Small and large artery elasticity indices in peripheral arterial occlusive disease (PAOD)

In peripheral arterial occlusive disease (PAOD), arterial compliance of the central arteries has been reported to be reduced. It is, however, not clear whether, in PAOD, decreased arterial compliance is also accompanied by similar changes in the peripheral arteries. Therefore the aim of the study was to determine the large (C1) and small (C2) artery elasticity indices in PAOD and their relations to its well-accepted characteristics (ankle-brachial index, ABI; pulse pressure, PP; absolute claudication distance, ACD). A total of 43 patients with PAOD (mean age 68 +/- 9 years; ABI of the limiting leg 0.65 +/- 0.14; SBP (systolic blood pressure) 149 +/- 20 mmHg, and ACD 488 +/- 187 m) were enrolled as well as 16 control subjects of comparable age (69 +/- 4 years) and blood pressure (SBP 147 +/- 27 mmHg). All subjects underwent non-invasive pulse wave analysis in order to determine arterial compliance of the aorta and major side branches (C1) and of the distal circulation (C2), using a modified Windkessel model. In PAOD, both C1 (1.41 +/- 0.56 ml/mmHg) and C2 (0.023 +/- 0.012 ml/mmHg) were comparable to values in an age and blood pressure-matched control group (C1, 1.25 +/- 0.66 ml/mmHg; C2, 0.027 +/- 0.008 ml/mmHg). C1 was significantly correlated with ACD (r = 0.36, p = 0.02), PP (r = -0.33, p < 0.02) and only borderline with ABI (r = 0.28, p = 0.07). C2 was correlated with PP (r = -0.38, p < 0.01), ABI (r = 0.36, p < 0.02) but not with ACD. Large (C1) and small (C2) artery elasticity indices in PAOD were decreased but comparable to values in an elderly group with isolated systolic hypertension. Moreover, C1 and C2 correlated with markers (ABI and PP) of severity of vascular disease.     

Basal cerebral blood flow is dependent on the nitric oxide pathway in elderly but not in young healthy men

OBJECTIVE: Brain perfusion is tightly regulated over a wide range of blood pressures by local regulation of cerebral blood flow (CBF). Ageing is associated with impaired CBF and impaired nitric oxide mediated vasodilator responses. The role of nitric oxide in the regulation of basal CBF in young and older subjects was investigated, using the nitric oxide synthase inhibitor L-NMMA as pharmacological tool. METHODS: We used a gradient echo phase-contrast magnetic resonance imaging technique to investigate the role of nitric oxide in the regulation of cerebral blood flow in young (25+/-7.1 years; n=8) and old (78+/-6.6 years; n=7) volunteers. The study was performed in a double-blinded fashion and consisted of two study days. On one day the effects of the intravenously infused L-NMMA on CBF and blood pressure was measured and on the other day the effects of a matching placebo. RESULTS: Basal CBF was significantly lower in old compared to young subjects (590+/-20 vs 704+/-20 ml/min), while the cerebral vascular resistance (CVR) levels were significantly higher (0.15+/-0.01 (arbitrary units) vs 0.12+/-0.01, respectively). Infusion of L-NMMA significantly increased mean arterial pressure in both groups (2.8+/-1.2 mmHg; p=0.02 in the young and in the old subjects 5.6+/-1.1 mmHg; p<0.001). Infusion of L-NMMA significantly decreased CBF (49+/-12 ml/min; p<0.001) and increased CVR (0.02+/-0.004; p<0.001) in the old subjects but did not significantly influence cerebral circulation in the young subjects. CONCLUSION: We conclude that compared to young subjects, in old people CBF is impaired, and dependent on the intactness of the nitric oxide pathway.     

