Meta-analysis of the effect of nicotinic acid alone or in combination on cardiovascular events and atherosclerosis

Objective

High-density lipoprotein cholesterol (HDL-C) concentration is a strong predictor of cardiovascular events in both naïve and statin-treated patients. Nicotinic acid is an attractive option for decreasing residual risk in statin-treated or statin-intolerant patients since it increases HDL-C by up to 20% and decreases low-density lipoprotein cholesterol and lipoprotein(a) plasma concentrations.

Methods

We performed a computerized PubMed literature search that focused on clinical trials evaluating niacin, alone or in combination with other lipid-lowering drugs, published between January 1966 and August 2008.

Results

Among 587 citations, 29 full articles were read and 14 were eligible for inclusion. Overall 11 randomized controlled trials enrolled 2682 patients in the active group and 3934 in the control group. In primary analysis, niacin significantly reduced major coronary events (relative odds reduction = 25%, 95% CI 13, 35), stroke (26%, 95% CI = 8, 41) and any cardiovascular events (27%, 95% CI = 15, 37). Except for stroke, the pooled between-group difference remained significant in sensitivity analysis excluding the largest trial. In comparison with the non-niacin group, more patients in the niacin group had regression of coronary atherosclerosis (relative increase = 92%, 95% CI = 39, 67) whereas the rate of patients with progression decreased by 41%, 95% CI = 25, 53. Similar effects of niacin were found on carotid intima thickness with a weighted mean difference in annual change of −17 μm/year (95% CI = −22, −12).

Conclusions

Although the studies were conducted before statin therapy become standard care, and mostly in patients in secondary prevention, with various dosages of nicotinic acid 1–3 g/day, this meta-analysis found positive effects of niacin alone or in combination on all cardiovascular events and on atherosclerosis evolution.     

绝经后妇女雌激素替代治疗对缺血性脑血管病患者的预防及治疗作用

目的观察替勃龙长期治疗（2年）对绝经后妇女氧化型低密度脂蛋白（ox-L DL）、一氧化氮（NO）、内皮素-1（ET-1）及颈动脉和椎动脉IMT的影响。方法有更年期症状的围绝经期妇女138例,随机分为治疗组（替勃龙2.5 mg/d）和对照组。替勃龙治疗前及治疗2年后检测血脂、ox-L DL、NO、ET-1及颈动脉IMT,颈动脉、椎动脉的RI。结果129例完成观察和治疗。替勃龙治疗2年后血TC、ET-1显著降低（P〈0.05）,LDL-Ch、ox-L DL、Lp（a）极显著降低（P〈0.01）,HDL-C略有降低（P〉0.05）,NO显著升高（P〈0.05）。替勃龙治疗2年CCA的IMT下降26.7%（P〈0.01）。CCA的RI从（0.72±0.06）下降到（0.68±0.06）,ICA的RI从（0.59±0.05）至（0.56±0.05）,VA的RI从（0.66±0.06）下降到（0.62±0.04）,P〈0.05。ECA的RI下降不明显P〉0.05。结论替勃龙对绝经后妇女动脉内膜具有保护作用,对缺血性脑血管病具有预防和治疗作用。     

Snakes based segmentation of the common carotid artery intima media

Ultrasound measurements of the human carotid artery walls are conventionally obtained by manually tracing interfaces between tissue layers. In this study we present a snakes segmentation technique for detecting the intima-media layer of the far wall of the common carotid artery (CCA) in longitudinal ultrasound images, by applying snakes, after normalization, speckle reduction, and normalization and speckle reduction. The proposed technique utilizes an improved snake initialization method, and an improved validation of the segmentation method. We have tested and clinically validated the segmentation technique on 100 longitudinal ultrasound images of the carotid artery based on manual measurements by two vascular experts, and a set of different evaluation criteria based on statistical measures and univariate statistical analysis. The results showed that there was no significant difference between all the snakes segmentation measurements and the manual measurements. For the normalized despeckled images, better snakes segmentation results with an intra-observer error of 0.08, a coefficient of variation of 12.5%, best Bland–Altman plot with smaller differences between experts (0.01, 0.09 for Expert1 and Expert 2, respectively), and a Hausdorff distance of 5.2, were obtained. Therefore, the pre-processing of ultrasound images of the carotid artery with normalization and speckle reduction, followed by the snakes segmentation algorithm can be used successfully in the measurement of IMT complementing the manual measurements. The present results are an expansion of data published earlier as an extended abstract in IFMBE Proceedings (Loizou et al. IEEE Int X Mediterr Conf Medicon Med Biol Eng POS-03 499:1–4, 2004).     

