and environment to the variation in FMD in a US population. Our results demonstrate a moderate genetic effect on brachial artery FMD, independent of traditional coronary risk factors. Our data also highlight the importance of unique environment on the variability in FMD.     

The −589C>T polymorphism in the interleukin‐4 gene (IL‐4) is associated with a reduced risk of myocardial infarction in young individuals

Summary. Background: Inflammatory reactions contribute to the development of arterial disease. We investigated the role of interleukin‐4 (IL‐4) in the development of myocardial infarction (MI) by genotyping patients with MI and control subjects for the ?589C>T (rs2243250) single nucleotide polymorphism (SNP), which tags a functional haplotype of IL‐4. Methods and results: Study of Myocardial Infarctions Leiden (SMILE) included 560 men with a first MI and 646 control subjects. The Valencia study included 305 patients with MI at ≤52 years (men and women) and 310 control subjects. In SMILE no clear overall association with the ?589C>T genotype was found [odds ratio (OR) 0.84; 95% CI 0.37–1.95 for ?589TT and 0.82; 95% CI 0.62–1.07 for ?589CT compared with ?589CC]. In patients younger than 50 years, carriership of one or two ?589T alleles was associated with a reduced risk of MI (OR 0.57: 95% CI 0.34–0.95). This result was replicated in the Valencia study, where carriers of one or two ?589T alleles had a reduced risk of MI (OR 0.67: 95% CI 0.47–0.95), with a strong protective effect of the ?598T allele in homozygous ?589T (OR 0.33: 95% CI 0.10–1.05). In the control subjects of the Valencia study, the ?589T allele was associated with reduced levels of F1+2. Conclusion: Our data indicate that the IL‐4 haplotype tagged by the ?589T allele reduces the risk of MI in young individuals.     

氧化、丙二醛修饰低密度脂蛋白的ELISA检测法及临床应用

目的 建立血浆氧化、修饰低密度脂蛋白(LDL)ELISA检测法并进行临床研究.方法 采用自制的多克隆抗体建立ELISA分别测定铜离子氧化型(Ox)和丙二醛(MDA)修饰型LDL,并对方法进行考核;对冠心病(CHD)患者、键康对照人群Ox-LDL、MDA-LDL水平进行分析.结果 抗Ox-LDL与MDA-LDL几乎没有反应性;Ox-LDL和MDA-LDL测定平均批内变异(CV)分别为6.1%和6.8%,平均批间CV分别为9.7%和10.1%;Ox-LDL和MDA-LDL测定平均回收率分别为95.1%和93.7%;两法检测限均为0.05～1.5 mg/L.CHD患者较正常人血浆Ox-LDL[(178.1±73.8)mg/L vs.(82.7±29.1)mg/L,P＜0.01]、MDA-LDL[(48.7±25.6)mg/L vs.(39.2±32.9)mg/L,P＜0.05]水平均升高;Ox-LDL作为预测动脉粥样硬化发生指标的价值优于MDA-LDL.Ox-LDL、MDA-LDL分别同TC、TG、LDL-C呈正相关,而与HDL-C呈负相关.结论 建立的方法特异、灵敏、准确,适于临床检测.高Ox-LDL、MDA-LDL与CHD密切相关.     

稳定和不稳定型心绞痛斑块CT特征的差异

目的比较稳定型心绞痛(SAP)与不稳定型心绞痛(UAP)患者冠状动脉斑块CT特征的差异。方法搜集UAP和SAP各32例患者的MSCT图像进行对照分析。结果 UAP组和SAP组正性重构的发生率(26/45和7/54)差异有统计学意义(P<0.01)。点状钙化的发生率(10/17和9/33)差异有统计学意义(P<0.05)。偏心性斑块的发生率(39/45和32/54)差异有统计学意义(P<0.01)。软斑块的平均CT值[(34.0±13.7)HU和(68.7±29.4)HU]差异有统计学意义(P<0.01)。结论 UAP患者冠状动脉粥样斑块的主要CT特征包括正性血管重构、斑块密度低和点状钙化等。     