冠心病患者血管内皮功能障碍与动脉弹性关系的研究

目的　探讨冠心病患者血管内皮功能障碍与动脉弹性的关系。方法　采用高分辨率血管超声法检测 30例冠心病患者与 30例正常对照组肱动脉血流介导的内皮依赖性血管舒张功能(FMD);应用动脉弹性功能检测仪测定受试者的大动脉弹性指数 (C1 )和小动脉弹性指数 (C2 )。结果　冠心病组血流介导的肱动脉舒张反应明显低于对照组[ (5 17±2 13)% 与 (11 10±4 36)%,P<0 05];冠心病组与正常对照组的C1 差异无统计学意义 [ ( 11 59±4 56 )ml/mmHg( 1mmHg=0 133kPa) ×10与 (12 11±3 82)ml/mmHg×10, P>0 05],但冠心病组的C2 明显低于正常对照组[ (4 20±1 80)ml/mmHg×100与 (6 26±2 36)ml/mmHg×100, P<0 05],冠心病组血流介导的肱动脉舒张反应与C2 呈正相关(r=0 53, P<0 05)。结论　冠心病患者肱动脉内皮依赖血管舒张功能受损和C2 降低,且两者之间呈正相关,提示C2 可作为一种评价血管内皮功能的新指标。     

Relationship between C-reactive protein and arterial stiffness in an asymptomatic population

Plasma concentration of high sensitive C-reactive protein (hsCRP) is used as a marker for inflammatory states and is directly correlated with the risk for coronary heart disease. Evidence concerning the role of inflammation in atheroma formation has been derived from several models of atherosclerosis. Inflammation should exert its adverse vascular effects by structural changes in the artery wall and consequently alterations in arterial elasticity, which could be detected already in asymptomatic early vascular disease. We hypothesized that CRP is related to large artery elasticity, but not to small artery elasticity in early vascular disease. Therefore, we examined the association between arterial stiffness of large and small arteries and inflammation in an asymptomatic population referred for primary prevention cardiovascular screening. Studies were performed in 391 subjects (age 21-82 years; 254 men, 137 women) who underwent screening at the Cardiovascular Disease Prevention Center. Large artery (C1) and small artery (C2) elasticity indices were obtained by the CVProfiler 2000 (HDI, Eagan, MN, USA). After overnight fasting, venous samples were taken for measurement of hsCRP, lipids, glucose. There was a significant inverse correlation between hsCRP (0.29 +/- 0.40 mg/dl) and C1 (16.7 +/- 5.8 ml/mmHg), r = -0.133, P = 0.01; there was no significant correlation between hsCRP and C2 (6.6 +/- 3.2 ml/mmHg). C2, but not hsCRP, was inversely correlated with age, abnormal lipids and glucose, whereas C1, but not hsCRP, was inversely correlated with age and systolic blood pressure (SBP). In multiple regression analysis, the relationship between hsCRP and C1 was not affected by age, body mass index, SBP, serum glucose or lipids. In conclusion, these findings support the hypothesis that hsCRP, a marker for acute and low-grade inflammation, is associated with large artery but not with small artery elasticity in asymptomatic individuals undergoing primary prevention cardiovascular screening.     

Relationship between arterial elasticity indices and carotid artery intima-media thickness

Functional and structural changes of the arterial wall appear to serve as early hallmarks of the hypertensive disease process. Structural vascular changes can be studied by the determination of the intima-media wall thickness (IMT) at the carotid artery. The elastic behavior of the proximal and distal parts of the arterial tree can be assessed from noninvasively recorded radial artery waveforms. The aim of the study was to compare large (proximal, C1) and small (distal, C2) artery elasticity indices in two age-matched study groups with high- and low-normal blood pressure (BP) and to assess the relation between elasticity indices and IMT. A total number of 22 subjects with high-normal BP (40 +/- 2 years; BP, 147 +/- 2.5/84 +/- 1.5 mm Hg) and 22 matched controls with low-normal BP (40 +/- 2 years; BP, 123 +/- 1.9/69 +/- 1.5 mm Hg) were enrolled. The IMT was echographically determined at the common carotid artery by the leading-edge technique. Large artery (C1) and small artery (C2) elasticity indices were calculated from a third-order, four-element model of the arterial circulation. In the group with high-normal BP large and small artery elasticity indices were significantly decreased versus controls with low-normal BP (C1: 1.63 +/- 0.08 v 1.99 +/- 0.09 mL/mm Hg, P < .01; C2: 0.059 +/- 0.005 v 0.076 +/- 0.007 mL/ mm Hg, P < .05) and IMT increased significantly (0.607 +/- 0.039 v 0.516 +/- 0.027 mm, P < .05). Moreover, there was an inverse relationship between IMT and small artery elasticity index (r = -0.60, P = .004). In subjects with a high-normal BP there is already a change in the IMT of the carotid artery versus normotension. The IMT is related to the small artery elasticity index (C2).     