The spectrum of persistence of testicular blastema and ectopic testicular parenchyma: a possible result of focal delay in gonadal development

Sex-cord formation and organization are important steps in testicular development and depend on adequate interactions between mesenchymal cells, pre-Sertoli cells, and germ cells. These elements form the testicular blastema, the precursor of the testicular parenchyma, morphologically characterized by poorly organized sex cords and mesenchymal components. Here, we study two uncommon testicular lesions, unrelated to other gonadal anomalies. In the first group, we describe the features of persistence of testicular blastema in three fetal autopsy cases, discussing its possible pathogenesis and clinical importance. In the second, we analyze 11 cases of ectopic testicular parenchyma in the tunica albuginea, an uncommon benign condition of uncertain clinical significance, whose main differential diagnosis is gonadal dysgenesis. Based on their similar topography within the testis, and on their possibly shared embryological origin, we propose that both lesions may represent the two extremes of a maldevelopmental spectrum resulting from a focal delay in testicular development. An erratum to this article can be found at     

缓释厄贝沙坦涂层支架置入对内膜增生的影响

目的:探讨缓释厄贝沙坦涂层支架置入对内膜增生的影响。方法:建立冠状动脉支架置入的广西种的微型猪动物模型,分别置入普通裸支架和缓释厄贝沙坦涂层支架。于支架置入后3、7、28、90和180d截取支架段血管连同邻近的近端正常血管段,通过病理组织学分析和聚合酶链反应技术检测支架局部内膜增生情况。结果:正常血管段表达PCNAmRNA在各个时间段差异没有显著性。普通支架置入后3d局部血管壁PCNAmRNA的表达明显增高,并在术后7d达到高峰。术后90dPCNAmRNA的表达呈现下降的趋势,但仍显著高于正常血管段,并且差异一直持续到术后180d。术后第3天药物支架段PCNAmRNA的表达明显增高,并在术后7d达到高峰。术后7d药物支架段PCNAmRNA的表达已显著低于普通支架段,并且差异一直持续到术后90d。术后90～180d药物支架段内膜加中膜面积明显小于普通支架段。结论:缓释厄贝沙坦涂层支架置入可在一定程度上减少支架置入后内膜的增生反应。     

代谢综合征患者静息心率与颈动脉内膜中层厚度的关系

目的探讨代谢综合征（MS）患者静息心率（RHR）与颈动脉内膜-中层厚度（IMT）的关系。方法对96例MS患者进行调查，每位患者均测RHR、血压、空腹血糖（FPG）、总胆固醇（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），颈动脉超声检测IMT，按RHR频率分RHR1组：RHR〈70次／min，RHR2组：70-80次／min，RHR3组：RHR〉80次／min。结果代谢综合征患者RHR与IMT呈显著正相关（r=0．432P〈0．01）；且RHR与FPG、TG呈正相关（FPGr=0．24，TGr=0．24，P〈0．05）。结论MS患者RHR与IMT有明显相关性。     

