高频超声检测高血压患者血管内皮舒张功能的探讨

目的：探讨高频超声检测高血压患者血管内皮依赖性舒张功能的临床价值。方法：应用高频超产检测高血压患者（25例）和正常血压患者（18例）休息、反应性充血时,舌下含服硝酸甘油后肱动脉内径的变化。结果：内皮依赖性血管舒张功能高血压组较正常血压组明显减弱（7.14±3.20）%∶（13.71%±6.3）%（P〈0.01）,高血压组和正常血压组比较血管内皮非依赖性舒张功能无显著性差异（P〉0.05）。结论：高血压患者存在血管内皮依赖性舒张功能失调,高频超声能准确可靠地检测血管内皮依赖性舒张功能。     

Impaired myocardial perfusion reserve but preserved peripheral endothelial function in patients with Fabry disease

Summary Fabry disease (McKusick 301500) is an X-linked lysosomal storage disorder due to deficient α-galactosidase A activity, which leads to accumulation of glycosphingolipids, especially in vascular smooth-muscle and endothelial cells. The effect of this accumulation on peripheral and cardiac vascular function is poorly known. We studied 15 Fabry patients (mean age 35 years and mean BMI 24.8 kg/m2) and 30 age- and BMI-matched healthy controls to examine whether myocardial perfusion reserve and peripheral artery endothelial function are altered. Myocardial perfusion was measured at rest and during dipyridamole-induced hyperaemia by positron emission tomography and H₂ ¹⁵O. Myocardial blood flow reserve was calculated as the ratio between the dipyridamole-induced maximal blood flow and resting blood flow. Peripheral artery endothelial function was assessed by measuring the brachial artery flow-mediated dilatation using ultrasound at rest and during reactive hyperaemia. The myocardial perfusion reserve was significantly lower in Fabry patients than in controls (3.3 ± 1.2 vs 4.4 ± 1.6, p = 0.02), while the brachial artery flow-mediated dilatation was similar (5.9% ± 3.9%vs 4.5% ± 3.6%, p = 0.27). Thus, inFabry disease, myocardial perfusion reserve is reduced while the peripheral artery endothelial function is preserved.     

Reproducibility of brachial ultrasonography and flow-mediated dilatation (FMD) for assessing endothelial function

Abstract Background : High-resolution brachial artery ultrasonography is used to study vasodilator response induced by physiologic reactive hyperaemia. We examined the reproducibility of measuring flow-mediated dilatation (FMD) on two occasions.
Aims : To determine the degree of variability of this technique in our vascular laboratory for the design of clinical research studies.
Methods : Nineteen subjects were studied on two separate occasions using an Acuson 128 ultrasound device and a 7.0 MHz linear array transducer. Reactive hyperaemia was induced in the brachial artery by inflation and release of a blood pressure cuff. Nitrate-induced dilatation was assessed in 11 of the 19 subjects. Measurements were made by two observers blinded to subject details.
Results : The 11 subjects given sublingual GTN during the first ultrasound study had a mean nitrate-induced dilatation of 20.7% (sd 9.6). The mean vessel diameter of 3.78 mm (sd 0.7) at rest and 3.89 mm (sd 0.7) during reactive hyperaemia yielded a mean FMD of only 3.0% (sd 2.7). The mean difference in FMD within-observers was 0.13% (sd 2.07), between-observers 0.06% (sd 2.17) and between-studies was 0.57% (sd 6.83).
Conclusions : The reproducibility of FMD measured by brachial artery ultrasound was poor and likely to render the measurements inaccurate for clinical research in our hands. Between-study variation contributed the largest proportion of total study variability. We suggest that investigators using this technique conduct their own careful reproducibility studies in order to avoid the misinterpretation of 'negative' studies.     