Blood pressure variability and silent cerebral damage in essential hypertension

BACKGROUND: It is recognized that blood pressure (BP) variability has prognostic significance in determining target organ damage and cardiovascular mortality and morbidity. The aim of this study was to analyze the association between blood pressure variability and the presence of silent cerebral white matter lesions in middle-aged asymptomatic essential hypertensives. METHODS: We studied 43 middle-aged untreated hypertensive patients. Blood pressure variabilities (short-term and long-term) were evaluated by using both non-invasive, beat-to-beat, continuous finger 24-hour monitoring (Portapres) and oscillometric automated discontinuous ambulatory blood pressure monitoring. All patients underwent cerebral magnetic resonance imaging to detect the presence or not of white matter lesions. RESULTS: Hypertensive patients with cerebral white matter lesions exhibited significantly higher values of long-term systolic blood pressure variability (standard deviation of 24-hour blood pressure) measured both by continuous beat-to-beat monitoring (16.2 +/- 3.7 v 13.7 +/- 3.6 mm Hg; P = 0.047) and by ambulatory blood pressure monitoring (15.2 +/- 3.8 v 12.8 +/- 2.7 mm Hg; P = 0.022). However, these differences were not independent on blood pressure elevation and did not maintain their significance after adjusting for 24-hour systolic blood pressure. Neither short-term systolic blood pressure variability, nor short-term or long-term diastolic blood pressure variabilities showed differences between patients with and without white matter lesions. CONCLUSION: The present study indicates that long-term systolic blood pressure variability is significantly related to the presence of silent cerebral white matter lesions in essential hypertensive patients, although this relationship is partially dependent on absolute blood pressure elevation.     

Assessment of repeatability and correlates of arterial compliance

OBJECTIVES: The aim of these studies was to assess repeatability of large (C1) and small (C2) arterial elasticity indices over various time intervals using the HDI/Pulsewave CR-2000 Research CardioVascular Profiling System (Hypertension Diagnostics, Inc., Eagan, Minnesota, USA). Non-invasive hemodynamic parameters using this device were compared to invasive measurements. METHODS: After a 5-min period of rest, 31 healthy hospital employees underwent cardiovascular profiling on two occasions within 1 h apart. Another 59 healthy hospital employees underwent cardiovascular profiling on two occasions, an average 52 days apart. An additional group of 23 patients underwent right and left heart catheterizations for routine clinical indications and hemodynamic assessment was performed invasively and non-invasively. RESULTS: For short-term repeatability, the mean difference of C1 was +0.25 +/- 2.83 ml/mmHg x 10 (P = NS) and C2 was -0.14 +/- 1.86 ml/mmHg x 100 (P = NS). For intermediate test repeatability, the mean difference of C1 was -0.415 +/- 2.97 ml/mmHg x 10 (P = NS) and C2 was -0.19 +/- 2.67 ml/mmHg x 100 (P = NS). In the invasive protocol, both aortic diastolic blood pressure (-4.74 +/- 9.7 mmHg) and systemic vascular resistance (-194 +/- 264 dyne x s x cm(-5)) were significantly lower invasively. CONCLUSIONS: Measurements with the HDI/Pulsewave CR-2000 Research CardioVascular Profiling System are repeatable over both a short and intermediate period of observation. Furthermore, non-invasive hemodynamic parameters reasonably agree with invasive measurements.     

