高密度脂蛋白对血管内皮依赖性舒张功能的影响

目的　探讨血清高密度脂蛋白 胆固醇 (HDL C)水平与肱动脉内皮依赖性舒张功能之间的关系。方法　测定 71例血清总胆固醇水平相对正常的冠心病患者和 34例对照者的血脂水平以及在反应性充血时和含服硝酸甘油后肱动脉的内径变化。结果　冠心病组血流介导的肱动脉舒张和硝酸甘油所致的肱动脉舒张均低于对照组 [分别为 (2 6 1± 2 91) %比 (8 0 1± 4 72 ) %和 (17 2 2± 6 76 ) %比 (2 3 13± 8 6 1) % ,P均 <0 0 0 1]。多因素线性逐步回归分析显示 :血流介导的肱动脉舒张与血清HDL C水平呈正相关 (r=0 32 4,P =0 0 0 2 ) ,与血清总胆固醇、甘油三酯和低密度脂蛋白水平无关 ;硝酸甘油所致的肱动脉舒张也与上述血脂水平无关。根据血流介导的肱动脉舒张程度将两组受试者合并再分为A、B两组 ,A组肱动脉舒张≤ 4% ,B组肱动脉舒张 >4%。结果显示 ,A组HDL C水平明显低于B组 [(1 15± 0 2 6 )mmol/L对 (1 38± 0 5 0 )mmol/L ,P <0 0 1) ]。结论　冠心病患者内皮依赖性及非内皮依赖性的血管舒张功能均受损。HDL C对血管内皮依赖性舒张功能有保护作用 ,该作用可能与其抗动脉粥样硬化作用有关     

失功能高密度脂蛋白与心血管疾病研究进展

高密度脂蛋白胆固醇被认为是心血管疾病的重要保护因素,它在血清中的水平与心血管疾病风险呈负相关。然而在心血管疾病中,高密度脂蛋白的蛋白质、脂质或microRNAs等发生变化,使其转变为失功能高密度脂蛋白,失功能高密度脂蛋白具有促进动脉粥样硬化、促氧化、促炎等特性。本文对失功能高密度脂蛋白的结构和功能改变进行概括。     

血清非高密度脂蛋白胆固醇在冠心病高脂血症中的诊断意义

高脂血症是冠状动脉粥样硬化发生、发展的主要危险因素。由于血脂分类繁多 ,不易被临床医师掌握。近年来 ,有学者 [1]提出了一个新的检测致动脉粥样硬化 ( AS)的脂蛋白指标—非高密度脂蛋白胆固醇( n HDLC) ,其能全面反映胆固醇的致 AS作用。本文从 1 999～ 2 0 0 0年干部查体中选取 2 62例冠心病稳定期合并不同类型高脂血症患者 ,与 2 1 0例正常健康者 ,分别测定 n HDLC进行比较 ,以探讨其临床意义。1　资料与方法1 .1　一般资料　本组 2 62例冠心病稳定期合并高脂血症患者 ,男性 1 46例 ,女性 1 0 9例 ,年龄 40～ 81岁 ,平均 5 9.87…     

高密度脂蛋白功能与动脉粥样硬化

冠心病是东西方各国发病和死亡的第一位原因。冠状动脉粥样硬化是多因素疾病,从危险因素的作用,内皮功能的失调,致动脉粥样硬化脂蛋白滞留于动脉壁,炎症反应,到泡沫细胞和纤维斑块的形成,斑块破裂和血栓形成,构成了冠心病发生、发展和转归的序列过程。在众多的危险因素中,胆固醇升高是具有因果性致病性因子,     

低密度脂蛋白胆固醇/高密度脂蛋白胆固醇、甘油三酯/高密度脂蛋白胆固醇和尿酸与冠心病的关系

目的探讨低密度脂蛋白胆固醇(LDL-C)/高密度脂蛋白胆固醇(HDL-C)、甘油三脂(TG)/HDL-C和血尿酸(UA)与冠心病的关系。方法检测203例经冠脉造影确诊的冠心病患者(冠心病组)和61例冠脉造影正常者(对照组)的血清总胆固醇、TG、LDL-C、HDL-C、UA含量,计算LDL-C/HDL-C、TG/HDL-C的比值。结果冠心病组的总胆固醇、LDL-C、LDL-C/HDL-C比值较对照组均显著升高,HDL-C显著降低(P<0.05)。而TG及TG/HDL-C比值两组间无显著差异。结论LDL-C/HDL-C和UA对冠心病有一定的预测价值,而TG/HDL-C比值的预测价值尚待研究。     

高密度脂蛋白基础与临床研究新进展

经历百余年的探索,人类已充分认识到低密度脂蛋白胆固醇(LDL-C)在冠心病发生、发展中的重要作用.应用他汀类降低LDL-C能显著减少冠心病事件,在冠心病防治史上具有里程碑意义,他汀类已成为冠心病防治的常规用药.今后关于LDL-C的研究重点在于探索适合的LDL-C目标值,提高LDL-C达标率,改善治疗的经济效益比.     