Handgrip exercise increases postocclusion hyperaemic brachial artery dilatation

OBJECTIVE: To examine the effect of handgrip exercise induced ischaemia on non-invasive assessment of endothelial function in the brachial artery. DESIGN AND SETTING: High frequency ultrasound was used to measure brachial artery diameter at rest and after reactive hyperaemia induced by forearm cuff occlusion with and without handgrip exercise induced ischaemia. SUBJECTS: 10 healthy subjects, < 40 years, without known cardiovascular risk factors. MAIN OUTCOME MEASURES: Brachial artery dilatation and blood flow. RESULTS: Hyperaemia following forearm occlusion with handgrip exercise induced ischaemia increased brachial artery diameter significantly more than hyperaemia following occlusion alone, 6.9 (3.2)% and 4.5 (1.6)%, respectively (95% confidence interval 0.3% to 4.5%). There was no difference in peak blood flow with and without exercise induced ischaemia CONCLUSIONS: Handgrip exercise induced ischaemia with forearm occlusion caused more pronounced brachial artery dilatation than occlusion alone without change in peak blood flow. This suggests continued brachial artery responsiveness to the stimulus of ischaemia despite maximum blood flow and peripheral vasodilatation with occlusion alone.     

原发性高血压合并高尿酸血症患者血管内皮依赖性舒张功能变化及临床意义

目的探讨原发性高血压（EH）合并高尿酸血症患者血管内皮依赖性舒张功能的变化及意义。方法选择EH患者30例、EH合并高尿酸血症患者60例及健康体检者30例,采用无创性高分辨超声技术检测三组休息、反应性充血、舌下含服硝酸甘油（GTN）后肱动脉内径的变化。结果EH及EH合并高尿酸血症患者肱动脉血流介导性扩张百分比明显低于正常组（P〈0．05）,EH合并高尿酸血症患者下降更明显（P〈0．01）;舌下含服GTN后EH合并高尿酸血症组肱动脉内径变化与正常对照组比较有统计学差异（P〈0．05）,EH组与正常对照组之间无统计学差异。结论EH合并高尿酸血症患者存在血管内皮依赖性舒张功能失调,高尿酸血症可加重血管内皮依赖性舒张功能的损害。     

Noninvasive Assessment of Endothelial Dysfunction in Essential Hypertension: Comparison of the Forearm Microvascular Reactivity with Flow-mediated Dilatation of the Brachial Artery

Endothelial dysfunction is detectable both in the forearm skin microcirculation by laser Doppler flowmetry and in the brachial artery by Duplex Ultrasound. The aim of the study was to evaluate whether endothelium-dependent vasodilation in the forearm microcirculation is related to endothelium-dependent flow mediated dilation (FMD) of the brachial artery. In 22 treated male essential hypertensive patients (EHT) who had impaired FMD of the brachial artery, and in 11 male normotensive subjects (NT) we measured first the postocclusive reactive hyperemic response (PORH), then the effect of two doses of acetylcholine (ACh) and sodium nitroprusside (SNP) on the forearm skin microcirculation. FMD resulted from forearm reactive hyperemia induced by 5 minutes of ischaemia and the vasodilation induced by sublingual nitroglycerine (GTN) were also measured. Responses were calculated as the maximal percent increase above baseline. PORH and the responses to ACh were significantly (p < 0.05, p <0.01) reduced in EHT (272 ± 180, 177 ± 194, 463 ± 302) as compared to NT (409 ± 123, 470 ± 467, 805 ± 603). Response to SNP was similar. FMD was significantly (p < 0.001) reduced in EHT as compared to NT (3.98 ± 2.2 vs 9.3 ± 2.88), while response to GTN was similar. There was no significant relationship (p = n.s.) either between maximal response to ACh and FMD (r = 0.28), or between PORH and FMD (r = –0.01). Endothelial dysfunction was detectable with both methods in EHT. Our results show that endothelium-dependent vasodilation in forearm microcirculation is not related to FMD of the brachial artery. This can be explained by the differences in vascular beds and mechanism involved in the hyperemic response. The study was supported by a grant of the Hungarian Scientific Council (OTKA T29420).     