Cerebral abnormalities in patients with cirrhosis detected by proton magnetic resonance spectroscopy and magnetic resonance imaging

Hepatic encephalopathy is a common problem in cirrhosis. The pathogenesis of this complication of advanced liver disease still remains unclear. Magnetic resonance spectroscopy was used to assess prospectively cerebral metabolism in 51 patients with histologically proven cirrhosis (Child-Pugh classes A, B, and C, 18, 18, and 15, respectively) and 36 healthy volunteers. According to the results of psychometric tests, overt hepatic encephalopathy, subclinical encephalopathy, and no encephalopathy were found in 14, 21, and 16 patients, respectively. Myoinositol/creatine ratios in gray (.36 +/- .17) and white (.35 +/- .22) matter voxel were reduced significantly (P < .0001) in cirrhotic patients compared with healthy volunteers (gray matter, .51 +/- .11; white matter, .64 +/- .16). In addition, patients showed a significant reduction (P = .024) in white matter choline/creatine ratio (.77 +/- .27) compared with controls (.92 +/- .25), and glutamine/glutamate level was elevated in cirrhotic patients compared with controls (gray matter, P < .0001; white matter, P = .036). Changes in cerebral myoinositol and glutamine/glutamate levels correlated significantly with the severity of hepatic encephalopathy (P < .0001). However, these metabolic alterations were also detected in patients without hepatic encephalopathy (normal psychometric test results). N-acetyl aspartate/creatine ratios did not differ between patients and controls. Magnetic resonance imaging detected bright basal ganglia in 37 patients, which correlated significantly with portal-systemic shunting and elevation of glutamine/glutamate, but not with the degree of hepatic encephalopathy. In conclusion, magnetic resonance imaging and spectroscopy showed that alterations of cerebral metabolism are common in patients with cirrhosis, even without evidence of clinical or subclinical hepatic encephalopathy.(Hepatology 1997 Jan;25(1):48-54)     

Prevalence and risk factors of silent cerebral infarction in apparently normal adults

Cerebrovascular disease is a major cause of death and disability in adults. Silent cerebral infarction (SCI) portends more severe cerebral infarctions or may lead to insidious progressive brain damage resulting in vascular dementia. This study was designed to evaluate the prevalence and risk factors of SCI in an apparently normal adult population. Nine hundred ninety-four consecutive symptom-free adults (mean age 49.0+/-7.7; men:women 830:164) who underwent brain magnetic resonance imaging at the Center for Health Promotion at Samsung Medical Center were assessed. All were neurologically normal in history and physical examination. A total of 121 SCI lesions was observed in 58 subjects. The lesion prevalence adjusted for patient age was 5.1%. There was no gender difference in prevalence. Ninety-nine lesions were <1 cm in diameter, 15 were between 1 and 2 cm, 3 were between 2 and 3 cm, and 4 were >3 cm in diameter. The most frequent site of the SCI lesion was basal ganglia, after which the periventricular white matter, cerebral cortex, and thalamus were the most frequent sites. Old age, hypertension, a history of coronary artery disease, evidence of cardiomegaly in chest radiographs, and high fasting glucose/hemoglobin A1c levels were associated with SCI on univariate analysis. Multivariate analysis demonstrated old age and hypertension to be independent risk factors for SCI, and mild alcohol consumption was revealed as an independent protective factor against SCI.     