高密度脂蛋白防治动脉粥样硬化的新进展

<正> 研究证实,HDL与冠心病风险呈负相关,同时,HDL潜在的抗动脉粥样硬化(AS)功能,使其成为AS性心血管疾病预防和治疗的主要靶向。但是2007年ILLUMINATE研究结果显示,胆固醇酯转运蛋白(CETP)抑制剂torcetrapib虽然能大幅增高HDL-C水平,但是torcetrapib组的死亡人数反而较对照组增多,差异有统计学意义,使研究被迫提前终     

高密度脂蛋白胆固醇与冠心病的相关性研究

高密度脂蛋白胆固醇降低是动脉粥样硬化性心血管病的独立危险因素,血浆中高密度脂蛋白胆固醇的水平与冠心病发生呈负相关,其机制包括高密度脂蛋白逆转运胆固醇、抗氧化、促纤溶、抗血栓等作用。目前对于低高密度脂蛋白胆固醇血症患者的干预主要有生活方式改变,药物治疗,以及新近的生物疗法等策略,达到降低心血管事件的发生率。     

Glycation impairs high-density lipoprotein function

Aims/hypothesis. To examine the effects of incubation of high-density lipoprotein (HDL) under hyperglycaemic conditions on several functions of HDL in vitro.¶Methods. Human HDL (5 mg protein) was incubated for 1 week at 37 °C in the presence or absence of 25 mmol/l glucose. Additional samples of human HDL were incubated in butylated hydroxytoluene to control for oxidation.¶Results. High-density lipoprotein incubated for 1 week in 25 mmol/l glucose had significant increases in the glycation product, fructoselysine and in the advanced glycation end product, N ?-(carboxymethyl)-lysine. High-density lipoprotein apolipoprotein AI and AII concentrations were not altered but glycated HDL had a 65 % reduction in paraoxonase enzymatic activity. Glycated HDL did not inhibit monocyte adhesion to human aortic endothelial cells in response to oxidised low-density lipoprotein in vitro (43 ± 4 monocytes bound vs 21 ± 2 monocytes for control HDL, p < 0.0001). Hepatic lipase-mediated non-esterified fatty acid release from HDL lipids was enhanced in glycated HDL compared with control HDL (25 ± 1 vs 16 ± 1 nmol non-esterified fatty acid hydrolysed/min, respectively, p < 0.0001). Direct glycation of purified paraoxonase protein by incubation in 25 mmol/l glucose caused a 40 % reduction in enzymatic activity. This glycated paraoxonase did not inhibit monocyte adhesion to human aortic endothelial cells in vitro (68 ± 3 monocytes vs 49 ± 2 monocytes bound for control paraoxonase, respectively, p < 0.001). We also measured a 40 % reduction in paraoxonase activity in patients with Type II (non-insulin-dependent) diabetes mellitus and documented coronary artery disease compared with non-diabetic subjects, p < 0.0001.¶Conclusions/interpretation. Alterations in function of HDL caused by exposure to hyperglycaemic conditions could contribute to the accelerated atherosclerosis observed in Type II diabetes. [Diabetologia (2000) 43: 312–320]     

Beyond high-density lipoprotein cholesterol levels evaluating high-density lipoprotein function as influenced by novel therapeutic approaches

A number of therapeutic strategies targeting high-density lipoprotein (HDL) cholesterol and reverse cholesterol transport are being developed to halt the progression of atherosclerosis or even induce regression. However, circulating HDL cholesterol levels alone represent an inadequate measure of therapeutic efficacy. Evaluation of the potential effects of HDL-targeted interventions on atherosclerosis requires reliable assays of HDL function and surrogate markers of efficacy. Promotion of macrophage cholesterol efflux and reverse cholesterol transport is thought to be one of the most important mechanisms by which HDL protects against atherosclerosis, and methods to assess this pathway in vivo are being developed. Indexes of monocyte chemotaxis, endothelial inflammation, oxidation, nitric oxide production, and thrombosis reveal other dimensions of HDL functionality. Robust, reproducible assays that can be performed widely are needed to move this field forward and permit effective assessment of the therapeutic potential of HDL-targeted therapies.     

Relation between high-density lipoprotein cholesterol and peripheral vasomotor function