Soy protein diet significantly improves endothelial function and lipid parameters.

BACKGROUND: Replacement of animal protein with soy protein in the diet is associated with decreased cholesterol levels. However, the effects of soy protein diet on endothelial function are not well known. HYPOTHESIS: The aim of the study was to investigate the effects of soy protein diet on plasma lipids and endothelial function parameters assessed by two different methods. METHODS: Twenty hypercholesterolemic, nonsmoker male patients (age 50.1+/-11.8 years), with a normal body mass index, were included. After calculating their daily requirements, a diet with 25-30% of energy from fats. 10-12% from proteins, and the rest from carbohydrates was instituted. Sixty percent of the animal source proteins of the diet were substituted by soy. The anthropometric measures, lipid parameters, and endothelial functions of the subjects were assessed at baseline and 6 weeks after soy protein diet. Flow-mediated endothelium-dependent dilatation (EDD) and plasma thrombomodulin (TM) levels were evaluated as endothelial function parameters. RESULTS: After diet, plasma total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, and triglyceride levels decreased significantly (p <0.001, p < 0.001, p = 0.039, and p = 0.001, respectively). The mean plasma TM levels were also significantly reduced with diet (p = 0.004). Studies of the brachial artery indicated a borderline dilatation in baseline brachial artery diameter (p = 0.05), however the diameter at reactive hyperemia was significantly larger after diet (p<0.001), resulting in a significant improvement of EDD (p = 0.002). CONCLUSION: Soy protein diet significantly improves plasma lipid profile in patients with hypercholesterolemia. Furthermore, the endothelial function, as judged by two different methods (EDD and plasma TM levels), also improves with soy protein diet.     

彩色多谱勒超声对原发性高血压患者血管内皮功能的评价

目的探讨彩色多谱勒超声(CDU)评价高血压患者血管内皮功能的临床意义。方法将50例原发性高血压患者分为Ⅰ(低/中危组)、Ⅱ(高/极高危组)两个实验组,并设对照组Ⅲ,实验组患者给予卡维地洛(Carvedilol)治疗12周,用CDU测定治疗前后基础状态下、反应性充血时和含服硝酸甘油后肱动脉内径及血流量变化。结果(1)原发性高血压患者反应性充血时肱动脉内径的扩张程度及血流量与正常对照组相比有显著性差异;(2)原发性高血压患者卡维地洛治疗12周后反应性充血时肱动脉内径扩张程度及血流量与治疗前相比显著改善。结论应用CDU可较准确、简便、有效地评价高血压患者血管内皮功能,并对临床药物治疗效果的评定也有一定参考价值。     

Does a glass of red wine improve endothelial function?

AIMS: To examine the acute effect of red wine and de-alcoholized red wine on endothelial function. METHODS AND RESULTS: High frequency ultrasound was used to measure blood flow and percentage brachial artery dilatation after reactive hyperaemia induced by forearm cuff occlusion in 12 healthy subjects, less than 40 years of age, without known cardiovascular risk factors. The subjects drank 250 ml of red wine with or without alcohol over 10 min according to a randomized procedure. Brachial artery dilatation was measured again 30 and 60 min after the subjects had finished drinking. The subjects were studied a second time within a week of the first study in a cross-over design. After the red wine with alcohol the resting brachial artery diameter, resting blood flow, heart rate and plasma-ethanol increased significantly. After the de-alcoholized red wine these parameters were unchanged. Flow-mediated dilatation of the brachial artery was significantly higher (P<0.05) after drinking de-alcoholized red wine (5.6+/-3.2%) than after drinking red wine with alcohol (3.6+/-2.2%) and before drinking (3.9+/-2.5%). CONCLUSION: After ingestion of red wine with alcohol the brachial artery dilated and the blood flow increased. These changes were not observed following the de-alcoholized red wine and were thus attributable to ethanol. These haemodynamic changes may have concealed an effect on flow-mediated brachial artery dilatation which did not increase after drinking red wine with alcohol. Flow-mediated dilatation of the brachial artery increased significantly after de-alcoholized red wine and this finding may support the hypothesis that antioxidant qualities of red wine, rather than ethanol in itself, may protect against cardiovascular disease.     