Circulating endothelial progenitor cell deficiency contributes to impaired arterial elasticity in persons of advancing age

Reduced arterial elasticity is a hallmark of ageing in healthy humans and appears to occur independently of coexisting disease processes. Endothelial-cell injury and dysfunction may be responsible for this fall in arterial elasticity. We hypothesized that circulating endothelial progenitor cells (EPCs) are involved in endothelial repair and that lack of EPCs contributes to impaired arterial elasticity. A total of 56 healthy male volunteers were divided into young (n=26) and elderly (n=30) groups. Large and small artery elasticity indices were noninvasively assessed using pulse wave analysis. The number of circulating EPCs was measured by using flow cytometry. Cells demonstrating DiI-acLDL and FITC-ulex lectin double-positive fluorescence were identified as EPCs. C1 large artery elasticity and C2 small artery elasticity indices were significantly reduced in the elderly group compared with the young group (11.73+/-1.45 vs 16.88+/-1.69 ml/mm Hg x 10, P<0.001; 8.40+/-1.45 vs 10.58+/-1.18 ml/mm Hg x 100, P<0.001, respectively). In parallel, the number of circulating EPCs was significantly reduced in the elderly group compared with the young group (0.13+/-0.02 vs 0.17+/-0.04%, P<0.05). The number of circulating EPCs correlated with C1 large and C2 small artery elasticity indices (r=0.47, P<0.01; r=0.4, P<0.01). The present findings suggest that the fall in circulating EPCs with subsequently impaired endothelial-cell repair and function contributes to reduced arterial elasticity in humans with ageing. The decrease in circulating EPCs may serve as a surrogate biologic measure of vascular function and human age.     

Voxel-based analyses of magnetization transfer imaging of the brain in hepatic encephalopathy

AIM: To evaluate the spatial distribution of cerebral abnormalities in cirrhotic subjects with and without hepatic encephalopathy (HE) found with magnetization transfer imaging (MTI). METHODS: Nineteen cirrhotic patients graded from neurologically normal to HE grade 2 and 18 healthy control subjects underwent magnetic resonance imaging. They gave institutional-review-board-approved written consent. Magnetization transfer ratio (MTR) maps were generated from MTI. We tested for significant differences compared to the control group using statistical non-parametric mapping (SnPM) for a voxelbased evaluation. RESULTS: The MTR of grey and white matter was lower in subjects with more severe HE. Changes were found in patients with cirrhosis without neurological deficits in the basal ganglia and bilateral white matter. The loss in magnetization transfer increased in severity and spatial extent in patients with overt HE. Patients with HE grade 2 showed an MTR decrease in white and grey matter: the maximum loss of magnetization transfer effect was located in the basal ganglia [SnPM (pseudo-)t = 17.98, P = 0.0001]. CONCLUSION: The distribution of MTR changes in HE points to an early involvement of basal ganglia and white matter in HE.     

Silent cerebral white matter lesions and cognitive function in middle-aged essential hypertensive patients

BACKGROUND: An association between midlife blood pressure levels and late-life cognitive impairment has been reported. Hypertension is one of the most important factors related to the presence of cerebral white matter lesions, which is a prognostic factor for the development of cognitive impairment. Studies have shown a relationship between white matter lesions and cognitive decline in elderly hypertensive patients. The aim of the present study was to evaluate cognitive function in asymptomatic middle-aged hypertensive patients according to the presence or absence of white matter lesions. METHODS: Sixty never-treated essential hypertensive patients (38 men, 22 women), aged 50 to 60 years (mean age, 54.4 +/- 3.8 years), without clinical evidence of target organ damage, were studied. All patients underwent brain magnetic resonance imaging to establish the presence or absence of white matter lesions, using the Rotterdam criteria. Cognitive function was evaluated by a neuropsychologic test battery measuring attention, memory, intelligence, anxiety, and depression. RESULTS: Twenty-three hypertensive patients (38%) were found to have white matter lesions on brain resonance. These patients exhibited a significantly worse performance on digit span forward, a standardized measure of attention than hypertensives without white matter lesions (4.86 +/- 1.14 v 5.51 +/- 0.97; P =.027). Hypertensive patients with white matter lesions showed no differences on both visual and logical memory tests when compared with patients without lesions. CONCLUSIONS: We conclude that the presence of silent cerebral white matter lesions in middle-aged hypertensive patients is associated with a mild decline in basic attention.     