Low levels of high-density lipoprotein (HDL) cholesterol are one of the most common lipid abnormalities in patients with coronary artery disease. Endothelial dysfunction is also highly prevalent in patients with coronary artery disease. We sought to determine whether HDL cholesterol levels are correlated with endothelium-dependent vasomotion in patients being evaluated for atherosclerosis. Peripheral vascular endothelial function was assessed by high-resolution brachial artery ultrasound. Flow-mediated dilation (FMD) during reactive hyperemia was defined as the percent change in arterial diameter following 5-minute arterial occlusion. All patients underwent stress testing with nuclear single-photon emission computed tomographic imaging to determine percent left ventricular ejection fraction and define the presence or absence of coronary artery disease. One hundred fifty-one subjects (87 men, 64 women) were enrolled (average age 58 +/- 11 years). Total cholesterol, HDL cholesterol, low-density lipoprotein cholesterol, and triglyceride levels were 188 +/- 48, 47 +/- 13, 108 +/- 37 and 154 +/- 88 mg/dl, respectively. The mean FMD for the entire group was 9.9 +/- 5.2%. Subjects with an HDL cholesterol of <40 mg/dl (n = 39) had lower FMD (7.4 +/- 3.6%) compared with those with an HDL cholesterol >/=40 mg/dl (11.0 +/- 5.5%, p <0.001). There was a significant correlation between FMD and HDL cholesterol level (linear regression, p <0.001), and in multivariate analysis, HDL cholesterol was an independent predictor of FMD. Peripheral endothelial function was abnormal in subjects with low HDL cholesterol and well-preserved in those with high HDL cholesterol. These data suggest that impaired endothelial function associated with low HDL cholesterol may be an additional, previously unrecognized mechanism contributing to the increased risk of atherosclerosis in these patients.     

Relationship between total cholesterol/high-density lipoprotein cholesterol ratio, triglyceride/high-density lipoprotein cholesterol ratio, and high-density lipoprotein subclasses

Alterations in plasma lipid levels can influence the composition, content, and distribution of plasma lipoprotein subclasses that affect atherosclerosis risk. This study evaluated the relationship between plasma total cholesterol (TC)/high-density lipoprotein cholesterol (HDL-C) ratio, triglyceride (TG)/HDL-C ratio, and HDL subclass distribution. The apolipoprotein A-I contents of plasma HDL subclasses were quantitated by 2-dimensional gel electrophoresis coupled with immunodetection in 442 Chinese subjects. The particle size of HDL shifted toward smaller size with the elevation of TC/HDL-C and TG/HDL-C ratios. The ratio of large-sized HDL(2b) to small-sized prebeta(1)-HDL (HDL(2b)/prebeta(1)-HDL) was about 4.7 in the subjects with TC/HDL-C of 3.3 or lower and TG/HDL-C of 2.5 or lower, whereas it was only approximately 1.1 in subjects with TC/HDL-C greater than 6 and TG/HDL-C greater than 5. Pearson correlation analysis revealed that the TC/HDL-C ratio was positively correlated with prebeta(1)-HDL and HDL(3a) but negatively correlated with HDL(2a) and HDL(2b), whereas the TC/HDL-C ratio was only inversely correlated with HDL(2b). The TC/HDL-C and TG/HDL-C ratios together may be a good indicator of HDL subclass distribution. When these 2 ratios increased simultaneously, the trend toward smaller HDL size was obvious, which, in turn, indicated that the maturation of HDL might be impeded and the reverse cholesterol transport might be weakened. In addition, the TG/HDL-C ratio might be a more powerful factor to influence the distribution of HDL subclasses.     

Mechanisms of high-density lipoprotein cholesterol effects on the endothelial function in hyperlipemia

High-density lipoprotein-cholesterol (HDL-c) has a favorable influence on the endothelial function, but the mechanisms of this protective action are not fully understood. We studied lipid parameters, soluble adhesion molecules (vascular cell adhesion molecule-1 [VCAM-1], intercellular adhesion molecule [ICAM-1], E-selectin) oxidized low-density lipoproteins (LDL), and brachial-artery flow-mediated vasodilation (FMV) in 184 hyperlipemic patients (90 men, age 54 +/- 10 years, waist/hip circumference ratio 0.89 +/- 0.07, LDL-cholesterol [LDL-c] 4.9 +/- 1.3 mmol/L, triglycerides 1.8 +/- 0.9 mmol/L, HDL-c 1.3 +/- 0.5 mmol/L) after excluding those with current smoking, diabetes, hypertension, and vascular diseases. Patients were divided into 2 groups on the basis of HDL-c levels: < 1.03 mmol/L (n = 53) v >or= 1.03 mmol/L (n = 131). Patients with low HDL-c showed significantly lower LDL-c (P <.05), higher triglycerides (P <.001), higher body mass index (P <.02), lower FMV (3.7% +/- 2.0% v 4.9% +/- 3.4%, P <.002), higher VCAM-1 (1,195 +/- 395 ng/mL v 984 +/- 303 ng/mL, P <.01), and higher ICAM-1 (406 +/- 78 ng/mL v 364 +/- 68 ng/mL, P <.01). E-selectin and oxidized LDL showed no significant differences. In a multivariate age, oxidized LDL and brachial artery diameter predicted a lower FMV, while HDL-c was an independent predictor of a greater FMV (P =.003). Increasing levels of VCAM-1 and ICAM-1 were predicted by lower HDL-c, while higher oxidized LDL predicted higher VCAM-1 (P <.05). Our data suggest that in hyperlipemic subjects free of cardiovascular disease low HDL-c negatively modulates endothelial function through a lack of oxidation inhibition and a concomitant overexpression of adhesion molecules.