Impairment of endothelium-dependent arterial dilation in Hashimoto's thyroiditis patients with euthyroidism

OBJECTIVE: Recent studies have shown that immune responses contribute to atherosclerosis, and endothelial dysfunction is an important early event in atherogenesis. The aim of this study was to investigate the alteration of endothelial function in Hashimoto's thyroiditis (HT) patients with euthyroidism. METHODS: Study subjects included 28 female HT patients with euthyroidism, 23 female HT patients with hypothyroidism, and 22 healthy women. High-resolution ultrasound was used to measure brachial artery diameter at rest, after reactive hyperaemia and after sublingual glyceryltrinitrate (GTN). RESULTS: Flow-mediated arterial dilation in HT patients with euthyroidism was significantly lower (3.88%) than in controls (4.98%, P = 0.000) and higher than in HT patients with hypothyroidism (3.26%, P < 0.001). Flow-mediated arterial dilation among HT patients with hypothyroidism was significantly lower than that in controls (P = 0.000). GTN-induced arterial dilation, baseline vessel size, and baseline blood flow were not significantly different among the three groups (P > 0.05). On multiple regression analysis, anti-thyroid peroxidase antibody (TPO-Ab), TSH, free T3, low density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] were found to be significant factors associated with endothelium-dependent arterial dilation. CONCLUSION: Endothelial dysfunction exists in HT patients with euthyroidism. Autoimmune reactivity and an elevated Lp(a) level might be responsible for the endothelial dysfunction.     

Coenzyme Q10 improves endothelial dysfunction of the brachial artery in Type II diabetes mellitus

Aim/hypothesis: We assessed whether dietary supplementation with coenzyme Q₁₀ improves endothelial function of the brachial artery in patients with Type II (non-insulin-dependent) diabetes mellitus and dyslipidaemia. Methods: A total of 40 patients with Type II diabetes and dyslipidaemia were randomized to receive 200 mg of coenzyme Q₁₀ or placebo orally for 12 weeks. Endothelium-dependent and independent function of the brachial artery was measured as flow-mediated dilatation and glyceryl-trinitrate-mediated dilatation, respectively. A computerized system was used to quantitate vessel diameter changes before and after intervention. Arterial function was compared with 18 non-diabetic subjects. Oxidative stress was assessed by measuring plasma F₂-isoprostane concentrations, and plasma antioxidant status by oxygen radical absorbance capacity. Results: The diabetic patients had impaired flow-mediated dilation [3.8 % (SEM 0.5) vs 6.4 % (SEM 1.0), p = 0.016], but preserved glyceryl-trinitrate-mediated dilation, of the brachial artery compared with non-diabetic subjects. Flow-mediated dilation of the brachial artery increased by 1.6 % (SEM 0.3) with coenzyme Q₁₀ and decreased by –0.4 % (SEM 0.5) with placebo (p = 0.005); there were no group differences in the changes in pre-stimulatory arterial diameter, post-ischaemic hyperaemia or glyceryl-trinitrate-mediated dilation response. Coenzyme Q₁₀ treatment resulted in a threefold increase in plasma coenzyme Q₁₀ (p < 0.001) but did not alter plasma F₂-isoprostanes, oxygen radical absorbance capacity, lipid concentrations, glycaemic control or blood pressure. Conclusion/interpretation: Coenzyme Q₁₀ supplementation improves endothelial function of conduit arteries of the peripheral circulation in dyslipidaemic patients with Type II diabetes. The mechanism could involve increased endothelial release and/or activity of nitric oxide due to improvement in vascular oxidative stress, an effect that might not be reflected by changes in plasma F₂-isoprostane concentrations. [Diabetologia (2002) 45: 420–426] Received: 14 August 2001 and in revised form: 15 November 2001     