大鼠血管紧张素Ⅱ2型受体基因转染对颈动脉球囊损伤后新生内膜形成的影响

目的　探讨腺病毒载体介导的大鼠血管紧张素Ⅱ2型受体(AT2R)基因转染对大鼠颈动脉球囊损伤后新生内膜形成的影响。方法　应用带有绿色荧光蛋白报告基因的重组腺病毒载体将大鼠AT2R基因转移至颈动脉球囊损伤模型中,2 1d后取材,应用免疫组织化学方法检测AT2R在动脉壁中的表达,图像分析观察其对新生内膜形成的影响。结果　在体大鼠颈动脉腺病毒载体的转染率达4 0 % ,AT2R基因在血管壁的新生内膜、中膜、外膜稳定表达,转染AT2R基因的球囊损伤后颈动脉与绿色荧光蛋白基因对照组相比,血管新生内膜 中膜面积比降低了4 8%。结论　AT2R基因转染可抑制颈动脉球囊损伤后新生内膜的形成,对血管成形术后再狭窄可能有一定的预防作用。     

初诊2型糖尿病患者亚临床动脉粥样硬化的超声检查及危险因素分析

目的探讨初诊2型糖尿病(2型DM)患者亚临床动脉粥样硬化(AS)的发生情况、危险因素及老年患者的临床特点.方法采用无创性高分辨超声血管成像技术筛查255例、病程≤1年2型DM患者的颈总动脉、髂总动脉及股动脉内中膜厚度(IMT)及AS斑块.分别比较老年组与中青年组、老年组有无亚临床AS者在性别、体重指数、腰臀比、血压、血脂谱、糖化血红蛋白水平、胰岛素抵抗等方面的差异.采用Logistic回归分析方法分析初诊2型DM患者亚临床AS发生的危险因素.结果老年组亚临床AS 14例(17.3%),中青年组16例(9.2%,P<0.01).股动脉亚临床AS检出率高于颈总动脉及髂总动脉(分别为8.6% 、 4.7% 和0.4%,P＜0.001).与中青年组收缩压水平[(120±22)mm Hg]比较,老年组较高[(126±19)mm Hg,P＜0.05];老年组无AS与亚临床AS比较,舒张压水平较高(P＜0.001).Logistic回归分析显示亚临床AS发生的危险因素为老龄化、胰岛素抵抗、舒张压水平增高及低水平的高密度脂蛋白胆固醇(P＜0.05).结论初诊2型DM患者部分存在亚临床AS,老年患者罹患率更高;不同部位亚临床AS的发生率存在差异;初诊2型DM伴亚临床AS的老年患者舒张压水平增高,其危险因素为老龄化、胰岛素抵抗、舒张压水平增高及低水平的高密度脂蛋白胆固醇.     

不同糖耐量人群颈动脉内-中膜厚度的对比研究及危险因素分析

目的探讨不同糖耐量人群颈动脉内-中膜厚度(IMT)的差异,揭示糖耐量低减(IGT)在动脉粥样硬化中可能的影响。方法收集正常糖耐量者40名、新诊断的糖耐量低减患者41名、门诊2型糖尿病患者40名,比较不同组间IMT及各项生理、生化指标的差异。结果糖耐量低减患者颈总动脉、颈动脉膨大处、IMT均显著高于糖耐量正常人群(P<0.01),低于2型糖尿病患者(P<0.01)。年龄、体质指数、收缩压、空腹血糖、胰岛素敏感性可能是影响IGT患者IMT的主要危险因素。结论糖耐量低减显著影响患者IMT,IGT,可能是动脉粥样硬化的独立预测因子。     

CDFI联合造影成像技术评价颈动脉IMT及粥样斑块与冠心病的相关性研究

目的：研究颈动脉彩色多普勒超声联合超声造影评价内膜一中层厚度及粥样斑块与冠心病的相关性。方法：选择118例来我院就诊的门诊及住院患者,因不明原因胸痛、心绞痛或心肌梗死,并接受冠脉造影检查者,冠脉造影检查前或造影后行颈动脉超声检查,并观察内膜一中层厚度及粥样斑块与冠心病之间的相关性。结果：颈动脉内膜一中层厚度检测可有效反映颈动脉粥样硬化程度,且与冠心病关系密切。结论：颈动脉超声联合造影为早期发现和筛选心脑血管疾病提供可靠依据。