老年人非酒精性脂肪性肝病与颈动脉粥样硬化的相关性研究

目的：非酒精性脂肪性肝病（NAFLD）和颈动脉粥样硬化（CAS）是老年人的常见病,本研究进一步探讨老年人中非酒精性脂肪性肝病（NAFLD）与颈动脉粥样硬化（CAS）的关系及临床意义。方法：根据超声检查结合病史将研究对象划分为老年非酒精性脂肪性肝病组和老年正常肝脏组,检查收缩压、舒张压、空腹抽血化验包括空腹血糖（GLU）、血胆固醇（TC）、甘油三酯（TG）、高密度脂蛋白胆固醇（HDL-C）、低密度脂蛋白胆固醇（LDL-C）、谷丙转氨酶（ALT）等;超声检测颈动脉内膜中层厚度（IMT）和颈动脉粥样斑块情况。结果：老年非酒精性脂肪性肝病组的甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）、谷丙转氨酶（ALT）明显高于非脂肪肝组（P〈0.05）;非酒精性脂肪性肝病组的颈动脉内膜中层厚度与非脂肪肝组存在显著差异（P〈0.05）,但是,在颈动脉粥样斑块发生率（%）方面,两组之间差异无统计学意义。结论：老年非酒精性脂肪性肝病与颈动脉内膜中层增厚密切相关。     

Assessment of carotid stenosis using three-dimensional T2-weighted dark blood imaging: Initial experience

Purpose:

To evaluate the use of a T2‐weighted SPACE sequence (T2w‐SPACE) to assess carotid stenosis via several methods and compare its performance with contrast‐enhanced magnetic resonance angiography (ceMRA).

Materials and Methods:

Fifteen patients with carotid atherosclerosis underwent dark blood (DB)‐MRI using a 3D turbo spin echo with variable flip angles sequence (T2w‐SPACE) and ceMRA. Images were coregistered and evaluated by two observers. Comparisons were made for luminal diameter, luminal area, degree of luminal stenosis (NASCET: North American Symptomatic Endarterectomy Trial; ECST: European Carotid Surgery Trial, and area stenosis), and vessel wall area. Degree of NASCET stenosis was clinically classified as mild (<50%), moderate (50%–69%), or severe (>69%).

Results:

Excellent agreement was seen between ceMRA and T2w‐SPACE and between observers for assessment of lumen diameter, lumen area, vessel wall area, and degree of NASCET stenosis (r > 0.80, P < 0.001). ECST stenosis was consistently higher than NASCET stenosis (48 ± 14% vs. 24 ± 22%, P < 0.001). Area stenosis (72 ± 2%) was significantly higher (P < 0.001) than both ESCT and NASCET stenosis.

Conclusion:

DB‐MRI of carotid arteries using T2w‐SPACE is clinically feasible. It provides accurate measurements of lumen size and degree of stenosis in comparison with ceMRA and offers a more reproducible measure of ECST stenosis than ceMRA. J. Magn. Reson. Imaging 2012;449‐455. © 2011 Wiley Periodicals, Inc.     

老年非酒精性脂肪肝与载脂蛋白B的相关性研究

目的探讨老年患者非酒精性脂肪肝(NAFL)与载脂蛋白B的相关性。方法选择住院患者226例,平均年龄(79.2±5.7)岁。分为非脂肪肝组和NAFL组。分析两组患者载脂蛋白B和其他代谢指标及影响因素的关系。结果 NAFL组的总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、载脂蛋白B(apoB)、丙氨酸氨基转移酶(ALT)、甘油三酯(TG)均高于非脂肪肝组;而肌酐(Cr)低于非脂肪肝组;NAFL组糖尿病、冠心病的发病率高;吸烟的比例高;差异均有统计学意义(P<0.05)。两组间年龄的差异无统计学意义。多元线性回归分析显示,NAFL与ALT、apoB正相关(标准化偏回归系数分别为0.444、0.364,P<0.05),其他指标未进入方程。结论 NAFL患者的TC、LDL-C、apoB、ALT、TG均高于非脂肪肝组;糖尿病、冠心病的发病率高;而Cr低。老年人发现NAFL后仍应干预血脂,进一步预防动脉粥样硬化和心脑血管事件发生。