Serum uric acid is associated with microvascular function in hypertensive individuals

We investigated the relationship of serum uric acid (UA) with resting forearm blood flow (FBF), reactive hyperaemia (RH) and flow-mediated dilation (FMD) of the brachial artery in hypertensive adults (n=506, mean age 62 years, 59% women). UA was measured by a colorimetric method. FBF, RH and FMD were measured by brachial artery ultrasound. Regression analyses were used to assess whether UA was associated with FBF, RH and FMD before and after adjustment for age, sex, systolic BP, diabetes, total and high-density lipoprotein cholesterol, smoking, body mass index (BMI), C-reactive protein (CRP), serum creatinine, alcohol intake, statin and diuretic use and brachial artery diameter (BAD). UA was significantly associated with FBF (P<0.0001) and RH (P=0.0001) but not with FMD (P=0.43). After adjustment for the covariates listed above, higher UA level remained independently associated with a higher FBF (P=0.012) and lower RH (P=0.004). The independent predictors were as follows: (a) higher FBF: lower age, higher BMI, history of smoking, statin use, higher CRP, higher BAD and higher UA levels; (b) lower RH: higher BMI, diabetes and higher UA levels; (c) lower FMD: greater age, male sex, higher BMI, history of smoking, statin use and higher BAD. We conclude that in hypertensive individuals, higher UA levels are associated with higher resting FBF and lower RH, markers of microvascular function, but not with brachial artery FMD.     

Protective effect of high density lipoprotein on endothelium-dependent vasodilatation

Low concentrations of high-density lipoprotein cholesterol (HDL-C) have been associated with increased risk of coronary heart disease (CHD) even when the total cholesterol (TC) and triglyceride (TG) levels are not elevated. The mechanism by which HDL confers protection against atherosclerosis remains speculative. Using high-resolution ultrasound, we measured the dilatation changes of brachial arteries during reactive hyperemia and after sublingual glyceryl trinitrate (GTN) in 63 patients with established (CHD) and 45 controls, in which the serum TC level was normal. The results showed that both flow-mediated dilatation (FMD) and GTN-induced dilatation of brachial arteries in patients with CHD were much reduced compared with control group (2.31+/-2.46% vs. 7.43+/-4.10% and 16.41+/-6.15% vs. 22.44+/-8.63%, respectively, P<0.001 for all). Univariate analysis indicated that FMD of brachial arteries was inversely related to age (r=-0.226, P<0.05), hypertension (r=-0.229, P<0.05), baseline diameter (r=-0.299, P<0.01) and LDL-C (r=-0.237, P<0.05) and positively related to HDL-C (r=0.491, P<0.01). GTN induced vasodilatation was inversely related to age (r=-0.216, P<0. 05) and baseline diameter (-0.476, P<0.01). Multiple stepwise regression analyses in two groups taken together showed that HDL-C and age were the independent predictors of the FMD of brachial arteries (beta=0.466, P=0.000 and beta=-0.184, P=0.020, respectively). Baseline diameter was significant predictor of GTN-induced vasodilatation (beta=-0.390, P=0.000). The analysis in the group of CHD patients showed that only HDL-C was significantly relate to the FMD of brachial arteries (beta=0.295, P=0.018 ) and in controls that hypertension and HDL-C were significantly relate to the FMD of brachial arteries (beta=-0.395, P=0.004 and beta=0.344, P=0.011, respectively). These finding suggest that endothelium-dependent and endothelium-independent vasodilatation are impaired in the patients with CHD. HDL exerts a protective effect on endothelium-dependent vasodilatation in TC being relatively normal population.     