Increased circulating CD31+/CD42- microparticles are associated with impaired systemic artery elasticity in healthy subjects

BACKGROUND: Impaired artery elasticity has been found in various pathological conditions related to endothelial dysfunction. Recently, CD31+/CD42- microparticles (MPs) emerged as a marker of endothelial injury. Whether CD31+/CD42- MPs, generated under physiological conditions, are correlated with artery properties has not been reported. METHODS: We evaluated brachia-ankle pulse-wave velocity (baPWV) (n = 76) and C1 large-artery and C2 small-artery elasticity indices (n = 56), using noninvasive devices for pulse-wave analysis in a group of healthy persons. The number of circulating CD31+/CD427- MPs (n = 76) was measured by flow cytometric analysis. RESULTS: Circulating CD31+/CD42- MPs were positively correlated with values of baPWV (r = 0.371, P = .008) and with C1 large-artery and C2 small-artery elasticity indices (r = -0.294, P = .037; and r = -0.310, P = .027, respectively). Multivariate analysis identified CD31+/CD42- MPs as potent contributors to the development of impaired systemic artery elasticity. CONCLUSIONS: The level of circulating CD31+/CD42- MPs, an important biomarker of dysfunctional endothelium and vascular injury, is closely associated with impaired systemic artery elasticity in healthy subjects. The present study suggests that CD31+/CD42- MPs may be a novel surrogate marker for the clinical evaluation of vascular damage.     

Effect of long-term treatment with rosiglitazone on arterial elasticity and metabolic parameters in patients with Type 2 diabetes mellitus: a 2-year follow-up study.

AIMS: Thiazolidinediones may influence the atherogenic process by improving cardiovascular risk factors. The present study was designed to determine the long-term effect of rosiglitazone on arterial compliance and metabolic parameters in patients with Type 2 diabetes. METHODS: In an open-label, prospective study, 65 diabetic patients received rosiglitazone orally (4-8 mg/day) for 6 months. After 6 months, the patients continued an open follow-up study and were divided into two groups: group 1 included patients continuing rosiglitazone for 2 years, group 2 included patients discontinuing rosiglitazone and receiving other oral glucose-lowering agents. Lipid profile, glycated haemoglobin (HbA1c), insulin, C-peptide, fibrinogen, high-sensitivity-CRP and homeostasis model assessment-insulin resistance were measured. Arterial elasticity was assessed using pulse wave contour analysis. RESULTS: In patients treated with rosiglitazone for 2 years: the large artery elasticity index (LAEI) increased from 10.0 +/- 4.6 to 13.9 +/- 4.7 ml/mmHg x 100 after 2 years (P = 0.003). The small artery elasticity (SAEI) index increased significantly from 3.2 +/- 1.2 to 5.1 +/- 1.9 (P < 0.0001). In patients who discontinued rosiglitazone: LAEI did not change after 6 months, but decreased from 12.1 +/- 5.4 to 8.9 +/- 3.9 ml/mmHg x 10 (P < 0.0001) at the end of 2 years. SAEI increased during the first 6 months of treatment, from 3.9 +/- 1.8 to 5.1 +/- 1.5 ml/mmHg x 100 (P < 0.0001) and decreased after discontinuation of rosiglitazone (P = 0.042). CONCLUSIONS: Prolonged treatment with rosiglitazone improved arterial elasticity. However, significant deterioration in LAEI and SAEI was observed in patients who discontinued rosiglitazone. The beneficial vascular effect of rosiglitazone on arterial elasticity was independent of glycaemic control.     

Silent cerebral infarction in the patients with essential hypertension]