Effect of fat distribution on endothelial-dependent and endothelial-independent vasodilatation in healthy humans

AIM: The present study aims to explore the relationship between inflammatory cytokines, plasma lipids, insulin, blood pressure (BP), total adiposity/markers of fat distribution and endothelial function in healthy people across a wide range of body fatness. METHODS: Seventy-three healthy people (44 women; age range: 24-64 years) with body mass index (BMI) range of 18.6-73.1 kg/m2 were recruited. All participants underwent assessment of conduit artery endothelial-dependent vasodilatation by using flow-mediated vasodilatation (FMD) of the brachial artery and endothelial-independent vasodilatation to sublingual GTN. They had blood taken for measurement of plasma markers of glucose homeostasis (fasting insulin and glucose), systemic inflammation (interleukin-6 (IL-6), C-reactive protein (CRP) and tumour necrosis factor-alpha receptor 2 (TNF-alpha R2)) and lipids (low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglycerides). Morphometric assessment (waist circumference, BMI and waist-to-hip ratio (WHR)) and systolic and diastolic arterial pressure were also measured. RESULTS: Markers of total body fat/fat distribution (waist circumference, BMI and WHR), inflammation (IL-6, CRP and TNF-alpha R2), metabolism (fasting insulin, HDL, LDL and triglycerides) and BP (systolic and diastolic) correlated with FMD. Among these measurements, WHR was the only independent predictor of FMD (r2 = 0.30; p = 0.0001). CONCLUSIONS: WHR is an important marker of endothelial dysfunction in healthy people across a wide range of body fatness.     

Atorvastatin therapy improves endothelial-dependent vasodilation in patients with systemic lupus erythematosus: an 8 weeks controlled trial

INTRODUCTION: Patients with systemic lupus erythematosus (SLE) have recognized reduction in endothelium-dependent vasodilation. Evidence demonstrates that statins are able to improve endothelial function independently on their hypolipemic action. OBJECTIVES: To evaluate the efficacy of atorvastatin in improving vasodilation in SLE patients with and without conventional risk factors for coronary heart disease (CHD). PATIENTS AND METHODS: Sixty-four SLE women, mean age 31 +/- 8 yrs, received atorvastatin 20 mg/day during 8 weeks. Thirty-one patients in this intervention group did not have conventional risk factors for CHD, while 33 others had hypertension, dyslipidaemia and/or obesity. Twenty-four SLE control patients, mean age 34 +/- 7.5 yrs, not receiving atorvastatin were followed during the same time period. High-resolution ultrasound was used to measure brachial artery diameter in resting conditions, during reactive hyperaemia and after sub-lingual glyceryl trinitrate (GTN). Measurements were performed at baseline and at the end of the study (8 weeks). RESULTS: Atorvastatin was associated with a significant increase in flow-mediated dilation (FMD) [3.8 (2.8-7.9%) vs 6.9 (4.2-10.7%), P < 0.001] while GTN-mediated dilation (GTND) was unaffected [20.9 (16.6-26.1%) vs 20.1(16.6-25.4%), P = 0.514]. FMD increase was observed in patients with conventional risk factors [4.1 (3.1-8.7%) vs 6.5 (4-10%), P = 0.046] and also for those without conventional risk factors for CHD [3.6 (2.6-7.3%) vs 7.1 (4.5-10.9%), P = 0.001]. Resting brachial artery diameter also increased significantly in patients receiving atorvastatin (2.79 +/- 0.30 mm vs 2.92 +/- 0.40 mm, P < 0.001). No significant difference in artery diameter and FMD was seen in control patients at the end of the study. When compared to the control patients, atorvastatin treatment was associated with significant increase in resting diameter (+0.13 +/- 0.1 mm vs -0.02 +/- 0.07 mm, P < 0.001) and FMD (+1.9 +/- 3.9% vs -0.3 +/- 1.8%, P = 0.009). CONCLUSION: Our results demonstrate that an 8-week 20 mg/day atorvastatin series improved endothelium-dependent vasodilation in SLE patients independently on the presence of conventional risk factors for atherosclerotic disease.     

高分辨率超声检测代谢综合征患者血管内皮功能

为了研究代谢综合征患者的血管内皮功能及与心血管危险因素的相关性 ,采用高分辨率超声测定 2 1例正常对照者、35例代谢综合征患者的肱动脉反应性充血及含服硝酸甘油后的血管内经和血流量的变化。结果发现 ,两组间甘油三酯、空腹血糖、餐后 2h血糖、收缩压、舒张压和体质指数差异有显著性 (P <0 .0 5或P <0 .0 1) ,而性别、年龄、总胆固醇、高密度脂蛋白胆固醇和低密度脂蛋白胆固醇差异均无显著性 (P >0 .0 5 )。两组间反应性充血后血管内径变化率、含服硝酸甘油后血管内径变化率和含服硝酸甘油后血流量变化率差异有显著性 (P <0 .0 1或P <0 .0 5 ) ,而肱动脉基础内径、肱动脉基础血流量、反应性充血后血流量、含服硝酸甘油后血流量、反应性充血后血流量变化率差异无显著性 (P >0 .0 5 )。两组反应性充血后血管内径变化率较含服硝酸甘油后血管内径变化率降低 (P <0 .0 1)。反应性充血后血管内径变化率与患者年龄 (r=- 0 .2 9,P <0 .0 5 )、甘油三酯 (r=- 0 .38,P <0 .0 5 )、收缩压 (r=- 0 .71,P <0 .0 1)、舒张压 (r=- 0 .6 1,P <0 .0 1)、空腹血糖 (r =- 0 .6 2 ,P <0 .0 1)、餐后 2h血糖 (r=- 0 .6 6 ,P <0 .0 1)和体质指数 (r=- 0 .4 7,P <0 .0 1)呈负相关。结果提示 ,代谢综合征患者存在血管内皮依     

Metabolic disorders induced by highly active antiretroviral therapy and their relationship with vascular remodeling of the brachial artery in a population of HIV-infected patients

Antiretroviral therapy has positively modified the natural history of HIV infection; but this treatment can induce metabolic abnormalities, including dyslipidemia, fat redistribution, high blood pressure, and insulin resistance. The metabolic syndrome, a clustering of the metabolic disorders, is frequently detected among HIV patients, especially those on antiretroviral treatment. All the arteries can modify their diameter in response to a chronic injury. This process, defined vascular remodeling, was demonstrated for the brachial artery. It is well known that the diameter of the brachial artery was correlated with the number of the elements of the metabolic syndrome and was associated with the severity of coronary artery disease. On this basis, we postulate that brachial arterial enlargement may be a process potentially correlated with the metabolic disorders induced by antiretroviral therapy. We tested this hypothesis in a large population of HIV-infected patients in which we measured brachial artery diameter, as an indicator of artery remodeling, by noninvasive, ultrasonographic technique. Our population consisted of 570 patients, with a mean age of 46.3 ± 7.1 years. All the patients were chronically treated with highly active antiretroviral therapy. Brachial artery diameter was correlated with insulin resistance, evaluated by the homeostasis model assessment of insulin resistance index (r = 0.18, P < .0001). There was a significant linear increase in brachial artery diameter as the number of components of the metabolic syndrome increased: brachial artery diameter for those with 0, 1, 2, 3, or + characteristics was 39.3 ± 7.2, 41.0 ± 6.8, 42.0 ± 7.3, and 43.8 ± 7.9 mm, respectively (P < .001 for trend). In multivariable logistic regression analysis, brachial artery diameter was independently correlated with the presence of metabolic syndrome. Our results are in line with the hypothesis that, among HIV-infected patients chronically treated with antiretroviral therapy, those with a larger brachial artery diameter are at high risk for metabolic disorders, including a more severe insulin resistance and the presence of metabolic syndrome.     