Evidence of old cerebral infarction of magnetic resonance imaging (MRI) is common in acute stroke patients without a prior history of stroke. This experience led us to investigate the incidence of silent cerebral infarction (SCI) in the patients with essential hypertension, as well-known major predisposing factor for stroke. The incidence, number, size and localization of SCI on MRI (MARK-J, 0.1 T) and the prevalence of risk factors for stroke were investigated both in 66 hypertensive patients (WHO stage I or II; 63 +/- 9 (mean +/- S.D.) years old) and in 42 age-matched normotensive patients (61 +/- 9 years old). Risk factors selected were as follows: diabetes mellitus, hypercholesterolemia, daily alcohol intake, cigarette smoking, obesity, cardiac disease (arrhythmia and ischemic heart disease), hyperuricemia and high hematocrit. In hypertensive patients, the relationships between the incidence of SCI and hypertensive damages in major organs were also investigated. SCI was found in 45 out of the 108 subjects studied and a total of 216 SCI lesions were detected. All of the SCI lesions were localized in the subcortical white matter or in the basal ganglia. All SCI lesions were smaller than 3 cm in diameter and 201 lesions (93%) were smaller than 1 cm. The incidence of SCI tended to be higher in hypertensive patients (47%) than that in normotensives (33%) and increased significantly with advancing age in hypertensives from 26.9% in the 50s to 86.7% in the 70s, while no significant increase was noted in normotensives.(ABSTRACT TRUNCATED AT 250 WORDS)     

年龄相关的循环内皮祖细胞变化与动脉弹性关系的研究

目的　研究年龄对循环内皮祖细胞及动脉弹性的影响,探讨循环内皮祖细胞水平与动脉弹性损伤的关系。方法　56例健康男性志愿者分成青年组(n=26)和老年组(n=30)。采用桡动脉脉搏分析法无创性评价健康志愿者大动脉弹性指数(C1 )和小动脉弹性指数(C2 ), 流式细胞仪测定外周血中CD34+单个核细胞的水平,单个核细胞体外培养2周,荧光显微镜鉴定FITC UEA I和DiI acLDL双染色阳性细胞为内皮祖细胞。结果　老年组与青年组相比较,C1 和C2 明显降低[C1(11. 73±1 .45)比(16 .89±1 .69)ml/mmHg×10, P<0. 001; C2 (8 .40±1 45)比(10. 58±1 .18)ml/mmHg×100, P<0 .001 ];循环内皮祖细胞数目明显减少[ ( 0 .13±0. 02 )比( 0 .17±0. 04 )%,P<0 .05];循环内皮祖细胞水平与动脉弹性指数变化呈正相关(r=0. 47, P<0. 01;r=0 .4, P<0. 01),荧光显微镜鉴定贴壁细胞FITC UEA I和DiI acLDL双染色阳性。结论　增龄导致循环内皮祖细胞数量减少,提示血管内皮修复能力下降和功能障碍,损伤动脉弹性,循环内皮祖细胞水平有可能作为评价血管功能的替代指标。     

Arterial compliance: is it reduced in antiphospholipid syndrome?

To assess vascular compliance in patients with antiphospholipid syndrome (APS), or antiphospholipid antibodies (aPLs) positivity in comparison to healthy people and diabetes mellitus patients. Twenty-five patients with APS or aPLs, 33 healthy people (HP), 28 patients with diabetes mellitus (DM) underwent pulse wave analysis. Data calculated included the small artery elasticity (SAE), large artery elasticity (LAE) and systemic vascular resistance (SVR). Statistical analysis was performed as appropriate. The patient group was divided into two subgroups: APS-1 with warfarin treatment, and APS-2 without warfarin treatment. All patients and healthy subjects were matched by gender, body mass index and lipid profiles. Patients in APS-1 group were significantly younger in comparison to three other groups. After the adjustment for age, we found that SAE in APS-1 group did not differ from SAE in the HP group (6.4+/-1.8 ml/mmHg x 100 and 5.54+/-3.4 ml/mmHg x 100, respectively, P>0.05). In contrast, SAE in the group APS-2 was significantly lower (3.41+/-1.2 ml/mmHg x 100) than in the APS-1 and was almost equal to SAE in the DM group (4.2+/-2.37 ml/mmHg x 100). The SAE in the APS-2, DM and HP groups was inversely correlated with age, whereas in the APS-1 group we did not find such correlation. This pilot study showed abnormal small vascular elasticity in the patients with positive aPL, relative to the healthy subjects. The APS patients, treated with warfarin had the normal vascular function. This data support the hypothesis that APS may be associated with diffuse changes in the arterial wall, and may be a risk factor for atherosclerotic disease.     