青年高血压病患者血管内皮依赖性舒张功能的无创伤性评价

为了评价无其它动脉粥样硬化因素及粥样斑块的青年高血压病患者的血管内皮依赖性舒张功能 ,用B型超声对 45例 35岁以下的青年高血压病患者和 2 0例健康对照者在反应性充血和舌下含服硝酸甘油后肱动脉内径进行了检测。结果发现 ,青年高血压病患者前臂加压后肱动脉内径增加的比例明显小于对照组 (前者为 12 .32 %± 4.94% ,后者为 16 .6 3%± 5 .87% ,P <0 .0 1) ,而在舌下含服硝酸甘油后肱动脉内径的变化两组间无显著性差异(前者为 18.94%± 6 .5 0 % ,后者为 2 1.0 2 %± 6 .6 5 % ,P >0 .0 5 )。提示青年高血压病患者虽然没有明显的动脉粥样硬化的证据和其它易患因素 ,但已经存在显著的血管内皮依赖性舒张功能障碍。     

Remnant lipoproteinemia is a risk factor for endothelial vasomotor dysfunction and coronary artery disease in metabolic syndrome

This study aimed to determine whether elevated levels of remnant lipoprotein, an atherogenic triglyceride-rich lipoprotein, might be associated with coronary artery disease (CAD) and endothelial vasomotor dysfunction in metabolic syndrome. The fasting serum levels of remnant lipoproteins (remnant-like lipoprotein particles cholesterol; RLP-C) were measured by an immunoseparation method in 210 patients with metabolic syndrome meeting ATP III criteria. Flow-mediated endothelium-dependent dilatation (FMD) in the brachial artery during reactive hyperemia was examined by high-resolution ultrasound technique. This study found that elevated RLP-C levels were a significant and independent risk factor for impaired FMD and angiographically proven coronary artery disease (CAD). Treatment with bezafibrate (n = 20) or atorvastatin (n = 20) for 4 weeks significantly reduced RLP-C levels, with a concomitant improvement in FMD. The % reduction in RLP-C levels from baseline after the treatment was independently correlated with the magnitude of improvement in FMD after adjustment for the % changes in levels of triglyceride, hsCRP, and IL-6, and HOMA index. Thus, elevated levels of RLP-C are a risk factor for CAD and endothelial vasomotor dysfunction, a predictor of coronary events, in metabolic syndrome. Measurement of RLP-C is useful for assessment of CAD risk and therapeutic effects in metabolic syndrome.     

阿托伐他汀对冠心病患者的血管舒张功能的影响

目的观察阿托伐他汀对冠心病患者血管舒张功能的作用。方法将入选60例冠心病并高胆固醇血症患者随机分为阿托伐他汀治疗组(A组)和对照组(B组)。分别测定血清胆固醇、三酰甘油、低密度脂蛋白胆固醇和高密度脂蛋白胆固醇。并应用高分辨率超声技术,检测治疗前、后两组肱动脉血流介导和硝酸甘油介导的舒张功能。结果治疗前,冠心病并高胆固醇血症患者肱动脉血流介导和硝酸甘油介导的舒张功能均低于健康对照组(P<0.01)。经阿托伐他汀治疗6个月后A组血浆总胆固醇、三酰甘油和低密度脂蛋白胆固醇显著降低(P<0.01),高密度脂蛋白胆固醇显著升高(P<0.01)。随着血脂的改善,肱动脉内皮依赖性血管舒张功能显著提高(P<0.01),但硝酸甘油介导的血管舒张功能未见改善(P>0.05)。结论冠心病并高胆固醇血症患者存在内皮依赖性血管舒张功能障碍,经阿托伐他汀调脂治疗后,受损的内皮依赖性血管舒张功能得到明显改善。