Reduced arterial elasticity is associated with endothelial dysfunction in persons of advancing age: comparative study of noninvasive pulse wave analysis and laser Doppler blood flow measurement

BACKGROUND: Endothelial dysfunction is the earliest marker for age-related abnormalities in vascular function, and examination of endothelial function has important clinical relevance. The present study was performed to evaluate effects of aging on arterial elasticity by using pulse waveform analysis and to investigate whether the changes in arterial elasticity might be used as a noninvasive measure for endothelial dysfunction. METHODS: A total of 24 healthy male volunteers were divided into young (n = 12) and elderly (n = 12) groups. Endothelial function was evaluated by delivering acetylcholine (Ach) and sodium nitroprusside (SNP) to the forearm vessels using iontophoresis, respectively, and measured blood flow using laser Doppler fluximetry. Large and small artery elasticity indices were noninvasively assessed using pulse wave analysis. RESULTS: Basal blood flow was similar between the young and elderly groups (14.58 +/- 3.4 v 13.52 +/- 3.41 PU, P = NS). Peak blood flow induced by Ach was significantly reduced in the elderly group compared with the young group (83.4 +/- 11.9 v 93.75 +/- 10.87 PU, P < .05). However, peak blood flow induced by SNP was similar in the two groups (119.17 +/- 16.76 v 128.33 +/- 21.29 PU, P = NS). In parallel, C1 large artery elasticity and C2 small artery elasticity indices were significantly reduced in the elderly group compared with the young group (11.42 +/- 1.67 v 16.75 +/- 2.09 mL/mm Hg x 10, P < .001; and 7.67 +/- 1.56 v 10.75 +/- 1.86 mL/mm Hg x 100, P < .001, respectively). The Ach-induced peak blood flow correlated with C1 large and C2 small artery elasticity indices. CONCLUSIONS: Advancing age is associated with endothelial dysfunction and reduced arterial elasticity. Reduced arterial elasticity parallels changes in impaired endothelium dependent vasodilation. It appears that reduced arterial elasticity may be used as a noninvasive measure for the determination of endothelial function.     

Use of joint fluid analysis for determining cartilage damage in osteonecrosis of the knee

OBJECTIVE: To assess the value of joint fluid analysis for determining cartilage degradation and prognosis in spontaneous osteonecrosis (ON) of the knee. METHODS: Synovial fluid was obtained from 30 knees with spontaneous ON (26 medial femoral condyles, 4 medial tibial plateaus) as well as from 50 knees with medial compartmental osteoarthritis (OA) as a control. Levels of chondroitin 6-sulfate (C6S), C4S, and hyaluronic acid were measured with high-performance liquid chromatography. The lesion size, appearance of the articular cartilage, and results of magnetic resonance imaging (MRI) were compared with the results of joint fluid analysis. RESULTS: The mean +/- SD level of C6S was 82.2 +/- 36.6 nmoles/ml in joint fluid from ON knees, which was significantly higher than the levels in knees with grade 2 (47.2 +/- 20.0 nmoles/ml) and grade 3 (55.8 +/- 29.2 nmoles/ml) OA. The C6S:C4S ratio was highest in lesions with mild articular changes and reflected the macroscopic alteration of cartilage overlying the ON lesion. The concentration of C6S in the 9 knees with lesions that covered > or = 40% of the condyle (99.0 +/- 32.9 nmoles/ml) was higher than that in the 17 knees with lesions that covered <40% of the condyle (67.2 +/- 31.7 nmoles/ml). Knees with bone marrow edema on MRI had a higher level of C6S than did knees with a fibrous-like appearance. CONCLUSION: While radiologic staging was useful for indicating the size of the ON lesion, it was less valuable for determining articular cartilage damage. Joint fluid analysis may provide more precise information about articular cartilage degradation in ON, and the findings may also be of prognostic significance.